US597787A - Charles e - Google Patents

Description

(No Model.)

0. E. SGRIBNER.

APPARATUS FOR TELEPHONE SWITGHBOARDfi 'No. 597,787. Patented, Jan. 25, 1898.

m5 mums PETERS no. PHOTO LYTHQ..WASH5NGTON, 0 c.

UNITED STATES PATENT Erica CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE lVESTE-RN ELECTRIC COMPANY, OF SAME PLACE.

APPARATUS FOR TELEPHONE-SWITCHBOARDS.

SPECIFICATION forming part of Letters Patent No. 597,787, dated January 25, 1898.

Application filed December 18,1896. Serial No. 616,128 (No model.)

This invention concerns means for auto-v matically controlling line signals of telephone lines in switchboards through the agency of the station apparatus of the line and for causing the edacement of the signal in the establishment of the required connection with the line.

Prior to this invention signaling appliances have been used consisting of subsidiary signals in the switchboard associated with the lines and relays controlling the line-signals responsive to cu. rren ts in the lines determined in the use of the telephones at the substations, and it has been proposed to cause the eiiacement of the line-signal or to return it to its normal inert condition in the operators act of making connection with the line in response to an initial call through the agency of a second relay excited incidentally through suitable circuits changed in that act and acting to shift the circuits of the subsidiary sig nal in a suitable way to effect the desired end. The present invention relates to organizations of this type; and it consists in a specific arrangement and construction of the relay connected with the line and controlling the signal to display it and of the relay excited in making connection with the line and controlling the same signal to efiace it, as follows: The magnets of the two relays act upon an armature common to both. The relay in the line when excited brings this armature into contact with an anvil and thus closes a local circuit through the subsidiary line-si na-l. The other or local relaybecomes excited when connection is made with the line in reply to this signal and retracts the armature in opposition to the force of the line-relay, thus breaking the circuit through the subsidiary signal and rendering that appliance inert. This local magnet is placed in a local battery circuit terminating in normally-separated contact-pieces in the spring-jacks of the line, which become connected together by a plug inserted in the spring-jack.

The invention is illustrated in the accompanying drawing, wherein two substations are represented with line conductors led to signaling and switching appliances in the switchboard, a single pair of plugs and their plug-circuit being shown in the switchboard in position for uniting the two lines.

The apparatus at the substation is of wellknown type, the apparatus being adapted to close the line-circuit as to continuous cur rents while the telephone is in use. The line conductors are connected in the switchboard at the central office with the line-contacts of spring-jacks a and a and are extended through windings of the relay b to the poles of a battery 0, which is common to the diiferent lines of the exchange. The spring-jacks are assumed to be upon difterent sections of V a multiple switchboard. The armature b of the relay b, with its contact 6 controls a local circuit 3, which includes a signal-lamp d, associated with spring-jack a, together with a source of current. The armature Z7 is also within the field of a magnet b which is included in a portion 4 of the local circuit which terminates in thimbles or contact-rings e of the spring-jacks of the line. The compleinentary portion of the local circuit is a conductor 5, which terminates in opposing contact-pieces c in the spring-jacks. This conductor includes a battery f. These parts 6 and e are designed to register with and be crossed together by a separate contact-piece in the plug which is used with them. The type of spring-jack is well known in the art of telephony.

The magnet 11 is constructed to have a greater eifect upon the armature b than the magnet b, and hence when excited acts to retract the armature to its normal position, in which it is separated from its switch-contact, and thus to open the local circuit 3.

The connecting-plugs g and g have each a pair of line-contacts h and h, which register with the springs e and e of the spring-jack, and a sleeve 71 which crosses together the IOU contact-pieces e and e of the spring-jack. The tips h of the plugs are united by a conductor 6 and the rings h by another conductor 7. These conductors constitute the plugcircuit. The usual calling-key t'is interposed in them in position to interrupt the connection between the two plugs and to loop a generator 7c of calling-current into circuit with the plug g, and the usual operators listeningkey Z is furnished to bring the operators telephone m into bridge of the plug-circuit. In a permanently-closed bridge 8 of this circuit the source of current a is contained, together with windings of impedance-coils 0. the windings, o, is included between one pole of the battery and the conductor 7. Two other windings, 0 and 0 are interposed between the battery and conductor 6. They are normally connected in multiple, but their.

multiple connection is controlled by switchcontacts Z and Z of the operators listeningkey for purposes of testing, as will be hereinafter described. That pole of battery 0 which is connected with conductor 6 is also grounded.

The sleeves 72 of the plugsg and g constitute the terminals or grounded conductors9 and 10, respectively, whose continuity is controlled by the switch-contacts ofrelays p and The magnet of the former of these is includedin conductor 7 of the plugcircuitbetween the plug 9 and the point of connection of battery 0 with the plug-circuit, and that of the latter is similarly included in conductor 7 between plug g and the battery. Hence each of the relayswill respond to current created by the battery in the plug-circuitand through the conductors of one only of the linesthat one with which the plug corresponding to the relay is connected. These conductors 9 and 10 include supervisory lampsignals q and g, respectively, each of which is associatedwith the plug formingtheterminal of the conductor which includes it.

The operationof these signals is as follows: The removal of the receiving-telephone from its switch atasubstation permits the battery 6 to create a current in the line-circuitvand through the windings of magnet b, whereby the magnet is caused to close the local circuit,

3, including the subsidiary signal-lamp cl. The lighting of this lamp calls the attention of the operator, who responds to the signal by inserting plug g into the answering-jack a. This'act creates an extension of the line conductors 1 2 through the conductors 6 and 7 of the plug-circuit, and thence to the oper-v ators telephone, the key Z having beenv depressed, so that the operator is broughtinto. communicationwith the subscriber. -It,als0 closes the local circuit 4 5 by crossingtogether the contact-pieces e and e of the springjack, whereby the armature b of the relay is retracted and the signal-lamp d is extin guished. At the same time the electrical condition of test-rings e of the line isalteredto indicate the busy condition of the line to an operator at a distant switchboard, the rings "office.

nection required,the operator makes the usual test of the line called for by applying the tip being raised to a difference of potential from the earth corresponding to the electromotive force of battery f. The conductor 9, terminating in the sleeve 71 of the plug, also becomes connected with this battery f in condition to permit the illumination of supervisory lamp q when the break in the conductor shall be closed by relay-p. It will be observed that this relay is now excited by current flowing from battery 0 through conductor 7, line conductors 1 and 2, and conductor 6 of the plug circuit, returning to battery 0 at the central Having learned the order for the conh of plug 9 to the test-ring e of the springjack of the required line. Obviously if no connection exists with that line no test-signal will be received, since the circuit which is completed from earth through winding 0 conductor 7 to the tip of the plug, and conductor t to earth includes no source of current. If, however, a connection with the line be already in existence, there will be a branch from the rings 6 through the plug, whereby the connection has been made to the contactpiece 6" and thence through battery f to earth. Then at each application of the test-plug to the test-ring a current will flow through the winding 0 of the impedance-coil to earth,

whereby a current will be induced in winding '0 which will circulate in the circuit including the operators telephone and will make an audible signal therein.

It will be noted that the conductor 6. of the plug-circuit forms a portion of the returncircuit of 'current'rt'rom batteryc through the line, and. hence its electrical condition will be altered by various changes in the conditions of the line and its utility as a portion of a circuitvfor testing the electrical condition of other lineswould be impaired, The function ofcontacts Z and Z and of windings 0 and o is, to separate the portion of conductor 6 lead ing to the tip of the plug from the remainder of the plug-circuit, preserving only an inductive connection between them. Then no change in the conditions of the circuit exinto the spring-jack brings the spring-jacks of-that line into condition to test busy subsequently. It. also causes the magnetb of that line .to holdthe armature Z2 against any force which the othermagnet b may exert and brings the battery f into circuit with conductor 10, including the supervisory signal q".

\Vhen the- Since no circuit as yet exists through the subscribers line to the station called, the telephone at that station being still on its switchhook, the relay 2) is inert and permits the closing of the break in conductor 10. Hence the supervisory lamp q is lighted and remains in that condition until the response of the subscriber called permits the battery 0 to create a current in the line.

While both supervisory lamps q and q remain dark, the operator may assume that the subscribers are in conversation. When both become lighted, this may be taken as indicating a signal for disconnection, after which the plugs may be removed from the springjacks and the appliances returned to their normal condition.

My invention is defined in the following claims: I

1. The combination with a telephone-line and means for determining the flow of current in the line during the use of the telephone, of a magnet responsive to current in the line, an armature therefor, a secondary signal, and circuits including the secondary signal controlled by switchcontacts operated by the said armature, a second electromagnet adapted to retract the armature, a circuit includin g said second magnet, and circuits closed to excite the said magnet in the act of making connection with the line, as described.

2. The combination with a telephone-line and means at the station thereof determining the flow of current in the line during the use of the telephone, of a magnet in the line, an armature for the magnet and switch-contacts therefor closed when the armature is attracted, a secondary signal and a local circuit including the signal controlled by the switchcontacts, a second magnet acting on the same armature and adapted to retract it, a local circuit including the latter magnet, a springjack for the line and a plug therefor, and normally-separated switch -contacts crossed together by the plug in the spring-jack completing the last-mentioned local circuit, as described.

In witness whereof I hereunto subscribe my name this 14th day of November, A. D; 1896.

CHARLES E. SCRIBNER.

Witnesses:

ELLA EDLER, Duncan E, WILLETT,

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