Improvements in Fluid Pressure Automatic Brake Mechanism.
Year: 1888

page_text: Date of Application, 6th Jan., 1888
Specification Accepted, 10th Feb., 1888
[Communicated from abroad by GEORGE WESTINGHOUSE, Junior, of Pittsburgh, County
of Allegheny, State of Pennsylvania and United States of America. Engineer.]
Improvements in Fluid Pressure Automatic Brake Mechanism.
!
1, CHARLES DENTON ABEL, of No: 28 Southampton Buildings, Chancery Lane, in
the County of Middlesex, Consulting Engineer, and Patent Agent, 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:
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In the Specification to Letters Patent No. 4676 of 29th March 1887 was described
fluid pressure automatic brake apparatus whereby, when a moderate reduction of
pressure was effected in the train pipe that supplies the auxiliary reservoirs of the
brake apparatus with air pressure, a communication was effected between the
auxiliary reservoir and the brake cylinder by means of the so-called triple valve
apparatus, so to cause the brakes to be applied with moderate force, while when it
was desired to apply the brakes rapidly with considerable force, a considerable
reduction of pressure in the train pipe caused a direct communication to be established
between the train pipe and the brake cylinder so that the air pressure could pass
directly from the former into the latter.
In the arrangements more particularly described for this purpose in the said
Specification, the piston or diaphragm of the triple valve apparatus was caused to
impart motion directly to a supplemental valve or slide that opened or closed the
said direct communication between the brake cylinder and train pipe.
The present invention relates to constructions whereby a valve or slide that opens
or closes the said direct communication is actuated by a piston or diaphragm separate.
from that of the triple valve apparatus, such piston or diaphragm being ether
dependent in its action upon that of the triple valve apparatus, or entirely independent:
therefrom.
Figs. 2 to 7 of the accompanying drawings shew one arrangement of valve
apparatus for this purpose. Fig. 1 shews a general plan of the underside of a
carriage with the brake apparatus attached. Fig. 2 shews a longitudinal section of

page_text: the valve apparatus on line ww Fig. 3, Fig. 3.shews a transverse section on line a
Fig. 2. Fig. 4 shews a front view of the main slide valve. Figs. 5 and 6 shew cross
sections on lines y y and z Fig. 4, and Fig. 7 shews a longitudinal section through
the main slidé valve chamber shewing the face on which the slide works.
In this arrangement the said piston or diaphragm and supplemental valve are
operated in conjunction with the triple valve apparatus which is generally of the same
construction as described in the before mentioned and previous patents, being enclosed
in a case 10 which, in this instance, is secured to one end of the auxiliary reservoir 6.
to the opposite end of which the brake cylinder 7 is connected. The triple valve case,
auxiliary reservoir and brake cylinder are fixed in any convenient position on or
under the sills or lower framing 1, of the car, to which the main air or brake pipe 2,
having the usual flexible connections and couplings, is likewise secured, and the brake
cylinder is fitted with a piston, by the movements of which, through proper lever
connections, the brake shoes are applied to and released from the wheels of the car in
the well known manner.
The portion of the triple valve case 10, which adjoins the auxiliary reservoir 6, is
lined with an open ended valve bushing 24, on which is formed the seat or valve face
of the main slide valve 14, the bushing 24, forming a chamber within which the
valve is fitted to reciprocate, and which continunicates at one end with the auxiliary
reservoir and at the other with a bushing 11. forming the chamber of a piston 12,
secured upon the stem 13, of the valve 14. A cap or drain cup 19, is secured upon
the end of the valve case 10. so as to close the chamber 11, and communicates with
the chamber through a series of ports 20. A supplemetal valve chamber 54 is cast
upon or secured to the triple valve case 10, on one side of the chamber 24 such
chamber 54 being preferably formed in two parts as shewn the inner of which is
cast upon the triple valve case, and provided with lugs to which the outer part or
cap is secured by bolts 55. The chamber 54 communicates, by a passage 17, with the
main air or brake pipe 2, and, by a passage 16, with the brake cylinder 7, com-
munication between the passages 16 and 17 being opened and closed as required in
applying and releasing the brakes by interposed valves 41 and 49, as hereinafter
described.
.
The chamber 24, is provided with ports 56. 57. 58 and 59 all of which are governed
by the main slide valve 14. The port 56 communicates with a channel or passage 60.
leading into the brake cylinder 16, the ports 57 and 58, which are located in line
transversely in the bushing, communicate with passages 61 (indicated in dotted lines
in Figs. 2 and 3) leading into the supplemental valve chamber 54, and the port 59
communicates with a channel 34, leading to the relief or exhaust port 15. The main
slide valve 14, is provided with a longitudinal passage 31, extending from its end
adjacent to the piston 12, to a point on its face, said passage being governed by a
graduating valve 29, upon a stem 30, which is fixed to the valve stem 13, and receives
a limited degree of traverse independently of the main slide valve 14, in order to
open and close the passage 31. To this end the collar 27. and shoulder 28 of the
valve stem by which the valve 14, is moved, are, as described in the previous patents,
set at a distance apart slightly greater than the length of the valve. A lateral
port 32, (Fig. 6) establishes communication between the part of the passage 31
heyond the valve seat and the chamber 24, and auxiliary reservoir 6, when the
graduating valve 29 is moved off its seat. A lateral recess or cavity 66, (Figs. 4
and 6) is formed in the face of the valve 14, adjacent to the opening of the passage 31,
in position to uncover the port 58, when brought in line therewith in the movements
of the valve; and an exhaust recess or cavity 62, which is widened at one-end to
extend over the openings of both the ports 57.and 58, is. formed in the face of the
valve 14, towards its opposite end. The exhaust recess 62, serves in one position of
the valve to establish..communications between the brake cylinder and the release
pon15, through the passages 60 and 34, and in another to put the inner end of the
supplemental valve chamber 54 in.communication with the release port 15 through the
passages 61. 57. 58 and 59-A supplemental port or passage 35 leads from the end
of the valve 14, adjacent to the auxiliary reservoir to a point on the face of the valve

page_text: so located that at the limit of the traverse of the valve stem and valve 14, in the
application of the brakes, communication will be established between the auxiliary
reservoir and the brake cylinder through the passages 35. 60. and 16.
A supplemental piston 63, is fitted to move in the inner end of the supplemental
valve chamber 54, and, in its outward movement to bear against the stem 64, of
a supplemental valve 41, which opens outwardly or in the direction of the brake
pipe passage 17. and is seated upon an opening in a transverse partition 65,
interposed between the two parts of the valve chamber 54. A check valve 49, which
opens inwardly and is seated adjacent to the outer end of the valve chamber 54,
governs the communication between the same and the passage 17, leading from the
brake pipe thereto. A spring 50, bears, at its ends, upon the stems of the valves 41
and 49, and holds them to their respective seats during such periods as a substantial
equilibrium of pressure is maintained in the brake cylinder and brake pipe and when
the valve 41, is not subjected to pressure by the piston 63. The check valve 49, may,
if desired, be omitted, the supplemental valve 41, being, in such case, held to its seat
by a spring sufficiently strong to retain within the brake cylinder a sufficient pressure
to stop the train in the event of a rupture of the brake pipe, or of the escape of air
therefrom by the train breaking in two.
In operation, the application of the brakes with such fraction of the maximum force
as is required for making ordinary stops, is effected, as in the prior constructions,
by discharging a portion of the air from the brake pipe through the engineers
valve, the preponderance of pressure thereby induced in the auxiliary reservoir,
moving the piston 12, stem 13 and main slide valve 14, in the direction of the drain
eup 19 until such movement is arrested by the decrease of pressure in the auxiliary
reservoir or by the tension of the spring 359, on the stem 36, against which the
stem 13, abuts. The graduating valve 29, having been meanwhile unseated by the
movement of the stem in the known manner compressed air from the auxiliary
reservoir passes through the port 32, passage 31 passage 60 (with which in this
position of the valve 14, the passage 31, communicates) and passage 16, to the brake
cylinder 6, forcing out the piston thereof and through the usual connections applying
the brakes.
When it is desired to apply the brakes with the greatest rapidity and greatest
available force, sufficient air is discharged by the Engineer from the brake pipe to
effect, a sudden and material reduction of pressure, as say twenty pounds per square
inch, in the brake pipe, the effect of which is to force the piston 12 and main slide
valve 14, to the extreme limit of their stroke in the direction of the drain cup 19.
When in such position, the port 58, of the Chamber 24, will be opened by the valve
recess 66, and the port 57, by the port 32 and passage 31, permitting the passage of
air from the auxiliary reservoir through the ports 57 and 58, and communicating
passages 61 to the supplemental valve chamber 54, on the inner side of its piston 63.
The pressure thereby exerted upon the piston 63, forces the latter outward causing it
to bear upon the stem 64, of the supplemental valve 41, so as to raise the latter from
its seat, upon which the preponderance of pressure in the brake pipe and connected
passage 17, opens the check valve 49, and admits air directly from the brake pipe
to the brake cylinder through the passage 17, chamber 54, and passage 16. The
passages 17 and 16 may be made of as large diameter as desired without interfering
with other portions of the mechanism, and as the traverse of the air from the brake
pipe to the brake cylinder is comparatively short and direct the air pressure will pass
rapidly and with full effect from the former to the latter. When the main slide 14 has
been brought into position to effect the admission of air from the brake pipe to the
brake cylinder as above described, its port 35, is in communication with the ports 56
and 60 so that air pressure will pass from the reservoir to the brake cylinder as well
as from the train pipe through the ports 35, 56 and 60. If the pressure in the brake
pipe be reduced below that in the brake cylinder, the check valve 49, is seated by
the higher pressure on its inner side, and by the spring 50, or if equilibrium of
pressure exists in the brake pips and brake cylinder by the spring 50 alone thereby
preventing return of air from the brake cylinder to the brake pipe.

page_text: For releasing the brakes, the pressure in the brake pipe is reinstated by the
admission of air from the main reservoir, when the increased pressure acting through
the passages 17 and 18 and openings 20, upon the adjacent side of the piston 12.
forces the latter and the connected main slide valve 14. in the direction opposite to
that in which it was previously moved, the first effect of which movement is to open
the ports 61, 57 and 58 to the release port 15, through the exhaust cavity 62, of the
valve 14, whereupon the piston 63, will be moved inwardly by the pressure upon its
outer side, thus releasing the supplemental valve 41, which, together with the Check
valve 49, will be seated by the spring 50, thereby closing communication between the
brake-pipe and brake cylinder. The further movement of the valve 14 opens the
passage 60) to the exhaust 15 through the recess 62, and allows the air to escape from
the brake cylinder through the said passage and recess, the piston of the brake
cylinder being then returned to its original position by a spring, and releasing the
brake shoes in its backward movement. The auxiliary reservoir is recharged As
described in the previous Patents by air which passes through a small feeding groove
in the chamber of the piston 12.
Figs. 8 to 11, shew a modification in which a different form of supplemental valve
is employed this being of the slide instead of the poppet type as in the case first
described. Fig. 8 shews à longitudinal section on linee Fig. 9. Fig. 9 is a section
on line u u Fig. 8. Fig. 10 is a section on linet Fig. 8 and Fig. 11 is an underside
view of the part 67. In this instance, a central chamber 67 is formed upon the
partition or division plate 65, of the supplemental valve, chamber 54, the chamber 67.
being open at its lower end to the part of the chamber 54, which is provided with the
brake cylinder passage 16 and communicating, by a lateral port or opening 68 formed
in a valve face or seat 69, on its side, with the outer part of the Chamber 54 or that
into which the brake pipe passage 17 leads. The stem 70 of the piston 63, is
prolonged to extend into the Chamber 67, and carries a head 71 fitting therein. A
spring 72 which bears against the head 71 and the end wall of the chamber 67,
maintains the piston 63, at the inner extremity of its traverse except when the piston
is moved by the pressure of air admitted through the ports 61, as previously described.
The supplemental valve 41 is a flat slide which works on the valve face 69 and is held
to a proper bearing thereon by a spring 73. The valve 41, is reciprocated to open
and close the port 68 by the piston 63, a projection 74 on the valve which traverses in
a longitudinal extension of the port 68 engaging a recess in the side of the head 71, of
the piston stem 70.
A check valve 49 which opens inwardly and is seated by a spring 50 closes the
communication between the chamber 54, and the brake pipe passage 17. The
operation is similar to that first described, the supplemental valve 41 being moved to
open the port 68, by the piston 63 on the application of pressure to the latter from the
auxiliary reservoir through the ports 57, 58 and 61 in the movement of the main
slide valve 14; and the check valve 49, being thereupon opened by the pressure of air
in the brake pipe and passage 17 and admitting the same to the chamber 54 and
brake cylinder passage 16.
Another modification of the invention shewn in Fig. 12 is designed for use in
connection with the ordinary or any desired form of triple valve for the purpose, as
in the previous instances of effecting quick and powerful action when required. The
supply of air from the auxiliary reservoir and triple valve to the brake cylinder 7, in
the application of the brake and its exhaust from the brake cylinder in their release,
is, in this case, effected through a piston chamber 75. which communicates with the
triple valve by a passage 76, formed on or fixed to its head or end plate 77, and by
ports or openings 78, leading out of said passage and through the head 77. The
opposite end of the piston chamber 75, communicates with the brake cylinder by a
passage 79, and a piston 63, is fitted to work in the chamber between the ports 78,
and passage 79. A port 80, extends through the piston 63, the said port being of a
diameter not exceeding that which will suffice to admit and exhaust air to and from
the brake cylinder in ordinary braking, that is to say, where full braking power is
not desired to be exerted, so that in such case the air may pass directly to the

page_text: piston of the brake cylinder without moving the piston 63, whilst the sudden
admission of a greater volume of air will impart movement to the piston. A valve
chamber 54, which is connected or adjacent to the piston chamber 75 communicates
with the brake cylinder 7, by a passage 16. and with the main air brake pipe by
a passage 17, communication between the said passages being governed by a supple-
mental valve 41. which opens outwardly, or in the direction of the brake pipe
passage 17, and is normally seated by a spring 50. The valve 41, is fixed upon a
stem 81. which extends into the piston chamber 75, and bears, at its end, upon the
piston thereof. The passage 17, may be provided with an ordinary check valve
opening inward to prevent the return of air from the brake cylinder on a diminution
of the pressure in the brake pipe below that in the brake cylinder.
In ordinary braking, air from the auxiliary reservoir and triple valve passes through
the passage 76, ports 78 piston and chamber 75, and ports 80 and 79, into the brake
cylinder to, effect the application of the brakes and is similarly discharged to the
exhaust in their release. When the brakes are to be applied quickly and with full
force, a greater quantity of air is suddenly admitted to the piston chamber 75, and
not finding sufficient discharge through the port 80, moves the piston 63, in the
direction of the valve 41, and through the stem 81, unseats said valve and admits air
directly to the brake cylinder from the brake pipe through the passages 17 and 16.
and chamber 54, as in the instances before described. In the release of the brakes
the valve 41, is seated by the spring 50.
Fig. 13, illustrates a further modification, the construction being adapted to be
used either in connection with the ordinary triple valve mechanism, as before
described, or without a triple valve, as an emergency brake apparatus. The admission
of air directly from the brake pipe to the brake cylinder is effected through a supple-
mental valve casing 54, having a passage 17, leading to the brake pipe and a
passage 16, leading to the brake cylinder. Communication between the passages 17
and 16, is controlled, as in the previous instances by a supplemental valve 41, which
is illustrated as of the slide type, although not limited thereto, and governs a port, or
ports 68, formed in a bushing 82, fixed in the casing 54. The valve 41, is connected
to a valve stem. 64, and is normally held in position to close the ports 68, by a
spring 72, bearing against a collar on the valve stem and against the cap of the
casing 54,
A check valve 49, which opens in the direction of the brake cylinder
passage 16, is interposed between said passage and the ports 68, and is normally
seated, to close communication between the ports and passage by a spring 50. One
end of the casing 54, on the side of the valve 41, which is open to the brake pipe
passage 17 constitutes part of a differential pressure chamber 83, within which is
fitted a movable piston, or, as illustrated, a diaphragm 84, which divides the
chamber 83, into two compartments and bears at its centre upon the valve
stem 64.
The outer compartment of the chamber 83 or that on the side of the piston or
diaphragm 84, furthest from the brake cylinder passages, 17 and 16, communicates by
a passage 85, with an auxiliary reservoir, which may be either the auxiliary reservoir
of the brake mechanism, in the case where the appliance is used in connection with a
triple valve, or a small special reservoir when used a special, emergency brake
apparatus without a triple valve. A small charging passage 86, is, in the latter case,
formed in the piston or diaphragm 84 to admit of the auxiliary reservoir being
charged with air from the brake pipe through the passage 17 and chamber 54.
In operation, there being an equilibrium of pressure on both sides of the
diaphragm 84, by reason of the pressure admitted to the auxiliary reservoir, the
supplemental valve 41, will be normally maintained in position to close the
ports 68. Upon a sudden and material. reduction of pressure in the brake pipe,
which is made when it is desired to apply the brakes with maximum quickness
and force, the excess of pressure in the chamber 83, on the face of the diaphragın 84,
which is in communication with the auxiliary reservoir passage 85. moves the
diaphragm and with it the valve sten 64, and valve 41, dowaward and thereby
opens the ports GS, Air from the brake pipe passing through said ports, unseats

page_text: the check valve 49, and passes through the passage 16. to the brake cylinder,
effecting the application of the brakes as before described. The reinstatement of
pressure in the brake pipe to release the brakes, moves the diaphragm 84, in the
opposite direction, causing the valve 41. to close the ports 68, and the auxiliary
reservoir is recharged. The check valve 49, which closes in the direction of the
brake pipe passage 17, prevents the return of air from the brake cylinder thereto.
The discharge of air pressure from the brake cylinder is effected by the ordinary
triple valve, when this is used in combination with the above described apparatus.
When the apparatus is used without a triple valve it is modified as shown at
Fig. 13, where a communication is established between the brake cylinder 16 and
a discharge opening 15 leading to the atmosphere through a passage 87 and
valve 88 held down by a spring so as to close the communication when the brakes,
are applied. The valve 88 has a stem passing through into the chamber 83, so
that when the diaphragm 84 is raised by the air pressure from the brake pipe, it
pushes open the valve so as to allow the air pressure to escape from the brake
cylinder to the atmosphere.
It will be evident that the several hereinbefore described constructions of apparatus
may by a slight obvious modification be made to operate vacuum brake apparatus,
that is to say apparatus in which the pressure in the brake pipe and auxiliary
reservoir is maintained considerably below that of the atmosphere for keeping the
brakes off, the brakes being applied by admitting air pressure into the brake pipe.
Thus the arrangement shown at Fig. 2 may be modified as shewn at Fig. 14 for this
purpose, the only difference being that the positions of the slide 14, pistons 12
and 63, valves 41 and 49 and their actuating springs 50 and 50 are reversed so
that when, for establishing a direct communication between the brake pipe and brake
cylinder air is admitted to the brake pipe so as to establish a considerable
difference between the pressure therein and that in the auxiliary reservoir, such
difference raises the piston 12 considerably thereby putting the space behind
piston 63 in communication with the vacuum of the auxiliary reservoir, so that the
valve 41 is pulled open by the inward motion of piston 63, allowing the air to pass
from the brake cylinder direct into the brake pipe through check valve 49,
which in this case serves to prevent air pressure from passing from the brake pipe
into the brake cylinder.
The passage 60 leading from the brake cylinder to the face of slide 14 is shewn in
dotted lines, being cut away in this section.
Fig. 15 shews the modified arrangement of the apparatus at Figs. 13 and 13" to
adapt it for vacuum brakes.
In this case also, the positions of the diaphragm 84, spring 72 and valves 49 and 88
are reversed so that when the brakes are off, spring 72 forces diaphragm 84 down-
wards, thereby opening valve 88 and keeping the brake cylinder in communication
with the atmosphere, while if air be admitted to the brake pipe so as to raise the
diaphragm against the action of the spring, the slide valve 41 will be raised so as to
allow the air from the brake cylinder to exhaust directly from 16 through check
valve 49 and openings 68 to the brake pipe at 17, the valve 88 being then closed by
its spring.
In a similar manner the construction shewn at Fig. 12 may be adapted for vacuum
brakes by arranging valve 41 and spring 50 to operate in the opposite direction to
that shewn, that is to say, so that when the triple valve arranged in the known
manner for vacuum action, is actuated so as to cause a sudden and considerable
opening of the communication between the exhausted auxiliary reservoir and the
brake cylinder the piston 63 will be moved downward by the air pressure passing
from the brake cylinder to the triple valve, and in thus pulling open the valve 41
against the action of the spring 50 will establish the direct communication between
the brake pipe at 17 and the brake cylinder.
We wish it to be understood that we do not claim generally the use of a valve or
slide for effecting a direct communication between the brake pipe and brake cylinder,
and actuated by a piston or diaphragm separate from the triple valve apparatus, as

page_text: such an arrangement was already described in the Specification to a previous
Patent.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :
1. In fluid pressure automatic brake mechanism, the use of a chamber establishing
a direct communication between the brake pipe and the brake cylinder, and containing
a valve or slide by means of which the said communication is permitted or intercepted,
such valve or slide being actuated by a piston or diaphragm which is subject to the
pressure of the atmosphere on both sides when the valve or slide is closed but which
is actuated by pressure from the auxiliary reservoir for opening the slide or valve,
substantially as herein described.
2. In combination with triple valve apparatus of fluid pressure brake mechanism, a
separate chamber having ports governed by the triple valve slide so as to communicate
cither with the auxiliary reservoir, or with the atmosphere, and thereby to actuate a
piston or diaphragm in the said chamber and a valve or slide controlling a direct
communication between the brake pipe and the brake cylinder such valve or slide
being made to open the said communication when the piston or diaphragm is moved
by the fluid pressure from the auxiliary reservoir and to close the communication
when such fluid pressure is allowed to escape substantially as herein described with
reference to Figs. 2 to 11 of the drawings.
3. In combination with triple valve apparatus of fluid pressure brake mechanism, a
separate chamber interposed between the triple valve and the brake cylinder and
containing a piston or diaphragm one side of which communicates with the triple
valve while the other side communicates with the brake cylinder and which has an
opening through which the air pressure passes from the former into the latter, a
second chamber establishing a direct communication between the train pipe and the
brake cylinder and a valve or slide controlling the said communication, the said piston
or diaphragm and valve or slide being so arranged that when the piston is moved by
sudden and considerable fluid pressure coming from the triple valve it opens the valve
so as to establish the said direct communication, substantially as herein described with
reference to Fig. 12 of the drawings.
4. In fluid pressure brake mechanism the use of valve apparatus for establishing a
direct communication between the brake pipe and the brake cylinder, such apparatus
consisting of a casing having a chamber containing a piston or diaphragm subject on
one side to the fluid pressure in an auxiliary reservoir and on the other side to the
fluid pressure in the train pipe, a second chamber communicating with the train pipe
and containing a slide or valve that closes a port or opening leading into a third
chamber communicating with the brake cylinder, the piston or diaphragm and slide
or valve being so arranged that on the former being moved by the excess of pressure
on the one or other side the latter is caused to open or close the communication
between the train pipe and brake cylinder, substantially as herein described with
reference to Fig. 13 of the drawings.
5. Arranging the valve apparatus referred to in the preceding claims so as to operate
with vacuum action, substantially as herein described.
6. In combination with valve apparatus such as is referred to in the preceding
ciaims, the use of a check valve so arranged in the direct communication between the
train pipe and brake cylinder as to prevent air pressure from flowing back from the
one into the other substantially as herein described.
Dated this 6th day of January 1888.
ABEL & IMRAY,
Agents for the Applicant.