Year: 1889

page_text: We, DAVID WILLIAMSON FLICK WIR and JOSEPH HOOK SANDS both residing at the
Corner of Mountain and Wilson Streets in the City of Roanoke, in the County of
Roanoke and State of Virginia, one of the United States of America, and NATHANIEL
JOHNSON PRITCHARD, residing at the Corner of Salem Avenue and Jefferson Streets,
in the abovenamed city, county, state and country Gentlemen, 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-
Our invention relates to improvements in Pneumatic Railway Brakes, and par-
ticularly to the devices used in applying the pneumatic pressure to the brakes, its
particular and preferred purpose and use being that of controlling and regulating the
admission of air to the brake cylinder, and the invention consists essentially in the
construction, arrangement and combination of parts substantially as will be hereinafter
described and claimed.
In the accompanying drawings illustrating our invention.
Figure 1 is a vertical section of our improved device for applying pressure
to pneumatic railway brakes and shows the piston at the upper limit of its stroke.
Figure 2 is a horizontal section on the line of Figure 1.
Figure 3 is a similar vertical section to that shown in Figure 1 with the piston
occupying its lowermost position, or the position taken when the greatest amount of
air is being introduced into the brake cylinder.
Figure 4 is an enlarged perspective view of the semi-cylindrical exhaust
valve.
Figure 5 is a sectional detail showing the relative position of the piston rod and its
discs, the semi-cylindrical ring with its ports, and the port leading to the brake
cylinder when a certain fixed amount of pressure is upon the brakes and is held there
with the port closed against the entrance of more air.
Figure 6 is a similar sectional detail showing the arrangement of the same parts
when air is permitted to pass through the ports and passages of the semi-cylindrical
ring and onward into the brake cylinder.

page_text: Figure 7 is a vertical section of a modified form of our improved device for
applying pressure to pneumatic railway brakes and shows the piston valve at the
upper limit of its stroke.
Figure 8 is a horizontal section on the line y y of Figure 7.
Figure 9 is a vertical section similar to that shown in Figure 7 with the
piston valve occupying the position where air is permitted to pass into the brake
cylinder.
Figure 10 is a perspective view of the double ended piston valve together with the
graduated or regulated piston used in this modified form of our invention.
Figure 11 is a detail view showing in perspective the exhaust valve used with the
piston just mentioned.
Figure 12 is a vertical section of a still further modification of our improved
automatic air piston for pneumatic railway brakes and shows the piston at the upper
limit of its stroke.
Figure 13 is a horizontal section on the line of Figure 12.
Figure 14 is a vertical section similar to that shown in Figure 12 with the piston
at the lower limit of its stroke.
Figure 15 is a detail elevation of the air supply pipe and the pipe which leads
to the brake cylinder, together with the other connections of this modification.
Figure 16 is a sectional detail of certain of the air pipes and shows the arrange-
ment of the plug valve when this modified form of the device is to be used with
straight air.
Similar letters of reference designate corresponding parts throughout the different
figures.
A denotes a cylinder of any suitable dimensions and made in any desired manner,
it being preferably adapted to be arranged in an upright position beneath the car or
other vehicle with which it is used. Itinay be made in one or more parts as preferred.
In the drawings a convenient construction is shown, consisting of the main cylin-
drical body, upon the top of which is a cap plate A¹ securely bolted thereto and
formed centrally with a short tubular box o, to receive the upper end of the piston-rod
and thus guide the same during the movements of the piston. The lower end of the
main cylindrical body is closed by means of a plate securely fastened over it and
carrying a bulb-shaped air chamber B, which is adapted to receive at its bottom any
drippings or other waste that may accumulate therein, whence they are removable
through a drain-cock a. The cylinder A is provided with ports at points where the
several pipes are coupled, that are used with the ordinary air brake and lead to the
. essential parts of the same. Thus C denotes a port where a coupling is made with
the pipe that leads to the air drum or auxiliary cylinder; D is the port where the
pipe is connected leading to the brake-cylinder; E is a port suited in the wall of the
bulb B, at a point where it is entered by pipe F that leads to the main air supply pipe,
and through said pipe Fair is introduced into the device. At port D is connected
a T-shaped pipe, having a horizontal portion extending outward from the cylinder A,
at right angles to which portion is another horizontal part H, a plug valve H¹ being
located at the junction of these two horizontal parts. This valve will be ordinarily
turned in the position shown in Figure 2, where the air may pass in one direction or
the other between the port D and the pipe I, leading to the brake-cylinder and
coupled to one end of the pipe H. A short distance below the port D in the wall of
the main body A, is located an exhaust port e. Through this exhaust port the air from
the brake-cylinder will have free egress when the brakes are relieved. A vertical
passage extends upward through the wall of the cylinder A, to the port C said
passage e having a communication near the bottom of the cylinder by port d with the
interior of the cylinder A. Through the port d, air coming under pressure from
the main supply pipe will pass into the passage c on its way to the air drum.
Within the central chamber of the device is located a suitable construction piston J
adapted to move vertically. To the piston J is connected a vertical piston-rod G.
whose upper end is received into the tubular box above mentioned. The piston J
is located near the bottom of the cylinder A and reciprocates within narrow limits in

page_text: that portion of the cylinder, the upper limit of its movement being shown in Figure 1.
and its lowermost position being shown in Figure 3. The piston-rod G is provided
with two flat circular plates or disks secured horizontally thereto, at a suitable distance
apart and at proper points in the length of the rod; the upper of these plates being
denoted by L and the lower by K. Between these two horizontal plates K and L, is
located a semi-cylindrical or semi-annular valve M. It is shown in perspective in
Figure 4. It has a semi-circular groove along one side which receives the piston-
rod. It has a radius of sufficient length to enable it to be situated closely between
the wall of the main body A and the piston-rod, although the fitting is loose enough
to enable the said ring M to have free movement up and down. A semi-ring is, used
instead of a complete ring in order to make the device cheaper and lighter, and for
the purpose of its construction it will serve equally well with a completely annular
ring. This valve M may vary in size, structure and shape without departing from the
spirit of our invention. Its vertical length is shorter than the vertical length of the
annular space between the plates K and L within which it is contained, as will be
evident upon inspection of the figures of the drawing. Hence it will be perceived
that the piston with its piston rod, and consequently the plates or discs K and L,
may have a certain amount of vertical movement without displacing the valve M from
its position. Said valve M is furthermore provided with a vertical groove g in its
outer surface, into which groove projects a screw or pin fixed in the wall of
the cylinder A. By means of this pin entering the groove g, the valve M may move
vertically without being susceptible of any rotary displacement. Also the valve is
recessed on its outer face at m as also at m². The recess m is cut out for a portion of
the circumferential distance of the valve, and is of sufficient size, so that when the
valve is adjacent to the ports D and e, as shown in Figure 1, they may be connected,
thus allowing the air to be exhausted from the brake-cylinder.
The under or bottom surface of the valve is provided with a port at 61, and the
outer surface of the valve is furnished with another port at 62, in the recess m¹. The
ports and 2 are connected by a passage b, running through the material of the
valve. The direction of this passage is of course un-important, but for convenience
in construction it preferably partakes of that direction shown in the drawing, where
it runs vertically and then horizontally. The port is adapted to be closed by the
disk or plate K. Said port has a packing of suitable material such as leather, gum,
rubber, or other suitable substance, so that a tight joint may be effected. The port 6³
is adapted to come into coincidence with the port D, during the upward and down-
ward movements of the valve Doubtless the construction of the valve may vary as
experience dictates, but it is thought that the general outline of this construction as
indicated herein will suffice to explain and define the essential features of this structure
and the main purposes of its use.
The operation of the device herein described, is as follows: Suppose the piston
to be in the position shown in Figure where it is at its uppermost limit. The
semi-ring now rests upon the lower plate K, the port being closed. It may be
noted in this connection that as the piston moves upward, the disk K, pressing on
the packing ring, pushes it up. As the piston moves downward, the disk L being in
contact with the ring M, assists it to descend. In Figure 1 air is entering the device
through the pipe F, passing upward beneath the piston J, thence out through port d
and along passage c into port and into the air drum. The pressure of the in-coming
air is sufficient to uphold the piston and its connections.
Suppose now that it is desired to set the brakes. The engineer will determine the
amount of pressure which he desires to apply to the brakes and adjust his regulating
valve accordingly. Whether a greater or less pressure is needed will, of necessity,
depend upon the circumstances of the case. The proper manipulation of the engineer's
valve will exhaust air from beneath the piston J, so that the said pressure beneath
the piston will be less than the pressure above it. Consequently the piston will
begin to descend, thus causing the disk to come in contact with the valve M, and
the disk K to be removed from the position on where it closes the port b
As the
piston continues its descent, the valve will be pushed downwards until at length the

page_text: port b² in said valve M, will come in coincidence with the port D in the manner shown
in Figure 6. Air will now begin to pass through the port 6' and upward through
the valve, then out through port 6' into port D and onward to the brake cylinder,
where it will act to set the brakes. The continued outflow of air to the brake cylinder
will in a short time cause the air pressure in the air drum and above the main
piston J, to be less than the air pressure beneath the piston, it being remembered
that the port d is now closed so that the air in the air drum is not subject to increase
at this time. The result of this inequality of pressure on the upper and lower faces
of the piston will be to cause the latter to adjust itself slightly; hence it will ascend
a little, just sufficient to close the port and prevent the outflow of any more air,
although the movement of the piston will not be sufficient to displace the valve from
position. The relation of the parts at this time is clearly shown in Figure 5, where
the disk K is covering the port ', and excluding any more air from entering it.
The brakes are now set with a certain pressure of air and this pressure of air will be
maintained steady and constant until the engineer wishes to change the condition of
things and again manipulate his valve. By the use therefore of this valve,
constructed as described, and so related to the other parts of the invention as we
have indicated it, the amount of air which is admitted to the brake cylinder may be
graduated, regulated and governed completely, so that the engineer is enabled to
set the brakes at a certain desired pressure and keep them at this pressure until ho
wishes to release them.
When the engineer desires to relieve the brakes enough air will be admitted below
the piston J, to drive it upward, causing it to resume the position shown in Figure 1
where the recess m in the valve, connects the port D and the exhaust e. Egress of
air in the brake cylinder can now easily take place by passing in the direction of
the arrow shown in Figure 1, through ports D and exhaust e.
When the engineer wishes to apply to the brakes the full amount of pressure of
which his apparatus is capable he will exhaust enough air from below the piston J to
compel it to assume its lowermost position, as shown in Figure 3. In this position
the air will not pass through the valve but will rush directly-as shown by the
arrows from the interior of the cylindrical body A, through port D to the brake-
cylinder.
In Figures 7, 8, 9, 10, and 11, we have shown a modification in the construction
of our device. A² denotes a cylinder, similarly constructed to the cylinder A above
described and having a cap plate A³, provided with a cylindrical extension P which
projects downward for a certain distance into the chamber within the main body A².
The wall of the cylindrical extension P is provided near its lower edge with a series
of apertures or orifices p. It is also furnished at a suitable point adjacent to the
cap plate A3, with a small port q. The cylinder A2 is provided with ports at points
where the several pipes are coupled that are used with ordinary air brake and lead
to the essential parts of the saine. Thus denotes the port where a coupling is
made with the pipe which leads to the auxiliary reservoir; D' is the port where the
pipe is connected leading to the brake cylinder; E' is the port located in the side
wall of the bulb at a point where it is entered by the main supply pipe. At port D'
is connected a T-shaped pipe having a horizontal portion extending outward from
the cylinder A², at the right angles to which portion is another horizontal portion,
a plug valve being located at the intersection of these two parts, which may be
turned into the position shown in Figure 8, where air will pass in one direction or
the other between the port D¹ and the pipe which leads to the brake cylinder. A
short distance below the port D' in the wall of the main body A² is located an
exhaust port el. A vertical passage extends upward through the wall of the
cylinder A from the bottom of the said cylinder to port C₁ near the top of the
cylinder A. Connection is established between the interior thereof and the passage c
by means of the port d, through which air coming under pressure from the main
supply pipe, may pass to the air drum. Near the center of the cap plate A3 a
port opens centrally into the cylindrical extension P and communicates with the
passage running horizontally through the cap plate and then through the wall of

page_text: body A until it reaches the port D¹.
Within the central chamber of the device is
located a suitably constructed piston. It is preferably made in the form of a double
ended piston; having the lower head L and the upper head M', said heads or ends
being connected by rods K' K. The head M' is flanged circumferentially at top
and bottom or otherwise suitably fashioned and shaped to afford an annular recess
capable of receiving an encircling annular ring N, made in two parts as shown in
Figure 11, to permit its easy adjustment, said ring serving as an exhaust valve. The
ring Nis loosely arranged around the piston end M¹. Said ring is recessed at n
for a portion of its circumferential distance, said recessed portion being situated
near the ports D1 and e¹, and being of sufficient size to connect said ports whenever
the position of the piston and consequently of the exhaust valve is such as to
permit of this connection. The vertical length of the exhaust valve is shorter than
the vertical length of the annular space within which it is contained, (see Figures 7,
8, and 9), hence it will be noted that the piston may have a certain amount of
vertical movement without displacing the valve from its position, for a purpose to be
hereinafter explained. The head M₁, of the piston is furthermore constructed in the
form of a cylinder to make it lighter and afford more space for air within the chamber
of the main body. The piston just described may vary considerably in the details
of its structure without departing from our invention. We have aimed herein to
give a general description of it without being confined to details. It has a vertical
movement up and down within the central chamber and in said movement it comes
into proper relation with the several ports and passages hereinabove mentioned, to
accomplish the results which will be further on more specifically stated.
It becomes necessary however in order to make our device practically and effectively
operative, to provide means whereby the amount of air which is admitted to brako
cylinder may be graduated, regulated and governed, so that the engineer may be
enabled to set the brakes at a certain desired pressure and keep them at this pressure
until he wishes to release them. By the use of the piston alone just described good
results may be accomplished in applying brakes, but the engineer cannot, without
an auxiliary device, automatically measure and maintain any desired amount of
pressure upon the brakes. In order to do this we provide a graduating piston, Q,
working within the cylindrical extension, P, and adapted to open and close the port q.
A piston rod Q, is connected to the piston, Q, and extends vertically downward,
passing through a central opening in the head, M, of the piston and provided-on its
end with an adjustable nut, Q. When the piston descends from its uppermost
position the piston end, M', will strike the nut, Q, and cause the piston, Q, to descend
likewise for a short distance.
Air
It remains to describe the operation of this modification shown in Figures 7, 8, 9, 10,
and 11. When the main piston occupies its uppermost position as seen in Figure 7,
air can easily pass from the brake cylinder through port, D¹, and around through the
recess n', into the exhaust, e', where it will escape into the atmosphere. Air coming
under pressure through the main air supply pipe will enter the air chamber, pass up
underneath the piston, then through the port, d, and passage c', to the air drum.
will likewise under the same pressure be upon the top or upper end of the piston since it
will pass through the apertures, p, in the cylindrical part, P. Likewise the air will
bear upon the piston, Q, holding it in its uppermost position so that the ports, g, and J',
will be closed. Suppose now that it is desired to set the brakes. The engineer will
determine the amount of pressure which he desires to apply to the brakes and adjust
his regulating valve accordingly. Whether a great or less pressure is desired will of
course depend upon the circumstances of each case. The proper manipulation of the
engineer's valve would exhaust air from beneath the main piston, so that said pressure
beneath will be less than the pressure above it. The piston in consequence will begin
to descend. In the course of this descent the piston end, M', will strike the nut, Q,
and draw down the piston, Q, opening port y. An outlet is thus at once afforded for
the air pressure above the main piston; hence the main piston will cease its further
downward movement, while the air above it is rushing through the small port, g, into
the space above the piston, Q, and thence through port, J, passage f¹ and on into the

page_text: brake cylinder. The continued outflow of air through the small port, 7, will in a
short time cause the air pressure in the air drum and above the main piston to be
less than the air pressure beneath the main piston. The result of these inequalities
of pressure from the upper and lower end of the main piston will be to cause the
latter to adjust itself slightly; hence it will ascend a little but not enough to
displace the valve, 'N', from the position shown in Figure 9, where the port, D¹,
is closed.
It has already been stated that the main piston is permitted a certain range of
movement without interfering with or compelling a change of position of the
valve, N¹.
After the main piston has risen to the slight extent just referred to it
will be evident that the piston end, M¹, will no longer be in contact with the
nut, Q, and hence the piston Q, will have its position regulated by the air pressure
above and below it. The air pressure above the piston, Q, will be less than the air
pressure below it, because this pressure below is the same as that in the air drum,
and since the port q is very small, a sufficient amount of air will not have passed
through said port to the brake cylinder in the short interval which has elapsed
since it began to flow through said port, to make the pressure above the piston, Q,
counterbalance the pressure below it. It is therefore clear that the upward pressure
on the piston, Q, will lift the same and close the port, q, thus leaving a constant
pressure applied to the brakes. The present position of all the parts will now be
maintained until the engineer releases the brakes. If he has applied a ten pound
pressure to his brakes, the graduating piston acting in conjunction with the main
piston in the manner just explained will cause the ten pound pressure, after it has
been placed upon the brakes, to be maintained. Similarly with a fifteen pound or
thirty pound pressure according as the engineer may have adjusted his valve
for the one or the other. When it is desired to relieve the brakes, air will be admitted
below the main piston, driving the same upward into the position shown in Figure 7,
where the valve, N', connects ports, D', and e¹, and enables an outflow of air from the
brake cylinder through the exhaust.
In Figures, 12, 13, 14, 15, and 16 we have illustrated a still further modification of
our improved automatic device for applying pressure to pneumatic railway brakes.
In this modification A* denotes a cylinder constructed similarly to the cylinder A, and
the cylinder, A2, above described. The cylinder, A', has upon the top a cap plate, A,
having an interior downward projection r. The bottom of the cylinder A4, is closed
by a plate carrying a bulb shaped air chamber. The cylinder A4, similarly to
cylinders A, and A2, is provided with a port, C2, leading to the air drum, a port, D²,
leading to the brake cylinder, and a port, E2, where the main supply pipo is coupled.
At port, D2, is connected a T-shaped pipe arranged in substantially the same manner
as the pipe shown in Figures 7, 8 and 9. In the wall of the cylinder, A', below the
port D, is located the exhaust, e². A vertical passage, c², extends through the wall
of the cylinder from the bottom thereof through port, C², communication being
established between said passago and the interior chamber of the cylinder near the
bottom thereof by a port, d². Within the central chamber is located a piston, R,
which is preferably a double piston having the lower head, S, and the upper head, T.
The head, T, is flanged circumferentially at top and bottom, or otherwise suitably
fashioned and shaped to permit an encircling ring U, to be loosely arranged about the
same, said ring being recessed for a portion of its circumferential distance. See
Figure, 12 and 13. When the piston occupies its uppermost position, during its
vertical reciprocations (see Figure 12) air can easily pass from the brake cylinder
through the pipe into port, D, and around past the recessed face of the encircling
ring, U, into the exhaust port, e, where it will escape into the atmosphere. When
the piston is in its lowermost position as shown in Figure 14, air will pass through
port, C², from the air drum into the interior chamber and out through port, D2, into
the brake cylinder where it will set the brakes.
It is unnecessary in connection with this modification to explain the general
movements of the air currents, as the general structure of the cylinder and ports,
is the same as has already been stated. Suppose now that it is desired to set the

page_text: brakes. If straight air is to be used all that need be done is to have the plug valve
located within the T-shaped pipe arranged as shown in Figure 16, then the engineer
by manipulating the valve upon the locomotive will cause air to rush through the
supply pipe, as shown by the arrow (Figure 16) onward into the pipe which carries it
to the brake cylinder. When automatic air is to be used the plug valve will be turned
to оссиру the position shown in Figure 13. If it is desired to set the brakes
automatically, the engineer will exhaust air by properly manipulating his valve so
that there will be less pressure beneath the piston than there is above it. This will
cause the piston to descend until it reaches the position shown in Figure 14, where it
has passed so low as to cease to cover port, D². Hence air coming under pressure
from the air drum into the chamber above the piston, will pass out through the
port, D, and rush into the brake cylinder and set the brakes.
It will be noticed that
the encircling ring which is loosely arranged about the head, T, of the piston, enables
our device to be susceptible of great delicacy of movement, for, suppose the piston to
be in the position shown in Figure 12; the exhausting of a small amount of air from
beneath it will cause it to drop to cover the port, d². A fall of the piston far enough
to enable the head, S, to cover the port, d², will not displace the ring, U, from its
position, as it will be seen there is sufficient space between the ring, U, and the
encompassing flange of the head to permit this movement. It will be noted that the
vertical length of this ring, U, is shorter or less than the vertical length of the annular
space within which it is contained, hence it is evident that the piston may have a
certain amount of vertical movement independent of any corresponding movement on
the part of the packing ring. This ring therefore enables the device to be susceptible
of a delicate movement. It is evident that the exhausting of a very small amount of
air from beneath the piston will cause it to drop far enough to cover the port, d².
The piston in falling in this manner however will not displace the packing ring as the
difference in vertical length between the packing ring and the annular space within
the piston head is sufficient to permit of enough movement on the part of the piston
to close port, , without interfering with the position of the packing ring. In
Figure 12, the parts are shown in the position occupied when air is passing out of the
brake cylinder through the exhaust on the one hand and air on the other hand is
entering through the main pipe into the air chamber and up into the air drum. The
engineer by exhausting a very small portion of air from beneath the piston can close
the port 2, in the manner just stated and yet will not interfere with the position of
the ring which connects ports, D, and e
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In a device for applying and relieving the pressure on railway brakes, the
combination with an enclosing case provided with properly arranged ports, of a
piston within the case, its piston-rod provided with circular plates or disks, and the
valve ring having suitable ports and passages and located between the disks, all
arranged and operated substantially as described.
2. In a device for applying and relieving the pressure on railway brakes, the
enclosing case having ports leading to the air drum, main pipe and brake-cylinder,
in combination with the piston, the disk provided piston rod, and the valve ring
located between the disks and having suitable ports and recesses to enable it to
operate in conjunction with the other parts, substantially as and for the purposes
described.
3. In a device for applying and relieving the air pressure on pneumatic railway
brakes, a piston rod having two disks, a semi-packing ring loosely between these
disks and constructed substantially as described, in combination with a cylindrical
case surrounding these parts, as set forth.
4. The combination with a cylindrical case having suitably arranged ports, the
piston, its piston-rod having two disks, the semi-packing ring between the disks

page_text: having a vertical length less than the distance between the disk and provided with
ports and passages, substantially as described.
5. The combination with the cylindrical case, the piston, and disk-provided piston
rod, of the semi-ring, M, having recess, in, ports, 6 and, 62, and passage b, connecting
these ports, substantially as described.
6. The combination with an enclosing case, of the piston, J, its piston-rod, G,
having disks, K, and L, the valve, M, located loosely between said disks as shown
having ports, and 62, air passage b and recess m, all operating substantially as
described..
7. In a device for applying and relieving the air pressure to air brakes, a
cylindrical case, A, having suitable ports and air passages, and a piston, J, within
the same, having the piston-rod, G, carrying the circular disks, K, and L, in
combination with a semi-packing ring, M, between the disks, having ports, 61 and 62,
circumferential recess, m, a vertical groove g, for receiving a pin, on the case, A,
substantially as described.
8. The case, A, having cap plate, A¹, formed with tubular box, o, and having also
ports, C, D, and E, in combination with the piston, J, the disk-provided piston rod,
and the semi-ring, substantially as described.
9. The combination with the cylindrical case, having cap-plate, A¹, formed with a
tubular, box, o, the piston, J, piston-rod, G, the upper end of which enters the
tubular box, the disks, K, L, on the piston-rod and the semi-ring loosely arranged
between the disks, substantially as described.
10. The combination with the case, A, having port, C, leading to the air drum,
port, D, leading to the brake cylinder, an air supply port, E, and also exhaust, e, of
the piston, J, having piston-rod, G, carrying disks, K, and L, and the semi-ring
having ports, b, and 62, and recess, m, substantially as described.
11. In combination with a cylindrical case having suitably arranged ports, a semi-
ring, M, having ports, b₁ and b², connecting air passage b, recess, m, recess m¹, a
vertical groove g together with a properly arranged piston within the case, substantially
as described.
12. In a device for applying and relieving the pressure on pneumatic railway
brakes, the combination of the enclosing case having ports leading to the air drum,
main pipe and brake cylinder, an exhaust port and a vertical passage extending
upward through the wall of the cylinder to the port that leads to the air drum, said
passage having communication near the bottom of the cylinder by a port with the
interior of the cylinder, the cap plate for the cylinder provided with a downwardly
extending tubular box, the piston and its piston-rod, the upper end of which is
received into said tubular box, the two flat circular plates or discs secured upon said
piston-rod, the valve located between said plates and consisting of a semi-cylindrical
piece of metal having a port in the bottom and a port in the side, which ports are
connected by an air passage, the opening to the lower or bottom port being controlled
by the flat plate beneath it, all the parts being arranged to operate substantially as
and for the purposes herein described.
13. In a device for applying and relieving pneumatic pressure on railway brakes,
the combination of the main cylindrical case, A, having the port, C, leading to the air
drum, port, D, leading to the brake cylinder, port, E, leading to the main air supply pipe,
an exhaust port, e, and a vertical passage, c, extending upward through the wall of the
cylinder to the port C, said passage c, communicating by port, d, with the interior of the
cylinder, A, the cap plate, A¹ for the main body, A, provided with a downwardly projecting
tubular box, o, the piston, J, and its piston-rod, G, whose upper end enters the tubular
box, o, the two flat circular plates K, and L, secured upon the piston-rod, the valve, M,
located between said plates. or discs. and having a bottom port 61, a lateral port, b²,
and a connecting passage b, between said ports, the port, 61, being adapted to be
closed or opened by the disc or plate, K, all the parts being arranged for joint
operation, substantially as described and for the purpose specified.
14. In an automatic device for applying and relieving the pressure on railway

page_text: brakes, the combination with an enclosing case, provided with properly arranged
ports, of the main double-ended piston and the auxiliary graduating piston, both
located and operating within said case, substantially as and for the purpose
described.
15. In a device for applying and relieving the pressure on railway brakes, the
combination of the enclosing case having ports leading to the air drum, main pipe
and brake-cylinder, the double ended piston located within said case, the valve
surrounding the upper end of the piston in the manner specified, and the graduating
piston, all parts being combined and arranged for joint operation, substantially as
described.
16. In a device for applying and relieving the air pressure to pneumatic railway
brakes, the combination of the cylindrical enclosing case having ports leading to the
air drum, main pipe and brake cylinder, suitable air passages as specified and also an
exhaust port, the cap plate for said enclosing case having a downwardly projecting
cylindrical extension provided with a port and apertures, the main double ended
piston operating within the enclosing case, and the graduating piston working within
the cylindrical extension on the cap plate,jall substantially as described and for the
purpose set forth.
17. In a device for applying and relieving the air pressure to air brakes, the
enclosing case provided with properly arranged ports as specified, in combination with
the main double ended piston, its surrounding valve, and the graduating piston having
its piston rod connected to and actuated by the inain piston, substantially in the
manner and for the purpose set forth.
18. The combination of the enclosing case having ports leading to the air drum,
main pipe and brake cylinder, together with connecting passages and exhaust ports,
the cap plate for said case having a downwardly projecting cylindrical extension
furnished with a small port and other apertures, the main double ended piston
carrying a valve arranged relatively thereto as described, the graduating piston
working in the cylindrical extension on the cap plate and having its piston-rod
connected to and adapted to be actuated by the main piston, all substantially in the
manner and for the purposes herein before described.
19. In an automatic device for applying and relieving the air pressure to air
brakes, a piston having two heads, the upper of which has a loosely encircling ring, in
combination with an enclosing case provided with properly arranged ports leading to
the air drum, main pipe and brake cylinder, substantially as described.
20. In an automatic device for applying and relieving the air pressure to air brakes,
the combination with a cylinder having ports leading to the air drum, main pipe and
brake cylinder, of a piston having two heads located and operating within the
chamber, the upper head being loosely surrounded by an encircling ring, all the parts
being arranged substantially as described.