An Apparatus for Rendering Small Sounds in the Human Body, or in all Solid Bodies in General, Distinctly Audible on a Magnified Scale.
Year: 1895

page_text: Date of Application, 23rd May, 1835
Complete Specification Left, 13th Jan., 1896-Accepted, 21st Mar., 1896
PROVISIONAL STEIFICATION
An Apparatus for Rendering Small Sounds in the Human Body, or
in all Solid Bodies in General, Distinctly Audible on a Magnified
Scale.
A communication from LEOPOLD WALLACH, of the Firm of "The Successors
of Martin Wallach," of 33 Wolfsschlucht, Cassel, in the Empire of Germany.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
scale.
This invention relates to
human body, or in all solid
The improved apparatus is based essentially upon the fact that an elastic
membrane or other body capable of vibrating is united to a body of a larger mass
and consequently greater inertia. When such a body laid upon another body in
which small noises, rustlings or murmurs continually occur, the membrane is set in
vibratory motion, in relation to the heavy, solid body, while the large mass of the
latter itself partakes not at all or only very slightly and in perceptibly in that
vibration.
an apparatus which renders small sounds in the
bodies in general, distinctly audible on a magnified
The vibrations or oscillations of the membrane are made audible in any.
appropriate manner; e.g. by means of a microphone or by propagation of the air-
vibrations created thereby.
The apparatus consists of a circular disc of heavy metal or other the like
material, of considerable weight, for instance like wood weighted with lead, and the
like. In the centre of this disc is provided a hollow, covered by a membrane of
hard rubber or similar material, constituting a diaphragm. Inside this hollow
space a weak spring may be provided so as to press upon the membrane or.
diaphragm This diaphragm is packed tightly against the edge of the hollow by
means of a ring, and firmly pressed on the disc by a hasp-ring.
Over the diaphragm is a somewhat thicker hard-rubber plate, encased in or
bordered by a ring, and secured on the hasp-ring or socket, by a bayonet lock-
fastening, or any similar means.
It will be found advantageous to provide this rubber-plate with a central orifice,
wherein may be screwed a hard-rubber rod. This rod is generally located on the
rear-side of the box, where it is secured by bands or staples.
On the rear-side of the disc or box are bored two holes, terminating in the
central hollow. Two hearing-trumpets or pipes may be inserted in these holes,
which tubes, whenever the apparatus is not in use, may be wound round the edge
of the box, groove-shaped for the purpose, and there retained by a suitable hook
or other device.
If this "phonendoscope" be brought into contact with any solid body, either by
the knob on the end of the rod, or by the freely exposed hard-rubber plate, the
tone-vibrations in that solid body will communicate themselves to the point of
contact with the knob of the diaphragm, while the mass and weight of the box, by
their greater moment will remain practically motionless; consequently the move
ments of the plate will show themselves, in comparison with those of the box as
enormously greater. These movements therefore generate strong changes of

page_text: volume in the hollow space and give rise to strong vibrations, which are communi-
cated to the sense of hearing by means of the hearing-trumpets.
The transmission of the vibrations of the diaphragm may also be effected with
the aid of a microphone; and the disc may be rectangular or of any other form.
Dated this 23rd day of May 1895.
BOULT & WADE,
Agents for the Applicant.
An Apparatus for Rendering Small Sounds in the Human Body, or
in all Solid Bodies in General, Distinctly Audible on a Magnified
Scale.
A communication, from LEOPOLD WALLACH, of the Firm of "The Successors
of Martin Wallach," of 33 Wolfsschlucht, Cassel, in the Empire of Germany.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, 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 :-
This invention relates to an apparatus which renders small sounds in the
human body, or in all solid bodies in general, distinctly audible on a magnified
scale.
The improved apparatus is based essentially upon the fact that an elastic
membrane or other body capable of vibrating is united to a body of a larger mass
and consequently greater inertia. When such a body is laid upon another body in
which small noises, rustlings or murmurs occur, the membrane is set in vibratory
motion, in relation to the heavy, solid body, while the large mass of the latter
itself partakes not at all or only very slightly and imperceptibly in that
vibration.
The vibrations or oscillations of the membrane are made audible in any
appropriate manner; e.g., by means of a microphone or by propagation of the
air-vibrations created thereby.
In the accompanying drawings:-
Figure 1 is a back-view thereof, as seen from above;
Figure 2 is a cross-section of the same;
Figure 3 a side elevation.
The apparatus consists of a circular disc S of heavy metal or other like material,
of considerable weight, for instance, wood weighted with lead, or the like. In the
centre of this disc is provided a hollow e covered by a membrane of hard rubber
or similar material, constituting a diaphragm m. Inside this hollow space a weak
spring may be provided so as to press upon the membrane or diaphragm. This
diaphragm is packed tightly against the edge of the hollow by means of a ring d
and firmly pressed on the disc S by a hasp-ring r.
Over the diaphragm m is a somewhat thicker hard-rubber plate p encased in or
bordered by a ring, and secured on the hasp-ring or socket r by a bayonet lock-.
fastening, or any similar means.
It will be found advantageous to provide this rubber-plate p with a central
orifice, wherein may be screwed a hard-rubber rod has shown in dotted lines in
Figure 2. This rod is generally located on the rear-side of the box, where it is
secured by bands or staples n.
On the rear-side of the disc S or box are bored two holes, terminating in the
central hollow. Two hearing-trumpets or pipes k may be inserted in these holes,

page_text: which tubes, whenever the apparatus is not in use, may be wound round the
edge of the box which is groove-shaped for the purpose, and there retained by
a suitable hook or other device.
If this apparatus be brought into. contact with any solid body, either by the
knob on the end of the rod, h, or by the freely exposed hard-rubber plate P, the
tone-vibrations in that solid body will communicate themselves to the point of
contact with the knob of the diaphragm, while the mass and weight of the box,
by their greater moment will remain practically motionless; consequently the
movements of the plate will show themselves, in comparison with those of the box
as enormously greater. These movements therefore generate strong changes of
volume in the hollow space e and give rise to strong vibrations, which are commu-
nicated to the sense of hearing by means of the hearing-trumpets, k.
The transmission of the vibrations of the diaphragm may also be effected
with the aid of a microphone; and the disc S may be rectangular or of any other
form.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent and in what manner the
same is to be performed, I declare that what I claim is :-
1. An apparatus for rendering small sounds more distinctly audible characterised
by connecting or uniting an easily vibrating diaphragm with a body of greater
mass so that in relation to the latter the former shall be set in vibration while
these vibrations are transmitted to the ears by means of air-pipes or electrically
substantially as described.
2. An apparatus such as described in Claim 1 characterised by a heavy box-
shaped disc such as S with a hollow such as e covered by a diaphragm m and
provided with holes or borings for the reception of external tubes k for hearing
substantially as and for the purpose described.
3. In an apparatus such as described in Claims 1 and 2 the arrangement of a
rod such as which can be screwed into a covering-plate p protecting the
diaphragm m substantially as and for the purpose described and illustrated in the
accompanying drawings.
Dated this 13th day of January 1896.
BOULT & WADE,
Agents for the Applicant.