Improvements in or relating to Air Brakes for Railway Vehicles.
Year: 1894

page_text: Date of Application, 27th Feb., 1894-Accepted, 28th July, 1894
COMPLETE SPECIFICATION..
Improvements in or relating to Air Brakes for Railway Vehicles.
A communication by MOSES LEOPOLD ROTHSCHILD, of 11-23, South Jefferson
Street, Chicago, in the County of Cook and State of Illinois, United States
of America, Manufacturer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street,
Manchester, both in the County of Lancaster, and 323, High Holborn, in the
County of Middlesex, Civil 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 :-
This invention consists in an improvement in air-brake systems for cars or
railway vehicles.
In the accompanying drawings:-
Figure 1 is a general plan view showing the improvements applied to a car so
that it may be operated from either end; partly in section, with the axle A & its
excentric shown in elevation, for clearness sake.
Figure 2 is a vertical section through the improved valve:
Figure 3 is a bottom plan view of the rotating part of the valve:
Figures 4, 5 and 6 are top plan views of the stationary part of the valve, showing
in dotted lines different positions of the rotating part of said valve: and
Figure 7 is a top plan view of the valve, showing in dotted lines the different
positions of the handle.
A, represents the axle of the car, B represents an air compressor operated by an
eccentric and connecting rod a, from said axle. The air compressor B is of the
type in which the suction valves are automatically unseated by air pressure when
such pressure reaches a predetermined limit so that the piston moves without
further compressing air, until a drop in the air pressure permits the suction valves
to re-seat. Several forms of such air compressors are known, but none of them is
this invention, and therefore no particular forms have been illustrated. C represents
an auxiliary reservoir; D, a main reservoir for compressed air: E, an air-brake
cylinder: b, a pipe connecting air compressor B with reservoir C, and c a pipe with
a weighted check valve W, connecting reservoirs C and D: as check valve W
resists the air pressure in reservoir C, both through the air pressure in reservoir D
and the spring or weight with which said valve is loaded, it is evident that said
valve may be adjusted to remain closed until the air pressure in reservoir D falls
to any desired extent below the air pressure in reservoir C. Pipe c and check
valve W may be omitted if desired. F represents a controlling valve, of which
there may be only one on a car, but preferably there are two on a motor or grip
car, one on each end of said car, as shown in Figure 1, the one at the right hand
of Figure 1 being shown with the cap removed for purposes of illustration.
Valve F consists of a shell G, through the seat of which are formed ports H, I, J
and K, and a rotary flattened disc or plate L, adapted to lie and rotate within
shell G, in the under side of which are formed two grooves M and N. Port K is
within the circle of ports H, 1 or J, and groove N is so formed that it can only
connect ports J and K. For the purpose of ensuring early connection between
ports J and K, and retaining this connection as long as possible, it is preferable to
offset one end of groove N, as shown in the drawings, thus permitting the brake
cylinder to exhaust freely and quickly.
O represents a cap adapted to bolt to shell G by bolts O and P represents a
stem, one end of which is connected to valve disc or plate L, while the other end

page_text: projects upward & is adapted to engage with a handle Q. R represents a screw
plug in cap O and S represents a spiral spring encircling stem P, one end of
which lies within screw plug R, while the other end. presses against valve disc or
plate Land holds it firmly in its seat against the air pressure in slot M.
n represents a groove in cap O, into which a projecting lug g on handle Q fits and
moves to steady said handle. The pipe k is connected by the branched pipes, hh
with the port H in shell G: reservoir D is connected by the branched pipe k with
the port I in shell G. Brake cylinder E is connected by the branched pipes with
the port J in shell G. Port K in shell G opens freely into the outer air.
.
As indicated by dotted lines in Figures 4, 5 and 6, the valve L may be turned
as in Figure 4, so that the groove M connects ports H and I, and groove N
connects ports J and K, or, as in Figure 5, so that groove M registers only with
port I, groove N still connecting ports J and K, or, as shown in Figure 6, groove M
connects ports I and J, while groove N registers only with port K, these positions
being indicated by the dotted lines 1, 2 and 3 in Figures 1 and 7. There is also a
position beyond that of Figure 6, marked 4 in Figures 1 and 7, in which neither of
the grooves M and N registers with either of ports H or I, and in which no air can
pass through valve F, thus rendering said valve inert.
The operation of the invention is as follows:-
The motion of the pump B compresses air into reservoirs C and D, and, assuming
the valve to be in position one, shown in Figure 4, air passes from reservoir C to
reservoir D, through pipe c, when there is no pressure in reservoir D, or when the
pressure therein is so small that the pressure in reservoir C opens the check valve W
in pipe c against the pressure in reservoir D plus the weight on the check valve, or,
if pipe c is entirely omitted, air passes through the branched pipes h into the
port H, thence through groove M into port I and through branched pipe i into
reservoir D until the pressure in reservoirs C and D becomes equal, when air will
cease to flow through said pipes. When the grip-man desires to apply the brake,
he moves handle from position 1 to position 2, which cuts off the connection
through groove M between ports H and I, thus preventing the escape of air from
reservoir C. By continuing the motion of handle Q into the position shown in
Figure 6, he causes groove M to connect ports I and J, which throws reservoir D
into connection with brake cylinder E through the pipe i, port I, groove M, port J
and branched pipe j, thus applying air to said brake cylinder and setting the brake
in a manner so well understood that it needs no further description. When the
car has been brought to rest, the motion of the handle Q is reversed, until the
parts come into the position shown in Figure 5, in which the port J is connected
through branch pipe and groove N with exhaust port K, and 'the pressure on
brake cylinder E is let off. In this position, groove M does not register with
port H, so that the pressure in reservoir C is maintained, and the air compressor B
is held out of operation by the unseating of the suction valves, as is well known.
After the car starts and attains proper headway, so that the action of the air
compressor will not absorb too much power, handle Q is turned back to the
position 1, thue bringing the grooves in the position shown in Figure 4, in which
reservoirs C and D are again connected through pipes h, port H, groove M, port I
and pipe i, thus again equalising the pressure in the two reservoirs. By the
meaus described, the air compressor is held out of operation in starting the car, and
consequently all available power can be utilised when the car is being started. If,
when the valve is in the position shown in Figure 5, another stop is to be made
before sufficient headway is attained to render it advisable to again connect
reservoirs C and D, the valve is again turned to the position shown in Figure 6,
drawing upon the supply of air contained in reservoir D, without diminishing the
pressure in reservoir C. The pipe c with its load or weighted check valve is
simply to guard against the neglect of the grip man to return the valve to the
position shown in Figure 4, as, in such case, when the pressure in reservoir D falls
too low, the pressure in' reservoir C will open the weighted valve in pipe c and
permit air to flow from reservoir C into reservoir D, and it is evident therefore

page_text: that pipe e with its weighted check valve is not necessary, and may be dispensed
with. Whenever two valves F are used, as shown in Figure 1, so that the grip
man may operate the brake from either end of the car, it is of course necessary
that the inactive valve be left in the position 4, Figure 7, in which no two of the
ports H, I, J and K are connected. For the purpose of facilitating placing the
valve either in the position 1 or 4, a lug g is formed on the lower side of cap O to
engage with a projection on valve L and stop said valve in its rotation either way,
at either the point 1 or the point 4.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. The combination, with an air compressor, a regulating reservoir, a car reservoir
for compressed air, connections between said reservoirs, and an air brake cylinder,
of a valve consisting of a shell having four ports formed in its bottom, the first
connected with an air compressor and regulating reservoir, the second connected
with the car reservoir, the third connected with the brake cylinder, and the fourth
opening into the air, and a rotary disc or plate having the bottom surface provided
with a series of grooves adapted to connect the second named port with either the
first or third, and to connect the third port with the fourth, or to isolate all of said
ports from each other, substantially as shown and described.
2. In combination with an air compressor of the type which is governed by the
resistance of compressed air, a reservoir for compressed air connected directly with
the compressor, a second reservoir for compressed air connected with said first
reservoir, an air brake cylinder, and a four-way cock controlling the connection
between said two reservoirs and also controlling a connection from said cock to
said air brake cylinder, whereby said reservoirs may be connected together, or
either may be connected with said air brake cylinder, substantially as shown and
described.
3. In combination with an air compressor of a type whose action is regulated by
the resistance of the air compressed, two reservoirs for the storage of air, one of
which is directly connected with the air compressor and the other of which is
connected with said first named reservoir, a connection from said second reservoir
to the air brake cylinder, and means for closing the connection between Baid
reservoirs in opening the connection from said second reservoir to said air brake
cylinder, substantially as shown and described.
4. In combination with an air compressor B and means for operating the same,
a reservoir C connected directly with said compressor, a reservoir D for storage of
compressed air connected with said reservoir C, a four-way cock F in the connection
between said two reservoirs, and an air brake cylinder E connected with said
four-way cock, substantially as shown and described.
5. In an air brake mechanism, the combination, with an air compressor of the
type whose operation is controlled by air pressure, of a regulating reservoir
connected with the discharge port of said compressor, a car reservoir for compressed
air, an air brake cylinder, and means, substantially such as described, whereby said
compressed air reservoir may be connected either with said regulating reservoir or
said air brake cylinder, substantially as and for the purposes set forth.
Dated this 26th day of February 1894.