BE353818A - - Google Patents

Description

       

   <Desc / Clms Page number 1>
 



  TELEPHONE SYSTEM.



   The present invention relates to telephone systems in general but relates more particularly to telephone systems in which local communications and long distance communications are established by means of an automatic switching mechanism, controlled by the subscriber. calling in a local call and controlled by the long-distance communications operator in the case of an oommunioa-

 <Desc / Clms Page number 2>

 .tien. long distance.



   The object of the present invention is to provide new and improved switching mechanisms to complement long distance and local communications so that the long distance communications operator is informed, when extending a call. long distance to a local subscriber, whether the desired subscriber is busy or free, and, if busy, whether it is in a local call or in a long distance call and so that if the desired subscriber is busy in a local call with another subscriber, the operator can cut off the conversation and complete the long distance call, and then release the unwanted subscriber from the call.



   A special feature of this invention is the production of a novel rotary connector improved to extend communications to private branch offices which connector selects a free trunk line from a group of trunk lines. 'extending to a desired branch office, provided there is one free, and which selects the first trunk line taken in service in the local call when all trunk lines in the group are busy in local or long distance communications.

   The long-distance communications operator receives a signal letting him know whether the call has been extended to a free trunk line or to a locally occupied trunk or if no call has been made. been prolonged as a result of all trunk lines being occupied in long distance communications. If a call has been extended to a locally busy trunk, the operator is likewise able to cut off the call and complete the long-distance call and release the unwanted subscriber from the communication.



   The different characteristics of the invention will be described in detail in the specification which follows, with the

 <Desc / Clms Page number 3>

      of the accompanying drawings comprising Figures I to 6 which show, by means of the usual diagrams of oirouit, the arrangement of a telephone system embodying the principles of the invention. To be fully understood # the drawings must be placed as follows; Figure 2 to the right of Figure 1, Figure 3 below Figure 2, Figure 4 below Figure 3 and Figure 5 to the left of Figure 4.



   Figure 1 shows a subscriber station A whose line terminates at the office in the individual line switch LS and is accessible in the fixed points of a group of connectors The line switch LS can be any a suitable type eg the well known rotary type having no normal position and moving in one direction only. The line switch LS i, as well as other similar line switches, has access to a group of first selector switches such as the first selector switch S '.



   From a mechanical point of view the SI selector is of the well known vertical and rotary type. The circuit arrangement of the SI selector is similar to that of the selector shown and is de- fined in detail in patent application No 275461, with the modi - fioation of an additional relay, the function of which is particular to the present invention and will be described in detail below. The selector S ', as well as other first similar selectors, has access to a certain number of groups of second looal selectors, with a separate group accessible at each stage.



   The second local selector S2 indicated by a rectangle in figure 2 is accessible for the group of first selectors containing the selector SI by means of the connection line comprising the conductors 201 to 203, mechanically and also for which oonoerns the arrangement of the circuits, the selector S2 can be of any suitable type. In the series of fixed contacts of the second selector there is access to a certain number of groups of individual line connectors

 <Desc / Clms Page number 4>

 (each group containing both local connectors and long-distance and long-distance combined connectors) and also one or more groups of long-distance rotary connectors, with a separate group accessible on each floor.



   The local rotary connector LRC is accessible to the group of second local selectors containing the selector S2, by means of the connection line comprising the conductors 211 to 213.



  From a mechanical point of view, the LRC local rotary connector is and of the well-known vertical / rotary type. The LRC local rotary connector, as well as other motors, has access to a number of groups of trunk lines extending towards private branch offices.



   The junction line including conductors 271 and 274 belongs to a group of three junction lines, extending towards the P.B.X. "N", and accessible for the LRC connector.



  This trunk line terminates at the main office in the line switch LS2 which may be analogous to the line switch LS and may have access, in common with the line switch LS, to the first selectors.



   Figure 3 shows a combined long distance and local TLC motor which is accessible to the group of second local selector switches containing the selector S2 by means of the junction line comprising the conductors 301 to 303 and is accessible to a group of second selectors for long distances (which will be mentioned later) by means of the junction line comprising conductors 304 to 307. From a mechanical point of view, the long distance and local connector TLC is of the well known vertical type and rotary. The circuit arrangement of the TLC co-ordinator constitutes a special part of the present invention and will be discussed in detail in the following.

   The TLC connector has access, along with other connectors, to individual subscriber lines such as the line including conductors 101 and 103 extending to post A and the line including inverters 6II and 613 s. 'extending to station A'. The line of the post is

 <Desc / Clms Page number 5>

   'also ends in a line switch (not shown) which can be similar to the LS line switch and can have access ,? in common with this one. to the first selectors.



   FIG. 5 shows the take-off end of the long-distance operator cord O, terminating in the plug P and provided with a listening key, K 'and a control key. oadran and bell K .. 'The oadran D can be associated with the 0 ordon circuit by the fact that the key K is moved to the right. Line 0 circuit can be of any suitable type and is therefore not shown in detail; only the elements related to the present invention have been shown.



   The long-distance communication operator has access to a group of long-distance transmission selectors by means of connection lines accessible to jaoks located at his station. The TTS long-distance transmission selector is accessible for the long-distance communication operator's panel, at the location of jaok J, by means of the connection line comprising conductors 3 and 4. At the me - organic, the long distance transmission selector TTS is of the well known vertical and rotary type and has access, in its series of fixed contacts, to a certain number of groups of second long distance communication selector switches, a separate group being accessible on each floor.

   The circuit arrangement of the TTS long distance transmission selector is a special part of the present invention and will be discussed in detail hereinafter.



   The second long distance selector TS, indicated in figure 4 by a dotted rectangle, is accessible to long distance transmission selectors by means of the connection line comprising conductors 505 to 508. From a mechanical point of view and also as regards the arrangement of the circuits, the selector TS can be of the vertical and rotary type, similar to the second local selector S2,

 <Desc / Clms Page number 6>

 except that the ringing command conductor of the junction line terminating therein is connected to a fourth wiper upon completion of the operation of the switch.

   In the series of fixed contacts of the long distance selector seoonds, there is access to a number of groups of combined long distance and looal connectors, and also to one or more groups of long distance rotary connectors, a separate group being accessible on each floor. The long distance and local TLC connector shown in Figure 3 is accessible for the group of second long distance motors containing the TS selector by means of trunk line conductors 304 to 307.



   The TRC long distance rotary oonototor can be used with the group of second long distance selectors containing the TS selector by means of the trunk conductors 405 to 408. From a mechanical point of view, the long distance rotary connector TRC is of the well known vertical and rotary type. The circuit arrangement of the TRC connector is a special part of the present invention, and will be described in detail.



  The sets of fixed contacts of the rotary connectors for long distance communications are connected in multiple with the sets of fixed contacts of the corresponding local rotary connectors. In this way, the rotary connectors for long distance communication have aooes, in common with the connectors. looaux rotary, to trunk groups extending to private branch offices.



   Figure 6 includes five diagrams 6A through 6E which show the different test potentials existing on the test contacts of the trunk lines to a private branch office under different circumstances.



   After this general description of the objects of the invention and of the apparatus employed, a detailed description of the operation will now be given. For this purpose, we will first assume that the subscriber of set A wishes to put himself in communication.

 <Desc / Clms Page number 7>

   with the subscriber of set A '. To complete this communication, the subscriber of set A removes his repeater and dials the directory number for the subscriber of set A '. Under the effect of the removal of the receiver at station A, the line switch LS operates in the usual manner and extends the communication to a first free selector which will be assumed to be the selector s'.

   Under the effect of the formation on the dial of the first digit of the called number, the selector S 'operates to raise its wipers to the level of the stage of fixed oontaots corresponding to the number formed on the dial, and then automatically chooses a line of free jonotion accessible on this floor, (A detailed description of the vertical and rotary function of a selector similar to selector S 'is given in patent application No. 275461). The windings of the relay 121 of the selector S 'are included in the conversation circuit but they are with differential winding so that the I2I relay is not energized when the current passes through the two windings in series with the line relay of the switch next.



  Under the action of the second number formed on the dial by 1 calling subscriber, the second selector S2 operates in a regular manner and extends the communication to the first free conneotor of the group accessible in the floor of fixed contacts corresponding to the number formed on the dial. .



  Assume that the connector chosen is the long-distance and local TLC connector shown in Figure 3, accessible by means of trunk line conductors 301 to 303.



  When the communication is extended to the TLC motor, the line relay 3II operates and prepares the connector for operation .; Under the effect of the formation, on the dial, of the third cipher, the vertical magnet 321 operates and lifts the switch wipers up to the corresponding floor of fixed contacts under the oommnade of the line relay 311, the relay in series 319 works in series with the AIS

 <Desc / Clms Page number 8>

 mant 321. At the end of the vertical movement, the relay 319 de-energizes and, forming the contact 389, it closes a circuit for the combined relay 3 14 for changing and controlling the oompter, the circuit containing springs. vertical out of normal, closed when the switch is moved for the first time.



   While operating, relay 314 places rotary magnet 322 in the pulse circuit instead of vertical magnet 321, closing contact 345 and opening contact 346, and opening contact 342 and closing contact 343 it prepares the circuit by means of which the auxiliary battery BB will later be applied to the release conductor 302. At contact 344, the relay 314 closes a restraint circuit for itself extending towards the earth through the contacts 331 , 356 and 339.



   Under the effect of the formation, on the dial, of the last digit by the calling subscriber, the rotating magnet 322 operates and rotates the oommutateur rubbers until prea with the series of contacts ending the line of the station a ' . If the line is busy, the 3I8 busy relay operates in the usual way (by means of its lower winding, its upper winding is of no use in this kind of call) and gives the calling subscriber the busy signal connected by means of conductor 309 and contact 383.

   If the line is free, switching relay 320 operates when relay 319 drops out and performs its usual circuit changes, including closing the signal circuit at contacts 391 and 398 and connecting it to earth potential. contact 392 with private contact 612 ', in this case via contact 336 of relay 312, which bypasses resistor R'.



   When the subscriber of station A 'answers, the functioning ringing interrupt relay 317 cuts off the ringing and completes the talk circuit, after which the rear bridge relay 310 is energized by means of the loop. subscriber called in series with the windings of the differential relay 313.

 <Desc / Clms Page number 9>

 relay 313, being differential winding, does not operate at this time. The rear bridge relay 310 operates in reverse and opens the holding circuit of relay 314- on contact.
331 and, by forming contact 324j, it forces the auxiliary battery BB to connect to the release conductor 302s, which causes the subscriber's counter M to operate.



   Shortly after its circuit has been opened, relay 314 releases after the direct earth potential is again connected to release conductor 302 by means of contacts 335, 342 and 324. In this type of communication, relays 315 and 316 do not are unauthorized and the operations of the TLC oonotor are similar to general oonotor operations, well known in the art, except for the operations of the relay 314, which have been described in detail. The release of the call upon completion of the conversation takes place in the usual manner under the effect of the raooroohage of the receivers of the two subscribers.



   It follows from the preceding description that when a subscriber completes a call to another subscriber, the normal private stations of the calling line and of the called line are directly earthed and according to the present invention they are thus marked. '' occupied looally. "The reversing current is supplied to the calling subscriber through the line relay an- ners of the connector used in the communication, in series with the windings of a different relay. - tiel in the first selector, the latter relay not being actuated due to its differential characteristic.

   The conversation current is supplied to the called subscriber via the windings of the rear bridge relay of the connector in series with the windings of a differential relay of the connector) the latter not being actuated. the same is due to its differential characteristic.



   For the remainder of the description of the invention, one supp-

 <Desc / Clms Page number 10>

 - will determine that the long-distance communication operator has picked up a long-distance call coming from a distant point, for the subscriber of set A '. To complete the call, the long-distance communications operator introduces the call card of a cord, the P card of oordon 0 for example, into the jaok of a free junction line, for example the jaok J. L inserting plug P into jack J places a bridge between junction conductors 3 and 4, which closes a circuit for the upper coil of line relay 24; this circuit extends from the earth at contact 33 and contains junction conductors 3 and 4 and contacts 35;, 69 and 98 in series.

   Line relay 24 operates and closes a point in the conversation circuit at contact 88 and closes the release relay circuit at contact 89. Relay 25 operates and connects the %erre to contact 91, it prepares the relay. pulse circuit at contact 92 and closes a circuit for the lower winding of the switching control relay 13 at contact 94, the latter circuit also including contacts 89, 49 ;, 84 and 40. Relay 13 operates and opens a point in the circuit of switching relay 12 to contact 43 and prepares a circuit for relay 14 to contact 42.



   After having inserted the plug P in the jaok J, the long distance communications operator / the key K in the maneuvering position of the dial and then on the dial dial the directory number for the subscriber of set A ' . after which the operator returns the K key to normal.



   Under the effect of the first digit formed on the dial, the vertical magnet 29 of the TTS long distance transmission selector operates and lifts the switch wipers up to the corresponding stage of fixed contacts. The out of normal vertical contacts close during the first advance and at contact 10 a circuit is completed for relay 14 which operates and opens contact 45 ,, At the end of the vertical movement of the switch, the rotating magnet 30 operates. under the oom-

 <Desc / Clms Page number 11>

 actuates the jerky advance relay 28 and turns the rubbers to junction with the series of fixed contacta ending a free junction line.

   After the junction line selection operation $ the switching relay 23 operates and performs its usual circuit changes $ y including closing points in the conversation circuit at contacts 80 and 87 connecting a earth means with the test wiper 502 at contact 82 and furthermore it earths the bell control conductor 100 by closing contact 83;

  , it opens the circuit of the lower winding of relay 13 by opening contact 84, and it prepares another circuit for the lower winding of relay 13 by closing contact 85. The operation of the transmission selector to long distance TTS, with respect to its vertical and rotary movement, is similar to the smooth operation of a selector as is well known in the art. A detailed description was therefore deemed unnecessary.



   It will be assumed that the chosen connection line is that comprising the conductors 505 to 508, terminating in the second long-distance communication selector TS. When this junction line is taken in service, a circuit for the line relay not shown of the second selector for long distances TS is closed circuit which includes the upper winding of relay 13, contact 38, the two right windings. of the repeater coil RC, contacts 46 and 44, oon duotors 8 and 6, and conductors 505 and 508 in series.

   Relay 13 is then kept energized by means of this oirouit, the initial circuit for its lower winding having been opened at contact 84, Relay 13 is made slow to prevent it from falling again during the short interval afterwards. that the outlet of its lower winding is open and before the cooked outlet enclosing its upper winding and the line relay of the second long distance selector TS is established.



   Line relay 24 operates under the effect of

 <Desc / Clms Page number 12>

 the next digit is put on the display and each time it is de-operated it opens the line relay circuit of the second long distance selector TS, at contact 88. The second long distance selector TS operates in the usual way and raises its wipers up to opposite the stage of fixed contacts oorrespon- ding to the number formed on the dial and then chooses a free junction line in this stage, A circuit is also closed for the lower winding of relay 13 each time the relay line 24 is de-energized, the latter circuit enclosing the contacts 90 ;, 92 and 85.

   Relay 13 is thus kept out by means of its lower winding during the intervals when the circuit of its upper winding is open at contact 88 to operate the second long distance selector TS, so that relay 13 is maintained. continuously excited.



   It will be assumed that the junction line chosen by the long distance selector switch TS is that comprising conductors 304 to 307, terminating in the long distance and local TLO connector. When this trunk line is taken up, the line relay of the second long distance selector TS is disconnected from the talk conductors (by the operation of the switching relay of the selector TS) and a new circuit is established for the upper winding of the switch. relay 13 by means of the windings of the line relay 311 of the TLO connector. The relay 13 of the long-distance transmission selector TTS is then kept energized by means of its upper winding in series with the line relay 311 of the TLO oonneotor.

   Line relay 311 also operates by this circuit and prepares the TLC connector for operation as previously described.



   Line relay 24 of the TTS long distance transmission selector switch operates again due to the formation of the third digit on the dial, which opens the circuit of line relay 3II of the TLC connector a corresponding number of

 <Desc / Clms Page number 13>

 , times and causes the operation of the vertical magnet 321 to advance the wipers of the switch to opposite the corresponding stage of fixed contacts.

   The relay 319 operates again in parallel with the vertical magnet 321, and at the end of the vertical movement it de-energizes by again closing the circuit of the relay 314 at the contact 389, The relay 314 operates, closing a circuit of locking itself at contact 344, by disconnecting the vertical magnet from the pulse circuit by opening contact 346 and connecting the rotary magnet to the pulse circuit by closing the switch 345, Relay 314 also closes a circuit for reverse control relay 316 by closing contact 341, with ground present on bell control conductor 306 (connected by conductor 507 to conductor 100).

   Relay 316 operates and opens its initial excitation circuit at contact 367 and closes on closing contact 366 a latch circuit for itself to the grounded long distance communication release conductor 305, it prepares. a circuit to energize the two-phase conversion relay 315 for its first phase by closing contact 369, it closes a positive for the upper winding of the bell interrupt relay 317 at contact 368 and it prepares a circuit restraint for bell interrupt relay 317 by closing contact 364.

   The bell interrupt relay energizes and closes its retaining circuit to the bell control conductor 306 at contact 371 'it opens points in the bell ringtone at contacts 370 and 377 and performs other circuit changes which will be described.



   Under the effect of the last number formed on the dial by the long distance operator, the rotating magnet 322 operates and rotates the switch trotters until engaged with the stationary contacts terminating the line to station A '. During the rotational movement, the relay 319 operates in parallel with the rotating magnet 322, it connects the relay 318 to the frot

 <Desc / Clms Page number 14>

 switch 602 by means of contact 385, and closes the energizing circuit of the lower winding of the two-phase conversion relay 315 at contact 388, the latter circuit also comprising oontaots 339, 356 and 369.

   Relay 315 operates to its first phase to close contact 353, which prepares the circuit by which it energizes to its second phase when contacts 388 are reopened.



   The called line can be busy in a long distance communication or in a local communication; in both cases the dbesai relay 318 is energized; but we will first assume that the called line is free at this moment ,,, At the end of the rotary movement, the relay 319 drops out and by opening the contact 388 it forces relay 315 to operate until its second phase by means of contacts 353, 367 and 341. Relay 315 opens contacts 347 and 360 so that rear bridge relay 310 and differential relay 313 have the windings are connected in series with the windings of the rear bridge relay 310 being disconnected from the conversation conductors. By opening contacts 349 and 361, line relay 3 II is disconnected from the conversation conductors.

   Relay 311 is released and at contact 333 it opens the circuit of relay 312 which after a short interval is released in turn. By closing the contacts 348 and 359, points are also closed in the conversation circuit. A point in the circuit of the release magnet 323 is open at switch 350. The release conductor 302 extending to the fixed switches of the local selectors is held grounded at contact 351 after the contact is made. 33 5 opens. At contact 352, a circuit is closed and this circuit contains the two windings of test relay 318 in series, but relay 318, being differential wound, is not energized.

   A circuit by which the operation of the long distance sound relay 18 in the long distance transmission selector TTS is controlled is prepared at contact 355, and a circuit for the lower winding of the switching relay 320 is closed for release it

 <Desc / Clms Page number 15>

   conductor 305 to contact 354. Switching relay 320 operates and performs its usual circuit changes involving closing points in the talk circuit at contacts 391 and 398, and placing the earth potential on the normal contact. private 612 'of the called subscriber line, by closing contact 392.

   In this case, however, the earth is connected to the private test contact of the called line, by means of the resistor R 'instead of being connected directly since the line relay 3II and then the release relay 312 return to normal after relay 311 is disconnected from the talk drivers, and therefore contact 336 is open. In this way, the line from station A 'is marked "long distance open", instead of being marked "locally occupied" when the direct earth is connected to the normal private contact; the purpose of this will be described in the following.



   When the line relay 3II is disconnected from the talk inverters, the circuit by means of which the upper winding of the relay 13 of the long distance transmission selector TTS is kept energized is interrupted. This relay then de-energizes and completes a circuit for the switching relay 12 by closing the contact 43, the non-normal contact 10 being closed during the first vertical advance of the switch.



  Relay 10 is energized and by opening contacts 33 and 35 and closing contacts 34 and 36, it reverses the direction of the current in the connecting conductors 3 and 4, the upper and lower windings of the line relay 24 being kept connected to jonotion conductors 3 and 4 respectively. At contact 40, a point is open in the circuit of the lower winding of relay 13. By opening contact 38, another point is opened in the circuit of the upper winding of relay 13, and by closing the relay. contact 39, the battery supply relay 20 is connected to the junction conductor 8 through the upper right winding of the RC repeat coil.

   By closing contact 41, the supply relay

 <Desc / Clms Page number 16>

 true ground 21 is connected to the junction conductor 6 through the lower right winding of the RC repeater coil. By opening contact 37, the short-circuit on the upper left winding of the repeating coil RC is removed, and by closing contact 37 ', the upper and lower left windings of the repeater coil are connected via the capacitor. As a result of the reversal of the current flow in the junction conductors 3 and 4, the polarized relay 2 of the operator's lead circuit 0 is energized and causes the light to light up L.



   The lighting of the lamp L at this moment indicates to the operator of long-distance communications that a free line has been connected and that he can send the signal to the subscriber called as soon as he is connected. - even is ready. To send the signal to the called subscriber, the long-distance communications operator flips the olef K to the left to send the ringing current through the trunk conductors. The bell relay II, which is in bridge between the junction conductors 3 and 4, operates under the effect of the bell current 'and closes the air-output of the relay 22 to the contact 32.

   The relay 22 operates and by opening the contact 78, it disconnects the earth of the bell control conductor 100 which is connected, through the conductor 507, to the bell control conductor 306 to which the alarm interrupt relay is locked. ringtone 317 of long distance and local TLC conneotor. As a result, the bell interrupt relay 317 de-energizes and, by allowing contacts 370 and 377 to close, initiates the regular automatic interrupted bell to alert the called party. While operating, relay 22 also closes a local hold circuit for line relay 24 by closing contact 76 to keep relay 24 energized while ringing current is applied to junction inductors 3 and 4.

 <Desc / Clms Page number 17>

 



  When the called subscriber answers, the ringing interrupt relay 317 operates, being energized by means of its lower winding by the called line boom. in the usual manner, and again closes its latch circuit at un-motor 306, at contact 317 ', and closes points in the talk circuit at contacts 371 and 376. After the interrupt relay ring 317 has operated, the two relays 20 and 21 of the TTS long-distance transmission selector operate through the loop of the called line.



  The operation of relay 21 has no consequence at this time. Relay 20 disconnects, while operating, the windings of line relay 24 from junction conductors 3 and 4, opening contacts 67 and 69, and closes a local holding circuit for line relay 24 by closing the relay. contact 68. Disconnecting the windings of line relay 24 from junction conductors 3 and 4 interrupts the circuit of polarized relay 2 in lead circuit 0. Relay 2 then de-energizes and extinguishes lamp L. lamp L notifies the operator of long-distance communications that the called subscriber has answered.

   After receiving this signal, the long-distance communications operation takes the necessary steps to complete the conversation connection between the calling subscriber and the called subscriber, after which these two persons can enter into a conversation.



   When the subscriber of station A 'hangs up his receiver at the end of the conversation, the circuit of relays 20 and 21 is interrupted. Relay 20, by de-operating ;, reconnects the coils of line relay 24 to junction conductors 3 and 4, which again establishes the circuit of polarized relay 2 in the operator's oordon 0 circuit. When energized, relay 2 turns on lamp L. Turning on lamp L at this time indicates to the long-distance communications operator that the called subscriber has hung up his receiver, after which the operator withdraws the jack P of the jaok J to release the switches used in. he.

 <Desc / Clms Page number 18>

 



    . Communication,
Removing plug P from jaok J opens the circuit of line relay 24 which then de-energizes and opens the switch-off of release relay 25. Relay 25 de-energizes and at contact 91 it opens the circuit of the de-energizing relay. oommunioation 23, the switching relay of the selector TS, and the holding circuits of the relays 315, 316 and 320 of the TLC connector, after which these relays de-energize and return to normal, The switching relay 23 de-energizes, de-energizing, the ground of the bell control conductor 100 by opening the contact
83. Removing the ground from bell control conductor 100 opens the bell interrupt relay hold circuit 317 of the TLO connector.

   Relays 315 and 320 close, returning to normal, a circuit for the release magnet 323 by closing the contact 350 and the contact 397 respectively. The release magnet 323 then operates and returns. do not switch wipers to normal. Releasing the TS selector switch relay also initiates the release of the TS selector wipers. Closing contact 90 by releasing line relay 24 also closes the release magnet 31, the vertical springs out of normal 9 having closed during the first vertical advance of the switch wipers. Magnet 31 operates and returns the switch trotters to normal.

   Relay 27 works in parallel with magnet 31 and at contact 98 it opens a point in the circuit of line relay 24 to prevent erroneous operation during release. All switches employed in the communication described above are now in the normal state and are ready to be used for establishing further communications.



   The operator can, while attempting to establish a long distance communication, complete the communication even if the desired subscriber is busy as long as he is busy in a local communication. In order to describe the operation of the long distance and local TLC oonneo tor when it is /;

   employed by

 <Desc / Clms Page number 19>

 a long distance communication operator to establish a long distance communication to a subscriber engaged in a looale communication, it will be assumed that the long distance communication operator has again extended a long distance communication to the connector TLC through cord circuit 0, the long distance transmission selector TTS and the second long distance selector TS and that the desired line to station A is busy at this time, 'As soon as the wipers of the TLC connector are rotated until they engage with the contacts ending in the line of station A ',

   the dressai relay 318 is energized by means of its lower winding from an earth potential (either direct or via a resistor such as R '. depending on whether the line is occupied locally or occupied at long distance) on test contact 612 '. Relay 318 operates and prepares a latch circuit for itself at contact 380; it opens a point in the circuit by which the switching relay 320 will be subsequently energized by opening the contact 381, it connects the conductor 308 connected to the switch 1 (figure 4) to the connection conductor 307 at the location of the oon taot 383, and at contact 378 it prepares the circuit by means of which the operation of the long distance sound relay 18 in the long distance transmission selector TTS is controlled.



   Shortly after the end of the rotational movement, relay 319 de-energizes and allows conversion relay 315 to operate to its second phase and perform the circuit changes described above. Relay 319 closed a latch circuit for the lower winding of relay 318 to bell commando conductor 306 by allowing contact 386 to close, and further prepares the circuit by which the operation of the control relay of the its 18 is controlled by allowing the contacts 384 to close, that is to say it connects the test wiper 602, by the contacts 378 and 355, to the connection conductor 304,

   The two relays

 <Desc / Clms Page number 20>

   317 and 318 are then locked to the bell control conductor 306. It should be noted that no current passes through the upper winding. of relay 318 at this time since the earth is connected to the two terminals of oelui-oi.



   Disconnecting line relay 311 from the connecting conductors again de-energizes relay 13 in the long-distance transmission selector TTS and as previously deorised, it forces the current in connecting conductors 3 and 4 to overturn and causes the connection of the relays 20 and 21 to the conductors 8 and 6 respectively, the first operation resulting in the lighting of the lamp L. ' As the terra potential is intermittently applied to the junction conductor 307 at the location of the long-distance and local TLC connector by switch 1 connected thereto in the manner previously described, a circuit is open and closed intermittently for the TTS long distance transmission selector relay 20.

   Relay 20 operates accordingly and disconnects the windings of line relay 24 from junction conductors 3 and 4 by opening contacts 67 and 69 each time it energizes, which intermittently opens and closes the relay. 2 bias relay circuit in operator 0 lead circuit. This causes the L lamp to flicker, a signal which indicates to the long distance operator that a busy state has been encountered.



   When operating, relay 20 also closes a circuit for relay 19 to contact 69 via the normally closed contact 72 of relay 21. Relay 19 closes, while operating, a locking circuit for itself at the contacts. 64, from earth to the location of the vertical springs out of normal 10 and through contact 59 and closes a restraining drive for relay 14 at contact 66 to keep this relay energized, its initial circuit energized. - tion being open at contact 42 when relay 13 de-energizes. ' By opening contact 62 and closing contact 63,

 <Desc / Clms Page number 21>

 relay 15 is placed instead of relay 22 under the control of bell relay II.

   At contact 65, relay 18 is connected by means of oontaots 57 and 48 to the lower connecting conductor.



  6.



   If then the called line is occupied in a local communication, the direct earth potential is present on the test contact 612 'received by the test wiper 602, which is currently connected by the contacts 384 and 378 to the conductor connection 304 connected to connection conductor 6. Relay 18 is thus switched off and remains without aotion. If, on the other hand, the line to station A 'is occupied in a long-distance communication, the potential ground is connected to test switch 612 'via a resistor such as resistance R in the connector used in the other long distance communication.

   In such a case, a sufficient quantity of current circulates by the relay 18 coming from the battery, by the intermediary of the resistor R connected to the junction conductor 304 by the contact 363 to make it work. , By functioning the relay 18 connects to the connection conductor 6 the conductor 9 to which a current of its characteristic is applied coming from the generator T. This current of its passing in the lower right winding of the repeater coil RC and in the winding of relay 20 is induced in the left windings of the repeater coil RC.



   On seeing the flickering of the lampa L, the operator of long-distance communications activates his key K1. if it is not already activated to put its headset in connection between the connection conductors in order to determine if the desired line is occupied in a long distance call or in a local call. If the operator hears the sound, he realizes that the desired line is busy in a long distance communication, after which he removes the plug P from the jaok J to undo the communication he has established in the telephone. intention to try to establish an oommunioation at a later time.

 <Desc / Clms Page number 22>

 



   If, on the other hand, the long-distance communications operator does not hear any sound, this indicates to him that the un-aired line is busy in a local call., The long-distance communications operator then momentarily activates the olef K to the left which applies the ringing current to junction conductors 3 and 4 and causes the ringing relay II to operate in the TTS long distance transmission selector. Relay II closes the circuit of relay 15 when it is operating.

   The relay 15 operates and at contact 47 it closes the excitation circuit for the lower winding of relay 16, which forces this relay to operate in its first phase and to prepare at contact 53 an excitation circuit by means of which it will function until its second phase as soon as contact 47 is opened again. Relay 15 also establishes a local withhold circuit for line relay 24 at contact 51 while ringing current is applied to junction conductors 3 and 4, and it opens the short-circuit between the terminals of resistor R5. at contact 49 ;, which removes the direct earth potential of the bell control conductor 100. This removes the short-circuit of the upper winding of the occupancy relay 318.

   The values of resistance R5 and of the resistance of the upper winding of the bell interrupt relay 317 and of each of the windings of the test relay 318 are approximately: equal, following which a bridge of Balanced Wheatstone is then formed, with equal values of the current passing through the upper winding and the lower winding of test relay 318.



  Since the windings of relay 318 are differential, relay 318 then de-energizes. By de-energizing, the relay 318 opens the circuit of its lower winding to the contact 380, it disconnects the conductor 308, connected to the earthed switch I, from the conversation conductor 307 by opening the oontaot 383, it unconnects the wiper 602 and also the battery by resistance R, of the conductor of oonversat.on 304 by opening

 <Desc / Clms Page number 23>

 contact 378, and by closing contact 381, it forms a wax through contact 354 for switching relay 320. Relay 320 then operates and performs the circuit changes described above, including closing. peak metering in the reversing circuit at contacts 391 and 398.



   After the key K is brought back to normal, the relata II and a moment after the relay 15 return to normal. The two-phase relay 16 operates until its second phase and closes a latch circuit for itself at contact 53 through contact 59 and the vertical contact out of normal 10, it prepares an excitation circuit for the two-phase relay 17 at contact 54, it grounds the ringing commando conductor 100 at contact 58, it opens a point of the sound control valve 18 at contact 57,

   and at contacts 52 and 56 it prepares the bridge by means of which the earth will later be relays to the two connecting conductors. '
The operator is then able to converse with the desired subscriber and informs him that there is a long distance call waiting for him, and he also informs the unwanted subscriber that he is going to be out of touch with communication. The operator then brings the olef K momentarily into the ringing position a second time. The bell relay II operates again and in turn causes the operation of the relay 15. By closing the contacts 46 'and 44', the earth potential is then applied to the two conductors 8 and 6.

   By the mature iron of the contact 47, an excitation circuit is closed for the lower winding of the two-phase relay 17, causing this relay to operate to its first phase and prepare an excitation circuit for the contact. 59 'circuit by means of which it will function until its second phase as soon as the contacts 47 are separated again.



   If it is assumed that the desired subscriber is busy in a local communication - in which he is the called subscriber, the

 <Desc / Clms Page number 24>

 placement of the earth potential on the two conductors 8 and 6 mat in short or a winding of the rear bridge relay and a winding of the differential relay in the connector used in the local communication corresponding to the lower winding of the relay 310 and the lower winding of the differential relay 313 of the TLC connector. Interruption of the current in a winding of the differential relay of the connector used in local communication causes this relay to operate and close, at the contacts which correspond to the contacts 340, the circuit for the release magnet of this connector.

   The release magnet operates and returns the connector wipers to normal. In this way the unwanted subscriber is disconnected from the desired subscriber in the long distance call.



   Finding himself disconnected, the unwanted subscriber then hangs up the receiver if he has not done so when he was informed of the arrival of long-distance communication for the other subscriber; it thus causes the release of the other switches used in the local communication. If the unwanted subscriber had reloaded his receiver as soon as the long distance switching operator informed both parties that a long distance call was on hold, all switches except the connector used in the local communication would have been released at this time., In both cases, however, the connector used in the local communication is released as described above.



   When the relay 15 drops out at the end of the second momentary actuation of the key K to the striking position, the two-phase relay 17 operates until its second phase, and at contact 59 it opens the restraint circuit. of the two-phase relay 16 and of the relay 19. By de-energizing, the relay 19 opens the circuit of the relay 14 at contact 66, it opens another point in the circuit of the long distance sound relay 18 at the contact 65, it opens another point in its own locking circuit at contact 64, and it replaces relay 22 under the control.

 <Desc / Clms Page number 25>

 command of bell relay II, When de-operating, relay 14 again connects relay 21 to connecting conductor 6 by closing contact 45.



   If the desired subscriber has held his receiver to his ear as he should, then relays 20 and 21 are energized with the result that, as described above, the lamp
L remains off. If, on the contrary, the desired subscriber has also connected his receiver, the relays 20 and 21 are not exaités and the lamp L lights up. The long range communications operator can then send the signal again to the desired subscriber by operating the key K to the left a third time, and thus operate relay 22 to remove the earth from the control conductor. ringtone 100.

   Oeoi starts the regular automatic ringing by causing the de-energization of the ringing interrupt relay 218 in the long distance and local TLC connector, which relay operates again when the receiver is removed at the called station after which the oonversation connection is completed.



   It was assumed in the above oas that a combined long distance and local connector was used in the local communication. It goes without saying that each individual line connector group includes both local connectors and combined long distance and local connectors, the local connectors being similar to the TLO connector, with relays 315 and 316 omitted. A busy local connector is released by the long distance communications operator in the same way as a combined long distance and local connector when used in local communication.



   In the above case, it has been assumed that the desired subscriber was engaged in a local call in which he was the called subscriber. If the desired subscriber is busy in a local call in which he is the calling party, the operator of long distance communications can likewise enter the call and detach from the telephone.

 <Desc / Clms Page number 26>

 munioation the unwanted subscriber.

   In such a case, the application of direct earth potential to the two connecting conductors, resulting in the operator activating his bell key and maneuvering the dial to the bell position momentarily for the second time in order to detaching from the communication the unwanted subscriber acts on the first selector used in the local communication instead of acting on the connector.



   To describe how a first selector is operated in such a communication, it will be assumed that the long distance communications operator has extended a call to a subscriber who at this time is engaged in a local call which he initiated by means. of selector S 'As will be remembered from the local communication previously described, the differential relay I2I has remained de-energized.



  The application of the potential will say earth to the two long-distance conversation conductors under the effect of the second momentary actuation of the ringing key and the operation of the dial vars the ringing position, in this case short- circuit that of the windings of the differential relay I2I which is connected in series with the grounded winding of the line relay of the connector used in the local communication, after which the relay I2I operated and closed the circuit of the release magnet 122 on contact 123.



   The release magnet 122 operates and opens points in the talk circuit of the local communication by opening the contacts 124 and 125, which causes the release of the next second selector switch, and it also returns the selector wipers to normal. S;

   The switching relay 120 of selector S; is kept actuated by means of a circuit extending from the release conductor II2 connected to the release conductor 102 to which a ground potential through a resistor such as resistance R 'is now applied in the long-distance and local connector used in long-distance communication, by link-

 <Desc / Clms Page number 27>

 bearing of the switching relay 120, the contacts I3I, 132, by the winding of the jerky advance relay II9, towards the battery. The connector used in the local communication is released when the called subscriber being disconnected hooked up his receiver.



   The description will now be given of the operation of the TRC Long Distance Rotary Connector, Figure 4, which, when used by the long distance communications operator to extend long distance communication to a private branch office. , chooses a free trunk line in the group extending to this office, provided there is a free trunk line, or chooses a locally busy line if all trunk lines are locally busy or long-distance busy., after which the long-distance communications operator is able to cause the existing call to be released by means of the locally occupied trunk which has been chosen.

   In order to perform the latter operation, local rotary oon- nectors such as the local rotary connector LRC shown in figure 2 are required. The manner in which these operations are accomplished will now be described and for this purpose it will be assumed that the operator of the long distance communications wishes to extend a call to the private branch office N and has established a call by means of the cord circuit. O, from the TTS long distance transmission selector and TS long distance communications selector, to the TRO long distance rotary motor.



   When the communication is extended to the TOO connector the line relay 4II operates and earths the conductor 406 to the contact 432 and closes a circuit for the lower winding of the bell interrupt relay 412 to the contact. 433. The relay 412 is energized and at contact 437 it closes a locking circuit for itself towards / the conductor of

 <Desc / Clms Page number 28>

   o Bell command 407 to which ground is applied in the TTS long distance transmission selector, it closes points in the talk circuit at contacts 436 and 440, and it prepares.; the pulse circuit at contact 438.



   As a result of the formation of the next digit on the dial by the operator, the vertical magnet 421 operates under the control of the line relay 411 and raises the switch wipers 481 to 484 to the front. of the fixed contact stage. in which are accessible the junction lines to the P.B.



  X. "N". Relay 413 operates in series with magnet 421, keeping the vertical magnet circuit closed at contact 442, vertical contact outside of normal 472 opening and contact 473 closing during the first vertical advancement of the contact sliders. switch. At the end of the vertical movement, relay 413 drops off and prepares the circuit of rotary magnet 422 by closing contact 443.



   As a result of the formation of the next digit on the dial by the long-distance communications operator, the rotating magnet 422 operates and rotates the switch wipers until they engage the series of contacts terminating the first trunk line in the group of trunk lines extending to PBX "N". Relay 415 energizes in series with magnet 422 and closes a circuit for relay 417 at contact 449, it closes a circuit for relay 416 at contacts 450, and opens a point in the winding circuit. lower of relay 418 to contact 451.

   While operating, relay 416 opens a point in the jerky feed relay 420 circuit at contact 453, it prepares a retainer circuit for relay 417 at contact 455, it closes a point in the lower winding circuit from relay 4I8 to contact 456. While operating, relay 417 closes a point in the circuit of the jerky advance relay 420 to contact 457, prepares the circuit for the energizing winding of the differential occupancy relay 414 to the contact 459, and at contact 460 it closes the initial relay excitation circuit

 <Desc / Clms Page number 29>

 two-phase 410, which forces this relay to operate until its first phase and to prepare an excitation circuit at switch 426,

     circuit by which it will function until its second phase as soon as contact 460 is opened again,
In the system shown in the drawings, it has been assumed that three junction lines make up the group extending towards the P.B.X. "N". the last of these lines comprising the conductors 271 to 274, accessible at the location of the fixed contacts 488, 489 'and 490. The conductors 271 and 274 terminate in the P.B.X. "N" in the jaok J'. The two test points for each junction line are connected together by resistors; contacts 489 and 489 'being connected by resistor R93.



  Each of the top test contacts such as contacts 486, 487 and 489 is connected to a chain relay which is energized when the trunk line is busy. When all of the string relays in a group of connecting lines are actuated, a string circuit is closed to connect the battery through a resistor to the upper test contact of the first line of. jonotion of the group.

   No junction line is connected to the series of contacts immediately following the series ending the last junction line of the group, but the equipment is established as follows: contact 491 is connected to the earthed switch I, the contact 492 is connected to earth by resistor R94, and fixed contact 493 is connected to the battery by resistor R96, contact 492 'is left disconnected
Figure 6 shows the different test potentials which exist on the test contacts of the junction lines under the different conditions., The resistors "a" and "b" respectively represent the switching relay of the terminating line switch. the jonotion line and the jonotion line chain relay.

   When a junction line is free, the two test contacts are free of earth potential as seen at 6A in figure 6. When a junction line

 <Desc / Clms Page number 30>

 .tion is occupied in a local communication, the direct earth potential is connected to the upper test contact as seen at 6B in figure 6. When a trunk line is occupied in a long distance communication, the poten - the direct earth connection is connected to the upper test contact, and the earth through a low resistance is also connected to the lower test contact as seen at 60 in figure 6.



   To continue the description of the operation of the TRC connector, we will first assume that one of the lines of the group, namely: the line comprising the conductors 271 to 274, is free at this moment, the other two connection lines being occupied. in long distance communication or in local communication. As this junction line is free, the chain relay 496 is in a de-energized position and the battery through resistor R95 is not connected to contact 486.

   Shortly after the end of the rotary movement, relay 415 drops out and opens the circuit of relay 416 at contact 450; it opens the initial circuit of relay 417 at contact 449, closes a hold circuit for relay 417 at contact 448, and closes a point in the circuit of the lower coil of relay 418 at contacts 451.



   In the assumed case, relay 418 is not sufficiently energized for its operation to be produced and therefore remains unactuated. Shortly after the circuit of relay 416 is opened, this relay de-energizes and a circuit is de-energized. closed on contact 453 for the jerky advance relay 420 circuit extending from the earth to the contact: test 486 by the wiper 482, the contacts 461 457, 452, 471 and by the coil of the relay of jerky advancement 420 towards the battery.

   Relay 420 energizes and closes a restraining circuit for itself to release conductor 406 at contact 469 and closes a circuit for rotary magnet 422 at contact 470, simultaneously closing for relay 417. a retention circuit which comprises

 <Desc / Clms Page number 31>

 picks up contacts 454 and 448. Magnet 422 operates and rotates the switch wipers until they engage with the fixed contacts terminating the second trunk line. While operating, magnet 422 opens the holding circuit of relay 420 at contact 471.

   Relay 420 then de-energizes and opens the circuit of relay 417 and magnet 422 at contact 470. As it has been assumed that this junction line is also occupied the earth potential is present on contact 487 as well and the relay of jerky advancement 420 is exerted again by again causing the operation of the magnet 422 as described above, the switch wipers being rotated until engaged with the fixed contacts 488, 489, 489 'and 490. As no earth potential is present on the fixed contact 489, this junction line being free, the jerky advance relay 420 is not actuated, and the switch rubbers are stopped in this. position.



   After an interval, relay 417 drops out, opens a point in the circuit from relay 420 to contact 457, and by opening contact 460, it allows two-phase relay 410 to operate to its second phase. By separating contacts 424 and 431, line relay 411 is disconnected from the junction conductors. By closing contacts 425 and 430, points are closed in a conversation circuit. At oon- taot 429, the earth brought by resistor R4 is connected by means of the wiper 483 to the test contact 489 '(and to the contacts connected in multiple therewith). By closing contact 427, a circuit is established for the two windings of test relay 414 and for switching relay 419.

   Relay 414 is differential winding and therefore is not actuated. Switch relay 419 operates and connects direct earth to test contact 489 at contact 466, through wiper 482, and closes points in the talk circuit at contacts 465 and 468.



   Disconnecting the line relay 411 from the conductors

 <Desc / Clms Page number 32>

 The switching operation in the long-distance transmission selector TTS starts again, releasing the relay I3I, after which the long-distance switching operation is warned by the lighting of the lamp L which indicates that a connection has been established with a free trunk line. To start sending a signal to the attendant at the private branch office, the long-distance operator activates the key K to the ringing position.

   Applying ringing current operates relay II which, as previously described;) causes the ringing control conductor 100 to be earthed. bell 412 of the TRO connector is released. Relay 412 closes by releasing the signal circuit which extends from the interrupted generator lead IG to contacts 441 and 435, which causes shutter 290 to operate at the attendant's station of the private branch office. N. The attendant answers the call by inserting the plug of a cord into the jaok J '.

   This operation disconnects shutter 290 and closes a DC circuit for the upper winding of bell interrupt relay 412 which operates this relay and latched it back to the bell control conductor 100 and also causes extinction of the lamp L. The agent can then converse with the operator of long distance communications, after which these two persons take the necessary measures to put the remote calling subscriber and the called subscriber in communication.



   At the end of the conversation, the attendant removes the plug of his cord from jaok J ', which causes the L lamp to light up as described above, after which the operator of the communications at long-haul removes the T-plug from the J-jack, which releases the TTS long-haul transmission selector and the second .TS long-haul selector as described above. Removing the earth from the release conductor 406 opens the relay 410 circuit and

 <Desc / Clms Page number 33>

   removing the ground from the bell control conductor 100 opens the bell interrupt relay circuit 412, whereupon these relays de-energize.

   Relay 410 opens, de-energizing the circuit enclosing the two windings of relay 414 and the circuit of relay 419, and closing switch 428, it closed the circuit of release magnet 423, the vertical contact out of range. normal 473 having been closed during the first vertical advance of the switch wipers. The release magnet 422 operates and returns the switch wipers to normal.



   In order to describe how the TRC long distance communications rotary connector chooses the first locally occupied trunk line in a group, in case the trunk lines are locally engaged or long distance engaged, it will now be assumed that the long-distance communications operator extended a long-distance communication through the TTS long-distance transmission selector cord circuit 0, from the second TS long-distance selector to the TRC long-distance rotary connector at a time when the first and second junction lines extending towards P.

   B.X. "N" are engaged in long distance communications and the trunk line comprising conductors 271 to 274 is engaged in a local call, the local call having been extended to P, BX. "N" by means of the LRC local rotary connector.

   (A detailed description of the operation of the LRC connector was considered unnecessary as its vertical and rotational operation under the effect of two digits formed on the dial is similar to that of the TSC connector when used in local communication. , and that its automatic junction line search operation is well known, this operation being controlled by the jerky advancement relay 219 which can be actuated in series with resistors such as R4 and R9I, which will be mentioned later ).

 <Desc / Clms Page number 34>

 



   At this time, the three chain relays 494, 495 and 496 are actuated and the chain circuit connecting the battery through resistor R95 to test contact 486 'is closed. The test contacts 486 and 487 are also both directly earthed and the test contacts 486 'and 487' are earthed by means of resistors such as resistor R4, as seen. in 6E and in 60; FIG. 6. The conditions prevailing on the test contacts 489 and 489 'are the same as those represented in 6B, the earth being connected to the contact 489 by means of the wiper 252 and the springs 250 of the LRO connector.



  In this case, when relay 415 drops out and closes contact 451 after the TRC connector wipers have been rotated into engagement with the series of contacts terminating the first trunk to PBX "N", a Sufficient current flows into the lower winding of test relay 418 through resistor R95 to operate this relay. While operating, the relay 418 closes a locking circuit for itself at contact 463, it connects the wiper 483 in the circuit of the jerky advance relay 420 instead of the wiper 482 by opening the contact 461. and by closing contact 462, it prepares the circuit from occupancy relay 414 to contact 464.



   After an interval after relay 415 has dropped, relay 416 drops out and initiates the rotary flushing operation. The switching relay 420 is actuated from the earth supplied by resistors such as resistor R4, connected to test contact 486 'and to test contact 487'.



  As a result, the switch wipers are rotated into engagement with the third set of fixed contacts. As has been assumed, the junction line ending in the third set of fixed contacts is occupied in a com - local communication, no earth connection appears on contact 489 ', but the direct earth is connected to the fixed contact

 <Desc / Clms Page number 35>

   .489. The value of resistor R93 is however high enough to prevent the passage through this resistor and in the winding of the jerk advance relay 420, of a current sufficient to operate the relay 420. The relay 420 therefore remains. offset and the wipers are stopped on this series of fixed contacts.

   The occupancy relay 414 is also energized by means of its lower winding from the earth on the fixed contact 489 via the wiper 482 and the contacts 464 and 459.



  While operating, the relay 414 connects the earthed switch I to the upper conversation conductor at the location of the contact 444, it opens a point in the circuit of the switching relay 419 at the contact 445, and prepares a circuit. lock for itself to the bell control conductor 407 at contact 447.



   Upon completion of rotary operation, relay 417 drops out and opens a point in the circuit of switching relay 420 at contact 457 and closes the latch circuit for the lower winding of the occupancy relay 414 to. the bell control conductor 407 by allowing the contact 458 to close. By the separation of the contacts 460, the two-phase relay 410 is again allowed to operate up to its second phase and to make the previously described circuit changes involving the disconnection of line relay 4II from the line conductors. of jonotion.

   The operator of long-distance communications then receives the busy signal by the flickering of the lamp L, the switch I now being connected to the upper conversation conductor, all as described previously.



   The way in which the operator of the long distance communications establishes the communication with the engaged participants and then causes a release of the local call in this type of communications is the same as when a call is extended to a subscriber line. individual occupied

 <Desc / Clms Page number 36>

 sword. The operator momentarily applies the ringing current to the junction conductors 3 and 4 and thus causes the de-energization of the occupancy differential relay 414. The relay 414 de-energizes and closes the circuit of the switching relay 419 which, when operating, closes points in the conversation circuit at contacts 465 and 468.

   A second application of the ringing current to conductors 3 and 4 causes the application of an earth potential to the two conversation conductors 8 and 6, which establishes an imbalance in the differential relay 218 of the LRC rotary connector used. in local communication. Relay 218 operates and at contact 223 it closes a circuit for release relay 242 which by operating returns the LRC connector wipers to normal. The long-distance communications operator is then connected to the private branch office by means of the third trunk line and the subscriber who was connected to this private branch office by this trunk line has been disconnected.



   If the long distance operator wishes to send a signal to the attendant at the private branch office, he can do so on a regular basis by applying ringing current to junction conductors 3 and 4, which currently causes relay 22 of the TTS long distance transmission selector to operate. By closing contacts 77 and 74, relay 22 applies ringing current to the connecting conductors to actuate the signal in the attendant cord circuit.



   In the above case, it was assumed that the locally engaged trunk which was chosen was busy in an extended call up to P.B.X. "N". If this trunk line had been busy in a local call from PBX "N", the first selector of the main office used in this local call would have been activated (as described previously) at the start. LRO connector place.

 <Desc / Clms Page number 37>

 



  If the three trunk lines going to the private branch office are busy in long-distance communications as the operator of the long-distance switches tries to extend a common to them! - oation, the wipers of the connector used , the long-distance rotary connector TRC for example, are rotated opposite the series of fixed contacts ending the last joining line and up to engagement with contacts 491. 492, 492 'and 493 and they will be stopped in this position, fixed switch 4921 not being equipped. The occupancy relay 414 is actuated by means of the contacts 459 and 464 from the earth connected to the contact 492 by the resistor R94, and then it connects the switch 1 to the upper reversing conductor at the location of the oontadt. 444.

   As the battery potential through resistor R96 is connected to the fixed contact 493, now in engagement with the slider 484, the long range sound relay 18 of the long range transmission selector also operates. The operator therefore not only receives the busy signal by flickering but also receives an acoustic signal indicating that all trunk lines to the private branch office are busy in long distance communications as a result of which the operator releases the call and tries again after a while.



   It is possible that after the long distance rotary connector TRC has turned into engagement with the contacts terminating the first trunk line of the group to a private branch office N and has determined that there is one line. free in the group (which is indicated by the absence of a battery connected by means of resistor R95 on test contact 486 '), that the only free line existing at this time be entered by another connector before the TRC long distance rotary connector can take it into service.



  This jonctioon will then be occupied when you try it on

 <Desc / Clms Page number 38>

 , and the long distance rotary connector TRC will continue to rotate on the other sets of occupied contacts, until it engages with contacts 491, 492, 492 'and 493. In this case, the occupancy relay 414 is obviously not not energized because relay 418 has remained de-energized, and switching relay 419 operates immediately following operation of relay 410. The long-distance communications operator then receives the same busy signals. only when all junction lines are found to be engaged at a long distance, as switch I is now connected to the upper junction conductor via fixed contact 491 and wiper 481.

   As before, the operator removes the plug from his cord to release the long-distance communication switches activated and resets the dialed number. In its second attempt, since now all trunk lines are busy, the operator obtains the call through the first locally occupied trunk line.



   CLAIMS: - - - - - - - - - - - - - -
I) - A telephone system in which first selector switches intended to be taken into service to establish a local communication are each provided with a relay mounted in the conversation conductors, this relay being arranged so as not to operate when A local call is being established but operating when a long distance call is extended to the subscriber commenting on the local call so as to effect release of the local call.

** ATTENTION ** end of DESC field can contain start of CLMS **.


    

Claims (1)

2) - A telephone system in which connector switches intended to be taken into service to establish a local communication are each provided with a relay connected to the conversation conductors, this relay being arranged in <Desc / Clms Page number 39> fapon not to be triggered when a local call is being established but to operate when a long distance call is extended to the subscriber commenting on the local call, so as to effect release local communication. 3) - A telephone system containing switches by means of which an operator is able to extend long distance calls, in which a control conductor extends from the first switch in the train to the last switch in the train, conductor by means of which a relay of the last switch of the train is intended to be energized after this switch has been taken in service so as to prevent the ringing current from being applied to the called line, except under the direct control of the 'operator. 4) - A telephone system containing switches by means of which an operator is enabled to extend long distance calls to lines engaged in long distance calls, the last switch in the train being accessible also to local subscribers within which when the final switch of the train has been transformed to function as a long distance communication switch and the chosen line has been shown, on test, engaged in a local call, the application of the ringing current to the first commu - train controller is intended to effect the establishment of a conversation connection by causing the operation, in the last switch of the train, of the relay which operates in a local call when a free line is found. 5) - A telephone system containing switches by means of which an operator is enabled to extend long distance calls to lines engaged in local calls, in which a relay located in the first switch of the train controls a signal of monitoring, is intended to be kept powered by a current coming from the last switch of the train when this last switch is taken in. <Desc / Clms Page number 40> service, and is intended to be released when the communication has been extended to the called line to cause a signal to be sent to the operator, the particular signal transmitted depending on the state of the called line. 6) - A telephone system incorporating a switch connector for use in long distance communications and also in local communications, in which if the desired line is busy when a long distance communications operator has extended a call up to at this line a visual signal is given to the operator, and if the desired line is engaged in a long distance call, an acoustic busy signal is also given. 7) - A telephone system containing a first selector switch intended to be controlled by an operator to establish long distance calls, in which a relay connected to one of the conversation conductors of this switch is intended, when a line occupied in a long-distance call is encountered, to be activated by means of a circuit enclosing this conversation conductor and the test wiper of the connector switch taken into service, and is intended to connect when it is operating a current of signal. 8) - A connector switch having movement in two directions, for use in long distance communications and in local communications in a telephone system, in which when this switch is taken in service by a long distance communications operator , it is intended to be converted for long distance operation in two phases, the first phase being carried out at the end of the first selection operation and the second phase being carried out at the end of the second selection operation. selection. 9) - A connector switch intended for use in a telephone system, comprising two circuits for controlling the release of the switches one obstinate to be. <Desc / Clms Page number 41> controlled by means of the calling line and the other intended to be controlled by a differential relay connected between the conversation conductors. 10) - A connector switch for use in both long distance communications and local communications in a telephone system, in which when a long distance call has been extended to a busy line, a test relay of this switch is intended to be kept actuated by means of a conductor controlled from an earlier point of communication, characterized in that the test relay is a differential winding and in that when a conversation connection must be extended to the called line, the flow of current in this conductor is intended to be reduced and thus cause the current flowing in the two windings of the test relay to be the same . II) - A connector switch for use in both long distance communications and local communications in a telephone system, in which when a long distance call has been extended to a busy line, characteristic conditions are placed on the conversation conductors of this switch, characteristic conditions one of which is used to indicate that this line is busy and the other of which is used to indicate whether the line is engaged in a long distance call or in a local call. 12) - A connector switch intended for use in establishing long distance calls to any line in a group of lines and comprising two test wipers, in which the relay determining the selection of a free line is intended to be connected to a series of wipers if a free line exists in the group, and to be connected to the other series of wipers if all lines (of the group are occupied. <Desc / Clms Page number 42> 13) - A connector switch intended to be used in establishing long distance calls to any line in a group of lines, in which the first line of the group is intended to give the test a different result depending on whether all the lines in the group are busy or not / depending on whether the first line itself is free, is busy in a local call, or is busy in a long distance call. 14) - A two-way connector switch for use in a telephone system, in which a relay which is intended to be actuated at the end of the first movement of the switch and a relay which is intended to be activated. - activated when the called subscriber answers, are intended to jointly control the application of a characteristic potential to the release junction conductor, with the aim of activating a counter. 15) - A first selector switch intended to be controlled by an operator to establish long distance calls and intended to send a potential forward in a ringing control conductor, in which when a line has been chosen, different electrical connections are intended to be established by the doorbell control conductor under the effect of the same determined control operation by an operator, depending on whether the selected line is occupied or is free. 16) - A first selector switch intended to be controlled by an operator for setting up long distance calls, in which the ringing current connected to the conductors entering the switch is intended to produce in certain circumstances the operation of a relay which in turn is intended to produce the operation of a relay to operate partially when the ringing current is connected and fully when the ringing current is disconnected. <Desc / Clms Page number 43> 17) - A first selector switch intended to be controlled by an operator to establish long distance calls, in which a double winding relay intended to control a signal is first energized by means of one of its windings during switch operation and then by means of its other winding after the switch has operated fully in a circuit extending to subsequent switches in the train. 18) - A telephone system according to claims 3 and 4, wherein when a free line is to be ringed, the application of the ringing current to the first switch of the train is capable of causing the release of the ringing command relay and connect the ringing current to this line. 19) - A telephone system according to claim 4, wherein the application of the ringing current to the first switch of the train is intended to cause the release of the test relay of the last switch of the train and to effect the establishment of a talk circuit to this line. 20) - A telephone system according to claim 3, wherein when the selected line is busy, the test relay of the last switch of the train is intended to be kept energized by means of the control conductor. 21) - A telephone system according to claims 4 and 19, in which when the ringing current is applied a second time, a potential is intended to be connected to the conversation conductors and to cause the release of the local call. 22) - A telephone system according to claim 5, wherein the relay in question is also intended, upon release, to make connections to the first switch so that when the called party answers, an additional monitoring condition is established. 23) - A telephone system according to claim 5, <Desc / Clms Page number 44> wherein upon release the relay in question is intended to reverse the direction of the current in the conductors extending to the operator station so as to establish a monitoring condition. 24) - A telephone system according to claims 1 and 2, wherein the relay in question is differential winding and is intended to complete, when actuated, a circuit for the release magnet. 25) - A telephone system according to claims 3, 4,19 and 20, wherein when the potential of the commando conductor is reduced by a resistance interposed at an earlier point of the communication. a balanced Wheatstone bridge is formed with equal values of current flowing through both windings of the test relay. 26) - A telephone system according to claim 3, in which the latter relay is also intended to be employed in looal communications, in which case this relay is not actuated until the called party has answered. 27) - A telephone system according to claims 3 to 5, wherein an AC relay of the first switch of the train is intended, when energized, to complete a circuit for one or the other of two relays , depending on the state of the selected line. 28) - A telephone system according to claim 27, wherein one of these relays is intended to mount a resistor in series with the control conductor and the other is intended to disconnect the potential of the control conductor. 29) - A telephone system according to claim 7, wherein said relay closes on operation a retention circuit for itself to the conductor through which the sound current is supplied. 30) - A switch connector according to claims 8 to 14, wherein when the switch is to be used as a long distance connector, it is taken into service. <Desc / Clms Page number 45> by means of a series of conductors and when it is to be used as a local connector it is taken in service by means of another series of conductors, characterized in that the reversing conductors of the two series of conductors are normally connected to the line relay. 31) - A switch connector according to claim 30, wherein when said switch is taken in service for a long distance call, the long distance talk conductors are disconnected from the line relay and are connected to the talk conductors s 'extending to the desired subscriber. 32) - A switch connector according to claim 30, wherein the test conductor of this second series of conductors is marked occupied when the switch is taken in service for a long distance call. 33) - A switch connector according to claim 10, wherein the test relay is actuated by means of one of its windings and is locked by means of the latter in parallel with the locking winding of the control relay. bell command, by short-circuiting its other winding. 34) - A connector switch according to claims 8 and 14, wherein a relay is intended to be partially actuated at the end of the first selection operation and to be fully actuated at the end of the second selection operation. 35) - A connector switch according to claim 12, wherein a relay connected to the second test wiper is intended to be actuated if all the lines of the group are occupied and thus to carry out the test by means of the second series. da contacts. 36) - A switch connector according to claims 12, 13 and 35, wherein if all lines of a group are engaged in long distance calls, the sliders are rotated into engagement with a special series of oon - <Desc / Clms Page number 46> tacts on which distinctive conditions of occupation are placed. 37) - A selector switch according to claim 16, in which the relay is intended to prepare, by fully operating, a circuit for the connection of the same potential to the two conversation conductors, this circuit being completed when the ringing current is connected again. 38) - A selector switch according to claims 16 and 37, wherein a further relay is intended to operate first partially and then fully when the ringing current is connected a second time. 39) - A selector switch according to claims 28 and 38, wherein this other relay is intended to change, in operation, the ringing current control circuit to the second relay. 40) - A selector switch according to claim 17, wherein the circuit of the second winding is open when the communication has been extended to the called line. 41) - A selector switch according to claims 17 and 40, wherein this relay is intended to cause, upon release, the placement of a monitoring condition on the incoming conductors dahs the switch. 42) - A selector switch according to claims 17, 40 and 41, in which the second winding of the relay is energized in series with the line relay of the following switches. 43) - A selector switch according to claims 17 and 40 to 42 in which a local circuit is provided to keep this relay energized when pulses are precisely transmitted to the following switches. 44) - A selector switch according to claims 17 and 40 to 43, wherein the line relay of the switch is intended to simultaneously repeat pulses to the following switches.at through a local circuit to the switch. <Desc / Clms Page number 47> 45) - A selector switch according to claim 44, in which this local circuit is established so as to first effect the operation of the switch and then to provide a local restraint circuit for a relay normally energized by means of of the circuit by means of which precisely pulses are sent to the following switches. 46) - A telephone system in substance as described above, and shown in the accompanying drawings. 47) - Selector switches in substance as they are described and shown in Figures 1 and 5 of the accompanying drawings. 48) - Connector switches in substance as they are described and shown in Figures 2, 3 and 4 of the accompanying drawings.