Improvements in Air Brake and Signalling Apparatus for Railway Trains.
Year: 1891

page_text: Date of Application, 14th Apr., 1891-Accepted, 16th May, 1891
Improvements in Air Brake and Signalling Apparatus for
Railway Trains.
A communication from HARRY ROWEN MASON, 341, Onkwood Boulevard,
Chicago, Illinois, United States of America.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
M.I.M.E., do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates to improvements adapted for use in connection with the
air brake system now in general use, wherein the brakes are applied automatically
by reducing the pressure of air in the brake-pipe, and released by increasing the
air pressure therein.
"
The mechanism for generating and controlling the air pressure in the class of air
brakes above defined, comprises, generally stated, au air-pump, a "main-reservoir"
connected with the pump and in which the pressure generated by the pump is
stored, all located upon the locomotive, and a "brake-pipe" extending from the
"main-reservoir" to "triple valves," "auxiliary-reservoirs" and "brake cylinders
on each car of the train, suitable shut-off cocks and couplings being provided along
the "brake-pipe" between cars; an operating valve called the "engineer's brake-
valve," is interposed in the "brake-pipe "upon the locomotive, between the main-
reservoir and brake-pipe, by means of which the flow of air to the "brake-pipe"
from the main-reservoir, for releasing the brakes, and the escape of air from the
brake-pipe" for applying the brakes is regulated.
<
As hitherto constructed the engineer's brake-valve above defined is defective for
the reason that, while the brakes are held released under pressure from the main-
reservoir the accidental parting of a coupling between the cars or sudden breakage
of, or undue leakage or venting from the brake-pipe or attendant parts, from any
cause unforeseen by the engineer, applies the brakes by permitting the rapid escape
of air from the brake-pipe and main-reservoir which quickly exhausts the pressure
in the main-reservoir and requires the renewal of the pressure supply by means of
the pump before the brakes can be again released. This, necessarily, occasions
delay before the train can be again started, and has in the past been the cause of
serious accidents.
וי
It
The object is to overcome the objection above set forth in the engineer's brake-
valves as hitherto constructed, by providing such a valve-device which will operate
automatically to check the flow of air from the main-reservoir to the brake-pipe
when the pressure in the latter is suddenly reduced through any undue cause.
is the object further to provide improved signaling mechanism consisting of a signal
within hearing of the engineer in direct communication with the brake-pipe to he
actuated by a reduction of pressure therein, and an exhaust valve or "conductor's
signal-valve upon one or more cars of the train in convenient location, at which
air from the brake-pipe may be caused to escape to reduce the pressure therein
One effect of this
sufficiently to actuate the signal without setting the brakes.
invention is, to dispense with the separate independent train-pipe, parallel with the
brake-pipe, which has been hitherto provided for signalling purposes, and thus save
the expense attendant upon its construction and repair, as well as giving other
advantages. The object is still further to provide means for preventing material
rebound of pressure in the brake-pipe when the escape of air therefrom is cut off at

page_text: Figure 2, an enlarged vertical central section, partly broken, of the engineer's
brake-valve, which is of the "flat" valve type;
6:
Figure 3, a top plan view of the lower stationary port or valve seat of the
engineer's brake-valve, the upper movable part or regulating-valve" being
removed;
Figures 4 and 5 bottom-plan and top-plan views, respectively, of the regulating-
valve;
Figure 6, a section taken on line 6-6 of Figure 2, and viewed in the direction of
the arrows;
Figure 7, an enlarged vertical central section of the conductor's signal valve;
Figure 8, a section taken on line 8-8 of Figure 7, and viewed in the direction of
the arrows; and
Figure 9, a vertical central section of a signal operating valve, the function of
which will appear later on.
A denotes the main-reservoir for compressed air which is connected by a pipe, z,
with a suitable air pump, not shown; A a pipe leading from the main-reservoir to
the engineer's brake-valve device B; C, the brake-pipe leading from the valve B and
extending along the train; C¹ a branch of the brake-pipe in which the triple valve
mechanism C (of a well-known construction) is interposed, and which communicates
with an auxiliary reservoir, C³, and brake cylinder C+; D a conductor's signal
valve, of my improved construction, upon a branch-pipe, C, of the brake-pipe C;
Con conductor's brake-valve also upon the branch-pipe C; E a signal operating
valve проп the locomotive in the line of the brake-pipe C F a supplemental air
reservoir upon the locomotive communicating through a pipe, F1, with the valve
device E; Ga signal (in the form of a whistle) communicating with the valve E
through a pipe, G; Ha pipe leading from the pipe F1 to the engineer's brake-
valve B; a pipe leading from the engineer's brake-valve to the pump-governor
(not shown); and a coupling of the well-known construction, in the line of the
brake-pipe between cars of the train.
is
The engineer's brake-valve B, shown, is formed with a shell or casing in two
separable sections B', B', the lower section B' affording the valve-chamber, and the
upper section B2 a screw-cap therefor. In the lower section is a valve-face or
seat, t, and fitted upon the latter is a rotary regulating-valve, s, which is held
in place by the pressure which is exerted against it by the air from the main-
reservoir which enters through the passage A². At the centre of the scatt
is a circular shallow socket, t, and at the centre of the valve is a circular lug, s',
which fits the socket t' and rotates therein. In the centre of the upper side of the
valves is a squared socket, s², to receive the squared end-portion of a valve
stem,, which extends through an opening in the cap 132 and beyond the upper
side thereof, where it is also squared and carries a lever-handle, s. The stem
suitably packed in the opening through the cap B to prevent leakage and admit of
its being easily turned by the handle, whereby it moves the valves axially upon
the valve seat t. The passage A is cored in the valve shell and enters the valve-
chamber above the valve s, and communicates at its other end with the main-
reservoir pipe Al In the valve-seat are a port, r, leading to a passage,, which
communicates with the brake-pipe (; a large exhaust port, 7, and a small exhaust-
port, 7, both communicating with the outside air; a small inlet port, H', com
municating with the pipe II and a port, g, which communicates through a
supplemental
valve-shell. Fang, with an auxiliary valve-chamber, p, on the side of the
the face of the valve-seat is a segmental recess or cavity, t2.
Extending through the valves is a passage, o. In the lower face of the valve s
are two recesses or cavities o', o³, which communicate with each other through a
passage, 3, (indicated by dotted lines) cored in the valve; and two recesses or

page_text: cavities of and o*. The ports and cavities in the valve-seat and in the regulating-
valves, should be, substantially, of the relative dimensions shown in the figures,
and should also be located in the relative positions shown.
The passage p' enters the auxiliary valve-chamber p³ at one end of the latter, and
at its opposite end the chamber communicates with the passage and consequently
the brake-pipe C through a passage, . In the chamber is a check-valve, p,
which may be in the form of a piston-valve fitting and sliding against the inner
wall of the casing. The piston is upon a stem, p, which, at one end, extends a
short distance beyond the face of the piston to abut against the end wall of the
chamber p afforded by a plug, p, and at its opposite end moves in guide-
socket, p, formed in the opposite end-portion of the shell. The seat of the valve p
is at p, which is in the direction of the passage p³. The piston is held normally
away from its seat by a graduating spring, p', and is prevented from advancing as
far as the passage pl by the contact of the forward end of the stem p' with the
screw-plug p. Near its circumference the piston is provided with a small
passage through it, p, and in the side of the chamber-wall is a longitudinal
groove, p, of about the relative dimensions illustrated. Opposite the passage p³
is a passage, y', communicating with the pipe y, which leads to the pump-governor,
as before described.
The signal operating valve E comprises a shell, which may, as shown, connect
with the brake-pipe C, at opposite sides of its upper part, and affords a piston-
chamber, E', and a small auxiliary valve-chamber, n.
The chamber E' is closed at
its lower end by a screw-cap, E, through the centre of which is a passage, G, from
which the pipe G extends to the signal G. The pipe F extends from the lower
part of the chamber E' to the supplemental reservoir F; and the branch-pipe H
extends from the pipe to the engineer's brake-valve, as before stated, where it
communicates with the small port II' which is called the "service stop inlet port."
The valve-chamber n communicates through a passage, n', at its top, with the
brake-pipe C, and through a passage, n', near its lower end with the lower part of
the chamber E¹. In the chamber n is a check-valve, n', which seats in the direction
of the brake-pipe and is held normally to its seat by a spring, n', of slight resistance.
Through the valve n is a small passage, n', which operates to afford communication
between the chamber E' and the brake-pipe, when the valve n is seated, whereby
the passage between the chamber E' and brake-pipe through the auxiliary valve-
chamber n is never entirely closed. The exact location of the passage is not
material, as a passage, in any desired position, which will serve to maintain and
open but properly limited communication between the brake-pipe C and supplemental-
reservoir F, is all that is required. E³ is a piston or movable diaphragm, in the
chamber E', upon a stem, E, which passes through a guide, E', on the cap E¹.
The piston E fits closely against a stationary bushing, E', on the wall of the
chamber E', to prevent leakage at its circumference, and it moves without material
friction. Housed in a screw-cap, E', at the top of the chamber E', and movable
longitudinally in a socket therein, is a graduating piston, Es, held normally at the
lowest limit of its play by a graduating spring, E. The piston E" is directly in
line with the stem E. At its lower end the stem E' seats normally upon
the cap
over the opening to the passage G, which it thus operates, normally, to close. In
the side of the chamber E' is a recess or groove, E, which exceeds somewhat in
ita vertical extent the thickness of the piston E. The lower end of the groove E¹º
is at about the plane of the upper side of the piston E, and the distance apart of
the lower end of the graduating piston E and the upper end of the stem E', when
the latter is in its lowest or normal position, is somewhat less than the length
of the groove E. Extending downward from the valve-shell at the top of the
chamber E', around the graduating piston is an annular projection or stop, E",
which operates to limit the descent of the graduating piston E and the rise of
the piston E'.
E'
The conductor's signal-valve D, of which there may be one upon each car of the

page_text: .
11
train, (if it be a passenger train) or upon only one car (the caboose, if a freight
train) is as before stated supported upon a branch-pipe, C, of the brake-pipe C.
It comprises a shell divided internally into two chambers, m, l, by a stationary
diaphragm, . The chamber m communicates through a passage, m³, with the
branch-pipe C. Cored through the diaphragm is a passage, m³, which extends
from the chamber m to the open air. Through the diaphragm are openings in³, m.
In the chamber in is a spring-controlled slide valve, m³, the stem, m, of which
extends to the outside of the shell through a stuffing-box in the top of the latter,
and beyond the shell the stem m' connects pivotally with a lever, m'. The
chamber in is in constant open communication with the brake-pipe C through the
passage m' and pipe C, but communication between the chambers m, I is normally
closed by the slide-valve m. In the slide-valve m' is a groove or recess, m³, which,
when the slide-valve is in its normal position, registers with the passages m³, m³,
and thus affords normally an open communication between the chamber and the
outside air. The slide-valve m' operates at all times to shut off communication
between the chamber m and the outside air. When the slide-valve is moved from
its normal position against the resistance of its spring, it closes the passage m³ and
opens the passage m'. The chamber m being as described in constant communica-
tion with the brake-pipe will contain the same pressure as the latter.
The
chamber is of internal dimensions, which, when the passage m is opened, will
cause the air expanded into it from the chamber m to reduce the pressure in the
latter chamber and consequently throughout the brake-pipe a predetermined
number of pounds, which will be a reduction sufficient to operate the signal but not
sufficient to apply the brakes. The lever may be connected to a cord, not
shown, which cord may extend along the car in the same manner as the bell-cord in
general use upon passenger trains in the United States. The conductor's brake-
valve C is of a common construction, and when opened it causes a rapid venting of
the pressure from the brake-pipe and applies the brakes.
Upon the operating handle of the engineer's brake-valve is the usual spring
indicators, which slides against the upper circumference of the shell B1, the latter
being provided with shallow notches with which the spring indicator engages in
the different positions of the valve, to hold the handle in adjusted position, and at
the same time indicate the axial position of the regulating-valve s with relation to
its scat t.
In practice the main air reservoir is charged by means of the pump or pumps
with the desired pressure for working the brake mechanism, which, for the sake of
illustration, we will say is eighty pounds. To explain the operation of the
engineer's brake-valve I have indicated upon the circumference of the regulating
valves (see Figures 4 and 5) a point, a, which corresponds with the relative position
of the spring indicator and at the circumference of the valve-seat t (see
Figure 3) I have indicated points a', a, a, a' and a with which the point a is to
be turned coincident to produce certain results. When the point a is turned
coincident with the point a' the passage o and cavity of register with the cavity 1,
the cavity of is at the port and the ports p, H', y', and y are closed. This is the
"direct feeding" position in which pressure from the main-reservoir through its
pipe A and the passage A² flows through the opening o to the cavity t' and thence
through the channel o², o³, o³, port and passage' to the brake-pipe, whereby the
latter is charged to the maximum degree of pressure, and the brakes are released.
When the point a is turned to a the valve is at the service feed" or running
position, wherein the pressure from the main-reservoir is directed through the
passage to the cavity and thence through the channel o', 0, 0, port
passage to the brake-pipe; the ports r, H', ', being closed. While
in this position any reduction of pressure due to slight leakages in the system will
be overcome, through the small opening the spring being sufficiently stiff to
prevent the slight excess of pressure behind the valve p', while such leakage is
being overcome, from causing any apparent movement of the valve p'. The opening
10
"
and

page_text: of a conductor's signal-valve D, which, as described, produces a more decided
though limited venting of the brake-pipe, may cause the valve p' to receive a slight
impulse in the direction of its seat and thus cause pressure to flow around the
valve through the groove p" in addition to that which will flow through
the opening po, but an impulse from such a cause will never be sufficient to drive the
valve p' to its seat at p. A. breakage of the brake-pipe or any of its connections,
the parting of coupling between cars, or the opening of a conductor's brake-
valve C, will cause such a material venting of the brake-pipe that the pressure
behind the valve p' in excess of what escapes through the passages p and p", will
be greater than the spring p' can withstand, and the valve will, therefore, be
quickly driven to its seat, thus shutting off the escape of air from the main-
reservoir to the brake-pipe.
10
When the point a is turned to register with the point a', the valve is on "lap,”
that is to say, the pressure from the main-reservoir through the passages A' and o
can go no farther than the cavity t, the channel o', o, o being cut off from the
latter. Thus all the ports in the valve-seat are closed and the brake-pipe cut off
from any supply of pressure from the main air reservoir, while at the same time the
pressure in the brake-pipe is held.
When the point a is turned to a', the valves is in the position called "service
stop," wherein the cavity of registers with the ports H', ', all the other ports being
closed. When the regulating-valve is in the position last described, pressure from
the brake-pipe passes through the signal-valve E by way of the passages n', n',
(opening the check-valve n³) and pipe F to the pipe H and through the latter,
port H, cavity of and port q' to the outside air. This is the position to which the
engineer's brake-valve is turned to produce a slow venting of the brake-pipe and a
consequent gradual application of the brakes, as when the train is nearing a station
or descending a grade.
When the point a is turned to register with the point a', the cavity o' registers
with both the ports p and r, and the cavity of registers with the exhaust-port
whereby a rapid venting of the brake-pipe is effected, and the brakes are applied
with great force and rapidity. This position is called the " emergency stop," and
the valve is turned to this position only in case of emergency, as the name implies.
When the brake-pipe is charged with pressure it fills the supplemental-reservoir I
through the passages n', n' of the signal operating valve E and through the pipe F³,
with the same degree of pressure. Any slight variations in pressure, due to
ordinary leakage in the system, and which would be overcome, as described, by the
passage of pressure through the valve p', would not materially effect the pressure
in the supplemental-reservoir F, and would never at any time produce such a
sudden exhausting of the brake-pipe as to cause the retrogression of pressure from
the reservoir F to move the diaphragm E³. Any such slight differences in pressure
between the reservoir F and the brake-pipe would be quickly equalized through the
small passage n in the check-valve n³.
Whenever the conductor's signaling-valve D is operated, communication is
opened between its expansion-chamber and the brake-pipe, and closed between the
chamber and the outside air, so that no matter how long the valve D is "held
open," the degree to which the brake-pipe is vented will be limited in each operation
by the capacity of the expansion-chamber !. If a conductor's signaling valve D
is operated while the engineer's brake valve is in the "service feed" or "running posi-
tion," described, the sudden, but limited venting, of the brake-pipe thereby effected,
will produce a sufficient reduction of pressure, to cause the pressure from the reservoir F
to raise the valve or movable diaphragm E' until its stem E' strikes the graduating
piston E.
The rise of the diaphragm E opens the passage G' and the air
escaping through that passage and the pipe to the signal G will actuate the
latter. In the meantime, the escape of pressure around the diaphragm E' through
the groove E" and through the passage n', and to the signal, will quickly equalize
the pressure on opposite sides of the diaphragm E' to an extent which will cause

page_text: The
the latter to rebound or drop, almost instantly, to the normal position.
operation described would be the same when the engineer's brake-valve is on "lap.”
In the event of a sudden evacuation of the pressure in the brake-pipe, such as
would happen should a conductor's brake-valve (be opened, etc., the sudden great
reduction of pressure on the brake-pipe side of the diaphragm E', would cause the
diaphragm to be driven up against the graduating piston E, force the latter
upward against the resistance of its spring E' and seat against the stop E", thereby
closing the passage E and thus prevent the air from the supplemental-reservoir f
from entering the brake-pipe through the passage E to delay the application of
the brakes. The signal in such an event will be actuated until an equilibrium is
again established on opposite sides of the diaphragm E', or the supplemental-
reservoir F is exhausted; and the engineer will thus be quickly apprised of an
emergency. Of course the same would happen when the engineer's brake-valve is
turned to " emergency stop."
"
When the engineer's valve is turned to "service stop," whereby, as described,
the pipe H is opened through the ports H', q' to the outside air, the pressure in the
supplemental-reservoir F and chamber E' under the diaphragm E' will be reduced
and pressure from the brake-pipe will open the check-valve n³ and pass in to fill its
place, until the brake-pipe is vented sufficiently to apply the brakes with the
desired force; then the "service stop will be closed by the engineer. When
the "service stop is closed, the supplemental-reservoir F will prevent such a
rebound of pressure in the brake-pipe as to effect the release of brakes. Were the
reservoir not present to operate as a cushion, the sudden closing of the "service
stop" outlet might have the effect of producing such a rebound of pressure in the
brake-pipe as to release the brakes on the forward cars of the train."
"
After the brakes have been applied, to release them, the engineer's brake-valve
is turned to the "release position," described, causing the brake-pipe and through
it the supplemental-reservoir F to be charged with pressure from the main-reservoir;
and when the proper pressure is established through the system the engineer's
brake-valve is turned to "running position," described. In the last-named move-
ment of the regulating-valve a, a sudden checking of the pressure from the main-
reservoir to the brake-pipe and supplemental-reservoir F is effected, which is apt to
produce a rebound of pressure from the latter sufficient to move the diaphragm E'
momentarily from its normal position and actuate the signal. To prevent such an
occurrence, provide in the lower face of the regulating-valves the recess of which
is in position to register momentarily with the "service stop" inlet and outlet
port H', ', as the valve is being turned from "release to running" position,
and causes a limited amount of pressure to escape from the supplemental-reservoir F,
which by reducing the pressure therein, for the instant, below that in the brake-
pipe, will overcome any tendency of the pressure in the supplemental-reservoir to
rebound, as described.
1
"
66
The small port k, shown in the passage A2 of the engineer's brake-valve, opens
into a pipe,, upon which is mounted the main-reservoir pressure-gauge.
The branch-pipe i extending from the pipe H leads to the brake-pipe pressure-
gange
While I have described the preferred construction which is employed in carrying
out this invention in detail, the various valves and other features are of course
susceptible of modifications, which would not, however, depart from the spirit of
the invention.
Having now particularly described & ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, & in what manner the
same is to be performed, I desire it to be understood that the invention is not
limited to the details of construction, but what I claim as my invention is:
1. The combination in an engineer's brake-valve device, of a main air-passage
and supplemental air-passage between the main-reservoir and brake-pipe, an

page_text: engineer's brake-valve between the main-reservoir and brake-pipe operative at will
to direct the air-pressure through either the main passage or supplemental passage,
and an auxiliary valve in the supplemental passage operating by abnormal
reduction of back pressure in the brake-pipe to shut off communication between the
latter and the main-reservoir through the supplemental passage, the said auxiliary
valve being exposed to back-pressure from the brake-pipe, substantially as and
for the purpose set forth.
2. The combination, in an engineer's brake-valve device, of a main air-passage
and a supplemental air-passage both leading to the brake-pipe, a passage A' leading
from the main-reservoir, an engineer's brake-valve operative at will to direct the
air-pressure from the passage A' to either the said main or supplemental passage,
and an auxiliary valve in the supplemental passage operating by abnormal reduction
of back-pressure in the brake-pipe to shut off communication between the latter and
the main-reservoir through the supplemental passage, the said auxiliary valve
forming the sole obstruction in the said supplemental passage, whereby it is
permanently exposed to back-pressure from the brake-pipe, substantially as and
for the purpose set forth.
3. An engineer's brake-valve device having the inlet, A', from the main-
reservoir, A, a direct outlet-passage, and a supplemental outlet-passage, which
communicate with the brake-pipe C, a regulating-valve in the valve-device
operating to direct the air-pressure from the inlet A' to either of said outlet
passages, and, when registering with the supplemental passage, to close the direct
passage, and an auxiliary valve in the supplemental passage, forming the sole
obstruction in that passage and operating by abnormal reduction of back-pressure
in the brake-pipe to shut off communication between the latter and the main air-
reservoir through the supplemental passage, substantially as described.
4. An engineer's brake-valve device, having the inlet A', from the main air-
reservoir, a direct outlet passage, a supplemental outlet passage, both of which
lead to the brake-pipe C, an exhaust port, q, a service stop inlet port, H', and
service stop outlet port, g', a regulating-valve in the valve-device affording at will
communication between the inlet A and either the direct outlet passage or
supplemental outlet passage, between the direct outlet passage and port %, or
between the service stop inlet and outlet ports, and an auxiliary valve in the
supplemental outlet passage, forming the sole obstruction in that passage and
operating by abnormal reduction of back pressure in the brake-pipe to shut off
communication between the main-reservoir and brake-pipe through the supplemental
outlet passage, substantially as described.
5. In an air-brake system for railway-trains, the combination with the brake-
pipe of signaling mechanism upon or near the engine cab, connected directly with
the brake-pipe and actuated by a reduction of pressure therein, and a conductor's
signaling valve upon a car of the train connected with the brake-pipe and provided
with air escape regulating mechanism, whereby in each operation of the conductor's
signaling valve only a limited reduction of the pressure in the brake-pipe can be
effected, without reference to the time which the conductor's signaling valve is
caused to remain open, substantially as described.
6. In a train signaling system, the combination with the conduit pipe charged
with artificially created fluid pressure, of a conductor's signaling valve upon a car
of the train, having an inlet port from the said conduit pipe, and an exhaust port to
the outside air, and air-escape regulating mechanism between the said ports,
whereby in each operation of opening the conductor's signaling valve only a limited
reduction of the pressure in the conduit pipe can be effected, without reference to
the time which the conductor's signaling valve is caused to remain open, substan-
tially as described.
7. In an air-brake system for railway-trains, the combination with the brake-
pipe of signaling mechanism upon or near the engine cab, connected directly with
the brake-pipe and actuated by a reduction of pressure therein, and valve

page_text: mechanism upon a car of the train connected with the brake-pipe, and provided
with an expansion chamber, whereby it is capable, with each operation, of
effecting a reduction of the pressure in the brake-pipe, limited by the capacity of
the expansion chamber, which is less than the reduction necessary to apply the
brakes, substantially as described.
8. In an air-brake system for railway-trains, the combination with the main-
reservoir, engineer's valve and brake-pipe, of a supplemental air reservoir near the
engineer's valve in the line of the brake-pipe, whereby when an exhaust port in the
engineer's valve is open, pressure in the brake-pipe and supplemental reservoir will
be reduced simultaneously to prevent rebound of pressure in the brake-pipe,
substantially as described.
9. In an air-brake system for railway-trains, the combination with the main air-
reservoir, engineer's brake valve and brake-pipe, of a branch passage extending
from the brake-pipe to the service-stop inlet-port of the engineer's brake valve, a
supplemental air-reservoir communicating with the brake-pipe through said branch
passage to be supplied with pressure from the brake-pipe, a valve device interposed
in the branch passage between the brake-pipe and supplemental reservoir, and
through which the pressure passes, and signal mechanism upon the said valve-
device, actuated automatically by the said valve-device when the pressure in the
supplemental reservoir exceeds that in the brake-pipe, substantially as described.
10. In an air-brake system for railway-trains, the combination with the main air
reservoir, engineer's brake-valve and brake-pipe, of a service-stop outlet-port and
a service-stop inlet-port in the engineer's brake-valve, a branch passage extending
from the brake-pipe to the service-stop inlet-port through which air is vented from
the brake-pipe when the service-stop inlet and outlet-ports are brought into
communication, a signal valve in the said branch passage, signal-actuating
mechanism in the signal-valve, a supplemental reservoir in the said branch passage
between the service-stop inlet-port and the signal-actuating mechanism, and
receiving its pressure from the brake-pipe, the signal-actuating mechanism being
operated by the retrogression of pressure from the said supplemental reservoir to
the brake-pipe, substantially as described.
11. In an air-brake system for railway-trains, the combination with the main air-
reservoir, engineer's brake-valve, and brake-pipe, of a supplemental air-reservoir
cominunicating with the brake-pipe, to be supplied with pressure therefrom, a valve-
device located between the brake-pipe and supplemental reservoir, and through
which the pressure passes, a movable diaphragm in the said valve-device, only
partly closing communication between the brake-pipe and supplemental-reservoir,
and to be moved from its normal position by pressure against it, from the supple-
mental reservoir, in excess of the pressure in the brake-pipe, and signal-mechanism
upon the said valve-device actuated by movement of the diaphragm, substantially
as described.
12. In an air-brake system for railway-trains, the combination with the main air
reservoir, engineer's brake-valve, and brake-pipe, of a supplemental air-reservoir
communicating with the brake-pipe, to be supplied with pressure therefrom, a
valve-device located between the brake-pipe and supplemental-reservoir, and through
which the pressure passes, a port in the said valve-device communicating with a
signal, and a movable diaphragm in the said valve-device normally closing the said
port, and partly closing communication between the brake-pipe and supplemental-
reservoir, and to be moved from its normal position by pressure against it, from the
supplemental-reservoir, in excess of the pressure in the brake-pipe, whereby the said
port is opened and air escapes to the signal to actuate the same, substantially as
described.
13. In an air-brake system for railway-trains, the combination with the main
air-reservoir, engineer's brake-valve, and brake-pipe, of a supplemental air-
reservoir communicating with the brake-pipe, to le supplied with pressure
therefrom, a valve-device located between the brake-pipe and supplemental-reservoir

page_text: and through which the pressure passes, a passage in the valve-device affording
constant communication between the brake-pipe and supplemental-reservoir, a
passage. E in the valve-device to supplement the other said pessage, a movable
diaphragm in the valve-device normally closing the passage E, and to be moved
from its normal position, by pressure against it from the supplemental-reservoir in
excess of the pressure in the brake-pipe, to open the passage E" and permit the
retrogression of pressure from the supplemental-reservoir to the brake-pipe through
the passage E as well as the other passage, and signal-mechanism upon the
said valve-device actuated by movement of the diaphragm, substantially as
described.
14. In an air-brake system for railway-trains, the combination with the main air-
reservoir and brake-pipe, of a direct air passage and a supplemental passage between
the main reservoir and brake-pipe, an engineer's valve-device operative at will to
direct the air pressure from the main reservoir through either the direct passage or
supplemental passage at will, a valve in the supplemental passage normally held
away from its seat and seating in the direction of the brake-pipe, and exposed to
back
pressure therefrom, a normally open feed-passage from one side of the said
valve to the other and a passage p supplementing said feed-passage arranged to be
opened by movement of the said valve toward its seat, whereby a limited reduction
of back-pressure in the brake-pipe will cause the said valve to be moved in the
direction of its seat to open the supplementing passage p" and thereby increase
the feed of air from the main reservoir to the brake-pipe, and whereby a sudden
great reduction of back pressure in the brake-pipe will cause the said valve to be
forced to its seat to shut off communication between the main reservoir and
brake-pipe, substantially as described.
15. In an air-brake and signaling mechanism for railway-trains, the combination
with the brake-pipe, signal and signal actuating mechanism, of a reservoir having
constant communication with the brake-pipe and a valve located between the brake-
pipe and reservoir, and arranged to permit a more rapid passage of air from the
brake-pipe to the reservoir than in the reverse direction, substantially as described.
16. In an air-brake system for railway-trains, the combination with the main
air-reservoir, engineer's valve and brake-pipe, of a supplemental air-reservoir
communicating with the brake-pipe, to be supplied with pressure therefrom, a signal-
operating diaphragm between the said supplemental reservoir and brake-pipe, partly
closing communication between the brake-pipe and supplemental reservoir, an open
passage and valve mechanism between the brake-pipe and supplemental reservoir,
whereby the retrogression of air from the supplemental reservoir to the brake-pipe
is rendered slower than the passage of air from the brake-pipe to the supplemental
reservoir, substantially as described.
17. In an air-brake system for railway-trains, the combination with the main air-
reservoir, engineer's valve and brake-pipe, of a supplemental air-reservoir
communicating with the brake-pipe, to be supplied with pressure therefrom, a
signal-operating diaphragm between the supplemental reservoir and brake-pipe
only partly closing communication between the brake-pipe and supplemental reservoir,
whereby an open passage is maintained between the two, and to be moved from its
normal position by pressure against it, from the supplemental reservoir in excess of
the pressure in the brake-pipe, and a valve in the said open passage, operating
substantially as described.
18. In an air-brake and signaling mechanism for railway-trains, the combination
with the brake-pipe, of a supplemental reservoir communicating with the brake-pipe
to be supplied with pressure therefrom, a valve-device located between the brake-
pipe and supplemental reservoir, having an outlet port to the signal, a diaphragm
in the valve-device normally closing said outlet port and to be moved from its seat
by pressure from the supplemental reservoir in excess of the pressure in the brake-
pipe, a yielding stop in the path of the diaphragm, a passage from the supplemental-
reservoir to the brake-pipe, normally closed and to be opened by movement of the
H

page_text: diaphragm to the yielding stop and again closed by further movement of the
diaphragm against the resistance of the stop, substantially as de-cribed.
19. In an air-brake system for railway-trains, the combination with the main-
reservoir, and brake-pipe, of an engineer's brake-valve, having service-stop inlet
and outlet ports, and a regulating-valve arranged to afford momentary communication
between the said ports while the valve is being turned from “release" to "
position, substantially as described.
Dated this 14th day of April 1891.
running
W. P. THOMPSON & BOULT,
Agents for the Applicant.