Combined Compressed. Air and Vacuum Automatic Brake
Year: 1887

page_text: Date of Application, 9th July, 1887
Complete Left, 9th Apr., 1888
Complete Accepted, 11th May, 1888
I EDWIN HELMORE TRELEASE of 22 Hetherington Road Clapham in the County
of Surrey Clerk do hereby declare the nature of this invention to be as follows :-
That said invention is a
my
"Combined Compressed. Air and Vacuum Automatic
Brake" and can be worked with Compressed air and a vacuum together or with either
separately-It is designed to work in connection with the Westinghouse Compressed
air or with the automatic Vacuum system.
That when working as first above mentioned the combined power of the Compressed
air and vacuum is brought to bear in drawing the blocks on the wheels.
That I employ 2 main pipes running the whole length of the train-one for Com-
pressed air hereinafter called the "Air main pipo"-and one for Vacuum-herein
after called the "Vacuum main pipe." On each coach it is necessary to fit the
following parts: Two small Reservoirs-one for the purpose of creating in and
maintaining a partial vacuum and one for storing Compressed air, to work the Brake-
a Brake cylinder fitted with piston and rod connected to the brake levers and rods for
drawing the blocks on the wheels-and suitable valves by means of which I obtain
the instantaneous automatic action.
These valves are four in number and in the following I briefly explain their use
and purpose-(I shall hereafter refer to them in the order in which name them as
Valve 1 Valve 2, etc.)
"1" is connected with the Air main pipe and is the means of communication
between the Brake cylinder and the Atmosphere for releasing, and between small
Air Reservoir and Brake cylinder, for applying, the brakes.
"2" is a Valve connected with the Vacuum main pipe and is the means by which
I effect the instantaneous release of the Brake when it is being worked with both
Compressed air and a Vacuum; and also the means by which I obtain the automatic
action of the brake when it is worked only with a partial Vacuum-It opens com-
munication between the Brake cylinder and Small Vacuum Reservoir and between
Brake cylinder and Vacuum Main pipe.

page_text: "3" is a valve which I place between 1 and 2 and the Brake cylinder, and the
passages from 1 and 2 respectively to the Brake cylinder pass through it-In its
normal state it closes the passage from Valve 1 to the Brake cylinder, while that
between Valve 2 and the Brake cylinder is open-It is worked by compressed air
admitted into it from Small Air Reservoir, on the application of the brakes, through
the action of Valve 1-By means of this Valve I obtain the combined action of the
two powers used to work the brake.
"4" is a small valve by means of which the brake-when worked with a partial
vacuum only can be instantly released by the driver.
Covering the passage into the Small Air Reservoir from Valve 1, I place a small
valve behind which is a spiral spring so that, while running, an extra pressure
(about lb. per square inch) is maintained in the air main pipe, which extra pressure
is necessary to compress another spring placed in Valve 1. By the action of the
latter spring on a small hollow slide valve, (also placed in Valve 1) air is admitted
from Small Air Reservoir-through Valve 1-into Valve 2, on the reduction of
pressure in the Air Main pipe (as hereafter explained); and also by the action of the
spring in Valve 1 any air introduced into the Brake cylinder for applying the brakes
can be maintained there, for the purpose of retarding a train down an incline or
otherwise.
On each Vehicle I also place a Hand Release valve so that in the event of the
Brakes being applied automatically-as hereafter explained-or when the locomotive
is not attached, the brakes can be released by pulling a cord at either end of the
vehicle This valve acts in the same way whether the brake is being worked both
with Compressed air and a Vacuum or with either separately.
To enable vehicles to be detached without setting the brakes I place in both main
pipes at each end of every vehicle, cocks which also serve to close the pipes at the
end of the train.
In the branch pipes on every vehicle leading from the main pipes to Valves 1 and 2
respectively I place cocks so that the apparatus on any one vehicle can be cut out of
the system.
On the Locomotive it is also necessary to place a pump for producing the Com-
pressed air, a Main Reservoir for storing air necessary to release the brakes and
recharge small air Reservoirs a Drivers Air Valve for regulating the flow of air into
the Air main pipe. Also an Ejector in connection with the Vacuum main pipe, for
creating and maintaining the necessary Vacuum.
The Drivers Air Valve is the means of communication between the Main Reservoir-
on the Locomotive-and the Air Main pipe-while running, between Air Main pipe
and Atmosphore for applying, and between Air main pipe and Main Reservoir for
releasing, the Brakes.
In each Guard's van I place a Valve which can be worked by hand to apply the
Brakes whether being worked with Compressed air and a Vacuum both, or
with either separately-It also works automatically when Compressed air and a
Vacuum are both used to work the Brake in the following manner: That should the
Vacuum in the Vacuum main pipe be destroyed-either purposely or by accident—
it will open a passage between the atmosphere and both main pipes, this-as here-
after described setting the brakes throughout the train with full force-That when
the brake is being worked with a Vacuum alone it admits air into the Vacuum Main
pipe on the application of the Brakes-at various parts of the train.
That in the above I enumerate and describe the parts necessary to fit a Locomotive
and every vehicle of a train with my said invention.
When Compressed air and a partial Vacuum are both used to work my said
invention the general principle of action is as follows:-
.
Air compressed by the pump on the Locomotive enters Main Reservoir and
flowing through drivers air valve and Main air pipe charges Small air Reservoirs
throughout the train-Also, by means of the Ejector on the locomotive, a Vacuum is
created in the Vacuum main pipe and in small Vacuum Reservoirs and in Brake
cylinders on both sides of Brake pistons-(The back-if placed horizontal-or the top-

page_text: if vertical of the Brake cylinder and piston on every vehicle is in direct communication
with the Small Vacuum Reservoir) The essential principle of the system is, that
maintaining the pressure in the Air Main pipe, and the vacuum in the Vacuum main
pipe keeps the brakes off, but the escape of air from, or the admission of air into,
either or both, respectively (purposely or by accident) instantly applies them. When
the Brakes are applied by the driver, however, they are regulated by the reduction of
power in the Air main pipe only, the vacuum in the Vacuum main pipe being
maintained through the action of Valve 3-On the pressure in the Air main pipe
being reduced the action of Valve 1 closes the exhaust passage to Atmosphere, admits
air into Valve 3 which rises closing passage from Valve 2 to front or bottom side of
Brake cylinder, at the same time opening passage from Valve 1 thereto, when air
will pass from small Air Reservoir into Brake cylinder in front or at bottom side
of piston, and acting on the vacuum on the other side of Brake piston and in Small
Vacuum Reservoir, immediately applies the brakes-By carefully regulating the
reduction of pressure in the Main air pipe any required pressure can-by action of
valve 1-be introduced gradually into the Brake cylinder for applying the brakes, and
maintained there for retarding a train down an incline or otherwise; but on a con-
siderable reduction of pressure in the Main Air pipe, or on the air being entirely
exhausted therefrom-by design or accident-the Brakes are instantly applied with
full force-The vacuum in the Vacuum Main pipe is not destroyed by the application
of the brakes in this way but acts in increasing the power of the brake by temporarily
adding to the size of the Small Vacuum Reservoirs it being in communication there
with through Valve 2, but should the Vacuum in the Vacuum main pipe become
destroyed, the Valve 2 immediately closes the communication between Small Vacuum
Reservoir and main pipe, and applying the brakes with full, force through the action
of the valves I place in each Guard's van-In the way above described with pressure
acting on one side of Brake piston and a Vacuum (maintained in Small Vacuum
Reservoir) on the other I obtain the combined power of both in drawing the Brake
blocks on the wheels-To release the brakes air is admitted into the Air Main pipe
from the Main Reservoir on the Locomotive, by the driver when the action of Valve
causes the air in Brake cylinder and in Valve 3 to be exhausted into the atmosphere
when the action of Valve 3 closes passage from Valvo 1 to Brake Cylinder and
opening passage between Brake Cylinder and Valve 2 when all air remaining in
Brake Cylinder at front or bottom side of piston, to atmospheric pressure only (all air
above atmospheric pressure having passed into the atmosphere through Valve 1. as
before explained) passes into Valve 2 and spreading throughout the system equalises
the pressure on both sides of Brake piston when the blocks are drawn off the wheels
by means of a light wire spring attached to the crosshead of Brake piston rod-This
spring is only necessary when the cylinder is placed in a horizontal position-When
a vertical cylinder is used the brakes fall off by gravity-The vacuum-only slightly
reduced by the air which remained in the Brake cylinder-is restored after the
brakes have been released.
When my said invention is worked with Compressed air only the general principle
of action is the same as above described, the only difference being the absence of a
vacuum in any part of the system.
When iny said invention is worked with a partial Vacuum only the general principle
of action is as follows:-By means of the Ejector on the Locomotive the air is drawn
out of the Vacuum main pipe and Reservoirs and Brake cylinder from both sides of
Brake piston through Valve 2 so that while running a more or less perfect Vacuum is
maintained throughout the system-To apply the Brakes air is admitted into the
Vacuum main pipe, when the action of Valve 2 immediately closes the communication
between Vacuum main pipe and Reservoir, and admitting air into the Brake cylinder
at front (or bottom) side of Brake piston which acting on the Vacum maintained on
the other side of Brake piston & in small Vacuum Reservoir immediately applies the
Brakes-To release the Brakes the Vacuum in the main pipe is restored-By means
of valve 41 obtain the instant release of the Brakes-It's action is as follows:
Directly the driver has begun to create, or restore (after the application of the Brakes)

page_text: the Vacuum in the main pipe this valve brings the Small Vacuum Reservoir and
main pipe and both sides of Brake piston into communication with each other—thus
releasing the Brakes immediately and having accomplished this, closes automatically
directly the Vacuum has been created. This valve can also be used with any other
vacuum automatic brake for the same purpose-It can also be used alone to obtain 5
the automatic action of any Brake-worked with a partial Vacuum, only—and I
claim for it the special advantage, of instantly releasing the Brakes, when required.
11
1
ст.
COMPLETE SPECIFICATION.
Improvements in Pneumatic Brakes for Railways.
I EDWIN HELMORE TRELEASE of 22 Hetherington Road Clapham in the County
of Surrey Clerk 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 :-
That these improvements consist in an apparatus arranged in such a manner that
the brakes may be worked by compressed air or other fluid pressure and vacuum
together or with either power separately so that greater brake power may be obtained
with greater safety and economy than at present. Also a valve to act with automatic
pneumatic brakes wherein the power is stored in a Reservoir and Brake cylinder on
both sides of a piston, & the reduction of power on one side applies the brakes, so
that after the brakes have been applied they may be instantly released by slightly
increasing the power in the train pipe.
That the first of these improvements is also designed to act in connection with the
Westinghouse Compressed Air and with the Automatic Vacuum systems.
To obtain the results mentioned above I employ two train pipes coupled from
carriage to carriage running the whole length of the train, one-bereafter referred to
as the "Air train pipe" is used for the transmission of Compressed air, from the
Main Reservoir on the engine, to apparatus on each carriage and the other hereafter
called the Vacuum train pipe" is necessary to draw the air out of those parts of
each apparatus in which a vacuum must be created. And in order that iny said
invention may be fully understood I shall now proceed more particularly to describe
the same & for that purpose shall refer to the several figures on the annexed sheets
of drawings the same reference numerals indicating corresponding parts of all the
corresponding figures,

page_text: Fig. 1 is a sectional view of apparatus according to my invention for one carriage
or vehicle. Fig. 2 is a cross section of part of the valvular apparatus. Fig. 3 is a
sectional view of a valve for automatic Vacuum brake apparatus. Fig. 4 is a similar
view of the Driver's or Engineer's valve, and Fig. 5 is a similar view of the Guard's
valve.
Referring to Fig. 4 (sheet 2) illustrating the details of the driver's valve which is
composed of an outer casing 41, in which are passages 42, 43 and 44, communicating
respectively with the Air train pipe, the Main Reservoir (also fitted on the Locomotive)
& the atmosphere. In this casing is fitted a small cylinder or hollow cock in
which are passages 46, & 47. The valve 48, above which is a spring 49, closes the
communication between 43 and 50 so that while the Brakes are off there is greater
pressure in the Main Reservoir than in the Air train pipe in proportion to the strength
of spring 49-usually 10 lbs. per square inch. At the same time 51 is in direct
communication with 43. There are three principal positions of the handle 52—which
is connected to 45-as follows: "A" for applying the brakes.
"B" while running
and "C" for releasing the brakes. As shewn it is in position "B" and the passage 42
is in communication with 50 so that the air compressed by the pump into the main
Reservoir passes through the valve 48 and by 50, 46, and 42 into the Air train pipe.
To apply the brakes the handle 52 is moved down causing 45 to turn which first
closes the passage 50 & a further downward movement of the handle to position "A"
brings 47 in communication with 44. Air will then pass from the Air train pipe into
the atmosphere by 42 46, 47 and 44. In this way any quantity of air may be
exhausted from the Air train pipe gradually or suddenly as a slight upward movement
of the handle closes 44 and at the same time 50 & 51 are closed so that no air can
pass from the Main Reservoir to the Air train pipe and the brakes are maintained on
as hereafter explained. To release the brakes the handle is moved to position "C.“
This closes 44 & opens 51 by 46 to 42 thus allowing the extra pressure maintained
in the Main Reservoir to expand freely into the Air train pipe causing the brakes to
be released as fully explained hereafter. The passage 53 communicates with the
pressure gauge.
To regulate the escape of air from and into the Vacuum train pipe if an Ejector is
used the most approved forms are arranged to do this, but the pump creating the
Compressed air may also be used to create the Vacuum. In that case another valve
or cock similar to that shewn in Fig. 4 may be used to regulate the pressure from
and into the Vacuum train pipe for the application and release of the brakes as herein-
after explained. In the case of a separate valve or cock being necessary the outer
casing of both valves may be made in one casting with the handles arranged side by
side working from the middle so that both may be moved at the same time or each
one separately.
Fig. 5 shews the Guards valve in section having connections with the Air and
Vacuum train pipes marked 1 and 2 respectively and with the pressure and vacuum
gauges & the open air at 53, 54 & 55 respectively. As shewn 56 is in communi-
cation with 2. On the air being drawn out of the Vacuum train pipe it is also drawn
out of 56 and space 57 above Hexible diaphragın 58 through hole 59. When the
brakes are applied by the admission of air into the Vacuum train pipe the air entering
by 56 below diaphragm 58 causes it to be forced up which upward movement opens
the valves 60 & 61 when air will be admitted from the atmosphere into the Vacuum
train pipe by 55, 61, & 62 increasing the pressure therein. At the same time the air
entering 62 is also admitted by the opening of valve 60 into the space 57 by holes 63,
which will balance diaphragm 58 causing it to descend and the valves 60, & 61 to
close, so that on a moderate increase of pressure in the Vacuum train pipe sufficient
air is admitted from the Engineer's valves & theso valves in each Guard's van to
set the brakes throughout the train with moderate force as hereafter explained. A
further increase of pressure by admission of air into the Vacuum train pipe will
cause this movement of the valve to be repeated and the pressure in the Vacuum train
pipe will be further increased so that the arrangement of this valve admits of the
perfect graduation of the brakes when worked by Vacuum.

page_text: The above explains the action of this valve when the brakes are being worked by
Vacuum separately. When the brakes are being worked by both powers together the
cock 64 may be moved by the handle 65 so as to close communication between 56
and 62 thus putting the valve out of use; but it is obvious another valve may be
added to this having communication with the Air Train pipe so that when both powers
are being worked and in the event of a leakage or any accident occurring which
caused air to be admitted to the Vacuum train pipe (the air train pipe not being
affected) the upward movement of the diaphragm 58 would open both train pipes to
the atmosphere. In this event however a spring would have to be placed above the
diaphragm 58 of sufficient strength to prevent it being moved by the slight admission
of air into the Vacuum train pipe on the release of the brakes when worked in this
inanner as hereafter explained. The Cock 4 as shewn closes the communication
from the Air train pipe but this cock may be turned by hand so as to open communi-
cation between both train pipes and the atmosphere by valve 61 which would be
opened by the pressure from the Air train pipe or by the diaphragm 58 being
forced up.
Referring to Fig. 1 (Sheet 1). According to my invention it is necessary to fit on
some convenient part of the underframe of each coach and on the Engine and Tender
a valve apparatus (having connection with the Air train pipe 1, and with the Vacuum
train pipe 2) in conjunction with two small Reservoirs, one marked 3 for storing
Compressed air, and one marked 4 to create a more or less perfect vacuum in, to
work the brake, Reservoir 4 communicating with the brake cylinder 5 by a pipe 6.
In the brake cylinder is fitted a piston 7 which may be connected to any approved
set of rods and levers constituting the means of applying the blocks to the wheels.
When my said invention is required to be worked by Compressed air or other Huid
pressure and a Vacuum together the mode of operation is as follows: Air compressed
by a pump on the Engine fills the Main Reservoir and train pipe 1 and passing
through pipe 8 enters by passage 9 the cylindrical space 10. This space is fitted
with a piston 11 having a stem 12 to which is fitted a valve 13. In the position
shewn the piston 11 uncovers a groove 13ª. The air entering space 10 passes through
this groove and by passage 14 into small Reservoir 3.
By means of an Ejector (or other suitable means) also placed on the Locomotive
the air is drawn out of the train pipe 2 & from Reservoir 4 & brake cylinder 5
from both sides of piston in the following manner: The passage 15-connected
by pipe 26-shewn by dotted lines to front of brake cylinder communicates by
passage 16 (Fig. 2) with space 17 above piston or flexible diaphragm 19 which is
kept in the position shewn by a spring 20. In this position the valve 21 is open and
the valve 22 closed, and the space 17 and the front of the brake cylinder are in
communication with the train pipe 2 by pipe 26, passage 15, bole 27, passage 18,
space 23, valve 21, passage 25 and pipe 24. When the train pipe 2 is exhausted
the valve 22 will be forced up by the superior pressure in the Reservoir or Vacuum
vessel 4, and the air in the latter and in the brake cylinder behind piston 7 will pass
through pipe 28 & by passage 29 & valve 22 into the space 23 and from thence
into the train pipe 2. Also on a vacuum being created in the train pipe 2 and con-
sequently above the diaphragm 19 the latter will be forced up, opening the valve 30
when the air in the space 31 will pass by hole 32-cut in 19-into the space 17
communicating with the Vacuum train pipe 2. When the reduced pressure above
and below 19 becomes the same the diaphragm 19 will return by gravity to the
position shewn and the valve 22 wid then close. A vacuum has now been created
in the small Reservoir 4, in the brake cylinder on both sides of piston 7 in the
space 31 below diaphragm 19 and in the train pipe 2 so that the reduced pressure in
all these parts is the same or nearly so & the brakes are kept off by a spring or
springs attached to the crosshead of the brake piston rod or in some other suitable
and convenient place. At the same time the train pipe being in communication with
the Reservoir 3 by 8, 9, 10, 13, and 14 the pressure in both is uniform or nearly so.
The spring 11 is of sufficient strength to overcome the resistance of spring 33* and
keep the slide valve 33 in the position shewn. The essential principle of my system

page_text: is that maintaining the power in both train pipes keeps the brakes off but reducing
the power in either or both purposely or accidently-instantly applies them. When
the brakes are applied by the driver however they are regulated by the reduction of
power in the Air Train pipe only. When the brakes are to be applied with moderate
force the pressure in the Air train pipe is reduced by allowing a portion of the
Compressed air to escape from it. The piston 11 is then pressed up by the higher
pressure existing in small Reservoir 3 passing beyond the groove 13. The upward
movement of the piston 11 relieves the pressure on the small slide valve 33 which is
then forced up by spring 33 closing 27 which communicates by 18, 23 & 21 with
the Vacuum train pipe. The further upward movement of the piston 11 and valve 13
partially opens the passage 34. The Compressed air now passes beneath 13 and by
passage 15 and pipe 26 to the front of Brake cylinder causing the piston 7 to be
forced in, and the brakes applied. When in this operation the pressure in the
Reservoir 3 is reduced by expansion of its contents into the Brake cylinder until it
is slightly below the pressure in the train pipe 1, the piston 11 descends closing the
communication between Reservoir 3 and Brake cylinder, so that the brakes are held
with a force proportionate to the reduction of pressure in the air train pipe, acting
with the vacuum maintained on the other side of brake piston and in small Reservoir 4.
On air being admitted from Reservoir 3 into the Brake cylinder it also passes through
passage 16 (Fig. 2) into the space 17 and pressing on the diaphragm 19 causes the
valve 35 to open and air to be admitted from the atmosphere by holes 36 into the
space 31 until the pressure is increased in proportion to the increase of pressure
above diaphragm 19, when it will return to position shewn in Fig. 1. As the pressure
admitted to the front of brake piston and consequently to the space 17 is increased,
this action is repeated until the pressure in space 17 rises above the pressure of the
atmosphere, when the diaphragm 19 will be held down, relieving the pressure on
the rod 37 which will then descend, and the valve 21 will close the communication
between space 23 and passage 25 and train pipe 2; so that no air above atmospheric
pressure can, on the release of the brakes, escape into the Vacuum train pipe. As it
is impossible to create a perfect vacuum a certain amount of air must remain in the
Reservoir and in cylinder 5 behind piston 7 therefore the application of the brakes
will cause this air to be slightly compressed by the movement of the piston 7. As
the vacuum, in the train pipe 2 is not destroyed by the application of the brakes,
tbis slight compression of the air remaining in Reservoir 4 will cause the valve 22 to
be forced up, bringing Reservoir in communication with train pipe 2 under which
condition the vacuum in each will become uniform, so that the vacuum in the train
pipe 2, once created is never entirely destroyed, but practically adds to the Reservoir
space and thus increases the power of the brake.
The brakes are taken off by restoring the pressure in the air train pipe causing the
piston 11 to move farther down. The valve 13 is thus caused to press upon the slide
valve 33 bringing it into position shewn in Fig. 1, and thus opening the front of brake
cylinder by 26, 15 and 27 to the space 18, when all pressure above atmospheric pres
sure will pass into the open air by valve 38. This will relieve the pressure on the
diaphragm 19, which will then be forced up by the spring 20 closing the valve 35 and
opening valve 21. The air remaining in front of brake piston and above diaphragm 19
will then expand into the vacuum train pipe causing the pressure in the space 17 to.
be farther reduced, when the diaphragm 19 is pressed up by the air in the space 31.
This movement of the diaphragm 19 opens the valve 22, thus bringing the Reservoir 4.
& Brake cylinder 5 behind piston 7 in communication with the space 23 which space
communicates with the front of brake piston by 18, 27, 15, 16 & 26 and with the
Vacuum train pipe by valve 21 and passages 25 and 24 under which condition the
brakes will be released by means of the spring or springs before mentioned attached
to some suitable part of the brake rigging. At the same time the upward movement
of the diaphragm 19 will cause the valve 30 to be opened, and the air in the space 31
to pass away through the hole 32, thus restoring the vacuum in the space 31, when
the diaphragm 19 will descend into position shewn on Fig. 1 and the valve 22 will

page_text: then close, but in the meantime all the air remaining in the brake cylinder in front of
piston 7 will have expanded into all the vacuum parts of the apparatus so that
the reduced pressure in the Reservoir 4, the brake cylinder 5, and in the Vacuum
train pipo will again be the same or nearly so. It is calculated that after a full appli-
cation on the release of the brakes in this way the vacuum throughout the system is
not impaired 15 per cent, so that once created the vacuum will cost little or nothing
to maintain, and as brakes worked according to my invention can be worked with a
Vacuum and Compressed air at a much lower pressure per square inch than brakes
wherein pressure only is used, the economy and safety of my apparatus is apparent.
When it is desired to apply the brakes with full force, the pressure in the Air train
pipe is largely reduced causing the piston 11 to move so far up that free communica-
tion is open, by the passage 34, from the Reservoir 3 to the front of brake piston,
thus allowing the compressed air to expand freely into the brake cylinder and to act
with maximum available pressure on the front of brake piston, the vacuum in
Reservoir and in brake cylinder behind piston 7 being maintained by the action of
the valves before explained, adding considerably to the power of the brake.
As the brakes are thus put on in consequence of reduction of pressure in the Air
train pipe, obviously the fracture of that pipe or its uncoupling by the separation of
the train, or a serious leakage from it will have the effect of putting on the brakes
automatically. In the case of a leakage in the Vacuum train pipe or any accident
occurring by which the vacuum was impaired (the Air train pipe being in no way
affected) the air entering the train pipe 2 would pass through valve 21 & by 23, 18,
27, 15, and 26 to the front of brake cylinder causing the brake piston to be forced in
and the brakes applied.
The three way cock 39 opens communication between the Reservoir 3 and the air
train pipe in the event of there not being sufficient pressure in the train pipe to
release the brakes. As shewn in Fig. 1 this cock opens communication between 8
and the space 10 by 9. This cock may also be used to close the communication from
the Air train pipe to the valve apparatus. A cock 40 is also fitted in the branch pipe
leading from the Vacuum train pipe to the valve apparatus so that any one apparatus
can be cut out of the system.
To release the brakes when the Locomotive is not attached to the train or in the
event of an automatic application of the brakes 1 place a valve 41 in the valve appa-
ratus shewn in Fig. 1 which valve may be opened by pulling a small wire cord from
either end of the vehicle thus bringing the Reservoir 4 & the brake cylinder behind
piston 7 in communication with the front side of brake piston by 17, 16, 15, & 26
under which condition the brakes will come off. This valve acts for the same purpose
whether the system is being worked with Compressed air and Vacuum together or with
either separately.
The above explains fully the action of my apparatus when it is worked by Com-
pressed air or other fluid pressure and Vacuum together.
When it is required to work my said invention by Compressed air alone the
general principle of action is the same as above described the only difference being
the absence of vacuum in any part of the system.
When it is required to work my said invention by Vacuum only the air is
drawn out of the Vacuum train pipe, Reservoir 4, brake cylinder from both
sides of brake pisten, above diaphragm 19 and in space 31 in the manner described
by me above in explaining my apparatus when both powers are used. Under this
condition the brakes are off. To apply the brakes air is admitted to the Vacuum
train pipe & to the front of brake piston by 24, 25, 21, 23, 18, 27, 15 & 26, thereby
applying the brakes, the vacuum on the other side of piston and in Reservoir 4
being maintained, and the vacuum in the space 31 being impaired, in proportion to
the amount of air admitted to the train pipe, by air being admitted by the valve 35
before described. To release the brakes the pressure in the Vacuum train pipe is
slightly reduced causing the diaphragm 19 to rise and open the valve 22 bringing
the Reservoir 4, train pipe 2 & both sides of brake piston in communication with each

page_text: other when the brakes will come off, after which the vacuum in space 31, & in
Reservoir 4 & train pipe 2 may be restored when the diaphragm 19 & valve 22 will
return to position shown as fully explained by me above.
Although I have described the brake cylinder as being in communication with the
Vacuum train pipe on one side, and with the Vacuum Reservoir on the other while the
train is running, and the admission of Compressed air from Reservoir 3 or from the
Atmosphere to one side of brake piston applies the brakes, I am aware that some
vacuum brakes are arranged so that while the brakes are off the cylinder is kept
open to the atmosphere. To apply the brakes one side of cylinder is brought into
communication with the Reservoir, previously exhausted, when the air on that side of
piston will expand into the Reservoir & the brakes applied by the pressure of the
atmosphere on the other side of piston. Now it is obvious that brake apparatus
according to my invention may be arranged with two Reservoirs, train pipes &
brake cylinder as before described in conjunction with a valve apparatus with similar
parts for controlling the communication between the vacuum Reservoir, train pipe,
& brake cylinder as shewn in Fig. 1 for controlling the communication of the Air
train pipe with the Air Reservoir and brake cylinder, so that while running the
cylinder on both sides of piston is in communication with the atmosphero, & on the
application of the brakes Compressed air is admitted to one side of Brake piston
from Air Reservoir & at the same time the other side of cylinder is brought into
communication with the Vacuum Reservoir causing the air on that side of piston to
expand into the Vacuum Reservoir, & reducing the pressure theroin below atmos-
pheric pressure, so that the same results are obtained in this way as by the apparatus
shewn in Fig. and described herein.
To enable vehicles fitted with my apparatus to be detached, without setting the
brakes, I place cocks in the vacuum as well as the air train pipe at each end of every
vehicle, which also serve to close the pipes at the end of the train.
Fig. 3 (Sheet 1) is a vertical section of a valve arranged for Automatic Vacuum
brake apparatus in which all the parts, corresponding with those in Fig. 1 are marked
with similar reference numerals.
passes
The passagos 25, 15, & 29 communicate respectively with the train pipe, one side
of brake cylinder, and the Reservoir, having communication with the other side of
brake cylinder. The passage 15 communicates with the space 17 above diaphragm 19.
When the air is drawn out of the train pipe, it is also drawn out of the Reservoir the
Brake cylinder from both sides of brake piston, & also out of the space 31 the air
therein escaping through hole 32. On air being admitted to the train pipe
by 25 & 15 into the brake cylinder & pressing on one side of brake piston applies the
brakes. At the same time air is also admitted to the space 17 and passing through 32
fills the space 31. To release the brakes all that is necessary is to slightly increase
the vacuum in the train pipe. This will reduce the pressure in space 17 and the
diaphragm 19 will then be forced up by the superior pressure in space 31. The
upward movement of the diaphragm will open the valve 22, thus bringing the
Reservoir, train pipe, and both sides of piston in communication with each other
under which condition the brakes will be instantly released. This valve arrangement
prevents the possibility of what is technically termed sticking, ie, insufficient power
in the train pipe to release the brakes. The valve 41 can be worked by a small wire
cord from each end of every vehicle to release the brakes in case of an automatic
application due to a breakaway or any accident occurring to the train or brake, or
when the locomotive is not attached.
Although I have shewn this valve as arranged for automatic vacuum brakes it is
obvious, that with a suitable invertion of parts it may be used for operating automa-
tically, in the same way as above, Compressed air or other fluid pressure brake
apparatus worked on the same principle, i.e. train pipe, Reservoir and brake cylinder
fitted with a piston subject on its one side to the pressure in the Reservoir, and on
the other to the pressure in the train pipe, the brakes being applied by lowering the
pressure in the train pipe.

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Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is
1. In pneumatic brakes for Railways, apparatus consisting of two train pipes,
Vacuum and pressure Reservoirs, and brake cylinder in conjunction with a suitable
valve apparatus in such a manner that while the train is running and the brakes off
tho Brake piston is in communication with the Vacuum Reservoir on the one side and
with the Vacuum train pipe on the other and on the application of the brakes the
pressure Reservoir is brought into communication with one side of brako cylinder
admitting pressure above the atmosphere which operates on one side of piston, while
the Vacuum in the Vacuum Reservoir is maintained on the other side, substantially
as and for the purposes herein set forth.
2. In pneumatic Brakes for Railways apparatus consisting of two train pipes,
Vacuum and pressure Reservoirs & brako cylinder in conjunction with a suitable
valve apparatus in such a manner that while the train is running and the brakes off
the cylinder-both sides of piston-is in communication with the atmosphere and on
the application of the brakes the passage from the open air to the cylinder is closed
and one side of cylinder is brought into communication with the Vacuum Reservoir
reducing the pressure on that side of piston, and at the same time pressure above the
atmosphere is admitted to operate on the other side of piston, from the pressure
Reservoir, substantially as and for the purposes herein set forth.
3. That in pneumatic brakes for Railways apparatus, arranged with 2 train pipes,
so that the brakes may be worked by pressure above the Atmosphere and a Vacuum
together, or with either power separately, substantially as and for the purposes herein
set forth.
5. In pneumatic brakes for Railways wherein the brake piston is subject on its one
side to the pressure in the Reservoir, and on the other to the pressure in the train
pipe, a valve arrangement so that after the brakes have been applied the Reservoir
and train pipe may be brought into communication with each other, on a slight
increase of power in the train pipe substantially as and for the purposes herein set
forth.
Dated the 4th dev of Auril 1888