USRE13710E - Telephone-exchange system - Google Patents

Description

- .H. G. WEBSTER. TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED JUNE3, 1903.

'Reissued Mar. 31

a citizen of the United States, residing at.

\ UNITED STATES PATENT OFFICE.

' HARRY G. WEBSTER, OF CHICAGO, ILLINOIS, ABSIGNOR, BY MESNE ASSIGNMENTS, TO

BTBOKBERG-CARLSON TELEPHONE MANUFACTURING COMPANY, 'OF ROCHESTER, NEW YORK, A CORPORATION 01 NEW YORK. v

TmnoNn-nxcnmen srs'rnn.

Specification of Bcissued Iietters Patent Reigsued Mar, 31, 1914,

original n. seam, dated December 10, 1001', Serial in. 41,042. Application for reissue filed June a, 1,903.

To all 071,0111 it may concern: v

Be it known that I, HARRY G. Wnns'rnn,

Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone-Exchan e Systems, of which the following is a fu 1, clear, concise, and exact description, reference being had to the accompanying draw,- in forming a part of this specification.

y invention relates to telephone exchange systems, and has for its object the provision of im roved linesignaling mechanism at the exe ange, whereby the employment of the present complicated cut-o relays and associated switching mechanism may be dispensed with.

Broadly stated, my invention consists in the provision at a central exchange of a line indicator and a cut-off relay, both of which are normally connected in the telephone line circuit. The line indicator is so constructed and so connected as to be sensitive to currents through the telephone line controlled by apparatus located at the associated substation. The cut-ofl' relay however, is not sensitive to currents controlled from the subscribers substation, control of the cut-off relay being effected by switchin devices un-' der the control of the centra station operator. The cut-off relay when actuated due to the control exercised by the central station operator destroys the substation control of the line indicator.

In accordance with my invention, I may em loy for the line indicating mechanism a diiierentially wound relay, the op sitely Wound coils of which, when included in circuit with the battery or other source of current, serve to exert a neutralizing effect upon each other; so that the armature of the difierentially wound relay will not be actuated. The armature of this relay normally rests against a back contactthat is connected with one terminal of a line indicator.

The indicator-and relay are so associated with the telephone line that a subscriber in initiating a call will efiect the passage of current through the coils of the relay and the said indicator or the electromagnet of the indicatorto effect operation of the same.

The arrangement is such that current flow- Serial ll'o. 150,915.

which may be used in systems employing my invention, is adapted upon connection with a line circuit to cause the establishment of a path of decreased resistance throu b one of the coils of the cut-off relay, where y the increased current through this coilcauses a net energization of the relay to attract its armature. The armature, when thus attracted, is removed from the back contact connected with the line indicator, whereby said indicator and the idle relay armature being thereupon brought into contact with an a by the circuit through the active relay coil is maintained during the closure of a concoil are cut out of circuit, the

ternate eontactanvil, whereductively continuous circuit through the isubstation apparatus associated with the In effecting the control of the cut-off relay and indicator by means of the line connecting apparatus, I preferably em loy an electroma net in the cord circuit, and I provide a switch controlled by said electromagnet, which, in its normal position, will afford a local circuit for that coil of the relay that is to remain inactive, said electroma net being adapted for inclusiondirectly m,

the line circuit when the relay armature is attracted from its normal to its alternate position, whereupon the elect-romagnet serves to operate its associated switch to 0 en the local circuit, the active coil of the re ay and the said electromagnet being thereupon inclu'dd preferably in a bridge of the circuit. A common battery is employed and is. profs erably located between the active coil of the line relay and the said electromagnet, ,the'

said active coil and the electromagnet thereby afl'ording the necessary impedance to prevent-the shunting of'voice currents.

-I will explain my invention more fully" by reference to the accompanying drawing,

which illustrates a multiple switchboard system constructed in accordance with my" invention. The invention, however, may be employed in connection with other systems.

' with magneto generators, but I do not wish to be limited to such a system. Each telephone line extends by its limbs to the exchange and is there connected with the tip line springs e of the line jacks. Two-plugs are preferably employed, having tip's'and sleeves connected by a tip strand 9 and a sleeve strand h.' The sleeve strand h includes a condenser z. Electromagnets k, 70 are included in a conductor that is in shunt of the condenser, while switches t, Z are included in branches that connect the tip strand with the sleeve strand.

The line signaling mechanism constructed in accordance with my invention comprises in its" preferred embodiment a relay having oppositely or differentially wound coils m, n, which create equal opposing effects; The armature 0 of the relay nor'mally includes the coils of the relay in series with the common battery p, which may be of forty volts pressure, and the line-indicator -or the electromagnet of the line indicator g, the said instrumentalities being preferably connected normally in series with the corresponding telephone line, so that when a subscriber removes his telephone from its switch hook a.

circuit is completed through the said instrumentalities, whereby a calling signal is manifested, which calling signal is maintained as long as the coils mand n exert their opposing effects, the armature 0 then remaining in its normal position. When the operator inserts a plug in response to a signal or in connecting a called subscriber, current from the battery p is principally confined to a path that includes the helix m, the tip line spring, the tip of the inserted plug, the separable contacts of the switch Z, the clearing-out indicator r and the conductor 8 that is connected withthe remaining terminal of the batter The current is confined principally to t is path,-as the winding (at the line indicator magnet is preferably oif comparatively high resistance, as, for example, 500 ohms, while each winding of the cut-off relay is of 200' ohms resistance. Each clearing-out indicator 1- may be in the form of a twenty volt lamp, so that the circuit through the coil m is of much less resistance than the circuit through the coil n. The neutralizing effect of the coils of the relay is thus overcome and the armature 0 is attracted toward its alternatecontact. .When the armature is thus attracted the 'circuit through the line indicator is opened and the magnet 70, that may be wound to 200 ohms resistance, is included in a circuit with the line, the circuit being traced from magnet through the conductor a, the

battery 77, coil m, one'limb of the telephone line that is connected with the tipline spring, and back through the sleeve or socket of the springj'ack to the saidelectromagnet, which is thereupon. energized to cut out the clearing-out indicator. The circuit through the rela winding m is then maintained through t e line circuit to the subscribers substation, rather than through the clearing-out indicator 7", whereby the,

armature 0 is maintained in its alternate attracted position. .WVhen the subscriber is through conversation he opens the circuit through the magnet is by replacing his receiver upon the switch hook, whereby the said electroniagnet is deenergized and the passage of current through the corresponding indicator 1" reefl'ected to convey the proper signal.- 7

It will be observed that I have provided a telephone system in which the sleeve contacts of sockets LfI of the line and answering jacks, which soc ets also form the test terminals. of these packs, are normally disconnected and insulated from all parts of the telephone line circuit. An actuation of the differential cut-ofi relay serves to connect these test terminals directly with a limb of the associated telephone line. The multiple jack wiring is used first as a local circuit for testingpurposes and then as a line circuit for purposes of communication between connected subscribers.

I have not seen fit to describe the operators listening outfit, telephone outfit and the signaling generator employed .by the exchange, as these instrumentalities are well known in the art.

While I have herein shown and particularly described the preferred embodiment of my invention, I do not wish to be limited to the precise disclosure herein 'set forth, but

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a telephone exchange system, the

combination with a telephone line extending,

from a subscribers station to an exchan e' of aline relay at the exchange-provided with differentially-wound coils, a line indicator, means controlled by the said'relay forgoverningthe operation of the said indicator, means controlled by the subscriber.

for directing current thropgh the said relay and line indicator to eife'ctthe operation of the latter, and switching apparatus cone the operator for increasing the magnetizing effect of-oneof the coil's' of therelay above that produced" by the other, to

trolled by effect the operation of the said. relay-controlled means and thereby cut out or render ineffective the line indicator, substantially as described. r

2. In a telephone exchange system, the combination with a telephone line extending .from a subscribers station to an exchange,

of a relay provided with differentiallywound coils, a source of current, means controlled by the subscriber for including the said coils in circuit with the said source of current,'a line indicator adapted to be operated by the said current when thus included in circuit, means controlled by the said relay for cutting out the said indicator, and means controlled by the operator whereby the magnetizing efl'ect due to one of the coilsof the relay may be increased above that due to the other, to effect the operation of the relay-controlled means and thereby render inefiective the line indicator, substantially as described.

3. In a telephone exchange system, the combination with a telephone line extending from a subscribers station to an exchange,-

of a relay at the exchange provided with difl'erentially-wonnd coils, a line indicator,

a switch adapted for operation by the said relay, a source of current adapted for inclusion in circuit with the same switch, the line indicator and the coils of the relay, means at the subscribers station for closing circuit through the said switch, line indicator, battery and relay coils, means controlled by the operator for producing a greater magnetizing effect in one of said coils above the other, whereby'the said switch, when operated, will cut out or render ineffective the line indicator and one of the relay coils, and maintain the remaining relay coil in a closed circuit, substantially as described.

4, In a telephone exchange system, the combination with a telephone line extending from a subscribers station to an exchange, of a differentially-wound relay, operators means for connecting the said telephone line with a second telephone line, circuit connections whereby the operators connecting means may effect a greater magnetizing effeet in one of the relay coils with reference to the other, and a switch controlled by the relay and operated thereby when the magnetizing effects of its coils are thus unbalanced, and serving, when operated, to cut out or render in effective the remaining coil of. the relay and the line indicator, substantially asvdeseribed.

In a telephone-exchange system, the combination with a telephone-line extending from a subscribers station to an exchange, of a line-relay at the exchange provided with differentially wound coils, a source of current, means controlled by the subscriber for including the said relay in circuit'of said source of current, whereby the relay remains inoperative, a line-indicator also the windings of the relay when the said switching apparatus is manipulated to connect the subscribers for conversation, the said local circuit being of lower resistance than the circuit closed by'the subscriber through the line relay and indicator, whereby the magnetization due to the saidcoil included in the local circuit, is increased above that due to its companion coil, and

a switch that is adapted thereupon to be actuated by the relay to'cut out or render ineffective the. line-indicator, substantially as described.

6. Ina telephone-exchange system, the

combination with a telephone-line extending from a subscribers station to an exchange, of a line-relay at the exchange provided with differentially-wound coils, a source of current, means controlled-by'the subscriber for including the said relay in circuit of said source of current, whereby the relay remains inoperative, a line-indicator also adapted for inclusion in circuit of the source of current by the said subscribers means, a local circuit at the exchange, an operators switching apparatus for connecting subscribers for conversation, means coacting with said switching apparatus serving to close the said local circuit through one of the windings of the relay when the said switching apparatus is manipulated to connect the subscriber for conversation, the said local circuit bein of lower resistance than the circuitclose by the subscriber through the line relay and indicator, whereby the magnetization due to the said coil included in the local circuit, is. increased above that due to its companion coil, a switch that is adapted thereupon to be actuated by the relay to cut out or render ineffective the line-indict tor, a switch included in the local circuit, an electromagnet for. actuating the said switch to open the local circuit, and means whereby the switch controlled by the relay may, when actuated, close circuit through thesaid ele ctromagnet, substantially as described.

7 In a telephone-exchange system, the combination with a telephone-line extending from a subscribers station to an exchange, of a line-relay at the exchange provided with differentially-wound coils, av source of current,- means controlled by' the subscriber for including the said relay in circuit of said source of current, whereby the relay remains inoperative, a line-indicator also adapted for inclusion in circuit of the source of current by the said subscribers means, a local circuit at the exchange, an operators switch-' ing apparatus for connecting subscribers for conversation, means coacting with said switching apparatus serving to close the said local circuit through one of the windings of the relay when the said switching apparatus ,is manipulated to connect the subscribers for conversation, the said local circuit being of lower resistance than the circuit closed bythe subscriber through the line relay and indicator, whereby the magnetization due to the said coil included in the local circuit, is increased above that due to its companion coil, a switch that is adapted thereupon to be actuated by the relay to cut out or render 'inefl ective the line-indicator, a' switch in- ,cluded in the local circuit, an electromagnet for actuating the said switch to open the local circuit, means whereby the switch controlled by the relay may, when actuated, close circuit through the said electromagnet,

' a clearing-out indicator included in the local circuit, and'means whereby, when a subscriber is through conversation, circuit through the said electromagnet will be opened and the local circuit restored to effect a clearing-out signal, substantially as described.

S. In a telephone-exchange system, the combination with a telephone-line extendingv from asub'scribers station td an exchange, of a relay at the exchange provided with differentially-wound coils, an indicator, means controlled by the said relay for gov- -erning the operation of the said indicator, means controlled by the subscriber for directing current through the said relay and indicator to control the operation of the latter, and switching apparatus for increasing the magnetizing effect of one of the coils of. the relay above that produced by the other, to effect the operation of the said relay-controlled means and thereby a change in the operative condition of the said indicator, substantially as described.

9. In a telephone-exchange system, the combination with a telephone-line extending from a subscribers station to an exchange, of a bridge-conductor at the exchange across the telephone-line. a differentially-wound relay, a battery and a line indicator included in the said bridge, a switch adapted for operation by the'said relay to cut out or render inefiective one of the coils of the relay'andthe line indicator, and means controlled by the operator for producing a. preponderatin magnetizing effect in the remaining coil 0 the relay to effect the actuation of the said switch, substantially as described.

10. In a multiple switchboard telephone exchange system, the combination with subscribrs telephone lines extending from subscribers stations to the exchange and each there ermanently connected'with a contact'of tli 85 diflerent sections ofthe multiple board, a

exchange system, the combination with sube several line jacks upon the battery at the. exchange for supplying talking current to the substation, one limb of each line extending to test contact portions of the jacks, a switch at the exchange being included in this limb of the line for opening and closing the same, an electromagnet for operating the switch, cord connecting apparatus serving to energize the magnet to operate the switch, the switch being adapted for automatic restoration when relieved of the influence of theelectromagnet to restore the test condition, and testing means, substantially as described.

11. In' a 'multiple switchboard telephone scribers telephone lines extending from 0 subscribers stations to theexchange and each there normally connected with a contact of the several line jacks upon the, different sections of the multiple board, a battery at the exchange for supplying talking current .to the substation, one limb of each line extending to test contact portions of the jacks, a switch at the exchange being included in this limbof the line. for opening and closing the same, an electromagnet for operating the switch, cord-connecting apparatus serving to energize the magnet to operate the'switch, the switch being adapted for automatic restoration when relieved 5 of the influence of the electromagnet to restore the test condition, and a local test circuit including a talking cord strand andthe portion of the limb of thetelephone line extending to the test contact jacks,esubstanti ally as described. 7

12. In a telephone exchange system, the combination with a=teleplione line extending from a subscribers station to an exchange,

of a relay at. theexchange provided with difierentially-wound coils, an indicator, f means controlled by the said relay for gov-' erning the operation of the said indicator,

' means controlled by the subscriber for (ii 7 current through the said relay to 11 rectin contro the operation: of the indicator, and switching a paratus for increasing the m'ag netizing e ect of one of the CQllS of therelay above that produced by. the other to efi'ect theoperation of the said relay controlled means and thereb a change in the operative condition of c said indicator,- substantially as described.

- 13. Ina telephoneexchange system, the combination with a telephone line extending 39 from "a subscriber.s station to an exchange,

of a relay at the exchange provided with dilferentially-wound "coils, an indicator,

means controlled by the said relay for' govarning the operation of thefsaid indicator, 135 means controlled by the subscriber for directing current through the-said relay :to;

control the operationof theindicator, and

o erators switching apparatus at the exc ange for. increasing the magnetizing effect portions of of one of the coils of the relay'. above that from a subscribers stat-ion to an exchan of a relay at the exchange 'provided with differentially-wound coils, an indicator,

means controlled by the said relay for governing the operation of the said indicator, means controlled by the subscriberfor directing current through the differentiallywound coils of the. relay, and switchin-g'a paratus' for directing current through t e relay at the exchange to change the operative condition of the indicator, substantially as described.

15. In a telephone exchange system, the combination with a metallic telephone line and a testing and talking line terminal normally disconnected therefrom, of a relay for connecting said terminal with the line, a second line terminal normally connected with said line, a cord circuit terminating in a con 'necting plug, a source of talking current' adapted to send current over the metalliccircult and means for closing the circuit of said .source through said relay when connection is made with the llne, said relay circuit 1nclud-' ing a talking strand of the cord circuit, a main terminal of the connecting plug, a line contact anda portion of a talking limb of the telephone line, substantially as described.

16. I11 combination, a telephone line, a source of currentadapted to supply talking and signaling current to said line, a cut-ofl relay having its windings so connected in the line circuit as to be insensitive to current controlled by a switch in the line circuit, and

a line indicator normally serially included in such line circuit. 17. In a telephone exchange system, the

' combination with a telephone line extending b its limbs from a substation to an ex- 0 ange, of a source of current at the exchange adapted to supply talking and signaling current to said line, a cut-cit relay having a winding permanently included. in one 0 said line limbs, and a line indicator included in one of said line limbs, substantially as'described.

-18. In atelephone exchange system, the combination with a telephone line extending by its limbs from a substation to an exchange, of a'source of current at the exchange adapted to supply talking current to said line, a cut-off relay havinga winding permanently included in 'the line circuit,

and a'line indicator in the line circuit. substantially as described.

19. In a telephone exchange system, the combination with a telephone line extendby its limbs froma substation to an exchange, of a source of current at the-exchange adapted to supply talking and sig- -naling current to said line, a -cut-off relay '70 in the te ephone line, a line 1nd1- .cator normally serially included in the telehavin a windin permanently serially in.- clude phone line, and a switch serving to disconnect the'line indicator from the line circuit upon the actuationof the cut-off relay.

20. In combination, a common battery telephone line extending to a central ofiice, a cord circuit at the central oifice for connectin'g said line with; another for conversation,

a cut-01f relay so connected in the line circuit as tolbe insensitive to current controlled by the substation switch, a linesignal normally included in the line circuit, and means whereby-the connection of the cord circuit with the line causes an actuation ofsaid cut 011* relay to destroy the substation'control of said line signal.

21. In a telephone exchange system, the

combination with a telephone line extending by its limbs from a substation to an exchange, of a source of current at the exchange adapted to supply talking and signalingcurrentto said line, cord-connecting apparatus for connecting said line with another for conversation, a cut-ofi' relay having a winding permanently included in the linecir'cuit, a line indicator in the line circuit, said line indicator being responsive to a control exercised from the substation, and means whereby the connection of said cordconnectingapparatus with said line causes the closure of a circuit of decreased resistance through said cut-01f relay, whereby the same is actuated to destroy the substation cont-rol of said line indicator, substantially as described.

22. In combination, a source of current and a line indicator in circuit with a telephone line, and a cut-ofl relay having its windings so connected in said circuit as to bo insensitive to current controlled by a switch'in the telephone line.

23. In combination, a telephone line extending from a substation to an exchange. a source of current included in the line at the exchange, a line indicator also included in the line circuit, and a cut-ofi relay having its windings so connected in the line circuit as to be insensitive to current controlled by the substation switch but sensitive to current controlled by an operators cord-connecting apparatus.

24. In' .a telephone exchange system, the combination with a telephone line extending by its limbs from a substation to an exchange, of a source of current located at the talking and a sigexchange for supplying ine, cord-connflttl g naling current to said apparatus for connecting said line with me.

other for conversation, line jacks having connection of said test terminals with the line circuit, substantially as described.

25. In a multiple switchboard'telephone exchange system, the combination with subscribers telephone lines extending from subscribers stations to the exchange and each there permanently connected-with a contact of the several line jacks upon the different sections of the multiple board, a battery at the exchange for supplying talking current to the substation, one limb of each line extending to test contact portions of the jacks, a switch at the exchange being includedin this limb of the line for opening and closing the same, an electromagnet for operating the switch, cord connecting apparatus serving to energize the magnet to operate the switch,

and testing means, substantially as de-' scribed.

26. In a multiple switchboard telephone exchange. system, the combination with subs'cribers telephone lines extending from subscribersfl stations to the exchange and each there normally'connected'with a contact of the several line jacks upon the different sections of the multiple board, a battery at the exchange for supplying talking current to the substation, one limb of each line extend- -in to test contact portions of the jacks, a

switch at the exchange being included in this limb of the line for opening and closing the same, an electromagnet for operating the switch, cord-connecting apparatus servmgto energize the magnet to operate the switch, and a local test circuit including a talking cord strand and the portion of the limb of the telephone line extending to the test contact portions of jacks, substantially as described.

-27. In a telephone. exchange system, the combination with a line indicator and a cutofi relay included in series .in a telephone line circuit, and means whereby the cut-off relay may be actuated to render the line indicator insensitive to control by a switch in the line circuit.

. 28. In a multiple switchboard telephone exchange system, the combination with sub: scribers telephone-lines extending from silhscribers stations tothe exchange and each there connected-with the several jacks upon the, different sections of the multiple board, onelimb of each line extending to test contact". portions of the jacks, a switch at the exchange being included in this limb of the line for opening and closing the same, a differentialelectrO-magnetic device for operat ing the switch, cord connecting ap aratus seIVlIlg to energize the magnet in sue a way as to operate the switch, and an operators testing circuit, substantially as described.

29; In a telephone exchange system, telephone lines each extending by its limbs from v a substation to an exchange, line signals in such line circuits, a source of electric energy at such exchange adapted .to supply talking and signaling current to such lines, line jacks for terminating such lines at such exchange, test contacts associated with such jacks normally disconnected from such line limbs and relays serially included in such line circuits for disconnecting such line signals and connecting such contacts to the corresponding line limbs.

30. In a telephone exchange system, a telephone line extending by its limbs from a substation to an exchange and there adapted to terminate in a pair of jack contacts, one of such contacts being normally disconnected from the line limbs, a line signal associated with such line circuit, a source of electric energy at such exchange adapted to supply talking and signaling/current to such hue and means in such line circuit for connect ing the normally, disconnected talking contact'to the corresponding line limb.

31. In a telephone exchange system,'.tele-. phone lines each extending by its limbs from a substation to an exchange, line signals in such line circuits, a source of electric energy at such exchange adapted to supply talking and signaling current to such lines, line jacks for terminating such lines at such exchange, talking contacts associated with such jacks normally disconnected from such line limbs and relays normally connected with such line limbs and adapted when actuated to disconnect such line signals and con.- nect such contacts to the corresponding line limbs.

32. In a telephone exchan e system,.the combination of a telephone ine extending by its limbs from a substation to an exchange, a spring jack at the exchange having main talking contacts adapted for connection with such line limbs, one of such contacts being normally disconnect ed therefrom,c ord connecting a paratus for .7

connecting said line with anot er for con; versationand a differentially wound electromagnet normally included in circuit with such line limbs and adapted to be actuated to connect the normally disconnected jack contact with one of such line limbs upon the connection of the cord circuit with suchspring jack. I

33. In atelephone exchange system, the combination of a telephone line extending by its limbs from a substation to an exchange, a spring jack at the exchange having main talking contacts adapted for connection with such line limbs, one-of such contacts being normally disconnected therefrom, cord connecting apparatusfor connecting said line with another for conversation and an electroma etic device having two windings, one 0 such windings being normally connected in circuit w1t-h the-linelimbs, and the other winding adapted to be energized by current flowin over the cord connecting apparatus upon t e connection of such apparatus with the spring jack of the line to cause the electromagnetic device to be actuated to connect the normally disconnected 'jack contact with one of such line limbs.

- 34. In a telephone'exchange system, the

combination of a telephone line extending by its limbs from a substation to an exchange, a spring jack at the exchan e having main talking contacts'adapted r connection with such line limbs, one of such contacts being normally disconnected therefrom, a line signal at such exchange nor,- mally under the control of cord connecting apparatus for connecting such line with another for conversation and an electromagnetic device having two windcombination of lugs, one of such windings being normally connected in circuit with the line limbs and the other winding adapted to be energized by current flowing over the cord connecting apparatus upon the connection of such apparatu's with the spring jack of the line to destroy-the substation control of such line signal. Q

35. In a telephone exchange system, the a telephone line extending by its limbs from a substation to an exthe substation,

five cents each, by addressing the waahlng'tbn, D. 3."

change, a spring jack at'the exchange having main talking contacts adapted for connection with such line limbs, cord connecting apparatus for connecting said line with another for conversation and an electromagnetic device having two windings, one of said -windings being normall connected with a line limb and the ot er winding adapted to be energized by current flowing over the cord connecting apparatus upon the connection of such aparat'us with the spring jack of the line to a ter the line connections. v I

36. In combination, and a line indicator in circuit with a telephone line, and a cut-off relay so connected to such circuit as to be insensitive to current caused to flow from said source through the winding of said relay by a switch in the telephone line. v

37. In combination, a source of current and a line indicator in circuit with a telephone line, a cut-off relay adapted to remove said indicator from said clrcuit, and a switch in circuit from ing of said relay.

In witness whereof I said source through the windrelay without operating said hereunto subscribe l my name this 26th day of May, 1903.

HARRY G. WEBSTER. Witnesses:

LYNN A. WILLIAMS, H mvnx L. HANSON.

" commoner of Patents,

a source of current the telephone line for closing a.

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