Year: 1887

page_text: Date of Application, 19th Mar., 1887
Complete Left, 16th Dec., 1887
Complete Accepted, 20th Jan., 1888
I, THOMAS HARDING CHURTON of Park Chambers (35, Park Square) Leeds,
Yorkshire, Engineer, do hereby declare the nature of this invention to be as
follows
The novelty of the instrument, which otherwise resembles the Mechanical or
Acoustic Telephones commonly used, consists in the following combination :-a
Diaphragm of Brass free to vibrato in a wooden case.
Dated this Eighteenth day of March 1887.

page_text: 1, THOMAS HARDING CHURTON, of Park Chambers, Park Square, Leeds, in the
County of York, Electrical Engineer do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Hitherto the diaphragms of mechanical telephones have been formed of wood or
other fibrous material which, having been for some time subjected to the tension of a
strained wire, are found to bulge in, thereby diminishing the efficiency of the
telephone.
As I have found that a diaphragm of thin sheet brass is very susceptible to
voice-sound vibrations and to be at the same time capable of entirely resisting the
tendancy which the strained line wire has to make it bulge in, I use such a diaphragm
which I enclose in a case or carrier of wood, vulcanite or other similar material.
And in order that my invention may be more completely understood, refference is
given to the accompanying drawings on which Fig. 1 is a sectional elevation and
Fig. 2 a front elevation of a telephone constructed according to my invention.
A is the outer casing or carrier of the diaphragm and it consists of two circular
plates a,
a' which are partly recessed on one side. Between these two plates which
have their recessed sides facing each other, is inserted a diaphragm C, made of thin
sheet brass. Screws f, f may be used to fasten the two plates of the diaphragm case
and the diaphragm together. In the centre of the plate a¹ is a hole through which
the line wire L is passed when it is fixed (in position) to the diaphragm. In the
centre of the front plate a, is a hole b, which exposes the diaphragm so that it may
be affected by sounds produced in its vicinity. The end of the line wire L may be
attached to the diaphragm by means of an ordinary copper rivet g, which is passed
through a hole in the centre of the diaphragm and which has a hole h, bored through
the pin the wire is threaded through the pin and fastened by twisting.
The case containing the diaphragm may be mounted on a block or patrass H, as
follows-One end of a square tube S, made of wood or other suitable material, is
attached to the back of the diaphragm case by hinges, a, and the other end of the
tube is attached in the same way to the patrass. A hole p is made through the patrass
through which to pass the line wire L.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
The manufacture and use of a transmitter and reciever for a mechanical telephone
consisting of a diaphragm made of thin sheet brass, supported in a case or carrier of
wood, vulcanite or other material substantially the same, and constructed as a whole
substantially as herein described and illustrated.
Dated this 16th day of December 1887.