Year: 1893

page_text: Date of Application, 30th Aug., 1893-Accepted, 21st Oct., 1893
8 is a pull rod connecting the floating lever 7 to the brake levers on one truck,
and 9 is a pull rod connecting the lever 7 with the brake levers on the other
truck.
10 is an extension to the floating lever 7.
11 is a supplemental cylinder containing a piston 12 with a hollow piston rod 13.
Inside the hollow piston rod is a push rod 14 connected by a pin to the extended
arm 10 of the floating lever 7. This push rod has a ratchet, or teeth, along its
length.
To the enlarged head 15 of piston rod 13 a pawl 16 is pivoted by pin 17. This
pawl is adapted to engage with the teeth of the push rod 14 in one position and to
be disengaged from said teeth in another position. When the arin 18 is pressed
against the cylinder cap 19 by the spring 20 which returns the piston the pawl 16
is disengaged from the teeth of push rod 14 and the rod is free to move through
the pawl in either direction. When the piston has pushed the pawl out far enough
to clear the arm 18 from cap 19 the spring 21 will revolve the pawl sufficiently to
engage the teeth of the pawl with the teeth on push rod 14 and thus communicate
any stress there may be on piston 12 to push rod 14 and thus to the floating
lever 7 and the brake rigging on the car. The piston 12 is brought into action
by means of valve 22 which is connected to the train-pipe by a pipe 23 and with
the main brake cylinder by a pipe 24.

page_text: Fig. 3 shows the actuating valve 22 in section. Inlet 23 is connected to the
train-pipe. Inlet 24 is connected to the main brake cylinder. Outlet 25 is
connected to the supplemental cylinder, and outlet 26 is open to the atmosphere.
27 is a slide valve with a recess which in running position connects the passage 25
with the outlet 26, as shown in the drawings.
28 is a piston for actuating valve 27. A spring 29 may be used to assist in the
return stroke. When in use the inner portion 30 of this valve case is in connection
with the train-pipe and has the same fluid pressure as the train-pipe; the outer
portion 31 is in connection with the main brake cylinder and has the same fluid
pressure as in the main brake cylinder. In the ordinary automatic brake system,
when the train is running, the brake cylinder is open to the atmosphere and the
train pipe has about seventy pounds of fluid pressure. Therefore the piston 28
would have atmospheric pressure on side 31 and about seventy pounds fluid pressure
on side 30.
In operation the functions of the train-pipe, triple valve, reservoir, and main
cylinder, are as usual in an automatic brake system. If the train pipe pressure is
reduced the triple valve will act to let fluid pressure pass from reservoir 4 to
cylinder 5 and thus push out piston 6 and move the floating lever 7 to the dotted
position, thus applying the brakes in the ordinary way. This motion of the
lever 7 with its extension arm 10 would draw the push rod 14 to the position
shown by the dotted lines. If valve 22 was cut out by fourway cock 32, there
would be no further action, and when the brakes were released the push rod 14
would be returned to its place as the pawl 16 is normally in a position that
will not engage the teeth on rod 14. If, however, the four-way cock 32 is open
as shown in Fig. 3, when the train pipe pressure is reduced and the brake is
applied through the triple valve and piston 6 and the lever 7 is moved to the
position shown by the dotted lines, the fluid pressure in the cylinder 5 will be
communicated through pipe 24 to the outside 31 of piston 28 (Fig. 3).
This will have no effect until the brake cylinder pressure exceeds the train pipe
pressure, when it will
cause piston 28 to move valve 27 and uncover the port
leading through 25 to the supplemental brake cylinder 11, at the same time
closing exhaust outlet 26. The train pipe pressure admitted to supplemental
cylinder 11 will cause piston 12 to move outward; a short outward motion of
the piston rod 13 will disengage the arm 18 from the cap 19 and allow the
spring 21 to throw the teeth of the pawl 16 into mesh with the teeth on the push
rod 14, and thus communicate the stress on piston 12 to the brake lever 7 and
thence to the brake system. As the lever 7 and push rod 14 will have already
been moved to the position shown by the dotted lines, and the pawl 16 will engage
with the teeth on the push rod after it is drawn out, a very short stroke of
piston 12 will communicate an additional stress on the brake system. Consequently
only a small portion of fluid pressure will need to pass from the train pipe to
accomplish this object. The attachment of this apparatus to the usual brake
levers may be made to add any desirable quantity to the force furnished by the
primary apparatus. As there would be open communication between the supple-
mental cylinder and the train pipe, the engineer could reduce the brake pressure
by releasing air on the engine, or could increase the brake pressure by increasing
the pressure in the train pipe at will, up to the pressure that would release the
regular triple valve brake. He could therefore obtain a very great braking
force when the train was at a high velocity and reduce that force at will as the
speed was reduced, and thus prevent sliding wheels, although using at first a greater
braking force than the weight of the cars.
In order to release the brakes the engineer increases the pressure in the train
pipe. This will increase the brake pressure momentarily, but when the pressure in
chamber 30 plus the spring 29, exceeds the pressure in 31 which will be the same
as in the brake cylinder 5 and reservoir 4, the piston 28 will close passage 25 from
the train pipe and open it to the atmosphere through exhaust 26, thus releasing the

page_text: fluid pressure from cylinder 11 and allowing spring 20 to return piston 12 to place.
This motion will draw back pawl 16 until its arm 18 has come in contact with
cap 19 and tilted the pawl out of engagement with push rod 14. As the fluid
pressure in the train pipe increases it will operate the triple valve to release the
main piston in cylinder 5, and the apparatus will return to the position shown in
the drawings. If the train pipe pressure should be reduced suddenly, an emergency
application would ensue in a quick action automatic brake; the same action as
above described would also then take place in this apparatus.
Further, this device may be used for increasing the braking power on loaded
cars, for the four-way cock may be set to cut it out on an empty car and only use the
ordinary cylinder, but it may be cut in when the car is loaded, whereupon the
additional braking force will be obtained on the loaded car without affecting
the other cars in the train whether loaded or empty.
So far I have described only that form of my invention shown in Figs. 1, 2, 3,
and 4, but as will be obvious many other forms of apparatus may be made which
will embody my invention. Thus the rod 14 need not occupy the piston rod 13 of
the supplemental cylinder 11; for obviously all that is necessary is that this rod be
in position to transmit the power of piston 12 to the brakes. In Fig. 5, I have
shown this rod 14 as pinned to piston rod 6 of brake cylinder 5, and as playing
freely through a clutch composed of levers 43 and 46, so long as piston rod 13 of
supplemental cylinder 11 is not forced out; but when pressure is admitted to
cylinder 11, as before described, the outward motion of piston 12 and its rod 13
will cause clutch arm 42 of lever 46 to grip rod 14; and thus the power of
piston 12 will act through rod 14 to increase the force with which the brakes
are applied as before described. Lever 43 has a fixed fulcrum at 44, and a
fixed stop at 50, and the grip on rod 14 by levers 43 and 46 will be clear from
Fig. 6 which is a detached view of levers 43 and 46 with rod 14 in section.
Of the many forms of my invention which I have contemplated I believe these
to be, on the whole, preferable; but obviously the form of clutch mechanism by
which supplemental piston rod 13 engages the brake rigging, the form of valve
device by which compressed air is admitted at the proper time to operate piston 12
of supplemental cylinder 11, and all other details of construction may be widely
varied; for my main invention is a supplemental brake cylinder, combined with
the main brake cylinder and operating to produce an additional stress on the brake
rigging, as fully explained; and a second feature of my invention is the variation
of the stress of the piston rod of this supplemental cylinder by varying the
pressure in the train pipe within limits as above explained; the supplemental
cylinder being when in operation open directly to the train pipe.
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 a fluid pressure brake system the combination with a main brake
cylinder, its piston and piston rod and suitable levers and brake rigging to com-
municate the power of the main brake cylinder to the brake shoes; of a supple-
mental brake cylinder; its piston and piston rod; and a clutch mechanism, one
member carried by the brake rigging and the other member operated by the
supplemental piston to connect the supplemental piston with the brake rigging, all
substantially as set forth.
2. In a fluid pressure brake system, the combination with a main brake
cylinder, its piston and piston rod and suitable levers and brake rigging to com-
municate the power of the cylinder to the brake shoes; of a supplemental brake
cylinder, its piston and piston rod, a clutch to connect the supplemental piston with
the brake rigging, a valve to open a passage from the train pipe to the supplemental
brake cylinder, and a piston controlled by the difference in pressure between the

page_text: train pipe and the main brake cylinder to actuate the valve, all substantially as set
forth.
3. The improvements in air brakes, substantially as and for the purposes herein-
before described, set forth, and illustrated in the drawings annexed.
Dated this 25th day of August 1893.
REGINALD W. BARKER.