IMPROVEMENTS IN TELEPHONES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, WILLIAM EDWIN IRISH, of Electric Works, Sunderland, in the County of
Durham, Electrician / Day, Davies & Hunt, Patent Agents, 321, High Holborn,
in the County of Middlesex, do hereby declare the nature of my Invention for
"IMPROVEMENTS IN TELEPHONES" to be as follows:-
This Invention relates to improvements in telephones in which magnets or electro-
magnets are used, and consists of an improved method of mounting the vibrating
diaphragms or discs thereof, the object of the Invention being to intensify the
vibrations of the diaphragms and to thereby render the instruments of increased
utility.
As hitherto applied, the diaphragms of such telephones have been held or firmly
secured circumferentially or around the outer edges or parts thereof by various
means or contrivances, and the inner or central part of the diaphragm has been left
free for the desired purpose of vibration; the disadvantage of this system of
mounting the diaphragm is that the vibrations thereof are injuriously limited in
their extent or intensity; and it is the object of the present improvements to
obviate this disadvantage which materially militates against the utility of the
instrument.
The characteristic feature of the present improvements is that the diaphragm (or
equivalent vibrating disc, sheet or plate whether made of wood, ebonite, thin sheet
inetal or other material suitable for the purpose,) is supported or mounted and held
or firmly secured at or adjacent to its inner or central part in such a manner as to
Jenve its circumference or outer edges or parts perfect freedom of vibration.
It is not material to the Invention that this improved method of mounting the
said diaphragms or discs should be effected in any particular way, or by the aid of
any particular means, as it may be effected with equal advantage by the employ-
ment of various appropriate means and in different suitable manners, and I have
hereinafter described by way of examplo simple and convenient means of carrying
the Invention into effect in applying it to telephones of different construction.
In applying the Invention to a telephone in which a single bar magnet or electro-
magnet is employed, the central part of the vibrating disc is or may be screwed
or otherwise fastened in any convenient manner to the pole of the magnet or
electromagnet, firstly interposing between the parts an insulating or non-magnetic
washer or equivalent means of preventing the magnet or electro-magnet and the

page_text: disc from touching, or the latter result may be obtained by making the pole of the
magnet or electromagnet of a hollowed or recessed formation, and inserting therein
a projecting part to which the centre of the said disc may be secured as aforesaid.
The Invention may be similarly applied and with increased advantage to tele-
phones in which two or more magnets are employed, and it may also be applied to
telephones in which other forms of magnets or electromagnets are employed.
I find the improved method of supporting the said vibrating discs to be of
peculiar advantage when applied to and used in combination with telephones the
poles of the contained magnet or of each magnet of which are turned up and sur-
rounded by one bobbin of wire that is by a bobbin of wire common to both poles
as described in the Specification of certain Letters Patent No 3944 granted to me
and bearing date the 12th day of September A.D. 1881, and in this application a
convenient means of applying the vibrating disc is to secure its central part by a
screw or other suitable means to a piece of ebonite or other non-magnetic substance
secured by and between the upturned poles of the magnet.
And in a similar application wherein a horse shoe magnet is used with turned
up pole pieces of hollow semi-conical form, the central part of the said disc may be
secured to a core rising between such pole pieces. In applying the Invention in
this and other ways to attain the said object, it is material to observe, ns herein-
before-referred to, that the said disc must not be allowed to touch the poles of the
magnet or electromagnet.

page_text: COMPLETE SPECIFICATION.
I, WILLIAM EDWIN IRISH, of Electric Works, Sunderland in the County of
Durham, Electrician, % Day, Davies and Hunt, Patent Agents, 321, High Holborn,
in tho County of Middlesex do hereby declare the nature of my Invention for
"IMPROVEMENTS IN TELEPHONES," 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 certain improvements in telephones in which magnets
or electro-magnets are used, and consists of an improved method of mounting the
vibrating diaphragms or discs thereof, the object of the Invention being to intensify
the vibrations of the diaphragms and to thereby render the instruments of increased
utility.
As hitherto applied the diaphragms of such telephones have been held or firmly
secured circumferentially or around the outer edges or parts thereof by various
means or contrivances, and the inner or central parts of such diaphragms
have been left free for the desired purpose of vibration, the disadvantage of this
system of mounting the diaphragms of such apparatus is that the vibrations
thereof aro injuriously limited in their extent or intensity; and it is the special
object of the present improvements to obviate this disadvantage which materially
militates against the utility of the instrument.
The characteristic feature of the present improvements is that the diaphragm (or
equivalent vibrating disc, sheet, or plate, whether made of wood, ebonite, thin shoet
metal, or other material suitable for the purpose,) is supported or mounted and
held or firmly secured at or adjacent to its inner or central part in such a manner
as to leave its circumference or outer edge or part perfect freedom of vibration.
It is not material to the Invention that this improved method of mounting the
said diaphragms or discs should be effected in any one particular way, or by the aid
of any particular means, as it may be effected with equal advantage by the
employment of various appropriate means and in different suitable manners, and
I have illustrated on the accompanying drawings, and hereinafter describe, by way
of example, simple and convenient means of carrying the Invention into effect in
applying it to telephones of different construction.
The improved method of supporting the said vibrating discs is of peculiar advan-
tage when applied to and used in combination with telephones the poles of the
contained magnet, or of each contained magnet of which, are turned up and
surrounded by one bobbin of wire, that is by a bobbin of wire common to both
poles as described in the Specification of Letters Patent N° 3,944, granted to me,
and bearing date the 12th day of September, A.D. 1881, and in this Application a
convenient means of applying the vibrating disc, 1, is to secure its central part by a
screw or other suitable means, 2, to a core or piece, 3, of ebonite or other insulating
or non-magnetic substance secured by and between the upturned poles, 4, of the
magnet, 5, as shown in Figs; 1, and, 2, which respectively represent a sectional
elevation, and plan view of such a telephone thus fitted. 7, represents the case of
the telephone and which may be of any usual formation.
The Invention may be similarly applied and with equal advantage to telephones
in which two or more magnets are employed, or in which other forms or arrange-
ments of magnets or electromagnets are employed, and various examples of which
are illustrated on the accompanying drawings and are hereinafter referred to,

page_text: DAY, DAVIES & HUNT,
321, High Holborn, Loudon, W.C.,
Agents for the Applicant.