Improvements in and connected with Pneumatic Brake Systems.
Year: 1893

page_text: Date of Application, 28th Mar., 1893-Accepted, 20th May, 1893
COMPLETE SPECIFICATION.
Improvements in and connected with Pneumatic Brake Systems.
WILLIAM CURTIS WHITACRE of No. 304 North 8th Street in the City of
St. Louis, State of Missouri, United States of America, Gentleman, 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 apparatus for operating car brakes automatically by
compressed air, and has for its object the simplification of the parts in the brake
cylinder and the consequent reduction in the operative parts in the connections
from the same to the brake beams. It consists in the novel features of improvement
in such appliances hereinafter described.
In the accompanying drawings, in which like characters of reference denote like
parts in the several figures,
Figs. 1 and 2 are, respectively, a side elevational outline view and a plan view
of the underside of a car, with my improved apparatus attached.
Figs. 3, 4, 5 and 6 are enlarged detail views of my improved brake cylinder,
being respectively, a longitudinal section, a front end elevation, a cross section
taken on the line 5-5 in Fig. 3, and an elevational view of the outer side of the
piston.
As illustrated in Fig. 3, the brake cylinder consists in the casing 1, one end
of which is closed, except where the piston-rod 2 protrudes therethrough, the
other end of which is closed by the removable head-piece, 12, secured thereto
by the bolts 13. In a central perforation in the head-piece 12, is secured the
end of a short pipe 34, through which communication is afforded from the
interior of the brake cylinder to the triple valve (not shown). The casing 1
is formed with two diametrically opposite external lugs or ears. 18, in which
There are pre-
are revolubly fitted the circumferentially grooved sheaves 19.
ferably, formed on each side of the casing 1, in line with the sheaves 19, a
hollow lug 17 for guides for the brake chain. The casing 1 is also formed with
a bracket projection 11, as shown in Figs. 4 and 5, by which means the cylinder,
as a whole, is secured to the under side of the car, as shown in Fig. 1.
Το
To the inner end of the piston-rod 2, is rigidly secured the piston 3.
the protruding end of the rod 2, is rigidly secured the slotted fulcrum block 4
in which is pivotally secured, by the pivot bolt 7, the equalizing lever bar 6.
The ends of the bar 6 are secured, respectively to one end of the brake chains 8
and 81 which lead therefrom, through the guide holes in the projections 17, around
the sheaves 19, toward either end of the car, the other ends of which are, respec-
tively, connected with the end of the brake rods 9 and 9. As shown in Figs. 1
& 2, the brake-rods 9 & 91, are, in each instance, connected with one end of the
live truck levers 24 which are fulcrumed in stirrups 25¹, secured to the outer
brake beams 22. To the other end of the truck levers 24, are secured, respec-
tively, one end of the connecting brake rods 23, the other end of which are con-
nected with one end of the dead truck levers 26, which are pivotally connected,
The other ends of the
by means of the stirrups 25, to the inner brake beams 22.
truck levers 25 are fulcrumed in the adjustable stirrup blocks 33 which are rigidly
secured, in any convenient manner, to the truck frame or the bottom of the car.
The object of thus securing the fulcrum end of the levers 26 in the adjustable
fastenings 33, is to provide for a take-up to compensate for the wear in the brake
shoes, etc.
As shown in Fig. 2, the brake cylinder is secured to the body of the car at right
angles to the direction of the pull in applying the brakes; i.e., transversely to the

page_text: length of the car. In this way the brake chains of the brakes at both ends of the
car can be directly attached to the single equalizing lever 6, of the brake cylinder,
dispensing with any additional dead equalizing lever for one set of brakes, as in the
heretofore used systems.
The principles of operation are as follows: When the driver's valve is turned to
withdraw the pressure from the train pipe, the triple valve, which is secured to the
brake cylinder 1, by the pipe 34, turns the pressure of the auxiliary reservoir into
the brake cylinder 1, by the pipe 34, driving the piston-head 3 in toward the closed
end of the cylinder, carrying with it the attached equalizing lever 6. This will
draw the chains forward around the sheaves 19, and this, through the connecting
rods and levers, will draw the brake beams at either end of the car, when placed
on the outside of the wheels, as shown in Fig. 1, together, setting the brakes 32.
When this pressure is removed, the piston-head 3, will return to its normal position,
being impelled in this direction by the internal re-acting spring 5.
In Figs. 3 and 6 is illustrated an improved expansion ring 16 for keeping the
piston-head packing ring 11, against the inside of the cylinder 1, to make it air-
tight in its operations. My improvement, in this particular, consists in an annular
piece of spring metal formed with an upturned lip portion at right angles to the
plane of the ring, as shown in Fig. 3. This ring as a whole, is then divided into
three parts by radial divisions, as shown in Figure 6, and each separate piece is
adjustably secured to the gasket clamping head-piece 10, by the screw-bolts 15, for
which are formed radial slots in the pieces 16. In this manner, the expansion ring,
as a whole, is made adjustable radially, the upturned edge pressing at all times
against the inside of the upturned edge of the leather gasket packing ring 11, in
the manner shown in Fig. 3.
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 :-
:-
I. A brake cylinder for pneumatic brake systems, consisting of a casing formed
with means for securing it to the under side of the car and diametrically opposite
lugs in which are revolubly secured sheaves for the guidance of the brake chains,
substantially as and for the purposes specified.
II. In a pneumatic car brake system, the combination with a brake cylinder
formed with diametrically opposite lugs, of sheaves revolubly secured in said lugs,
a piston-rod, an equalizing lever, pivotally secured in the extending end of the
piston-rod, chains secured to the ends of said equalizing lever, brake beams, and
intermediate connections between the said chains and the brake beams, substantially
as described and for the purposes specified.
III. In a brake cylinder for pueumatic brake systems, the combination with a
cylinder casing formed with diametrically opposite lugs, of sheaves revolubly
secured in said lugs, and guide lugs formed in the said casing in line with said
sheave lugs, combined substantially in the manner and for the purposes specified.
IV. In a pneumatic brake system, the combination with a brake cylinder, of a
piston therein provided with an expansion head, a pipe leading to the front end of
said casing, a spring surrounding the piston at the back of the head, an equalizing
bar carried by said piston, brake beams, and connections between said equalizing
bar and beams, whereby the thrust of the piston will operate the beams, substan-
tially as described.
Dated the 28th day of March 1893.
PHILIP M. JUSTICE,
Chartered Patent Agent for the Applicant.