Year: 1898

page_text: We, EDOUARD HARDY and RUTONAY PICARD, both of 30, Rue St. Lazare, Paris,
France, Manufacturers, do hereby declare the nature of this invention to be as
follows:
-
The subject of the present invention is a microphone on pivots adapted for
application to microphonic boxes or cases for submarine use, and to the sub-
marine acoustic telegraphy which results therefrom, to the determination of
the apparent direction of a telephonic signal either in the air, or in water and
to all ordinary telephonic transmissions.
This microphone consists essentially of a vibrating plate mounted upon a
frame, beneath which plate and in accordance with the centre thereof is fixed a
small carbon disc electrically insulated from the said vibrating plate.
Pivoted elements in greater or less number are arranged radially around the
above mentioned carbon disc. Each pivoted element consists of a metal balance
beam traversed at or near its centre by an axis having very fine pivots, in such a
manner that the said balance bean is capable of moving very freely around
this axis. The balance beam carries at one end of its extremities a carbon pencil
and at the other a movable counterpoise or balance weight adjustable along the
second arm of the said balance beam, which arm is screw-threaded in order to
admit of the balance weight being brought to a greater or lesser distance from
the above mentioned axis.
This balance weight may be replaced by a suitable spring the tension of which
can be regulated with precision. In certain cases it is found advantageous to
replace the carbon forming the small disc, and that fixed to the central extremity
of the balance beam by pieces of silver or of platinum.
The axis supporting the balance lever pivots in a metal piece carried upon an
insulated support; which support is fixed to the framing which supports the
vibrating plate, or else is fixed on the edge of the vibrating plate itself. The
pivots of the axis traverse the above mentioned piece and are considerably longer
than the thickness of that piece,. and metal boxes formed on this latter surround
the free ends of the pivots and are each closed by a screw. Before placing the
screw in position, mercury is poured into the hole in the box which is intended
to receive the said screw, and whilst screwing in this latter the excess of mercury
is discharged or runs through the very small annular clearance which exists
between the pivot and the piece which supports it, but the box which encloses
the extremity of the pivot remains full of mercury, so that the free end of the
pivot is plunged in the mercury. In this manner electrical contact between the
supporting piece of the axis and the said axis is insured, without the free move-
ment of this latter being interfered with in the slightest degree.
The pivoting elements placed radially round the small disc hereinabove men-
tioned may be grouped either in tension or in shunt.
The operation of the microphone described is based upon the inertia of the
balance lever, the weight of this piece should therefore be determined in accord-
ance with the results that it is desired to obtain.

page_text: In order to apply the above described microphone for the reception of the
sonorous waves transmitted by water, with the object of obtaining by its aid a
submarine acoustic telegraphy, the microphone is mounted in a water tight
metal box, the upper part of which is closed by a vibrating metallic plate forming
a membrane or diaphragm, and the air in the interior of the box is compressed
in such a manner as to equilibrate the pressure of the water on immersion.
An electric cable having two wires penetrates into this microphonic box and
admits of the electric current being delivered to the microphone. This box
being immersed at the bottom of the sea at a certain distance from the coast,
and the microphone being put in connection with a telephonic receiver fixed on
the coast, this receiver will reproduce all the sonorous vibrations transmitted
by the water, even at very considerable distances; the blows struck in the hull
of a ship's boat, for example, are perceived in the telephonic receiver.
This arrangement forms then a real submarine acoustic telegraphy very useful
in case of shipwreck during foggy weather, admitting of help being afforded
from the coast to the shipwrecked parties embarked in the ship's boats, and simply
striking upon the hull of their boat in a predetermined manner in order to
demand help.
The following is the principle upon which rests the determination of the
direction of the sound by means of the microphone. Two microphones are
placed upon a vessel, the one in the fore part and the other in the stern; the one
in the fore part is connected to a telephonic receiver which the observer places
to his right ear, the microphone in the stern is connected with a receiver which
the operator places to his left ear. If the sonorous waves arrive towards the
vessel in accordance with its axis the observer first perceives the signal in the
right ear afterwards in the left ear. If the sonorous waves arrive in a direction
perpendicular to the axis of the vessel, the observer hears the signal at the same
time in both ears. In order to render it possible to determine the apparent
direction of the sound four pivoted microphones are employed two being placed in
accordance with the longitudinal axis of the vessel, the other two transversely.
with an observer for the two first, and one for the two second microphones. A
greater degree of precision can be obtained in the observation by the employ-
ment of a suitable registering or recording apparatus.
By suitably regulating the pressure of the carbons, which terminate the balance
levers of the pivoting microphones, upon the central plate, and by employing as
a vibrating membrane or diaphragm, a small wooden table or sound board similar
to that used in ordinary telephones, it is possible to obtain pivoting microphones
a transmission of sounds much more clear and more intense or stronger than
those obtained by means of the apparatus actually in use.
Dated this 22nd
1000
J. P. BAYLY,
18, Fulham Place, London, W., Agent for the Applicants.
Improvements in and relating to Microphones.
We, EDOUARD HARDY and RUTONAY PICARD, both of 30, Rue St. Lazare, Paris,
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 improvements in microphones, the object being to
provide an apparatus of this kind in which the sound-waves are received by a
suitable vibrating plate and transmitted therefrom to pivotally mounted receivers

page_text: having suitable means for adjusting the pressure of the engaging carbon or
graphite pins on said vibrating plate.
With this object in view, the invention consists in the construction, arrange-
ment and operation of parts, hereinafter fully described and specifically set
forth in the claims.
In order that the invention may be the more readily understood and carried
into practical effect, we have illustrated the same in the accompanying explana-
tory drawings, in which:-
Fig. 1, is a bottom plan view of a microphone constructed in accordance with
my invention, with parts thereof shown in section;
Fig. 2, is a side elevation of same, two pivoting elements being omitted for
the sake of clearness of the drawings;
Figs. 3, 4, 5 and 6, are diagrams hereinafter referred to and fully explained.
Referring particularly to the drawings B indicates a vibrating plate which
may be made of any suitable form and material. but is preferably circular in
shape and made of any metal. To the centre of said plate is suitably secured
a small disk A. of carbon electrically insulated in any suitable way. The plate B
is secured near its periphery and at determinate points thereof, to an annular
support H by means of screws or otherwise, so that the same may freely vibrate
and receive sound-waves to be transmitted to suitable elements, which in
accordance with the principle evolved by this invention, are pivotally and adjust-
ably mounted on suitable supports and preferably arranged by fours around the
above named carbon disk A. In the drawings these elements are indicated by
numerals 1, 2, 3, and 4, 1 and 2 being connected with the positive pole and 3
and 4 with the negative pole of the device. However, I would it have under-
stood that any preferred number of elements may be employed without departing
from the scope of the invention.
Each receiving element consists of a metal piece or lever D, having at about
the medium point thereof a suitable pivot-pin E extending through said lever
and journaled in specially constructed bearings G hereinafter described. Said
lever D carries at one end, a pin C of carbon, and at the opposite end. an adjust-
able balance-weight F. consisting preferably of a suitable nut screwed on a
threaded portion of said lever and adapted to be easily brought to or removed from
said pivot-pin E. whereby the pressure of pin C on disk A may be controlled as
desired. Instead of employing said balance-weight F, I may use any other
suitable means, as for instance a spiral-spring the tension of which may be
easily adjusted as required. In certain cases, it is preferable to employ metal
parts, for instance of silver or platina, in lieu of the above named parts A and C
of carbon.
As previously stated. the pivot-pin E is journaled in metal bearings G, suitably
secured on insulating base-plates I, and said base-plates are in turn secured to
the above named annular frame H, or may be secured to the rim of the vibrating
plate B: the journals of pivot pin E extend through said bearings G into suit-
able metal boxes J. secured to or made on with said bearings and provided at
their outer end. with a circular threaded opening receiving a corresponding
screw K. (Fig. 1, see Element 1).
Said circular opening is for the introduction of a drop of mercury into box J.
and the mercury being shed into said box and the screw K fitted into the open-
ing, the excess of mercury escanes through the minute annular space between
journal E and bearing G. said box J being always filled with mercury: thus.
the free end of said iournal immerges into the mercury and the electric contact
between pivot pin E and bearing G is always secured without affecting the
movement of said pin.
The pivoting elements may be connected in derivation or in series (Fig. 1) in
accordance with the results to be attained. Furthermore the disk of carbon
may be divided into a plurality of sections, electrically insulated from each
other.

page_text: It will be seen from the afore-going construction and organization that the
operation of the improved microphone is based upon the inertia of lever D),
the weight of which is therefore to be adjusted in accordance, with the result
to be attained.
In order to further explain our invention and to set forth the advantages
thereof, we will now proceed to describe some applications of the improved
microphone in practice.
Firstly our improved microphone may be employed for receiving and register-
ing sounding vibrations or sound waves transmitted by water, so as to obtain a
new submersed acoustic telegraphy.
To this end, the microphone is housed within an absolutely tight box made of
thin metal and constituting a vibrating diaphragm, and the air in said box will
he compressed to balance the pressure of the water as the box is immerged. An
electric cable having two wires extends through a tight joint into said "micro-
phonic box" to lead the necessary current thereto.
The microphonic box thus fitted being let down upon the ground or bottom of
the sea at some distance from the coast, an ordinary telephonic receiver, con-
nected with said microphone, will reproduce any sounding vibrations trans-
mitted by the water even at great distances. Thus, the blows struck on the hull
of a launch are particularly transmitted by the water to the vibrat-
ing diaphragm of the microphonic box and easily and clearly regis-
tered by the telephonic receivers. The arrangement may be there-
fore employed to provide a real submersed acoustic telegraphy which may be used
very advantageously in certain cases, for instance. in case of wreck near the
coast all what is required is to strike some heavy blows on the launch according
to a certain rhythm to call for help.
Four (or more) microphonic boxes being immerged at suitable intervals (800
to 1000 meters) along the coast, the guardian of the look-out will be enabled to
indicate approximately the direction in which the life-boat must be started to
meet with the wrecked ship. Furthermore by substituting a suitable amplifier
for the ordinary telephonic receivers, the calls for help may be easily heard
without the usual hearers.
By striking one blow for representing a point, and a number of blows for
representing a dash, a complete correspondence may be transmitted either from
the ship to a semaphore or from an isolated light-house to the coast.
A further application of the invention consists in employing my improved
microphone for determining the direction of a sound for instance on ships,
which result may be attained by the following arrangement:-Two vibrating
diaphragm M and N (Fig. 3) are disposed on the fore-body or bow and the after-
body or stern of the ship respectively, both carrying a microphone at the centre.
The microphone M is connected with a telephonic receiver which the observer
applies on his right ear, and the microphone N is connected with a second tele-
phonic receiver which the observer holds near his left ear.
The signal coming from a short sound, being produced at any point Qin
line with the axis of the ship and before the latter, the sound waves first reach
the diaphragm M and at the same instant the observer hears the signal at his
right ear. The sound waves reaching the diaphragm N after a time depending
on the distance between the two diaphragms, the observer will hear the same
signal a second time at his left ear.
The phonic signal being produced at Q¹ situated on a line running at right.
angles with the axis of the shin and being at equal distances form diaphragms M
and N. the sound waves from Q will reach said diaphragms at the same instant
and the observer will hear the signal by his two ears at a time.
In order to enable the observer to determine the direction of a sound produced
at any point with relation to the axis of the ship. we dispose four diaphragms M,
N. R, and S (Fig. 4) at suitable distances from each other (about 20 to 30 meters).

page_text: said diaphragms being in combination with suitable ear-trumpets to increase the
action of the sounding vibrations. Une observer may be sufficient for deter-
nining the direction of a sound by making two successive observations, with
diaphragms M, R and N, S respectively, but it is preferable to employ two
observers for the axial diaphragms and those on the broad-sides respectively.
Thus the direction of the signal may be determined nearly instantaneously.
The method of simultaneously observing without microphone may also be
applied; to this end, four ear-trumpets, arranged at 20 to 30 meters irom each
other must be connected by means of suitable tubes of equal lengths to the
observer's ear. But this arrangement is not desirable and obliges the observer
to place himself in the centre of four ear trumpets.
The accuracy and precision in determining the direction of a signal may be
highly increased and improved by the employment of a suitable registering
apparatus. To this end, the microphones arranged on each diaphragm M, N, R,
S are so controlled as to break the electric circuits as the passage of the sound
waves produces the vibrations of the corresponding diaphragm. The current
passing through microphone M flows to an electro-magnet a (Fig. 5), the current
passing through microphone B, flows to a second electro-magnet b, and so on for
the other microphones. Said electro-magnets a bare adapted to mark a sign at
each break of the electric current passing through the corresponding microphone,
said sign being marked, on a rotary cylinder or preferably on a strip of paper
actuated or unrolled by the action of a suitable clockwork. In like manner the
time is recorded on said strip of paper by marking the vibrations of a diapason or
tuning-fork thereon. The mark of these vibrations and also those produced by
the passage of the sound-waves of the diaphragms, may be received on lamp-
black or in any way similar to that of the usual syphon-recorder. These parts
being well known and in use, we will not further describe the same. If necessary
the current may also be shunted through telegraphic relays, and in this case the
current from a local battery will actuate the electro-magnets of the recorder.
The phonic signal being exactly produced at a point S in line with the axis
of the ship and ahead the latter, the strip of paper will receive the marks shown
in Fig. 5 of the accompanying drawings. The mark M corresponding to diaph-
ragm M, has been first produced and the distance between mark M and mark R
will correspond to about ten double vibrations of the diapason. The marks N
and S have been produced at the same instant, so that the same are located on a
line running across the strip of paper, as shown.
The phonic signal being produced at a point S ahead the ship but at 10 degrees
on the right of the axis thereof, the strip of paper will receive the marks shown
in Fig. 6 of the accompanying drawings. The mark M has been first
produced and the distance between the mark M and mark R corresponds
to about ten double vibrations of the diapason but the marks N and S have not
been produced at the same time, mark S having been produced before mark N
which means that the signal comes from the right of the axis of the ship. The
distance between mark N and mark S corresponds to about one double vibration
and a half of the diapason, as shown.
A previously arranged scale permits the ready and easy determination, in
accordance with the number of vibrations of the diapason found between the
registered marks, of the number of degrees between the evident direction of the
phonic signal and the axis of the ship.
Our improved microphone is furthermore particularly convenient to be applied
to telephony, in properly adjusting the pressure produced by the carbon pins C
(Figs. 1 and 2) on the central disk A, in giving the movable parts of the micro-
phone a suitable weight, and in substituting a thin wooden board for the vibrating
metal plate B shown in the drawings.
Thus the microphone is adapted to transmit sounds and words in a more per-
fect, clear and intensive way than any similar device constructed hitherto.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. In a microphone the combination with a preferably circular vibrating
plate of any suitable material, of pivotally mounted vibration receiving devices
maving pressure controlling means, substantially as set forth.
2. In a microphone the combination with a preferably circular vibrating
plate of any suitable material, of pivotally mounted vibration receiving devices
having pressure controlling means, said devices being arranged on electrically
insulated supports and connected in any way with the current wire, substantially
as set forth.
3. In a microphone the combination with a preferably circular vibrating plate
of any suitable material, of a movable lever having vibration receiving parts and
suitable pressure controlling means, said lever being pivotally mounted on metal
bearings arranged on electrically insulated supports, and suitable means for
securing the electric contact between said lever and bearings, substantially as
set forth.
4. In a microphone the combination with a preferably circular vibrating plate
of any suitable material, of four oppositely arranged levers having vibration
receiving end parts and suitable pressure controlling means, said levers being
pivotally mounted on metal bearings secured on electrically insulated supports,
and suitable means for securing the electric contact between said levers and the
corresponding bearings, substantially as set forth.
5. In a microphone the combination with a preferably circular vibrating plate
of metal, and a portion of carbon secured to said plate, and suitably insulated
therefrom, of a pivotally mounted lever, a carbon pin on one end of said lever
and contacting with said carbon ou the vibrating plate, and a movable balance
weight on the opposite end of said lever, substantially as set forth.
6. In a microphone the combination with an electrically insulated support,
of metal bearings secured on said support, said bearings having journal boxes
on opposite sides thereof, and a lever journaled in said bearings, said journal
boxes being afterwards filled with mercury, substantially as set forth and for the
purpose specified.
7. In a microphone, a circular vibrating plate secured to suitable contact-
parts of carbon, a plurality of pivotally mounted vibration receiving levers
having means for controlling the pressure of their contacting ends on said vibrat-
ing plates, metal bearings for said levers, suitably arranged insulating bases for
said metal bearings, and means for securing the electric contact between said
levers and metal bearings without affecting the movement of the levers, sub-
stantially as set forth.
8. The combination of the microphone substantially as described with a
microphonic box to be immersed into the sea to obtain an acoustic telegraphy,
for the purpose specified.
9. The improved microphone in combination with the method of determining
the direction of a phonic signal produced either in the atmosphere or in the
water substantially as set forth.
10. The improved microphone constructed and regulated to be applied to any
telephonic transmission substantially as set forth.
Dated 1001 1. f Aumat 1900
J. P. BAYLY,
18, Fulham Place, London, W.,
Agent for the Applicants.