US1751260A - Automatic telephone system - Google Patents

Description

J. WICKS AUTOMATIC TELEPHONE SYSTEM March 18, 1930.

4 Sheets-Sheet 1 Original Filed May 6, 1920 HHL L I'WWTT Jul-m .Mwks

March 18, 1930. J, w c s 1,751,260

AUTOMATIC TELEPHONE SYSTEM Original Fil'e'd May 19 4 Sheets-Sheet 2 h was (wo 8% J. WICKS AUTOMATIC TELEPHONE SYSTEM March 18, 1930.

Original Filed May 6. 1920 4 Sheets-Sheet 3 GS V v Inusn or Jul-m Drlmks flm H J. WICKS AUTOMATIC TELEPHONE SYSTEM Original Filed May 3. 1920 March 18, 1930.

4 Sheets-Sheet 4 WQ %3 wwwm @ww Patented Mar. 18, 1930 arr N oFFic JOHN WICKS, 01-? OAK PARK, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC, INC., OF CHICAGO, ILLINOIS, CORPORATIGN 0F DELAVARE AUTOMATIC TELEPHONE SYSTEM.

Original application filed. May 6, 1920, Serial No. 379,217. Divided and. this application filed December My invention relates in general to automatic telephone systems, but is concerned more particularly with'the provision of an improved connector circuit for use in applying a semiselective ringing scheme to an auto matic system.

There are various other features disclosed, but not claimed, these other features being covered by icks Patent No. 1,586,057, issued May 25, 1926, and a second Wicks Patent No. 1,681,351, issued June 7, 1927. The present application is a division of the said first mentioned patent.

Referring to the drawings, comprising Figs. 1, 2, 3, and i, I have shown therein by means of the usual circuit diagrams the apparatus required to establish a complete connection from a toll line terminating in jack J,

Fig. 1, to a local subscribers station A, Fig. 4.

This apparatus comprises the cord circuit 0, Fig. 1, located at a toll operators position in a toll switching station or office; the two conductor trunk line extending from jack J in the toll switching office to the toll first selector D, Fig. 2, in a main exchange of the system; the toll transmission repeater E; the toll second selector F, Fig. 3; and the combination toll and regulator connector H, Fig. 4. The repeater, second selector, and connector mentioned are in the same oliice or exchange as the toll iirst selector D, which as indicated above may be one of the main offices or exchanges of a large multi-oifice system. In addition to the abovel have also shown means common to all'the trunk lines ext-ending from the toll switching ofiice to the local. ofice, and which is used to collect or refund deposited coins at any subscribers station, such as station A with which it may be connected via the toll service trunking system. This additional means or apparatus comprises the special cord circuit 0, Fig. 1, which special cord-circuits may be supplied in quantities of one or two per position; the trunk line extending from jack J in the toll switching office to the local office; and the special connector M, Fig. 2, in which the said trunk line terminates and which has access to all the toll first selectors such as the selector D. 4

Serial No. 74,6?9. i

In view of the well known character of the apparatus and the descriptions thereof in the publications previously referred to, I

will not describe such apparatus in detail in the present application, but will proceed at 5 once to explain the operation of the circuits with a view to pointing out the new improvements. For this purpose it will be assumed that the subscriber at substation A, F ig. 4, has placed a long distance call with a toll recording operator and that the ticket containing the usual data concerning the desired connection has been forwarded to the toll operator having the cord circuit 0, Fig. 1,

cord circuitO in the said jack J, the double throw listening and calling device K being thrown to callingposition at'thesame time. Upon theinsertion of the plug in the jack J a circuit is completed for relays20 and 21 in i series; and the latter relay, upon energiz ing, lights the busy lamp L at its armature 23,-establishes a locking circuit for itself at its armature 2ft, and at its armature 25 prepares a circuit whereby relay 22 may later be bridged across the trunk conductors 30 and 31, this circuit being open for the time being, however, at armature 26 of relay 20, which relay pulls up in series with relay 21.

It is understood that the outgoing trunk jacks. and lamps are multipled at other opera ators positions in the'usual manner, and the multiple busy lamps at the other positions are, of course, lighted in parallel with lamp L The key K being in calling position, as be-' fore stated, the operators head set, including the calling device S in series therewith, will tor D over the trunk conductors and 31 in series. Upon the completion of this circuit the line relay 51 is energized and closes the circuit of the slow acting release'relay '52. Upon energizing, the latter relay prepares the'selector switch foroperation in its vertical movement in the usual manner.

The toll operator will now operate her calling device S in accordance with the telephone number of the subscriber at substation A.

When the calling device dial is operated in accordance with the first digit of the number, a series of interruptions is produced in the circuit of the line relay 51 of the toll selector D. The line. relay '51 is,-therefore, deenergized a plurality of times corresponding to the digit called, and at each deenergization sends a current impulse through the slow acting series relay 53 and the vertical magnet 56 to battery. By the operation of the'vertical magnet the switch shaft is raised step by step until the wipers '707 3, inclusive, stand oppo-- site the horizontal level of bank contacts which are terminals of trunk linesleading to the desired thousand group. The slow actrelay 53 is energized in series with the vertical magnet, maintaining its armature continuously attracted during the vertical operationof the switch, and at the first upward movement of the switch shaft closes a circuit for the stepping relay 54. Upon energizing, relay 54 establishes a locking circuit for itself at its upper armature and at its lower armature prepares a circuit for the rotary magnet 57 7 At the end of thevvertical movement of the switch, the slow acting relay 53 is deenergized and completes the aforesaid circuit for the rotary magnet, which isaccordingly energized and advances the wipers 70-7 3, in-

- clusive, into engagement with the first set of bank contacts in the level opposite which they were raised. 1 Near the end of its stroke the rotary magnet breaks thelocking circuit of the stepping .relay 54, which is accordingly deenergized to open the circuit of the rotary magnet Both the rotary magnet 57 and the stepping relay 54'hav'ing deenergized, the operation now depends upon whether; the test contactwith which the test wiper 71 is in engagement is busy or is not busy If thistest contact is busy, it will have a round poten- V tial upon it and'a circuit 'will be established byway of the said test wiper, whereby'the stepping relay 54 is again energized to again close the circuit of the rotary magnet .57,

which in turnoperates to advance the switch wipersinto engagement with the next setof bankcontacts; This operation continues as long asthe test wiper 71 continues to engage grounded test contacts. As soon. as the first nonegrounded test contact is reached, which.

we will assinne to be the testcontact75 associated with the trunk line extending to the repeater E, the stepping relay 54 will not again be energized, and the rotary movement of the switch will cease. The switching relay 50, which heretofore has been short cirthat the stepping relay 54 is not energized.

Upon energizing, relay 50 connects the grounded conductor 58to the test wiper 1 at armature 61; opens the circuit of the release 1 magnet "at its armature 62; and at its armatures and 64 disconnects the incoming trunk line conductors 30 and 31 I"romfthe windings of the linerelay 61 andextends them by way of wipers and 73, bank contacts "4'4 and 77, left hand windings of the repeating coil R, and normally closed con: tacts or" the relay 101 to the upper and lower windings, respectively, of the'line relay 104 of the toll transmission repeater E. The line relay 104 is accordingly energized and closes a circuit for theslow acting release relay 105 which, vupon energizing in turn, closes the talking conductors through the repeater by means of its armatures and 118, and also at its armature 116 completes a holding circuit in the usual manner which extends? by way of conductor 144 back to the selector D where it serves to maintain the switching relay 50 energized throughout the connection."

Ground'potential is also'placed on the multiples of' test contact 75 by means of thiscirselected trunk busy cuit inorder to make the to other selectors. p V I When the line relay 104 ofthe repeater E was energized as previously explained, a control or operating circuit extending to the line relay 1510f the toll second selecter F, Fig. 3.

completed as follows: Ground a r G armature 126 and t-s work ng contact, conductor 143, armature and its res contact, andthe winding 01 the linerelay 151 to battery. 7 Upon theclosure oi the above circuit, the line relay 151 is energized andconie .pletes aw circuit-for the slow acting release relay 152 inthe usual manner.

gizing, relay 152 grounds the release trunk Upon 'enerconductor 144locallyat'its'upper armature,

and at its lower armature prepares the .Cli'

cuits oi' the selector for the vertical oper- 9 ion thereof LU A I r The toll operator may new 0 aerate the dial of her calling deviceS. in" accordance with thesecond digit in thenumber of thesub scriher at substation A. The interruptions produced bythis operation are repeated by V the line reiay 104 ofthe repeaterE, which relay causes a ser es of the linerelay 151 of the line relay 151 itlalso sends a series of deenergizations. of selects-r5, While the line relay104 is repeating iinpuises to in inclusive, in engagement with bank co pulses through the slow acting relay 106, which operates to disconnect the A. C. relay 121 and also to short circuit the lower right hand winding of the repeating coil These operations render the control circu' more eliicient. The toll second selector F is very similar to the selector D and its operation, therefore, will not be described in detail. will be sufficient to say that the deenergizations of the line relay 151 bring about the operation of the vertical magnet through the mediun'i of which tie s raised step by step until the wipers 70 inclusive, stand opposite the how 1i or" bank contacts which are terminals 0; t lines leading to the desired group of: ncctor switches. The slow acting relay is energized in series with the vertical magnet and at the first upward step or the rattcloses the initial energizing circuit of the stepping relay by way of the oil norm contact springs 150. The stepp locks itself as usual and prepares a 01 for the rotary magnet 15?. At the end of .e vertical movement of the switch, the slew acting relay 153 is crgized and, the switch wipers are rotated in rch of an idle trunk line by means of to net 157, which is controlled by the sre lay 15a and the'test wiper 171. l Vhcn the lie trunk line is reached, which we will assume to be the trunk line (3011)1i ductors 178-181, inclusive, the rota ion o switch will cease, leaving the wipers 1701'"" 17 l-177, inclusive. The switchir is now energized and at its armati 163 connects the tall ngconduct, i 1 145 with the line wipers 170 and 173, re-

spectively. Relay 150 also extents conductors 1&2 and 143 by of its armature 162 and 160, wipers 171 and 172, and Jank contacts 175 and 1. 6 to conductors 170 and 180. The conductor 143 is included in the control circuit of the toll selector 1 and when it is extended as above mentirned. line relay 151 and the release rela the selector are, of course, deen selector being maintained in op' tion by the continued energizatio switching relay 150, which is ground over the conductor 14 i the repeater E.

The switch control circuit having been tended, as above stated, to the conductor 180. it may be further traced by way of the said conductor 180, the upper winding of the re- 4:, contact springs controlled by bridge relay 200, and the upper winding of the connector for vertical operation in the 305, and 306 which terminates in bank contacts 301, 302, and 303,respectively, Fig.

These bank contacts are assumed to be located the banks of one or the regular selectors referred to, and the ground pot ntial upon conductor 305, and the test contact 302 and its multiples, render the connector H busy.-

A branch of the conductor 305 may be traced from junction point 306 by way of conductor 305, winding of relay 207, conductor 179, bank contact 17 5, Wiper 171, armature 162 and its working contact, conductor 142, armature 128 and its resting contact, and the resistance '111 to battery. By

current flow over the above circuit the relay 207 is energized and at its armatures 236 and 237 prepares circuits for the ring cutoff relay 205 which will be explained later. Relay 207 also closes a circuit for the switching relay 20% by means or" its armature 238, and the latter relay, upon energizing, produces a number of circuit changes in the connector which are brought about for the purpose or enabling it to function as a toll connector rather than as a regular connector. These circuit changes include the opening of the permanent locking circuit of the ring cutofi relay 205 at armature 225, the shifting of the locking circuit oi the busy test relay 206 at armature 224, the disconnection of the regular trunk line conductors and 306 at armatures 223 and 226, and the preparation of a supervisory signaling circuit for the toll operator at armature 223. These circuit changes and the results effected, thereby will be mentioned more in detail hereinafter. Before proceeding turther with the explanation a few more details concerning relays 207 and 204 may be inserted wlth benefit. Relay 207 is'ot relativelylow resistance, and the circuit traced through its winding from the grounded conductor'305 to the conductor 179 and test contact 17 5 places a potential upon the said test contact 175 and its multiples, which is sufiiciently near to ground potential to render the connector H busy to the toll second selectors. With regard to relay 204, the upper Winding of this relay, which is included in the circuit of line relay 201, is of low resistance and is not necessarily strong enough to energize the relay by itself, but isstrong enough to hold -'ing system which have access to the the said relay in operated position after it has been completely operated by the closure of the circuit through its lower winding. In order to reduce the impedance of the upper Winding so as not to interfere with operating impulses transmitted 'to thelinerelay 201, the relay 204i is provided with a copper slug as indicated in the drawin I The connector H is now ready to be operated under the control of the calling device S, when the dial is actuated in accordance with the next digit in the number of the sub scriber at the substation A. A series of interruptionsis produced as before, which are repeated by the relay 104 of the repeater E to bring about a series of deenergizations of the line relay 201. At each deenergization the line relay 201 transmits a current impulse through the vertical magnet 210 over the following circuit: Ground at G armature 215 and its resting contact, armature 2 16 and its working contact, 0E normal springs 222 and 220, winding of the slow acting series relay 203, and winding of the vertical magnet 210 to battery. This is the circuit over Which the first impulse is transmitted. At the first upward step of the switch shaft, however, the off normal springs are shifted, and the'circuit extends from the working contact of armature 216 by way of off normal springs 222 and 221, armature 217 and-its working contact, (relay 203 being'now energized) winding of the relay 203, and the winding of the vertical magnet 210 to battery. By the operation of the vertical magnet the switch shaft is raised step by step until the wipers 270- 272, inclusive, stand opposite the level of bank contacts in which the line of substation A is terminated. The slow acting relay 203 which is energized in series with the vertical magnet, maintains its armature attracted throughout the vertical operation of the switch. lVhen this relay energizes at the beginning of the'vertical movement it closes the follow ing circuit for the ring cutoff relay 205: Ground at G armature 218 and its working contact, armature 219 and its'working con tact, working contact of armature 2'37 and the said armature, and the lower winding of thering cutoff relay 205'to battery. Upon energizing, relayj205 opens contactsincluded in a later established signaling circuit at its farmatures 227 and 229, and at its armature 5 1228'establishes a locking circuit for itself as follows Grounded conductors 305, working contact of armature 228 and the sald armature I 236 and its working contact,and'thelower ,scriber at substation A.

winding of relay 205to battery. At the end of the vertical movement of the switch, the slow acting relay 203 deenergizes and prepares the connector for operation in its ro-i tary movement. 7 e r v The tool operator now operate the dial of the calling device S in accordance with he final digit in the number of the sub- The' interruptions produced are repeated as before through the medium of relay 104-, cause another series of d cenergizations of the line relay20lofthe relay 206 to battery.

connector H. At each deenergization, the line relay 201 now sends a current impulse through the rotary magnet 212 over the following path: Ground at G armature 215 and its resting contact, armature 216 and its working contact, normal springs 222 and 221, armature 217 and its resting contact, resting contact of armature 233 and the said armature, armature 246 and its resting contact, and the Winding of the rotary magnet 212 to battery. In response to these impulses the rotary magnet operates to rotate the wipers 270-272, inclusive, into engagement with the particular set of bank contacts in which the line of substation A terminates, these bank contacts being the contacts indicatedin the drawing by the reference characters 273, 274, and 275. gized in parallel with the rotary magnet and retains its armatures attracted throu hout the rotary movement of the switch. it its armature 239, relay 208 connects the test wiper 271 to the winding of th'e'busy test relay 206,

The slow acting relay 208 is ener-' and at its armature 240, relay 208 closes a shunt around armature 233 of relay 206 and its resting contact to guard against the possibility of the saidrelay' being momentarlly energized while the test wiper 271 is passing 7 over busy test contacts. In order to afford an opportunity to explain the operation of the H busy test circuits it will be assumed that when the line of substation A is called at this time it is busy. In such case the testcontact 27 1 will be grounded and when the test wiper 271 makes connection with the saidtest contact, the test relay 206 will be energized, thecircuit' being traceable as followszGrounded test contact 27 1, test wiper 2'71, contact springs controlled byarmature 244 of relay 209, armature 239 and its working contact,

arl'nat'ure 243 and its resting contact, and the winding of the test relay 206 to battery. The 7 test relay is energized over the'above circuit and when the slew acting relay. 208 deenergizes at the end of the rotary movement of the switch, the test relay becomes locked up by.

means of the following circuit Grounded test contact 274e, test wiper 271, working contact of armature 22d and the said armature,

workingcontact of armature 230 and the said armature, contact springs controlled by armature 239 of relay 208, armature 2 1 3 and its resting contact, and the winding of the test The various circuit changes eficcted by the operation of the test relay will now lie-briefly pointed (out. Its '7 locking circuit which is closed at armature 230 has ust beenrexplalned. At armature 231 the circuit of the switching relay 209 is opened, at armature .232 a shunt is connected around the armature 236 of relay 207 and its working contact in order to prevent accidental deenergization of the ring cuto'li' relay 205 (by movenientof ringing key at the operators cord circuit), at armature 233 the circuit of the'rotary magnet 212 is opened in order to prevent the switch wipers from being rotated off the contacts of the called line, and at armature 235 a lead from the busy signaling machine Q isconnected to the lower line conductor 181. The conductor 181 extends back through the selector F to the lower right hand winding of the repeating coil and it follows that the toll operator will be given an audible busy signal indicating to her that the called line busy. This busy signaling operation is similar to methods in common use, and will be understood without further explanation.

The toll operator will now restore her listening key K and may proceed to workon other connections while waiting for the line of substation A to become idle, first, however, removing the plug from jack Jr in order to prevent the busy tone from passing out over the toll line. When key K is restored the supervisory relay 6 is connected in bridge of the trunk conductors 30 and 31 in place of the operators head set and this relay 6 would be energized in series with the line relay 104 of the repeater E were it not for-the fact that the connector H is waiting on a busy line. In order to make this clear a circuit will be traced which was completed by the busy test relay 206 and which extends as follows: Ground at G, resting contact of armature 241 and the said armature, armature 234 and its working contact, working contact of armature 223 and the said armature, conductor 178, bank contact 174, wiper 170, working contact of armature 161 and the said armature, conductor 141, armature 123 and its resting contact, armature 115 and its working contact, upper right hand winding repeating coil R, and the winding of relay 100 to battery. Current flow in the above circuit serves to operate relay 100 which closesa circuit for the relay 101. Upon energizing, the latter relay disconnects the incoming trunk line conductors from the windings of the line relay 104 and at the same time closes a local circuit for the upper winding of the said line relay. The exchange battery is thus entirely disconnected from the trunk line and it will be evident, accordingly, that the supervisory relay 6 will not be energized and the lamp L .will not be lighted.

l/Vhen the line substation A becomes idle, ground potential is removed from the test contact 274 and the locking circuit of the test relay 206 is broken. The test relay, therefore, deenergizes, disconnects the busy signaling machine Q, opens the circuit of relay 100 at the repeater E, and establishes a circuit for the switching relay 209 which may be traced as follows: Grounded conductor 305, resting contact and armature 231, upper winding of the switching relay 209, resting contact of armature 239 and the said armature, contact 55 springs controlled by armature 244, test wiper 271, test contact 274, winding of the switching relay 317 of the individual line switch C, and thewinding of the stepping magnet 318 to battery. Upon the closure of the above circuit relays 209 and 317 are energized in series, and the latter relay is operated. to disconnect the line conductors 320 and 321 from their normal connections in the line switch. Relay 317 is not completely operated because of the fact that the line relay of the line switch 1as not been energized, and does not connect the line conductor with the wipers of the line switch. In the connector H, the relay 209, upon energizing, opens the circuit of the rotary magnet 212 at armature 246, establishes a locking circuit for itself at armature 245, connects ground G to the test wiper 271 at armature 244, thus closing the circuit of the switching relay 317 of the'line switch over a new path excluding the upper winding of relay 209 which was formerly included in the circuit, and at armatures 242 and 247 closes in the preceding paragraph, the circuit of relay at the repeater is broken as previously stated, and this relay and also relay 101. are deenergi'zed. The incoming trunk conductors are thereby connected again to the windings of the line relay 104 and current is supplied to the bridged supervisory relay 6 at the operators cord circuit. Relay 6 is, therefore energized and lights the supervisory lamp L to advise the operator that the called line has become idleand that connection thereto has been completed.

The next operation is to ring the subscriber at substation A. For this purpose the operator throws the key K momentarily to ringing position, thereby projecting ring ing current out over the trunk line with which the cord circuit 0 is connected, to operate the alternating current relay 121 at repeater E. Upon attracting its armature 128, relay 121 breaks the previously described circuit of the relay 207 at the connector H; Relay'207 accordingly deenergizes and at itsarmature 236 breaks the locking circuit of the ring out OK relay 205. Relay 205 then deenergizes and at its armatures 227 and 229 opens the talking conductors and establishes the usual signaling circuit which includes the ringing current generator Gen and its own upper winding. There is no special novelty in the signaling circuit itself, although it is believed that the provision of a pick up relay, which is rendered necessary by the fact that semi-selective of substation A is a party line, substation A being a so called two bell station while submer locking circuit, t

station A. is a one bell station. The operations following the deenergizat-ion of the ring cutoff relay 205 may be explained more in detail as follows: When relay 205 fallsv 'mature 28 i finally closes the signaling circuit,

after which thebell at substation A'will be rung automatically as long as the'receiver remains on the hook. During the ringing operation the operator is given the well known ringing current induction, provided, of course, that she is listening on the line, to notify her that the ringing is proceeding satis factorily. of the inductive path which extends from armature 2et7 of relay 209 by way of the low capacity condenser 299 to the resting contact of armature 235 of relay 206. Condenser 299 is of very low capacity, preferably about .005 microfaradaand permitsjust enough ringing current to leak'back in: the direction of the operator togive her an easily distinguished signal. 3

When the subscriber at substation A removes his receiver inresponse to the ringing of his bell the ring cutoff relay 205 will be operated by currentfrom the exchange bat.- tery in series with the ringing current generator Gen, or by current from the exchange battery in series with the booster battery as sociated with the'generator,and uponattracting its armature 228 will reestablish its torhe operator having restored her ringing key by this time to permit the energization of relay 207. The ring out off relay also disconnects its own uper winding and the ringing apparatus at its armatures 227 and 229, respectively, and closes the talking conductors at these same armatures. The transmitterat substation A is now sup plied with talking battery through the winding of the battery feed relay 100 at the repeater E. This circuit will not be traced in detail, but it will be observed that the lower line conductor extends uninterruptedly back through the connector H and the selector F to the lower right hand winding of the repeating coil R, whence it extends through the resistance 113 to ground, while the upper line conductor 320 extends backthrough the cons nector l and the selector F tothe-upper right hand winding of the repeating coil R. from which point it may be traced through the said winding and through the windingot the relay 100 to battery; Relay 100 isenergized by current flow through the transmitter at substation A, and upon attracting its armature closes the circuit of'relav 101, which again operates to close a local circuit for line relay 104:, and breaks the circuit of'thesupervisory This is accomplished by means relay 6 atthe operatorsv cord circuit, thus causing this relay to deenergize and extindeposited the operator is given an audible signal over the telephone circuit in the usual manner so that she will know that the right amount has been deposited, and also the polarized magnet of the paystation is connected to the line in order that the operator'may thereafter either collect or refund the coins;

Everything is now in readiness fbrconver- 1 sation to begin, at least so far as the conne c.- n to the party at substation A is concerned.

wed in the distant exchange, the oper- ,tor' .vill now complete the connection at her cord circuit the connected parties can converse desired; It will be observed that suming that the desired party has been the connection. includes' a twoconductor trunk line from the toll: switching station to ain or local exchange (the trunk comi rng conductors-'30:and81) ,which is a decided economy over the former arrangements conductor trunk lines. Another advan tage which may be pointed out is found lnithe arrangement by which the called subscriber controls the release ot the connection, while his receiver is oft, through the medium of relays and 101, the latter of which controls local circuit for the line relay 104. This 'angeinent makes it possible for the toll rater to change cord circuits after a called :ablished connection.

rs will hang uptheir receivers; Upon placement of the receiver at substation relays 100 and 101 at the repeater E are "core -l th 1' l 104 onolicr izec ant. e me .e a is a ain acted across the conductors of the incom- I 6 at the operators cord circuit is enered and the'lamp L is lighted to give the operator a disconnectsig'nal. Before releasing the connection the operator will have to coll e .t whatever coins weredeposited, and th? operation will now be explained.

The trunk line extending from jack J in the toll switching station to the connector M in the iocal exchange and comprising conductors 352, and 353 is one of a limited r of similar trunks which are used exatrons. Any one of these trunks may be made se of to collect orrefund at any subscribers ri hen the connection is finished botlrsub- 0 at least three and sometimes even party has answered without releasing the es- 7 -unk line. As a result the supervisory station in the local exchan e in uestion which has been connected with via the toll senice trunking system. When the toll ope. or gets ready to collect, then, on the connection just described, she will insert the plug of special cord circuit 0 in the jack of an idle collect trunk, and we will assume that the trunk line shown in the drawing is the one taken for use. V-Jhen the plug is inserted in jack (i a circuit is completed over the sleeve of the jack which includes the calling device S and the relay 350 in series. Upon energizing, relay 350 lights the busy lamp'L and, its multiple lamps at other positions (not shown), and also closes a circuit over trunk :ontluctor 352 Wi'llCll includesthe line relay 360 of the connector M at the distant local exchange. Upon energizing relay 360 closes a c? rcuit tor the slow acting release relay 361 which upon energizing in turn prepares the circuit of the vertical magnet at its lower armature in the usual manner. Relay 361 also closes a circuit through the upper or polarizing winding of the electro-polarized relay 364.

The operator will now operate the calling device S in accordance with the number of the toll service trunk line in use inthe connection for which it is desired to collect, it bcing understood that all the toll service trunks extending to the local exchange in qu tion are numbered consecutively in acco': .nce with the bank numbering of the connector M and associated connectors. Assuming that connector H is a one hundred line switch, it may have access to one hundred toll service trunks numbered from 01 to 99. To proceed, when the. calling device S is operated in accordance with the first digit of the number the relay 350 is deenergized a plurality 0t times, causing a like plurality ct deenergizations of the line relay 360 o t.

t the connector M. lhe latter relay controls lie connector M in substantially the same way that the line relay 201 controls the comh'nation conne tor H and on thataccount the e plnation will not be given in detail. fly, at each denergization, line relay 360 sends a current impulse throughthe vertical magnet 367 which operates to raise the switch shet't step by step until the wipers 370, 371, and 372 stand opposite the level in which is terminated the branch line which is a multiple of the particular toll service trunk to be collected over. The slow acting'series relay 362 is energized in series with the vertical magnet, maintains the vertical magnet cirit intact after the oil normal springs have s t d at the first upward step of the shaft,

" and at the end of the vertical movement deenergizes and shifts the operating circuit to the rotary magnet 368.

hen the calling device S is operated in accordance with the next and last digit in the number, the line relay 360 sends a series of current impulses to the rotary magnet 368' which in response thereto operates to rotate the wipers 370372, inclusive, until they come to rest in engagement with the bank contacts 37 337 5, inclusive. At the first rotary step the rotary ofi' normal springs 369, which are. included in the rotary magnet circuit, are separated, but the magnet circuit is maintained closed by the slow acting series relay 363 until the last rotary impulse is received after which the said relay deenergizes and the magnet circuit is opened.

An independent connection has now been established with the toll service trunk by way of the collect trunk and the connector M. Vhile the toll operator is operating the dial of calling device S to establish the branch connection she has her listening key K in the cord circuit 0 in operated position and as soon, therefore, as the connector M establishes connection with the branch comprising con'ductors 30, 300, and 31, and, the slow operation of the connector M, either of which would cause connection to be established with some other toll service trunk than the one over which it is desired to collect. If the operator does not hear the tone she willylrnow that something is wrong and will call the number over again. The manner in which the tone signal is placed on the trunk line will be easily understood, It will be noted that the lower wiper 372 of the connector M is connected to the lower terminal of the grounded secondary winding of the induction coil associated with high frequency generator Gen, while the upper wiper 370.

is connected to ground through a condenser. With this arrangement when connection established with the bank contacts 373-375, inclusive, the secondary of the induction coil is bridged across the branch conductors 30 and 31, resulting in the transmission of an audible signal to the operator as stated.

Having perceived the O. K. signahthe operator will immediately operate the collect key winding; but relay 365 is operated and closes the following circuit: From the positive pole of grounded battery B through the resistance lamp in series therewith, resting contact of armature 381 and the said armature, armature382 and its working contact, inding of marginal relay 366, wiper 371, bank contact 37 conductor 300,:1rmature and its working contact, wiper '72, bank contact, 70, conductor 180, winding of relay 107, and the high resistance 109 to ground. Current flow in the above circuit operatesrelay 107 the relay 386 remaining inoperative due to the high resistance of relay 107'and resistance 109.

Upon energizing, relay 107 closes a circuit for relay 108 which, upon attracting its armatures 123 and 124;,opens the heavytalklng conductors at the repeater E and connects con-.

ductors 141 and 14:5 to conductor'130. A relatively low resistance'branch path to ground is thus established which is in parallel with the relay 107 and resistance 109 and which may be traced readily by way of conductors 141, 178, and 320 to the substation A, whence the circuit extends through. the po 7 larized magnet of the paystation mechanism to ground. Battery B is a high voltage battery and produces a current flowin the above traced branch circuit which is in the proper direction to operate the polarized magnet to collect the deposited coin or coins, the paystation mechanism being reset at the same time. When the branch circuit through the aolarized ma net is established the reSultin 2:; 23

collect circuits are all right and that presum= ably the coins have been collected. The collect key is now restored and relay 365 is thereby deenergized, whereupon the battery B is disconnected and relays 366, 107, and

108 are deenergized. Also, since the paystation mechanism at substation A has beenreset by the polarized .iagnet, when the battery B is disconnected and the polarized magnet is thereby permitted to restore its armature the said magnet is disconnected from the line. The toll operator will now operate her collect key once more, thereby again connecting battery B to the line of substation A as before described. This time, however, since thepolarized magnet at the paystation has been disconnected the marginal relay 366 will not be operated and the operator will not getthe interruptedftone back on the line. By this the operator knows that the collecting operation has been successful and she will again restore the collect key.

If the operator desires to refund a deposited coin rather than collect it she may do so by operating the refund key instead of the collect key. Assuming the same circuit conditions to exist as in the previous case, where the operator collected the coins, if the refund key is operated the exchange battery is connected 7 her.

in bridge of trunk conductors 3-51 and 353 as before, except that it isreversed, and as a. re-

sult the electro-polarized relay 3% at the con larity, the deposited coins are refunded in stead of collected. Except as pointed out, the refunding operation is the same as the collecting operation, and the operator is given supervision bynieans of the interrupted tone in the same way. a

The special collect trunks are used only for collecting or refunding, which takes but a few seconds, andare at once restored to common use. When the plug is removed from jack J relay 350 is deenergized and breaks the circuit of the line relay 360 of the conductor M. Relays 3G0 and 361 are thereupon deenergized and the s wi'tclris restored to normalby means of the release magnet 885 in the usual manner.

The release of the main connection over the toll service trunks is also brought about by V The busy lamp L r ticed also that relay 21 maintains a test 120- tential on the sleeve of jack J, which permits the usual audible busy test circuits to be used in the operators cord circuits if desired. Now when the called subscriber hangs up his receiverrelays 100 and 101 at the repeater R are deenergized and the line relay 104 is connected across the incoming trunk conductors as explained heretofore in considering the control of the supervision. The effect of this is to energize the slow acting relay 22 which was bridged across the trunk conductors 30 and. 31 by the deenergization' of relay 20. Upon ener izing, relay 22 breaks the locking circuit of relay 21, and this latter relay, upon deenergizing, disconnects relay 22 from in bridge of the trunk. Relays 22 and 10s are, therefore, deenergized. The latter relay breaks the circuit of the slow acting release relay 105 and also breaks the operating cir cuit extending to the connector H. By the latter operation relays 201. and 202 are deene'r gized and the connector H is restored by means of release magnet 213 in the usual man- When the relay 105 at. therepeater E deenergizes it removesground from the com ductor 14 .4, thereby permitting the. switching.

relays 50 and 150 of selectors D and F, respectively, to deenergize. Thereupon these switches are restored by means of their reconnection with the present invention, and,

besides, they have already been described in certain of my prior applications previously referred to; therefore it is believed to be unnecessary to go into such further details now.

What is claimed is:

1. In a telephone system, a party line, a series of automatic switches includng a final connector switch for extending a connection to said line, a common code ringing machine and a plurality of common generator leads extending therefrom, a source of ringing cur k rent, means in said ringing machine for connecting said source to said leads at intervals in accordance with different codes, a pick up relay in said connector for connecting one of said leads to the connected called line to signal a desired station thereon, and a circuit for said relay controlled by said ringing machine and effective to energize said relay only while the said generator leads are discon-' nected from said source of ringing current.

2. In a telephone system, connectors, a called party line, a plurality of branches of said line accessible from the connectors, code signaling mechanism for applying signaling current to the called line in a predetermined series of alternate live and dead periods, automatically applied means for causing the signaling current to be applied to the called line only at the starting of the first live period of the next series responsive to the-operation of a connector in eflfecting connective relation with the called line regardless of the time said operation occurs, and automatically applied means for causing a specific said code series of signaling current to be'applied to the called line in correspondence with the branch of the called line a connector is operated into connective relation with so that a difierent code series of signaling current will be applied to the called line depending upon what branch of the called line is connected with.

3. In an automatic telephone system, automatic connectors, a called party line, a plurality of branches of said line accessible from the connectors, code signaling mechanism for applying signaling current to the called line in a predetermined series of alternate live and dead periods, automatically applied means for causing signaling current to be applied to the called line only at the starting of the first live period of the next series responsive to the operation of a said connector in effecting connective relation with the called line regardless of the time said operation occurs, and automatically applied means for causing a specific said code series of signaling current to be applied to the called line in correspondence with the branch of the called line a said connector is operated into connective relation with so that a ditferentcode series of signaling current will be applied to the called line depending upon what branch of the called line is connected with.

4C. In a telephone system, a connector switch, a called line, a current interrupter having means included in a signaling curconnector to the connected called line in successive trains of series, automatically applied means made operative solely responsive to efiecting the connection to the called line for V causing said application of signaling current to be initiated, and means controlled by the said interrupter whereby the application of any portion of a said train of series will be disabled from being initially through the connector after the interrupter has started the application of-a train. 7

5. In a telephone system, a plurality of connector switches, called lines, a current interrupter having means included'in a'multipled signaling current path, each path including one of said connectors, the said interrupter for controlling the application'ot signaling current from a connector to its connected calledline in successive trains of series, automatically applied means made operative solely responsive to effecting the connection to the called line for causing said application of signalling current to be initiated, and means controlled by the said interrupter whereby the application of any portion of a said train of series will be disabled fromvbeing initially applied through a-said connector to its connected called line after the interrupter has started the application of a train.

6. In a telephone system, a plurality of connector switches, called lines, a current interrupter having means included in a multipled signaling current path, each, path including one of said connectors, the said interoperative solely responsive to efiecting the Q connection to the called line for causingsaid application of signaling current to beinitiated, means controlled by the said interrupter whereby the application of any portionof a said train of series will be disabled from being initially applied through a said connector to its connected called line after the interrupter has started the application of a train without effecting the application of ourrent/from other of said connectors controlled by the interrupter, and means which will enable the signalling current to be applied over the said disabled connector at the initiation of the next succeeding train thereafter.

7. In an automatic telephone system, an

automatic connector switch, a called line, a

current interrupter having means included in a signaling current path of the connector for controlling the application of signaling current from the connector to the connected called line in successive trains of series, automatically applied means made operative solely responsive to effecting the connection to the called line for causing said application of signaling. current to be initiated, and means controlled by the said interrupter whereby" the application of any portion of a said train of seriesowill be'disabled from being initially applied through the connector after the interrupter has started the'application of a train. I

8. In an automatic telephone system, an automatic connector switch, a called line, a current interrupter having means included in a signaling current path of the connector for controlling the'application of'signaling current from the connector to the connected called line in successive trains of series, automatically applied means made operative solely responsive to efiecting the connection tothe called line for causing said applicaapplied means for causing the signaling current to be applied to the called line only at the starting of the first live period of the next series responsive to the operation of the connector in effecting connective relation with the called line regardless of the time said' operation occurs.

In Witness whereof, Ihereunto-subscribe my name this 8th day of December, A; D.

, JOHN WrcKs;

tion of signaling current to be initiated, and

rent to be applied to the called line only at the starting of the next live period responsive to the operation of the connector in effecting connective relation with the called line regardless of the time'said operation occurs.

10. In a telephone system, a connector, a called line accessible from the connector, code signaling mechanism for applying signaling current to the called line in a predetermined i series of alternate live and dead periods,

means for preventing the initial application of signaling current to the called line intermediate of a said series, and automatically

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