Valve Arrangements for Equalising the Action of Pneumatic Brakes in case of Rupture of Coupling Pipes.
Year: 1891

page_text: Date of Application, 22nd July, 1891
Complete Specification Left, 14th Apr., 1892-Accepted, 4th June, 1892
PROVISIONAL SPECIFICATION.
Valve Arrangements for Equalising the Action of Pneumatic Brakes
in case of Rupture of Coupling Pipes.
I, LEÓN CHABERT, of 23, Boulevard de Strasbourg, Paris, France, Engineer,
do hereby declare the nature of this invention to be as follows:-
When there is rupture of any of the flexible coupling pipes for railway brakes
worked by compressed air such as those operating on the Wenger system, the
brakes next the ruptured part arc, owing to the rapid escape of the compressed air,
put on before those more distant, and accidents may result from want of simultaneity
in the stoppage of the several carriages. My invention relates to valve arrange-
iments whereby, when a rupture occurs, the train pipe is throttled so that the
compressed air cannot escape from it rapidly, all the brake apparatus throughout
the train being thus brought gradually but simultaneously into action. For this
purpose, I fit across the train pipe in each carriage a sluice valve with a small
hole through it, this valve being however held up by a spring so as to leave the
passage of the train pipe quite free while the pipe and its couplings are sound. On
the stem of the sluice valve is fixed a piston packed with cup leather, past which
compressed air, when the pipe is charged, can pass to a closed cavity above the
piston. Should a rupture occur, the pressure of this air, acting on the piston.
forces it down depressing the sluice valve and so throttling the train pipe, the only
passage along it being through the small hole of the valve.
The arrangement of the valve and piston may be inverted, the spring pushing
down the valve when the pressure under the piston is suddenly relieved; in this
case the cavity above the piston is open to the air.
In some cases it is of advantage to employ two valves for each carriage, one at
each end, the one arranged to act when a rupture causes the air to flow in the one
direction, the other to act when the flow is in the opposite direction. In this case
the valve is in the form of a flap with a small hole through it, this flap usually
resting on the mouth of a cavity below, which cavity becomes charged through
the small hole with compressed air from the train pipe. When rupture takes place
beyond the hinged side of this valve relieving the pressure above it, the excess of
pressure below it causes it to turn up on its hinge and close the passage for air
except through the small hole.
Dated this 22nd day of July 1891.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Valve Arrangements for Equalising the Action of Pneumatic Brakes
in case of Rupture of Coupling Pipes.
I, LEÓN CHABERT, of 23 Boulevard de Strasbourg, Paris, France, Engineer,
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:-
When there is rupture of any of the flexible coupling pipes for railway brakes
worked by compressed air such as those operating on the Wenger system, the
brakes next the ruptured part are, owing to the rapid escape of the compressed
air, put on before those more distant, and accidents may result from want of
simultaneity in the stoppage of the several carriages. My invention relates to
Prion 9.71

page_text: valve arrangements whereby, when a rupture occurs, the train pipe is throttled so
that the compressed air cannot escape from it rapidly, all the brake apparatus
throughout the train being thus brought gradually but simultaneously into action.
For this purpose, I fit across the train pipe in each carriage a sluice valve with a
small hole through it, this valve being however held up by a spring so as to leave
the passage of the train pipe quite free while the pipe and its couplings are sound.
On the stem of the sluice valve is fixed a piston packed with cup leather past
which compressed air, when the pipe is charged, can pass to a closed cavity above
the piston.
Should a rupture occur, the pressure of this air, acting on the piston,
forces it down depressing the sluice valve and so throttling the train pipe, the only
passage along it being through the small hole of the valve.
The arrangement of the valve and piston may be inverted, the spring pushing
down the valve when the pressure under the piston is suddenly relieved; in this
case the cavity above the piston is open to the air.
In some cases it is of advantage to employ two valves for each carriage, one at
each end, the one arranged to act when a rupture causes the air to flow in the one
direction, the other to act when the flow is in the opposite direction. In this case
the valve is in the form of a flap with a small hole through it, this flap usually
resting on the mouth of a cavity below, which cavity becomes charged through the
small hole with compressed air from the train pipe. When rupture takes place
beyond the hinged side of this valve relieving the pressure above it, the excess of
pressure below it causes it to turn up on its hinge and close the passage for air
except through the small hole.
Fig. 1 of the accompanying drawings is a section and Fig. 2 is a sectional plan
of a valve arrangement according to this invention.
A is the valve case having branches B B connected to the train pipe. The valve
stem C is made with a piston P provided with cup leather a working within a
cylindrical lining b. The stem C terminates below in a rectangular slide valve D
having a small hole o through it; at the top of the stem C is fixed a disc E under
which is a spring F.
A small passage c allows compressed air to pass from the train pipe into the
valve casing above.
When the train pipe is not charged with compressed air, the valve D is raised
by the spring F leaving free passage under it, and this remains the same when the
train pipe is charged with compressed air, some of which passing through c and
past the cup leather a charges the space S above the piston.
Should there be a rupture of the train pipe suddenly reducing the pressure in it,
then the pressure of the air on S acting on the piston P forces it down depressing
the slide valve D so that there is only the small hole o giving passage along the
train pipe.
According to the modification shewn in Fig. 3 the spring F¹ is arranged to urge
the valve D down, the cup leather a being in this case reversed, and the space S
being open to the air.
While the train pipe is charged with compressed air the valve D is kept up by
the pressure on the piston P exceeding the force of the spring F'. But when the
pressure in the train pipe is rapidly reduced, the spring F¹ forces down the
valve D so that the only passage along the train is through the small hole o.
The valve arrangements shewn in Figs. 1, 2 and 3 operate whichever be
the direction of the flow of air along the train pipe. The valve arrangement shewn
in Fig. 4 serves only when the flow is in the one direction, and therefore each
carriage should have a pair of these, one at each end, the one suited for flow in the
In this case a flap
one direction and the other for flow in the opposite direction.
valve G having its edges faced with leather d and having a small hole o through
it, rests over a space H which is charged from the train pipe with compressed air.
In case of a rapid reduction of pressure in the train pipe, the air in H expanding
raises the valve, which is carried over by the current so as to seat itself on m n
leaving only the hole o for passage along the train pipe. The valve may have a

page_text: projecting tongue / on which the current can act so as more certainly to throw the
valve over.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. For equalising the action of pneumatic brakes in case of rupture of coupling
pipes, a valve arrangement whereby the train pipe passage becomes in that case
automatically throttled, substantially as described.
2. The valve arrangement herein described with reference to Figs. 1 and 2.
3. The modified valve arrangement herein described with reference to Fig. 3.
4. The valve arrangement described with reference to Fig. 4.
Dated th: 14th 1
T
ABEL & IMRAY,
Agents for the Applicant.
ABEL & IMRAY,
Agents for the Applicant.