US1186398A - Detectophone. - Google Patents

Description

J. E. B. HOLLADAYJ DETECTOPHONE.

APPLICATION nuzo AUG.22. 1913.

1 1 86,3 98 Patented June 6, 1916.

THE COLUMBIA PLANOGRAPH co WASHINGTON D C UNITED STATES PATENT onnion.

JOSEPH E. B. HOLLADAY, OF SUFFOLK, VIRGINIA, ASSIGNOR TO THE HOLLADAY DETECTO COMPANY, INC., VIRGINIA.

OF SUFFOLK, VIRGINIA, A CORPORATION OF DETECTOPHONE.

Application filed August 22, 1913.

To all whom it may concern Be it known that I, JOSEPH E. B. HOLLA- DAY, a citizen of the United States, residing at Suffolk, in county of Nansemond and State of Virginia, have invented certain new and useful Improvements in Detectophones, of which the following is a specification.

This invention relates to an improvement in detectophones, which consists of an apparatus which may be placed in a room and the conversation between individuals occupying the room can be distinctly and clearly heard in another room on the same floor of the building, or in another room at practically any distance therefrom.

The invention consists of certain novel features of construction and combinations of parts which will be hereinafter described and pointed out in the claim.

In the accompanying drawing, I have disclosed a diagrammatic view, setting forth a system of wiring connecting the battery, transmitter, receiver, and induction coil.

As set forth in the drawing, the battery B has wires 0 and f leading therefrom, the wire 0 leading to the contact terminal as, and the wire f leading to a binding post A. A wire C leads from the binding post A to the receiver R, and thence to the transmitter T. The switch S has a wire 9 leading to the binding post B, and a wire d leads from the binding post A to the transmitter. An in duction coil IC has a wire 7' leading to the binding post A, and a wire 9 leading to the wire 9, so that the primary coil of the induction coil is connected to the battery circuit upon the switch S being thrown into contact with the contact terminal as by the knob y. A wire it of the secondary coil is connected to the wire g.

Specification of Letters Patent.

Patented June 6, 1916.

Serial No. 786,140.

With the use of this apparatus or system, the transmitter can be placed in a room and concealed, if desired, and the receiver and other apparatus, such as the battery and induction coil, can be placed in another room in any part of the building desired, and by placing the receiver to the ear, the conversation taking place in the room in which the transmitter is locatedcan be distinctly heard and the voices of the conversationists recognized.

With such an apparatus the uses are practically unlimited, as for instance, it can be used in detecting the persons operating illegal houses, such as gambling dens and the like, as persons entering these places can be recognized by their voices, and their entire conversation heard by the person holding the receiver, and the stenographer, for instance, who has the receiver, can take down stenographically the conversations taking place.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

A telephone system comprising a two wire circuit, a receiver and transmitter arranged in series in said circuit, an induction coil the primary winding of which is connected in shunt across the main circuit, while the secondary coil is connected in shunt with one of said wires of said main circuit, and a switch interposed between the main circuit and the shunt circuit.

In testimony whereof I aflix my signature, in the presence of two witnesses.

JOSEPH E. B. HOLLADAY.

Witnesses:

EMILY F. CAMP, WATTS F. ,ESTABROOK.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner otlatents,

Washington, D. 0. i

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