IMPROVEMENTS IN PNEUMATIC SIGNALLING APPARATUS "
Year: 1882

page_text: LETTERS PATENT to George Porter of Cullum Street, in the City of London,
Engineer for an Invention of "IMPROVEMENTS IN PNEUMATIC SIGNALLING
APPARATUS
"
PROVISIONAL SPECIFICATION left by the said George Porter at the Office
of the Commissioners of Patents on the 12th August 1882.
GEORGE PORTER, of Cullum Street, in the City of London, Engineer,
MENTS IN PNEUMATIC SIGNALLING APPARATUS
"
" IMPROVE-
My invention relates to pneumatic signalling apparatus applicable for domestic"
use, for signalling on railways, and also as a means for transmitting signals to and
from the engine-room on board of a steam-ship, or for similar purposes.
The pneumatic signalling apparatus heretofore constructed has usually been
provided with a transmitting or communicating device having an air-bag or bellows
acted upon by means of a push-knob, or by other suitable means. These air-bags
or bellows are objectionable because they are liable to become hard, to crack, and
thus be rendered inoperative. Air-bags or bellows have also been used for actuating
the indicating apparatus and the mechanism for striking the bell, and these bellows
have usually been arranged to expand and contract horizontally, which has
necessitated the use of mechanism more or less complicated.
According to my said invention I obviate these inconveniences in the following
manner, that is to say, I employ, in place of the air-bags or bellows, cylinders of
suitable diameter within which are fitted pistons having cup leathers, or packed in
any suitable manner. The piston of the transmitting device is provided with a
rod arranged to be acted upon by a push-knob or a lever, or in any well known
manner, and a spring is arranged in connection with the said piston to force the
same back to its original position when it is released. One end of the said cylinder
is open to the atmosphere and the other end is connected; by means of a tube or
pipe, to the lower or closed end of the cylinder of the indicating apparatus, which
cylinder is, by preference, placed with its axis vertical. The piston in this cylinder
has a rod passing through a guide at the top of the said cylinder, or at the end
which is open to the atmosphere. The said rod is provided at its upper end with

page_text: a tee-piece or cross-bar upon which are supported two levers.or arms, one of these
arms is pivotted upon a shaft or rod carried in bearings in brackets attached to the
frame or casing of the indicating apparatus. This arm is longer than the other,
and is curved upward at its outer end, upon which the tablet of the indicating
apparatus rests, and from which it is disengaged by the same operation which
causes the bell to be sounded. The other arm is fixed to the said shaft or rod and
is coupled to a link or connecting rod which is attached at its upper end to the
.toothed segment or other suitable part of any well known mechanism for sounding
the bell. In some cases I fix to the said shaft or rod another arm which is connected
to the said link. Or a pin may be fixed in the said link so as to rest upon the said
arm. I sometimes dispense with the cross-bar or tee-piece above described, in
which case I bend the shorter arm at its outer end so that it will rest upon the end
of the piston rod and will also support the longer arm. The tablets are arranged
in such a manner that they may be re-adjusted when necessary. For this purpose
I support the shaft or rod, upon which they are carried, in suitable bearings, and
fix to it a small rod extending from end to end so that any one of the tablets may
be raised thereby, or all of the said tablets may be thus raised simultaneously.
I sometimes employ the above described mechanism in combination with an air-
bag or bellows arranged to expand and contract vertically instead of horizontally ;
in this case the bellows acts upon the two levers or arms in a similar manner to
the piston rod of the apparatus hereinbefore described.
The said pistons and cylinders may be employed in combination with any kind
of mechanism suitable for the purpose, and may, if desired, be arranged horizontally
instead of vertically, the essential feature being the employment of cylinders and
pistons in the transmitter as well as in the indicator, which permits of signals being
transmitted to a greater distance than when the usual air-bags or bellows are
employed. The above described apparatus can be adapted to transmit signals
upon railways, ships, or in other places, in the following manner, that is to say, I
provide a cylinder and piston, constructed as above described and connected with
an indicator, at each place where it is desired to transmit or receive the signal.
Where two or more signals require to be used, I employ one cylinder and piston
and one indicator for each signal at each of the said places. By this means, when
a signal is transmitted to an engine-room, for instance, the engineer has merely to
press the push-knob or lever corresponding to the signal transmitted, and thereby
actuate the indicator at the other end and give a signal in reply corresponding to
that received by him, to inform the captain or other person that he has received
the order.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Porter in the Great Seal Patent Office on the 12th
February 1883.
GEORGE PORTER, of Cullum Street, in the City of London, Engineer,
MENTS IN PNEUMATIC SIGNALLING APPARATUS
"
" IMPROVE-
My invention relates to pneumatic signalling apparatus applicable for domestic
use, for signalling on railways and also as a means for transmitting signals to and
from the engine-room on board of a steam-ship, or for similar purposes.
Pneumatic signalling apparatus as heretofore constructed is usually provided
with a transmitting or communicating device having an air-bag or bellows acted
upon by a push-knob or other suitable means. These air-bags or bellows are
objectionable because, being made of leather or india-rubber, they are liable to
harden and crack and thus become inoperative. Air-bags or bellows have also
been used for actuating the indicating apparatus and the mechanism for striking
the bell, and these bellows are usually arranged to expand and contract horizontally,
which necessitates the use of mechanism more or less complicated.
According to my invention I construct the apparatus in the following manner,
that is to say, I employ, in place of the air-bags or bellows, cylinders of suitable
diameter within which are fitted pistons having cup-leathers, or packed in any
suitable manner. The piston of the transmitting device is provided with a rod
arranged to be acted upon by a push-knob, a lever, or other suitable and well known
means, and a spring is arranged in combination with the said piston to force the
same back to its original position when it is released. One end of each of the said
cylinders is open to the atmosphere. The other end of the cylinder in the trans-
mitting device is connected by means of a tube or pipe to the lower or closed end
of the cylinder of the indicating apparatus, which cylinder is, by preference, placed
with its axis vertical so that, when the push-knob of the transmitting device is
released, the weight of the piston and its rod will cause them to descend.
The piston-rod of the indicating apparatus is arranged to actuate a lever or
levers to cause the bell to be sounded and the indicating tablet to be released
Bimultaneously. When one indicating apparatus is to serve for a number of trans-
mitters or communicators, the said apparatus is provided with a corresponding
number of cylinders and pistons and each piston has a rod arranged to act upon
two levers in the manner hereinafter set forth. One of these levers is fixed to
a shaft and the other is fitted loosely on the said shaft in such a manner that, when
either of the pistons is raised it will sound the bell and release the corresponding
tablet without interfering with the other tablets. A small rod or bar is fixed to
the shaft carrying the said tablets; this bar extends nearly from end to end of the
shaft and is arranged in such a manner that, when one or more tablets have been
released, they can be readjusted by rotating the said shaft by means of a handle
outside the casing of the apparatus. I provide for operating the bell in the
following manner, that is to say, one of the aforesaid levers, or another lever fixed
to the same shaft, is connected to a toothed segment which gears with a pinion
fixed to a ratchet wheel; a pawl upon an escapement wheel is adapted to engage
with this ratchet-wheel when the latter is rotated in one direction, and I combine
with the said segment a spring or weight so that when the said segment is moved
in one direction by the piston-rod and lever the ratchet-wheel turns independently
of the wheel, and when the piston-rod descends the spring or weight causes the
segment to move in the opposite direction, and the said pawl engaging with the
ratchet wheel, the said escapement wheel is caused to turn therewith and sound
the bell by means of a hammer provided with an ordinary escapement-lever.

page_text: In the accompanying drawings I have illustrated how my invention may be
conveniently and advantageously carried into practice.
Figure 1 is a central. longitudinal section of a transmitting device constructed
according to the said invention
Figure 2 is a front elevation of the same
Figure 3 is a side elevation of an indicating apparatus, the side of the casing
being removed.
Figure 4 is a front elevation of an indicating apparatus with a number of cylinders,
the front of the casing being removed,
Figure 5 is a plan of the same, and
Figure 6 is a section on the line x, x, figure 5
Like letters indicate the same parts throughout the drawings
E is
In Figures 1 and 2, A represents the cylinder of the transmitting device, which
is fitted with a piston B, having a hollow rod or stem C which fits upon a pin or
guide-rod D fixed in the bottom of the cylinder, or forming part of the same.
a spiral spring tending to press the piston against the stop E¹ and thus retain it in
its normal position. The rod C is provided with a head C¹ arranged to be acted
upon by the lever or quadrant F which has a projecting handle F, or the said rod
may be connected with an ordinary push-knob; a small pipe G is fitted near the
bottom of the cylinder A and communicates with the cylinder of the indicating
apparatus by the tubing G. The cylinder A is fixed in any desired place so that
it can be easily operated.
In Figure 3, A¹ represents the cylinder of the indicating apparatus, which is
provided with a piston B¹ having a piston-rod H passing through a guide J at the
top of the cylinder; a small pipe G2 is fitted in the bottom of the cylinder to
receive the tubing G. The lever a is pivotted upon a rod b and rests upon the
top of the piston-rod H. This lever is connected to the toothed segment c of the
bell mechanism by the link d. The tablet e is pivotted upon the rod f which is
carried in bearings in brackets f¹ and has a handle f³ for rotating it, and the lever a
is of sufficient length to permit the tablet to rest upon it as shewn.
The operation of this apparatus is as follows, that is to say when the piston B
of the transmitting device is pushed inward, the air is compressed between the said
piston and the closed end of the cylinder A, and this pressure, being communicated
through the tubing G¹ to the cylinder A¹, causes the piston B¹ to move
upward and thus sound the bell and release the indicating tablet, which may be
readjusted by means of the handle få after the piston B¹ has descended, the
shaft being provided with a stop to engage with the said tablet in the ordinary
manner.
In Figures 4, 5 and 6, A¹, A¹ represent the cylinders of the indicating apparatus,
each of which is provided with a small pipe G³ for connecting it with a
transmitting device similar to that shewn in Figures 1 and 2. B¹, B' are the pistons
and H, H are the piston-rods; g.is a shaft or rod carried in bearings in brackets h
attached to the frame or casing of the indicating apparatus. The arms or levers i
are fixed to the sleeves or tubes k which are fitted loosely upon the rod g and are
retained in position by the levers 7 and the pins . The levers i rest upon the
upper ends of the piston-rods H and the ends of the said levers support the
indicating tablets e when the latter are adjusted. In order that the bell K may be
sounded when either of the pistons is raised, the arms or levers are fixed to the
shaft or rod g; another lever m is also fixed to this shaft and is coupled to a link d
which is attached at its upper end, to the toothed segment c. The arms or levers
are bent at their outer ends, as shewn in Figure 5, so that they will rest upon the
arms or levers i, and, when one of the levers i is raised, it will lift the lever / resting
upon it and thus move the shaft g, the other levers rising independently of the
levers i, upon which they rested. The tablets are arranged in such a manner that
they may be readjusted when necessary. For this purpose the shaft or rod n, upon
which they are carried, is supported in suitable bearings in the brackets h, aud a
small rod or bar p. is fixed to the shaft n- extending nearly from end to end

page_text: thereof as shewn, and the slinft n is provided with a handle n¹ whereby the said
shaft can be rotated, so that one or more of the tablets may be thus raised and
adjusted without interfering with those already adjusted.
I sometimes employ the above described arrangement of levers. in combination
with an air-bag or bellows arranged to expand and contract vertically instead of
horizontally; in this case the bellows or air-bag acts upon the lever or levers in a
similar manner to the piston-rod of the apparatus herein before described.
The said pistons and cylinders may, if desired, be employed in combination with
mechanism other than that above described, and suitable for the purpose, and the
said cylinders may, if desired, be arranged horizontally instead of vertically, the
chief feature of this part of the invention being the employment of cylinders and
pistons in the transmitter as well as in the iudicating apparatus, which permits of
signals being transmitted to a greater distance than when the usual air-bags or
bellows are employed.
The improved bell-sounding mechanism is shown in Figures 4 and 6, L. is the
framework supporting the bell K, and the mechanism for sounding the same; c is a
toothed segment mounted on the arbor or shaft q, and r is a spiral spring surrounding
the said shaft, one end of which spring is attached to the said segment and the
other end to the framework L.
The segment c gears with the pinion 8 mounted and free to rotate on the arbor
or shaft 8; the flange t of this pinion is formed with ratchet teeth on its periphery.
An escapement-wheel u is fixed on the shaft and is provided with a pawl v and
a spring tending to keep the said pawl in engagement with the ratchet
wheel t.
The hammer w is carried by an arm w fixed to the escapement lever w² which is
fixed upon an arbor or shaft and arranged to gear with the escapement-wheel u.
The operation of this mechanism is as follows, that is to say, when the segment c
is moved in the direction indicated by the arrow, Figure 6, it will cause the
pinion & and ratchet wheel t to rotate upon the shafts and will not move the
escapement wheel.
When the force applied to the segment c is removed the elastic force of the
spring r will cause the said segment to move in the opposite direction, the pawl v
will engage with the ratchet wheel t, and the escapement wheel u will consequently
be rotated with the ratchet wheel and will cause the hammer to strike the bell a
number of blows in regular succession.
It will thus be seen that the operation of my improved mechanism is the reverse
of that of the mechanism ordinarily employed, and that its operation will be
independent of the rapidity with which the said segment is moved by the
pneumatic apparatus.
Instead of the spring 7, I sometimes employ a weight attached to the toothed
segment c as shown in dotted lines in Figure 6.
The above described apparatus can be adapted for transmitting and receiving
signals upon railways, ships, or in other places, in the following manner, that is to
Bay, I provide a combined transmitting and receiving device or apparatus in which
are arranged a suitable number of cylinders and pistons with push-knobs or the
like as above described, and a corresponding number of cylinders and pistons in
combination with indicating tablets and a bell.
Assuming that it is desired to transmit and receive signals between two places,
in such case, I fit up one of these combined devices at each place, and I connect the
transmitting cylinders at one of the said places with the indicating cylinders at the
other place and vice versa. By these means when a signal is transmitted to an
engine room, for instance, the engineer has merely to press the push-knob or lever
corresponding to the signal transmitted and thereby actuate the indicator at the other
end and give a signal in reply corresponding to that received by him; he can thus
inform the captain or other person that he has seen or heard the said signal.
Although I have described my improved apparatus especially for use with air

page_text: pressure it is obvious that the said apparatus will work equally well with oil,
water, or other liquid as the medium through which the impulse is to be imparted.
Having thus fully described my said invention and the manner of performing
the same I wish it understood that I claim, in a pneumatic signalling apparatus.
First. A cylinder in the transmitting device communicating, by means of a pipe
or tube, with a cylinder in the indicating or receiving apparatus, the said cylinders
being fitted with pistons having rods connected with devices or mechanism
substantially as described, whereby an impulse may be transmitted to simultaneously
release a tablet and sound a bell in the indicating apparatus, as above set forth.
Second. The combination, with the cylinder and piston of the indicating apparatus
(or with an ordinary air-bag or bellows), of the lever or levers arranged substantially
as above described to operate the sounding mechanism and release the tablet
simultaneously.
In witness whereof I. the said George Porter have hereunto set my hand
and seal this Twelfth day of February in the year of Our Lord One thousand
eight hundred and eighty three.