BE522048A - - Google Patents

Description

       

  BELL TELEPHONE MANUFACTURING COMPANY S.A., residing in ANTWERP.

  
  <EMI ID = 1.1>

  
crossed, divided into primary and secondary. One of its main purposes is to provide an economical arrangement of switches and switch control, for a telephone system serving a block of a defined number of

  
  <EMI ID = 2.1>

  
Sees divided into primary and secondary, for the respective divisions; and

  
a common group of crossbar switches divided into primary and secondary having access to each of these separate groups.

  
We will first give a general description of the system.

  
  <EMI ID = 3.1>

  
crossed lines, primary and secondary, of any group serving a separate line division, are linked together by line references

  
forming the primary-secondary distributor for the group of switches. These switches, with their associated control devices, are mounted on a

  
  <EMI ID = 4.1>

  
The primary and secondary crossbar switches of the

  
common group are interconnected by block references forming the primary-secondary distributor of the common group. These common switches, with their associated control devices, are mounted in a bay called a block bay.

  
They are called primary block switches and secondary block switches.

  
Cross-bar switches will be briefly described. Dam the example of embodiment shown, these switches are assumed to be of a type

  
known which is crossed by ten horizontal connections (represented respectively by the ten rows of sets of selective contacts) and by a desired number of vertical connections (represented respectively by the columns of sets of contacts which cross the rows).

  
We will briefly describe the row bays.

  
  <EMI ID = 5.1>

  
which number of line bays (or divisions of the assembly block) is chosen having regard to a convenient size and arrangement of the line switches, primary and secondary, such that each line bay serves a relatively large number lines, making comparatively efficient use of the Initial and Final trunk groups employed respectively to serve calls to or from lines served by a bay of lines.

  
In the exemplary embodiment shown, the block of a number de-

  
  <EMI ID = 6.1>

  
primary. Traffic observations showed that ten two-way referrals
(represented respectively by the ten horizontal connections crossing the crossbar switch) can adequately serve up to?

  
  <EMI ID = 7.1>

  
by a primary line switch., given that a normal ten to ten cross between primary and secondary switches includes ten primary switches, and 250 (ten times 25) is a submultiple of thousand, thousand being the chosen dimension for the block.

  
Functionally, ten secondary switches are required in a normal ten to ten crossover with ten primary switches. One of the features of this invention is that it uses only five secondary line switches to perform the essential functions of ten. Each of these secondary switches is arranged so as to effectively serve as two

  
  <EMI ID = 8.1>

  
sections each having its own set of ten horizontal connection paths. The advantages of this arrangement are 1 [deg.] Than five larger switches
(longer) are mounted more compactly and more efficiently than ten shorter switches, and 2 [deg.] that the number of frames, bars and electros of the secondary switches is reduced by half.

  
At the secondary end, the hundred line feeds end! on the rows of the ten secondary sections, ten cross references per section o In each section, some of the columns serve as connection points for the initial junctions, and the rest, for the final junctions.

Line control devices will be briefly described.

  
  <EMI ID = 9.1>

  
economically. This equipment comprises a line controller and associated connector devices. It must be able to service calls to and from associated lines, and calls must be disconnected.

  
  <EMI ID = 10.1>

  
we extended the connections.

  
Another characteristic of the invention is that the primary and secondary selection electros of a row bay are connected in series according to a crossing pattern corresponding to the crossing of the row feeders, which eliminates the need to specifically associate the control device with a particular secondary switch.

  
Another characteristic of the invention resides in the use of cross-bar switching devices (two line controller switches in the example shown) as associated connector devices mentioned, in order to individually associate the line controller with the switch. of primary lines serving the calling line or the called line

  
  <EMI ID = 11.1>

  
the line controller with the calling line or called line considered. These switches perform their mentioned connection functions employing a minimum amount of systemized switchgear of contacts and electros, compared to previous arrangements of individual relays, which were used for generally analogous junctions.

  
A feature of the line controller is to use a device

  
  <EMI ID = 12.1>

  
five lines selected by the line control connectors, which simplifies the line selection functions of these switches, reducing them to the selection of a packet of five lines containing the calling line or called line.

  
In the example shown, the line controller comprises a control relay device. He can be considered a perfect-

  
  <EMI ID = 13.1>

  
mayor initial, final primary and packet of five) to control the line controller switches, and the mentioned chain of units that cooperates with them.

  
2) The line controller goes through its entire operating cycle to extend a calling line, through an assigned path, to a trunk

  
  <EMI ID = 14.1>

  
nor successive attempts to extend a line which cannot be successfully extended.

  
  <EMI ID = 15.1>

  
operate in cascade to be in a state of falling back in cascade, which simplifies the arrangement of the circuit, increases the cycle time for a given number of timer relays and eliminates the need to use, as before, a slow start relay during operation.

  
4) The total number of initial junctions to be tested when pro-

  
  <EMI ID = 16.1>

  
other until a free junction is found in one of them, which significantly reduces the necessary number of test relays. a totalizing device is used to stop the test operation when all the junction beams have been taken and tested.

  
5) The assignor of choice is arranged so as to pass

  
  <EMI ID = 17.1>

  
primary and 3 [deg.] packets of five on a primary switch, which distributes the load of the initial trunks more evenly among the secondary sections, and makes it less likely that calls from a given line will be blocked by faults that could occur in a primary switch, or in. a packet of five among the lines served by this switch.

  
Additional characteristics of the line bay devices will appear in the remainder of the description.

  
The block bay will now be briefly described.

  
Another object of the invention is to make savings possible in the switchgear and to make the service more flexible, in dif-

  
  <EMI ID = 18.1> all the digits designating the called line have been made on the dial, to then select a free and usable final junction,

  
  <EMI ID = 19.1>

  
those which can be extended through the line bay to the called line, by a free line forwarding. This deferred control system gives rise to the following advantages

  
1) By selecting a free final junction provided that it is one that can be extended to the desired called line by a free line forwarding, the switchgear of the block bay, in addition to the selection of the bundle of junctions desired and a free final junction in that bundle, eliminates the need for a tertiary switching device that would otherwise be required on the line bay. Such tertiai-

  
  <EMI ID = 20.1>

  
aforementioned.,

  
2) By delaying the selection of a path to the called line until all line digits have been sent, we do not have to divide the block of lines into powers of ten (including the second, or cent, would be the only useful), which allows it to be divided into divisions of 250 lines mentioned, larger and more economical.

  
3) An additional advantage is that only one set of bridge relays
(battery operated) and related control relays need to be used for any connection, rather than having to repeat these relays on each of the two bays that the connections pass through.

  
4) Another advantage of the deferred control system which it

  
  <EMI ID = 21.1>

  
further in detail, intended to provide interception services, transferred numbers and common numbers, in a single point, processing lines

  
of all row bays as a single group,

  
Another object is to allow the block of switching equipment to serve as a complete telephone office, interconnected with other offices by external junctions arranged and grouped as may be necessary. This is accomplished in the embodiment shown 1 [deg.] by bringing the incoming outer junctions (or the incoming branch of two-way junctions) towards the incoming side of the block bay and 2 [deg.] by starting the outgoing outer junctions (or the outgoing branch of the junctions two-way) on the outgoing side of the block bay to other desired offices.

  
In the example shown, the initial number made on the dial is

  
  <EMI ID = 22.1>

  
to be inadvertently simulated, as is well known, one manages to absorb it so as to leave nine initial digit values (2 through 9 and 0) available to be assigned as office digits. One of these initial digit values is used to designate the local 1000 line office, leaving eight initial digit values available to be assigned to other offices reached directly from the local office.

  
Sending the assigned initial digit to the local office does not immediately cause switch operations on the block bay (this operation being deferred, as mentioned, until all row digits have been made. on the dial); on the other hand, sending an initial number assigned to any other office causes an immediate switch to the block bay, in order to establish a connection, via a free junction, to the called office.

  
Another object of the invention is to provide control arrangements which allow the crossbar switches in the block bay to establish a connection to a free outgoing trunk while remaining well beyond the normal interval between connections. figures, which presents itself during the manipulation

  
  <EMI ID = 23.1>

  
digits without interruption in the case where the called office is provided with an automatic switch ready to receive the dial pulses arriving at the junction mentioned last.

  
In the illustrated embodiment, the aforementioned rapid extension of outgoing calls through the block bay is made possible by an arrangement described later, intended to give preference to outgoing calls over locally terminated calls, by setting separately control operations on the block bay, relating to the establishment of locally terminated calls.

  
In the exemplary embodiment shown, the complete equipment of the

  
  <EMI ID = 24.1>

  
secondary, interconnected, row by row by one hundred pairs of block references, ten pairs for each switch. The two hundred block referrals thus obtained are more than sufficient to serve busy hourly traffic beyond the probable maximum requirements.

  
Each primary switch and each secondary switch in the block bay consists of twenty columns (for twenty junctions with the bay) and ten dual path rows, each receiving a separate pair of block referrals.

  
The initial junctions from the row bays correspond to the respective columns on the primary block switches. The outer incoming junctions (or the incoming branch of two-way trunks) are respectively assigned to other columns on the primary block switches.

  
The two hundred primary columns provided on the fully equipped block bay (twenty columns per primary block switch) can be re

  
  <EMI ID = 25.1>

  
your.

  
The two hundred secondary columns planned on the block bay
(20 per secondary block switch) serve as connection points for

  
  <EMI ID = 26.1>

  
In the exemplary embodiment shown, the first 16 columns of each secondary block switch are used respectively as connection points from which the final junctions originate; the last 4 columns of each of these switches serve as connection points for the respective outgoing junctions.

  
Block couplers will be briefly described.

  
Each junction (initial junction or incoming junction) going to the block bay has a block coupler inserted between it and the column assigned to it on a primary block switch. Each block coupler includes a sufficient quantity of equipment to couple the associated junctions, initial or incoming, with the switching devices provided on the block bay, in connection with the control of the switching devices in response to the sending of the number. called; to supply the talk current to the calling line, and the ringing current and the talk current, to the called line; and to perform the related functions required of the junction equipment in an office of the type referred to.

  
Each block coupler includes a number of

  
  <EMI ID = 27.1>

  
Numbers dialed on the dial are received, with recorders for noting the respective numbers dialed on the dial. These recorders include an initial digit recorder, recorders for the hundred, ten and unit digits respectively, and a recorder for an extension digit sent after sending the unit digit.

  
Certain characteristics of the invention residing in block couplers or implicating them are in particular the following:

  
  <EMI ID = 28.1>

  
Through the block bay, block couplers should only be associated with the common device in the bay, one at a time. Preferably relay chains are used for this. Each block coupler is included in two alternative chains, which are used respectively depending on whether a bundle of outgoing junctions or a local line is called. The dual chat device is employed as part of the aforementioned device, intended to give preference to outgoing calls, over local line calls.

  
  <EMI ID = 29.1>

  
including those which are assigned to the same primary switch, Considering either the local chain or the outgoing chain of the couplers, such a chain has a main part (comprising a chain preferably of section), from which branches leave towards the chains respective coupler sections. This arrangement allows the common apparatus to easily identify the primary block switch to be employed for a connection being extended, and has the advantage that a string inadvertently opened circuit in any section. block couplers leave the common chain and its remaining branches intact.

  
  <EMI ID = 30.1>

  
your; and it only engages the block bay common device after sending all digits of a local line number.

  
4) Remainder positions in the sequence device are employed to aid in the measurement of conversation time, which greatly reduces and simplifies the time measurement and control apparatus which remains employed for this purpose.

  
Additional features of the block coupler will become apparent as the description progresses.

  
We will now briefly describe the common control equipment of the block bay.

  
Another object of the invention is to provide the block bay with efficient common control equipment, which receives the information from the block couplers and extends the connections through the block bay according to this information, cooperating with line controllers to extend calls through line bays to local lines. This common control equipment includes the following

  
1) A block control connector (generally similar to each of the line control connectors, and controlled by either chain, preferably block couplers), to make the required connections with the line switch. primary block serving the block coupler which engaged the common device.

  
2) A block controller, which (like the control connector

  
block) is initiated by all calls, either outgoing or local

  
  <EMI ID = 31.1>

  
connections. On outgoing calls, it combines a free path through the block bay, from the primary switch concerned, with a free block forwarding, to an outgoing trunk in the called group. On terminating calls, it cooperates with the line controller of the line bay concerned to combine a path to the called line by means of the interested primary block switch, a free block forwarding, a free final junction going to the line bay concerned, and a free line forwarding accessible from this junction and going to the primary line switch serving the called line,

  
3) A block translator (used only in locally terminated calls), which translates Information comprising the digits of hundreds, tens and units of the requested number, into information composed of primary packets of five and units, usable on the bay of lines serving the division of 250 lines requested;

  
4) An outgoing controller, which receives Information composed of the initial digit, from a block coupler, on an outgoing call, and notes the circuit status for the bundle of junctions requested, showing which ones are occupied and which are free.

  
The block translator, the outgoing controller and the controller

  
Each block consists largely of a group of relays linked together so as to fulfill their respective functions, including the general functions indicated above.

  
  <EMI ID = 32.1>

  
block.

  
A special characteristic of this translator is that, although its arrangement and its connections make it normally translate the line digits of the requested number according to the fixed position of the attachments of the respective lines on the line bays, - it is provided with flying distributors and associated relay devices which allow it to leave the fixed translation if necessary and replace it with another translation, which will establish the connection to another line on the same bay of lines, or to a line on any other bay of lines, as required. This arrangement of the translator gives rise to the following characteristics

  
1) If desired, the number assigned to a line attached to a certain position on the line bay can be transferred to a line attached to any other position on any line bay. The great utility of this feature is that one can correct the traffic imbalance between the various primary switches of a line array without changing the line numbers, this correction consisting of swapping high traffic lines attached to a line switch. primary with low traffic lines attached to other primary line switches, The service following this feature is called the number transfer service ,,

  
2) Groups of lines with a common number can be formed at will. On receipt of the number assigned to a group of lines with a common number, the translator removes the fixed translation of this number, engages the body children of the lines of the group for the test, and chooses a free line, and establishes a new translation, corresponding to the position of the bay and the position

  
in primary, packs of five and units, of the line chosen on the bay of lines concerned.

  
3) The translator detects calls from cut lines as well as calls from cut extensions on shared lines (by means of appropriate flying forward wires), after which it deletes the fixed translation for any such call and substitutes a translation for it. who routes the call to an intercept operator. A special aspect of this feature is that the substituted translation varies to coincide with the position of a line which the translator has found to be free in a group of lines serving the intercept operator. The service following this characteristic is called the interception service.

  
We will now briefly describe the characteristics of the con-

  
  <EMI ID = 33.1>

  
preparations for extending a connection to a requested local line in order to give priority to an outgoing call which must be terminated during the in-

  
  <EMI ID = 34.1>

  
crossed bars, during the final establishment of a connection to a local line, which avoids confusion in operations, the result of which could be either the loss of the local call, or its double extension.

  
2) On a call from a local line in the office, the block controller closes the control circuits for the primary and secondary switches of the block bay and the requested line bay, provided that the information has been received out of the box. -normal for each of the two bays, indicating that the affected junction on each bay has been mechanically selected on the interested busbar switches in those bays.

  
3) The block controller initiates the final trunks going to the called trunk line bay, generally in accordance with a corresponding characteristic of the line controller regarding the Initial trunks. However, on each engagement of the final junctions, these junctions are presented to the test in separate order, corresponding respectively to the pairs of block referrals going from the primary block switch concerned to the switch.

  
of secondary block, in agreement with the different crossing which occurs in the final junctions compared to their separate engagement beams.

  
We will now briefly describe the characteristics of the control

  
  <EMI ID = 35.1>

  
1) - The outgoing controller includes test relays corresponding respectively to the outgoing junctions (four started from each switch

  
secondary block), with groups of contacts controlled respectively by the initial digit relays, and a flywheel distributor allowing any relay

  
  <EMI ID = 36.1>

  
re with the contact arrangements controlled by the test relays to allow a junction from any hardware position on the block bay to be included in the junction harness to which is assigned any initial number. The same normal PBX device is thus made

  
  <EMI ID = 37.1>

  
as to the number of outgoing beams and as to the number of junctions in the respective beams.

  
2) On sending an initial, unused digit, the common device

  
  <EMI ID = 38.1>

  
the outgoing controller has notified him that no free path can be combined

  
through the block bay, to the called (non-existent) bundle, the block controller transmits a signal that causes the block coupler in use to place a busy tone on the calling line to indicate that the attempted connection cannot be established This feature ^ in cooperation with the previous one, allows block couplers to be wired in the same normal way for a large number of situations involving the use of various combinations of used and unused initial digits

  
Additional features of the monitoring device

  
the block bay will appear in the remainder of the description.

  
The accompanying drawings will now be briefly described. These drawings, which include Figures 1 to 37, show a preferred embodiment of the invention, as follows: Figure 1 shows three interconnected telephone desks A, B and C, of which the office B contains the PBX realizing functions. characteristics of the invention;

   Figure 2 is a single-line junction diagram of the devices in Office B, which is employed in establishing connections to or from lines in the office and in establishing connections to the junctions between Office B and desks A and C from these junctions Figure 3 (parts 1 to 4) is a complete single line junction diagram, showing the relationships between the crossbar switches, used to make connections to the lines and junctions at office B of Figures 1 and 2, coming from these lines

  
  <EMI ID = 39.1>

  
of Figure 2 to show, in greater detail, the circuits and electrical equipment closely associated with them, which are employed to establish the conversation connections shown in Figure 2; FIG. 4 shows devices of the line bay A of FIG. 2; Figure 5 (parts 1 and 2) shows the circuit details of the block couplers on the block bay of Figure 2; <EMI ID = 40.1> apparatus of the block bay shown in figure 2;

  
and FIG. 7 shows, with more detail in the circuits, the devices of the line bay B of FIG. 2;

  
  <EMI ID = 41.1> on any line array; Figure 9 is a wiring diagram of any secondary switch on any line bay; <EMI ID = 42.1> are wiring diagrams of the line connectors on any line bay; - '; Figure 12 (parts 1 to 5) is a circuit diagram of the line controller on any line bay; Figure 13 is a wiring diagram of any primary switch on the block bay; <EMI ID = 43.1> on the block bay; Figure 15 (parts 1 and 2) is a wiring diagram of the block control connector provided on the block bay, as well as a circuit diagram of the associated relay apparatus; <EMI ID = 44.1> their block on the block bay;

   Figure 17 (parts 1 and 2) is a circuit diagram of the outgoing controller provided on the block bay; <EMI ID = 45.1> relay section of the block translator on the block bay, and Figure 19 (parts 1 to 5) is a circuit and wiring diagram of the tie bar section of the block translator; FIG. 20 is a diagram of the -circuits of the bay of couplers this junctions and of the apparatus of junction couplers which it carries; Fig. 21 (parts 1 to 4) shows the line numbering and translation system with respect to the four line bays A, B, C, D; figure 22 (parts 1 and 2) shows the block coupler of <EMI ID = 46.1> combination of harmonic ringing and coded ringing, and to satisfy
20 stations on a line instead of a maximum of 10;

  
  <EMI ID = 47.1> and

  
Figures 29 to 37 likewise show the suitable assembly of Figures 13 to 22.

  
  <EMI ID = 48.1>

  
The general operation of the automatic switch will now be described with reference to Figures 1 and 2.

  
  <EMI ID = 49.1> networks A and C are each connected to office B by junctions on which connections can be made in both directions. The equipment shown in figure 2 is entirely located in office B in figure 1.

  
In FIG. 2, the apparatus of the office B comprises a main MDF distribution bay by means of which the subscriber lines and the junctions are connected to the switching devices; four A-line bays,

  
  <EMI ID = 50.1>

  
shown at 251, and a junction coupler bay shown at 252.

  
The general purpose of the switchgear of office B is to connect, at will:, the subscriber lines of the office to each other and with the junctions between offices as well as to connect, at will, the junctions between offices.

  
In the chosen embodiment of the invention, each of the four bays of lines A to D, receives 250 lines, giving a capacity of
1,000 lines for the office.

  
Considering for example the line bay A, its function is to connect any calling line among the 250 subscriber lines that it serves to a free junction, in a bundle of initial junctions, such as junction 203A, and to connect any of its final junctions, such as 207A, with any subscriber line that is connected to the bay. For this, line bay A is provided with a certain

  
  <EMI ID = 51.1>

  
900A line secondary mutators. The subscriber lines are fed into the primary switches as shown for the calling line.

  
  <EMI ID = 52.1>

  
on its own individual vertical position, on the primary line switch 800A.

  
The initial junctions go from the respective vertical positions. on branch line switches, such as the one shown for the initial trunk 203A. The final junctions are connected at their own positive vertical position on the branch line switches, as shown for the final junction 207A. The primary and secondary line switches are interconnected by a suitable number of line feeders, one of which is shown at 202A.

  
  <EMI ID = 53.1>

  
the complete circuit diagram of figure 8, and a secondary line switch such as 900A is shown likewise in figure 9. The specific mutual relationship between the line switches, primary and secondary, by means of the line feeders is shown in figure 3, part 1.

  
Line bay A devices further include line control equipment, including line control connectors.

  
  <EMI ID = 54.1>

  
control are 1000 and IIOOA and they are connected to the line controller 1200A by a harness of 24 OA control wires.

  
The general purpose of the mentioned line tester is to check the connection of lines with junctions by switches.
800A and 900A by means of two-way references 202A. This general control resides mainly in the 1200A line controller.

  
The purpose of the control connectors is to connect the controller

  
  <EMI ID = 55.1>

  
by conductors such as 211A and 212A. Line bay B (shown in
25 OB) contains an apparatus similar to that of the line bay A. This corresponding is shown by using the letter B to index each reference digit-applied to the line bay B, while the letter A is used to index the references applied to line array A.

  
The purpose of the block bay shown at 251 is to extend the connections arriving through incoming junctions such as 2085 and through initial junctions such as 203A, to a free outgoing junction such as 2020 in a called bundle, or, through one. free final junction such that

  
  <EMI ID = 56.1>

  
To this end, the block bay is provided with a number of primary block switches such as 1300 and a number of secondary block switches, such as 1400, linked together by block references 206. complete circuits of switches 1300 and 1400 are shown in Figures 13 and 14, respectively.

  
It is necessary that the incoming and initial junctions such

  
  <EMI ID = 57.1>

  
on the bay, block so that the necessary information in figures concerning the destination of the call is recorded and received a follow-up. This general function is assigned to block couplers 500, individual at the respective incoming and initial junctions. The incoming block coupler 500-1 is connected

  
  <EMI ID = 58.1>

  
205 extend the incoming and initial junctions 2085 and 203A past the block couplers to the respective vertical positions on the primary block switches 1300.

  
The outgoing and final junctions (such as 2020 and 2007B) depart from the respective vertical positions on the secondary block switches 1400.

  
The specific mutual relationship between the primary and secondary block switches through the block references is shown in the general junction diagram, figure 3, parts 3 and 4.

  
General control over the primary and secondary switches in the block bay is exercised by the block controller 1600, shown as a complete circuit diagram in Figure 16. When a connection that has reached

  
  <EMI ID = 59.1>

  
1500 (shown as a complete circuit diagram in Figure 15) operates to connect block controller 1600 to the primary block switch of interest such as 1300. Then, the calling block coupler is connected directly to the block controller 1600 by conductors. of bundle 221.

  
  <EMI ID = 60.1>

  
outgoing trunk such as 2020), an outgoing controller 1700 is put

  
in play by an initial digit wire of the ID harness. This controller is connected to the outgoing junctions by respective conductors 227, and to the block controller by the conductors of the bundle 241. Its function is to determine which junctions of the called bundle are free, and to properly transmit this information to the block controller.

  
When the connection served by the block coupler associated with the block controller is made in view of a called line in the local office, the information regarding hundreds, tens, ones and places has been stored in a block coupler and is passed to the 1800 block translator, by

  
  <EMI ID = 61.1>

  
The block translator 1800 is shown as a complete circuit diagram in figure 18 which shows its section of the relays, and in figure

  
  <EMI ID = 62.1>

  
block is to determine, on the basis of the information concerning the digits sent, which of the four bays of lines A to D carries the called line, as well as the specific position of the called line on this bay, and to transmit translated information suitable for line control equipment on the called line bay, depending on the position of the called line on this bay.

  
  <EMI ID = 63.1>

  
The line control equipment of the called line array acts on the information received from the block translator in order to prepare the extension of the connection to the specific called line. Among other things, this device identifies the line bay called by the block controller
1600, after which the block controller and the line controllers cooperate to extend the connection to the called line by a free path. The cooperation between the block controller and the line control devices provided on the line bays is controlled by the respective conductor bundles 222A to 222D.

  
We will now describe the operation of the system when the

  
  <EMI ID = 64.1>

  
..The subscriber to the set SI on line 200, to call the subscriber at set S2, on line 210, picks up his telephone, waits for the sending tone which must come from a local block coupler; he then dials the complete number of the S2 station, containing 5 digits, namely: the initial digit and the hundreds, tens, units and positions digits.

  
When the receiver is off-hook at the calling station SI, the calling line 200 is looped in the usual way in order to activate its usual line relay at the office B. This causes the operation of the control connectors.

  
  <EMI ID = 65.1>

  
of primary lines 800A to which the calling line is connected. After that, the line feeds (such as 202A) serving the primary switch 800A are tried by the line controller 1200A through the respective conductors 2I2A, and the respective initial trunks, such as 203A, are tested by

  
  <EMI ID = 66.1>

  
gnes combines a free path to extend the calling line to a free block coupler, for example, the path through line forwarding 202A and the initial trunk 203A. When this is done, the line controller commands the primary and secondary switches 800A and 900A to perform a mechanical selection of the combined line forward 202A, and it energizes

  
  <EMI ID = 67.1>

  
then return to common availability, leaving the calling line
200 connected to local block coupler 500-L through line feed 202A and initial 203Ao junction

  
On receipt of the sending tone via the established connection, from the block coupler 500-L, the subscriber to the calling station Si activates his usual sending device to transmit pulses representing the five digits of the telephone number. directory of the station called S2. These figures include

  
an initial number indicating office B and the numbers of hundreds, tens, units and extensions indicating the called line and the called extension

  
S2 on this line. These numbers are noted on the respective loggers in the 500-L block coupler, before any external switching action occurs. As soon as the extension digits have been sent, block connector 1500 associates block controller 1600 with primary switch 1300 which serves block coupler 500-L. At the same time, the block coupler 500-L associates with the block controller 1600 through the conductors of harness 221. At the same time, too, the information sent regarding hundreds, tens, ones and positions, is transmitted to the block translator 1800 by the respective conductor bundles H, T, U

  
and ST.

  
The de-block translator then determines the line bay which serves the called line (the line bay 250B), and transmits to it (by conductors of the bundle 223D), the translated information concerning the digits,

  
  <EMI ID = 68.1>

  
as to the specific vertical output of the called line on this switch. This done, the 200B line controller identifies itself on the controller <EMI ID = 69.1>

  
then by the respective conductors 212B, and the test information is communicated to the block controller 1600 by the respective conductors of the harness
222B. The body wire 211B of the called line, 210 is now extended to the block controller 1600 by a conductor of the bundle 222B; this allows the block controller to test the called line to determine whether it is busy or free.

  
If the called line is tested free, the block controller combines a free path to it by a block return such as 206, a trunk

  
  <EMI ID = 70.1>

  
block and final junctions are tested by conductors respectively
225 and 226.

  
When this free passable path between the block coupler 500L and the called line has been determined, the block controller 1600 closes suitable selector circuits to perform the mechanical selection of the block return 206 on the switches. primary 1300 and secondary

  
  <EMI ID = 71.1>

  
block 1600 acts by a conductor of harness 221 so as to close the appropriate circuit in the primary switch 1300 to extend the connection

  
  <EMI ID = 72.1>

  
close the appropriate connection in the secondary switch
1400 in order to extend block forwarding 206 to the final junction 207B, and to cause the extension of this junction to the selected line forwarding

  
  <EMI ID = 73.1>

  
202B on called line 210;

  
After the completion of the foregoing operations, the local block coupler 500-L begins to apply ringing current to the called line to signal the call to called station S2, connected to that line, through the connection established to across block bay and across called line bay; however that the elements of the common switchgear (the <EMI ID = 74.1>

  
common availability, leaving the connection between the calling line and the called line intact.

  
When the call has been answered, the subscribers of the SI and

  
  <EMI ID = 75.1>

  
front and rear that it had held closed until then, after which the existing connection is broken to each of the switches 800A, 900A, 1300, 1400, 99B, and

  
  <EMI ID = 76.1>

  
We will now describe the case where the Si set calls the office

  
  <EMI ID = 77.1>

  
When the subscriber of set Si, connected to line 200, wishes to call a subscriber from office C, he picks up his telephone, waits for the sending tone, and then dials the directory number of the subscriber of the office C. This number includes an initial number whose value is specifically assigned to lines in office C.

  
When the telephone is picked up at the calling station SI, the operations described above occur on the bay. lines A for pro-

  
  <EMI ID = 78.1>

  
again that the calling line is extended to the block coupler
500-L by forwarding lines 202A and the Initial 203A junction,

  
When the Initial digit specifically assigned to office C has been sent and noted in the 500-L block coupler, a connection is immediately made, through a wire of the initial digit ID harness, to engage the outgoing controller 1700 and for the put in the specific position which relates to the junctions of the harness leading to the office called C. This occurs concurrently with the association of the block coupler 500-L with the block controller 1600 by the conductors 221, and with the operation of the connector of block 1500 which associates the block controller 1600 with the primary switch 1300. When the block controller and the outgoing controller have both been thus engaged, the block controller is put in the specific state suitable for extending the connection to a free junction in the called outgoing group.

   The arrangement of the circuits is such that the operations which are necessary to prolong the required connection occur quickly enough so that the calling subscriber is not obliged to introduce an additional delay had to proceed to the transmission of the other digits of the desired phone number.

  
If the block forwarding '206 and the outgoing junction 2020 are both free (as shown by the tests made by the respective conductors
225 and 227), the block controller 1600 taking into account the information that

  
  <EMI ID = 79.1>

  
appropriate cross points in switches 1300 and 1400 in order to connect conductor 205 exiting the block coupler to the outgoing junction conductor 2020 by means of blox return 206; which extends the calling line through the 500-L block coupler to the 2001 trunk coupler located on bay 252, and from there through the 2023 trunk extension and jumper
2024, to the outgoing trunk conductors to office C. When this has happened, the 500-L block coupler gives the mechanical connection, as ex-

  
  <EMI ID = 80.1>

  
a device for retransmitting the pulses of the following digits through: The junction to the switchgear in the office C. This device can be similar to the switching devices in the office B. Along with the mechanical connection operation mentioned for the block coupler, the Elements of the block bay's common equipment (control connector 1500, block controller 1600, and outbound controller 1700) are disassociated from the established connection and revert to common availability.

  
The connection established from the calling line to the outgoing junction,

  
  <EMI ID = 81.1>

  
2001 trunks when the receiver is later hung up at the calling station Si.

  
We will now describe the case of a call from office A.

  
When office B is called from office A, the call from office A reaches office B through an incoming trunk such as the one shown. This junction is extended by parts 2082 to 2085 and the jar-

  
  <EMI ID = 82.1>

  
local block, except that preferably, it does not send a send tone when engaged. The junction in question can be taken in: office A by the operations previously described with respect to taking a junction going from office B to office Co

  
After an incoming block coupler is seized, the call can be extended to office C by sending an appropriate initial digit to block coupler 500-1, or it can be extended to any desired called line from office B by sending the appropriate initial digit, followed by the hundreds, tens, units and extensions of the directory number of the line called and of the extension connected to that line. The connection can be extended from block coupler 500-1 to line 200 through bundle 232 and the associated vertical position on primary switch 1300, and from there in the manner previously described for a call from a local extension Si ,

  
We will now describe the general diagram of the junctions re-

  
  <EMI ID = 83.1> <EMI ID = 84.1>

  
the line bays shown in Figure 2, is shown in a more complete manner.

  
We will first describe the row bays.

  
Referring to part 1 of figure 3, there is, on the bay

  
of lines A, ten primary SOOA switches, of which we have shown the first two

  
  <EMI ID = 85.1>

  
three-digit 25 x 10 switch, which is a switch having 250 three-wire crossover points. The 25 subscriber lines that can be connected

  
  <EMI ID = 86.1>

  
Line bay A has 5 secondary line switches
200Ao In fact, these five switches serve as ten separate secondary switches, because the horizontal or longitudinal paths of each are cut through the middle to form two separate groups, each of 10 rows. That is, each of the 10 secondary switches includes a left section L and a right section R, each section having its own cross, vertical and horizontal paths. Five two-section 900A secondary switches are more economical to manufacture and require less rack mounting space than ten fully separate secondary switches.

  
The left and right sections of the secondary switches
900A, considered in the regular order from number 1 to number 10, are called the ten secondary sections. Each secondary section has eight vertical positions of which the first four serve as connection points for the respective final junctions 207A, while the last four serve as connection points for the respective initial junctions 203A. The ten secondary sections thus contain 40 final junctions and 40 initial junctions for the line bay A ..

  
One hundred two-way line referrals 202A interconnect the

  
  <EMI ID = 87.1>

  
900Ao Secondary Switches For convenience, these line feeds are numbered 1 through 100 at their clips on the primary switches. Line feeders connect primary switches with secondary sections in what is called normal crossover, in which all ten feeders from any primary switch go to corresponding secondary sections, respectively, and the ten line feeds connected to any secondary section There are respectively corresponding primary switches.

  
  <EMI ID = 88.1>

  
mier primary switch 800A in rows 1 of the respective secondary sections; references 11 to 20 go from the second primary switch 800A to rows 2 of the respective secondary sections; and so on until the tenth

  
  <EMI ID = 89.1>

  
In view of the numbering and testing operations, we consider the
40 initial 203A junctions which start from columns 5 to 8 of the 10 sec-

  
  <EMI ID = 90.1>

  
respective res; the junctions II to 20 (group 2) start from the columns 6 of the respective secondary sections; junctions 21 to 30 (group 3) start from columns 7, and junctions 31 to 40 (group 4) start from columns 8 of the respective secondary sections.

  
Likewise, the final 40 junctions 207A that arrive at line bay A of the block bay are considered to consist of 4 groups of 10.

  
  <EMI ID = 91.1>

  
10 secondary sections. The first 10 final junctions go to the respective secondary sections in regular order, and the final junctions of groups 2, 3 and 4 connect to the secondary sections with a gradual shift of one column. That is, any final junction of group 2, 3 or '4 is connected to the secondary section immediately behind the position to which the corresponding junction of the immediately preceding group is connected. This shifting of the connections of the 4 groups of final junctions to the secondary sections is provided to improve the possibilities of combination using the final junctions, as will appear later.

  
On the line bay A, groups of fasteners 321A and 322A are provided respectively for the final and initial joints, in order to serve as a connection point between the conductors belonging to the line bay and the conductors of the cable going from the bay lines to block bay. Similar fasteners for line B, C and D bays are my-

  
  <EMI ID = 92.1>

  
203B and 207B to 203D and 207D are connected to these clips.

We will now describe the block bay.

  
  <EMI ID = 93.1>

  
Crossbar switch, provided on the block bay, includes 10 primary switches 1300 and 10 secondary switches 1400. The description assumes that each of these switches is a 20 x 20 three-digit switch.

  
  <EMI ID = 94.1>

  
horizontal or longitudinal paths. Each pair of horizontal paths contains a lower path L and an upper path U, each representing

  
a separate block return 206. Each switch 1300 or 1400 receives 20 junctions on its columns and 10 pairs of block returns 206 on its rows.

  
There are 200 block referrals 206, comprising 100 pairs and pairwise crossed between the primary and secondary block switches 1300 and 1400 as shown for the crossing of the 100 single line referrals 202A between the primary line switches 800A and the branch sections formed by branch line switches 900A. That is, from any primary block switch 1300, the 10 pairs of block referrals go respectively and in regular order to secondary switches 1400. Block referrals are employed in pairs rather than being used separately as line referrals, due to the increased traffic crossing the block bay.

  
Each primary switch 1300 is associated with a group of 20 block couplers, such as block couplers 500-1 and 500-L in Figure

  
2. These groups of block couplers bear the references 500-1 to 500-10 in FIG. 3. We will refer below to each of these groups of block couplers as a section of block couplers, with a section separate for each primary switch 1060.

  
The initial junctions coming from the two lines A, B, C and D are led from the line bays to the block bay by the cables of initial junctions.

  
  <EMI ID = 95.1>

  
to 323D. Forty inbound trunks are contained in an ITC inbound trunks cable running from the 252 trunking coupler bay to the block bay and terminating at 3231 clips. The three wire inbound junctions have

  
  <EMI ID = 96.1>

  
fasteners of the initial and incoming junctions, as required, to the respective fasteners of groups 324-1 to 324-10. Hitch groups shown, 323A

  
  <EMI ID = 97.1>

  
that they constitute an intermediate distributor bay on which we

  
  <EMI ID = 98.1>

  
making the desired initial and incoming junctions available to the respective block couplers, only as required for the actual service of the traffic, and to allow these junctions to be varied in the various block coupler sections in any way which from time to time can be advantageous.

  
  <EMI ID = 99.1>

  
final, 40 for each of the bays in rows A, B, C and D. Columns 1 of
10 secondary switches 1400 serve as a starting point for the junctions <EMI ID = 100.1>

  
nes 3, for the junctions A-21 to A-30 and columns 4 for the final junctions A-31 to A-400 The 40 final junctions Bl to B-40 for the bay of rows B start from the same columns 5 to 8 of the switches 1400; the 40 junctions

  
  <EMI ID = 101.1>

  
Ends for row array D start from columns 13 through 16 of secondary switches 1400.

  
TA, TB, TC, and TD end splice cables run from block bay clips to end splice clips on line bays

  
  <EMI ID = 102.1>

  
starting point for outgoing junctions and outgoing branches of two-way junctions (such as 2020, figure 2) contained in the cable of

  
  <EMI ID = 103.1>

  
The manner of varying the capacity of the system will now be described.

  
The capacity of the junction system shown in figure 3,

  
  <EMI ID = 104.1>

  
served and 2 [deg.] the traffic demand of these lines, such as the number of these lines requesting to be served simultaneously during the busy hour.

  
If, for example, you only need to install 250 lines first, you only need to install line bay A first, as well as a minimum of equipment on the block bay. Line bays B, C and D can be added later, all at the same time, or one at a time, as needed.

  
  <EMI ID = 105.1>

  
health,

  
On a line array, primary switches can be omitted when the full capacity of the array (250 lines) is not required. The omission of each of the primary line switches reduces the capacity of the line array by 25 lines. It is envisioned that all 5 secondary switches 900A will always be provided on a line array, regardless of any reduction in the number of primary switches. By this arrangement, all
10 line forwardings remain available for use on each switch.

  
  <EMI ID = 106.1>

  
which would not have been the case if one or more of the secondary switches
900A had been omitted.

  
Since there is no expensive piece of equipment (such as a block coupler) individually associated with any final junction, it is envisioned that all 40 final junctions will be provided for each bay.

  
of lines, regardless of any final low traffic that may be observed. In this way, the calls lost due to the unavailability of the final junctions remain at a minimum value, which makes it possible to reduce

  
the initial trunks, which need to be fitted with relatively expensive couplers, to a number more than sufficient so that the total number of calls lost during the busy hour is kept at a figure which does not exceed that specified for Installation.

  
In the ordinary case the total number of primary switches
1300 that should be expected on the block bay is just one twentieth of the total number of block couplers needed to service the Initial traffic

  
and entering. That is, for each required section of 20 block couplers, it is necessary to install a separate primary switch 1300. Telephone traffic experience shows that all 10 primary switches 1300 will only very rarely be needed. , even if the four bays of lines A to

  
D are planned and fully equipped.

  
When omitting a primary switch 1300 which is not required, as well as the associated section of block couplers 500, the jumpers

  
  <EMI ID = 107.1> and inbound used at block couplers associated with 1300 primary switches installed.

  
Preferably, one installs on the block bay every 10 commu-

  
  <EMI ID = 108.1>

  
1300 used. Then, each installed primary switch 1300 has full use of its 10 pairs of block referrals 206, and the number of final trunks per line array is not reduced, nor is the number of outgoing trunks.

  
We will now describe the complete establishment of calls, starting with the action of a block coupler (Figures 4 to 7).

  
These figures show, with more detail in the circuits, the apparatuses shown in Figure 2, Figure 5 showing the circuit of the block coupler 500-L in full detail. This part of the description covers in all its details the operation of the parts of the devices, directly engaged in the conversation paths crossing the line bays and the block bay. The following parts of the description cover the func-

  
  <EMI ID = 109.1>

  
separate, 2 [deg.]) of the elements of the common control equipment and 3 [deg.]) of the equipment of the junction coupler bay.

  
The 500-L block coupler will first be described.

  
As shown in Figure 5, the local block coupler 500-L

  
  <EMI ID = 110.1>

  
518 and magnetic pulse counters SE, IDR, HR, TR, UR and SR.

  
We will now describe the functions of the circuits of the coupler
500-L.

  
The local block coupler 500-L only processes locally originated calls, which it receives through its assigned initial trunk 203A, arriving from the

  
  <EMI ID = 111.1>

  
outgoing call, 2 [deg.]) as a local termination call, or 3 [deg.]) as a return call. The 500-L block coupler performs following main functions of the circuits;

  
1 [deg.]) Normally it applies the battery potential indicating the availability to the body wire of the initial junction attached to it.

  
2 [deg.]) On all calls

  
  <EMI ID = 112.1>

  
calling line until the first digit is sent and 2 [deg.]) it removes the availability potential of the body wire from the attached original junction and substitutes it for a potential of occupied ground.

  
2b. if the start of the shipment is delayed by the tolerance period

  
  <EMI ID = 113.1>

  
occupation of the body wire of the attached initial junction, in order to allow loosening and cutting to occur on the line bay.

  
  <EMI ID = 114.1>

  
dialed or produced otherwise.

  
3 [deg.]) On an outgoing call g

  
3ao it receives and stores a single digit for transfer to the outgoing controller.

  
3b. it temporarily takes the outgoing chain from its local block coupler section, provided that chain is free, and then occupies the taken chain so that it is not taken by another block coupler.

  
3co it transfers the only digit stored to the controller going out following the taking of the outgoing chain.

  
3d. on a signal from the block controller that no free path

  
  <EMI ID = 115.1> <EMI ID = 116.1>

  
bere the outgoing chain taken,

  
3rd. on a busy pilot signal, coming from the block controller, that the connection can be extended by a combined path up to a free outgoing junction, in the called bundle, 1 [deg.]) it goes into mechanical connection on the combined path and 2 [deg.]) it releases the outgoing chain taken.

  
3f. it is then maintained by an earth received by the body wire of the extended connection, and it returns to rest when this earth is removed,

  
  <EMI ID = 117.1>

  
4a. it receives and stores the five digits (an initial ID digit, a hundreds digit H, a tens digit T, a units digit

  
U and a station digit ST) for transfer to the block translator.

  
4b. if the next digit to be sent is delayed by the period

  
normal time tolerance, it stops time as previously mentioned.

  
  <EMI ID = 118.1>

  
local block couplers provided that this chain is free and occupies the chain taken so that it is not taken by other block couplers,

  
  <EMI ID = 119.1>

  
is busy, or that no free path can be combined to this line,

  
  <EMI ID = 120.1>

  
company, from the primary block switch, that the connection has been extended by a combined path to the called line, 2 [deg.]) it applies a ring tone to the called line and 3 [deg.]) releases the local channel taken,

  
  <EMI ID = 121.1>

  
normal time rancid, it stops time, as mentioned earlier.

  
4h. when the call has been answered, 1 [deg.]) it stops the ringing circuit, 2 [deg.]) it completes the conversation connection and 3 [deg.]) it reverses the flow of current on the tip and nape conductors of the attached initial junction, provided a hook command of the called line.

  
  <EMI ID = 122.1>

  
4j, if the connection remains maintained by the two lines at the end

  
  <EMI ID = 123.1>

  
time, as previously mentioned, but applying an advance pulse

  
  <EMI ID = 124.1>

  
minute before.

  
4k. if the connection remains maintained by the calling line, after cutting the called line, it stops the time at the end of the normal tolerance period.

  
  <EMI ID = 125.1>

  
calling line is cut, it returns to idle and releases the entire connection by removing the occupying earth from the incoming body wire and the front connection body wire.

  
on a return call (when the calling subscriber sends the regular directory number of his own line)

  
5a. it works as said in the previous paragraphs 4a.

  
  <EMI ID = 126.1>

  
5b, on a signal from the block controller, that the call is a return call (back to the calling line), - 1 [deg.]) It applies a ring back tone to the calling line and 2 [ deg.]) it frees the free local channel.

  
5c, When the phone is hung up on the calling line,

  
  <EMI ID = 127.1>

  
hold connection and 2 [deg.]) it sends ringing current back over its associated initial trunk to the calling line.

  
5d. when the return call has been answered, it unlocks and returns to rest, removing the occupying earth of the body wire from its associated Initial junction, in order to allow loosening and cutting to occur. produce on the associated line array.

  
We will now describe the functions of the relays in the coupler.
500-L.

  
The following main functions are assigned to the fifteen re-

  
  <EMI ID = 128.1>

  
trants of the junction in metallic connection with the outgoing conductors in the outgoing calls and in return.

  
  <EMI ID = 129.1>

  
that a locally terminated call is answered, to reverse the tip and neck conductors under the hook control of the called line.

  
Relay 503 (line) operates when the coupler is seized, and then returns to idle, under the control of the calling device or hook, whenever the calling line is cut.

  
  <EMI ID = 130.1>

  
it falls back to the beginning of a train of Dial Impulses, to actuate

  
the SE sequence counter; and it only works again when the line relay stops again in the working position, being slow in operation due to a taut adjustment of the spring,

  
  <EMI ID = 131.1>

  
copper sleeve under its winding; ., it is actuated by the line relay; it remains on during pulses, but releases when the line relay remains off for a significant fraction of a second.

  
Relay 506, (ring reversal) is actuated by the block translator, on an extension digit between 5 and 9, to apply ringing current to the other line wire, for ringing, divided.

  
  <EMI ID = 132.1>

  
copper collar surrounding the core on the side of the pallet, and it is actuated by the direct current which enters the ringing circuit when one

  
  <EMI ID = 133.1>

  
Relay 508 (call-back) is actuated by the block controller to put the block coupler in the state of a call-back.

  
Relay 509 (connection) is actuated when a locally terminated connection is extended to the called line, to release the final chain and to close the bell circuit etc.

  
Relay 510 (occupancy) is actuated by the

  
  <EMI ID = 134.1>

  
local result after sending the number of positionsj it takes the final chain of the local block couplers for its exclusive use.

  
Relay 513 (start time) is actuated as needed to start the final part of the normal delay period or talk time period to allow the common timer to release communication.

  
  <EMI ID = 135.1>

  
Relay 515 (transfer) is activated during the ringing period to transfer the ten wires controlled by the extension recorder

  
SR, from the wires of stations associated with the block translator, to the ten wires of interrupted generators.

  
We will now describe the functions of the pulse counters in the coupler 500-L.

  
  <EMI ID = 136.1>

  
single digit dant, to distribute trains to IDR to SR recorders.

  
The IDR counter (initial digit recorder) records the number of pulses of the first digit sent, the initial digit,

  
The HR counter (hundreds recorder) records the number of pulses of the hundreds digit.

  
The TR counter (tens recorder) records the number of pulses in the tens digit.

  
The UR counter (unit recorder) records the number of pulses in the ones digit.

  
The SR counter (station recorder) records the number of pulses in the station digit.

  
The following additional functions are assigned to the comp-

  
  <EMI ID = 137.1>

  
resistor 532 for occupation of the body wire; it controls the Release Pulse relay 514; and he takes cadenced steps 6 to 9 in the measure of the talk time.

  
IDR initial digit recorder cuts the tone wire

  
  <EMI ID = 138.1>

  
command cooked for SE.

  
The HR Hundreds Recorder selects between outgoing busy tone and final busy tone.

  
The tens recorder TR chooses between the metal connection relay 501 for outgoing calls and the connection relay for outgoing calls,

  
  <EMI ID = 139.1>

  
res 4 to 7.

We will first describe the start of the call.

  
When you pick up the telephone (not shown) at the IS station of

  
  <EMI ID = 140.1>

  
peak and neck T and R of line 200, by the HP pilot contacts of the associated maintenance electro 403 in the primary line switch 800A '

  
  <EMI ID = 141.1>

  
damnation 402 to mark the conductor M, individual to the calling line., and the conductor F, which is common to the five lines constituting the packet of * five in which the calling line is located.

  
The grounding of the bundle conductor F applies an earth potential, through the bundle resistor FR-1, to the primary conductor P, which is common to the twenty-five lines served by the primary switch. <EMI ID = 142.1>

  
primary line switch.

  
Grounding the P wire shown in Figure 4 places the IOOOA and 1100A line control connectors to the 1200A line controller on the calling primary switch 800A, with specific reference to the pack of five including the calling line. . Having been thus put in place, the line connectors close the cut-off points indicated therein. Line controller 1200A then combines a free path between: Calling line 200 and an initial trunk 203A. The circuit for testing the 202A line return by the 1200A line controller runs from the LT line test lead through the contacts of one of the line connectors to the body lead

  
  <EMI ID = 143.1>

  
battery on the return body, which is supplied through the LR resistor shown in the line controller, the LB return battery lead and the contacts of one of the control connectors. If the referral.

  
  <EMI ID = 144.1>

  
as busy while when the forwarding is free, 9 'the battery potential' of availability is actually received by the line controller.

  
When the initial 203A junction (which is connected to the coupler

  
  <EMI ID = 145.1>

  
body conductor S of the initial 203A junction, contacts 1 of release relay 505, contacts of test jack TJ, contacts 1 of relay

  
  <EMI ID = 146.1>

  
initial 203A is engaged, the battery potential of availability on the body conductor S is replaced by an earth potential.

  
After having combined a path by reference 202A to the junction

  
  <EMI ID = 147.1>

  
reference, LSM, by closing a circuit passing through the contacts of one of the control connectors and through the selection electro wire, for

  
  <EMI ID = 148.1>

  
er the mechanical selection of return 202A on the primary switch 800A and on the secondary switch 900Ao When the two electros 404 and 405 have operated to make the said selection, a battery potential coming from the resistor CR in the line controller 1200A is conducted by the con-

  
  <EMI ID = 149.1>

  
the, to the non-normal primary-secondary wire PO-ON going to the line controller,

  
When it has received the battery potential through the PS-ON wire, the con-

  
  <EMI ID = 150.1>

  
dre the calling line by the selected line forwarding 202A to the assigned initial junction 203Ao The line controller controls the holding electro 403 by applying a ground potential to the shown wire of SU body units, which is extended by the contacts from one of the control connectors to the body wire

  
  <EMI ID = 151.1>

  
terie through the maintenance electro 403 and the locking relay 402, in series. Having worked, the maintenance electro 403 closes the battery of contacts

  
  <EMI ID = 152.1>

  
of the usual cut-off relay), after which relay 401 releases.

  
After having operated in series with the maintenance electro 403, the conversation relay 402 prepares the locking state of the associated line if necessary.

  
The 1200A line controller operates the 406 holding electro by directly applying the ground potential to the NT-213A combination test lead, closing a circuit through the left coil of the electro.

  
  <EMI ID = 153.1>

  
block coupler 500-Le by the path previously indicated. Having worked, the hold electro 406 connects the TR and S conductors of the line forward 202A, respectively to the corresponding conductors of the initial junction 203A, completing the extension of the calling line to the calling junction. At the same time, the maintenance electro 406 is blocked by its contaotpilot and its right coil, to the earth on wire S of junction 203A. Initially, the blocking earth on the body wire is held by the left coil of the hold electro 406 and by the body wire controlling the line.

   The 1200A line controller keeps the control circuits of the 403 and 406 appliances closed for a sufficient time interval to allow the block coupler taken 500-L to return the blocking earth to the body wire of the initial junction taken 203Ao Little afterwards the 1200A line controller returns to idle and allows the IIOOA control connectors and

  
  <EMI ID = 154.1>

  
an earth applied to its body wire by the block coupler taken.

  
The taking of a 500-L block coupler will now be described.

  
When the block coupler 500-L is taken by the extension, which has just been described, of a connection coming from the calling line 200,

  
  <EMI ID = 155.1>

  
503 activates the release relay 505 via contacts 3 of relay 501.

  
At its contacts 1, release 505 transfers the body wire from Initial junction 203A, from the battery through resistor 532, to a hand earth. held by the closed contacts 2 of relays 512 and 513. The connection established between the calling line and the block coupler is maintained in this way after the release of the line control devices, shown in the figure. <EMI ID = 156.1>

  
for its own winding through the associated resistor 531. At its contact 3, the relay 505 opens a point of the release pulse relay circuit 514 and prepares the local pulse circuit for the IDR to SR digit recorders, eg the contacts of the SE sequence device.

  
At its contact 2, the line relay 503 closes a circuit for the train relay 504 by the contact 8 of the relay 507. The relay 504 operates after a delay, and at its contact 1, it. place the send tone on the calling line, from a common DT send tone wire, through a capacitor

  
  <EMI ID = 157.1>

  
earth the common tone start wire to start the tone device if it is not already functioning; to its contact 2, it connects the time start relay 513 to the common wire of TP, clocked pulses, to start

  
  <EMI ID = 158.1>

  
on IDR contacts, to prepare for the advancement of SE.

  
The reception of the digit pulses will now be described.

  
On hearing the signal of the mentioned sending tone, the calling subscriber dials the digits of the directory number of the line or extension called on the dial.

  
Each time the sending device is actuated to send

  
  <EMI ID = 159.1>

  
for each impulse of the train, which consists of one to ten impulses, depending on the number composed

  
The 505 release relay remains on during all

  
  <EMI ID = 160.1>

  
slow release because of its mentioned copper sleeve, and also because of the holding effect of the auxiliary current flowing through the associated resistance
531. This resistor has a value such that the release relay cannot stay working indefinitely in series with it, but can maintain

  
its spring-loaded contact load in the absence of the normal current in its winding, longer than otherwise.

  
Train relay 504 drops out quickly on the first drop of line relay 503, being slow in operation due to relatively inductive winding and relatively hard adjustment of the return springs, so that it remains idle for the whole series, corresponding to one digit, of momentary fallout from the line relay.

  
The release relay 505 being kept constantly at work, each drop of the line relay 503 sends an impulse to its contact of

  
  <EMI ID = 161.1>

  
relay 510, on wire 550. The connections between contact sets 1B and 2A5 of the SE sequence device are such that the first set of Pulses applied to wire 550 is transmitted to the lower or control windings of the appliances of the Initial IDR digit logger.

  
  <EMI ID = 162.1>

  
again in response to the durable closure of its circuit and closes an advancement circuit for the SE sequence device. This circuit passes through the IDR recorder open contact 1 (which is closed as described later) and through the open contact 5 of relay 5 07 and 3 of relay 514.

  
The first advance pulse, which is applied to the device

  
  <EMI ID = 163.1>

  
rest 1A disconnects resistor 532 to prevent re-application of the availability potential to the incoming body wire of the coupler before the release of the SE device; and the contacts 1B disconnect the incoming pulse wire 550 from the first IDR recorder and transfer it to the second HR recorder through the rest contacts 2 and the open contacts IB.

  
At the following steps of the sequence device 'SE (which, occur in return calls and local calls), contacts 2 work to transfer the 55o pulse wire to the tens recorder TR, its contacts 3 work- to transfer wire 150 to the UR unit recorder; its 4 contacts work to transfer wire 550 to the recorder

  
SR post; and its contacts 5 operate after registering the station digit to cut pulse wire 550 and close a point in the final chain relay circuit 512.

We will now describe the recording of the initial digit.

  
When the pulses of the initial digit are applied through wire 550, to the control windings, of the initial digit register

  
  <EMI ID = 164.1>

  
are actuated successively, in response to the respective impulses of the digit,

  
  <EMI ID = 165.1>

  
send tone DT to its idle contact 1, in order to avoid re-application of the send tone after new operations of train relay 504 .; and its working contact 1 prepares the advance circuit indicated above for the sequence device SE.

  
  <EMI ID = 166.1>

  
produced otherwise, for example by untimely operation of the hook or a disturbance on the line. Therefore, the digit "1" cannot be assigned as the effective initial digit.

  
When the initial digit received contains only one pulse, the.

  
  <EMI ID = 167.1> <EMI ID = 168.1>

  
end of the digit recording Initiate the Release Pulse relay 514 operates on a given earth by the working contact 5 of the relay

  
  <EMI ID = 169.1>

  
upper (release) of the six pulse counters to release the SE and IDR counters by neutralizing the residual flow of maintenance of each

  
At its contact 3, the relay 514 opens the control circuit of the counter SE to allow the flow of the release current to act effectively on this counter.

  
  <EMI ID = 170.1>

  
completely release all activated counters. Relay 514 opens the meter release circuit and reconnects the windings of the counters.

  
  <EMI ID = 171.1>

  
sending authority to the calling line to signal that the calling subscriber should start sending digits again.

  
We will now describe the outgoing calls.

  
When sending any initial digit from 2 to 0, the IDR recorder establishes a connection with the corresponding wire of 10 initial digit wires, ID2 to ID10, which go to the outgoing controller 1700. One of these conductors (ID6 in the example of embodiment shown) corresponds to the initial number assigned to the block of 1000 lines of local numbers, and it is rendered inoperative at the outgoing controller, as shown in FIG. 17. The other ID wires can correspond to the respective bundles of outgoing junctions and extend to the block controller through the respective initial digit relays of the outgoing controller,

  
We will now describe the engagement of the block controller by the outgoing call and the marking to the beam controller.

  
When the initial digit sent is a digit assigned to a

  
  <EMI ID = 172.1>

  
The outgoing string is said to be free, in which case a ground potential is present on the outgoing string engagement wire in the first coupler in the section containing the calling block coupler 500-L. For this section

  
  <EMI ID = 173.1>

  
nant of the block control connector 1500 of figures 2, 6 and 15. This wire goes from one of the sectional preference relays, shown in figure 15,

  
  <EMI ID = 174.1>

  
through the chain contacts of all block couplers in the section to the outgoing end of chain conductor OTG-CH-END, multiple on all couplers in the section. The earth potential, applied to the OTGCH-END conductor, then passes, through closed contact 3 of relay 511, the winding of this

  
  <EMI ID = 175.1>

  
beam called in the outgoing controller, and 2 [deg.] to inform the block controller that an outgoing call has been received. After that, the outgoing controller informs the block controller about the state, busy or free, of each of the outgoing trunks, in the called bundle, while the block controller proceeds

  
to the combination of a path through the block bay to one of the free junctions.

  
We will now describe the capture and custody of the outgoing chain.

  
In the outgoing chain relays (figure 15) associated with the block control connector 1500, the relay, preferably of section, inside

  
  <EMI ID = 176.1>

  
block coupler sections, and to control block connector 1500 to select primary block switch 1300 which serves the block coupler section containing the calling block coupler.

  
In the calling block coupler 500-L, the outgoing chain relay 511 operates in the indicated circuit to jam on the conductor

  
  <EMI ID = 177.1>

  
isolates (at its rest contacts 2 and 3), the associated end of chain OTGCH-END wire from the chain in order to keep the chain coming out of a socket by another block coupler of the same section, whereby their Common block bay control devices are temporarily made individual to the coupler

  
  <EMI ID = 178.1>

We will now describe the outgoing occupation state.

  
In the event that no outgoing junction of the called trunk group is available (for example, when all the junctions of the called trunk group are occupied, or when it is not possible to combine a path to a free junction of this trunk), or at In the event that an unassigned initial digit has been sent, the block controller will ground the common OTG-BU wire (shown as being in the 222A cable), which activates the occupancy relay 510 of the switch.

  
  <EMI ID = 179.1>

  
pulse wire 550 to its contact 5 to prevent other digits from being recorded if they are sent; at its contact 2, it doubles the contacts of the re-

  
  <EMI ID = 180.1>

  
thus releasing this relay, if it is at work, to start a new time limit period in case digits are still being sent;

  
and it applies an outgoing busy tone to the calling line starting from the common OTG-BT busy tone wire, through the contacts of the HR recorder at rest, contact 1 of the occupancy relay 510 and the capacitor

  
  <EMI ID = 181.1>

  
Distinctive character of outgoing occupation, thereby causing the normal release of the connection. Otherwise, the connection is cut off at the time limit. as described later.

  
We will now describe the combination and the selection of an outgoing path.

  
Normally there is a free and available junction in

  
the called outgoing bundle, such as junction 2020, in which case a free path is combined to this junction via a block forwarding such

  
  <EMI ID = 182.1>

  
2020 is indicated in the outgoing controller 1700 by an availability battery potential that applies: normally to the body wire S of this junction the junction coupler 2001 and which reaches the outgoing controller through <EMI ID = 183.1>

  
that 206U and 206L is determined by the block controller by means of the respective body wires 225, which extend into them by the contacts of the control connector: 15000 This connects body resistors RU and RL to the respective body wires 225, thus applying the availability potential

  
to each of them, which can be masked by the earth potential which can be applied to them in the references currently used.

  
When the path through the elements 206U and 2020 has been determined by the combining operation of the 1600 and 1700 controllers, the 1600 block controller closes a circuit through the contacts of the 1500 block connector and the SM wire of the main selection electros. 605 and
606 in series In order to select the combined upper diversion
206U of the pair shown, distinct from its lower reference 206L, the block controller 1600 closes a circuit going from the ground through the electro of

  
  <EMI ID = 184.1>

  
associated SMU wire and the block connector contacts, the block controller leads and contacts, the SMU wire going to switch 1400, and from there to the battery through the upper auxiliary selector switch SMU-

  
  <EMI ID = 185.1>

  
An out-of-normal or pilot circuit is now established from the earth through the out-of-normal contacts controlled jointly by the

  
  <EMI ID = 186.1>

  
contacts controlled by any of the ten main selection appliances
606, the contacts controlled jointly by the auxiliary selection electros
607 and 608, and from there through the SON secondary off-normal wire to the

  
  <EMI ID = 187.1>

  
We will now describe the taking of the junction and the metallic connection

  
Having received the earth, as has been said, by the associated conductor SON, the block controller closes circuits in order to prolong the con-

  
  <EMI ID = 188.1>

  
combination MT-227 by the block controller, which closes a circuit through the left coil of the 609 holding electro, and from there through the body wire S of the outgoing junction 2020 to the battery in the block coupler

  
  <EMI ID = 189.1>

  
vertically with the 606 electro), which partly extends the two block references of the pair shown, and by closing its upper auxiliary stack U (aligned with the 607 selection electro) to connect the T conductors,

  
R and S of the block return 206U, respectively to the T, R and S conductors of the combined outgoing junction 2020.

  
The circuit closed by the block controller 1600 to effect closure of the combined connection to the primary switch 1300 goes through the outgoing UTG-SW lead wire (shown in cable 222A), and from there through

  
  <EMI ID = 190.1>

  
of the outgoing junction 20200

  
The maintenance electro 6 02 also earths the HP maintenance pilot wire of the bundle 205, thus closing a control circuit passing through contact 1 of the tens recorder TR, for the connection relay <EMI ID = 191.1>

  
This relay works quickly because of its excitation by

  
  <EMI ID = 192.1>

  
on contact 4 the outgoing closed chain, which causes the common devices 1500, 1600 and 1700 to return to rest and release of the chain relay

  
  <EMI ID = 193.1>

  
tip and nape wires from the original junction attached to the T and R wires of extension bundle 205, which is now extended through the block bay to the 2001 junction coupler. (fig 7) associated with the outgoing junction taken . The line and release relays (not shown on the <EMI ID = 194.1> if in this place a holding earth to the body wire to maintain the prolonged connection,

  
The described operation of metal connection disconnects and makes

  
  <EMI ID = 195.1>

  
a slight interval, the release relay drops out and removes the local connection of the body wire holding earth, leaving the connection established.

  
  <EMI ID = 196.1>

  
only one that remains at work in the 500-L block coupler.

  
The pulses constituting the remaining digits of the called number

  
  <EMI ID = 197.1>

  
below for the 2001 junction coupler shown in figure 20.

We will now describe the release of an outgoing call.

  
When the junction coupler 2001 of the tapped outgoing junction releases in response to hanging up on the requested line, it removes the ground potential of the body wire of the established connection, thereby breaking the connection.

  
  <EMI ID = 198.1>

  
maintenance tros 403 and 406 (Fig. 4) on the line bay. Releasing the 502 primary holding electro on the block bay removes the earth from the

  
  <EMI ID = 199.1>

  
500-La block coupler

  
Release pulse relay 514 is now on-

  
  <EMI ID = 200.1>

  
1 of SE), in order to excite the neutralizing windings with residual flux, connected in series, from SE to SR, by releasing the activated counters

  
  <EMI ID = 201.1>

  
ment, by completing the release of the 500-L block coupler.

  
We will now describe the local calls.

  
When followed by the described socket of the 500-L block coupler, the initial digit sent is the digit "6", serving as a thousand digit to denote the local block of thousand line numbers, the corresponding initial digit wire LD6 ( not shown in Figure 5) is selected by the LDR initial digit recorder in that it is connected to wire 520 through the connectors.

  
  <EMI ID = 202.1>

  
nes, tens, units and positions.

  
The sending of the initial digit is followed by that of the hundreds, tens, units and extensions in the called number. They are en-

  
  <EMI ID = 203.1>

  
respectively of the SE device. The SE device advances to its position 5
(activates its contacts 5) at the end of the recording of the tens digit to disconnect SR and engage the block controller

  
block. We will now describe the local re-engagement of the block controller

  
When the SE sequence device takes its fifth step to

  
at the end of sending the station digit, its idle contact 5 opens the pulse circuit of the SR recorder to guard against the possibility of further

  
  <EMI ID = 204.1>

  
local rage TER-ST of the block controller.

  
If the final chain is closed to the section preference relays (Fig 15, part l) and is closed in this section of block couplers, the ground potential is extended through a relay and contacts of the section preference relays up to -'to the end chain engagement wire, TER-CHIN, in cable 224, from there to the first coupler of that section, and continues from there (through chain contact 4 of relay 512 of each) until

  
  <EMI ID = 205.1>

  
section. The earth applied to this last wire is then prolonged, through the closed contact 3 and the coil of the relay 5129 by the contacts 3 and 5 of the relays.
510 and 509 and SE working contact 5, to the final start wire TER-ST,

  
  <EMI ID = 206.1>

  
local seat.

  
We will now describe the catch and guard of the chain.

  
By the circuit traced above, the section preference relay

  
  <EMI ID = 207.1>

  
primary block switch 1300, and keep the common final chain from its socket by some other section of bloco couplers The final chain relay
512 is actuated in the circuit indicated, in this block coupler, to take the final chain and keep it from its socket by some other coupler of the same section, locking itself (at its forward contact 3) on the wire of commitment of

  
  <EMI ID = 208.1>

  
At its normally closed contact 2, the final chain relay 512 disconnects the body wire S from the attached initial junction, from ground to closed contact 2 of relay 513, and at its closed contact 2, it transfers it to earth of the SG body ground wire of the block controller? following the test

  
  <EMI ID = 209.1>

  
TER-BU final tion of the block controller, and the RR ring reversal wire of the block translator.

  
We will now describe the translator's digit command.

  
The relay 512 further performs the control of the block translator according to the stored digits of hundreds, tens, ones and positions, in

  
  <EMI ID = 210.1>

  
SR to its contacts 6 to 9, which earths the one which was previously selected, spreads the wires of each bundle H, T, U and ST, going to the translator.

  
  <EMI ID = 211.1>

  
We will now describe the control of the split ring

  
In case one of the extension digits 0, 2, 3 or 4 has been sent,

  
  <EMI ID = 212.1>

  
by the block translator (by the ring reversal wire RR) if the information on the extension digit which it has received shows that one of the extension digits 5 to 9o has been sent When it is thus activated, relay 506 reverses

  
  <EMI ID = 213.1>

  
Having received the retransmitted digit information, the block translator transmits a suitably translated version of the digits.

  
  <EMI ID = 214.1>

  
which terminates the called line, using the extension digit information only at the stated end of ringing control, and for extension pickup purposes which will be explained later.

  
If the station shown S2 is the one being called, it is served by line bay B, which includes the devices shown in figure 7. In this case, the translated training on the numbers is sent to the line controller 1200B by the 223D cable conductors.

  
Having received the translated information on the numbers, indicating the

  
  <EMI ID = 215.1>

  
as to the position on this switch of the line called in packets of five and in units, the line controller 1200B identifies itself to the

  
  <EMI ID = 216.1>

  
one of them extends the S-211B body conductor from the line called by the body wire of the SU-240B units to the 120QB line controller, from where it is extended by a conductor of the 222B cable to the block controller 1600 to allow the called line to be tested for its busy or free state. At the same time, each of the ten drop body wires associated with the primary switch called 800B is connected to the line controller through one of the line control connectors. For example, the return body wire shown is connected by the return body wire LS-212B and the return test lead LT. The dropout resistor LR is connected to this body wire through the LB conductor and other contacts of the control connectors to provide a live potential on the dropout body wire unless it is taken.

   The busy or free state of the line forwarding serving the primary switch

  
  <EMI ID = 217.1>

  
pectives of the 222B cable.

  
We will now describe the operation in the case of the final occupation.

  
After testing the called line, if the block controller 1600 finds it busy, or does not find any free path that can be combined

  
  <EMI ID = 218.1>

  
felt in the 222A cable), thus activating the occupancy relay 510 in the block coupler 500-L by the contacts 10 of the relay 512. At its contact 4,

  
  <EMI ID = 219.1>

  
SE; it opens its contact 3 to release relay 512 and release the final chain; it closes its contact 2 to double the working contact 2 of the relay

  
  <EMI ID = 220.1>

  
a new period of time limitation in the case of sending other digits; and closes its contact 1 to apply busy tone current to the calling line from the final busy tone wire TERBT through the working contact 1 of the hundreds HR recorder.

  
If the calling subscriber does not hang up his receiver in response to the final busy tone signal returned to him, so as to cause the normal release of the connection, the connection is released or the control of the common timer. the end of the normal time limitation period measured starting from the sending of the item number, as will appear later.

We will now describe the taking of the called line.

  
If the called line is free, and if a path to it can be combined, the block controller combines such a path, for example by

  
  <EMI ID = 221.1> <EMI ID = 222.1>

  
to the block controller by a circuit going from the battery to the control resistor OR of the line controller 1200B, by the series contacts of the appliances

  
  <EMI ID = 223.1>

  
PS-ON, and from there to the block controller by a wire of the 222B cable.

  
On receipt of the signals mentioned, that the selection electros have operated on the block and line bays, the block controller
1600 earths the body wire of the line called 210 (figo 7) passing through these mentioned test extensions, thus activating the electro

  
  <EMI ID = 224.1>

  
Selected lines 202Bo The block controller 1600 also grounds the body wire of the affected final junction 207B (by means of the MT-226 wire), which

  
  <EMI ID = 225.1>

  
condaire HM-706 on the line bay, this extends the 206U block return through the TR and S wires of the 207B junction, to the 202Bo line return.The 1600 block controller also grounds its TER- lead wire. SW (shown in cable 222A), by closing a circuit passing through contact 1 of relay 512 of the 500-L block coupler and through the SW conductor which extends it, to actuate the associated primary holding electro HM2-602 in order to complete the connection to the called line through the combined path

  
  <EMI ID = 226.1>

  
Having operated, the connection relay 509 opens its contact 5 to drop the relay 512 and release the final chain and the devices.

  
  <EMI ID = 227.1>

  
to prevent the start of a new time limitation period in the event that other digits are sent, its contact 6 earths the common generator start wire, GEN-ST in order to start the switchgear- generator and switch ringtone, if it is not already functioning; his contact

  
7 completes the blocking circuit of relay 506, if it is activated; its contact 8 activates the transfer relay 515 to disconnect the ten output wires of the SR station recorder from the ST station wires of the block translator and

  
  <EMI ID = 228.1>

  
at 9 and 0; contacts 2 and 3 of relay 509 close the ringing circuit to the called line, - and its contact 1 applies the ringing tone to the

  
  <EMI ID = 229.1>

  
mittent is returned to the calling line from the RT wire to Inform the calling subscriber that the ringing operation has started.

We will now describe the call of the requested line

  
Block couplers and their associated common ringing equipment can serve up to ten harmonic ringing, ringing stations.

  
  <EMI ID = 230.1>

  
be wires on the line depending on the set called, as shown in the following ringing table
  <EMI ID = 231.1>
 This ringing system allows:

  
1 [deg.] A semi-selective service (single ring - and double ring) for ten bridge stations (bridge bells on the line);

  
2 [deg.] Fully selective service for ten split-ring extensions (the bells of the single-ring extensions connected between the

  
  <EMI ID = 232.1>

  
connected between the neck wire and the earth).

  
In order to satisfy the mentioned service of the ringing of shared lines, ten interrupted generator wires INT-GEN 0 to 9 are controlled by the mutual common ringing apparatus (not shown) that frequencies 1 to 5 are applied to the numbers respectively. 0, 1, 2, 3 and 4,

  
  <EMI ID = 233.1>

  
twice per ring cycle.

  
The bell circuit goes from that of the INTGEN generator wires 0 to 9 which has been selected, by the associated work contacts of the transfer relay 515, the associated contacts of the SR station recorder, the conductor.

  
  <EMI ID = 234.1>

  
ringing reversal relay 506 is therefore not actuated), by rest contacts 2 of relays 506 and 607, or 2 [deg.] to the back conductor R of the called line (if the digit has been sent 5 to 9 and the ringing reversal relay 506 is therefore actuated), by the NO contact 2 of the relay 506 and the NC contact 3 of the relay 507.

  
A. Return path to earth for the trans-

  
  <EMI ID = 235.1>

  
is not actuated), by normally closed contacts 3 and 1 of relays 507 and 506

  
and the NO contact 2 of relay 509, to the GEN-GRD earth wire of the generator, or 2 [deg.] by the peak conductor T (when the relay 506 is actuated), by the NO contact 2 of the relay 507 and the NO contacts 1 and 2 of the relays
506 and 509, over GEN-GBD.

  
The 507 bell stop relay, including the line winding

  
is included in the ringing circuit, does not work before the call has been answered, since each bell (not shown), connected to the called line is provided with the usual capacitor in series with it to block the passage direct current, and because of the delay collar surrounding the end of the core, adjacent to the paddle of relay 507 which prevents this relay from responding to the alternating ringing current. ,

  
To allow actuation of the bell stop relay

  
  <EMI ID = 236.1>

  
of any applied frequency is in series or superimposed on the li-

  
  <EMI ID = 237.1>

  
during the silence period, the battery alone is applied to each of the generator wires (INT-GEN 0 to 9) instead of the generator current in series with the central battery.

  
  <EMI ID = 238.1>

  
line 210, closing the usual conversation bridge on the called line causes the direct current to flow on this line, from the generator wire used, by

  
the 507 bell stop relay operating by its sufficient line winding

  
  <EMI ID = 239.1>

  
2 and 3, the relay 507 cuts off the ringing circuit and establishes the conversation circuit; to save current, its contact 8 cuts and drops

  
  <EMI ID = 240.1>

  
tact 7 removes the local earth from the GEN-ST wire; its contact 1 disconnects the ringer tone wire RT; and its contact 5 transfers the control winding of the sequence device SE to the wire of time measurement pulses TP, concurrent with the measurement of the talk time.

We will now describe the supervision of the response state.

  
The 502 rear axle relay is now working on the line

  
  <EMI ID = 241.1>

  
the flow of current in the calling line, for all useful supervision purposes, and at its break contact 3, it cuts and drops the time start relay 513 (if it is working) to remove the limitation period normal, which was running since the end of sending the digits.

  
During the conversation, the following five relays of the 500-L block coupler are energized.

  
1.502 rear axle relay

  
2.line relay 503

  
  <EMI ID = 242.1>

We will now describe the release of a local call.

  
If the called subscriber (at set S2, freeze 7) is the first to hang up his telephone at the end of the conversation, the rear bridge relay 502 drops off as a result, reversing the current on the calling line back to direction. normal, and reconnecting relay 513 to start a new normal limitation period.

  
When the telephone is hung up on the calling line, relay 503 drops out and cuts the release relay at its working contact 1
505, which drops out a moment later, removing the earth potential at its working contact 1 on the body wire S of the connection established. This is thus released, by the release of the maintenance electros, primary and secondary, 403 and 405, from the calling line bay, the main appliances.

  
  <EMI ID = 243.1>

  
primary and secondary maintenance, 706 and 703, of the called line bay. The release of the primary holding 1-electro 602 on. block bay sup-

  
  <EMI ID = 244.1>

  
The 505 release relay also removes the earth on the wire
519 to drop the bell stop relay, and it operates the release pulse relay 514 on its previously described circuit. Relay
514 closes the serial release circuit described for the SE to SR counters, returning them all to idle. The SE counter drops relay 514, which completes the release of the block coupler.

  
We will now describe a return call

  
To make a return call (call another set connected to the same line as the calling set), 1. ' calling subscriber picks up his re-. cepteur; he answers the sending tone by sending the regular directory number of the called station: he hangs up his receiver after hearing a distinctive return call tone, which instructs him to do so; wait a reasonable time for inrush current to be applied to the line to send a signal to the called station; and picks up his receiver again for the conversation. It can be assumed, for this description, that the subscriber at the

  
  <EMI ID = 245.1>

  
sent the number of another extension on the calling line 200 When the block coupler 500-L is used for a return call, it functions-

  
  <EMI ID = 246.1>

  
Common block bay switchgear was engaged after sending the complete number and registering it on the IDR to SR recorders. This includes ? operation of the final chain relay 512, which among other things, at its contact 2, performs the described substitution of the body earth wire, set to

  
  <EMI ID = 247.1>

  
hold, applied normally to the S body wire entering the 500-L block coupler.

  
In this example, since the number sent is that of the thousand (200) served by the bay of lines A, as shown in the figure.

  
  <EMI ID = 248.1>

  
hundred, ten and unit of the number called on the wires included in the 223A cable, to the 1200A line controller ,. which responds in the manner described for the 1200B line controller by positioning, in an appropriate manner

  
  <EMI ID = 249.1>

  
Test extension of the S body wire from called (and calling) 200 line to block controller 1600 through S-2IIA wire, the contacts of-6 line connectors, 240A wire, and one wire from 222A cable.

  
The state of the block coupler for the return call will now be described.

  
Holding earth applied to the 200 calling line body wire by the 500-L block coupler causes that line to be tested busy when the 1600 block controller tests it by the extended body connection that has been described before processing. the line called as normally busy, when it has tested, as said, that it was busy, the block controller inserts a resistor in series with its SG body ground wire (shown in wire 222A). As earth is now applied to the body wire S of the connection through the SG wire, through the NO contact 2 of the relay
512, this shows a partial battery potential on the S wire of the calling line. The presence of this potential on the line under test characterizes the call as a return call.

  
Ringing a return call is a reverse ringing process that does not require a connection in front of the block coupler. Therefore, the block controller now does not perform any combination operation, immediately ground its SW lead wire and RC callback wire (shown in wire 222A), thereby actuating the relay. call back 508 together with the primary maintenance electro 602 on the block bay. As no combination has been made, no selection electro is actuated on switch 1300. Consequently, the holding electro

  
  <EMI ID = 250.1>

  
Relay 509 drops relay 512 to release the final chain; it establishes the ringing circuit to the outgoing tip and back conductors, T and R,. not extended from the coupler; and it performs its other functions previously mentioned. On contact 2, the call relay in

  
  <EMI ID = 251.1>

  
ringing back the call; and at its working contact I, it places the ringing tone back on the called line from the tone wire

  
  <EMI ID = 252.1>

  
ring the call back.

  
The change in the block coupler will now be described.

  
When the receiver is hung up on the calling line, the <EMI ID = 253.1>

  
from their normal input connection and then transferring them to the outgoing wires

  
peak and nape, not extended, the ringing current, applied as previously described to these outgoing wires not extended by the relay contacts

  
  <EMI ID = 254.1>

  
send a signal to the called station which is connected to this line.

  
The relays that are now working in the block coupler
(during ringing back call) are the numbers 501, 505, 508, 509,

  
  <EMI ID = 255.1>

We will now describe the release on response.

  
When the receiver is off-hook at the called station, connected to line 200, or when it is picked up at the calling station If, after sufficient time has elapsed for the ringing back call to occur, the

  
  <EMI ID = 256.1>

  
ground to conductor 519; on its contact 8, it drops the transfer relay 515 and the relay 506, if it had been activated; to his contacts 2 and

  
3, it disconnects the ringing current and substitutes for it the rear axle relay 502, which operates, but only momentarily, as will be seen.

  
The relay 507 also cuts the hold circuit of the release relay 505 which drops out after a slight delay to remove the holding earth on the associated body wires. This operation releases the connection in

  
  <EMI ID = 257.1>

  
electro 602 removes the earth on the associated HP conductor by releasing relays 508 and 5090

  
  <EMI ID = 258.1>

  
Release sions 514 is actuated, as previously described, to send a neutralization pulse, in order to release the counters SE to SR, and falls back when the counter SE is released.

  
The 500-L block coupler is again in a normal free state

  
We will now describe the condemnation of the line in the return calls.

  
^ At the 800A primary line switch, freeze 4, when the earth is removed on the body conductor S of the connection established, the relay

  
  <EMI ID = 259.1>

  
falls after its momentary delay. However, the line 200 is now looped to one of the stations, calling and called, or to both, connected to it, so that q &#65533; line relay 401 operates again immediately after being reconnected.

  
  <EMI ID = 260.1>

  
busy, during the call back conversation. To the internal work contacts of the relays 401 and 402, the earth is placed on the common permanent alarm PA wire to signal that at least one line is looped or earthed and thus remains locked for normal service.

  
When the return call conversation is finished and the receivers have been hung up at both stations, relays 401 and 402 drop out. <EMI ID = 261.1> We will now describe the arrangements made to limit the times.

  
The arrangements referred to above, intended to limit the time of the 500-L block coupler include:

  
1 [deg.] The permanent time limitation which includes releasing the connection to release the block coupler when it has been seized by a line which is "permanent" (presents a fault state simulating a call), or well that becomes permanent before the connection is released and

  
  <EMI ID = 262.1>

  
chement of the connection, to release the block coupler, when the talk time exceeds a predetermined duration.

  
A line can become "permanent (acquire a more or less permanent call or blocking state) because of a fault in the satellite or in the line (a short-circuit, a loop or a ground), or because the receiver would not hang up after use, or would be accidentally moved. A line is treated as permanent each time the operation which is to follow (sending a digit, answering or hanging up) is delayed for a longer time than the normal duration assigned to limit the time.

  
The limitation provisions are controlled by a common limitation unit (not shown) from which the common conductors TF, TH and TW depart (time pulses, time hold and warning

  
  <EMI ID = 263.1>

  
timer, and the TP and TW leads are normally isolated from ground. The minu-

  
  <EMI ID = 264.1>

  
t momentarily from earth the TA wire, 2 [deg.] reaches almost immediately after a starting position where the TP wire momentarily earths and 3 [deg.], towards the

  
  <EMI ID = 265.1>

  
conversation is 8 minutes, plus a prior period of 0 to 2 minutes.

  
We will first describe the permanent limitation.

  
The permanent limitation begins at the block coupler 500-L when

  
  <EMI ID = 266.1>

  
relay 513 to the TP conductor via contact 3 of relay 513.

  
a) a variable latching interval starts from the operation <EMI ID = 267.1> reaches its latching position, the consequent earthing of the TP conductor (by the timer) activates the time start relay 513 by the contact

  
  <EMI ID = 268.1>

  
3 of relay 502. At its working contact 3, relay 513 is blocked locally to earth and disconnects its coil from the momentarily earthed wire TP, and at its contact 2, it transfers the incoming body wire S , from its local source of holding earth to the time blocking wire TH, normally earthed c) If the train relay 504 remains constantly on, (due to no sending of digits), the relay start time 513 is always blocked when the timer reaches its limit position the next time. In this case, the momentary removal of ground from the TH conductor by the timer removes the holding earth on the S body conductor of the 500-L block coupler.

   This frees the connection; the calling line is sentenced to normal service until released (as described for sentencing on return appeal); and the block coupler is released and returned to common use.

  
  <EMI ID = 269.1>

  
of one digit) before the common timer reaches its limit position, the time start relay 513 is thereby released, and it commands a new normal limit period after the next actuation of relay 504. at the end of the sent digit.

  
In a locally terminated call, a similar normal limitation period runs after any subsequent digit of the requested number has been sent.

  
  <EMI ID = 270.1>

  
When a busy state is encountered, either in a locally terminated call or in an outgoing call, the 510 busy relay doubles the

  
  <EMI ID = 271.1>

  
which releases the connection after that, at the end of the current normal limitation period even if the calling subscriber momentarily dropped relay 504 by sending digits while the busy tone signal is applied.

  
When the connection relay is operating, to start the ringing period, (in a normal local call, or in a return call), it similarly doubles the last mentioned contact of relay 504 to produce the inevitable release of connection if the ringing is still on at the end of the normal limitation period.

  
  <EMI ID = 272.1>

  
permanent limitation during conversation. However, when the called subscriber hangs up his receiver, before the calling subscriber, the relay 502 drops back and closes its contact 3 to start a new normal limitation period, provided that the connection is still held by the calling line.

  
The limitation of talk time will now be described.

  
When a normal local call has been answered, and the conversation period has started (relays 507 and 502 operating), contact 3 of the rear axle relay 5 C2 disconnects the permanent limitation circuit of the time start relay. 513 (as mentioned above) to remove the permanent limitation during the conversation. At its contact 5, the relay 507 gives the start of the talk limitation period by transferring the lower control windings of the counter SE to the time Pulses TP. This transfer occurs with the SE counter being in its fifth

  
  <EMI ID = 273.1>

  
The talk time limitation period includes a variable hook period, followed by four cycles of the common timer. When using a 2 minute timer, the hooking time is 0 to 2 minutes, and the time including the next four cycles, is 8 minutes.

  
When the common timer reaches its latching position the next time, it transmits an impulse through the TP wire to the SE control windings (through the working contact 5 of relay 5 07, and contact 3 of the

  
  <EMI ID = 274.1>

  
sixth position (activates its set of contacts 6), thus beginning the fixed period, of four cycles of the conversation limitation. NO contact 6 of SE opens a point in the blocking circuit of the occupancy relay
510, and the SE working contact 6 prepares the control of the relay 510 by the conductor TW during the last cycle of the period.

  
  <EMI ID = 275.1>

  
advance the SE device to its 7th, Semé and 9th positions respectively.

  
When the SE device is driven to its 9th position, (the

  
  <EMI ID = 276.1>

  
time 513 operates on the same time pulse and is blocked in the same way.

  
  <EMI ID = 277.1>

  
which starts the 4th and last period of a cycle of the fixed conversation limitation period.

  
If the connection is still maintained during this final interval of a cycle, then when the common timer reaches its warning position (i.e. half a minute before its cut-off position), a brief application of earth to the TW time warning wire activated the occupancy relay
510 (by NO contact 1 of relay 513 and NO contact 6 of the SE device) to temporarily apply a busy tone current to the conversation path from the TERBT busy tone wire, through the contacts working 1 of HR and 510 and the capacitor 518. The subscribers in conversation are thus warned that the connection will be released shortly. The occupancy relay 510 does not block at this time because the NO contacts 6 of SE are open.

  
If the conversation still continues when the common timer next reaches its limiting position, the resulting momentary disconnection of the ground of the TH conductor, which results in, removes the ground potential of the body conductor of the connection, thus freeing the connection and by causing the condemnation of the two lines involved, in the manner described for

  
line 200, until the receivers hang up there

  
We will now describe the TJ test jack.

  
The TJ test jack can accommodate a three-wire test plug
(not shown) when it is desired to make a test connection to the tip, neck and body incoming wires of the 500-L block coupler. When

  
the plug is inserted, the break contacts of the jack open the connection through which the battery resistor 532 normally applies the ready battery potential to the body wire S of the connected initial junction
203A, causing the block coupler to test that junction as busy at the 1200A block controller for the duration of the test connection. When desired, a dummy plug can be inserted into the TJ jack to have the 500-L coupler and 203Ao junction occupied.

  
We will now describe the line switches (figs. 8 and

  
  <EMI ID = 278.1>

  
Figures 8 and 9 are circuit diagrams of a primary line switch 800 and a secondary line switch 900 respectively. The primary line switch 800 represents any one of ten primary line switches on any of the four line bays A, B, G and D of Figures 2, 3, 4 and 70

  
In Figures 8 and 9, the respective elements are shown substantially in the relative positions which they occupy in the construction of cross-bar switches to which the present description refers.

The primary line switch 800 will be described first.

  
The primary line switch 800 (fig. 8) is designated as

  
  <EMI ID = 279.1>

  
three-digit contact elements. These columns are designated as VI, V25, respectively. The first and the last column (VI and V25) are shown, the intermediate columns being omitted.

  
  <EMI ID = 280.1>

  
tenth rows are shown, the intermediate rows being omitted.

  
The 250 selective stacks of the 800 switch include a

  
  <EMI ID = 281.1>

  
of fixed contacts 802 with which the former respectively establish a connection by the bending which they undergo after the selection and the operation of the stack. The horizontal bands 803 of the bench which are shown

  
(10 sets of three) connect the flexible elements of the stacks as shown to form 10 horizontal channels through the switch. These strips are provided with terminals (shown to the left of the bank), to which the conductors forming the line feeders 202 are connected. The 25 games

  
  <EMI ID = 282.1>

  
(shown above the bench), to which the conductors forming 25 subscriber lines (arriving from the MDF main distributor) are connected as shown.

  
  <EMI ID = 283.1>

  
represented. These selection electros correspond respectively to the 10 rows of the switch bank. Selection appliances, considered as

  
  <EMI ID = 284.1>

  
805, shown in dotted outline. The selection bars (not shown) attached to the reinforcements pass through the switch bench in association with its

  
  <EMI ID = 285.1>

  
out-of-normal contacts 806, as a pilot indication when a desired selection operation has been performed.

  
  <EMI ID = 286.1>

  
HP maintenance pilots are respectively associated with the maintenance electros. Any HP stacking is actuated by any excitation of the associated holding electro, independently of the selection operation. On the other hand, a stack

  
  <EMI ID = 287.1>

  
dant has been energized so as to rotate the associated selection bar
(not shown) in order to perform the mechanical selection of the corresponding row of stacks.

  
On the primary line switch 800 of figure 8, are

  
  <EMI ID = 288.1>

  
Each line relay controls, through the contacts of its associated LO relay, one M marking wire and one five F wire. On each primary line switch, there are 25 M marking wires (a separate wire for each line served by the switch), but there are only 5 wires of five F, i.e. a separate wire for five lines ,, From each primary switch 800, one wire

  
  <EMI ID = 289.1>

  
on wire P by the associated five resistor to signal the call to the line controller without the need for a third working contact on the line relay concerned.

  
We will now describe the secondary line switch
9000

  
The secondary line switch 900 shown in figure

  
  <EMI ID = 290.1>

  
primary line switch 800, except that its contact bank has two sections, a left section 950 and a right section 951. Dahs
- this' goal, the horizontal bands of bench 903 are cut between the last <EMI ID = 291.1>

  
of right. This arrangement offers 20 places for the 202 referrals which must be connected to the terminals, shown to the left of the respective sections.
950 and 951.

  
  <EMI ID = 292.1>

  
HM-IL to HM-8L holding electros are associated with the respective columns of the left section of the secondary switch, while HM-IR to HM-8R holding electros are associated respectively with the columns.

  
  <EMI ID = 293.1>

  
ied to the maintenance electros in columns 5 to 8 of each section, but does not need to be associated with the maintenance electros of the first 4 columns of each section. In each section of the switch 900, final junctions 207 are connected respectively to the first 4 columns and initial junctions 203 are respectively connected to the last 4 columns. The initial junctions go to terminals in the block bay where they pass through a jumper distributor which connects them at will to couplers of

  
  <EMI ID = 294.1>

  
extend between the secondary line switches of Figure 9 and the secondary block switches such as those shown in Figures 2, 3 and 7 described above. MT combination test leads are respectively associated with the initial junctions 203 and extend between the secondary line switches and the associated line controller 1200
(figure 12).

  
  <EMI ID = 295.1>

  
respective bodies of the redirects 202, go from each switch 800 to the

  
  <EMI ID = 296.1>

  
by which the line controller tests the redirects 202 to determine their busy or available state.

  
  <EMI ID = 297.1>

  
consecutive selection electrodes provided on each switch 800 receive the control battery respectively by 5 selection electrodes

  
  <EMI ID = 298.1>

  
of the ten primary switches 800 respectively. That is to say that the electros for selecting the secondary switches are connected in series with those

  
  <EMI ID = 299.1> with two newlines with consecutive numbers, as will appear later. The 50 wires of selection electros SM interconnecting the primary or secondary selection electros SM of figures 8 and 9 are crossed in accordance with the crossing of the line references between the primary switches and the secondary switches, which was explained above in

  
  <EMI ID = 300.1>

  
Selection electrodes for the 100 line feeders, since each selection switch SM of a secondary switch 900 represents two consecutive line feeders, one connected to the corresponding row of the left section
950, and the other to the corresponding row of the right section 951.

  
  <EMI ID = 301.1> <EMI ID = 302.1>

  
Referring to Figures 10 and 11, we will describe respectively the line control connectors 1000 and 1100.

  
As shown in Figures 2, 4 and 7, each line bay A, B, C or D has two control connectors 1000 and 1100, placed between

  
  <EMI ID = 303.1>

  
ning or intended for any associated line, the connectors 1000 and 1100 are used to connect the line controller 1200 with that of the ten primary switches 800 which serves the calling or called line concerned, and to connect them according to the packet of five lines which, on the connected primary switch, contains the calling or called line Interested.

  
Achieving the above goal requires the selective switching of 760 wires from control connectors to primary line switches and associated line feeders. One hundred of these wires (the one hundred body wires of the LSI to LSIO cross-references of the ten primary switches 800 (Figure 8)

  
  <EMI ID = 304.1>

  
mutation required for 8600 As shown, the two control connectors
1000 and 1100 have a total of 18 50-point columns (VI to V9, on each switch). The 18 columns, each of which has 50 contact pairs, provide a total of 900 contact pairs. The 40 unused contact pairs are

  
  <EMI ID = 305.1>

  
Since it has 9 columns, each with ten selective stacks of five pairs of contacts per stack, each row control connector is referred to as a 5-wire 9 x 10 switch. Due to the specific circuit closing function of each control connector, no

  
  <EMI ID = 306.1>

  
1000 or 1100 as a 5-wire 9 x 10 switch, without horizontal multiplication.

  
Each control connector has 9 HM holding electros

  
  <EMI ID = 307.1>

  
ment to the 10 associated primary switches 8000

  
We will first describe the operation for outgoing calls.

  
On outgoing calls, control connectors 1000 to

  
  <EMI ID = 308.1>

  
  <EMI ID = 309.1>

  
served by the bay of lines concerned, the associated LR relay
(figure 8) operates on the interested primary switch 800. This relay

  
  <EMI ID = 310.1>

  
where the calling line is located.

  
The line switch concerned is identified in the line controller 1200 by a resistance potential to earth applied to the primary wire P of this primary switch, derived from the earth applied to one

  
  <EMI ID = 311.1>

  
Indicated mayor 800 (by making a preferential selection if lines are calling on two or more primary switches at the same time), and

  
  <EMI ID = 312.1>

  
1000. Consequently, the earthing of one of these wires actuates the selection eleciro SM in each control connector to perform the mechanical selection of the primary switch 800, Indicated as calling, by pivoting the associated bar among the 5 selection bars (not shown), in <EMI ID = 313.1>

  
each control connector, there is mechanical selection of the first row of selective stacks (associated with the first primary switch 800) in each control connector, in response to the operation of the associated armatures
1006 and 1106 and the mentioned selection bars linked to them.

  
3 [deg.] Electrical selection of the calling primary switch: non-normal contacts 1007 and 1107, associated with reinforcements 1006 and 1106 which

  
have been actuated, apply a connection to earth in series on switch 1100, to the out-of-normal common wire CON (going to the line controller 1200) and to the HKL wire of the holding electro, connected to the previous one, extending Between

  
  <EMI ID = 314.1>

  
to the line controller return test leads LT1 to LT10, with a view to testing by the line controller, of the ten line transfers, serving the selected primary switch.

  
  <EMI ID = 315.1>

  
primary-secondary crossing) by the line controller after the combine operation.

  
30 c. Connecting the wires of five: the mentioned operation

  
  <EMI ID = 316.1>

  
subsequent transmission of a signal on this wire.

  
4 [deg.] Selection of packs of five. Line Controller 1200 now works by means of the connected five wires (FI to F5) to select the five line packet marked on the concocted switch 800, exercising a preferential selection between five packets in case two or more of these packets contain calling lines. In this way, it earths the corresponding wire among the holding electrodes HM5 to HM9 of the control connector 1100 and the corresponding multiple wire, in the

  
  <EMI ID = 317.1>

  
each switch to select the five-line packet containing the calling line.

  
4 [deg.] A. Connecting the body wires of packs of five:

  
in the control selector 1000, the operation of the electro selected

  
  <EMI ID = 318.1>

  
to the SUI to SU5 unit body wires of the line controller.

  
  <EMI ID = 319.1>

  
in the control connector 1100, the operation of the electro select among the holding electros HM5 to HM9 connects the individual marking wires

  
  <EMI ID = 320.1>

  
to select the calling line in the packet of five selects exercising a preferential selection when more than one line is calling in the same packet of five. This action selects the body wire of the calling line as

  
  <EMI ID = 321.1>

  
to me this will appear later.

  
6 [deg.] Combination of the maintenance pilot earth: the maintenance electrodes HMl to HM5 and one of the maintenance electrodes HM5 to HM9 having been actuated in each of the two control connectors, a series connection to the earth is established (in control connector 1000) on the HP holding pilot wire going to the line controller. This connection goes, from earth through the HP contact of the first 4 columns of switch 1000, to the HP contacts of any one of the last five columns of switch 1000, the

  
  <EMI ID = 322.1>

  
low) which selects a free line forwarding by means of which the calling line can be extended through a secondary switch 900, to an initial trunk 203.

  
7 [deg.] Selection of a forwarding: the line controller puts

  
  <EMI ID = 323.1>

  
trôle 1100 for the interested selection appliances, primary and secondary
(Figures 8 and 9) in series.

  
8 [deg.] Primary-secondary out-of-normal signal: the selection electros, primary and secondary, of figures 8 and 9 which have been activated establish a series connection (starting from the secondary wire SC, by the contact

  
  <EMI ID = 324.1>

  
primary selector selected, thus extending the battery to the off-normal primary-secondary PS-ON wire of the line controller through the closed stack contacts of the V4 column of switch 1100. This potential serves as a completion signal selection to the line controller.

  
9 [deg.] Circuit extension: in response to the signal mentioned last, the line controller earths an MV wire (figure 9) in order to activate the secondary holding electro HM associated with the affected initial junction 203 , and it grounds the body wire S of the line called in

  
  <EMI ID = 325.1>

  
caller on switch 800. The primary and secondary maintenance appliances mentioned now work in order to extend the calling line by forwarding lines assigned 202 to the assigned free initial junction

  
  <EMI ID = 326.1>

  
by cutting off the excitation of the selection electros in each of the control connectors. The holding electrodes which had been actuated in the control connectors cease to be energized in response to the opening of the out-of-normal contacts 1007 and 1107, after the removal of the excitation of the selection electrodes. The two connectors of control are thus reduced

  
  <EMI ID = 327.1> We will now describe the operation in incoming calls,

  
In incoming calls, control connectors 1000 and 1100 operate as follows:

  
  <EMI ID = 328.1>

  
serving an incoming call through a line bay, the associated line controller 1200 is set by block translator 1800 according to the primary, five, and unit digits of the translated line number, thus determining the interested primary switch 800, the packet of five lines connected to this switch and containing the called line and the called line in the pack of five.

  
2 [deg.] Mechanical selection of the called primary switch having been put in position, the line controller earths the one of the

  
  <EMI ID = 329.1>

  
mayor received. The earth applied to this wire activates the corresponding selection electro SM in each of the control connectors 1000 and 1100 in order to make a mechanical selection, in each, of the corresponding row of selective stacking, as mentioned in the description of the operation. during outgoing calls.

  
3 [deg.] Electrical selection of the primary switch: the out-of-normal contacts 1007 and 1107, associated with the actuated selection electrodes, apply a series connection to the earth, to the out-of-normal TON common wire, and

  
  <EMI ID = 330.1>

  
which operates in each, the first four HM holding electros, as described.

  
3 [deg.] A. Connection of the return body wires: in the control connector 1000, the operation of holding electrodes 1 to 4 connects the return body wires of the selected primary switch, respectively

  
  <EMI ID = 331.1>

  
serving the called primary switch, select 800.

  
3 [deg.] B. Connection of the wires of the return selection appliances:

  
  <EMI ID = 332.1>

  
three selection, primary and secondary, depending on the return of lines which will then be assigned.

  
3 [deg.] C. Connection of the wires of five: the maintenance electro 3 of the

  
  <EMI ID = 333.1>

  
selects, respectively to the children of five of their lines, but this connection is of no use in the operation during the calls analyzed.

  
3 [deg.] D. Connection of the primary wire out of normal: the HM4 holding electro of switch 1100 connects the PON wire of the selected primary switch.

  
  <EMI ID = 334.1>

  
sequence of a signal on this wire.

  
4 [deg.] Selection of a pack of five: the mentioned earthing

  
  <EMI ID = 335.1>

  
selection of the two control connectors, closes a prepared circuit going

  
  <EMI ID = 336.1>

  
each connector 1000 and 1100, at the same time as the described operation of their maintenance electros HM1 to HM5.

  
4 [deg.] A. Connection of the body wires of the packs of five: in switch 1000, the operation of the one that has been selected among its holding electros HM5 to HM9 connects the pack of five body wires (If to

  
  <EMI ID = 337.1>

  
of lines.

  
4 [deg.] B. Connecting the marker wires from the pack of five

  
in switch 1100, the operation of the holding electro select among its holding electros HM5 to HM9 connects the individual marker wires of the selected pack of five, respectively to the marker wires of the line controller units, but this connection does not 'is of no use in the operation of incoming calls.

  
5 [deg.] Test of the called line: in the operation during incoming calls, which is being described, the selection of the units has already been accomplished by placing in the described position, according to the figures, of the row controller by the block translator. Therefore, the above-described connection of the body wires from the selected pack of five connects the body wire F of the called line, which is then fully selected, passing through line controller 1200, to block controller 1600 in order to allow the called line to be tested and then to activate its associated holding electro.

  
With the holding electrodes having been actuated in the two control connectors, as described above, the series connection to earth previously described is established to the HP holding pilot wire going from the switch 1100 to the line controller, thus closing a through circuit. through the line controller to the block controller to start the test of the called line.

  
  <EMI ID = 338.1>

  
The line test operation is followed by a combine operation (together in the block controller and the line controller) in order to combine a free path through the block bay, from there to a final junction 207

  
and through the line bay, to the called line.

  
7 [deg.] Line feed selection: block controller 1600, operating through line controller 1200, now sets

  
  <EMI ID = 339.1>

  
selection, primary and secondary, which have been activated on the line bay, establish the previously described serial connection of the battery to the wire

  
  <EMI ID = 340.1>

  
a potential to the non-normal PS-ON primary-secondary wire of the row controller, through the contacts of column V5 of switch 1100. This gives a signal through the row controller, to the block controller, that the selection of the reference was made mechanically to the switches, primary and secondary, on the line bay.

  
9 [deg.] Circuit extension: when the block controller receives signals indicating that the selection has been completed, on the block bay and on the line bay, it grounds conductors in order to operate the

  
  <EMI ID = 341.1>

  
block, to take the assigned block referral, comprising a circuit destina

  
to actuate a secondary maintenance electro HM (figure 9) of the line bay to take the affected line forward. At the same time, the block controller,

  
  <EMI ID = 342.1>

  
previously tested body of the called line, to activate the primary maintenance electro HM (figure 8) associated with this line to take the affected line feed. The aforementioned operation of the maintenance appliances, primary and secondary, on the two bays extend the connection to the called line, passing through the affected unit forwarding, the final junction and the line forwarding.

  
  <EMI ID = 343.1>

  
and line controller 1200 are now free. Thereupon, the selection and holding electros actuated on the li-

  
  <EMI ID = 344.1>

  
state of rest.

  
Line controller 1200, shown in Figure 12, will now be described.

  
This controller represents one of four row controllers, with a separate controller provided for each of the four 250 row bays A to D, in Figures 2, 3 and 4 to 7.

  
We will first describe the purpose and arrangement of this controller.

  
  <EMI ID = 345.1>

  
previously described connections from the calling line, through the associated line bay, to the initial free junctions, and (2) to cooperate with the block controller to extend the connections, as described, through the block bay and the called line bay to the called free lines of the latter.

  
In accomplishing these purposes, the two associated control connectors, shown in Figures 10 and 11, are employed as described, to select and connect to the line controller the primary line switch 800 concerned and the five line packet concerned. , served by this switch.

  
The 1200 line controller includes more than 100 relays (such as 12 to l) and associated circuit apparatus. These members are suitably connected to each other and to the illustrated outer wires of the line controller to perform all the control and last operations required of the line controller. It can be noted that all the calls going to the lines of the associated line bay, or coming from these lines, are served by the line controller 1200 associated with this bay, one call at a time.

  
We will first describe the operation of the line controller during outgoing calls.

  
In outgoing calls from the normal, released state, the general operation of the line controller 1200 is as follows:

  
  <EMI ID = 346.1>

  
on wire P of any primary line switch 800 through a calling line, the line controller responds to it by selecting the primary switch, exercising a preference order if two or more wires 2 are grounded; it blocks the selection; and open all the P wires to avoid interference that could occur through these wires.

  
  <EMI ID = 347.1>

  
12B8, which avoids - interference with final calls; it starts a time limit operation to prepare each fast operation if the initial call operation is somehow blocked, so that its normal completion cannot take place; and it grounds the SN wire of the control connector selection electro, which corresponds to the selected line primary switch, causing the selection of this switch by the two control connectors 1000 and 1100, which are

  
  <EMI ID = 348.1>

  
the control connectors, the line controller performs a continuous test of all the feeders of the selected primary switch with regard to the availability battery on the body wire, in preparation for the combination.

  
  <EMI ID = 349.1>

  
contacts of a line relay operated) by a five F wire of the selected hand switch 800, the line controller selects the corresponding packet of five lines, exercising an order of preference if two or more wires of five are connected Earth; it locally blocks the selection of five and disconnects the wires of five to prohibit subsequent interference on. these wires, and it actuates one of the holding electros 5 to 9 of each control connector so that the connector 1000 extends the body wires of the lines in the group of five selects, and that the connector 1100 extends the wires Individual marking lines in the selected package of five, as described,

  
5 [deg.] Selection of units: receiving a ground (from another contact of the actuated line relay) through an individual marking wire M in the selected pack of five, the line controller selects the corresponding wire as the calling line (by connecting to the body wire F of this line), exercising an order of preference if there are two or more lines that call-

  
  <EMI ID = 350.1>

  
units and opens its units chain circuit to prohibit subsequent interference with the established unit selection.

  
6 [deg.] Line test: the line controller now tests 39 body wire of the calling line, verifying the presence on this wire of a battery through the associated holding electro HM.

  
7 [deg.] Combination; first engagement: provided that a pilot hold signal has been received showing that all the desired hold solenoid valves have been actuated in the two control connectors, the line controller begins the combination operation by extending the combination test leads MT of the calling group of initial trunks immediately following the one taken (in the previous start operation) and tests the MT wires in combination with the feeder body wires, to find a free combined path. As the ten line forwardings from any primary switch go to the ten secondary sections respectively, there are ten Initial trunks in any commit group, respectively from the ten secondary sections.

   An availability test of these Initial junctions requires that they have been connected by jumpers to a block coupler.
500-L, which provides a spare battery to its body wire.

  
  <EMI ID = 351.1>

  
can be combined between the calling line and an Initial trunk of the first trunk engaged, the line controller engages the next trunk of ten initial trunks, and repeats the combination attempt with respect to

  
this beam, continuing to engage the beams one after the other until all four have been engaged. If no free path can be combined with the fourth engagement, the line controller immediately releases and returns to the normal state, releasing the associated control connectors.

  
9 [deg.] Combination; path preference: Combining a free path requires line forwarding and the initial junction of, that path both provide an availability test. If two or more paths give an available test, in the same commitment of initial junctions, the line controller exercises an order of preference to select one of these paths as a combined path.

  
  <EMI ID = 352.1>

  
tion of the combined path, the line controller closes, as described, a series circuit for electros ae selection, primary and secondary (by the contacts of the control connector 1100), so that the combined line return is mechanically selected on the 800 and 900 switches.

  
  <EMI ID = 353.1>

  
the PS-ON wire, that the line feed has been mechanically selected on the primary switch and on the secondary switch, the line controller simultaneously closes a circuit for the secondary holding electro associated with the combined initial junction, and for the primary maintenance electro associated with the called line. These maintenance appliances work as described to extend the calling line to the original combined trunk, connecting it to the primary end of the combined line forwarding, and connecting the original combined trunk to the secondary end of that forwarding. .

  
  <EMI ID = 354.1>

  
initial junction seized, in order to maintain the holding, primary and secondary electros which have been activated, the line controller is released, allowing the control connectors to be released as described.

  
13 [deg.] Preference offset: After each initial operation, the line controller operates to change the preference with respect to the primary switches and secondary sections. The first choice goes from

  
  <EMI ID = 355.1>

  
offset, the previous first choice becomes the last choice. At each even step, the first choice advances to the next five-line packet on a primary switch.

  
  <EMI ID = 356.1>

  
not completed within a cycle delay that is long enough to allow an attempt to combine in each of the four engagements, initial junctions, the cycle delay device releases the row controller and returns it to the normal state for a new start .

  
  <EMI ID = 357.1>

  
successive attempts without success, in order to extend a calling line by forwarding a free line to an initial free junction, it places itself in a temporary idle state, in which it does not answer the lines called.

  
  <EMI ID = 358.1>

  
Whenever it takes a timeout (entering its temporary idle state), it grounds its initial lost OCL call wire to activate a corresponding counter.

  
We will now describe the general operation of the line controller in the case of incoming calls.

  
  <EMI ID = 359.1>

  
Their 1200 lines, starting from the normal free state, is as follows:

  
1 [deg.] Reception of the translated digits P, F and U: when it receives from the block translator 1800 (by one of the ten sons P, one of the five sons S and one of the five sons U) the information concerning the translated digits, identifying a primary switch 800, containing a called line, the packet of five lines of that switch and the called line in the packet, the line controller stores the information on respective relay chains.

  
2 [deg.] Start-up: the line controller activates its control relay.

  
  <EMI ID = 360.1>

  
outgoing 12BIO, thus preventing interference with incoming calls.

  
  <EMI ID = 361.1>

  
4 [deg.] Primary selection: the line controller earths the electro SM selection wire of the control connector corresponding to the registered primary digit, which causes the selection of the primary switch.

  
  <EMI ID = 362.1>

  
switch, as described, <EMI ID = 363.1>

  
control connectors the line controller makes a continuous test of all feeders from the primary switch selected for the availability battery on the body wire. For each available line feed tested, the line controller closes the corresponding NSM feeder selection electro wire to its corresponding LK feeder wire, thereby signing to the block controller that the corresponding line feed is available,

  
  <EMI ID = 364.1>

  
when a combined path has been selected by the block controller.

  
6 [deg.] Selection of a pack of five: receiving a ground by the out-of-normal controller wire CON, which shows that both control connectors have made the selection, completes a circuit prepared by the controller. lines for the holding electrode 5 to 9 of each control connector that corresponds to the registered number of five, which extends the connection of the body wires S of the lines included in the selected pack of five, through the control connector 1000.

  
7 [deg.] Selection of units: the units digit being recorded,

  
  <EMI ID = 365.1>

  
peeled CLF to the block controller, for testing.

  
8 [deg.] Release: After the operations mentioned, the line controller remains idle while the block controller performs its operation, including combining a path to the called line and controlling the switches that establish that path. After that, the block translator removes the information about the translated digits, whereupon the row controller releases together with the two associated control connectors.

  
9 [deg.] Digit alarm: If a fault causes the block translator 1800 to ground two or more digit wires in the primary, packet of five, or unit harness, the line controller Notifies the

  
  <EMI ID = 366.1>

  
LC-AL line controller, until an alarm stop key 1207 has been activated.

  
We will now describe the functional groups of relays

  
The 1200 line controller relays include the following functional groups

  
(in the table below, o means use in Initial operation, and T. use in final operation

  

  <EMI ID = 367.1>


  
We will now describe the detailed operation in the outgoing calls.

  
;

  
In outgoing or initial calls, the detailed operation of the 1200 line controller is as follows:

  
1 [deg.] Marking of units, packs of five and primary; when a call starts on any of the 250 lines served

  
  <EMI ID = 368.1>

  
five in which the calling line is located.

  
2 [deg.] Primary selection: Grounding any F wire of a primary line switch places a derivative earth through a resistor on the primary wire of that primary switch, which wire is one of ten wires PI to PIO (figure 12) going from the ten primary switches 800 to the line controller. The line controller 1200 being in its normal state shown, the earthing of one of these P wires closes a circuit passing through a contact

  
  <EMI ID = 369.1>

  
2 [deg.] A. Exercise of preference: A battery potential, coming from a supply resistor 1209 is normally present on the lower winding of each relay 12A2 to 12AI1. The attribute of choice (figure 12,

  
  <EMI ID = 370.1>

  
10 from beam 1251, to the associated relay, and from there, by an endless chain of

  
  <EMI ID = 371.1>

  
in order to prevent the effective operation of all the following relays.

  
After having actually operated, a primary relay 12A2

  
at 12A11 opens first (at its rest contact 2) the continuation towards the front of the endless chain preferably, then it closes its working contacts 1, 3 and,

  
4. At its normally open contact 1, it applies an earth to the terminal of its upper winding via the normally closed contact 2 of the release relay 12B18.

  
  <EMI ID = 372.1>

  
lines by actuating the initial start relay 12B10 by the closed contact 5 of the final start relay 12B8 and the closed contact 10 of the start relay 12B9 of the rest group. At its normally closed contact 9, relay 12BlC disconnects final start relay 12B8 to prevent interference between the initial operation that has been started and a subsequent call for

  
  <EMI ID = 373.1>

  
thereafter.

  
4 [deg.] Timer start: Relay 12B10 starts by sound

  
  <EMI ID = 374.1>

  
as a control earth to relay 12B11 via closed contact 2 of the relay

  
  <EMI ID = 375.1> <EMI ID = 376.1>

  
dropping, short-circuit the next relay. The time required for the cycle delay device to complete its indicated cycle exceeds the maximum time that the line controller can take to complete Initial call operation and become free. Most of this time is provided by the release time of relays 12B11 to 12B14 successively

  
  <EMI ID = 377.1>

  
earth at its contact 8 passing through the normally closed contact 3 of the final start relay 12B8 and through the open contact 4 of that of the relay

  
  <EMI ID = 378.1>

  
in order to perform the electrical selection of the control wires associated with the calling primary switch 800.

  
6 [deg.] Line feed test. In the described selection of the primary switch, the control connector 1000 connects the battery wires

  
  <EMI ID = 379.1>

  
vement to the LS body wires of the line transfers 202 serving the selected primary switch. At the same time, this control connector connects these

  
  <EMI ID = 380.1>

  
of lines, and consequently at the input of the upper windings of the relays

  
  <EMI ID = 381.1>

  
return test is grounded, so that each of these relays now operates in series with its corresponding one of the supply resistors.

  
  <EMI ID = 382.1>

  
12, part 4) unless the corresponding line forwarding is busy. In this case, the earth applied to the return body wire short-circuits the relay.

  
  <EMI ID = 383.1>

  
now the combination.

  
7 [deg.] Selection of five. By making the primary selection described, the control connector 1100 connects the wires of five FI to F5 of the selected primary switch, respectively to the associated wires FI to F5 (figure 12, part on top) of the line controller, which closes a circuit going from one

  
  <EMI ID = 384.1>

  
12A23 and by the upper winding of the relays of five corresponding 12A25 to 12A29, to the battery by the chain preferably associated and the contacts of

  
  <EMI ID = 385.1>

  
position (or only relay 1204 is actuated), wire 1 of harness 1252 going from the assignor of choice to the chain of five is connected to the battery by the work contact 2 of the first assignor relay 1204, the contact of

  
  <EMI ID = 386.1>

  
12B10. This gives the first choice to the first relay of five, 12A25.

  
If two or more wires of five are grounded, two or more of the chain relays of five, 12A25 through 12A29, try to operate, but only one relay of five actually operates, the first in order of preference counting. from the one who momentarily has the first

  
  <EMI ID = 387.1>

  
condemnation described for the primary chain.

  
  <EMI ID = 388.1>

  
at 12A29, is blocked at its contact 2 on the earth which actuates its upper winding, and at its contact 5, it actuates the cut-off relay 12A23 to de-. connect wires of five to contacts 1 to 5. After that, all relays of five that have been activated without effect drop out.

  
8 [deg.] Selection of five on the control connectors. Relay

  
switch 12A23 activates its auxiliary relay 12A24 through its contact 6 to connect the non-normal wire of the controller CON to the wire of the main- <EMI ID = 389.1>

  
12A24 relay pull provides sufficient time to ensure the complete release of all relays in the chain of five that have been activated without effect.

  
If, for example, the first relay of five 12A25 is the one that has

  
  <EMI ID = 390.1>

  
their CON (which appears in response to the described operation of the selection electrodes in the control connectors) is now extended by contacts 1 of relays 12A24 and 12A25, up to the HM5 holding electro wire which goes to the two control connectors , thus activating the corresponding holding electro HM5 in each connector to select the first packet of five lines served by the selected primary switch.

  
9 [deg.] Selection of units. In line control connector 1100, the mentioned selection of packs of five connects the wires.

  
  <EMI ID = 391.1>

  
ment described. The marking earth applied to any of these wires re-establishes a circuit for the upper coil of that of relays 12B2 to 12B6 of the chain of units which is associated, by the make contact 4, normally closed, of this relay, the common end of chain wire 1210, the chained rest contacts 3 of the relays 12B6 to 12B2, to the battery via the con-

  
  <EMI ID = 392.1>

  
in the case of relay 12B2 ;, and by the chain of contacts 3 in the case of

  
  <EMI ID = 393.1>

  
the upper terminal of its winding, earth applied by the work contact 2 of the initial start relay 12B10, in order to maintain the selection of the lines independent of the continued excitation of the line relay called.

  
After a slight interval, sufficient to allow the return to rest of any transient state resulting from two or more relays in the chain of units attempting to operate 12B1 operates by the con-

  
  <EMI ID = 394.1>

  
body wire of the selected calling line to the line controller. This extension is prepared by the described action of selecting the five, by the control connector 1000, which connects the body wires of the lines of the group.

  
  <EMI ID = 395.1>

  
lines. The one of these wires which corresponds to the selected calling line is now extended (by contact 1 of the chain relay of units 12B2 to 12B6

  
  <EMI ID = 396.1>

  
work, wire 1221 is connected by contact 10 of this relay to earth through the winding of the line test relay 12BI6.

  
  <EMI ID = 397.1>

  
lante being thus extended, up to the line test relay 12B16, if there is a battery on this wire (through the winding of the associated holding electro of the primary switch 800), this relay operates indicating that the calling line has been selected and can be extended. Due to the relatively strong resistance of the line test relay 12B16, nor the holding electro

  
  <EMI ID = 398.1>

  
are = actuated prematurely, but the test current flowing through the relay
12B16 initiates the holding electro sufficiently for it to operate promptly when its control circuit closes later.

  
  <EMI ID = 399.1> the selection of the five on these switches), through contact 1 of the initial start relay 12BlOj to the combination start wire 1222 going to the totalizer, commit assignor and engage pulse ( figure
12, part 5). Ground applied to the start wire 1222 starts the engage impeller (relays 12C14. To 12C16) to control the stepping of the engage assignor during combination, if necessary.

  
12 [deg.] First engagement. The commitment allocator (the relays
12C17 to 12C21 is a four-position counting chain arranged

  
such that one or the other of these counter relays 12CI $ to 12C21 is always in the actuated state. When the commitment allocator is in

  
its first position, which is shown (the relay 12C18 actuated and all its other relays at rest), the mentioned extension from the earth to the combination start wire 1222 closes through it two circuits of

  
  <EMI ID = 400.1>

  
and the working contact 3 of relay 12C18, to the battery through the first

  
  <EMI ID = 401.1>

  
contact 4 of relay 12C18, to. the battery through the first junctions engagement relay 12C26. The 12C22 relay then operates and is blocked to register the first engagement of initial junctions, and the relay
12C26 works to make the first engagement of the initial junctions

  
  <EMI ID = 402.1>

  
initials of the first engagement harness, to contacts 2 of the return test relays 12D1 a. 12D10, respectively.

  
As previously described, the ten Initial junctions of any engagement harness come respectively from the ten secondary sections provided on the line bay. The ten line feeds, provided on each primary switch 800 of the same line array go respectively to these secondary sections. The success of extending a calling line to an original trunk depends on the availability of that trunk and the availability of that trunk.

  
  <EMI ID = 403.1>

  
As will appear later, when a combination occurs after an initial junction engagement, the combination pilot relay

  
  <EMI ID = 404.1>

  
appointment to prevent further advancement of the appointment grantor. until the line controller is released.

  
13 [deg.] Following commitments. If no combination occurs at the first engagement of the initial junctions, the pilot combination relay

  
  <EMI ID = 405.1>

  
engagement impeller to advance the engagement allocator by actuating its counter relay according to 12C19 and by saying to drop the previously actuated relay 12C18. This advancement causes the release of the actuated junctions engagement relay 12C26 and the operation of the following relay.
12C27, accompanied by the operation and blocking of the following relay 12C23 of the

  
  <EMI ID = 406.1>

  
If no combination occurs, on the second engagement of the Initial junctions, the engagement impeller advances the engagement assignor again, releasing the actuated junction engagement relay and actuating the next relay. , together with the third totalizer relay.

  
If no combination occurs on the third engagement, the actuated engage relay drops out, and the last relay operates to engage the fourth and last bundle of the initial junctions, in order to test them.

  
As the corresponding engagement totalizer relays
12C22 to 12C25 are actuated at the same time as the engagement relays of

  
  <EMI ID = 407.1>

  
no combination occurs on the fourth engagement, subsequent operation of engagement impeller relay 12016 closes a circuit by '

  
  <EMI ID = 408.1>

  
for the 12B18 release relay, in order to release the line controller and return it to the idle state, with the control connectors, as described below.

  
14 [deg.] Combination. As said previously, the line transfers serving the selected primary switch are tested respectively by

  
  <EMI ID = 409.1>

  
see corresponding lines are available (that they do not have a ground on their body wire which would bypass the return test relay.

  
Since the ten line breaks serving any primary switch each go to a different section of the ten secondary sections, the ten initial trunks of any committing trunk each originate from a different secondary section. Consequently, each one can only be used with its corresponding line forwarding, and again if the line forwarding and

  
junction are both available.

  
During any engagement of the initial junctions, the combination test leads of the ten junctions of the engaged harness (by one of relays 12026 to 12C29) are extended by contacts 1 to 10 of this relay to armatures 2

  
  <EMI ID = 410.1>

  
battery availability tential, applied to the connected MV wire, shows that the corresponding path (passing through a forwarding 202 going to a secondary section and through an initial junction 203 starting from this section) is available, in that the line forwarding and the initial junction combined in the path are both available,

  
If, for example, the first transmission of lines coming from the selected primary switch is available, the return test relay 12D1 is actuated as previously described. Therefore, the combination test wire MT which is extended to armature 2 of this relay by the engagement operation, is then extended by the NO contact of this relay and the

  
  <EMI ID = 411.1>

  
Availability battery tential is supplied to its MT combination test lead from the S body lead of the connected block coupler 500, through the S body lead of the initial junction 203 and through the connection coil.

  
  <EMI ID = 412.1>

  
exclusion of any other available path. For this purpose, an endless chain blocking circuit is provided, passing through contacts 3 of the test relays.

  
  <EMI ID = 413.1> <EMI ID = 414.1>

  
sant advance the point of the blocking chain to which the earth is applied

  
blocking.

  
With the chosen assignor in its first position shown (with relay 1204 actuated and all other relays at rest), the earth

  
  <EMI ID = 415.1>

  
and consequently to the secondary section 1 represented by this relay and the return test relay 12D1. If now the junction test relay

  
  <EMI ID = 416.1>

  
actuated state of any other junction test relay, and hold open the

  
  <EMI ID = 417.1>

  
actuated then, this blocks the first following actuated junction test relay, by the chain comprising the rest contacts 3 of the previous junction test relays.

  
  <EMI ID = 418.1>

  
blocking of the test relay, disconnecting the test windings of the junctions

  
  <EMI ID = 419.1>

  
also activates its auxiliary relay 12DI2, the attraction time of which allows all actuated test relays except the one which has been blocked, to drop out.

  
Having operated, the auxiliary relay 12DI2 disconnects at its

  
  <EMI ID = 420.1>

  
ment by preventing the operation of relay 12DI6. Therefore, the relay

  
  <EMI ID = 421.1>

  
born.

  
15 [deg.] Operation of the selection, primary and secondary electros. At its contact 2, the auxiliary relay 12DI2 of the combination pilot group earths the associated work contacts, one of the junction test relays 12D13 to 12D22, which extends the earth through the work contact 1 of that of these relays which is blocked towards the corresponding wire of the wires of electro selection return LSMl to LSM10, which closes a circuit (by the closed contacts as described by the control connectors 1100) for the primary selection electro SM ( figure 8) associated with the combined line forwarding,

  
  <EMI ID = 422.1>

  
three selectors operate in series to mechanically select the return

  
  <EMI ID = 423.1>

  
re. The non-normal contacts 807 and 907, connected in series, associated with

  
the selection electros, actuated, primary and secondary, extending the battery potential (taking into account the control resistance CR, figure 12, part 5 and the secondary control wire SC) through the connector contacts

  
control 1100, to the PS-ON primary-secondary non-normal conductor, between the

  
  <EMI ID = 424.1>

  
placed on the PS-ON wire completes a circuit for the control relay 12B17, grounded by the open contact of the actuated line test relay 12B16.

  
  <EMI ID = 425.1>

  
closes independent circuits to control the primary holding electro associated with the calling line and to control the secondary holding electro-

  
  <EMI ID = 426.1>

  
The primary holding electro is actuated by closing contact 4 of relay 12B17, and earths the body wire S of the calling line by bypassing the line test relay 12B16 which was previously kept working on this wire. , as described. The tip, neck and body wires TR and S of the calling line (such as 200, FIG. 4) are thus extended respectively to the primary end of the corresponding wires of the combined line return 202.

  
The secondary holding electro associated with the initial combined junction is actuated by the closing of contact 5 of relay 12B17, and earths the associated working contact 2 of each test relay of junctions 12D13 to 12D22, thus extending earth, by the open contact 2 of the junction test relay activated and blocked, by the associated working contact of one, the one which is activated, of the engagement relays of

  
  <EMI ID = 427.1>

  
9) of the combined initial junction. The control winding of the associated maintenance electro (such as HM8R) is thus excited in a circuit passing through the body wire S of the associated initial junction, to the battery in the associated block coupler 500, as previously drawn. . By the operation of this maintenance electro, the tip, neck and body conductors TR and S of the combined initial junction 203 are thus connected respectively to the corresponding wires of the line return 202, and by them, to the corresponding wires of the calling line.

  
The previous extension of the calling line, by the associated line forwarding, to the combined initial junction, constitutes the socket of the block coupler 500 which serves this initial junction. This block coupler

  
  <EMI ID = 428.1>

  
trant (as described above), substituted for the availability battery potential which hitherto appeared on this wire, thus forming a holding circuit for the holding electros, primary and secondary, effectively allowing them to be maintained after the release of the line controller device.

  
17 [deg.] Release. Line test relay 12B16 drops out in response to a short circuit established by the mentioned grounding of the calling line body wire as a result of operation of the associated primary holding electro. The appreciable time it takes for relay 12B16 to drop out in response to a circuit grout is sufficient to allow the seized block coupler to return the holding earth through the body wire of the established connection before the line controller releases.

  
As the I2B17 control relay is actuated and blocked, the dropout

  
  <EMI ID = 429.1>

  
which was actuated, which is followed by the release of the cut-off relay I2A23 and its auxiliary relay 12A24; to its contacts 4 and 2, it removes the chain battery preferably and the blocking earth of the upper windings of the relays 12B2 to 12B6 of the chain of the units, releasing the one that was actuated, which is followed by the dropout of their auxiliary relay 12BI; at its contact 6, it removes the starting earth of the cycle delay device

  
  <EMI ID = 430.1>

  
ted, primary and secondary, to drop, and the release of the relay of -the chain of five, 12A25 to 12A29, which was released the corresponding pair of holding electro in the control connectors. In response to each of <EMI ID = 431.1>

  
12B18 release relay, which leaves this relay stuck on the out-of-normal conductor of the CON controller, if this is still grounded.

  
After the mentioned release, the primary chain relay locks

  
  <EMI ID = 432.1>

  
cié SM, by allowing the two control connectors (lOOO and 1100) to be released. Releasing the SM selection electrodes in these switches opens contacts 1107 and 1007, which removes the earth on the conductor

  
  <EMI ID = 433.1>

  
Releasing relay 12B18 completes the release of the line controller, except for a partial operation of the engage impeller, which causes the commitment assignor to make an intermediate advance.

  
At its contacts 1 and 2, the release relay 12B18 resets a blocking earth and a string battery preferably on the

  
the initial primary chain, which makes the line controller susceptible again to receive a call at the start, The contacts 5 of this relay put a ground on the armature spring 2 of the final start relay 12B8, which again makes the line controller capable of receiving an incoming call,

  
  <EMI ID = 434.1>

  
originated to combination start wire 1222, but this wire remains provisionally grounded for the engagement impeller, in which the relays
12014 and 12015 are at work (as will be described later), while

  
  <EMI ID = 435.1>

  
connected by relay 12D12.

  
Having dropped out as has just been described following the dropout of relay 12B10, relay 12D12 again connects wire 1223 to combination starter wire 1222, earthed, to which the relay
12C16 works by preparing for the advancement of one step yet from the commitment assignor. This successively resets relays 12C14 to 12C16. At this point, the operation ends, because the driving earth is removed from the combination starter wire by contact 1 of relay 12014. When falling,

  
  <EMI ID = 436.1>

  
(such as 12019) of the Commit Assignor, as will be described below, thereby preparing the engagement of the next bundle of initial trunks when the line controller is brought back into service for an Initial call operation.

  
19 [deg.] The commitment allocator, including the control relay

  
  <EMI ID = 437.1>

  
its allocation positions, the one it automatically takes when current is applied for the first time to the line controller.

  
At this moment, the odd branch 1233 of its control wire 1231 is grounded by the rest contact 2 of the relay 12Cl6 and the rest contact 1 of the relay 12C17, by activating the first allocator relay 12018

  
  <EMI ID = 438.1>

  
odd branch 1233 of the grounded control wire 1231, but the relay
12C17 is not working at the moment, being short-circuited by the earth applied to the control wire 1231 by the normally-open contact 2 of relay 12C16.

  
  <EMI ID = 439.1>

  
later the second assignor relay 12019 through the even branch 1232 of the control wire 1231; and to its contacts 3 and 4, it connects the first relay 12026 of the junction engagement group and the first relay 12022 of the engagement totalizer, to the combination start wire 1222. The assignor

  
  <EMI ID = 440.1>

  
When the starter wire 1222 is then grounded, the relays 12028 and 12026 connected to it, operate, as described, with the relay 12022 locking directly on the conductor 1222.

  
Engage impeller relay 12014 operates now through contact 1 of relay 12C16 and, at its I contact, grounds starter wire 1222 at another point to ensure completion of the cycle.

  
  <EMI ID = 441.1>

  
has taken place, to achieve the described interim advancement of the Commitment Grantor.

  
On contact 2, relay 12014 actuates relay 12C15, which

  
  <EMI ID = 442.1>

  
Successive actuation somewhat exceeds the time required for a combination to occur and for the pilot relay 12D12 to operate if the combination can occur on the first engagement.

  
When relay 12016 then operates (during or after the

  
  <EMI ID = 443.1>

  
control wire 1231 and on its connected branch 1233, which removes the short circuit of the lower winding of relay 12C17. The control relay 12017 is now energized in series with the relay 12018, which remains blocked at its contact 1. The wires 1231 and 1222, entering the allocator, are thus transferred respectively from their odd branches 1233, 1235 and 1237, to their even branches 1232, 1234 and 1236. The attribute is thus in the po-

  
  <EMI ID = 444.1>

  
When relay 12016 then drops out by reapplying earth to control wire 1231, earth is thus applied to even branch 1252 of the control wire, energizing the holding winding (the winding).

  
  <EMI ID = 445.1>

  
2 of relay 12C18, to the battery via contacts 4 and 2 of relays 12020 and
12C21. In response, relay 12019 operates and blocks directly at the

  
  <EMI ID = 446.1>

  
the NO contacts 3 and 2 of the 12C17 control relay; finally at its contact 3, relay 12019 removes the chain battery from relay 12018 ,, by releasing it in this way. The 12CI7 control relay remains actuated by its coil.

  
  <EMI ID = 447.1>

  
The engagement allocator is now in position 2.

  
The following operation of the engagement impeller (relay
12C16) cuts the earth of wire 1231 to release control relay 12C17, leaving only relay 12019 actuated in the assignor. The assignor is thus in position 2 1/2.

  
  <EMI ID = 448.1>

  
12020 assignor operates on the odd branch of the control wire, through the 12019 relay contacts to work. Having worked, it hangs on the odd branch of the control wire and to earth through the winding

  
  <EMI ID = 449.1>

  
of the third relay in the engagement totalizer and in the junction engagement group, and it opens its chain contact 4 to release the second counter relay 12C19. The engagement allocator is now in position 3.

  
When the I2C16 relay is then actuated to remove the

  
  <EMI ID = 450.1>

  
is released from the short circuit again and energizes, this time in series with relay 12C20. Relay 12C20 remains actuated, and relay 12017 operates again. The allocator is now in the 3 1/2 position.

  
  <EMI ID = 451.1>

  
control wire, the last 12021 assignor relay operates on the even pin of the control wire, in parallel with the upper coil of the relay

  
  <EMI ID = 452.1>

  
only on the even branch of the control wire and opens its chain contact

  
2 to disconnect and release relay 12C20. The commitment allocator is thus in position 4.

  
When the engagement impeller relay 12C16 operates

  
  <EMI ID = 453.1>

  
again to return the commitment allocator to its position 1 which is shown, which starts a new operating cycle.

  
  <EMI ID = 454.1>

  
ne to stop a control pulse to the commit assignor, the assignor advances to a half-step position, in that the counter relay

  
  <EMI ID = 455.1>

  
The action prepares the next step of the assignor and effectively disconnects the pair of relays which is connected at this moment in the commitment totalizer group and in the junction engagement group, in preparation for the connection of the next pair without recovery.

  
The total result of the operation of the commitment allocator

  
  <EMI ID = 456.1>

  
The Initial Junctions engagement groups continuously until a combination occurs or until all four have been engaged without there being a combination, and (2) considering the four beams as arranged in a continuous chain, or in a circle, the first beam of junctions engaged after an operation of the line controller is that which follows the beam engaged last in the previous operation of the line controller. The effect is to load the four calls with an equal number of calls.

  
  <EMI ID = 457.1>

  
engagement harness should contain approximately the same number of initial junctions equipped as any other, bearing in mind that the number

  
  <EMI ID = 458.1>

  
the respective block couplers) for the reason that this number will rarely be needed. Preferably, the initial unequipped trunks do not match in the different engagement groups, so that the line forwardings of any group of ten serving a primary line switch 800 are also loaded. That is to say that the total number of the initial junctions equipped should be distributed approximately equally among the ten secondary sections of the line bay,

  
200 Operation of the choice assignor. The assignor of

  
  <EMI ID = 459.1>

  
specialized metering chain, arranged so as to successively take allocation positions 1 to 10, in cycle. Its purpose is to successively shift the first choice among the ten associated primary switches 800, among the ten secondary sections (sections of the five switches 900) and among the five packets of five lines served by any primary switch.
800.

  
  <EMI ID = 460.1> even. Relay 1203 is used to disconnect relay 1204 when the

  
  <EMI ID = 461.1>

  
of the commitment grantor.

  
The preferred assignor is shown in position 1. In this position, the first assignor relay 1204 remains working on the

  
  <EMI ID = 462.1>

  
against the load of its springs until the residual magnetism is neutralized. Each of these relays has series windings, differentially coupled.

  
Control relays 1201 and 1202 are first controlled by cycle timer relay 12B15, which is actuated at the start of each initial run and is released when the line controller releases. The arrangement is such that advancement of the choice assignor from one position to the next occurs as a result of the line controller release operation, between successive operations for outgoing calls.

  
With the cycle delay relay 12B15 at rest, and the two relays

  
  <EMI ID = 463.1>

  
by the rest contact of relay 1201. With the two windings energized in opposition, as shown, relay 1202 remains at rest. Relays

  
  <EMI ID = 464.1>

  
When the I2DI5 relay then operates, after the line controller has been plugged in for an initial operation, its contact 4 disconnects the earth of the two windings of the 1202 relay (leaving it at rest) and the

  
  <EMI ID = 465.1>

  
lower, only excited. While operating, it disconnects the upper winding of relay 1202 from its parallel coupling with the lower winding of this relay. Relays 1201 and 1202 are now in position 1 1/2, relay 1201 being the only one working.

  
When the line controller then releases, contact 4 of relay 12B15 again transfers the earth of the circuit of relay 1201 to this-

  
  <EMI ID = 466.1>

  
job.

  
When relay 12B15 then operates, after resuming the line controller for service at the start, it again removes the earth on the circuit of relay 1202 (leaving this relay attracted by the ma-

  
  <EMI ID = 467.1>

  
by exciting its two windings. The upper winding (armature side) acts by reversing the magnetic flux in the end of the core (not shown) on the armature side, and in the armature (not shown), which releases the relay when the flux passing through it approaches zero. Having released, the relay does not operate again until the two different windings

  
  <EMI ID = 468.1>

  
  <EMI ID = 469.1>

  
release of the line controller, the upper winding (armature side) of relay 1202 is energized in parallel with its lower winding (by the contacts of relay 12CI at rest), which drops relay 1202

  
  <EMI ID = 470.1>

  
The relays 1201 and 1202 are again in position 1 (both at rest), at the starting point for a new cycle.

  
  <EMI ID = 471.1>

  
(both at rest), (l) relay 1201 operates first to put them

  
  <EMI ID = 472.1>

  
in position 2 1/2 (relay 12C2 only activated); and (4) relay 1202 drops back to return them to position 1 (both at rest).

  
  <EMI ID = 473.1>

  
the first position, which is shown, all its relays are at rest, except the first allocation relay 1204. This relay is actuated by the earth, the closed contacts 3 of the relay 1202, the odd control wire 1241, the contacts

  
  <EMI ID = 474.1>

  
The incoming wires from the allocator (the control earth at contact 3 of relay 1202 and wires 1243 to 1246) are thus connected to their respective odd branches by rest contacts 3, 1, 2, 5 and 6 of the control relay. control 1202, and the odd branches of wires 1243, 1244 and 1246 are connected to their respective output wire 1 by the make contacts 1, 2 and 4

  
of relay 1204.

  
The assignor of choice remains in its position which is shown again, until the second control relay 1202 operates to put relays 1201 and 1202 in position 2 (both working) at the end

  
from the first call operation to the outgoing which follows. In operation, relay 1202 switches input wires 1243 through 1246 from their Odd branches to their even branches, thereby advancing the assignor to the 1 1/2 position.

  
By its contact 3, closing before breaking, relay 1202 transfers the control earth of the odd control wire 1241 to the even control wire 1242, thus opening the initial circuit of relay 1204 and energizing three windings in series by the contacts 3 of relay 1204, These

  
  <EMI ID = 475.1>

  
of 1204 and the winding of the cut-off relay 1203. The holding winding of the 1204 relay is used to keep this relay working after

  
  <EMI ID = 476.1>

  
relay 1205 (via contact 3 of relay 1204) is kept intact. Relay 1203 operates to disconnect the upper winding of relay 1204 from the odd wire 1241, and it is arranged so as to be kept at work through the holding windings of the following assigning relays Until is reached, in operation of the assignor of choice, the point at which that relay must be released to connect again

  
  <EMI ID = 477.1>

  
control of relay I2C6; to its contacts 1 and 4, it connects the associated wires

  
  <EMI ID = 478.1>

  
1246; and at its contact 2, it connects wire 1 of group 1252 to the odd branch of wire 1244. The allocator is held in position 2 (the relays
1201 to 1205 at work).

  
The next outgoing first service from the line controller releases relays 1201 and 1202 as described. The relay 1202 disconnects the even branches of the input wires and their substitutes, the odd branches. The assignor is thus advanced to position 2 1/2 (relays 1203 to 1204 activated).

  
Returning the control ground from the even control wire 1242 to the odd control wire 1241 opens the mentioned control circuit (winding). <EMI ID = 479.1>

  
control (upper winding) of the third assignor relay 1206 in series with the lower winding of relay 1205 and the winding of 1203. By

  
  <EMI ID = 480.1>

  
From this point on, the operation of the choice assignor continues in a gradual and wavy movement in which the last previous assignor relay is kept working in the control circuit of the one that has just been actuated, while the penultimate previous assignor relay has its circuit cut and drops out.

  
Therefore, except for a momentary space of half-time

  
  <EMI ID = 481.1>

  
  <EMI ID = 482.1>

  
last born closes effective allocation circuits, due to the action of control relay 1202 which pushes input wires 1243 to and fro

  
  <EMI ID = 483.1>

  
When the assignor reaches its ninth position, the 9 [deg.] Assignor relay 12012 is actuated by earth on the odd control wire

  
  <EMI ID = 484.1>

  
working in this circuit, while all other assignor relays are in the idle state.

  
  <EMI ID = 485.1>

  
assignor relay 12013 is actuated by contact 3 of relay 12012 in series with the holding winding of the latter, but this circuit does not contain

  
  <EMI ID = 486.1>

  
When the control relay 1202 then drops out, removing the resulting ground on the even control wires 1242 releases the relays 12012 and 12013., and resetting the odd control wire to ground.

  
  <EMI ID = 487.1>

  
1203, which has dropped, to return the choice assignor to the first position shown, in order to start a new cycle of operation.

  
  <EMI ID = 488.1>

  
according to the above, that the battery of wire 1241 is successively applied to the ten choice wires la 10 of group 1251 going to the initial chain

  
  <EMI ID = 489.1>

  
feel respectively.

  
  <EMI ID = 490.1>

  
assignor of choice to the chain of contacts preferably associated with the upper windings of the five relays 12A25 to 12A29) is connected to the

  
  <EMI ID = 491.1>

  
etc. to 12012 and 12013) that the choice assignor comprises, the first choice relating to the blocking battery applied to the wire 1244 is successively moved among the packs of five that these relays represent respectively. These packet shifts occur in the respective odd assignor positions.

  
The blocking earth potential (represented by wire 1246) is applied successively to the ten choice wires 1 through 10 of harness 1254, going to test and junction relays 12D13 through 12D22, thus gradually moving the first choice from. The first line section secondary to the second, sections which are represented respectively by the junction test relays.

  
Shifting the preference among primary switches ensures that a call from any primary switch will eventually find access to the line controller, regardless of circuit conditions and combination conditions regarding other primary switches; moving the preference among packets of five lines on a primary switch does the same to ensure final access to the line controller of a line of any packet of five, regardless of the conditions surrounding the lines of the lines. other groups of five served by the same primary exchange; and moving the preference among the ten secondary sections of a line bay acts to evenly distribute outgoing calls among those sections.

  
By assigning the first choice to the secondary sections in a regular order, in combination with the previously described operation of the commitment allocator, it is possible to almost completely equalize the

  
  <EMI ID = 492.1>

  
uniform traffic load and (2) that any tendency to have an unbalanced load distribution, which could result in the failure to successfully combine into an outgoing action, unnecessarily, is greatly diminished.

  
21 [deg.] Cycle timer operation. The cycle timer (relays 12B11 to 12B15) is mainly intended to release the line controller and return it to the normal state when the release operation does not go normally. As noted above,

  
the cycle timer shall delay the start of its release operation for a period of time long enough to allow the line controller to operate normally when four successive engage operations

  
junctions are required. The waiting time provided by the timer

  
  <EMI ID = 493.1>

  
successively fall back into the slow release conditions in short circuit

  
When the initial start relay 12BIO operates, its contact 6 applies a start earth to the cycle timer, as mentioned above, by successively actuating the relays 12B11 to 12BI5. Relay
12B11 is controlled by closed contacts 2 of relay 12BI5, and each of relays 12B11 to 12BI4. closes, at its contact 2, a control circuit for the following relay o Relay 12BI5, at its closing contact before breaking 2, blocks itself and blocks the previous relays on the incoming grounded control wire (in preparation for the successive dropout of relays 12B11 to 12B14), at the same time opening its first control circuit to avoid interference with the desired rapid dropout of all the relays immediately

  
  <EMI ID = 494.1>

  
On contact 1, relay 12BI5 earths the release wire for relays 12B11 to 12B14, thereby directly shorting

  
  <EMI ID = 495.1>

  
operation of relays 12B12 to 12B15, after the operation of 12B11, ensures that the current reaches substantially its full value in the winding of

  
  <EMI ID = 496.1>

  
short-circuit the winding of the next relay. When the line controller ends its normal operation and becomes free before the action

  
of the cycle timer has reached the point where relay 12B14 releases, removal of the cycle timer control earth at contact 6 of the

  
  <EMI ID = 497.1>

  
te a local series blocking circuit for relays 12BI4 and 12BI5. This circuit goes from the earth, through contacts 1 of relays 12B15 and 12B13, the coil of relay 12BI4 and its contact 2, and the coil of relay 12B15, to the battery. When this circuit has effect (after opening of contact 6, previously closed, of relay 12B10), the current flowing through the winding of relay 12B14 is reversed causing the reversal of the flux in the magnetic structure (not shown) . During this inversion, relay 12B14 drops out, opening the aforementioned accessory local blocking circuit at its contact 2. In response, relay 12B15 drops out. The action is the same when a relay preceding anyone of the cycle timer is still on when relay 12B10 drops out.

   As the mentioned current reversal results in the rapid and satisfactory release of the cycle timer, the circuit has been left in its simple form which is shown, rather than providing it with a sufficient number of pairs of contacts on the circuit. relay 12B10 or on relay 12B15, to isolate the different circuits.

  
When the line controller has not released, during the time when cycle timer relay 12BI4 releases in response to the short circuit applied to it after releasing relay 12B13, the release relay

  
  <EMI ID = 498.1>

  
working tact 3 of relay 12B15 to start the release operation.

  
22 [deg.] Time out group. The time-out group (relays 12BI9

  
  <EMI ID = 499.1>

  
for a short period of time (e.g. 9-18 seconds) when at least ten successive attempts to extend a calling line have occurred without success

  
  <EMI ID = 500.1>

  
each of the primary line switches a first choice access to the initial primary chain.

  
The purpose of this dead time feature is to minimize unnecessary operation of the line controller relays and its switches 1000 and 1100.

  
Two circumstances other than a circuit disturbance in

  
the line controller or its switches may cause the line controller to perform a series of initial operations without success.

  
First, the traffic load on the line forwarding and

  
the initial junctions may be large enough so that for a period of time no combination is possible to a free initial junction from any primary switch.

  
Second, when the body circuit of a calling line
(between its body wire S and the battery) is open, its holding electro cannot be operated to extend it. This condition is detected

  
in the line controller by the failure of the test relay

  
of lines 12BI6.

  
When an initial operation of the line controller is followed with success, the control relay 12B17 operates, as described, (to control the maintenance electros concerned, primary and secondary), before the operation of the release relay 12B18, but when the initial operation is not successful, relay 12B17 does not operate. The 12B18 release relay is then actuated, either by the chain contacts

  
  <EMI ID = 501.1>

  
release relay 12B18 operates while the control relay 12B17 is still at rest, the earth is actually placed on the en- wire.

  
  <EMI ID = 502.1>

  
to the dead time group This earth is applied by the rest contact

  
2 of the control relay 12B17, contacts 7 and 4 of relays 12B10 and 12B18, to wire 1245. Provided that the assignor of choice is in position 10, the earth, applied to input wire 1245, is extended by contacts

  
5 of relays 1202 and 12C13 to wire 10 of time-out group 1253, by activating time start relay 12BI9. Relay 12BI9 is blocked

  
to earth through the normally-open contact 2 of relay 12B17, the open contact 2 of relay I2B19 and the normally-closed contact 10 of relay 12B21.

  
If initial operation occurs successfully in one of the next nine attempts made by the line controller, the relay

  
  <EMI ID = 503.1>

  
if none of the following nine initiated operations of the line controller is successful, the start relay 12B19 remains blocked to work to put the line controller in idle time after the assignor of choice has advanced, from position 10 and by positions 1 to 8, up to position 9.

  
In this event, the earth applied to the input wire 1245 of the assignor of choice is extended by the rest contact 5 of the relay 1202, the work contact 5 of the relay 12C12; wire 9 of harness 1253 and work contact 1 of the start time relay 12B19, up to the start relay 12B20, The start relay 12B20 operates and is blocked by its contact 5, by contact 1 of the start relay 12BI9; at contact 4, he prepares

  
  <EMI ID = 504.1>

  
directly on the associated input wire 1245 of the assignor of choice; at

  
  <EMI ID = 505.1>

  
dead time (relays 12E22 to 12B24). The line controller is now at the start of its idle period, where it does not respond to calls from its associated line bay, since the initial start relay
12BIO is disconnected at contact 6 of the start relay 12B20.

  
  <EMI ID = 506.1>

  
successively and successively fall to generate drive pulses intended for the assignor of choice during the idle time period

  
  <EMI ID = 507.1>

  
set to output drive pulses to the preferred assignor at a relatively slow frequency, such as one pulse every second or two. The arrangement is such that nine preferred assignor steps are required to return the. line controller in the active state with regard to

  
  <EMI ID = 508.1>

  
seconds, depending on the setting of the dead time pulse relays.

  
After each operation and release of the relays of this impeller, relay 12B23 transmits through its contact 2, a driving pulse to the relays

  
  <EMI ID = 509.1>

  
for cycle timer relay contact 4 12B15, advancing the assignor of choice one step each time the idle time impeller is operated.

  
Nothing else happens in the timeout relay group until the assignor of choice has moved forward nine steps, after running.

  
  <EMI ID = 510.1>

  
impellers 12B22 and 12B23 at rest and relay 12B24 at work.

  
The starter relay 12B20 being at work, and the assignor

  
  <EMI ID = 511.1>

  
12B20 drops back and removes start earth on the idle time impeller before its next cycle begins. At its contact 6, relay 12B20 ends the dead time period by reconnecting the initial start relay 12BIO.

  
23 [deg.] Traffic count. The line controller is designed to operate two counters (not shown) which indicate the disposition of outgoing calls that it serves. These counters are activated by the OCC wire of completed initiated calls and the OCL wire of lost initiated calls (fig.

  
  <EMI ID = 512.1>

  
Each time the control relay 12B7 operates (due to the closing of the circuits of the holding electrodes in the normal course of operation following the combination), it earths the wire.

  
  <EMI ID = 513.1>

  
successfully extended across the bay of lines.

  
Counting lost initiated calls is not accomplished so easily, since the operation of the line controller, which finds no usable combined path, does not necessarily mean that the call is lost, as the calling subscriber often has to. wait a short time for a path to become available. However, it is considered that any state causing the timeout group to operate in the manner described, to remove the line controller from operation at the outset (after at least 10 unsuccessful attempts on initiated calls) causes a delay which is worth a lost call. Therefore, whenever the start relay 12B20 operates to start a period of idle time, it will ground the OCL wire of lost initiated calls to record an initial lost call. Reading

  
However, the lost call counter is not intended to show the precise number of initiated lost calls. In this regard, it will be noted that a calling line that has an S body wire cut will cause repeated OCL wire grounds until its condition is remedied.

  
We will describe the detailed operation during incoming (final) calls.

  
  <EMI ID = 514.1>

  
five and units.

  
When the block translator 1800 receives the encrypted information from a calling block coupler 500, identifying a connected line

  
  <EMI ID = 515.1>

  
it translates this information into a primary digit, a five digit and a units digit and transmits the translated encrypted information to the line controller concerned by simultaneously grounding one of ten P wires, one of . five F wires and one of the five U wires which connect the block translator to the line controller, These three wire harnesses are shown towards the lower edge of figure 12, part 1. These harnesses correspond respectively to the digits, primary, of five and units, translated information.

  
Grounding of an F wire or U wire by the block translator has no immediate effect, as the control battery remains cut off from the associated lower windings of the five and five chain relays. chain of units until the auxiliary relay 12B9 of the final control group has operated to close its contacts 1 and 2. This prevents interference with the initial control action, if any. In progress,

  
2 [deg.] Primary selection. The earthing of the selected P wire, coming from the block translator, causes the immediate operation of the associated relay, among the ten relays 12AI2 to 12A21, in the final primary chain for the selection of the corresponding primary line switch. Having

  
  <EMI ID = 516.1>

  
earth of the associated electro selector wire SM going to the control connectors, and at its contact 2, it grounds the control wire for the final start relay 12B8. The relay circuit 12B8 includes the normally closed contact 9 of the initial start relay 12B10, whereby the relay 12B8 does not function.

  
  <EMI ID = 517.1>

  
3 [deg.] Taking of the final control group. Having operated, the final start relay 12B8 opens at its contact 3, the incoming earth wire to the selector contacts of the initial primary chain, and at its contact 4. it locks in operation independently of contact 9 of relay 12B10, in order to to give the final operation an indisputable preference in the event of competition

  
  <EMI ID = 518.1> its associated end bay TF wire to identify the called line bay in block controller 1600; at its contact 5, it transfers the control wire

  
  <EMI ID = 519.1>

  
4 [deg.] Selection of five and units. At contact 4, auxiliary relay 12B9 connects the CLS body wire of the called line, as a

  
  <EMI ID = 520.1>

  
controls to the control coil the relays of five and units (12A25 to 12 A29 and 12B2 to 12B6), after which the selected relay in each chain operates

  
  <EMI ID = 521.1>

  
thus grounding the SM wire of the selection electro corresponding to the selected primary switch.

  
  <EMI ID = 522.1>

  
control connectors 1000 and 1100 now work as described to move into position based on the primary switch selected

  
  <EMI ID = 523.1>

  
6 [deg.] Return test. Incidentally to the primary switch selection operation it performs, the control connector 1000 connects

  
  <EMI ID = 524.1>

  
tively to the body wires S of the line references 202 coming from the switching

  
  <EMI ID = 525.1>

  
that their corresponding line referrals are available, as described for operation initially. Having worked, each relay

  
  <EMI ID = 526.1>

  
dants, connected in series. The battery thus placed on any LK wire informs the block controller 1600 that the corresponding connected line feed is available. In addition, the closing of the mentioned contact 1 of any line test relay, prepares a circuit for the control of the corresponding selection electros, primary and secondary, on the line bay if a path is combined through the line return. corresponding.

  
7 [deg.] Selection of five on the control connectors. During the primary selection they make, the control connectors, taken together, ground the out-of-normal control wire CON (fig-

  
  <EMI ID = 527.1>

  
blocks relay 12B8 by its contact and completes a circuit passing through contact 1 of auxiliary relay 12A24 and working contact 1 of relay of five actuated (12B25 to 12B29), through the associated wire, HM5 to HM9, in order to control the hold electro, HM5 to HM9, in the two control connectors, which corresponds to the pack of five lines selected on the selected primary switch 800. As previously described, the body wires S of the five lines of the selected pack of five are thus respectively connected to the five SU unit body wires arriving at the line controller.

  
  <EMI ID = 528.1>

  
lée. The selection of the units having been made in the line controller, by the described operation of one of the unit relays 12B2 to 12B6, the SU wire which represents the body wire of the called line is now extended by the contact 1 of the actuated units relay (12B2 to 12B6), one contact, 2 to 6, of the actuated auxiliary relay, 12B1, the local body wire,.
1221 and contact 4 of relay 12B9, to the called main line CLS wire going to the block controller 1600, which allows the block controller to test the called line through this wire and later to control the called line. electro for maintaining the line called by this same wire.

  
. 3 [deg.] Start of .. line test The operation .. mentioned, last <EMI ID = 529.1>

  
re open in the line controller at contact 1 of the relay this initial start I2B10, but a branch of this wire is extended to the block controller in this case the test start wire TS, the TF wire of this controller

  
  <EMI ID = 530.1>

  
acts in the block controller to start the test of the called line.

  
  <EMI ID = 531.1>

  
a line return 202), the block controller first causes the selection of the elements of the combined path and then commands the appropriate holding electros in order to determine the extension of the connection passing through these elements, to the called line.

  
To cause the selection of the combined line feeder, the block controller earths the corresponding LK feeder wire, by activating the relevant selector electros, primary and secondary, on the line bay, by making contact 1 of the associated return test relay (12D1 to 12DIO) of the line controller and the associated LSM wire of electro

  
forward selection. The operation of these selection electrodes extends the battery to the PS-ON wire, as described above. The non-normal ON wire (figure 12, part 2, bottom) is multiple on the previous one, extending the battery to the block controller, as a signal that the line feed selection has occurred.

  
The maintenance electros, primary and secondary, and the secondary electro on the line bay are operated as described. The individual maintenance electro on the called line is actuated (to connect the called line to the primary end of the combined line forwarding) by an earth placed on the CLS wire by the block controller, this wire having been connected, as described, along the body of the called line,

  
  <EMI ID = 532.1>

  
Block Tracer 1600 and Block Translator 1800 become free. Releasing the block translator opens the circuit of the actuated digit relay in the final primary chain, in the chain of five and in the chain of units of the line controller, and drops it again. This allows the relays as-

  
  <EMI ID = 533.1>

  
end opens the SM wire, previously grounded in order to free the control connectors, and it opens the upper winding of the de-

  
  <EMI ID = 534.1>

  
relays 12B8, 12B9, and 12A1 drop out :, by completing the release of the line controller.

  
12 [deg.] Control and supervision of digit wires. Faults in the circuits of the block translator 1600., or at the terminals of the conductors of the cable which connects this translator to a line controller 1200, can cause]

  
  <EMI ID = 535.1>

  
two of the wires of U units that go from one to the other. Unless avoided, this can cause two or more relays to operate in the line controller's interested digit string, which would mark one or more other lines in addition to the called line. However, operation in the block translator of two or more relays in the same string of digits is avoided by chaining the command bank for each string of interest in the line controller.

  
As an alarm supervision measure, each string of digits

  
  <EMI ID = 536.1>

  
between wires attempts to operate two relays in the same chain of

  
  <EMI ID = 537.1>

  
12A21, opens when operating its chain contact 1 to cut the battery

  
  <EMI ID = 538.1>

  
that when earth appears on the P wires arriving at two or more of these relays, the relay with the lowest number in the chain operates normally, while any relay that follows it in the chain fails or drops out quickly as soon as possible. that its control battery has been disconnected by the preferred relay in the chain. The relay that tried to

  
  <EMI ID = 539.1>

  
  <EMI ID = 540.1>

  
  <EMI ID = 541.1>

  
connected from the chain. While operating, relay 12A22 blocks its upper winding to earth at contact 1 through the alarm stop key 1207. The associated primary alarm lamp 1201 lights up in parallel with the winding.

  
  <EMI ID = 542.1>

  
the LC-AL line controller alarm wire going to the alarm supervision equipment (not shown), in order to signal the fault status in the line controller.

  
Note that the circuit arrangement still allows a call to end in the normal state referred to. Such a call has an equal chance of reaching the desired called line, since that of

  
  <EMI ID = 543.1>

  
feel the correct translation, about half the time.

  
The chain and alarm arrangement is similar in the chain of five and in the relay chain of the units, where the alarm relays 12A30 and 12D7 are provided, together with their associated alarm lamps 1202 and 1203 and resistors 1205 and 1206.

  
14). We will now describe the block switches (Figures 13 and

  
Figures 13 and 14 are circuit diagrams of a primary block switch 1300 and a secondary block switch 1400, respectively. Switch 1300 represents any of the ten primary block switches 1300 of Figures 2, 3 and 6,

  
As indicated for Figures 8 and 9, the respective parts of the switches shown in Figures 13 and 14 are shown.

  
  <EMI ID = 544.1>

  
cross-bar mutators of the construction assumed to be used in this system.

  
Each switch 1300 or 1400 has 20 columns, the first and the last (VI and V20) of which are represented in full, the intermediate columns (V2 to V19) being omitted. Each column of one of the com-

  
  <EMI ID = 545.1>

  
The stack, designated respectively, by U and L, Each column VL to V20 of a switch further comprises a thirteenth stack, called the HP maintenance pilot stack.

  
Each of the 1300 and 1400 switches has 20 holding electros

  
  <EMI ID = 546.1>

  
Any HM maintenance electro, when it has been turned on, invariably actuates its HP maintenance pilot stack but does not actuate any stack in the associated column V, only if this has been selected.

  
Each 1300 or 1400 switch has 10 main selection electros

  
  <EMI ID = 547.1>

  
1 to 10 in the various V columns of the switch, and of the SMU and SML extension selection electros which correspond respectively to the U and L extension stacks in each V column.

  
The corresponding stacks 1 to 10 of each switch are connected together, in rows, by ten sets of horizontal multiple wires.
(six bands per set) shown at 1303 in Figure 13 and 1403 in Figure 14. Each set of six horizontal multiple bands includes three upper U bands and three lower L bands. Each set of three includes elements T, R and S which correspond respectively to the tip, neck and body conductors of the telephone connection.

  
In any vertical column V of each switch 1300 or 1400, six bands of vertical multiples are employed. They are represented in
1305 in figure 13 and at 1405 in figure 14. Three of these bands of each column V interconnect contacts of an extension stack U-with the contacts of the three pairs of upper contacts-of each of the main stacks 1 to 10 of the column, while the other three bands of the vertical multiple interconnect the contacts of the extension stack L with the contacts of the three lower pairs of the main stacks 1 to 10 of the columns, as shown. The movable blades of the U and

  
L of each column V are connected together, as shown, to provide a common input path for three associated junction conductors TR and S.

  
On each of switches 1300 and 1400, the ten pairs of block references 206 are connected, as shown across the end

  
  <EMI ID = 548.1>

  
206 of each pair are designated respectively by U and L, depending on whether they are connected to the contacts of the three upper pairs of each stack or to the contacts of these three lower pairs. The block references 206 are crossed between the ten primary switches 1300 and the ten secondary switches 1400 in the manner which has been described above in relation to FIG. 3. That is to say that of each primary switch 1300, the pairs of block referrals 206 go to the ten secondary block switches 1400, respectively.

  
On each primary switch 1300, there are 20 body wires connected to the S body wires of the 20 related block references 206, and going to, or coming from, control connector 1500 of Fig. 15. On every 1300 switch, they are called the body wires,

  
  <EMI ID = 549.1>

  
following the block references they represent respectively. These are the wires by which the block controller 1600 tests for block returns, Detx of these wires are shown as SU-225 and SL-225 in Figure 6.

  
  <EMI ID = 550.1>

  
between switches 1300 and switches 1400. For each main selection electro of a primary switch 1300, the battery is supplied

  
  <EMI ID = 551.1>

  
secondary mutators 1400, the one to which the corre-sponding pair of blox 206 referrals is led. For this purpose, the electro-selector wires

  
  <EMI ID = 552.1>

  
ten secondary switches 1400 are crossed in accordance with the crossing

  
  <EMI ID = 553.1>

  
tion with figure 3. The series coupling between the main selection electros of switches 1300 and 1400 per pair is shown in figure 6 for the selection electros associated with the pair of block references
206 which is represented therein.

  
Each of the SMU and SML extension selection appliances

  
of each primary switch 1300 is grounded and controlled upon receipt of a battery potential, by the associated wire, of the SMU and SML wires, shown in Figures 13 and 6, as going between a primary switch
1300 and the control connector 1500 (figure 15). Each of these SMU or SML extension selection electros of a primary switch is actuated in series with the corresponding SMU or SML extension electro of each

  
  <EMI ID = 554.1>

  
SML, shown as going between switch 1400 and block controller 1600 of Figure 16. These conductors are also shown in Figure 6 for the switch 1400 shown there.

  
  <EMI ID = 555.1>

  
mutator 1300 and a switch 14.00 requires the operation of one or the other of the secondary selection electros SMU and SML in each, and the

  
  <EMI ID = 556.1>

  
selection of switches 1300 and 1400 are connected accordingly. On each primary switch 1300, the out-of-normal contacts 1307 'apply an earth potential to one contact of each pair of out-of-normal contacts
1307. Closing a pair of contacts 1307 prolongs the potential of

  
  <EMI ID = 557.1>

  
earth applied to the PON wire up to the pair of contacts 1407 '. Operation of this latter pair of contacts extends the ground potential to the non-normal secondary conductor SON, which is multiple on all secondary switches 1400 and which goes to block controller 1600 to provide a Pilot Indication, which full selection has been made on the interested switches, primary and secondary, 1300 and 1400.

  
On each primary switch 1300 there are 20 sets of conductors, 205-1 through 205-20, coming from the respective block couplers 500, as shown in Figures 5 and 6 for the block couplers 500-1 and 500-L .

  
On each secondary switch 1400, the respective final junctions 207 start from the terminals associated with columns VI through V16, as shown for column VI and shown for column V16. Junctions

  
  <EMI ID = 558.1>

  
MT combination test are connected to the block controller 1600 in the figure
16 to allow testing and checking of the corresponding final junctions 207. The last four MT combination test leads similarly go to the outgoing controller 1700 of Figure 17 for testing and checking the corresponding outgoing junctions 2020.

  
In Figure 14, each MT combination test lead passes through the normally closed MB occupancy contacts. These contacts include the upper pair of contacts of the associated holding pilot stack, where they are mounted only for convenience, since their operation is manual and is not affected by energizing or de-energizing of the electro. associated maintenance HM. Opening a pair of MB contacts acts to mark the associated final junction 207 or outgoing junction 2020 as busy, depriving its associated combination test lead MT of the battery potential of availability.

  
We will now describe the block control connector and the section preference relays (Figure 15).

  
This connector will be described with reference to FIG. 15 (par-

  
  <EMI ID = 559.1>

  
by which connector 1500 is controlled,

We will first describe the block control connector 1500.

  
As shown in Figures 2 and 6, the block bay has a control connector 1500 interposed between the associated block controller 1600 and the primary block switches 1300. On each call traversing the block bay, connector 1500 is put on. Position under the control of the section preference relays 1550 to connect the block controller 1600 with that of the ten primary switches 1300 through which calls from the calling section of block couplers are served.

  
The accomplishment of the aforementioned object requires the selective switching of 20 feeder body wires and 12 selector electro wires on each of the ten primary switches 1300. The 20 body wires

  
of each primary switch each requires two pairs of contacts in the control connector, bringing the number of pairs of contacts per primary switch to 52, or a total of 520 for the ten primary switches,

  
  <EMI ID = 560.1>

  
1500 II columns VI to VII, each of which comprises ten stacks with five wires, 1 to 10. Of the 550 pairs of contacts thus provided, 30 remain unused in the last column Vil.

  
  <EMI ID = 561.1>

  
to save space on the drawing. Omitted columns are the same as columns VI, V2, V7 and V8.

  
Columns VI through V8 make up four pairs, each of which has its own local horizontal multiple. Otherwise, there is no horizontal multiple on connector 1500.

  
The columns of switch 1500 serve the wires of the various primary switches 1300, as follows:

  
1. Columns VI and V2 serve the SUI body wires at

  
  <EMI ID = 562.1>

  
2. Columns V3 and V4 (not shown) serve body wires SU4, SU5 and SL3 to SL5;

  
  <EMI ID = 563.1>

  
5o Column V9 serves the wires of selection electros SML to SM5 of switches 1300;

  
  <EMI ID = 564.1>

  
7. The VU column serves the SMU and SML selection electrodes.

  
  <EMI ID = 565.1>

  
HM control branch wire included in the 1560 cables and to the HM control branch wire led between the control connector and the 1600 block controller.

  
  <EMI ID = 566.1>

  
the corresponding rows of stacks 1-10 correspond respectively to the ten associated primary block switches 1300, as well as to the respectively associated sections 1-10 of the block couplers 500, as shown more clearly in FIG. 3.

  
We will now describe the section preference relays
1550.

  
The 1550 section preference relays include ten relays

  
  <EMI ID = 567.1>

  
final chain relays 15C21 to 15030 are also associated respectively with the sections of block couplers, to which They are connected respectively-

  
  <EMI ID = 568.1>

  
Normally closed contacts 1 of relays 12C11 through I5C20 are in series to form the main outgoing string through which earth is normally applied to end of string 1554, which is connected normally to each of the block coupler sections by contacts 2

  
associated relays, through their windings, and through the incoming wires

  
outgoing channel. The outgoing channel is supervised by an alarm relay
15D14, normally excited by an earth applied to the conductor 1554., so

  
to keep cut off the associated alarm lead AL.

  
Contacts 1 of relays 15021 to I5C30; normally closed, are coupled in series to constitute the final main chain, which normally extends the earth to its end of chain conductor 1551, from which the earth is normally extended through contacts 2 of the chain relays and their windings, at the respective sections of block couplers, through the final warp incoming yarns. Alarm relay 15D15 supervises the final main chain as it is normally actuated by earth applied to conductor 1551, to keep the alarm wire AL disconnected.

  
  <EMI ID = 569.1>

  
whose purpose will appear in the course of the description.

  
We will now describe the outgoing operation.

  
The 1550 Section Preference Relays and

  
  <EMI ID = 570.1>

  
Operation in an outgoing call takes place as follows:

  
1 [deg.] Localization of the outgoing channel with the receiving section. After the outgoing chain has been taken by any section of couplers

  
  <EMI ID = 571.1>

  
outgoing warp, figure 5), the corresponding incoming outgoing warp thread

  
  <EMI ID = 572.1>

  
block crying, preferably from section relays, is connected to the battery by outgoing chain relay 511 of block coupler 500, a

  
  <EMI ID = 573.1>

  
main aunt. At its rest contact; 1, it opens the main outgoing chain, and at its contact 2., it disconnects its own winding from the conductor

  
  <EMI ID = 574.1>

  
tions, of the chain. By this operation, the corresponding section of block couplers is selected, together with the associated primary switch, and the closing of a circuit passing through any other branch of sections of the outgoing chain is prohibited.

  
2 [deg.] Section preference. In case two or more of the relays
15011 to 15C20 operate at the same time, only the one with the lowest number remains working, since each of them cuts, at its normally-open contact 1, the chain earth of the holding circuit of the following relays. Gold-

  
  <EMI ID = 575.1>

  
following, from the first primary switch (and the first block coupler section), to the tenth.

  
  <EMI ID = 576.1>

  
through relay 15D11 coupled in series or by conductor 1555) to the associated selection electro wires (SML to SMLO) of the control connector

  
  <EMI ID = 577.1>

  
series.

  
4 [deg.] Channel preference. At its contact 1, relay 15D11 disconnects the earth of relay 15D12 (and consequently, of associated contact 3 of

  
  <EMI ID = 578.1>

  
control in the event that a final call requests the section preference relays before the outgoing call is cleared.

  
5 [deg.] Operation of the selection electro. In the connector

  
  <EMI ID = 579.1>

  
block and the associated primary block switch) energizes its connected selection electro in order to perform the mechanical selection of the corresponding stacking row.

  
6 [deg.] Operation of the maintenance electro, The operation of a selection electro closes the associated non-normal contacts 1507, this

  
which earths the non-normal ON wire included in the 1560 cable. The 15D13 holding pilot relay being in the rest state, and the 15D11 relay being at work, the mentioned earth applied to the ON wire is extended by

  
  <EMI ID = 580.1>

  
not shown) are connected to the corresponding wires of the selected primary switch 1300, and a battery-ready potential is applied to these body wires through the respective resistors 1561. On the colon-

  
  <EMI ID = 581.1>

  
their block are connected to the corresponding selection electro wires of the selected primary switch. On column Vil, the SMU and SML selection electro wires coming from the block controller are connected to the corresponding wires of the selected primary switch 1300.

  
  <EMI ID = 582.1>

  
HP holding pilot stacks are placed in their other position, thus cutting off the ground of the HP2 holding pilot wire at all points and

  
  <EMI ID = 583.1>

  
7 [deg.] Combination, With the mentioned wire OTG-MG having been shed, the block controller and the outgoing controller, acting together, combine a path to a free junction in the called outgoing bundle. This operation includes testing the 20 block returns 206, (ten pairs) from the connected primary block switch 1300 to the secondary block switches 1400. This test is performed by the block controller using its 20

  
  <EMI ID = 584.1> control tor 1500, to the corresponding body wires of the connected primary switch 1300. The availability battery, applied through the associated resistor 1561, appears on the body wire of each of the feeders, unless that the return is busy, in which case it is marked by the holding earth applied to the body wire of the return.

  
  <EMI ID = 585.1>

  
As described in relation to Figures 4 to 7, the block controller 1600 closes the necessary selection electro circuits in order to produce the mechanical selection of the combined block return on the Interested block switches, primary 1300 and secondary 1400 Part of this

  
  <EMI ID = 586.1>

  
control coming from the block controller, which grounds the corresponding wire of the connected primary switch. This activates the electro of se '* -

  
  <EMI ID = 587.1>

  
in series with the main secondary selection electro which serves the pair of block references which include the one which has been combined.

  
  <EMI ID = 588.1>

  
the one that is necessary, of the two auxiliary selection electros SMU and

  
  <EMI ID = 589.1>

  
corresponding wire, SMU and SML wires (going between the block controller
1600 and its connector 1500), which actuates this auxiliary secondary selection electro in series with the corresponding auxiliary selection electro (SMU or SML, connected to earth, of the connected primary switch 1300).

  
9 [deg.] Closure of the combined path. After the completion of the mechanical selection of the combined path on the switches, primary and secondary, circuits are closed through the block controller to control the desired holding electro on the primary switch and on the secondary switch, in order to extend the connection through the block bay, through the affected block return 206, up to. the selected outgoing junction 2020.

  
10 [deg.] Release, After establishing the connection via the plug

  
  <EMI ID = 590.1>

  
  <EMI ID = 591.1>

  
their normal state represented.

  
We will now describe the final or arrival operation.

  
With section preference relays 1550 and control connector 1500 in their normal state shown, their operation during a final call is as follows:

  
1 [deg.] Location of the final chain with the gripping section. After taking the final chain by a section of block couplers the

  
  <EMI ID = 592.1>

  
sections 1550, is connected to the battery, by the final chain relay (512, figure 5) of the block coupler taking 500 and the final start relay
16A6 of the block controller 1600. A circuit is thus established passing through the interested incoming wire of the final chain, through the winding of the associated relay among the relays 15C21 to 15C30, through the normally closed contact 2 of &#65533; relay and the end of chain wire 1551, to earth by the final chain. <EMI ID = 593.1>

  
very relays, mentioned in a series circuit, and at its make contact

  
  <EMI ID = 594.1>

  
At its rest contacts 1 and 2, it opens the main string and disconnects its own winding from the end of string conductor 1551, thus isolating each of the other branch branches from the earth of the final string. By this operation, the corresponding section of block couplers is selected together with the associated primary switch, and the other sections of block couplers are prevented from taking the final chain.

  
2 [deg.] Section preference. In the event that two or more of the relays 15C21 to 15C30 are operating at the same time, only the one with the lowest number remains working, since each of them opens the earth applied to the chain, going to the relay circuit, maintaining the relays. following. Order

  
  <EMI ID = 595.1>

  
at 15C20 about the main outgoing channel.

  
3 [deg.]) Earthing of the corresponding selection electro wire

  
to the selected section. After the effective operation of one of the relays 15C21 to 15C30, the earth is applied, by the closed contact 1 of the 15D11 relay, the winding of the 15D12 relay and a closed contact 1 of the 15D13 relay, the conductor 1552 and the contact 3 of the relay actuated, 15C2 The 15C30 is applied

  
  <EMI ID = 596.1>

  
rapid dropout after opening of its circuit by the 15D11 series relay in the event that a request is received for an outgoing operation.

  
5 [deg.]) Operation of the selection electro. In the control connector 1500, the mentioned operation of the selection electro performs the mechanical selection of the row of corresponding stacks,

  
6 [deg.] Operation of the maintenance electro. The operation of any selection electro closes the associated non-normal contacts 1507 to ground the non-normal ON wire, included in the 1560 cable.

  
  <EMI ID = 597.1>

  
with the wire out of normal ON, is extended by the working contact 2 of the relay
15D12 and the NC contact 2 of relay 15D11 up to the main electric wire.

  
  <EMI ID = 598.1>

  
parallel control, in order to close all the stacks in the selected row.

  
6 [deg.] A. Connection of the block controller to the selected primary switch. "As noted, with respect to outgoing operation, columns VI through V8 of control connector 500 operate to connect

  
  <EMI ID = 599.1>

  
availability terry through the respective resistors' 1561., to the body wires of the respective block returns 206, serving the connected primary switch 1300; the V9 and VIO columns connect the electrical wires

  
  <EMI ID = 600.1>

  
from the block to the corresponding wires of the same primary switch.

  
6 [deg.] B. Pilot maintenance operation. ] Relay 15D12 being

  
  <EMI ID = 601.1>

  
At its rest contact 3, relay 15DI3 opens a point in the circuit previously traced for the HM holding electros of the control connector, relative to outgoing operation, and to the contact of

  
  <EMI ID = 602.1>

  
the selection electro actuated, reducing the current, from the operating value to a lower holding value.

  
The main purpose of the 15D13 hold pilot relay is to control the switching of the position of the block connector 1500, at the same time as the change of the block controller 1600 from final operation to outgoing operation, when the outgoing chain enters forward action. that the current final operation is completed. This operation is described in detail below.

  
7 [deg.] Combination. Block controller 1600, cooperating with line controller 1200 of the called line array, now combines a path to the called line. This operation includes testing the block returns 206 going from the connected primary block switch 1300 to the commu- '

  
  <EMI ID = 603.1>

  
outgoing.

  
8 [deg.] Selection of the combined path. After a path has been combined through the block bay and called line bay, the block controller grounds the selector wires necessary to cause mechanical selection of the combined, line and block feeders. As described for outgoing operation, this includes closing a circuit

  
  <EMI ID = 604.1>

  
SMU and SML, ranging from block controller 1600 to control connector 1500.

  
9 [deg.] Closure of the combined path. When the mechanical selection of the feeds, block and lines, has been completed, the block controller 1600 closes circuits, as described, to control the required holding electros, primary and secondary, on the block bay and the switch bay. lines called. This extends the connection of the calling block coupler to the called line.

  
  <EMI ID = 605.1>

  
biné, the block coupler in service 500 opens the final chain to its section
(at contact 5 of relay 509 of coupler 500-L), thus releasing the three relays which were held in operation by this chain, including the relay

  
  <EMI ID = 606.1>

  
preference of sections. The release of this last relay releases the normal final chain, which returns to its normal closed state, and opens the closed wire.

  
  <EMI ID = 607.1>

  
in the control connector. The control connector holding electros are thus released; removing the earth on the pilot wire from main-

  
  <EMI ID = 608.1>

  
Preferably section relays 1550 and block control connector 1500 are thus fully released and are back to normal.

  
We will now describe the overlapping socket of the two chains, outgoing and final, and in particular the operation of the section preference relays 1550 and of the block control connector 1500 in relation to this socket.

  
  <EMI ID = 609.1>

  
at the same time, the 15D11 and 15DI2 series relays are both operating, each in series with a selector switch 1500, corresponding to the chain relay actuated in its associated main chain. With no shafts to turn, the 15D11 and 15DI2 series relays operate before a switch-connector selection electro can turn its relatively heavy shaft. In this case, relay 15D11 <EMI ID = 610.1>

  
However, as described, the final chain which has been taken must wait until the conclusion of the action occurring as a result of the taking of the outgoing chain, before having access to the control connector. When this occurs, operation proceeds as described.

  
2 [deg.] Outgoing channel taken first. If the outgoing channel

  
is taken before the final chain, the 15DI1 relay is already working when

  
  <EMI ID = 611.1>

  
following, the electro selection circuit, partially prepared, remains open

  
  <EMI ID = 612.1>

  
outgoing call. After that, the final operation can proceed as described.

  
3 [deg.] Final chain taken first. When taking the chain

  
  <EMI ID = 613.1>

  
work in section preferably relays, together with 15D12 series relay and 15D13 hold pilot relay, as described. In the

  
  <EMI ID = 614.1>

  
maintenance of the control connector have been released and put back in position under the control of the selection electro corresponding to the chain relay

  
  <EMI ID = 615.1>

  
may be, and most likely is, from a different section of block couplers than that for which switch 1500 was set.

  
3 [deg.] Calls from different sections of block couplers. When the seizing of the outgoing chain occurs, under the assumed conditions, in a section different from that in which the final chain seizure occurred, the consequent operation of the corresponding relay of the outgoing chain 15C11 to 15C20, closes a circuit for the associated selection electro of the control connector, passing through the 15DII series relay, as previously described. Having worked, the serial relay
15DI1 opens on contact 1 the electro selection circuit, previously

  
  <EMI ID = 616.1>

  
which had been established and previously indicated, of the control connector holding electrodes, and at work contact 2, it prepares a new circuit for these electrodes, by the closed contact 2 of the 15D13 holding pilot relay.

  
Like resistor 1553 included in the circuit by the relay
15D13 reduced the current flowing through the selection electro by its value

  
  <EMI ID = 617.1>

  
drops out immediately, and the previously energized selection electro de-energizes quickly and allows the associated selection shaft to quickly return to idle.

  
  <EMI ID = 618.1>

  
this, the maintenance pilot relay 15D13 releases and again connects the maintenance electrodes to the non-normal ON wire by its rest contact 3 and

  
  <EMI ID = 619.1>

  
can operate again, the previously operated selection bar has returned to idle, as mentioned.

  
When the newly excited selector switch operates

  
  <EMI ID = 620.1>

  
of the non-normal conductor ON, which results from it, closes a circuit by the rest contact 3 of the released maintenance pilot relay 15D13 and by the open contact 2 of the 15DII series relay, to activate the appliances again

  
  Newly performed <EMI ID = 621.1>.

  
As soon as the control connector holding electros

  
  <EMI ID = 622.1>

  
rest tact 2 of the pilot holding relay 15D13, released.

  
The section preference relays and the control connector were thus put in a new position to serve the outgoing call in preference to the final call that was in progress. However, this final call

  
  <EMI ID = 623.1>

  
loose.

  
3 [deg.] B. Both calls come from the same section of block couplers. When the existing final call and the newly arriving outgoing call come from the same section of block couplers, the operation is shown.

  
  <EMI ID = 624.1>

  
che pas, being kept at work by the one which was activated, among the outgoing chain relays 15011 to 15C20. Therefore, the non-normal ON wire remains grounded. However, the control connector 1500 holding electros release, as described above, after the 15D11 relay has operated and remain released until the holding pilot relay

  
  <EMI ID = 625.1>

  
ment described.

  
  <EMI ID = 626.1>

  
final operation in progress is just being completed by the block controller at the moment the outgoing chain is taken, the holding ele.
-% of the control connector are kept working by an earth placed on the HM holding electro wire by the block controller 1600. The relay
15DII operates, and relay 15D12 releases, and the position of the holding electros is moved, as described, but the I5D13 holding pilot relay remains on, maintained by the HP contacts which are held closed by the holding electros. In addition, while the block controller normally switches from final operation to output operation after energizing <EMI ID = 627.1>

  
it does not do so when it continues to apply earth to the associated hold-down electrical wire HM of the control connector 1500 during the completion of its final operation.

  
Under assumed conditions, as soon as the block controller has completed its final operation, it switches to outgoing operation and removes the earth from the HM holding electrical wire from the connector.

  
  <EMI ID = 628.1>

  
is applied to the outgoing combination earth wire oTG-MG (through the HP1 conductor and the NC contact 2 of the 15DI3 relay), in order to enable the outgoing call to be served by the block controller.

  
We will now describe the supervision of the main chain.

  
As mentioned previously, the alarm relays

  
  <EMI ID = 629.1>

  
other of the main chains is open, either as a result of a fault in this chain or in response to its socket in the manner previously described, the one which corresponds to these two relays releases and connects the holding pilot wire HP2, normally set to the earth, to the associated alarm wire AL. When

  
  <EMI ID = 630.1>

  
associated main, earth remains on the maintain pilot wire HP2 and therefore on the alarm wire AL, causing the alarm state to be reported. The alarm state is also signaled if one of the

  
  <EMI ID = 631.1>

  
to earth by a normally closed contact of each HP maintenance pilot stack of the control connector.

  
Normally, the maintenance appliances all work and thus remove the earth on the HP2 wire and on the AL alarm wire before the alarm is actually given by these wires.

  
We will now describe the block controller 1600 (fig. 16) and

  
  <EMI ID = 632.1>

  
'In all calls using the block bay and is shown in figs. 2, 3, 5 and 6, the control connector 1500, (fig. 15) is controlled by the associated section preference relays 1550, as described.

  
  <EMI ID = 633.1>

  
block coupler, primary 1300, which serves calls from the block coupler section 500 which is involved at the relevant time.

  
The 1600 block controller is required for all calls through the block bay, including outgoing and final calls; while the outgoing controller 1700 is only used for outgoing calls.

  
We will first describe the general operation of the block controller 1600 and the outgoing controller 1700 which takes place as follows:

  
1 [deg.] Test and combination.

  
1. On all calls, the block controller 1600 tests the block referrals 206 going from the interested primary switch 1300 in the block bay, to the secondary switches 1400 in that bay, and perform a combine operation accordingly.

  
2. On outgoing calls, the outgoing controller 1700 indicates

  
  <EMI ID = 634.1>

  
elements 1600 and 1700 (harness 241, fig. 2), which junctions 2020 are available in the called outgoing trunk, allowing the block controller to combine an available outgoing trunk with an available block forwarding.

  
3. On final calls, the block translator 1800 is used as previously mentioned, but it does not give any information directly to the block controller. Instead, the block translator passes the translated information about the digits, primary, fives, and units, to the bay

  
  <EMI ID = 635.1>

  
in play on this bay, the packet of five lines containing the line called

  
and the unit identity of the called line in the pack of five. The device-

  
  <EMI ID = 636.1>

  
number of lines then works as described to select the primary switch
800 Indicated, the packet of five on this switch and the line called in

  
the pack of five; it identifies the line bay on the block control; and it indicates to the block controller which line feeds of interest 202 are available. After that, the block controller 1600 tests the line called by a temporary test connection made to the body wire of the line called by the line control equipment.

  
4. If the called line gives an available test, the block controller combines an available block return 206 with a dis-

  
  <EMI ID = 637.1>

  
line control equipment, provided on the called line bay,

  
2 [deg.] Operation of the selection appliances.

  
  <EMI ID = 638.1>

  
largely by circuits prepared by the control connector 1500, a primary selection electro and a secondary selection electro on

  
  <EMI ID = 639.1> nant the block return, selected by the combination operation.

  
2. On the final calls, the block controller acts by means of the line control equipment provided on the called line bay, to actuate a primary selection electro and a selection electro.

  
  <EMI ID = 640.1>

  
1. On all calls, the block controller 1600 activates the interested maintenance electros HM, primary and secondary, on the bay of

  
  <EMI ID = 641.1>

  
3. On the final calls, the secondary hold electro (switch 900) of the called line bay is actuated by the call controller.

  
  <EMI ID = 642.1>

  
from the block bay. The primary holding electro (switch 800) of the called line bay is actuated by the block controller through the mentioned temporary test connection to the called line body wire.

  
  <EMI ID = 643.1>

  
were dialed before block controller 1600 and associated common equipment were engaged. Therefore, it makes little difference in a final call that the normal completion time of that call (one second or less) is somewhat extended when a coincidence of exchange requires it. However, with outgoing calls to another exchange, the time to complete

  
  <EMI ID = 644.1>

  
to be dialed continuously, and (2) the pulses of the next digit and all other digits of the called number must be repeated through the outgoing trunk as they are dialed. As a result, any outgoing call is given preference over the final calls, so that it is extended to a free trunk in the outgoing trunk during the usual Digit Interval. For this reason, the section preference relays 1550 (figure 15), the control connector 1500 and the block controller 1600 are arranged so that they interrupt the operations and the course of the operation relating to a final call, immediately. that they have been entered by an outgoing call, unless transactions relating to

  
to the final call are just being completed. This has been described more

  
  <EMI ID = 645.1>

  
For the purposes of uniformity and simplification of circuits, all outgoing calls (whether to an automatic exchange or a manual office),

  
  <EMI ID = 646.1>

  
hence the preference over final calls, as mentioned.

  
We will now describe the groups of functional relays.

  
The relays of the block controller 1600 (figure 16) and the outgoing controller 1700 (figure 17) are divided into separate functional groups, as follows:

  
  <EMI ID = 647.1>

  

  <EMI ID = 648.1>
 

  

  <EMI ID = 649.1>


  
Note: (T) means use in final calls,

  
(0) here means use in outgoing calls.

  
2 [deg.] Functional relay groups of the outgoing controller 1700.

  
  <EMI ID = 650.1>

  
as following :

  

  <EMI ID = 651.1>


  
2.17B12 to 17B20, initial digit relay, respectively controlled by the

  
  <EMI ID = 652.1>

  
We will now describe the operation in outgoing calls.

  
An outgoing call operation includes the operations involved

  
  <EMI ID = 653.1>

  
res 2, 3, 5 and 6, to a free trunk 2020 in the called outgoing trunk, as opposed to final call operation, where the call terminates at a local called line. As mentioned previously, the common equipment elements employed in outgoing call operation are;

  
1. Relays preferably sections 1550 (figure 15);

  
2. The control connector 1500 (figure 15);

  
3. The outgoing controller 1700 (figure 17) and

  
  <EMI ID = 654.1>

  
outgoing call operation.

  
1 [deg.] General. As described above, an outgoing call is made by dialing the initial digit assigned to the desired outgoing trunk; however, only 8 of the 10 possible values of the initial number can be used to designate bundles of junctions. When the initial number 1 is

  
  <EMI ID = 655.1>

  
and one of the other values is used to designate the local block of 1000 line numbers.

  
In the embodiment of the outgoing controller 1700, represented in FIG. 17, the initial cipher 6 is used to designate the block of numbers of the 1000 local lines; the digits 2 to 5 are unused and the original digits 7 to 0 are assigned to respective groups of outgoing trunks. Two of the four outgoing beams can be the ones

  
  <EMI ID = 656.1>

  
presented).

  
2 [deg.] Socket for block controller 1600 and associated common equipment. When the initial digit dialed and stored in any block coupler 500 in the manner described above has any value between 7 and 0, operation of the block coupler at the end of sending this initial digit closes a through circuit. by the associated section of the outgoing chain, which includes 4 relays in series, as follows:

  
1.of the earth, as traced above, through that of the relays

  
  <EMI ID = 657.1>

  
the section in which the calling block coupler is located; by the thread of the associated section OT &-CH-IN;

  
  <EMI ID = 658.1>

  
3. Through the corresponding initial digit relay, 17B17 to 17B20, in the outgoing controller 1700, through the OTG-ST wire and

  
  <EMI ID = 659.1>

  
calling block 500 acts to keep the branch of the associated section of

  
the outgoing chain, from its socket to another block coupler in this section, and connects the taking block coupler to the associated OTG outgoing wires of the block controller, as described;

  
The main outgoing chain relay operation, 15011

  
  <EMI ID = 660.1>

  
aunt from its socket by some other section of block couplers and, acts to position the block control connector, according to the switch

  
  <EMI ID = 661.1>

  
call;

  
The operation of the initial digit relay, 17B17 through 17B20, in the outgoing controller 1700, acts to position the latter (as described below) according to the called group of outgoing trunks and

  
  <EMI ID = 662.1>

  
block controller 1600 starts the block controller to make it perform the series of operations described below, in order to establish a connection with a free trunk in the called outgoing trunk.

  
3 [deg.] Positioning of the outgoing controller 1700. When, for example, the initial digit dialed is 7, relay 17B17 is that of the initial digit relays which is actuated in the outgoing controller 1700, by the initial digit wire ID7 . After that, relay 17B17 works to connect relay 17B26, which closes each of its 14 pairs of contacts, 1 to

  
14. The fourteenth pair of relay contacts 17B26 is used to actuate up to

  
  <EMI ID = 663.1>

  
at will to the 40 outgoing junction clips, which are respectively represented by the columns V17 to V20 of the secondary block switches
1400, as explained above. Each of these columns is represented at its

  
  <EMI ID = 664.1>

  
outgoing controller.

  
The 40 pairs of clips 1701 to 1740 are respectively associated

  
  <EMI ID = 665.1>

  
1741, go from the desired pairs of contacts, 1 to 14, of the connection relay 17B26, respectively to those of the attached pairs 1701 to 1740 which represent the ends of the outgoing junctions of the bundle 7. One of these fasteners can be that of the outgoing junction 2020, figures 2 and 7.

  
After the mentioned operation of the connection relay 17B26,

  
  <EMI ID = 666.1>

  
the corresponding pair of contacts of the connection relay, operated provided that the associated outgoing junction 2020 is free. For example, when the 2020 junction associated with the outgoing junction relay 17D10 is free when the connection relay 17B26 is operating, the relay 17D10 operates on the following circuit: from the battery to the body wire S of the outgoing junction (normally held on this wire through the block coupler to the-

  
  <EMI ID = 667.1>

  
left of the associated holding electro (HM609 of figure 6, HM20 of figure 14), the combination test lead connected MT (MT-227 of figure 6,

  
  <EMI ID = 668.1>

  
Earth. The 17D10 relay operates in the circuit just traced, but the strong resistance of its winding keeps the current flowing through the associated secondary holding electro winding below the operating value.

  
When the aforementioned junction 2020 associated with the outgoing junction relay 17D10 is occupied, the standby battery normally applied to the body wire S of the junction is replaced by a holding earth. Relay 17D10 then remains at rest for lack of operating current.

  
When the associated junction is free, the mentioned operation of relay 17D10 accomplishes two changes in the circuits. The contact

  
2 of this relay disconnects the associated ground input wire G-IN-10 from the

  
  <EMI ID = 669.1>

  
as an indication to the block control equipment that a free junction of the called bundle is served by the tenth secondary switch
1400 block bay. Contact 1 of relay 17D10 disconnects the OP10 control wire from the NC-contact chain circuit, passing through NC contact 1 of successive associated relays, and transfers it to the junction point of the winding of the 17D10 relay and the associated wire TR, in preparation for the control of the associated secondary maintenance electro, if the associated outgoing junction 2020 is the junction included in the path being combined.

  
For each outgoing 2020 junction, free at the time considered,

  
  <EMI ID = 670.1>

  
operation, as described for relay 17D10.

  
4 [deg.] Start of block controller for outgoing operation. In the block controller 1600, the described operation of the outgoing start relay 16A17 (through the OTG-ST wire and contact 3 of the busy relays
16A1Ô and 16A19) closes a circuit for the auxiliary outgoing start relay 16A15. This relay then operates to start the sequence of operations necessary to extend the connection to a free outgoing junction in the called bundle.

  
N / O contact 2 of relay 16A15 disconnects the earth of the circuit of the final start auxiliary relay 16A7 in order to prevent this relay from operating later, or to release it if it is on.

  
The NO contact 4 of relay 16A15 closes a conducting circuit

  
  <EMI ID = 671.1>

  
fert 16A20 via wire 5 of harness 1601, in series with combination complete relay 16E7. At its working contacts 1 and 2, the transfer relay
16A20 prepares the circuits to actuate a primary holding electro and a secondary holding electro on the block bay, and on its contact of <EMI ID = 672.1>

  
section preference relays) to the associated contact strip of the associated choice assignor (relays 16D1 to 16D3 and 16E1 to 16E10).

  
5 [deg.] Positioning of the block feedback test relays. Having been positioned as described above, control connector 1500 conditions the body wires of the 20 block returns 206 (10 pairs) serving the connected primary switch, connecting a resistive battery to each. At the same time it connects the body wires, respectively to the in-

  
  <EMI ID = 673.1>

  
by 20 SL-1 to SU-10 body threads. After that and accordingly, all test relays 16D11 to 16D30 operate on the mentioned resistant battery, provided that the associated return is free. If one of the 20 interested block returns 206 is in use, ground applied to its body wire S short-circuits the corresponding block return test relay.

  
6 [deg.] Outgoing combination. On an outgoing call, there are two conditions for combining a possible path: (1) the block forwarding 206 of the path must be free and (2) the outgoing trunk 2020 taken in this path must be in the called trunk and must be be free.

  
  <EMI ID = 674.1>

  
Upon entering the primary switch serving the connected block coupler, it grounds its OTG-MG wire, as described. With transfer relay
16A20 At work, as described, the combination ground is applied by this relay, through wire 1617, to the associated part of the contacts of the choice assignor (figure 16, part 3). With the assignor of choice in its position 1 which is represented (the 16E1 relay at work and all the other relays of the assignor, at rest), the first choice appears on the first switch.

  
  <EMI ID = 675.1>

  
the endless chain of the NO contacts 3 on the 20 block feedback test relays 16D11 to 16D30. This endless chain is the main part of the outgoing combination chain circuit used for outgoing calls. This chain has 10 branches 1 to 10, normally open, going to the outgoing controller 1700.

  
  <EMI ID = 676.1>

  
G-OUT earth output as well as an MG combination earth wire, associated with the previous ones.

  
The 10 branches mentioned correspond respectively to the 10 secondary switches 1400. As there are two block references 206 which will go

  
  <EMI ID = 677.1>

  
In the outgoing controller 1700, if all 40 relays in Figure 17, part 1 were shown, they would have 10 rows of 4 relays each. Each of these rows, shown vertically in the drawing, relates to one sub-block switch 1400, of the 10 sub-switches, as previously described.

  
  <EMI ID = 678.1>

  
primary switch 1300 to first secondary switch 1400 are free, test relays 16D11 and 16D12 are both actuated. Therefore, the mentioned earth, applied to wire 1 of harness 1602, is disconnected from the next part of the chain and is transferred to earth wire G-IN-1, going to the outgoing controller.

  
In the outgoing controller 1700, if any of the 4 junctions 2020 served by the first secondary block switch 1400 is assigned to called bundle 7, and if it is free, the corresponding relay

  
  <EMI ID = 679.1>

  
crit for relay 17D10.

  
Therefore, the endless combination chain remains interrupted at this point, since it has been transferred to the MG-1 combination ground wire. Earth applied to wire G-IN-1 now reaches wire MG-1 (through make contact 2 of one of the relays 17 Al to 17D1), as an indication that a combination exists, borrowing the first secondary switch 1400.

  
On the other hand, if there is no free junction in the called bundle coming from the first secondary switch'1400, the junction relays

  
  <EMI ID = 680.1>

  
extended by the NO contacts 2 of these relays, to the ground output wire G-OUT-1, which returns to the block controller and enters the main outgoing endless chain at the second point. The chain effect is the same as if none of the 16D11 and 16D12 feedback relays had worked.

  
When a combination does not occur on the first secondary switch, a combination is carried out passing through an outgoing junction 2020 starting from the second secondary switch, if either of the return relays 16D13 and 16D14 is actuated. , and if one or the other of the junction relays 17 A2 to 17B2 of the outgoing controller is actuated. Otherwise the main outgoing chain earth progresses uninterrupted to the parts of the circuits associated with the third block switch and so on up to the loeme,

  
It will be assumed that the combination cannot occur by any of the

  
9 first secondary switches'1400, and that it occurs by the leme secondary switch. In this case, if the junction connected to the column

  
  <EMI ID = 681.1>

  
free, as previously assumed, the combined path includes this junction, because outgoing controller 1700 relay 17D10 stays on in its previously mapped circuit. In this case, if relay 16D29 is actuated,

  
the complete outgoing combination circuit is as follows:

  
starting from the earth on the outgoing combination earth wire OTG-MG arriving at the block controller 1600 said control connector 1500, through contacts 3 of relay 16A20, wire 1617, rest contact 3 of

  
  <EMI ID = 682.1>

  
outgoing controller), to the movable spring '3 of the 16D13 relay associated with the second secondary switch, and likewise, through the part of the outgoing chain associated with the second to the ninth secondary switches, to the movable spring 3 of the 16D29 relay associated with the tenth secondary switch
1400, then by the NO contact 3 of the feedback test relay 16D29, which is actuated, 'the associated ground input wire G-IN-10' going to the outgoing controller 1700, the NO contact 2 of the relay 17D10 , the earth wire

  
  <EMI ID = 683.1>

  
combination pilot lais 16D10, to the battery. Relays 16E29 and 16D10 operate in series in this circuit.

  
7 [deg.] Operation of the selection, primary and secondary electros. At its contact 6, the combination relay 16E29 (which corresponds directly to the block feedback test relay 16D29) prepares a control circuit, which will be traced below, for the associated secondary holding electro.

  
  <EMI ID = 684.1>

  
This selection electro is actuated in series with the secondary selection electro which controls the selection of the same pair of block returns on the secondary switch (the loeme), to which the pair of returns goes.

  
  <EMI ID = 685.1>

  
The main selection three involved mechanically selects the pair of referrals including the one that has been combined.

  
Since the 16E29 combination relay is the first relay of the pair, it represents the upper block return of the combined pair. To its contact 2, relay 16E29 connects the SMU-10 conductor (representing

  
  <EMI ID = 686.1>

  
through contact 3 of the 16E7 combination completion relay, which is on, to the SMU conductor going from the block controller to the control connector 500. The SMU conductor is connected to earth through the SMU selector electro of the switch. primary switch connected 1300, while the SMU-10 conductor goes to the battery through the SMU selector electro of the tenth secondary switch. Consequently, these two extension selection electros are actuated in series and select the upper transmission 206 of the selected pair.

  
  <EMI ID = 687.1>

  
connected block 1300, the operation of the mentioned main selection electro SM and of the extension selection electro SMU closes the non-normal contacts, connected in series, 1307 and 1307 'in order to extend the non-normal earth, by the associated PON wire to the secondary switches 1400.

  
  <EMI ID = 688.1>

  
has occurred), the operation of the mentioned main selection electro SM and of the extension selection electro SMU closes the out-of-normal contacts 1407 and 1407 '', connected in series, - 'in order to extend the potential off-normal earth, which was mentioned, to the secondary SON out-of-normal conductor, going from the secondary switches to the block controller.

  
9 [deg.] Operation of the maintenance, primary and secondary electros. The application of an earth to the non-normal secondary SON wire entering the block controller 1600 closes two circuits in parallel by the respective working contacts of the relay transfer 16A20, which is at work. A

  
  <EMI ID = 689.1>

  
tion outgoing OTG-SW, to go to the interested primary holding electro, such as HMZ-602 (figure 6), through the connected block coupler, such as 500-L (figure 5). The other circuit is as follows: from earth, through a working contact 2 of transfer relay 16A20, wire 6 of harness 1601, working contact 6 of combination relay at work 16E29, OP-10 command going to the outgoing controller 1700, and through the make contact 1 of the outgoing junctions actuated relay 17B10, at the junction point of the winding of this relay with the associated wire TR.

   The earth brought to this point short-circuits the winding of relay 17D10, thus increasing the test current which previously passed through the winding of the associated secondary holding electro HM20 of the tenth secondary switch 1400, up to to the operating value. Although in short circuit,

  
the 17D10 relay, which is slow to release, remains on for a sufficient time for the intended purpose.

  
The operation of the secondary maintenance electro mentioned

  
results in the connection of the tip, neck and body conductors of the combined outgoing junction, respectively to the same name wires of the secondary end of the combined block return, which has been mechanically selected by the described operation of the appliances. secondary selection.

  
At the same time, the mentioned operation (on the outgoing switching wire OTG-SW) of the primary holding electro \ associated with the coupler

  
block connected, connect the outgoing tip, neck and body wires of the block coupler, respectively to the same name wires from the primary end of the same block return, completing their extension to the same name the combined outgoing trunk 2020.

  
10 [deg.] Metal connection. The primary holding solenoid pilot contacts actuate the metal connection relay
501 of the connected block coupler, by metallically connecting its incoming tip, neck, and body wires to the corresponding outgoing wires and disconnecting the bridge from the line relay, as previously described. This momentarily extends the holding earth forward, through the block coupler body wire to hold the main and secondary holding electros of the block bay in the established connection.

   The metal connection operation performed by the block coupler takes the outgoing junction 2020 and the associated junction coupler by having a holding earth placed by the junction coupler on the body wire of the extended connection, as previously described, before that it is deleted in the block coupler.

  
11 [deg.] Release. The mentioned operation of the metal connection relay 501 of the connected block coupler opens on this relay the outgoing chain circuit, releasing the following four relays, previously held to work, in this circuit:

  
1. the outgoing chain relay 511, in the interested block coupler 500;

  
2. the outgoing chain relay (15C11 to 15C20) which is at work in the relays preferably of sections 1550;

  
3.the initial digit relay 17B17 which is at work in the outgoing controller 1700 and

  
  <EMI ID = 690.1>

  
1600.

  
Releasing the outgoing chain relay in the block coupler detaches the block coupler from the common switchgear, as described.

  
The section preference relays 1550 and the associated control connector 1500 release, as described, in response to the mentioned release of the outgoing string relay in these relays, opening the circuit to release the selection, primary and secondary electros, previously working on the block bay, and disconnecting and releasing the block return test relays 16D11 through 16D13 from the block controller.

  
Releasing the initial digit relay 17B17 in the outgoing controller will drop to the associated connection relay 17B26, in return.

  
  <EMI ID = 691.1>

  
actuated by the contacts of the connection relay.

  
In the block controller 1600, the release of the reset relay

  
  <EMI ID = 692.1>

  
outgoing 16Al5, to return the block controller to its normal state shown. This involves opening the circuit and releasing the

  
  <EMI ID = 693.1>

  
7). The combination relay which is at work (such as 16E29) is thus released,

  
  <EMI ID = 694.1>

  
calls passing through the block bay are serviced by the block controller and associated common equipment on a 1-at-a-time basis, if the progress of outgoing call operations in the block controller is suspended or substantially delayed, the block controller must be released quickly to make it available to serve other outgoing calls. The

  
  <EMI ID = 695.1>

  
the block controller, are used successively to set a time limit for the progress of outgoing call operations. Relay 16A18 limits the time allowed between taking the block controller in an outgoing call and completing it.

  
  <EMI ID = 696.1>

  
outgoing combination and metal connection. Each of the occupancy relays 16A18 and 16A19 is slow to operate due to a relatively high inductance winding and relatively hard adjustment of the return spring.

  
12 [deg.] A. Occupation of all outgoing paths. When the relays

  
  <EMI ID = 697.1>

  
auxiliary cable 16A15 extends the earth, through contacts 2 of relay 16A7, to wire 1 of harness 1601, by earthing wire 2 of this group

  
  <EMI ID = 698.1>

  
applied to this wire completes a circuit for the first occupancy relay
16A18.

  
If all possible combination paths going to the junctions of the called bundle are occupied, the combination does not occur. As a result, the combination pilot relay 16D10 remains idle until the end of the busy relay 16A18 delay. At this time, this relay operates.

  
At its advanced NO contact 1, relay 16A18 grounds the outgoing OTG-BU busy wire, thereby actuating the 510 busy relay (figure 5) in the connected block coupler 500, to return a outgoing busy tone and to initiate the common equipment release operation as described.

  
On contact '2, relay 16A18 locks to earth on conductor 1 of harness 1601, and on contact 3, it disconnects the outgoing start relay 16A17 to cause the release operation of the common equipment, independently of the operations mentioned in the connected block coupler. The relay 16A18 is released by the opening of the make contact 2 of the auxiliary starting relay 16A15 in the normal course of the release operation, of the block controller.

  
The described operation of the occupancy relay 16A18 occurs in response to a delay occurring for some reason in the combining operation, such as a circuit fault in the outgoing controller 1700, in the relays preferably of. sections 1550, in the control connector 1500 or in the block controller 1600.

  
12 [deg.] B. Advancement time after combination. When the pi- relay

  
  <EMI ID = 699.1>

  
from the combine operation, it disconnects the control earth from the first occupancy relay 16A18 and transfers it to wire 3 of harness 1601, connected to the second occupancy relay 16A19. The phase before combination of the advancement delay is thus terminated, and the phase after combination has begun.

  
If the block controller did not take the combined path, or if for some reason it did not become free, by the time the post-combination delay has elapsed, the second forward delay relay

  
  <EMI ID = 700.1>

  
have been described for relay 16A18, causing the transmission of a busy signal on the calling line and determining the return to common availability of the common equipment.

  
13 [deg.] Unused trunk group calls. Sending by the dial an unused initial digit (one of the initial digits 2, 3, 4

  
or 5 when the outgoing controller 1700 is equipped as shown in the figure

  
17), is called a call to an unused trunk group. For example, when sending the initial digits 2, the initial digit relay 17B12 is actuated by the associated initial digit wire ID2 and the OTG-ST wire, as described for relay 17D17. However, the 17B12 relay does not have a connection relay (such as 17B26) associated with it, so its operation has no effect. Consequently, none of the outgoing junction relays 17 A1 to 17B10 is actuated. Block controller 1600 is therefore unable to close a combination circuit for any combination relay, 16E1 to 16E30. Therefore, the block controller treats the call as if all the junctions of the called trunk group are busy.

   The occupancy relay
16A18 operates as has been described with respect to outgoing call advancement delay, so as to cause an outgoing busy tone to be returned by the connected block coupler 500, and to begin release of the common apparatus.

  
We will now describe the operation in final calls. (calls on arrival).

  
As previously mentioned, final call operation includes the operations involved in routing a final connection through the block bay, through a free final trunk 207 and through the called trunk bay, to the called line. , by difference with the operation in outgoing calls, where the call ends on a free trunk of the called outgoing trunk group. The elements of the common switchgear which are used on the block bay in a final call operation are:

  
1. the section 1550 preferably relays (figure 5);

  
2. the control connector 1500 (figure 15);

  
3.the block translator 1800 (figure 18) and

  
4. the 1600 block controller (figure 16).

  
The outgoing controller 1700 (Figure 17) is not used in final call operation.

  
1 [deg.] General. As described so far, a final call is made by sending on the dial the initial number assigned to the local block of
1000 line numbers, followed by the sending of the digits of hundreds, tens, units and extensions, dialing the number. While any desired initial digit from 2 to 0 can be used to denote the local block of 1000 line numbers, the initial digit 6 is used in the outgoing controller 1700, as shown in Figure 17, to denote the local block. . Therefore, the 17B16 relay associated with the ID6 initial digit wire is disconnected from the outgoing OTG-ST starter wire in order to make the dial sending the local initial digit 6, ineffective in any block coupler.
500 to engage the common switchgear.

  
  <EMI ID = 701.1>

  
End of sending the station digit closes a circuit passing through the associated section of the final chain, which includes three relays in series, as follows:

  
1.from the earth as drawn above, by one of the relays of the main final chain, 15C21 to 15C30 (figure 15), the one corresponding to the section in which the calling block coupler is located, by the one

  
  <EMI ID = 702.1>

  
2.thence, as traced, through the final chain relay 512
(figure 5) in the calling block coupler and

  
  <EMI ID = 703.1>

  
block controller relay 16A13 contacts 2 and through the final start relay 16A6.

  
The operation of the final chain relay 512 in the calling block coupler acts, as described, to keep the branch of the associated section of the final chain from being taken by another block coupler, and connects the calling block coupler to them. "end" wires of the block controller, simultaneously grounding the wires of the selected digits, hundreds, tens, ones and positions which are multiplied between the block couplers and which go to the block translator.

  
The operation of the main final chain relay in the section preference relays keeps the main final chain (15C21 to
15C30) from its socket by another block coupler section and acts as described to position block control connector 1500 according to primary block switch 1300 which serves the block coupler section in which the call was made. issued.

  
The operation of the final start relay 16A6 in the block controller 1600 starts, in the block controller, the sequence of operations described below leading to the extension of the connection to the called line.

  
3 [deg.] Start of the cycle timer. Having operated, the final start relay 16A6 of the block controller actuates the auxiliary final start relay 16A7 through the normally-open contact 2 of the relay 16A15. Relay
16A7 adapts the block controller to the operation of final calls by opening certain points of the circuits and by preparing certain circuits which will be closed later. It also starts the operation of the cycle timer
(relay 16A8 to 16A11), by extending the earth, by its contact 4 and by contact 3, normally closed, of relay 16 AU, towards the relay winding
16A8. Relays 16A8 to 16A11 now operate in fast cascades, each of relays 16A8 to 16A10 actuating the next relay.

   When relay 16A11 operates, its contact 3 blocks its own winding and those of relays 16A8 to 16A10, directly to earth on contact 4 of the relay
16A7, by opening the initial control circuit of these relays to prepare the release of relays 16A8 to 16A10 in a delayed cascade.

  
Contact 2 of relay 16A11 applies a short-circuit earth potential to the junction point of the winding of relay 16A8 and the associated resistor that supplies it with battery, causing this relay to drop out after a predetermined interval, followed by successive release of relays 16A9, 16A9 'and 16A10 at the end of similar intervals.

  
Note that the cycle timer, of the block controller
(relays 16A8 to 16A11) is similar in purpose and operation to

  
  <EMI ID = 704.1>

  
described above.

  
Normally, the block controller completes its final call operations and becomes free before the cycle timer has completed.

  
4 [deg.] Positioning of the block feedback test relays. The control connector 1500 closes, as described previously, circuits of

  
  <EMI ID = 705.1>

  
block, 16D11 to 16D30 respectively. Each of these relays then operates on the condition that the corresponding block return is free in the
20 which serves the connected primary switch.

  
The block controller waits for (now the final bay information, which is received indirectly from the block translator 1800.

  
5 [deg.] Translation of the requested number. In response to the mentioned earthing (by the connected block coupler) of the digital wires corresponding to the hundreds, tens and units sent, the block translator 1800 determines, from these sent digits, which of the 4 bays of 250 lines A, B, G or D, serves the called line, and transmits the translated information of the digits to that bay, indicating the primary switch 800 which serves the called line, the interested five-line packet on that switch and the unit identifying the line called in the pack of five.

  
6 [deg.] Positioning of line control devices. The line testers (the line controller 1200 and the two associated control connectors 1000 and 1100) respond, in the manner described to the information translated from the digits, by grounding their associated wire.

  
end bay TF (one of the TFA to TFD threads of the block controller 1600, shown in Figure 16, part 5); they select the called line and the primary switch which serves it, and for each free line forwarding serving the selected primary switch, 'they connect a battery, by the corresponding selection electro wire, to the corresponding wire of the ten forwarding wires LK. These are the wires LK1 to LK10 provided for each bay A to D, as they appear on the block controller, figure 16, part 6.

  
Incidentally to their aforementioned operations, the called line bay line testers connect the called line's CLS body wire (going from that line to the block controller) to the called line's body conductor and ground. the associated test start wire, TS, serving as a signal to the block controller, that the called line test can begin.

  
7 [deg.] Positioning of the block controller according to the line bay called. The mentioned earthing of the TF end bay wire by line testers positions the block controller 1600 according to the line bay that the called line terminates at. For example, if

  
  <EMI ID = 706.1>

  
bay A, in the final junctions engagement group, in parallel with relay 16C3 in the line feeders engagement group. Relay 16B11 connects respectively the output wires 1621 to 1624 of the engagement allocator (figure '16, part 4) to the engagement relays of final junctions 16B12 to 16B15, which correspond to the four bundles of

  
  <EMI ID = 707.1>

  
on, and also connects the wires from bay A, namely, TSA, CLSA and ONA, to the corresponding wires TS, CLS and ON of the block controller. The 16C3 relay

  
  <EMI ID = 708.1>

  
A, to the ten corresponding local wires 1630 of the block controller, which go to engage relays 1607 to 16C10, which operate in succession.

  
  <EMI ID = 709.1>

  
lines in line bay A (assumed to be called) connect the associated trunk wire called CLSA to the body wire of the called line, as previously described, and ground the associated start wire of TSA test, it closes a circuit going from earth to the TSA wire, through the 16B11 relay contacts to work, the TS wire of the controller

  
  <EMI ID = 710.1>

  
to the battery through the lower winding of the occupancy relay 16A3, in the line test group, of the block controller. Operation

  
of relay 16A3 is slowed down due to the relatively hard adjustment of its return springs and the short-circuit applied to its upper winding (armature side) by its rest contact 3 to produce a delay effect.

  
  <EMI ID = 711.1>

  
peeled, but the resistance of the 16A1 relay winding is high enough that the holding electro does not work in series with it. Relay
16A1 then activates the availability relay 16A2 before the delayed occupancy relay 16A3 has time to operate. The availability relay

  
  <EMI ID = 712.1>

  
on the TS wire, earthed, to its working contact 4.

  
9 [deg.] Combination start. The contact 5 of the availability relay 16A2 activates the combination start relay 16A5 by the open contact 5 of the relay 16A7 and the closed contact 5 of the relay 16A3. Relay 16A5 starts the combination operation by earthing at its contact 2 the combination starter wire 1610 and at its contact 3, the spawned combination wire 1611, by the normally closed contact 15 of the auxiliary starting relay outgoing 16A15. Ground applied to wire 1611 goes through contact 3 of the combination pilot relay 16D10 to the spawning combination relay 16D9, which operates to prepare the combination.

  
Earth applied to 1610 combination start wire starts

  
  <EMI ID = 713.1>

  
step-by-step advancement, during the combination, of the associated commitment allocator, if this advancement is necessary.

  
10 [deg.] First engagement of the final junctions. The commitment allocator (relays 16B2 to 16B6) is a 4-position counting chain, arranged so that at any time, one or the other of the counting relays 16B3 to 16B6 is at the working condition. When the commit assignor is in its first position, which is shown (relay 16B3 on and all of its other relays off), earth, applied to combination start wire 1610, reaches the first commit wire. 1621 by the NO contact 2 of the guide relay 16B2 and the NO contact 3 of the activated counter relay 16B3. Earth applied to the 1621 Commit wire now actuates the first 16B7 Commit Totalizer Relay, which locks on the 1610 Combination Starter Wire.

   Ground applied to feeder wire 1621 also actuates feeder engagement relay 16C7 to connect the local wires from feeders 1630, to the wires included in bundles 1605 and 1606, in a manner specifically corresponding to the first group. commitment of the final junctions.

  
The earth applied to the first engagement wire 1621 still closes a circuit passing through a working contact of the actuated relay, bay A, 16B11, for the first engagement relay 16B12 of the final junctions, associated with the called line bay. A. Relay 16B12 connects the wires from

  
  <EMI ID = 714.1>

  
commitment on the line bay A, respectively to the ten test relays 16G11 to 16C29 of the final junctions, with odd numbers. Each of these 16C11 to 16C29 relays will now operate provided that the final connected junction is free, in which case it has battery potential available.

  
  <EMI ID = 715.1>

  
nation HT-226 of Figure 6, the MT combination test lead of a final junction 207 is an extension of the body conductor S of this junction, and the battery potential which is normally applied to it through the two electros of maintaining associated secondary, such as 610 on the block bay and 707 on the line bay (Figures 6 and 7). However, when a final junction 207 is occupied, the holding earth applied to its body wire and to the MV wire connected to it prevents the interested, grounded test relay, 16C11 to 16C29, from operating on that wire. .

  
It will be remembered that the final junctions of any engagement bundle include ten junctions coming from the respective secondary sections provided on the called line array.

  
As will be described more fully below, the combine operation can occur now in order to select a path through any of the final junctions of line bay A commit harness 1, provided ( 1) that this final junction 207 be free

  
  <EMI ID = 716.1>

  
be reached is free, and (3) that the line forwarding by which the final junction must be extended to the called line is free. As will be described, when the combination occurs, the combination completion relay 16E7 is actuated to open the control circuit of the engagement impeller relay 16C2, to temporarily prevent the assignor. of commitments to advance to the following commitment of final junctions.

  
11 [deg.] Following commitments. If no combination occurs on the first engagement of the final junctions, the combination complete relay
16E7 fails to function, allowing the impeller to engage (figure
16, part 4) to advance the commitment allocator by activating the next ten counter relays 16B4 and releasing the relay previously working, namely relay 16B3. This results in transferring the earth from the first engagement wire 1621 to the second engagement wire 1622. The actuated engagement relay pair, 16C7 and 16B12 are thus released, and the next pair, 16C8 and 16B13 operate. The following relay (16B8) of the engagement totalizer is now operating and is blocked. Test leads

  
  <EMI ID = 717.1> nales 207 of bay A, are thus substituted for the combination test leads.

  
  <EMI ID = 718.1>

  
If no combination occurs in the second engagement of the final junctions, the engagement impeller advances the engagement allocator again, releasing the actuated engagement relay pair 16B13 and 1608 'and operating , by wire 1623, the next pair (16B14 and 16C9), at the same time that the third totalizer relay 16B9 operates and is blocked.

  
If no combination occurs in the third engagement of the final junctions, the third pair of engagement relays (16B14 and
16C9) falls and the fourth pair (16B15 and 16C10) is actuated by the

  
wire 1624 to engage the fourth and last final trunk in line bay A for testing, and the fourth commit totalizer relay 16B10 operates and locks out.

  
11 [deg.] A. Occupation of all final roads. If no combination occurs in the fourth engagement of the final junctions, the following operation of the engagement impeller relay 16C2 closes a series circuit, via contacts 1 of the engagement totalizer relays 16B7

  
  <EMI ID = 719.1>

  
TER-BU, which sends back, by the connected block coupler 500, a busy tone to the calling line and which releases the common equipment at the same time = it activates the release relay 16A13, with the above results described s.

  
12 [deg.] Final combination. The essential preparations for the final combination can be briefly summarized as follows:

  
1. The 16D11 to 16D30 block feedback test relays are connected to the S body wires of the 206 block returns serving the connected primary switch, respectively, so any 16D11 to 16D30 relays are now on as long as the feedback corresponding block is free.

  
2. In any engagement of final junctions, the test leads of

  
  <EMI ID = 720.1>

  
16B11 to 16B15, are extended respectively to the windings, connected to earth, of the final junction test relays, 16011 to 16C29. Each of these relays operates as described provided that the corresponding final junction 207 of the group engaged is free.

  
  <EMI ID = 721.1>

  
are associated respectively with line forwardings serving the primary switch 800 to which the called line is connected. For each of these referrals which is free, an availability battery potential is applied to the corresponding LK wire starting from the corresponding selection electro wire on the line bay.

  
Consider for example, the described commitment "1" of the final junctions (relays 1603 and 16C7): (1) if the two block referrals 206 are released in the first pair serving the connected primary switch
1300, the block feedback test relays 16D11 and 16D12 are actuated;

  
(2) if the first final junction 207 of the first engagement beam is

  
  <EMI ID = 722.1>

  
the first line feeder serving the connected primary switch 800 is free, there is a battery on the LKl feeder wire of bay A. If the three previous conditions are met, the first of the ten possible pairs of combination circuits is closed as following :

  
from the battery to the LKl lead wire of the bay A group
(figure 16, part 6), through the open contacts of bay relay A 16C3, the local feeder wire 1630-1, the open contacts of the relay <EMI ID = 723.1>

  
wire 1631-le the working contact 1 of relay 16D9, and from there through parallel branches by working contacts 2 of relays 16D11 and 16D12 to earth through the test windings, with high resistance, 'of the first pair of 16E11 and 16E12 combination relays. Therefore, combination relays 16E11 and 16E12 both work.

  
  <EMI ID = 724.1>

  
being in its first position, which is shown, the blocking earth is applied, by the contacts 1 of the relays 16A7 and 16A15, the wire 1614, the

  
  <EMI ID = 725.1>

  
on wire 1 in the blocking harness preferably 1603 entering the blocking chain of contacts 5 of combination relays 16E11 to 16E30. Therefore, relay 16E11 has a blocking preference over all other combination relays. Having operated, relay 16E11 closes a blocking circuit going from the earth applied to wire 1 of harness 1603 by its working contact 5 through its upper winding to the battery through the winding of the 16D10 combination pilot relay, disconnecting at the same time the blocking earth of the blocking armatures of all the following combination relays. Therefore, the second 16E12 combination relay cannot block on work, nor can any next relay in the combination chain.

  
The 16D10 combination pilot relay works in series with the 16E11 combination relay. Its contact 3 cuts the spawning combination relay 16D9 circuit and causes it to drop. The ten 1631 combination wires running from the make contacts of the 16C11 end-junction test relays to
16C29, at contacts 2 of the block feedback test relays 16D11 to 16D29 are thus \ cut by opening the circuit of the connected test windings

  
to earth, of all combination relays 16E11 to * 16E30. Relay 16E11 remains on work on its mentioned blocking circuit, but all other combination relays that have been actuated drop out immediately, not having been able to block on work since the assignor of choice is in its first position and that the NC contact 5 of the relay
16E11 is open.

  
The final combination operation is now complete. The blocked state of Combination Relay 16E11 (with all other Combination Relays dropped) identifies the combined path as passing through the first (upper) block return 206 of the first pair serving the connected primary block switch, and then through the first final junction of the commitment bundle connected at the time in question (the first), and by the first of the ten line forwardings serving the primary switch concerned 800 on the line bay called A.

  
Contact 11 of spawn combination relay 16D9 extends earth to conductor 1609 through contact 2 of relay 16D10 to close a control circuit for combination complete relay 16E7.

  
Normally closed contact 4 of this last relay cuts the earth of the wire
1612 to stop the operation of the engagement impeller by depriving the third relay 16C2 of the control earth, thus signaling that the final junctions engaged at the moment considered include those by which a path could be combined. The engagement equipment is thus prevented from advancing to the next engagement position of the final junctions.

  
13 [deg.] Operation of electro-selection, primary and secondary. At its working contacts 1, 3 and 4, the combination relay completed
16E7 closes three prepared selector circuits, two on the block bay and one on the called line bay, in order to select the block and line returns, which have been combined.

  
The selection of the first pair of block references (containing the one that has been combined) is accomplished by contacts 1 of relays 16E7

  
and 16E11, which ground the first SM1 select electro main wire running from the block controller to the 1500 control connector. The top wire selection of the pair, which has been combined, has been accomplished.

  
  <EMI ID = 726.1>

  
secondary 1400 block bay. The selection electros, primary and secondary, associated with the block return in the combined path, are thus controlled to select the combined block return in the manner described for outgoing operations.

  
The selection of combined line forwarding occurs in response to the extension to earth through the make contact 4 of relays 16E7 and 16E11, the associated wire 1 of harness 1606, and the make contact 1 of the re-

  
  <EMI ID = 727.1>

  
linked to the line forwarding selected in the combined path, are controlled in series on this wire to perform the mechanical selection of this forwarding.

  
  <EMI ID = 728.1>

  
to select the combined block return, they make the described serial earth connection, across the block bay, to the secondary out-of-normal SON wire (figure 16, part 5) entering the block controller. This extends the earth, through the normally open contacts 3 of the outgoing auxiliary starting relay 16A15 and through the open contact 3 of the auxiliary final starting relay 16A7, to the terminal of the upper winding of the control relay 16A14.

  
15 [deg.] Non-normal line forwarding battery. When the selection appliances, primary and secondary, have been ordered on the line bay called A to select the combined line feed, they extend the described battery connection in series through the line bay and through the switchgear. line control, up to the out-of-normal ONA wire of bay A (figure 16, part 5), thus extending the battery by a working contact of bay A relay 16B11, to the local ON wire of the controller

  
block, and from there, via NC contact 1 of the reset relay
16A12, to the terminal of the lower winding of the control relay
16A14.

  
16 [deg.] Operation of the maintenance electros. An earth potential having been applied to the upper winding of the 16A14 control relay, and

  
  <EMI ID = 729.1>

  
now to close three control circuits for each holding electro, as follows:

  
1.Contact 1 of relay 16A14 earths the final switch wire TER-SW to control the primary block hold electro (such as 602), associated with the connected block coupler 500, passing through the circuit previously trace;

  
2. its contact 5 earths wire 4 of harness 1601, extending the earth, through work contact 3 of relay 16E11, wire 1 of harness 1604 and contact 1 of relays 16E11 and 16E12, up to the wire test

  
  <EMI ID = 730.1>

  
associated secondary maintenance tro on the block bay and, in parallel, that of the line bay, as shown in Figures 6 and 7 for the

  
  <EMI ID = 731.1>

  
3. its contact 7 earths the main line wire called CLS to close a circuit passing through a working contact of the

  
  <EMI ID = 732.1>

  
cie to the called line (such as 703, figure 7).

  
The 4 maintenance appliances mentioned work to extend the connection to the line called by the combined unit forwarding, the combined final junction and the combined line forwarding, as previously described.

  
17 [deg.] Release. The release of the block controller 1600 and the associated common apparatus is caused from two points. First the connection relay 509 of the connected block coupler 500, having been actuated, as previously described (by the HP holding pilot contacts of the connected primary block switch 1300), opens the associated section of the final chain. Then, the release relay 16A13 of the block controller is actuated by the contact 6 of the relay 16A14. The release relay is set to be relatively slow to operate, to allow time to operate for the mentioned holding electros.

  
When the release relay 16A13 operates, its contact 2 opens the final start wire TER-ST. The final closed chain circuit, through which the common switchgear had been taken, is thus open at two independent points to ensure its release. The three relays mentioned
(one of which in the sections 1550 preferably relays, one in the connected block coupler 500 and one in the block controller 1600), which were previously kept working in the final chain, release after that.

  
In the connected block coupler 500, the mentioned release of the final chain relay disconnects the block coupler from the various "end" wires going to the block controller, and it releases the block translator.
1800 by removing the earth from the previously marked digital wires. In response, the line control devices release on the line bay called A.

  
The section preference relays 1550 release as described in response to the release of their final chain main relay, allowing the block control connector 1500 to release.

  
In the block controller, the final start relay 16A6 responds to the mentioned opening of the final chain by opening the circuit of the associated auxiliary relay 16A7 and dropping it. Relay 16A7 opens

  
  <EMI ID = 733.1>

  
and its contact 1 removes ground from wire 1614 of the assignor of choice, releasing and releasing the blocked combination relay 16E11 and the combination pilot relay 16D10, followed by releasing the combination complete relay 16E7. Combination start relay contact 2 16A5 removes the initial connection to ground, of the combination starter wire 1610, but the earth which is held by relay 16B1 until the engagement impeller has completed its operation. duty cycle, which had stopped by the operation of the combination completion relay 16E7.

  
  <EMI ID = 734.1>

  
line test group relay, when the line control device of the called line bay becomes free as mentioned.

  
The reset relay 16A12 is actuated by the relay
16A13 to open the circuit of relay 16A14 and release it, allowing relays 16A14, 16A13 and 16A12 to cascade again.

  
17 [deg.] A. Intermediate advancement of the assignor of commitments. The block controller 1600 is now released and returned to its normal state shown, except for the relays which are kept working by

  
the earth which remains applied to the combination start wire 1610 by contact 2 of relay 16B1 of the engagement impeller.

  
When the combination complete relay 16E7 drops out, as in

  
  <EMI ID = 735.1>

  
1601 and 16C2 fall successively. The operation of the engagement impeller ends at this time, since relay 16B1 removes the blocking earth of the combination starter wire 1610. The operation and de-energization of relay 16C2 advances the assignor d. 'associated commitments. The bundle of engagements following final junctions is thus advanced to the first engagement position for the next operation in final call.

  
The operation of the devices shown in part 4 of the <EMI ID = 736.1> Block Controller Commitment Lizer) is not described in detail, as these elements work as described for the corresponding equipment in Figure 12, Part 5, Line Controller 1200, previously described. The only difference in the circuit is that each of the engagement totalizer relays 16B7 through 16B10 has a second blocking coil that allows them to be actuated directly from the engagement wires 1621 through 1627, instead of requiring a group. -separate contacts in the attri-

  
  <EMI ID = 737.1>

  
does not work, being shorted to the holding earth applied to the individual S body wire at the called line. Under these conditions, the availability relay 16A2 has not yet functioned when the slowly operating occupancy relay 16A3 operates after the time for which it is set. A moment later, the slow test cutout relay
16A4 is working. Its work contact 1 earths the occupancy wire

  
  <EMI ID = 738.1>

  
occupancy 510 in the connected block coupler 500, and the release relay 16A13 is actuated in parallel with this relay. A busy signal is thus returned to the calling line, while the common equipment is released as described.

  
19) Call back. As previously described, the return calls are served, by means of the block couplers 500 and the block controller 1600, when the subscription number of an extension connected to the same line as the extension is dialed on the dial. appellant. The "called" line, also being the calling line, is always busy during the test when a return call is made. Therefore, each time the busy relay 16A3 operates, the block controller 1600 must perform a call back test before it can treat the called line as a normally busy line, as described above.

  
When the occupancy relay 16A3 operates as described, its break contact 3 opens its upper winding in a short-circuit, to make it fast to drop out, and its work contact 4 closes a circuit.

  
  <EMI ID = 739.1>

  
as shown for relay 16A3, to provide the required time interval for the call back test.

  
During the time that passes between the operation of the occupancy relay 16A3 and that of the test cut-off relay 16A4, the direct earth is removed, at the NO contact 2 of the relay 16A3, from the associated SG body earth wire, not leaving on this wire only a ground applied through the associated resistor 1613. As previously described, the SG wire is an extension of the incoming body wire S of the connected block coupler 500. Therefore, the sustaining ground is provided by this wire. conductor to the maintenance electros of the line switches, primary and secondary, of the calling line bay, through resistor 1613. If the calling line is the same as

  
  <EMI ID = 740.1>

  
the calling line and is therefore actuated in parallel with resistor 1613. It then actuates the availability relay 16A2. The operation of this relay, after the operation of relay 16A3, signals a return call instead of a call to a called line normally busy. The RG callback wire and the final TER-SW lead wire are each grounded (through NO contacts 2 and 1 respectively, relays <EMI ID = 741.1>

  
to operate at the. way of a call ringing switch, as previously described. The block coupler 500 then causes the operation

  
  <EMI ID = 742.1>

  
operation of the block controller and associated devices during final call operation, is timed by the cycle timer, comprising the

  
  <EMI ID = 743.1>

  
cycle has gone to the end.

  
When the release operation occurs before the cycle timer expires, releasing relay l6A7 opens the circuit.

  
  <EMI ID = 744.1>

  
days at work. Thereupon, all cycle timer relays drop out quickly.

  
This cycle timer operates in detail in the manner fully described for that of the line controller 1200 (relays 12

  
  <EMI ID = 745.1>

  
are preferably set for a longer cycle to allow the block controller to wait until the line controller concerned has completed an initial operation which could be engaged

  
If a fault in the circuits in the block controller or associated common devices, or in the devices of the line controller concerned, suspends the normal progress of the operations of a final call, the cycle timer of the block controller arrives at the front end. that the block controller is released. Under these conditions, the cycle timer of the

  
  <EMI ID = 746.1>

  
are thus actuated to thereby start the described release of the block controller and associated common equipment by opening the final start wire TER-ST.

  
  <EMI ID = 747.1>

  
works as described for the commit assignor of a line controller 1200. In its four positions, this assignor connects the combination starter wire 1610 to four commit wires 1621 to 1624.

  
The. overall result of the operation of the commitment allocator of figure 16, part 4. tel. that it is controlled by the engagement impeller

  
  <EMI ID = 748.1>

  
finalions one after the other, until a combination has occurred, or until, all four have been engaged without any combination having occurred, and (2) considering the four end junction engagement beams 207 going to each row bay as arranged in a continuous chain, or in a circle, the first engagement bundle engaged during block controller operation is the engagement beam

  
  <EMI ID = 749.1>

  
specialized metering system that can successively take the allocation positions

  
  <EMI ID = 750.1> <EMI ID = 751.1>

  
at 12C13 (figure 12). Its purpose is to successively shift the first choice among the 10 secondary switches 1400 of the. block bay.

  
  <EMI ID = 752.1>

  
describes me at the start of each final call operation and is released. when the block controller then becomes free.

  
  <EMI ID = 753.1>

  
The choice assignor of Figure 12, the OTG-MG outgoing combination ground wire is successively applied to the ten choice wires of harness 1602, going to the ten entry points of the outgoing combination string passing.

  
  <EMI ID = 754.1>

  
thus shifting the first choice into outgoing calls, gradually from the first to the tenth secondary block switch 1400, which these ten pairs of relays represent respectively.

  
In addition, the blocking ground wire 1614 is successively connected to the ten choice wires of the 1603 harness going to the blocking chain.

  
  <EMI ID = 755.1>

  
thus the first choice in final calls, progressively from the first to the tenth secondary block switch 1400, which these ten pairs of relays represent respectively.

  
Giving secondary switches the first choice for outgoing calls in a regular order tends to balance the traffic load on the secondary switches and on the trunks throughout.

  
called outgoing trunk groups, which evenly distributes the outgoing call load more or less equally among the block forward pairs serving each primary block switch 1300.

  
Giving the secondary switches for final calls first choice in a regular order, in combination with the previously described action of the commit assignor averaging final trunks, almost completely achieves this end. that any tendency for an imbalanced load distribution, which could result in unnecessary jumps of combinations, is greatly minimized

  
23 [deg.] Stirring of the final junctions. The following four tables give the number and identity of each of the forty final junctions of-

  
  <EMI ID = 756.1>

  

  <EMI ID = 757.1>
 

  

  <EMI ID = 758.1>
 

  

  <EMI ID = 759.1>
 

  

  <EMI ID = 760.1>


  
  <EMI ID = 761.1>

  
condaire, either on the left or on the right, of a secondary switch 900 of a line bay, as previously explained; and "C" is an abbreviation of

  
  <EMI ID = 762.1>

  
final junction, and it identifies the secondary section, with its column, on the line bay, where the junction ends.

  
Considering the final 40 junctions going to each line bay, the bundle of 10 including the first engagement goes "straight", or

  
  <EMI ID = 763.1>

  
on the secondary sections is referred to as the brewing of one. The junctions of engagement 3 go to the secondary sections with a shuffle of 2,

  
  <EMI ID = 764.1>

  
The purpose of shuffling final trunks is to increase the likelihood of combinations during periods of heavy traffic by presenting the call forward block referral pairs in a new order on each engagement.

  
  <EMI ID = 765.1>

  
(figure 16, part 6) are provided in order to connect the return wires

  
  <EMI ID = 766.1>

  
the 1630 extension wires (to which the LK wires of the line bay called A, B, C or D have been connected by the relevant relay of the re-

  
  <EMI ID = 767.1>

  
borrow the wires of the 1606 bundle, pass through the contacts of the line feeders engagement relays in the same order as the paths appearing from the block referrals, through the final junctions, to the line feeders.

  
The overlapping operation of a final call and an outgoing call will now be described.

  
Since, as described, two separate chains (an outgoing chain and a final chain) are provided passing through the block couplers 500 and the section 1550 relays preferably for the outlet of the block controller 1600 and associated apparatus, overlapping seizure may occur, since seizure by one of the chains does not prevent seizure by the other, As has been described, in relation to the relays preferably of sections 1550 and control connector 1500, the two separate kittens (as well as two separate sets of two control wires between the block couplers 500 and the block controller 1600) are provided to allow outgoing call operations to take a priority over operations

  
  <EMI ID = 768.1>

  
likely; that is, in all cases except the special case where the block controller is just finishing a final call operation at the time the outgoing call seizure occurs. The cases in which overlapping take of the block controller and common devices by the outgoing chain and the final chain can occur, are described separately as follows:

  
  <EMI ID = 769.1>

  
thus completely during the called line test and final call combining operations while the outgoing call operation proceeds as previously described. The described arrangement of the chain preference in the 1550 Section Preference Relays is such that the final chain grip is temporarily ignored when the strings are pulled together, so the control connector 1500 is set to the right position. 'after the primary block switch through which the outgoing call is to be served.

  
When the outgoing call operation is completed, the

  
  <EMI ID = 770.1>

  
final pel on standby, to the line control devices on the called line bay, which had carried out the operations described, in preparation for the test of the line called by the block controller, If the line control devices are ready, the test of the called line starts Immedia-

  
  <EMI ID = 771.1>

  
the TS test starter lead to its contact 7. In the assumed example, the completion of the operation of the final call on the test controller

  
  <EMI ID = 772.1>

  
relatively fast on outgoing call, which was preferred because this latter operation took place during a short interval of the normal wait time on the block controller [deg.]

  
  <EMI ID = 773.1>

  
30 Final calls are answered first. When the seizure of the block controller and related devices in final call occurs before the overlapping seizure for outgoing call operation, the Immediate result depends on what the outgoing call acceptance occurs

  
  <EMI ID = 774.1> <EMI ID = 775.1>

  
This suspends ongoing final call operations. However, to ensure the quicker release of the combination relay circuits

  
  <EMI ID = 776.1>

  
After outgoing operations have been liquidated and relays 16A17 and 16AI5 have de-energized, the final start auxiliary relay
16A7 again operates as described to re-start interrupted final call operations in the block controller.

  
  <EMI ID = 777.1>

  
rations of final calls have progressed far enough that the operations described for combining and operating the selector appliances have been

  
  <EMI ID = 778.1>

  
confusion in the circuits, such as for example the operation and blocking of some of the maintenance electros concerned but not others.

  
With the 16AI4 control relay actuated, earth, applied to its contact 3, remains in the auxiliary starting relay circuit.

  
  <EMI ID = 779.1>

  
control connector holding electrodes 1500 to keep the connector in position for the final call notwithstanding the return of its selection electrodes (as previously described), for the outgoing call.

  
When the described operation of the holding electro occurs

  
  <EMI ID = 780.1>

  
outgoing call, which has been described, of the block controller begins in the connected block coupler 500, as well as the operation of the

  
  <EMI ID = 781.1> released to allow control connector 1500 to be returned to position for 1 * outgoing call, after which the OTG-MG wire is set.

  
earth by section 1550 preferably relays to control the outgoing combination operation.

  
  <EMI ID = 782.1>

  
runs along the earth to the Lower terminal of the 16A20 transfer relay to actuate this relay in series with the Lower winding of the control relay

  
  <EMI ID = 783.1>

  
is short-circuited by the earth applied to the associated SON wire until the selection electros, primary and secondary, of the block bay have fallen back to remove the earth from this conductor., When the earth is thus removed of the SON driver, the transfer relay 16A20 operates in

  
  <EMI ID = 784.1>

  
who looks forward to the results described above.

  
By the foregoing operations, the operation of final calls which is about to be terminated has the possibility of advancing to its normal termination, after which the operation of the outgoing call, temporarily delayed, proceeds normally.

  
We will now describe the block translator 1800 (figures 18,

  
19).

  
The block translator 1800, shown as a rectangle in Figures 2 and 6, is shown completely in Figures 18 and 19. Figure 18 (parts 1 to 8) is called the relay section, since it shows the part that includes relays and associated circuit elements, such as resistors. Figure 19 is called the Tie Pin section, since it shows the section of the block translator which includes the blocks or columns of isolated tie pins on which the jumper cables can be placed at will so that the normal fixed translation of the selected called lines or extensions be replaced by the exceptional translation to direct the Interested calls to other line terminals as part of the operation which must provide the translation. <EMI ID = 785.1>

  
We will describe the purpose and functions of the translator.

  
The block translator has both general goals and functions.

  
  <EMI ID = 786.1>

  
sant a special translation which is an exception to the normal fixed translation, as indicated above.

  
  <EMI ID = 787.1>

  
As the thousand lines served by the devices described by means of line bays A, B, G and D, are grouped on these bays in a non-decimal way.

  
  <EMI ID = 788.1>

  
sic of the called line on the Interested line bay in order to direct the call there, The preferred grouping and numbering of the lines are shown in figure 21, which shows the position of each 000 to 999 on the line bays, together with the translated equivalent of each line number. The main purpose and function of the block translator is to perform this

  
  <EMI ID = 789.1>

  
digits of hundreds, tens and units of the called number, the block translator selects the line bay concerned and sends it the equivalent translated number, containing the translated digits, primary, five and units, respectively identifying the primary switch involved on the called line array, the five-line bundle on the primary switch, and the units position of the called line in the five-line bundle. We refer

  
to the translation according to Fig. 21 as to the normal fixed translation.

  
  <EMI ID = 790.1>

  
has ten double lines of numbers (l to 10). These lines refer respectively to the ten primary switches 800 on the Interested line bay. In each of these double lines, the upper row of numbers comprises the 25 row numbers assigned respectively to the rows connected to columns VI to 25 of the primary switch while the lower row comprises the translated equivalents of the respective row numbers of the upper row

  
  <EMI ID = 791.1>

  
lines served by primary switches 1 to 10 of line bay A; numbers 250 to 499 are assigned to line bay B; the numbers

  
  <EMI ID = 792.1>

  
assigned to the D line bay; and that the row numbers are applied consecutively, from the first column VI of the first primary switch

  
  <EMI ID = 793.1>

  
10 of the line bay Do It will also be noted that on each line bay, the translated numbers go successively (by tens, packets of

  
  <EMI ID = 794.1>

  
that bay of lines. The block translator directs one of these translated numbers to the bay of lines on which the called line ends.

  
2 [deg.] Special services by exceptional translation. The second purpose and function of the block translator is to direct the routing of services.

  
  <EMI ID = 795.1>

  
number (2) for the interception service, (3) for the service of common numbers and (4) for the coded ringing service for 20 extensions. The Block Translator performs all these special services for an assigned called number by abandoning the normal fixed translation in favor of an exceptional translation the effect of which is to direct the call to a different, pre-assigned line position, or on a free line of a group assigned in advance.

  
The above special services can be defined more fully as follows:

  
  <EMI ID = 796.1>

  
service transfers the call to a new position on any of the four line bays when the terminal position of the called line

  
  <EMI ID = 797.1>

  
traffic on primary switches, which avoids changing line numbers.

  
2. When using the interception service, this service transmits

  
  <EMI ID = 798.1>

  
pels requesting the directory number of a group of lines (such as a PBX group) on a free line in the group

  
  <EMI ID = 799.1>

  
when the block couplers 500 are modified according to Figure 22 to provide a coded ringing service instead of a harmonic ringing service. This is a special case of the number transfer service, and is used for up to 50 lines at 20 extensions in the fourth packet of five of each.

  
  <EMI ID = 800.1>

  
dant of the fifth packet of five is assigned to each of these lines. When the second line number is called, the block coupler 500, according to figure 22, is enabled by the block translator to modify the ring code in order to ring the corresponding extension in the second group of ten on the called line.

  
Normal fixed translation is performed by means of relays

  
of figure 18, whose contacts establish a permanent interconnection of the wiring. The exceptional translation, when done for a few called numbers, is done by means of the jumper connections between the tie pins shown in Figure 10.

  
The additional equipment, composed of the relays of FIG. 18, which is not used in the normal fixed translation, is thus brought into play in the manner which will be described.

We will now describe the groups of functional relays.

  
The block translator relays include separate functional groups as follows

  
  <EMI ID = 801.1>

  
20-station coded ringtone. They are only used with block couplers such as the one shown in figure 22, in which case the

  
  <EMI ID = 802.1>

  
tion, called to play only when an exceptional translation is required. They act to erase the normal fixed translation and to

  
  <EMI ID = 803.1>

  
numbers. When a line has been transferred from one attachment position to another by a change in the jumpers on the main distributor, without change corresponds, of the number of the transferred line, a relay

  
  <EMI ID = 804.1>

  
perform an exceptional translation, to cause the call to be directed to the new position of the called line instead of its original position.

  
4o Relays 18D5 to 18D14 make up a group assignor with ten relays. This assignor is engaged each time the number emitted by the dial indicates that the call is intended for a group with a common number.

  
Its role is to test up to ten lines in the called group in order to indicate an exceptional translation which will direct the call to a free line in the group.

  
  <EMI ID = 805.1>

  
be assigned as a call number to control these relays in order to submit the lines of the group to the test by the group assignor. The relays

  
  <EMI ID = 806.1>

  
in a group with a common number which is referred to as the PBX4 group. This relay can be controlled by any assigned line number to submit the lines in that group for testing by the PBX assignor. Relays 18D25 to
18D28 (not shown) and relay 18D29 are similar relays controlling respectively the groups of three trunks which are referred to as PBX groups 5 to 9.

  
  <EMI ID = 807.1>

  
assigned respectively to lines requiring an interception service.

  
At will, the 18D30 engagement relay can be controlled directly by

  
  <EMI ID = 808.1>

  
may depend on more than one given extension during a call on the affec line. téeo When activated, relay 18D30 engages both relays (l8D3 and

  
  <EMI ID = 809.1> <EMI ID = 810.1>

  
of five. They correspond respectively to the first five lines (0 to 4) of a group of ten and to the last five lines (5 to 9) of this group

  
13. The translator relays 18B23 to 18B26 make up the group of

  
  <EMI ID = 811.1>

  
me groups of 25 lines (00 to 24, 25 to 49, 50 to 74 and 75 to 99) in each group of hundred. These relays are controlled by the recording relays

  
  <EMI ID = 812.1>

  
corresponding respectively to the bays of lines A, B, G or D, which in turn correspond (see figure 2l) to the first, second, third and fourth groups of 450 lines (000 to 249, 250 to 499, 500 to 749 and 750 to
999) in the block of 1000 lines. These relays are controlled by the hundreds log relays 18AI to 18A10, with the help of relays 25, 18B23

  
  <EMI ID = 813.1>

The attachment pin blocks will now be described.

  
The tie pins are shown in Figure 19 as individual small circles. They preferably consist of attachment pins passing through blocks or a plate-shaped insulating element,

  
  <EMI ID = 814.1>

  
tether pin preferably passes directly through the rear face of the equipment to provide an exposed inner end, to which a local cable conductor or fitting is attached, and an exposed end on the rear face of the equipment to receive a garter.

There are 1800 attachment pins shown in Figure 19.

  
  <EMI ID = 815.1>

  
twenty pins per column, and in twenty levels, with ten pins in one level. For quick identification of the 20 pin levels in a sestion, these levels are divided into four groups of five levels, 1 through 4.
200 spindles of a section thus comprise four smaller groups, of
50 each

  
  <EMI ID = 816.1>

  
next trimmed, according to their function
  <EMI ID = 817.1>
 1 [deg.] Detector bench. The 1901 section of attachment pins makes up the detector bank The first 10 levels of this bank (groups 1 and 2) are assigned respectively to the registered hundreds digits 0 to 9

  
  <EMI ID = 818.1>

  
genes from any of the hundreds groups and terminate hundreds, 00 to 99 threads.

  
As explained below, the passage of a detection jumper

  
  <EMI ID = 819.1>

  
The detector, at the attachments of the detector bench which correspond to the three digits of a desired line number, energizes the two windings of this detector relay, only in the case where this line number is stored in the translator.,

  
The connections going to the fasteners of the detector bench are made

  
  <EMI ID = 820.1>

  
2 [deg.] Common bench .. The tie pin sections 1902 and 1904. are called the common bench because they contain terminals which must be jumpered to those of all other banks. Common bench terminals include the following separate functional groups:

  
2 [deg.] Ao Terminal groups for common numbers. The first three groups of five levels, 1 to 3, of section 1902 are assigned respectively to the bundles of ten junctions of common numbers, called groups

  
  <EMI ID = 821.1>

  
and body) for each of the ten lines constituting the respective junctions of the beam.

  
The five-level 4 group of section 1902 receives the three-trunk groups of common numbers, called PBX trunk groups 4 to 6, on

  
  <EMI ID = 822.1>

  
of numbers. Section 1904, Level 3 and 4. Groups receive the digit wires from ST-0 through ST-9, controlled by the station relays. <EMI ID = 823.1> Any terminal 1 to 3 assigned to any Interception relay can be connected (for example by a jumper 1956) to any level of pins desired in the group of stations ^ according to the number of stations forming part of the number directory of an extension that has been disconnected from a shared line and placed on intercept service. If the called line is

  
  <EMI ID = 824.1>

  
garter 1957). this earth can be found on any tie pin in level 20 of the body bench, section 1905.

  
  <EMI ID = 825.1>

  
are referred to as a body bench because the first three levels of any group of five levels, 1 through 4, of that bench serve as an attachment point for thirty S transfer body wires, wired between the block translator and the bundling blocks (not shown) on the li-

  
  <EMI ID = 826.1>

  
lines make it possible to have up to thirty lines on each bay serving as junctions in groups with common numbers. Each of these body wires before its use in the translator is connected by jumpers (on the line bay concerned) to the body wire of a desired line position on this bay, for example at the terminal from which the conductor leaves.

  
  <EMI ID = 827.1>

  
common.

  
The first three body wires SI to S3 starting from the bay of

  
  <EMI ID = 828.1>

  
PJ, for the use of three lines from line bay A, as a bundle of three intercept junctions going to the operator's switchboard

  
  <EMI ID = 829.1>

  
which case unnecessary body garters are omitted on the

  
  <EMI ID = 830.1>

  
3 [deg.] Ao Reserve levels on the body bench. On the Body Bench (Section 1905), Body Transfer Wires only use three levels in each group of five, leaving the fourth and fifth available for other uses.

  
In group 1 of the body bench, on levels 4 and 5 ended

  
  <EMI ID = 831.1>

  
number dialed on the dial and the presence of a connection between the corresponding contacts of the two levels.

  
In group 4 of the body bank, the fifth level contacts are connected together and grounded to provide ground terminals for the previously mentioned jumpers, relating to interception service for individual lines.

  
  <EMI ID = 832.1>

  
corresponding respectively to line bays A, B, C and D. In the reset bench, the terminals of each level. are connected between

  
  <EMI ID = 833.1>

  
tiers of repositioning.

  
In each repositioning section, 1906 to 1909, the

  
first ten levels of attachment pins receive a multiple of the primary wires (P) going to the associated line bay the next five levels

  
  <EMI ID = 834.1>

  
at the same bay.

  
The reset bench terminals receive reset, three-wire jumpers (such as 1954)., Going to each

  
  <EMI ID = 835.1>

  
We will now describe the operation of the normal fixed translation.

  
With particular reference to Figure 18, parts 4 to 8, the operation of the block translator of Figures 18 and 19 in serving a call requiring only normal fixed translation will be described.

  
The battery is normally applied to the upper terminal of each of the hundreds, tens, units and positions registering relays,

  
  <EMI ID = 836.1>

  
tiel of earth marking applied to the wire of hundreds, tens, units or stations, which is connected to it.

  
  <EMI ID = 837.1>

  
sent by the dial to any block coupler 500, for a

  
  <EMI ID = 838.1>

  
and SR of the block coupler 500 (Figure 5, part 2). When the number of stations has been registered and if the final chain is then free, the final chain relay 512 in the block coupler used is activated.

  
  <EMI ID = 839.1>

  
thus grounded to the recorded numbers of hundreds, tens, units and positions.

  
At the same time, the associated main relay of final chain in the 1550 sections preference relays and the final start relay

  
  <EMI ID = 840.1>

  
final block coupler taking. The control connector is thus commanded to associate the block controller with the primary block switch serving the receiving section of block couplers, and the block controller is started for final operation, all as previously described.

  
In the block translator, the mentioned application of the marking earth to the four digital wires, selected by the loggers, energizes the corresponding relay in groups of hundreds, tens,

  
  <EMI ID = 841.1>

  
2 [deg.] Preliminary translation. Consider the ten wires of each of the four sets of digital wires H, P, U and ST going from the block couplers
500 to the block translator, in order of 1 to 10. This is in accordance with the

  
  <EMI ID = 842.1>

  
For ten extensions, the digits of hundreds, tens, units and extensions of the directory number range from 0000 to 9999.

  
  <EMI ID = 843.1>

  
and the order of the numbers in the row and item numbering table is taken into account in translator 1800 by a preliminary internal translation operation within each of the ten bundles of

  
  <EMI ID = 844.1>

  
correspond respectively to the numbers 0 to 4 made on the dial, while the last five logging relays of the group correspond respectively to the numbers 5 to 9.

  
3 [deg.] Operation of translator relays. Three sets of translator relays (figure 18, part 8) are used to cooperate with the re-

  
  <EMI ID = 845.1>

  
slow translates digits of hundreds, tens, and units of line numbers recorded on these latter relays. These relay games

  
  <EMI ID = 846.1>

  
ao Two relays of five, 18B15 and 18B16

  
bo Four relays from 25, 18B23 to 18B26 and

  
c, Four relays from 250, 18B27 to 18B30.

  
3 [deg.] Ao Relay translators of five. The translator relays of five, 18B15 and l8Bl6, are controlled by the unit recording relays.

  
  <EMI ID = 847.1>

  
relay 18B15 represents the first five lines (0 to 4) of a decimal group of ten, while relay 18B16 represents the other five lines
(5 to 9) from the same group.

  
  <EMI ID = 848.1>

  
split a decimal group of 10 consecutive lines into two groups of five in order to make it easier to divide the lines of a group of one hundred into four groups of 25g and to divide a group of 25 into five groups of 5, as re-

  
  <EMI ID = 849.1>

  
to 18B26, of the outgoing group represent the four groups respectively. of 25 lines, with consecutive numbers, in each of the ten groups of hundred

  
  <EMI ID = 850.1>

  
the first twenty lines of the hundred, therefore included in the first group of 25 lines. Consequently, the operation of each of the relays

  
  <EMI ID = 851.1>

  
4, the first relay of 25 18B23, through wire 1 of harness 1835, to indicate that the called line is in the first group of 25 lines called.

  
  <EMI ID = 852.1>

  
When the tens digit is 29 contact 4 of the 3rd re-

  
  <EMI ID = 853.1>

  
relay of 5 18B15 is working, its contact 6 connects the earth wire 2 of harness 1835 to the. first relay of 25, 18B23, operating to indicate that the line is in the first group of 25 of the hundred. But if <EMI ID = 854.1>

  
te wire 2 mentioned to relay 18B24, 1..9 activating to Indicate that the called line is in the second group of 25 in the hundred and not in the first. The second relay of 25 18B24 is also controlled (by wire 3 of harness 1835) by contact 4 of the tens register relays

  
  <EMI ID = 855.1>

  
these five tens relays respectively control the relays of -25, 18B25 and 18B26, while the tens, intermediate relay 18AI8 actuates either relay 18B25 or relay 18B26, depending on whether it is the first relay of five 18B15 or the second relay of five 18B16 which has been activated and at its contact 7 closed.

  
  <EMI ID = 856.1>

  
to 18B30 correspond respectively to the four groups of 250 lines in which the numbers included in the block of 1000 lines are divided, as

  
  <EMI ID = 857.1>

  
harness 1836 to control the first relay of 250, 18B27 to Indicate that the called line is in the first group of 250 lines of the

  
  <EMI ID = 858.1>

  
pe of 50 of the group of 100 which is called, the earth, applied to the aforementioned wire 2 passes through contact II of relay 18B25 or 18B26 to control the second relay of 250, 18B28.

  
  <EMI ID = 859.1>

  
4 [deg.] Line numbers translated. As shown in the figure
21, each line number called (000 to 999) has an equivalent translated number,

  
  <EMI ID = 860.1>

  
same order for each of the four row bays. Each number-translated

  
  <EMI ID = 861.1> <EMI ID = 862.1>

  
transmit each of these numbers by means of one of 4 digital wire bundles 1841 to 1844 (part 8 of figure 18), which goes to the bay concerned, A, B, C or D, Each of these bundles contains ten wires primary P, 5-wire

  
  <EMI ID = 863.1>

  
4 [deg.] Ao Translated primary digits (a 0). For each bay of

  
  <EMI ID = 864.1>

  
presented respectively by the ten primary wires mentioned, Pi to PIO,

  
  <EMI ID = 865.1>

  
hundreds wire 0 to 9, the contacts 1 to 10 of these relays have 4 extension branches, one for each of the 4 groups of 25 lines contained in the group of 100 concerned. These 40 branches make up the 40 P wires,

  
  <EMI ID = 866.1>

  
towards them. The five values (l to 5) of the translated digit of five are trans-

  
  <EMI ID = 867.1>

  
(00 to 99) into 4 groups of 25, and on the further division of each group of 25 into five groups of five, as shown in the following table

  
Translation table for groups of five for a rump of 100 lines

  

  <EMI ID = 868.1>


  
The numbers in the table above are the numbers

  
tens and units of lines forming packets of five successive ones in

  
  <EMI ID = 869.1>

  
nes 0 and l) provide the first 4 groups of five in the first group of 25 of the hundred while the third group of tens (tens digits 2) includes the last five lines of the first group of 25 and the

  
  <EMI ID = 870.1>

  
ten (tens digits 3 and 4) provide the last two groups of 5 in the second group of 25. Therefore, the value of the translated digit of five ranges from 1 to 5 for the 5 groups of 25 comprising lines 00 to 24 ,

  
  <EMI ID = 871.1>

  
the third groups of 25 in the hundred each start with two whole groups of 10 lines and end with the first half of the next group of ten lines, while the second and fourth group of 25 in a hundred start with the last 5 lines of 'a group of 10 lines and end with the following 2 groups of ten lines.

  
Earth is applied to contacts 2 of the recording relays

  
  <EMI ID = 872.1>

  
agree with the above. For the first 50 lines of a hundred,

  
  <EMI ID = 873.1>

  
very 50 lines of the hundred, being multiple on contacts 2 of the last five tens recording relays, 18A16 to 18A20, respectively representing the tens called 5 to 9.

  
  <EMI ID = 874.1>

  
units 18A21 to 18A30. These wires are connected to the wires of UA, UB, UC or UD units of line bays A, B, C or D depending on that of relays 250, 18B27 to
18B30 which is actuated.

  
For each translated number, the common units thread that is put

  
to earth depends only on the recorded units number. The correspondence is as follows

  
Unit digits Unit digits

  
recorded translated

  

  <EMI ID = 875.1>


  
The stored unit digits 0 to 4 and 5 to 9 correspond

  
  <EMI ID = 876.1>

  
the first five lines of a decimal group of 10 make up a packet of five on a primary switch, and the last 5 lines of the decimal group make up a separate packet of five on that primary switch or on the next switch, as seen in the previous translation table for packs of five, or in figure 21.

  
In agreement with the above, the first five unit logging relays 18A21. to 18A25, and the last five, 18A26 to 18A30., put

  
  <EMI ID = 877.1> <EMI ID = 878.1>

  
of harness 1833. The earth, applied to this wire, is extended by contact 2 of the actuated relay of 25, 18B23, to the fifth primary wire PA5 of the

  
  <EMI ID = 879.1>

  
contact 7 of the first relay of 250 18B27.

  
By the previous operation, the supposed recording of: The

  
  <EMI ID = 880.1>

  
provided on the line bay A, responds as described to the primary digits and five, 5 and 3 of the translated line number by activating the connectors.

  
  <EMI ID = 881.1>

  
pack of five.

  
As previously described, the called line bay 1200 line controller ground its end-bay TF wire, which identifies that line bay to the block controller, after which the block controller goes into a state, as described, to route 15 'calls to the identified line bay

  
  <EMI ID = 882.1>

  
the call to the particular called line selected by the control connectors and the line controller.

  
7 [deg.] Release. When the operations necessary to extend the connection to the called line, if this is free, have been completed, the block controller causes the previously described release, which includes the release of the final chain relay 512 which had been activated,

  
  <EMI ID = 883.1>

  
the ground of the wires marked, hundreds, tens, units and positions, going to the 1800 block translator. When this occurs, the digit logging relays in Figure 18 that had been actuated, releasing. Others

  
  <EMI ID = 884.1>

  
We will now describe the general operation of the exceptional translation.

  
As previously mentioned, the block translator has the following special services by substituting an exceptional translation for the normal fixed translation for called and internal line numbers.

  
  <EMI ID = 885.1>

  
  <EMI ID = 886.1>

  
cific in translator 1800. The dialing of this line number in the translator must be detected in a special way so that the predetermined exceptional translation, required according to the service assigned to that specific line number, takes the place of the normal fixed translation. of that line number.

  
The mentioned detection operation is performed by relays

  
  <EMI ID = 887.1>

  
is set so that it only works if both windings are energized o For each detector relay, as described, these windings are wired

  
  <EMI ID = 888.1>

  
group 1 or 2 of this bank while the other is a tens and units pin of group 3 or 4 of this bank. Earth does not appear on these pins

  
both when calling a specific number The detector relay then operates with its two windings energized, each by a prepared wire of the mentioned detection jumper. The 1951 to 1953 garters provide three examples of the two-wire sensing garters mentioned.

  
  <EMI ID = 889.1>

  
tively through the first ten levels These levels thus form detection busbars of hundreds.

  
  <EMI ID = 890.1>

  
to the registered combination of tens and units digits is grounded through contact 1 of the actuated tens logging relay, passing through the relevant wire, 0 to 9, of harness 1832, and through a contact, l

  
  <EMI ID = 891.1>

  
The reset relay 18D3 is controlled by the detector relays to suppress the normal fixed translation, and pin them from the

  
common bench are controlled by these relays to provide exceptional translation by means of the jumpers going to the pin levels connected in the reset bench (sections 1906 to 1909). to which

  
  <EMI ID = 892.1>

  
to line bays.

  
We will now describe the number transfer service.

  
However, the ten line forwardings 202, -of a primary switch 800 are more than sufficient to give a good quality service, during the busy hour, for 25 connected lines having more than average traffic. 9 these ten forwardings can be overloaded during the busy hour if too many of the 25 lines connected are busy lines.

  
The obvious remedy for an overloaded 800 primary switch is

  
  <EMI ID = 893.1>

  
pal (Figures 2, 4 and 7) in order to transfer some of these high traffic lines to reserve positions ,, provided for lines for other primary line switches. well, if there are not enough spare positions, low traffic lines are transferred in the other direction to replace the transferred high traffic lines. Such a jumper transfer, when done, detaches the transferred line from a primitive directory number and associates it with the one that belongs to its new line home position. If nothing more was done :, any line transferred would require a new directory number.

  
As the changes to the directory numbers of the lines in service are annoying for the operating company and for the subscribers, the block translator has been arranged to offer exceptional translation, in order to perform the number transfer service by allowing at each line transferred de_ keep its original directory number. With this service, the transferred line is forwarded to the directory number.

  
  <EMI ID = 894.1>

  
meros must be applied to a transferred line (to allow, as indicated, to keep its old directory number), this line is assigned

  
  <EMI ID = 895.1>

  
Referring to Figure 21, it can be assumed that as a result of the traffic load balancing, parai the primary switches, my-

  
  <EMI ID = 896.1>

  
be on the transferred line to keep its directory number. The transferred line
(512) was originally served by the first primary switch of

  
  <EMI ID = 897.1>

  
the was C133. In its new position (910), line 512 is served by the 7th primary switch of line bay D, 3rd packet of five, 1st line. Its required exceptional translation is therefore D73lo Therefore, registering the number 512 in the block translator should result in

  
  <EMI ID = 898.1>

  
can be assigned to transfer calls for transferred line 512 to its new position. The first column of group 2, at five levels, of the

  
  <EMI ID = 899.1>

  
normal fixed tion (0133) whenever directory number 512 is registered in the translator, and a reset, three-wire jumper,
1958, is set up to ensure the exceptional translation (D73l), corresponding to the new position of the terminals of the transferred line.

  
  <EMI ID = 900.1>

  
directory of the transferred line.

  
The hundred digit 5 is detected by the connection wire Dl of

  
  <EMI ID = 901.1>

  
The combination of tens and 12 digits is detected by connecting wire D2 of the 1952 jumper as shown, to the tie pin which is in tens level 1 and ones column 2 of the bank of. detection.

  
  <EMI ID = 902.1> leading the 1958 three-wire reset garter, as shown

  
  <EMI ID = 903.1>

  
The previous preparation makes the 1800 block translator capable of offering the outstanding D731 translation for the transferred line number

  
  <EMI ID = 904.1>

  
2 [deg.] Operation of number transfer. The garters mentioned 1952 and 1958 having been fitted for the first transfer relay of

  
  <EMI ID = 905.1>

  
transferred, the resulting record, the hundreds, tens and units digits 5, 1 and 2 of the directory number in the translator will work.

  
  <EMI ID = 906.1>

  
time-., the recording of the tens and units digits 1 and 2 shows the earth, through contact 1 of the tens relay 18A12. wire 1 of harness 1832, contact 2 of relay 18A23 and wire 12 of harness DF2, on the attachment pin 12 of the tens and units of the detection bench, which closes

  
  <EMI ID = 907.1>

  
if only one of its windings was excited, now works because q &#65533; both windings are energized. Its contacts 1 to 3 connect the as-

  
  <EMI ID = 908.1>

  
called line, by removing the earth of the connected wires, primary, of five and of units, of the harness 1843. The reset relay 18D3 also extends the earth-, through the wires 1803 and the normally closed contacts 1 to 3 of the discount relay

  
  <EMI ID = 909.1>

  
group 1 of the PF10 harness and by their attached attachment pins, to each

  
  <EMI ID = 910.1>

  
exceptional D731 at normal fixed translation Cl33o

  
2 [deg.] C. Line controller response. The 1200 line controller

  
  <EMI ID = 911.1>

  
lines than the normal fixed translation which has been deleted the relay groups making up the digit recorders in the Interested line controller drop out when relay 18D3 operates as described and are immediately reset by the exceptional translated number.

  
When the ensuing operations are completed as previously described, the release of the hundreds, tens,

  
  <EMI ID = 912.1>

  
we want to change the directory number (for example after editing a new directory), or if the normal movement and the new line assignments allow the transferred line mentioned 512 to be returned to its original position on l switch, we remove the transfer jumpers of the numbers concerned, 1952 and 1959, by releasing the transfer relay

  
  <EMI ID = 913.1>

  
We will now describe the interception service.

  
As previously indicated, the number interception service is provided by the block translator 1800 because it allows exceptional interception translation for calls aimed at disconnected lines or extensions, in order to redirect these calls to an operator. 'interception. We can

  
  <EMI ID = 914.1>

  
1 [deg.] Assignment of interception relays. When the number interception service is to be applied to a line, it is assigned a re-

  
  <EMI ID = 915.1>

  
a two-wire line detection jumper and a 1-wire station detection jumper are fitted, as shown in 1953 and 1956 for the 20th interception detector relay 18F20.

  
  <EMI ID = 916.1>

  
interception must be provided for line N [deg.] 959, or for an extension disconnected from this line, if it is a shared line, the interception detector relay
18F20 can be assigned, if available, to its line number.

  
The position on the attachment pins of the interception relay 18F20

  
  <EMI ID = 917.1>

  
hundreds digit 9 which is connected to an attachment pin in the H9 level of the detector bench, while the second wire of the jumper detects the tens and units digits 5 and 9? when connected to pin 9 of the tens level 5 of the detector bank, opposite the tens digit 5 and below the units digit 9., on the drawing With this two-wire detection jumper fitted, the relay 18F20 works provided that the number of

  
  <EMI ID = 918.1>

  
attachment pins of the group of five assigned to relay 18F20 (those of section 1904., under annotation 20 and opposite numbers 1, 2 and 3, in the drawing) can be assigned respectively to positions which have been disconnected from.

  
  <EMI ID = 919.1>

  
respective values of relay 18F20.

  
  <EMI ID = 920.1>

  
is an individual line, all calls to it must be intercepted. in this case, one of the mentioned pins 1 to 3 is connected by a jumper to the earth on level 20 of the pin bank, as shown for the post jumper 1957 which is associated with set 19 belonging to the interception sets When such a jumper is fitted for intercept set 20, current flows through this jumper from the ground.

  
  <EMI ID = 921.1>

  
18F20 works regardless of the number of extensions stored, this operation is called line pickup.

  
  <EMI ID = 922.1>

  
line 959 to which relay 18F20 has been assigned by jumper 1953, is a shared line from which a certain extension has been disconnected, one of extension pins 1 to 3 of the aforementioned Intercept set 20 is connected to the bus bar of sets corresponding to the set number of the disconnected set. The

  
  <EMI ID = 923.1>

  
The STO to ST9 shift bars include the pins connected horizontally in the levels where the STO to ST9 wires of the CF12 harness terminate.

  
These wires are earthed respectively by contacts 1 of the relays in-

  
  <EMI ID = 924.1>

  
With the 1953 and 1956 jumpers in place, relay 18F20 operates whenever line number 959 is registered, but has no effect, except when extension number 2 is registered, which terminates

  
  <EMI ID = 925.1>

  
wire 1 of subgroup 20 of harness CGII and contact 1 of relay 18F20 to relay 18D30.

  
  <EMI ID = 926.1>

  
tion 20) are connected to the respective station bus bars. When three stations disconnected from this line are on the Intercept service, the three station pins 1 to 3 are connected to the respective station bus bars.

  
  <EMI ID = 927.1>

  
When more than three stations in a line are on the intercept service at the same time, two or more intercept detector relays can be assigned to the same line number to obtain the required number of station intercept pins, in order to to connect them to the bus bars of the respective stations.

  
2 [deg.] Interception Commitment. As described above, the intercept engagement relay 18D30 is driven by a ground applied by

  
  <EMI ID = 928.1>

  
to the group assignor. The normal fixed translation of the called line number has thus been erased and the circuits are prepared for the transmission of the exceptional translation under the control of the group assignor.

  
  <EMI ID = 929.1>

  
tees), the intercept engagement relay 18D30 also engages the body and reset wires of the PJ harness, representing the three

  
  <EMI ID = 930.1>

  
as Interception junctions.

  
2 [deg.] A. Body wires of Interception junctions. As shown in Fig. 19, part 3, the body wires Si to S3 of the bundle PJ, engaged by the relay 18D30, respectively represent extensions of the first three body wires (Si to S3) of the 30 transfer body wires Si to S30 going from the block translator to the grouping block of the previously mentioned body wires (not shown) of the line bay Ao If the

  
  <EMI ID = 931.1>

  
intercept, the three body wires mentioned SI to S3 are connected by jumpers on the bay of lines A to the respective individual body wires S of these lines. The individual body threads of the three. lines used as Intercept junctions are thus connected now res-

  
  <EMI ID = 932.1> is represented). The lower terminal of each relay allocating

  
  <EMI ID = 933.1>

  
tion preferably, which comprises an end of chain wire common to the ten relays and a series chain comprising the contacts 5 of all these relays.

  
  <EMI ID = 934.1>

  
The resulting blockage provides the assigning relay with ample operating current and effectively bypasses the associated primary holding electro (such as 403-HM) to prevent it from operating at this time.

  
3 [deg.] Exceptional translation for the first intercept junction. Each mentioned assignor relay blocks, at its contact 5, its lower winding terminal on the associated incoming earth wire of the locking chain preferably, and opens the locking chain to the next relay. At its contact 6, each of these relays disconnects its terminal

  
  <EMI ID = 935.1>

  
scorer of groups work at the same time, whoever has the first position in the chain works and effectively blocks, releasing the others.

  
  <EMI ID = 936.1>

  
PJ ceau. As shown in Figure 19, the resetting wires are wired to the corresponding resetting wires of the translator,

  
  <EMI ID = 937.1>

  
normal fixed station corresponding to the called number.

  
When the first junction of the intercepting beam is oc-

  
  <EMI ID = 938.1>

  
sent) and by the group 4 to 8 contacts (not shown) of relay 18D30, to reset wires P5, F3 and U2 of harness PJ, causing the transmission of the exceptional translated number A532 in order to extend the ap-

  
  <EMI ID = 939.1>

  
5 [deg.] Release. When the connection to the line constituting the selected junction indicated by the exceptional translated number has been completed, earth appears, as previously described, on the body wire of this line, thus bypassing the relay concerned (such as 18B5). of the assignor

  
  <EMI ID = 940.1>

  
to fulfill its function, since a relay in short circuit releases slowly When the translator is released as described, the interception relay 18F20 which was activated, drops out followed by the engagement relay 18D30.,

  
  <EMI ID = 941.1>

  
6 [deg.] All interception junctions are busy. When all three intercept trunks are busy, when tested by the group assignor, no relay. the assignor is not functioning, so that the normal fixed translation of the called number, which is deleted, is not replaced by an exceptional translation. The block controller is therefore unable to follow the call, needs a signal identifying a bay, which would arrive by a TF wire, therefore, it does its time by means of the cycle timer, as described, and puts the coupler connected block 500 in a state to return a normal busy tone to the calling line.

  
  <EMI ID = 942.1>

  
line. Both number transfer service and number intercept service can be applied to the same line, for example when a transferred shared line has been provided with transfer service

  
number to avoid a change of the directory number, after which an extension was disconnected from the transferred line. Thereupon, the directory number of the disconnected set is jumpered for interception service, as described. In this event, when calling the line number

  
  <EMI ID = 943.1>

  
intercept (such as 18F20) both work on detection of the called number.

  
When calling an extension in service on the line, the relay

  
  <EMI ID = 944.1>

  
Transferring numbers has the effect of causing an exceptional translation to direct the call to its transferred lines position. But if the mentioned disconnected station is called, the engagement relay 18D30 is actuated, i.e.

  
  <EMI ID = 945.1>

  
number transfer is thus left out in favor of the required intercept translation.

We will now describe the service of common numbers

  
  <EMI ID = 946.1>

  
at its premises ordinarily wishes that a common directory number be assigned to the group, and that the call be established to any free line in the group when it calls the common number. These li-

  
  <EMI ID = 947.1>

  
PBX9 (figure 18, parts 2 and 3), which can be assigned to groups, of respective lines with common numbersso Each group of 10 trunks with common numbers

  
  <EMI ID = 948.1>

  
can naturally serve a group containing any desired number of junctions less than 10, while a relay equipment for three junctions

  
  <EMI ID = 949.1>

  
represent the translated digits, primary, fives and units and the body wire? for an affected junction, as described for junction sets <EMI ID = 950.1>

  
Relay for three trunks, PBX4 to PBX9 is such that two or three equipments for three trunks combine to serve a group of six trunks or a group of nine trunks, at will. This combination is

  
  <EMI ID = 951.1>

  
to relay equipment for three trunks, PBX4 to PBX9, with the progression given in the following table s

  

  <EMI ID = 952.1>


  
  <EMI ID = 953.1>

  
PBX (or a similar group with common numbers), a call number is assigned to the group at the same time as the specific lines which are to be used as rushes.

  
  <EMI ID = 954.1>

  
two-wire connection to identify the affected relay equipment with regard to the assigned called number and one leads a body wire jumper and a three-wire reset jumper, for each line which is to form a junction of the group.

  
  <EMI ID = 955.1>

  
digits of hundreds, tens and units 0, 0 and 0 to a group of ten junctions to be formed, one can use, if available, the equipment of

  
  <EMI ID = 956.1>

  
of these levels represent the primary, five, unit and body sons

  
  <EMI ID = 957.1>

  
tion of the group and may or may not be assigned to the group as its junction 1. If, for example, line 485 is assigned as junction 1 of the group, a 1954 three-wire reset jumper of pins P, F and U

  
  <EMI ID = 958.1>

  
so as to predetermine the translated number B031, in order to direct the call to line 485 when the first trunk of the group is selected.

  
  <EMI ID = 959.1>

  
by a 1955 one-pin garter available from the 30 body pins corresponding to bay D, such as the body pin S10 in group

  
bay B. The corresponding body pin on the body bundling block (not shown) on line bay B is jumpered to the body wire of the line concerned 485. In a similar manner.

  
  <EMI ID = 960.1> one of the other lines that should serve as junctions in the group.

  
  <EMI ID = 961.1>

  
groups. The pairs of jumpers, comprising the 1954 and 1955 junctions are therefore connected to the respective relays of the group allocator.

  
  <EMI ID = 962.1>

  
junction free at the moment considered in the group connected, operates effectively and is blocked on the battery placed on the LB wire by the relay

  
  <EMI ID = 963.1>

  
the normal fixed translation of the called number is erased, and an exceptional translation is performed (via a jumper such as 1954) according to the position on the PBX of the first free trunk in the group, which directs the call to this position , as explained for the number interception service.

  
  <EMI ID = 964.1>

  
block 500 to return a busy signal, as described,

  
3 [deg.] Formation of three-junction groups. The three-junction relay equipment (relays 18D24 to 18D29) are represented by columns of attachment pins in the last five levels of the section

  
  <EMI ID = 965.1>

  
linked by jumpers to the required points of the detection bench (section 1901) in order to ensure the operation of the relay of three associated junctions
(18D24 to 18D29), and the three sets of wires P, F, U and S are connected by jumpers to the required terminals, for reset and for the body, cosme described for the group of ten junctions.

  
  <EMI ID = 966.1>

  
the detection bench, by operating the two relays of three junctions when the assigned group number is registered in the translator. The six junctions of the combined group are then tested as one

  
  <EMI ID = 967.1>

  
  <EMI ID = 968.1>

  
in 2200, figure 22, the block translator 1800 provides the coded ringing service for 20 sets. In the embodiment shown, this service

  
  <EMI ID = 969.1>

  
primary switch 800 on line bay A. When this service is applied, the block translator 1800 will ground the CC code control wire (going from the translator to the block couplers 2200) whenever the extension is called on a 20-station line is one of the last ten stations on that line.

  
As described in detail hereinafter, block couplers 2200 are normally arranged to provide a code according to the station number dialed on the dial for each of the first ten stations on a line.

  
  <EMI ID = 970.1>

  
Code 2251 control relay of the connected block coupler 2200 is actuated and locked to emit a preliminary ring signal just before transmission of the selected code, thereby identifying the corresponding station in the second group of ten. That is to say that the other ten codes are the same as the first ten except that each code of the second ten has a preliminary ringing.

  
Each 20-extension line requires two line numbers:

  
  <EMI ID = 971.1>

  
the first ten station codes, and (2) a second line number which suffixes the number of stations for the ten other station codes of the 20 station line. The first five line numbers and the five second line numbers corresponding to five 20-station lines served by a primary switch 800 on line bay A, are those normally assigned to the fourth and fifth line packets on the switch. . For example. Referring to figure 21, part 1, if the first primary switch 1 in line bay A is assigned to the 20 station coded ring service, the lines included in the fourth packet of five on that switch are lines with 20 stations, Their first numbers

  
  <EMI ID = 972.1>

  
occupying the fifth packet of five on the primary switch.

  
By assigning this primary switch to service at 20 stations, we

  
  <EMI ID = 973.1>

  
Therefore, arrangements are made to assign the primary switches of line bay A to the 20 station coded ringing service only as needed in order to reduce the need. less line capacity possible without doing more than what the installation requires at the time.

  
  <EMI ID = 974.1>

  
the body bench.

  
When one of the primary switches in line bay A

  
  <EMI ID = 975.1>

  
  <EMI ID = 976.1>

  
primary 2, 3 and 4 in the service at 20 stations.

  
2 [deg.] Primary detection for 20 stations. The 1960 fittings being fitted as shown, when a call is made to one of the switches

  
  <EMI ID = 977.1>

  
called is served by a primary switch which has been assigned to the

  
  <EMI ID = 978.1>

  
the translator. On the other hand, if the called number is one of the last five line numbers assigned to the primary switch, the fifth wire of five

  
  <EMI ID = 979.1>

  
F in bundle 1831, which erases the normal fixed translation of the five. The working contact 2 of relay 18D2 places a ground on the fourth wire

  
  <EMI ID = 980.1>

  
face the number of five translates 5 and substitutes for it the exceptional number of five 4 in order to transfer the call, from the position of the called line

  
  <EMI ID = 981.1>

  
laying in the fourth package of five. For example, with the I960 fittings in place, numbers A25I through A255 are changed to translated numbers

  
  <EMI ID = 982.1>

  
CC code to signal to the connected block coupler 2200, Fig. 22, that a 20 station line has been called using the second line number assigned to it. In response, this block coupler operates as previously described to add a preliminary ringing to the station code, in order to signal the corresponding station in the second group of ten instead of the station in the first group of ten on the called line.

  
  <EMI ID = 983.1>

  
two separate lines, and an available interception detector relay (18FI to I8F20) is connected by Jumpers to detect one or the other of the numbers of the line, as needed, and a terminal of these stations is

  
  <EMI ID = 984.1>

  
previously described,

  
The divided ringing service will now be described. The split ring service, which is provided by ^ block couplers 500 or
2200, is controlled by the RR ring reversal wire going from the translator

  
  <EMI ID = 985.1> tracks 18B6 to 18BIO recording allowances when an item number 5

  
  <EMI ID = 986.1>

  
ringing current on the neck wire R of the called line instead of

  
  <EMI ID = 987.1>

  
We will now describe the control and supervision of digital wires.

  
Circuit difficulties within a block coupler, or at any point along the multiple of the digital wires between the block couplers and the 1800 block translator, can cause contacts between two wires of hundreds H, two son of tens T, two son of U units or two son of ST stations. Unless warned, this could cause two or more relays to operate in the interested digital group of the Block Translator, which would compose a translation for another line or extension besides the called line or called extension. .

  
  <EMI ID = 988.1>

  
The digital block translator is prevented by chaining the command bank for each digital group in the manner previously explained for row controller 1200.

  
  <EMI ID = 989.1>

  
the control battery of all subsequent relays in the chain. When earth appears on two or more of the associated hundreds wires H, the hundreds relay connected to the lower numbered H wire, operates normally, while the hundreds relay connected to a subsequent H wire brought to the ground. earth, either does not work or drops out quickly after its control battery has been disconnected by the contact

  
3 of the chain's preferred relay.

  
It will be noted that this arrangement of the circuits allows all

  
  <EMI ID = 990.1>

  
called line wanted, since whichever of the two hundred threads crossed that has the lower number should represent the correct sent hundreds digit about half the time.

  
As an alarm supervision measure, each digital group

  
  <EMI ID = 991.1>

  
ne when a state of broken wires tries to actuate two relays in the same digital group .. In the group of hundreds, for example, the logging relay that tries to operate unsuccessfully, finds a battery across the winding upper, high resistance, alarm relay

  
  <EMI ID = 992.1>

  
to work, in series with the upper winding, of high resistance of the alarm relay, but the latter relay operates whenever a logging relay tries to feed on the control battery coming from

  
  <EMI ID = 993.1>

  
TR-AL alarm in order to sound the alarm by a suitable device (not shown) indicating an abnormal state in the block translator.

  
The chain alarm arrangement is similar in the tens, unit and station relays, for which the relay relays are provided.

  
  <EMI ID = 994.1>

  
We will now describe the bay of the junction couplers.

  
Figure 20 shows the details of the circuit apparatus employed on the junction coupler bay 252 of Figures 2, 3 and 7.

  
As previously described in relation to FIG. 3, the external connections going to the bay of the junction couplers 252 comprise

  
  <EMI ID = 995.1>

  
Junction couplers and the MDF main distributor; (2) 40 sets of three-wire incoming junctions, contained in the cable from ITC incoming junctions going to 'terminal 3231 of the block bay, and 40 sets of outgoing three-wire junctions' 4 contained in the cable of outgoing OTC junctions going on the secondary switch side of the block bay, to the junction coupler bay. Three of the mentioned two-wire sets are shown in Fig. 20 in 2023, 2053 and 2083; two of the sets of three outgoing junctions

  
  <EMI ID = 996.1>

  
Three-wire trants are shown in the same figure at 2085 and 2085 '.

  
We will first describe the outgoing one-way junctions.

  
The set of outgoing junctions 2020 extends to the coupler

  
  <EMI ID = 997.1>

  
re two-wire 2022 'connects the outgoing part of the 2021 junction coupler to the 2023 pair of conductors going to the main distributor, or the 2024 junction extends the pair of conductors to the pair of wires shown.

  
  <EMI ID = 998.1>

  
the availability battery holder by the rest contact 1 of relay 2005 and resistor 2006, allowing coupler 2001 to be taken by the set of junctions 2020, as previously described.

  
When the set of conductors 2020 is taken ;, the wires of the calling line are extended to the T and R conductors of the set 2020, by actuating the line relay 2004 of the junction coupler 2001 by the wires of the junction 2021, the contacts 1 and 2 of relay 2003, normally closed, and the left windings of the repeater coil 2002o Contact 2

  
  <EMI ID = 999.1>

  
2003, electrically polarized, bridged over the conductors of the associated junction between the offices, through the right windings of the repeater coil 2002 and through the conductors of the 2022 jumper, the wires
2023 and the jumper wires 2024. This prepares a block coupler entering office C, for the operation that has been described for block coupler 500-1.

  
Contact 1 of the 2004 line relay activates the 2005 release relay. Contact 2 of the latter energizes the local winding of the 2003 supervision relay. The latter does not operate at this time, because it requires that its two windings are excited in a concordant sense, while

  
  <EMI ID = 1000.1>

  
be excited in opposition,

  
Contact set 1 of relay 2005 disconnects resistor 2006 and substitutes a ground potential for it on body wire S of joint set 2020, in order to establish a holding circuit for the connection.

  
When the rest of the digits of the called number have been sent by the dial, the line relay 2004. responds by repeating the Impulses through its contact 2, while the bridge established across the outgoing conductors is momentarily interrupted at each impulse. Slowly released 20Q5 relay stays on during pulse repetitions

  
When the connection has been extended to the called line, the direction of the current is Reversed on the conductors of the junction connecting

  
  <EMI ID = 1001.1>

  
of the 2003 supervision relay On this, this relay operates, reversing the direction of the current in the tip and neck wires of the 2020 junction set and, therefore, in the calling line, or in the junction wires. incoming, as appropriate.

  
When the receiver is hung up on the called line, the relay
2003 drops out .. because the ensuing current reversal causes the windings of this relay to oppose each other again. This restores power to the tip and neck wires of the 2020 set in the normal direction.

  
When the receiver is hung up on the calling line, the

  
  <EMI ID = 1002.1>

  
contact 2, by opening the 2005 release relay circuit to its lo contact The 2005 release relay drops out shortly after. Its contact 2 opens the local circuit of the 2003 supervision relay, and its contact l removes the

  
holding earth of the associated body wire, allowing the established connection to break free.

  
We will consider the case of an incoming one-way junction. The conductors shown along the lower edge of Figure 20 represent the connections to the main IDF splitter and to bay 252, for an incoming one-way trunk. The junction shown is inbound from office A, being the one shown in Figure 2 and Figures 4 and 5.

  
The track passes from the pair of wires shown, entering from office A, to the main MDF distributor and from there, through jumper 2082 on the distributor, through the pair of conductors 2083 included in the cable connecting the MDF distributor and bay 252 , the two-wire jumper 2084 on bay 252 and through the T and R conductors in the incoming set 2085.

  
We will now describe a two-way junction.

  
  <EMI ID = 1003.1>

  
outgoing 2020 'is extended to the outgoing branch of the trunk coupler 2031, and the incoming trunk set 2085' is connected to the incoming branch of the same coupler. Jumpers 2052 and 2054 connect the double-track branch of coupler 2031 to the pair of wires shown,

  
  <EMI ID = 1004.1>

  
Normally, the two wires of the double-track junction are connected by elements 2054., 2053 and 252, the normally closed contacts 1 and 2

  
  <EMI ID = 1005.1>

  
T and R of the set of incoming junctions 2085 '. Set 2085 'is connected to an incoming block coupler, such as the one indicated at 500-1 on the figure.

  
  <EMI ID = 1006.1>

  
block crying. The body wire S of this block coupler normally carries a readiness battery potential applied to it through a resistor 532, as shown for the body wire of the coupler 500-L. This potential is communicated normally, by the body wire S of the set 2085 ', figure 20, a conductor of the jumper 2056, the lower winding, of low resistance, of the transfer relay 2007, the closed contact 1 of the relay of release 2005 'and a wire from the garter 2021', to the body wire S of the incoming junction set 2020 ', which normally provides this set with a potential battery of availability to allow it to be taken in the manner previously described for a free outgoing junction.

  
  <EMI ID = 1007.1>

  
which is associated the coupler of junctions 2031 is taken in the remote office C, the bridging of the wires of this junction which results from it, makes

  
  <EMI ID = 1008.1>

  
block input connected in the office Bj by the rest contacts 1 and 2 of the transfer relay 2007 and passing through the tip and neck wires of the set 2085 ', which prepares the incoming block coupler for operation, as before described. As a result, the block coupler removes the availability battery potential from the associated body wire S and substitutes a ground potential for it, causing the replacement of the availability battery potential, normally applied to the S-wire of the set of cables. outgoing junctions 2020 ', by an earth potential. The double junction

  
  <EMI ID = 1009.1>

  
After the dial transmits the remaining digits in the desired number, the last-mentioned block coupler operates as previously described, in order to complete the connection.

  
2 [deg.] Sortanto operation When the two-way junction associated with the 2031 junction coupler is taken by it in the office

  
B (passing through the set of conductors 2020 ') this temporarily applies an earth potential to the body wire S of the set 20209 (through the coil-

  
  <EMI ID = 1010.1>

  
series, passing through NC contact 1 of relay 2005 ', for the lower, low-resistance winding of transfer relay 2007, through a wire of

  
  <EMI ID = 1011.1>

  
in the connected incoming block coupler, the 2007 transfer relay is

  
  <EMI ID = 1012.1>

  
light, which closes a local blocking circuit through the upper winding of relay 2007, to earth on the associated S body wire. Excitation of this last winding causes the 2007 relay to operate immediately to the end. 1, 2 transfer the wires from the inter-bus junction

  
  <EMI ID = 1013.1>

  
instead of relay 2004, by activating the release relay on its contact 1
2005 '. Contact 2 of relay 2005 'energizes the local winding of supervision relay 2003', and its contact 1 disconnects the battery potential of

  
  <EMI ID = 1014.1>

  
lower element of the 2007 transfer relay, substituting a ground potential for it which acts on the body wire as a holding ground potential for the established connection.

  
The wires of the inter-office junction are now placed on

  
  <EMI ID = 1015.1>

  
of the relay 2003 ', and the right windings of the repeater coil 2002', and by the working contacts 1 and 2 of the transfer relay 2007, which is blocked during working. In response to the closure of this bridge, the equipment in remote office C is prepared for operation, and the double-serve junction is kept there.

  
  <EMI ID = 1016.1>

  
as described for relay 2004, and relay 2003 ', electrically polarized, operates as described for relay 2003.

  
  <EMI ID = 1017.1>

  
Release Relay 2005 ', which removes the holding earth from the associated body wire to allow the release of the established connection, and also to unblock and drop the 2007 transfer relay.

  
The wiring arrangement that is shown, in which the

  
  <EMI ID = 1018.1>

  
block, and in which the pairs of wires 2023, 2053 and 2083 extend between the sets of pins located on the one hand on bay 252 and on the other hand

  
  <EMI ID = 1019.1>

  
to be connected by, jumpers to serve as part of a single way junction or a double way junction ,, This arrangement includes the wiring of each junction coupler on the sets of pins of the rack
252, which can be jumpered to other sets of pins as desired as part of the fixed wiring arrangement described.

  
As an example of the flexibility of the arrangement provided on the bay of the junction couplers 252, it is possible to provide if one wants an incoming junction coupler (pulse repeater or the like, not shown) and can be inserted into the junction to single track shown by removing the jumper 2084 and replacing it with two jumpers connecting the sets of wires 2085 and 2083 to this coupler.

  
The block coupler for coded ringing 2200 will now be described.

  
In figure 22, the block coupler for code ring 2200 is shown as inserted in place of the block coupler 500-L of fig.

  
  <EMI ID = 1020.1>

  
block 500 is likewise replaced by a block coupler 2200.

  
In block coupler 2200, similar references have been given to elements similar to those of block coupler 500-L &#65533; but in the 2200 series instead of the 500 series. Its pulse counter devices

  
  <EMI ID = 1021.1>

  
2212 to control the circuits of the added relays 2251 and 2252. The relay
2253, which is one of the added relays, is a code relay which is actuated to apply a ringing current in accordance with the code assigned to the called station; relay 2252 is a latching relay, which works to start the ringing operation only between code transmissions by 1? common coded ringing equipment (not shown) ;; and relay 2251 is a control relay of coded $ ;: actuated by means of the DC wire by the block translator 1800 so that the latching relay 2252 is actuated in a first part of the coded ringing cycle, in order to cause thus the transmission of a preliminary ring to the called station when this station is one of the last ten on a line called at
20 positions.

  
  <EMI ID = 1022.1>

  
wires INT-GEN-0 through INT-GEN-9 of Figure 5.

  
We will now describe the places of unequipped block couplers.

  
Block coupler 2200 is shown as provided with a CBP chain detour key, which is unique to it. Preferably each

  
  <EMI ID = 1023.1>

  
CBP includes two inner rest contacts for opening wires 226l, which are in series with the incoming body wire S of the block coupler. The open, upper and lower CBP key contacts are inserted into conductors 2262 and 2263 to double chain contact 4 of final chain relay 2212 and chain contact 3 of outgoing chain relay 2211, respectively, when the CBP key is activated

  
A separate CBP key is provided on each of the 20 block coupler places in a section. When a block coupler is installed in the place associated with a key, the latter is placed in its rest position shown to activate the associated block coupler. In any block coupler place from where the block coupler is going to be removed, its CEP key is actuated. The external contacts of the key close its

  
  <EMI ID = 1024.1>

  
end of the section concerned ^ are thus diverted from the vacant block coupler place. The internal contacts of the CBP key open <EMI ID = 1025.1>

  
remain in neither of the two chains when the CBP key is activated.

  
The CBP key is actuated at each unequipped block coupler position, avoiding the use of temporary jumper wires, which should be removed after installing a block coupler.

  
The normal operation of the coded ringtone will now be described.

  
When using a 2200 block coupler to call a line on which there are no more than ten extensions, the common control wire of

  
  <EMI ID = 1026.1>

  
ringing operation is ready to begin, block coupler 2200 has been taken by incoming conductors 203, and operations have taken place, as previously described for coupler 500-L, to extend the outgoing wires
205 to a line called through a 1300o primary switch At this time,

  
  <EMI ID = 1027.1>

  
2209 connection relays are in the working position. Contacts 2 and 3 of relay 2209 extend the generator earth to contact 1 of bell invarsion relay 2206, on the one hand, and the displacement winding, connected

  
  <EMI ID = 1028.1>

  
2 of relay 2206, on the other hand. From the contacts 1 and 2 of the relay 2206, these wires are extended by the contacts of repqs 2 and 3 of the relay 2207, to the wires T and R of the outgoing bundle 205, and consequently to the called line.

  
Contact 8 of relay 2209 activates transfer relay 2215 to transfer the output leads of the SR-22 station recorder,

  
  <EMI ID = 1029.1>

  
9, depending on the position, which was given to the SB-22 station recorder.

  
The code 2251 control relay being at rest, as we have

  
  <EMI ID = 1030.1>

  
In the normal operation of the coded bell, of the common switchgear, the latching relay 2252 is activated on this earth. Its contact 2 blocks it on the locking wire L and disconnects the hooking wire PU2. Contact 1 of relay 2252 connects common wire 2224 of the SR-22 recorder

  
  <EMI ID = 1031.1>

  
disconnects the displacement winding from relay 2207 and substitutes for it the common generator wire GEN, through which the common source of ringing current is applied. This transmits ringing current to the called line

  
  <EMI ID = 1032.1>

  
successive operations of the 2253 code relay during the current cycle of the common ringing machine, transmit the ringing current to the called line, in accordance with the code assigned to the station called on this line,

  
  <EMI ID = 1033.1>

  
wire L, releasing and releasing all the latching relays 2252

  
which have been activated [one hundred] which function again subsequently if the call

  
had no response when the hooking position is reached

  
from name to.

  
The 2206 ring reversal relay operates as described for relay 506, to send ringing current to the neck conductor R (instead of the tip conductor T) for the last five stations

  
  <EMI ID = 1034.1>

  
if desired.

  
  <EMI ID = 1035.1>

  
the 2252 code relay has dropped out if it was on at the time, the upper winding of the 2207 bell cut-off relay is energized on the line called by contacts 3 and 2 of relays 2209 and 2206, and to earth

  
  <EMI ID = 1036.1>

  
ringing circuit and closing the conversation circuit. In addition, contact 9 of relay 2207 releases latching relay 2252 (if it is then working), thus disconnecting code relay 2253. The rest of the operation of block coupler 2200 and its release are such that 'they

  
have been previously described for the 500-L block coupler.

  
We will now describe the ringing at 20 stations.

  
When calling a 20-station line, the normal coded ringing operation of the 2200 block coupler, which has been described, still occurs if the called station is one of the first ten on the called line, that is,

  
  <EMI ID = 1037.1>

  
ro directory of the line which is normally assigned to the interested line, as previously described, relative to the operation of the block translator 1800.

  
When the extension called on a line called at 20 extensions is one of those designated by an extension suffix following the second line number assigned to the line, the block translator 1800 operates, as previously described, to apply the earth potential to the common wire

  
  <EMI ID = 1038.1>

  
final chain slack 2212 is at work, which closes a circuit, passing through contact 12 of this relay, for the code check relay

  
  <EMI ID = 1039.1>

  
When the connection relay 2209 operates, its contact 9 connects the latching relay 2252 through the contact 9 of the relay 2207, the contact 2 of the relay 2252, normally closed, and the contact 1 of the relay 2251, to the PIEU latching wire. As a result, relay 2251 is actuated so as to start coded bell operation as soon as the pU! Wire is reached. is grounded.

  
The common ringing equipment, previously mentioned, is of the well-known type, which first momentarily earths the hook wire.

  
  <EMI ID = 1040.1>

  
Distinctive preliminary signal on that of the code wires that has been selected by the SR-22 recorder and transmits a corresponding preliminary ring signal, followed by the station code indicated by the current position of the SR-22 station recorder. The transmission of the preliminary ring signal identifies the called station as belonging to the second group of ten on the called line instead of the first group.

  
The rest of the operation of the block coupler 2200 is as previously described.

Finally, we will describe the groups of lines not equipped.

  
As discussed here in the particular description of how to vary the capacity of the system, when the office where is

  
  <EMI ID = 1041.1> 1,000 lines in service, one or more of the line bays A to D may only be partially equipped with 800 primary line switches and one or more of the line bays B to D may be omitted if they are not needed.

  
All 25 lines for which no primary switches have been installed are called an unequipped group. Inadvertent calls to unequipped lines can be serviced in two ways

  
  <EMI ID = 1042.1>

  
ceptés.

  
First, when calls to unequipped lines are to be served by the block controller as calls to busy lines, operation depends on whether the line bay concerned (B, C or D) has been Installed or not. If it has not been installed, there is no line controller to apply earth to the interested end bay wire, TF-B, TF-C or TF-D (figure 16, part 5) . In this case it

  
the line test operation cannot be performed, and the cycle timer (Figure 16, part 2) proceeds, as previously described, by causing a final busy tone to be applied to the calling line by the block coupler connected, as described. When the call is for a line in a group of 25 unequipped on an installed line bay, the block controller begins the line test operation as described, upon receipt of

  
  <EMI ID = 1043.1>

  
appellant.

  
Second, when calls to unequipped lines are to be served by the block translator as calls to be intercepted, one of the sets available, among the 20 sets of intercept pins.

  
  <EMI ID = 1044.1>

  
is suitably connected by garters for this purpose. The intercept pin set 18 was arbitrarily chosen for this service. Pin 1 of this set is grounded through the 1958 garter to make the

  
  <EMI ID = 1045.1>

  
said detector relay (by energizing its two windings) each time the 1959 jumper receives an earth. As indicated by the mention associated with it, the 1959 garter is extended and is connected to the wire P

  
  <EMI ID = 1046.1>

  
sections 1906 to 1909. The garter-1959 having thus been fitted, the call of each unequipped group applies a ground to its corresponding P wire
(such as PD1 to PDIO), as previously described. Grounding the

  
  <EMI ID = 1047.1>

  
The call and the garter 1958. Thereupon, the call is intercepted and transferred to the intercept operator, as previously described.

  
Although the present invention has been described in relation to

  
  <EMI ID = 1048.1>

  
to the said example and that it is, on the contrary, susceptible of numerous variations and modifications, without departing from its field.


    

Claims (1)

ABSTRACT . The invention relates to a 1000-line PBX system forming part of a similar PBX network and equipped with crossbar switches. <EMI ID = 1049.1> mine (block bay). Various facilities are provided for serving, in particular dispatchers, allowing lines to be transferred without changing their directory number. - - - The equipment provides for the recording of a suffix digit designating one of the ten or 20 stations which can be connected to the mine line and for sending to these stations a coded ringtone.