Improvements in Automatic Fluid Pressure Brakes for Railway Vehicles.
Year: 1895

page_text: Date of Application, 27th Apr., 1895
Complete Specification Left, 23rd Jan., 1896-Accepted, 29th Feb., 1896
PROVISIONAL SPECIFICATION.
Improvements in Automatic Fluid Pressure Brakes for Railway
Vehicles.
I, ALEXANDER MELVILLE CLARK, of the Firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Chartered
Institute of Patent Agents,, do hereby declare the nature of this invention
(a communication to me by Alexander Hill Moyes, of Ogden, in the County of
Weber, and Territory of Utah, United States of America Machinist) to be as
follows:-
This invention relates to fluid pressure brakes of the Westinghouse type, and
its object is to provide certain new and useful improvements in fluid pressure
brakes whereby a quick and positive action of applying and releasing the brakes
is obtained and the tension of the brakes is graduated without completely releasing
the same.
The invention consists principally of a double acting valve connected with the
train pipe, and a brake cylinder and slide valve controlled from the piston of the
said double acting valve and adapted to connect the brake cylinder with the outer
air.
The invention. also consists of certain parts and details and combinations of the
same, as will be fully described hereinafter.
The automatic fluid pressure brake comprises a brake cylinder attached to each
earriage and provided with a piston carrying a push rod connected with a lever
having a connection by a link with the brake mechanism of the car, A spring
presses on the piston so as to hold the latter in its normal position-that is at the
rear end of the cylinder. The cylinder is connected with a double acting valve
containing a piston in another cylinder connected by a port with a branch pipe
leading from the train pipe connected in the usual manner with the engine-driver's
valve and the main reservoir. The last mentioned piston carries a slide valve in
the passage leading from the upper end of the said cylinder to a port leading into
the brake cylinder near the front end thereof. The said slide valve normally
closes two ports located one above the other so that when the piston moves down-
ward in the cylinder upon reducing the pressure in the train pipe then the slide
valve moves with the said piston and uncovers first the one port and in case of
emergency also uncovers the other port to connect the interior of the brake
cylinder with the outer air. A spring pressed disc in the bottom cap of the
double acting valve is engaged by the said piston as the latter moves downward
upon a reduction of air pressure in the train pipe, as previously described. A feed
groove in the cylinder of said piston serves to connect the lower end thereof with
the passage above mentioned to permit of charging the brake cylinder with air from
the train pipe whenever the engine-driver's valve is moved into the corresponding
position. In the rear end of the brake cylinder is arranged a feed groove into
which opens a check-valve provided with a spring pressed valve held normally
on its seat and adapted to be lifted off its seat by pressure passing into the brake
cylinder and to the feed groove to the under side of the said check valve. A port
in the body of the check-valve connects the latter with the interior of an auxiliary
reservoir which forms an integral part of the brake cylinder and is connected with
the rear end thereof by an opening in the rear head of the cylinder. Into the

page_text: auxiliary reservoir extends a small cylinder terminating with its inner open end
near the said opening, and in this cylinder is fitted to slide a piston on a piston
rod forming part of the piston of the brake cylinder. On the push rod of the
brake cylinder piston is arranged a piston operating in a cylinder attached to the
front end of the brake cylinder.
The operation is as follows:-When the air from the train pipe passes through
the branch pipe and port into the cylinder of the double acting valve and forces
the piston in the said cylinder into an uppermost position, so that the ports are
closed by the slide valve and the air can pass through the feed groove, passage,
and port, into the brake cylinder. The brake cylinder piston is now in its rearmost
position so that the brake mechanism is in a released position and the feed groove
is uncovered to permit the air to pass from the brake cylinder through the feed
groove into the check valve to lift the spring pressed valve therein to permit the
air to pass into the auxiliary reservoir to charge the latter with the same pressure
as that contained in the train pipe. Now when it is desired to apply the brakes,
the pressure in the train pipe is reduced, and consequently a reduction of pressure
takes place in the cylinder of the double acting valve whereby the piston of said
cylinder is forced downward by the preponderance of pressure in the brake
cylinder. The slide valve uncovers the one port and in case of emergency stop,
the other port also. The brake cylinder is thus connected at its front end with
the outer air and consequently the air in the said cylinder passes to the outside
thereby leaving a preponderance of pressure in the auxiliary reservoir to act
against the rear end of the brake cylinder piston and force the latter forward to
apply the brakes in the usual manner. The spring acting on the brake cylinder
piston is now compressed, and whenever it is desired to release the brakes, air is
permitted to pass from the train pipe into the double-acting valve, to force the
piston therein upward, to close the two ports, and allow air to pass through the
double acting valve into the brake cylinder, to move its piston back to its forward
position. The above described operation is then repeated, that is the auxiliary
reservoir is recharged in case of any leakage taking place.
Dated this 27th day of Anril 1895
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
Improvements in Automatic Fluid Pressure Brakes for Railway
Vehicles.
I, ALEXANDER MELVILLE CLARK of the Firm of A. M. and Wm. Clark of
53, Chancery Lane in the County of Middlesex, Fellow of the Chartered Institute
of Patent Agents, do hereby declare the nature of this invention (a communication
to me by Alexander Hill Moyes of Ogden, in the County of Weber and Territory
of Utah, United States of America, Merchant), and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement :-
This invention relates to fluid pressure brakes of the Westinghouse type and it
has for its object to provide certain new and useful improvements in fluid pressure
brakes whereby a quick and positive action of applying and releasing the brakes
is obtained and the tension of the brakes is graduated without completely releasing
the same.
The invention consists principally of a double acting valve connected with the
train pipe, and a brake cylinder and slide valve controlled from the piston of
the said double acting valve, and adapted to connect the brake cylinder with the
outer air.

page_text: The invention also consists of certain parts and details and combinations of the
same, as will be fully described hereinafter and then pointed out in the claims.
Reference is to be had to the accompanying drawing forming a part of this
Specification, in which the figure is a sectional side elevation of the improvement.
The automatic fluid pressure brake is provided with a brake cylinder A attached
in any suitable manner to each carriage and provided with a piston B carrying a
push rod C connected at its outer end with a lever D having a connection by a
link E with the brake mechanism of the carriage. A spring F presses on the
piston B, so as to hold the latter in its normal position as shown in the drawing―
that is, at the rear end of the cylinder A.
The cylinder A is connected with a double acting valve G containing a piston G
in a cylinder G connected by a port G³ with a branch pipe H', leading from the
train pipe H, connected in the usual manner with the engine driver's valve H' and
the main reservoir H. The piston G' carries a slide valve G in the passage Go
leading from the upper end of the cylinder G2 to a port A¹ leading into the
cylinder A near the front end thereof. The slide valve G normally closes two
ports G and G7, located one above the other as shown in the drawing, so that
when the piston G' moves downward in the cylinder G³ upon reducing the pressure
in the train pipe H, the slide valve G moves with the said piston and uncovers first
the port G and in case of emergency also uncovers the port G, to connect the
interior of the cylinder A with the outer air.
A spring-pressed disk G8 in the bottom cap of the valve G, is engaged by the
piston G, as the latter moves downward upon a reduction of air pressure in the
train pipe, as previously described. A feed groove G in the cylinder G2 serves to
connect the lower end thereof, with the passage G³, to permit of charging the
cylinder A with air from the train pipe whenever the engine driver's valve H² is
moved into the corresponding position.
In the rear end of the cylinder A is arranged a feed groove A³, into which opens
a check-valve I, provided with a spring-pressed valve 1¹ held normally on its seat,
and adapted to be lifted off its seat by pressure passing into the cylinder A and to
the feed groove A² to the underside of the said valve 1. A port 1" in the body of
the check-valve I connects the latter with the interior of an auxiliary reservoir J
which forms an integral part of the cylinder A, and is connected with the rear end
thereof by an opening A³ in the rear head of the cylinder, as is plainly shown in
the drawing.
Into the auxiliary reservoir J extends a small cylinder K, terminating with its
inner, open end near the opening A³; and in this cylinder K is fitted to slide a
piston B¹ on a piston rod B forming part of the piston B. On the push rod C of
the piston B is arranged a piston C, operating in a cylinder L attached to the front
end of the cylinder A.
The operation is as follows:
When the several parts are in the position shown in the drawing, the air from
the train pipe passes through the branch pipe H¹ and the port G³ into the
cylinder G of the double acting valve G, to force the piston G' in the said
cylinder into an uppermost position, so that the ports G and G' are closed by the
slide valve G, and the air can pass through the feed groove G³, passage G³ and
port A¹ into the brake cylinder A. The piston B is now in its rearmost position,
so that the brake mechanism is in a released position and the feed groove A³ is
uncovered, to permit the air to pass from the cylinder A through the feed
groove A into the check valve I, to lift the valve I¹ therein, to permit the air to
pass through the port 1 into the auxiliary reservoir J, to charge the latter with
the same pressure as that contained in the train pipe H.
When it is desired to apply the brakes, the pressure in the train pipe H is
reduced, and consequently, a reduction of pressure takes place in the cylinder G³,
whereby the piston G is forced downward by the preponderance of pressure in
the cylinder A. The slide valve G uncovers the port G, and in case of an
emergency stop, the other port G7 also. The cylinder A is thus connected, at its

page_text: :
front end, with the outer air, and consequently the air in the said cylinder A
passes to the outside, thereby leaving a preponderance of pressure in the
auxiliary reservoir J, to act against the rear end of the piston B and force
the latter forward in the direction of the arrow a¹ to apply the brakes in the
usual manner.
The spring F is now compressed, and whenever it is desired to release the brakes,
'air is permitted to pass from the train pipe H into the double acting valve G, to
force the piston therein upward, to close the ports G and G', and allow air to pass
through the double acting valve G into the cylinder A, to move the piston B back
to its forward position-that is, in the inverse direction of the arrow a).
The above described operation is then repeated-that is, the auxiliary reservoir J
is recharged in case of any leakage taking place..
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. An automatic fluid pressure brake, comprising a brake cylinder, a piston and
double acting valve connected with the train pipe and with the forward end of the
said brake cylinder, the said double acting valve carrying on its piston a slide
valve for connecting the interior of the brake cylinder with the outer air,
substantially as shown and described.
2. An automatic fluid pressure brake, comprising a brake cylinder containing a
spring-pressed piston, a double acting valve connected with the said brake cylinder
and with the train pipe, and an auxiliary reservoir connected with the rear end of
the said brake cylinder and also connected with a feed groove in the brake cylinder
by a check valve, substantially as shown and described.
3. An automatic fluid pressure brake, comprising a brake cylinder containing a
spring-pressed piston, an auxiliary reservoir opening into the rear end of the said
cylinder, a check valve for connecting the feed groove of the brake cylinder with
the said auxiliary reservoir, and a double acting valve connected with the forward
end of the said brake cylinder and with the train pipe, the said-double acting valve
being provided with a piston and a slide valve operating over two ports connected
Iwith the outer air, substantially as shown and described.
Dated this 23rd day of January 1896.
A. M. & WM. CLARK,
53 Chancery Lane, London, Chartered Patent Agents.