BE367264A - - Google Patents

Description

       

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 EMI1.1
 



  AR2A = vG? L: TS OF POTJEI CIRCUITS SEMI-AUTO TELEPHONE SYSTEMS 1,, UTIUrîS, PATTTCTJIT; '' 1, ": T APPLICABLE TO RURAL NETWORKS.
 EMI1.2
 



  This invention relates to telephone systems of the type in which a number of semi-automatic central offices are connected directly to the main central office, or are linked to the latter through ID or several semi-automatic offices in. tandem, the operator of the main central office being able to control the establishment of the connections between the good ones of the same semi-automatic office, or between the subscribers of 'different semi-automatic central offices.



   The invention is especially applicable to networks comprising a large number of small remote central offices and one.

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 smaller number of central offices in tandem. It therefore particularly concerns rural telephone networks.



   The offices in the network are arranged in tandem formation, so that the main office has access to one or more regular rural offices and one or more rural tandem offices, each of the latter having. Access in turn to one or more remote or satellite offices, the arrangement being continued according to the requirements of the system.



   The aim of the invention is to provide an improved arrangement for connecting two subscribers to each other which can be placed in the same office or in different offices of the network, according to one of the characteristic features of the invention, in a telephone system comprising two or more rural offices each connected by one or more trunk lines to a tandem rural office which is connected by one or more trunk lines to an operator position of a main central office , a common line, in a rural office, is automatically connected to a trunk line extending between the rural office 'tandem and the' main office, where the operator, after having received the requested number,

   controls the establishment of a connection to the called subscriber of the same rural office or another rural office through automatic switchgear. An alternate connection is then established between the calling subscriber and the called subscriber, d <. so that the junction line between the tandem office and the main office can be released.



   According to another characteristic fact of the invention, in a telephone system comprising two or more remote rural offices, each being known by one or more trunk lines -, with an operator position placed at a main central office, provision has been made for a means by which a calling line in one of said rural offices is automatically extended through a trunk line to an operator of the main central office who controls the selection of an extended trunk line.

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 to the requested remote rural office, and which controls the section of the line requested at the latter office.

   A connection between the calling subscriber and the called subscriber is then established, which is independent of the trunk line to the main central office.



   Another characteristic feature relates to a circuit arrangement comprising a series of rural offices connected in tandem formation with a main central office, and in which connections are made under the control of an operator at the main central office. A means is provided for connecting the calling line through one or more tandem offices to the main office attendant who controls the extension of the call to the line of the called subscriber through one or more buses. tandem rings. An alternate path, comprising only the offices in the chain between the calling subscriber and the called subscriber, is established, and the trunk, or trunk lines not used in such path are released.



   A circuit arrangement is also described for establishing an automatic connection from one subscriber to another under the control of an operator at a remote central office, the establishment of the connection being controlled through a trunk line which is then released. , the changes of circuits carried out during the establishment of the connection being effected by pulses for supervision signals transmitted through one of the conversation conductors of the trunk line. The pulses, due to the dialing disc, for the control of the automatic switching devices are, in one of the preferred arrangements, transmitted through the other conversation conductor of the trunk line.



     The path, between the operator and the called subscriber, uses common devices at each office or route by which the alternate path between the two subscribers is completed independently of these common devices.



   The call is preferably directed from the calling subscriber to

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 the attendant through one or more trunk switches, one of which is placed at each office that is on the next route, after which the connection is routed from the attendant to the called subscriber through one or several recording mechanisms, one of which can be placed at each office located on the route followed.



  One or more connection circuits, each comprising a series of seeker switches, may also be provided at each office; the arrangement being such that the switches of one of said connection circuits in the office which is furthest away. of the central office, and which also has access to the calling and requested offices, are frozen in accordance with the position of the trunk switches and the recording mechanism respectively used at this office, thus preparing an alternate path between the calling subscribers. and called.



   One or more junction circuits having a finder switch may also be provided at each office, the arrangement being such that the switch of such a junction circuit in each of the offices between that which is furthest from the office. central office, and whoever has access to the calling and called offices, positions himself in accordance with the position of the recording mechanism of this office, thus preparing an alternate path between the two subscribers. Furthermore, this junction circuit can be the same as that used to extend a connection from the calling subscriber to an operator.



   The arrangement may be such that when the alternate path between the two subscribers is completed, these subscribers are automatically disconnected from the operator at the central office, who therefore cannot overhear the conversation from a distance.



   When a subscriber sends a call, and the operator cannot respond promptly, said subscriber replaces his receiver and waits for a call back, the connection being maintained until the operator answers, If the subscriber sends a call and abandons it without replacing its receiver on the switch hook, a means

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 is provided by which the attendant can break the connection.



   Finally, arrangements are made to establish trunk lines serving for service calls and transmitting alarm signals, indicating to the central office faults which occur at rural offices on conversation circuits, the office where this fault occurred being indicated to the central office.



   The invention is better understood from the following description based on the accompanying drawings. On these, Figure 1 shows a diagram intended to understand the principle on which the system is based; Figure 2 shows a cord circuit for rural or tandem trunk lines; Fig. 3 shows a rural tandem office line circuit; Figures 4 and 6 show a single junction rural office arrangement for tandem work; Figures 3, 6 and 7 show a circuit arrangement for a rural single junction office without tandem work; Figure 8 shows a trunk circuit for a tandem office such as office 6 of Figure 1; the. Figure 9 shows a control circuit at the same office; and Figure 10 shows a local connection circuit also at the same office.



   Turning first to Figure 1, two main desks M1 and M2 of the manual type are shown to the right of the drawing, which have access to a main tandem desk A of the semi-automatic type. the latter office has access to a small rural office such as F, a tandem rural office such as D, and another tandem office such as 13. It can be seen that office D is connected directly to two small rural offices E and 0, while office B is connected to both a rural office G and through another junction line to an intermediate tandem office H which has access to a series of rural offices such as I and J across the lines junction L1 and L2.



   The invention is better understood by the description of the establishment of connections with an intermediate tandem office such as H. When a call is sent by a subscriber placed at office H,

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 or in one of the rural offices I and J, a connection is extended through the tandem office H, the junction line J, the tan dem office B. to an operator of the semi-automatic tandem office A which marks on its disk the number of the subscriber called in the usual way. If the called subscriber belongs to b, ureau H, after the connection is established, the junction line J is released and can be used for the establishment of another call, while the subscribers, calling and called, talk to through a local connection circuit from the H.

   If the called subscriber belongs to office I, the. trunk line J is released after the connection is established as before, and in this case the subscribers speak through local connection circuits of offices H and I and through the local trunk line L1.



   Likewise, if the call originates from a subscriber in Office I or Office J, the trunk line J is released after the connection is established, and the subscribers speaking through the local trunk line L1 have L2, or across these two lines, whichever office they belong to.

   For specific calls
In other offices, such as F.C.D, G, they are served in the same way by the operator of office A, the junction lines extending to these offices being released as in the previous case,
The devices in office A are practically similar to those provided in office B, except that keys are provided at operator furrows 0 through which these operators can trace the connecting lines extending to the rural offices lined with junction seeker switch benches, and may extend the junction circuits to lines extending to the main manual office M1.

   In this way, all calls which are normally served by the attendant at office A are automatically extended through this office to the manual office.
Ml, in a manner similar to extending calls through office B. The operator at office Ml then controls the establishment.

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 the connection requested through a trunk line, in the same way as the operator in office A.



   We first describe the establishment of a connection when a subscriber of one of the rural offices, such as C, E, D or F, connected directly or through a tandem office with office A, sends a call.



   Considering now figures 2,3,4,5,6,7, when a subscriber S, belonging to an office such as that shown in figures 4 and 5, or 6 and 7, actuates his magneto, the line relay Lr of the figure 5 or 7 is excited and hangs, disconnecting from the line. The blocking circuit comprises: ba.ttery, Lsr relay, (common to all line relays), working contact of the combined contact (closed before being broken) of the Lr relay, resting contact of Cor, Lr coil, and earth. The relay Lsr, by energizing, connects, through the winding of the relay Br, the earth to the conductor b of the junction line going to the manual office, which activates the relay of this junction line. to said bu- rea.u manual, and ignition of the corresponding lamp.

   If the subscriber belonged to a satellite office, the same maneuvers would take place at this satellite office, and the earth connected to conductor b of the junction line, going towards the tandem office, would energize the relay Jlr in this tandem office. This relay Jlr, when energized, would connect the earth through the relay Br to the conductor b, of the junction line, going to the manual office, in the same way that the relay Lsr connects it in the case of 'a called line belonging to a local subscriber.



   The operator answers. when the attendant, whose cord circuit is shown in fig. 2, inserts her plug into jack J (figure 3) of the junction line, in response to a call, a ground is connected to the conductor at this line, causing the Ar relay to energize (fig. 4 or 5). This Ar relay in turn causes the excitation of the Hr relay, which in turn excites Hbr. By attracting its reinforcements, this last relay moves away the earth which was connected

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 through relay Br to conductor b of the junction line, and the earth of the opening contact of Ar, which actuates the relay Hr, is also connected through a rest contact of Hbr to the changeover contacts of the first relay Lr, of which the normally closed contact is connected to the changeover contacts of a second rele.is, and so on.

   This establishes a circuit preferably in series so that the first energized relay Lr connects the earth to its associated Cor relay. The Cor relay is energized and blocked through the rest contact of the local connector relays Aor and Ccr, the working contact of Hbr, and earth. The Cor relay must be actuated and blocked before Hbr operates, breaking the excitation circuit. The relay Cor, by energizing, connects the battery connected to the rest contact of Hbr through a high resistance, and the winding of Lr in order to prevent this one from being neutralized before Hbr does not operate. so that the earth will not be transferred to the neighboring line relay to cause the operation of another Cor relay.



   The operation of the Cor relay closes the line passing through Bar and Asr. If the subscriber remains on the line, the Bsr relay, energized, operates the Sr relay, closing the conversation circuit through the junction line, and connecting the earth, through the Br relay, to conductor b of the junction line. This turns off the supervisory lamp at the operator's cord circuit. If the subscriber does not remain on the line, the attendant sees her supervisory lamp on in the cord circuit and then proceeds to ring the subscriber. To this end, the attendant must activate the key on the dialing disk and then reset it to prepare a ringing circuit before ringing.

   Since the operation of the key produces a break in the conductor a when it is actuated, and again when it is re-established, the relay Ar responds to two pulses The rest contact of the relay Ar, connects the earth to the contact of the Hbr relay, energizing Dkr on the first pulse. At the end of this, the relay Dkrl, is energized in series with Dkr, transferring the operating circuit to the relay Ror for the

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 second impulse. Relay Rcr energizes, and at the end of the second pulse, relay Rcr1 energizes in series with Rc1, Rela lais Rcr1 transfers conductor b from the junction line of relay Br to one side of the subscriber's line.

   The relay Bar connects the conductor of the trunk line to the other side of the subscriber line through a 1MF capacitor, in order to complete the ringing circuit. The attendant then activates her call and ring keys, sending ringing current to conductor b of the trunk line. The ringing circuit goes through conductor b, one side of the subscriber line, returns through the other side, conductor cr, 1MF capacitor, Asr relay, and earth. The purpose of the capacitor is to reduce the ringing current to conductor a so that the relay Ar does not neutralize during ringing. When the subscriber answers, the attendant restores to. both ringing and listening keys, producing a further break of the conductor at the trunk line.



  The Ar relay responds to this pulse, causing the Olr relay to be energized, and at the end of the pulse, the 01r1 relay is energized in series with Olr. The operation of O1r1 releases the relays Dkr and Dkr1 'while the relay Dkr1 releases the relays Rcr and Rcr1' The reestablishment of the relay Dkx1 still closes the subscriber's line to the Bsr relay which operates through the closed circuit.



   The Bsr relay causes the Sr to be energized, closing the subscriber line through the 2MF capacitors at the trunk line, and also connecting to the ground of conductor b through the Br relay. This produces a transmission circuit. balanced which turns off the attendant supervisory lamp in the cord circuit. The attendant then waits for the requested number.



   Establishment of a local connection between two subscribers in a tandem rural office, such as the one shown in Figures 4 and 5. When a call is reversible, the attendant operates the disk key and marks the line number. requests.



  The operation of this key produces a break of the conductor a., This

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 which operates the relays Dkr and Dkr1 ', By its excitation, the relay
Dkr connects the earth of the make contact of sr through the break contact of Lbr, to relay T1r. The latter when excited connects the earth of the Lbr rest contact to a common conductor to effect a contact on all the Cor relays. The Cor relay, energized, connects this earth through the local connector relays. The local connector circuit which is free, has a battery of the rest contact of the relay Lbr connected to the exciter winding of the relay Cor, so that the first part connected to the local circuit will be connected to the calling side.

   The Cor relay operates and transfers the subscriber's line to the Lcr supervision relay and to the relay.
Gor, The Lor Relay gets energized through the subscriber line and the Gor Relay ground. By its excitation, this relay connects the earth to the blocking contact of Cor, and at the same time closes the circuit of
Lor. The latter, by his excitement, transfers it. battery from the Car driver coil to the Acr relay, so that the second line will be connected to the response side of the local connector circuit. The Dor relay also cuts off the earth used for energizing the local connector relays. The Cor relay on energizing opens the Cor relay blocking circuit, but keeps this relay energized through the combined contact until Lbr operates, so that Cor is neutralized before Ccr is blocked.

   The calling subscriber then waits on the local connector circuit for the called subscriber.



   The operator operates her numbering disc. When relay Dkr is energized, it connects an earth to relay Br through a compensating resistance equivalent to 1500 ohms minus the resistance of conductor b from the junction line to the manual office. Relay Drk1 unblocks the line of the Bsr relay which leaves its armatures, neutralizing the Sr relay, which frees the junction line in order to allow the disc to be operated. Relay Dkr 1 connects the earth to the armature of the relay Br for producing the pulses, as well as the blocking earth for the counter relays.

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   The disc operating key connects the battery to conductor b through the calling device, so that the pulses produced are transmitted through conductor b, activating relay Br. The rest contact of Br controls the Scr and Ter counter relays in the usual way, i.e. the Scr relay operates the break contact of Br, closing a blocking circuit in series with the Tcr relay, so that when the Br relay breaks its normally closed contact, the Tor relay is energized in series with Scr. The Tcr1 relay transfers the pulse conductor to the Scr2 and Tcr2 relays so that the second pulse acts on the second pair of meter relays. When the Tcr2 relay energizes at the end of the second pulse, it breaks the blocking circuit of the Scr1 and Tcr1 relays.

   The meter relays continue to operate in this manner until the end of the digit, except that when the torus relay energizes, it closes the pulse conductor at the first pair of meter relays, and it also energizes if relay Adr which closes a blocking circuit through the, relay Adr1, If the number is greater than five, TCr1, by energizing for the second time, releases the relays Sors and Tcr5, Le relay Tcr5, neutralized, breaks the shunt of Adr1 allowing it to operate in series with Adr. The Adr and Adrl relays transfer the counter relays of the first five cut-off relays every five seconds.



   The slow recovery Dsr relay is connected to the pulse conductor and is blocked during the series of pulses.



  At the end of the digit, Dsr is neutralized, connecting an earth to the work contact of Scr through the exciter winding of Btr, the work contact of Tc4, and the corresponding Cor relay. The same earth passes through a break contact from Btr to the slow excitation relay Otr, so that if the line is busy and the Btr relay does not have a closed circuit, the otr relay operates and produces a auditory busy signal, 'If Btr finds a closed circuit through the Cor relay, it energizes and locks up at the

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 same earth, short-circuiting the operation winding, which provides earth for energizing the Cor relay,

   
When the attendant restores the operating key of the disc producing a break in the a conductor of the trunk line, the relays Rcr and Rcr1 are energized, closing a ringing circuit through Cor, like this has been previously described for the calling subscriber's call.



   The operator rings. After having reset her disk key, the attendant activates her listening key to check whether the line is busy. Now that the listening key is activated, it operates the bell key intermittently until the subscriber answers. when this occurs, the attendant restores her two ringing and listening keys, causing a break in conductor a of the trunk line, which energizes the Olr and Olr1 relays. By its excitation, Olr1 frees Dkr and Dkr1 and the neutralization of Dkr1 frees Rcr and Rcr1.

   The Clr1 relay also connects the earth through the working contact of Tlr to the conductor common to all the relays uor, in order to energize the local con necting relays, Since Lbr becomes energized when the calling subscriber is connected. on the local connector circuit, only Acr relays have a battery connected to their windings.



   The Aor relay of the called line is then energized by the earth connected to the working contact of C1r1 transferring the subscriber line to the Lar and char relays. The supervision relay Lar is energized through the circuit of the subscriber line and the earth placed on the relay Gar ,, and blocks Acr. this one breaks the air. Bakes Cor's blockage, but keeps Cor energized through the combined contact until Tlr is released, so as to ensure that Aor is blocked before Cor is neutralized. The subscribers, calling and called, are then connected to each other through a capacitor and the impedance of the conversation circuit.



   The operator remains in her listening position. When the relay O1r1 is energized, it connects the a and b conductors of the

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 junction line to the listening connection of the local connector circuit through a 2MF capacitor placed in each of the conductors, so that the operator can observe the beginning of the conversation. The Tlr relay was blocked to an earth connected to the Hbr work contact, and the Olr and O1r1 relays are also blocked until the attendant removes the jaok plug from the junction line. After the attendant observes the start of the conversation on the local connector circuit, she pulls out her plug, releasing all relays except those maintained by the local connector circuit.



   Restore the local connector circuit. At the end of the conversation on the local connector circuit, one or other of the subscribers, by replacing its receiver, releases the super relay. corresponding vision Lcr or Lar, which in turn releases the corresponding local connector relay. If the calling subscriber hangs up his receiver first, reestablishing the Ler relay moves the blocking earth away for the two local connector relays, but if the called subscriber hangs up first, the reestablishment of Lar releases only Acr and the Lcr relay maintains the Lbr relay energized and the local connector circuit busy, as long as the calling subscriber has not hung up.



   Case where the local connector circuit is busy when a call is received. If a connection exists on the final connector circuit when a call is received, the Lbr relay is energized and prevents Tlr from being actuated when the dialer disk operating key is lowered. The Lor relay operates. This prevents the calling subscriber from being connected to the local connector circuit, but the operation of Dkr1 disconnects the subscriber's line from Bar, causing the re-establishment of this relay and that of Sr. The latter. , by its deactivation, disconnects the subscriber from the trunk line, while the operator operates his disk.



   The excitation of Lor causes oelle de otr and opens the impulse conductor, preventing the operation of the relays-oomp-

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 Lor blocking contact, or an Otr working contact, causes the Tr relay to act as a buzzer. The auditory signal thus produced is induced in the secondary winding of Tr and is sent to the junction line through the capacitor of 2MF by the working contact of Otr,
When the drive control of the disc is restored to idle, the Rcr and Rcr1 relays are energized and the attendant, actions ning her listening key before ringing, hears the auditory signal.



   The ringing circuit from the conductor b to the subscriber's line is open at the Otr relay, so that the attendant cannot ring the subscriber's line. The attendant then activates the sober key and restores the ringing and listening keys, causing the 01r and Olr1 relays to be energized while the Dkr, Dkrk, Rcr, Rcr1 relays are neutralized as before.

   By neutralization, Dkr, reconnects the subscriber's line to the Bsr relay which operates through the line circuit to the subscriber, which energizes sr which reconnects the subscriber through the capacitors to the trunk line, so that the operator can inform the calling subscriber that the requested line is busy at the local connector circuit, The requested line is occupied by the connector circuit loca reestablishment of Dkr1 frees Lor, which in turn free Otr and Tr, this which stops the auditory busy signal. By its excitation, the relay Lor also transfers the blocking circuit of the relays Olr and Olrl to earth at the working contact of Dkr1 'so that O1r and Olr1 are released when the relay Dkr1 is neutralized.

   This prevents the operator from being connected to the. listening connection on the local connector circuit.



   Case where the local connection is free and the called subscriber does not answer. In the case where the local connection is free when the operating range of the disc is lowered, the calling subscriber. is connected to the calling side of the local connector circuit, as was previously discussed when establishing a local connection.

   If the called subscriber does not answer, the attendant restores his listening and ringing keys, activating the Olr relays.

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 and OLr1 as above. The relay Tlr, being energized when the calling subscriber is connected to the local connector circuit, hold;
Olr and Olrl excited, which connects the attendant to the listening connection of the local connector circuit, then informing the calling subscriber that the called subscriber is not responding. When the plug is removed from the trunk line, all relays are released except local connector relays which are released when the calling subscriber hangs up his receiver.



   Establishment of a connection between a local subscriber belonging to a tandem rural office (fig.4 and 5) and a subscriber belonging to a satellite office (fig.6 and 7). when the subscriber appelpnt belongs to a tandem rural office (fig. 4 and 5), the operator rings him in the manner previously described. When the disk operating key is operated to mark the requested number /, the calling subscriber is then connected to the local connector circuit as before. The first number marked closes a circuit through the relay Cor of the junction line going to the satellite shown in figs. 6 and 7. At the same time an earth is applied to the conductor a in order to excite Ar, Hr and Hbr in a satellite office.

   The Cor relay is energized in the same way as before by the earth coming from the Btr relay. The JKr pilot relay, which is common to all Cor trunk relays, operates in series with the Cor relay. The Jkr relay, by energizing, activates the Jcr relay which connects the blocking earth for the Cor relay through the Jbr relay which energizes and locks to earth at the Dkr working contact.



   The earth for the Jor relay also passes through the Jor rest contact to the Jpr and Pr relays. The Jor relay, being slow-acting, gives the Par relay sufficient time to operate before breaking its contact. rest. The excitation of Pr produces a break in the conductor a from the junction line to the satellite, and the relay Ar of this latter office, responding to this impulse, actuates Dkr and Dkr1. This makes the circuit in

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 the office.satellite ready to receive the impulses resulting from the operation of the disc.



   The slow acting relays Jpr and Pr are designed to produce a break in the conductor at the satellite office of the desired time for the extreme voltage limits. The Jor relay also releases the meter relays in the office and transfers conductor b from the junction line of the manual office, directly through conductor .1 from the junction line to the office. tellite. In this way, the pulses due to the operation of the disc for the second digit are received directly in the satellite office. At the end of the second digit, the Cor relay of the called line is actuated through the path established by the meter-relays, and which is the same as that previously described in the tandem office.

   When the drive key to the disc is reset, producing a break in the conductor a from the trunk line to the tandem office, the relays Rcr and Rcr1 are energized as before. By its excitation, Rcr connects an earth through the rest contact of Rcr1 to the work contact of Jor,, ¯ causing the excitation of the Jpr and Pr relays, which produces a break in the conductor a of the line junction to the satellite office, and this causes the excitation of the relays Rcr and Rcr1 at this office.

   This establishes the conductor b ring circuit from, the trunk line coming from the manual office directly through the conductor b from the trunk line to the satellite office, to one side of the subscriber line at the. earth through relay
Asr from the satellite office and through the 1MF capacitor to the a conductor of the, trunk line to the tandem office, which is similar. connected to the relay Asr and earth, through the 1MF capacitor of the conductor a from the junction line to the manual office. When the subscriber answers, the operator, by restoring her ringing and listening keys, produces a break in conductor a, causing the O1r and O1r1 relays to be energized at the tandem office.



   By its excitation, the relay O1r connects the earth to the con-

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 tact Jor worked through the rest contact of O1r1, again energizing Jpr and Pr, which produced a break in the a conductor from the junction line to the satellite office. The relays
Olr and O1r get horny at this desk. Excitation of O1r releases relays Dkr and Dkrl, connecting the subscriber line to the trunk line through a capacitor and the impedance of the conversation circuit. The circuit includes the Ber relay, the Asr relay, and the 2MF capacitors. The Bsr relay, when energized, causes Sr to operate which releases O1r and O1r1 and connects an earth to conductor b through Br. This reestablishes a balanced transmission circuit and also produces supervision at the tandem office.

   Relays Olr and O1r1 at the tandem office remain energized as a result of the blocking circuit established by the excitation of Tlr which energizes when the calling subscriber has been connected to the local connector circuit, and connects the trunk line to the satellite on the responding side of the local connection circuit in the tandem office, as has been described in the case of a local connection.



   The operator also listens on the local connection to observe the start of the conversation. When this operation removes the jack plug from the trunk line, all relays are released except those maintained by the local trunk circuit, and the trunk line from the tandem office to the manual office is released. released.



   At the end of the conversation, the local connection circuit is released as before, except that if the called subscriber in the satellite office replaces his receiver first, the Bsr link is neutralized in the satellite, which frees sr and moves the earth of conductor b away from the junction line going to the tandem office. The supervision relay Lar is released in its turn in the local connection circuit, which disables the relay Acr of this circuit.

   If the calling subscriber replaces his receiver first, the Lcr relay is released, which in turn releases the Ccr and Acr relays of the local connection circuit The Aor relay

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 close the conductor b of the satellite office junction line to the relay J1r, which creates a momentary call until the called subscriber has replaced his receiver. if the local connection circuit in the tandem office is busy Empress receives the auditory busy signal and informs the called subscriber. as has already been described.

   If the local connection circuit in the tandem office is free, and if the called subscriber is busy in the local connection circuit of the satellite office, the calling subscriber is connected to the calling side of the local connection circuit, and the operator receives the busy signal from the satellite office.



   The operator then rings and restores her ringing and listening keys, producing a break in the conductor a from the junction line to the tandem office. This causes the excitation of Olr and 01r1 which in turn excite Jpr and Pr. This produces a break in the a conductor from the junction line to the satellite office, which causes the excitation of the Olr and c1r1 relays. from this office. The relays producing the auditory ocupation signal are then released in the same way as before. Relay T1r, being actuated in the tandem office, maintains olr and
O1r1 excited while connecting the attendant to the listening position on the local connection circuit to inform the calling subscriber.

   At the same time, the trunk line at the satellite office is connected to the answering side of the local connection circuit, but since there is no subscriber on the line at the satellite office, the t conductor of the trunk line is connected to the earth, and the junction line becomes free.



   In the event that the called subscriber does not answer, the operator connects to the local connection circuit in the same way. to inform the calling subscriber.



   In the case where the calling subscriber is part of a satellite office, the operation is the same, except that there is a trunk line and that the excitations of the Cor and pilot relays

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Ukr cause Jcr's excitement. When the attendant activates her disk key and restores it to ring the subscriber who initiated the call, a circuit is closed through the rest contact of Sr, the rest contact of Dkr1 'the relay and the Dkr work contact, and Jar work contact. This excites the Jor relay. Earth for the Jor relay passes through the normally closed contact, operating Jpr and Pr and producing a break in the a conductor of the trunk line going to the satellite office.



   This causes the excitation of Dkr and Dkr1 at the satellite. The second break in the conductor a, when the operating key of the dis that is restored, energizes the relays Rcr and Rcr1 in the tandem office and is repeated at the satellite by the earth of the working contact of Rcr1 'operating the relays Jpr and Pr in the manner already described.



   The ringing circuit is then connected through the tandem office and the satellite office to the subscriber line.



   Another difference is that the trunk line from the satellite to the tandem office is not connected to the calling side of the local connection circuit until after the first digit has been marked on the disk.



   The earth of the working contact of Sr, which operates the relay,
T1r when Dkr gets excited, is kept discarded by the Jcr relay.



   When the Dsr relay is neutralized after the first digit, establishing an earth at the Btr relay, it passes through a rest contact of Btr to the Jor relay which, being energized, closes the circuit through the rest contact of Lbr to Tir instead of Otr. The Jcr relay, being energized, also keeps the circuit open for the Btr winding, thus preventing the called line from horn operation until the calling trunk line has been connected to the local connection circuit and the Cor relay of the junction has been released. This reestablishment leads to Jkr's, which in turn frees Jcr closing the circuit through Cor of the called line. Therefore the operation of the circuit is the same as before.

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   In the event that the local connection circuit is busy on these conditions, the Lbr relay is energized and the earth of the Jor's make contact passes through the Lbr's make contact, operating Lor which is blocked and gives the signal of occupation at the operator.



   Establishment of a local connection between two subscribers. in one of the satellite offices, such as the one shown in figures 6 and 7,
When a subscriber in a satellite office (figs. -6 and 7) requests a connection with a subscriber of the same office, the calling subscriber is ringed after the connection has been established in the same way as that already described. ..The calling subscriber is not connected to the local connection circuit in the tandem office, until after the first digit has been marked on the disk. As this first figure is the number of the same junction line, it connects the blocking earth of the cor relay through the counter relays to the blocking contact of the Djr relay, keeping the latter energized.

   When the relay
Dsr is neutralized, after the first digit, the earth of its rest contact is connected to the work contacts of Djr and Jcr, causing Jor to excite. The earth for the Jor relay pushes through a closed contact, actuating the Jpr and Pr relays, which produces a break in the conductor "a" of the junction line and which causes the operation of Drk, and of Dkr1 at the satellite office, so as to connect the calling subscriber to the local connection circuit in the satellite office, as has been described in the case of the tandem office.

   By its excitation, the Jor relay releases the meter relays to the tandem office and transfers the driver "b" of the junction line of the manual office directly to the driver "b" of the junction line at the satellite office, L ' called subscriber is connected to the local connection circuit, then is rung as before. Relays 01r and 01r1 of the satellite are kept exalted by relay Tlr, thus connecting the trunk line to la. listening connection on the local connection circuit.

  <Desc / Clms Page number 21>

 



   A ground of a make contact of relay 01r1 is channeled through a make contact of Lbr and the winding of relay Br, to conductor "b" of the junction line of the office tan dem, which energizes the relay. Bsr at this tandem office. By its activation, this Bsr relay causes the operation of the Sr relay, which frees the Olr and 01r1 relays and prevents the attendant from being connected to the listening connection of the local circuit in the tan dem office. The trunk line coming from the manual office is connected to the trunk line from the satellite office through the normal capacitor and the impedance of the talk circuit.



   After the attendant notices that the conversation has started, she removes the plug from the trunk jack, releasing the Ar, Hr and Hbr relays at the tandem office, which disables the uor relay on the trunk line. to the satellite office and brings the Ar, Rr, Hbr relays back to rest at this office.



   The junction between the manual office and the tandem office, and the junction between the tandem office and the satellite office are then both released.



   In the event that the called subscriber does not answer, or in the event that the local connection circuit is busy, the operator receives an auditory busy signal from the satellite office after the disk has been operated and informs the operator. calling subscriber, as explained above,
Establishment of a connection between a subscriber of a satellite office (fig.s6 and 7) and a subscriber of another satellite office with equipment similar to that shown in figs. 6-and 7.



  In this case, the calling subscriber is rung in the satellite office in the same way as that previously described, and the connection with the called subscriber of another satellite office, similar to that shown in figs. 6 and 7, is established. in the same way already described. The calling subscriber is connected to the calling side of the local trunk of the tandem office (figs 5 and 4) through the trunk of the calling satellite office, after the first number has

  <Desc / Clms Page number 22>

 been marked to the disc, and the called subscriber is connected to the re-band side of the local connection circuit of the tandem office (fig. 4 and 5) through the trunk line of the called satellite office in the same way as before.

   When the attendant removes the plug after observing that the conversation has started, the junction from the manual office to the tandem office is released in the ordinary way, leaving the junction of the respective satellite offices connected to the local connection circuit in the tandem office. Either subscriber, by replacing his receiver, moves the earth of conductor "b" away from the junction line of his respective satellite office to the tandem office, thus freeing himself from the local connection circuit in the usual way. .



   Establishment of a connection between a subscriber of a manual office and a subscriber of a rural office (as shown in figs. 6 and 7).



  When a subscriber of a manual office calls a subscriber of a rural office, the operator marks on the disk the number of the requested subscriber, as before, but since the relay Sr is not energized. when the disc control key is actuated, relay Tr1 returns to rest. When the attendant produces a break in conductor "a" after ringing, causing the Olr and 01r1 relays to be energized, the called subscriber is not connected to the local circuit, but the Bsr relay is energized. which produces the excitement of Sr.



  Ralis 01r1 and 01r1 are neutralized and the subscriber line is connected to the junction circuit through a capacitor and the impedance of the conversation circuit. If the called subscriber is busy through the local connection circuit, the operator receives a busy signal after the operation of the dialing disk, as has been described previously.



   Case of a long distance connection. When the operator marks on her disc a number concerning an interurban connection and receives an auditory busy signal after the disc operation, she can connect to the local circuit in order to offer the

  <Desc / Clms Page number 23>

 known as long distance connection. To this end it operates the key to its nerie, then restores both the listening and bell keys, producing a break in the "a" conductor, which energizes the Olr and Olrl relays.

   By its excitation, 011'1 neutralizes Dkr and Dkr1 which in turn neutralize Bcr and Rcr1 ', Relay Lre being energized, transfers the blocking circuit of 01r and 1r1 to the working contact of Dr1' so that the neutralization of this last relay causes that of the Olr and o1r1 relays, The Lor relay is blocked on the same earth, but since it is slow recovery, it ensures the reestablishment of 01r and 01r1, The attendant then activates the disc operating key and resets it, producing two breaks in the conductor "a" of the junction line, which causes the operation of relays Dkr and Rcr.

   It then activates the listening and bell keys, then restores them, which brings about another break in conductor "a" and consequently the operation of relays 01r and 01r1 The excitation of 01r1 frees again the dkr and Rcr relays, but the Lcr relay being neutralized, allows the normal blocking circuit to be closed for the Olr relays which remain energized, connecting the attendant to the monitoring connection on the local connection circuit,
After having offered the long distance connection to the subscriber of the local connection circuit, the operator decides to cut this local connection. It operates the operating key of the numbering disc and marks the number of the requested subscriber. The operation of this key energizes the relays Dkr and Dkr1 in order to prepare the disk circuit.

   When Dkr energizes, it connects earth to conductor "b" of the junction line through relay Br. The latter energizes, and when Dkr1 operates, it connects earth to the armature of relay Br through the idle contact of Ror, and the work contacts of Br and Olr. The Bdr relay is energized and connects the earth of the working contact of 01r1 to the Sr relay which operates and releases 01r and 01r1,
The Bdr relay locks to the earth of the Dkr relays and opens the blocking circuit for the Dkr relays of the closed contact.

  <Desc / Clms Page number 24>

 of 01r1 'so that when the relays Rcr and Rcr1 are energized, the relays Dkr and Dkr1 are neutralized. The Bdr operation also breaks if the blocking earth for the local connection circuit, and the blocking earth for the Cor relays.

   When the Dsr relay is neutralized, after the number is marked on the disc, which closes the earth at the exciter winding of Btr, it finds a closed circuit towards the relay Cor of the called subscriber, which brings l excitation of the Cor relay of the requested line. when the attendant restores the operating key of the disc,, causing the excitation of the relays Rcr and rcr1 ', the relays Dkr and Dkr1 are released following the operation of the Bdr relay, as explained previously . Restoring drk12 frees Bdr, which in turn frees Rcr and Rcr1 'which are held through to the working contact of Bdr.



   The relay Bdr is slow recovery, in order to keep the relay Rcr1 energized and ensure the recovery of Dkr. The neutralization of Bdr, re-establishes the blocking earth for the Cor relay, before the exciter path is broken by the re-establishment of the counter relays.



   The requested line is now connected to the Bsr and Asr relays, which operates the Sr relay and connects the line to the trunk circuit for conversation.



   Offending jonstino line. If the conductor "b" of the junction line connecting the manual office to the tandem office is earthed, the line relay is energized, lighting, in a permanent manner, the lamp placed in front of the operator. If conductor "a" is earthed, the Ar relay is energized, in turn actuating the Hr and Hbr relays, which connects a earth to the thermally heated relay Thr through the rest of relays Sr, Dkr1, Dkr and Olr.

   If this circuit is not broken at the end of a time equal to approximately one minute, the thermally heated relay connects the earth to the Pgr relay which is blocked at

  <Desc / Clms Page number 25>

 make contact of Ar and breaks the circuit at relay Hr, which neutralizes Hr, Hbr and Thr. The Pgr relay connects to the manual desk a ground to the conductor "b" of the junction line, activating the line relay, which permanently lights the lamp.



   If the fault is eliminated, relay Ar is neutralized and Pgr, by giving up its reinforcements, restores the circuit to its normal position.



   Decommissioning of a faulty anointing line, a satellite office. If a junction line going from a satellite office (figs.6 and 7) to a tandem office (figs.4 and 5) becomes faulty, either on conductors "a" or "b", the earth connected to the driver "b" energizes relay Jlr at the tandem desk, thereby creating a permanent lamp signal at the manual desk. The operator recognizes the faulty line by ringing through it, and notes that it is a junction link to a satellite office, since the relays of the local subscriber lines are connected to the earth and do not not excite through a faulty line.



   In order to determine which trunk line is at fault, the attendant makes a test call on each trunk line, up to 9. that the said faulty line is found.



   The attendant then disables this line by marking the disc the number "O" followed by the number of the junction line, and then removes the plug from the jack. When the number "0" is marked on the disc, the gold relay is actuated through the working contacts of Adr and Ter56. The relay 'Or, by energizing, closes a circuit for the relay Jr through the rest contact of
Ter.5 so that when the second digit is marked on the disc, the Tcr5 relay is neutralized and the Jr relay is energized.

   The excitation of Jr transfers the conductors operating Cor from Tcr1-4 to the respective relays Jdr, so that when Dsr leaves its reinforcements after the second digit, the earth is connected to the relay Jr of - the junction line whose the number was marked on the disc. The Jdr relay, by being excited, opens the conductors "a" and "b" of the junction line and locks itself through the conductor "b". When the

  <Desc / Clms Page number 26>

 fault is eliminated, the Jdr relay is neutralized and the junction line is ready to operate.



   Alarm fuses. The circuit is fused with relays Ar, Otr, Lor and Tr on a rear part of the main fuse, so as to give m hearing signal to the operator when any fuse is blown except this one.



   A burnt fuse connects the battery to the alarm bar of the fuse panel, actuating the Far relay which connects earth to conductor "b" of the junction line through the relay Br, actuating the line relay which gives a permanent lamp signal. When the attendant pushes the plug into the junction line jack, activating the Ar relay, it connects the earth through the working contact of Far, which energizes Lor, otr and Tr, and sends the auditory signal to occupation on the junction line.



  This auditory signal distinguishes between a permanent lamp signal for a burnt fuse and a permanent lamp signal for a faulty trunk line. When the attendant removes the plug from the junction line jack, the Ar relay is neutralized, thus releasing the Lor, 0tr and Tr relays. So these relays are only active during the time when the operator is connected to the trunk lines.



   , Charging the battery. When the battery is charged from the manual office through the trunk line, the Chr polarized relay is connected between the "a" conductor of that trunk line and the Ar-relay. A negative 48 volt battery or higher potential is connected through the normally closed contact of the line relay and the cut-off relay at the manual office, to the "a" conductor, The current passes through the energizing winding of the .Chr relay, and the Ar relay, towards the. rural office battery. The Chr polarized relay operates when the current is reversed, disconnecting the earth from the armature of the Ar relay, so as to prevent Hr and Hbr from being energized.

   When the attendant inserts the

  <Desc / Clms Page number 27>

 plug into the junction line jack, applying earth to the "a" conductor, the current flow is reversed through the polarized relay which energizes in the opposite direction, restoring the earth to the armature of the Ar relay, from so that the circuit works in the normal way. The Chr blocking winding is energized every time the circuit is in operation, aiding the exciter winding in maintaining a firm contact for ground at the Ar relay armature.



   When the junction line is chosen by a call arrives at the manual office, the operation of the line relay moves the load current away, and similarly, when the junction line is chosen by the operator inserting her plug into the jack , the operation of the cut-off relay moves the load current away from the line.



   The batteries in the satellite offices are charged in the same way by connecting the charging battery to the conductor "a" of the trunk line to the satellites in parallel, and in parallel with the battery of the tandem office through the re-
 EMI27.1
 distance "n.



   Operation of the Chr relay at the tandem office actuates the Cjrd relay, connecting the charge battery through the "D" resistors in parallel with the "C" resistor. The values of these resistors depend on the resistance of the junction line between the manual desk and the tandem desk, and the resistance of the junction line to the various satellite offices, as well as the load current required for each of them. is obtained.



   As can be seen from the previous description, the offices 0, E, D, F, are of very small capacities and are provided with relay switching devices. However, office B is assumed to have a capacity of 50 to 99 and to have 10 trunk lines going to other offices. There are therefore 40 or 89 local subscriber lines. Stepper switches are used instead of connector relays, but as will be seen from the following description

  <Desc / Clms Page number 28>

 boasts for a few types of connections, the. general method of operation is exactly similar to that already described in connection with relay desks.



   The circuits used in an office such as B are shown in Figures 8,9,10, and are now described.



   Local call.



   Subscriber calls: When a subscriber turns the magneto of his station, the line relay Lr (fig. 8) is energized and blocked, disconnecting from the line. By energizing the relay Lr places a battery potential on its terminal "H" and, through a high resistance, energizes the common starting relay Lsr. The operation of the latter causes the Str relay to be energized by an earth at the test relay Tsr, which sets in motion the line seekers of all free junction circuits, looking for the calling line, and closes the earth. of the neutral contact of the relay
Tsr to actuate the switches step by step, The first junction circuit which finds the line has its switch which stops due to the operation of the relay Tsr,

   which in turn activates the Ovr relay. Operation of Cvr connects earth to Tor's low resistance winding, which makes the line busy and bypasses the common start relay Lsr, thus stopping the search of all switches in other rush circuits.



   By its operation, the Cvr relay connects the earth through the Obr delay relay to the conductor "b" of the junction circuit going to the operator, which causes the operation of the line relay in this circuit, giving thus the desired signal to the operator.



   The operator answers; When the attendant inserts the plug into the junction circuit jack, the. Cord circuit ground is connected to conductor "a", causing operation, of the Oar relay which in turn controls the Hr and Hbr relays. The operation of the Car relay moves the earth of the conductor "b" away from the junction circuit, thus lighting the supervision lamp in the

  <Desc / Clms Page number 29>

 cord circuit, and indicating that the subscriber is not on the line,
The attendant rings: when the attendant operates her ringing olé producing a break in conductor "a" of the junction circuit, the Oar relay responds to the pulse.

   When this relay closes its rest contact, it connects the earth to one of the windings of the relay Rlr through the make contact of Hbr, causing the operation of this relay R1r. This being slow recovery remains excited until Car again closes its working contact.



   At this moment, the relay Car blocks the relay R1r by its second winding in parallel with the exciter winding of Ccr which is energized and connects the control circuit to the junction circuit. The Cor relay closes the battery through its blocking winding to earth in the control circuit in series with the Cr relay of this circuit. The operation of the latter connects the earth to the blocking conductor for the relay Cr of the junction circuit.



   The Cor relay, in the junction circuit, being energized, closes the blocking conductor for the Cr, cr1 and Cr2 relays. The Cr relay, when energized, closes a blocking circuit, so that the junction cooked air remains connected to the control circuit until the selection is finished or until the attendant removes her plug. When the Cr1 relay energizes, it transfers the "a" and "b" conductors from the operator's junction circuit to the control circuit. The Cr relay in the control circuit operates the DKr and DKr1 relays in series, and also operates the Hr relay, which in turn drives the Hbr relay. when the latter. is energized, it links the blocking earth to the relays Dkr and releases the relay cr, as well as the relay Ccr of the junction circuit.



   The Ar relay is energized through the "a" conductor of the operator's junction air, after which the Cr1 relay in the control circuit transfers the "a" conductor of the junction circuit. Relay Ar blocks relay Hr, after which relay Cr

  <Desc / Clms Page number 30>

 neutralizes itself. The relay Sr, in the junction circuit, being aU, rest, the earth, connected to its rest contact, is connected through the working contacts of the Cvr and Cr relays of the junction circuit and the working contact of the Cr relay of the control circuit., to the Rsr relay winding.



   The Rsr relay energizes and locks, closing a circuit for the Rcr relay, which circuit passes through. earth of the working contact of Ckr1, The operation of the relay Rcr closes an earth through the working contact for its non-inductive winding, which bypasses this winding. When the Rsr relay is neutralized, it moves the shunt away from the Cr1 'relay, allowing the latter to operate in series with the Rcr relay. By its excitation, Rcr1 transfers the conductor "b" from the trunk line of the operator to the subscriber line for ringing. The other side of the subscriber line returns through the junction circuit to earth through the Asr re-greening coil in the control circuit.

   The Rcr relay also closes a return path for ringing current through a 1.M.F. capacitor. in parallel with the Asr coil.



   When the subscriber answers, the operator checks the requested number, then does not mess around. The listening wrench breaks the "a" conductor of the trunk line. The Ar relay in the control circuit responds to this pulse, and the earth of its rest contact activates the Olr relay followed by the operation of
1or1 in series with xelais Olr at the end of the pulse. The operation of 01r1 releases the Dkr relay. Neutralization of Dkr causes the junction circuit to be disconnected from the control circuit by breaking the blocking earth for the Cr, Cr1'Cr2 relays in the junction circuit.



     The neutralization of Cr1 transfers the a and to conductors from the subscriber line of the control circuit to the Asr relays and
Ber in the junction circuit, and the conductors a and b of the air-

  <Desc / Clms Page number 31>

 operator's junction cable are reconnected to the Car relay and to the Obr delay coil.



   With the subscriber now on the line, operates Bsr which in turn operates Sr, which connects the talk capacitors in the transmission circuit. If the requested subscriber belongs to the manual office or beyond, the attendant completes the connection by his cord circuit. The operation of Sr connects earth through the Obr relay, to conductor b of the trunk line which turns off the supervision almpe in the operator's cord circuit, and when the subscriber replaces the receiver on the hook. switch at the end of the conversation, the Bsr relay deactivates, releasing Sr. in its turn. The supervision lamp is re-ignited in the cord circuit.



   When the attendant removes the cord circuit plug from the junction line jack, Car is neutralized and actuated Rlr which is blocked to earth through the rest contact of Sr, the working contact of Cor, and the rest contact of Cr. The slow recovery relays Hr and Hbr begin their recovery - when Car turns off. When Hbr closes its rest contact, it connects the earth through the working contacts of Rlr and Cvr, and the brush R of the switch, to the Lr relay which is neutralized.



   By its neutralization, Lr moves the battery away from terminal H, thus releasing the relay Tsr. This causes the neutralization of Cvr which in turn releases Rlr, thus returning the junction circuit to the normal position.



   Establishment of a local connection. If the called subscriber belongs to the same office as the calling subscriber, the operator activates his disk key after having restored his listening key. The operation of this disk operating key causes a P breaker in the conductor a of the junction line, and the Car relay responds to this impulse, causing the junction circuit to reconnect to the control circuit, as has been done. originally described, except that the subscriber being on the line

  <Desc / Clms Page number 32>

 does not cause the Rar and Rcr rela.is to operate, but causes the Bar relay to be energized in the control circuit. The Dkr relay connects the earth through the compensating resistor to the Br relay for the operation of the disc.



   The cord circuit connects to the local connection circuit The operation of Bsr, in the control circuit, activates Tlr which in turn operates Lcr1 and Lcr2 The relay Lcr1 connects the earth to the wire preferably in series of the circuits local connection, thus causing the operation of relay Cq4 of the first free local connection circuit. The control circuit relays Lcr1 and Lcr2 transfer all the conductors necessary to establish the connection of the junction circuit to the local connection circuit, and the relays C1r1, C1r2, C1r3 close all the con- duotors of the control circuit to its own local connection circuit.



   By its excitation, Tlr connects the battery through a low resistance, back on the junction circuit, to the searcher's broom in order to mark the calling line. Girl's operation of the local connection circuit closes the path for activating the line seekers on the calling side of the local connection circuit to locate the calling line.



     When the switch arrives on the terminal of this line, the relay
Ctr of the local connection circuit operates and stops the motor solenoid. Conductors a and b are not transferred from the trunk circuit to the local trunk circuit until the called line is tried, or until it is determined that the call is not a reversible call.



     The operator activates her numbering disc. The operator can begin operating the disc while the local connection circuit searches for the calling line. The called subscriber is a local subscriber, the first digit of the number is 1. The relay Br responds to the impulses from the disk which are sent through the con- troller.

  <Desc / Clms Page number 33>

 conductor b of the junction line and actuates the electromagnet of the SMS marker switch in the control circuit in series with the slow reset relay Dsr. The latter operates for the first digit, bringing on the excitation of Fdr, and at the end of the pulse, when Dsr is neutralized, Fdr1 is excited in series with Fdr.



  The marker switch brush No.2 earth is connected through terminal No.1 and the working contact of Fdr1 to relay Lor, which locks to the main earth of the working contact of Dkr.



   The Gold relay transfers the conductors for marking and testing from the junction circuit terminals to terminals ten of the selector switches. The marker switch responds to the pulses of the second digit and activates the selector in the local connection circuit by means of the earth of the Mtr rest contact through the brush 2 of the marker. The test of the marked terminal takes place by the battery through Mtr and brush 4 of the marker switch.



   At the end of sending the second digit, after the Dsr relay is neutralized, moving the shunt away from Sdr, the selector of the local connection circuit finds the marked tens terminal.



  The Mtr relay is energized, stopping the motor electromagnet and causing the excitation of Sdr. The latter transfers the impulse conductor from the marker motor electromagnet to the selector motor electromagnet through the marker brush 3. The third digit is thus received directly by the selector in the local connection circuit. when the relay Der energizes at the start of the pulses of the third digit, it causes the operation of Tcr which moves the earth away from the armature of Mtr, and opens the circuit of the Mtr winding. The Tor relay operates the slow reset Ltr relay, in preparation for the line test.



   Test of the line. At the end of sending the third digit, when the Dsr relay is neutralized, Tcr1 is energized in series with Tcr and connects Tbr to the selector's brush R, in order to try the lig-

  <Desc / Clms Page number 34>

 not called. ' If this is free, the earth is connected to the Lr and Tbr relays which must not be excited. When Tcr1 energizes, it causes the reestablishment of the slow reset relay Ltr, and when it closes its normally closed contact and Tbr has not yet attracted its armatures, the earth is connected to the closed contact of Tbr and to the relay Ltr1.



   By its excitation, Ltr1 connects the battery to the selector brush R in order to actuate the line relay Lr of the called line. At the same time, Ltr1 connects the earth of the rest contact of Olr to the Ocr relay of the local connection circuit. By soh excitation, Oor operates Ccr which connects the calling line to the local connection circuit, and also connects earth through the low resistance winding of Ctr to terminal H of the calling line to keep it occupied. The Tsr relay is thus bypassed in the junction circuit, causing it to be restored to the normal position.



   Ocr also connects the earth to the winding of Atr through the selector brush H, which operates as soon as the line relay energizes, applying a battery potential to terminal H. The energization of Atr causes that of Acr which connects earth through the low resistance winding of Atr to terminal H, in order to make the called line busy.



   Acr connects the conductors and b of the called line to the control circuit, the relay ocr keeping these conductors open to the battery and to the earth in the local connection circuit. The operation of Acr causes that of str in the baked air of. control, which transfers the conductors and b from the junction air- baked to the local connection circuit for the bell.



   Ringing of the requested line. When the attendant activates the bell key, it causes a break in conductor a of the trunk line. The Ar relay responds to this pulse and causes the operation of the relays-Rcr and Rcr1. The latter transfers the driver b. from relay Br to conductor b of the line

  <Desc / Clms Page number 35>

 subscriber for the call. Inrush current returns through conductor a of the subscriber line to earth through Asr in the control circuit.

   The Rcr relay also closes a return path for the inrush current through a 1.M.F capacitor, to conductor a of the operator's junction circuit. uconnection of the calling and called lines. when the called subscriber answers, the attendant resets the listening key causing a break in conductor a of the junction circuit, which energizes the Olr and 01r1 relays. The Olr excitation neutralizes Ocr in the local trunk circuit, which connects the called line to the calling line through the transmission circuit in the local trunk circuit.



   Excitation of 01r1 in the control circuit connects conductors a and b of the operator's junction circuit through capacitors of 2.M.F. to conductors a and b of the local connection circuit, so that the attendant can observe the start of the conversation. 01r1 also releases the relays Dkr and Dkr, which neutralizes Rcr and Rcr1. The ur relays in the junction circuit are kept energized after Dkr is neutralized, and this by means of the earth connected to the working contact of
Str. Disconnection of the control circuit from the junction circuit is thus avoided and the connection between the control circuit and the local connection circuit is maintained.



   When the attendant removes the plug from the junction circuit jack, the Ar relay in the control circuit is released, which neutralizes Hr and Hbr. The reestablishment of Hbr causes that of T1r, which in turn neutralizes Lcr1 and Lcr2 ', as well as Clr1'C1r2 and C1r3 in the local connection circuit. In this way, this local connection circuit is disconnected from the control circuit.



   Str in the control circuit is thus released and in turn neutralizes the Gold relays of the junction circuit, disconnecting them from the control circuit t leaving the local connection circuit under the control of the subscribers in line. conversation.

  <Desc / Clms Page number 36>

 



   Restoration of the local connection circuit. When 1, one or the other of the subscribers connected to the losal connection circuit places its receiver on the switch hook, it releases the corresponding supervision relay Lcr or Lar. The normally closed contact of either of these relays connects the earth to the selector brush R on the corresponding side of the local connection circuit, thus releasing the line relay, this moves the battery away from the H terminal, this that neutralizes the test and cut relays Atr and Aor, or the relays utr and Cer. Disabling these relays activates the selector switches on the corresponding side of the local connection circuit, and these switches return to their normal positions.



   The Lar and Lar supervision relays being both neutralized, release the Lbr relay which leaves the local connection circuit free.



   Case where the called subscriber belongs to a tandem office.



   In this case, the first digit of the number is between 2 and:, depending on the number of the trunk line going to the tandem office. When the marker switch of the control circuit goes beyond, terminal 1, it begins to mark the junction line (s), and at the same time activates the selector in the local connector circuit to search for the junction line. marked terminal.



   If there is more than one trunk line going to a tandem office, the selector automatically advances to the first free line or to the last line of the group. At the end of the first
 EMI36.1
 figure, when.Dsr is neutralized allowing the excitation of] dr1 a circuit is closed towards the relay Tcr through the work contact of Mtr and the rest contact of Lor.



   By its excitation Tcr releases Mtr, which allows Tcr1
 EMI36.2
 to operate 1'd el / Î'alsllne.ex / lamllre already described. The Lor relay not being energized, indicates to the tandem office that the calling line is a trunk line, and the ground of its de'repos contact is connected through the tra-

  <Desc / Clms Page number 37>

 bringing vail of Tor to excite jer and prepare the circuit causing a break in the conductor a of the called junction line, after it has been tried, then to connect it to the control circuit.

   When this has taken place, the excitation of Str connects the earth to the coil that to the conductor a of the junction line in order to actuate the relays Ar, Hr and Hbr in the tandem office.,
The earth of the str make contact, through the work contact of Jcr, energizes the slow operating relay Jor and at the same time operates the slow recovery relay Pr. By its excitation, Pr pulls the earth which is connected away. through Asr to the conductor a of the trunk line, thus producing a pulse to prepare the tandem office to receive the second digit
The operation of Jor transfers the conductor of the trunk line of the operator of the relay Br in the metallic control circuit through the conductor 1 of the trunk line to the tandem office.

   The pulses of the second digit are then. stirs directly in this tandem office. When the operation of the disc is completed and the attendant operates the bell key, producing a break in the conductor a of the junction line, the relays Rcr and Rcrl of the control circuit are actuated as before. The operation of Rcr causes the excitation of
Pr through the rest contact of Rc1, and the excitation of Rcr1 releases pr, producing a break in the a conductor of the called junction line in order to actuate Ror in the tandem office. The operation of Olr and 01r1 in the control circuit, after the ringing, excites pr in the same way to cause a break in conductor a of the called line in order to actuate 01r in the tandem office. The local connection is then established as before.



   Reversible call. If the calling subscriber is a subscriber of a tandem office and calls a subscriber of the same office, the first digit of the number corresponds to that of the trunk line or

  <Desc / Clms Page number 38>

 group of trunk lines through which the calling subscriber is connected, and the stepping switch on the calling side of the local connection circuit finds the calling line in the same way as before.



   When the Fdr relay in the control circuit energizes at the end of the first digit, it connects earth to brush six of the marker vers. the T terminal of the step switch on the calling side of the local connection circuit. This switch being stopped on the terminal corresponding to the number of the junction line called, the earth of terminal T passes through the ba.lai T and operates the reversible call relay Rvr of the control circuit. Operation of Rvr overrides the line test by opening the circuit for the Tbr test relay and Tbr normally closed contact, thus preventing ltr1 from operating.

   Relay Rvr releases successful Tlr, which in turn releases Lcr1 and Lcr2 'which disconnects the control circuit from the local connection circuit.'
The called side of the local connection circuit searches for the terminal / marked of the called line according to the usual method, and it stops as a result of the operation of Mtrf of the control circuit, before Fdr1 energizes at the end of the digit. Mtr's make contact earth energizes the Tcr and TCr1 relays in the usual way, and Jcr is also energized, since the called line corresponds to a tandem junction line.



   When Tlr is neutralized, it connects an earth from the break contact of Sr in the junction circuit through the make contacts of Cvr and Or, to the make contact of Jcr, in order to energize the Jor and Pr relays. This produces a break in the conductor .a of the trunk line to which the calling subscriber is connected.

   The Jor excitation transfers the conductor b to the conductor b of the tandem junction line, as has been described previously., But STr being normal, it is connected back to tre towards the junction circuit instead from being to the local connection circuit.- The disc maneuver for the second and the third

  <Desc / Clms Page number 39>

 digit, and the ringing call of the called subscriber is then made through this circuit, and when Olr and 01r1 are operated, releasing Dkr, the relays Cr in the junction circuit are released disconnecting the junction circuit of the control circuit.



   The tandem office trunk line is then connected through the conversation circuit to the attendant trunk circuit, which can observe the start of the conversation.



   When the attendant removes the jaok plug from the trunk line, the trunk line relay is released as it was for the subscriber line, making the trunk line free at the tandem office and the junction circuit.



   Appal from the manual office. When the attendant inserts the plug into a junction line jack to answer a received call, earth is connected to the a conductor of the line,, energizing the oar relay, which in turn energizes Rr and Hbr. The operation of Hbr connects the earth of the rest contact of Tsr through the rest contact of Cr3 to the motor electromagnets of the stepper switches, returning them to the normal position.



   The operation of the numbering key produces a break in the conductor a of the trunk line, which connects it to the control circuit, as has been described previously.



   Since there is no calling subscriber on the line, the control circuit does not connect to a local connection circuit, but leaves all the conductors necessary to operate the step-by-step switches and test the connected lines. return to the junction circuit. When the marker switch in the control circuit is actuated by the pulses of the disk, it marks the trunk lines and the ten terminals, as has been described for local connections, except that the step switches of the control circuit. junction searches for the marked terminal.



   When the Fdr relay in the control circuit is actuated at the beginning of the first digit, it connects the earth through the Lori break contact to the junction circuit for

  <Desc / Clms Page number 40>

 energize relay Cr3 which closes the control circuit conductors to actuate the step-by-step switches and begin restoring to the normal path. Connection establishment, line testing, and subscriber ringing take place in the trunk circuit in the same manner as described for a local connection.



   When the Clr relays in the control circuit are energized after ringing, the junction circuit is disconnected from the control circuit by re-establishing the Ur relays in the junction fired, and the subscriber line is connected to the attendant 'through the conversation circuit in the trunk circuit.



   Audible busy signal If the called line is oc-
Cut off, a battery potential is connected to the R terminal of the line, and when Tbr in the control circuit is connected to the R terminal for the test of the line, it gets excited causing the excitation of Ctr . The excitatory winding of Tr is connected through, through its own rest contact in parallel with otr, and interrupts itself, which produces an auditory signal in the secondary winding. The Otr relay connects the conductors of the secondary winding De Tr to conductors a and b of the junction line to the operator.



   When the attendant activates her listening key after having maneuvered her disc and receives the busy signal, she operates the bell key and restores the listening key, causing the relays Rcr and clr to operate. the. usual way. The operation of 01r1 releases Dkr which in turn releases Fdr, sdr, Tcr and Otr, which moves the auditory signal away from the junction line.



   Since the Str relay has not been actuated, because the line is busy, it is possible to restore Cr in the junction circuit and disconnect the control circuit,
The reestablishment of Cr1 in the junction circuit, re-connects the subscriber to the operator through the conversation circuit

  <Desc / Clms Page number 41>

 so that the operator can inform this subscriber that the requested line is busy.



   Offer of a long distance line and termination of an existing connection for this line. When the attendant calls a number for a long distance connection, and she receives a busy signal, she can activate her ringing key, then reinstating both these ringing and listening keys, causing the operation of relays Rcr and Olr in the control circuit. When the Otr relay energizes, it connects the earth of the Tlr rest contact to the Tor relay. Relay Tr is blocked at the make contact of clr and connects a ground to the blocking conductor of relays Cr in the junction circuit, so that when the relays Dkr are neutralized, the junction circuit does not disconnect from the circuit. control.

   Tor operation also connects the talk leads from the make contacts of C1r1 to the listen leads to the junction circuit that are connected to leads a and b on the Cvr relay selector. The operator can then offer the. long distance connection to the called subscriber ... if the operator decides to break the connection and substitute the long distance call, she must press the key on the dialing disc and mark the desired number again.



   The Ar relay, in the control circuit, responds to the breaking of the a conductor of the junction circuit produced by the operation of the disc operating key, which causes the operation of the Dkr and Dkr1 relays. The operation of Dkr connects the earth through the compensating resistor to the relay Br and hand holds this relay energized. When Dkr1 operates, it connects the earth to the armature of Br and through its make contact and that of Tor, energizes the relay Bdr.



   The operation of Bdr neutralizes the O1r relays, which in turn neutralizes the Tor relay, The working contact of Bdr connects the earth to the junction circuit to free the conductor,

  <Desc / Clms Page number 42>

 
 EMI42.1
 causing the line relay on which the selector is stopped, in order to release and to. break the connection. The slow recovery Bdr relay locks to earth on the recovery conductor long enough to release the Lr relay. When Dkr is neutralized, the earth of its rest contact restores the marker to the normal position while the operator offers the. long distance connection.

   The relays Fdr, Sdr and Tcr are also neutralized so that the control circuit is in its normal condition to receive the impulses from the disk. when the attendant activates her disc again, the test of the line indicates that it is free and the connection is established through the junction circuit in the usual way. If the subscriber calls to one of the tandem offices and is occupied by a local connection to his own office or to an intermediary office, the operator receives the auditory sipnal of occupancy of this office. tandem. When the bell key is activated and then restored, causing the operation of the Rer and rela.is.

   Olr of the control circuit the relay Pr is energized as previously described, producing a break in the conductor a of the tandem office junction circuit, and causing the same operation at this office. By its activation, the O1r1 relay of the control circuit releases Dkr which neutralizes the Cr relays of the junction circuit, disconnecting the control circuit e +, connecting the junction line of the tandem office to the attendant through the conversation circuit in the junction circuit. The Olr relays in the tandem office remain energized and connect the attendant to the listening position of the local connection circuit, in order to provide the long distance connection.

   To break the connection, the attendant activates her operating key on the dialing disk and marks the number again, which reconnects the junction circuit to the control circuit in the usual way.



     . The junction circuit, being connected to the tandem office,

  <Desc / Clms Page number 43>

 caused the control circuit to connect to the local connection circuit, and when the operator marks the first digit of the number on the disc, it operates as has already been explained for a reversible call. The break in the conductor s of the junction line of the tandem office, produced by the relay Pr after the first digit is marked on the disk, causes in the tandem office to break the connection in a regular manner.



   Faulty junction line. If the conductor of the junction line is earthed, or if this line is short-circuited, the Car relay energizes in the junction circuit which in turn actuates the Hr and Hbr relays. By its excitation, the latter connects the earth to the thermal relay Thr which, if it is not disconnected for the normal operation of a call, operates after a period of time of about 30 seconds and energizes the Pgr relay. . this is blocked on working contact with oar, which frees the Hr, Hbr and Thr relays. The excitation of Pgr moves the earth away for the seeker from the junction line, which deactivates this cooked junction air.

   The Pgr relay connects the earth to conductor b of the junction circuit, which, if not faulty, causes a permanent call. When the fault is repaired, the Car relay is neutralized, releasing the Pgr relay and placing the junction line in working condition.



   Decommissioning of a faulty tandem office Junction line. If a junction line of a tandem office is faulty, a ground connected to the conductor b energizes the relay J1r of the Urn circuit thus causing a call ... if the attendant operates the key of the numbering disc, the junction circuit connects itself to the control circuit in the usual way, and this control circuit connects to a local connection circuit whose calling side searches for the calling line in the usual way.



   The operator marks the number zero on the disc, and when Fdr1 in the control circuit operates at the end of the number, it connects the earth to brush six and terminal ten, which excites Dr. The same earth is connected. through terminal 10 to brush 5 of the marker

  <Desc / Clms Page number 44>

 in order to activate Mtr and stop the selector on the called side of the local connection circuit for the. research. by his excitement, Dr opened the circuit of the Tbr relays and
Lrt1, while, connecting the earth to the local connection circuit through the brush D of the selector on the calling side of the connection circuit operating the relay Jdr which deactivates the trunk line on which the switch is stopped.

   The relay Jdr opens the conductors a and b of the junction line and locks at the conductor b, thus keeping the junction line out of service until the fault is eliminated.



     Cleverly with the capacity of 50 to 99 lines. For this purpose it is necessary to add a step-by-step switch to each junction circuit and to each side of the local connection circuits. The brushes of the second switch are connected before the first and the brushes of the first switch are connected to the normal terminals of the second switch. Wiring shown in blue on the circuits is added and the connections, indicated by asterisks, are broken.



   Considering the remaining figures of the drawings, a system, offering facilities similar to those of the system described above, is shown, but the connections are always made by means of automatic switches controlled by a mechanism. The recorder placed at each office, the connection being established under the control of an operator at the central office as before. Figure 11 shows a diagram of a network comprising a number of offices with different elements thereof. Figure 12 relates to the circuit of a security station. Fleure 13 relates to a line circuit for the subscriber's call office.

   Figure 14 shows a recording circuit which can be used at any of the rural offices. La, fig.15 relates to a modification of the recorder of fig. 14 which can be used in an office with a larger capacity than that which is to be served by the recorder of fig.14df. Fig. 16 shows a

  <Desc / Clms Page number 45>

 connection circuit which can be used in any rural office to complete an alternate path between two subscribers. Fig. 17 shows a junction circuit acting in both directions.



  Figure 18 shows a tandem line circuit. Fig. 19 shows the end of a tandem trunk from a rural office to a city office. Figure 20 shows an expansion and alarm circuit with the necessary changes to the two-way acting junction circuit with which it is combined.



   The invention is better understood by first considering the diagram shown in fig.ll.



   In figure 11, an urban office or main office is indicated at D with one or more junction lines extending to a tandem rural office A. this includes a number of outgoing circuits, some of which lead to subscribers placed in the same office A, while others go to a similar tandem rural office such as B, and still others go to an extreme rural office BB. Office B has a number of outgoing circuits similar to those of A and extending either to local subscribers or to other extreme rural offices such as C. A group of tandem trunk lines connect to the rural office tandem A which correspond with the group of main junction lines connecting office A to urban office D.



   A description of the connections for serving a call between subscribers located at some of the four rural offices, or at the main office D, is now given.



   When subscriber S2 of office B calls subscriber S1 of urban office D, he makes the call by turning his magneto. A relay in the SLB line circuit responds to this maneuver and a JSB free trunk finder connects to the calling line.



  A relay in the TLB tandem line circuit of office A then operates, and a JSA free junction finder connects to the line in use. A supervision signal operates vis-à-vis the attendant

  <Desc / Clms Page number 46>

 from the main office D, which completes the connection manually to the requested subscriber S1, and this in the usual manner.



   If subscriber S2 of office B wanted to speak to subscriber S3 of the same office, the connection to the operator of main office D would be established in the same manner. The attendant, on receiving a call, connects the junction circuit JA by means of a plug to the registrar RA of office A. She then marks on the disk the number corresponding to the group of tandem junction lines. JLB and the RSA line selector of the RA recorder connects to the JLB tandem line in use. The JB trunk circuit is connected to the RB recorder instead of to the JSB trunk line finder. The attendant then operates her disc sending pulses into the RB recorder through the RA recorder, pulses which correspond to the number of the requested subscriber (two digits).

   The RSB line selector of the RB recorder searches for the requested line leading to subscriber S3, easa, ye this line, and sends signals to the operator of office D. At this moment, the selector switch SB1 of the LB connection circuit is placed on the 'terminals, corresponding to those assumed by the switch JSB, is to say on the line of the subscriber S2. The switch SB2 of the LB circuit is placed on the terminals corresponding to those assumed by the switch RSB, that is to say on the line leading to the subscriber
S3. A connection circuit is thus prepared between the subscribers through the connection circuit LB which is independent of the recorder, and the lines extending towards the main office. The operator then rings the subscriber S3 through the recorders RA and RB.



   When the subscriber 53. answers, the connection is established to the subscriber S2 through the connection circuit LB and the switches SB1 and SB2, and a signal is transmitted to the operator or office D. This operator removes the connection. plug, and the RA and RB recorders return to repetition. When the operator removes the plug from the circuits, JA and JB neutralize each other.



   In the case of a connection between subscriber S2 of office B

  <Desc / Clms Page number 47>

 and the subscriber S4 of office BB, the connection is established to the operator of office D in the same way as before. The attendant inserts her connection establishment form and marks in the RA recorder the number corresponding to the group of junction lines in tandem JLBB leading to office BB. The attendant marks the number requested through the RA recorder in the RBB recorder. The RSBB selector of this RBB recorder is brought to the line of the subscriber S4, which line is tested, while a signal is transmitted to the operator. At this time the JSB finder of the trunk circuit is already brought to the calling line.



  The switch JSBB of the office junction circuit BB is placed on the terminal corresponding to that assumed by RSBB, that is to say on the requested line leading to the subscriber S4. The searcher SA1 of the connection circuit LA is placed on a terminal corresponding to that assumed by the switch JSA, that is to say on the line JLB, while the switch SA2 is brought to the terminals corresponding to those assumed by the RSA switch, that is to say on the JLBB line. The operator then rings the subscriber S4 through the recorders RA and RBB. When the subscriber S4 answers, the recorder RBB is released and the junction circuit JBB is connected to JSBB. A connection is made through LE junction circuit JB, connection circuit LA, and junction circuit JBB.

   A signal is then transmitted to the operator. This removes its plug and the RA recorder is released as before. When she removes her regular plug, the JA jdnotion circuit is released.



   In the case of a connection between subscriber S2 of office B and subscriber S5 of office C, the connection is established in the same way as that between subscribers S2 and S3, until the cir - JB junction fired is connected to the RB recorder. The operator then marks through the recorder RA, in the recorder RB a number corresponding to the group of junction lines in tandem JLC leading to office C.

   The RSB recorder then searches for a free trunk line in the group, and the JC circuit is connected.

  <Desc / Clms Page number 48>

 tee to the recorder circuit 4C. The operator marks the number of the subscriber requested through the RA and RB recorders in the RC recorder. the RSC line selector in the RC recorder is brought to the requested line: S5 which is tested, and a signal is sent to the operator at office D. Seeker SB1 from office B is brought to the corresponding terminals to those assumed by the JSB switch, that is to say on the calling line S2, and the pager. cheur SB2 is brought to the terminals corresponding to those jumped by the selector RSB, that is to say on the JLC line leading to office C.

   The JSC switch is brought to the terminals assumed by the RSO selector, that is to say to the terminals of the requested line S5. The operator transmits from the ringing circuit to S5 via the recorders RA, RB, RC. When subscriber S5 answers, the recorder
RC turns off and the JC junction circuit is connected to the JSC switch instead of to RC. A connection is therefore established through the connection circuit LB and the junction circuit JC.



   A signal is sent to the attendant. the latter removes its establishment form. The RA and RB recorders neutralize each other, and when the attendant removes her regular card, the JA and
JB return to their normal state.



   In the case of a connection between subscribers Sl of office D and S4 of office BB, the operator inserts her two cards into the jacks of a free junction line JLA leading to office A.



  The JA junction circuit is then connected to the RA recorder.



   The operator marks in the recorder RA a number corresponding to the group of junction lines in tandem JLBB. The RSA selector of the RA recorder searches for a free trunk line in this group, and the JBB circuit is connected to the RBB recorder. The operator marks the number of the requested subscriber through RA in the RBB recorder. The RSBB selector brings its brushes to the terminals of the line S4 which is tested, while a signal is transmitted to
Empress. The JSA switch is placed on the terminals corresponding to those assumed by RSA, that is to say on the JLBB line,

  <Desc / Clms Page number 49>

 while JSBB is placed on the terminals corresponding to those assumed by RSBB, that is to say on line S4.

   The attendant rings line S4 through RA and RBB. When subscriber S4 answers, RBB is released and JBB is connected to JSBB. When the attendant removes her establishment card, RA is released and the JA circuit is connected to JSA. A conversation connection is therefore established.



   Considering the circuits shown in figures 12 to
20, one can describe the operation of the system in the establishment of various kinds of local calls, that is to say calls between the subscribers included in the rural network shown in fig.ll. We can consider the operations corresponding to the four rural offices shown schematically in this figure. We therefore envision an office A directly accessible from a manual urban office D, in which case there is therefore no office code; offices B1 and B2 connected to office A by groups of trunk lines and having respectively office codes 3 and 4, an office C connected by a group of tandem trunk lines to B1 and having an office code 34.

   Offices A and B1 are tandem offices and therefore have the wiring and equipment shown in dotted lines in the drawings. There are two groups of tandem lines on A, so relays 34 and 33 are fitted, but 32 is not needed. There is one group only on Bl, so 34 is equipped but 32 and 33 are not needed. Offices B2 and C can be non-tandem offices and can be equipped according to the solid lines of the drawing. The establishment of a connection for the subscriber 361 of an urban office is first envisaged.



   This call involves offices B1, A and D, a tandem trunk line between Bl and A, and a main trunk line between A and D. To produce a call, the subscriber activates his generator and removes the receiver. switch hook. The generator (fig. 12) is connected through the line, and the alternating current actuates the relay L of the subscriber line to the office Bl (fig.

  <Desc / Clms Page number 50>

 



  13). This relay L is blocked through L1 in series with the common start relay 15 in the operating recorder. A battery potential is connected to the T terminal of this line in the banks of all the junction line seekers, in order to identify it. -In 15, relay 22 is assumed to be normal, earth is connected to the chain, and operates S towards the first junction line released (fig. 17). If a trunk line is busy or otherwise out of service, the chain is extended to the neighboring trunk line via BK, KL, H2 or Bl. When S operates, it blocks independently of H2 in S5, closes a circuit for DM, the junction line switch electromagnet, through its own switch contacts S1, and also closes a test circuit for H in S2.



    The trunk line switch begins its search, and when the appended line is found, H operates at the battery identifying the test terminal for that line. By its excitation H opens the contact Hl and is blocked through H6 to the earth T7. Additionally it connects a ground to the test brush at H5, shorting L. Relay H extends the string to the next junction line at H2 and connects the battery through A to the negative side of the junction at H7. The relay L is neutralized and opens the circuit of 15 which is reestablished followed by - At office B1 there are therefore the following conditions: The brooms of the switch of the junction line are stopped on the terminals of the calling line.

   H is actuated and locked to earth at T7 independently of any action on the part of the subscriber. The calling line is made busy at a test selector by a earth connected to brush T at H5. The battery is connected to the negative side of the trunk line to extend the call to office A, and Q and R are in a condition to receive a battery from office A through the positive side.



   The junction line appears at A as a tandem line (fig. 18), and operates the battery on the negative side, A (fig. 18), and L operates on the battery on the negative side. A in B1 should not get excited in. this circuit because of the high resistance

  <Desc / Clms Page number 51>

 of the. In L3 a circuit is closed for 15 in the register of this office. In L1 the battery is moved away from the test conductor, causing the line to be occupied, but is connected to terminal T for its identification. Relay 15 closes a circuit for S in the first free trunk line, as before, and S activates the trunk line switch, closing a test circuit. When the calling line is found, H operates and locks to earth at S3, turns off the switch and extends the chain.

   The battery is connected to the negative side and the brush T is earthed, which operates CO (fig. 18). This CO relay is blocked through COS independently of L1, and disconnects L from the line in CO1. The L relay is neutralized, followed by 15 and S. The L and S relays are slow reset. During the recovery time of L, the, earth is connected to the conductor S of the tandem line through L2 and Co2, and until S is neutralized, T is connected to the brush S through S4. So T operates during this intermediate condition and is blocked through HS to earth at contact Tl.



  Then relay C operates through B3 and H8. With 0 and T operated, H locks independently of S3 to earth in T7.



   In office A, the following conditions are met: The brushes of the switch of the trunk line are stopped on the terminals of the calling tandem line which, in turn, has the brushes of its own switch in the office Bl stopped on the terminals. line terminals of the calling subscriber. H is actuated and locks to earth at T7.



  CO is actuated to earth at H5, which also makes the tandem line busy. Relays T and 0 are energized across earth at Tl. The battery is connected to the negative side of the trunk line to signal a call to city office D.



   At office D, relay Y (fig.19) is energized on the battery connected to the negative side, and closes a circuit for the calling lamp at Yl. Relay A at office A does not operate because of the high resistance of Y. To answer the call, the attendant inserts the plug of one of her regular cord circuits into the jaok of

  <Desc / Clms Page number 52>

 conversation (fig. 19), and C gets excited, opening the lamp circuit at C3 and connecting it. low polarity battery across Z to the positive side of the junction line in C1. At office A, relay Q operates but not R. A low polarity battery, balancing through Y is connected in C2 to the negative side, and Y neutralizes.



  Relay Q operates B which pulls the calling battery away from the negative side at B2, connecting the latter to the place of Q, in order to balance the bridge. In B3 and B4, the negative and positive sides are extended to the tandem line. The relay a is neutralized, but H is not maintained by the earth at B5. The low polarity battery through P is connected to the positive side at B4 and operates Q, but not R at B1. As in office A, relay Q at office Bl activates B which moves the battery away from the negative conductor of the junction line, balances the bridge and blocks H. Relay B at office Bl extends the operator's conversation connection to the calling subscriber.



   We now have the following conditions: The low polarity battery, connected in D to the positive side, maintains Q and A which in turn maintains B, which blocks H. The low polarity battery via B4 at the office To, blocks Q at office B1, which in turn blocks B and H. The train is thus kept under the control of the operator. If the receiver is still hooked to the station, a ground is connected to the negative side (fig. 12). This land operates C at office Bl.

   At C1 (T being normal) an earth is far away from the negative side of the tandem trunk line, and C at office A is Normal. At Cl (T being energized) an earth is maintained on the negative side of the main trunk line, and Y at office D is normal, turning on the supervisory lamp at Yl. If on the other hand the receiver is off hook, C at office B is normal, C at office A is energized, Y at office D is energized, and the supervisory lamp is off. Positive supervision between the subscriber and the operator is therefore planned.



   If the subscriber does not remove his receiver immediately, the operator can ring it.

  <Desc / Clms Page number 53>

 special gift is inserted into the desired jack and the bell key is activated. The earth is therefore connected to the manohon of the plug and D operates, disconnecting the main junction line from Z and
Y, while connecting it to the tip and ring of the cord. The tip is connected to a high potential battery which maintains the Q relay of office A and in addition excites R, In R2 (T being energized), the high potential battery is connected to the positive side of the junction urn in tandem, and this keeps relay Q at office B1 and energizes R. T4 prevents a discontinuity while
R2 changes.

   At this office (T being neutralized) R connects the positive and negative conductors to the subscriber line in R2. Returning to office A, R disconnects 0 from the negative conductor of the tandem line in Rl. the earth through Q and A is also disconnected at c1 (T being operated) from the negative conductor of the main junction line. We therefore have a direct connection, without branching between the ring of the D-plug and the negative conductor of the tandem junction circuit. At office E1, R disconnects, 0 from the negative conductor of the subscriber's line at R1, but 0 remains energized to earth at T6. Relay C does not neutralize during the inversion of Rl due to the damping effect of the shunt through C3.

   The 'earth through Q and A is already far from the negative branch in
C3 (T being neutralized). Here too there is a direct connection without branching between the negative conductor of the tandem junction and the negative conductor of the subscriber line, but in this case the positive conductor of the subscriber line is also connected. When the office ringing key D is activated, P operates and sends ringing current to the ring of the forwarding plug through P4. and P3, and this current has a direct path to earth through the subscriber station bell, which can be connected either between the negative conductor and earth or through the line with its midpoint grounded.

   When the ringer is restored, P and D at desk D neutralize each other followed by R at desk A and by R at desk B1, During the first period of silence, after the a-

  <Desc / Clms Page number 54>

 bonné has removed its receiver, C at office B1 is canceled, C at office A is edited. Y at the office D gets excited, the supervisory light is off, and the attendant removes the referral form.



   By subscribing the conversation key to its regular cord, the operator can converse with the calling subscriber and complete an urban call in the ordinary way.



   At the end of the call, the attendant receives a disconnection signal, as has already been explained. By removing its plug, 0 and D neutralize each other, moving the battery away from the positive conductor and freeing Q, B, H, CO and T at office A, and Q, B, H and C at office B.



   It should be noted that if the attendant removes the plug before the subscriber has hung up his receiver, the sux office connection
A and B1 is not broken, because at office A, H is maintained through the working contacts C2 and T2, independently of B5, and at office B1, H is maintained through the rest contacts of C2 and
T2. outside of C's recovery at office D, with Y still excited, the call lamp is still on, informing the operator of her, thus 'error.' We see / that the connection is normally maintained until the subscriber has replaced his receiver and the operator has removed his card in the desired order.



   However if the rural subscriber. does not replace his receiver in a suitable time after the urba.in subscriber has hung up, the operator can force the connection to be reestablished.



   To do this, she removes the regular plug, inserts the operating cord return plug into the desired jack, and activates the reset key. A ground is connected to the jack sleeve and
D energizes, which disconnects the main junction line from Z and Y and connects it to the tip and ring of the cord circuit.



     The tip is connected to the high potential battery which operates
Q at office A and adssi R. In R2 (T being excited), said battery is connected to the positive branch of the jonotion in tandem, and this operates and R at -office Bl. At office A, R disconnects C from the conduc -

  <Desc / Clms Page number 55>

 
 EMI55.1
 negative tor of the junction in tYJd & m efi Rl, and C is neutralized.



  At office B1, R disconnects C from the negative conductor of the subscriber's line in Rl, and connects it to earth at T6. Relay C operates. At offices A and B1, H is now blocked to ground at B5 with the AC blocking circuit through T7 and 02 being open. at both desks, the operator then resets the reset key and D is neutralized, moving the positive conductor battery away from the main trunk line. The Q and R relays of office A are neutralized. Relay Q releases B, which releases H, which neutralizes T. Relays B or R move the battery away from the positive conductor of the tandem junction line, releasing Q and R at office Bl. Relay Q releases B which releases H. Relay B or R releases C.

   In office B1, relay C has a sufficiently slow recovery, as a result of the shunt on C3, to allow H to neutralize itself before the closing of its alternate blocking circuit. When C at office B has neutralized, a circuit is closed for C at office A. Likewise, C at office A is slow enough to allow H to neutralize himself before his alternate blocking circuit is closed. The connection to the two offices is thus re-established. Although the subscriber has not now replaced his receiver, another call may be served since his line relay at Office B requires generator current to operate.



   Setting up a call from subscriber ¯361 to subscriber 352 is now described. This call continues to office Bl only in the final connection, ¯and after the establishment of this operator call to office D releases the junction between offices D and A and between offices A and Bl which were used.



   Subscriber 361 makes the call, as has already been described, by activating a generator and removing his receiver from the hook switch. Connections take place as soon as the trunk lines are ready through offices B1 and A to office D, and the calling lamp lights up in front of the operator. Cel. this inserts the plug of one of its regular cord circuits into

  <Desc / Clms Page number 56>

   the Jack of the junction line and receives the subscriber's indications. As the call concerns subscriber 352, that is to say a subscriber born from the same rural office, this call is established by the operator by means of its special cord circuit ...



   The attendant inserts the plug of this cord into the jack of the trunk line through which the call arrived. A ground on the body of the plug excites D, which in D3 disconnects the calling lamp and lights the guard lamp. At D1 and D2 the positive and negative conductors of the trunk line are disconnected from the jack at Z and Y, and are connected to the tip and ring of the jack and hence to the cord circuit.

   The tip of this circuit: cord is connected to the battery through the two windings' of M, and Dl being a combined contact, the low voltage battery is held on the positive lead, which keeps Q energized at desk A The ring of the jack is connected to the battery through Nt * and this high voltage battery causes the relay A of the office
Has to get excited.

   'In A2 a circuit is closed for relay 1 in the recorder (fig. 14) provided that this recorder is in its rest position. If the recorder is out of the normal range, as a result of the attendant inserting the card again immediately after releasing a previous call, relay 1 is not energized and M operates in series with R and Q, igniting the supervisory larp. ; This delay in the operation of Relay 1 does not occur normally and in some will break for a short time unless the recorder is disturbed. Relay 1 energizes and closes a circuit for 2 in 12. At 22 a ground is far away from 151, so that no junction circuit finder can operate while the recorder is in use.

   An earth is connected, through A1, in the junction line taken in use, to K which gets excited and blocks in K2 independently of Al. In K4 the blocking circuit of H is transferred from B5 to 61 . In K9 the negative conductor. Is disconnected from A which is released, and is connected to which now maintains itself through this circuit independently of

  <Desc / Clms Page number 57>

 A2. In K8 the positive condactor is disconnected from Q which is released followed by B, The relay B4 disconnects the battery which maintains Q in Bl, and Q is neutralized followed by B at the office Bl, but the junction circuit is not released because that Q is restored before the bonnie hangs up, as has already been explained.

   At 24, at office A, an alternative earth is provided for 1, so that this relay does not deactivate when the selector leaves its idle position. The positive conductor is now disconnected, so that M at the office D is neutralized and the supervision lamp goes out,
We now have the following conditions: In office B1, relay H is blocked through H6, break contact of K4, C2 and break contact of T7. The junction line is made occupied by H2. The. appealnt subscriber link is made occupied by H5.



  In office A, relay H is blocked through H6, the work contact of K4 and 61. The calling tandem line is busy and CO is maintained by H5. The junction line is occupied by Kl. Relay T is maintained by H3. The operator is no longer connected to the. calling line. Since it must now establish the connection with the. called line, and that it uses the same trunk line, this is a desirable condition. Both the supervisory lamp and the calling lamp are off, but the back lamp is burning and indicates that a logger is being held. The battery through the springs of the numbering disc keeps relay 1 energized which blocks relay 2, which blocks relay K.



   The attendant marks the digits of the requested number on the disc. Relay 1 responds to the pulses of the first digit, and at each break closes a circuit for relays 22 and 3 across 12,21,254,101,51 and 11. Relay 22 repeats the pulses to the motor electromagnet DM of the selector. Relay 3 being slow reset remains energized until the end of the digit and actuates 27 and 32.



     If 111 of the digits 1,2,8,9 or 0 has been marked on the disc

  <Desc / Clms Page number 58>

 by mistake, no connection results (it is assumed that the relay 32 is not equipped and that therefore with the number 6, the relay 141 is connected to terminal 72). If the number two has been marked on the disc, the selector remains on the terminals of line 72, and when relay 3 is neutralized, a circuit is closed for relay 5 through 31,243, brush R, 141,53, the winding of 5,64-and 23. If the numbers 1,8,9 or 0 have been marked on the disc, a circuit for 22 is closed in 271 as soon as 27 is neutralized, and the selector 'moves its brushes to until line 72 or 61 is reached, when 6 is energized in an analog circuit.

   Relay 5 either blocks through 53 and opens the motor circuit at 51, which also makes the other marked digits ineffective. Relay 5 closes a circuit for 12 through 52, 91 and 121, and since 12 interrupts its own circuit, an auditory signal is produced. This is induced in the line winding of 1 and transmitted through the junction line to the operator who then removes the special plug. The high-voltage battery is disconnected from the negative conductor, and upon neutralization of D, the low-voltage housing is replaced on the two conductors.

   Relay 1, at office A, is neutralized followed after a certain interval by 2, which in turn releases 5 and K and closes a reset circuit for the selector, controlled by 22 through brush H, switches DM , 21,254,101 and 51. Relay 3 also operates through 11, energizes 27 ,, which prevents other seekers from advancing to 272. When the selector is still in its home position, the recorder has been fully released. . The operator then reinserts the card and marks the number again.



  *

   It is assumed that the number 3 has been correctly marked on the disc. 'The selector takes three steps and its brushes are stopped on the terminals of line 73. At the end of the number, when 3 is neutralized-, a circuit is closed for 33, through 31,243, the gbalai R, 242, the winding of 33,143, and 23. The relay 33 is blocked through - towards 333 and operates 24 in 334. In 336, the relay 8 is connected ed

  <Desc / Clms Page number 59>

 levels R of the terminals of the tandem lines in group "3", that is to say, for the indicated wiring, with lines E, F and G. Relay 24 operates 31 to + rp towards 2410,264 and 85, and relay 31 connects the characteristic conductors of all the tandem lines to the contacts of 33 or 34.

   Relay 33 alone is actuated and en 335 extends the characteristic conductors of the lines in group "3" to relay 26. Through @ 410,311, K6, and the finder's brush S, the battery is connected to the conductor S of the tandem calling line, which is in group "3" since the requested number is 361. This battery is connected through 335, the winding of 26, K3, H6, and K4 to ground in 61, of so that 26 operates. Relay 26 is blocked at 265, disconnects 31 at 264, and energizes 31, When. relay 3 is neutralized, relay 27 returns to idle. Relay 24 also closes a motor circuit for the selector, controlled by 22 through brush H, switches DM, 245,81,101 and 51.



  The selector has now reached the calling tandem line, and therefore a circuit is closed for relay 8 through 23,84,336 the brush R, 243,263, the brush S of the selector, the characteristic conductor, the bay S of the seeker, K6,264 and 2410. In 242,246, 247 and 241, the relay 24 disconnects 33,34,3,8,13 and 14 respectively from the terminals over which the brush R passes during this search. Relay 8 opens the motor circuit at 81 and unlocks at 84. Relay 8 closes a circuit for 25 through 62,88,244, 173, and for 4 through 251. Relay 25 is blocked through 266 In 256 a earth is placed on the T broom to maintain CO from the calling tandem line. Through 42, 257 and 252 the low voltage battery is connected to the positive conductor of the tandem line and energizes Q of the B1 office.

   The Q relay operates B which connects and links the earth to the negative conductor in B2. Through 255, 92 and 13, the high voltage battery is connected to the negative conductor and this operates A at desk B1, which associates the recorder with the tandem trunk line, in exactly the same way as the recorder at office A was associated with the trunk line

  <Desc / Clms Page number 60>

   main. Relay 25 operates slowly, thus giving 4 a pulse before it opens its circuit at 251. Relay 4 is slow to neutralize and holds 23 away from the positive conductor at 42 until K has operated. office B1. When reset from 4, relay 23 is connected to the positive conductor and waits for a ground signal from office B1.



   The operator then marks the second number five. Relay 1 at office A responds but must not feed the recorder because the exciter circuit of 22 is open at 254. Relay 3 must not energize. The pulses are repeated at the B1 office through 13 which is shunted by a spark damper consisting of a 2M.F. capacitor. in series with 100 ohms. Count - repetition is done by opening the circuit in which 1 is blocked in Bl, Relay 1 responds and advances the selector to this office. Relays 3 and 27 energize during pulse kidney.

   The selector has now taken five steps and stops on the terminals of line 75, When 27 is neutralized, a circuit is closed for 8 through traversai, 243, the brush R, 247,273,84 and 23. The r ela is 8 operates and is blocked through 84. At 81 the motor circuit for the selector is kept open so that the selector remains on the terminals of the. line 75, ie at the beginning of the group of fiftieth. -In 87, -a circuit is closed for 16 through 164,87,261,172,
E3, H6, K4.61. Relay 16 operates and blocks through 164.



   At 168, a test is made to determine if there is a free connection circuit at office B1. If the first line chosen is occupied or out of service, the chain is closed through H9 or BK, and, a circuit is closed for lice 7 through 23,64,168, H9 or BK, and 75. Relay 7 operates, is blocks through 75 and in 71-79 changes to the second line, If this is occupied, the chain is further extended through H9 or BK to 5, and this relay operates, locking through 53. Relay 5 closes a circuit producing an auditory signal at, 62, and the attendant is informed either that she has marked a wrong number or that there is no free line.

   The-

  <Desc / Clms Page number 61>

   Peratrice then frees the recorders by removing the special plug. If it is certain that the number marked on the disc is correct, it informs the calling subscriber, who has been reconnected to his station by the action of relay Q and by relays B at offices A and B1, that he does not there is a free start line. Otherwise, it marks the requested number on the disc again.



   If the attendant does not hear any sound at this time, she marks the third digit two. Relay 1 at office A responds and repeats the pulses to relay 1 at office Bl, and the latter relay moves the selector forward. Relays 3 and 27 at office B1 are energized during the pulse train. Relay 27 closes a circuit for 4 through 274,244,88 and 52.



   It should be observed that with the type of wiring shown, and with 32 unequipped, 51,52,53 are the only suitable lines in the row of fifty. In accordance with the number 3, 89 will be connected to the terminal of line 54. If 54 or higher, has been marked in error, relay 5 operates as soon as line 54 is reached, through 83, the brush R, 89,248,53, the winding of 5,64 and 23. Relay 5 blocks through 53, stops the selector, and makes the other digits marked on the disc ineffective at 51. In addition a circuit producing an auditory signal is closed in 52. This auditory signal at this time informs the operator that she has marked an incorrect number, and she can release the recorders to operate the disc again.



   If it is assumed that the number two has been correctly marked, at the end of this number the brushes stop on the terminals of line 52, that is to say of the line requested, and relays 3, 27 and 4 in turn neutralize each other. During the reset period of 4, a circuit is closed for 11 through 43,274, 244,88 and 52. Relay 11 operates 10 through 113 and 23. At 101, the stepping circuit for the selector is open. , so that a subsequent operation of the disc is inefficient. At 104, a terr is connected through 9 to the positive conductor of the line

  <Desc / Clms Page number 62>

 junction in tandem, causing the excitement of 23 at office A.



   Relay 23 operates 10 through 231. Relay 10 operates 6 through 105 and Ill, and relay 6 blocks through 64. Relay
10 also connects the earth through 9 bare positive conductor of the main trunk line, and this operates in office D. Relay M turns on the supervision lamp which informs the operator that the numbering and testing of the line requested are completed. When relay 4 turns off, 11 is connected through 43,86 and 114 to brush T.



   If the requested line is busy, there is a ground at the test terminal, and relay 11 remains energized. The relay 11 establishes an auditory signal produced in the circuit 115, 41, 91 and 121, and this auditory signal is transmitted to the operator. The hearing signal and the lamp together inform the operator that the requested line is busy. The operator can then either release the recorders and inform the calling subscriber that the called subscriber is busy, or she can offer the call to the latter. For this it activates the so-called tender key, which connects the low resistance winding of M directly to the tip, and the strong current operates 9 at the office A. In 93, relay 1 is cut off from the negative conductor. and is connected to a blocking battery. The auditory signal circuit is opened at 91.

   At 96, the low resistance winding of 23 is connected to the positive conductor of the tandem junction line, which exits 9 at office B1. This relay 9 moves the relay 1 away from the negative conductor as in office A, and at 94 and 92 connects the tandem junction line to the called line. The operator can then offer the call to the called subscriber, and if the latter accepts it, she asks him to hang up his receiver. She then resets the key, freeing it to both desks, and she hears again. the auditory signal. When the called subscriber a. hung up, its existing connection is broken and an earth is moved away from its test terminal.



   His line is free again.



   If the line requested is free, 11 is deprived of its cir-

  <Desc / Clms Page number 63>

 bakes and neutralizes, disconnecting the auditory signal at 115, and connecting 10 to ground at 23 through 113,103, and 174. Relay 6 then operates through 105 and 111, and locks up through 64.



  Relay 6 opens the circuit of H at 61, but H is held to earth at 106. Through the make contact of 16l, 62, K6 and the ba.lai S of the junction finder, an earth is connected to the con- S driver of the calling line. Through 185,167,65 and 71, the relay 18 is connected to the brush S of the seeker A. Through 61, 262,171,166 and the work contacts 181 and 77, a motor circuit is closed for this seeker. When its brushes are stopped at the calling line terminals, 18 operates and opens the motor circuit in 181, will also make a motor circuit for seeker B through 78. Through 67 and the selector brush S, the battery is connected to the characteristic conductor of the called line.

   Through 176,182 and 79, relay 17 is connected to brush S of researcher B, and when the brushes of this researcher are stopped on the terminals of the called line, relay 17 is energized, and opens the motor circuit at 171, it locks at 176 and connects 10 to the negative conductor of the called lifne through 113,103,174,255,92 and 253. Relay 10 remains earthed at the subscriber station.



   It can thus be seen that a derivative connection between subscribers 361 and 352 has been prepared at office B1, the brushes of finder A remaining on the terminals of the calling line and the brushes of finder B remaining on the terminals of the requested line. .



   As she hears no sound, the attendant activates the bell key. Relay P is energized through the earth of this key, disconnecting the operator at Pl and P2, and connecting the high voltage battery through M to the positive conductor of Pl. This energizes relay 9 at office A, which disconnects 1 from the line and connects the high voltage battery to the positive conductor of the tandem junction line at 96. Relay 9 at the desk B1 energizes, disconnects 1 as before, and connects the positive conductor of the line of tandem junction to the two conductors of the e- line

  <Desc / Clms Page number 64>

 bonné through 11,294 and 252 on the one hand and 92 and 253 on the other hand,
We now have a direct path between the ground at the subscriber station bell and the current source of the operator cord.

   Ringing current is applied to this path at P4, thereby activating the subscriber's ringing tone. Relay 23 at office A is in series with relay $ at office 131, which keeps 10 energized. M is in series with '9 at desk A, keeping the supervisory light on. When the key is restored to idle, P is neutralized, followed by 9 in office A and 9 in office B1, and relay 10 in office
Bl is reconnected to the calling line.



   During the first period of silence, after the subscriber has removed its receiver, relay 10 is deprived of its blocking earth and, neutralizes, moving the earth of the positive conductor of the tandem trip line away and preventing any further operation. ratino durelais 9. Relay 23, at office A, is neutralized. the earth is moved away from the positive conductor of the main junction line, which frees M at office D, which turns off the supervision lamp, By neutralizing 10 at office B1, a circuit is closed for 'H in the circuit of connection through 61,262,171,
102,165 and 72 Relay H operates and blocks through H8, S2, T2,
K2, G2 and the earth in BK.

   The calling and called subscribers are now connected to each other through capacitors and H2, H3, H6, H7. Their lines are made busy in H1 and H5. The circuit through which H of the trunk line was blocked is opened at 106, and this relay turns off.



   When the supervisory lamp goes out, the attendant knows that the call has been established and removes her two plugs. When this is done, the battery is moved away from the two conductors and relay 1 at office A is permanently neutralized. This relay neutralizes relay 1 at office Bl and relay 2 at office A. Relay 1 at office B1 causes the reestablishment of relay 2. The neutralization of 2 at office A causes that of K, 6,8,24 25 , 26,33, and the selector reset circuit, controlled by 22, is

  <Desc / Clms Page number 65>

 closed through brush H, switches DM, 21,254,101 and 51.



  Relay 3 also operates until the switch is idle through 11 th, operates 27 which at 272 prevents any trunk finders from operating. when the selector has returned to its idle position, and 3 and 27 have neutralized, the recorder is still in its normal position and can be selected for another call. Similarly in B1, when 2 is neutralized, relays K, 6,7,8,16,17 and 18 are reestablished, the selector returns to its rest position, and the recorder is still in the normal position.



   The conversational connection between the two subscribers is now established through an office connection circuit B1, and is completely under their control. When one or the other of the subscribers hangs up his receiver, S or T operates on the earth at the corresponding station, and if this earth persists for a sufficient time, the H relay is reestablished in S2 or T2. The connection is then broken and the connection circuit is still normal and ready for another call due to the opening of H9. The subscriber lines are no longer occupied at H1 and H5.



   The establishment of a call between subscribers 361 and 474 is now described.



   In the final connection, this call includes offices B1 and B2, and tandem trunk lines between B1 and A, and between A and B2. After the call is established, the attendant can free the trunk line between offices D and A.



   Subscriber 361 produces the call which is received by the attendant at office D. This attendant inserts the special card, connects the recorder to office A, and proceeds to mark the requested number on the disc. Relay 1 responds to the pulses of the first digit (4) and stops the selector. Relays 3 and 27 are activated. At the end of this figure, the selector brushes stop on the terminals of line 74 (not the requested line which is at office B2). When 3 is neutralized, a circuit is closed for 34 to

  <Desc / Clms Page number 66>

 through 31,243, the brush R, 246, the winding of 34,143 and 23. The relay 34 is blocked through 341 and operates 24 in 342. The relp.is
24 causes the excitement of 31.

   The latter connects the battery to the characteristic conductor of the calling tandem line as before, but 26 does not operate since it is only connected to the lines in group "4" through 343. When 3 is neutralized 27 also neutralizes, followed by 31. Relay 26 is disconnected from these lines. Relay 24 also closes a motor circuit for the selector, which is controlled by 22 at 245.



   The selector brush T is connected to the balsi R through 263 at, rest and 243. All free tandem lines in any, any group, 'have 20 ohms to the battery on their terminals T through CO3 and 'He. The T terminal of line 61, i.e. the line immediately following the tandem lines, is connected to the battery through 249. The R terminal of this line is connected to 5 through 132, 141 and 53 The T terminals of the tandem lines in the required group souk, ie with the special wiring as shown by lines A, B, C, D are connected to 8 through 344 and 84. The, selector now searches for a free tandem line in group "4".

   In 246, 247 and 241, the rela.is 24 respectively disconnects 34, 8 and 13, and 14 of the terminals through which the brush R can pass during this search.



   If all the lines in the group are busy, the selector moves its brushes to the terminals of line 61. When 5 operates, locks up and closes a circuit producing an auditory signal at 52. This informs the attendant that ' it mishandled the disk number or that there is no tandem line available. The operator releases the recorders and removes the special card. If it is certain that the number marked on the disc is correct, it informs the calling subscriber that no outgoing circuit is free. In the opposite case, it operates the disc again.



     : If we assume that there is a free tandem line in the

  <Desc / Clms Page number 67>

 group required, 8 is energized as soon as its terminals have been reached, opening the motor circuit, locking itself and actuating relay 25.



  At 256, the earth is connected to the brush T to activate the CO relay of the tandem line which has been chosen. Relay 25 connects the low voltage battery to the positive conductor of this line.



  257, in order to operate Q, at office B2. The high voltage battery is connected to the negative conductor at 255 in order to associate the controller with this desk.



   When 8 at office A is operating, a circuit is closed for 16 which is blocked, and in 168 closes a circuit in which 7 operates if the first chosen connection circuit is busy., Relay 5 o- father if both connection circuits are busy.



   It is assumed that the connection circuit is free at office A. The attendant, hearing no auditory signal, marks the second number on the disc 7. Relay 1 at office A responds and repeats the irapulsions at relay 1 of office B2. The selector of this office moves its brushes seven steps and stops them on the terminals of the line 52. When the relay 3 is neutralized, a circuit for
14 is closed through 31, the brush R, 131311 9 winding of 14,82 and 23. The relay 14 energizes, blocks through 143 and closes m motor circuit for the selector, which is controlled by 22 through- to 145. At 144, relay 8 is connected to the terminal of line 60, that is to say to the line immediately preceding the group of "70".

   At 141, relay 5 is disconnected from a terminal through which the selector is ready to pass. When the selector reaches the terminals of line 60, relay 8 operates through 31, brush R, 144,84, windings of 8 and 23, then locks up through 54 and opens the motor circuit at 81.



   The operator then marks the third number. Relay 1 to office B2 responds to the impulses and activates the selector.



   It should be observed that in 71,72,73,74 and 75 there are only suitable lines in the group of "70", so that if it marks 76 or a higher number, it constitutes a maneuver is-

  <Desc / Clms Page number 68>

 regular. If-76 or higher has been marked in error, relay 5 operates as soon as line 51 is reached, through 83, broom R, 142,53, hoarseness of 5,64 and 23. L ' operator hears an auditory signal. Unless she is certain that the number has been correctly marked, she releases the recorders and operates her disc again.



   If the number 4 has been correctly marked, the selector brings its terminals to line 74, that is to say to the requested line. During the series of pulses, relays 3,27 and 4 have been activated, and when 27 is neutralized, the line is tested.

   If it is free, relays 10 and 6 at office B2 operate, followed by 23, 10 and 6 at office A., the operator rings the requested subscriber,
When relay 6 at office B2 is energized, the battery is connected to the characteristic conductor of the line called through 67 and the brush S of the selector. Relay 17 is connected to the brush S of the searcher in the line of junction which has been taken in use through 176,161 at rest, 62 and K6, At 61 a motor circuit is closed for this seeker through 171,166 at rest, K7 and Hl. When the finder reaches the terminals of the requested line, the relay 17 energizes, hangs through 176, and opens the motor circuit at 171.



   When 6 at office A gets excited, the brushes of finder A and finder B in the connecting circuit are placed respectively on the terminals of the calling and called tandem junction lines - A circuit is also closed for C in the connection circuit through 74,163,63K8, H3 and Tl. When 18 energizes, a circuit is closed for K in the connection waxit through K4, 73,184,162 at work, and 2411. These two relays operate and lock themselves out. quent through. G4 and K4 respectively, H4,76 and 183. In G3 and K3 circuits are closed for S and T.



     It can also be seen that a branch connection between subscriber 361 and subscriber 474 is now established, because: at office B1, ¯ the junction finder scans remain on the calling line;

  <Desc / Clms Page number 69>

 at office A, the bansis of researcher A remain on the terminals of this line and the brushes of researcher B remain on the terminals of a tandem line; at office B2, the researchers' brushes remain on the terminals of the requested line,
Hornue the operator hears no auditory signal, she rings the unsuccessful subscriber. In the first period of silence after this subscriber answers, relay 10 at desk B2 turns off, followed by 23 and 10 at desk A and M at desk D, turning off the supervisory lamp.

   When relay 10 at office B2 turns off, a circuit is closed for H in the trunk line through 61, 171,102,156 at rest, and K3. When 10 at office A is neutralized, a circuit is closed for H in the connection circuit through 61,262,171,102,165 at work, and 72. Relay H is blocked through H8 and the work contacts of S2 and G2, K2 and T2 in parallel and the earth in BK. The G and K relays are blocked to earth at H4.



  When relay 10 de-energizes at office A, H's circuit in the trunk line is opened at 106. Relays S and T are still held to earth at 183 and 2411, respectively. When relay 10 de-energizes, the Circuit 25 is opened at 107, and this relay is re-established, removing the high voltage battery from the negative conductor of the tandem trunk line at 255, and releasing the recorder at desk B2. When reestablishing 1 at office B2, relays 3 and 27 energize and at 275 a blocking circuit for H in the trunk line is maintained until K neutralizes, reconnecting H to earth at T7 at rest.



   When H, in the connecting circuit, operates, a direct connection between the calling and called tandem trunk lines is established through H2 and H3, Hé and H7, and these trunk lines are made occupied by a earth at H1 and H5 respectively The low voltage battery across P energizes Q at office B1 which in turn energizes B, and the latter connects the calling subscriber line to the tandem trunk line. If es assumes that the calling subscriber is still on the line, C at office Bl remains neutral and

  <Desc / Clms Page number 70>

 a blocking circuit for S at office A is provided through C1.



  Likewise, the low voltage battery across Q at office A operated at office B2 which in turn operates B, and the connection between calling and called abominations is now complete. If the called party is still on the line, C at office B2 remains neutralized and closes a blocking circuit for T at office at A.



   As the supervision lamp goes out, the operator removes the two plugs, releasing the recorder at desk A and the connecting line between desks A and D.



   The conversatioh connection is now established through the connection circuit a.u office u A and is completely under the control of the calling and called subscribers. When one of these hangs up, for example the calling subscriber, relay C at office Bl gets energized, relay S at office A is neutralized and the high-voltage battery is connected to the positive conductor of the telephone line. tandem junction to office B2 through S1 and Gl. This battery energizes R at office B2, which energizes C, which in turn frees T at office A. With relays S and T neutralized, H's blocking circuit is open, and if this condition persists, H is released. .



  Relay H neutralizes G, and K at office H4, and the connection circuit is completely free. When the battery is. away from the junction lines at H3 and H7, the junction lines at B1 and B2 are both made free.



   The establishment of a call from subscriber 361 to subscriber 3467 is now described.



   In the final connection, this call comprises offices B1 and -0, as well as a tandem trunk line between them. After the call has been established, the operator releases the trunk line between offices D and A and between offices A and B1 which were used.



   Subscriber 361 initiates the call which is received by the operator at office D. This operator inserts the establishment form associated with the recorder at office A, and marks the number 3. Relays 33,24 , 36, 8 and 25 get excited and the recorder at the office B1 is associated with the tandem trunk line already taken in use.

  <Desc / Clms Page number 71>

 



   The operator marks the number four. At the end of the pulses 34, the buresu B1 is energized, followed by 24, and the selector searches for a free tandem junction line in group "4", that is to say the group giving access to the office C. If a free line is found, relays 8 and 25 operate and the recorder at the office
C is chosen and associated with this line. The operator then marks the number six. The pulses are repeated from relay 1 at office A to relpis L at office B1, and then at relay 1 at office C, and the selector at this office is set in motion towards the terminals of line 51.



   At the end of the pulses, relay 3 is neutralized and a circuit is closed for relay 13 through 31, brush R, 142, the winding of 13,82 and 23. Relay 13 operates and is blocked through 134 and in 133 connects relay 8 to the terminals of line 50, that is to say to the terminals immediately preceding the group of "60". When relay 27 is neutralized, a motor circuit is closed for the selector, which is controlled by 22 at 271. When the halais reach the terminals of line 50, relay 8 operates through 31, the brush R, 133 , 84, the windings of 8 and 23. It blocks through 84 and opens the motor circuit at 81. Relay 16 operates and blocks, and an esssi is made to find a free connection circuit.



   The attendant marks the final number seven, and the selector at desk C is moved step by step towards the terminals of the requested line. At the end of the pulses, the line is tested. Relay 10 gets excited in office C, followed by relays 23,10 and 6 in office B1,23,10 and 6 in office A, and M in office D. The supervision lamp comes on. If the line is free, relay 6 at office C is energized, and the junction finder brushes are placed on the terminals of the requested line. When the relay 6 at the B1 office is energized, the brushes of the finder A and the finder B in the connection circuit are placed respectively on the terminals of the calling line and of the called trunk line.

   When

  <Desc / Clms Page number 72>

 18. 'Energizes at office B1, a circuit is closed for K in the connection circuit through K4,73,184,162 at work, and 2411. Relay K is blocked at tragers K4, H4,76 and 183. Relay T gets excited through K3,74,184,162 at work and 2411. 'subscriber We thus see that a derivative connection between subscriber 361 and subscriber 346 7 has now been prepared, because in office B1 the brooms, of researcher A are remained on the terminals of the calling line, and the brushes of the finder B are rectified on the terminals of a line of tandem junction. The brooms from the researcher to office C remained on the dundee line terminals.



   ¯¯ ¯ on reception of the lamp signal, and hearing no auditory signal, the attendant rings the called subscriber. In the first period of silence, after this subscriber has answered, the relay
10 at office C is neutralized, followed by 23 and 10 at office B1 and
23 and 10 in the office A. The supervision lamp D goes off. When
10 at the office 0 is neutralized, H in the junction circuit operates,
When 10 at office B1 is neautralized, H in the connection circuit !! excites it and blocks it through H8, K2 at betrays, T2 at work, and earth at BK.

   Thus, when 10 in B1 is neutralized, H in the junction circuit abandons its reinforcements, Likewise 10 in office A is neutralized, as well as H in the junction line. when H in the trunk line gets energized, the calling subscriber is connected to the called trunk line. the low-voltage battery at tra, to Q, at the office. u B1 operates Q at the C office, which energizes B, which completes the connection with the called subscriber.

   If the latter is still on the line, the relay C at the office C remains inactive and a blocking circuit for T at the office B1 is closed at 01. Seeing the supervision lamp off, the attendant removes the two plugs, .. releasing the anrepgietreur at office A; When relay 25 de-energizes, the battery is moved away from the negative lead of the tandem junction and the desktop recorder B1 is released in a similar manner.



   'The conversation connection is now established at

  <Desc / Clms Page number 73>

 through a connection circuit to office B1, and is completely under the control of the calling and called subscribers. If the called subscriber hangs up first, C at office C operates, followed by T at office B1, and if this condition persists, H is neutralized, breaking the connection. On the other hand if the calling subscriber hangs up first, S at office B1 operates and in Si connects the high voltage battery to the positive conductor of the junction line operating R 'at office C. Relay R operates C which frees T at office B1, and after a certain interval, H neutralizes and breaks the connections as before
Consider now a call between an urban subscriber and subscriber 474.



   The operator receives information from the subscriber and makes a call to a rural system by inserting the call plug of the regular cord circuit and the establishment plug of its operating cord circuit in the jacks. a free junction line. Recorder at office A is associated with this trunk line, and Relair 1 responds to pulses marked on the disc.



  At the end of the first digit, relays 4,34 and 24 operate and the selector searches for a free tandem line in group "4". Relay 8 operates as soon as a line is found, opens the motor circuit, and operates relay 25. This in turn energizes the CO relay of the tandem line and associates the recorder with the B2 office with it. The second and third digits place the selector at office B2 on the terminals of the requested line which is then tested.



  Relay 10 at desk B2 operates, followed by 23,10,6 at desk A. The main trunk line finder, socket in use, is placed on the tandem line terminals. If the line is free, relay 6 at office B also operates, and the finder for the tandem trunk line is placed on the terminals of the requested line. In 63 at office A, a circuit is closed for T in the junction circuit through 2411,162,63 and 168.



   We see that a branch connection between the urban operator and the subscriber 474 is now prepared, because in office A the

  <Desc / Clms Page number 74>

 junction finder brushes line the terminals of the tandem junction, while the B2 office finder brushes remain on the terminals of the requested line.



   Hearing no auditory signal, the attendant rings the called party. In the first period of silence, after he has answered, relay 10 at desk B2 turns off, followed by 23 and 10 at desk A, and M at desk D. The supervisory lamp goes out
When relays 10 at offices B2 and A neutralize, the circuits are closed for H in the trunk circuit at these offices through 61,262 (at office A) 171,102,165 at rest, and K3. When
10 at desk A. is neutralized, circuit 25 is opened and this link is reestablished, freeing the recorder at desk B2. When K at office B2 is re-established, relay H remains blocked through H6, K4,
C2 and T7 at rest.

   When H at office A operates, T gets stuck in travert
T1 and H3; and this earth also operates C through B3, H8, Rl.



     When the supervision lamp is off, the attendant removes the establishment card, freeing the recorder at office A.



   When the relay K is neutralized, H remains blocked through H6, K4, C2 at work, and T7 ... The regular plug is still in the conversation jack, so that Q and B in turn exit at the office
A, followed by Q and B at office B2. A direct connection is then established between the two subscribers. Positive supervision is provided between the called subscriber and the operator, precisely as in the case of a call from a rural subscriber.



   Faults and extension of alarm signals to the urba.in. Two types of fa, utes are foreseen: melting fuses and setting of switches. The battery at all the switches is supplied through a common pilot relay 19 (fig. 20), and this relay operates when any switch operates. Relay
19 energizes a damper relay 35. If a switch sticks or otherwise takes current from the current for more than five seconds, relay 35 operates and at 351 closes a circuit for 20. This is boluqe through 203,302 and the key. recovery, distance

  <Desc / Clms Page number 75>

 the switchboard battery in 203.

   Similarly if the main fuse blows, one circuit is closed for 20 through the alarm fuse. When the battery is removed, either by the operation of 20 or by the blowing of the fuse, all the relays in the office are neutralized, and at the office B2 a signal to restore is given to all the junction lines which are at this time in use. Some conductors in trunk line No.1 are ready through contacts 20 and 30.



   As soon as the relay Q in this junction circuit turns off, when the call is broken, the relay 30 energizes through 303,205, Q1,201 and 304, and locks up through 301 to earth at the key to recovery. When 302 is open, relay 20 remains blocked through 306,204, R1 and 202. A new call is made on this trunk line through B2,304,201, Q1,205 and 303. Relay 20 also operates a ringtone. alarm in 207, and a point in this ringing circuit is connected to trunk line No. 1 through 206, so that as soon as the attendant answers the call, she hears an auditory signal distinctive informing that an office is out of order.



   Since the office may be several times away from the city office, this call occupies a number of tandem trunk lines, and the main trunk line. By applying the usual forced restoration, this call can be broken, because as soon as R at the offending office operates; the circuit of 20 is open in Rl. Relay 20 de-energizes, pulling the calling battery away from the trunk line and, unless the bell cut-off key is normal, this stops the bell. Relay 30 is kept blocked by the reset key and keeps the battery disconnected from switchboard 306. The operator can then determine which office is at fault by writing its number on its disk and noting at which office the recorder cannot be connected,
Call from a rural office.

   One line for call desk

  <Desc / Clms Page number 76>

 is provided with a regular post to which is attached some type of coin collector, which transmits an auditory signal as soon as the coins are inserted. At the rural office, a special line circuit is provided, which includes the ordinary line relay, two auxiliary relays, a capacitor, and a buzzer (fig.13). A call from a calling office is produced in the same way as that of a regular telephone by the person activating his magneto. Relay L gets excited and hangs. Connected in parallel with the blocking winding of L, is a winding of B which also operates and blocks through B1 while disconnecting from L to B2.



   In B3 the negative conductor of the office line is disconnected from the bancos of the junction seekers, and A is connected to its pla.ce.



   The call takes place in the usual way at the urban office and the operator inserts a plug activating the relalis Q and B at the intermediate offices. In the office considered, A (fig. 13) operates in series with C (fig. 17), but the latter does not operate due to the high resistance of A. Le'relais A is blocked in series with u through Al independently of B3, and relay 13 is neutralized at A2. A circuit for the buzzer is closed at A2, and the auditory signal is transmitted through the capacitor to the negative conductor to the operator.

   In A3, the negative conductor of the call office line is kept open so that the caller does not hear the auditory signal and so that A will not be bypassed if the subscriber replaces his receiver. 'The operator still knows when the call comes. a call office, and in order to remove the auditory signal, she momentarily removes her plug. On the neutralization of B at the office in question, A is devoid of its battery and neutralized, disconnecting from the negative conductor, and closing the line of the call office. The buzzer circuit is open.



   If the call concerns an urban subscriber, the operator completes the connection with the regular cord circuit, requesting and hearing the coins in the usual manner.



     If the call is for a rural subscriber, the operator calls

  <Desc / Clms Page number 77>

 the subscriber called for another series, and having obtained from him in the usual way that the correct number has been marked on the disc, asks him to temporarily replace his receiver. She then breaks that connection, asks the subscriber and hears the necessary coins. She notices the number of the called subscriber, and the call is set up precisely as if it came from a rural subscriber.



   In figure 14 a modification of the recorder previously described and shown in fig.13 has been shown. The recorder shown in fig. 14 is similar to that shown in fig. 13 from the point of view of its operation and the facilities provided, but it can work with desks having a large capacity, that is to say a large number of lines per office. The selector switch in fig. 5 is filled in figure 14 by M and P switches of 5 points and 2-4 rows, and these two switches are finally placed on the terminals of the chosen row, which - the terminals are divided between the two switches. Thus the switch p has the positive and negative terminals, a control bank, and a restoration bank.

   Switch M has the test and characteristic terminals and also a test and reset bench. The operation of this circuit is better understood if relay 32 is omitted with its wiring to terminals 51 to 55 of the Mr.



   If the number 3 is marked on the disk, relay 1 responds and closes a stepping circuit for the PDM solenoid of switch P through 11,25,254,52 and 81. Relays 3 and 27 are activated. - tent during the pulse train. The selector stops with its brushes on the terminals of line 90 and a circuit is immediately closed for 33 through 296,246, the brush PR, 63, the winding of 29,13,88 and 23 Relay 33 energizes and locks through 331, but 28 does not energize due to the high resistance in series with it. The relay 33, 'energizes the relay 24. At the end of the pulses, 3 and 27 are neutralized in their turn slowly.

   In

  <Desc / Clms Page number 78>

 245, a motor circuit for the MDM electromagnet of the switch M is closed through the brush PH, 245,21, the MDM switches, 86, 261,51 and 62. The switch M operates. In the time interval between the excitation of 24 and the neutralization of 27, relay 26 has a chance of operating to determine whether the calling tandem line or a tandem line is free in the group where the . research must take place. If no free line is found, the MR brush finally searches for line 61 and relay 5 is energized through 249, the MT brush, 263,243,293, the MR bali, 2410, and 54. The relay 5 is blocked at through 54, and in 51 opens the motor circuit.



  In 52 any subsequent impulse is rendered ineffective. Relay
5 also closes a circuit producing an auditory signal which gives the 'ordinary indication' to the operator.



     If the calling tandem line has been reached, relay 28 energizes as soon as it is found, through 248,264, K6, bay 8 in the. junction line, the characteristic conductor of the line; .. calling, the 'MS brush, 263 at work, 243,293, the mr brush, 333, the Pr brush, 333, the winding of 28,13,88 and 23. If, on the other hand, a free line in group 3 has been reached, 28 is energized in series with the non-inductive winding of the relay co through CO3, Lt, le, brush MT, 263 at rest, and the circuit above.



   Relay 28 opens the motor circuit at 281, and as soon as 27 is neutralized, a circuit is closed for relay 8 through 283 and 272. Relay 8 locks in 88 and releases 28, Al, 81,82 and 85. The PDM and MDM, pulse and motor circuits are interchanged. Relay 8 also closes m circuit for 29 through 83 and 244, and relay 29 closes m motor circuit for switch P through 297, PDM switches, 86, 281, 51, and 81 In 2910 the battery is connected to through the brush MS at the terminals of which the switch M is stopped, and since the bank MS is multiplied to the bank PR, this battery is connected to the terminal to which it is required to bring the switch P.

   When the latter reaches this position, 28 operates through 2910, the MS broom, the mul-

  <Desc / Clms Page number 79>

 tiple, the brush PR, 63, the winding of 28,295 and 23. It opens the motor circuit in 281. In 284 a circuit is closed for 25 through 53,298,242,173 and 284. A circuit is also closed for 4 through 251 Relay 25 operates and picks up the recorder at the next office. Relay 4 is released. The requested line is then tested, and if it is free, relay 6 operates and at 63 closes a high resistance blocking circuit for 28. Relay 6 also disconnects 28 from the twenty ohm coil, so that it This can be used to place the switches of the connection circuit or the trunk line.



   When the attendant releases the recorder, L and 2 are neutralized, as well as all the relays, except 8. Since the switch P is out of the normal range, 8 is maintained across the PH and 21 , and a reset circuit for switch P is closed from this earth through 297, switches PDM, 86, 281,51 and 81. As soon as switch P reaches its rest position, relay 8 is neutralized and a circuit reset is closed for switch M through PH brush, MH brush, MDM switches, 86 to 81, 51 and 82. When switch M reaches its home position, this circuit is opened, and saved. treur is completely neutralized.

   The earth is still connected to 1 through the PH and MH brushes, and the recorder can therefore be chosen again,
If the number 4 has been marked on the disc, the switch P is actuated across line 51. When the PR brush passes terminal 90, a circuit is closed for 33 while 13 is closed, but this is insufficient to excite 33 As soon as the PR brush reaches terminal 51, a circuit is closed for 34 through 292, 247, the PR brush, 63, the winding of 28,13,88 and 23. ¯ Relay 34 energizes and turns blocked but not 28. The remainder of the call is similar to that described previously.



   If the number 5 is marked, switch P is actuated

  <Desc / Clms Page number 80>

 to the terminals of line 52. As soon as these terminals are reached A, a motor circuit is closed for the selector M through the PH brush, 21, the MDM switches, 86,281,51 and 82. Terminal 52 in the PR bank is connected to terminal 90 in the Mr. bench. As soon as the Mr brush reaches this terminal, 28 operates through 243.293, the Mr brush, 63, the winding of 28,13,88 and 23. The motor circuit is open in 281. As soon as 27 neutralizes, a circuit is closed for 8 through 272 and 283. Relay 8 operates and locks in 88 releasing 28.

   The brushes of the switch M are placed on the terminals of the. line 90, that is to say from the line immediately preceding. group of fifty. The next digit is received as 1 and a stepping circuit for switch M is closed through 11,25,101,254,52 and 82. Relays 3 and 27 energize during the pulse train. Relay 27 closes a circuit for 29 to, through 83,272 and 23. Relay 29 locks up through 294 and closes a motor circuit for switch P through 297. With link 32 omitted, the lines 51 and 55 are the only ones possible in this group, and in accordance with the number 3, the relay 87 is connected to the terminal 56.



   If the second digit is greater than five, as soon as the MR brush reaches terminal 56, a circuit is closed for link 5 through 248,87, the MR brush, 293 and 54. Relay 5 opens the circuit. motor of the switch P at 51, rendering any digit ma, queried to the disc ineffective at 52 and closing a circuit producing an auditory signal.



   If the second digit is less than five, the M switch brushes remain on me on lines 51 to 55. As soon as the PR brush reaches the terminal of that line, 28 operates through
2910, the MS broom, the multiple, the PR broom, 63, the winding of 28
295 and '23. The motor circuit for the P switch is open.



   It can be seen that the brushes of the two switches P and M have been brought to the terminals of the chosen line. With the relay
27 released and 28 excited, m circuit is closed for 11 through 53,

  <Desc / Clms Page number 81>

 
298,242,273,282 and 43. As soon as the relay 43 is released, the requested line is tested, If it is free, the relay 11 is neutralized, the relay 6 operates, and a high resistance blocking circuit is closed for 28 in 63 .



   If one of the digits 6,7,8 or 9 has been marked, the switch P is brought to the terminals of lines 53,54,55 or 56. As soon as this switch reaches the terminals of line 52, a motor circuit is closed for switch M. Terminals 53,64,55 and 56 in the PR bench are connected to terminals 50,60,70 and 80 respectively in the MR bench. As soon as the brush MR reaches the terminals connected to one of which PR is stopped, 28 operates and opens the motor circuit. The brushes of the M switch are now placed on the terminals of the line immediately preceding the required group. The call then takes place as in the previous case.



   If the number one is marked on the disk, switch p brings its terminals to line 98, and as soon as 27 turns neutral, a motor circuit is closed for switch M.
98 in the PE bank is not connected to any terminal in the MR bank, and the switch M continues its search until the terminals of line 91 are reached. A circuit is then closed for 5 to through 243,293, the MR brush, and 54. Relay 5 gets blocked and closes a circuit producing an auditory signal.



   If the number zero is marked on the disk, switch M begins its search as soon as switch pa reaches the terminals of line 52, and as in the previous case, 5 turns on as soon as switch M reaches the terminals of line 91.



    CLAIMS.
 EMI81.1
 



  ----------------------------
1 - In a telephone system comprising two or more rural offices, each connected by one or more trunk lines to a tandem rural office, which is connected by one or more

  <Desc / Clms Page number 82>

 several trunk lines to an operator position of a main office, means by which a calling line in one of said rural offices is automatically connected to a trunk line extending between said tandem rural office and said main office, and means by which an operator at said main office controls the establishment of a connection to a requested subscriber in the same rural office or in another rural office through automatic switching devices,

   after which an alternate connection is established between the calling and called subscribers to allow breaking of the trunk line between said tandem office and said main office.



   2 - In a telephone system, comprising two or more remote rural offices, each connected by one or more trunk lines to a tandem rural office, which is connected by one or more trunk lines at a position of 'o- peratricd at a main office, the means by which a calling line in one of said rura.ux offices is' automatically extended to a trunk line at said main office, and the means by which an operator at said main office controls the selection of a trunk line extending to the requested remote rural office and controls the selection of the requested line through it, after which a connection between the called and calling subscribers is established, which is independent of the said jonctioin at the main office.



     3 - A circuit arrangement comprising a series of rural offices connected in tandem forrratian to a ricn- pal office, and in which connections are established under the control of an operator at the main office, characterized in that a means is provided to extend a call line through one or more tandem offices to an operator of the main office which controls it, extension of a connection to the line of the called subscriber, through one or more tandem offices , after

  <Desc / Clms Page number 83>

 that an alternate path, comprising only the offices in the chain between the calling and called subscribers, is established,

   while the unused trunk line (s) in that path are released.



   4 - An arrangement of circuits for establishing a connection from a subscriber to a nutre in a telephone system, through an automatic switch mechanism, under the control of an operator at a remote main office, characterized in that 'A connection is automatically extended from the calling subscriber to said operator through a series of trunk lines, means being provided by which the office, containing the line of the dende subscriber, is chosen by said operator. and an extended connection to that office through one or more of the same trunk lines, after which an alternate path is prepared between said subscribers, called and calling, on the completion of which one or more of said trunk lines. common junction are freed,

     5 - An arrangement of circuits to establish an automatic connection from one subscriber to another under the control of an operator placed at a remote office, the establishment of this connection being controlled through a trunk line which is then linked. - Beree, co-arranged in that the circuit changes carried out during the establishment of the connection are carried out by supervision signaling pulses transmitted through one of the conversation conductors of the junction line.



   6 - Circuit arrangement in which a connection between two subscribers of the same rural office or of different rural offices, is established through an automatic switching mechanism by an operator placed at a remote office, and in which the said connection is controlled and monitored through a trunk line of the remote office, said trunk line then being released, characterized in that the automatic switch mechanism is selectively selected under the control of pulses from

  <Desc / Clms Page number 84>

 operation of a disc and transmitted through a conductor of the junction line, the supervision being performed by supervision signals transmitted through the other conductor of the junction line.



     -7. - Telephone system comprising a first rural office and a second rural office interconnected By a trunk line, another trunk line extending from the first rural office to a third remote office, an automatic switching mechanism to the said rural offices to extend connections between subscribers of the same rural office or of different rural digital offices under the control of impulses / transmitted through said second mentioned trunk line, and means to said rural offices responding to supervisory signal impulses sent through one of the conductors of the said second mentioned junction line to effect changes of circuits at the said rural offices during the establishment of the connexion.



     8 - A circuit arrangement, as claimed in any one of the preceding claims from 1 to 4, in which means is provided at said operator position for sending pulses due to the maneuver. of a disk through a conductor of a trunk line extending from said main office to control the automatic switching mechanism and to send supervisory signals through the other conductor of said trunk line in order to make circuit changes at said main office while establishing a connection.



   9 - a telephone system, as claimed in 1,2,
3, 7 or 8, in which the tandem office (s) is or are provided with means for repeating signaling pulses for supervision across an interconnecting trunk line to a subsequent office.

   tral 10- A telephone system, comprising a central office provided with one or more operator positions, an office

  <Desc / Clms Page number 85>

 rural tandem connected by a junction line to said central office, two or more remote rural offices or satellites connected by junction lines to said rural tandem office, an automatic switching mechanism to extend the connections between subscribers of the same rural office or different rural offices under the control of an operator at the central office, and means in the said rural offices adapted to respond to the supervision signaling pulses received through the trunk lines for make circuit changes during the establishment or existence of a connection.



   11. A circuit arrangement, as claimed in any one of the preceding claims, in which means is provided for, upon generation of a call by a subscriber, a signal to be sent through m of the conductors of the subscriber. one or more trunk lines to report the operator to the main office.



   12 - An arrangement of circuits, as claimed in}
2, 3 or 7, in which means is provided for, on the production of a call by a subscriber of a rural office referred to the main office through one or more tandem offices, a signal is transmitted through a conductor of the trunk line extending to one or more tandem offices, means being provided at the tandem offices to repeat said signal to the main office for the purpose of informing the operator.



   13 - An arrangement of circuits, as claimed in 1, 2, 3, 4, 5 or 6, in which the cord circuits provided at said operator position, are each provided with an operating key of a dialing disk, means allow the said key to be first activated and then restored after the operator has inserted a plug in the jack of the calling trunk line, two supervision pulses being transmitted on one of the conductors trunk line to prepare a ringing circuit for a callback from the calling subscriber.

  <Desc / Clms Page number 86>

 



   14 - An arrangement of circuits, as claimed in 13, in which the operator's cord circuits are each provided with a key for the operation of a dialer disk, 'la, which when it is restored. after the number of the called subscriber has been marked., causes the transmission of another supervision pulse through said junction conductor, this pulse effecting changes of circuits in the switching mechanism to the offices at the otter end of said trunk line to prepare a circuit to ring the called subscriber.



   15. A circuit arrangement, as claimed in 13 or 14, in which the calling and called subscribers are rung from the manual office by the lowering of a ringing key in the operator's oordon.de circuit.



   16- A circuit arrangement as claimed in any one of claims! previous ones, in which a means is provided so that after the establishment of a connection, a listening connection is completed for the operator at the main office so that this operator can observe the initiation of the call. conversation.



   17- A circuit arrangement, as claimed in? , in which the attendant cord circuits are so arranged that when the ringing and listening keys are re-established after establishing a connection, a signaling pulse for supervision is sent through one of the conductors of the trunk line, this impulse causing changes in circuits through which the operator is able to listen to the start of the conversation.



   18. A circuit arrangement, as claimed in 17, in which means is provided at the tandem office (s) for repeating said supervisory pulse to a remote satellite office when both subscribers, calling and called, belong to the same one. office..

  <Desc / Clms Page number 87>

 



   19 - uneappegmeent of c'rucits, as claimed in 6, 7 or 8, in which the said rural offices are provided with three pairs of relays which are adapted to respond successively to said supervision signals and thereby effect the changes of circuits required.



   20 - A circuit arrangement, as claimed in any one of the preceding claims, in which a rural office is provided with local connector circuits to which calling and called subscribers can be connected by means of individual relays to subscriber lines or to telephone lines. junction of offices, the said relays being actuated under the control of the operator of the main office.



   21 - A circuit arrangement as claimed in 20, wherein means are provided so that in the event of calls made by a subscriber through a tandem office, the calling line is connected to the local connecting circuit in response to a call. super vision pulse sent through a conductor of the trunk line of the manual office before the / operation of the disc, while in the case of calls produced by a subscriber of a satellite office, the calling line is connected to a local connector circuit in response to a supervisory pulse sent automatically through a conductor on the trunk line of the tandem office after the first digit has been marked on the disk.



   22 - A circuit arrangement, as claimed in 20 in which chains of meter relays are provided at rural offices, which are adapted in response to impulses from the operation of the disc to select and cause the operation of a relay suitable for connecting a requested line or league of, jonc; ion to a local connector circuit.



   23 - A circuit arrangement, as claimed in 8, in which means is provided by which in response to supervisory pulses transmitted through said trunk line after an operator has marked the disk a number for a con

  <Desc / Clms Page number 88>

 intercity connection, and has received an auditory busy signal, circuit changes are made to allow
Empress to offer the so-called long distance connection.



   24- An arrangement of circuits, as claimed in
23, in which means is provided so that when the operator marks the number of the called subscriber on disk, the existing connection is automatically terminated and a connection is extended to the called subscriber's line.



   25 'A circuit arrangement, as claimed in any one of the preceding claims, in which means is provided for the operator after establishing a connection with a faulty trunk line existing between two rural offices, may by a special operation put out of service the said junction line.



   26 - A circuit arrangement, as claimed in any one of the preceding claims, in which means is provided for charging batteries in rural offices through a trunk line from said main office, clothing means provided. to disconnect the load current when the trunk line is chosen in either direction.



   27- A circuit arrangement, as claimed in any one of the preceding claims, in which means is provided for charging the batteries of the remote or satellite rural offices through a junction icon coming from the main water supply and a or more trunk lines coming from the tandem offices, means being provided for disconnecting the current. load when any of the said junction lines is chosen in either direction.



   28. A circuit arrangement, according to any preceding claim, wherein a rural office is provided with a group of trunk circuits, each provided with a switch adapted to function both as a searcher.

  <Desc / Clms Page number 89>

 lines to extend a connection to a calling line or trunk line, and as a selector to choose a requested local line or trunk line.



     29 - A circuit arrangement, according to claim 28, in which a control circuit is commonly associated with a group of trunk circuits, with any of which it is adapted to be operatively associated.



   30. A circuit arrangement, according to claim 29, in which said control circuit is also associated with a group of local connection circuits terminating at each end in an automatic switch.



   31 - An arrangement of circuits, as claimed in
29, wherein a common marker switch in said control circuit is adapted to entrust the selective operation of the switches with said junction circuits and said local connection circuits.



   32 - An arrangement of circuits, as claimed in
29, in which means is provided for said control circuit to be operatively connected with a trunk circuit, which has established a connection with a calling line or a calling trunk line in response to an operation of the trunk. from an operator in the main office.



   33 - A circuit arrangement, as claimed in 32 in which means is provided for said control circuit to be operatively connected with a local connector circuit in response to another operation by an operator in the office main.



   34 - An arrangement of circuits, as claimed in
31, in which means is provided so that if the marker switch in the control circuit is brought to a position indicative of a call to a subscriber in the same office as the calling subscriber or in a tandem office placed between the calling office and the

  <Desc / Clms Page number 90>

 main office, the local connector circuit is automatically released and the connection is extended to the requested subscriber directly through the trunk circuit.



   35- An arrangement of circuits, as claimed in
1 or 2, in which the operator controls the establishment of a connection to the called subscriber through the same trunk line as that through which the calling line is extended to the main office.



   36- A circuit arrangement, as claimed in any one of the preceding claims, characterized in that the junction lines 9 'extending from the main office, are also adapted to form part of the conversation circuits between. the calling and called subscribers.



   37- An arrangement of circuits for establishing a connection from one subscriber to another in a telephone system under the control of an operator at a remote office, characterized in that the connection is automatically extended from said calling subscriber to the said operator through a trunk line, a mcyen being provided by which another office containing the liger of the requested subscriber is automatically chosen by said operator, and the extended connection through the same trunk line , after which an alternate path is prepared between the said calling and called subscribers on the completion of which the said common line is released.



   38- A circuit arrangement for establishing a connection from one subscriber to another in a telephone system under the control of an operator at a remote office, characterized in that the connection is extended automatically from the subscriber calling to the, said operator through a series of trunk lines, means being provided by which the office containing the line of the called subscriber is chosen by said operator and the prolonged connection to this office through the same line of rush-

  <Desc / Clms Page number 91>

 after which an alternate path is prepared between said calling and called subscribers upon completion of which said common trunk lines are released.



   39 - An arrangement of circuits, according to claims 37 and 38, in which said calling and called subscribers can be placed either on the same office or in different offices, the connection to the main office being such that the connection of the The operator to the two subscribers can be extended through one or more common trunk lines, as far as the office furthest away, in the network, from the main office, which has access to the offices containing the two a - good.



   40 - An arrangement of circuits, as claimed in
37 and 38, in which means is provided so that when establishing the connection of the operator at said main office to the requested line, the calling subscriber is disconnected from said operator.



   41 - An arrangement of circuits, according to claims 37 and 38, in which the response of 1: the calling subscriber causes the disconnection of this subscriber with said operator at said main office, and completes an alternate path to the subscriber calling for the purpose of conversation.



   42 - A circuit arrangement for establishing a connection from one subscriber to another in a telephone system under the control of an operator at a remote office, characterized in that the connection is extended automatically from the subscriber calling to said operator through one or more trunk lines, a means being provided by which the office containing the line of the requested subscriber is automatically chosen by said operator and the connection extended to the line requested through the one or more same trunk lines, after which an alternate path is completed between said calling and called subscribers who are automatically disconnected from said operator at said main office.

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   43 - A semi-automatic telephone system, in which the connections between subscribers belonging to small offices are established under the control of an operator at a main office, characterized in that the said small offices are placed by relationship to the main office in tandem, and in that a means is provided whereby, when a connection is extended to said operator of a calling line of any of said small offices, that connection can be automatically chosen. by said operator to said main office through a path, after which a different path is automatically prepared between the. said calling line and said requested office, and the connection between said operator and said called line is automatically broken.



   44 - An arrangement of circuits for extending connections between subscribers placed at semi-automatic telephone offices linked in tandem with a main office, characterized in that a connection to a subscriber placed in a semi-automatic office any one in the network is established under the control of an operator at said main office, this connection being extended by one or more digital switching mechanisms, a means being provided by which, when said connection is completed, said digital switch or switches is or are released, and an alternate path is automatically completed which is independent of the digital switch mechanism (s).



   45 - An arrangement of circuits, in accordance with claim ¯44, in which a digital switch mechanism is placed in each of said semi-automatic offices, each digital switch mechanism being taken into use at its turn as the extension of the call proceeds from one office to another, until the required office is reached.



   46 - In a telephone system, an arrangement of circuits to extend connections from one subscriber to another, the subscribers being -placed either in the same office or in offices

  <Desc / Clms Page number 93>

 different arranged in tanden and controls of a main office, means being provided to automatically extend a connection from the calling subscriber to an operator at said main office through a path containing a junction line, and thereby means of the operator can extend the connection to the requested subscriber automatically through a second path also comprising said junction line, other means being provided by which, as soon as said connection is established to the subscriber from- called, the said first path extending towards the said operator is broken,

   and when the called subscriber answers the said second path going to the operator is broken.



   47 - In a telephone system, a circuit arrangement according to claim 10, in which means is provided so that, upon the answer of the called subscriber, an alternate path between said subscribers is completed for the purpose. conversation through the office furthest from the main office which has access to the offices to which the calling and called subscribers belong respectively, other means being provided by which, the said alternate path being complete, the path through which the connection was established is released.



   48 - An arrangement of circuits for extending con- nections between subscribers placed at small offices, connected through common trunk lines with a main office., Characterized in that the connections are established from one office to a putre su meyen of one or more recording mechanisms, controlled in tpndem from said main office, means being provided which cooperate with one or more of said recording mechanisms to automatically complete a conversation circuit between subscribers, which is independent of the path extending through said recording mechanism.



   49 - An arrangement of circuits, according to claim.



  48, in which, as soon as the connection with the requested line is. established through the recording mechanism (s), the connection

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 between the = calling line and the main office is automatically broken, and an alternating path between said called and calling lines is automatically prepared.



   50 -, A circuit arrangement, as claimed in 49, in which, on the answer of the requested subscriber, said alternate path is automatically completed, and the path of the requested line to the main office, through which the. connection was established, is automatically terminated.



   51. A circuit arrangement, according to claim 50, such that when the alternate path is completed, one or more of said recording mechanisms are automatically released.



   52- An arrangement of circuits, following. claim 49, 50 or 51, in which said alternate path is completed through a non-digital switching mechanism, located in the office, remote in tandem from the main office, which has access to the offices respectively containing the calling and called subscribers, 53 A circuit arrangement in which connections between subscribers in small offices connected in tandem with a main office, can be established by automatic switches controlled by an operator at the office main, characterized in that the connection is extended through each, of a number of small offices in tandem, until, the requested office is reached,

   after which an alternate path, comprising only the chain offices between the calling ¯ and called subscribers, is automatically prepared, while the path through which the established prop.1 connection is released.



   54. A circuit arrangement, according to claim 53, wherein said connection is extended through a series of recording mechanisms, one of which is located at each of said offices in the chain, a set of switching devices being provided at each location. each of the said offices, one of which cooperates with

  <Desc / Clms Page number 95>

 
 EMI95.1
 known as mécP: .isr:, es, ':: C; :::': "5tr'OUt'S to complete the said cistern path between the said pbor, born as soon as the connection through all the recording mechanisms in the chain is completed .



  55 - A c> rrp. ', CeYJ1ent de cirouita, according to claim 54, in which none of the said switching devices of a group in the said assembly, is used to connect a subscriber calling to the main office, after whereby each of said switching devices of another group in said set is employed to prepare the alternate path between said calling and called subscribers.



   56 - A circuit arrangement, according to claims 54 and 55, in which one of the switching devices, of said other group, cooperates with a recording mechanism and with one of the switching devices of said first group, in order to prepare the said tank path between said subscriber stalls.



   57 - A circuit arrangement, according to claim 54 or 55, in which one of the devices. switches of said first group cooperate with a recording mechanism in order to prepare said alternate path between said subscriber stations.



   58 - an arrangement of circuits, according to claim 54 or 55, in which means is provided so that, if the subscribers are placed in different offices, a switching device of said other group, placed in the office which is the closer to the main office, is used to prepare said alternate path which is completed through as many switching devices of said first group as are required to reach the office to which the other subscriber belongs.



   59 - A circuit arrangement, according to claims 54, 55 and 58, in which each of the switching devices of said other group comprises two seeker switches, one of which is adapted to move in accordance with the movement of the switching device. used to extend a connection from? subscriber calling at the main office, while the other is adapted

  <Desc / Clms Page number 96>

 to move in accordance with the dismantling of said recording mechanism.



   60 --A switching mechanism can be used in telephone systems, which is adapted to receive impulses and to choose a file in a rump of lines, characterized in that said mechanism is provided with a series of Selective switches, one of which receives a series of pulses, while another receives a second series of pulses, the two switches cooperating with each other in such a manner that both are placed on the terminals of the requested line.



   61 -A switch mechanism, following claim
37, wherein when said first selector switch is actuated by the first train of pulses, the second switch is automatically actuated to a position marked by said first switch, after which a second series is fitted to bring the switch on. said second switch on the terminals of the requested line.



   62-A commutative mechanism, according to the claim
38, wherein said first switch cooperates with said second switch in such a way that it can also move across the terminals of the requested line
63. A telephone office system, according to any one of the preceding claims, in which means is provided for the operator to release one or more trunk lines and the circuits associated with them, if the subscriber left his receiver off-hook after a RESUME conversation.



   The intention relates to a telephone system of the semi-sutomatic type and includes the new features shown and described here:
1 An arrangement of circuits to establish a connection. under. the control of an operator at a remote office, the connection

  <Desc / Clms Page number 97>

 
 EMI97.1
 6talt extended a, .tGr.1, -I; iqu "wnent from the calling subscriber to the operator at travex-s li, junction lie, means being provided by le8qU.els <1 /..- 1: ze '0) .1.'e, u,' eq "el belongs to the line of the called subscriber, is or, -, - t J. 0 'ue, Yent p3 , r the operator, and the connection prolo'Yl [ée j..i; q.-1'à, it through the same junction line, after qaoi 1..n caàer¯iri 1 + errt:

  if is pre-learned between the subscribers on the a.chèveYrlen "t è.uquelln. liye of common junction is released.
 EMI97.2
 
 EMI97.3
 



  .. LeL \ 8.bo;. Nei-ivent Fppnrteiiir the, m and the other at the same office yes at 4, are different b'e, lA, connection to the bvt main network etf; .yl: such that the operator's connection to the two 8 subscribers can be extended through one or more lines of jor, ction CO; '1JYIUneS, to the furthest bar [born, dar .Ls the network, du bl., The 88U: pri;: oipa1 which has access to the offices containing
 EMI97.4
 both subscribers.
 EMI97.5
 



  : 3 .. Lp,:;, r.c: ion is controlled and monitored through the junction link of the office. remote which is ens.zite released, the teamep1el: t ..: O - ;. '1ï, r'p.tOJX l1.'¯o'llr1tique' - by which the connection is extended e'8 nt operated select i veno'1t under the control of pulses coming from In! J'.fl: '. work of a risk) transmitted through a conductor of the junction li ["" "', e ) the supervision being carried out ppi of the Si [11E \ 0.X '\; rr L; :: r, tiS to t, r2.V0rs the 8 other conductor of the
 EMI97.6
 junction.
 EMI97.7
 



  4 - The,; v.; O: nexions are established from one office to another C-tu by means of one or more recording mechanisms controlled in tpndern of the b;,; xer, u principle, l, means being px ;, evus which cooperate.



  ? With lin oii "lrs of recording mechanisms to complete f 'utomp ticY1 <2Y1 @ -in the conversation which is independent of the path 6.pnè .. "f! T trq through the!:! Recording ecar.isms.



  1- mr¯ TA '). T1:, T1] I'C Tat "' \