IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY Brakes by Fluid PRESSURE
Year: 1881

page_text: LETTERS PATENT to George Westinghouse, junior, of Canal Road, King's
Cross, in the County of Middlesex, for an Invention of "IMPROVEMENTS IN
APPARATUS FOR WORKING RAILWAY Brakes by Fluid PRESSURE.”
PROVISIONAL SPECIFICATION left by the said George Westinghouse, jr., at
the Office of the Commissioners of. Patents on the 8th August 1881.
GEORGE WESTINGHOUSE, junior, of Canal Road, King's Cross, in the County of
Middlesex. "IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY BRAKES
BY FLUID PRESSURE."
Air is applied to work brakes on railway trains, either by employing it at a
pressure above that of the atmosphere, or by rarefying it so that the atmosphere
operates by its excess of pressure over that of the rarefied air. As both these
methods are in use, it sometimes happens that a carriage fitted with brake
apparatus worked in the one way may form part of a train having brake apparatus
worked in the other, way. My Invention relates to a modification of the couplings
used to connect the pipes that communicate pressure throughout the train so as to
render them available, whether the air be compressed or rarefied, and to a valve
arrangement available for use in working the brakes when the air is rarefied, and
so constructed that when the carriage on which it is fitted forms part of a train
having generally brakes worked by compressed air, the working of these brakes
is not interfered with by the presence of this carriage and its brake fittings.
The coupling to which my present Invention relates is of a kind described in
the Specifications of Patents formerly granted to me; it consists of two equal
and symmetrical halves which have nozzles connected to the pipes on their
respective carriages by pieces of flexible hose. Each half coupling has a lateral
aperture provided with a lip of caoutchouc or other elastic packing material. For
connecting the halves they are brought together face to face so that their lateral
apertures coincide and their packing lips are pressed together; they are then turned
in opposite directions partly round the common axis of their lateral apertures, and
a projecting segmental flange of the one is thus made to engage in a segmental

page_text: .
hollow of the other so as to hold the halves together. When the pipes connected
by these couplings convey compressed air along the train, the pressure within them
serves to press firmly together the packings of their apertures, preventing leakage out-
wards at their junction. In order that the junction may be rendered tight also when
the air in the pipes is rarefied, I provide within the half coupling a cage of cylindrical
form with lateral apertures; one end of the cage is made with a rounded hollow
lip which bears on the interior of the packing ring, and the other end of the cage
is in contact with one side of a flexible diaphragm, the other side of which is
subject to the pressure of the atmosphere admitted through a hole in the cap of
the coupling; thus when the air in the pipes and couplings is rarefied the excess
of atmospheric pressure on the diaphragm tends to bulge it inwards, pressing the
cage against the packing and forcing its lip outwards. Both half couplings having
their packing lips thus pressed against each other, leakage of air inwards at their
junction is prevented. Sometimes the couplings are provided with valves which
are automatically opened when the halves are connected. To provide for the case
of a half coupling, modified as above described, being joined to a half coupling
having a valve, I make the. cage above mentioned with a central stem, which,
when this half coupling is connected to one having a valve, unseats the valve, and
thus gives free passage for air through the coupling.
The valve arrangement according to my present Invention is suited for brake
apparatus of the following known kind:-Each brake carriage has a brake
cylinder and piston or their equivalent, a closed vessel divided by a flexible
diaphragm, the piston or diaphragm being connected to the brake levers. The
cylinder or diaphragm vessel is at one end connected to an auxiliary reservoir or
vacuum vessel, or is enlarged so as to present capacity at that end equivalent to
such a reservoir. This end of the cylinder or diaphragm vessel with the reservoir is
connected to the pipe that extends along the train through one nozzle of the valve
box which I am about to describe, the other end of the cylinder or diaphragm
vessel being connected through another nozzle to the train pipe in one position of
the valves, and to an aperture to the outer air in another position of the valves.
Within the valve box is fixed a flexible diaphragm, the stem of which works in
bushes with lateral passages, so arranged that the stem governs them as a slide
governs ports; this stem also when it makes its full stroke in one direction butts
against and unseats a valve governing the aperture to the outer air. The action
of the valves is as follows:-When the train pipe is exhausted the diaphragm
takes such a position in the valve box that both ends of the brake cylinder, as well
as the auxiliary reservoir, being put in communication. with the pipe become also
exhausted, the outer opening being closed by its valve; in this condition the brake
piston is in equilibrium as to pressure, and the brakes are kept off by suitable
weights or springs. If now it be desired to put on the brakes, the vacuum in the
train pipe is lessened or destroyed by admitting air into it purposely, and this will
also result automatically from the accidental rupture of the train pipe or separation
of the train. The diaphragm in the valve box is now by the increased pressure on
its one side caused to bulge in one direction, and its stem closes the passages from
the train pipe to the cylinder, and opens the air valve so as to admit air pressure
to act on one side of the brake piston, which, moving in obedience thereto, puts on
the brakes. To take off the brakes the train pipe is again exhausted, and the
valves resume their former position, putting the brake piston under equal pressures
on both sides. In case a carriage fitted with this apparatus should form part of a
train having its other brakes worked by compressed air, the valve diaphragm is
bulged by the pressure in the train pipe so that a boss upon its stem seats as a
valve, closing the passages to the brake cylinder and auxiliary reservoir which are
rendered inoperative on that particular carriage by being cut off from the train
pipe which remains available for working the other brakes of the train.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Westinghouse, jr., in the Great Seal Patent Office on the
30th January 1882.
GEORGE WESTINGHOUSE, junior, of Canal Road, King's Cross, in the County of
Middlesex. IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY BRAKES BY
65
FLUID PRESSURE.”
Air is applied to work brakes on railway trains either by employing it at a pressure
above that of the atmosphere, or by rarefying it so that the atmosphere operates
by its excess of pressure over that of the rarefied air. As both these methods are
in use, it sometimes happens that a carriage fitted with brake apparatus worked in
the one way may form part of a train having brake apparatus worked in the other
way. My Invention relates to a modification of the couplings used to connect the
pipes that communicate pressure throughout the train so as to render them
available whether the air be compressed or rarefied, and to a valve arrangement
available for use in working the brakes when the air is rarefied, and so constructed
that when the carriage on which it is fitted forms part of a train having generally
brakes worked by compressed air, the working of these brakes is not interfered
with by the presence of this carriage and its brake fittings.
The coupling to which my present Invention relates is of a kind described in
the Specifications of Patents formerly granted to me. It consists of two .equal
and symmetrical halves which have nozzles connected to the pipes on their respective
carriages by pieces of flexible hose. Each half coupling has a lateral aperture
provided with a lip of caoutchouc or other elastic packing material. For connecting
the balves they are brought together face to face, so that their lateral apertures
coincide, and their packing lips are pressed together. They are then turned in
opposite directions, partly round the common axis of their lateral apertures, and a
projecting segmental flange of the one is thus made to engage in a segmental
hollow of the other, so as to hold the halves together. When the pipes connected
by these couplings convey compressed air along the train, the pressure within
them serves to press firmly together the packings of their apertures, preventing
leakage outwards at their junction. In order that the junction may be rendered
tight, also when the air in the pipes is rarefied, I modify the coupling as shewn in
Fig. 1 of the accompanying Drawings, which is a longitudinal section of a half
coupling according to my present Invention; A is the nozzle to which is attached
the piece of flexible hose connecting the half coupling to the pipe of its carriage.
The passage from A turns at right angles to the lateral aperture B which is as
usual provided with the caoutchouc lip c. The segmental projecting flange D and
the corresponding hollow E are made for engagement in the usual way. According
to the modification which is the subject of my present Invention, I provide within
the body of the coupling a cylindrical cage F having lateral apertures, which cago,
on screwing down the cap G, is made to press on the outer edge of the packing
ring C, and also on that of a flexible diaphragm H, which is thus secured between
the cap G and the cage F. Under the diaphragm H and between it and the
packing e I introduce an inner cage K which has also lateral apertures. The cap G
has a hole g opening to the outer air, and in the enlarged lower part of this hole is
placed a spring L pressing on the diaphragm H. . When the coupling is used for
connecting pipes for a vacuum brake, when the pressure within the coupling is
less than that of the external atmosphere, then the excess of the atmospheric
pressure acting on the upper side of the diaphragm H conspires with the spring L
to force down the inner cage K, and its lower curved edge k squeezes the
packing c so as to press the packings of the two half couplings firmly together, and

page_text: so prevent leakage of air between them into the pipes. When on the other hand
the couplings are used for pipes conveying compressed air, then, though the
diaphragm H is deflected upwards and the packing c is relieved from the pressure
of the cage K, yet the excess of the internal pressure of air acts on the packing c
so as to force its lip outwards, and the packings of the two half couplings are thus
pressed firmly together, preventing leakage of air out of the pipes. The cage K is
made with a central stem, which by abutting against a valve in the other half
coupling (when such valve exists) opens that valve for free passage of air when
the half couplings are connected.
The valve arrangement according to my present Invention is suited for brake
apparatus of the following known kind. Each brake carriage has a brake cylinder
and piston, or their equivalent, a closed vessel divided by a flexible diaphragm, the
piston or diaphragm being connected to the brake levers. The cylinder or
diaphragm vessel is at one end connected to an auxiliary reservoir or vacuum
vessel, or is enlarged so as to present capacity at that end equivalent to such a
reservoir. This end of the cylinder or diaphragm vessel with the reservoir is
connected to the pipe that extends along the train through one nozzle of the valve
box which I am about to describe, the other end of the cylinder or diaphragm
vessel being connected through another nozzle to the train pipe in one position of
the valves and to an aperture to the outer air in another position of the valves.
Fig. 2 is a vertical section of the valvo box with its valves which are arranged
and operate as follows:-The valve box is made in two parts A and B, secured
together by bolts. passing through their flanges which clamp between them the
outer edge of a flexible diaphragm D. The inner edge of this diaphragm is
clamped between a flange E and a disc F secured on the stem G of the flange E.
The stem G is bored up the middle about as far as the flange E, and from the end
of the bore holes g are bored diagonally so as to escape the upper part H of the
stem. The lower end of the bore hole in G is closed by a plug g¹, and just above
the plug a hole g₁ is bored laterally into the central bore. The lower part of the
stem G is reduced in diameter and fitted to slide in a bush K let into a recess in
the body of the lower part A of the valve box. A spring L butts on the bush K
and against the shoulder of G. Holes a make communication between the lower
nozzle M and the space under the diaphragm D. The space above the diaphragm
communicates by a passage b with a side nozzle N. The upper part h of the
stem H is fitted to slide in a bush O from which there is a lateral passage to
another side nozzle P, and the stem H is partly cut away at the sides at h, so as
to give passage for air while the parts not cut away serve as guides. The upper
part of the bush O forms a seating for a valve Q, which is a disc faced with
caoutchouc pressed down to its seat by a spring R. The stem g of the valve Q
projects down and terminates some distance above the top of the stem H. Above
the valve there is a nozzle S opening to the outer air, and preferably provided
with a strainer of porous material to prevent access of dust or dirt. This valve
box having its nozzle M connected to the train pipe, its nozzle N to the auxiliary
reservoir (which is always in communication with one end or back of the brake
cylinder), and its nozzle P connected to the front of the brake cylinder, the
operation is as follows:-The train pipe M being exhausted the diaphragm becomes
deflected, as shewn in Fig. 2, and air passes from the auxiliary reservoir and back
of the brake cylinder by N and b, and from the front of the brake cylinder P past
the ports h of the stem H and through the holes g and g³, and the valve Q being
closed the brake cylinder is thus equally exhausted at both ends, and the brake
piston being in balance the brakes are held off by suitable weights or springs. If
now the pressure in the brake pipe be increased either purposely or by the
accidental rupture of the pipe or separation of the train, then the diaphragm D is
pressed upwards, closing the lateral passage g³, closing also the passage by h, and
thereafter by the stem A bearing against 9 opening the valve Q. Thereupon
while the vacuum is maintained on the one side of the brake piston with which N
communicates, air entering directly past the open valve Q flows by P so as to

page_text: press on the other side of the brake piston, and the piston is thus urged so as to
put on the brakes. On again exhausting the train pipe the diaphragm becomes
again deflected, valve Q closes, and the air is withdrawn from the front of the
brake cylinder, so that the brake piston is again under equilibrium of pressure,
and the brakes are taken off by their weights or springs. When the train pipe is
employed for working the brakes by compressed air, the pressure communicated
through M raises the diaphragın till the upper face of G is pressed against .the
lower face of O. The passages g and h are thus closed, and the brake cylinder and
auxiliary reservoir are cut off from communication with the train pipe, which is
left available for working the other brakes of the train by compressed air.
.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim in respect of apparatus for working brakes by
fluid pressure,―
First. The combination with the pipe coupling of a moveable cage K and
diaphragm H, arranged and operating as herein described with reference to Fig. 1.
Second. The construction of valve box herein described with reference to Fig. 2.
In witness whereof, I, the said George Westinghouse, junior, have hereunto
set my hand and seal, this Twentieth day of December, in the year of our
Lord One thousand eight hundred and eighty one.