An Improvement in Triple Valves for Pneumatic Railway Brakes.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Improvement in Triple Valves for Pneumatic Railway Brakes.
I, ALBERTUS KAPTEYN, of The Westinghouse Brake Company Limited, of York
Road, King's Cross, in the County of London, do hereby declare the nature of this
invention to be as follows:
In the Specification No. 275 of 1888 were described several forms of triple valves
for pneumatic railway brakes, so arranged that, by their means, in cases of
emergency, the maximum pressure could be brought to act in the brake cylinder in
the shortest possible time. It has been found in practice with such valves that,
although it is of great advantage to bring some pressure to bear on the brake
piston in the shortest possible time, it is better to apply at first moderate pressure
and increase it gradually. The present invention relates to a modification of the
triple valve described in the Specification No. 275 of 1888, above referred to, in
such a manner as to attain this result.
For this purpose, referring to Fig. 2 of the drawings annexed to the said
specification, the check valve there marked 49, is loaded by a spring so as to limit
the pressure of the air thus passing to the cylinder from the train pipe, and a hole
is bored through the piston marked 63 for passage of air from the the auxiliary reser-
voir to the brake cylinder, this hole being of such area that the increase of
pressure in the brake cylinder due to the amount of air passing through it in
addition to that passing the valve 41 from the brake pipe, is gradually raised to
the maximum. When the slide valve has, as shewn in the Specification No. 275
of 1888, a passage which, in case of emergency, allows air to pass from the auxiliary
reservoir to the brake cylinder, the hole through the piston 63 is unnecessary.
According to a modification, the valve 49 is dispensed with and the space beyond
the valve 41 is closed by a partition having an opening furnished with a spring
loaded valve, so that when, on an emergency, the valve 41 is opened by the action
of the piston 63, this spring loaded valve opens to admit air from the train pipe to
the brake cylinder at a pressure dependent on the force of the spring. In order to
provide against leakage where the stem of the piston 63 passes through the
partition over the space beyond the valve 41, this stein is made with a collar formed
as a valve seating against the partition. Also, besides the spring loaded valve
above referred to opening from the space beyond the valve 41 to the brake cylinder,
another spring loaded valve opens to a passage leading to the atmosphere, in order
to produce a more marked reduction in the brake pipe pressure than that caused
by the exhaust into the brake cylinder alone.
According to a further modification both spring loaded valves last described may
be dispensed with, an opening to the atmosphere being provided from the covered

page_text: space beyond the valve 41, so that on the valve 41 being opened in case of emer-
gency, air can pass freely from the train pipe, the pressure being thus rapidly
reduced in the successive lengths of the train pipe from vehicle to vehicle.
Dated this 20th day of April 1897
ABEL & IMRAY,
Agents for the Applicant.
An Improvement in Triple Valves for Pneumatic Railway Brakes.
I, ALBERTUS KAPTEYN, of The Westinghouse Brake Company Limited, of York
Road, King's Cross, in the County of London, 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:-
In fluid pressure automatic brakes of the Westinghouse kind employed on rail-
way trains, each brake carriage is provided with a brake cylinder, an auxiliary
reservoir holding a store of compressed air and what is known as a triple valve
governing the connections of the auxiliary reservoir and the brake cylinder to each
other to the pipe by which the compressed air is transmitted throughout the train
and to the escape. When it is desired to apply the brakes, the pressure in the
train pipe is more or less reduced and this reduction acting on organs in the triple
valve causes compressed air to pass from the auxiliary reservoir to the brake
cylinder and act on the brake piston. When it is desired to apply the brakes
quickly and with full force, the pressure in the train pipe is rapidly and consider-
ably reduced, and this has the effect of causing compressed air to pass into the
brake cylinder not only from the auxiliary reservoir but also from the train pipe
itself thus causing pressure in the cylinder to rise rapidly from zero to the maxi-
mum pressure. The object of the present invention is to avoid too sudden and
energetic action on the brake piston and to render the action of the brakes very
smooth even on the longest trains by providing means of applying only a moderate
amount of brake pressure in the shortest possible time to all the brake carriages of
the train, and then of gradually increasing that pressure to the maximum.
For this purpose, certain modifications are made in the triple valve as will be
described with reference to the accompanying drawings.
Figure 1 is a section on the line wow of Figure 2 which is a section on the
linex of Figure 1, shewing one form of triple valve modified according to the
present invention. Figure 3 is a view of the face of the slide valve, Figure 3* is a
transverse section at ss and Figure 4 is a view of the facing on which it works.
Figure 5 is a section of a modified form of the triple valve, Figure 6 is a section
on the line y y of Figure 7 which is an elevation on the line of Figure 5.
Referring first to Figures 1 to 4 inclusive, 15 is a passage to the outer air; the
auxiliary reservoir communicates at 27 with the case of the slide valve 14, 16 is
the passage to the brake cylinder, and 17 is the passage to the train pipe which
To the stem 13 of the slide
communicates by passage 18 with the chamber 19.
valve is attached the piston 12 working in the cylindrical cavity 11 which com-
municates by holes 20 with the chamber 19. In a chamber 54 at the side of the
alide valve case works a piston 63, this chamber communicating at 16 with
the brake cylinder and being separated by a valve 41 and a check valve 49 from the
passage 17 to the train pipe. The slide valve governs a passage GO to the brake
cylinder by 16, a passage 59 to the chamber 54 and a passage 56 leading to the out-
let 15. In the slide valve is a longitudinal passage 31 governed by a graduating
valve 29 on a stem 30 fixed to the valve stem 13, with which it moves, while the
slide valve itself has play between the collars 27 and 28 on the valve stem.
The

page_text: piston 63 bears on the stem 64 of the valve 41 which is kept closed by a spring 50
within the stem of the check valve 49 on which bears a spring 55.
The slide valve being provided with suitable ports governing ports in the facing
on which it works, the operation of the apparatus is as follows:--
For applying the brakes with moderate force for ordinary stoppages, the engineer
by his valve allows escape of air from the train pipe so as to reduce to a certain
extent the pressure therein. The excess of pressure in the auxiliary reservoir
thereupon moves the piston 12 and slide valve 14 until the piston is stopped by
the decrease of pressure in the reservoir. The graduating valve 29 being unseated
by the movement of the stem 13 relatively to that of the slide valve, compressed air
from the auxiliary reservoir passes by 31, 60 and 16 to the brake cylinder acting
on the piston so as to put on the brakes.
When it is desired to apply the brakes with great force and rapidity the engineer
suddenly and greatly reduces the pressure in the train pipe, so that the piston 12
and with it the slide valve, is moved to its full extent, and a port is opened by
which air passes to act on the piston 63. This piston being pressed forwards opens
the valve 41, and thereupon the check valve 49 opens allowing air to pass from the
train pipe 17. to the chamber 54 and thence to the brake cylinder, which is also
supplied with compressed air, from the auxiliary reservoir through a small hole w
in the piston 63. By the spring 55 the valve 49 is closed as soon as the pressure
in the brake cylinder has attained a certain moderate amount. The flow of air
from the main pipe is thus cut off, whilst the air from the auxiliary reservoir con-
tinues to feed through the small hole w, thus gradually increasing the pressure in
the brake cylinder to the maximum.
For taking off the brakes the pressure in the train pipe is increased so as to force
the piston 12 back, carrying the slide valve with it to such a position that first the
space behind the piston 63 is put in communication with the outlet 15, so that the
piston 63 is moved back and the valve 41 closes and then the passage 60 is put in
communication with 15 so that air freely escapes from the brake cylinder allowing
the brake piston to be pressed back by a spring taking off the brakes. The
auxiliary reservoir is charged by air from the train pipe passing through a small
hole or groove in the piston 12 or a groove in the wall of the piston chamber.
Referring now to Figures 5, 6 and 7 in which parts corresponding with those in
Figures 1 and 2 are marked by similar numerals, a cavity 61 is formed between the
chamber of the valve 41 and that of the piston 63 and from this chamber there
is a passage to the chamber 54 governed by a spring loaded valve 65 and another
passage governed also by a spring loaded valve 66 to outlet ports 68. The stem of
the piston 63 bears against, but is not attached to the stem 64 which has formed on
it a collar 69 acting as a valve to prevent leakage of air around the stem 64, the
lower portion of which bears against a spring within a sleeve 67 fitted within the
tubular stem of the valve 41.
When in case of an emergency, the pressure in the train pipe is rapidly and
greatly reduced, the piston 12, as previously described, moving the slide valve 14,
causes the pressure in the auxiliary reservoir to act on the piston 63 which, being
thus moved, opens the valve 41 allowing air to pass from the train pipe by the
valve 65 and passage 16 to the brake cylinder. As the pressure of the air admitted
to the cavity 61 exceeds that due to the spring on the valve 66, that valve is opened
The amount of air pass-
allowing a portion of the air to escape by the outlets 68.
ing by the valve 65 to the brake cylinder is thus so far lessened, and the initial
pressure in the brake cylinder is correspondingly lessened.
Instead of employing valves 65 and 66 as described both the passages governed
by them may be closed, and an outlet made to the open air from the space 61 as
indicated by the dotted lines 70. Thus when the valve 41 is opened, the air which
passes from the train pipe to the space 61 freely escapes by the passage 70 and the
pressure in the train pipe is rapidly reduced so that the quick action is quickly
transmitted to the other triple valves of the train.
The general construction and action of the triple valves above described being

page_text: already known and having been set forth in the Specification to Patent No. 275
of 1888, it is to be understood that no claim is herein made except to the improve-
ments defined by the following claims, that is to say:-
Having thus particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In combination with the valves 41 and 49 the spring 55 bearing upon 49 and
operating in conjunction with a small passage such as w from the auxiliary
reservoir to the brake cylinder substantially as and for the purpose set forth.
2. In combination with the chamber of the valve 41 and the piston 63, the inter-
inediate cavity 61 provided with spring loaded valves 65 and 66, substantially as
described.
3. In combination with the chamber of the valve 41 a cavity 61 with outlet 70
substantially as and for the purpose set forth.
Dated this 28th day of December 1897.
ABEL & IMRAY,
Agents for the Applicant.