Improvements in Brakes for Rail-road Cars.
Year: 1887

page_text: COMPLETE SPECIFICATION.
Improvements in Brakes for Rail-road Cars..
I, GEORGE ALBERT BOYDEN, of the City of Baltimore, in the State of Maryland,
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 :-
My invention relates to a brake for railroad cars wherein the brakes are applied
by the pressure of springs, and released, and controlled by the pressure of compressed
fluid supplied through a continuous train-pipe leading from the locomotive.
The invention is illustrated in the accompanying drawing, in which
Figure 1 is a diagram showing the relative position of the various parts of the
brake-mechanism equipped on a locomotive and two cars.
Figure 2 is a view of the power-mechanism and slack take-up, in which the heavy
black lines denote a section. The parts are shown in the position they occupy when
the brakes are released and held off by the compressed air.
Figure 3 is a like sectional view of the same, showing the position of the parts when
the brakes are on, that is, when the compressed air has been exhausted.
Figure 4 is a side view of the same parts as seen from a transverse direction.
Figure 5 is a plan view of a car frame with the brake-mechanism attached, and the
levers in the position they occupy when the brakes are released.
Figure 6 is a sectional elevation of a car showing the hand-wheel shaft, the power
brake-mechanism, and the "foundation-gear "connecting with both the said hand-wheel
shaft and power brake-mechanism.
The letter A designates an expansible chamber for compressed air; this chamber, in
the present instance, is a metal box or drum having a rigid side, c, see Figure 2, and
a movable side d.

page_text: The form of movable side here shown is called a flexible diaphragm, which is
secured to the metal box-part in any suitable manner. Other known forms of
expansible chamber, such as cylinder and position may be used.
An opening, e, in the rigid side of the chamber A provides for a connection with the
train-pipe, B, and a frame or open cover, f, shaped like the rigid side, c, is secured to
the said chamber A over the flexible diaphragm d. One or more tubular-shaped
pockets, C, are rigidly secured to the said frame f, and a spiral spring D, occupies
oach pocket and is in contact with the diaphragm plate d', and presses the diaphragm
toward the rigid side c, of the chamber. When air under pressure enters the expansible
chamber A, the flexible diaphragm d, is forced back against the spring D, as shown
in Figure 2, and the latter will be contracted, and the brakes held off; when air-
pressure is exhausted from the chamber A, the springs in the pockets will expand
causing the diaphragm to take position against the rigid side, c, of the chamber, as
shown in Figure 3, and the brakes will be applied.
The expansible chamber A is secured on the car frame E.
A slack-lever, F, has a slot, i, and is pivoted through the said slot by a fixed pink,
said lever may, therefore, turn on the pivot, and when it has turned from the position
shown in Figure 2 to the position shown in Figure 3, it will disengage from the pivot k,
and slide or reciprocate in the direction of its length.
The rod, G, connects the movable side, d, of the expansible chamber, with the
slack-lever F. When the said movable side and rod draws on the slack-lever, the
latter will first turn through an arc of about ninety degrees, from the crosswise position
which it has in Figure 2 to the end wise position seen in Figure 3; where it is parallel
with the diaphragm-rod G, and while in this parallel position the lever and rod may
reciprocate in unison. A rod, n, connects the slack-lever to one end of the floating-
lever, o, of the "foundation-gear," and a rod, P, connects one end of the said
floating-lever, o, with the bean-lever, a, on one truck. For the other truck is
similar floating lever, o', and a rod, pl and a rod and chain, r, connects one end of the
floating-lever, o', with the upright hand-wheel shaft b. A central rod, q, connects the
said two floating-levers o and o; the levers, a, are attached to the beams, y, which
carry the shoes or blocks, a, that bear against the wheels.
The parts thus far described relate to the brake-mechanism on the cars.
a
The locomotive is provided with an air-pump H, which is worked by a steam-
cylinder I; a pipe, s, leads from the air-pump to a tank or reservoir J. The air-pump
condenses air into the said tank to the desired density, say from 60 to 80 pounds to
the inch. A pipe B leads from the air-tank J and extends along the cars of the train,
and on each car connects with the expansible chamber A; between each two cars a
flexible hose, g, is used to couple the train-pipe B. A three-way cock, L, in the pipe
is located on the locomotive, and enables the engineer or driver to control the
compressed air that passes to the brake-mechanism on the cars.
The springs D, expansible chamber A, and slack-lever, F, comprise the "power-
mechanism," which is controlled by the engineer through the medium of condensed
air in the train-pipe B.
In operating this brake on a train of cars, the train-pipe B should first be connected
with the locomotive and thence throughout the train; the brakes of all the cars must
then be applied by the hand-wheel, b, on each car, the pressure exerted on the
different cars being made to correspond, as near as may be possible, with the load each
car may be carrying, and the hand-wheel shaft & secured from accidental releasing by
a suitable pawl, b, after which the brakes are to be operated by the action of the spring
and the compressed fluid and controlled entirely by the engineer, in the following
manner; as just stated, the brakes before starting are first applied by the hand-whoel
on each car. When it is desired to release the brakes, the engineer turns the brake-
cock L to permit compressed air to pass from the reservoir J on the locomotive to the
train-pipe, B, which supplies all the expansible chambers A, and thereby compresses
or contructs the springs, D, and releases the brake-shoes ; as long as the train-pipe
is full of compressed air, the brakes will be held off. When the engineer desires to
apply the brakes wholly or partially he turns the cock L to release the compressed air

page_text: from the train-pipe, in accordance with the brake-pressure which is to be applied to
the car-wheels.
It will be seen that the brake is fully under the control of the engineer, and in case
of the train accidentally separating in two or more parts, the brake on all the
cars will be automatically applied by reason of the escape of the compressed air from
the train-pipe. In case any of the hose connections, g, between the cars should burst,
or from any cause the compressed air should escape, the brakes will be promptly
applied by the action of the spring D and the train stopped.
When the locomotive is disconnected from the train the brakes on the cars will
remain applied, and may be released by the hand-wheels, b, in the usual manner.
The spring, as a prime mechanical power to be used as herein described for applying
car-brakes, has advantages over compressed air, one of which is that as a breaking
power certain to act in an emergency, the spring will invaribly ensure control of a
train, whereas air or other compressed fluid is subject to leakage, to the chance of
an insufficient air pressure on the locomotive, and other incidents inherent to
its usc.
It is not essential that the springs employed be of the spiral form.
It is also obvious that the parts herein shown and described may be varied or
changed in their form and construction.
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:
1st. A mechanism for actuating railway car-brakes comprising the combination on
each car of an expansible chamber for compressed air; a spring for applying the
brakes; and a disengaging slack-take-up device, whereby the first portion of the
spring's movement is applied to the slack-take-up device, and the latter portion of the
spring's movement is applied to force the brakes hard against the wheels.
2nd. In a car-brake, the combination of the foundation-gear; an expansible
chamber a train-pipe having its terminals at opposite ends of the car and connected
with said expansible chamber; a spring for applying the brakes and a disengaging
slack-take-up device connecting the movable side of the said chamber with the
foundation-gear.
:
3rd. A mechanism for actuating railway car-brakes comprising the combination on
each car, of an expansible chamber A; spring pockets C containing springs; a slack-
take-up device attached to the said spring-pockets; and a connection uniting the said
movable side of the chamber and slack-take-up device.
4th. A mechanism for actuating railway car-brakes comprising the combination of
the box or drum c; a frame or cover secured to the said box or drum; a flexible
diaphragm d clamped between said box and frame; a spring D hearing on the
diaphragm; and a disengaging slack-take-up device for the purpose set forth.
5th. A mechanism for actuating railway car-brakes comprising the combination of
the box or drum c; a frame or cover secured to the said box or drum; a flexible
diaphragm d clamped between said box and frame; a tubular pocket C secured to the said
frame; a spring D occupying the pocket; and a disengaging slack-take-up device,
for the purpose set forth.
6th. A mechanism for actuating railway car-brakes comprising the combination of
an expansible chamber for compressed fluid; a spring; a fixed pivot pin k; a lever
pivoted by said pivot pin and also adapted to slide thereon; and a connection G
uniting the movable side of the expansible chamber with the said lever whereby the
first portion of the spring's movement is converted into a greater movement by the
swing of the lever, and the latter portion of the spring's movement is applied direct
by the sliding of the lever.
7th. In a car-brake, the combination of hand-wheel; a spring for applying the
brakes; an expansible chamber for compressed air; a disengaging slack-take-up
device; and a foundation-gear connecting with both the said hand-wheel and
spring.

page_text: 8th. In a car-brake, the combination of an air-pump H on the locomotive; an air
tank J connected with the air-pump; a spring on the car to apply the brakes; an
expansible chamber A on the car to release the brakes; a train-pipe B leading from
the air-tank to the expansible chamber; and a three-way cock L in the said
pipe.
9th. The method of operating fluid-pressure brakes of cars by using the ordinary
hand-wheel shaft to set the brakes of the respective cars of a train, with a pressure
corresponding to the load each car may be carrying; and then using the power-
mechanism to operate the brakes at the pressure thus predetermined.
Dated this Twentieth day of October 1887.