Year: 1888

page_text: A communication from JULIUS EMMNER, junior, of Washington, in the District of
Columbia, United States of America, Electrician.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. 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 telephone transmitters.
The invention consists in the combination with a diaphragm electrode, of carbon,
iron, platinum, or aluminium, of movable or balanced electrodes hung upon a rod or
bar of metal mounted upon the diaphragm and insulated therefrom; furthermore the
invention consists in the combination with a diaphragmn-electrode of balanced
electrodes hung upon a rod or bar of soft metal, and a piece of soft rubber, serving at
once as an insulator, and, being adjustable, as means for regulating the distance of the
lower ends of the balanced electrodes from the diaphragm-electrode, while presenting
a cushion to lessen the danger of breakage of the balanced electrodes in their adjust-
ment and in their action; furthermore the invention consists in a telephone
transmitter in which aluminium is employed as an electrode; and finally the invention
consists in various novel details of construction all as hereinafter more fully set forth
and shown in the drawings.
In the accompanying drawings, is illustrated one form of embodiment of the
invention.
Fig. 1 is a view from above.
Fig. 2 is a central, vertical section taken through the diaphragm, the movable
electrodes and the adjustable cushion.
Fig. 3 is a vertical section of a transmitter box.
In these drawings A designates a transmitter-box which may be of any preferred
construction and within which is suitably secured a diaphragm B which may be an
ordinary disc diaphragm.

page_text: At or near the centre of this diaphragm is rigidly secured an electrode C parallel
with the diaphragm and in electric contact therewith, which electrode is termed the
diaphragm-olectrode and which may be made of carbon, platinum, iron or aluminium
one side of which electrode is of greater thickness than its opposite side, thus giving
it an oblique upper face. This electrode is connected to the diaphragm by a
screw b.
At opposite sides of the diaphragm and secured thereto by screws or other means
of fastening are provided posts the upper reduced portions of which are threaded
and extend outward from the diaphragm at an angle thereto.
Resting upon a shoulder upon each of the posts 6' and extending outward perpen-
dicular to the post, is placed a projection or arm & composed of hard rubber or other
non-conducting material, upon the end of which arm is mounted a binding post b³
between which and the post upon the opposite side of the diaphragm, similarly
mounted, is connected a rod or bar 6 of metal, screw-threaded at one or both ends,
and upon which is mounted a series of movable or balanced electrodes D, their
lower ends reduced and pointed, and the points being held directly above the upper
inclined face of the diaphragm electrode.
These electrodes are perforated at or near their contres through which perforations
the supporting rod or liar, upon which they hang, passes. The rod is also provided
with a nut or screw near one end at one side of the balanced electrodes, and near its
other end and upon the opposite side of the electrodes has a similar nut or screw, or,
if preferable, a stationary button or washer to prevent lateral movement in this
direction. The movable or balanced electrodes are thus rendered laterally adjustablo,
the nut or screw tending to crowd them together or permitting them to be separated,
as desired.
Upon the reduced portion of the screw post. & and resting against the insulating
arın or projection is mounted a washer, against which abuts a small coiled spring,
also mounted upon the post, upon the other end of which rests a hard rubber or
other non-conducting bar & the opposite end of which bar rests upon a corresponding
spring, similarly mounted upon the post at the opposite side of the diaphragm. This
bar luas secured to its inner face, a strip of soft rubber 6 against which the lower
pointed ends of the balanced electrodes rest and which strip of soft rubber nets as a
cushion to lessen the danger of breakage of the balanced electrodes and also as an
insulating medium between the diaphragm and the balanced electrodes in that
direction.
Upon the outer ends of the posts and in contact with the bar & aro mounted
small sleeves held in place by set-screws upon the ends of the posts by means of
which in connection with the spiral springs at the opposite side the bar and cushion
are adjusted upon the rods, thereby bringing the balanced electrodes into close
relation to or removing them further from the diaphragm electrode, as may bo
required.
The electrodes are evenly balanced and are hung upon the rod or bar with easy
play and movement and at an angle of about 45°. The pointed ends near the
diaphragm electrode, resting against the adjustable soft rubber cushion, which is also
mounted substantially at right angles to the diaphragm, are arranged to follow the
adjustment either toward or from the diaphragm thus croating a moro perfect and
delicate adjustment.
The apparatus is placed in a battory circuit and connected with the primary portion
of the induction coil E by the wires ee which are connected respectively to the
diaphragm electrode by a small piece of metal secured between the diaphragm and
diaphragm-electrode by the screw band to the balanced or movable electrodes by the
metal rod upon which the electrodes hang and which, as herein previously shown, is
thoroughly insulated from the diaphragm, the arms upon which it is mounted being
made of non-conducting material.
The sovoral alectrodes may all be composed of the same material, or each of a
different material and any one or all of them may be composito in their character.
The cheapest material known to my correspondent is carbon in its usual form, but

page_text: good results have been attained from electrodes composed of iron, silver, platinum or
aluminium, especially the last named. It will be observed that inasmuch as all of the
electrodes are mounted upon and carried by the diaphragm, no one of them can vary
in its adjustment, as the provisions for adjustment are such that the rubber cushion
must press equally upon all the movable electrodos.
A distinguishing characteristic and peculiarity of this prosent transmitter is,
that it operates by the employment of a broken current of electricity of an inter-
mittent form in contradistinction to a constant current of electricity of a wavy or
undulatory form, that is to say, by the employment of electrical intermissions, in
contra-distinction to electrical undulations.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is :-
1. The combination with a suitable diaphragm-electrode arranged as described of
movable or balanced electrodes mounted upon the diaphragmn but insulated therefrom
substantially as described.
2. The combination with the movable electrodes of a rubber cushion.
3. The combination with a diaphragm-electrode of movable or balanced electrodes
hung upon the diaphragm and an adjustable cushion substantially as set forth.
4. A telephone transmittor in which aluminium is employed as an electrode.
5. The combination with the movable or balanced electrodes of a rod or bar
supporting the same, and means for moving the electrodes laterally upon the rod or
bar crowding them together, or permitting them to be separated substantially as
described.
6. The combination with the movable or balanced electrodes of a metal rod or bar
supporting the same and an adjustable cushion for said movable electrodes, substan-
tially as described.
7. The combination with a diaphragm-electrode of posts mounted upon the
diaphragm, movable balanced electrodes mounted upon said posts and an adjustable
cushion also mounted upon said posts, the cushion to regulate the adjustment of the
balanced electrodes substantially as set forth.
8. The combination with a diaphram electrode, of posts mounted upon the diaphragm
said posts carrying an adjustable cushion, springs for increasing the distance between
the cushion and the diaphragm electrode, and screws for depressing the spring and
decreasing the said distance substantially as specified.
Dated thin 2-1 If T1 1000