IMPROVEMENTS IN TELEPHONE RECEIVERS
Year: 1884

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
TELEPHONE RECEIVERS 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 this Invention is to provide a double telephone-receiver, which
may be readily applied to both ears simultaneously, and in which the diaphragm
cells adapt themselves automatically to the ears, and thus exclude extraneous
sounds, and bring both ears into use.
The Invention consists in the combination with two diaphragm cells, of a holder,
composed of two arms hinged together and pivoted to the diaphragm cells, and
drawn toward each other by a bow-spring attached to the free ends of the said arms,
and forming an electrical connection between the terminals of the two receiver
bobbins,
Figure 1 is a side elevation of the improved adjustable double telephone receiver.
Figure 2 is a side elevation of the reverse side of the improved telephone receiver.
Figure 3 is a transverse section of the diaphragın cell, and of the parts contained
therein. Figure 4 is a rear view of the diaphragm cell, with the cap removed to
show the receiver magnet. Similar letters of reference indicate like parts in the
different Figures of the Drawing.
Two levers A, curved sufficiently to receive between them the head of the user
of the telephone, are provided with handles B, and are connected together at the
upper ends of the handles by a hinge C. To the free ends of each curved lever A,
are secured, two curved metallic arms D, D', which are apertured at their free
ends to receive the pivotal screws a, which pass through the arms D, D¹, into
diametrically opposite sides of the diaphragm cells E, forming pivots upon which
the cells may swing to adapt themselves to the ears of the user.
The screws a,
are connected with the terminals of the telephone bobbin b, and serve to conduct
the telephone current through the sides of the diaphragm cell.
The ends of the arms D, of the opposite levers A, are connected with each other
by a wire bow-spring F, which conforms to the general curve of the levers A, and
draws them toward each other, and at the same time serves as an electrical conductor
between the bobbins of the two diaphragm cells. The ends of the arms D¹, which
[ Price L

page_text: are secured to the levers A, are prolonged toward the hinge C, and provided at
their extremities with binding posts G, for receiving the usual telephone conductor.
When the diaphragm cells E are drawn towards each other by the spring F, the
handles B, are separated, and to limit the movement of the levers A, a hook c,
extends from one handle into a mortise in the other, in position to engage a pin c¹
passing transversely through the mortise when the handles are separated.
The diaphragm cells E, each contain a bobbin b, surrounding the end of a
permanent magnet d, which is curved in a spiral e, to bring it within the compass
of the cell. The magnet d, is clamped by screws f, against the fillet g formed in
the diaphragın cell. The diaphragm cell contains the usual diaphragm h, which is
opposed to the magnet, and is partly covered by. the apertured cap i.
The adjustable telephone receiver is applied to the ears by separating the
diaphragm cells E, by pressing on the handles B, then placing the head between
them, then releasing the handles so that the bow-spring F may draw the diaphragm
cells against the ears. When thus applied both ears are used and all extraneous
sounds are effectively shut out. By this construction the volume of sound is
greatly increased and faint sounds are rendered more effective.
This improved receiver facilitates telephonic communication in noisy places, and
permits of receiving telephonic messages by currents too weak to operate the
ordinary receiver effectively. It is therefore especially adapted to long distance
telephony, where the currents arriving at the receiving end of the telephone line
are but a fraction of the current sent out by the transmitter.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I.declare that what
I claim is:-
1st The combination in a telephone-receiver of two curved spring-acted levers,
hinged to each other, and two diaphragm cells attached to the free ends of the said
levers, and capable of being pressed by the levers against both ears of the user, as
specified.
2nd The combination with the curved levers A, hinged to each other and
provided with handles B, of the bow-spring F, for pressing the free ends of the
levers together as described.
3rd The combination with the levers A, hinged together as described, of the
arms D, D¹, and diaphragm cells E, pivoted in the said arms, and capable of
adapting themselves automatically to the ears of the telephone user, as specified.
4th The combination with the hinged levers A, of diaphragm cells E, arms D,
bow-spring F, secured to the said arms, and forming an electrical connection
between the same, and arins D', prolonged toward the hinge of the levers A, and
provided with binding posts G, as specified.
5th The combination with the handles B, on the levers A, of the hook c, and
stop-pin c', for limiting the movement of the said levers and handles, as specified.
6th The combination with curved levers, hinged to each other as described, of
pivoted diaphragm cells carried by the said levers, and containing bobbins in
electrical communication with each other, and with the telephone circuit as
specified.