US330059A - Chaeles e - Google Patents

Description

(No Model.)

. O. E. SGRIBNER. MULTIPLE SWITCH BOARD TESTING APPARATUS.

N0. 330,059. Patented NOV. 10, 1885.

A) A AA 3am, Aw

mam

yw/p C/WMJ MSWJWM n gmplmr. Washmgwn. o. c,

rrn *rnrrns Arena tries.

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WESTERN ELECTRIC COMPANY, OF SAME PLACE.

WlULTlPLE-SWlTCH-BOARD TESTING APPARATUS.

fiPECIFICATIQN formiag part of Letters Patent No. 330,059, dated November 10, 1885.

Application filed October 15, 1883. Serial No. 108,985. (No model.)

To all whom it may concern.-

Be it known that l, CHARLES E. SORIBNER,

a citizen of the United States, residing at Ohicago,in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Multiple-Switch-Board Testing Apparatus for Telephone-Exchanges, of which the following is a full, clear, concise, and exact description, reference being had to the ac companying drawing, forming a part of this specification.

My invention relates to multipleswitchboard testing apparatus for telephone exchanges. The connecting-cords at the differ- 1 ent boards are arranged in pairs and provided with the usual terminal plugs. The different pairs of plugs at each board preferably rest in contact with a common connectingpiece. The frames of the different spring-jack switches are normally insulated from the telephonelines, the frames,however, of a series of switches belonging to a given line being connected together. At each multiple board I provide a battery in the circuit of the operators telephone and transmitter. The battery may consist of only one or two cells.

In the drawing, which is illustrative of my invention I haveshown three multiple switchboards, 1,2, and 3, and two telephone-lines, a and b, connected each with a switch upon each board and through an annunciator to ground. The frames of the switches of each line are connected together. Thus the frames of the switches of line a are connected by wire 0, and the frames of the switches of line b are connected by wire d, as indicated by dotted .lines in the drawing. The frames of each series of switches, though connected together, are normally open to earth. The insertion of a plug in any switch of a series crosses all the switches of the series with the line which is connected with said plug.

My invention herein is designed to enable an operator to test to determine whether there is such a cross on a line wanted by means of the same plug with which he is about to establish a connection with the line wanted.

I have shown so much of the operators apparatus at each of the three boards as is nec- 5o essary to illustrate my invention. I will describe this testing apparatus in detail as shown at board 3.

The terminal plugs e f of the pair of fleXible connecting-cords rest in contact with the common connecting-pieceg. The clearing-out annunciator h is included in the circuit of the cords in the usual manner. The'branch circuit z is connected between the two spools of the electromagnet of the clearing-out annunciator and extends to the key is of the opera- 6o tors telephone Z. The testing-battery m is included in the circuit with the telephone. The calls of the subscribers are sent in in any well-known way. The operator whose business it is to answer the calls of a given subscriber, as soon as she sees the callingannunciator fall, inserts a plug of one of the pairs at her board in the calling subscribers switch. This is illustrated at board 2, plug it being inserted in switch 0 of line b. The line b is thus cut off from board 3 and connected to ground through the testing-battery m and telephone Z. When the other plug, n, is inserted into switch 0 of another subscriber, the two subscribers will be connected together 7 5 through the pair of cords, while the telephone Z and battery in will be out of circuit.

The test to determine whether a line called for is in use is made by the operator while in the act of inserting the plug. The operator at the moment of making the connection with the line of the calling subscriber tests to determine whether a connection has been made with the said line during the few seconds which may have elapsed since the call was sent in. This test is made at the first contact of plug a with the frame of switch 0. If at this first contact of plug it with switch 0 a click is heard in the telephone Z, the operator will know that a plug is inserted in some other 0 switch of the line, forming across,which gives circuit to test battery 11?. through telephone Z. Therefore, when the click is heard, the plug it should not be inserted; but if no click is heard in the telephone Z the operator at 5 once inserts plug it into switch 0, as shown at board 2. The-same plug is used for testing and for making the connection with the telephone-line.

The operator having learned which line is called for, must also test to determine whether the line wanted is in use. In order to determine this the opera-tor takes the plug from the switch of the calling subscriber and applies it to the switch of the subscriber who has been called for. Thus, as shown at board I, plug 17 touches the frame of switch q of line b. The

' line being in use, as shown at board 2,the frame of switch (1 will be found crossed with line b. The operator will discover this by listening at telephone Z when the battery m 'is closed to line as the plug 19 touches the frame ofswitch q. The circuit may be traced from the ground at the central office through telephone Z the transmitter, and battery m to the common connecting-piece, and thence to plugr, and thence through the pair of cords to plug p, and thence to the frame of switch q, and thence by line (2 to the frame of switch 0 of the second board, and from the point of the plug a to line 12. Thus, if the battery m is closed to line, the operator will hear a click at telephone Z. If she hears noclick, she

will insert the plug 19 in switch qand send a call to line b in the usual manner. The other plug, 7', of the pair may then be lifted fromthe common connecting-piece and inserted inthe switch of the subscriber who sent in the call. The two lines will thus be connected together through the pair of flexible cords, and the telephone Z and the test-battery will be out of the circuit. v

The telephone-key may be usedto connect the telephone with the circuit of the connected lines to enable the operator to listen out.

There are modifications of my invention that will readily suggest themselves to an electrician which may be made in my apparatus without departing from myinvention. The operators telephone and battery,for example,may be included in any part of the circuit between the plugp and the central-office ground, and any well-known switching apparatus may be used to cut out the said telephone and battery from the circuit of two connectedlines. Other forms of switches may also be used upon the multiple switch-boards. I therefore do not limit myself to the special constructions shown; but

I claim, broadly 1. In amultiple-switch-board system, atest- I circuit consisting of a pair of connecting-cords and their terminal plugs, acommon connecting will know that this line, d is open, and the lineb not being in use sheers without including the piece with which the plugs are normally in contact, a ground-connection for said common connecting piece, and a telephone and testbattery included in said ground-circuit, substantially as and for the purpose specified.

2. The combination, at any one of the multiple switch-boards of a telephone-exhange, of one or more pairs of plugs and cords with a common connecting-piece, to which the different pairs of plugs are normally connected, and a testing-battery and telephone,whereby when either plug of a pair is applied to the switch of a subscribers line the telephone and testing-battery will be included in the circuit between said, plug and the central-office ground.

8. The combination, with the switches of a multiple switch-board, of a circuit including a telephone-receiver, a test-battery, and pairs of cords and plugs normallyin connection with said circuit, whereby a test and connection may be made by means of either one of the plugs of any pair.

4-. The combination,with a pair of connecting plugs andscordsand a common connectingvpiece-with whichv said plugs are normally in contact, of a branched ground circuit, one branch of saidground-circuit being connected through a battery to the common connecting- 7 piece and'the other branch connected through a normally-open listening-key to thecircuit of the connecting-plugs, whereby a connection :may be established through the telephone-receiverto the connected lines of two subscribbattery in circuit, substantially asset forth. V 1

5. The combination, with a pair of connecting plugs and cords, a common connectingpiece withwhich said plugs are normally in contact, and a clearing-out annunciator in circuit between the plugs, of a branched groundcircuit, one branch of said ground-circuit containing a battery and being connected to the common connecting-piece, the other branch containing a listening-key and being connected between the spools of the clearing-out annunciator, substantially as and for the purpose set forth.

In wi-tnesswhereof I hereunto subscribe, my

name ,t h i s .l-2th day of October, A. D. 1883.

CHARLES. E. SGRIBNER.

Witn .esses GEORGE P. BARTON, PAUL A. STALEY.

ICC

Images