Improvements in Mechanical Telephones.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improvements in Mechanical Telephones.
I, ALFRED LISSACK SIMPSON, of 64, Broadway, in the City, County, and
State of New York, United States of America, Merchant, 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 :-
This invention relates to acoustic telephones, the object being to increase their
sensitiveness to sounds and promote economy in their manufacture.
The invention consists in the novel features hereinafter particularly described
and defined in the claims.
Reference is to be had to the accompanying drawings, forming a part of this
Specification, in which similar letters of reference indicate corresponding parts in
both the figures.
Figure 1 is a front view of a telephone embodying my improvements, and
Figure 2 is a central longitudinal section.
The case A of my improved telephone is made of metal in one piece and
fashioned to form the rearwardly flaring resonating body a and the integral mouth
or bell a', the case thus being made flaring both front and rear, the body as well as
the mouth being bell shape but flaring oppositely. At the back, the case departs
outwardly from the body a to form the flat and narrow annular seat a to which the
diaphragm B is secured within the case by bolts bor the like. From the outer
edge of the seat a² the case is bent twice at right angles to form the flange a³
parallel with the diaphragm seat a² and a neck a which spaces the said flange and
seat. Thus when the flange a³ is secured, by screws for instance, to a wall or
other support C a chamber is formed between the said support and the inner side
or back of the diaphragm.
In connection with the case and diaphragm thus arranged I provide an improved
resonator D within the case at the front of the diaphragm, such resonator being of
metal, made bell shape and formed with a central Hat seat d adapted to be seated
against the face of the diaphragm so that the resonator flares outwardly in the
direction of the mouth a, the size of the resonator at the edge being greater than
the width of the contracted neck a formed by the junction of the body a and
mouth a. This resonator is held to the diaphragm solely by the tension of the
line wire E which passes through a central aperture in the diaphragm through
the seat of the resonator D and through a separate washer F at the outer face of
the seat d. After being passed through the washer F the strands of the line wire
at its extreme end are slightly untwisted and a drop of solder is applied and made
so that a somewhat conical head E' is formed for preventing the wire from being
drawn through the parts.
It will be seen that in securing the line wire and the resonator, none of the parts
are secured or fixed to the diaphragm, the whole being sustained in proper relation
solely by the tension of the line wire. In this way the vibratory attributes
of the diaphragm are fully preserved, so that it will be sensitively responsive
to sound.
By forming the complete case in one piece of metal, which is spun to form
the body, mouth, diaphragm seat, and securing flange, the vibrations of the body
5 resulting from the sounds deflected from the resonator will be communicated to
the diaphragm without being deadened or appreciably lessened, there being no
intermediate joints to take them up, and these vibrations, coupled with those
produced by the direct action of the voice on the resonator, greatly increase the
efficiency of the telephone. Further, the case, it will be seen, may be very cheaply
0 produced.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, declare that what I
claim is-
1. An acoustic telephone comprising a metal case having a bell shaped mouth, a
flaring resonating body, an annular diaphragm seat, a neck extending from the
seat and an attaching flange extending from the neck parallel with the said seat, a
diaphragm secured near its periphery only to the seat, and a bell-like resonator
held to the outer face of the diaphragm by the tension of the line wire only,
substantially as described.
2. In an acoustic telephone, the combination of a case consisting of a body
having a forwardly flaring mouth, a diaphragm held to said case, and a bell-like
resonator held to the outer face of the diaphragm by the tension of the line wire,
substantially as described.
3. An acoustic telephone consisting of a case having a bell-like body flaring
rearwardly and a forwardly flaring mouth; a diaphragm held to the rear of
said body and a bell-like resonator held to the face of the diaphragm by the
tension of the line wire and flaring in the direction of the mouth, substantially
as described.
4. An acoustic telephone consisting of a metallic case comprising a bell-like body
flaring rearwardly and an integral forwardly flaring mouth, a diaphragm held to
said body and a bell-like resonator held to the face of the diaphragm in line with
and flaring in the direction of the mouth, the said resonator being maintained in
place by the tension of the line wire and having no positive connection with the
diaphragm, substantially as described.
5. An acoustic telephone consisting of a case fashioned from a single piece of
metal to form a bell-like body, a flaring mouth at the front of the body, an annular
seat at the rear of the body forming a seat for a diaphragm secured thereto, and a
securing flange parallel with said seat and spaced therefrom, a bell-like metallic
resonator held to the front of the diaphragm and having a flat seat for contacting
with the latter, a washer on said seat, and a line wire having a conical head, the
washer and resonator being sustained in place by the tension on the line wire, sub-
stantially as described.
6. The improved acoustic telephone constructed substantially as shewn and
described.
7. The improved acoustic telephone having a diaphragm and a resonator held to
the diaphragin by the tension of the line wire only.
Datad this 96th day of Iul 1905
A. L. SIMPSON,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agent.