US572223A - Apparatus for telephone-switchboards - Google Patents

Description

N M d 1.) .e o. E. SCRIBNBME P. R. MOBBRTY. APPARATUS FOB. TELEPHONE SWITGHBOARDS.

No. 572,223. w Patented Deo. 1', 1896.-

@aviles E 23,07%' 522er @m76 R. 7769/367??y UNITED STATES PATENT OEEICE.

CHARLES E. SCRIBNER, OF CHICAGO, AND FRANK R. MCBERTY, OF

DOYVNERS GROVE, ILLINOIS, ASSIGNORS TO THE VESTERN ELEC- TRIC COMPANY, OF CHICAGO, ILLINOIS.

APPARATUS FOR TELEPHONE-SWITCHBOARDS.

SPECIFICATION forming part of Ietters Patent No. 572,223, dated December 1, 1896.

Application filed June 6, b894- Serial No. 513,719. (No model.)

To all whom vit may concern:

Beit known that we, CHARLES E. SCRIBNER, residing at Chicago, in the county of Cook, and FRANK R. MGBERTY, residing atDowners Grove, in the county of Du Page, State of Illinois, citizens of theUnited States, have invented a certain new and useful Improvement in Apparatus for Telephone-Switchboards, (Case No. 356,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

Our invention relates to the keyboard apparatus of telephone-switchboards, more particularly to the switching apparatus for connecting the operators telephone and the generator of si gnaling-current with the plug-circuit in the operation of establishing communication between two telephone-lines comprised within the exchange.

In switchboards commonly in use each telephone-line terminates in a socket upon the switchboard, and the attendant operator at the switchboard is provided with a number of pairs of connecting-plugs adapted to lit the sockets, the members of each pair being electrically united. In combination with the conductors uniting the two plugs of a pair several switch-keys are arranged, usually one for switching the operators telephonie appliances into and out of connection with the plugs and others for looping either plug into circuit with the generator of signaling-current for operating the signaling-bells at the substations. In establishing connect-ion between two telephone-lines the operator is required to insert one plug of a pair into a socket of each of the lines to be connected and to manipulate first her listening-key 'both for connecting and disconnecting her telephone from the plugcircuit and afterward the callin g-key for signaling to the substation of the line with which the connection has been completed-the answering-line.

It is the object of our invention to perform these operations of connecting and disconnecting the telephone and the generator of signaling-current automatically at suitable times in the process of making the desired connection, thus relieving the attendant of the manipulation of all mechanism excepting the connecting-plugs themselves, and at the same time dispensing with switch-keyson the face of the switchboard. To this end we have provided a local circuit in the exchange, normally open and terminating in a contact-piece upon the spring-jack switch or socket of the telephone-line and in a cooperating contactpiece upon the connecting-plug, and a relay of peculiar construction included in this local circuit having switch-contacts controlling the circuits between the connecting-plugs and the telephone and signaling-generator. The operation of inserting the connecting-plug into a spring-jack to make or complete a desired connection closes the Alocal circuit, whereby all the necessary switching of other appliances into and out of circuit is performed.

The instruments which it is especially desirable to thus automatically switch into connection with the plug are, as beforev mentioned, the telephone and generator of sigmaling-current, and when our relay is required to control the circuits of these appliances only it may consist of a lever connected with one conductor of the plug-circuit normally resting against an anvil constituting a terminal of the telephone, but brought, when attracted, against a lever which is connected through a suitable yielding connection With a pole of the calling-generator, the yielding connection being adapted to follow its lever only a short distance, separating therefrom and thus breaking the circuit of the calling- .generator before the relay-lever shall have reached its extreme forward position. The lever carrying the yielding connection, or this connection itself, may be considerably retarded, if desired, to prolong the moment of connection between the lever and the generator. In combination with metallic circuits it is desirable to. duplicate the switch parts, in order to make the necessary connections simultaneously with both conductors of the metallic plug-circuit.

It will be understood that our relay is equally well adapted to perform any other desired or usual operation of switching whose accomplishment is required during the time IOO the operator is handling the connectin g-plu gs, and, of course, the details of construction herein described are uncssential toits operation.

Our invention is especially adapted to use in connection with that type of telephoneswitchboard in which the annunciators are of the self-restoring or self-resetting form, a local circuit being provided in combination with the spring-jacks adapted to be closed through the resetting-magnet of the annunciator when a connecting-plug is inserted into a spring-jack of the corresponding line. In this type of switchboard the local circuit mentioned commonly terminates in two normally-separated springs in each spring-jack, which springs arey adapted to register with and be crossed together by an insulated ring upon the connecting-plug springs is grounded through a battery or other source of electric current and the other spring` through the resetting or restoring magnet of the individual annunciator. In adapting our invention to this switchboard we `provide a conductor or cord' strand extending to this insulated ring upon the plug and grounded through `the magnet of our relay, this connection being preferably made with the test-plug or that member of a pair which is employed in completing the connection;that is, the one which is designed to be inserted into the spring-jack of the answering subscriber.

Our invention is illustrated in the accompanying drawings.

Figure l of the drawings represents in perspective viewthe relay which performs the operation of vswitching the different appliances. Fig. 2 is a diagram of two telephonelines extending from substations to a telephone-exchan ge and terminating at the exchange in annunciators and spring-j acks upona switchboard, the telephone-lines being supplied with local annunciator-restoring circuits, and plugs and plug-circuits for uniting the lines equipped with our improved relay and arranged with certain connections appropriate thereto.

' Referring to Fig. l, it will be observed that our relay comprises, as before described in a general way, an electromagnet a., controllingan armature l), carrying two levers c and c', which normally rest against adjustable anvils d and cl,but which may be brought against the extremities of-pivoted levers c and e. These levers c c are continued `in flexible extensions ff, which normally rest upon contact-anvils g g. rlhe armature h is carried upon a lever h, pivoted in trunnion-screws 7L h2. The lever 7L carries a horizontal `arm h3, provided at its extremity with an adjustable hook attached tota retractile spring h4,

' whose other extremity is iixed to a projection of the frame of the instrument. The levers or arms c c' are rigidly connected with this armature-lever h, but are insulated therefrom by an interposed plate of hard rubber.

One of these -their contact-stops g and g".

The adjustable contact-anvils or stops d d are insulated from. the frame by bushings of hard rubber.

The levers e c' are likewise in mechanical connection with but electrically insulated from a block i, pivoted on trunnion-screws t" t2, and also provided with an extension 3, fixed to the free extremity of a retractile spring t4. The block or lever 'L' carries a rigid arm t5, to which the plunger of a dash-pot i is pivoted, retarding the movement ot' the lever.

In the normal position of this apparatus the armature b is drawn back from its magnet by spring 71,4, and the contact-levers c and c' rest against their stops d and d. The lever vl is also retracted by its spring t4 into a position in which the yielding extensions f and f rest upon their anvils g and g, these being adjusted, however, so that the levers c and c.

do not touch the extremities of levers c and c'.

Vhen the. magnet a is excited, armature b is attracted, withdrawing levers yc and c from their resting-stops and closing them against the extremities of levers e and e'. In the further motion of armature b the levers e and c are carried with it in opposition to spring i4, the motion being-retarded by the dash-pot i6. After the levers c e have passed through a certain predetermined range of motion the yielding extremities f and f' are lifted from 'When the inagnet d is again demagnetized, the levers c and c instantly separate from the levers e and c, which latter slowly follow to their normal position, impeded by the dash-pot i6.

.Referring now/to the diagram, Fig. 2, we will trace the organization and `operation of our invention in connection with a telephoneswitchboard.

The substations 7c and k are equipped with the usual apparatus, comprising a telephone Z, a genera-tor Z', a signal-bell l2, and an automatic switch Z3, adapted to be controlled by the telephone to switch the telephone and the signaling apparatus alternately into circuit, according as the telephone is removed 'from or replaced upon the switch-hook. Each substation is connected by line-wires with the usual apparatus at the exchange. Thus from vstation 7c extend line-wires l and 2, which are connected at the exchange with a spring m and a thimble in", respectively, of each of two spring-jacks n and n and with the extremities of the main or operating coil of an individual annunciator o. The springjacks n and n may be assumed to be located upon different sections p and p of a multiple switchboard, the annunciator 0 being upon the section p.

In addition to the line-contacts m and m each spring-jack is provid-ed with two local contacts or springs m2 m3, the former being connected also with asmall ring mAL at the front of the jack for, testing purposes. Springs fm2 of the different spring-jacks are connected together by a conductor 3 and are IOS IIO

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grounded through the restoring or resetting magnet q of the annunciator 0. The springs m3 are connected together by a conductor 4c and are grounded through a battery r.

The apparatus of substation Zt" is connected with like mechanism at the exchange by linewires 5 and 6, the spring-jacks being lettered in the drawings n2 and n3 and the annunciator o. The annunciator 0 is supposed to be located upon the section p of the multiple switchboard, so as to be under the attendance of a different operator. The conductors 7 and 8 of the corresponding local circuit are also arranged in a manner exactly similar to those of station lo, the batteries r being identical, if desired.

The switching mechanism provided for the attending operator is shown at switchboard p only, a single pair of plugs and accessory devices being represented for the sake of clearness. The plugss and s' each comprise a central tipi, adapted to register with the line-spring m, an insulated ring or sleeve t to cross together the springs m2 and m3, and a sleeve t2, adapted to make connection with the ring 'In'. The tipst of the two plugs are connected together by a conductor 9 and the sleeves t2 by a conductor lO. The ring t of plug S is insulated, but that of plug s is connected by a separate flexible conductor ll to earth through the magnet a. of the relay'. A clearing-out annunciator u is provided in a permanent bridge connection between conductors 9 and lO. The levers c and c of the relay are connected with conductors 9 and l0, respectively, while their resting-stops d and d constitute the terminals of the operators telephone set v. The resting-contacts g and g of levers c and e constitute the terminals vot" a continuously-operating generator a: of signaling-current. The circuit of this generator is carried through the restoring or retaining magnet u of clearing-out annunciator u., in order that when the generator is connected in a bridge between conductors 9 and l0 the clearing-out annunciator shall not be operated by the current shunted through its main magnet, it being rendered unresponsive at that moment by the current of generator x through its restoring-magnet.

To follow the operation of this system, assume that subscriber at station 7s desires to communicate with subscriber at station k. The generator Z at station 7s being rotated, current is transmitted over the line and through the main magnet of annunciator o, causing the latter to display its indicator. The operator at switchboard cl, observing this signal, inserts the plug s into the spring-jack n of the correspondingline at her switchboard. By this means the conductors l and 2 are extended through the tipiL and the sleeve t2 of the plug s to the conductors 9 and 10, thence to the levers c and c', and thence to the operators telephone r. The operator is thus in position to receive the oral order of subscriber at station k for the desired connection. The operation of inserting plug s into spring-jack n has crossed together the springs m2 and m3, completing the local circuit of battery r through restoring-magi] et q of annunciator o and thus resetting this annunciator to its normal position.

Having received the order, the operator tests the line called for in the usual way, to determine whether or not it is already in `use--that is, by applying the tip of plug s' to the test-ring m4 of spring-jack n3-and having found the line free she insertsthe plug fullyinto spring-jack n3. Local springs nm of this spring-jack are thus closed together, completing the local circuit through the restoring-magnet of annunciator o', and at the same time conductor ll, through the medium of ring t", is connected with battery r and current finds circuit therefrom through magnet a. The latter being excited attracts its armature. In the irst movement of the latter the telephone fu is disconnected from conductors 9 and l0, the levers c and c being drawn from their contact-anvils d and Cl. An instant later levers c and c/ make contact with levers d and d', and since the yielding extensions of these levers still rest against their stops g and g the generator :r is closed in a bridge connection between conductors 9and 10. A signaling-current is thus transmitted to the substations, operating the bell Z2 at station 7c', where the telephone is still upon the switch-hook. The levers c and c' now carry with them the retarded levers e and c, by which the connection of the latter with anvils g and g is soon interrupted, after which the levers o and c/ are disconnected from all other circuits.

The operations of disconnecting the telephone and of signaling to the substation of the answering subscriber to call his attention to the telephone are thus performed automatically,without the manipulation of any switching apparatus by the operator.

\Vhen the subscribers have completed their conversation, either or both may give the usual signal for disconnecting by rotating his calling-generator Z', the signal being received and indicated by the clearing-out annunciator u. The operator then withdraws the plugs s an d s from the spring-jacks. Circuit through magnet a is thus interrupted and the relay is permitted to return to its normal position, in which the telephone o is connected with conductors 9 and l0, in condition for communication as soon as plug s is inserted into another spring-jack to answer a call.

As we have before stated, our invention herein described is of abroad and general character, and we do not desire to limit ourselves to any specific form of relay or to any particular appliances which the latter may switch into or out of circuit; and

lVe therefore claim, broadly, as new and desire to secure by Letters Patentl. The combination with a telephone-line,

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' itwith another line by means of a spring-jack' 1 thereof, a relay controlling switch-contacts included in the circuit of the telephone, and a local circuit containing the magnet of the said relay terminating in registering contactpoints of the said plug and spring jack; whereby the operators telephone is connected with the line until the plug is inserted in the said spring-jack, and is reconnected With the line when the plugis removed from the springj ack, -as described.

2. The combination with a pair of Aplugs adapted for insertion into spring-jacks of telephone -lines, the plugcircuit uniting the plugs,'and:an operators telephone in a bridge of the plug-circuit, of switch-contacts included in the bridge containing the telephone, an electromagnet controlling the switch-com vtacts, and a 4local circuit terminating. in reg- Y istering contacts'upon one ofv the plugs and the spring-jacks, completed when the plug is inserted into a spring-jack substantially as described.

3. The combination withv telephone-lines terminating in spring-jacks, of a connectingplug adapted for insertion into one of the spring-jacks, and the plug-circuit thereof, a generator of signaling-current, and an electromagnetic switch adapted When excited to connect the generator of signaling-current with the plugcircuit, a local circuit independent of the line including the electromagnet of said switch terminating in contactpieces adapted to be closed together in the act of inserting the plug into the sprin g-j ack, substantially as described.

4. The combination with a connecting-plug and an operators telephone, of an electromagnet connected with a circuit of the plug 'adapted to be'closed during the insertion of the plug in a spring-jack, and switching mechw anism actuated by said magnet to interrupt the circuit of the telephone, substantially as described.

5. lIn combination, a conductor forming a part or extension of a line to atelephone-substation, a relay having a lever c connected with said conductor, normally yresting upon a stop CZ connected with a telephone, adapted to makeconnection with and to carry with it a lever e when it is attracted to its magnet, a contact f'electrically conneetedWith said lever c and adapted to be separated thereby from its restingstop g, means for retarding Vthe movement of lever e, and a generator of signaling-current connected with stop g, substantially as described.

In Witness whereof We hereunto subscribe our names this l'7thfday of May, A. D. 189i.

'CHARLES E. SCRIBNER. FRANK R.1MCBERTY.

lVitnesses:

GEORGE L. CRAGG, W. GLYDE JoNns.

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