US1693029A - Cord circuit - Google Patents

Description

Nov. 27, 1928.

R. F. GOULD CORD CIRCUIT Inventor E'n F Bauld.

Nov. 27, 1928. 1,693,029

R. F. GOULD CORD CIRCUI T Filed March 25, 1927 2 Sheets-Sheet 2 Imren 01 j Eu F Gould. m m-1 Patented Nov. 27, 192 8.

nuirrasmrss ROY F. GOULD, OF

CHICAGO, ILLINOIS, ASSIGHOR, TO RESERVE HOLDING COIvIPtzI-TY, OF

KANSAS CITY, MISSOURI, A CORPORATION OF DELAW'ARE.

com) cinema;

Application filed March 23, 1927. Serial No. 177,548.

The present invention relates in general to cord circuits for telephone systems, but is particularly concerned with the provision of cord circuit which is suitable for use in handling incoming calls from an automatic exchange when connections are desired with subscribers of a common battery exchange of the type in which a source of current is permanently connected to the subscribers lines One object of the invention s to prov de a cord circuit wherein the operator has her headset automatically connected in bridge of the incoming trunk when theanswering plug is inserted in the answering jack, and wherein her headset is automatically disconnected and ringing automatically takes place the instant the calling plug is inserted in the ack' the desired line. Another object is to provide a peculiar ringing arrangement necessary due to the peculiar type of manual equipment used, and

in the provision of a novel circuit arrange ment for cutting off the ringing current as a result of the response of the called subscriber.

A further feature has to do with an arrangement in the cordfor causing a reversing relay in the repeater of the incoming trunk to be actuated for the purpose of operating a suhscribefis meter or for supervision.

Other features of the invention not specifically mentioned will become apparent from the detailed description and claims which follo-w. 3

In order to assist in describing the invention the same has been illustrated in set of drawings comprising Figs. 1' and 2, which, when placed together with their correspondlines in alignment, show sufficient of a e vention to be t lephone system to enable the in exp i'ained and understood.

of the usual type used inautomatic telephone systems, while the one shown in Fig. 2 is of the type commonly used in common battery manual systems. I

The circuits of automatic switches available to the substation A .have'not' been shown, as switches of this character are well known and have no particular bearing on the invention.

'lwoautomatic switches C and D, respectively, have been represented by the dotted rec angles which indicate a line switch in which the calling line terminates and which,

The substation circuit shown in Fig. l is in turn, has access to a selector group as is customary.

The repeater E is of the general type ordinarily used in trunks extending between automatic and manual exchanges and is provided primarily. to avoid the necessity of extending three conductors between the two exchanges. This circuit has been slightly modified and will be described in detail later. In F 2 is shown t-heanswering jack of the trunk extending to zthe repeater E which is typical of answering equipn'ient ordinarily used for this purpose. a

The cord circuit 0 is for use in answering calls originating in the automatic exchange and for completing calls to the subscribers of .the'manual exchange. This cord circuit previously stated, has quite a number of features of novelty all of. which will be described hereinafter.

The answering jack J and its associated relay group is of the type used in a common battery manual telephone system, developed by the Erickson Company ofSweden and installed in the U nion of South Africa.

The various circuits and apparatus used having been generally described the invention will now be explained by giving a detailed accountof the circuit operations wh ch takes place consequent to-theestablishment' of a connection from the substation A of the automatic exchange to the substation B of the manual exchange.

The subscriber at substation'A upon desire,

ingto extend a connection to the substation B of the manual exchange removes his receiver, responsive to whichthe lineswitch' G, in the Well known manner, extends the line to a first selector, indicated at D. The calling sub scriber thereupon operates is calling device to position the switch D opposite a level of bank contacts in which terminate trunk multiples connectedwith the manual exchange.

In the present instance we will assume that connection is extended to the repeater E.

I Responsive to the seizure of this repeater the line relay 17 energizes and at its armature 14F connect the trunk conductor 26 ,to the winding of relay 24 and ground, and at its armature 10 causes the energization of holding relay 18. The relay 18 upon operating,

its arn'iature 19 disconnects the trunk conductor 25 from the winding of relay 23 and latter-y and connects conductor 25 to winding the release of the lineswitch C and the selector D, and atits armature 21 prepares an operating circuit for the slow release relay 22.

As soon as the Windingof relay 2% is connected to conductor 26, it energizes in series with the relay Connected to the ring terminal of the jack J. The relay 2 operates and completes a circuit for slow release relay 23 Which in turn operates for a purpose Which will later be made clear. operating, causes the lamp L to light and to informthe operator of the incoming call.

The operator responds by inserting the plug l? of the cord into the jack J thereby openingthe circuit of relay 70- and extinguishing the calling'lamp L". The insertion of the plug l? into the jack J also causes the battery supply for 1 24 in the repeater to be transferred to th relay via the lower left-hand Winding of the repeating coil R, and ring conductor 28. The relay 80 operates, at its armature l1 disconnects the release supervisory lamp L of the cord from the grounded sleeve conductor 29, and at its armature a2 and its Working contact closes a point in the outgoing branch of the cord. As soon as the plug P is inserted in the jack J a circuit is also completed for the operators headset cuton relay 40,.r'rom battery, Winding of relay {L0, armature 58 and its restin contact, armature g l'and its resting contact, to the sleeve of the plug and jack to ground. The relay 40, therefore, operates and at its armatures l3 and ll connects the operators headset across the right-hand windings of the repeating coil. B so that the operator may inquireand obtain from the calling party the number of the de sired party.

Since it scriber at substation B is desired the operator Will proceed to test the line to determine Whether the same is busy or idle. This is done in the usual manner, by the operator touching the tip of her plug to the sleeve of the jack. .VVe Will. assume that the desired station is idle and therefore thatthe operator proceeds by inserting the plug 1? into the jack J. Responsive to this operation the relays 47 and 67 operate. Relay 47 at its armatures 51 and 52 and their Working contacts connects interrupted battery and interrupted ground, respectively, out over the tip and ring sides of the cord; in this manner although the indings 68 and 69 used for 'leeding current to the substation B are permanently connected to the'line conductors, they do not interfere.

ith the transmisison oi ringing current. Interrupted battery, or interrupted gcnerator, as indicated on the drawing, F 2, is meant to, designate rin ig current superinr posed on battery current and applied intermittently, in conformance to the usual prac- T he relay 70 upon has been assumed that'the sub During the ringing operation a small amount of the ringing current leaks back to the calling line through the condenser 53 to inform the calling subscriber that the called The relay H at its .7

line is being signalled. armature 4l8'and its grounded Working contact completes a circuit for the supervisory at this time. Relay 55 at its armature 58' opensa point in the circuit of relay 40 causing I this relay to restore and to disconnect the operators head. set, and at its armature 57 prepares a point in the operating circuit of relay Should the calling subscriber replace his receiver'ivithout having obtained the response of the called subscriber, line relay 1'? will re store and at its armature l l'break the circuit oi supervisory relay 30. This latter re-' lay upon restoring, at its armature 41 closes circuit for lamp L to give the operator disconnectsupervision and at its armature 42 disconnects the interrupted generator so that signalling of the called line is immediately discontinued.

We will assume that the called subscriber responds. While ringing current is actually being transmitted out over the line the Winding of relay 68 is shunted. Accordingly, the removal oi the receiver at the called station will be Without effect until a silent period occurs. As soon, however, as the ringing current is interrupted momentarily, providedthe called party at substation B has removedthe receiver,line relay 68 energizes and connects batteryby Way oi? its Working contact and armature, armature and Working contact of relay 6'? directto this latter relay, thereby short circuiting relay L, causing it to re store, to cut-oil the ringing current. This relay also at its armature a8 opens the circuit of the lamp L to notify the operator that the called subscriber has responded; at its arn'iature 50 breaks the circuit of slow release relay 55 and at therestingcontact of this armature momentarily completes a circuit, via Working contact and armature 57, for the relay 35. This latter relay upon operating, at'its armatures 36 and 39 opens points in the interrupted ground and interrupted generator ringing circuit so tl at the subsequent energization of the ringing relay 4:7 will be ineiicctive to again transmit ringing current to the called line, and atthc working contacts oil ari'natures 36 and 39 connects the tip and ring conductors GOaiTd 61 to the right hand windings of the repeating coil. This relay also at its armature 39 and its orking contact connects relay 32 to the outgoing ring conductor 61 of the cord which has battery supplied to it through the Winding 69. Relay 32, therefore, operates and .at its armature 33 looks up relay .35 independent of relay 55. The relay 35 also, at its armature 38 opens the circuit used .during the ringing operation to inform the calling subscriber that the called subsoriber was being signalled, and at its armature 37 closes an operating. circuit for relay of the repeater E, via the grounded retardation coil 15, working contact and armature 3'7, resting contact and armature. 4L9, tip conductor 27 of the cord, trunk conductor 25, armature 19 andits working contact. The relay 15, upon operatingcauses the operation ot'the reversing relay 16 which,.in a well :understood manner reverses the direction o'fcurrent flow back over the calling line to ope ate metering, pay station or supervisory equipment de endin u )011 the Joint from which the call originated.

In the description just given it will be re called that the operator had her headsetautomatically connected to the incoming trunk when the call was answered and that when she. extended the connection this equipment was automatically cut off. It is'desirable in certain instances for the operator to come in on the connection to further supervise the call and in order to facilitate doing this an emergency key K is provided. This key may be operated at any time. by the operator to cause the energization of relay 40 to connect her equipment with the cord. It will be under stood however that-this key is ordinarily used only in an emergency.

The connection having been established it will now be assumed that the. conversation has beencompleted andthe calling subscriber is the first to restore his receiver. Responsive to this act line relay '1? deenergizes, at its armature 14 opens conductor 26 of the trunk, which causes the deenergization of relay 24 in the repeater E and of the supervisory relay 30 in the cord O, and at armature 10 breaks the. circuit of relay 1-8 and momentarily closes a circuit for relay 22. The relay 18, upon deenergizing, removes ground from the holding conductor 13 to permit the switches D and C to be released from theconnection so that they may restore to normal, and at its armature-19 switches the conductor from the winding of relay 15 to the Winding of slow release relay 23; Consequently the relay 15 and the reversing relay 16 controlled by it restore to normal, While the relay 23 is held energized independent of relay 24 and, following the deenergization of relay 22, its circuit having been broken at armature 21, applies ground to conductor 13, so long as the operators cord circuit 0 remains connected with the answering and call- 1 111g acks, to make the trunk busy to selectors such as Inthecord O the deenergization of the relay at armature -41. causes disconnect lamp L to light up, and at armature 42 breaks the circuit of relay 32 which in turn breaks the holding circuit ofrelay 35. Relay 32 upon restoring at its armature 34 also .completes a circuit for the relay 4:0 frointhe grounded sleeve of the jack J, sleeve conducs tor of the cord, resting contact and armature 34:, resting contact and armature 58, and the winding of relay to battery. This relay therefore responds .to again connect the op erators set across the cord so. that she may ascertain the reason for the subscriber lat. substation B not having restored his receiver.

It the receiver is replaced at the'substation B before the subscriber replaces his-receiverat substation A relay 68 Will restore removing the short circuit. from relay 47. This relay will accordingly-be energized and at its armature 18 light the supervisory lamp L to inform the operator that the called subscriber has replaced his receiver.

1. In a telephone system, called lines, asource of current permanently connected in bridge thereof, a cord circuit for answering incoming calls and for extending connections to said lines, a source of intermittent. ringing current for signalling said lines, a

relay responsive to the connection of the cord with a line to cause said ringing current source to be applied thereover without disconnecting said current. source in bridge of the called'line, and a relay placed under control of the called subscriber, each time an interruption occurs in the application of ring ing current to the called linefor disconnects ing said ringingcurrent.

i 2. I In a telephone system, a called line comprising tWo line conductors terminating in a jack, a current source and aiirst relay permanently connected in bridge oi? said c-onduc-' tors, a cord circuit for ettectingconnections to said line, a source of intermittent ringing current, a second relay responsive to the connection of said cord with said line for applying said ringing current thereover with out disconnecting said first relay and said current source from across said line conductors, means at said called line for actuating said first relay, and means operated by said first relay for disconnecting said ringing current.

'3. Inatelephone system, a called line comprising two line conductors terminating in:

a jack, a current source and a first relay permanently connected in bridge of said conr If the subscriber o1 thezautoinartic exchange current.

4. In a telephone system, a called line comprising two line conductors terminating in a jack, a current source and a first relay permanently connected in bridge of said conductors, a cord circuit for effecting connections to said line, a source of intermittent ringing current, a second relay responsive to the connec'tion of said cordwith said line for applying said ringing current thereover without disconnectin said first rela and said current source trom across said line conductors, means at said called line for actuating said first relay, and means operable by said first relay and efii'ective only during an interruption in the application or said ringing current. for short circuiting said second relay to discontinue the application of ringing current.

5. In a telephone system, calling and called lines, each comprising two line, conductors terminating in a ack at an operators position, a current source and a first relay permanently connected in bridge of the line conductors of said called line, a cord circuit for establishing connections between said lines, a source or intermittent ringing current, a second relay in said cord for automatically connecting the operators telephone to said calling line upon connecting the cordtherewith, a third relay in said cord for automatically disconnecting said operators telephone and for automatically connecting said source oi ringing current to said called line upon connecting said cord therewith, Without disconnecting said first relay and said source of current from across said called line, means at said called line for actuating said first relay, and means operated by said first relay for disconnecting said rin ing current. V

6. In a telephone system, calling and called lines, each comprising two line conductors ;erminating in a jack at an operators position, a source of current and a first relay permanently connected in bridge of the line conductors of said called line, a cord circuit for e."- tablishing connections between said lines, a source of intermittent ringing current, a second relay in said cord for automatically con necting the operators telephone to said calling line upon connecting the cord therewith,

a third relay in said cord for automatically disconnecting said operators telephone and for automatically connecting said source of ringing current to said called lineiupon con necting said cord therewith, without discone necting said first relay and said source of current from said called line, means at said called line for actuating said first relay, and means operable by said first relay and effective only during an interruption in the application of said ringing current for disconnecting said ringing current.

7. In a telephone system, calling and called lines, each comprising two line conductors terminating in a jack at'an operators posi-' tion, a source of current and first relay permanently connected in bridge of the line conductors of said called line, a cord circuit for establishing connections between said lines, a source of intermittent ringing current, a second relay in saidcord for automatically connecting the operators telephone to said calling line upon connecting the cord therewith, a third relay in said cord for automatically disconnecting said operators telephone and for automatically connecting said source if ringing current to said called line upon connecting aid'cord therewith, without disconnecting said first relayand said source of current from said called line, means" at said called line for actuatingsaid first relay,'and means operable by said first relay andeffective only during an interruption in the application "of said ringing current for short circuiting said'third relay to discontinue the application of said ringing current. V

8. Ina telephone system, calling and called lines, each comprising two line conductors terminating in a jack at an operators position, a source of current and a first relay per manently connected in bridge of the line conductors of said called line, a cord circuit for establishingconnections between said lines, a

source of intermittent ringing current, a second relay 1n sald cord for automatically connecting. the operators telephone tosaid calling line upon connecting the cord therewith, a third relay in said cord for automatically disconnecting said operators telephoneand for automatically connecting-said source of ringing current to said called line; upon connecting said cord therewith, without disconnecting said first relay and said source of cur I rent from said calledlin-e, means at said called calling line for supervisory purposes upon the disconnection of said ringing current.

9. Ina telephone system, a calling l1ne a two conductor trunk line'accessible thereto and terminating in a jack at an operators position, a called line having two line conductors terminating in a secondjack at said position, a source of currentpermanently connected to said called line, a cord circuit for establishing connections between said trunk line and said called line, means in said cord circuit for automatically connecting the operators telephone to said trunk line responsive to connecting the cord therewith, a source of intermittent ringing current, means in said cord circuit for automatically connecting said ringing current to said called line and for disconnecting said operators telephone responsive to connecting said cord with said called line, without disconnecting said permanently connected current source from said called line, means controlled by said called line and including said permanently connected current source for disconnecting said ringing current, means for maintaining a current flow over said trunk line prior to the disconnection of said ringing current, and means for then altering the current flow over one conductor of said trunk line for supervisory purposes. Y

10. In a telephone system, a callingline,

a two conductor trunk line accessible thereto and terminating in a jack at an operators position, a called line having two line conductors terminating in a second jack at said called line, means controlled by said called.

line and including said permanently "connected current source for disconnecting said ringing current, means for maintaining a current flow over said trunk line prior to the disconnection of said ringing current, means forthen altering the current flow over one conductor of said trunk line, and means res sponsivethereto for altering the current flow over said calling line for supervisory purposes. 1

11. In a telephone system, a calling line, a two conductor trunk line accessible thereto and terminating at an operatorsposition, a called line, a cord circuit for establishing connections between said lines, means'in said cord circuit for maintaining a current flow over both conductors of said trunk line after establishing connection therewith, but prior to the completion of a talking connection with said called line, means in said cord circuit responsive after completion of said talking connection for altering the current flow over one conductor of said trunk line, and means responsive thereto for altering the current flow over said calling line.

In witness whereof, I hereunto subscribe my name this 21st day of March, A. D. 1927.

ROY r. GOULD.

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