Year: 1889

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine Lake & Co., Patent Agents,
Southampton Buildings in the County of Middlesex 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:-
My invention relates especially to that class of telephone transmitters which are
provided with pivoted electrodes; and it consists in certain novel features as herein-
after fully set forth and claimed, the object being to produce a simpler, cheaper and
more effective device of this character than is now in ordinary use.
The nature and operation of the improvement will be readily understood by all
conversant with such matters from the following explanation.
In the accompanying drawing
Figure 1 is a top plan of my improved transmitter and the electrical connections.
Figure 2 is a vertical transverse section of the transmitter taken on line a, a, in
Figure 1.
Figure 3 is a like view showing a modification in the form of the speaking tube;
and
Figures 4 and 5 are views similar to that shown in Figure 2 representing the
electrodes overlapping.
Like letters and Figures of reference indicate corresponding parts in the different
figures of the drawings.
A represents the speaking tube, B the body of the transmitter, C the diaphragm
and D the electrodes.
The body B, consists of a disc of wood or other non conducting material and
is chambered at b, on the upper face leaving an annular flange d at its edge.
The speaking tube A is preferably arranged horizontally beneath the body B, and
opens centrally through the bottom thereof.

page_text: The diaphragm C is disposed horizontally on the flange d, and is secured thereon
by two semi-circular metallic plates or holders fy secured to the body B, by screws m.
Should the diaphragm be composed of metal it is to be insulated in any suitable
manner from the holders. A space k, is left between the end of the holder f, and g,
sufficiently broad to prevent the passage of an electric current from one to the
other.
A carbon disc H, is mounted on a pliable cushion, composed of cork or similar
substance secured centrally to the diaphragm. The electrodes 1) are composed of
carbon or similar conducting material of the second class, and are pivoted at intervals
in ears h, on the circular holders f, g, the free ends of said electrodes being curved or
bent downward and resting on the carbon disc H.
A conducting wire. P. leads from one pole of an ordinary electric battery K, and
is connected with a metallic holder f. The conducting wire N, leading from the
opposite pole of said battery is connected to one end of a primary wire n of an
ordinary induction-coil L.
A conducting wire M, connects the opposite end of the primary wire m, of said coil
with the metallic holder g.
I
One end of the secondary wire p. of said coil is connected by a wire with the
ground G. in the usual manner, the opposite end of said secondary wire being
connected by a conducting wire R, with a receiving station.
It will be seen that a complete circuit is thus formed from the battery k, through
the wire p, to the metallic holder f; thence.by.its electrodes D, to the carbon disc H;
thence by means of the opposite electrodes D, and holder g; through the wire A, to
the primary wire n, of the induction coil L; and thence through the conducting
wire N, to the battery.
In the use of my improvement the vibrations of the diaphragm_caused by the
sound passing through the tube A, are communicated to the disc H, causing the
degree of contact of the electrodes D, to constantly change and thereby produce
variations in the electric current.
The strength of the current in the primary wires of the induction coil L, is corre-
spondingly affected, like currents being thereby imparted to the secondary wires of
said coil, and conducted to the receiver of a distant station by the wire R, in a manner
which will be readily understood by all conversant with such matters without a more
explicit description.
I do not confine myself to the shape or number of electrodes shown, the number
employed being dependent upon the degree of resistance in the transmitter.
The disc H, may also be dispensed with if desired, the free ends of the electrodes of
one holder in this case resting on the diaphragm and overlapped by those of the
opposite holder, in order to complete the circuit.
The electrodes overlapping as described may rest on the disc H, if desired, (see
Figure 5) said disc in this case being composed of non-conducting material.
It will be obvious that the apparatus described requires no adjustment, the weight
of the electrodes holding them lightly in contact with the disc or diaphragm and
rendering them substantially self adjusting and the instrument exceedingly sensitive
to sound impulses.
Moreover, by this method of construction, very heavy battery influences may
be carried without injury, rendering the device especially applicable for use in.
transinitting sound over long distances and through high resistances.
In the modification shown in Figure 3, the tube A, is constructed in the shape of a
cap or cover enclosing the electrodes and disposed on the body B, with its mouth piece
above the diaphragm instead of entering through the body below said diaphragm.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to
me by my foreign correspondent I declare that what I claim is :-
-
First In a telephone transmitter a body provided with a diaphragm in combination
with pivoted electrodes having their free..ends in gravitative contact with said

page_text: diaphragm, certain electrodes being connected with opposite poles of an electric
battery substantially as described.
Second In a telephone transmitter the combination of a body a diaphragm secured
thereto; electrodes pivoted to semi-circular plates on said body and having their free
ends in gravitative contact with said diaphragm whereby they are rendered self-
adjusting to the vibrations thereof; an electric battery having its conducting wires
respectively connected with different semi-annular plates or holders, each wire being
common to all electrodes in its plate; and an induction coil disposed in the circuit of
said battery substantially as described.
Third In a telephone transmitter the combination of a body a diaphragm secured
thereto; a conducting disc cushioned on said diaphragın; electrodes pivoted to said
body and having their free ends resting on said disc an electric battery the conducting
wires of which respectively connect with different portions of said body and an
induction coil in the circuit of said battery substantially as described.
Fourth In a telephone transmitter the combination of the body B; the diaphragm C
secured to said body by holders f, g, said holders being respectively connected with
opposite poles of an electric battery; the electrodes D, having their free ends in
electrical contact with said diaphragm ; and an induction coil disposed in the circuit
of said battery substantially as described.
Fifth In a telephone transmitter the combination of the body B; the diaphragm C,
secured thereto by holders f, g; the conducting disc H provided with cushions i;
the electrodes D, pivoted to said holders with their free ends in contact with said dise;
the battery K, having its connecting wires respectively connected with said holders;
and an induction coil in the circuit of said battery substantially as described.
Sixth In a telephone transmitter the combination of a body; a diaphragm secured
thereto by clamping plates; a conducting disc cushioned on said diaphragm ; self-
adjusting electrodes pivoted to said plates and having their free ends in contact with
said disc; a speaking tube; a battery having its conducting wires connected to
opposite plates; and an induction coil interposed in said circuit by its primary wires,
the secondary wires thereof connecting with the earth and a receiving station
substantially as described.
Seventh-In a telephone transmitter the combination of a body B, provided with the
tube A; the diaphragin C, secured to said body by holders f, g; the disc H supported
by the cushion on said diaphragmn; the battery K, having its conducting wires
respectively connected with the holders f, g; the induction coil L, interposed in the
circuit of said battery by its primary wires; and the self adjusting electrodes D,
pivoted in ears h, on said holders and having their free ends resting on said disc, all
being arranged to operate substantially as described:
Eighth In a telephone transmitter the combination of a body; a diaphragm secured
thereto by clamping plates, self-adjusting-electrodes pivoted to said plates and having
their free ends overlapped on said diaphragm; an electric battery with conducting
wires ;
and an induction coil in the circuit of said battery substantially as described.
Ninth In a telephone transmitter the combination of a body; a diaphragm secured
thereto by clamping plates; a conducting disc cushioned on said diaphragm ; self
adjusting electrodes pivoted to said plates and having their free ends overlapped on
said disc; a battery having its conducting wires connected to opposite plates; and an
induction coil in the circuit of said battery.
11391000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.