Improvements relating to Automatic Valves for Air Brakes.
Year: 1891

page_text: Date of Application, 3rd Mar., 1891
Complete Specification Left, 9th May, 1891--Accepted, 25th July, 1891
PROVISIONAL SPECIFICATION.
Improvements relating to Automatic Valves for Air Brakes.
I, ALBERT PARSONS MASSEY of Watertown County of Jefferson State of New
York United States of America Engineer do hereby declare the nature of this
invention to be as follows:-
My invention relates to improvements relating to automatic valves for air brakes
and more particularly to brakes of the Westinghouse type.
In air brakes as long used the air reservoir and brake cylinder are connected to
a pipe (commonly called the train pipe) by means of a contrivance commonly called
a triple valve so constructed that a reduction of pressure in the train pipe operates
the triple valve in one direction thereby applying the brakes by increasing the air
pressure in the brake cylinder while an increase of pressure in the train pipe operates
the triple valve in the other direction thereby opening the brake cylinder to the
atmosphere and releasing the brakes and also opening a passage from the train pipe
to the auxiliary reservoir so as to recharge it with compressed air.
My improvements consist in an improved construction of the said "triple valve"
whereby it is rendered more effective in operation and my improved valve is
constructed and operates substantially as follows.
The outer casing of said valve has suitable connections for the train pipe
auxiliary reservoir and brake cylinder. Within the said casing are chambers having
valves contained and working therein to control the communications between the
several openings and passages.
Within the main chamber is a piston exposed to train pipe pressure on the one
and reservoir pressure on the opposite side. When the train pipe pressure is
reduced by the driver or through any other cause the excess of pressure upon the
reservoir side causes the piston to move thereby cutting off the flow of air from the
train pipe to the reservoir through a port which in the normal position of the valve
remains open and opening another port thereby connecting the reservoir with the
brake cylinder.
If the train pipe pressure is considerably reduced the said piston will remain at
its extreme position keeping the said port open until the pressure in the brake
cylinder is equal to that in the auxiliary reservoir. If the pressure was but slightly
reduced the piston will remain at the extreme limit of its stroke until the pressure
upon the reservoir side had become slightly lower than that on the train pipe side
when the piston will be started back by the excess pressure, the port will be closed
and the brakes applied with but a moderate force by the air within the brake
cylinder.
When the train pipe pressure is suddenly reduced to a considerable extent the
valve acts as above described but direct communication is also established through
certain passages (which are controlled by suitable valves) between the train pipe
and the brake cylinder, allowing the compressed air within the train pipe to supple-
ment that within the auxiliary reservoir thereby applying the brakes in a more
rapid and effective manner.
When it is desired to remove the brakes the train pipe pressure is increased
which causes the several parts to resume their normal positions and restores the
pressure in the auxiliary reservoir until it equals that in the train pipe. At the
same time the air in the brake cylinder is allowed to escape into the atmosphere
through a port provided for the purpose.
Dated this 2nd day of March 1001
HORN & SON,
Applicant's Agents.

page_text: COMPLETE SPECIFICATION.
Improvements relating to Automatic Valves for Air Brakes.
I ALBERT PARSONS MASSEY of Watertown in the County of Jefferson, State
of New York United States of America, Engineer, 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:-
In order that my invention may be more readily understood reference should be
made to the accompanying drawings in which
Figure 1 is a section on line 1 1 of Figure 2 and
Figure 2 is an end view with parts removed and other parts shewn in section on
line 22 of Figure 1 of one form of my valve.
Figures 3 and 4 are details described below.
In air-brakes as long used the air reservoir and brake cylinder are connected to
a pipe (leading along the train from the engineer's valve commonly called the train
pipe) by means of a contrivance commonly called a triple-valve so constructed that
a reduction of pressure in the train pipe operates the triple valve in one direction
thereby applying the brakes by increasing the air-pressure in the brake cylinder,
while an increase of pressure in the train-pipe operates the triple valve in the other
direction, thereby opening the brake cylinder to the atmosphere and letting off the
brakes and also opening a passage from the train pipe to the auxiliary reservoir, so as
to recharge it with compressed air. A. variety of these contrivances known as triple
valves are well known and my invention relates to contrivances of this class and it
consists first in a novel combination of a piston or valve operated by difference of
pressures on its opposite sides with two valves which it operates in a peculiar
manner all more fully described below, and secondly in the combination of a piston
or valve operated by difference of pressure on opposite sides, with a piston and a
valve controlled by it, which valve controls a passage from the train pipe to the
brake-cylinder, as more fully described below.
In the drawings A. is a passage to the train pipe B is a passage to the auxiliary
reservoir and C a passage to the brake cylinder. For convenience the casing bis
made in three parts as shewn and a casting (not shewn) covers the passages B and C
and has passages through it which are continuations of B and C as will be well
understood by all skilled in the art without further description.
The piston or valve D is so mounted in its cylinder that an excess of air
pressure on the left will drive it to the right and vice-versa. It is strictly a piston
but in function it is also a valve, for it controls the passage through which com-
pressed air passes from the train-pipe to the brake-cylinder that is when the piston
or valve D is in the position shewn in Figure 1 compressed air flows from the train-
pipe through passage 3 into chamber 4 and passes by piston D by means of passage 5
into chamber 6 and from chamber 6 through passage B until the pressure is
equalized on both sides of piston D-that is the pressure in the auxiliary reservoir
and chamber which are connected by passage B is substantially the same as that
in the train pipe and chamber 4 connected by passages 3. The passage 7 by which
the auxiliary reservoir is connected to the brake cylinder-that is passage B
connected with passage C-is controlled by the valve F and the passage 8 by which
the brake cylinder is connected to the atmosphere-that is the exhaust from
passage C is controlled by the valve G. These three valves D, F, and G act
automatically as follows: When in the position shewn, the air pressure is equal in
the train pipe, chambers 4 and 6 and the auxiliary reservoir. The brake cylinder
is open to the atmosphere with the brakes off and the train moving. If the brakes
are to be applied so as to slow up the train, the engineer reduces the pressure in the
train-pipe slightly (in a manner too well understood to require description) thereby
making the pressure in chamber 4 slightly less than that in chamber 6, and piston. Ď
is.at once moved from right to left carrying with it valves F and G. This motion
-

page_text: of valve G closes the exhaust 8 from passage C, and this motion of valve F
connects passages B and C-that is the reservoir and brake cylinder-and com-
pressed air flows from chamber 6 and the reservoir through passage 7 into the brake
cylinder, applying the brakes with slight force for passage 7 past valve F is small:
but as soon as the expansion of the compressed air in chamber 6 and the reservoir
has reduced the pressure on the right of piston D slightly below the pressure on
its left, piston D is moved to the right until it forces valve F on its seat thereby
cutting off chamber 6 and the reservoir from passage 7. This motion of piston D
is not enough to nove valve G nor to uncover passage 5, so that the brakes remain
applied with slight pressure. If it becomes necessary to apply the brakes more
forcibly, the engineer again reduces slightly the pressure in the train pipe with the
same result as before except that the valve G is not moved and so for a further
reduction of pressure in the train pipe until the brakes are gradually applied with
force enough to bring the train to a stop.
To start the train, the engineer increases the pressure in the train pipe (in a manner
too well understood to require description) thereby moving piston D to the position
shewn in Fig. 1., and this full forward stroke of piston D not only forces valve F
more firmly on its seat (by compressing spring f) but also shifts valve G back to
its position, as shown in Fig. 1., thereby opening passage C to the atmosphere and
allowing compressed air to escape from the brake cylinder through passages C and
exhaust-passage 8.
:
My invention, as embodied in the contrivance just described is the combination of
the three valves D, F, and G, with the passages A, B, and C,- a passage connecting A
and B controlled by valve D, a passage connecting B and C controlled by valve F
and an exhaust passage from passage C controlled by valve G and while I am
aware that other triple valves are known, yet, so far as I have any reason to believe
I am the first to use the two valves F and G, both controlled by the valve D, the
valve controlling the passage which connects the passages B, and C, and
the valve G controlling only the exhaust from the passage C, for heretofore in all
triple valves known to me the valve which most nearly resembled my valve G,
controlled not only the exhaust from passage C but also controlled a passage
connecting B and C, and required to be moved whenever the valve D moved-but
in my contrivance the valve G is moved only at the first stroke of valve D from
right to left, and at the last stroke of valve D from left to right, and remains
stationary during the intermediate motions of valve D thereby making valve D
More-
far more sensitive than in any other contrivance of this kind known to me.
over the full function of valve F is simply to connect and disconnect passages B
and C, and this also is a novel feature and it is owing to this that I am enabled to
keep valve G at rest while valve D is acting merely as a piston.
It will be obvious that the valves F & G must have a motion not only with but
relative to the stem of piston D and I have shewn convenient devices for those
purposes, which will be plain from Figure 1, but these details of construction are
obviously capable of large variation, the gist of the matter being a valve which
controls a passage from B to C and a second valve which controls the exhaust
from C, but these valves being controlled by D which not only controls their valves,
but also controls a passage from A to B.
The second feature of my invention relates to the sudden application of the
brakes on an emergency, and this I do by means of the valve H which is acted
upon on one side by the train-pipe pressure aided by the spring hand on the other
side by the pressure in chamber 6, so that any sudden and large decrease of pressure
in the train-pipe will cause the pressure in the chamber 6 to move valve H against
spring and thereby uncover passage 9.
The compressed air in the train-pipe will then act through passage 9 upon
piston J and move it in cylinder j, so as to open valve K (which is attached to the
said piston), when the compressed air in the train-pipe will lift check-valve k and
escape past valves & and K into the brake-cylinder.

page_text: Moreover this sudden large decrease of pressure in the train-pipe will also operate
piston D, closing valve G and opening valve F, as before described.
The main purpose of opening valve K, which controls a passage connecting the
train pipe with the brake cylinder is to aid in the sudden and large reduction of
pressure in the train pipe for in a long train the brakes will not be applied to the
rear cars speedily and with full power unless there be some escape of air provided
from the train-pipe other than the escape through the engineers valve; but with a
passage at each car from the train pipe to the brake-cylinder for use in an emergency
the sudden application of the brakes at the first car reduces the pressure in the
train-pipe almost instantly and that reduction applies the brakes to the next car,
and so on, as will be well understood by all skilled in the art without detailed
description, for I am aware that I am not the first to provide a passage from the
train pipe to the brake cylinder but so far as I have any reason to believe I am the
first to do this by means of an automatic valve which sets in operation a second
valve controlling a passage from the train-pipe to the brake-cylinder.
The action of the valves K and is as follows;-The pressure of the air in the
train-pipe A will raise the valve & until the pressure in the chamber K' is equal to
that in the train-pipe when the valve will be closed by gravitation. Upon the
piston J and the valve Kattached thereto falling as before described the compressed
air in the chamber K will escape past the valve K into the passage C. The air
pressure being therefore lower upon the upper than upon the under side of valve k
the said valve will allow the air to pass into the chamber K¹ and thence into the
brake cylinder as before described.
The check valve is not essential but serves a useful purpose in governing the
pressure in the brake cylinder after the pressure in the train pipe becomes less than
that in the brake cylinder which is particularly applicable in case of an accidental
rupture of the train pipe.
The seat of the valve H is shaped as clearly shown in Figs. 3 and 4 which are
essential details illustrating the proposed construction of the valve H and its seat.
The seat is of course secured to casing b.
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
In a triple valve, the main valve piston having one side open to pressure from
the auxiliary reservoir, and the other side open to train-pipe pressure, combined
with a valve controlling a direct passage leading from the train-pipe to said piston,
and a valve controlling said passage and subject on one side, to auxiliary-reservoir,
pressure and on the other to train-pipe pressure.
Dated this 9th day of May 1891.