Improvements in Magneto-telephonic Instruments.
Year: 1885

page_text: Improvements in Magneto-telephonic Instruments.
We, SILVANUS PHILLIPS THOMPSON, of 20 Arundel Gardens, Notting Hill, in
the County of Middlesex, Doctor of Science and Professor of Experimental
Physics, and PHILIP JOLIN, of 35 Narrow Wine Street, in the City of Bristol,
Engineer, do hereby declare the nature of this Invention to be as follows:-
Our Invention relates to Magneto-telephonic instruments for use primarily as
telephonic receivers, but which may be used also as telephonic transmitters; and,
by the construction and principle according to our Invention, we obtain a light and
powerful instrument.
A long narrow triangular strip of steel, having a circular hole or slot cut out
of its broader end, is bent so that the narrow end passes up into the said hole
or alot. The curved strip is then magnetized so that the narrow end constitutes
one pole and the edges of the slot the other pole. In the annular space between
the poles the coil is placed, its ends being secured to suitable terminals which are
screwed into an insulating block or blocks fixed to the instrument at some
convenient point. A light but strong steel spring also is fastened to the strip so
that its end or other part passes over the central pole, and the said spring may
be prevented from being brought into actual contact with the pole by the inter-
position at some point of a cushion of cork or india-rubber. To the said spring
at or near that part of it which is immediately above the pole is attached or
rivetted a hollow metallic dish of a convenient size to fit to the ear and it is not
fixed at any other part than at or near its central part where it is attached or
rivetted to the spring. The spring may be attached at one end or both; or it may
be triangular and attached at points along one side.
•

page_text: COMPLETE SPECIFICATION..
Improvements in Magneto Telephonic Instruments.
We SILVANUS PHILLIPS THOMPSON of 20 Arundel Gardens Notting Hill in
the County of Middlesex Doctor of Science and Professor of Experimental
Physics and PHILIP JOLIN of 35 Narrow Wine Street, in the City of Bristol
Engineer 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 :-
The
Our Invention relates to Magneto Telephonic instruments for use primarily as
Telephonic receivers but which may be used also as telephonic transmitters and
by the construction and principle according to our Invention we obtain a light
and powerful instrument. We will describe our. Invention with reference to the
accompanying Drawing. Figure 1 represents a long narrow triangular or tapering
strip of steel A having a circular hole or slot cut out of its broader end at a.
said strip is bent as represented so that the narrow or small end a³ passes up into
the said hole or slot a. The curved strip is then magnetized so that the end a
constitutes one pole and the edges of the slot or hole a, the other pole of the
magnet. In the annular space between the poles, the coil B is placed as shewn in
figure 2, its ends being secured to suitable terminals, one or both of which is or
are screwed or otherwise fixed or fitted into an insulating block or into insulating
blocks fixed to the instrument at any convenient part thereof. A light but strong
spring, preferably of steel or other magnetic material O, is fastened to the part A
so that one of its ends or part of it passes over the central pole at in the part A
and the said spring may be prevented from being brought into actual contact with
the pole by the interposition at some point of a cushion of cork or India-rubber
or of a brass pin or its equivalent. To the said spring C at or near that part
of it which is immediately above the pole a³ is rivetted or otherwise secured, a
dish or cup D of metal ebonite celluloid or other similar hard material of a
convenient size to fit to or place over the ear and it is not fixed at any other part
than at or near its central part where it is attached or rivetted, preferably by
* an iron rivet to the spring C.-The spring C may be attached to the part A at
one end or at both ends or it may be triangular and be attached at points along
one side. .
:
13 1
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that we
claim is:-
First. A telephonic instrument consisting of a magnetized part A formed as
described and provided with a coil and with a dish or cup or the like mounted
upon a spring or equivalent yielding part substantially as described and
Hled

page_text: Second. In a Telephonic Instrument, the employment of a cup or dish, attached
at its centre to a spring or other equivalent yielding support, and not attached at
any other part, and arranged so as to be capable of receiving from a neighbouring
coil or coils and transmitting magneto-electric impulses.
Dated this eighth day of August 1886,
SILVANUS P. THOMPSON.
PHILIP JOLIN,