Year: 1886

page_text: Date of Application, 22nd Sept., 1886.
Complete Left, 20th June, 1887.
Complete Accepted, 22nd July, 1887.
I, RICHARD THEILER, of 86, Canonbury Road Islington, in the county of Middlesex
Telegraph Engineer do hereby declare the nature of my said invention to be as
follows:-
This invention relates to a telephone working by electricity. The object of this
invention is to combine the transmitter with the receiver in such a manner that the
two parts constitute a single, complete, convenient and easily portable telephone which
will transmit as well as receive speech when held to the ear, requiring no shifting from
that position when used as a transmitter nor requiring the speaker to direct his voice
towards any particular object.
For this purpose I enclose the receiver and the transmitter in one and the same
receptacle, generally a small drum or cylinder of metal or ebonite, in such a manner
that one end of the said drum is closed by the tympan of the receiver and the other
end by the tympan of the transmitter. A cover with an aperture protects the receiver
tympan and conveys the received speech to the ear of the listener in the usual way.
Into the cover of the opposite or transmitter tympan 1 insert and fix a tube or
cone of metal or any other suitable substance with a polished interior surface and
of such a shape that it collects, reflects and concentrates the sound waves from
the speaker's voice upon the said transmitter tympan without incommoding the speaker
in any way and at the same time serves as a convenient handle to the telephone.
The receiver herein mentioned generally consists of a small magnet and coil acting
upon a steel or iron tympan. The transmitter may be a microphone of any suitable
form connected to a battery and induction coil in the usual manner.
If the magnet
and coil of the receiver are made large or powerful enough and are arranged in such a
way that the sound waves entering through the tube or cone hereinbefore described
impinge upon a steel or iron tympan, the microphone and its battery may be dispensed
with.
Sometimes I close the open end of the said tube or cone by a membrane and attach
the microphone thereto or to the tube or cone itself.

page_text: Improvements in Electrical Telephones.
I, RICHARD THEILER of 86 Canonbury Road, in the county of Middlesex,
Telegraph Engineer do hereby declare the nature of my said invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
The object of my invention is to combine the transmitter with the receiver in such
a manner that the two parts constitute a single, convenient and easily portable
instrument which will transmit as well as receive speech when held to the ear,
requiring no shifting from that position for transmitting nor requiring the speaker to
direct his voice towards any particular object.
For this purpose, I generally enclose the receiver and the transmitter in one and
the same box as shown in transverse section at Fig. 1 of accompanying drawing.
The said box consists of a small drum or cylinder N, of metal or ebonite, closed at one
end by the tympan A of the transmitter and at the other end by the tympan B of the
receiver. A screwed cover P with a central aperture p, and of the usual cup shape
protects the receiver tympan and permits of the latter being held close to the ear.
Into the cover-plate R of the opposite or transmitter-tympan I insert a tube or
cone W, of metal or other suitable substance of a polished or smooth interior surface
and of such a shape that it collects and concentrates the sound waves from the speaker's
voice upon the said transmitter-tympan without inconveniencing the speaker in any
way, at the same time serving as a handle to the instrument.
The shape of this cone or tube is of great importance and that shown at Fig. 1 has
only been arrived at after many experiments.
It will be seen that the opening V, of the said cone is not placed in front or across
the speaker's mouth when in use but at the side. By this means inconvenience to the
user and the objectionable condensation of his breath upon the cone is avoided.
It will be further seen that the sound waves impinge only upon the outer curve of
the cone and would be conveyed to the tympan A, by that curve alone. Therefore a
row of holes C1, C2, C3, C4, does not interfere with, but on the contrary assists the
clear transmission of the sound waves along the cone W.
At Fig. 2, I show a transverse section of the combined receiver and transmitter,
omitting however the tube or cone just described and shewn at Fig. 1. In order to
get the receiver into a small space, construct it with a circular permanent magnet O,
one pole of which induces the iron core M, inserted into the coil or helix L. The
other poles induces the thin steel or iron tympan B. This construction of the receiver
may however be modified in many ways if more space is given to it than I have shown
at Fig. 2.
Almost any kind of microphone may be used as a transmitter, but as it is desirable
that a portable or land telephone should act in any position without requiring any
adjustment or careful handling, I construct the transmitting part of my combination
telephone as follow: A (Fig. 2) is a very thin tympan of steel or other highly

page_text: elastic material firmly clamped between the edge of the box N, and the cover plate R.
To the centre of this tympan a thin carbon disc F, is fastened constituting one of the
electrodes of a battery circuit. To the back of this tympan is glued a disc J, of felt or
other spongy material with a hole e, in its centre, which hole or chamber is filled with
hard carbon granules and closed by another thin steel or other elastic disc to which a
weight d, is fixed, constituting the other electrode. A screw K, may traverse the
weight d, and enter the chamber e, to reduce the distance and consequently the electrical
resistance between the two electrodes d, and F.
A modified form of the microphone just described is shown detached from the box
at Fig. 3.
In this modification, the felt disc J, is pierced with several holes and into each of
these a cylindrical piece of hard carbon or metal a, is inserted so as to touch the carbon
disc F, and is then secured in that position. These several contact pieces I generally
connect together as shown at Fig. 3A in order to reduce the resistance of the
microphone.
The binding posts required for connecting the telephone to a flexible conductor are
placed on the outside of the drum N, in such a manner that a cover tube G, may be
slipped over them, only one of these binding posts is shown at C Fig. 2. S, is a ring
by which the telephone may be conveniently suspended when not in use.
By increasing the size and power of the permanent magnet and the thickness of
the tympan in the receiver, the microphone may be dispensed with altogether. In
this case the sound waves entering the box through the cone W may be caused to
reach the tympan B, through the hollow magnet core M, as shown at Fig. 4.
Sometimes I close the end of the cone or tube-handle herein described by a tympan
and attach the microphone thereto instead of mounting it in the box with the
receiver.
This construction is shown at Fig. 5.
The handle-tube, in this case, is straight, terminating in a curved extremity V, into
which a microphone of any suitable construction is inserted, the tube serving as a
conduit for a flexible conductor I, as shown.
The same form of handle-tube may however also be used open at the curved end,
with the microphone placed inside the box N.
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
claim is :-
1. In a portable- or hand-telephone a cone or tubular handle as and for the purpose
herein set forth.
2. A combined telephone receiver and transmitter provided with a cone or tube as
herein described and substantially the same as shown at Figs. 1, 2 and 4 of the accom-
panying drawing.
3. In a portable telephone a handle to the end of which a microphone is attached
substantially as herein described and shown at Fig. 5.
Dated this 30th of June 1997
RICHARD THEILER.