US543901A - Charles e - Google Patents

Description

UNITED STATES PATENT OFFICE.

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THEVVESTERN I ELECTRIC COMPANY, OF SAME PLACE.

TELEPHONE-EXCHANGE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 543,901, dated August 6, 1895.

A li atio fil d November 12, 1894. Serial No. 528,527. (No model.)

To aZZ whom it may concern: branches of the line at the sub-station, one, Be it known that 1, CHARLES E. SCRIBNER, at least, of which must always be closed. In

a citizen of the United States, residing at Chiorder to conform to the requirements of either cago, in-the county of Cook and State of Illiof the methods of automatic signaling de- 5 nois,have invented a certain new and useful scribed, one of these branches must be con- Improvement in Telephone-Exchange Sysstructed of great resistance, so as to practitems, (Case No. 364,) of which the following cally open the line-circuit. The expense of is afull, clear, concise, and exact description, the system is thus increased while its effi- 6c reference being had to the accompanying ciency is somewhat reduced.

I0 drawing, forming a part of this'specification. In my invention herein I have aimed to ac- Myinvention relatesto signaling appliances complish the automatic transmission of the for telephone-exchange systems, its obj ectbe required signals without making the branches ing to produce a new organization in which containing the signaling telephonic applithe various necessary signals from the subances of Widely-different resistances.

:5 station to the central station may be trans- In myinvention Iprovide means at the submitted automatically in the use of the substation for momentarilyinterrupting the curstation telephone. rent in the line-circuit, and any annunciator It is usual in telephone-exchange systems or signaling device in the line at the central to provide each sub-station with a device for station adapted to display its signal in re- 20 transmitting the call or initial signal to the spouse to an interruption of the current central station to indicate to the attendant through it. In order to prevent the immeoperator that a connection is desired, and also diate elfacing of the signal at the central stato transmita disconnection-signal to indicate tion, I construct the annunciator with switchto the operator that an established connection contacts connected to open the circuit through 25 is no longer required. -These signals have it when the signal is displayed. I have also sometimes been transmitted automatically, combined with the line-circuit and annunciavarious devices having been employed for this tor an auxiliary or local circuit adapted to purpose. Of these the most common organibe closed in the act of making connection zation has comprisedasource of current at the with the line, in response to a call, to effect 0 central station connected with each telephonethe resetting of the annunciator, or to retain line through an individual or line annunciait inoperative independently of the continuity tor, the continuity of the circuit being conof the line-circuit when connection is made trolled at the sub-station by suitable switchwith the line in compliance with an order contacts in connection with the automatic from a different subscriber. Suitable clear- I 5 telephone-switch. In some instances these ing-out annunciators constructed in the same switch-contacts have acted to open the linemanner and also adapted to be operated by circuit, retaining it discontinuous as to curthe interruption of the line-circuit are emrents of constant direction during the use of ployed in connection with the plug-circuit for the telephone, the annunciator being in this uniting diiferent subscribers lines.

' 40 case adapted to display its signal upon and My invention comprises then, in general, during the interruption of current through its means at the sub station for momentarily magnet. In other forms the switch-contacts breaking the line-circuit, an annunciator in have acted to close the circuit during the use the line adapted to respond to such an inter of the telephone, the annunciator being arruption, and, having responded, to open its 5 ranged to respond to its current through coils. circuit to prevent its re-energization, together It will be understood, however, that in pracwith a source of current in the line, a local rice the circuit of the telephone-line must circuit for resetting the annunciator when be closed at the sub-station as to current of connection is made with the line, and clearsome character in order to permit communiing-out annunciators adapted to be operated 5o cation by signals or by means of the telephone by a final interruption of the line-circuit upon from the central station to the sub-station. the completionof conversation.

This has necessitated the employment of two My invention is illustrated in the accompanying drawing. Therein two sub-stations A and A are represented connected by means of lines 1 and 2, respectively, with the switching and signaling appliances at the central station, together with plugs and accessory apparatus provided for the operator in connecting the ditferent lines.

The apparatus at the sub-station comprises the usual telephone a and transmitter a and the signal-bell a in separate branches from the line-circuit, and a telephone switch-hook a [or automatically establishing connection with the telephonic or signaling appliances when the telephone is removed from or replaced upon the switch-hook. This switch is constructed to effect a momentary break in the line-circuit as it passes from one position to the other.

The line-conductor 1 connects at the central station with the line-spring b of a springjack 0 upon a telephoneswitchboard, and

with one terminal of a line-annuneiator (Z, whose other terminal is grounded through a battery 6, which is common to all the lines at the exchange. The annuneiator d comprises a magnet 01 and an armature d therefor, which is pivoted atits lower edge, so as to fall outward when unattracted by the magnet. Before the armature is pivotally suspended a light shutter or shield d in position to be struck by the armature d in its outward movement and to be thrown into aliori- Zontal position, thereby disclosing a number or other indication painted on the face of armature d This armature carries a light spring (1 which is adapted to cross together two contact-points d 61 when the shutter is attracted. These contact-points are included in the line-conductor between the line-wire and the annunciator d.

The spring-jack 0 comprises, in addition to the line spring 17, a tubular thimble b',which is connected by a conductor 3 with the lineterminal of annunciator d.

The connecting-plug, as f, is adapted to make connection with both the line-spring b and the thimble Z). The two plugs fand f of a pair are united through a conductor 4. This conductor includes two calling-keys 7t and 7t, and is rendered discontinuous as to currents of constant direction by the interposition in it of a condenser Two clearing-out anunnciators 7c and 7c are employedone in a branch5 and the other in a branch 6 from conductor 4 on eitherside of condenser i-the branches being connected by a common conductor 7 with the free pole of battery 0.

The calling-keys h and h are of peculiar construction, having, in addition to the usual contacts, a pair of switch connections comprising a spring Z and its anvil Z. The anvil Z is grotmded,while the springl is connected with the conductor, including the corresponding clearing-out annunciator. Either key acts to disconnect the tip of the corresponding plug from the other plug and to connect it with one terminal of a generator 171. of signalingcurrent, and at the same time to close the circuit of the corresponding annunciator to earth.

The usual listening-key n is provided for the operator to form a connection between the conductor 4 and her telephone-set 0.

Having thus described the mechanism and circuits of my invention, I will trace its operation.

In the normal condition of the apparatus current from the battery 6 finds circuit through annunciator d and its switclrcontacts d d 'to line 1,and thence thronghswiteh a and bell a to earth at the sub-station. Magnet (1 of the annunciator is excited and retains the armature d in its upright position, the shutter 61 concealing the indication on the face of the armature.

Assuming that subscriber at station A wishes to communicate with subscriber at station A, he removes the telephone a. from its switch-hook, which rises to close the circuit through the telephone and thus momentarily interrupts the current flowing in line 1. During this interruption of the current the magnet dof annnnciator cl loses its magnetism and releases armature (1 In its first outward movement this armature removes the circuit connection between contacts cl (1, thus opening the line-circuit at the aniiunciator, and in its subsequent movement it raises the shield d and discloses the iurlication on the face of the armature (1, thus signifying to theopcrator that connection is desired by the subscriber calling. The operator observing this, inserts plugf into springjack 0. Line circuit 1 is thus extended, through the medium of spring I) and plug f, to the conductor 4 of the plug-circuit, and

thence, key it having been depressed, to the operators telephone-set 0, and the subscriber gives his order orally for the desired connection.

By the insertion of plug fin the springjack the thimble b is connected with line 1, whereby a circuit is provided from battery 0 through magnet d to the line. The magnet 01' is again excited and retracts armature (l eifacing the signal and again closing contacts d cl together. It may also be noted that circuit is provided from battery 6 through conductor7, clearing-out annunciator 7c, and conductor 5 to the plugf, and thence to earth at the sub-station, whereby the clearing-out annuneiator is placed in readiness to respond to any interruption of the line-circuit, and hence to indicate the replacement of tele phone a upon the switch-hook after the completion of conversation.

Having received from subscriber at station A his order for connection with sub-station A, the operator inserts plug f into spring jack o of that line and depresses calling-key h to connect the signaling-generator m with the line. Since the piece I) of spring-jack c is connected with the line, circuit through the annunciator of line to station A is thereby completed and this annunciator is prevented from responding either to the signaling-current, which may find circuit through it, or to the subsequent interruption of the line-circuit when the telephone at station A is removed from the switch-hook.

It will be observed also that during the operation of signaling by means of key h, a temporary circuit is created through clearingout annunciator so that the latter is not released and does not disclose its indication during the'interruption of conductor 4 at the signaling-key. When the subscriber at station A responds to the call-signal and removes his telephone from the switch-hook, the circuit from battery e through clearing-out annunciator 70' to earth at the sub-station is momentarily interrupted and the clearing-out annunciator displays its signal. This is not, however, interpreted as a signal for disconnection, but indicates to the operator who has just completed the connection with the subscriber at that station that he is in communication with the calling-subscriber. The operator, therefore, replaces the signal without withdrawing the cords from the other springjacks. Similarly if either signal should be alone operated at any time during the existence of the connection this will indicate to the operator that the corresponding subscriber had replaced his telephone on its switch-hook, but that conversation has not yet been finished since the other subscriber is still at his telephone; but it both signals were operated this would indicate that both subscribers, having terminated their conversation, had replaced their telephones on their switch-hooks. The operator would, therefore, proceed to disconnect the lines by Withdrawing the plugs f and f from the springjacks.

Having thus described my invention and its mode of operation, I claim as new and desire to secure by Letters Patent- 1. The combination with a telephone line, of an an nunciator and a battery normally included in the circuit of said line at the central station, a switch at the subscribers statiou adapted to open the circuit of said line, and a pair of contact points in said line normally connected together, controlled by said annunciator and adapted to be opened to disconnect said annunciator from the line when the circuit of said line is interrupted by the of an annunciator and battery normally in circuit therewith at the central station, a switch at the subscribers station for opening the circuit of said battery, contacts controlled by said annunciator adapted to be opened when the circuit of said battery is interrupted, and switch contacts closed together in the act of making connection with the line adapted to bridge the interruption of the circuit at the annunciator to restore the annunciator.

3. The combination with a telephone line, of an annunciator and a battery normally in circuit with said line at the central station, contacts controlled by said annunciator adapted to be opened when the circuit through said annunciator is interrupted, said line being provided at the subscribers station with two branches of substantially equal resistance, one of said branches containing the telephonic apparatus and the other the calling apparatus, and a switch adapted to alternately include said branches in circuit with the line, and to momentarily open the circuit of said battery by the act of changing the connection through said branches.

4. The combination with a telephone line, of an annunciator and a battery in the line,

contact points controlled by the annunciator adapted to open the circuit through the annunciator when the magnet of the annunciator is unexcited, a springjack for the line, and

contact points therein adapted to be closed together when a plug is inserted in the springjack and to again connect the annunciator with the line, and means for interrupting the line circuit at the subscribers station to operate the annunciator, substantially as described.

5. The combination with a telephone line, of means for interrupting the line circuit at the substation, a battery in the line at the central station, two annunciators in parallel branches of the circuit at the central station, each having contact points controlled by it adapted to open the circuit through it when the current through it is interrupted, and a circuit formed temporarily in the springjack, bridging the switch contacts of one of the annunciators, substantially as described.

In witness whereof I hereunto subscribe my name this 8th day of November, A. D. 189;.

CHARLES E. SORIBNER. Witnesses:

ELLA EDLER, FRANK R. MCBERTY.

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