An Improved Automatic Continuous Railway Brake.
Year: 1890

page_text: Date of Application, 19th Aug., 1890-Accepted, 4th Oct., 1890
COMPLETE SPECIFICATION.
An Improved Automatic Continuous Railway Brake.
I JOSEPH JAMES SWITHIN LIST of Rockdale near Sydney in the Colony of New
South Wales, Joiner do hereby declare the nature of this invention 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 an improved automatic continuous railway brake actuated
by fluid pressure which brake is simple and cheap in construction as well as effective
and economical in operation.
This improved automatic continuous railway brake consists of three main parts, a
reservoir (hereinafter termed the auxilliary reservoir) a compound cylinder (with
connected pistons) and a back pressure valve preferably of peculiar construction all
of which are combined and arranged with other parts of well known construction as
a through "train" pipe a main reservoir of power and a regulator or triple valve
with pressure gauges &c. &c. The auxilliary reservoir is connected to the train pipe
(which leads from the main reservoir) by the back pressure or dead valve and is also
connected to one end of the compound cylinder. The compound cylinder has a larger
and smaller cylinder with their centres longitudinally in the same plane and having
cross-sectional areas in the ratio of not less than 2 to 1 and they are cast in the
one piece without division of any kind between them and are fitted with pistons
connected by an internal piston rod. The larger piston is connected to the outer gear
or brake levers by side rods running from said piston through the set-off of the large
cylinder from the small one, parallel to and embracing said small cylinder and con-
necting with a cross-head to which the brake levers &c. may be attached. The back
pressure or dead valve which I prefer to use has two valves and seats the one above
the other the stem or guide pin of the upper one reaching nearly to the top of the
lower valve whose stem or guide pin in turn passes out of the casing so that a lever
provided outside may be pressed upon the protruding stem to open both valves.
The improved automatic continuous railway brake constructed substantially as above
set forth is actuated by fluid pressure say by compressed air from a pump and reservoir on
the locomotive as well understood through the train pipe and connections to the auxiliary
reservoir (by way of the back pressure valve) and to the compound brake cylinders
so that both auxiliary reservoir and brake cylinders are supplied with the same pressure
at the same time-say this pressure supplied throughout the train is eighty pounds
to the square inch. Now to prepare the brake for use a certain amount of the pressure
in the train pipe and in the larger cylinder is released through the regulator until the
total of the original pressure on the piston of the smaller cylinder is about equal to
the total of the lesser pressure on the piston of the larger cylinder. In applying the
brake the lesser pressure in the train pipe and larger cylinder is still further reduced
at the rate desired by escape through the regulator or triple valve and the pressure
which is always the original pressure (less leakage) on the smaller piston will
apply the brakes. In releasing the brakes the pressure of the main reservoir is turned
into the train pipe and on to the larger pistou and moves the whole gear to the normal
positions.
But in order that this invention may be clearly understood reference will now be
made to the drawings herewith in which
Figure 1 is a plan partly in section of a brake cylinder and auxiliary reservoir
constructed according to this invention with the pistons in the normal or
"brakes off.""
position.
Figure 2 is a similar view in part of the same with the pistons in the "brakes on "
position.

page_text: .
Figure 3 is a transverse elevation of the brake apparatus under a carriage &c.
Figure 4 is a sectional elevation of the back pressure valve.
A is the auxiliary reservoir-B and C) the compound brake cylinders-D the back
pressure valve and E the "train pipe." A' is connecting pipe to compound cylinder
B is the smaller or as hereinafter termed the high pressure cylinder and C is the
larger or as hereinafter termed the low pressure cylinder-B and C are pistons-
B2 connecting piston rod-02 are side piston rods-D₁ is entrance and D2 exit
branch D³ back pressure valve--D4 valve stem-D valve seat-D is valve-
D' valve stem-D8 valve seat-D is hand lever-E¹ and E2 are connecting pipes
to auxiliary reservoir and low pressure cylinder respectively-F is cross-head and Fl
brake rod or lever.
In use this brake is made ready for operation by opening the pipe E by any well
known regulating apparatus to the main reservoir and charging the auxiliary
reservoir A with the fluid pressure say compressed air therefrom through the valve Ď
the air passing in through branch D₁ between valve D³ and seat D³ branch D² and
connecting pipe E¹; the compressed air also passes direct into the low pressure
cylinder C through pipe E2 and through pipe A into high pressure cylinder B thus
keeping the pistons B and C in equilibrium if their respective areas (as I prefer) be
in the ratio of one to two, or if the respective areas be in a ratio of one to more than
two then the pressure on the larger piston will keep the whole apparatus in the
extreme "brakes off" position. Now this charging having taken place the pipe E is
closed to the main reservoir and opened to escape until the pressure therein is so
reduced that the total of the high pressure which is shut in the auxiliary reservoir and
the cylinder B by the closing of back pressure valve D³ on seat D³ upon the smaller
piston B¹ will equal the reduced pressure in the pipe E and the total of such pressure
upon the larger piston C. This degree of pressure in pipe E &c. having been reached
the brake is ready for application which may be carried out quickly or slowly and to
the extent required up to the pressure in auxiliary reservoir A by the speed and extent
of a further reduction of the pressure in the train pipe E controlled by the regulator
as understood. To remove the brakes again sufficient pressure is allowed to pass
from the main reservoir into the train pipe E and larger cylinder C and such pressure
is again reduced to "make ready" as before described. When a car or vehicle
out of a train and being shunted or otherwise moved the brakes are always "on
until the hand lever is pressed inwards and opening valve De from seat D³ also presses
stem D* and lifts valve D³ from seat Ds and if the couplings of the train pipe be closed
allow the pressure in both cylinders B and C to equalize and by the larger area of
piston C¹ cause the brake gear to take extreme "brakes off" position. Now if the
brakes are required to be applied in second shunting the opening of the coupling will
reduce the pressure in the train pipe with the effect of applying the brakes as before
described. But if an end coupling be open when valve handle D is manipulated to
open valves D and D³ all pressure will escape through said coupling from the auxiliary
reservoir A and high pressure cylinder B and leave the brakes free.
cut
"
Having now particularly described and explained the nature of this said inven-
tion and the manner in which the same is to be performed I declare that what I
claim is :-
First. An improved automatic continuous railway brake consisting of brake rods
brake blocks and other well known parts and essentially of an auxiliary reservoir
connected by means of a back pressure valve with a train (pressure supply) pipe from
a main reservoir and compound cylinders the respective areas of which range in ratio
from one to two to one to not less than two and the smaller of which is adapted to
receive pressure from said auxiliary reservoir while the pressure in the larger is
regulated and controlled by means of said train pipe and its connections substantially
as herein described and explained.
Second. An improved automatic continuous railway brake consisting of, the
combination and arrangement with the brake blocks and under-carriage of a railway

page_text: vehicle and with a continuous supply pipe having connections regulators &c. of the
compound cylinder the auxiliary reservoir and the back pressure valve substantially as
herein described and explained and as illustrated in the drawings.
Third. In an improved automatic continuous railway, brake of the class set
forth the combination and arangement with an auxiliary reservoir such as A and train
pipe such as E of the back pressure valve constructed and operating as explained and
as marked D' to D' substantially as herein described and explained and as illustrated
in the drawings.
Dated this Seventh day of July One thousand eight hundred and ninety
Dated this 19th day of August 1890.
JOSEPH J. S. LIST.
Abel & Imray,
Agents for the Applicant.