IMPROVEMENTS IN RAILWAY BREAKS ACTUATED BY THE PRESSURE OF THE ATMOSPHERE
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by Michel Siegrist at the Office of
the Commissioners of Patents, with his Petition, on the 14th August
1863.
I, MICHEL SIEGRIST, of Ewell, in the County of Surrey, Gentleman, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN RAILWAY
BREAKS ACTUATED BY THE PRESSURE OF THE ATMOSPHERE," to be as follows:-
My Invention consists of an improved mode of applying atmospheric
pressure to the levers of the breaks of railway carriages, engines, and
luggage vans, so that the breaks of the engine vans and all the carriages
of a train can be put in action at once by a person at any part of the
train, and in case of the engine or any van or carriage breaking away
through any accident the whole of the breaks of the train will act of
themselves, and the progress of the whole train arrested. My Invention
also admits of the engine or any of the vans or carriages being coupled
or uncoupled without the action of the breaks being at all interfered
with.
I will now describe my Invention as applied to the levers of breaks as
usually constructed, that is to say, where the breaks are applied in front
of the hind wheels and behind the fore wheels of a railway carriage by
levers the ends of which are depressed by a force acting downwards in
the centre of the carriage, and it will be obvious how my Invention can
be applied to any other description of break which is pressed against the

page_text: wheels or upon the rails. I fix underneath the centre of the carriage an
air-tight cylinder having a piston working in it. The cylinder is so placed
that the rod of the piston is perpendicular, and passes through an air-
tight stuffing box in the centre of the bottom of the cylinder. The piston
is furnished with one or more valves which open upwards. The top of
the cylinder is closed with an air-tight cover, and there are stop-cocks at
the lower ends of the cylinders to admit air when necessary below the
pistons. The lower end of the piston rod is attached to the ends of the
break levers, so that when the piston descends, the breaks are forced
against the wheels, and there is a spiral spring within the cylinder, one
end of which is fastened to the under side of the cover, and the other
end to the upper surface of the piston; the effort of this spring is to
raise the piston. Two pipes communicate with the upper part of the
cylinder running horizontally one towards the front and one towards the
back of the carriage. These pipes are continued from either end of the
carriage by indian-rubber tubes having coiled wire within them sufficiently
strong to resist the pressure of the air when the air is exhausted from
the tubes. There are valves placed in the ends of the indian-rubber tubes,
and a contrivance for uniting the tube of one carriago to the pipe of the
next when coupled, herein-after described. The indian-rubber tubes should
be of such a length as to admit of their hanging loosely when they are
connected and the carriages coupled. There is also another pipe to admit
air to the upper part of the cylinder when necessary, one end of which
communicates with the upper part of the cylinder; the other end is fur-
nished with a stop-cock placed where it can be conveniently reached by
the person or persons whose duty it is to apply the breaks.
The pipes,
which run horizontally along the carriages and communicate with the
cylinders, and which when the carriages are coupled, are attached together
by the indian-rubber tubes as above mentioned, communicate through a stop-
cock with a closed vessel, in which a vacuum is produced as herein-after
described, placed either on the engine tender or luggage van as may be
most expedient. The air in this vessel, which I call the vacuum vessel, is
exhausted by an air pump which is worked either by a donkey engine on
the locomotive engine, or by hand, or by an eccentric on one of the axle-
trees of the engine tender or van. In the latter case the pump can only
be worked when the train is in motion. The pipe which runs to the back
of the last carriage is kept closed by the valves at its end and at the end
of the indian-rubber tube attached to it as herein-after described. The
action of the apparatus as above described is as follows:-The stop-cocks

page_text: at the lower ends of the cylinders and also those at the ends of the pipes
to let air into the upper part of the cylinders being closed, and the stop-cock
through which the pipe from the cylinders communicates with the vacuum
vessel being opened, the air in the cylinders and vacuum vessel is exhausted
by the air pump worked as above described, the air in the cylinders below
the pistons being withdrawn as well as that above, as the valves in the
pistons which open upwards, admit of this being done. When the exhaus-
tion of the air is complete, the stop-cock, through which the pipe from the
cylinders communicates with the vacuum vessel, is closed When it is
desired to apply the breaks, the stop-cocks at the ends of the pipes for
admitting air to the upper parts of the cylinders or one of them are
opened, and the air rushes into the upper part of the cylinders and presses
the pistons down, which through the piston rods communicate a downward
pressure to the break levers, and so force the breaks against the wheels.
The vacuum in the cylinder below the piston is maintained, as the valves
in the pistons only open upwards, consequently the air cannot pass below
the pistons. When it is desired to remove the pressure of the breaks, the
stop-cocks at the ends of the pipes for admitting air to the upper part of
the cylinders are closed, and the stop-cock, through which the pipe from
the cylinders communicates with the vacuum vessel, opened. A portion of
the air which has been admitted into the upper part of the cylinders passes
into the vacuum vessel, and a sufficient exhaustion is in this manner
obtained to allow of the pistons being raised by the spring within the
cylinders, and the pressure of the break thus removed. By the action of
the air pump, which must be worked whenever there is occasion, the vacuum
in the cylinders and vacuum vessel is soon completely restored.
In case
of an accident whereby the engine or any van or carriage breaks away.
from the rest, the indian-rubber pipes which form the communications
between the cylinders of that carriage and the next will be broken, and
the air will then rush into the upper part of all the cylinders, and tho
breaks throughout the whole train will immediately be applied, and the
train stopped.
I have described one vacuum vessel only as being used, but I consider
it desirable to have two, either of which may be used. It is also desirable
to have vacuum guages so fixed that the persons whose duty it is to
apply the breaks and attend to the air pump may know what amount of
vacuum exists.
The mode of uniting the pipes of one carriage with those of another
is as follows:-The ends of each pipe farthest from the cylinder is divided

page_text: so that it has two mouths; to one is attached the indian-rubber tube
before mentioned, and the other enters a horizontal cylindrical box, the
end of which farthest from that at which the pipe enters is open and
flanged. The mouth of the pipe is closed by a valvo opening outwards,
which when the carriages are disconnected is kept closed by a spring.
The valve has a lever, which when pressed upon as herein-after described
forces it open. The valve, lever, and spring are all contained within the
box. The end of the indian-rubber tube is furnished with a similar box,
valve, spring, and lever, with this difference only, that the cylindrical box
on the indian-rubber tube is small enough to slide as air-tight as possible
within the cylindrical box at the end of the pipe, and the flange instead
of being at the end of the box is at such a distance from it as when
the box at the end of the indian-rubber tube is forced within that at the
end of the pipe a flat indian-rubber band, which is slipped over the end
of the box on the indian-rubber tube, shall be tightly compressed between
the flanges of each box. The box on the end of the indian-rubber tube
is furnished with a spring lever catch which when the last-mentioned box
is forced within the box at the end of the pipe hooks over the flange
of the latter. Each box contains a projection which presses upon the
lever of the valve of the other box, and forces the valve open, when one box
is forced within the other as above mentioned. In coupling the carriages,
the box at the end of the indian-rubber tube of one carriage is forced
within that at the end of the pipe of the other carriage until the spring
lever catch hooks over the flange as before described, the valves in both
boxes. being thereby caused to open, and in uncoupling the flange of the
box at the end of the pipe is liberated from the spring catch which is
hooked over it by depressing the lever of the catch, and the one box
withdrawn from the other, both valves immediately closing by the action of
their respective springs.
The object of having the ends of the horizontal pipes divided, one
mouth being furnished with a box and valve, and the other continued by
an indian-rubber tube as above described, is to enable a carriage to be
coupled so as to travel with either end first as may be desired. The
indian-rubber tubes when not in use may be hooked up to hooks on the
ends of the carriages.
All the parts of the apparatus above described, except where otherwise
expressed, and except the stop-cocks, valves, and cylindrical boxes should
be of iron or other suitable metal, and the stop-cocks, valves, and cylindrical
boxes of brass or gun metal.

page_text: With regard to the dimensions of the different parts of the apparatus,
the diameter of the cylinders must be according to the pressure required,
having regard to the fact that the pressure will be from 12 to 15 pounds
on every square inch of the upper surface of the piston. The length of
stroke of the pistons will depend upon the length of the break levers.
I consider that a stroke of two inches will generally be found sufficient.
The vacuum vessel should have a capacity at least twenty times greater
than the aggregate capacity of the cylinders in a train of average length.