Improvements in Electrical Apparatus for Reproducing Sound.
Year: 1890

page_text: Date of Application, 11th Sept., 1890
Complete Specification Left, 10th June, 1891-Accepted, 11th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in Electrical Apparatus for Reproducing Sound.
I, JULES ERNEST ROULEZ of 3 Rue Rossini, Paris in the Republic of France
Electrician do hereby declare the nature of this invention to be as follows:-
The improved electrical apparatus forming the object of the present invention is
employed for reproducing speech and other sounds and is constructed with a
vibrating membrane or diaphragm of a material (such as retort or other carbon,
graphite and the like) which is a semi or imperfect conductor of electricity and one
or more blocks of the same or like material directly attached to the said membrane
by screws or otherwise but electrically insulated therefrom and containing, in cells
or cavities provided for the purpose, on the side turned towards the membrane, a
body or material through which the electric current is caused to pass between the
membrane and the block and which is composed of semi conducting material in
the form of dust or powder or preferably in the form of broken or short filaments
not exceeding about 5 of an inch in section or thickness.
The principal objects of this construction are to obtain an intimate and complete
union of the vibrating membrane or diaphragm with the blocks so that they form
one piece which is attached to the support solely by the edges of the said membrane
or diaphragm and to provide a hollow space or chamber in front of the vibrating
membrane so as to concentrate the sound waves and involve and bring into play
the entire surface of the said membrane which communicate with the blocks through
the aforesaid filaments of semi conducting material.
In the construction of an apparatus according to this invention the cellular block
is insulated from the membrane by a sheet or plate of non-conducting material
perforated with as many holes as there are cells in the block so that the filamentary
substance or material is in direct contact with the membrane which is attached to
a board or support perforated with a circular aperture slightly smaller than the
diameter of the membrane so that the latter closes the aperture being attached at
its edges to the said support by a metal washer or ring which is placed over the
edges of the membrane and screwed to the support.
This support and membrane are covered by a relatively thin board or plate
perforated with a central hole over the centre of the membrane. This covering
plate forms between itself and the membrane a space or chamber so that the entire
surface of the membrane is bare and the membrane is free to vibrate under the
influence of the sound waves that may impinge against it. The apparatus is placed
in communication with any suitable source of electricity by means of conductors.
The current enters by the membrane and leaves by the block or blocks or vice
versa.
When the sound waves strike the membrane the resulting vibrations owing to
the way in which the parts are connected together are transmitted to all the other
parts simultaneously and without shock thus obviating the hissing or frizzling and
other disadvantages resulting from unstable contacts which are liable to prejudice
the clearness or sharpness of the sounds transmitted or reproduced.
The intensity of the effects obtained is regulated by reducing the diameter of
the hole in the covering plate or by providing it with a mouthpiece; in the former
case the intensity is diminished, in the latter case it is augmented.
This apparatus may be constructed of any suitable form and dimensions and the
covering plate and chamber over the diaphragm and other parts of the improved
arrangements hereinbefore described may be combined with commutators electro

page_text: magnets and the like and with microphonic, telephonic and other similar apparatus
of any known or suitable construction.
Dated this 11th day of September 1890.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.
COMPLETE SPECIFICATION.
✓ Improvements in Electrical Apparatus for Reproducing Sound.
I, JULES ERNEST ROULEZ of 3 Rue Rossini, Paris in the Republic of France
Electrician 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 improved electrical apparatus constituting the present invention is intended
to be employed for reproducing speech and other sounds at a distance which may
be considerable.
The said apparatus is constructed with a vibrating membrane or diaphragm of a
material which is a semi or imperfect conductor of electricity (such as retort or
other carbon, graphite or the like) and a block or blocks of the same or like
material attached to the said membrane by screws or otherwise but electrically
insulated therefrom and containing, in cells or cavities open on the side presented
towards the diaphragm a body or material through which the electric current is
caused to pass between the diaphragm and the block or blocks which material is
composed of semi-conducting material in the form of dust or powder or preferably
in the form of broken or short filaments less than 1 millimetre or not exceeding
about 5 of an inch in section or thickness.
The principal objects of this invention are to obtain an intimate and complete
union of the vibrating diaphragm with the block or blocks so that they form
virtually one piece which is attached to the support solely by the edges of the said
diaphragm, and to provide a hollow or vacant space or chamber in front of the said
vibrating diaphragm, so as to concentrate the sound waves (without exposing the
diaphragm to accidental shocks) and bring into play the entire surface of the said
diaphragm which communicates with the block or blocks through the aforesaid
semi conducting material.
And in order that my said invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawings represents in elevation the back of the
diaphragm composed of semi conducting materials and provided with one insulated
.
block.
Figure 2 represents the apparatus in vertical section (the section being taken on
the line 1-2 Figure 1) and
Figure 3 represents a horizontal section taken on the line 3-4 (Figure 1).
The drawing shews one block with three cells but the blocks and cells may be in
any desired number.
The apparatus is provided with a circular diaphragm M of semi-conducting
material (such as retort carbon agglomerated carbon, graphite, or the like) and of
suitable dimensions according to the degree of sensitiveness to be obtained in the
instrument.
To this diaphragm a block B of semi-conducting material (which may be of the
same kind as that of the diaphragm) is attached by means of screws v suitably
insulated.
In the block B. are formed cavities or cells b open at the side towards the
diaphragm, which cavities or cells, are filled with short or broken filaments of semi-
conducting material as aforesaid.

page_text: These filaments may be replaced by the material in the form of dust or powder,
but I prefer the filaments.
The block B. is insulated from the diaphragm M. by a sheet or plate c of non-
conducting material perforated with as many holes as there are cells in the
block B. so that the material in the cells is in direct contact with the diaphragm,
which is attached to a board or support A (which may advantageously be
about 4 or 5 millimetres or say of an inch thick) perforated with a circular
aperture slightly smaller than the diameter of the diaphragm so that the latter
closes the aperture being attached at its edges to the said support by a metal
washer or ring a which is placed over the edges of the diaphragm, and secured by
screws d.
The opening in the support A. is covered by a relatively thin board or plate P.
perforated with a central hole p of any suitable dimensions.
This plate P. forms between itself and the membrane a vacant space or chamber
preferably of about the same width as the thickness of the support A. so that the
entire surface of the diaphragm M. is free to vibrate under the influence of the
sound waves that may impinge against it.
The apparatus is placed in communication with any suitable source of electricity
by means of conductors and y.
The current enters by the diaphragm M and leaves by the block or blocks B.
or vice versa.
When the sound waves strike the diaphragm the resulting vibrations (owing to
the way in which the parts are connected together) are transmitted to all the other
parts simultaneously and without extraneous shock, thus obviating hissing or
frizzling sounds and other disadvantages resulting from unstable contacts which
are liable to prejudice the clearness or sharpness of the sounds transmitted and
reproduced.
The intensity of the effects obtained is regulated by reducing the diameter of
the hole p or by providing it with a mouth piece: in the former case the intensity
is diminished, in the latter case it is augmented.
This apparatus may be constructed of any suitable form and dimensions and the
covering plate P. and chamber in front of the diaphragm and other parts of the
described arrangement may be combined with commutators electro magnets and
the like and with microphonic, telephonic, and similar apparatus of any known and
suitable construction.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
First. In microphonic and other similar electric apparatus for the purpose of
transmitting simultaneously and without shocks the vibrations produced by sound
waves, the arrangement of a membrane or diaphragm M. of semi-conducting
material supporting an insulated block or insulated blocks B. of semi-conducting
material connected to the diaphragm and forming one piece so that the block or
blocks and diaphragm are supported by the attachment of the edges of the said
diaphragm substantially as hereinbefore described with reference to the accom-
panying drawings.
Second. In microphonic and other similar electric apparatus in combination with
the vibrating membrane M and the insulated block or blocks B. the application of
broken filaments of semi-conducting material of less than one millimetre in section
the said filaments being arranged in a cell or cells b in the block or blocks B. and
acting as current transmitters substantially as hereinbefore described with reference
to the accompanying drawings.
Third. In microphonic and other similar electric apparatus a hollow or vacant
space or chamber in front of the vibrating membrane or diaphragm M enclosed by
a plate or board P perforated with a central orifice p and fixed to the support of
the membrane or diaphragm M. The said space acting in combination with the

page_text: said membrane or diaphragm in the manner and for the purpose substantially as
hereinbefore described with reference to the accompanying drawing.
Fourth. As an electrical apparatus for reproducing or conveying sound the
combination of arrangements referred to in the preceding claims namely a vibrating
membrane or diaphragm M rigidly attached at its edges and insulating block or
blocks B, the intermediate or connecting body between the said membrane or
diaphragm composed of broken filaments not exceeding one millimetre in section
and a board or perforated plate P fixed on the support A and forming a hollow or
vacant space in front of the membrane M all in the manner and for the purpose
substantially as hereinbefore described with reference to the accompanying
drawing.
Fifth. The combination of the aforesaid sound conveying or sound carrying
apparatus with the ordinary supplementary parts of microphones and with a
telephonic apparatus in such a manner as to constitute a complete microphonic
station.
Sixth. In the aforesaid sound conveying or sound carrying apparatus the
arrangement of a number of cells formed in the block or blocks B in combination
with the broken filaments of semi conducting material held thereby substantially
as hereinbefore described with reference to the accompanying drawing.
Dated the 10th day of June 1891.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.