IMPROVEMENTS IN RAILWAY BRAKES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents on the 24th March 1881. A. com-
munication from abroad by John Meissner and Henry Heischman, both of
the City, County, and State of New York, United States of America.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. *"* IMPROVEMENTS IN RAILWAY BRAKES." [A communi-
cation from abroad by John Meissner and Henry Heischman, both of "the City,
County, and State of New York, United States of America.]
This Invention is designed as an improvement on a particular arrangement of
brake, in which the brake shoes are immediately above the wheels, instead of at
either side thereof, as usual, the same being especially applicable to carriages of
the American type, supported on bogie trucks (to which the following description
applies); and the object of the Invention is to simplify and reduce the cost of the
operating parts of a brake that will apply to the wheels when running on curves
as when running on a straight line.
The Invention consists of a horizontal frame having bowed or curved end bars,
and provided with side sockets for holding the brake shoes, said frame being held
in position against the bottom of the car by longitudinal movable clamps or racks
in such a manner that it is free to accomodate itself to the relative positions of the
bogie truck, and the body of the carriage when running on curves, said clamps or
racks being connected with brake rods or shafts, whereby said frame may be moved
longitudinally for applying or throwing off the brake. And it consists further of
a device for preventing the accidental application of the brake when the car is
running on a curve where the outer rail is higher than the inner one, all of which
will be hereafter described.
The brake shoe frame has straight parallel sides and bowed ends struck from
the bogie pin. On each of the sides there are two sockets for holding the brake
shoes, said sockets having hinged outer sides that may be thrown open for inserting
or removing the shoes, and are secured closed by a screw or other device. On the
under side of the car bottom, near the front thereof, is a slotted rack held to the
car bottom by a bolt, and gearing with a pinion keyed on the lower end of a
vertical shaft provided with the usual handle or hand wheel. This rack has on its

page_text: inward end two lugs that hold the forward bowed end of the brake shoe frame
between them in such a manner that said front end of the frame is thereby held up
in position, while at the same time it can swing in a horizontal plane sufficiently
to accomodate itself to the position of the bogie truck wheels as they move on a
curve of the road. The rear end of the brake shoe frame is held between down-
wardly projecting lugs on a plate that is screwed on the end of a central longitudinal
connecting rod, held up on the underside of the car bottom, the opposite end of
said connecting rod being attached to a like plate that pertains to the brake
attachment of the rear bogie truck of the car.
The wooden brake shoes are above the wheels, and are cut out on their lower
edges to correspond or nearly so with the curves of the periphery of the wheels.
They are provided with broad metallic caps to strengthen and make them more
durable, and when inserted in the sockets of the brake shoe frame these caps rest
on the upper edges of the said sockets, and the shoes are thereby held above and just
clear of the wheels.
To the inner face of the brake shoe frame on the sockets are rigidly secured,
depending angle plates or guards that reach nearly in contact with the wheel
axies.
When running on a curve where one rail is higher than the other, the higher
ends of the wheel axles will press upward against the bottoms of the two guards
on that side, and thereby elevate the brake shoe frame and the brake shoes on that
side, and thus prevent the breaking of the wheels which would otherwise occur,
there being also, as parts of this preventive device, yokes holding elastic buffers on
top of the metallic caps of the brake blocks, which yokes have their ends slotted,
and engaged over the projecting ends of the said caps, so that said yokes can move
up and down with the elastic movements of the buffers.
These buffers serve by their elasticity not only to keep the car body in a
horizontal plane when running where one rail is higher than the other, but
serve also to prevent any sudden jar as the axles come in contact with the said
guards.
To apply the brakes, the brake shaft and pinion are turned in one or other
direction according to which way the car is running, and this motion and force are
transmitted through the rack to the brake shoe frame, which is moved longitudinally
and thereby forces the brake shoes in contact with the wheels wedging said shoes
and the buffer frame at the same time between the wheels and the bottom of the
In this position the brake shoes brake the wheels effectively, the force applied
being supplemented by the weight of the car upon the upper surfaces of said buffer
frame, and thereby upon the brake shoes. Consequently it is obvious that the
greater the weight of the car and its load the greater will be the influence they
exert in braking the wheels.
car.
As the brake frame is free to swing within certain limits, and as the brake shoes
extend below and outside the flanges of the wheels, it follows that when the car
is running on a curve, that the wheel flanges will bear against the sides of the
brake shoes, and thereby keep them and the brake frame in the same relative
position with the bogie truck, so that the wheels can be braked as readily when
running on a curve as when running on a straight line.