US559367A - Switching apparatus for telephone-exchanges - Google Patents

Description

Trice..

ATENT JOSEPH P. DAVIS, OF NEW YORK, N. Y., ASSIGNOR TO THE AMERICAN BELL TELEPHONE COMPANY, OF BOSTON, MASSACHUSETTS.

SWITCHING APPARATUS FOR TELEPHONE-EXCHANGES.

SPECIFICATION forming part of Letters Patent No. 559,367, dated May 5, 1896.

Application led August l0, 1895. Serial No. 558,821. (No model.)

To @ZZ whom it may concern.:

Be it known that I, JOSEPH P. DAVIS, residing at New York, in the county of New York and State of New York, have invented certain Improvements in Switching Apparatus for Telephone-Exchanges, of which the following is a specification.

My invention concerns switching apparatus of telephone-exchanges, being a device for permitting the subscriber to designate to an attendant at a central station a particular group of subscribers among which the desired correspondent may be found. In exchange systems comprising several oiiices in which subscribers lines center, the subscriber may thus designate the particular office in which the required line terminates, the call being immediately trunked to an operator at the ofiice indicated.

This invention contemplates the use, with a switching system comprising an annunciator or receiving-board in which the subscribers line terminates in a signaling instrument, several switchboards, each containing terminal connection-sockets of a different group of lines, and office trunk-lines extending from the annunciator-board to the switchboards, of a signaling instrument or indicator for each-line at the annunciator-board controlled from the substation, whereby the subscriber may indicate to the attendant at the annunciator-board the switchboard at which the line required terminates. This signaling device may be any of the well-known contrivances for designating a particular one of several requirements by the display or actuation of an indicator by mechanism controlled at the distant station. A form of the Vheatstone dial-telegraph is perfectly suitable for use in the present invention.

This improved-switching system is illusi trated in the accompanying drawing, in which a number of subscribers7 lines are represented connected with the switching apparatus of the exchange-offices.

The drawing shows only three of the sub-` scribers lines as being provided with indicators and connection-sockets upon an annunciator-board as sufficient for purposes of explanation, it being obvious that the other lines represented on the drawing may be provided with similar indicators and connections at the same annunciator-board or at another but similar one.

There are in the exchange system here shown three switchboards A, B, and O, which may be assumed to be located at different ofiices, and an annunciator-board D, which may be in the same office with switchboard A. The three substations E, F, and G are equipped with transmitting instruments of the dial-telegraph, represented in the drawing by the dial andv index only.` These stations are connected by lines l, 2, and 3, each with a connection -socket d and a dial-receiving instrument cl2 in the annunciatorboard D and each with a connection-socket d in the switchboard A. Lines 4. and 5 from substations I'I and I lead each to a connection-socket b in switchboard B, and lines 6 and 7 to connection sockets c in switchboard O.

One or more interoflice trunk-lines, 8, extends from annunciator-board D to switchboard A, terminating in the usual plugs m, and m2 for making connection with the sockets. Another trunk, 9, extends from board D to switchboard B, and still another, l0, from the annunciator-board to switchboard C. These trunk-lines may be equipped with any of the well-known devices for informing the operator at the switchboards, automatically or otherwise, when connection is made with the trunk-line at the annunciator-board and for signaling to the switchman at the latter board the disconnection of the trunk-line at the switchboard. The switchboards are supposed to be furnished with the usual telephones, calling apparatus, and keys for the use of the operators in establishing connection with the lines.

In operating this system the subscriber must know what group or office forms the terminal of the station with which he wishes to communicate. Suppose, for example, the subscriber at station E should wish to have his line connected with line to station I'I. He will have information that station H belongs to group or ofiice B. I-Ie will place the index of his transmitting instrument at B, whereby IOO 2 was@ the index of the corresponding receiving instrument d2 in annunciator-board D Will be caused to indicate B. At this signal the attendant switchman Will insert into the springjack d of the same line the terminal plug m of the trunk-line 9, extending to switchboard B. The operator at switchboard or office B,

having received information that the line of a calling subscriber has been connected with trunk-line 9, will bring her telephone into circuit with that trunk-line, learn from the subscriber the number of the particular line with which connection is desired, and perform the required switching in the usual Way.

If the calling subscriber should require connection with a member of the same group with himself, he would turn the index of his transmitting-dial to A to indicate to the switchlnan that the call should be trunked to switchboard A, or if he should require communication With station K or L he would turn the index to C, knowing that these lines terminated at switchboard C.

I claim as new and desire to secure by Letters Patent- 1. In combination, several telephone-lines extending to terminal connection-sockets, an indicator for one of the lines adapted to indicate any of several objects, means for controlling the indicator from the substation of the line, and switching apparatus for making connection from the socket of the line having the indicator to the terminal socket of any other line, as described.

2. In combination, several telephone-lines terminating in connection-sockets on dierent switchboards, an indicator adapted to indicate any of several objects for one of the lines in an annunciator-board and means for phone-lines terminating in connection-sockets in different sWitchboards, trunk-lines eX- tending from the annunciator-board to eachswitchboard, and switching apparatus at the annunciator-board and at the switchboards for making connection between any trunkline and any socket, as described.

In testimony whereof I have signed my name to this specication, in the presence of two subscribing witnesses, this 5th day of August, 1895.

JOS. P. DAVIS.

lVitnesses:

GEO. WILLIS PIERCE, FRANK C. LocKWooD.

Images