Improvements in Pneumatic Brakes for Railway Vehicles.
Year: 1895

page_text: Date of Application, 8th Oct., 1895-Accepted, 16th Nov., 1895
COMPLETE SPECIFICATION.
Improvements in Pneumatic Brakes for Railway Vehicles.
We, FRANK ROBINSON of 41 Summer Street, Bangor, Maine, Mechanic, and
JAMES HALE SEWALL, of 100 Exchange Street, Worcester, Massachusetts,
Manufacturer, both in the United States of America, do hereby declare the nature of
the said invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The invention relates to improvements in pneumatic brakes for railway vehicles
and more particularly in the construction of a lock for the take-up joint, whereby it
can only be operated by releasing the lock, and thus prevent the accidental
operation of such take-up.
The invention further consists in the peculiar construction and arrangement of
the parts, all as more fully hereinafter described.
In the drawings,
Fig. 1 is a perspective view of the improved construction, showing the take-up
connection applied between the two cylinder levers.
Fig. 2 is a plan view showing the take-up connection between one cylinder lever,
and a lever attached to the car at or near the opposite end thereof, and
Fig. 3 is a vertical, enlarged section through the take-up connection, showing in
full and dotted lines, the different positions of the lock.
A is the air brake cylinder, B is the piston rod therein, C is the cylinder lever
actuated thereby, which lever is connected at its end to the brake mechanism by
the connecting rod C¹.
This lever is provided with a take-up mechanism, for the slack, comprising the
bar D, having a ratchet on its upper face, and sliding within the sleeve shaped
rod E carrying the dogs or pawls F. This section E at its end is bifurcated to
permit the engagement between of the end of the cylinder lever C, which has a
limited movement between the bolt G and the stop or web H, referring especially
to Fig. 1.
Referring to Fig. 2. I is a lever similar to the lever C, pivotally supported near
one end of the car, and connected by the connecting rod J with the brake
mechanism on the truck at that end of the car.
Each of the levers is provided with the take-up device just above described, that
for the lever I being indicated at K, and that for the lever C being represented by
the letter E. D' and D indicate respectively the ratchet bars for the take ups K
and E, which bars are attached at a and to the bottom of the car. The
operation of the take-ups when applied to the different ends of the car, as above,
is similar to that of the take-up shown in Fig. 1, the parts D and D' however
being attached to the car instead of to the lever fulcrumed on the brake cylinder
as in that figure. Cis the rod connecting the lever C with the brake mechanism
at that end of the car adjacent to the lever C and serves to transmit motion from
the lever to the brake.
L is a tie rod, acting as a fulcrum rod for the two levers, formed of two parts,
the meeting ends being provided with a take-up joint of the kind as described on
the levers C and I.
In the operation of such a device, when the shoes wear, the abnormal movement
of the levers C, striking the stop or web H will shorten up the take-up device, so
that when the piston returns to its initial position, it will actuate the take-up joint
in the tie rod, so that in the next operation of the brake, the levers C and I will
fulcrum upon the shortened tie or fulcrum rod and thus take up the slack with
substantially a uniform pressure to the piston.

page_text: In the use of such take-up devices, it has been found that stones, or pieces of
iron lying on the track will sometimes be picked up and thrown by being struck by
hanging portions of the gear, for instance, and such flying missiles have been known
to strike the take up device and actuate it, taking up slack when the brakes
were not being set by the air. This is undesirable, as it may cause the brakes to
remain set slightly all the time, and thus rapidly wear off the shoes, as well as
impede the motion of the train.
To prevent this, and to prevent tampering with the take-up device, or its
accidental displacement by workmen working under the cars, we have provided a
lock for the take-up device, which is operated by the actuating device of the
take-up which in this case is the levers C and I.
This lock is shown as consisting of the lever M, pivoted on top of the sleeve
section of the take-up, having the tooth O. at one end, adapted to pass through an
aperture in the top of the sleeve and engage with the ratchet P, having its teeth
reversely arranged to those with which the pawls engage, thus acting to prevent
the telescoping of the two parts of the take-up device, until the locking tooth had
been disengaged from its ratchet.
The lever M at the opposite end, has the arm Q, extending down through an
aperture in the sleeve section, this arin having the foot R, the upper face of which
has the inclined bearings S, adapted to be struck by the inner edge of the lever C,
to rock the lever upon its pivot into the position shown in full lines in Fig. 3.
Thus, it will be seen, that at all times, except when the lever C would act to
shorten the take up device, the parts thereof are locked. When the lever reaches
the point where it would shorten the take-up device, it trips the lock, and permits
the parts to telescope, and the lock is applied just as soon as the lever withdraws.
While we have shown a specific form of lock, and a specific way of actuating it,
we do not desire to be limited thereto as we believe we are the first to apply such
a lock to a take-up device, with means for unlocking it by the actuating devices
for the take-up or upon the actuating of such take-up.
The construction of the parts where the levers C and 1 are at opposite ends we
also consider especially advantageons.
Having now particularly described and ascertained the nature of our said inveu-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a rake slack adjuster, the combination of a "take-up" joint, actuating
menns for the joint, and a lock for the joint adapted to be released upon the
actuation of the joint.
2. In a brale slack adjuster, the combination of a "take-up" joint, actuating
means for the joint, and luck to the joint released by the said actuating
mcans.
3. In a brake slack adjuster, the combination of "take-up" joint in the brake
actuating mechanism, a lock the relor, and a lever of the Irake actuating mechanism
adapted to release the lock and to actuate the "take-up."
4. In a brake slack adjuster, the combination of the lever C actuated from the
brake cylinder, the take up device as described pivoted to the car at one end and
having a loose connection with said lever at the opposite end, the lever I, the
take up device as described pivoted to the car at one end and having a loose
connection with said lever at the opposite end, a fulcrum or tie rod, connecting said
levers and a take-up joint in said tie rod, as and for the purpose described.
T
Tun
FRANK ROBINSON.
JAMES MALE SEWALL.
Haseltine, Lake & Co.,
5 Houthamton Buildings, London, W.C., Agent for the Applicants.