US2433359A - Multirural semiautomatic telephone exchange system - Google Patents

Description

5N r J MULTIRURAL SEMI-AUTOMATIG TELEPHONE EXCHANGE SYSTEM Filed July 23, 1945 5 SheecS Sheet l I (.7/ M AGENT F. P. GOHOREL Dec. 30, 1947.

MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed July 25, 1945 5 Sheets-Sheet 2 INVENTOR FIR/Wino RGGIIOIPKL W AGE Dec. 30, 1947. GOHOREL 2,433,359

MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed July 23, 1945 5 Sheets-Sheet 3 i dsla/ 7?) SUBSEQUE/VT FIND-5R6 AGEN Dec. 30, 1947. F. P. GOHOREL MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed July 25, 1943 5 Sheets-Sheet 4 INVENTOR Ff/P/V/I/V/J P. 60/1/0199 Dec. 30, 1947. F. P. GOHOREL MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed July 23, 1945 ,5 Sheets-Sheet 5 soooaooooo o n 00 n u on van 0 v o u a we a o u 0 00000 c on a O INVENTOR FE/PNfl/VD I? Gal/06 :1

AGENT Patented Dec. 30, 1947 MULTIRURAL SEMIAUTOMATIC TELE- PHONE EXCHANGE SYSTEM Fernand P. Gohorel, Sceaux, France, assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application July 23, 1943, Serial No. 495,847 In France May 13, 1941 11 Claims. (Cl. 179-27) 1 The present invention relates to semi-automatic telephone systems and more particularly to systems including rural exchanges in which the establishment of connections is controlled by a distant operator located at a manual central office to which the rural network or district is connected, The various rural networks of a district are connected to the manual central, either directly or indirectly, via one or more rural switches.

In known rural systems, the number of digits of the called subscribers numbers vary, depending on the position of the switch in the rural group to which the subscriber is connected and on the capacity of the switch. The central operator must know over which circuits the different subscribers may be reached, as well as the numbers that must be added to the subscribers regular number, which are needed for operating All this slows downthe operation of a rural district and often necesthe intermediate switches.

sitates additional operators for handling the traffic of the district.

One object of the present invention is to provide translators for sending the trains of impulses necessary for the intermediate selecting operations to select the rural area of the called subscriber as determined by the first digit or digits of the called number. Thus, the subscribers lines of a rural district may be uniformly num- According to another feature of this invention, when the operator is connected with a calling subscriber by a finder, she rings the called subscriber over an inter-rural connection jack. If the called subscriber belongs to the same rural area as the calling subscriber, then the selector is not used and the translator impulses are sent over the rural line via a pre-selector connected with the inter-network jack and the finder tha is already in contact with the said line.

In one embodiment of this invention, the translator registers the digits which cause the sending of the series of impulses controlling the intermediate switches and at least partially the switch to which the called subscriber is connected. The connection may be completed by sending one or more trains of impulses that are registered but-not translated. Since the number of impulses sent by the translator depends on the position of the subscriber in the district and on the capacity of the switch to which he is connected, arrangements are made that numbers that correspond to certain positions of the translator be absorbed and not sent by the translator.

According to another embodiment of this invention, the operator manually selects the rural area of the called subscriber according to the first digit or digits of the called number, The impulses for eiiecting the selections in the intermediate centrals are sent by a translator set in accordance with one or more digits of the called number dialed by the operator. The complete or partial control of the switch to which the called subscriber is connected, is effected by the operator when dialing the last digit or digits of the called number.

Various other features will be set forth in the following description and claims.

In the drawings:

Fig. 1 shows a diagram of the connections of the different pieces of equipment in the manual central in the case when the selection of the circuits is effected automatically after dialing of the subscribers call number by the operator;

Fig. 2 is the connection arrangement of an outgoing selector such as S in Fig. 1, shown schematically;

Fig. 3 is the connection arrangement of incoming equipment such as C in Fig. 1, shown schematically;

Fig. 4 is the connection arrangement of 'a translator such as E of Fig. 1, shown schematically;

Fig. 5 shows the manner in which the various figures 2 to 4 are to be connected with one another; and

Fig. 6 is the connection diagram of a translator fused in the case when the selection of the outgoing circuit is made by the operator according to the indication of the first calling figure or 'figures of the subscriber.

In the following specification, the relay contacts that are closed when the relay is energized, i. e. in operating position, are indicated with the letter T in front of the number of the spring,

and the contacts that are closed when the relay is not energizedfi. e. in the resting position, with the letter R in front of the number of the spring. Furthermore, certain rotary switches have been arranged to use ll-direction switches. .These switches are provided with a certain numher of wipers which are arranged in such a way as to come into contact with their banks during one or more quarter turns; the quarter turns for which a wiper is in engagement with its bank are indicated by Roman numerals after the reference indication for the wiper.

Referring to Fig. 1, an explanation will first be given of the general mode of operation of one of the devices according to the invention, which makes it possible to give all the subscribers in the rural district call code numbers that comprise the same number of figures, the selection of the circuits that correspond to the subscriber's area as well as the different selections via the switches being effected auomatically.

Two groups of lines are used. One of them is multiplied on the calling jacks such as G and the other on the inter-rural paired answering and connection jacks L and L.

Each of the lines G comprises a multipled jack in association with the busy lamp L01 and connected to a selector S; the rural mixed and special outgoing circuits such as ER and ER. are multipled on the banks of the selector. The translators such as E, which serve at the same time as control switches ,for the selectors, are connected to the said selectors during the time of selection.

Each of the line assemblies LL' comprises two multipled paired jacks, .one of them being connected to a finder C that has access to the mixed rural circuits such as .ER and to a preselector P which has access to the selectors S, while the other is connected to a preselector P which has access to the same selectors S. A calling lamp LA is associated with the jack L and a busy lamp L02 is associated with the jack L,

When a rural subscriber makes a .call, he turns the magneto of his set or sends any other suitable calling signal, and his call is registered in the rural switch to which he is-connected. When the connection circuits with the district central, 1. e. the manual exchange, becomes tree, the cal1- ing line is connected to the said district central via the equipment ER. A free finder such as C hunts for the callin circuit and, when this hunting is finished, the calling lamps such as LA light up in front of the operators. One of them re- .plies by inserting an answering plug of a twostrand cord in the jack L; the calling lamp LA then extinguishes and the busy lamp L02 lights up. If the calling subscriber has not hung up after ringing, the supervisory lamp of the cord circuit extinguishes .and the operator notes the required communication. If the calling subscriber has hung up, he is rung automatically and the supervisory lamp flashes and then extinguishes when the subscriber replies.

When the plug of the cord circuit is withdrawn :from the lack L. the c nnections-5 released.

In case the communication is intended for a vsubscriber who is connected to the manual can. tral and who can be reached directly, th op ra tor roceeds to test the called line and completes the communication in the usual way In the case where the communication is intended for a subscriber or ,thesame rural district as the calling subscriber, the operator does no have to bother about knowing whether the called subscriber does or does not belong :to the same rural area as the calling subscriber.

The operator insertsthe secondplug of the twostrand cord into the jack 'L" and thus, via a p16- selector such as 'P', seizes :a selector such as 4 which is associated with a translator or register such as E.

The dial lamp lights up and the operator sets up on her dial the number of the called subscriber. The translator E registers the combination of numbers, translates it and directs the selector S to connect the first circuit of the group of circuits that are in connection with the called rural area.

If the circuit does not belong to the same group as the calling circuit (communication between subscribers of two different rural areas), the selector hunts for a free circuit among the circuits of the called group and the translator sends back the figures necessary for making the selection .among the various rural switches that are passed over.

On termination of the'selection, the supervisory signals at the operators position, the ringing of the wanted subscriber and the release upon termination of the call are effected by any suitable one of the well known methods.

If the circuit to which the selector S is directed belongs to the same group as the calling circuit (local or intra-area communication) the translator E sends back the figures required for the selection in the reverse direction to the calling circuit. via the preselector P and the finder C. When the selection is finished, the selector S and the translator E are released, and the communication between the two subscribers is established under the conditions usual for a local call between rural subscribers. When the communication is established, the operator withdraws the plugs of the cord circuit and this effects the release of the finder C and of the circuits not used by the local call. The release upon termination of the call is effected by any well known method.

In case the calling subscriber has hung up after having made his call, the operator calls back the subscriber by inserting the answering plug of a cord circuit in a free jack L and thus connects herself by means of the pre-selector P, which is associated with the jack L, to a free selector S and translator E. She thus puts herself in communication with the calling subscriber who tells her the number of the called subscriber.

The operator then rings the called subscriber by inserting the calling plug of the same cord circuit in the jack L which is paired with the jack L. She thus connects herself via the preselector P that is associated with the jack L to another free selector S and register E, and this register may be the same as the one that served ,for establishing the connection with the calling party. The operator sets up the called subscriber's number and, if the subscriber belongs to a different rural area from that of the calling party, the communication is established via the selectors S, the pre-selectors P and P and the cord circuit.

If the called subscriber and the calling subscriber are connected to one and the same area, the second selector S directs itself over the same group of lines as the first selector and the register .E repeats back the trains of impulses via the preselector P, the pre-selector P and the first selector to the circuit by which the calling subscriber has been reached.

Calls proceeding from outside subscribers or from other districts are routed by using a jack G.

The mode of operation of the device will now be explained in detail with reference to Figs. 2, 3 and 4. The equipment of the rural circuit ER has not been shown because the details of its operation are not necessary for the understanding of the invention.

Call by a rural subscriber.-When a call by a rural subscriber such as A is registered, by known method, on the equipment ER of a rural circuit, a battery is connected to the wire X, and this causes excitation of the relay I via RiIl. At TI2' relay I completes over R2I the circuit of the electromagnet RC. The call finder 0 starts out and proceeds to hunt for the calling circuit. When the wipers of the said finder reach the bank contacts of the equipment ER, the following circuit of relay 2 is completed: battery connected to the equipment ER, over the wire 1* to the receiving end of the call, bank contact and wiper R, the windings, in series, of relay 2, TI3 and earth.

Relay 2 comes into the holding position and opens at R2I the circuit of the electromagnet RC. Accordingly the finder C stops at the desired position.

At T23 relay 2 completes the circuit of the calling lamp LA, which lights up. At T2I it completes the circuit of its own low resistance bottom windingand thus denotes the occupation of the circuit.

When the operator inserts the answering plug of a cord circuit into the jack L, a battery is connected to the sleeve of plug CL and completes the following circuit of relay 6: battery on CL, R13, R64, T22, bottom winding of relay 6 and earth. At T65 and T66 the said relay 3 connects the springs NL and TL of the jack L to the conductors a and b of the equipment ER via the wipers A and B of C. V

The equipment ER then assumes the ringing position if the calling subscriber has hung up, or it passes to the talking position if he has held the line, and the connection is established with the operator who makes a note of the called subscribers number and then proceeds to call back the calling subscriber and to ring the called subscriber, as will be explained, further on.

As soon as it is energized, relay 6 has completed at T63 the circuit of the upper winding of relay II which pulls up, and at TESI relay 6 completes its holding circuit by its upper winding because of the earth applied to the wire it in the equipment ER, while at T64 it returns the circuit of the sleeve of plug CL over the wire S. Relay II, which has pulled up, returns at TI II the starting wire to the next finder, and at RI II it opens the circuit of relay I which falls back, thus causing the release of relay 2. At TI I2 relay I I completes the circuit of the busy lamp L02 which lights up.

Establishment of a call between two subscribers of the rural district-The operator first calls back the calling subscriber. To do this, she inserts the answering plug of a cord circuit into a free jack L. The following circuit of relay II! is complete: battery applied to the sleeve of the jack L by the plug, R13, R54, R22, RI2I', winding of IO and earth.

Relay I8 pulls up and at Tilli it completes the circuit of the upper winding of relay II which pulls up and causes the lighting up of the busy lamp and the return to the starting wire. At TIil3 relay I0 completes the circuit of the rotary electromagnet R2 of the pre-selector P via R9I and RI23.

The wipers of P advance in free rotation hunting for a free selector which will be assumed to be that of Fig. 2.

As has been'shown in Fig. 1, a certain number of selectors like that of Fig. 2 are associated with a, register like that of Fig. 4. When the register is free, relays I3 and I5 in each of the selectors will be in the holding position. The holding circuit of relay I3 is as follows: ground, winding of I3, RI42, RII2', wire 0, R33I, bank contacts and wiper b of the switch X3 in the resting position, bank contacts and wiper b of the switch :02 in the resting position, bank contacts and wiper a of switch .125 in the resting position, bank contacts and wiper a of switch $4 in the resting position, resistance RI and battery. The circuit of relay I5 is completed at TI3I. At RI5I relay I5 opens the circuit of the busy lamp L01.

When the wipers of P reach their free selector, the following circuit of relay 9 is completed: ground, TI02, windings of relay 9 in series with each other, wiper T1 of P, bank contact of the free selector wire t1, upper winding of relay I4, RII2' and battery on the wire 0 over the previously mentioned circuit.

Relay 9 pulls up and opens at R9I the circuit of the electromagnet R2. The wipers of P stop at the desired position. At T92 relay 9 short-circuits its high resistance bottom windings and at T9I it completes the circuit of the bottom winding of relay I2 which comes into the holding position. At TI22' and TI23 relay I2 returns the talking conductors to the selector, at RI23 it makes a second cut-01f in the circuit of the electromagnet R2, at T I 24 it applies a ground to the holding wire, and at TI:2 I it returns the wire of the sleeve CL of the plug to the wiper S1. The battery CL con nected to the Wiper completes via RII3 the circuit of the bottom winding of relay I8 which pulls up and connects the selector of Fig. 2 to the register of Fig. 4. Moreover, relay I4 becomes energized over the circuit of the test wire t and it disconnects the selector from the multipling circuits in the direction of the outgoing jacks such as G. At RI42 it opens the circuit of I3 which falls back and causes I5 to drop due to the circuit opening at I3I The circuit of the busy lamp L01 is completed at RI5I.

The battery of the sleeve CL of jack L completes the following circuit of relay 33: battery on CL, R13, R64, R22, TI2I, wiper S1 of P, Wire s1, TI43, RIB3, TI82, wire se, both windings of 33 and earth.

Relay 33 comes into the holding position and completes the following circuit of relay 32; ground, winding of 32, T33 I non-inductive upper winding of 34 and battery. Relay 32 pulls up and via T325 it short-circuits the high resistance bottom winding of relay 33 via R24I and R255, and this results in bringing the supervisory relay into the holding position and accordingly causing the lighting up of the supervisory lamp of the cord circuit.

The operator is thus notified that she can proceed to dial the subscribers code digits and she depresses her dial key. One result of this manipulation is the connecting of the impulse circuit of the operator's dial to the plug conductor that is connected to the springand the following circuit of relay 3i: battery, on spring NL, R'II, TIZZ', wiper A1 of P, wire an, RBI, TIBI', wire ac, winding of relay 3|, and ground. Relay 3| comes into the holding position and at TSII it closes a new circuit for the relay 32; ground, winding of 32, R33I, T3II, non-indicating upper winding of 34 and battery. By its various contacts, relay 32 prepares the registers operating circuit, and at T323 it places an earth in. engagement;

Manipulation ofrthe; dial key; has-furthermore had the effect of shortrcircuitingin the cord cir.- quit the battery that had, been applied on the; plugs sleeve CL and this, causes the'release of relay 33 of'the register.

At T322 relay 32' (Fig. 4-) completes the circuit ofrelay 38 over the wire 71. and TlB-l to the upper windingofrelay I8; Relay 38- pulls' up andcompletes the circuit of the electromagnet of switch X4": ground, T382, wiper C of X4-at the resting position, contact and electromagnet X4, battery.

The switch X4passes to the first Working position. As soon asthe wiper. a has-left its resting position, the circuit of the abovementioned test. wire;- isopened. All the relays l3 and !5..oi the selectors associated with the register fall back and at Rll the circuit of.the-busy lamps such as L01 is completed;

Since relay 3| is energized, thecirc-uit of X4 is completed'by: ground, T3l2, wiper; C at' the first working position, contact and-electromagnet X4- and battery. The wipers-of X4 pass-.to the second working position.

The operator. will now proceedto. dial the code. digits of the called subscriber. It. will be. as-- sumed, for example, that all thesubscribers oi the rural district have a four figure call number. The operator proceeds to dial the first figure. The manipulation of the calling dial causes cutoils" on thebattery connected to the spring NL of- L.

Relay 3! of the. register. will then. follow the impulses emittedbythe operators dial. Upon each dropping of relay 3|, the following circuit is completed: ground, R3l2, T324, w-ipera of X4. at the. second working position, electromagnet X5. and. battery. The. wipers of. the switch X5, Will then advanceby as many-steps as there are impulses receiving on relay 3|.

At the first dropping of. relay 3!, the following circuit of relay 34 is completed: battery, series, windings of. 34, T32I, R33l, R3-H andv ground. This relay 3| pulls up and holds up during the receiving of a train of.impulses,-owing to the fact that it is retarded bythe-short-circuiting of its bottom. winding over a circuit including: right hand-terminal of the winding, T3, R331, T32iand left hand outlet of the winding.

When relay 34 has pulled up, it completes the circuit of the electromagnet X4 via T345 across the wiper c. This electromagnet attracts its armature. Upon termination of the receipt of the train of impulses, relay 34' falls back and opens at T345 the circuit of the electromagnet which releases its armature. The wipers of X4 pass to the third working position. It has been assumed, for example, that the capacity of the rural district is limited to 2,00.0.-subscriber lines.

The first of the figuresreceived on theregister will determine on which of the wipers b or d of theswitch X5 thesecondgfigure will beregistered, i; e. will effect the selection of the. thousand digit, in which. the calledsubscribers line. is. For ex ample, according to the-connections. shown in the drawings for the bank contacts. associated. with the wiper a, if thefirst figure is 8, the following circuit of X4 is. completed when the Wipers. of the. switch pass to they third working position. after relay 34 falls back: ground, T382, wiper a of X4. at the thirdtWorkin-g position, bank contacts and wiper a of: X5 at the eighth working position, wiper c of X4 at the third: working position. contact and e1ectromagnetX4 andbattery.

Theelectromagnet X4'makes the wipers pass to.

the fourth working position.

If; the first figure received had been 9, the ground of the wiper a of X5 would have completed the circuit of relay 31 which would have pulledup. At T31! relay 3'! closes its holding contact, on the ground of T382, at T312 it puts into service. the Wiper d of X5, and at T313 it closes the circuitof the electromagnet X4 which makes its Wipers pass to the fourth Working position.

When the wipers of.- X4 reach the fourth work'- ing position, the following circuit is completed: ground, T382, wiper a of- X4, bank segments and wiper C of X5, contact and electromagnet X5 and battery. The. wipers of X5 advance in free rotation and pass into. the resting position that corresponds to the second quarter turn.

Wipers e, d, b are engaged and wipers a and. c are disengaged. The following circuit of the elec-. tromagnet X4 is completed: ground, T382, wiperd of X5 at the resting position, wiper c of X4 at the fourth working position, Contact and electromagnet X4 and battery.

The electromagnet X4 makes its wipers pass to the fifth Working position.

The second train of impulses will be received on. the electromagnet X5 via: ground, R3! 2, T324, wiper a of X4 at the fifth position. electromagnet X5 and battery.

The wipers b, d and e of X5 will advance on. their bank contact by av number of. steps equal to the figure received.

Upon termination of the receipt of the second train of impulses, the electromagnet X4 which had attracted its armature when relay 34 pulled up, releases it when T345 is opened and the wipers of the switchX pass to the. sixth working position.

The third train of impulses is then received on the electromagnet X2 which advances its wipers by a number of steps corresponding to the number of impulses received.

When relay 34 falls back, the electromagnet X4 advances its wipers to the seventh working position. The following circuit of the electromagnet X3 is then completed: ground, T382, wiper a of X4 at the seventh position, wiper a of X3 at the resting position, contact and electromagnet X3 and battery.

The electromagnet X3 moves its wipers to the first working position. The following circuit of the electromagnet X4 is completed: ground, T382, wiper b of" X3 at the first working position, wiper C of X4 at the seventh working position, contact and electromagnet of' X4 and battery. The electromagnet X4 moves its wipers to the eighth position and then advances via the ground placed on the bank contacts to the resting position that corresponds tothe second quarter turn.

Wipers a and c are disengaged, and the other wipers are engaged.

Thefourth figure is then received on. the switch X4 over:- ground, R3l2, T324, Wiper d and bank contact for the, first figure, T342, Wiper d and bank contacts for the next figures. The switch X4 will advance its wipers during the 2d quarter turnby a number of steps equal to the number of impulses received.

An explanation will, now be given of how the translator TR is controlled and how the impulses are repeated back by the register. When the wipers of switch X3 are at the first working position, the following circuit of the electromagnet RD of the translator TB is completed: ground, R2! I, wiper d of X3 at the first working position, contact and electromagnet RD and battery.

It will be noted that at the banks of contacts of th switch of translator TR it has been assumed that each bank contacts of the wipers b and d of X4 has been multipled on five bank contacts. For the total of ten bank contacts of the wipers b and d of X there will accordingly be one hundred contacts on the switch of the translator. Only some of these contacts are shown in the drawings. Moreover, for each position of the translators switch, the marking wipers (e, f, g and it) have access, by means of the distribution frame Re and the relay set C, to twenty marking positions on the switch X, and this gives for the total 100 contacts of the said translator switch the marking positions for the 2,000 or less subscribers for whom it is assumed to be arranged.

The switch wipers advance, since the circuit of the electromagnet RD is closed, as mentioned.

When the Wipers a, b of RD reach the contact carrying members that correspond to th combination of the first three digits registered, the following circuit of relay 2| is completed: ground, series windings of relay 2|, wiper a of X2 at the position to which it has been brought by the third train of impulses, bank contact associated with the wiper b of RD, wiper a and, for example, bank contact of the wiper b of X5 to which the said wiper has been brought by the second train of impulses, wiper b, R312, resistance R2 and battery.

Relay 2| pulls up and opens at R2| the circuit of the electromagnet RD. The wipers of the translator stop at the desired position, and this position depends on the first three impulses receiving on the register.

At T2|| relay 2| forms the circuit of the electromagnet X3 over the wiper a at the first Working position. This electromagnet advances the switch wipers to the second working position. At the latter position, the circuit of relay 2| is opened at the wiper C; the said relay falls back and completes the circuit of the electromagnet X3 over the wiper a at the second working position. The

wipers of X3 pass to the third working position.

The starting circuit of the selector of Fig. 2 is completed over: ground, R2l I (Fig. 4), wiper d at the third working position, wire 1, Tl86, RI'H, contact and electromagnet R and battery.

The electromagnet R will advance the wipers of the selector S in free rotation in order to proceed with the control of the selector to the group of lines of the rural area that corresponds to stopped, control wire FC, wiper C1 of selector S,

H83, wire C, resistance R2 and battery. Relay 2| pulls up and opens at R2|| the circuit of the electromagnet R of S. The wipers of the said,

selector stop at the free line associated with a rural equipment such as ER.

In the example shown in'the drawings, if the third digit registered is an even number 0, 2, 4, 6, or 8, the following circuit of relay C of the translator is completed: battery, winding of relay C, wiper b of X2 at an even number position, wiper b of X3 at the third working position, T382 and ground. Relay C pulls up.

When relay 2| has pulled up, it has completed at T2 the circuit of the electromagnet X3 which advances its wipers to the fourth working position or position of discrimination.

. The following circuit of relay 22 is completed:

battery, common relay D, series windings of relay 22, wiper b of X3 at the 4th working position. T382 and ground. If there is no other register in a position of discrimination (position 4 of a switch X3), relay 22 becomes energized and short-circuits its high resistance upper winding in order to make impossible the energization of relay 22 of another register coming into the position of discrimination. At T224 it completes the circuit of relay 24: battery, winding of 24, R262, T224, R2 and ground; at T223 it connects the wire (I to the upper winding of relay 25 and connects a ground in series with the resistance R3 on the wire d. In the case under consideration, the circuits of wires (1 and d do not enter into action.

Relay 24 becomes energized and pulls up and at T246 it completes the following circuit of relay 2|: ground, windings of relay 2|, T246, wire it, T|84, RI'I5, wiper T of S, wire t and battery connected to the wire t in the rural equipment ER. The relay 2| pulls up.

At T243 relay 24 completes via the wiper a of X3 at the fourth working position the circuits of the electromagnet X3 which becomes energized and advances its wipers to the fifth working position.

At this position the circuit of relay ll of the selector is completed: ground, T2||, wiper b of X3 at the fifth position, wire 1, Tl83, winding of relay I! and battery.

At R|15 relay l'l opens the circuit of relay 2| which falls back. The following circuit of relay 25 of the register is completed: battery, upper winding of 25, wiper C of X3 at the fifth working position, wire ss, Tl8l, TI'H, Wiper s of selector S, wire s and ground applied on the wire s in the rural equipment ER.

When relay 2| has fallen back, the advance circuit of switch X3 is completed: ground, R2| T255, wiper a at the fifth working position, electromagnet X3 and battery. The wipers of X3 pass into the sixth working position. For this position the battery connected over the wiper C is suppressed on the wire es and consequently on the wire s that terminates at the rural equipment, and this results in passing the equipment into dialing position.

The battery over relay 23 is shunted by the wiper b of XI, which is in resting position, with the battery over the springs of impulses I2 and resistance R5. When the ground in the rural equipment ER is applied to the wire a to indicate that the equipment is ready to receive the dialing impulses, the ground is received over TI" and TI82 on the wire as, and Over T245 the wiper C of X3 at the sixth position energizes the relay 23 when the cam I2 opens its contact.

The wiper b of X3 at the sixth position connects a battery to the wiper a of TR over the resistance R6.

The four wipers e, f, y and h control the sending of the trains of impulses. In the example shown in thedrawings it can be seen that the first three digits of the registered number can effect the control of the selector connected to the register, and also the sending of four trains of impulses, i. e. five selections in all. In case one or more trains of impulses are not to be sent, the bank contacts that correspond to the wipers e, f, g, h are connected at Re to the terminal Y and this causes the advance of the corresponding positions by the electromagnet X3.

When relay 23becomes energized upon the opening of the impulse springs I2, it closes the cirsent over the circuit via: battery, resistance R impulse springs 12, wiper c of X3, T245, wire as, TI82, TI'I4, wiper A of S, wire a and impulse relay of the equipment ER.

u Theswitch XI advances under the action of the impulses emitted by the impulse springs I1 over the circuit: ground, springs I T381, R2I4, RI, wiper c of XI, electromagnet XI and bat- When the wipers of XI have advanced by the :number of steps that correspond to the number of impulses to be sent, which is determined by the connection made on the distribution frame Re of TR, the following circuit of relay 25 is completed: ground, bottom winding of 25, wiper a of XI, bank contact to which there is connected in Re the wire that belongs tothe contact of the wiper e on which the wiper has stopped, distribution frame Re, bank contact and wiper e of RD, wiper b of X3 at the sixth working position, resistance R6 and battery. I

Relay 25 pulls up and at T252 it short-circuits the impulse springs 12 and this stops the sending of the impulses over the line equipment. At T253 ,it closes its holding circuit over the resistance 34, andat T25I it completes the automatic rotation circuit of XI: battery, electromagnet XI, wiper c of X1, wiper d of X1, T25I, interruptor spring of X1 and ground. The switch X1 thus advances in free rotation as far as its sixteenth position, In order to retard its return to the resting position, the advance to the last positions is controlled by the ,cam I1 over the circuit: battery, electromagnet X1, bank and wiper d of X1, T331, impulse springs I and ground; and for the last 1 bank contact but one over; bank and wiper d of 3. T 1. im l e pr I, and nd. When the switch XI has returned to its resting position, the wiper s'shortcircuits the relay 2 5 which falls back, and relay 23 is again connected to the wire as over the wiper c OfXl at its restingposition. r v H p v During the passage of the wiper o of XI a ground impulse is sent to the electromagnet X3 over the circuit: ground, spring contacts I1, T381,

wiper b of XI at the last position, R2I3, wiper a of X3 at the sixth position, electromagnet X3'a'nd'" I battery. The wipers of X3 pass to the seventh working position for which the battery over the resistance R6 is applied to the Wiper J of the translator TR.

The above indicated procedure isrepeated for each train of impulses whose sending is caused by the ground applied to the wire as from the rural equipment ER, the ground effecting the energization of relay 23, as has been explained. The

stoppage of the sending of the impulses is ef-' fected, as shown for the first digit, when the wiper a of XI reaches the bank contact to which is connected the wipers f, g, or h of TR that controls the emitted impulse.

, As has been shown, some of the registered digits may not be repeated back by'the translator. In

this case, the bank contacts'of the'wipers' e, f, g, it that correspond to the said figures are concts ie th i m a iqfli are when the H ers of X3 reach the corresponding" position, the

Eircuit of relay 2I is completed over the wiper b of X3, the resistance R6 "and the battery. Relay 2I pulls up and'opens at RZ'I 4the advance circuit of switch XI, and at T2 I3 it springs I1, T361, T2I3, wiper a of X3, "electromognet X3 and battery. The electromagnet X3 advances its wipers to the next position.

If, for example, it is assumed that each position of the translator corresponds to a group of 26 subscribers, i. e. two of 10: 00 to 19, 20 to 39, etc., the wire controlling these'nding of the tens impulses should'be connectable to two difierent contacts in the bank of sender XI. Thus for the tens beginningwith 0 and 1, this wire is connected to the second contact of the wiper a of XI for the tens beginning with 1, and to the'tenth contact for the tens beginning with 0, and to the contacts 3 and 4, etc.,'for thete'ns beginning with 2 and 3, etc. This switching to one contact or the other is effected by the relay C of TR, the operation of which has been explained for the fourth working position of the switch X3,

When all the trains ofimpulses that have been determined by' the position of the translator TR have been sent, the switch X3 will have brought its wipers to the tenth working position. The sending of the impulses of the units whose number is determined by the received digit that has been registered on the switch X4 will now take place. The battery over the resistance'R5, the

wiper b of X3 and the wiper 1:: of X4, is connected to the control wire that corresponds to the registered number, the control wire beingco'nnected to the contact that corresponds to the bank of wiper a of the switch XI. The sending of the impulses accordingly takes place in the already described manner.

When the wipers of the switch XI reach the last contact but one of the bank, after the sending of the unit digit, they stop, since the advance circuit is open on the wiper d of the switch X3. Relay 32 is short-circuited by the circuit: ground, wiper b of XI at the ninth working position, wiper a of X3 at the tenth working position, left hand terminalof the winding of relay 32. The relay falls back and-opens at T322 the circuit of the relays 38 of the register and I8 of the selector, which fall back.

The circuit of relay 36 is'completedzg'round, bottom winding of 36, R38I, segments and wiper ,f of X4, contactand ele'ctromagnet X4 and battery. Relay 36 pulls up and at T364 it completes the return to rest circuits of the switches X4, X5,

X2 and X3. V

The'circuit of X4i's: ground, T364, REBI, segments' and wiper f, contact and electromagnet X4 and battery. This circuit 'is' opened when the switch X4 has returned to its resting'position.

Circuit of X5: battery, electrom'agnet'X5, segments and wipers C or 6 according to the position of the 'switch, R384, T364, and ground.

Circuit of X2: battery,"electromagnet X2, segments and wiper C, R336, T364 and ou Circuit of X3 :"battery, elec'tromagnet X3, wiper gases, T3 64 and ground.

When these various switches have ret'urned'to the resting position, the'following short-circuiting fcircuit of relay 36 is completed: ground, T363,

T36I, wiper b of "X3 atits resting position, wiper b of X2 at its resting position, wiper a of X5 at its r'esting position, wiper a ofX4 at its resting'position, right hand outlet of the upper winding of relay'36. Relay 36 falls back and closes at V36I the engagement circuit of the register.

Upon the falling back'of relay 38, the switch XI will have cleared the ninth workingposition via the circuit: ground, contact of the electromagnet XI, R388, wiper b at the ninth position, electromagnet XI and battery. The tenth position is cleared by the circuit: ground, contact of XI, R361, wiper b at the tenth position, electromagnet X and battery. The switch XI returns to the resting position. When relay I8 has fallen back, since its circuit is open at R323 of the register, it will have cut on? the connections with the register and will have completed at RI8I' the connection of the rural area to the cord circuit. The operator can then ring the called subscriber and enter into conversation in the usual manner.

It will be noted that, after the dialing of the subscriberhas been completed and the operator lifts her dial key, the ground that had been applied to the third wire of the cord circuit, i. e. to the sleeve CL of the jack L, is suppressed and the battery is applied again to the sleeve and this again causes relay 33 of the register to come into holding position on the above-mentioned circuit. The supervisory lamp of the cord circuit will flash as a result of the ground applied at T4IJI by the impulsing relay 46 on relay 33 for short-circuiting its high resistance bottom winding. This flicker will continue during the entire time of sending of the impulses and will end when the register is again released.

The operator will now proceed to call the wanted subscriber. For this purpose she inserts the second plug of the cord circuit that was used for calling back the calling subscriber in the jack L associated with the jack L used for the recall. A battery is connected to the sleeve CL of the plug L and it completes over RM and R33 this circuit of relay 3 which pulls up.

The starting circuit of the preselector P is completed via earth, T32, RSI, RM, contact and electromagnet RI of P. V

The wipers of P advance, hunting for a free selector, which will be a selector identical to that of Fig. 2. In the hereunder given description the explanations will be given as if referring to the diagram of Fig. 2, although in reality this particular selector is in engagement with the rural circuit of the calling subscriber as already explained.

When the wipers of P reach the free selector,

the circuit of relay 5 is completed thus: ground,

T3l, series windings of relay 5, Wiper T of P, bank contact and wire t of the free selector, upper winding of relay I4, RI'I2' and battery on the wire via the register that isassociated with the selector as mentioned in the preceding case. Relay pulls up and completes at Till the circuit of the bottom winding of relay 4, which becomes energized.

The operator then receives the same supervisory signals and proceeds to perform the same operations as mentioned in the preceding case for the call back to the calling subscriber. If the called subscriber belongs to a different rural area from that of the calling subscriber, the procedure for routing the call is the same as in the preceding case. After disconnection of the register, the subscribers are put in communication over: rural equipment ER of the called subscriber's circuit, a selector like the one of Fig. 2, a preselector P, the jack L, the cord circuit, the jack L, a preselector P, a second selector like the one of Fig. 1, and an equipment ER of the called subscribers rural circuit.

' The supervisory signals are given in the supervisory lamps of the'cord circuit according to one of the methods adopted for rural networks.

Upon termination of the conversation, the operator withdraws the plugs of the cord circuit, the battery is suppressed on the wires 8 and the selectors are released.

If the called subscriber belongs to the same rural area as the calling subscriber, the following circuit of relay 26 is completed when the register passes into position 4 (discrimination): ground, resistance R3, T222, wire d, TI 85, wire 01, wiper D of the preselector P, T46, R82, upper winding of relay 8, R62, TI24', wiper DI of the preselector P, wire (II and, in the selector in engagement with the calling subscriber, TI'M, wiper D, wire at multiplied on the selector banks, wiper D of the selector used for calling the wanted subscriber, TI83, common wire d, T223, upper winding of relay 26 and battery.

Relay 8 does not become energized owing to the value of the resistance R3.

At T26I relay 26 completes its holding circuit on its bottom winding over the ground of T382, and. at T266 it short-circuits the resistance R3 of the wire 11, at R262 it opens the energization circuit of relay 24 before the relay becomes energized; at T263 it completes the circuit of the electromagnet X3 over the wiper a at the fourth Working position and the ground of RZI l. The switch X3 passes to the third working position for which the circuit of the electromagnet is again completed across the wiper a and the ground of T264. The switch X3 passes to the sixth working position.

When the resistance R3 is short-circuited, the intensity of current becomes sufficient to cause energization of relay 8 (Fig. 3) over the circuit that has been mentioned. At T8I it completes its holding circuit over the ground of T124 (relay I2 has pulled up as mentioned when discussing the call of the wanted subscriber). At T82 relay 8 completes the circuit of relay I over the ground of wire d.

Relay I pulls up and at R13 it cuts ofi the battery of CL on the wire s in the direction of the equipment ER of the circuit on which the call back of the calling subscriber has been made, and this results in the passing of the equipment to the dialing position; at T" it connects the dialing wire A, which comes from the register across the preselector P and a selecton to the dialing wire that is connected to the equipment ER via the preselector P and the selector which effects the calling of the wanted subscriber.

When the circuit can receive impulses, the

ground applied to the wire a in the equipment ER causes energization of relay 23 over the circuit:

ground across the dialing relay of ER, wire a, wiper A of the selector used forthe call back of the calling party, T, I74, RIBI, RIGE, wire a1, wiper A1 of the preselector P, TI22, TII, wiper A of the preselector P, TI22, TII, wiper A of the preselector P, wire a, selector used for calling the wanted subscriber, TI84, common wire a, R24 (Fig. 4) wiper c of X3 at the positions 6 to 10 and, on the one hand, wiper c of XI at the resting position of relay 23 and, on the other hand, impulse springs Z2, resistance R5 and battery.

The sending of the impulses is then effected in the way mentioned in the preceding case.

When the register has returned to the resting position after the impulses have been sent, the selector used for calling the wanted subscriber assothe wires 01 and t of the preselectorFP'..is suppressed and this causes thefallingeback'of the re- --lays-4'and l (Figr3).

1 the equipment ER of the rural :circuitracrosszthe cpreselector Rand the selector that. isiassociated with it.

dated withthe selector is released asrrnentioned inthe preceding case. "Thisiselector hadubeen controlled to the called :direction,:but the'.connection had not been made; this connection had been -made impossible owing to the energizationioftrelay 26 of the register which. had .prevented the excitation of relays 24 of the-register: and [110i the selector.

Upon the release of the selector, the groundion The conductors ofthe plug used forithe call back of the callingpartyare again connected to The equipmentpasses into the'calling and con- -versation positions .in the normal manner, and

withthe usual supervision for establishing com-.1

-munication between two subscribers of: one: same area.

When relay ti'fallsbackdFig. 3) ,a supervisory circuit (rapid fiicker) is established by the supervisory lamp of the plug usedfor calling the,

wanted subscriber. This supervisory circuit -warns the operator that this plug is to" be withl. drawn: supervisory circuit, wire CL. of plu .L', 1 RM, ground, on the onehand; and low value resistance :R8 and ground on the contact of the beater-relay i St, on the other hand.

T83, relatively high resistance 7R1, Land Whenever the operator .ccmpletes'the' connection between two .subscribers of the 'l'ur'aldis trict without calling back the callingsubscribers,

The mode of operation is the-sameas in the preceding case, but, in the equipment of-Fign 3,

:r'elay l2 has not become energized'while relay 6 has become energized and maintained-pulled up as in the case of thereply to a call from a rural subscriber. The circuit of relay 26 of the register used for calling 1 the 'wantedsubscriber is then completedin the following wayt ground, resistance R3 (Fig. 4), T222ywire'd'; T|8 6,"wired',

wiper D of the preselector-P',T46, R82; upper winding otrelay 8,'T62,---wiper D ofcgwireid *mu1tipled on the banks ofthe-selectors, wiper 'D of the selector used for callinggthe'wanted-subscriber, Tl83', common'wire' d, T223, upper Winding of relay 26 and-battery.

'It is only in this case that the equipmentat :the input endshown-inFig. 3 remains in: engage- :-.ment untilthe operatorhas withdrawn the plugs of the cord circuit used for establishing the local connection.

When the operatonestablishes communication between a subscriber outside of the rural district and a subscriber within the district isheycaniuse the jack G (Fig.1 2) of a-ireaoutg-oing. selector. The general mode of-operation is thecsamelas that described in-thecase of'the :call back- 'of-the calling subscriber,- exceptthat theequipmentac-f Fig; 3 does not come into play and relay I l-(Fig.

' 2) remains inthe resting positionhsince theconnection of the conductors. ofthe two-.strandcord "with the circuit'is 1effected'by';Ri4 4, Rl'43 and "RMS.

- It-wil1 be noted that after -a---register hasbeen 16 .a'seiz'ed; if-forzany reason (SIOWHESSTOf' the operator *in'setting .up the number,: congestion of the-rural .circuits, etc.) the succession of operations does not-take; place normally, the already established connections are -released after a certain time (varying from 20 to 40 seconds) and the operator 11BC8iVES the busy signal. Forthis'purpose, the 10am lefiectsthe energization' of relay35 on its upper/Winding. .If relay 34has; fallen back-relay :35 completes its holding circuit at T35I on the 5 ground ofT382. When the cam 2 closes its contact, the circuit of relay 16 of the selector iscom- .i pleted by T352, wire 9', TI 86', upper winding of I6. rAt Tlfil and Tl63 it closes its holding circuit across the cord circuit, eitheron the wire a or on the wires; atTlfilitconnects the busy signal which is sentto the operator, and at- R|63 it efz-fects the release of the register.

"Inthe device: shown .in Figs. 1- to 4, that has just been'described, :ithas been seen that the choice of the circuit as .well as the ,diiferent selections, were effected: automatically by the translater.

The operator does'not'have to worryabout the ruralarea to which the called subscriber belongs; it is suflicient for her to use a free jack and to .2 dial the code digits of the subscriber for the connection to be set up.

Referring to Fig. 6, an explanation will now be given of a device that permits simplification of the preceding equipment and that can be used in small district centrals. Thisdevice which is associated :with .each operating position makes it possible to give' the subscribers'of one. district call numbers comprising the same number of figures. The

-'choice of the'circuit is made by the operator while making the call with the actualnumber of the called subscriber. For example, in the case of a 'four figure dialing-the choicecorresponding t0 the first digit is made by the operator by plugging into a certain jack, and the device only registers and translates the hundreds digit. In case the rural subscriber is connected to a rural exchange that only-requires a single digit, the tens digitis absorbed in the deviceand only the units digit is sent to the rural switchboard.

In the illustration-of Fig. 3 it has been -assumed, for example, that this translator could serve anetworkcomprising 4,000 numbers, i. e. 40 exchanges-or'hundreds, each of the switches XI and X2 havinga capacity of 20 exchanges orhun'dreds.

The hundreds "digit may be translated by 0, '1,

*2 or 3 selections'(connections of the banks Xla',

IXIb', Xl'e' to the-banks:X3a" (I), X30 (III), and X3e' (I) of the sender switch X3). The connections at'theterminalsd and d determine whether the two last figures (tens digit and units digit) or if only the last' figure. (units digit) will be :sentdirect over the rural circuit.

' When the operatonhas-inserted the plug of a :cord circuit inthe corresponding jacket the called -subscribers area and shehas received the dialin signal from-the rurallequipmenushe depresses the dial key and relay 22 (or relay 22' and one of the relays 2|, 23 or-24)'becomesenergized by the ground applied-on the-wire .C (or Cl, C2 or .The wire C. is multipled onall the dial keys of circuits-thatservaior example, the calling numbers of ,the first thousand, Cl'lon those of the 1 second thousand, C25 .on thoseof the third thou- 17 lay I: ground, T225, closed contact of the dial CR, resistance RI, winding of I and battery. When relay I' has pulled up, the circuit of relay 2 is completed: ground, T225, RBI, TI2 wiper d of the switch X2 at the resting position, wiper g of XI at the resting position, windin of relay 2 and battery.

The circuit of the dial lamp LC is completed over: ground, T25, R53, lamp LC and battery.

When the dial lamp has lighted up, the operator sets up the hundreds digit on the dial CR. This dialing will control the switch XI, or X2 depending on whether the number is comprised in the 3d or 4th thousand in the example shown in the drawing.

Assuming that the subscribers number is comprised in the third thousand, the circuit of the electromagnet XI, will be completed over: ground, T225, R62, RIZ (at each falling back of relay I whose circuit is open on the impulse springs of the dial CR), T22, R24I, electromagnet XI, and battery.

As soon as the dial CR leaves its esting position, the circuit of relay 4 is completed: ground, T225, right hand contact of Cr which is closed during the entire time of dialing, relay 4 and battery. At T4I, relay 4 completes over T24 the holding circuit of relay 2 whose holding up circuit is opened as soon as the wiper g of XI leaves its position of rest.

Upon termination of the series of impulses, relay 4 falls back, since its circuit is opened on the right hand contact of the dial, and at T4I it opens the circuit of relay 2 which falls back. Ground is applied to the wipers a, b, c, and d of XI by the circuit: ground, T225, R43, R23I, R242, R2I I and Wipers.

The circuit of the electromagnet X3 is completed by: ground, wiper i of XI out of its resting position, T22I', R2I, impulse springs I2, R33, R63, wiper h of X3 at its resting position, electromagnet X3 and battery.

Upon each cut-off of the impulse springs I2, the electromagnet X3 advances its wipers by one step. After the first step, the circuit of the electromagnet X3 closes over: ground, wiper i of X out of its resting position, T22I, R2I, impulse springs I2, R33, R63, R82, T224, wiper b of X3.

The bank contacts of the wipers a, b, and c of VI are connected to the bank contacts of the wipers e, c and a'of X3 by means of the distribution frame Re in such a way as to translate the registered figure by 0, 1, 2 or 3 selections.

Let us assume, for example, that the receiver figure is to be translated by three selections, the first of which consists of a train of two impulses, the second by a train of seven impulses and the third by a train of ten impulses.

In this case the bank contact on which the wiper a of XI" has stopped will be connected to the third contact of the bank of the wiper a of X3, the bank contact on which the wiper b of XI has stopped will be connected to the bank of the wiper c of X3, and the bank contact on which the wiper c of XI has stopped will not be connected (sending of impulses).

As has been shown, the electromagnet X3 advances its wipers under the action of the cut-offs of the impulse springs I2.

After the first step of the switchX3, the impulse springs I'2 are connected to the wire A which is joined to the impulse circuit of the rural equipment over: battery, resistance R2, impulse 18 springs II, RBI banks and wiper f of X3, R52 and wire A.

It can be seen that for each step after the first one by which the switch X3 advances, an impulse is sent over the wire A, i. e. to the impulse circuit of the rural equipment.

In the example under consideration, when the wiper a of X3 reaches the third bank contact, i. e. the second working contact, the following circuit of relay 8 is completed: ground on the wiper a of XI over the above-mentioned circuit, connection at the distribution frame Re, third contact and wiper a of X3, R'I2, series windings of relay 8 and battery. At R8I the impulse circuit is opened and the sending of impulses terminates. At T83 relay 8 closes its holding circuit on the ground of T223, and at T82 it completes the automatic rotation circuit of the electromagnet X3: ground, contact of the electromagnet X3, T82, T224, wiper b of X3 for the first and third quarter turns and wiper d for the second and fourth quarter turns, electromagnet X3 and battery.

The electromagnet X3 advances its wipers as far as the sixth position of the second quarter turn in which its circuit is open. At this position relay 8 is short-circuited by the circuit: ground, T225, wiper b of X3 at the sixth position and left hand outlet of the windings of relay 8. The circuit of the electromagnet X3 is then completed over: ground, wiper i of .XI, T22I, R2I, impulse springs I'2, R33, R53, R82, T224, wiper d of X3, electromagnet X3 and battery, and for the sixth position: R84, wiper d of X3, electromagnet X3 and battery. The wipers of X3 then advance step by step underthe control of the impulse springs I2. The object of this arrangement is to retard the return of the switch X3 to its resting position so as to leave sufficient time for the falling back of the slow relay that is associated with the impulse relay on which the train of impulses that have just been sent are received before the said switch passes to its last bank contact.

When the wiper b of X3 passes to the last contact of its bank, it completes the circuit of relay 3' on the battery connected to. the wire A over the rural equipment: ground, bottom winding of relay 3, wiper b of X3 at the last working position, R52 and wire A. Relay 3' remains pulled up as long as the selectors in the rural exchange are not in a position to receive the next train of impulses.

At R33 relay 3 makes a cut-ofi in the advance circuit of the switch X3.

As soon as the rural exchange is in a position to receive the next train of impulses, the battery on the wire A is removed, according to one of the known methods, and relay 3 falls back.

The above-mentioned circuit of the electromagnet X3 is again completed and the train of impulses that corresponds to the next figure are sent over the rural circuit in the same way as has been shown for the preceding figure.

The wiper C of X3 is then engaged with its bank (3d quarter turn). When it reaches its eighth bank contact after seven impulses have been sent across the wiper f of X3, the circuit of relay 8 is again completed. The said relay becomes energized over the circuit: battery, series windings of 8, R12, wiper e on the seventh working position, wire I at the distribution frame Re connected to the wire on which the wiper b of XI has stopped, wiper b, R2I I, R242, R3I', R43, T225 and ground.

Relay 8 stops the sending of impulses and advances the switch X3 as described for the sending of the preceding digit.

The wipers of X3 that are now in engagement with their bank contacts are those of the foul th quarter turns.

When the wiper b of X3 passes to the 8th position of its bank, relay '1 becomes energized over the circuit: ground, T225, bank contact and wiper b of X3, banks and wiper g, relay I and battery.

The relay i" pulls up and at T14 it closes its holding circuit on the ground of T225, at T'I2' it connects the circuit of relay 8' to the bank of the wiper e of X3, and at T'II it prepares the circuit of relays 5 and 6.

The other successive operations are carried out as indicated above, particularly the .pullling up of relay 3".

When relay 3 falls back, the electromagnet X3" starts again and the third train of impulses is sent over the rural circuit. Since there is no connection in the iliustrated example between the bank contacts of the Wiper c of XI and e of X3, relay 8 only becomes energized when the wiper b or X3 is on the first contact of its bank, i. e. after the sending of 10 impulses, as the impulse circuit is opened when the wiper of X13 has left its bank.

The electromagnet X3 advances its wipers to the resting position of the third quarter turn. Relay 3' is connected in and the following circuit of relays 3 and 6 is completed over the resting position of the wiper C of X3: ground, T225, R43, RZBI R242, R21 I, Wiper d of XI and bank contact connectedeither to terminal D or D, T73, wiper C of X3 in the resting position, relay 5, bottom winding of relay 3 and battery. At R63 the advance circuit of the electromagnet X3" is opened.

If the next digit, the tens digit, e. g., is not to be sent, the bank contact of Wiper d is connected to the terminal D, and the resistance R4, which is then inserted in the just mentioned circuit of relays 5 and 6, prevents energi-zation of relay 5.

If the tens digit is to be sent, the bank contact of wiper dis connected to the terminal D and relays 5 and 6 become energized in series.

If the tens digit is to'be absorbed when relay 6 becomes energized, while relay 5 remains at rest, the circuit of the lamp of dial LC is completed over: ground, T65 and R53. The lamp lights up and the operator responds by setting up the tens digit on her dial. Relay 4 becomes energized as soon as the dial CR leaves its resting position and closes the circuit of relay 2' over: ground, T41, T64, relay2 and battery. When the dial effects the cut-offs on the dialing springs, relay I beats, but its contact TI I is open at T52 and that of its contact TI2 at RSI.

Upon termination of the train'of impulses, relay fl falls back when thedialCR has returned to its resting position and before the energization of relay 2' which is slow? in falling back, and the'ci'rcuit of relay '5 is completed over: ground, Rel, T23, T62, upper winding of relay 5" and battery.

'Relay'fi pulls up; at T51" it-completes its holdi'ng "circuit over the ground of T225; at T52 it connectsthe bottom winding of re 1ay'3 to wire A a'cr'oss TH; and at T53 it prepares the circuit of'thel'amp o'f th'e'dial LC. Whent'he rural central is ready to receive the last digit, the units digit, relay 3' falls 'back and the circuit of the' iii-3,355

20 lamp LC is completed over: ground, R lI; R3! and T53.

The operator sets up on the dial CR the units digit and everything takes place in the way described, for the tens digit, except that the impulses transmitted at RI I via relay I are sent over the wire A of the circuit across T52,

The testing of the called sub'scribers line is done in any convenient well-known manner and, when the operator lifts the dial key, the translator becomes released, since the circuit of relay 22 is open.

At T225 relay 22 opens the holding circuit of relays 5, 6 and 'I' and closes the releasing circuit of the rotary switchescircuit XI: ground, wiper 2' out of its resting position, R22I', spring and 'electromagnet XI, battery.

Circuit of X3: ground, interrupter spring of X3 and on the one hand, R226, wiper g of X3 at the resting position, electromagnet X3, battery and, on the other hand, R224, wiper d on the second and fourth quarter turns or wiper h on the first and third "quarter turns, electromagnet X3 and battery,

When the wipers of the switches reach their resting position, the releasing circuits are opened and the switches stop.

It will be noted that the banks of the wipers a, b, c of XI are respectively connected to the bank contact of the resting position of the wipers a, 0 (across R73) and e of the switch X3 via the wire (1 (distribution frame Re) if the train of impulses that corresponds to this position is not to be sent. This connection causes energization of relays 5 and 6 in the way already described for the circuit of the wiper d of Xi, and the trains of impulses that correspond to the last two digits are sent by the dial over the rural circuit.

If the connection isfma'de by the contact d, the resistance that is inserted in the circuit prevents the energization of relay 5 and the tens digit is absorbed in the already described manner.

It is of course understood that the above embodiments have only been given as examples without limitation of the invention thereby, and that it is possible, without departin from the scope of the invention, to provide any arrangement of switches or relays that makes it possible to obtain the desired translations, to replace the rotary switches by relays or vice versa, and to provide other modifications that may be necessary for integrating the devices in any rural systerm.

I claim:

1. In a-telephone exchange system, a plurality of rural exchanges and a main exchange, subscribers lines terminating at said rural exchanges, said lines being designated by numbers havin the same number of digits, automatic selector switches at said .rural and main exchanges over which calling and called subscribers lines may be inter-connected, an operators position at the main exchange, 'a'calIin'g device and a register operable in accordance with all the digits of the called numbers "for controllin the establishment of connections between two'subscribers"lines over a certain number 'of selector switches and betweentwo 'otherlines'ov'er a different number of selector switches.

2. In a telephone exchange'system, aplurality ofrural exchanges-subscribers lines terminating at said exchanges, said 'lines being designated 'by numbers having'the same number of digits, automatic switches at said exchanges for inter-connecting said subscribers lines, a main exchange, an operators position at the main exchange, line finders for connecting said position to calling lines at the rural exchanges, a calling device and a translator for controlling the switches at rural exchanges over a switch at the main exchange, and means for operating said translator to control the switches at the rural exchanges over a line finder.

3. The system according to claim 2 and preselectors for connecting selectors at the main exchange with the operators position.

4. In a telephone exchange system, a plurality of rural exchanges, subscribers lines terminating at said exchanges, a main exchange, selector switches at said exchanges for inter-connecting calling and called lines, an operators position at the main exchange, a calling device at the operators position, a translator at the main exchange controlled by the calling device, nonnumerical switches at the main exchange for connecting a, rural exchange with the operators position, means operable when the 'called subscriber belongs to the same rural exchange as the calling subscriber for operating said translator to send impulses to a selector t the called rural exchange over a selector at the main exchange, and means operable when the called subscriber belongs to a diflerent rural exchange from the calling subscriber for sending impulses to the called rural exchange via a non-numerical switch.

5. In a telephone exchange system, a plurality of groups of rural exchanges, subscribers lines terminating at said exchanges, a main exchange, selector switches at said exchanges for interconnecting calling and called lines, an operators position at the main exchange, calling device at the operators position, a translator at the main exchange controlled by the calling device, a pre-selector and a line finder at the main exchange for connecting a rural exchange with the operators position, means operable when the called subscriber belongs to the same rural group as the calling subscriber for operating said translator to send impulses to the rural exchange via a selector at the main exchange, and means operable when the called subscriber belongs to a different rural groupfrom the calling subscriber for sending impulses to the called rural exchange via a pro-selector and a line finder.

6. In a telephone exchange system, a plurality of groups of rural exchanges, subscribers lines terminating at said exchanges, a main exchange, selector switches at said exchanges for interconnecting calling and called lines, an operators position at the main exchange, a calling device at the operators position, a translator at the main exchange controlled by the calling device, a preselector and a line finder at the main exchange for connecting a, rural exchange with the operators position, means operable when the called subscriber belongs to the same rural group as the calling subscriber for operating said translator to operate a selector at the main exchange to select the called rural group and then to send impulses via the operated selector to operate selectors for connecting with the called subscriber, and means operable when the called subscriber belongs to a difierent rural group from the calling subscriber for operating said translator to operate a selector at the main exchange to select the called rural group and then to send impulses to the called rural exchange via a preselector and a line finder.

7. In a telephone system, a plurality of groups of rural exchanges, lines terminating at said exchanges, selectors at said exchanges for interconnecting calling and called lines, a main exchange, an operators position at the main exchange, a translator, a calling device at the operators position for operating the translator in accordance with the first digit of the called number to select the group to which the called rural subscriber belongs, and means for operating the translator for sending impulses to control selectors'at the called rural exchange.

8. In a telephone exchange system, a plurality of rural exchanges, subscribers lines terminating thereat, selector switches at said exchanges for inter-connecting calling and called lines, a main exchange, an operators position thereat,

a translator at the main exchange, a, selector switch at the main exchange, a calling device at the'operators position for operating said translator in accordance with the digits of the called number, means. controlled by the translator for operating the selector switch at the main exchange and the selector switches at the called rural exchange, and means in said translator for absorbing certain digits of the called number.

9. ma telephone exchange system, a, plurality of rural exchanges, a, central exchange comprising an operators position, the numerical designations of all the lines terminating at the rural exchanges being composed of the same number of digits, trunk lines between said exchanges, automatic switches at said rural exchanges for establishing connections with subscribers lines, numerical and non-numerical switches at the main exchange, connections from each numerical switch to the operators position and to the nonnumerical switches in multiple, connections from the position to the non-numerical switches, a

translator arranged to be connected with the numerical switches, a first and a second rural circuit link, multiple connections from the first circuit link to the numerical and the first nonnumerical switch and multiple connections from the second link to the numerical switches, means responsive to the initiation of a call by a rural jsubscriber for operating the first non-numerical switch to extend the calling line over the first rural circuit link and the first non-numerical switch to the operators position, means controlled by the operator for establishing a connection with a called rural subscriber over a numerical switch, and over a non-numerical and numerical switch in series, the last-mentioned means including a calling device operable in accordance with the numericaldesignations of the called rural line,

means in the translator for registering the digits sent out by the calling device, means controlled by the translator for operating said numerical switch to select a rural circuit link depending on the location of the called subscriber and for controlling the operation of the switches at the called rural exchange to select the called subscriber, means controlled by the translator when the called subscriber is located within the same exchange or group of exchanges as the calling subscriber for sending impulses over the operated non-numerical switches and the first rural circuit link for operating the switches at the called rural exchange to connect with the called subscriber, and means operative upon the establishment of the connection between the calling and called rural subscribers for releasing the translator and all the switches at the main exchange.

10. In a. telephone exchange system, a plurality 23 of group o'f'rura'l exchanges, a central exchange comprising an operators position, other an changes, subscribers terminating at "said exchanges, the numerical designations of all the lines terminating at the rural exchanges-being composed of the same number zit-digits, trunk iines between said exchanges, automatic'switches at said rural exchanges 'forestablishing connections with subscribers line's, selector, finder and pre-selector switches at the main exchange; said position having first means "over which connections from said other exchanges to the rural ex chan'ges can be established, second'means over which connections between rural subscribers can be established, connections from each selector to a firstmea'ns calling jack and to the pro-selectors, connections from each second means to a -brie-selector, connections from certain second means to a finder, a translator arranged "to be connected with the selectors, a first and a second rural circuit link, connections from the first cir-- cuit link to th finders and the selectors, connections from the second linkto the selectors, means responsive to the initiation of a call by a rural subscriber for operating said finder switch to extend the calling line over the first rural circuit link and a finder to the operators position over the second means, means controlled by the operator .for establishing a connection with a called rural subscriber over a first means and the associated selector, and over asecond meanathe associated pro-selector, and a selector, the lastmentioned means including a calling device operable in accordance with the numerical designations of the called rural line, means in the translator for registering the digits sent out by the calling device, mean controlled by the translator for operating said selector to select a rural circuit link depending on the location of the called subscriber and for controlling the operation of the switches at the called rural exchange to select the called subscriber, means controlled by the translator when the called subscriber is located within the same exchange or groupof exchanges as the calling subscriber for sending impulses over the operated pro-selector, the operators position, the finder and the first rural circuit link for operating the switches at the called frura'l exchange to connect with 'the'called subscriber, and means operative upon the'establishment of the connection between the callingand called rural subscribers for releasing the translator and all the switches at the main exchange.

11. In a telephone exchange system, a plurality of groups of rural exchanges, a central exchange comprising an operators'position, other exchanges, subscribers lines terminating at said exchanges, the numerical designations of all the lines terminating at the rural exchanges being composed of the same number of digits, trunk lines between said exchanges, automatic switches at said rural exchanges for establishing connections with subscribers lines, selector, finder and pre-selector switches at the main exchange, each having a terminal bank and wipers cooperating therewith, said position having calling jacks over which connections from said other-exchanges to the'irura-l exchanges can be established, and intar-rural paired'answering and connecting ,jacks over which connection with rural subscribers can be established, connect-ions from the Wipers of each selector to a calling jack and to the terminal'banks of the pre-selectors in multiple, connections from'ea-ch connecting jack to the wipers of a pre-selector, multiple connections from each answering .jack to the wipers of a ,pre-selector and a finder, a translator arranged .to be connected with the wipers of the selectors, a first and a second rural circuit link, multiple connections froirn the first circuit link to the terminal banks of the finder and the selectors and multiple connetctions from the second link to the selectors, means responsive to the initiation of a call by a rural subscriber for operating said finder switch to extend the calling line over the first rural circult :link and a finder to the associated answering jack, imeans controlled by the operator ior establishing a connection with a called rural subscriber over a calling jack and the associated selector, and over an answering or a connecting jack, the associated pre-selector, and 'a selector, the last-mentioned means including a calling device operable .in accordance with the numerical designations of the-calledrural line, means in the transiator for registering the digits sent out by the calling device,means controlled by the translator -foroperating said selector to select a rural circuit link depending on the location of the called subscriber and 'for controlling the opera- :tion of the switches at the called rural exchange to select the called subscriber, means controlled by the translator when the called subscriber is located within the same exchange or group of ,exchanges as the calling subscriber for sending impulses over the operated gore-selector, the associated jack, the .finderand the first rural circuit link for operating the switches at the .called rural exchange to connect with the called subscriber, means operative upon the establishment of the connection between the calling and called rural subscribers for releasing the translator and all the switches at the main exchange, means controlled by the operator for ringing a subscriber over a circuit including a connecting jack and the associated pre-selector and selector, and means controlled by the operator for ringing a rural subscriber over a connection including an answering jack and the associated pre-selector and selector.

.FERNAND P. GOHOREL.

REFERENCES CITED The a'ollowing vreferences are of record in the ule-of this patent:

UNITED "STATES PATENTS Number Name Date "1,788,411 :Powell Jan. v13, 1931 3,105,;0-12 Saunders Jan. 11, 1938 2,158,945 Peterson May 16, 1939 2,145,127 Peterson J an. 24, 1939 4 5783309 Currier Mar. 30,1926

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