Improvements in Apparatus for Rendering Audible any Sounds which are Conveyed through Water.
Year: 1891

page_text: Date of Application, 8th Dec., 1891
Complete Specification Left, 10th Oct., 1892-Accepted, 12th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Rendering Audible any Sounds
which are Conveyed through Water.
I, CHARLES AMBROSE McEvor of 69 Victoria Street, in the City of
Westminster, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention has mainly for its object the prevention of surprise attacks from
torpedo boats also the prevention of collisions between ships at sea, at night or in
foggy weather, but may be used for other purposes.
In carrying out my invention I construct the apparatus which I denominate a
hydrophone of a hollow casing which may be in the form of a cube or other form
with an opening through some or all of its sides and ends and having each opening
covered with a flexible diaphragm of thin metal or india rubber or other suitable
material. To the top of the casing I attach the base of a hollow cone from the
apex of which a pipe preferably a flexible one of india rubber is led away to a cup
shaped ear piece of any suitable material which may have a diaphragm across it at
such a distance from the mouth of the cup that it cannot be brought into contact
with the ear.
In
When a hydrophone constructed as described is submerged in the water the noise
or sounds made by the paddle wheels, or propellers of moving steamers would act
concussively on its diaphragms and be transmitted through the tube to the ear.
this way sounds may be heard at considerable distances from the source from which
they proceed.
Dated this 9th dow of December 1891
COMPLETE SPECIFICATION.
Improvements in Apparatus for Rendering Audible any Sounds
which are Conveyed through Water.
I, CHARLES AMBROSE MC Evor, of 69 Victoria Street, in the City of
Westminster, 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 :-
My invention has mainly for its object the prevention of surprise attacks from
torpedo boats also the prevention of collisions between ships at sea, at night or in
foggy weather, but may be used for other purposes.
In carrying out my invention I construct the apparatus which I denominate a
hydrophone of a hollow casing which may be in the form of a cube or other form with
an opening through some or all of its sides and ends and having each opening covered
with a flexible diaphragm of thin metal or india rubber or other suitable material.
To the top of the casing I attach the base of a hollow cone from the apex of which
a pipe preferably a flexible one of india rubber is led away to a cup shaped ear piece
of any suitable material which may have a diaphragm across it at such a distance
from the mouth of the cup that it cannot be brought into contact with the ear.
When a hydrophone constructed as described is submerged in the water the noise
or sounds made by the paddle wheels, or propellers of moving steamers would act
In
concussively on its diaphragms and be transmitted through the tube to the ear.

page_text: This way sounds. may be nearu at considerable distances from
they proceed.
The annexed drawings show apparatus in accordance with my invention.
Figure 1 is a side elevation. Figure 2 is a plan and Figure 3 is a vertical
section.
In Figures 1 and 2 the ear piece and the connecting pipe are omitted. Figure 4
is an elevation and Figure 5 is a section of the ear piece drawn to a larger
scale.
Figure 6 is a vertical section of a similar apparatus with an addition hereinafter
described. Figure 7 is a section to a larger scale of a portion and Figures 8 and 9
show details of the same apparatus.
Figures 10 and 11 are elevations and Figure 12 is an underside view of the ear
piece for use with the apparatus represented by Figure 6.
In Figures 1, 2 and 3 a is a cubical box it is preferably cast in gun metal and is
sufficiently heavy although hollow to sink when lowered into the water.
In every
side of the box, the bottom excepted, there is a circular hole, and the holes in the
four sides of the box are closed by diaphragms bb. I make these diaphragms
preferably of aluminium bronze rolled into a sheet about as thick as a visiting card.
The diaphragm rests in water-tight contact with a truly turned face upon the box,
to which it is clamped by a ring c. c, c', are tap screws passing through the ring
and the diaphragm and screwing into the casting a. The hole in the top of the
cubical box is closed by a conical or funnel like cover d which also is preferably
cast in gun metal; it is firmly held in its place by tap screws, the joint being made
perfectly water tight. On the nozzle d' of the cover a screw thread is cut and by
an ordinary screw union a flexible pipe preferably of stout india rubber is
connected. The pipe e is of a convenient length, if the apparatus is to be used from
a boat 9 or 10 feet will be sufficient but if from a ship a greater length will be
required. At the other end of the pipe e the ear piece shown by Figures 4 and 5 is
attached. The ear piece as here shown consists of two discs f and 9 which may be
of vulcanite; they are fixed together by screws and a metal ferrule is secured to
the disc The ferrule h receives the end of the flexible pipe e. I sometimes
.clamp a diaphragm of thin india rubber i between the discs f and g to cover the
holes in these discs or prolongation of the passage of the pipe e. The diaphragm i
serves to prevent the accidental entrance of water into the pipe e; where there is
no danger of this the diaphragm is not needed.
g.
When required for use the box part of the apparatus should be lowered into the
water from a boat or ship at rest or nearly so; this is done by means of a cord not
shown in the drawings. The box should be immersed to a depth of six feet or
thereabout and it should hang freely suspended. Then on applying the ear to the
ear piece sounds produced by the screws of passing ships or the oars of boats can
be heard from a very considerable distance and at night or when the view is
obscured notice of the proximity of vessels may thus be obtained.
In Figure 6 an electric bell is shown mounted upon a suitable support within
the box a. and are the circuit wires of the bell, one passes to the metal of the
box, the other to a metal peg 1, passing through a vulcanite plug m inserted into the
nozzle d' of the cover. The plug m is perforated with several holes for the passage
of the sound waves as is shown in Figure 8. Into the screw union another vulcanite
plug or cross bar n shewn in Figure 9 is inserted and a metal peg o passes freely
through it. The peg o is pressed forward by a spring which abuts upon a head
with which the pin is provided, hence when the union is screwed up the pegs 1 and o
are in contact and pressed firmly together. Two covered wires pass down within
the pipe e, one of them is connected with the metal of the screw union and so to the
box a the other wire is fixed to the peg o. At the ear piece the same wires are
connected the one with a metal fixing p and the other with a spring tongue q. On
the ear piece there is also a press button which when the finger is placed upon it
comes against the spring tongue 9 and deflects it bringing it into contact with
another fixings similar to p. In each of these fixings there is a hole to receive a

page_text: metal plug. t't' are plugs, they are both inserted into a ebonite handle u and by
wires they are connected with the poles of a bell battery. The battery is thus
connected in circuit when the plugs t¹t are pushed into the holes in the fixings p
and s.
Pressure on the press button then serves to close the bell circuit and the bell
The sound so produced can be heard by the use of a similar apparatus at a
distance, both of the apparatus being immersed as already described. Thus boats
at a considerable distance apart can communicate.
sounds.
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:
1. Apparatus for rendering audible, sounds conveyed through water, and con-
sisting of a box adapted to be immersed and provided with openings fitted with
diaphragms and connected by a pipe with an ear piece substantially as described.
2. Apparatus substantially as herein described and shown.
Dated this 8th day of September 1892.
C. A. MCEVOY.