US866714A - Telephone system. - Google Patents

Description

PATENTED SEPT. 24, 1907.

H. 'P. GLAUSEN. TELEPHONE SYSTEM. APPLICATION FILED 00125, 1-901.

names.

UNITED sTA rns PATENT OFFICE.

HEN RY P. CLAUSEN, OF CHICAGO, ILLINOIS, ASSIGNOR TO AMERICAN ELECTRIC TELEPHONE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

TELEPHONE SYSTEM.

Specification of Letters Patent Patented Sept. 24, 1907.

Application filed 0ctober2 5, 1901. Serial No. 7 9.900.

.of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Telephone Systems, of which the following is a specification.

My invention relates to telephone systems in general; but more particularly to systems of the central energy type, and especially to systems in which complete me-r tallic circuits are provided for talking and ringing the bellsat the substations.

Generally stated, the object of my invention is to provide certain details and features of improvement which will tend to increase the general efiiciency of a telephone system of this character.

Certain'special objectsare to provide a'circuit ar rangement which will permit the central operator to answer a call without producing objectionable or disagreeable sounds in thereceiver at the substation, and which will" permit the signaling current to hold the calling signal in operation until the call is answered, it being also an object of the invention'to provide a circuit arrangement of such character as to enable the signaling battery to operate or light a calling signal lamp through a short local circuit of comparatively low and unvarying resistance.

Other special objects of my invention are to provide an improved construction and arrangement by which the relay which connects the normally disconnected jack-with'the' subscribers line is energized over a ,cir

which is absolutely independent of the ground at the subscribers stations, whereby the subscribers in signaling for a disconnection do not use the ground he tween the substations and the'exchange or central station; to provide an improved construction and arrangement whereby it will not be' necessary to use a series of normally open contacts in the normally dis-' connected jacks for closingthe energizing 'circuits through the relays which have the double function of disconnecting the individual' line signals and establishing connectionwithlthe subscribers lines when- I ever an operator s'cord-plug is inserted to'make con-.

nection with the line, to provide an improved constructionand arrangement whereby the coil or winding of the individual line relay may have two energizing circuits, one a line circuit for initially energizing the relay and the other a local circuit adapted to displace or supplant the line circuit for the purpose of clearing the line of current and looking or holding the line signal in operation until the operator answers the call; and to provide a construction and circuit arrangement whereby a centralized source of talking and signaling current is adapted to supply talking current to the subscribers transmitters and at the same time energizethe relays which connect the normally disconnected jacks with the line over' circuits including the flexible connecting cord bywhich theoperator temporarily establishes connection between any two subscribers lines. I

It is also an object, as will hereinafter more fully appear, to provide certain novel combinations and circuit arrangements which will tend to increase the genoral efiiciency and serviceaibility of a telephone exthe cord or plug circuit. It will be readily under stood that the subscriber s substation apparatus can be of any suitable known or approved character. 'At the exchange or central station, the jacks J and J are nor-. mally disconnected from the subscribers lines to which they are allotted, and the cut-off relays IV- each have one terminal connected with the grounded pole of the common battery B and'the other terminal connected with the sleeve or thimble of the associated jack. It will be understood that the batteries B and 'B can be one and the same battery-that is to say, one

battery c'an'be employed if desired The operators cordconnecting'apparatus comprises the answering 'plug P and the calling plug P which are, as usual,

similar line relay R at the right is individual to the line leading from thesubstation S. The supervisory relay n at the left is associated with the answering plug of the operators cord circuit, and the similar supervisory relay R at the right is associated with the of course, be of any suitable known or approved form of construction consistent with the mode of operation of the system and the various results and advantages to be obtained thereby. The arrangement of suchapparatus in a system embodying the present improvements willperhaps be most readily understood by tracing the circuits existing in the system from-time totime as the several different'possible connections of the systeinaremade, as follows: If subscriber S wishes a-conhection hecalls the operator at the central station by liiting hisreceiver from the hook H. This imme diately completes a circuit from the hook, through the contact, 1, and the primary -2 of the induction coil. of

thereceiver circuit, and through the line 3,- to one of the armatures 4 of. the duplex relay 3., thence through contact 5, lamp L, and. coil of another relay R and through connection 6 to battery; thencefrom the batterythrbughthe groundQconnect-ion E to another ground connection 7 and contact 8 to the other-armature?) of the relay R, and thence through line 10 and trans-' 'mitter T backv to the hook H; The flow of current through. the circuit thus established. will cause. the relay R: toattractitsarmaturer against adjacent contact pointslZ and 13 and close a localrcrosscircuitfrom the line 3 through connection 11, contact, 12, armature.

1', contact 13, and-connection 14 tothe line 10, and the flow of current resulting in this local circuit will light a signal lamp 1 connected therein and thus attract the operators attention to the fact that a. connection is wanted, the flowoicurrent to feed the lamp then being from battery B, through 6 and R to the lamp and from back to the batteryB.

the lamp-through 5, 4, 11, 12, r, 13, a, s, 7, and, E,

Theoperator rsspondsby placing theplug Pin thesubsci-iberls jack J whereupon a circuit will be established from the battery B through an impedance moil 16 and, line 17'to asupervisorylamp l,- andjrom this 1lamp-through connection. 18, a sleeve 19of= theplug to the-sleeve 20 of thejack, thence through connection 21 and thmughthe coil-of -relay R into the ground at, 22,

' and, thence through the-earth back tothe: battery by way of ground connection. 23. The flow of. current through'this circuit wills, cause the reIayR. to attract both-of its armatures 4 and 9,, andatoestablisha talking circuit fromjthe battery through a repeating coil.24 and;

throughthe coil ofa relay R andrconnec'tion 25, 'to theintermediate ring 26'of-the plug, and fromthis interme:

- diaterin g through the intermediate spring 27 of the jack andcontact 28f: the armature 4- of the relay R. and thence through the line 3, e011 2 and contact 1-, to the 1 switch H andtransmitterT; thence back throughline.

10,, armatur'el), contact 29, tip spring 3;) ofthe jack, tip

j 81 of. the plug and repeating coil,32, thenceto the battry. The shifting of the armature 4 of the-relay R willialso open the circuit through the relay R and-permitits armature r to fly back and disconnect the contactel2 and 13, thus opening the ,circuit: through the signal-damp Z, and restoring onexting'uishing, the latter.

heoperator then presses the listening key K andtcome The telephone in pletes a circuit from the battery B through the other side of the repeating coil 32, connection 33, key K. conback tojthe battery. The operator can consequently now talk inductively with subscriber-S and find out thenumber of the station with which connection is wanted. This may be assumed to be station S with which the operator proceeds to make connection by placing the plug P in the jack J" corresponding to that station. The insertion of this piug completes a circuit from the battery B, through impedance coil 47 and connection 48, to a supervisory lamp I and from the lamp through a connection 49 to the sleeve 190ithe plug P, thence through the sleeve 20 of the jack by connectionZl to the coil of. theduplex relay R and thence to ground and into the ground at 22, and thence-through the earthand through ground connection 23 ,back to the battery. The supervisory lamp I will thereupon light iip and. will remain-lighted until the subscriber at station S removes his receiver t from the hook. The energizing-of the relay R will also attract armatures 4' and 9, against contacts28 and 29, respectively, and'thus enable the operator to call upstation S by pressing the ringing key K to bring the ringing generator G into circuit with the bell of station S The circuit connections will then be from the generator G through connection 50 and contact.

51, key Kl, tip 31, tip spring 30, contact 29, armature 9,

line l0, connection 52, contact 53, hook H, and contact 54:to the bell 55 and from the bell through condenser56,

line 3, armature 4, contact 28, jack spring 27, plug ring- 26, connection 57, key K contact 58 and connection 59 tip spring 30,- contact, 29, armature 9,- andline 10, to the m transmitter T and-hook H and thence through contact.

1, induction coil2; line'3, armature4, contact 28, jack 'spring27, plugring26, connection 57, key K contact. 63, connection 64, relay R connection40, and.repeat,-.

ing coil 24, backto the battery. This puts stations=S and' S into talking communication inductively through the repeating coils 24 :and'32, and at the same time moves the armature 65 of-the relay R and short circuits and I, extinguishes the supervisory lamp- 1' through a contact 66 and impedance coil- 67. The re-' placing of the receiver t upon the hook (if-station S will;

however, open the;circuit through relay R? again;and-

drawal of its plug irom its jack. In themeantimathe supervisory-lamp.Z. forstation S'wilLnot have lighted.

owing to .the fact that the sameact of-inserting the =pl ug P which completed :the circuitthrough-thelamp by. way 'oimonnections l7j-and 1 8, will'alsohavabroughtiaboutt rent from the line.

as with lamp 1., the replacing of the receiver t upon its hook will open the circuit through the relay R and per mit the armature 65 to drop back and open the shunt,

thus directing the current through the lamp Z causing the latter to light up and remain lighted until the line to station S is opened by the withdrawal of the plug P.

Thus it will be seen that the connections 11 and I4,

and the armature r constitute a short circuiting connection or arrangement by means of which the battery B and the relay B may be made part of either a local or the substation circuit. When a call is sent in from the substation the local or short circuit immediately closes and takes up the signaling current and excludes it from the line. station practically out of circuit with the battery, and consequently the insertion of the plug and the operation of the cutout relay R. does not cause an unpleasant sound in the receiver. As stated, the conductors l1 and 14 and the armature 1' constitute a short-circuiting connection, which is normally open, but which closes as soon as a call is sent in. This short-circuiting con-' nection is preferably of low resistance and when closed operates to effectually exclude the calling signal cur- In other words, this short-circuiting connection operates to automatically short-circuit the substation from whence the call came. This shortcircuited condition of the substation continues until after the local circuit has been broken or opened up for the purpose of extinguishing or restoring the calling signal. In this way, the breaking of the line circuit' in'answering a call does not produce any sound in'the receiver at the substation, inasmuch as no current is onthe line at the time this breaking of theline circuit occurs. Furthermore, the arrangement has the advantage of enabling the battery B to light lamp -l through a short local circuit of comparatively low" and unvarying resistance. This lamp, which is the calling signal, remains lighted ,until' the plug P is inserted in the jack J, regardless of whether the receiver at the substation is hung up or not.

Preferably, and in order to insure thebest results,

the jacks arenormally insulated frdm the lines. In other-words, each jack is normally disconnected-from the line to which it is allotted. The. cut-out relays,

however, serve to establish connection between the lines and the jacks, upon the insertion of the cord plugs. These cut-out relays, as stated, also serve to sever the connections between the battery and the lines. Preferably, one terminal of each cut-out relay is per-- manently connected with a source of current, and the other-terminal of such relay is preferably permanently connected with the sleeve'contact or thimble of the adjacent jack. The coil of each line relay is adapted and arranged to form part ofeither the line or the local line lamp circuit. It will be readily understood that the resistance of thevarious relays and resistance coils can be adjusted or regulated by those skilled in the art to give the desired results, and in accordance with the conditions of any particular case. Preferably, the battery for supplying the signaling currentrhas both poles normally connected with both sides of .the line. The jacks and ,the cord-circuit, as illustrated,-arepreferably This leaves the receiver of the sub-.

by those skilled in the art of telephony.

three-way in character, the jacks and plugshaving the usual tip, ring, and'sleeve contacts.

An important feature of my invention-is the energizing of the cut-off relays R over circuits including the cord strands. As shown, the third strand of the cord is used for this purpose. It will be understood, however, 7 that for this feature of my invention I do not limit my self .to any particularnumber of parallel strands. Furthermore, and as a feature of special improvement, the cord strand energizing circuit for the cut-off relay is combined with a supervision which is independent of the ground between the subscribers stations and the central station. -With this combination, as set forth, the signaling is all carried on over the line, and without using the ground at the substation.

The cut-off relays R not only serve when energized to connect the lines with the normally disconnected jacks or line terminals, but also to disconnect-the individual line signals from the lines.

The bells or ringers 55 are bridged across the lines, and thecondensers 56 stop the flow of battery current through said bells or fingers, but leave the latter responsive to ringing currents supplied from the bridged generator G, whereby the ground is not used for ringi It will also be seen that I combine acommon bat tery normally disconnected jack system with a supervision which is absolutely independent of the a ground at the substations.

The short circuit closed by any energized line relay R has the double function of quieting the line and locking or holding the line signal in operation until the operator answers. Each line relay has two energizing cir cuits, one a line circuit, and the other a local circuit, the latter displacing or supplanting the former when the subscriber calls. Both ,of these circuits are,- it will be seen, controlled by relay contacts. The line circuit for initially energizing the line relay includes both sides of the line in series, substantially as shown.

While I have elected to illustrate all of the features and combinations of my invention in connection with a full common battery telephone system, it will be seen that the said features and combinations are more or less applicable. to other systems, and for this reason I do not limit myself altogether to a common battery system. i I Qbviously,xthe foregoing and other features and advantages will be readily understood and appreciated If my invention or improvements are used change, where such is necessary, it is evident that any well known or suitable form of busy test can be employed.

With my improved circuit arrangement and'combinations, the two normally disconnected jack contacts 27 and 30 are both included in. the talking circuit, the

supervisory relay energizing circuit, the ringing circuit, and the batterycircuit. for the-transmitter T. In this way these two contacts which are normally discon nected from the line have a'plurality of important functions or functional relations to other elements.

With further reference to the quieting of the line, when the operator plugs in, 'it will be seen thatthe battery current is removed from .thewinding of the line relay before the short-circuit is removed'from across.

in an ex- 115 as previously explained, preventing clicks on noises in the receiver which the calling subscriber is holding to hisear atthe time that the operator answers the call.

What I claim as my invention is,

1;, In a telephone system, the combination of stationsand line connection between the-same, a calling; device at one of saidstati ns, a calling signal and,a battery at the other station, a normally open local circuit including said battery, said battery being normally cdnnected with the line, and a relay for closing said local circuit, the opera rion 01' said calling device causing the currentot-said battery to first flow over the line, the energization of. the relay then operating to transfer thecurrent to said local circuit, and a talking circuit including both sides of the calling circuit i 2. In a telephone system, the combination ot= asubstation and a central station, a line circuit connecting said substation and said central station, a calling device at said substation, a calling signal and a relay and a battery at the central station, anormally open local circuit including said battery andrelay, said battery being normally connected with the line, said local circuit when ciosedbythe relay operating to completely short-circuit the said substation, so as to permit the operator to answer a call without producing sounds in the receiver at said station, and-a talking circuit includingboth sidesoi. the calling circuit.

8. in a telephone system, the combination of a substation and a central station and suitable line connection between the same, a calling device at said substation, a

calling signal at the central station, a relay and a battery at said central station, a normally-open local circuit inciuding saidbattery andrelay, said relay and said calling signal being responsive to said callingdevice, and the local circuit when closed by the relay operating to hold or iock the calling signal in operation until the call is answered-by the-operator, and-a talkingclrcuit including both sides. of the calling circuit,

4. Ina telephone system, the combination or a sub station and a central station, suitable line connection between said stations, a hook-switch at the sub station for opening fllld' closing the line circuit, a spring-jack at the central station normally insulated from the line, a normally open short-circuit connection across thetwo limbs 01' the lineat the central statlon, a battery normally connected with one limb oi. the line, a line relay for operating a line signal and arranged to close-said normally open short-circuit connection, a normally open local circuit in-- ciudlng said relay and battery, and also including said short-circuit connection, a cord circuit having a plug adapted for insertion in said jack, said cord-circuit. being connected with a suitable source of current supply, and a cut-out relay adapted to be energized when the'plug is inserted in the jack, said cut out. relay whenenergized establishing connection between the jack and theline, and also operating to break the said local circuit and denergize' said line relay.

5. In av telephone system, a substation and a central-station and line connection between the same, -a calling signal and a battery for operating the same atthe central station, said battery and signal being normally connected with the line, the signal serving as a medium ofconnection between the battery and line, a calling device at the substation -1or operating said calling signal, theline being normally open at the substation and a normally open local circuit which closes when a call is sent in and which holds the calling signal in operation until restored\by the operator, and a talking circuit including both sides of the calling circuit.

6. In a telephone system, a substation and-1a central staf tion and normally open line connection between the same, a calling signal consisting oi. a lamp arranged to light when a call is sent in from thesubstation, a relay associated withsaid lamp :1 suitabiedevice at the substation-- tor causingthe operation otssid calling signal, abattery at the central station for supplying current to said lamp said battery being normally connected with the line through said relay and lamp, and a local circuit. which is closed when a call is sentin and which aflords a short circuit of comparatively low and. unvarying resistance through which the current from said battery purpose oi. lighting said lamp.

7; A telephone system comprising a substation, with the normally open line thereof a battery and relay at the centlfll-Stdiilflll, saidiinenormally connected with thebattery and relay at the central station, a local circuit normally.

open but closed-by said relay when a call is sent in from said substation, said local circuit when-closed operatingto exclude the currentot said battery from the substation, a calling signal dlsplayed=when saldlocaLcircuit is. closed, and a circuit. breaking device for opening said localclrcuit, a metallic talking clrcuitfand means for using both sides of said talking circuit in calling. Q i

8. A telephone system comprising a substation and a central station with line connection, a battery and a local circuit. at the central station, a relay for closing the current of said battery through said local circuit when a cal1 line through said relay, and the relay forming a part of both line and local circuits, a calling device at the substation for operating said relay, and a calling signal at the central station associated with said relay and operated by said battery, and a talking circuit including both sides of the calling circuit.

is sent in the battery being normally connected withthe 9. In a telephone system, a substation and a central station with complete metallic line connection between the same, a relay and calling signal and a battery for operating the same at the central station, a short-circulting connection between the line terminals at the central station;

said short-circuit connection being normally open, a calling device at the substation adapted to operate said relay and thereby close said short-circuit connection, the said caiiingsignai being also responsive to said calling device a local circuit including the battery and reiay and shortcircuit connection, the said short-circuiting connection operating to exclude the current of saidbattery from the substation line as soon as the relay is operated by a. call, and

a circuit-breaking device for opening said local circuit and thereby restorifig said signal.

10. In a telephone system, a substation and a; central station and a complete metallic line connection between the same, a calling device at the substation, a lamp and a relay and a battery for operating the same at'the central station, and a short-circuit connection between the substation line terminals at the central station, said shortclrcuiting connection being normally open but closed by said relay when a call is sent in, said relay and short-circuiting connection forming part of a local circuit of comparatlvely lowvand unvarying resistance through which the I current from said battery flows for the purpose of. lighting said lamp, and a circuit-breaking device for openingup said local circuit andresforing or extinguishing said lamp.

11. In a telephone system,-. a substation and a centralstation and complete metallic line connection between the same, a lamp signal anda relay and abattery for operating the same at the central station, a short-circuitconnection between the line terminals at the central station, said short-circuit connectionbeingnormally open, and a calling device at the substation for. operatingmiaid relay andthereby clo'singthe said short-circuit, a cut-out relay jor open ing up said short-circuit connection and extinguishing said lamp, a spring-jack and a plug and cord circuit with a battery for operating said cut-out relay.

12. In a telephone system, a substation anda. central station and a complete metallic line connection between the same, a spring jack and a plug and a cord circuitwith a clearing out signal, a complete metallic line circuit which is opened to operate said clearing-out signal, a. calling signal ands reiayand a battery for operating the same at the central station, a short-circuit connection between the terminalsof the line at the central station, said short-circuit connection being normally open a local circuit including the battery and relay and short-circuit connection, and a calling device at'the substation for operatingsaid reiayandthereby closing said shortficlrcuit connection normally open, a signal lamp and a relay and a battery foroperatiug the same located at the central station, a normally open local circuit including said battery and relay,

and also said normally open connection, a receiver-hook or switch at the substation for operating said relay and thereby closing the said normally open connection between the line terminals, sons to cause current from said battery to flow through said lamp, 0. spring jack and a plug and a cord-circuit with a clearing out signal, and suitable connections for supplying battery current to the line through the talking strands of said cord-circuit, the complete metallic line circuit being opened to eltectthe operation of said clearing-out signal.

il-i. In a" telephone system, the combination of a substation and a central station with a complete metallic line connection between the same, a short-circuit connection be tween the line terminals at the central station, a relay having its armature adapted and arranged to close said short-circuit connection when a'call is sent in from said substation, a battery which operates the relay when the calling device at the'substatlon is operated, the short-circuit connection when closed forming part of the local circuit for the current of said battery, a calling signal lamp located in said local circuit at a point outside of said short-circuit connection, the-latter when closed thereby hperating to exclude the current of the signal battery from the main line, acut-out relay for opening-up said.

short-circuit and thereby extinguishing said lamp, a spring jack having suitable connection with said cut-out relay, a plug and cord circuit with a battery, :1 clearing-out signal in said cord circuit, and a complete metallic-line circuit which is'opened to operate said clearing-out signal.

. 15. In a telephone system, the combination of asubscriber's line, a hook. switch for opening and closing the line circuit, abattery normally connected with the line, a line relay for operating 'the line signal, a normally open short-circuit connection across the line terminals at the central station, said short-circuit connection being closed by the energization of the line relay when a,call is sent in,

and a local circuit including said battery relay and'shortcircuit connection, the said relay being located in a' conductor formingpart oi both the line and local circuits.

16. In a telephone system,- a line circuit normally openat one station; a switch or like circuit-changer therefor at said station a source of current, a relay, and a signal receiving device all at another station, and a normally open associated local circuit atsald other station leading through the contact points of said relay and controlled thereby; the said source, relay, and signal device being in a section of conductor forming part of both line and local circuits. 17. The-combination in a centrul battery telephone ex change, of a-maln circuit normally open at a substation and extending therefrom to a central station and a circuit-changing switch therefor at said substation; with a normally open associated local circuit, a source oi! current, a relay responsive to the operation of said circuitchanger and a signal receiving devlceyall at said central station; the said source, the magnet of said relay, and the signal device being serially connected in the main circuit, and together with contactpoints of said relay in the associated local circuit also; and the said relay" constituting a switch to close said local circuit, and to divert the current of the source from said main circuit through the said local circuit for the operation of said signal device.

18. mn telephone system, thecombination of a, me-

tallic main circuit normally open at a. substation and ex tending therefrom to acentral station; a clrcuit-changing switch therefor at said substation; and an earth conncction normally attached to one main conductor of said metallic circuit at said central station with a source of current, agcutoff relay controlling the conection of said source with the. main circuit conductors; an independent relay responsive to the action of said circuit-changer; and a normally detached auxiliary earth connection for the other main conductor of said metallic circuit leading through and controlled by the contact points of said independent relay; the said source and the magnet of said independent relay being serially connected in the main circuit; and the said auxiliary earth connection being branched from its associated main conductor at a point external to the cutoif relay connection of said source;

whereby a short circuit for said source is constituted be tween the said two earth connections immediately pursuant to the operation of said substation circuit-changer to transmit a call signal, and the consequent operation of said independent relay.

19. In a central battery telephone exchange system, the combination with a main or subscribers circuit normally open at a substation and extending therefrom toa central station; a telephone receiver and a telephone suspension switch both at said substation, the latter being adapted on the removal of said receiver therefrom to close said circuit and thereby transmit a call signal to said central station; a battery supplying current to said main circuit; switchboard devices for answering call signals transmitted over saidmain circuit by the operation of said substation switch; and a cutod' relay responsive to the normal operation of said switchboard devices, and acting to sever the normal connection of said battery with said main circuit, all at said central station; of associate switching and signaling devices, also at said central station, comprising an independent relay responsive to the signaling operation of said suspension switch, and a signalu'eceiving device controlled thereby, bothnormaily connected in series in said main circuit together with said battery; and means actuated by said independent relay for short-circ'ulting the current of said battery through said relay and signal device when acall signal is transmitted from said substation, and before said cutoff relay is operated by said switchboard call answering devices to sever the connection of said battery with said main circuit.

20. In a central battery telephone exchange system, the combination with a main or subscribers circuit normally open at a substation and extending therefrom to a central station; a telephone receiver and a telephone suspension switch, both at said substation, the latter being adapted on the removal of said receiver therefrom to close said circuit and therebytransmit a call signal to said central station; a battery supplying current to said main circuit; switchboard devices'for answering call signals transmitted over said main circuit by the operation of said substation switch; and acutofi relay responsive to the normal operation .of said switchboard devices, and acting to sever the normal connection of said battery with said main circuit all at said central station; of associate switching and signaling devices, also at said central station, comprising an independent relay, and a signal receiving device controlled thereby both normally connected together with said battery in ,series in said main circuit; and a normally, open local circuit leading through the contact pointsof said relay, and also containing said battery, relay, and signa device; the said relay being responsive to call signals msmitted by said suspension switch, and adapted when operated to close the'said local circuit, and thereby divert the battery current from the main circuit thereto; whereby the saidsignal device may be operated by current flowing in said local circuit, and maintained in operation by said relay, and whefeby abrupt changes in the electrical condition of 'the main circuit when the battery is disconnected therefrom by the cutofli relay, and sounds produced by such changes in the substation receiver may be prevented.

21. In a telephone system the combination of subscribers lines, subscribers hook switches for opening and closing the line circuits, jack springs normally insulated from the line, a battery normally connected with the lines, line relays for operating line signals and adapted to be energizcd when the line circuits are closed by the said hook switches, normally open connections across the line terminals at the centrahstation, said normally open connections being closed when the said line relays are energized, an operator's cord-circuit provided with plugs adapted for insertion in said jacks. saidlcord-circuit being connected with a suitable source of current supply, local circuits including said battery and line relays and also including said norniallyopen connections, cut out relays connected and z 'i'aiiged to. be energized by the insertion of the said plugs in said jacks. said cut out relays when energized establishing connection between the jacks and the'lines, and also operating to break the said local circuits and deeuerg .c said line-relays.

2 A telephone system comprising a' subscriber's line consisting of two metallic limbs, suitable substation apparatus. suitable central station. apparatus, a normally open low resistance connectionv across the terminals of the two limbs at the central station. and a relay for closing said connection. said connection, when closed operating to short-circuit the'said substation apparatus.

'23. in a telephone system. the combination of a subscriber's line. means for closing the line, a three-way also including said line relay,

spring jack normally insulated from the line, a three-way cord circuit providedwlth a plug adapted for insertion in said jaclca central source of current supply connected with the line and the cord-circuit. a line relay for operat ing a calling-signal, a cutout relay for establishing connection between the jack and-the line, said cut-out relay being energized by the insertion of the plug in the jack, :1 local circuit including said source of current supply, and said local circuit being broken when the cut out relay is energized, and the local circuit for said cut out relay including said source of current supply and also including the sleeve'contacts of the jack and plug and the third strand of the cord-circuit.

Z-i. In a telephone system. the combination of a subscriber's line, a subscrihers hook-switch for opening and closing the line,.a spring-jack normally insulated from the line. an operator's cord circuit having a plug adapted for insertion in said jack. a line signal, adapted to be operated when the line circuit is closed. a source of current connected with the cord circuit, a cut-out relay for establishing connection between the line and the jack, said cutout relay being energized when the plug isinserted in the jack, one terminal of said cut-out relay being permanently connected with said source. of current supply, the local circuit of said cut-out relay including the sleeve contacts of.

the jack and the plug.

' In a telephone system, the combination of a subscrlbers line. a subscriber's hook switch for opening and closing the line circuit. a three-way spring jack normally insulated from the line, an operator's three-way cord-circult provided witha plug adapted for insertion in said jack. a battery bridged across the strands of the cordcircuit, a line signal adapted to be operated when a call is sent in and the line-circuit closed, a cut-out relay for restoring said line signal and adapted to establish connections between the jack and the line, said cut-out relay having one terminal connected with a sleeve or testing ring of said jack, and the other terminal of said cutout relaybeing permanently connected with said source of current supply.

26. In a telephone system, the combination of a subscribers line. a subscribers hook-switch for opening and closing the line circuit, a normally open connection across the line terminals at the central station, a source of cur rent supply normally connected with the line, a line relay adapted to be energized when a call is sent in, and arranged to close said normally open connection, a spring jack and an operator's cord'circuit provided with a plug adapted for insertion in said jack, a supervisory lamp associated with said cord-circuit, a normally open shunt around said lamp adapted to be closed while the plug" is inserted in the jack and the line-circuit is closed and a cut-out relay for restoring the line signal and adapted to be energized when the plug is inserted in said jack.

27..In a telephone system. the combination of a subscriherFsline, a subscriber's hook switch 'for opening and closing,tl1e-line. a spring-jack normally insulated both from vthe line and the ground, a source litcui'i-ent connected with theoperator's cord circuit. a'normally open short-circuit connection across the'linr terminals at the central station, a line relay adapted to respond to calls sent in from the 'sub-stationand arranged to close said I' normally open short-circuit connection. a line signal oper ated by said line relay. a. -ut-out relay for restoring said line signal and adapted to establish connection between the "jack and the line. the said cut-out relay being ener gized by theinsertion of the plug in the jack, a supervisory lamp associated withthe shunt around said lamp. said shunt being closed while the plug is in the jack andthe line circuit closed, but said shunt opening and causing said lamp to glow when the line circuit is broken.

28. In a telephone system, the combination of sub-stations and a central station, complete metallic line connections between said stations, subscribers hook switches at the sub-stations for. opening and closing the lines, springjacks at the central station normally insulated from the lines. normally open short-circuit .connections across the line terminals at the central station, a source of current normally connected with the lines, line relays adapted to be energized by the closing of the line circuits and to close said normally open short circuit connections, line lamp signals in series with said line relays, an operators cord circuit provided with plugs adapted for insertion in said jacks, a source of current bridged across the said cordcircuit. supervisory lamps associated. with said cord-circuit, normally open shunts around said supervisory lamps, said shunts being closed while the plugs are in the jacks and the line circuits closed, but said shunts being'opened controlling said shunts, and cutout relays for restoring the line signals and establishing connection between the be energized by the insertion of the plugs in the jacks, each cut-out relay having oneterminal permanently connected with the source of current connected with the cord circuit, and the other terminal of each cut-out relay being cent spring-jack.

relay,. means for supplying current through the line' circuit for initially energizing said relay, a normally open local circuit associated with said line signal, the coil and thenormally separated contacts of said relay being included in said'local circuit, the 'relay coil being also included in the line circuit, and means'for calling over both station and complete metallic line connection between the same.' a lamp signal ,and a relay and a'battery for operating the some at thecentral station, a short-circuit connectioubetwcen the line terminals at the central station, said short-circuit connection being normally open, and a calling device at the substation for operating said relay and thereby closing. the said.short-circuit, a cutting-out said battery, a spring jack and a plug and cord :1 battery for operating said cut-out relay.

32. The combination with a telephone line and a connection terminal therefor normally not in operative relation with said line. of a connecting plug and cord'circuit adapted to cooperate with said line, a supervisory signal controlling magnet and a battery associated with said cord circuit, a switch at the subscriber's station, and means controlled by the insertion of the plug 'into the jack for placing said jack in operative relation with the line \vhei ebysa'id signal controlling magnet is placed under the control of the subscriber.

circuit with 33. The combination with a.telephone line and a con nection terminal in the form of a spring jack normally not in. operative relation with said line, of a cord circuit and connecting plug. supervisory signaling apparatus associated with said circuit, a central source of current associated with said line and circuit to operate said supercord-circuit, and a normally open" when the line circuits are broken, supervisory relays for,

jacks and the lines, said cut-out relays being adapted to 1 connected with the sleeve. contact or thimble of the adja- 29. In a telephone system, the combination of a 'sub .scribers line, a line relay, a, line signal operated by said 31. in a telephone system, a substation ands central relay for opening up said short-circuit and cutting out .metallic circuit for talking purposes, means for operating said relay from said source when connection is made with the line by current flowing over a path including a portion of the cord circuit, and means for sending a calling-current over the line of the,called subscriber only and at the same time maintaining said relay in operated condition.

35. The combination with a telephone'line and a con.

nection terminal therefor normally not in operative relation with the line, of a connecting plugand cord-circuit to coiiperate with said line, a supervisory signal controlling magnet and battery associated with said cord-circuit, a telephone transmitter and a switch at the subscribers station, and means controlled by the insertion of the plug into the jack for placing the jack in operative-relation with the line by current flowing over a path includinga portion oi? v the cord-circuit, whereby talking'current is furnished to said transmitter and said magnet is placed under the control of the subscriber.

36. The combination with a telephone line, and a connection terminal therefor normally not in operative relation with said line, of a connecting plug and cord circuit adapted to codperate with said line, a supervisory signal controlling magnet and a battery associated with said cord circuit, a switch at the subscriber's station, and means including a contact connected with the cord circuit controlled by the'insertlon of the plug into the jack for placing said jack -in operative relation with the line,-

whereby said signal controlling magnet is placed under the control of the subscriber.

37. The combination with a telephone line and a connection terminal in the form of a spring jack normally not in operative relation with the line, of a cord circuit and a connecting plug, a central source .of current associated with said line and circuit to furnish talking current to the substations, and means including said source -01 current actuated by the insertion of said plug in the jack and by current flowing over a part of the cord circuit' for placing said jack in operative relation with said line.

38, The combination wlth a telephone line and a connectlon terminal in the form of a spring jack normally not in operative relation with said line, of a cord circuit and connecting plug, supervisory signaling apparatus associated with said circuit, a central source of current associated with said line and circuit to operate" said .supervisory apparatus, and a relay adapted'to be energized from said source over a path including a portion of the cord circuit to place said jack in operative relation with the line when said plug is inserted in said jack.

39. The combination with a telephone line, and a connection terminal in the form of a spring jack, of a connecting plug and a cord circuit, a central source of current associated with said line and circuit to furnish current for talking purposes, supervisory signal apparatus associated with the cord circuit and operated from said .source of current, and a relay actuated from said source'by the insertion of said plug into and its withdrawal from said jack for controlling the operative relation of said jack with said line, said relay being actuated by current flowing over a portion 01' a strand of the cord circuit, a contact of the plug andjack.

40. In a telephone system, a metallic circuit line, a con a cord circuit, a signaling device normally in operative relation with said line, a central source Jot current and supervisory signaling apparatus associated with-said line and cord circuit, said source being adapted to furnish current for the operation or said apparatus and for talking purposes, and l relay actuated from Ilid source over a'portion ot-the cord circuifwhon' Illd plug in insertedin said jack to place llld signaling device in inoperative relation with said line and said jack in operative relation with said 'line. l

41. The combination with a telephone line having a limb extending to the central station,of a linecontact for said limb normally disconnected therefrom, a c0rd,circuit and connecting plug. supervisory signaling apparatus c0nnected with said circuit, a central source of current associated with said line and circuit to furnish current for talking purposes, and for the operation of said supervisory apparatus, and means actuated over a portion of the cord ,current for talkingpurposes and for the operation of said apparatus, and a relay energized from said battery and connected directly-t0 the cord circuit and adapted to disconnect said limb from said signaling device and to connect the same with the line contact when ,a connection is established with the line. Y

43.- The combination witlra telephone line having a limb extending to the central station, ofa spring or moving part with which said limb connects at the central oiiice, a signaling device connected with said spring or part in its normal position, a line contact for said limb, a cord circuit and connecting plug, ,a central battery associated with the said line circuit, supervisory signals also asso' ciated with the circuit, said battery being adapted to furnish current to the substations for talking purposes and for operating said supervisory signals, and a relay'also energized from said battery over a circuit including a portion of the cord circuit and adapted to disconnect said spring or part from the signaling device and to connect it with the line contact when a connection is established with the line.

44. In a telephone system, the combination of a'subsc'ribrs line, a jack having linecontacts bothfot which are normally disconnected from therline, a cord circuit and plug, a relay'for connecting the jack with the line, and a battery for energizing said relayover a path including'the sleeve of said plug and a strand or said cord circuit.

45. The combination of a. subscribers line, a jack having line-contacts both of which are normally disconnected from the line, a relay for establishing connection between the jack and the line, 1a cord circuit and plug, and a battery for energizing said relay over a path including the sleev contacts of said jack and plug. 7

-16. The combination of a subscriber's line, a jack normally disconnected from the line, a relay for establishing connection between the line and said jack, a cord circuit and plug, a supervisory relay and a supervisory lamp associated with said cord circuit, and a battery for energizing both of said relays and lighting said lamp, the said first mentioned relay being energized over a path including said lamp.

47. A telephone system comprising a subscribers line, both sides of which are normally disconnected from the spring jack, an electro magnet for an opening and closing connection between the line and spring jack, and a central source of current and an operators cord strand included in the energizing circuit 0! said magnet.

48. The combination with a telephone line and a connection terminal therefor normally not in operative relation with said line, of a connecting plug and cord circuit adapted to cooperate with said line, a supervisory signal controlling magnet and a battery associated with said cord circuit, a switch at the subscriber's station, and means controlled by the insertlon of the plug into the jack for placing said jack in operative relation with the line, whereby said signal controlling magnet is placed under the control or the subscriber, together with a supervisory or disconnecting circuit including both sides of said line in series, and a substation switchfor opening said supervisory circuit to give a signal.

49. The combination with a telephone line and a connection'terminal in the form of a spring jack normally not in operative relation with said line, of a cord circuit andconnectingplug, supervisory signaling apparatus associated with said circuit, a central sourcev of current associated with said line and circuit to operate said supervisory apparatus, and a reiay'adapted to be energized from said source to place said jack in operative relation with the line when said plug is inserted into said jack, together with a supervisory or disconnecting circuit including both sides of said line in series, and a substation switch for opening said supervisory circuit to give asignal.

50. In a telephone system, a subscribers line, a line relay, a central source of electric current, a normally open line circuit for energizing said relay, and a normally open local circuit controlled by the said relay and including an energizing coil thereof, whereby the said local circuit is substituted for the said line circuit when the relay is energized, each circuit including said source of current, and the said apparatus thus provided including relay contacts controlling said line circuit, 'and an armature i'or operating said contacts.

51. In a telephone system, the combination of stations and line connection between the same, a calling device at one of said stations, a callng signal and a battery at the other station, a normally open local circuit including said battery, said battery being normally connected with the line, and a relay "for closing-said local circuit, the operation of said calling device causing the current oi. said bat tery to first flow over the line, and the energization of the relay then operating to transfer the current to said local circuit, a normally disconnected jack, a relay individual to the line and adapted when energized to connect the jack therewith, an operator's connecting cord, and a local energizing circuit for said individual relay, said cord.

'52 In a telephone system, the combination of a substation and a central station, a line-circuit connecting said sub'station and said central station,-a calling device at said substation, a calling signal and a relay and a bator lock the calling signal in tery at the central station, a normally open local circuit including said battery and relay, said battery being nor- "m'ally connected with 'the line, said local'circuit when closed by the relay operating to completely short-circuit the said substation, so as to permit the operator to answer a call without' producing sounds in the receiver at said station, a normally disconnected jack, a relay individual to the line and adapted when energized to connect the jack therewith, an operator's connecting cord, and a local energizing circuit, for said individual relay, said energizing circuit including a strand of said connecting cord. 53. In a telephone system, the combination of a substation and a central station and suitable line connection between the same, a calling device at said substation, a

calling signal at the central station, a relay, and a battery at said central station, a normally ,open local circuit ineluding said'battery and relay, said relay and said calling signal being responsive to said calling device, and the local circuit when closed by the relay operating to hold operation until the call is answered by the operator, a normally disconnected jack, a relay individual to the line and adapted when energized to connect the jacktherewith, an operator's connecting cord, and a local energizing circuit for said individus relay, said energizing circuit including a strand of said connecting cord.

54. In :1 telephone system, a substation and a central station and line connection between the same, a calling signal and a battery for operating the same at the central station, said'b'at'tcry and signal being normally connected with the line, the signal serving as medium of connection between the battery and line, a calling device at the substation for operating said calling signal, the line being normally open at the substation, and 8. normally open local circuit which closes when a call is sent in and which holds the calling signal in operation until restored by the operator, a normally disconnected jack, arelay individual to the line and adapted when energized to connect the jack therewith, an operator's connecting cord, and a local energizing circuit for said individual relay, said energizing circuit including a strand of'said connecting cord.

55, In a telephone system, a substation and a central station and normally open line connection between the same, a calling signal consisting ofa lamp arranged to light when a call is sent in from the substation, a relay associated with said lamp, station for causing the operation of said calling signal, a battery at the central station for supplying current to said lamp, said battery being normally connected with the line throughsaid relay and lamp, and a local circuit a suitable device at the subwhich is closed when a call is sent in and which attords a shortcircuit of'comparatively low and unvarying resistance through which the current from said battery flows for the purpose oflighting said lamp a normally disconnected jack, a relay individual to the line and adapted when energized to connect the jack therewith, an operators connecting cord, and a local energizing circuit for said individual relay, said energizing circuit including a strand of said connecting cord.

56. In a telephone system, ,a substation and a central station and a complete metallic line connection between the same, a spring jack and a plug and a cord circuit with I a clearing-out signal, a complete metallic line circuit which is opened to operate said clearing-out signal, a calling sig' nal and a relay and a battery for operating the same at the central station, a short-circuit connection between the terminals 01 the line at the central station, said shortcircuit connection being normally open, a local circuit including the battery and relay and shorbcircuit connection, and a calling device at the substation for operating said relay and thereby closing said short-circuit connection to exclude the signal current from the main line after a. call is sent in, a normally disconnected jack, a relay individual to the line and adapted when energized to connect the jack therewith, an operators connecting cord, and a local energizing circuit for said individual relay, said energizing circuit including a strand of said connecting cord.

57. In a telephone'system, a line circuit normally open at one station; a switch or like circuit-changer therefor at'said station; a source of current, a relay, and a signal receiving device all at'another station; and a normally open associated local circuit at said other station leading through the contact points of said relay and controlled thereby; the said source, relay, and signal device being in a section of conductor lforming part of both line and local circuits; a normally disconnected jack'; a relay individual to the line and adapted when energized to connect the jack therewith; an operator's connecting cord, and a local energizing circuit for said individual, relay, said energizing circuit including a strand of said connecting cord.

'58. -A telephone system comprising a substation and a central station with line connection, a battery and a local circuit at the central station, a relay for closing the current of said battery through said local circuit when a call is sent in, the battery being'normally connected with the line through said relay, and the relay forming a part of both line and local circuits, a calling device at the substation for operating said relay, and a calling signal at the central station associated with said relay and operated by said battery, a normally disconnected jack, a relay individual to the line and adapted when energized to connect the jack therewith, an operator's cord, and a local energizing circuit for said individual relay, said energizing circuit including a strand of said connecting cord 59; In a telephone system, the combination of a subscriber's line, a hook switch for opening and closing the line circuit. a battery normally connected with the line, a

line relay for operating the line signal, a normally open short-circuit connection across the line terminals at the energizing circuit for said individual relay, said energizing circuit including a strand of said connecting cord.

60. In atelephone system, the combination of a sub scriber's line, a line relay, a line signal operated by said and a local energizing circuit for said individual relay,

said energizing circuit including a strand of said connecting cord.

61. In a telephone system, the combination of a subscribers line circuit, a local circuit at the central exchange,

means for supplying. current through said circuits,-a line relay responsive to calls and adapted for closing said local circuit, the coil of said relay being connected and arranged to'form part of both line and local circuits, and

a line lamp located in said local circuit, a normally disconnected jack, arelay individual to the line and adapted when energized to" connect the jack therewith, an operators connecting cord, and a local energizing circuit for said individual relay, saidenergizing circuit including a strand of said connecting cord.

62. A telephone system comprising a subscribers line consisting or two metallic limbs, suitable substation apparatus, suitable central station apparatus; a normally open low resistance connection across the terminals of the two limbs at the central station, and a relay for closing said connection, said connection when closed operating toshort-circult the said substation apparatus, a normally disconnected jack, a relay individual to the I line and adapted when energized to connect the jack therewith, an operators connecting cord, and a local energizing circuit for said individual relay, said energizing circuit including a strand of said connecting cord.

I 63. In a telephone system, the combination of stations and line connection between the same, a calling device at one of said stations, a calling signal'and a battery at the other station, a'normally open local circuit including said battery, said battery being normally connected with the line, and-a relay for closing said local circuit, the opera tion of said calling device causing the current of 'said battery to first flow over the line, and the energization of the relay then operating to transfer the current to said local circuit, a supervisory'relay,and a complete metallic line circuit for energizing said supervisory relay.

64.- In a telephone system, the combination of a substation and a central station, a line circuit connecting said substation and said central station, a calling device at said substation, a calling signal and a relay and a battery at the central station, a normally open local circuit including said battery and relay, said battery being normally connected with the line, said local circuit when closed by the relay operating to completely short-circuit the said substation, so as to remove liattcrycurreut therefrom and permit the operator to answer a call without producing sounds in the'recei'ver at said station, a supervisory relay, :1 complete metallic line circuit for energizing said supervisory relay, and a talking circuit inclnding'said calling device.

(lfi'fln a telephone system, the combination of a substation and'a central station and suitable line connection between the same, a calling device at said substation, a. 'talking circuit including said calling device a calling signal at the central station, a relay'and a battery at 'said centralstation, a normally open'local circuit including said battery and relay, said relay and said calling signal being responsive to said calling device, and the local circuit whenclosed by the relay operating to hold or lock the calling signal in operation until the call is answered by.

the operator-,m supervisory relay and a complete metallic line'circuit for energizing said supervisory relay, from said battery. I 7

.66. In a telephone system, a substation and a central station and line connection between the same, a calling signal and a battery for operating the same at the central station, said battery and signal being normally connected with the line, the slgnal'serving asmedium'ot connection between the battery and'line, a'calling device at the sub- 'stationfor operating said calling'signah, thelinebeing' normally open at the substation, and. if normally open local circuit which closes when a call is sent mind which holds thecalling signal in operation until restored by the operator, a supervisory relay, and a complete metallic line circuit for energizing said supervisory relay.

67. In a telephone system, a substation and a central station and normally open line connection between'thesame, a calling signal consisting of a lamp arranged to" light when.a-call is sent in from the substation, a relay associated withv said lamp, :1 suitable device at the sub; station for causing the operation of said calling signal,

a battery at the central station tor supplying current to said lamp, said battery being normally connected with the line 'throughsaid relay and lamp,-and a local clrcuit'wlilch is closed when a call is sent in and which aflords a short circuit oi. comparatively low andunvarylng resistance through which the current from said battery flows for the purpose of lighting said lamp, asupervisory relay;.aud a complete metallic line circuit for energizing said superv visory relay.

68. In a telephone'system, a substation and a central station and a complete metallic line connection between the same, a spring jack and a plug and a cord circuit with .operating said relay and thereby closing. said short-circuit connection so as to exclude the signal current from the mainline after a call is sent in, a supervisory relay, and a complete metallic line circuit for energizing said supervisory relay. I 69. In a telephone system, a line circuit normally open at onestation; a switch or like circuit-changer therefor at said station; a source of current, a relay,'and a signal receiving device all at another station; and a normally open associated local circuit at said. other station leading through the contact points. or said relay and controlled thereby; the said source, relay, and signal device being. in a-section of conductor forming part ofbothline and local circuits;v a supervisory .relay, and a complete metallic line circuit for energizing said supervisory relay.

70. A telephone systemgcomprlsing a substation and a central station with line connection, a battery and a local circuit at the'central-station, a relay for closing the cur rent of said battery through said local circuit when a call is sent in, the battery being normally connected with the line through a winding of said relay, and the relay winding'and battery forming a part of both line and local circuits, a calling device at the -substation for operating said relay, and calling signal at the central station associated with said relay and operated by said battery, 21

energizing said supervisory relay.

71. In a -telephone system, the combination of a subscriber's line, a hook switch for opening and closing the line circuit, a battery normally connected with theline, a line relay for operating the line signal, a normally open short-circuit connection across the line terminals at the supervisory relay, and-a complete metallic line'circ'uit for .centraLstatiOn, 'sdid short-circuit connection being. closed by the energization of the line relay when a call is sent in, and a local. circuit including said battery relay and short-circuit connection, the saidrelay being located in a 'conductor forming part of both the line and local circuits, a supervisory relay, an'da complete metallic line circuit for energizing said supervisory relay.

72.- In a telephone .system, the'combination of a subscribers line, a line relay, a line signal operated by said relay, means. forsupplying current through the line circuit for energizing said relay, and a normally open local circuit associated with "said line signallpth'e coil and \the znor mally separated contacts of said relay belng included in said local circuit, and the relay coil being also included in the line circuit. a supervisory relay, and a complete metallic line circuit for energizing said supervisory relay. '73. In a telephone system, the combination of a sub scribers line circuit, a local circuit at the central exchange, means for supplying current through said circuits, a line relay responsive to calls and adapted for closing said local circuit, the coil of said relay being connected and arranged to form part of both line and local circuits,

and a line lamp located in said local circuit, a super- 75. In a telephone system,' the combination of stations and line connection between the same, a calling device at one of said stations, a calling signal and a battery at the other station, a normally open local circuit including said battery, said battery being normally connected with both sides of the line, and a relay for closing said local circuit,

the operation of said calling device causing the current of said battery to first flow ovcr'both sides of the line, and

the energizing of the relay then operating to transfer the current'to said local circuit, an operators connecting cord.

and a supervisory signal under the control of the sul)-- scriher when the cord is connected with the line.

76. Ina telephone system, the combination of a substation and a central station, a lineconnecting said substa tion and said central station, a calling device at said substation, a calling signal and a relay and a battery at the central station, a normally open local circuit including said battery and relay, a line circuit closed while the subscriber is waiting for the operator to answer, and including the battery in series with the receiver at the substation, said battery being normally connected with the line, said local circuit -when-closed by the relay operating to completely shunt or short-circuitthe saidsubstation, to remove bat tei-ycurrent therefrom and permit the operator to answer without producing sounds in the receiver at said' station, an operator's connecting cord, and a supervisory signal under the control of the siibscriber when the cord is com nected with the line,

17. In a telephonc system, the combination of a substation and acentral station and suitable line connection between the same, a calling device at said substation, a calling signal at the central station, a relay and a battery at said central station, a normally open local circuit including said battery and relay, said relay and said calling signal being responsive to said calling device, and the local circuit when closed by the relay operating to hold or lock the calling signal in operation until the call is answered by the operator, anoperator-s connecting cord, a talking circuit including both sides of the calling circuit, and a supervisorysignal under the control of the subscriber when the cord is connected with the line.

78. In a telephonesystem, a substation and a central station and line connection between the same, a calling sig nal and a battery for operating the same at the central station, said battery being normally connected with both sides of the line, the signal serving as medium of connection between the battery and one side of line, a calling'de- .vice at the substation for operating said calling signal} the line being normally open at the calling device of the substation, and a normally 'open local circuit which closes in parallel with the line when a call is sent in and which holds the calling signal in operation until restored by the operator, an operator's connecting cord, and a supervisory signal under the control of the subscriber whenthe cord is connected with the line.

79. In a telephone system, a substation and a central station and normally open line connection between the same, a calling signal consisting ofalamp arranged to light when a caliis sent in from the substation, 'arelay associated with said lamp. a suitable device at the substation for causing the operation of said culling signal. a battery at the central station for supplying currcut in said lamp, said battery being normally connected with the line through said relay and lamp, and a local circuit which is closed when a call is sent in and which altordsa short circliit of comparatively low and unvc t: resistance through which the current from said battei y ilows for the purpose of lighting said lamp. an opcratous connecting cord, and a supervisory signal under the control of the subscriber when the cord is connected with the line.

station and a complete metallic line conncc'tion lie'twccn the same, a spring jack and a plug and a cord circuit with a clearing-out signal, a complete metallic line circuit which is opened to operate said clearing-out signal, a callsame at the central station. a short-circuit connection between the terminals 01' the line at the central station, said short-circuit connection being normally open, a local cir- 'cuit including the battery and relay and short-circuit'connection, and a calling device ut the substation for operating said main line after a'call is sent in, an operator's connecting cord, and a supervisory relay under the control of the subscriber when the cord is connected with the line.

81. In a telephone system, a line circuit normally open at one station; a switcli or like circuit-changer,therefor at said station; a source of current, a relajv,,:\nd a signal receiving device all'at another stationyand anormally :through the contact points of said relay and controlled thereby; the said source, relay, and signal devicebcing in a section ofconductor forming part 01' botlrline and local circ nitspan operator-s connecting cord and a supcrvisory signal under the controlofihe, subscriber when the cord is connected with the line. V

82. A telephone system comprising a substation and a central'station with line connection, a batter and alocal under-the control of the subscriber when the cord is connected with the line.

circuit'conncctiou, the said relay being located in a con ductor forming part of both-the line and local circuits, an operator's connecting cord, and a supervisory signal under the control of the subscriber when thc cord is connected with the line. 7

84/111 a telephone system, the combination of a subscribcrs linc, a transmitter a line rclay, a li'nc signal operutcd by said relay, means for supplying current through the transmitter and line circuit for initially encrgizing said relay. and a normally open local circuit associai'ed with suidlinc signal, the coil and the normally separated contacts ot' s:iid rclay being includcd in'said local circuit. and the relay coil being alsolncludedin the line circuit in series with said transmitter, an operator's connecting cord, and a supervisory signal only under the control of the subscriber when the cord is connected with the line.

85. in a telephone system, thecombination of a subscribcr's liuc circuit a local circuit -at.thecentral exchange, menus for supplying current through said circuits,

80. In a telephone system, a substation and a central,

ing signal and 'a relay and a battery for-operating theopen associated local circuit at said other station leading and a supervisory signal 83, In a telephone system, the combination of a sub the line terminals at the and a local circuit including said battery relay and shortrelay and thereby closing said short-circuit connection so as to excludethe signal current from thecircuit at the central station, a relay for closing the cura. line relay responsive to calls and adapted tor closing said local circuit, the coil said relay being connected -andarranged to form party of both line'an'd local circuits,

and a line lamp located in said local circuit, an operators connecting cord, and a supervisory signal under the conlow resistance connection across the terminals of the two limbs at the central station, and a relay for closing said connection, said connection when closed operating to short-circuit the said substation apparatus, an operator's connectingcord, and a supervisory signal under the com froi of the subscriber when the cord is connected with the line. v v

87. ln a telephone system, the combination of stations and line connection between the same, a calling device at. one or said stations, a calling signal and a battery at the other station, a normally open local circuit including said battery, said battery being normally connected with the line, and a relay, for closing said local circuit, the operation of said, calling device causing the current of said bat- .tery to'llrst flow over theline, and the energizationof the relay then'operating to transfer the current to said local circuit. a subscriber's calling circuit for getting the atten tion of the operator, said circuit including a winding of said relay and both sides of the line in series.

' SS. in a telephone system, the combination of av substation and'a central station, a line'clrcuit connecting said substation and said central station, a calling device at said substation, a calling signal and a relay and a battery at the central station, a normally open bridge of practically no resistance across the line at the central station, :1 normally open local circuit including said battery and relay .and bridge, said battery being'normaily connected with the line; said'local circuit when closed by the relay operating to. completely short-circuit the said substation, so as t0 take battery curren't away from the substation and permit .the operator to answer a call without producing sounds in the receiverat said station, a subscriber's calling circuit for getting theattentlon of the operator, said circuit including both sides of the line in series. 1

so. in a telephone system, the combination of a substation and a central station-and suitable line connection between the same, a' calling device at said substation, a call-- ing'signal at the central station, a relay anda battery at said central station, a normally open local circuit including saidbattery and relay, said relay and said calling signal being responsive-to said calling. device, and the local circuit when closed by the relay operating to hold or look the calling signal in operntlonuntil the call is answered by the'operator, a subscriber's calling circuit for getting the attention of the operator, said circuit including a wind- .when the operator answers,

90. in a telephone system, a substation and. a central station and line' connection between the same, a calling signal and a battery for operating the me nt the central station. said battery and signal being normally connected with the line, the signal serving as medium of connection between the battery and line, a calling device at the sulr station for operating said c'alling signal, the line being normally open at. the substation, and a normally open local circuit which closes when a call is sent in and which holds the calling signal in operation until restored by the operator, a. subscribers calling circu'lt i'or getting the attention of the operator, said circuit including both sides of the line in series.

91. In a telephone system. a substation and a central station and normally 'open' line connection between the same. a calling signal. consisting of a lamp arranged to light when rt call is sent in from the substation, a relay associated with said lamp, .1 suitable device at the substa- .tion i'or causing theoperation of said calling signal, a

battery at the central station for supplying current to said lamp, said'battery being norr allyconnected with the line through-said relay and lamp, and a local circuit which is closed when a call is sentln and which affords a short circuit of comparatively low and nnvarying' resistance through which the current from said battery flo'ws for the purpose of lighting said lamp, a subscriber's calling circuit for getting the attention of the operator, said circuit in-' cluding both sides of the line in series.

92. In a telephone system, a substation and a. central "station and a complete metallic line connection between the same, a spring jack and a plug and a cord circuit with a clearing-out signal, a complete metallic line circuit which is opened to operate said clearing-out signal, a calling signal and a relay and a batteryfor operating the same at the central station. a short-circuit connection be tween the terminals of the line at the central station, said short-circuit connection being normally open, a-localcircuit including the battery and relay and short-circuit connection, and a calling device at the substation for operat- -ing said relay and thereby closing said short-circuit connection so as to exclude the signal current from the main.

line after a call is sent in, a subscriber-s callingcircuit for getting the attention of the operator, said circuit including' both sides of the line in series.

93. In a telephone system, a line circuit normally open at one station; a switch or like circuit-changer therefor at said station; a source of currentfa'. relay, and a signal receiving device all at another station; and a normally open associated local circuit at said other station leading through the contact points of said relay and controlled thereby; the said source, relay, and signal device being in circuits; a suhscribers calling circuit for getting the attention of the operator, said circuit including both sides or the line in series. 7 I

94. A telephone system comprising a substation and a central station with line connection, a battery and a local circuit at the central station, a relay for closing the current. of said battery through said local circuit when a call is sent in, the batterybeing normally connected with one sideof theline through a winding ot'said relay, and the relay winding'forming a part of both line and local cir cuits, a calling device at the substation for operating said relay, a visual calling signal at the central station assoelated-with said'relay and operate'd by said battery,.and a subscribers calling circuit for getting the attention of the operator, said circuit includingfboth sides of the line in series.

95. In a telephone system, the combination of a sub--' scrlbers line, a'hook switch for opening and closing the line circuit, a battery normally connected with the line, a

line relay for operating the line signal, a normally open short-circuit connection across the line terminals at the central station, said short-circuit connection being closed bythe energlzation of the line relay when a call is sent in, and a local circuit including said battery relay. and shortcircuit connection, the said relay being located Ju a conductor forming part of'both the line and local circuits, a

subscribers calling circuit for getting the attention of the operator, said circuit including both sides of the line in series.

96. In a telephone system, the combination at a sub scribers line, a line relay, a line signal operated by said relay, means for supplying current through the line cira section of conductor forming part of-both line and local 4 cuit for energizing said relay, and a; normally open-local :1 line relay responsive to calls and adapted for closing said localclrcuit, the coil of said relay eing connected and arranged to form part of both line an local circuits, and a line lamp located in said local circuit, a subscrlbers calling circuit for getting the attention ofithe operator. saidclrcuit including both sides of the line insei-les.

98. A telephone system comprising a subscriber's line .with said line and cord to furnish current for consisting of two metallic limbs, suitable substation apparatus, suitable central station apparatus, a normally open low resistance connection across the terminals of the 100. The combinationwith a telephone line and a con nection terminal therefor normally not in operative rela tion with said line, of a connecting plug and cord circuit adapted to cooperate with said line,, a supervisory signal controlling magnet and a battery associated with said -cord circuit, a switch at the subscriber's station, and

means controlled by the insertion of the plug into thejack for placing said jack in operative relationwith the line, whereby said signal controlling magnet is placed under the control'of the subscriber, a normally open low resistance connectlonbridged across the line at the central station, and means for closing said connection to short-circuit or shunt the-line when the subscriber calls, 1

'101. The combination with a telephone line, and a connection' terminal in the form of a spring jack normally not connecting plug, with said-line'and circuit to furnish talking current to rentactuated by placing said jack normally open low resistance connection line at the central station, nection to short-circuit or scriber calls. I v

102. The combination with a telephone line and a connection terminal in theform of a spring jack.normally bridged across the and 'meansfo r closing said con shunt the line when the sub not in operative relation with said line, of a cord circuitsupervisory signaling apparatus as and connecting plug, sociated with said circuit, a central source of current associated with said line and circuit to operate said supervisory apparatus, and a relay adapted to be energized from in operative relation with the line when said plug is mserted into said jack, a normally open low resistance connection bridged across the line at the central station, and means for closing said connection to short-circuit or shunt the line when the subscriber calls.

103. The combination with a, telephone line and a con nection terminal in the form of a spring jackfof a connect-- ing plug and a cord circuit, a central source of current for controlling the operative relation of said jack with said line, a normally open low resistance connection bridged across the line at the central station, and means for closing said connection to short-circuit or shunt the line when the subscriber calls.

104. In atelephone nection terminal in the form of a spring jack normally not in operative relation with said line, a central source of current and supervisory signaling apparatus associated circuit, said source being adapted the operation of said apparatus and for talking purposes, and a relay actuated from'said source plug and cord circuit towhen said plug is inserted in said jack to place said signaling device in inoperative relation with said line and said jack in operative relation with said line, a normally open .low resistance connection bridged across the line at the central station, and means for closing said connection to short-circuit or sham the line when the subscriber-calls.

105. The combination with a telephone line having a limb extending to the central station, of a line contact for said limb normallydisconnected therefrom, a cord circuit and connecting plug, supervisory signaling apparatus connected with said circuit, a central source of current associated with said line and circuit to furnish current for and circuit to furnish current for system, a metallic circuit line, a con-.

ing or shuntingthe line talking purposes and for the operation of said supervisory apparatus and means for automatically connecting said line contact with said limb when the lineisin use and for disconnecting the same therefrom when'theline is not in use, a normally open low resistance connection bridged across'the line at the central station, and means for clos- 'ing said connection to sllort-circuit or shunt the line when the subscriber calls.

106. The combination with a telephone line having a limb extending to the central station, oi. asignaling device line, normally disconnected therefrom, connecting plug, supervisory signalinga apparatus associated with said cord circuit, current for talking purposes and for the operation of said a central battery to furnish,

connection bridged across the line at the central station,

and means for'closing said shunt the line when the subscribercalls. H

107. The combination with a telephone line having a limb extending to the central station, of a spring or moving part with which said limiconnects at the central otiice,

line contact for said limb, a cord cuit and connecting plug, a central batteryassociated with the said line circuit, supervisory signals also associated with the circuit, said battery being adapted to furnish current to the substations for talking purposes and for operating said supervisory signals, and a relay also cnergized to disconnect said spying or part and to co'nnectit with thefline from said battery'adapted from the signaling device contact when a connection is established with the lineQla' connection to short-circuit or cir- I normally open low resistance eonhection bridgedacross the line at the central station, and means for closing said con: nection to short-circuit or shunt the line when thesubscriber calls.

108. The combination with a'telephone line and a connoction terminal thcrefor normally not in operative rela-- tion witlrthe line, of a connecting plug and cord circuit to x cooperate with said line, a supervisory signatcontrolling under the control of the subscriber, a local circuit for short-circuitiug or shunting means controlled by the insertion of theplug into the jack for placing s'aid jack in operative relation with the line, whereby said signal controlling magnet is control of the subscriber,

made with the line. i 110. The combination with a telephone line, and a connection terminal in the form of a spring jack normally not in operative relation with the line, of a cord circuit and a placed under'the' a local circuit for short-circuit-- when the subscriber calls, and means for opening said local circuit when a connection is i connecting plug, a central source of current associated with said line and circuit to furnish talking r'-1rrent to the substations, and means including said sou .e of current actuated by the insertion of said plug in the jack for placing said jack inoperative relation with said line, a local circuit forshort-circuiting or shunting the line when the subscriber calls, and means for openingsaid local circuit when a connection is made with the line.

1 with the'line when said plug is inserted into said jack, a local circuit for short-circuiting or shunting the line when the subscriber calls, and meansfor opening said local circuit when aconnection is made with the line.

112. The combination with a telephone line and a con nection terminal in the form of a spring jack, of a con necting plug and a. cord circuit, a central source of current associated with said line and circuit to furnish current for talking purposes, supervisory signal apparatus associated-with the cord circuit and operated from said source of current, and a relay actuated from said source by the insertion of said plug into and its withdrawal from said jack for controlllngthe operative relation of said jack with the line, a local circuit for short-circuitlng or shunting the line when the subscriber calls, and means for opening said local circuit when a'connection is made with the line.

1-13. In a telephone system," a metallic circuit line, a

connection terminal in the form of a spring jack normally not in operative relation with said line, a connecting plug'and a cord circuit, a signaling device normally in operative relation with said line, a central source of current and supervisory signaling apparatus associated with said line and cord circuit, said source being adapted to furnish, current for the operation of said apparatus and for talking purposes, and a relay actuated from said soul-cc when said plug is. inserted in said jack to place said signaling device in inoperative relation with said lineand said jack in operative relation with said line, a local circuit for short-circuiting or shunting the line when the subscriber calls, and means for opening said local circuit when a connection is made with the line.

ll-l. The combination with a telephone line having a limb extending to the central station, of a line contact for said limb normally disconnected therefrom, a cord circuit and connecting plug, supervisory signaling apparatus connected with said circuit, a central source of current assoelated with said line and circuit to furnish current for 115, The combination with a telephone line having a limb extending to the central station, of a signaling device normally connected with said limb, a line contact for said line normally disconnected therefronnn cord circuit and connecting plug; supervisory signaling apparatus asso' ciated with said cord circuit, a central battery 'to furnish current for talking purposes and for the operation of said apparatus, and a relay energized from said battery adapted to disconnect said limb from said signaling dcviceand to connect the same with the line contact when a connection is established with the line, a local circuit for short circuiting or shunting the,liue when the subscriber calls,

and means for opening said local circuit when a connection is made with the line.

lid. The combination with a telephone line having a limb extending to the central station, of a spring or mov ingpart with which said limb connects at the central office. a signaling device connected with said spring or part in it's normal position, a line contact for said limb, a cord circuit and connecting plug, a central battery associated with the said line circuit, supervisory'signals also associated with the circuit, said battery being adapted to furnish current to the substations for talking purposes and for operating said supervisory signals, and a relay also energized from said battery, adapted to disconnect said spring or part from the signaling device and to connect it with the line contact when a connection is established with the line, a local circuit for short-circuiting or shunting'tho line when the subscriber calls, and means for opening said local circuit when a connection is made with the line.

117. The combination with a telephonedin'e and a connection terminal therefor normally not' in operative relation with the line, of a connecting plug and cord circuit to coiiperate with said line, a supervisory signal controlling magnet and a battery associated with said cord circuit, a telephone transmitter and a switch at the subscriber's sta tion, and means including a local circuit controlled by the insertion of the plug into the jack for placing the jack in operative relation with the line when the subscriber calls, whereby talking current from said battery is furnished to said transmitter and said magnet is placed under the control of the calling subscriber, a subscriber-s bell or ringer, a source of ringing current adapted to be bridged across the line to operate said bell or ringer, and a ringing circuit including both sides of the line.

. 118. The combination with a telephone line and a connection terminal therefor-normally not in operative rela tion with said line, of a connecting plug and cord circuit adapted to coiiperate'with said line, a supervisory signal controlling magnet and a battery for energizing the same nssociated'with' said cord circuit, aswitch at the subscriber's' station, and means controlled by the insertion of the plug into the jack for placing said jack in operative relation with the line, whereby said signal controlling magnet and battery are placed under the control of the subscriber, a subscriber's hell or ringer, a source of ringing current adapted to be bridged across the line to operate said hell I or ringer, and a ringing circuit including both sldcs of the in operative relation with the line, of a cord circuit and a connecting plug, a central source of current associated with said line and circuit to furnish talking current'to the substation, means independent of said line, including said source of current, actuated by the insertion of said plug in the jack, for placing said jack in operative relation with said line, when the operator answers a call, a subscriber's hell or ringer, a source of ringing current adapted to be bridged across the line to operate said boil or ringer, and a ringing circuit including both sides of the line.

120. The combination with a telephone line and a con: nection terminal in the form of a spring jack normally not in operative relation with said line, of a cord circuit and connecting plug, supervisory signaling apparatus associated with said circuit, a central source of current associated with said line and circuit to operate said supervisory apparatus, and a relay adapted to be energized from said source to place said jack in operative rehiiion with the line when said plug is inserted into said jaclt. a subscribers hell or ringer, a source of ringing current adapted to be bridged across the line to operate said hell or ringer, and a ringing circuit including both sides of the line.

121. The combination with a telephone line and a conncction terminal in the form of a spring jack, of a con necting plug and a cord circuit, a central source of current associated with said line and circuit to furnish current for talkingpurposes, supervisory signal apparatus associated with the cord circuit and operated from said source of current. a relay actuated from said source by the insertion of said plug into and its withdrawal from said jack. for

controlling the operative relation of said jack with. said line, a locul.circuit closed to keep said relay energized while the line is in use for talking purposes, a subscriber's hell or ringer, a source of ringing current adapted to be bridged across the: line to operate said hell or ringer and a ringing circuit including both sides of the line 122. in a telephone system, a metallic circuit line, a connection terminal in the form of a spring .jack normally 133. The combination witha telephone line having a .hmh extending to the central station, of a spring or moving part with which said limb connects at the central otiice.

a signaling device connected with said spring or part in -it s normal position, a line contact for said limb, a cord circuit and connecting plug, a central battery associated with the said line circuit, supervisory signals also associated with the circuit, said battery beingadapted to furnish current to the substations for talking purposes and for operating. said supervisory signals, and a relayalso energized from said battery adapted to disconnect said spring or part from the signaling device and to connect it adapted to be closed by the opening of said energizing circuit.

134. The combination with a telephone line and a spring jack therefor normally totally disconnected therefrom, of a connecting plug and cord circuit to cooperate with said line, a supervisory signal controlling magnet and a battery associated with said c'ord circuit, a telephone transmitter and a switch at the Subscriber's station, means controlled by the insertion of the plug into the jack for placing the jack in connection with the line, local circuit closed by the plug and jack while the line is in use for talking purposes, whereby talking current is furnished to said transmitter and said magnet is placed under the control of the subscriber, a' subscribers hell or ringer. and a condenser for stopping the dew of battery current through said hell or ringer, together with provisions by which the supervision is independent of the ground between the subscriber's station and the central station. 12-15; 'Ihe'combination with a telephone line and a spring jack therefor normally totally disconnected therefrom, of a connecting plug and cord circuit adapted to cooperate with said jack. a supervisory-signal controlling magnet and a battery associated with said cord circuit, a switch at the subscribers station, means controlled by the insert'ion oi the plus into the jack for placing said jack in connection with the line, whereby said signal controlling magnet is placed under the control 01. the subscriber, a

subscriber's bell or ringer, and a condenser for stopping the llow of battery current through said hell or ringer, together with provisions by which the supervision is independent of the ground between the subscriber's station and the central station.

136. The combination with a telephone line, and a conncction terminal in the form of a spring jack normally not in operative relation with the line, of a cord circuit and a connecting plug, a central source of current associated with said line and circuit to furnish talking current to the substations, and means including said source 01 current and actuated by the insertion of said plug in the jack for placiun said jack in operative relation with said line, said means comprising a local circuit closed OW l cord strand while the line is in use for talking purposes, a subscribers boil or' ringer. and a condenser for stopping the ilow of battery current through said hell or ringer, together with provisions by which the supervision is independent of the ground between the subscriber's station and the cell,-

tra l station.

1557. The combination with a telephone line and a connection terminal in the form of a spring jack normallynot .in operative relation with said line. of a cord circuit and supervision. is independent of the ground between the subscriber's station and the central station.

138. The combination with a telephone line and .a consaid means including a.

nection terminal in the form of a spring jack, of a connecting plug and a cord circuit. a central source of current as sociated with said line and circuit to furnish current for talking purposes. supervisory signalapparatus associated with the cord circuit and operated from said source of current. and a relay actuated from said source by the-insertion of said plug into and its withdrawal from said jack for controllinw, the operative relation of said jack with said line. 21 subscribers hell or ringer, and a condenser for stopping the How of battery current through said hell or ringer, together with provisions by which the supervision is independent of the ground between the subscriber's sta tion and the central station. 139. In a telephone system. a metallic circuit line, a connection tenminalin the form of a-spring jack normally not in operative relation with said line, a connecting plug and a cord circuit, a line signaling device normally in operative'relation withsaid line, a central source of-battery current and supervisory signaling apparatus associated with said line and cord circuit, said source being adapted to furnish current for the operation. of said apparatus and for talking purposes, and a relay actuated from said source when said plug is inserted in said jack to place said signaling device in inoperative relation with said line and said'jack in operative relation with said; line, a line signaling circuit excluding all winding of said relay, :1 subscriber's hell or ringer, and a condenser for stopping the flow of battery current'through said hell or ringer, together with provisions by which the supervision is independent of the ground between the subscriber's station and the central station. H

H0. The combination with a telephone line having a limb extending to the central station, of a line contact for said limb normally disconnected therefrom, a cord circuit and connecting plug, supervisoryjsignaling apparatus connected with said circuit, a central source of current associated with said line and circuit to furnish current for talking purposes and for the operation of, said supervisory apparatus, and means independent of the line outside the central station for automatically connecting said line contact with said limb when the line is in use and for disconnecting the same therefrom when the line is not in use, a subscrihei"s hell or ringer, and a condenser for stopping the tlow of battery current ,through said hell or ringer, together with provisions by which the supervision is independent of the ground between the subscrihci"s station and the central station.

141. The combination with a limb extending to the central station, of asignaling device normally connected with said limb, a line contact for said line normally disconnected thereform, a cord circuit and connecting plug, supervisory signaling apparatus associ' ated withsaid cord circuit, a central battery to furnish current for talking purposes and for the operation of said apparatus, and a relay energized from said battery adapted to disconnect said limb from said signaling device and to connect the same with the line contact when a con ncction is established with the line, a normally open local energizing circuit for said relay, closed when the operator answers a' call, a subscriber's hell or ringer, and a condenser for stopping the flow of battery current through said hell or ringer, together with provisions by which the supervision is independent of the ground between the subscriber's station and the central station.

142. The combination with a telephone line having a limb extending to the central station, of a spring or movbig part with which said limb connects at the central othce, a signaling device connected with said spring or part in its normal position, a line contact for said limb, a cord circuit and connecting plug, a central battery associated with the said line circuit, supervisory signals also associated with the circuit. said battery being adapted to furnish current to the substations for talking purposes. and for operating said supervisory signals. and a relay also energized from said battery adapted to disconnect said spring or moving part from the signaling device and to connect it with the line contact when a connection is established with the line, the line connection with the battery excluding all winding of the said relay, a subtelephone line having a niitter .and connecting' plug,

srribers hell or ringer, and a condenser for stopping the tlow of battery current through said hell or ringer, to

gcther with provisions by which the supervision is 'indc-.

v pendent of the ground between the subscrihtrs station and the central station.

142%. lhe combination with a telephone line and a connection terminal therefor normally not in operative relation with the line. of a connecting plug and cord circuit to ,coiiperate withsaid line, a supervisoigv signal t'olillulling" magnet and a battery associated with said cord -circuit. a telephone transmitter and a switch at the. subscrihcfls 1d means controlled by the insertion ot-t.he plug ,mtothe ack 'for placing the jack in operative relation with the line whereby talking current is furnished to said trans and said magnet is placed under the control ot. the subscriber. the supervision being absolutely independent of the ground between the subscriber's station and-the central statiom 144. The combination with a telephone line and'a con nection terminal therefor normally not in operative relation. with said line, of a connecting plug and cord circuit adapted to cooperate with said line, a supervisory signal controlling magnet and a battery for energizing the same associated with said cord circuit, a switch at the subscrihers station, and'meaus controlled by the insertion of the plug into the.jack for placing said jack in operative relation with the line, whereby said signal controlling magnet and battery are, placed under the control of the subscriber, the supervision being absolutely independent of the ground between the subscriber's station, and the central station.

145. The combination with a telephone line, and a connection terminal-in the form of a spring jack normally not in operative relation with the line, of -a cord circuit and a connecting plug, a central source of current associated substations, and means including said source of, current actuated by the insertion of saidplug in the jack for placing said jack in operative relationwith said line, the

nection terminal in the form of a spring jack normally not in operative relationwith said'line, of acord circuit supervisory signaling apparatus associated with said circuit, central source of current associated with said line and circuit to operate said super- 'visory apparatus, and a relay adapted to be. energized from said source to place said jack in operative relation with said line and circuit to furnish talking current to thewith the line when said plug'is inserted intothe said jack,

the supervision being absolutely independent of the ground between the subscriber's station and the central station.

147. The combination with a telephone line and a connection terminal in the form of a spring jack, of a connecting plug and'a cord c'ircuit,' a central source of current associated with said line'and circuit to furnish current for talking purposes, supervisory signal apparatus associated with the cord circuit and operated trom said sonrce'ot" relation with said line, a central source of current and.

supervisory signaling apparatus associated with said line and cord circuit, said source being adapted to furnish current for the operation of said apparatus and for talking purposes, and a relay actuated from said source when said plug is inserted in said jack to place said signaling device in inoperative relation with said'line. and said jack in operative relation with said line, the supervision being absolutely independent of the ground between the subscriber's station and'the central station.

14!). The combination with a telephone line-having a limb extendingto the central station, of a line contact for said limb normally disconnected therefrom, a cord circuit and connecting plug. supervisory signaling apparatus connected with said circuit. a central source oi current associated with said line and'circuit to furnish current for talking piil'poscs and for the' operation of said supervisory apparatus, and .means for auttnnatically connecting said line contact with said limb when the line is in use and for disconnecting the same thcrelrom when the line is not in use, the supervision beingabsolutely independent of the round between the subscrilwrs station and the central station.

150. The combination with a telephone line having a limb extending to the central station, of a. signaling device vnormally connected with said limb, a line contact for said line normally disconnected therefrom, a cord circuit: and connecting plug, supervisory signaling apparatus associated with said cord circuit, a central battery to furnish established with the line, and anenergizing circuit i'orsaid signalling device. said relay provided with a windingcr cludcd' from the said energizing circuit, the'supervision being absolutely independent of the ground between the snbscribens station and the central station.

151. The combination with a telephone line having a iimb extending to thecentral station, of a spring or moving part with which said limb connects at-the central otlice, a

signaling device connected with said springor part in'its normal position, a line contact for said limb, a cord circuit and connecting plug. a central battery associated with the said line circuit, supervisory signals also associated with the circuit, said battery beingadapted to fnrnislrcurrent to the substationsfor talkingpurposes and for operating said supervisory signals, a relay also energized from said battery, adapted to disconncctsaid spring or'part from the signaling device and to connect it with the line contact when a connection is established with-the line, and an energizing circuit for said signaling device, said -relay provided with awinding'excluded from the said energizing circuit, the supervision being absolutely independent of the ground between the subscriber's station and the centralstation. Y I I I 152. In a telephone system, a subscriber's line, a line relay, a source of electric current, a normally open line cir iit'tor energizing said relay, and a normally open local circuit controlled by the said relay and including an 9111913? gizing coil thereof, whereby the said local circuit is substitnted for the said line circuit when tlie'i'elay is energized, each circuit including. said source of current, said line circuitincluding both sides of the. line in series.

153. ,In a telephone syste1n,-'a sub'scribers line, a'line. relay. :1 source of electric current, a normally openline circuit for energizing said relay, and a normally open local circuit controlled by the said relay and including an ener gizing coil thereof, whereby the said local circuit is substituted for the said line circuit when the relay is energized,

each circuit including said source of current, said lin'e circuit being provided with-normally closed relay contacts for opening the same.-

154. In a telephone system, a ,subsccibefls line, a line relay, :1 source of'electric currenta normally open line circuit for initially energizing said relay overboth sides of the line, and a normally open local eircnit'controlled by the said relay and including an energizing coilthel'eof, whereby the said local circuit is substituted for thesaid line circuit when the relay is energized, each circuit .in- 'cluding said source of current, and a subscriber's hook switch controlling the said line circuit atthe subscriber's station.

The combination of a telephone line, a substation substation: v

156. The combination of a plurality of subscriber's telephone lines, a substation for each line, normally dis circuit or shuntthe line and thereby quiet the same at the connected jacks for said lines, metallic line signal and supervisory signal circuits between the. exchange and the substations, metallic talking and ringing circuits between and plugs for connecting lines together, and energizing circuits for said relays including portions of the cord, service between lines and the operations of all said instrumentalities being independent of the ground at substations.

157. The combination of'a substation, a normally open metallic telephone talking circuit, a normally open metallic connecting said contacts ,with the talking circuit when theoperator answers a call emanating from said substation.

158. The combination of a subscrlbers telephone line, a jack or switchboard terminal individual to said line and normally disconnected therefrom, a subscribers common battery transmitter and hookswitch, a common battery adapted to supply current to the line for both talking and signaling purposes, a line' signal relay, an energizing circuit for said line relay including said'battery and line and hook switch and transmitter, a cut-off relay for automatic ally retiring the line signal and connecting the jack with the line when the operator answers a call, an operators connecting cord and plugs, an energizing circuit for said cut-off relay including said battery and a portion of said connecting cord, a supervisory signal relay, an energizing circuit for said supervisory relay including the said transniitter and hook switch, both sides of the line, normally disconnected contacts of the jack, the battery/anda portion of the said cord, said battery permanently" bridged between .the talking strands of the connecting cord and normally bridged between the normally disconnected limbs of said line,a subscribers call belLor signal, a ringing generator, an operators switch for bridging said generator between the talking strands of the cord to operate the said call hell or signal, another subscribers line terminal adapt ed to be connected with said first-mentioned line through the medium of said cordand plugs, a complete metallic circuit for energizing said bell or signal, another supervisory signal relay, and an energizing circuit for said last-mentioned supervisory relay, which energizing circuit is opened by said operators switch when the generator isused for operating the subscribers ca'll hell or signal.

Signed by me at Chicago, Cook county, Illinois, this 22nd day of October 1901.

HENRY P. CLAUSEN.

Witnesses:

CHAS. C. BULKLEY,

HARRY. P, BAUMGARTNER.

Images