Air Brake Regulator.
Year: 1899

page_text: Date of Application, 14th Feb., 1899-Accepted, 8th Apr., 1899
COMPLETE SPECIFICATION.
Air Brake Regulator.
We, PACIFIC CAR EQUIPMENT Co., of 906, Broadway, Oakland, County of
Alameda, State of California, U.S.A., a corporation organized and existing under
and by virtue of the laws of the State of California, and ALEXANDER CARSON
RUMBLE, Engineer, of the same address, 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 an apparatus for regulating the pressure of brake
shoes upon the wheels of railway cars and the like when such brakes are applied
through the medium of compressed air acting through train pipes, brake cylin-
der, and the usual mechanism employed for such purposes. It consists essen-
tially of a relief valve operated by the rotation of the wheels and axles of the
cars, and controlling escape-openings in a pipe or passage which is connected
with the brake cylinder of the car, so that whenever the friction of the brake
shoes upon the wheels is so great that the wheels commence to slide upon the
track, the relief valve will allow air to escape, the pressure in the brake cylinder
to be reduced, and the pressure of the brake shoes upon the wheels to be cor-
respondingly relieved so that the wheels will again commence revolving.
In connection with this is a lifting and retaining valve operating auto-
matically and in conjunction with the brake and relief mechanism.
Referring to the accompanying drawings-
Figure 1, is a general view in elevation of the improved air-brake regulator,
and
Figures 2 and 3 are views on a large scale of portions of its mechanism.
As shown in the drawing,-A is one axle of a railway car, the outline of the
wheel being shown in dotted lines.
B represents the body of a car, and C is the brake cylinder of any usual or
well known air brake mechanism, one of these cylinders being fixed beneath
each car and having a piston movable therein, a piston rod extending out through
one end of the cylinder and adapted to be connected with the brakes in any
usual or well known manner not here shown, so that when air under pressure
is admitted to the brake cylinder through the train pipe E, the piston will be
moved so as to apply the brakes.
When trains of cars are made up, the cars having varying weights and loads
will have a corresponding difference of pressure upon the wheels and the con-
sequent variation in the adhesive powers of said wheels to the rails, therefore,
if the brakes be applied with sufficient force to hold the heaviest cars in the
train, the pressure upon the wheels of those which are lighter, will be so great
that they overcome the adhesion of the wheels to the rails, and the wheels will
then slide upon the track losing, in great measure, the power to hold and check
the train, which is greater when the wheels are rolling than when they are
sliding, and becoming flattened on the surface where they slide, until they
become dangerous or useless and must be replaced by new ones.
No care on

page_text: the part of the engineer will overcome this difficulty and the expense of replacing
the wheels is very great.
This invention is designed to so regulate the brake pressure upon any set
of wheels independently of any other set, that any tendency of the wheels to
hesitate or slide upon the track will be instantly counteracted by partially
releasing the brake pressure to a point where the wheels will again commence
to revolve, and as soon as this object is accomplished to again apply the air
pressure so as to make the brake effective, to automatically place the parts in
operative condition, or throw them out of action, and to retain a sufficient pres-
sure in the brake cylinders to ultimately stop and hold the train.
F is a pipe extending from the brake cylinder to a point near the axle of the
innermost wheels of the trucks upon which the cars are supported and carried.
This pipe lies approximately parallel with the train pipe and is of sufficient
length to have considerable elasticity, or independent movement. It is here
shown bent downward in a curve, so that its lower end approaches the axle A
at a point just above it.
At the end of this pipe F is formed a yoke or other support G, through one
arm of which extends a passage which forms a continuation of the pipe F and
a hollow shaft H is supported in this yoke and forms a journal upon which the
drum I is freely revoluble.
Holes are made in this axle or shaft and the exterior of the shaft is also
preferably given a slight taper as shown.
Jis a sleeve having the interior tapered to correspond with the taper of the
axle, and this sleeve is slidable so that it may pass over the holes h and close
them, or it may be withdrawn so as to expose the holes.
KK are.
balls or weights of any desired shape having arms L which are
fulcrumed to one side of the case I, as shown at M.
The inner ends of the arms L engage with a circular groove made in the end
of the valve J so that when the drum or case I is stationary, these balls will
fall by gravitation toward the axle, and will push the valve J along the shaft
so as to expose the holes h.
When the drum I is rotating at considerable speed, the weights K will fly
out by-centrifugal force, and the inner ends of the arms will then act to push
the valve forward and close the holes h.
When the valves are thus closed, any pressure of air applied within the brake
cylinder will be retained and the brakes will be applied with corresponding force.
If the rotation of the drum becomes less rapid or ceases, the weights falling
toward the axle will slide the valve J until the holes h are exposed and the air
escaping through these holes will immediately reduce the pressure in the brake
cylinder and correspondingly relieve the wheels from the brakes.
The rotation of the druin or case I is produced by bringing it into contact
with the axle A and its rotation ceases when it is removed from the axle.
This is effected by means of a piston N fitting within a cylinder which is
here shown as having a tee upon it which serves to couple it with the pipe F
so that air passing through this pipe under pressure may act upon the piston N.
The piston N is fixed to a stem or rod P which extends up through the upper
end of the cylinder and is connected in any suitable manner with some fixed
portion of the car, and when air under pressure is admitted into the brake
cylinder C, the pipe F also receiving the same air pressure, and the piston N
not being movable, the cylinder O and pipe F will be forced downward by the
action of the air until the periphery of the drum I is brought into contact with
the axle A.
A diaphragm 0¹ closes the passage through the pipe F, and this diaphragm
extends up and merges into the wall of the cylinder O of which it forms a part.
Exterior to the cylinder is a passage 02 and a small hole 03 connects the
upper part of the passage 02 with the cylinder 0 at a point which is normally
above the piston N.

page_text: Whenever the piston N rises above the hole 03 by reason of the depression
of the pipe F and the connected cylinder O, the air which enters F from the
brake cylinder can pass through the opening 0, thence through the passage (2
and into the axle H, upon which the drum I revolves, thus maintaining a direct
communication between the brake cylinder and this axle as long as the air
pressure in the brake cylinder is sufficient to keep the pipe l' depressed and the
piston N above the passage 03.
Within the cylinder is a spring R which normally acts against the upper
side of the piston N, and its tendency is to raise the pipe F and the cylinder
and to maintain the piston N in the lower part of the cylinder.
By any suitable regulating device the spring R is maintained at such a
tension that an air pressure as great as is necessary to stop a train moving at
a low rate of speed, or to hold such a train on any grade, will always be main-
tained in the pipe and the brake cylinder without forcing the drum I into
contact with the axle.
This pressure has been found by practice to be about 20 pounds, more or less.
The operation of the device will then be as follows: When brakes are to
be applied to the train, air is admitted through the train pipe E to all the brake
cylinders C of the train, the pressure being the maximum which it is desired to
use. The same pressure passing through the pipe F will act upon the piston N
and overcoming the tension of the spring R will force the piston N up until
the air can pass through the passage 02, 03, into the pipe F beyond the cylinder,
and thence into the axle H.
As soon as this action upon the piston N takes place, the drum I will be
depressed and its periphery which is preferably covered with rubber or other
suitably elastic or frictional material, will be brought into contact with the
revolving axle A.
The drum will then be caused to rotate and throwing the weights K outward
by centrifugal action will force the valve J to cover the ports h and thus pre-
vent any escape of air while the axle and drum are rotating. Under these
conditions the brake will be applied with full force, unless the wheels or any
pair of them commence to slide upon the track.
When this occurs the rotation of the drum driven by that pair of wheels, is
partially or wholly stopped momentarily, and the weights falling by gravita-
tion toward the axle, will force the valve J back and expose the ports h, and
this will allow the air in the pipe F and in the brake cylinder to instantly
escape through the holes h, thus reducing the pressure in the brake cylinder and
correspondingly relieving the wheels from the brake pressure.
This relief does not ordinarily reduce the pressure sufficiently to raise the
drum out of contact with the axle, and as soon as the axle again commences to
revolve freely, the ports h will be again closed by the movement of the valve J
and the brakes will be again applied.
The device thus acts as a most delicate governor, applying the brakes and releasing
them upon the least sign of hesitation and sliding of the wheels, and again
applying them as soon as the wheels commence to revolve freely. In this
manner all danger of sliding of wheels is prevented, the wheels are maintained
in perfect condition and the brakes can be applied by the engineer to their
fullest capacity without the danger aforesaid.
The device also acts as an automatic release of the air when the train has
slowed down to a speed of two or three miles an hour without any attention
from the engineer.
This low rate of speed being insufficient to keep the weights K thrown out
by centrifugal action, they will fall inwardly and open the valve J, allowing
the air to escape from the brake cylinder down to the necessary pressure to
complete the stop of the train, which is done without any of the recoil often
noticed when the air is suddenly released at the time of the stoppage of the
train.

page_text: This pressure being, as before stated, about 20 pounds will be sufficient for
the purpose, at the same time the spring R will act to raise the drums I out of
contact with the car axles and they will then cease to rotate.
The valve J and its connected mechanism being all contained within the
drum I are protected from dust and dirt, and only sufficient openings are made
in the sides of the drum I to allow the air which is released through the valve J
to escape.
Practice has shown that the escape of this air is sufficient to blow all dust or
foreign substances which may collect, outwardly and practically prevent any
clogging or difficulty from this source.
Having now particularly described and ascertained the nature of this said in-
vention, and in what manner the same is to be performed, we declare that what
we claim is:-
-:
1st. A regulator for air brakes consisting of a hollow axle having peripheral
perforations, a pipe connecting said axle with the brake cylinder, a drum
revolving upon the axle, a valve within the case slidable upon the axle adapted
to close or open the perforations, and weights fulcrumed within the case engag-
ing the valve, and a cylinder connecting with the first named pipe with a piston
movable therein whereby the drum is forced into contact with the axle when
the air is applied to the brake cylinder and removed therefrom when the pres-
sure is reduced.
2nd. An air brake regulating device consisting of a pipe connecting with
the brake cylinder, an axle supported at the outer end of the pipe, a substantially
closed cylindrical drum journaled and turnable upon said axle, a valve slidable
upon the axle within the drum, and ports in the axle which are opened or closed
by the movements of the valve, lever arms engaging the valve and having
weights at the outer end which act to close the valve when the drum is in rota-
tion and to open it when the rotation ceases, a cylinder connected at right angles
with the pipe from the brake cylinder having a spring-pressed piston movable
therein whereby the drum is normally retained out of contact with the axle,
and forced into contact with the axle when air is admitted to the brake cylinder
to apply the brakes, and a passage controlled by said piston whereby communica-
tion is made directly between the brake cylinder and the axle ports within the
arum.
arum.
Dated this 14th day of February 1899.
For the Applicants,
GEDGE & FEENY,
Chartered Patent Agents, 60, Queen Victoria Street, London, E.C.