US1586057A - Automatic telephone system - Google Patents

Description

-May 25 1926.

J. WICKS AUTOMATIC, TELEPHONE SYSTEM ori in l Filed may 1920 4 Shee ts-heet 1 Inusn U1"- Jqhg 1 2 i? HIT.

May 25 1926.

J. WICKS AUTOMATIC TELEPHONE SYSTEM.

4 Sheets-Sheet Original Filed y 6. 1920 May 25 1926;

J. WICKS AUTOMATIC TELEPHONE SYSTEM 4 Sheets-Sheet 4 Original Filed y 6. 1920 Patented May 25 1926. r

barren stares PATENT OFFICE.

JOHN wICKs, OE CHICAGO, ILLINOIS, AssICNoR, BY MESNE ASSIGNMENTS, To AUTO- MATIC ELECTRIC INC., on CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

AUTOMATIC TELEPHONE SYSTEM.

Application filed May 6, 1920,-Seria1 No. 379,217.. Renewed October 21, 1925.

My invention relates in general to automatic telephone. systemsbut is concerned more particularly with methods of handling long distance calls in such systems; and the object of the invention, in general, is to provide a new and improved toll service trunking system for connecting local subscribers in automatic exchanges with long distance lines, either as calling or Called subscribers.

Toll service trunking systems of the above character have been known before, and ref erence is made to my U. S. Patent No. 1,- 315,444, issued on Sept. 9, 1919, which'show s and fully describes a modern system of toll r service trunks, and also to my pending applications Serial Numbers 155,640, filed March 19, 1917, and 346,323, filed December 20, 1919, which show various improvements in such systems. .teferencc is made, furthermore, to my pending application, Serial Number 364,069, filed lilarch '8, 1920, which shows a toll service trunking system especially designed for use in a telephone system where the subscribers stations are equipped with coin collecting devices or paystations; and the System of the present application may properly be considered as an improvement on the system disclosed in the latter application.

More specifically, then, the principal object of the invention may be stated to be the provision of a new and improved toll serv-' ice trunking system, containing suitable circuit arrangements and other provisions whereby the toll operators can connect with desired calling or called lines which are] equipped as paystations, and can thereafter collect or refund deposited coins as occasion requires. It may be mentioned that the paystations intended to be used are of the type commonly known as Gray paystations, which are shown and described in the U. S. patent to Forsberg, No. 1,043,219. In addition, thereare a number of other improvements which have more to do with the trunking system itself and are not especially concerned with the measured service feature. These in'iprovements will be pointed outin the course of the detailed specification, which follows, although-they are being claimed in divisions of this application bearing Serial Nos. 458,174 and 74,67 9,'filed April 2, 1821, and Dec. 11, 1925, respectively. 7

Referring to the drawings, comprising Figs. 1, 2, 3and 4, I have shown therein by means of the usual circuit diagrams the apparatus required to establish a complete connection from a toll lineterminating in jack J, Fig. 1, to a local subscribers station, station A, Fig. 4. This apparatus-comprises the cord circuit, Fig. 1, located ata toll operators position in a toll switching station or cities; the two conductor trunk line extending from jack J in the toll switching oflice 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, 3; and the combination toll and regular connector H, Fig. 4. The repeater,'seco nd selector, and connector mentioned are in the same office or exchange as the toll first selector D, which as indicated above may be one of the main ofiices or exchanges of a large multi-ofiice system. In addition to the above I have also shown means which is common to all the trunk lines extending from the toll switching oilice to the local cities, and which is used to collect or refund deposited coins at any subscribers station, such as station A, which is connected with via the toll service trunking system. This additional means or apparatus comprises the special Cord circuit 0, Fig. 1, these special cord circuits may be supplied at the rate of one or two per position; the .trunk line extending from jack J in the toll switching oflice 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.

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 once to explain the operation of the circuits with a view to pointing out the new improvements. For this purpose it will be assume-d that the subscriber at substation A, Fig. 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, for completion.

Having extended a connection to the desired distant exchange over one of her toll lines, as for example the toll line which terminates in jack J, Fig. 1, and having ordered the proper local line to be connected up in that exchange, the toll operator will next proceed to call the subscriber at substation A by way of the toll service trunking system. Observing that the toll service trunk terminating in jackJ is idle, as indicated by the unlighted condition of the busy lamp L the operator will insert the calling plug of cord circuit 0 in the said jack J, the double throw listening and calling device key K being thrown to calling position at the same time. Upon the insertion of the plug in the jack J a circuit is completed for relays 20 and 21 in series; and the latter relay, upon energizing, lights the busy lamp L at its armature 23, establishes a locking circuit for itself at its armature 24, and 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 operators 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 before stated, the operators head set, including the calling device S in series therewith, will be bridged across the upper and lower strands of the cord circuit, resulting in the closure of a circuit for the line relay 51 of the toll selector D over the trunk conductors 30 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 for operation 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. hen 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 56to battery. By the operation of the vertical magnet the switch shaft is raised step by step until the wipers 73, inclusive, stand opposite the horizontal level of bank contacts which are termin-als of trunk lines leading to the desired thousand group. The slow acting relay 53 is energized in series with the vertical mag-- net, maintaining its armature continuously attracted during the vertical operation of the switch, and at the first upward move ment of the switch shaft closes a circuit for the stepping relay 54. Upon energizing, re lay 54 establishes a locking circuit for itself at its upper armature and at its lower armature prepares a circuit for the rotary magnet 57. At the end of the vertical movement of the switch the slow acting relay 53 is deenergized and completes the aforesaid circuit for the rotary magnet, which is accord ingly energized and advances the wipers 70-73, inclusive, into engagement with the first set of bank contacts in the level opposite which they were raised. Near the end of its stroke the rotary magnet breaks the locking 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 having deenergized, the operation now de pends upon whether the test contact with which the test wiper 71 is in engagement is busy or is not busy. If this test contact is busy, it will have a ground potential upon it and a circuit will be established by way 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 turn operates to advance the switch wipers into engagement with the next set of bank contacts. This operation continues as long as the test wiper 71 continues to engage grounded test contacts. As soon as the first non-grounded test contact is reached, which we will assume to be the test contact 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 circuited, is now energized over the following circuit: grounded conductor 58, winding of the switching relay 50, off normal springs 59 and the winding of the stepping relay 54 to battery. Relay 50 is of such high resistance that the stepping relay 54 is not energized. Upon energizing, relay 50 connects the grounded conductor 58 to the test wiper 71 at armature 61; opens the circuit of the release magnet 55 at its armature 62; and at its ainrnitures 60 and 64 disconnects the incoming trunk line conductors 30 and 31 from the windings of the line relay 51 and extends them by way of wipers 70 and 73, bank contacts 74 and 77, left hand windings of the repeating coil R, and normally closed contacts of the relay 101 at the upper and lower vindings, respectively, of the line relay 104 of the toll transmission. repeater E. The line relay 104 is accordingly energized and closes a circuit for the slow acting release relay 105 which, upon energizing in turn, closes the talking conductors through the repeater by means of its armatures 115 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 1) 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 this circuit in order to make the selected trunk busy to other selectors.

l/Vhen the line relay of the repeater E was energized as previously explained, a control or operating circuit extending to the line relay 151 of the toll second selector l Fig. 3, was completed as follows: ground at G, armature 126 and its working contact, conductor 143, armature 160 and its resting contact, and the winding oi the line relay 151 to battery. llpon the closure of the above circuithe line relay 151 energized, and completes a circuit for the slow acting release relay 152 in the usual manner. Upon energizing, relay 152 grounds the release trunk conductor 1 14c locally at its upper armature, and at its lower armature prepares the circuits of the selector tor the vertical operation thereof.

The toll operator may now operate the dial of her calling device S in accordance with the second d' "he number of the subscriber at substation A. The interruptions produced by this operation are repeat-- ed by the line relay 10 1 of the repeater E, and cause a series or deenergizations of the line relay 151 of the selector F. While the line relay 10 1 is repeating impulses to the line relay 151 it also sends a series of impulses through the slow acting relay 106, which operates to disconnect the A. C. relay 1.21 and also to short circuit the lower right hand winding of the repeating coil B. These operations render the control circuits more ctl'icient. The toll second selector F is very similar to the selector 1) and its operation therefore will not be described in detail. It will be sutlicient to say that the deenergizations of the line relay 151 bring about the operation of the vertical magnet 156 through the medium or" which the switch shaft is raised step by step until the wipers 170173. inclusive, stand opposite the horizontal level of bank contacts which are terminals of trunk lines leading to the desired group of connector switches. The slow acting relay 153 is energized in series with the vertical magnet and at the first upward step of the shaft closes the initial energizing circuit oi? the stepping relay 1 by way of the oil normal contact springs 159. The stepping relay 154: looks itself as usual and prepares a circuit for the rotary magnet 157. At the end of the vertical movement of the switch, the slow acting relay 153 is deenergized and the switch wipers are rotated in search of an idle trunk line by means of the rotar magnet 157, which is controlled by the stepping relay 154 and the test wiper 171. lVhen an idle trunk line is reached, which we will assume to be the trunk line comprising conductors 178181, inclusive, the rotation of the switch will cease, leaving the wipers 170-17 3, inclusive, in engagement with bank contacts 174i-177, inclusive. The switching relay 150 is now energized and at its armatures 161 and 163 connects the talking conductors 14:1 and 1 15 with the line wipers 170 and 173, respectively. Relay 150 also e2;- tends conductors 142 and 14:3 by way of its armatures 162 and 160, wipers 171 and 172, and bank contacts 175 and 176 to conductors 179 and 180. The conductor 143 is included in the control circuit of the toll elector F, and when it is extended as above mentioned, the line relay 151 and the release relay 152 of the selector are of course de-energized, the selector being maintained in operated posi-' tion by the continued en rgizution oi the switching relay 150, which is supplied with ground over the conductor 14 1 coming from the repeater E.

The switch control circuit having been extended, as above stated, to the conductor 180, it may be further traced by way 01 the said conductor 180, the upper winding of the relay d of the combination connector ll, Fig. 1, contact springs controlled by the back bridge relay 200, and the up er winding of the line relay 201 to battery, Upon the extension of the control circuit over the above path, the line relay 201 is energized and completes a circuit for the slow acting release'relay 202, which at its armature 216 prepares the connector 1 rverticul operation in the usual manner. At its upper armature 218, relay 202 connects ground (i with the release trunk conductor 305, which conductor extends to and is njiultipled in the banks of the second selectors of the regular or:- change trunkingsystem which have access to the combination toll and regular connector H. Conductor 305 the release trunk conductor of the trunk line comprising conductors i, 305 and 305 which terminate in bank contacts 301, 302, and 303, respectively. 3. These bank contacts are assumed to be located in the banks of one or" the regular selectors referred to, and the ground potential upon conductor 305, and the test contact 302 and its multiples, render the connector H busy.

A branch of conductor 305 may be traced from junction point 306 by way of conduc tor 305, inding of relay 207, conductor 179, bank contact 17 5, wiper 171, armature 162 and its working contact, conductor 14-2, armature 128 and its resting contact, and the resistance 111 to battery. By current flow over the above circuit the relay 207 is onergized and at its armatures 236 and 237 prepares circuits for the ring out oilv relay 205 7 which will be explained later. Relay 207 also closes a circuit for the switching relay 20%1 by means of 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 of enabling it to function as a toll connector rather than as a regular connector. These circuit changes include the opening or the permanent locking circuit of the ring cut oil relay 205 at armature 225, the shifting of the locking circuit of the busy test relay 206 at armature 224, the disconnection of the regular trunk line conductors c0 1 and 306 at armatures 223 and 220, and the preparation of a supervisory signalling circuit for the toll operator at armature lhese circuit changes and the results eii ected thereby will. be mentioned more in detail hereinafter. Before proceeding further with the explanation a few more details concerning relays 207 and 20% may be inserted with benefit. Relay 207 is relatively low resistance, and the circuit traced through its winding from the grounded conductor 305 to the conductor 179 and test contact 175 places a potential upon the said test contact 175 and its multiples, which is suificiently near to ground potential to render the connector H busy to the toll second selectors. lVith regard to relay 20 1-, 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 is strong enough to hold 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 windingso as not to interfere with operating impulses transmitted to the line relay 201, the relay 20a is provided with a copper slug as indicated in the drawing.

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 subscriber at the substation A. A series of interruptions is 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 transmits a current impulse through the Vertical magnet- 210 over the following circuit: ground at G armature 2'15 and its resting contact, armature 216 and its working contact, off 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 s itch shaft, however, the otii' normal springs are shifted, and the circuit extends from the working contact of armature 216 by way of oti' 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 270272, inclusive, stand opposite the level of bank contacts in which the line of substation A is terminated. The slow acting rela 203 which is energized in series with the vertical magnet, maintains its armature attracted throughout the vertical operation of the switch. 7 hen this relay energizes at the beginning of the vertical movement it closes the following circuit for the ring cut-oil relay 205; ground at G, armature 213 and its working contact, armature 219 and its working contact, working contact of armature 237 and the said armature, and the lower winding of the ring cutoii' relay 205 to battery. Upon energizing, relay 205 opens contacts included in a later established signalling circuit at its armatures 227 and 229, and at its armature 228 establishes a locking circuit for itself as follows: grounded conductor 305, working contact of armature 228 and the said armature, armature and its working contact, and the lower winding of relay 205 to 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 rotary movement.

The toll operator may now operate the dial of the calling device S in accordance with the final digit in the number of the subscriber at substation A. The interruplions produced are repeated as before through the medium of relay 104, and cause another series of deenergizations of the line relay 201 of the connector H. At each deenergization the line relay 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, oil normal springs 222 and 221, armature 217 and its resting contact, resting contact of armature and the said armature, armature 240 and its resting contact, and the winding 01 the ma net 212 to battery. in re sponse to these impulses the rotary magnet- Les to rotate the wipers 270-272, inclusive, into engagement with the particular set or bank contacts in which the line of substation A terminates, these bank contacts being the contacts indicated in the drawing by the reference characters 273, 27 1, and 275. The slow acting relay 208 is energized in parallel with the rotary magnet and retains iii) energized while the test wiper271 is passing over busy test contacts. In order to afi'ord an opportunity to explain the operation of the 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 test cor.- tact 21'' will. be grounded and when the test wiper 271 makes connection with the said test contact, the testrelay 206 will be one: gized, the circuit being traceable as tollows: grounded test contact 274, test wiper 271, cont-act springs controlled by armature 2 1-1 of relay 209, armature 239 and its working contact, armature 243 and its resting contact, and the winding of the test relay 206 to battery. The test relay is energized over the above circuit and when the slow acting relay 208 deenergizes at the end of the rotary movement of the switch, the test relay becomes lockcd up by means of the following circuit: Grounded test contact 27 1, test wiper 271, workingcontact of armature 22 1 and the said armature, working contact of armature 230 and the said armature, contact springs controlled by armature 239 of relay 203, armature 2923 and its resting contact, and the winding of the test relay 206 to battery. The various circuit changes effected by the operation of the test relay will now be briefly pointed out. Its locking circuit which is closed at armature 230 has just been explained. At arn'iature 231 the circuit of the switching relay 209 is opened, at armature a shunt is connected around the armature 236 of relay 207 and its work ing contact in order to pr vent accidental decnergization of the ring cut off relay 205 (by movement of ringi g 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 oil the-contacts of the called line, and at armature 235 a lead from the busy signalling machine Q; is connected 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 is busy. This busy signalling 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 Work on other connections while waiting for the line of substation A to become idle, first, however, removing the plug from ack J 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 and 31 in place of the operators head set and this relay 6 would be energized in series with the line relay 10 1 of the repeater E were it not for the fact that the connector H is waiting on a busy line. In order to make right hand winding 01' repeating coil R, andthe winding of relay 100 to battery. Current flow 1n the above circuit erves to operate relay 100 which closes a 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 atthe same time closes alocal 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.

When the line of substation A becomes idle, ground potential is removed from the test contact 27 1- and the locking circuit 01 the test relay 206 is broken. The test relay therefore deenergizes, disconnects the busy signalling 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, armature 231 and its resting contact, upper winding of the switchingrelay 209, resting contact of armature 239 and the said armature, contact springs controlled by armature 24A, test wiper 2? 1, test contact 274, winding of the switching relay 317 of the in dividual line switch J, and the winding 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 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 theline switch has not been energized, and does not connectthe line conductors 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 2416, establishes a locking circuit for itself at armature 24:5, 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 wind ing of relay 209 which was formerly included in the circuit, and at armatures 242 and 247 closes the talking conductors through to the line wipers 27 0 and 272,

iao

The connection has now been established with the line of substation A. lVhen the busy test relay 206 is deenergized and the connector cuts through onto the called line as described in the preceding paragraph, the circuit of relay at the repeater is broken as previously stated, and this relay and also relay 101 are deenergized. The incoming trunk conductors are thereby connected again to the windings of the line relay 10a 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 idle and that connect-ion thereto has been completed.

The next operation is to ring the subscriber at substation A. F or this purpose the operator throws the key K momentarily to ringing posit-ion, thereby projecting ringing 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 arn'iature 128, relay 121 breaks the previously described circuit of the relay 207 at the connector H- Relay 207 accordingly deenergizes and at its armature 236 breaks the locking circuit of the ring cut oil relay 205. Relay 205 then deenergizes and at its armatures 2-27 and 229 opens the talking conductors and establishes the usual signalling circuit which includes the ringing current generator Gen and its own upper winding. There is no special novelty in the signalling circuit itself, although it is believed that the provision of a pick up relay, which is rendered necessary by the fact that semi-selective ringing is used, is new in an automatic system of this kind. As shown herein, the line of substation A is a party line, substation A being a so called two bell station while substation A is a one bell station. The operations following the deenergization of the ring out off relay 205 may be explained more in detail as follows: When relay 205 falls back, a circuit is prepared at its armature 281 for the pick up relay 282, and as soon as the pick up common conductor 285 becomes grounded during a silent period the said circuit is closed. Upon energizing, relay 282 looks itself at its armature 283, and at its armature 28 1 finally closes the signalling circuit, after which the bell 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 satisfactorily. This is accom plished by means of the inductive path which extends from armature 247 f re -.ay

209 by way of the low capacity condenser 299 to the resting contact of armature 235 of relay 200. Condenser 299 is of very low ca pacity, preferably about .005 microt'arad, and permits just enough ringing current to leak back in the direction of the operator to give her an easily distinguished signal.

When the subscriber at substation A. removes his receiver in response to the ringof his bell the ring cut off relay 205 will be operated by current from the exchange battery in series with the ringing current generator Gen, or by current 'l'rom the exchange battery in series with the booster battery associated with the generator, and upon attracting its armature 228 will re-establish its former locking circuit, the operator having restored her ringing key by this time to permit the energization of relay 207. The ring cut of? 1' lay aiso disconnects its own upper winding and the ringing apparatus at its armatures 22? and 229 respectively, and closes the talking conductors at these same armatures. The transmitter at substation A is now supplied with talking battery through the winding of the battery feed relay 100 at the repeater it. 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 118 to ground, while the upper line conductor 320 extends back through the connector H and the selector F to the upper right hand winding of the repeating coil 11, from which point it may be traced through the said winding and through the winding of the relay 100 to battery. Relay 100 is energized by current fiow through the transmitter at substation A, and upon attracting its armature closes the circuit of relay 101, which again operates to close a local circuit for line relay 104, and breaks the circuit of the supervisory relay 6 at the operators cord circuit, thus causing this relay to deenergize and extinguish the supervisory lamp L The operator will now come in on the line again by throwing her key K to listening posit-ion, and after ascertaining that the proper person is at the telephone, will request such person to deposit the correct coin or coins to pay for his connection. When the coins are deposited 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 n order that the operator may thereafter either collect or refund the coins.

Everything is now in readiness for conversation to begin, at least so far as the will be observed that the connection iii-- cludes a two conductor trunk line from the toll switching station to the main or local exchange tthe trunk comprising conductors 30 and 31), which is a decided economy over former arrangements requiring at least three and sometimes even "four conductor trunk lines. Another advanta e which may be pointed out is found in the arrangement by which the called subscriber controls the release of the connection, while his receiver is off, through the medium of relays 100 and 101, the latter of which controls a local circuit for the line relay 104. This arrange ment makes it possible for the toll operator to change cord circuits after a called party has answered without releasing the established connection.

When the connection is finished both subscribers will hang up their receivers. Upon the replacement of the receiver at subs-t..- tion A, relays 100 and 101 at the repeater E are deenergized and the line relay 10 i is again connected across the conductors of the incoming trunk line. As a result the supervisory relay 6 at the operators cord circuit is energized and the lamp L is lighted to give the operator a disconnect signal. Before releasing the connection the operator will have to collect whatever coins were deposited, and this operation will now be explained.

The trunk line extending from jack J in the toll switching station to the connector M in the local exchange and comprising conductors 351, 352 and is one of a limited number of similar trunks which are used exclusively for collecting and refunding operations. Any one of these trunks may be made use of to collect or refund at any subscribers station in the local change in question which has been connected with via the toll service trunking system. When the toll operator gets ready to collect them on the connection just de scribed, she will insert the plug of special cord circuit 0 in the jack 01 an idle collect trunk, and we will assume that the trunk line shown in the drawing is the one taken for use. When the plug is inserted in jack J a circuit is completed over the sleeve of the jack which includes the call ing device S and the relay 350 in serie- Upon energizing, relay 350 lights the busy lamp L" and its multiple lamps at other positions (not shown), and also closes a circuit over trunx conductor which includes the line relay 800 of the connector M at the distant local exchange. Upon energizing relay 360 closes a circuit for the slow acting release relay 361 which upon energizing in turn prepares the circuit oi the vertical magnet at its lower armature in the usual manner. llelay a a circuit through the upper or pol: winding of eiecitro-polari7: a rela The operator wi l now operate the calling device S in accordance with the number oi the toll service trunk line in use in the connection for which it is desired to collect, it being understood that all the toll service trunks extending to the local exchange in question are numbered consecutively in act-a-nl: numbering of the cordance with the connector d and associated connectors. Assuming that connector M 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 is operated in accordance with o the first digit of the number, the relay 850 is dcenergized a plurality of times-causing a like plurality oi deenergisations of the line relay 360 of the connector lvLI. lhe latter relay controls the connector M in substantially the same waythat the line relay 201 controls the combination connector H and on that accountthe explanation will not be given in detail. Briefly, at each deenergization, line relay 360sends a current impulse through the vertical magnet 867 vhich operates to raise the switch sha'l t step by step until the wipers 870, 371, and 372 stand opposite the level in which is ter-- minated the branch line which is a multiple of the particular toll service trunk to he collected over. The slow acting series relay 362 is energized in series with the vertical magnet, maintains the vertical magnet circuit intact after the oil normal springs have shifted 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.

V i hen the calling device S is operated in accordance with the next and last oigit in the number, t e line relay 360'sends a series of current impulses to the rotary magnet 868 which in response thereto operates to rotate the wipers 370-372 inclusive, until they come to rest in engagement with bank contacts 3?3375, inclusive. At the rotary step the rotary off normal springs 360, which are included in the rotary magnet circuit, are separated, but the magnet circuitis maintained closed by the slow act'- series relay 363 until the last rotary in.- pulse 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 oi the collect trunk and the connector M; While 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 conductors 30, 300, and 31, and the slow acting relay 363 has deenergized, the operator is given an audible high frequency tone which notifies her that she has connected with the proper toll service trunk. This tone signal is provided to prevent any error in collecting which might arise due to faulty manipulation of the calling device or faulty 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 will know 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. 1t 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 conneet ed to ground through a condenser. lVith this arrangement when connection is established with the bank contacts 373375, inclusive, the secondary of the induction coil is bridged across the branch conductors 30 and 31, resulting in the transn'iission of an audible signal to the operator as stated.

Having perceived the O. K. signal, the operator will in'imediately operate the collect key in the cord circuit 0. By this operation the exchange battery at the toll switching station is bridged across the trunk conductors 851 and 353 and a flow of current is produced in the winding of relay 365 and the lower winding of the electropolarized relay 364, these relays being bridged across conductors 851 and 353 at the connector M. When this current flow is established, relay 364 is not operated, due to the opposition of its polarizing 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, armature 382 and its working contact, winding of marginal relay 366, wiper 371, bank contact 37 i, conductor 300, armature 63 and its working contact, wiper 72, bank contact 76. conductor 130, winding of relay 107, and the high resistance 100 to ground. Current flow in the above circuit operates relay 107, the relay 366 ren'iaining 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 heavy talking conductors at the repeater E and connects conductors 141 and 145 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 extendsthrough the polarized magnet of the paystation mechanism to ground. Battery B is a high voltage battery and produces a current flow in 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. lVhen the branch circuit through the polarized magnet is established the resulting current flow is suthcient to operate the marginal relay 366 and this relay upon attracting its armature 883 substitutes an interrupted tone signal for the continuous tone signal, thereby advising the toll operator that the collect circuits are all right and that presumably 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 been reset by the polarized magnet, when the battery B is disconnected and the polarized magnet is thereby permitted to restore its armature tie 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 oi substation A as before described. This time, however, since the polarized magnet at the paystation has been disconnected the marginal relay 366 will not be operated and the operator will not get the interrupted tone 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. cuit conditions to exist in the previous case, where the operator collected the coins, if the refund key is operated the exchange battery is connected in bridge of trunk eonductors 351 and 353 as before, except that it is reversed, and as a result the electropolarized relay 364- at the connector M is operated as well as the relay 365. It follows that battery B will be connected to the line of substation A instead of battery B and battery B being of the opposite polarity. the deposited coins are refimded. instead of collected. Except as pointed out, the refunding operation is the same as the collecting operation, and the operator is given Assuming the same cirsupervision by means of the interrupted tone in the same way.

The special collect trunks are used only for collecting or refunding, which takes but a few seconds, and are 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 connector M. Relays 3G0 and 361 are thereupon deenergized and the switch is restored to normal by means of the release magnet 385m the usual manner.

The release of the main connection over the toll service trunks is also brought about by the removal of the plug from the jack, at least this is true if the called subscriber has replaced his receiver. In order to ex plain this fully, it will be assumed that the plug is removed from jack J before the subscriber at substation A has hung up, By the removal of the plug the circuit of relay 20 is broken and this relay is deenergized, but relay 21 remains locked up. The busy lamp L and its multiples are thus kept lighted to indicate that the trunk is busy. It will be noticed also that relay 21 maintains a test potential 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 receiver relays and 101 at the repeater E are deenergized and the line relay 10 1 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 81 by the deenergizatimi of relay 20. Upon energizing, relay breaks the locking circuit of relay 21, and this latter relay, upon deenergizing, disconnects relay 212 from in bridge of the trunk. clays 22 and 10 1 are therefore deenergized. The latter relay breaks the circuit of the slow acting release relay 105 and also breaks the operating circuit extending to the connector H. By the latter operation relays 201 and 202 are de energized and the connector H is restored by means of release magnet 213 in the usual manner. When the relay 105 at the repeater E deenergizes it removes ground from the conductor 14%, thereby permitt ng the switching relays a0 and 150 of selectors D and 1*, respectively, to deenergize. 'lhereupon these switches are restored by means of their respective release magnets 55 and 155 and all the apparatus will have been returned to normal position.

The description of my improved toll service trunking system is now believed to be complete; at least all the various features which have to do with the invention are believed to have been covered. It is true that the operations of the combination toll and regular connector H when used by a local subscriber rather than by a toll operator have not been gone into, but these operations have no especial connection 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.

lVhat I claim is:

1. In a telephone system, a toll board and a local exchange, trunk'lines extending from said toll board to the said exchange, cord circuits at the toll board and automatic switches at the exchange whereby toll and local subscribers lines may be connected over said trunk lines, paystation equipment at the stations on the local lines, a number of special collect trunks extending from the toll board to the local exchange, means whereby the toll operator can obtain access to any established toll connection at the local exchange by way of one of said collect trunks and means for controlling the paystation equipment on the connected local line over the collect trunk in use in order to collect or refund coins deposited to pay for the connection.

In a telephone system, a toll switching station and a local exchange, a group of trunk lines and a plurality of automatic switches whereby a toll operator can connect toll lines terminating at said station with'local lines terminating in the said exchange, paystation equipment at the stations on said local lines, a second group of trunks connecting said switching station and local exchange, means including the trunks of said second group whereby the toll operator can connect with the trunks of said first group at the local exchange while said trunks are in use in established connections, and means whereby the toll operator can control the collection or refunding of coins deposited to pay for such connections over the trunks of said second group.

3. In a telephone system, a toll switching station and a local exchange, a group of trunk lines and a plurality of automatic switches whereby a toll operator can connect toll lines terminating at said station with local lines terminating in the said exchange, paystation equipment at the stations on said local lines, a special collect and refund trunk terminating in an automatic switch at the local exchange, means whereby the toll operator can control said switch to connect with any trunk of said group which is in use in an established connection, and means whereby the toll operator can control the collection or refunding ofcoins deposited to pay for the established connection, the control being exercised over said special trunk line.

a. In a telephone system, a toll switching station and a local exchange, a group of trunk lines and a plurality of automatic switches wl ereby a toll operator can connect toll lines terminating at said station with local lines terminating in the said on change, paystation equipment at the stations on said local lines, a special collect and retiund trunk tern'iinating in an automatic switch at the local exchange, means whereby the toll operator can control said switch to connect with any trunk of said group wiiich is in use in an cstablisluul coimection, and means in said switch for collecting or refunding coins deposited to pay for the established connection, the said means being controlled by the toll operator over the said special trunk line.

5. In a telephone system, a toll line and a subscribers telephone line, means comprising an operator's cord circuit and a system of toll service trunks for connecting said lines, means including a special trunk line whereby the o1 erator can obtain access to the established connection over a new path, a paystation mechanism at the station on said telephone line, and means controlled by the operator over said special trunk line to collect or refund coins deposited in said mechanism to pay for the connection.

.6. In a telephone system, a toll line and a subscribers telephone line, means comprising an operators cord circuit and a system oi toll service trunks tor connecting said lines, means including a special trunk line whereby the operator can obtain access to the established connection at a point between her cord circuit and the subscribers line, paystation mechanism at the station on said telephone line, and means controlled by the operator over said special trunk line to collect or retund coins deposited in said mechanism to pay for the connection.

7. In a telephone system, a toll line and a subscribers telephone line, means including a series of automatic trunking switches whereby a toll operator can connect said lines, means including a special trunk line whereby the toll operator can obtain access to the established connection at an intermediate point, paystation mechanism at the station on said telephone line, and means controlled by the operator over said special trunk line to collect or refund coins de posited in said mechanism to pay for the connection.

8. In a telephone system, a toll line and a subscribers telephone line, means including a series 01" automatic switches whereby a toll operator can connect said lines, a branch line extending to one of said switches, means including a special trunk line terminating in an automatic switch whereby the toll operator can connect with said branch line, paystation lilCCl'ittDiSlD at the station on said telephone line, and means controlled by the operator over said special trunk line to collect or refund coins deposited in said mechanism to pay for the connection.

9. In a telephone system, a toll line and a subscribers telephone line, means including in serial relation a iii-stselector, a repeater, a second selector, and a connector, whereby a toll operator can connect said lines, means including a special trunk line whereby the operator can obtain access to the established connection over a new path, paystation mechanism at the station on said telephone line, and means controlled by the operator over said special trunk line to colcct or refund coins deposited in said mechanism to pay tor the connection.

10. in a telephone system, a toll line and :1 subscribers telephone line, means including a plurality of serially related automatic switches and a repeater whereby a toll operator can connect said lines, a special switch through the medium of which the operator can obtain access to the established connection, paystation mechanism at the station on said telephone line, a high voltage current source, and means including a relay in said special switch controlled by the operator whereby said source can be connected to said telephone line to collect coins deposited in said paystation.

11. In a telephone system, a toll line and a subscribers telephone line, means including a plurality of serially related automatic switches and a repeater whereby a toll operator can connect said lines, a special switch through the medium of which the operator an obtain access to the established connection, paystation mechanism at the station on said telephone line, sources o'i' high voltage current of opposite polarity, and means including a relay in said special switch controlled the operator whereby either of said sources can be connected to the said telephone line to collect or refund coins deposited in said paystation,

12. In a telephone system, a toll line and a subscri 'n s telephone line, means incli'uh ing a plurality of serially related automatic switches and a repeater whereby a toll operator can connect said lines, a special switch through the medium of which the operator can obtain access to the established connection, paystation mechanism at the station on said telephone line, sources oi' high voltage current of opposite polarity for collecting and refunding deposited coins, means including a relay in said special switch controlled by the operator for con nccting either of said sources through to the said repeater, and a relax in said rcocatcr automatically responsive to further extend the connected source into connection with said telephone line.

13. In a telephone system, a toll line and a subscribers telephone line, means including a series of automatic switches whereby a toll operator can connect said lines, paystation mechanism at the station on said telephone line, high voltage current sources of opposite polarity for collecting and refunding deposited coins, a circuit including a high resistance relay, means wherelr" the operator can connect either of said sources in said circuit, and means controlled by said relay for connecting the said telephone line in said circuit in parallel with said relay.

14.111 a telephone system, a toll line and a subscribers telephone line, means including a series of automatic switches whereby a toll operator can connect said lines, paystation mechanism at the station on said telephone line, high voltage current sources of opposite polarity for collecting and refunding deposited coins, a circuit including a high-resistance relay, means whereby the operator can connect either of said sources in said circuit, a second relay controlled by said first relay for connecting said telephone line in said circuit in parallel with said first relay, and a polarized magnet at said paystation incliuled. in the said yarallel branch. 7 r 15. In a telephone system, a toll switch ing svation and a local exchange, a group ct trunk lines and a plurality of automatic switches whereby a toll operator can connect toll lines terminating at said station with local lines terminating in the said exchange, paystation equipment at the stations on said local lines, a second group or trunks connecting said switching station and local exchinige, means including the trunlrs of said second group whereby the toll opera tor can connect with the trunks o'l said first group at the local exchange while said trunks are in use in established coiniections, means whereby the toll operator can control the collection or refunding of coins deposited to pay for such connections over the trunks of said second group, and means for trans-- mitting a distinctive audible tone to the toll operator over any established connection while collection or refunding taking place.

16. In a telephone system, a toll switching station and a local exchange, a group of trunk lines and a plurality oi automatic switches whereby a toll operator can connect toll lines terminating at said station with local lines terininatingin the said exchange, paystation equipment at the stations on said local lines, a special collect and refund trunk terminating in an auto-. matic switch at the local iii-(change, i'ncans whereby the toll operator can control said switch to connect with any trunk of said group which is in use in an established connection, means whereby the toll operator can control the collection or refunding of coins deposited to pay for the established tions on said local lines, a special collect and refund trunk terminating in an automatic switch atthe local exchange, means whereby the toll operator can control said switch to connect with any trunk of said group which is in use in an established 0011- nection, means in said switch for collecting or refunding coins deposited to pay for the established connection, the said means being controlled by the toll operator over the said special trunk line, and means for transmitting a distinctive audible tone to the toll operator over the trunk line used in such established connection to notify her that the collecting or refunding operation is actually taking place.

18. In a telephone system, a toll line and a subscribers telephone line, means comprising an operators cord circuit and a system of toll service trunks for c'onnect ing said lines, means including a special trunk line whereby the operator can obtain access to the established connection over a new pathya, paystation mechanism at the station on said telephone line, means con-. trolled by the operator over said special trunk line to collect or refund coins deposited in said mechanism to pay for the connection, and means for signalling the operator ever part of the said toll service trunking system to advise her that the collection or refunding is actually taking place.

19. In a telephone system, a toll line and a subscribers telephone line, means comprising an operators cord circuit and a system of toll service trunks for connecting said lines, means including a special trunk line whereby the operator can obtain access to the established connection over a new lath, a paystation mechanism at the station on said telephone line, meanscontrolled by the operator over said special trunk line to collect or refund coins deposited in said mechanism to pay for the connection, and

means for transmitting a distinctive audible J. i 1 Z tone to the toll operator over part 01 the toll service trunking system to advise her that the collecting and refunding apparatus operating successfully.

20. lna telephone system, a toll line tlii and a subscribers telephone line, means including a series of auton'iatic trunking switches whereby a toll operator can connect said lines, means including a special trunk line whereby the toll operator can obtain access to the established connection at an intermediate point, paystation mechanism at the station of said telephone line, means controlled by the operator over said special trunk line to collect or refund coins deposited in said mechanism to pay for the connection, and means for signalling the operator over part of the established connection to advise her that the collecting or refunding operation is actually taking place.

21. In a telephone system, a toll line and a subscribers telephone line, means including a series of automatic trunking s itches whereby a toll operator can connect said lines, means inclucing a special trunk line whereby the toll operator can obtain access to the established connection at an intermediate point, paystation mechanism at the station on said telephone line, means controlled by the operator over said special trunk line to collect or refund coins deposited in said mechanism to pay for the connection, and means for transmitting an audible signal to the toll operator over part of the established connection while the collecting or refunding operation is taking place. i

22. In a telephone system, a toll board and a local exchange, trunk lines extending from said toll board to the said exchange, cord circuits at the toll board and auton'iaticswitches at the exchange'whercby toll and local subscribers lines may be connected over said trunk lines, paystation equipment at the stat-ions on the local lines, a number of special collect trunks extending from the toll board to the local exchange, means whereby the toll operator can obtain access to any established toll connection at the local exchange by way of one of said collect trunks in order to collect or etund coins deposited to pay for the connection, and means for placing" a distinctive audible tone on such toll connection when the same is connected with by way of said collect trunk in order to assure the toll operator that access has been obtained to the desired toll connection.

93. In a telephone system, a toll switching station and a local exchange, a group of trunk lines and a plurality of automatic switches whereby a toll operator can connect toll lines terminating at said station which in use in an established connection, means placing; a distinctive audible tone on the connected trunk to notify the toll operator that the desired trunk has been conne "ted with, and means whereby the toll operator "an control the collection or refunding of coins deposited to pay for the established eon ection, the control being exercised over said special trunk line.

2%. ln a telephone system, a toll line and a subscribe "s telephone line, means compris ing an operators cord ci 'cuit and a system of toll service trunl-Is for connecting said lines, means including a special trunk line whereby the operator can obtain access to the established connection over a new path, and means actuated independent of the operator for placing a distinctive audible tone on the established connection to notify the operator that the connection over the new path has been established.

35. in a telephone system, a toll line and subscribers telephone line, means comprisin an o er-atone cord circuit and a system toll service trunks for connecting said lines, n'icans including a special trunk line whereby the operator can obtain access to the established connection over a new path, and means for automatically signalling the toll operator ov r part of the said toll service trunitir system to notify her that access to the es li ished connection over the new path b s been obtained.

In a telephone s 'stem, a toll line and a subscribefis telephone line, operators equipment and a series of automatic switches for coi'inecting said lines, a paystation control trnnl-z terminating in another automatic switch, and means whereby the operator can actuate said last mentioned switch to obtain access to the established connection over said control trunk at a point between the said eqi pment and one of the switches in said series.

In a telep ione system, a toll line and a subscribefis telephone line, operators equipment and a series of auton'ial'ic switches for connecting said lines, a pay 'tation control trunk terminating in another automatic switch, means whereby the operator can actuate paid switch to obtain access to the established connection over said control trunlt at a point between the said equipn'ient and one of the switches in said series and means for signalling the operator over a portion of the first established connection to notify her that the second connection has been established.

28. In a telephone system, a toll line, a subscribefs line provided with paystation mechanism, means including a seies of auh'm'iatic switches whereby a toll operator can connect said lines, sources of high voltage current of diilerent character for operating said payslation mechanism to collect or refund coins, a circuit including a relay, means whereby the operator can connect eithn' of said sources to said circuit to operate said trunk at a point between the said equipment relay. and means operable by said relay for causing the source used to be also connected to said line.

In a telephone system, a :nibscribers line, a toll line, means including a se. i s of automatic switches whereby a toll operator 'an connect said lines, paystation mechanism associated with said subscribers line, sources of positive and negative high voltage battery for operating said mechanism to collect or refund coins, two relays, means including an automatic switch whereby the operator can connect said relays in a series circuit, means whereby the operator can connect either source in said circuit to operate one of said relays, means responsive to such operation for causing said source to be also connected to the SHbSCllbGi S line to operate said paystat-ion mechanism, the increased current flow being effective to operate said second relay. and a signal controlled by said second relay.

30. In a telephone system, an operatofis switchboard in one exchange, subscribers lines in another exchange, interexchange trunk lines connecting said exchanges, means including operator controlled switches in the second exchange for extending connections from said switchboard to wanted subscribers lines over said trunk lines, a special trunk line extending from said switchboard to the said second exchange and there tern'iinating in another automatic switch, said last mentioned switch having access to all said trunk lines at the distant end thereof, and means whereby the operator can obtain access to any established connection over said special trunk line by operating said last mentioned switch to connect with the inter-exchange trunk line in use.

31. In a telephone system, a toll line and a subscribefis telephone line, a group of automatic selector switches, operators equipment for connecting said lines through the medium of one of said selectors, another switch having access to said group of selectors, and means whereby the operator can obtain access to the established connection by operating said other switch to connect with the selector in use.

32. In a telephone system, an operators switchboard, a subscribers line, means in cluding a train of automatic switches controlled by the operator for extending a connection from said switchboard to said line, a special trunk terminating in another automatio switch, and means whereby the operator can operate said other switch to obtain access to the established connection over said special trunk.

a second exchange, a trunk line in the second exchange having a plurality 01- branches, one branch terminating in a jack at the first exchange and another of said branches terminating in bank contacts of an automatic switch in the second exchange, an (n'ieratoi"s cord circuit for use in connecting subscribers of said first exchange with sub- .scribcrs'ot said second exchange via the'first branch of said trunk, and operators means for also setting the automatic switch of the second exchange into connection with the other branch.

34:. In a telephone system, an operators switchboard, subscribers lines, trunk lines having numbers assigned difiering from the numbers of said subscribers lines, operator controlled means for extending a connect-ion from said switchboard to one of said subscribers lines over one of said trunk lines, an automatic switch, and operator controlled means for dircctively operating said switch in accordance with the number of the trunk line in use in order to enable the operator to obtain access to the established connection over a new path.

35. In a telephone system, a subscribers line equipped with pay station mechanism and terminating in a central exchange, op erator controlled means including a series of automatic switches whereby a connection may be established with said subscribers line, high voltage current sources of oppo site polarity, a high resistance relay, operator controlled means for connecting said relay in circuit with either current source, and means controlled by said relay for connecting the said telephone line in circuit with the said relay.

36. In a telephone system, a subscribers line equipped with pay station mechanism, an established connection between said line and an operators switchboard, high voltage current sources of opposite polarity, a high resistance relay, operator controlled means for connecting said relay in circuit with either current source, and means controlled by said relay for connecting the said telephone line in circuit with the said relay.

37. In a telephone system, a subscribers line provided with pay station mechanism, means including a series of automatic switches for extending a connection to said line, sources of high voltage current of different character for operating said pay station mechanism to collect and refund coins, a circuit including a relay, means for connecting either of said sources to said circuit to operate said relay, and means operableby said relay for causing the source used to be also connected to said line.

38. In a tele hone system, a subscribers station provide with coin collect apparatus, a trunk line, means includin a plurality of automatic switches for ester fishing; a con:

nection between said subscribers station and an operators switchboard, high yoltage current sources, a circuit including a high resistance relay, means whereby an operator can connect either of said sources in said circuit, and means controlled by said.

relay for connecting the said telephone line in said circuit in parallel with said relay.

39. In a telephone system, a toll line and a subscribers line, means comprising an operators cord circuit and a system of toll service trunks for connecting said lines, means JOHN WICKS.

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