IMPROVEMENTS IN VACUUM BRAKES
Year: 1879

page_text: LETTERS PATENT to John Audley Frederick Aspinall, of Inchicore, Dublin, in
the County of Dublin, Engineer, for the Invention of "IMPROVEMENTS IN
VACUUM BRAKES."
Sealed the 8th July 1879, and dated the 17th February 1879.
PROVISIONAL SPECIFICATION left by the said John Audley Frederick
Aspinall at the Office of the Commissioners of Patents on the 17th February
1879.
JOHN AUDLEY FREDERICK ASPINALL, of Inchicore, Dublin, in the County of
Dublin, Engineer. "IMPROVEMENTS IN VACUUM BRAKES."
This Invention relates to improvements in apparatus for regulating the flow of
air in vacuum brakes in a simple and efficient manner, all as hereinafter described.
I place in the guard's van a valve or valve device, by the use of which I ensure
that as soon as the vacuum in the train pipe for actuating automatic railway brakes,
such as those described in the Provisional Specification of my Patent dated 7th
November 1878, No. 4521, is seriously impaired, the said valve at once, by the
automatic action of the atmosphere against a vacuum on its upper side, opens and
thereby establishes a complete communication between the train pipe and the outer
air, and thus effects the instant application of the automatic brakes throughout the
train. The valve device consists of a head or plate fixed to a flexible diaphragm,
above which there is a closed chamber which may be similar to the upper part of
my improved "Hardy sack;” this diaphragm head or a continuation thereof seats
itself in the lowest position of the diaphragm on a valve seating, and closes the
communication between the train pipe and one or more apertures to the atmosphere.
There is a very small pipe or communicating hole between the chamber above the
diaphragm and the underside of the valve. The lever for actuating this valve
device by hand is so balanced relatively thereto that when a vacuum is created
throughout the train pipe, and by the small communicating hole aforesaid also in
the chamber above the diaphragm, the valve is almost in equilibrium, but remains
sufficiently tight on its seat to prevent air admission to the train pipe. When the
vacuum in the latter is seriously impaired the equilibrium is destroyed, the atmo-
sphere having, as before, access to the underside of the diaphragm, will then force

page_text: the latter up, raising the valve from its seating and admit air completely to the
train pipe at this place, atmospheric air will now gradually find its way into the
chamber above the diaphragm through the small aforesaid hole; the valve will then
descend again by gravity and close the air admission to the train pipe. By means
of a vacuum gauge connected to the chamber above the diaphragm the brake power
available may be constantly indicated.
This valve device is applicable to the single pipe system and the double pipe
system; in the latter case it is connected with the pipe communicating with the
lower or smaller portion of brake cylinder under the guard's van.
Another portion of my Invention consists in valve devices for use in automatic
brakes, such as those described in the Provisional Specification of my aforesaid
former Patent, where double lines of pipe are used, and by which valve devices, in
casc air is admitted to either or both pipes from some part of the train behind the
tender, the air will be directed to the lower part of the sacks, and the vacuum upon
the upper side of the sack diaphragms will be maintained; or the exhaust may be
continued from the upper side of the diaphragms where only one pipe is severed,
or air is admitted by driver or guard to the lower side of the sacks. The valve
device has four valve seats meeting in one centre line and arranged in a casing
which at two opposite sides communicates respectively with the two train pipes,
and at two other sides respectively with top and bottom of "sacks." The valve is
made of one continuous piece of leather or rubber having three metallic centres to
stiffen it. Or the four valve seats may be arranged to meet two and two, and I
place a flap valve in between two of them and a flap valve on the outside of each
of the two others. The space between two of the seats communicates with the top
or larger portion of the brake cylinders; and the space between the other two seats
communicates with the bottom or shallow portion of the brake cylinders.
I arrange improved valve devices for the purpose of closing the connection
between the upper portions of the "sacks" and the train pipe, and at the same
time ensuring that the same shall be reopened either by the creation of a vacuum
in the train pipe equal to or less than that in the upper portion of the sacks or by
hand where it becomes necessary. This valve, which, when seated, closes the
connection between train pipe and top of sacks, is formed with a hollow stem
communicating by one or more perforations with the train pipe (and thus also with
the bottom of the sacks), and passes air tight through the wall of the valve
chamber; its outer open end terminates in a chamber, one side of which is formed:
by a head on the stem of the valve, the said head being by a diaphragm attached
to the sides of the valve chamber in a similar manner to that of the diaphragm of
a Hardy cylinder; to the stem in the part open to the atmosphere is connected a
lever for moving it by hand.
Or the stem may be solid and a side passage be formed between the aforesaid
chamber and the communication to the train pipe.
Or instead of this I use a hollow valve made to work between two pipes or
chambers and attached to the end of each by means of a flexible diaphragm. One
of these pipes communicates with the top of the sack, and has a fixed seat in it for
the hollow valve to rest on; the other pipe communicates with the train pipe and
bottom of sack.
The diaphragm at the train pipe side is made of greater area than the other, and
the atmosphere is free to play on the outside of both. Suitable gear may be
attached thereto for moving it by hand,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Audley Frederick Aspinall in the Great Seal Patent Office on
the 16th August 1879.
JOHN AUDLEY FREDERICK ASPINALL, of Inchicore, Dublin, in the County of
Dublin, Engineer. "IMPROVEMENTS IN VACUUM BRAKES."
This Invention relates to improvements in apparatus for regulating the flow of
air in vacuum brakes in a simple and efficient manner, all as hereinafter described.
I place in the guard's van a valve or valve device, by the use of which I ensure
that as soon as the vacuum in the train pipe for actuating automatic railway brakes,
such as those described in the Specification of my Patent, dated 7th November
1878, No. 4521, is seriously impaired, the said valve at once by the automatic
action of the atmosphere against a vacuum on its upper side opens, and thereby
establishes a complete communication between the train pipe and the outer air, and
thus effects the instant application of the automatic brakes throughout the train.
Figure 1 of the accompanying Drawings is a vertical section through a valve
appliance of this description. It consists of a head or plate a fixed to a flexible
diaphragm b, above which there is a closed chamber C which may be similar to the
upper part of my improved "Hardy sack;" this diaphragm head a or a continuation
thereof in the form of a valve a¹, as shown, in this instance seats itself in the lowest
position of the diaphragm b on a valve seating a³, and closes the communication
between the train pipe c and one or more, in this case four, apertures d to the
atmosphere. There is a communicating hole through the valve a, a¹, or otherwise,
a very small pipe establishing a certain degree of communication between the
chamber C above the diaphragm and the under side of the valve. The lever e for
actuating this valve a, a, by hand is so balanced relatively thereto that when a
vacuum is created throughout the train pipe c, and by the small communicating
hole aforesaid also in the chamber C above the diaphragm, the valve a, a¹, is almost
in equilibrium; but as the head a¹ is greater in area than the diaphragm head b
remains sufficiently tight on its seat a³ to prevent air admission to the train pipe c.
When the vacuum in the latter is impaired the equilibrium is destroyed. The
atmosphere having, as before, access to the underside of the diaphragm b will then
force the latter up, raising the valve a' from its seating a³ and admit air completely
to the train pipe c at this place by the openings d; atmospheric air will now
gradually find its way into the chamber C above the diaphragin through the small
aforesaid hole; the valve a, a', will then descend again by gravity and close the
air admission to the train pipe c. By means of a vacuum gauge connected to the
chamber the brake power available may be constantly indicated.
This valve device is applicable to the single pipe system and the double pipe
system, (such as described in my aforesaid Patent, Specification No. 4521 of 1878 ;)
in the latter case it is connected with the pipe communicating with the lower
portion of brake cylinder under the guard's van or any other vehicle.
Another portion of my Invention consists in valve devices for use in automatic
brakes, such as those described in the Specification of my aforesaid former Patent,
No. 4521, of 1878, where double lines of train pipe are used, and by which valve
devices, in case air is admitted to either or both pipes from any part of the train,
the air will be directed to the lower part of the sacks and the vacuum upon the
upper side of the sack diaphragm will be maintained or the exhaust may be
continued from the upper side of the diaphragms where only one pipe is severed;
or air is admitted by driver or guard, or by accident, to the lower side of the
sacks.
Figure 2 is a cross section of one such directing valve appliance. It has four valve
seats e, f, g, h², meeting in one centre line and arranged in a casing which at two

page_text: pipes, and at two other sides, viz., at d¹ and at c¹ respectively, with top and bottom of
sacks. The valve is made of one continuous piece of leather or rubber having three
metallic centre or intermediate pieces to stiffen it. Or according to another arrange-
ment, shown in three sections in Figures 3, 4, and 5, the four valve seats e, f², g², h³,
may be arranged to meet two and two, and I place a flap valve g' in between two
of them, viz., h² and g², and a flap valve e¹ and f' respectively on the outside of
each of the two others; the valve gl may rest on the seat g² or on the seat h²; tho
space between two of the seats, vis., f and e², communicates by the pipe d with
the top or larger portion of the brake cylinders, and the space between the other
two seats, viz., h² and g², communicates by the pipe C with the bottom portions of
the brake cylinders. The valve case is closed by the lid k, which may be removed
without disturbing any of the pipe connections of the valve case, if it be desired,
either to examine or renew any of the flap valves e¹, f¹, or g¹. By this valve
arrangement, which is placed between the two train pipes, I automatically regulate
the flow of air from the top and bottom of the sacks, or to the bottom of the sacks
underneath a vehicle which may be turned end for end without affecting the
working of the brake.
Figure 6 is a section, and Figure 7 a plan of a directing valve to be used on the
engine by the driver for the purpose of putting on and releasing the brakes.
This valve is used in combination with the valve shown in section and end
elevation respectively in Figures 8 and 9. This latter valve regulates the flow of
air to the bottom of the engine and tender sacks.
By the combination, of these two valves, Figures 6 and 7, and Figures 8 and 9,
I do away with the use of the engineman's valve, and the valve at the back of
tender described in my aforesaid Patent Specification, No. 4521, of 1878.
The valve device, Figures 6 and 7, is constructed in two parts which are similar
to one another.
The pipe q leads to the ejector and to the top of the engine and tender sacks.
The ejector exhausts the air from the train pipes c and d, which flows past the
valves and s to the pipe q. The valve r is formed with a spindle having two
leads, the head r seats itself on the seat 71, and shuts off communication between
the pipe c and the ejector pipe 7. The head t is attached by means of a diaphragm
t¹ to the flanges of a chamber u which communicates with a similar chamber over
the valve spindle of 8 by means of the opening u¹. There is a small hole t causing
communication between the pipe q and passage n¹. A pipe v upon top of which is
a flap valve v¹ communicates with the chamber u.
The pipe w communicates with the train pipe c, and terminates with a flap
valve w¹.
To apply the brakes, the driver lifts this valve w¹, air flows to c, and forces r
onto its seat ¹. A vacuum has been formed above the head t through the small
hole t²;
is therefore in equilibrium. The ejector goes on exhausting through the
train pipo & as the valves remains in the position shown upon the Drawing; to
take off the brakes, the driver closes the valve 20¹, and opens the valve v¹.
Air now rushes to the top of the head t, and this being larger in diameter than
the head r, it forces it from its seat r, and the air in the train pipes c once more
flows to the ejector; as soon as the brakes are off the valve v may be dropped on
its seat, when the head t will once more be put in equilibrium by the air being
drawn out of the chamber u through the hole t².
Should air be admitted by accident or otherwise to the train pipe d, the valve s
will act in a precisely similar manner, and may be reopened by opening the valve v'.
Should air be admitted to both train pipes by accident or otherwise, both valves
rands will close, the brakes on the engine and train will be applied, and the
ejector will continue to exhaust from the top of the sacks on the engine and tender,
and the brakes will be released by opening the valve v1.
The valve shown in section at Figure 8 and in end elevation in Figure 9, is
placed between the train pipes c and d upon the engine, and directs the flow of
air to the bottom of the engine and tender sacks. The pipes c and d are not

page_text: connected with the top of the engine and tender sacks, but only with the bottom
of such sacks through the said valve, Figure 8. This valve x is formed with
two seats x1, x2. It has three branch pipes, of which c and d communicate
with the train pipes c and d; the third branch y leads to the bottom of the
sacks. If air is admitted to c, the valve flies over to its seat ¹ as the ejector
continues to exhaust through the pipe d. If air is admitted to d, the valve
seats itself on ³, and the ejector continues to exhaust through the pipe c. In
either of the above cases the air flows to the bottom of the engine and tender
sacks through the branch y, and the brakes are applied. If air is admitted
to both c and d, it flows to the bottom of the sacks through y, and applies the
brakes. I arrange improved valve devices for the purpose of closing the connection
between the upper portions of the "sacks" and the train pipe, and at the same
time ensuring that the same shall be reopened either by the creation of a vacuum
in the train pipe equal to or less than that in the upper portion of the sacks or by
hand where it becomes necessary. It is used either with the single or the double
pipe systems to enable communication between the ejector and the top of the sacks
to be established after the brake has been applied, and after that the power of
producing as good a vacuum in the train pipe as there is in the top part of the
sack has been lost. This valve, which is shown in section in Figure 10, will, when
seated on the seat 7, close the connection between train pipe and top of sacks; it is
formed with a hollow stem im communicating by one or more perforations with the
train pipe (and thus also with the bottom of the sacks) and passes airtight through
the wall of the valve chamber being attached thereto by a leather sleeve or tube m²;
its outer open end terminates in a chamber n, one side of which is formed by a
head on the stem of the valve, the said head being by a diaphragm g attached to
the sides of the valve chamber in a similar manner to that of the diaphragm of a
Hardy cylinder, the head h is fixed to the hollow stem m by means of the nut f
to the stem; in the part open to the atmosphere is connected a lever o for moving
it by hand. Or the stem may be solid, and a side passage be formed between the
aforesaid chamber and the communication to the train pipe. Or, instead of these
arrangements of valve, I use a valve shown in end view in Figure 11 and in cross
section in Figure 10; m is a hollow valve made to work between two pipes or
chambers i and j, and attached to the end of each by means of flexible diaphragms
and j¹, the area of j¹ being slightly greater than that of . One of these pipes,
viz., i, communicates with the top of the sacks, and has a fixed seat 7 in it for the
hollow valve m to rest on; the other pipe, viz., j, communicates with the train pipe
and bottom of sack. The diaphragm at the train pipe side is made of greater
area than the other ¹, and the atmosphere is free to play on the outside of both.
The two pipes i and j are connected by the brackets k, k. Suitable gear may
be attached to the valve for moving it by hand; o is a lever for that purpose.
If
a vacuum is created in the train pipe the valve m will leave its seat l, and the air
will pass out of the top of the sack by openings round 1, and pass on to
train pipe through the hollow valve m. If air is admitted to the train pipe the
valve m will close on its seat l. If now a vacuum of say 18" only can be pro-
duced in the train pipe, and there is a vacuum of 20" in the top of sack the atmo-
sphere acting upon the diaphragm j' will force the valve m off its seat l, and the
vacuum being equalised above and below the piston in the brake cylinder or sack
the brakes will fall off. These diaphragms and may be proportioned to suit
any difference in vacuum. I make use of this valve for another purpose, viz., to
take off the brakes on the arrival of the train at a terminal station. For this I
carry a rod u, Figure 11, across the carriage, and support it on the brackets k. To
this rod is attached the lever o, which may be brought in contact with the snug p
on the valve m, so as to force it from its seat and allow air to flow to the top of
the sacks. Where this valve is used in the single pipe system the ordinary flap
valves are not required. I also use a modification of this valve with diaphragms

page_text: of equal area instead of the flap valve mentioned above. And having thus described
and ascertained the nature of this Invention I declare that I claim,-
First. The valve, Figure 1, for admitting air to the lower portion of the brake
cylinders automatically as soon as the vacuum in the train pipe is impaired, and
for admitting air at will by hand, substantially as described and shown.
Second. The reversing or directing appliances for automatically regulating the
flow of air to the bottom and from the top of the brake cylinders, or from both top
and bottom of same, substantially as described with reference to Figures 2, 3, 4, 5,
6, 7, 8, and 9.
Third. The valves, Figures 10ª, 10, and 11, for facilitating the release of the
brakes, substantially as described and shown.
In witness whereof, I, the said John Audley Frederick Aspinall, have here-
unto set my hand and seal, this Sixth day of August, in the year of our
Lord One thousand eight hundred and seventy nine.
JOHN AUDLEY FREDERICK ASPINALL, (L.S.)