IMPROVEMENTS IN PNEUMATIC DOMESTIC SIGNALLING APPARATUS
Year: 1878

page_text: LETTERS PATENT to John Thomas Gent, of Leicester, in the County of
Leicester, Electriciau, for the Invention of." IMPROVEMENTS IN PNEUMATIC
DOMESTIC SIGNALLING APPARATUS."
Scaled the 21st January 1879, and dated the 23rd July 1878.
PROVISIONAL SPECIFICATION left by the said John Thomas Gent at the
Office of the Commissioners of Patents on the 23rd July 1878.
JOHN THOMAS GENT, of Leicester, in the County of Leicester, Electrician.
IMPROVEMENTS IN PNEUMATIC DOMESTIC SIGNALLING APPARATUS."
This Invention consists in the construction of a simple, cheap, and effective
apparatus for signalling, the main object of the improvements being to simplify the
construction and avoid complication, so that the apparatus shall be little liable to
get out of order, and thus be rendered specially suitable and applicable for domestic
use, and the improvements consist in effecting the ringing of an alarum or bells,
and actuating an indicating tablet by the arrangement and combination of
mechanism herein-after described.
In carrying out my Invention I employ a tablet, which is fixed in the room or
other place where the signals are to be given. On this tablet I arrange, side by side,
a number of elastic bags or air vessels, from each of which passes an air pipe to the
place or room from whence the signal is to be given, where the said tube is provided
with any suitable arrangement for causing a current of condensed air to be sent
along the tube. In front of each bag is a disc or plate having a lug or lugs
working on a horizontal shaft in suitable brackets or bearings on the said tablet,
and in front of each disc is an indicating tablet fixed on a rod or lever working on
another horizontal shaft placed in front of the herein-before described shaft, the
said indicating tablets being so placed that when pushed out of the perpendicular
line, they fall forward.
The shaft carrying the discs is provided with a projection jointed to a vertical
lever, carrying at its upper end a striking plate with two pins. I provide a
movement consisting of a toothed quadrant gearing with the pinion of a small

page_text: wheel which gears with the pinion of an escapement wheel, and the pallets of the
escapement carry a hammer which strikes against a pair of suitably placed bells, as
herein-after described, the action of the escapement being stopped by a lever on
the arbor of the escapement wheel, and instead of giving motion to the movement
by means of a spring, as heretofore has been done, I provide the arbor of the
herein-before described quadrant with a weighted lever, the fall of which operates
the movement; the said weight is raised as herein-after described. The whole is
enclosed in the usual case with glass front.
By this arrangement of apparatus if a current of compressed air be caused to
pass down any one of the herein-before described air tubes, the bag in which the
tube terminates will be expanded, and will press forward the disc in front of same,
and the disc will push forward its corresponding tablet. The disc in moving
forward rotates the shaft on which it is placed, and thereby raises the lever of the
striking plate so as to release the escapement, which is operated by the herein-
before described weight, and the hammer continues to strike the bells alternately
until the lever on the escapement arbor is caught by one of the pins of the striking
plate, when the striking plate falls, carrying back the discs. The shaft carrying
the indicating tablets is provided with a handle, by raising which the tablets are
carried back to their normal position by means of pins, and at the same time the
said shaft operates a lever arrangement, which partly rotates the said quadrant, and
raises the herein-before described weight; a spring on the shaft brings it back to
its normal position.
The indicating tablet retains its position without the aid of any latching appa-
ratus, and simply by its own weight over the perpendicular, and by being pushed
over falls by its own weight against the glass, but for safety and for purposes
where the tablets may be required to be out of upright a stopwork at the centre of
the lug attached to the discs comes against the projection forming part of the centre
of the indicating tablet.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Thomas Gent in the Great Seal Patent Office on the 23rd
January 1879.
JOHN THOMAS GENT, of Leicester, in the County of Leicester, Electrician.
"IMPROVEMENTS IN PNEUMATIC DOMESTIC SIGNALLING APPARATUS."
This Invention consists in the construction of a simple, cheap, and effective appa-
ratus for signalling, the main object of the improvements being to simplify the
construction and avoid complication, so that the apparatus shall be little liable to
get out of order, and thus be rendered specially suitable and applicable for domestic
use and for use on board vessels, and the improvements consist in effecting the
ringing of an alarum or bells and actuating an indicating tablet by the arrangement
and combination of mechanism herein-after described.
In carrying out my Invention I employ a tablet, which is fixed in the room or
other place where the signals are to be given. On this tablet I arrange side by
side a number of elastic bags or air vessels, from each of which passes an air pipe to
the place or room from whence the signal is to be given, where the said tube is
provided with any suitable arrangement for causing a current of condensed air to be
sent along the tube. In front of each bag is a disc or plate, having a lug or lugs
working on a horizontal shaft in suitable brackets or bearings on the said tablet;
and in front of each disc is an indicating tablet fixed on a rod or lever working on
another horizontal shaft placed in front of the herein-before described shaft, the
said indicating tablets being so placed that when pushed out of the perpendicular
line they fall forward.
:
Each disc may be provided with a weighted catch for carrying back the disc, and
serving to hold the indicators, as herein-after described.
The shaft carrying the disc is provided with a projection jointed to or operating
a vertical lever, carrying at its upper end a striking plate with two pins, or the
striking plate may be dispensed with, as lierein-after described. I provide a move-
ment consisting of a toothed quadrant gearing with the pinion of a small wheel
which gears with the pinion of an escapement wheel, and the pallets of the escape-
ment carry a hammer which strikes against a pair of suitably placed bells, or a single
bell, as herein-after described, the action of the escapement being stopped by a lever
on the arbor of the escapement wheel; and instead of giving motion to the move-
ment by means of a spring, as heretofore has been done, I provide the arbor of
the herein-before described quadrant with a weighted lever, the fall of which
operates the movement; the said weight is raised as herein-after described. The
whole is enclosed in the usual case with glass front.
But to make my Invention better understood I will proceed to describe the same
by reference to the accompanying Drawing, in which,―
Figure 1 is a front elevation of my improved pneumatic domestic signalling
apparatus; Figures 2 and 3, end views of the same, the case being shewn in
section.
Figure 4 is a front elevation of the apparatus, the case being removed; Figures 5
and 6, sections of same on lines A, B, and C, D, of Figure 4 respectively.
Figure 7, back view of the apparatus.
Figure 8, part front elevation, and Figure 9, section of a slightly modified con-
struction of apparatus.
Similar letters in all the Figures represent similar parts.
a, a, is the tablet fixed in the room or other place where the signals are to be
given; b, b, b, are the elastic bags or air vessels; and c, c, c, are the air tubes or
pipes passing from the same to the place or room from whence the signal is to be
given; d, d, d, are the discs or plates in front of the bags b, b, b; e, e, e, are the
lugs of the discs or plates working on the horizontal shaft f in the brackets g, g;
h, h, are the indicating tablets (one in front of each disc) fixed on the rods or

page_text: levers working on the second horizontal shaft j; k, k, k, are the weighted catches
for carrying back the discs, and serving to hold the indicator, as herein-after
described; is a lever or arm on the disc shaft, which presses against a spring m
for releasing the escapement, as herein-after described; n is the toothed quadrant
of the movement gearing with a pinion o of the wheel p, which wheel p gears with
the pinion of the escapement wheel q; r are the pallets carrying the hammer 8,
which strikes against the bells t, t; u is the lever on the arbor of the escapement
wheel; and is a fork on the spring m, which catches the said lever u for stopping
the motion of the escapement and of the hammer, as herein-after described; wis
the weight on the lever x fixed on the shaft of the quadrant, and jointed at y to
the vertical lever z, having a projection ¹; a¹ is a corresponding projection on the
indicator shaft j for raising the indicator tablets; d', spring on the shaft j for
carrying it back to its normal position; e', counterweight of the shaft f; A is the
case enclosing the apparatus; B, glass front of same.
.
The action of the apparatus is as follows:-If a current of air be caused to pass
down any one of the air tubes c, c, c, the bag b in which the said tube terminates
being inflated will push forward its corresponding disc d, and the arm f¹ of the
disc will push forward its corresponding tablet h into the position shewn in
Figure 6; the disc in moving forward rotates its shaft f, and consequently moves
back the lever or arın 7 which presses back the spring m so as to remove its fork v
free of the lever u, and thereby release the escapement which will consequently be
operated by the falling of the weight w; and the hammers will alternately strike
the bells t, t, until the escapement has completed half a revolution, when the other
end of the lever u will be caught by the fork v and thereby stop the action of the
movement; and the pressure in the air tube being relieved the disc will be carried
back to its normal position by means of the counterweight e¹ and by the weighted
catches k, k, k. I would here observe that the catches of the weights k, k, k, are
only required for ships' use, the catches holding the indicators in position (until a
signal is to be given) so as to prevent their being moved forward by the motion of
the vessel.
To move back the indicators the shaft j is partly rotated by its handle b', where-
upon the pins c¹, c¹, c¹, will press against the rods or levers i, i, i, of the indicators
and carry them back, at the same time the projection a¹ on the shaft j will come
against the projection z¹ of the vertical lever and move down this latter, and
thereby raise the weight w, so that the act of moving back the tablets winds up
the movement.
In Figures 8 and 9 it will be observed that the construction is somewhat different
from that herein-before described, although the principle is substantially the same;
in this arrangement the weighted catches of the discs are dispensed with and a
striking plate is employed for releasing the escapement.
In these Figures g₁ is the striking plate fixed on the upper end of the vertical
lever h¹;,, are the pins in the striking plate, the lower end of the said lever
being jointed to a projection ¹ on the disc shaft f.
When any one of the discs is forced forward by the expansion of its air bag, as
herein-before described, it rotates its shaft f, the projection k¹ of which moving
with the shaft raises the vertical lever h¹ and striking plate g¹ so as to move one of
its pins from the lever u on the escapement arbor, and thus allow the hammer 8
to strike the bells; the pressure of air being discontinued the weight of the lever h¹
will carry back the shaft f and with it the disc to its normal position, and the action
of the movement will be stopped by the pin of the striking plate.
The indicators are carried back by the handle of the shaft f, as herein-before
described, the said shaft moving down in its motion the vertical lever 2, the upper
end of which is provided with a pin z¹ which bears against the projection a² on the
arbor of the quadrant and thus raises the weight.
:
is a stop on the disc shaft, the object being to prevent the indicator falling
forward by the apparatus being placed out of the perpendicular position.
Having thus described my said Invention and the best means with which I am

page_text: acquainted for carrying the same into effect, I wish it to be understood that I do
not confine myself to the precise details herein laid down, and shewn in the
Drawing, as the same may be varied without departing from the peculiar character
of my Invention; but what I do claim is,-
Firstly. The general arrangement and construction of the improved pneumatic
domestic signalling apparatus, as herein-before described, and represented in the
accompanying Drawing.
Secondly. The employment of a weight or weighted lever for operating the
clock work mechanism for giving motion to the hammer for striking the bell or
bells, as herein-before described.
Thirdly. The method of liberating the escapement when the signal is to be given
either by means of a fork on a spring operated by a lever from the disc shaft, or by
the raising of a striking plate on the falling of the indicator tablets, or any mere
modification thereof, substantially as herein-before described.
Fourthly. The arrangement of the indicator tablets, whereby they are caused to
retain their position by their own weight over the perpendicular position, and fall
forward when pushed over the perpendicular position by the expansion of the air
bags, as and for the purposes herein-before described.
Fifthly. The construction and application to the discs of the weighted catches, as
and for the purposes described.
Sixthly. The employment, in place of the said weighted catches, of a stop, as
herein-before described, and shewn in Figures 8 and 9 of the accompanying
Drawing.
Seventhly. The method of raising the weight operating the clockwork mechanism,
and of replacing the indicator tablets in one operation, as herein-before described,
and represented in the accompanying Drawing.
In witness whereof, I, the said John Thomas Gent, have hereto set my hand
and seal, this Twenty-second day of January, in the year of our Lord
One thousand eight hundred and seventy-nine.
JOHN THOMAS GENT. (L.S.)