IMPROVEMENTS IN BRAKES OR RETARDING APPARATUS
Year: 1854

page_text: application for Letters Patent was not given within the time prescribed
by the Act.)
PROVISIONAL SPECIFICATION left by James Birsch Robb at the Office of
the Commissioners of Patents, with his Petition, on the 1st November
1854.
I, JAMES BIRSCH ROBB, of Boston, in the United States of America,
Counsellor at Law, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN BRAKES OR RETARDING APPARATUS" to be as follows:-
This Invention relates to a peculiar arrangement and construction of brake,
self-acting or otherwise, for railway purposes, whereby the injurious strain on
the axles and wear and tear upon the peripheries or tires of the wheels is greatly
reduced. The brake or retarding apparatus consists of a brake of friction
pulleys, of about one-third the diameter of the running wheels of the carriage
or truck on which they are to operate; these friction wheels or rollers may
be carried on the ends of transverse rods or shafts running across the under
side of the carriage framing near the surface of the rails. The peculiar mode
of attaching the friction wheels to their shafts, upon which they run loosely,
also forms another feature of the Invention. A double conical collar is
employed, which is put on to the ends of the shaft in two halves, and the
interior of the hubb of the wheel is bored out to correspond. One half of
the collar is first placed upon the shaft, and the friction wheel is placed upon
it; the second half of the collar is now inserted into the hubb and on the shaft,
and is secured thereto by a pin or key. The first half of the collar is now
tightened up by a set screw, but a space is left inside the hubb between the two
halves to allow of subsequent tightening up, and afford space for lubricating

page_text: matter. The shafts are supported in bearings in metal plates, which work
loosely at their upper ends on the axle of the carriage; these plates are con-
nected by "toggle" or knee joint levers, and the shafts and friction pulleys
may be raised or lowered by simply depressing or elevating the central joint
of the levers. For this-purpose a vertical rod is attached-at its..lower end to
the knee joint levers, and connected at its upper extremity with a lever arm,
working on a fixed centre in the carriage or waggon framing. From this last-
mentioned lever a horizontal rod runs along the side of the carriage, and may
be acted upon by the buffers of the same when the steam is shut off, and so
constitute a self-acting brake; or it may be connected with the ordinary
mechanism for actuating by hand. When the brake is out of action the
friction pulleys are elevated slightly above the rails, and are free from con-
tact with the running wheels of the carriage; but when they are to be
brought into action, the vertical.rod, herein-before referred to, is caused to
"draw up the knee joint levers, which will have the effect of contracting the
space of the metal plates, and bringing thereby the friction wheels into close
contact with the periphery of the running wheels and with the surface of
the rails simultaneously. The rotation of the running wheels will now cause
the friction pulleys to revolve at a much higher velocity in a contrary direc-
tion, that is, in an opposite direction to that in which the train is running;"
and this rotation, by producing great friction on the running wheels and
rails simultaneously, will not only check the revolutions of the running
wheels, but will tend ultimately to reverse them, or cause them to revolve
in an opposite direction to the motion of the train. As the running wheels,
however, are never held stationary, it follows that the friction will be equally
distributed over the entire surface of their peripherys in place of at one point
only, as is the case with ordinary brakes when the running wheels are brought
to a stand.
Various modes of suspension or connection of the friction pulleys may be
employed; as, for example, instead of their being carried by moveable plates,
and actuated by a "toggle" or knee joint, they may be fitted to vertical rods
running direct up to the framing. The main feature of the Invention is, how-
ever, the application of a friction roller or rollers in such a manner as to cause
the said rollers to act simultaneously upon the periphery of the running wheels
and the surface of the rails, and also the mode of attaching the friction wheels
to their carrying shafts.