Improvements in Valves for Automatic Air-brakes for Railway Cars.
Year: 1892

page_text: Date of Application, 16th Aug., 1892-Accepted, 1st Oct., 1892
COMPLETE SPECIFICATION.
Improvements in Valves for Automatic Air-brakes for Railway Cars.
I, GEORGE ALBERT BOYDEN, of No. 2100 East Biddle Street, Baltimore,
Maryland, United States of America, 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 relates to a valve for automatic air-brakes, and has for its object
to provide for admitting air-pressure to the brake-cylinder from both the train-pipe
and the auxiliary-reservoir, thereby effecting a more powerful and also a quicker
application of each brake, and at the same time so quickly reducing the air-pressure
in the train brake-pipe adjacent to the said valves, that all the brakes of a train will
be applied at nearly the same time.
Referring to the drawings:
Figure 1 is a section of the auxiliary-reservoir and brake-cylinder with a side-
view of the new valve, and the train-pipe.
Figure 2 is a cross-section of the auxiliary-reservoir with a side view of the new
valve attached thereto, showing the passages by which communication is established
between the reservoir and the valve and brake-cylinder.
Figure 3 is a side view of the valve-piston and the parts attached thereto, as seen.
when removed from the valve-case.
Figure 4 is a longitudinal section of the new valve.
Figure 5 is a view of that end of the valve-case which is to be attached to the
auxiliary-reservoir.
In this invention I use a check-valved feed-passage leading from the train-pipe
through the triple-valve chamber, and thence both to the auxiliary-reservoir and
the brake-cylinder for the double purpose of supplying the auxiliary-reservoir with
air and also enabling train-pipe air to be vented directly through the main-valve
chamber into the brake-cylinder to aid in applying the brakes for emergency stops,
and this is done without interfering with the usual operation or functions of the
"triple-valve," and also without the aid of the auxiliary-valve heretofore
required for the purpose.
In order to accomplish this I combine in the valve-structure a passage from the
train-pipe; a passage from the auxiliary-reservoir which is more restricted than
said train-pipe passage; and a valve co-acting with both of said passages and
controlling communication between them and the brake-cylinder whereby when
applying the brakes for emergency stops, train-pipe air and auxiliary-reservoir air
will both pass to the brake-cylinder through the same valve.
:
The branch-pipe 33 from the train-pipe 34 is connected to the valve by its
nozzle, 1, and a union-nut, 2, which screws thereon. A drip-chamber, E, extends
below the valve-case to drain water therefrom and from this chamber it is drawn
off by removing the plug, 4. The cap-plate, 3, is secured to the body, 5, by suitable
bolts, 6, and the joint between is made tight by a washer.
The body-piece, 5, is provided with a cylinder, D, lined with a bushing, 8; a
large passage, A, communicating between the auxiliary-reservoir and said piston-
chamber; a valve-chamber, C, having at one end an opening lined with a brass
bushing, 9, which serves in part as a partition and separates the piston-chamber, D,
from the valve-chamber, C; a small or restricted passage, B, opens in the present
instance between the piston-chamber, D, and the valve-chamber, C, and forms a
communication through which air from the auxiliary-reservoir is admitted to the
valve-chamber and vice versa; at the opposite end of the valve-chamber is a
bushing, 10, forming a port, c, which is closed by the main-valve, 22; at this end of.

page_text: the body-piece is a passage, g, leading to the brake cylinder, and an exhaust-
passage, G, opening to the atmosphere.
It is obvious the restricted communication by which auxiliary-reservoir air flows
to the valve-chamber, C, may open directly between the auxiliary-reservoir
passage, A, and the valve-chamber, as at, B1, in dotted lines; however located
this passage is much smaller than the passage, A., between the piston-chamber, D,
and the auxiliary-reservoir.
The piston, 29, is provided with a packing-ring, 30, and moves in the cylinder, D,
according to the changes in the preponderance of the pressure on its opposite sides.
Integral with the piston is a sleeve, F, which fits and moves in the bushing, 9.
A cap, 25, is secured to the sleeve, F, by the screw, 21, which passes cross-wise
through the cap and also through a stem, 18. A bushing, 11, is fitted in an
opening at the end of the body-piece, 5; this bushing has a central passage, h, and an
annular passage, h; a release-port, i, connects said two passages, and the annular
passage has a connection with the exhaust-passage, G. A cap, 12, fits into the
bushing and a washer, 13, makes a tight joint between the cap and bushing. The
cap has a central passage conforming in size to the central passage, h, of the
bushing and is practically a continuation thereof; the release-port, i, before
mentioned, is formed where the inner end of the cap adjoins the annular passage, h¹.
In this cap is arranged an abutting piece 14, which has a limited movement by
means of a slot, j, and the pin, 15. A spring, 16, presses against the abutting-
piece, 14, and forms a resistance, in graduating, to the end of the stem, 18, and to
the movement of the piston, 29, and its attached parts.
The release-valve, 17. is secured to the valve-stem 18, by a screw, 19, which
extends into the stem and a washer that binds it. The release-valve is movable like
a piston in the central passage, ½, of the bushing, 11, and cap, 12, and opens and
closes the release port, i. The graduating-valve is formed by the valve-stem, 18,
having a passage, o, with an opening, k, at one end, a port, k', at the other end, and
with the main-valve, 22, loose on the said stem, 18.
The main-valve, 22, closes the large port, c, which leads to the brake-cylinder,
and this valve seats on the packing-rings, 23, and 24. In the present instance this
valve is wholly supported on the stem, 18; I term it a floating valve because it
may move freely on the stem.
In the piston-sleeve, F, is arranged the check-valve 26, which is held closed by a
spring, 27, the seat of the check-valve being formed by the packing-ring, 28; the
piston-sleeve has openings, o¹, which communicate with the valve-chamber, C.
As shown in Figure 1, the auxiliary-reservoir, I, is attached to the brake-
cylinder, J, in which moves the piston, L, that acts on the brake gear of the car.
The valve-body, 5, is attached to the side of the auxiliary-reservoir by studs and
nuts, 35, and the large passage, A, in the valve-body communicates with the
auxiliary-reservoir, I, through the passage, m.
It is not necessary that these parts shall be attached together in the particular
manner shown in Figure 1; they may be otherwise attached.
Communication between the valve and the brake-cylinder, J, is established
through a passage, p, in the reservoir, which communicates with the passage, 9, in
the valve-body.
It will be seen that the valve-structure here described, provides for the ready
inspection and cleansing of the parts; by simply removing the cap-plate, 3, all the
movable parts of the valve may be drawn out. No pipe connections are disturbed
and only one joint is broken.
The operation of the valve is as follows:
To charge the auxiliary-reservoir, the compressed air from the train-pipe passes
in through the nozzle, 1, and moves the valve-piston, 29, to the position shown in
Figure 4, where the graduating-valve and main-valve are closed, and the release-
valve port, i, is open; the air then opens the check-valve, 26, and passes through
the openings, o', in the sleeve, F, to the valve-chamber C, from which it passes
through the restricted passage B, into the piston-chamber, D, and thence through

page_text: the large passage, A, to the auxiliary-reservoir which will be filled to the maximum
pressure.
To apply the brakes by graduation, a slight reduction of the pressure in the train-
pipe is effected by moving the valve in the driver's cab; this reduction moves the
piston, 29, and its attached parts until the shoulder, q, on the stem, 18, comes
against the main-valve, 22, (the main-valve remaining immovable on its seat owing
to the air-pressure in the valve-chamber, C, holding it thereon); this movement
closes the release-valve port, i, and draws the graduating stem, 18, through the
main-valve, 22, sufficiently far to expose the graduating port, k', in the stem to the
air-pressure in the valve-chamber, C. The air then passes from the auxiliary-
reservoir by way of the large passage, A, and small passage, B, into the valve-
chamber, C, and then through the graduating port, k¹, passage, o, and opening, k,
in the valve-stem and the passage, g, to the brake-cylinder, where it moves the
piston, L, and partly applies the brakes.
This operation is due to the fact that the restricted communication, B, through
which the auxiliary-reservoir air enters the valve-chamber, C, is larger than the
graduating port, k², and therefore the air-pressure in the valve-chamber is kept
substantially equal to that in the auxiliary-reservoir; this pressure holds the main-
valve, 22, and the check-valve, 26, seated on their respective ports. The piston, 29,
and its attached parts will remain in the same position, to wit, with the stem-
shoulder, q, in contact with the main-valve, 22, until the pressure has been reduced
in the auxiliary-reservoir below that in the train-pipe; the greater train-pipe
pressure will then cause the piston to move to the right till the end of the valve-
stem 18, comes in contact with the spring-held abutting piece, 14, which retards
further movement. When the movable parts are in this last position the
graduating port, k', in the valve-stem, 18, is closed by having passed into the
main-valve, 22, and thus prevents any further accumulation of air-pressure in
the brake-cylinder. While in this position the valve, 17, which controls the release
of the air from the brake-cylinder has not moved sufficiently far to uncover the
release-port, i, that leads to the atmosphere, but said valve, 17, will remain directly
over this port, and thereby the pressure in the brake-cylinder is retained and exerts
the desired braking force. If it is desired to gradually increase the air-pressure in
the brake-cylinder the above operation may be repeated.
To release the brakes, the valve in the driver's cab is moved and thereby the
maximum pressure is restored in the train-pipe which, pressing on the piston, 29,
overcomes the resistance of the abutting spring, 16, and moves the piston, 29, and
its attached parts to the right to the extreme limit of their movement, as shown in
Figure 4, which causes the release-valve, 17, to uncover the port, i, and allow the
air to pass from the brake-cylinder back through the passage, g, then into the
central passage, h, around the stem, 18, through the release-port, i, to the annular
passage, h, from which it passes through the passage, G, to the atmosphere. At
the same time that the brakes are releasing, the restoration of the pressure in the
train-pipe will recharge the auxiliary-reservoir for future use.
To apply the brakes fully for an emergency stop, the train-pipe pressure is
suddenly reduced at the valve in the driver's cab, from 10 to 20 pounds, which
quickly moves the piston, 29, and its attached parts their full stroke to the left;
this will unseat the main-valve, 22, and close the release-valve port, i. By opening
the main-valve, a passage is provided from the train-pipe direct to the brake-
cylinder, through which air from the train-pipe will pass; this passage is as
follows; through the piston-sleeve, F, the check-valve, 26, and into the valve-
chamber, C, and as the main-valve, 22, is off its seat, the air will pass through
valve-port, c, directly from the train-pipe to the brake-cylinder. This operation
of the valve is due to the co-action of three momentary differential pressures
immediately after the piston, 29, has moved its full stroke to the left; these
pressures, approximately, are 70 pounds passing through the large passage, A,
from the auxiliary-reservoir acting on the piston, 29, holding it to the extreme
left of its stroke; that on the train-pipe side of the piston being from 50 to

page_text: 60 pounds, due to the reduction by the discharge at the driver's valve; and 5 pounds
in the valve-chamber, C, due to the supply thereto being restricted through the
small passage, B, and the discharge therefrom through the large port, c, being so
much greater. The 50 or 60 pounds pressure from the train-pipe will at once
lift the check-valve, 26, and pass through the openings o', to the valve-chamber, C,
and thence through the open valve-port, c, directly into the brake-cylinder,
thereby performing two functions, to wit:--partially emptying the train-pipe
which quickens the action of the triple-valve on the following car, and partially
charging the brake-cylinder with the same train-pipe air, which increases the
power or force of the brake application. After the pressure in the train-pipe
and brake-cylinder have equalized, the check-valve, 26, will close and compressed
air will continue to pass from the auxiliary-reservoir to the brake-cylinder until
there is an equalization of pressure in the auxiliary-reservoir and the brake-
cylinder.
It will thus be seen that the sudden uncovering of the main-port, c, leading toa
the brake-cylinder, by the movement of the main-valve, opens communication
between the train-pipe and brake-cylinder, and also between the auxiliary-reservoir
and the brake-cylinder and that the flow of the higher pressure air from the
auxiliary-reservoir into the brake-cylinder is retarded by being compelled to
traverse a relatively small orifice or passage while the lower pressure train-pipe..
air is permitted to flow freely through a larger orifice or passage.
In the embodiment shown in the drawing the main-valve of the triple-valve is
of the so-called "floating" form, but my invention is not limited to this form of
main-valve, nor to the particular forms of graduating and release valves shown.
My invention includes any form or structure of triple-valve wherein a single
valve of any suitable type admits both train-pipe air and auxiliary-reservoir air to
the brake-cylinder in applying the brakes for emergency stops and which structure
is provided with means for restricting or retarding the flow of auxiliary-reservoir
air to the brake-cylinder as compared with the flow of the train-pipe air thereto.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
1 claim is :-
1st. In valve-mechanism for automatic air-brakes, the combination of a passage
from the train-pipe; a passage from the auxiliary-reservoir which is smaller ora
more restricted than said train-pipe passage; and a single valve co-acting with
both of said passages and controlling communication between them and the brake-
cylinder, whereby when an emergency application of the brakes is desired,
train-pipe air and auxiliary-reservoir air will both pass to the brake-cylinder
through the same valve.
2nd. In valve-mechanism for automatic air-brakes, the combination of a com-
munication with the brake-cylinder from both the auxiliary-reservoir and train-
pipe a single valve controlling said communication; and means to retard or
restrict the flow of the auxiliary-reservoir air when applying the brakes, in
comparison with the flow of train-pipe air, whereby train-pipe air at lower pressure
than said auxiliary-reservoir air will pass said valve when making an emergency
application of the brakes.
3rd. In a valve-mechanism for automatic air-brakes, the combination with a
suitable chamber, of a port therefrom to the brake-cylinder; a valve controlling
said port; and passages to the said chamber from the train-pipe and from the
auxiliary reservoir, the latter passage being of less capacity than the former.
4th. In a valve for automatic air-brakes, the combination of a communication
with the brake-cylinder; a suitable valve controlling said communication; two
air-passages co-acting with said valve and relatively proportioned as to their
capacity to allow the flow of both train-pipe air and auxiliary-reservoir air each
at a different pressure to pass said valve when open; and a check-valve to prevent
the return of air to the train-pipe.

page_text: 5th. In a valve for automatic air-brakes, the combination of a chamber having
a port leading to a brake-cylinder; a passage opening into said chamber and
which supplies auxiliary-reservoir air thereto; a piston-chamber and piston; a
valve controlling said port and operated by the piston; and a passage from the
auxiliary-reservoir direct to said piston-chamber and avoiding the chamber first-
mentioned and which is larger or of greater capacity than the said passage which
supplies auxiliary-reservoir air.
6th. In valve-mechanism for automatic air-brakes, the combination of a main-
port communicating with a brake-cylinder from both the train-pipe and the
auxiliary-reservoir; a suitable valve controlling said main-port; a graduating-valve
which admits air-pressure in small volume to the brake-cylinder; and air-passages
co-acting with said main-port and relatively proportioned as to their capacity to
allow both train-pipe air and auxiliary-reservoir air each at a different pressure to
pass to said main-port when the latter is open.
7th. A triple-valve for automatic air-brakes having in combination, a valve to
release the air from the brake-cylinder; a piston actuated by air-pressure; a
main-port, c, leading to the brake-cylinder and located between the said release-
valve and piston; a stem having one end suitably connected with the piston and
which passes through said port and imparts movement to the said release-valve;
and a valve which is free to slide or float on said stem and open and close the said
main-port.
8th. A valve for automatic air-brakes having in combination a port, c, leading
to the brake-cylinder; a piston actuated by air-pressure; a stem having one end
suitably connected with the piston and constructed to act as a graduating valve ;
a main-valve 22 loose on said stem and which is wholly supported thereby and
opens and closes the said port leading to the brake-cylinder; and a stop-shoulder
on the stem to come in contact with the said main-valve.
9th. A valve for automatic air-brakes having in combination a port com-
municating with the brake-cylinder from both the auxiliary-reservoir and the
train-pipe; means for restricting the flow to the said port of auxiliary-reservoir
air when applying the brakes for an emergency stop as compared with the flow of
train-pipe air; a piston actuated by air-pressure; a stem having one end suitably
connected with the piston and which is provided with a small passage for the flow
of auxiliary-reservoir air to apply the brakes by graduation; and a main-valve
which is wholly supported by said stem and opens and closes the said port
communicating with the brake-cylinder and which also controls the said small
graduation passage.
Dated this 16th day of August 1892.
HERBERT J. ALLISON,
Agent for the Applicant.