IMPROVEMENTS IN APPARATUS FOR WORKING BRAKES BY SPRINGS, VACUUM, AND AIR PRESSURE, APPLICABLE TO RAILWAY ROLLING STOCK AND OTHER PURPOSES."
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Henry Kesterton at the Office of the
Commissioners of Patents on the 12th July 1877.
HENRY KESTERTON, of Birmingham, in the County of Warwick, Engineer.
"IMPROVEMENTS IN APPARATUS FOR WORKING BRAKES BY SPRINGS, VACUUM, AND
AIR PRESSURE, APPLICABLE TO RAILWAY ROLLING STOCK AND OTHER PURPOSES."
I use spring discs so shaped as to have a constant tendency to either spring
outwards or inwards, so as to be suitable as either a vacuum or air brake. Two of
these discs or dished plates are fastened together by rivets or otherwise in such a
manner as to form a hollow chamber or space between the two plates. Communi-
cating with this hollow space is a pipe for either forming a vacuum or for an
internal pressure of air.
I apply one or more of these spring disc chambers formed by the dished plates to
the brake blocks, to act either direct upon the wheels or through rods and levers, as
may be convenient.
When the pressures inside and outside the chambers are equal, the maximum
brake power is exerted upon the wheels, but when the air is withdrawn from the
chamber, or a pressure of air forced in to exceed that of the atmosphere, the spring
discs are bent outwards or inwards, and by their action the brake blocks are with-
drawn from pressing against the wheels.
I supply the air to and withdraw the air from these spring chambers by means of
a distributing valve constructed from two spring plates similar to those used for the
brakes before mentioned; one side of this distributing valve communicates with
and is fast to the vacuum pipe (which passes along the train) by means of a short
piece of pipe carried through the chamber and connected by T pieces to the spring
disc chainbers attached to the brake blocks; the other side of this valve carries a
short sleeve, projecting partly inside and partly outside the chamber, which fits
accurately the short pipe passing through the valve; this short pipe has a stop or
blank piece. cast or fastened at any convenient part of the inside, and is pierced on
each side with holes to allow the air to pass between the plates, expanding or
contracting them (whether pressure or vacuum valves), and thus moving the sliding
sleeve along the fast pipe and over holes beyond the centre stop, and through the
branch pipes into the brake spring disc chambers, and thus the brakes are held
from the wheels, or the sleeve part would be made stationary and the inside pipe

page_text: would move with the action of the disc plate or plates, the air being allowed to
escape through the valve formed by the inside pipe at the lower end.
To apply the brakes a little air is allowed to escape through a similar valve to
the above at the engine or guard's van, which allows the valve to expand or collapse
sufficiently to cover one set of air holes inside the chamber, and also to uncover
another set of holes in the pipe outside, the chamber communicating with the brake
chambers direct; by this means only a little waste in air or vacuum is necessary
either to apply the brakes in the most gradual manner or with the greatest
promptness.
I connect trains of carriages together with union couplings of conical shape; each
coupling is drawn up closely together by means of an outside sleeve carrying a
thread or threads which is cut away at a portion or portions of its circumference to
allow the sleeve to slide over; then; by turning, this sleeve round a short distance,
the threads are brought into contact with each other, and the coupling secured.