Improvements in Air Brake Mechanism for Railway Vehicles.
Year: 1897

page_text: Date of Application, 6th Mar, 1897-Accepted, 28th Aug., 1897
COMPLETE SPECIFICATION.
Improvements in Air Brake Mechanism for Railway Vehicles.
I, JOHN SHOUREK of Susquehanna Street, Pittsburg, Pennsylvania, U.S.A.,
Machinist, 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 mechanism for gradually, more quickly, and very quickly
and with maximum pressure applying air brakes to arrest the momentum of a railway
train.
In the accompanying drawing Fig. 1 is a sectional view on line x-x of Fig. 2 of
the brake mechanism of this invention. Fig. 2 a section on line y-y of Fig. 1.
Fig. 3 a section on line -- of Fig 1 showing the rotary valve in the " emergency"
stop position. Fig. 4 a detail view of the rotary valve. Fig 5 a section on line 5-5
of Fig. 2. Fig. 6 a detail view of the "quick action" valve.
A is the casing of the mechanism provided with an internally threaded nipple 1
to receive one end of a train pipe of the ordinary kind. 2, 3, are the casing covers.
39 a piston chamber. 8 a piston arranged in said chamber and having its rod
extending through a suitable bearing 6 fitted in a passage formed in a projection 5
rising from the centre of the cover 2. The end of the casing A, covered by this cover 2,
is arranged adjacent to the auxiliary reservoir, in which air is maintained under
pressure, but as this reservoir is commonly used in this class of apparatus and its
construction forms no part of the invention it is not shewn. The interior of the
casing A communicates with the auxiliary reservoir through a series of ports 4,
formed in the cover 2 around the projection 5 thereon. The cover has also formed
therein a port or passage 9, through which air can pass from the casing A to the
brake cylinder, (not shewn).
The passage of air through the port 9 is controlled by the main rotary valve,
which is arranged in a valve chamber 14, that communicates with the piston
chamber 39, the valve itself being connected to, and adapted to be actuated, by the
piston rod or stem 7. As shewn, this valve consists of a body 10, cylindrical in cross
section and provided at its ends with trunnions which are mounted in suitable socket
bearings forined in the inner walls of screw covers a', by which the ends of the valve
chamber 14 are closed.
The body 10 of the valve is provided at diametrically opposite points with
projecting flanges 22, which support and actuate the other portion 21 of the valve.
This member 21 of the valve is held close against the adjacent surface of the valve
chamber 14 by means of coiled springs 23, fitted in sockets in the valve body 10
and contacting with the inner surface of the said member 21. In the outer surface or
wall of this member 21 there is formed a guideway or groove in which is fitted a
sliding plate a, having formed in its outer surface a way or groove a¹. This sliding
plate a covers a port or aperture in the body of the member 21 of the valve. In the
outer member 21 of the valve there are formed three other ports. Two of these, 16, 17,
extend directly through the body of such member and are adapted to align
with passages extending through the body 10 of the valve. The other port opens at

page_text: its inner end through one of the straight edges of the member 21, and its other end
communicates with a T shaped groove or way 18, formed in the outer surface of the
member 21. When the brakes are off and the parts are in the positions shewn in
full lines in Fig. 1, this latter port 19 (Fig. 1) is closed by a conically shaped pin or
projection 20, carried by one of the flanges 22 on the valve body 10.
The port 16 and way 18 in the valve are arranged in the same transverse plane
and are adapted to successively align with a port c, forined in the wall of the valve
chamber 14, as the valve is moved, and the way or groove a¹ in the sliding plate a is
adapted at different times to connect a port 25, formed in the wall of the valve
chamber 14, with the piston chamber 39 and with an exhaust port 24, also formed in
the wall of the valve chamber 14. The port 17 is arranged in a longitudinal plane at one
side of that of the port 16 and is adapted to communicate with one end of a short
passage or duct d when the valve has been rotated sufficiently far to cause the way
or groove a¹ to connect the piston chamber with the port 25.
The valve mechanism last described is connected with and actuated from the piston 8
as follows:-12 is a link or connecting rod, one end of which is threaded and
screwed into a suitable socket or passage in the valve body 10. The other end of
the rod 12 is bifurcated, and in such bifurcated end is pivotted one end of another
link 13, the opposite end of which is pivotally connected to the stem or. rod 7 of the
piston. It will thus be seen that there is a toggle like connection between
the piston rod and the rotary valve, and by reference to Fig. 1 it will be seen that the
piston rod is bowed or curved away from the valve somewhat to allow free movement
of the connection 12, 13.
which passes through the
This spring is adapted to
indicated in full lines in
piston rod and having its
The stem 7 of the piston extends through a sleeve 6,
cover plate 2, and about which is fitted a coiled spring 61.
normally hold the piston rod and piston in the positions
Fig. 1, a cap 7' being secured on the upper end of the
underface or surface in contact with the upper end of said spring.
Between the piston chamber or compartment and the train pipe inlet is interposed
a quick action valve 28. This valve, which is preferably of the cross sectional form
shewn in Fig. 1, is arranged in a suitable chamber 37, that communicates with the
inlet 1 through a short passage 38. The valve is somewhat shorter than the length
of the chamber 37 and is normally held in the position shewn in full lines in Fig. 2,
by means of a coiled spring 43, which is arranged within a socket formed in one of
the detachable heads or caps 44, by which the ends of the chamber 37 are closed.
The valve is prevented from turning by means of a pin 35, extending through the
wall of the chamber 37 and projecting into a longitudinal groove 35 formed in the
valve. The valve consists of two heads 30, 31, and a connecting member having a
concave face on the side adjacent to the passage 38. In the connecting member,
which, as shewn in Fig. 1, is substantially crescent shape in cross section, and at a
point relatively near the head 31 there is formed a port 33, adapted, when the valve
is forced into such position as to compress the spring 43, to connect the passage 38
and inlet 1 from the train pipe with a duct 29; formed in the casing A between the
piston chamber and the valve chamber 37. The other end of the duct 29, which is
normally closed by a puppet valve 27, opens into a channel or passage 26, formed in
the casing A adjacent to the cover 2. This passage 26 serves also to connect the
ports c and 25 in the wall of the valve chamber 14 with the port 9 in the cover
plate 2.
The puppet valve 27 is normally maintained in its closed position by a
coiled spring 27¹.
The piston chamber 39 is connected with the valve chamber 37 through a duct or
passage 40, and the two valve chambers 14 and 37 are connected by a duct or passage
41, leading from the duct d, before described, to and communicating with one end
of a duct or passage 42, the other end of which opens into the chamber 37 near the
end opposite to the coiled spring 43.
45 is a spring pressed puppet valve adapted to close a passage or duct provided at
its ends with branches 47, 48, that communicate at their inner ends with the piston
compartment or chamber. Gaskets are arranged between the caps and the body of

page_text: the casing A and between the cover 2 and the auxiliary reservoir for the purpose of
maintaining air tight joints between the parts.
When the brakes are off and the parts of the apparatus occupy the positions shewn
in full lines in Figs. 1 and 2, the pressure from the train pipe on one side of the
piston and from the auxiliary reservoir on the other side thereof are equal, and the
tension of the spring arranged between the sleeve 6 and inner wall of the passage in
the projection 5 holds the piston and rotary valve in such position that the ports of
the latter are all closed, and the groove or way a¹ in the sliding plate a of the valve
connects the port 25 with the exhaust port 24, so that the air in the brake cylinder
is exhausted into the atmosphere. The spring 43 holds the valve 28 in such position
as to maintain the port 33 thereof out of line with the air inlet, 1, and the spring 27¹
is sufficient to hold the puppet valve closed and prevent the passage of air from the
train pipe to the brake cylinder. When it is desired to apply the brakes slowly and
gradually, the engineer reduces slightly, by opening a suitable valve, the pressure in
the train pipe. Instantly the pressure on the piston from the auxiliary reservoir,
which is now greater than that on the other side, causes the piston to move towards
the position shewn in dotted lines in Fig. 1. This causes the valve body, 10 to rotate
slightly, the first action being to cause the sliding plate , which, as shewn, rests on
the flange 22 farther from the piston, to move sufficiently to bring the solid part
thereof across the exhaust port and break the connection between such port and the
port 25.
Simultaneously with this movement of the sliding piece the conical
shaped pin 20, carried by the other page 22 of the valve, is withdrawn from its port,
and such port being in line with the opening between the valve chamber 14 and the
piston chainber, air from the auxiliary reservoir and piston chamber can pass through the
same into the way 18, which aligns with the port c, and from there through the port 9
into the brake cylinder. The air will continue to pass from the auxiliary reservoir
to the brake cylinder in the manner just described, until the pressure exerted by the
air in the piston chamber and the reservoir on the piston is less than that exerted
by the train pipe, when the piston will be returned to its normal position. If,
however, the pressure in the train pipe is reduced to a somewhat greater extent than
is necessary to open the port normally closed by the pin 20, the piston will be
moved correspondingly farther from its normal position and the valve in the chamber '14
rotated a correspondingly greater distance. As the valve body 10 rotates the
flange 22 thereof, which, as above described, serves to move the sliding member a
towards the piston, comes in contact with the adjacent straight side or surface of the
member 21 of the valve and as it continues to move brings the port 16 into
alignment with the port c and allows a greater amount of air to pass from the
auxiliary reservoir to the brake cylinder, and the brakes will be applied inore suddenly
than when the air passes through the port controlled by the pin 20.
If the pressure in the train pipe is suddenly and materially reduced, the piston
will be instantly forced into the position indicated by dotted lines. This movement
of the piston imparts a correspondingly increased movement of the valve in the
chambe: 14. That is, said valve is rotated to such an extent that the port 17 therein
aligns with the duct d and the way or groove a¹ in the sliding member a of the valve
connects the port 25 with the piston chamber and the auxiliary reservoir, thus
allowing or providing a relatively large passage from the auxiliary reservoir to the
brake cylinder. As soon as the port 17 aligns with the duct d and establishes
communication between the piston chamber and the passages 41, 42, the quick
action valve 28 is moved into the position indicated by dotted lines in Fig. 2,
compressing the spring 43 in its socket and bringing the large port 33 into line with
the inlet 1 and the passage 29. The pressure of the air in the train pipe when the
parts are in this position sufficient to raise the valve 27 and establish communica-
tion between the train pipe and the brake cylinder through the passages 29 and 26
and the port 9.
It will thus be seen that the pressure of the air is utilised in the auxiliary reservoir
to positively open the valve controlling the passage direct from the train pipe to the
brake cylinder, and when the parts are in the positions last described the entire

page_text: pressure of both the reservoir and the train pipe will be exerted on the piston in the
brake cylinder, thereby causing an instant setting of the brakes.
When the brakes have been set and the pressure in the brake cylinder and passage 26
equals that in the train pipe, the valve 27 is closed and the spring 43 returns the
valve 28 to the position shewn in full lines in Fig. 2. Air from the train pipe then
passes through the passage 40, the controlling valve in the train pipe having been
previously closed, into the piston chamber 39 and forces the same toward the full
line position in Fig. 1. The instant such movement begins, the flange 22, adjacent
to the piston of the valve in the chamber 14, moves the sliding piece a sufficiently
to prevent the passage of air from the auxiliary reservoir and piston chamber through
the groove or way a¹, and as the movement continues, said groove or way again
connects the ports 24, 25. After the piston has moved sufficient distance to carry
the groove a entirely into the valve chamber 14, it passes and exposes the inner
end of the passage 48. Air can then pass from the piston chamber 39 on the side of
the piston adjacent the passage 40 through the passage 48, 47, lifting the valve 45,
into the piston chamber and the auxiliary reservoir on the opposite side of the piston
head. By the time the piston has reached the full line position of Fig. 1. the pressure
on opposite sides of the piston head is equal, and the ports in the main rotary valve
are all closed.
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 I claim is :-
1. In an air brake mechanism, the combination with a train pipe, a brake cylinder,
and an auxiliary reservoir, of a piston chamber communicating with the train pipe
and with the auxiliary reservoir, a piston arranged in said chamber, a valve chamber
having a port 25 communicating with the brake cylinder and an exhaust port, a
rotary valve arranged in said chamber and having a sliding member provided with a
groove or way adapted to connect the port 25 with the piston chamber and the
auxiliary reservoir or with the exhaust port, and connections between the piston and
the valve substantially as described and shewn.
2. In an air brake mechanism, the combination with a train pipe, an auxiliary
reservoir, and a brake cylinder, of a rotary controlling valve consisting of a body
portion having laterally projecting flanges on opposite sides thereof, and another
member, fitted between said body and the wall of the valve chamber and adapted to
be moved by the flanges on the body, substantially as described and shewn.
3. A valve for an air brake mechanism consisting of a rotary body having laterally
projecting flanges on opposite sides thereof, and another member partially surrounding
the rotary body and adapted to be moved by the flanges thereon, said rotary body
being adapted to have a limited movement independent of the other member, and
the latter having formed therein a port adapted to be closed by one of the flanges on
the rotary body, substantially as described and shewn.
4. A valve for an air brake mechanism consisting of a rotary body 10, having
laterally projecting flanges on opposite sides thereof, another member, 21, partially
surrounding the rotary body and adapted to be moved by the flanges thereon, and a
sliding plate fitted in a way in the member 21 and having its ends in contact with
both of the flanges on the body 10 and a passage or groove formed in its outer face,
substantially as described and shewn.
5. The general arrangement and combination of parts constituting the air brake
mechanism substantially as described and shewn.
Datad this fith day of March 1897
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C., Agent for the Applicant.