Improvements in Valves for Air Brakes.
Year: 1898

page_text: Date of Application, 21st Feb., 1898—Accepted, 26th Mar., 1898
Improvements in Valves for Air Brakes.
I, WINFIELD ORLAndo Gunckel, of the town of Terre Haute, in the County of Vigo,
and State of Indiana, one of the United States of America, Mechanical 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 valves for the air brakes used on railway trains; and it
consists in the novel construction and combination of the parts hereinafter fully
described and claimed.
In the drawings: Figure 1 is a longitudinal section through the valve. Figure 2
is a cross-section taken on the line xx in Figure 1. Figure 3 is a longitudinal
section through the valve, showing a modification. Figure 4 is a cross-section taken
on the line y-y in Figure 3.
A is a portion of the auxiliary reservoir for the compressed air, and a¹ is a pipe
which leads into the brake cylinder. B is the casing of the triple valve having its
rear end secured to the said reservoir and having a cylinder C formed in it and three
chambers b, c, and d. The chamber b communicates with the cylinder C, and is
separated from the chambers c and d by a faced-plate D. The pipe a¹ is connected
to the chamber d; and the chamber bis constantly connected with the reservoir A by
a passage b¹.
The faced-plate D is provided with an inlet port 2, and an exhaust port 3 extending
through it from the chamber b into the chamber d; and 4 is an exhaust passage
arranged between the ports 2 and 3. The passage 4 opens into the chamber 6 and is
always in communication with the atmosphere. The faced-plate is also provided with
a port 5 extending through it into the chamber c.
E is a pipe which is connected to the train pipe in the usual manner, and is screwed
into a plug e which is screwed into the casing B so that it projects within the
chamber c.
E is a valve pivoted to the plug e and closing over the end of the pipe F. A
passage el is provided for connecting the interior of the plug e with the front end of
the cylinder C and thereby establishing a constant communication between it and the
train pipe.
F is a cover for the front end of the cylinder, provided with a recess f. F¹ is a
support or stop secured between the cylinder and its cover, and provided with an
annular portion f¹ projecting into the recess f.
G is a cup which normally rests against the stop F¹, and g is a strong spring
arranged between the bottom of the cup G and the bottom of the recess f. H is a
cup which bears against the piston I which is slidable in the cylinder C, and h is a
spring which is weaker than the spring g and which is interposed between the bottoms
of the cups G and H.
The piston I is provided with a piston rod i which is guided in a hole in the rear
end of the valve casing, and which projects into the reservoir A.
J is a slide valve secured to the piston rod i and provided with an exhaust cavity j.

page_text: K is an intermediate slide valve arranged between the slide valve J and the faced-
plate D. The slide valve K is provided with two projections and ¹ for the slide
valve J to strike against as it approaches the respective ends of its stroke so that the
slide valve K may be operated by it, but the two slide valves may be operatively con-
nected in any other approved manner.
The slide valve K is provided at its rear end with a very small port 6 extending
through it and normally communicating with the port 2, but the port 6 is much
smaller in area than the port 2. The slide valve K is provided at its front end portion
with a port 7 communicating with the port 5, and a check valve 8 which normally
covers the port 7. The valve 8 works in a chamber 9 in the valve, and 10 is a lateral
hole connecting the chamber 9 with the chamber b.
The slide valve K is also provided with a port 11 extending through it and con-
necting the exhaust cavity with the exhaust passage 4. A passage 12 of large area
is formed in the face of the slide valve K next to the faced-plate D, and 13 is a port
extending through the valve and connecting the passage 12 with the exhaust
cavity j.
The differential springs g and h and the pressure of the air in the front end of the
cylinder normally hold the piston and slide valves in the position shown in Figure 1
of the drawing. The slide valve J is much narrower than the slide valve K, and it
slides in a groove m in the back of the valve K, as shown in Figure 2. The slide
valve K is guided laterally by the sides of the valve casing.
The operation of the parts is as follows:-The auxiliary reservoir is first charged
with compressed air, of about 70 pounds pressure, from the train pipe. The com-
pressed air enters through the pipe E and valve E¹ and passes into the chamber c,
and also passes through the passage e¹ into the front end of the cylinder C. The com-
pressed air in the chamber c passes through the ports 5 and 7 and the valve 8, into
the chamber b, and thence through the passage 61 into the auxiliary reservoir A.
The pressure is now equal upon both sides of the piston I, and the brakes are not
applied because the brake cylinder is in communication with the atmosphere by means
of the pipe a¹, chamber d, port 3, passage 12, port 13, exhaust cavity j, port 11, and
exhaust passage 4.
When an ordinary service stop is to be made the pressure in the train pipe is
decreased from one to two pounds. The piston is now forced forward in its cylinder
by the excess of pressure behind it which is greater than the tension of the light
spring h. The slide valve J is moved to the left closing the exhaust port 11 and
opening the small supply port 6. The compressed air in the reservoir passes into the
brake cylinder through the ports 6 and 2, the chamber d, and the pipe a¹, and
actuates the brakes. The compressed air from the reservoir cannot pass back into
the train pipe because the valves 8 and E¹ close automatically.
When the pressure in the train pipe is again increased the piston moves the
valve J to the right, closes the port 6 and re-opens the exhaust, thereby releasing
the brakes.
When a more sudden service stop is to be made the pressure in the train pipe is
decreased by from 3 to 5 pounds. The piston moves suddenly to the left until the
cup H strikes the cup G. The exhaust is closed the same as before and the port 6
is opened, but the continued motion of the slide valve J to the left moves the slide
valve K to the left also, because the slide valve J strikes the projection k¹. The
valve K uncovers the port 2 which is of much larger area than the port 6 and
admits a free supply of compressed air to the brake cylinder, thereby applying the
brakes with greater_force.
The slide valve J strikes the projection k and restores the slide valve K to its
original position when the pressure in the train pipe is again increased.
When an emergency stop has to be made and it is desired to apply all the brakes
on the train very quickly and strongly, the pressure in the train pipe is decreased by
about 15 pounds. The piston then moves suddenly to the left so that the strong
spring g is compressed by the cup H which presses the cup G away from its stop.
The port 2 is opened by the valve K as hereinbefore described, and the continued

page_text: motion of the valve K to the left places the port 5 in communication with the port 3
by means of the passage 12. The pressure in the chamber d is for the time being
less than in the chamber b and in the auxiliary reservoir A because the passage b¹ is
of much larger area than the port 2. The compressed air in the train pipe therefore
raises the valve El and passes through the port 5, passage 12, and port 3, which
are all of large area, into the chamber d and into the brake cylinder, producing a
strong pressure therein.
When the pressure in the train pipe, chambers cand d, and in the brake cylinder
becomes equal, the valve E¹ closes automatically, and an excess of pressure still
remains in the auxiliary reservoir because of the smallness of the port 2. This excess
of pressure in the reservoir becomes reduced by the air feeding through the port 2, and
the valve E¹ is held shut and the brakes are held on by it until the pressure in the
train pipe is again increased.
Various modifications may be made in carrying out this invention, for instance, the
valve E¹ may be dispensed with altogether, also the spring h and cup H.
The valve 8 and chamber 9 can also be dispensed with by making a passage n,
shown in Figure 3, which is similar in function to the passage e¹, of considerably
larger area than the port 7 or the port opening through which compressed air is admitted
from the train pipe and the chamber c to the chamber b and the auxiliary reservoir.
In Figure 3 the port 7 is a mere notch in the end of the valve, and the valve uncovers
the port 5 slightly. The notch may be dispensed with however and the air admitted
through the narrow port opening only.
is
When air is admitted through the pipe E it forces the piston rearward to the
position shown in Figure 3 the same as previously described with reference to Figure I,
and the auxiliary reservoir is charged through the narrow port opening or the
notch 7. When the pressure in the train pipe is suddenly decreased, the piston
moved forward by the pressure of the air in the reservoir because the area of the
passage n is much greater than the area of the port opening at the front end of the
valve K. The ordinary service stop is effected when the valve J uncovers the port 6
and the piston rod strikes the cup G. A more sudden service stop is effected when
the port 2 is uncovered and the spring g is partially compressed. The emergency
stop is effected when the cup & strikes the bottom of the recess f and the brake
cylinder is placed in direct communication with the train pipe.
In the modification shown in Figures 3 and 4, the chamber b is formed of a
cylindrical tube which is secured in the casing B eccentric of the cylinder C. This
tube is preferably split or cut through longitudinally upon one side, and has holes p
drilled in its ends at the said split p¹. Tapered plugs q are driven into the holes p
after the tube has been placed in the casing B, so that the tube is expanded and
secured in the casing. The tube however may be secured in any other approved
manner. The faced-plate D is secured by soldering or brazing it inside the tube,
and the slide valve K slides in a groove m¹ in the faced-plate.
The valve 8 and chamber 9 shown in Figure 1 can be applied to the valve K shown
in Figure 3, if desired, and can be used as a means for constraining the air supply to
pass slower between the train pipe and the rear end of the cylinder than between the
train pipe and the front end of the cylinder, instead of relying on a small port opening
as previously described herein. The light and strong springs shown in Figure
also be applied to the valve shown in Figure 3, if desired.
can
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 valve, the combination, with a triple valve casing provided with
a faced-plate, of an intermediate valve sliding on the said faced-plate, and a valve
sliding on the said intermediate valve, the said faced-plate and valves being provided
with ports and passages enabling them to effect three stops of different suddenness,
substantially as set forth,

page_text: 2. In an air brake valve, the combination, with a triple valve casing provided with
a faced-plate having ports 5, 3 and 2, and an exhaust passage 4 between the ports 2
and 3; of an intermediate valve provided with a port 6, said ports 2 and 6 effecting
two service stops of different suddenness, a passage 12 for connecting the ports 5
and 3, a port 13 and an exhaust port 11; and a separate valve operating to uncover
the port 6 and provided with an exhaust cavity for connecting the port 11 with
the port 13 and passage 12, substantially as set forth.
3. In an air brake valve, the combination, with a triple valve casing provided with
a faced-plate, of an intermediate valve sliding on the said faced-plate, a valve sliding
on the intermediate valve, said faced-plate and valves being provided with ports and
passages enabling them to effect three stops of different suddenness, and a reservoir
check valve carried by the said intermediate valve, substantially as set forth.
4. In an air brake valve, the combination, with a valve casing, and a slidable valve;
of a light spring and a strong spring pressing the said valve in one direction, a support
for the strong spring connected to the said casing, and means for compressing the
strong spring after the light spring has been compressed to a prearranged extent,
substantially as set forth.
5. In an air brake valve, the combination, with a triple valve casing provided with
a cylinder, a passage connecting the front end of the cylinder with the train pipe, and
separate ports connecting the rear end of the said cylinder with the train pipe and
with the brake cylinder respectively; of a piston in the cylinder, and valves operated
by the said piston and effecting three stops of different suddenness, the compressed
air being constrained to pass slower between the train pipe and the rear end of the
cylinder than between the train pipe and the front end of the cylinder, substantially
as set forth.
6. In an air brake valve, the combination, with a triple valve casing provided with
a cylinder, and a cylindrical chamber secured in the said casing eccentric of the said
cylinder and provided with a faced-plate on one side of a piston in the said
cylinder, and a slide valve operatively connected with the said piston and sliding
on the said faced-plate, substantially as set forth.
Dated this 21st day of February 1808
CASSELL & Co.,
22, Glasshouse Street, Regent Street, London,
Agents for the Applicant.