IMPROVEMENTS IN TELEPHONES
Year: 1884

page_text: I, JOHN THOMAS LISTER, of number 29 Mason Street, Cleveland Ohio, in the
United States of America, Machinist, do hereby declare the nature of said invention
for IMPROVEMENTS IN TELEPHONES, to be as follows:-
The object of my invention is to provide an attachment to the transmitter of a
telephone by which the words of the speaker may be conveyed thereto the more
readily, fully and distinctly than they are by the provisions for speaking now
common in telephones. In the prevailing construction of telephones in relation to
the speaker, there is an unavoidable scattering of the sound-waves before they
reach the orifice of the transmitter by which they are secured and conducted to tho
diaphragm. By said scattering of the sound-waves the words expressed by them
reach the diaphragm in an imperfect form, and with loss of distinctness of pulse,
and thereby are conveyed along the line to the ear of the hearer with weakness
and deficiency of articulation. This said weakness or deficiency is remedied by my
invention.
The invention is performed by taking a tube made of vulcanized rubber, and
moulded in a single piece. It is conical in its general longitudinal form, with both
ends open, one end being the mouth piece for the speaker, and the other end being
adapted to be applied closely to the face of a transmitter.
The applying end is provided with the outwardly extending annular flange,
having its face suitably felted or cushioned to act as a buffer to the face of the
trarsmitter, and also to prevent the lateral escape of sound-waves as the tube is
oratively applied. Directly in rear of said: flange is an enlarged chamber the
design of which is to provide for the expansion of any reflex sound waves from
the diaphragm that might interfere to confuse the direct sound-waves from the
speaking end of the tube. A metallic band encircles the tube at a suitable point,
and hinged to a folding arm. The latter is jointed to arm which in turn is jointed
to a bracket secured to the wall. Said connected arms swing in such a horizontal
plane as bring the applying end of the tube entirely and centrally over the orifice
of the transmitter.
It will be seen that when one end of the tube is thus applied over the orifice of
the transmitter, there can be no loss or scattering of the sound-waves from tho
speaker, on their way to the diaphragm. Also that reflex waves from the diaphragm,
are disarmed of their confusing agency by the expansion chamber.

page_text: I, JOHN THOMAS LISTER, of 29, Mason Street, Cleveland, Ohio, United States,
Machinist, do hereby declare the nature of my invention for IMPROVEMENTS IN
TELEPHONES, and in what mauner 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 provide an attachment to the transmitter of a
telephone by which the words of the speaker may be conveyed thereto the more
readily, fully and distinctly than they aro by the provisions for speaking now
common in telephones. In the prevailing construction of telephones in relation to
the speaker, there is an unavoidable scattering of the sound-waves before they reach
the orifice of the transmitter by which they are secured and conducted to the
diaphragm. By said scattering of the sound-waves the words expressed by them
reach the diaphragın in an imperfect form, and with loss of distinctness of pulse,
and thereby are conveyed along the line to the ear of the hearer with weakness
and deficiency of articulation. This said weakness or deficiency is remedied by my
invention.
In the drawings Fig 1 is a plan view, showing my invention in operative position
with a transmitter; Fig 2 is a front elevation of the invention; Fig 3 is a
longitudinal central section of the speaking tube.
A is a tube made of vulcanized rubber, and moulded in a single piece. It is
conical in its general longitudinal form, with both ends open, the end a being the
mouth piece for the speaker, and the end b being adapted to be applied closely to
the face of a transmitter B. The applying end b is provided with the outwardly,
extending annular flango c, having its face suitably felted or cushioned to act as a
buffer to the face of the transmitter, and also to prevent the lateral escape of sound-
waves as the tube is operatively applied. Directly in rear of said flango is the
enlarged chamber d, the design of which is to provide for the expansion of any
reflex sound-waves from the diaphragm that might interfere to confuse the direct
sound-waves from the speaking end of the tube. C is a metallic band encircling
the tube at a suitable point, and hinged to the folding arm D. The latter is jointed
to arm E, which in turn is jointed to a bracket G secured to the wall. Said
connected arms swing in such an horizontal plane as bring the applying end 6 of
'the tube entirely and centrally over the orifice of the transmitter.
It will be seen that when the end b of the tube is thus applied over the orifice of
the transmitter, there can be no loss or scattering of the sound-waves from the
speaker, on their way to the diaphragm. Also that reflex waves from the diaphragm,
are disarmed of their confusing agency by the expansion chamber d.
While I preferably make my speaking attachment in one piece, it may be in
several pieces or sections. In size also, it may be varied. Also, any adequate
material may be used. Also, the tube may be fastened firmly and permanently to
the transmitter, or it may be independent of it, as shown in the drawings.

page_text: 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
1. In a telephone, a speaking device adapted to confine the sound-waves and
conduct them without loss from the mouth of the speaker to the diaphragm of the
transmitter, substantially as set forth.
2. In a telephone, an independent speaking attachment adapted to confine the
sound-waves and conduct them without loss from the mouth of the speaker to the
diaphragm of the transmitter, substantially as set forth.
3. A telephone speaking attachment, provided with an enlarged chamber at its
end that is adjacent to the transmitter, substantially as set forth.
4. In a telephone attachment, a conical speaking tube, provided with an enlarged
chamber near its smaller end, adapted to control reflex sound-waves from tho
diaphragm, substantially as set forth.
5. A telephone speaking attachment, consisting of a conical tube and an enlarged
chamber at the smaller end of said tube, said chamber being provided at its
discharge end with an annular flange, substantially as set forth.
6. A telephone speaking attachment, cylindrical and conical in one of its portions,
enlarged into a chamber in another of its portions, and provided at its discharge-
end with an annular flange, said flange baving its outer face cushioned, substantially
as set forth.
7. In a telephone, the combination with a transmitter, of a speaking attachment
independent of said transmitter and provided with an annular flange adapted to be
seated over the receiving orifice of said transmitter, substantially as set forth.
8. A telephone speaking attachment, adapted to be seated over the outer orifice
of the transmitter, and provided with a swinging device to bring it directly into
line with said orifice, substantially as set forth.