IMPROVEMENTS IN TRANSMITTING SOUNDS AND SIGNALS
Year: 1871

page_text: LETTERS PATENT to Wilhelm Walcker, of Boulevard de Strasbourg,
23, Paris, Manufacturer, for the Invention of "IMPROVEMENTS IN
TRANSMITTING SOUNDS AND SIGNALS."
Sealed the 15th August 1871, and dated the 21st June 1871.
PROVISIONAL SPECIFICATION left by the said Wilhelm Walcker at
the Office of tho Commissioners of Patents, with his Petition, on
the 21st June 1871.
I, WILHELM WALOKER, of Boulevard de Strasbourg, 23, Paris,
Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN TRANSMITTING SOUNDS AND SIGNALS," to be as follows :—
These improvements relate,-
First. To certain essential organs which receive directly the action of
a column of air to produce the transmission of signals.
And secondly. To various mechanical arrangements to suit the various
purposes to which the Invention can be applied.
According to one form or arrangement of apparatus I attach a flexible
bag or a membrane on a rigid vessel, which can be acted upon by

page_text: a column of air forced through, a pipe by pushing in a thumb button
fitted to a chamber at one part of a building. The flexible bag or
membrane is in connection by wheel work or otherwise with a detent
which is caused to act upon a bell or other sound giving instrument at
another part of the building, or it can be effected by means of a draw- 5
out knob to draw the air in the reverse direction, and thus produce a
downward action of the bag or membrane.
In large establishments any number of these apparatus can be
arranged in groups so as to bring all the rooms into communication,
and the pipes from each may all lead to one bell or to several bells, as 1
desired.
Wheel mechanism and levers may be also arranged with the bells
so that indicators can be operated upon to expose signs.
When the apparatus is fitted for giving signals between passengers
and guards in railway trains, or other vehicles, bellows and levers can 1
be operated to move a disc or a lamp into an altered position, and also
if necessary to expose a light at the same time.
For giving signals on board ship, such as between the bridge and
engine room, I arrange a series of pipes in a circle, and attach a revolving
nozzle to the indicating handle so that the mouth is brought opposite a 2
pipe leading to a corresponding indicator fitted at a distance.
Sometimes I arrange the shaft of the receiving instrument with a
number of flaps or studs of various lengths, so that whatever part of
the sending instrument the handle is moved to a corresponding motion
takes places with the receiving index.
The sending or receiving instruments may be connected to a time-
pièce, so that the movements can be indicated upon a sheet or cylinder
of paper, which is pierced by points as it revolves.
2

page_text: draw out knob to draw the air in the reverse direction, and thus
produce a downward action of the bag or membrane.
' In large establishments any number of these apparatus can be
arranged in groups so as to bring all the rooms into communication,
and the pipes from each may all lead to one bell or to several bells, as
desired.
Wheel mechanism and levers may also be arranged with the bells so
that indicators can be operated upon to expose signs.
When the apparatus is fitted for giving signals between passengers
and guards in railway trains, or other vehicles, bellows and levers can
be operated to move a disc or a lamp into an altered position, and also
if necessary to expose a light at the same time.
For giving signals on board ship, such as between the bridge and
engine room, I arrange a series of pipes in a circle, and attach a revolving
nozzle to the indicating handle, so that the mouth is brought opposite
a pipe leading to a corresponding indicator fitted at a distance.
Sometimes I arrange the shaft of the receiving instrument with a
number of flaps or studs of different lengths, so that to whatever part of
the sending instrument the handle is moved to a corresponding motion
takes place with the receiving index.
The sending or the receiving instruments may be connected to a
time-piece, so that the movement can be indicated upon a sheet or
cylinder of paper, which is pierced or marked by points as it revolves.
I proceed to describe my Invention with reference to the accom-
panying Drawings.
First, with regard to the essential organs receiving directly the action
of a column of air to produce the transmission of signals, my improve-
ments will be readily seen on comparing them with the arrangements
hitherto most frequently employed.
In the latter, as will be seen on reference to Figure 1, a column of
air plays between two india-rubber membranes a and b which are
respectively placed over a metal platform A. and cup B. A compression
exerted upon the bag or membrane a produces in a conducting pipe c
an instantaneous displacement of the air, which lifts the membrane b,
and thus causes in the receiving apparatus a sound accompanied by a
signal.

page_text: The employment of these two membranes in contact with metal leaves
much to be desired as regards duration and sensibility. I have there-
foro invented the arrangement shown in Figure 2, in which the two
membranes and their metal accessories are replaced by a receiver A and
a bag B, both moulded from one piece of vulcanized india-rubber. Thus
my improvement in this part of my Invention consists in the substitution
for the semi-rigid organs hitherto used of elastic organs moulded from
ono and the same piece of india-rubber.
I proceed now to describe various apparatus which I have arranged
to transmit the signal and sound formed by the means just described.
Nearly all these apparatus work equally well by aspiration as by
compression.
My system is applied in private houses to the ordinary bell, the
indicating table, or to the carriage gateways; in large public or private
establishments to the porter or sentinel's boxes; in ships for the trans-
mission of orders from the commander to all parts thereof; and in
railways to the alarm bell or guard communicator.
•
The first application of my improved system is to the ordinary bell in
apartments. This bell, which is placed generally in kitchens or ante-
chambers, is acted upon as shown in Figure 3 through an india-rubber
air chamber P, upon which rests a disc a rivetted to the extremity of a
rack 6 gearing with a pinion c fixed concentrically to a ratchet wheel d,
and free to turn upon the axis of the escape wheel e. The latter is only
put in movement by the aid of a spring of fixed by one of its extremities
upon the same wheel, and supported by its other extremity upon a little
catch g which tends constantly to engage into the teeth of the ratchet
wheel d. The escape wheel e in its rotation causes a pallet or anchor
to oscillate; this pallet is mounted upon the same axis as the hammer i,
which strikes successivo blows upon a bell of steel or other metal fixed
on the box which encloses the mechanism. All the organs of this
mechanism are mounted upon two plates j attached to one another by
stays k, l, and m. The spring & acting with one of its ends against the
upper part of the rack brings the latter into its first position as soon as
the pressure exerted by the manipulating apparatus ceases to act. In
order to readily comprehend the action of this mechanism, suppose the
apparatus thus described in direct communication through a pipe with
au india-rubber ball or a manipulating button situated at the opposite
end or in some part of the apartment. As soon as pressure is exerted

page_text: upon the latter the column of air is displaced and the receiver P imme-
diately inflated, so as to lift the rack 6 and produce through the inter-
mediation of the pinion and toothed wheels the oscillating movement of
the hammer i, and in consequence its striking the bell. As soon as
the pressure is removed from the manipulating button the receiver P
subsides to its normal form and the spring s acting upon the rack causes
it to redescend, which it does easily by the gliding of the ratchet
wheel d upon the catch g without sounding the bell. The bell can
also be actuated by the aspiration of the column of air instead of by
the compression, a simple reversing of the movements described being
necessary.
The indicating table, generally placed like the bell board in places
frequented by servants, serves to give the signal calling to different
rooms of the house.
As shown in Figures 4 and 5 the mechanism in this apparatus is
composed of one, two, or several metal plates a placed one above the other
and stayed together by columns 6. Upon each of them are fixed two iron
axes c and d; the first, c, fixed upon its two supports e, f, serves simply
as a centre of rotation to the different indicating platforms g maintained
in the same position by means of screws / fixed upon the axis, and
engaged into a groove made in each platform. The second axis & can
on the contrary turn upon its two bearings and receives its rotating
movement by means of little screws j, which serve as abutments to the
hooks in order to draw the axis as soon as any one of the hooks obeys
the pressure of air exerted in the india-rubber receiver ¼ with which
it is in connection. This latter axis is also provided about the middle of
its length with a pin serving to move vertically upon a shaft m, which
acting upon a lever n, o, p, makes it lift out of the tooth of a circular
cam q, and in consequence the spring r coiled around the axis of a
toothed sector & gives to the latter a rotating movement. Gearing
similar to that described with reference to the bell suffices to impart the
movement and to allow the sector to retrograde without the rest of the
mechanism being deranged, which is necessary for the remounting of
the sectors. The intermediate zone gearing with a pinion x mounted
upon the axis of the escape wheel y brings about the oscillation of the
pallet z and of the hammer w, and the sounding of the bell in conse-
quence. The lower cross piece of a frame running upon the back of
the apparatus enables through the intermediation of the rod k¹ to the

page_text: button the indication which appeared at the moment of the call to
disappear, and to return it to its first position without having made a
sound. After that each time the servant obeys the call given he removes
the signal, and by doing so raises the toothed segments without making
the sound.
The application I have made of my improved system to the staples of
carriage gateways and others is very simple, and will be readily under-
stood on reference to Figures 6 and 7. In this application the flexible
organ a receiving the compression of the interior air acts upon a spring
lever 6 which in turning round its axis c, d, causes the square. lever g
to oscillate through the intermediation of a pin f which it carries.
The latter in oscillating in the direction of the arrow withdraws the
nose h and allows the lever i to escape while turning round its axis x, x,
under the impulse from the spring k. The lever i which terminates
behind the staple by an arch shaped projection holding the bolt or
movable panel of the door in oscillating makes the projection / enter
into the staple and allows the bolt to escape, and the door to open in
consequence under the action of a strong spring hidden in the rebate.
A simple pressure therefore made upon the india-rubber enlargement
which terminates the column of air is sufficient to make all these levers
oscillate and to make the door open of itself under the action of the
spring. When the door is closed all the mechanism returns to its first
position.
In Figures 8, 9, and 10, I have shown the application which I have
made of my improved system of atmospheric transmission to railway
trucks and carriages in order to warn the driver or guard as soon as
any traveller requires their assistance, should he find himself suddenly
assaulted, or for other reasons. In each compartment of a railway
carriage I arrange a button a which is supported by a small plate 6
against a caoutchouc ball or pocket c fastened in the partition. This
ball c communicates by the tube d with a pair of bellows f which is
closed when at rest. These bellows are in direct connection with a bent
lever which acts upon a lifting lever ½ oscillating upon a point i and
pressed against by the spring j. The oscillating lever h serves to retain
tho lever p fixed to the shaft k mounted upon trunnions in the sides of
the box A, A. Upon this shaft k are secured two little grooved pulleys
and a mitre wheel m; it is these 2 organs, the pulleys and mitre wheel,
which divide the double indication. The mitro wheel mis calculated so

page_text: as to cause the wheel n into which it gears to make a quarter turn and
in consequence the shaft B, B, and lantern L at its top. The pulleys /
hold at one portion of their groove chains C which hook on to projections
of the weight P. On this weight P is a caoutchouc bellows 8, rigidly
held at its upper face on a support of the box A. The bellows S is
directly in communication with the tube w, proceeding from the bellows
to the sounding instrument placed close to the driver. As soon as the
traveller, if attacked, or for other reasons, presses the button a the
bellows frises by the compression of the air and produces the lifting
of the lever p, immediately the shaft k turns under the action of the
weight P the bellows S stretches and causes the sounding instrument
near the driver to sound in consequence of the aspiration caused through
the tube w. At the same time the lantern L has turned a quarter of a
revolution and has directed its light toward the driver to show him
immediately the carriage in which the button has been pressed.
In the interior of the lantern L I have arranged a mechanism which
operates the lighting of the candle 6º at the same moment that the
lantern makes its quarter turn upon the shaft B. Upon the side of the
candle holder b³ is fixed a little cap or cup ³, in the bottom of which
some fulminate is placed in which a conducting match m² is plunged
which proceeds therefrom to the wick of the candle. Another point p
mounted upon a rod t lowers with this rod under the action of a spring 7
which continually forces the rod to rest by a roller g³ upon a little
inclined plane. During the revolution of the lantern L around the
axis B the point p³ strikes the fulminate in the capsule h³, and the
lighting of the candle is immediately produced under the action of the
conducting wick m³. The crank o serves to restore the whole to its
normal state. I have arranged upon the outer side of the carriage a
little door painted a bright colour in the interior, which opens and
attracts the attention of the driver as soon as the lifting above indicated
takes place.
In order to establish the communication between the tube of one
carriage and that of the carriage following it, I adopt a combined
arrangement of two organs, one fixed to the carriage, Figure 9, and
terminating the tube, the other serving only as a flexible junction,
Figure 10. The organ fixed to the two ends of the tube of each carriage
is composed of a tube D, with a pierced cap 8, Figure 9. In this is
a double disc of copper and india-rubber t with a concave buffer u; this

page_text: disc is constantly pressed against by an inner spring R and against the
cap 8, so as to form a perfectly tight joint. The bottom of the tube D
is in direct communication with the tube X of the carriage and w of
the apparatus. The flexible organ of junction between the ends thus
arranged of the tubes of two successive carriages is formed of an
india-rubber tube N, Figure 10, surrounded by a flexible metallic tress
and terminated at both ends by a special mouth piece. This mouth
piece is formed of a strong cap o of india-rubber rigidly fixed to the
tube N. A small tube with lateral holes x is firmly held in the said
mouth piece and communicates with the tube N. The mouth piece o is
brought over the tube D (Figure 9) by friction, and then the end of the
tube compressing the disc t (see the dotted lines, Figure 9) establishes
the communication of the column of air, while at the same time it forms
a perfect air-tight joint with the mouth piece o.
The application of this improved system of atmospheric compression
to the control of sounds in workshops, warehouses, and establishments is
shown in Figure 11. The object of this application is to ascertain at
stated hours the position of the workmen in the places to which they
are appointed, whatever may be the distance separating them from
the controller.
The mechanism of this apparatus consists in the combination of the
movement of an ordinary pendulum with a wheel plate A gearing with
an hour wheel and having the same number of teeth; upon this wheel
a mitre wheel B is placed serving as the connection to five other mitre
wheels c, d, e, f, g, in order to transmit by the aid of three rectangular
shafts x, x, x¹¹, the movement of a cylinder M in copper covered with
a sheet of paper graduated with the fractions of 24 hours. Several steel
points h, h, corresponding in number with the points to control, are
arranged vertically beneath and following the same scale of the cylinder,
each of them rivetted upon a little metal disc i, i, placed upon an india-
rubber receiver n of my system fixed at the end of a tube, with a column
of air terminating by an india-rubber bag or ball, the volume of which
is sensibly larger than that of the receiver. This bag or ball in order to
be sheltered from unauthorized manipulations is generally enclosed in a
box of cast iron fastened to the wall or wedged in the floor at the fixed
station for the sound, so that the man charged for this service provided
with a key stops at each station at the stated hours, and opening the box
compresses with the hand or the foot the bag or ball it contains which

page_text: lifts the corresponding point h, which then pricks the paper of the
cylinder M, thus producing a trace of the passage of the man or
sentry appointed at the place to be watched.
Lastly. The application of my system to ships for the automatic
transmission of the orders of the captain comprises two combinations,
the manipulator and the receivers. The manipulator is represented in
Figures 12, 13, and 14. It corresponds at the same time with the
receivers at the helm and engine.
A needle a is provided with a pin o (see Figure 14), which can enter
at will into the little holes 6 so as to be placed with regard to one or
other of the inscriptions on the dial. The handle c produces the move-
ment desired by the operator by acting by compression upon the india-
rubber pocket A. The apparatus is mounted upon a pedestal d in
which a sounding apparatus is placed, serving to indicate the despatch
and the reception of the signals.
At Figure 13 is shown the action of the india-rubber tubes f.f, upon
the tubes g, g, of the cage h of the distributing cock i, the longitudinal
section of which is represented in Figure 14. This cock is pierced at
its axis with a passage, so that the tube k can be as easily placed in
communication with any of the tubes f.
Figures 16 and 17 are two longitudinal and transverse sections of the
receiver at the bottom of the vessel; Figure 15 shows the front face of
the receiver.
The needle g turns upon its axis over the dial, where are written the
various directions. The india-rubber pockets r, r, which are connected
to the tubes g inflate under the compression of the air, and respectively
lift the arm of the lever 8,.8, through the intermediation of the little
rods t, t. All the lever arms are keyed upon the same horizontal
shaft u, but they are of unequal lengths, seeing that the pockets r, r, are
not at equal distance from this shaft. In consequence the little conical
pinion which gears with the segmento describes a more or less large
arc of a circle, and causes the needle q to arrive opposite one or other of
the signals of the dial.
The number of signals may vary as well as the number of pockets
according to the needs and requirements of the service.
Having thus described several practical applications of my improve-
ments in transmitting sounds and signals, I would have it observed that

page_text: they all involve the compression or aspiration of a column of air in
highly clastic envelopes, and that the different modifications of the
mechanism employed are only such as to apply the improvements for
the particular purpose for which they are required. And I do not desiro
to limit myself strictly to the particular arrangements described, as the
variations therefrom necessary to apply my improvements to other
objects come within the scope of my Invention.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim,—
First. The compression or aspiration of a column of air enclosed in a
highly elastic envelope or envelopes in order to produce the transmission
of sounds and signals, as described and as shown particularly in Figure 2,
and in several examples in the accompanying Drawings.
And, secondly. The various mechanical arrangements, substantially as
herein-before described and shewn in the accompanying Drawings,
whoreby signals and sounds are transmitted in private houses, workshops,
railway trains, on board ships, and in other such establishments and
places.
In witness whereof, I, the said Wilhelm Walcker, hath hereunto
set my hand and seal, this Sixteenth day of December, in the
year One thousand eight hundred and seventy-one.
WILHELM WALCKER. (L.S.)
Witness,
CHARLES ARMENGAUD,
Civil Engineer,
23, Boulevard de Strasbourg á Paris.