Improvements in Brake Mechanism for Railway and similar Vehicles.
Year: 1895

page_text: Date of Application, 27th Aug., 1895-Accepted, 26th Oct., 1895
[Communicated from abroad by CHARLES OLIVER BAIRD, of Darby, City of
Philadelphia, State of Pennsylvania, United States of America, Gentleman.]
Improvements in Brake Mechanism for Railway and similar
Vehicles.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 :-
The object of this invention is to provide simple and efficient means for increasing
the braking power, and compensating for wear of the brake shoes or slack in the
brake-applying gear, of brake mechanism of that character of which the well-known
"Bemis" and "Peckham" brakes are examples.
This object is attained in the manner and by the means hereinafter described,
reference being had to the accompanying drawing, in which,-
Figure 1 represents a plan view of sufficient of a car truck and braking
mechanism of the type to which my invention relates to afford a proper
understanding of the invention.
Figure 2 is a similar view showing some of the parts in a different position; and
Figure 3 is a view illustrating a modification of part of the invention.
A and B represent the two axles of the car carrying the wheels A' and B' as
usual, and D and F represent the two brake-beams, the beam D having shoes a for
acting upon the wheels A' and the beam F having shoes b for acting upon the
wheels B'.
In connection with each of the brake beams D and F, is employed a
supplementary beam D¹ or F, and hung to each brake beam is a lever G,
the lever of the beam D being connected by a rod d to the brake-operating shaft
at one end of the car, and the lever of the beam F being connected by a rod f to
the brake-operating shaft at the opposite end of the car, it being understood that
this class of brake is intended mainly for application to street cars having a brake-
operating wheel or crank at each platform.
The supplementary beams D¹ and F1 are connected together by rods g and, in
the usual construction of braking mechanism, the lever Ġ of each brake beam is
connected to the corresponding supplementary beam by means of a link so that a
pull in the direction of the arrow upon each rod d or will cause the application of
the brake shoes to both sets of wheels; for instance, if the power is applied to the
lever G of the brake beam D, said brake beam and its shoes will be forced
towards the wheels A', and the beam D' will be forced away from said wheels,
and this movement of said beam D¹, will be transmitted by the rods g to the
bean F and thence to the beam F, so as to draw the shoes of the latter into
contact with the wheels B¹.
Springs, each connected at one end to one end of the brake beam and at the
other end to a bracket on the truck frame, serve to draw the beams D and F away
from the wheels as soon as the pull upon the lever G is slackened.
Braking mechanism of this character usually has no means for compensating for
wear of the brake shoes, or slackness in other parts of the gear, hence, after the

page_text: shoes become worn, the desired prompt and powerful application of the said shoes
to the wheels of the car cannot be effected.
My invention therefore has in view the provision of devices whereby wear or
slack in any part of the brake gear can be automatically compensated for, and the
surface of each shoe, when the brakes are off, caused to be maintained at a normal
and pre-determined distance from the tread of the wheel, whereby the brakes can
be as quickly and as powerfully applied when the shoes are worn as when they are
new and without any more extended movement of the brake handle.
Instead of connecting the brake lever G directly with the supplementary beam
adjacent thereto, my invention provides for mounting upon said supplementary
beam an eccentrically pivotted disk i constituting in effect a rotary wedge against
which the lever bears at a point comparatively close to its fulcrum, hence, as the
lever is moved in the direction of the arrow, there will not only be a separation of
the brake beam from the supplementary beam, due to such movement of the lever,
but, if the wear of the brake shoes permit it, a further separation due to the
turning of the eccentric disk or rotary wedge i by contact with the bearing face of
the lever G, the latter being preferably curved or cam-shaped at the bearing point,
as shown, so as to facilitate such turning movement; and being, if desired, toothed
or roughened for the purpose.
The eccentric disk i is provided with a segmental rack m with which engages a
spring pawl n, so that any forward movement of the disk is caught and held by the
engagement of said pawl with the rack; and the excess of separation of the main
and supplementary brake beams, which may be permitted by wear of the brake
shoes, is thus rendered permanent, and the shoes, when the brakes are off, are
normally held in close relation to the wheel treads, so that the brakes may be
always applied with full power with a minimum movement, say a three-quarter
turn, of the brake wheel or handle on the platform of the car, the parts being
preferably so arranged that the movement of the brake wheel or handle
terminates when it is in such position that the power can be most effectively
applied to it.
In order to prevent the highest point of the eccentric disk from passing beyond
the point of contact with the brake lever, I provide said disk with an armn s which,
by contact with a stop pin t on the supplementary brake-beam, will prevent any
further turning movement of the disk after its highest point has been brought to
bear against the lever; hence, after the main and supplementary brake beams
have been separated to the maximum extent there can be no approach of said
beams such as would permit the brake shoes to swing further away from the
wheels.
Irrespective of the compensating function of the eccentric disk or rotary wedge i,
it serves as a means of materially increasing the power of the brake, the disk and
lever having an action somewhat similar to that of a knee or toggle joint, whereby
the beans D, D', F, F, are cau-ed to be separated.
In order to insure the most effective action of the lever and disk it is necessary
that they shall be held firmly in contact with each other at all times, that is to
say, either when the brakes are applied, or when they are off, and the springs a in
the present combination perform this function in addition to their usual function of
withdrawing the brake shoes from contact with the wheels.
Although I prefer in all cases to use the eccentrically pivoted disk or rotating
wedge as the compensating device, other forms of the wedge may be employed
without departing from the main features of my invention, for instance, in Figure 3,
I have shown a sliding wedge suitably guided on the supplementary beam D'
and having an inclined face acted upon by the lever G, the back of the wedge
having a rack engaged by a spring pawl n' whereby said wedge is held in its
successive positions of advancement, a pin s on the wedge, serving, in connection
with one of the guides for said wedge, to prevent excessive forward movement of
the same.

page_text: In the drawings my invention is shown as intended for application to a car with
brake-operating device at each end, but it is obvious that it can be applied with
equal advantage to cars intended to run always in the same direction, and having
brake operating devices at one end only, the supplementary brake beam at the
front end of the car being in this case connected by the rods directly to the main
brake beam at the rear of the car. It is also obvious that it is immaterial whether
the lever G is hung to the main or to the supplementary beam, the compensating
wedge being hung to or carried by the other beam.
As the springs always serve to withdraw the brake beams to the same extent,
the brake operating wheel or handle is likewise always retracted to the same
extent, so that it constitutes an indicator showing to the driver or motor man the
condition of the brake, and it is always in the same position, when the brake is off,
so as to be conveniently grasped.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. The combination in car braking mechanism, of a main brake beam, a
supplementary brake beam connected to braking mechanism at the opposite end of
the car, a brake operating lever hung to one of said beams and an eccentrically
pivoted disk hung to the other beam and acted upon by said brake operating lever
so as to be turned thereby when slackness or wear of the gear permits such turning
movement, substantially as specified.
2. The combination in car braking mechanism, of a main brake beam, a
supplementary brake beam connected to braking mechanism at the opposite end of
the car, a brake operating lever hung to one of said beams, and a movable wedge
carried by the other beam and acted upon by said brake operating lever so as to
be advanced thereby when slackness of gear or wear of the shoes permits such
advance, substantially as specified.
3. The combination in car braking mechanism, of a main brake beam, a
supplementary brake beam connected to the braking mechanism at the opposite
end of the car, a lever hung to one of said beams, an eccentrically pivoted disk or
its equivalent sliding wedge, hung to the other beam and acted upon so as to be
turned or advanced by said lever, and a rack and pawl or other equivalent means
for retaining said disk or wedge in its successive positions of advancement,
substantially as specified.
4. The combination in car braking mechanism, of a main and supplementary
brake beam, a brake operating lever hung to one of said beams, a sliding wedge or
its equivalent disk eccentrically pivoted to the other beam and acted upon by said
lever so as to be advanced thereby, and stops s and t for restricting such movement
of the wedge or disk, substantially as specified.
5. The combination in car braking mechanism, of a main brake beam, a
supplementary brake beam connected to braking nechanism at the opposite end
of the car, a brake operating lever hung to one of said beams, an eccentrically
pivoted disk or its equivalent movable wedge carried by the other beam and acted
upon by said lever so as to be advanced when slackness of gear or wear of the
shoes permits such advance, and resilient means whereby the brake beam is
retracted on the release of the lever, said resilient means also serving to maintain
the lever and the wedge constantly in contact with each other, substantially as
specified.
6. The combination in car braking mechanism, of a main brake beam, a
supplementary brake beam connected to the braking mechanism at the opposite
end of the car, a brake operating lever hung to one of said beams, an eccentrically
pivoted disk or its equivalent movable wedge carried by the other beam and acted
upon by said brake operating lever so as to be advanced thereby when slackness
of gear or wear of shoes permits such advance, means for retaining the wedge in

page_text: its successive positions of advancement, and resilient means for retracting the
brake beam and maintaining the wedge and lever constantly in contact, substantially
as specified.
Dated this 27th day of August 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.