US258234A - Annunciator-board and circuit for telephone-exchanges - Google Patents

Description

(No Model.) 2 sneets sneet'a M. C; KELLoCC. ANNUNCIATCE BOARD AND CIRCUIT FOR TELEPHONE EXCHANGES. C No. 258.284. PatentedMayZB, 1882 minqs ses I I V Jil n-nay N. PETERS, Phulo-Lilhogmphor. Wishinglnn. D.C.

To all whom it may concern:

- IUNITED STATES PATENT ()FFICE.

MILO Gr. KELLOGG, OF HYDE PARK, ASSIGNOR TO THE WESTERN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS.

ANNUNCIATOR-BOARD AND CIRCUIT FOR TELEPHONE-EXCHANGES.

SPECIFICATION forming part of Letters Patent No. 258,234, dated May 23, 1882.

"ill

Be it known that I, MILO G. KELLOGG, of Hyde Park, county of Cook, Illinois, and doin g business in Chicago, in said State, have dis covered certain new and useful Improvements in Annunciator-Boards and Circuits of Telephone-Exchan ges, of which the following is a full, clear, concise, and exact description.

In the drawings, Figure 1, Sheet 1, Ais the switch-board at the central office. B and B are annunciator-boards. Fig. 2 is a detail section of a modified form of the jack-knife switch. Fig. 3, Sheet 2, is a diagram of the circuits of the telephone-lines from the switch-board to the annunciator-boards. Fig. t is a detail of 'a connecting-bolt.

The telephone-lines a a a? u e, &c., are connected in any well-known way at the stations of the subscribers, and converge to the central office, where they are connected with their respective switches b1) b b I), &c.,on the switchboard A in the usual manner. The lines are now divided into groups, each group containing as many lines as can be conveniently attended to upon an annunciator-board. The number of groups will depend upon the size of the exchange and the demands of the subscribers. An exchange of five hundred subscribers should be provided with five annunciatorboards under ordinarycircumstances, while an exchange of a thousand subscribers would require from eight to ten annunciator-boards under the same conditions. An attendant is stationed at each annunciator-board, and one or more switch men at the switch-board. The several telephone-lines run through their respective switches on the switch-board and through their respective annunciators on the annunciator-boards, and thence to ground, so that the call of a given subscriber is received by the attendant at the annunciator-board upon which is placed said subscribers calling-annunciator. When the attendant has received a subscribers order he informs the switchman what connection is wanted, and the switchman connects the switch of the calling subscriber with the switch of the subscriber called for through a c1earing=out annunciator in the usual manner.

Application filed April 4, 1881. (No model.)

Lines a and a are shown thus connected by means of flexible cords and plugs. When the plugs are inserted, as shown, the annunciators and ground-connections are automatically removed. On removing the plugs the normal circuits of the lines are restored, and the subscribers are enabled to send in their calls, as 5 5 before indicated.

The normal circuit of line a may be traced as follows: from switch I) by line 0 to connecting-bolt d, and thence by line 0 to the armature f of the calling-annunciator of the line, and thence through the drop or shutter g to line h, and thence through the electro-magnet iand by line 70 to ground. When a. current is sent over this circuit from line a the shutter 9 falls, and the attendant at board B is thereby notified of the call. The attendant thereupon connects his telephonel into the circuit in any suitable manner, preferably by holding plug m against the connecting-bolt d. The whole circuit of line a may be thus directed through theitelephone of the listening attendant at annunciatorboard B. The subscriber and attendant are thus in direct communication, and the subscriber gives the name of the one with whom he wishes to speak.

The normal circuit from theconnectingbolt, instead of passing through the armature and shutter, may pass directly through the electromagnet, in which case the ground'wonld'not be taken off automatically when the shutter 86 falls, and the circuit passing through the telephone would be a derived circuit. A circuit thus derived would be sufficient for all practical purposes.

A listening attendants outfit and callingbattery n is provided at the switch-board. When two subscribers are connected, as shown,

a current is sent to line by depressing key 0. The subscriber called for is thus summoned, while the caller is notified that the ofiice is dogo in g its duty. By connecting the key 10 to line a,- as shown, and depressing the key 0 the clear ing-out annunciator may be used to indicate whether the line called for-that is to say, line a-is open or closed. In case both subscribers 5 should forget to send in the clearing-out sig nal the listening operator by depressing key 19 may tap their circuit, and by means of the derived circuit passing through his telephone q determine whether the subscribers have stopped talking.

By the use of my system it will be seen that a large exchange may he successively worked upon a single switch-board, the duty of the switchnien being confined to connecting and disconnecting the switches in response to the orders of the attendants at the annunciator boards. In case a subscriber called for is already connected the switchman sees the plug inserted in his switch and the caller is notified that the one asked for is busy, and thus all confusion is avoided.

I claim- 1. In a telephone-exchange, two lines connected together for conversation, in combination with two keys, one of which, on being (lepressed, grounds the lines through the centraloftice telephone, and the other of which, on being depressed, grounds the lines through the central-office signaling-battery.

2. In a telephoneexchange, the combination of a switch-board at the central oftice, provided with spring jack-switches, one switch for each line which enters the central oflice, two or more annunciator-boards, upon which the lines are grouped, annunciators upon each of the annunciator-boards, one annunciator for each line of the group, and. telephone-lines, each line passing first to its switch on the switchboard, thence to its annunciator of its group, and to ground, whereby an annunciator of a group is disconnected from its line when a line is connected atthe switchboard with another line, substantially as shown and described.

3. In a telephone-exchange system, the combination of two lines connected together for conversation, a clearing-out annunciator in the circuit of said lines, and a battery and callingkey at the central oftice, so connected that when the calling-key is operated so as to signal to line the clearing-out annunciator responds or indicates that the signal has been sent.

4. In a telephone-exchange system, the combination, at the central office, ot' a switch-board at which is performed the switching between all the lines which center at the office, two or more calling-annunciator boards, among which the wires are grouped and at which the ca1ling-signals are received, and clearing-out annunciator-s, on which the clearing-out signals are received when the lines are connected together for conversation.

5. In a telephone-exchange system, the combination, at the central office, ofa switch-board at which is performed the switching between all the lines which center at the oflice, two or more annunciator-boards upon which the wires are grouped, each annunciator-board having annunciators and contact-plates, one annunciator and one contact-plate for each line of its group, operators telephones, one for each annunciator-board, each operators telephone being grounded on one side and connected on the other side by a flexible cord with a metallic contact-peg, and telephone-lines, each line passing first to the switch-board, thence to its contactplate on the anininciator-board, and thence to its annunciator-magnet and to ground, as and forthe purpose specified.

MILO G. KELLOGG.

Witnesses:

Guns. A. BROWN, JAMEs L. BAIRD.

Images