IMPROVEMENTS IN RAILWAY BRAKE APPARATUS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Gordon Donaldson Peters at the Office
of the Commissioners of Patents on the 17th September 1879,
GORDON DONALDSON PETERS, of Bunhill Row, in the County of Middlesex, Mer-
chant. "IMPROVEMENTS IN RAILWAY BRAKE APPARATUS."
My Invention relates to railway brake apparatus, and is designed to provide
more efficient means for causing the brake blocks or shoes to be applied to and
removed from the wheels of the vehicles than any heretofore in use."
In carrying the said Invention into practice I attach to the underside of each
vehicle to be braked, two main tubes or pipes of suitable diameter; each pipe
extends from one end to the other end of the underside of the vehicle and the
extremities are furnished with suitable means to enable them to be connected by
flexible tubes with the correspoding pipes attached to the adjoining vehicles, namely,
the one in front and the one at the rear in forming a train.
Beneath each of the said vehicles I attach a cylinder furnished with a piston
and piston rod, the part of the latter extending outside the cylinder, being suitably
connected with the levers or other parts controlling the movement of the brake-
blocks, so that the motion of the piston rod inward or outward will have the effect
of applying the blocks to the wheels or removing them therefrom.
At the rear of the last vehicle of the train the ends of the two said pipes are
suitably connected, one of the pipes being closed by a stop cock hereinafter men-
tioned, or each pipe may be provided with a stop cock, both of which will be closed,
and the pipes at the other end of the train are connected upon the engine or
locomotive by a three-way cock, in order that the engine-driver may be able to
close and open the pipes on one side of the train without closing or opening those
on the other side, as is required in operating the apparatus.
Each of the aforesaid cylinders is connected to the main pipes or tubes under
its own vehicle by means of two branch pipes, one of which communicates with
one end of the cylinder and the other with the opposite end thereof. The parts of
the apparatus are so relatively arranged that each piston will be in; or about in
the centre of its cylinder when the brake blocks are not in contact with the
wheels.
'
The said tubes are placed in connection with an air-pump or compressor of any
suitable kind, also with an injector or other suitable apparatus for exhausting air,
all placed upon the engine and under the immediate control of the engine-driver...

page_text: All the pipes in a train having been suitably connected, the air-pump or com-
pressor is put in motion, the said three-way cock being so placed that both sections
of the pipes ore open. By this means all the pipes and all the cylinders become
charged with compressed air and the pressure being equal on both sides of the
pistons they are maintained centrally in their cylinders, that is to say in the
position which keeps the brake-blocks out of contact with the wheels. When it is
desired to apply the brake-blocks to the wheels to stop or retard the motion of the
train, the engine-driver closes that part of the three-way cock in connection with
the pipes communicating with the end of the cylinders through which the piston
rod enters and which will hereinafter he called the upper end. And he also brings
the injector into operation to exhaust the air from the other section of the pipes
and from the other or lower end of each cylinder. A vacuum is thereby created
in this section of the pipes and in the lower end of each cylinder, and the pistons
are all driven forward by the power of the compressed air in the upper part of
each cylinder, the brake-blocks being thus all instantaneously applied to the wheels
with greater power. It will be seen that I not only remove the pressure of the
compressed air on the lower end of the pistons but I also remove the ordinary
pressure of the atmosphere therefrom, so that the compressed air in the upper part
of the cylinders and in the pipes, and that in the receiver of the pump or com-
pressor, is caused to act upon the pistons in a very advantageously manner.
To remove the brake-blocks from the wheels the engine-driver has only to
operate the aforesaid three-way cock in such a manner as to put both sections of
the pipes into communication with each other, where upon a portion of the com-
pressed air in the upper end of each cylinder immediately escapes through the
pipes, and operating upon the other side of each piston forces it back to its central
position, the pressure on each side of all the pistons being thus again equalized
and the pistons ready for being again operated when it is required to apply the
brake-blocks to the wheels.
Every time the brake-blocks are so applied and released there will be some
reduction in the pressure of the compressed air within the pipes and cylinders, but
the desired compression is readily readjusted by means of the air-pump or com-
pressor and the pressure is thus brought up to the normal degree again which will
vary according to circumstances.
A reservoir for the compressed air may be provided upon or under the engine to
increase the pressure in the cylinders whenever required, without having to operate
the air pump on every occasion on which this is necessary.
In order to cause the said apparatus to operate automatically in the event of
the vehicles becoming detached through an accident or otherwise, I provide a stop-
cock on one of the coupling tubes between each vehicle, that is to say, on one of the
coupling tube joining the pipes which are in connection with the upper end of each
piston. The said stop-cock is connected to some part of the vehicle, by a cord or
otherwise, in such a manner that it will operate the stop-cock to close this tube
when the vehicles commence to separate; then when the other tube becomes
divided the excess of air will escape therefrom and from the lower end of the
cylinders, whereupon the compressed air in the section of pipes closed by the said
stop-cock acts upon the pistons with a force due to the preponderance of the pressure
exerted by the compressed air over the ordinary. atmospheric pressure on the other
side of the pistons. The brake-blocks therefore become instantaneously applied to
the wheels.
The pipes may if desirable be also connected with the guards' vans in such a
manner that by operating a cock the guards may also be able to cause the brakes
to be operated.
The said cylinders need not be bored out accurately at their upper parts as the
pistons travel only from the centre towards the other end, and I prefer that the
upper part of the cylinders should be of somewhat smaller diameter than that of
the other end.

page_text: In some cases I may employ one main tnbe or pipe only instead of two as above
described, in which case the branch pipe to the upper end of the cylinder will be
provided with a valve to prevent any escape of air from this end when the other
nd is being exhausted, or when the train separates through accident or otherwise,
this valve will be suitably constructed so that it may be opened when desired to
allow of the escape of air from this end of the cylinder.
By means of my said improvements fewer parts are required than in similar
apparatus heretofore used, and the parts may also be of lighter construction. The
fact of the cylinder being also a reservoir is of great advantage in an apparatus of
this kind.