US1693962A - Telephone system - Google Patents

Description

1,693,962 L. L. RUGGLES TELEPHONE SYSTEM Filed Match 1'7, 1927 2 Sheets-Sheet Mi lgd \I gm Q N 7 94 [w i L I l "C I -flllfllg @i i f w} y [m LsunardLEugglas Dec. 4, 1928.

1.. L. RUGGLES TELEPHONE SYSTEM 2 Sheets-Sheet 3 Filed March 1.7. 1927 Patented Dec. 4, 1928.

UNITED STATES A N OFFICE-,3

LEONARD. L. RUGGLES, or WHEATON, ILLINOIS, ASSIGNOR TO nnsnnvn nonnme com.- PANY, or KANSAS orrnnissouni, A CORPORATION OF DELAWARE. v,

TELEPHONE SYSTEM.

Application filed March 17, 1927. Serial No. 175,953;

of near-by towns served by manual systems,

and the automatic telephone exchange serves as a switching center for the community in the establishment of the toll connection, each of the manual exchanges being connected to the automatic exchange-by toll trunks. It is with such telephone systems that the present invention is concerned, and it is an object of this invention to provide such a tele phonesystem wherein a toll trunk that connects a manual exchange with the auto matic exchange maybe used in making toll calls within the community as well as toll calls extending outside of the'community, the toll connections between the towns within the community being set up automatically and handled on a single ticket basis, and the toll connections to towns outside of the community being set up manually and handled on the usual two ticket basis. These and other objects of the invention will be apparent from the accompanying specification including he three figures of drawings forming apart thereof.

The drawings illustrate one preferred embodiment of the invention. I do not, however, wish to be limited to the precise construction shown,the same being for illu trative purposes only. WVhat I consider new,

and desire to procure by Letters Patent is more particularly pointed out in the appended claims. a 1 Referring to thedrawings, Fig. 1 is a schematic illustration of the layout of the various exchanges. Figs. 2 and 3 when arranged next to each other show the circuit arrangement whereby the various functions are obtained. A

Referring now to Fig. 1, at E, is shown a central automaticexchange and at A, B, C, and D are shown manual exchanges of adjacent towns. At M, N, and O are shown toll trunks connectin the town E which is the switching center For thecommunity with distant cities. The towns A, B, C, and D are rather close to the town E, they may for in'- stance be suburbs of that town, and there may be a considerable amount of tralfic notonly between the adjacent towns and the town E but alsobetween the towns A, B, C, and D. The exchange at E serves as a switching'center in the establishment ot-con-' nections between subscribers in the respective towns A, B, G, D, and E and also as'fa switching center in the establishment of connections betweenthe respective towns and the trunk lines M, N, and 0 leading to more remotecit-ies. In a communitysuch as is here served, although theremay bean appreciable amount of toll telephonejtraflic between the neighboring towns which does not inyolve Subscribers in the town E, still by far the greater percentage-of" the toll. trafi lc will either originate 'or terminate in the town E. Since toll: connections; within the community served by the exchanges A, B, G, D, and E are setup automatically without the aid of the toll operator in the exchange E, the record of the amount to be charged for thecalls may be kept/b the respective operators in the towns A, 3,0, and D, a single record'being suflicient The operator at each of the outlying towns keeps the record of the charges for all outgoing toll calls, 'and also for all incoming calls from subscribers in thetown'E.

All incoming and outgoing calls over the long distance toll trunks M, N, and O, for the community pass through the toll ope'r ators switchboard at E. i

Reterring'now to Figs. 2 and'S, there is shown in Fig. '2, a toll trunk .36 terminating in ajack. J. at the operators switchboard in the. exchange A. The operators switchboard is further providedwith anumbcrof jacks,not shown, over which the oper- I ator has access to local subscribers lines, and a number of cords which are used iniestablishing local connections. Q-For establishing. toll connections, any standard toll cord'hav ing battery potential on the sleeve may be i scribefls line may be connected by means of a line switch LS, to any one of a number of first selectors such as S the selectors being of the well known Strowger automatic type. The contacts in the banks of the first nine levels of the selector repeater TS are multi plied with the corresponding contacts in the C, which connectors in turn each have access] to one hundred-subscribers lines in the town first nine levels of the first selectors such as S and lead to the second selectors such as 8,. The bank contacts inthe tenth level of the firstselectors'lead as usual to the toll position. The second selectors recordin such as 2 have access toconnectors such as E. The second selectors such as S and the connectors such as Gare also of the Well known Strowger type. The bank contacts in the tenth level of the toll selector TS are multipled with the Correspondin contacts in certain second selectors of whic S is one, and lead to a number of rotary connectors of which only one, RC, has'been shown. The rotary connectors may be ofthe type shown at H in Fig. 2 of the patent to J acobsen,

- Number 1,349,381, granted August 10, 1920.

The rotary c0nnect0rs have access to the toil trunks connecting the exchange E with exchanges in the towns A, B, C, and D. The

connection to the trunk leading to the exchangeatA is shown.

Abranch from the trunk exchange at A with the exchange at E leads to-a jackJ, at the toll operators switchboard in the' latter exchange. The toll I switchboard at E is provided with anumber of-such jacks connected tothe trunks extending to the other towns B, C, and D, and likewise with a number of jacks terminating the long distance trunks M, N, and O. The toll operator at E is provided with a number of cord circuits for establishing connections between the jacks in her switchboard. Any standard toll cord having batterypotential on the sleeve may be used. A. suitable cord is shown in Fig. 1 of'the patent to \Vicks above referred'to; The toll operatorat E is. also provided with the usual toll service trunks whereby she may set up a connection to an automatic subscribers line in the town Eand connect that line to the jack ofone of the lines M, N, or 0. It is apparent that she may, if necessary, connect the automatic subscribers line with a trunk leading to the towns A, B, C, or D. a

It will be assumed that the operator at ,A has, received a call for subscribersline in the town E; She thereupon insertsthe I b plug of one of the toll cords at her switchboard into a jack such as J, which terminates a trunk leading to the town E andoperates the dial key DK preparatory to operating the automatic switches in the exchange E.

It is. of course understood thatthe other end of the cord circuitis connected to the calldialing key, to ground at the connecting the ing subscribers line. The relay 50 operates over a circuit from battery at the sleeve of the cord extending through the lower front contacts on the dialing key DKL At contacts 52 relay 50 establishes a holding circuit for itself independent of the dialing key,

and at contacts 51 it prepares a holding circuit for the automatic switches. V The operation'of the key DKcauses the-supervisory relay and therelay 100 to operate in series over a circuit extending frombattery at thev relay 100, through the upper winding of the relay, back contacts 81 "of relay 80, conductor '72 to the mid point of the left-hand side of the repeating coil R5 thence through conductors 35 and 36 connecting the two exchanges, to. the mid point of the right-hand windings of the coil R thence through the realy 60, frontcontacts 16 of the jack J front contact 17 of the ulsing contacts of the sending device. Re ay 60 at its front contacts (31 closes a circuit for the supervisory lamp L, while the realy 100 at its front contacts 102'establishes a circuit-for the relay 110. Relay 110. at contacts 112- places ground upon the test'conductor 46 g rendering the trunk 4445. busy. at the banks of the rotary connectors, and at front contacts 113 it'prepares the circuit for the vertical Inagnet VM of the toll selector repeater TS, at contacts 112 a circuit is also established for the righthand winding of shunt field relay 80. Relay 80,is, however, so constructed that before it can operate current must bejflowing through the two windings so as to produce fluxes in opposite 7 The relay 80 therefore does not directions. operate at this time. Relay 140 operates over the test conductor 46 which is grounded'at contact 112, and at its contact 144 establishes a circuit for the relay 150 and for the visual V. V The visual indicates to the toll operator the .busy condition of the trunk leading to the exchange A. The operator. at A now pro coeds to dial the first digit of the subscribers trunks. {Vhen the vertical magnet takes.

its first step, the ofi-normal contacts 125 close and establish a circuit for the relay 130 by way of front contact 121 of relay 120 to ground at the front contact 112 of relay 110, Relay 130 operates and at contacts 131 establishes a locking circuit for itself by way of the interrupter contacts 145 of the rotary magnet R, and vat-contact 132 prepares acircuit for the rotar -niagnet. Upon the cessation of the impul ses the relay. 120 falls back, and at the back contact Controlled by the armature 121 completes a circuit'for the rotary'magnet from ground ,at the front contact 112, back contact 121, and front connow depend upon whether the wiper. 152 isresting upon thebank of a busy or an idle trunk. Assuming thatthe trunk is busy and therefore there is ground potential upon the bank with which the wiper 152 is in contact, there is established an operating circuit for the relay 130 as follows: from groundat the Wiper 152, through back contact 92 :of relay 90, backcontact 145 of the rotary magnet R, vertical off-normal contact 125, through the relay 130, to battery and ground. Relay 130 therefore operates a second time and at its contact 132again establishesthe circuit for the rotary magnet R, which magnet again operates, and again opens the circuit for the relay 130 at itsarmature 145, and AlSUmOVGS the wipers 151 and 153 opposite the next trunk in the level. This continues until the bank ofan idle trunk is reached. It is to be noted that when the wiper 152 is in contact witha grounded bank-terminal, the

relay-9O is short circuited from ground at armature 112 extending to one side of the relay, and ground at the wiper 152-eXtend ing to the other side ofthe relay by way of back contact 92 of said relay. *When an idle trunk isreached, the wiper 152 does not find ground potential and therefore no circuit is established forthe relay 130 as previously traced. The relay '90 .is now not circuit for therelay 130 and the relay 90' in series, said circuit extending from grounded battery at relay 130, off-normal contacts 125, back contact 145 of rotary magnet, lo'wer terminal of relay 90, through the relay, to ground at front contact 112 of relay 110. Relay '130 can not "operate over' this circuit due to the high resistance of relay 90, which latter relay owever operates. The opening of backcontact 92 of relay 90 opens the previous short circuit around the relay 90, and at the front contact 92 the said relay extends ground fromthe frontcontact 112 of relay 110 to the Wiper 152, thereby immediately rendering the seized trunk busy to other toll selectors. At contacts'91 and 9 1, relay 9O completes a loop across the wipers 151 and153, said loop-extending from the wiper151, through front contacts'101 and 91-, the upper right-hand repeating-coil R back contact 71 of relay and front, I

contact 111 of, relay 110, through the lefthand winding ofurelay to. the lower-might.- I hand winding of the repeating coil R thence through the lower talking conductor 43.;and. through front contact 94 to. the wiper .153. Assuming that. the wipers 151 and 153 are resting upon the banks .of the trunk 154, v

156, which happens 'to be the, first idle trunk. reached, the closed loop previously traced.

extends over. said conductors to the second 7 selector S This closed loop causes the operation of the usual relaysin the selectors,

preparing that selector to receive the next group of impulses. The relay 80. 'does not operateits contacts over the above traced loop although both windings are at this time energized, due to the fact that the current is flowing in the wrong direction in 13116161515 hand winding of the relay.

The operator at A now operates the-calling device S in accordance with the next digit inthe wanted subscribers number, With each interruption at the calling' device the circuit for therelay is again opened and the relay 100 falls back each time. At this time the previously traced circuit for the vertical magnet ofthe toll selector repeater TS is open at the front contact 93*of the relay 90. l/Vith each interruption in current at the callingdevice'the contacts 101 open and break the previously traced closed loop across the wipers 151 and 153 thereby causing the step by step operation ofthevertical magnet in the second. selector s ga the well known manner. The second selector'S operatesin the usual manner to extend the connection to an idle connector in the selected group of connectors. The operator-atA then operates her calling device J in. accordance with the last two digits 'in the wanted subscribers number, threby operating the-selected connector C in the usual-manner to n v extend the connection to the line P. short circuited, and there is established a The operator at A having'dialed the last digit now restores the dialing-key DK. This is of no effect at this time inso far as the automatic switches are concerned since the circuit'for the relay 100 and the relay 60-is now maintained from groundat the Contact 51 of relay 50 extending by Way of the back contact of-the dialing key'now restored to the front contact 16 of-the jack J If the called line happens to be busy the connector'operates in'the usual manner-to apply a busy tone current'to the talking conductors-of the calling line, said current being repeated by way of the repeating coils R, and R, to the calling party. If the called line is idle the connector operates to apply ringing current to said line to signal the 2 subscriberthereat. Upon the answering of the call by the called subscriber the..usu.al relay in the connectorioperates to reverse the currentover the talking conductorsextend-.

I Relay70 does not operate at this time because the conductor 72 is alsopgroundedat the other end by way of the sendingdevice S before the key DK is restored, and at coning to therepating' coil The reversed current in the bridge including theleft hand winding of the shunt field relay 80 causes the relay to operate. Relay 80 at its front contact 82 establishes a circuit for the lower winding of the relay 100thereby maintaining said relay operated. At contacts 81, relay80 opens the initial circuit for the upper winding of the relay 100 and extends the conductor 72 to the grounded relay 70.

tact 51 after the key is restored. The relay '60 being deprived of battery through upper winding of relay 100 releases and extinguishes the supervisory lamp L. The parties may now converse.

If the called party terminates the callfirst,

the battery connection to the line is reversed at the connector causing the release of relay 80. At contacts .82, relay 80 opens the circuit for the lower winding of the relay 100,

and at its upper contacts 81 reestablishes the previously traced circuit for the upper winding of the relay 100 in series with the relay 60, ground being received by wa of front contact 51 and the back contact 0 the key; DK instead of through the contact 17 and the contacts of thesending devices.

The relaylOO is maintained operated thus maintaining the toll selector TS in. position. At contact 61 relay 6O closes the cir- I cuit for the supervisory lamp L thereby indicating to theoperator at A that the calledparty has terminated the call, If the calling party has not at this time also terminated the call, the operator at A may converse with that party and determine if the connection hasbeen completed and if it has not been completed she may again set up the connection to rering the line P. If the call has been completed the operator at A removes the plug from the jack J thereby causing the release of. the relay 50, andtheconnection {of battery potential at the back contact 16 of the jack J, to short circuit the relay manner, upon the opening of the loop tacts 95, and back contacts 113, 93, and 102 to ground. This causes the release ofthe selector. The releaseof the selector S and the connector C-takes' placein the usual 9 across the talking conductors at contact 101..

If the callingparty should replace'the receiver before the called party does, the

operator at A getting the customary signal 1 in the cord circuit connected -to J, causes the release of the train of automatic switches by withdrawing the plug from the jack J When the plug is withdrawn from the jack .the relay 50 ceases to receive battery from the sleeve of the jack and falls back. :At

the back contact 16' of the jack battery potential is placed upon the conductorextending to the relay 60 and through'the repeaters to [the conductor'72 in the/toll selector. .This'battery potential extends by way of conductor "72 and front contact 81 of .relayg80, which relayis still in its operated position dueto'the fact that the called party has not tcrmi'nated the call, to"

ground by way of the relay 70. Relay 70.

operates, and at its contact 73 establishesa locking circuit for itself byway of olf-' normal contacts .to battery through the release magnet. The release magnet does not operate over this circuit due to the high:

resistance of the relay 70. At contact 71 relay 70 opens the circuit for the left-hand winding of the shunt field'relay 80thereby causing the release ofsaid relay. Relay. 80

at front contact 82 opens the circuit; for

the lower winding of relay but at its back contact 81 does not again establish a circuit for the upper winding of the relay 100 because the conductor 72is at this time.

connected to battery instead of to ground;

Relay 100 thereupon falls back and is followed by relays and 90, thereby causing the release of'theselector in the previously described manner. Upon the opening of the otf-normalfcontacts 95 relay 70als0 releases;

The selector S and the connector C were released in the. custoinarymanner when the relay 70. at contact 71*opened the direct current bridge across the wipers 151 and Ali-explanation will now be given of the manner in whicha subscriber at the auto-n matic exchange E may extend a connection" to the operators position atfA to call a'party in that exchange. Upon the removal of the receiver at the station P, theline-switch LS operates in the well known manner to exy tendthe line to an idle first selector, such as S The subscriber at P now dials the first two digits of the number assigned, to them:- change A, causingthe operation of thefirst selector S and thenthe secondselector S to extend the line to one of a number of ro-- tary connectors BC. The last level of cer-.

tain second selectors such as S is-assigned to rotary connectors RC instead of to the usual connectors'Q' The banks of the rotary connector RC lead to the various adjacent towns'such as A, B, C, and D, shown in Fig.1. The subscriber now dials the next digits of the number assigned tothe exchange Athereby operating the connector in the manner explained in connection withthe :in the manner ,explained'in the above referred to patent. This ground potential automatically renders that trunk busy to other rotary connectors. Cut off relay 140 operates from grounded conductor 46 and at contacts 144 establishes a circuit for the re- I lay .150 and for tlie visual V. Relay 150 operates its contacts 151 to. short circuit the drop 170. The visual'indicates to thc'operator the busy condition of the trunk leading V lease of relay llOwhich relay atits'contact to exchange A. A moment later the rotary connector RC operates to prO ect ringing current overthe talking conductors 44, 45.

The ringing current does .not operate the drop 170 ,due to the open contacts 143. r The ringing current is projected by way of the conductors, 44, 45, to the repeating coils R and. is there repeated to the repeating coils B A circuit is then established by .way of the left-hand windings of the repeating coils R through the back contacts 1 of the jack 'J l to the drop 15 at the operators p-osition at A. Thedrop operates and at its contacts 14 establishes a circuit for the relay 50 which at its contacts 51 prepares a circuit for the relay 1 00, and at contact 52prepares a locking circuit for itself. The operator at A, noting the condition of the drop, inserts the plug of a cord circuit into the jack J The relay 5O ismaintained operated over the sleeve of the jack J A circuit is also completed for the relay 1-00 and the relay as previously traced. 'Relay 100 operates, and establishes a circuit for the relay 110 which relay also operates. At

contacts 111, relay 110 establishes a direct current loop across the talking conductors '44, 45 leading to the rotary connectortRC, said loop extending from the wipers of the rotary connector RC through the conductors 34, 45, the right-hand repeating coils of R thence being completed by way of back con- .tact 71' of relay70, front contact "111, and

the left-hand winding of relay 80. This causes the cutting off of the ringing current at the rotary connector BC, The current flowing in the above traced: loop is in the proper direction to cause the operation of the relay 80. Relay 80. at its front contact 82 establishes a holding circuit for the relay.

100 through its lower winding, and at 81 shifts the conductorsd72 to the grounded winding ofthe relay 70. The relay 60, theupper winding of relay 100, and relay are now deenergized, their circuitsbeing the same as previously traced when .relay operated. The operatorat Amay now converse with the calling-party at}? and deter-- mine the number wanted. She then extends the connection to the desired line.

Upon the termination of the'call' by the calling party the selectors S andJS I and the rotary connectorRC are release'd'lin the usual manner. Upon the release of'th'e ro- 1 00 and the relay 60 in series. The operator at A noting the lighted condition of the lamp L pulls down-the. connection. A When. this is donethe relay 100 releases in a manner; previously pointed out, thereby causing the re- 112 removes ground from the conductor ,46 causin whichin turn causes the releaseof relay 150 and jof the visual 'V. The operatorat J noting the released condition of the visual now knows thatthe line 44,45 is not busy.

The relay 150 opening its contact 151 removes the-short' circuitfrom across the drop 170 thereby again allowing the operator-at A to call the operator at E should she so desire. Upon theremoval of the'phig'from the release of cut-oil; relay 140,

the jack J, the relay 50 falls back, its circuit .being broken at the sleeve of'the jack. All

therela-ys having restored," the circuits are now again ntheir 1n1t1al cond1t1on.

From the above description it is'nowap-t parent that the operator at A may automatically call the operatorat B, C, or Dby operating the toll selector repeatenTS to its tenth level and then operating the 'rotary connector RC which is seized, to extend the connection to the near-bytown. y When it is desired to extend-a connection from a toll linesuch as, M, N, or O, to oneof the adjacent towns, the toll operatoratQE .may call the operator at A, B, C, or inserting the plug of a cord circuit into ajack such as J terminating a trunk leading .to thedesired town a-nd then proj ecting ring- .ing' current over the talking conductors. ,Battery from the, sleeve of theplugjon the cord causes the operationof relay 160, which relay at contact 161 makes the'conductor 46 test' busy, and also causes the operation of relay 140 and also relay 150. The ringing current projected over the talking conductor causes the operation of'drop 15 inthesame manner as was. previouslypointed out. 1131s of course understood that the cord inserted in the jack J 2 is at itsother end connected to the toll line such as M,N, or 0 over which the call was received. For the sake of further explaining the operation of the system it will now ,beassumed I that the operator at A has received a toll call for a point outside ofthe commun ty, that s,

' for .a call that must over one ofthe .ing conductor of the cord circuit.

current is sent through the left-hand coilsot the repeating coil R at the exchange A andis repeated at the right-handfcoils of the retoll lines, M, N, or O. r The operator at A now, as before, inserts the plug of one of the toll cords at her switchboard into a ack such as J, which terminatesa trunk leading to the town E, but now instead of operating the dialkey DK as before, she operates a ringing key to project ringing currentover the talk- Ringing peating coil R, which is located in exchange ,E.. A circuit is then established for the drop 170 by way of conductors 4445,141

162,.the back contacts on the aok J and the back contact143 of relay 140. The drop 170 operates and at contacts 171 places ground upon the test conductor 46 leading to the r0 1 20 I tary connector, thus busyin the trunk to incoming calls. The grounc at 171 further completes acircuit for the cut-off relay'140,

which relay, at its contact-143, opens the circuit for the drop, and at contact144estab- Ulishes an operating circuit forthe visualy and for the relay 150. The'dropj170 s or the type that must be manually restored. This may be done mechanically when a plug is inserted into the jack' J The relay 150 further short circuits the drop. The operator in the exchange E noting the condition of the drop inserts the plug of a cord circuit into the jackJ fAny standard toll cord circuit having battery on the sleeve may be used. Upon the insertion of the plu'g into the jack, relay 160 operates from battery at r @the sleeve of the jack, and at contacts 161 maintains the ground upon the test conductor 46 sothat althoughthedrop is restored upon the insertion of the plug into the jack J "the relay 140'will not restore.

The toll operator atE may now converse withthe operator at A. The operatonat E then extends the connection over a trunk such as M, N, or O, as instructed, in the usual manner.

Uponthe termination of the 'lcallthe re Ispective operators receive the customary sig- Enal fr'om their cord circuits and take down the connection When the plug is removed fi-om the jack J t the relay 160 releases and at contacts 161 removes ground from the test conductor. 46 thereby causing the release of relay.140, and furtherremoving the busy guarding potential]. from the bank of the rotary connectors. Relay 140 upon dropping ,back opens the circuits for the relay 150 and 1' for the visual,1which a moment later restore.

1 it ispossible totalk over that trunk, toll con-.

nections from the towns A, B, C, or D, to

points within the switching community may It is now apparent that if, due to temporary disorders, it is impossible to dial over a trunk connectlngthe town E with one of the adjacent towns, A, B, C, or D, while ters Patent is :I v p r 1. In a telephone system, a trunk ternnn be handledby the toll operator at E. Under these conditions theoperator in one of the towns A, 'B, C, or D would pro ect ringing current over the talking conductors of. the

trunk leading to the town E to call thetoll operator at E. The operator at E would then extend the connection by means of a cord circuit to the trunk'leading to an ad- (iacent town, or bymeans of theusual toll "relay 140. With reference to this matter,

it is to be noted that when the tr11nlr35-36 is in use in connection withfthe automatic switches in the exchange E, battery and ground potential are applied to the two automatic'switches, and the condenser between the right hand repeating coils R is short circuit-ed. At this time' relays 140 and 150 are energized, therefore the drop 170 isshort circuited at 151, and'is disconnected from the talking conductors at 143.

Upon the termination of the call by the opconductors. V sw tches .IBlBHSGflGBNIIIg the condenser in the charged condition, and then'the relays. 140 and 150 restore. After the relay 140 talking conductors 42-43 byway of the 'erator at A, the short circuit across the condenser isremoved. The condenser is ,then charged by the potential across the talking A. momentlater the automatic has released 'andberore the release'ofthe relay 150, the talking'conduetors'4243 are short circuited by Way of conductor 141, back contact at the tip of jack' J back contact .143, and front contact 151, back contact 6 V at the ring side of jack. J conductor 162,

thence through conductor 44 to "conductor. 43 and the lower side of the right-hand repeater' B This offers a discharge path for the condenser in the right-hand repeating coil R The drop 170 is short circuitedat front contact 151, When'the relay 150 releases and reconnects the drop to the talk ing conductors thejcondenser will'have been. discharged. Thus there is no possibilityof the drop from the condenser. V

Having described my invention, WhatfI consider new and desire 70. being operated by a. discharge to procure by f I ating at one end at an; operators switchboard in a manual exchange, and at the other end in an automatic exchangeydireo tively'operated automatic switches at ;the automatic. exchange having access to the trunk, a relay at the end terminating at the switchboard arranged to be operated responsive to the seizure ofthe trunk by an'automatic switch,- means effective responsiv'efto elusive ofthesignahthereby preventing the signal from being operated by the condenser V discharge;

the operator at the manual exchange answering: the incoming call to lock the relay in its operated position and to-establish a di r'ect current loop across the end of the trunk terminating n the automatic exchange.

2. In a telephone system, a trunk includ 111g two talking conductors terminating at which terminates at the operators switch-.

board, means for operating the signal for indicatingtothe operator an incoming call,-

means for locking said relay in its operated position when thecall is answered, means eifective responsive to the locking of the relay in its operated position for establishing a direct current path across the end of the trunk in'the' automatic exchange, an additional circuit including the dialing'key for operating the relay responsive to the operator initiating a call over the trunk line, automatic switches at. the automatic exchange operated overthe trunk line, and a circuit controlled by the relay for maintaining the switches operated.

3. In a telephone system a trunk line, a condenser bridged across the talking conductors at one end thereof, a signal connected across the trunk to be operated thereover,

and means effective upon the termination of a call over the trunk to momentarily provide a discharge path for the condenser ex- 4. In a telephone system a trunk line, a

condenser bridged across the talking conductors atone one thereof,'a signal connected across the trunk to be operated. thereover, means for disconnecting the signal from the. line when the line is in use, and means effective upon the termination of a call over the trunk tomomentarily provide a discharge path for the condenser exclusive of the signal, thereby preventing the signal from being operated by the condenser discharge.

5. In a community telephone switching system wherein there are a number of manual telephone exchanges each connected by a tolltrunk to a central automatic exchange which constitutes the switching center for the community, an automatic switch ac- V cessible to and having access to the toll trunks, a local selector in the automatic exchange having access to the automatic switch, and means controlled over the toll trunks for seizing said local selector;

6. In a telephone system wherein an automatic exchange serves as a switching center in the establishmentof toll connections to and from manual. exchanges in near-by towns, tol-l trunks connecting l each i of the manual exchanges with the automatic BX- change, local subscribers lmes terminating in the automatic exchange, 'aselector, means controlled over any local subseribefs line for connecting the subscribers lineto the selector, means controlled over the toll trunk for connecting thetolltrunkto the selector,

local subscribers lines and to the toll' trunks accessible to said selector.

" 7. In a telephone system wherein-an auto matic exchange servesas a-swi'tching' center in 9 the establishmentof 'tollconnections to and from iiianual'excha-nges in near-by towns, toll trunks connecting each'of the manual exchanges with thea-utomatio exchange, au-

tomatic switches for extending local connections between subscribers of the automatic exchange, an automatic switch having access .to said toll trunks, and means in the automatic exchange for extending a" connection from a toll'trunkto said last named automatic switch over either oftwo paths,one of the paths including a least one ofthe first mentioned automatic switches and the otherpath excluding all o f the first mentioned switches. p

g 8. In a telephone systemwherein an-automatic exchan-ge serves as aswitching center in the establishment of toll connections .to

and "from manual; exchanges in near-by towns, toll trunks connecting each of the "manual exchanges-with the automatic exchange, automatic switches for extending local connections between subscribers {of the automaticexchange, an automatic switch havmg access to said toll trunks, means in the automatic 'exchangefor extending a connection and automatic switches having access to the l from a toll trunk tosai'dl'a'st named autoothertpath excluding all of thefirst men- 9. Ina telephone sys tem, a manualteld phone exchange, an automatic telephone I exchange, l a trunk line connecting the two, said trunk line-terminating in an opmatic switch over eitherof two paths, one of the paths includingat least one of the ,first mentioned automatic switches and the tioned switches, atoll operators switchboard "in the automatic exchange, and a. branch from each' toll trunk terminating at the switchboard.

exchange.

to, the operators switchboard in the manual A community telephone switching systemcomprising an automatic telephone exchange, a plurality of neighboring manual telephone exchangeseach in a jdifl'erent neighboring town, toll trunks connecting each of the manual exchanges with the automatic exchange and terminating each in an automatic switch at the: last named exchange, a branch extending each toll trunk to' atoll operators switchboard in the automatieex= controlled over, atolltrunk or over a local subscribersline to rextend connections to a subscribers line or to" a toll trunk at 11. community telephoneswitching system wherein an automatic telephone exchange serves asa switching center in the j establishment of toll connectionstoand :from

manualexchanges in nearby towns within the community, toll trunks connecting the manual exchanges with the automatic exchange, automatic switches in. the. automatic exchange automatically 1 accessible to the trunks and also; having access to the trunks, atolloperators switchboard in the automatic exchange, a branch from each trunk terminating at said switchboard, and toll lines extending outside of the community also terminating at said switchboard.

tem wherein an automatic telephone exchange serves" as a switching center inthe establishment of toll connections to'and from 5 :manualexchanges in nearby. towns with n the community, toll trunks connecting the manual exchanges with the automatic 'exchange, automatic switches in the automatic exchange automatically accessible to the trunks and also havin access to thetrunks,

ity also terminatingat said'switchboard.

13. In aycoininuiiity telephone switching system wherein an automatic telephone cx- .change servesas a switching center in the establishment ot toll connect ons to and from the 'coinmunity,tollq trunks connecting the manual exchanges with the automatic ex-- change, toll 'lines connecting the automatic exchange with points outside of the commu nity, and means whereby toll calls With- 1927. v in the ffml'lmlllllty may be ihandledon Sill-v niunity by way of said automatic exchange without the aid of an operator in ,the automatic exchange, and means whereby the op- ;erator .in the automatic exchange may set up toll connections between the toll lines and the toll trunks.

e 14. In a telephone systenna trunk line {one end of which has two branches,;a condenser in-the portion of the trunk circuit common to those branches, signalling means intone of the branches normally connected across theycondenser and operated from the other end of the trunk line, a connector havling acee ss to the 'otherbranch of the trunk. line, a shunt circuit, means responsive to the answeringof a call extended overthe trunk line by the connector for renderingsaid'sigo nections between the towns withinthe Conn nalling means'inoperative and for connect- .ing the shunt circuit across the condenser, ineansresponsive to the called party disco'n 'uecting first for opening the shunt circuit,

wherebythe condenser becomes charged, and

means for discharging the condenser when the connector releases and before the signalling means again becomes operative, wheredeiiser discharge isprevented.

e V v :15. In a telephone system, an automatic 12. A community;telephone switching sys exchangaa trunk line one end ofwhich ter ininates at said exchange, a condenser, Sig-- sive to the application of alternating current to the other end of said trunk line, automatic switches at said exchange, means responsive to digit impulses transmitted'froin said other end of the trunk line for, operating the switches to extend aconnection, saidj condenseri. being in i the talking circuit, means responsive when a call is so extended for rendering the signalling meansv inoperative, a shunt circuit around said condenser during the connection, means for opening said ,90 by. the operation ofthe signal a con-' shunt circuit if the connection is released b efore the called party disconnects, whereby the condenser becomes charged, and means for discharging the condenser when the re- [lease takes place and before tliesignalling manual exchanges in near-by towns with n means is, restored to normal condition,

(lciiserdischarge is prevented. in witness wl iereoflyl hereunto subscr b my name th s 10th dayvof March, A. D;

LEoNARnL. mews;

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