Improvement in Air-brakes.
Year: 1890

page_text: 6
COMPLETE SPECIFICATION.
Improvement in Air-brakes.
I, THERON SOLYMON EUGENE DIXON, of Hyde Park, in the County of Cook and State
of Illinois, United States of America, do hereby declare the nature of my invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
Referring to the accompanying drawings, wherein similar reference-letters indicate
the same or corresponding parts, Figure 1 is a plan view showing the general
arrangement; Fig. 2, a section illustrating the preferred form of governing-valve to
be used with my present improvement; Fig. 3, a longitudinal vertical section of
limiting-valve E, taken in line 3-3 of Fig. 4; Fig. 4, a transverse vertical section of
the same, taken in line 4-4 of Fig. 3; Fig. 5, a vertical section of the limiting-
valve Ex; Fig. 6, an elevation of a jacketed air-pump, having a portion of the outer
wall broken away; Fig. 7, a section showing the typical construction of the
differential regulating-valves; Fig. 8, a horizontal section showing the practical
application of the differential regulating-valves; Fig. 9, a partial vertical section of
the way-cock and one of the differential regulating-valves; Fig. 10, a partial eleva-
tion of the way-cock, showing portions in vertical sections; Fig. 11, a horizontal
section in line 11-11 of Fig. 10, and Fig. 12 a horizontal section of the cut-off
cock A2 and its connections.
In the following Specification and claims for purposes of brevity I use the term
way-cock" to denote the engineer's valve or other device operated by the attendant
to initiate or produce variations of train-pipe pressure, the term "governing-valve
to indicate the valve device, whereby such variations control the brake-cylinder ports,
and the term "brake mechanism as meaning the group of instrumentalities, under
each car, consisting of the brake-cylinder, auxiliary reservoir, and governing-valve
coacting together. I regard as general equivalents a cock and a valve, a diaphragm,
and a piston, and where I describe a spring for producing differential action upon a
valve I intend to include its known equivalents for that purpose-such as a weight,
a differential piston or diaphraga, an independent column of fluid under pressure--
and I use the term "differential valve" to indicate a valve capable of being moved in
one direction by a fluid-pressure insufficient to move it in the opposite direction. In
mentioning pounds of air-pressure I mean pounds per square inch.
This invention relates more particularly to that class of air-brakes commonly known
as "automatic air-brakes," in which an air-pump actuated by the steain-pressure of
the locomotive-boiler compresses air into a main reservoir, or main reservoirs, on the
engine or tender, from which it is delivered to the train-pipe, and thence to the
auxiliary reservoirs along the train, and from them to the several brake-cylinders,
the auxiliary reservoirs being charged by venting air from the main reservoir or main
reservoirs into the train-pipe, and the brakes being applied at the will of the engineer
by sufficiently reducing the pressure in the train-pipe and released by sufficiently
increasing such pressure.
While applicable in many different forms of air-brake and vacuum-brake apparatus,
my present invention will best attain all its advantages when employed in connection

page_text: with the brake apparatus for which Letters Patent of the United States of America
were granted to me, dated April 30, 1889, No. 402,418, a portion of which, merely
for purposes of illustration, is outlined in Fig. 2.
A, Fig. 1, represents one of the auxiliary reservoirs ; B, one of the brake-cylinders;
D, the train-pipe; and in Fig. 2, C indicates the governing-valve having a main
valve cand a supplementary valve c¹, and provided with a spring c to arrest the
outward movement of the main valve when it arrives at the service-port, as will more
fully appear by reference to mv said patent.
The objects of my present invention are, first, to increase the general efficiency and
reliability of the automatic air-brake system; and, secondly, to enable the engineer to
operate it easily and without danger of error.
To these ends my invention comprises, first, improved means for enabling the main
reservoir or reservoirs to carry unlimited pressures, but vent only the properly limited
pressure into the train-pipe; secondly, means for increasing the efficiency of the air-
pump for the production of such high pressure; thirdly, means for automatically
regulating the flow of air to and from the train-pipe when the way-cock is open; and,
fourthly, an improved method of controlling said automatic regulation.
Other improvements will be sufficiently indicated by the description and the claims
appended thereto.
These improvements may be used conjointly or separately, and in various forms of
apparatus, the form here illustrated being preferred because it enables me to com-
bine them in a structure which occupies but little room in the locomotive-cab, and
to operate them by a simple form of way-cock having substantially the same
movements as those of the old and well-known way-cock already familiar to loco-
motive-engineers. I will now proceed to describe them in the order above indicated.
The old reducing-valve arranged in the way-cock or in the passage leading from the
main reservoir to the train-pipe, for the purpose of reducing the normal pressure of
the latter about twenty pounds below the pressure in the former, is objectionable for
at least two reasons-viz.: first, it involves the practical necessity of employing
devices to regulate or limit the action of the air-pump in order not to charge the
main reservoirs too high, and thus unduly limits their storage capacity; and, secondly,
it unduly limits the maximum pressure of the train-pipo when the main reservoir has
become partially depleted. The true principle is to charge the main reservoirs to
their full capacity, and to employ in said passage a limiting-valve, which will auto-
matically close it when the train-pipe pressure reaches its allowed maxi.num, but leave
the passage free at all other times. Attempts have already been made to apply this
principle, but by devices more or less defective in their operation.
One of my improvements consists in combining with the train-pipe and main
reservoir a valve which is opened by a force independent of the main-reservoir pressure
and closed by a rise of train-pipe pressure sufficient to overcome said force, and which,
when closed, is tightly held to its seat by the superior pressure of the main reservoir.
The best form in which I have contemplated the application of this improvement is as
follows:
Assuming by way of illustration that the ordinary maximum limit of pressure
allowable in the train-pipe and auxiliary reservoirs for working purposes should be,
say, sixty pounds to the square inch, and that for quick and certain release of the
brakes when the auxiliary reservoirs are full or nearly full the engineer should be
able to raise the train-pipe pressure for a few moments-say, twenty-five pounds
higher than this limit-till the release is effected. I provide as usual two passages,
or a passage having two branches o o' from the main reservoir to the train-pipe, both
controlled by the way-cock, one of which passages or branches o¹ (herein termed the
"sixty-pound passage") is intended to raise the train-pipe pressure to the sixty-pound
limit, and the other o (herein termed the "eighty-five-pound passage or high-
pressure passage,") is intended to raise the train-pipe pressure to a possible maximum
of about eighty-five pounds, using one main reservoir, or two 00', as may be pre-
ferred by the constructor. In the sixty-pound passage I place the limiting-valve
device E, Figs. 3 and 4, the construction of which is as follows:
"

page_text: E18 the valve-casing containing two chambers EE, separated by a valve-seat,
provided, preferably, with two ports e e and a central recess e¹. E is a slide-valve
seated on the partition E', having ports to register with the ports e, and preferably
held to its seat by a spring E.
E' is a diaphragm, subject at its inner side to the air-pressure in chamber, E³ and
at its outer side to atmospheric pressure and the action of a strong spring E³, which
tends to hold it normally at the inner limit of its traverse.
E is a screw-cap, serving to inclose and adjust the spring; and E" is a rod,
suitably guided at e, which by means of an arm e, connects the diaphragm E7 to the
slide-valve E, so that movements of the former will actuate the latter to open and
close the ports e e. Preferably the rod or stem E10 is passed through a hole in the
arm E³, which it accurately fits and is secured by a screw et, the end of the arm
extending into a recess in the valve E', and slightly rounded at the lateral points of
contact, so that the valve while responding to the slightest movement of the stem will
be able at all times to adjust itself accurately to its seat, as it would not be able per-
fectly to do were the arın integral with the valve, instead of being, as here shown,
practically integral with the stein. The spring E8 is to act with a force equal to, say,
sxty pounds air-pressure per square inch on the diaphragm, and should be adjusted
accordingly. I prefer to make the diaphragm of rubber faced with filled leather or
other suitable material to protect the rubber from the oil contained in the air after
its passage through the air-pump. The diaphragm is subject to effective air-pressure
only on one side, and to support it against this pressure I arrange behind it a
block E, closely fitting the walls of the chamber which incloses the spring and
slightly round the approximate corners of the block and the casing, as shown at e e,
so as to present convex surfaces to the diaphragmn instead of the concave surfaces
hitherto generally employed in connection with a Hexible diaphragm, and thus more
effectually support the diaphragm.
In the passage leading from the limiting-valve to the train-pipe the constructer
may, if he prefer, place a check-valve, seating backward toward the limiting-valve;
but I do not deem it necessary to illustrate the check-valve, as its form is well known
to mechanics.
The operation is as follows:
First. When the way-cock is turned to the proper position, the eduction end of the
passage o¹ is put into communication with the train-pipe, and the diaphragm E7 is
therefore subject to train-pipe pressure. So long as this is below sixty pounds
spring E8 will hold ports e e open and allow air to pass freely from the main reservoir
to the train-pipe; but the moment it rises above sixty pounds it will overcome the
spring force, close said ports, and cut off the flow, no matter how much the main-
reservoir pressure may exceed the sixty-pound limit. The superior force of the main-
reservoir pressure tends to hold the limiting-valve to its seat when closed, rendering
its operation reliable and effective for the purposes of its use under all conditions of
service.
Second. In the passage o a limiting-valve similar to that above described may be
used, if preferred, but adjusted to a limit of, say, eighty-five pounds instead of sixty
pounds. In this passage, however, I prefer to employ at Ex, as a limiting-valve, the
construction shown in Fig. 5, in order to insure a very copious flow during the brief
period while this passage is open to the train-pipe. In this figure ee are two coned
annular valve-seats, the smaller end of the larger seat being equal in diameter to the
larger end of the smaller seat and in line therewith, so that the valve e, having faces e
corresponding to said seats, can readily be introduced and ground to a perfect bearing.
An annular recess is made in the wall of the casing between the valve-seats,
and a corresponding recesses in the valve between its bearings, so that air at the
induction side of the valve will extend entirely around it, balancing it both laterally and
longitudinally. A passage e extends centrally through the valve, and is spanned by
an arme, to which the valve-stem E10 is fastened by a screw-nut or other device
The stem is connected to a diaphragm E', actuated by air-pressure at its inner face
and by the eighty-five-pound spring E at its outer side, as already described. I prefer

page_text: to make the diaphragm of steel, tempered, nickel-plated in the rough, and lined
with brass or German silver to protect it from corrosion. I also prefer to arch the
casing above the valve, as shown at eo, in order to deflect the air-currents downward
through the central opening 2, providing passages e to admit air-pressure to the
face of the diaphragm. With this construction when the valve unseats, air will vent
around it both upward and downward in the directions shown by the arrows through
spaces of such great length that a slight opening movement will produce an ample
discharge. When the air thus vented reaches a pressure of eighty-five pounds to the
inch at the eduction side of the valve-ports, the valve will automatically close and stop
further increase.
To insure a quick and certain release of the brakes at any time, it is only necessary
that the train-pipe pressure should be raised for a moment about twenty-five pounds
higher than the auxiliary-reservoir pressure existing at the time, and any greater
increase of train-pipe pressure than this is for many reasons undesirable. As a further
improvement, therefore, the constructor may, if he prefer, set the spring Es, Fig. 5,
at about twenty-five-pounds pressure, and by a pipe A' (shown in Fig. 5 in dotted
lines) admit to the back of the diaphragm E7 air from one of the auxiliary reservoirs,
preferably the one in use on the tender. In such case whenever the way-cock is
open to admit air from the main reservoir through the passage o to the train-pipe,
the pressure in the train-pipe will rise twenty-five pounds higher than the pressure
existing in the auxiliary reservoirs along the train, and thereupon the limiting-valve
will automatically cut off the rapid flow, and the brakes being now release: the
engineer will close the way-cock to prevent the auxiliary reservoirs from attaining too
high a pressure.
If from defective construction or long use the diaphragm E' of Figs. 3 and 5
should accidentally break, the engineer can readily close the spring-containing
chamber by turning the screw-cap E, and thereby prevent loss of main-reservoir air,
the chamber having a vent-hole e, which in Fig. 3 is closed by screwing the cap
down, and in Fig. 5 by merely turning the cap.
Fig. 1 shows the service-main reservoir O and reserve-main reservoir O¹ of my
said patent, the connections to the air-pump being effected by a pipe of, provided with
a check-valve o, seating toward the service-main reservoir.
Third. In charging the main reservoirs even to the limited pressure heretofore
allowed, the air-pump has been liable to occasionally become heated, and when
heated its working capacity is known to be considerably impaired. In charging to
the high pressures now rendered available by substituting limiting-valves for the old
reducing-valve, the air-pump will be rendered still more liable to over-heating, and
therefore I provide means for obviating this difficulty. To this end I jacket the air-
pump P, or so much thereof as may be necessary, with the jacket shown at P¹,
Fig. 6, and connect the feed-water pipe P2 from the tank to the chamber within the
jacket, and thence to the feed-water pump or injector P3, Fig. 1, so that the latter
will draw or. force the feed-water through the jacket and in contact with the walls of
the pump, and the current thus established will carry off and utilize any excess of
hoat that may be liberated by the action of the pump. The same provision protects
the pump from freezing in extremely cold weather. This improvement will be an
advantage in all cases where an air-pump is used on the locomotive.
Fourth. In three of my improvements-viz., the means for applying the brakes or
grading up their pressure at will without accidentally applying the emergency-stop,
the means for grading down their pressure at will without accidentally releasing
them, and the means for refilling the auxiliary reservoirs without releasing the brakes-
I combine the way-cock with an automatic differential valve in such a manner that
the turning of the way-cock to a predetermined position in each case will cause the
train-pipe pressure to be preliminarily increased or reduced to the desired extent
above or below the auxiliary-reservoir pressure, and thereupon the valve will take
control of the train-pipe pressure and automatically maintain substantially the relation
'thus established so long as the way-cock remains open, even though the auxiliary-
reservoir pressure be meanwhile reducing by venting into the brake-cylinders, or

page_text: creasing by renting from the tram-pipe.
means of a supplementary device, termed by me the "differential regulating-valve,"
consisting, essentially, in a differential valve controlled by two opposed fluid-pressures,
one of which is in turn controlled by the valve and also by the way-cock, the
differential force being so applied as to aid the fluid-pressure, which tends to hold the
valve-port open, or, as the equivalent thereof, to resist or reduce the effective action
of the fluid pressure which tends to hold said port closed. One of these two fluid-
pressures serves as a controlling or regulating force; the other as the pressure which
is to be directly controlled or regulated thereby. For the former the constructer may
employ any fluid-pressure whose initial force and rate of variation therefrom adapt it
to the purpose.
For the latter he will employ the train-pipe pressure itself, or some
fluid-pressure which, by suitable mechanism, governs the train-pipe pressure, the
ultimate object being to so control the train-pipe pressure directly or indirectly as to
cause it to assume and to maintain at the will of the engineer such a relation to the
auxiliary-reservoir pressure as is competent to effect the desired result at the govern-
ing-valves along the train without producing any undesired result. The principle of
operation involved consists in causing the opening of a passage by the way-cock to
freely increase or reduce the regulated pressure to a given extent and then causing the
differential valve to take control of said passage and automatically regulate its flow to
a substantial correspondence with that which may be taking place at the time into or
out of the receptacle containing the regulating-pressure, thereby continuously holding
the regulated pressure in the desired relation to the regulating-pressure, whether the
latter be meanwhile subject to variation or not, and whatever may be the means
employed to produce such variation.
While, as above stated, the differential regulating-valve is adapted to operate
with any suitable regulating fluid-pressure, great practical advantages result from
the direct use of the auxiliary-reservoir pressure itself as the controlling or regulating
force, and one of my inventions resides in the new method, or improvement in the art,
involved in the employment of the auxiliary-reservoir pressure as a regulating-force
to regulate the flow of air into or out of the train-pipe at the engine when the way-
cock is turned to the proper position therefor. Coming now to the mechanical
embodiment of these principles, the differential regulating-valve is typified in the
device shown in Fig. 7, wherein F F' are two fluid-pressure chambers or receptacles
of any preferred form, separated from each other by a flexible diaphragm G. G' is a
valve connected to and operated by the diaphragm G, ani provided with a port g,
which acts in conjunction with a port or passage in the wall of the casing, and G2 is
a spring act ng against the diaphragm or valve. The movement of the diaphragm
may be limited by stems g1 g striking against stops 93 g, and wooden blocks or other
sound-deadening material 9 may be interposed to receive the impact of the stems
against the stops. The spring is employed to aid the air-pressure in one direction and
thus render the valve differential in its action, and the effective force of the spring
determines the amount of the differential. If strong springs are preferred, they may
readily be employed by arranging two of them so as to oppose each other's action,
and making one sufficiently stronger than the other to create the differential required-
for example, by placing a spring at each side of the diaphragm. If it be desired
to limit the possible decrease of fluid-pressure in chamber F to a certain number of
pounds below that in chamber F1, then the port a will be so arranged and the spring-
force so applied that the fluid-pressure in chamber plus the spring-force will tend to
hold the port gh open against the resistance of the fluid-pressere in chamber F', and
the passage will be arranged to communicate with the atmosphere and will he used
as an exhaust. On the other hand, if it be desired to limit the possible increase of
fluid-pressure in chamber F to a certain number of pounds above that in chamber Fi,
then the port will be so arranged and the spring-force so applie that the fluid-
pressure in chamber F plus the spring-force will ten to hold the port gh open
against the resistance of the fluid-pressure in chamber F, and the passage will be
arranged to communicate with the sixty-pound passage from the main reservoir and
used as a supply-port. The former, termed by me "differential regulating-valve No. 1,”

page_text: :
is the arrangement shown at L, Fig. 8, for reducing the train-pipe pressure a given
number of pounds below the auxiliary-reservoir pressure, to apply the brakes or grade
up their pressure at will without danger of accidentally applying the emergency-stop;
and the latter, termed by me "differential regulating-valve No. 2," is the arrangement
shown at M, Fig. 8, for increasing the train-pipe pressure a given number of pounds
above the auxiliary-reservoir pressure to grade down the brake-pressure at will without
danger of accidentally releasing the brakes, and also shown at N, Fig. 8, for increasing
the train-pipe pressure to a smaller extent above the auxiliary-reservoir pressure, to
automatically refill the auxiliary reservoirs without accidentally releasing the brakes.
Fifth. For applying the differential regulating-valves No. 1 and No. 2 to their
respective uses the simplest and best form of means which I have contemplated is as
follows J, Figs. 8, 9, and 10, is a casting adapted to support the several members.
I is a hollow conical way-cock so arranged in casting J as to communicate at its
lower end with the train-pipe and provided with two ports i through its wall.
Through the wall of the casing J are arranged, preferably, six ports, viz. A port k,
leading to the atmosphere; a port 1, leading to chamber F of differential regulating-
valve L a port m, leading to chamber F of differential regulating-valve M; a
port, leading to chamber F of differential regulating-valve N; a port o²,
communicating with the sixty-pound main-reservoir pipe o, and a port ; com-
municating with the high-pressure pipe o from the main reservoir. In each of the
differential regulating-valves the chamber F¹ communicates, through the pipe A', with
one of the auxiliary reservoirs, preferably the one in use in the brake mechanism of
the tender. The port h in regulating-valve L communicates with the atmosphere, in
regulating-valve M with the sixty-pound pipe of, and in regulating-valve N, preferably
by a pipe or passage R, with chamber of regulating-valve M, although it may
communicate directly with the sixty-pound pipe o, if preferred. It is best to connect
pipe A to the lower side of chambers F1 and ports 1 m n, at the lower edge of
chambers F, to drain off any water that may deposit in said chambers. In the
differential regulating-valves L M the spring should be adjusted to act with an
effective forco equal, say, to three pounds fluid-pressure on diaphragms G, and in
differential regulating-valve N to act with a force of, say, one pound fluid-pressure on
the diaphragm.
The operation is as follows:
First. Upon turning the way-cock, so as to bring port i to port k, the train-pipe
pressure will suddenly exhaust to the atmosphere and apply the emergency-stop.
Second. Upon turning port i to port the train-pipe pressure will reduce three
pounds below the auxiliary-reservoir pressure and apply the service-stop, or grade np
the brake-pressure, if it has already been applied. In either case the auxiliary-
reservoir pressure will reduce by venting into the brake-cylinders along the train;
but through the action of the differential regulating-valve the train-pipe pressure will
reduce with it and keep just three pounds below it so long as the way-cock is open.
This continues to hold the service-ports open and grade up the brake-pressure. When
the engineer is satisfied with the amount of brake-pressure obtained, he closes the
way-cock and stops further increase; or he may, if he desires, allow the brake-pressure
to run up till the brake-cylinders and auxiliary reservoirs equalize, whereupon the
valve G will automatically close port h and stop further outflow from the train-pipe.
Third. Upon turning port i to port m fluid-pressure from the sixty-pound pipe o¹
will pass through chamber F of regulating-valve M to the train-pipe and raise the
pressure of the latter three pounds above the auxiliary-reservoir pressure. This, with
my brake mechanism patented April 30, 1889, in the U.S. America, will move
the supplementary valves c¹ inward without disturbing the main valves c, and
will thereby open a leak from the brake-cylinders to the atmosphere and grade
the brake-pressure down. During the operation, if the governing-valves are
provided with equalizing-ports, as contemplated in my said patent, the air will
slowly equalize from the train-pipe to the auxiliary reservoirs, thus tending
to reduce the pressure in the former and raise that in the latter; but the
differential regulating-valve M will automatically keep the train-pipe pressure three

page_text: pounds higher than the auxiliary-reservoir pressure so long as the way-cock is open,
notwithstanding such action of the governing-valves. Whenever the way-cock is
closed, the equalization referred to will immediately cause the governing-valves to close
the leak from the brake-cylinders. Hence this device enables the engineer to grade
the brake-pressure down at will without danger of accidentally releasing the brakes.
If the governing-valves are not provi led with equalizing-ports, then the differential
regulating-valve will allow the train-pipe pressure to rise three pounds above the
auxiliary-reservoir pressure and will hold it there, the regulating-valve itself remaining
open only so far as is necessary to supply the loss occasioned by any accidental leakage
from the train-pipe, and in this case the engineer stops the grading down whenever
he desires by discharging a pound or two of air-pressure from the train-pps.
Fourth. Upon turning port to port o² air at sixty-pounds pressure will vent freely
into the train-pipe and release the brakes if the auxiliary reservoirs are not already
substantially refilled. If they are, the way-cock should be turned to the next port to
release the brakes.
Fifth. Upon turning port i to the next port o³ air at a pressure twenty-five pounds
higher than that existing at the time in the auxiliary reservoirs will vent into the
train-pipe and insure the quick release of the brakes.
Sixth. After the engineer by turning the way-cock to any of said positions has
effected the result desired, he turns it back to the normal position, wherein port i¹
communicates with port n. Air reduced in chamber F of regulating-valve M to a
pressure three pounds above the auxiliary-reservoir pressure now passes through
pipe R to regulating-valvo N, where its head of pressure is reduced to, say, one pound
above the auxiliary-reservoir pressure, and it is thence vented through the feed-
ports ni¹ to the train-pipe. This small increase of train-pipe pressure is insufficient to
move the supplementary valves c¹ of the governing-valve apparatus along the train,
but will vent through suitable refilling-passages provided therefor into the auxiliary
reservoirs and slowly refill them to their allowed maximum of sixty pounds, the
regulating-valves M N holding the train-pipe pressure just one pound higher than the
auxiliary-reservoir pressure so long as the refilling is taking place. The engineer
leaves the way-cock in this position to supply any accidental leakage through the
couplings. The refilling-passages may be provided in the governing-valve devices
along the train by suitably enlarging the small equalizing-leak described in my Patent
of U.S. of America dated April 30, 1889, or in any other appropriate manner.
In those positions of the way-cock which open the ports il, im, or in the train-
pipe pressure can never rise above or fall below the auxiliary-reservoir pressure to an
amount exceeding the differential force of the spring; hence no effect upon the
governing-valves which requires a greater variation of pressure can possibly be
produced. To accomplish precisely the result which he desires in each instance, the
engineer is therefore required to exercise no judgment or skill, but merely to turn the
way-cock to the proper port, and when the result is seen to have been accomplished
turn it back to the normal. At the normal the feed-port i¹n is open and the
apparatus at once commences automatically to refill the auxiliary reservoirs to their
allowed maximum of sixty pounds, whether the brakes be held set or released. In a
brake system thus guarded against accident the springs 2 of the governing-valves
may be set at eight or ten pounds resistance instead of fifteen or twenty, as heretofore,
and the emergency-stop be thereby rendered considerably quicker of application. It
will be observed that when in action the valves G', controlled by the varying auxiliary-
reservoir pressure, never quite close the ports gh but simply regulate their capacity
to the requirements of the occasion, furnishing an automatically-regulated flow which
holds the two opposing pressures in the exact relation desired. This automatic action
in applying the brakes for a service-stop prevents any accumulation of fluid-pressure
in the front end of the train-pipe tending to accidentally release the brakes on the
forward cars when the way-cock is suddenly closed, because at the moment when the
way-cock is thus closed the vent that is taking place from the train-pipe is very slow,
being equal only to that which is taking place from one auxiliary reservoir into its
brake-cylinder, and hence no material " rain of air-pressure is effected by such
closing.
"

page_text: Seventh. Another provision also enables me to counteract the effect of any such
ram and generally to render the movements of air in the train-pipe equable and
uniform. This provision consists in an expansion-chamber D¹ at the forward end of
the train-pipe made, preferably, by simply enlarging the diameter of said pipe
immediately behind the way-cock. An outflowing air-current suddenly stopped by
closing the way-cock, or an inflowing current suddenly produced by opening the way-
cock will initially crowd the expansion-chamber and then flow back through the
smaller train-pipe much more regularly and equably than when such chamber is not
employed. Should air accumulate by leakage in any of the small chambers F while
the way-cock is closed and vent suddenly through the way-cock when opened, this
provision will distribute its momentary pressure through the expanding-chamber, and
so reduce its head as to prevent it from producing any disturbing effect upon
the sensitive governing-valves. As one result of the expansion-chamber a relatively
small train-pipe may be used with corresponding economy of air in practically
operating the system.
Eighth. In order to save room in the cab and to produce a way-cock of neat and
handsome appearance, I design attaching the casting J to the floor of the cab, and
preferably to the under side thereof, where it will be out of sight as well as out of the
way, and bolt-holes ; are provided for its attachment to the floor. In such case
I screw a vertical tubular standard J¹ to the upper end of the casting J. leaving a
space, if desired, to be filled with oil through a hole and used as a lubricating-
chamber. A tube or rod I'. constituting an operating-shaft or spindle, extends up
through the standard J', and supports the handle 12 at its upper end, connection being
made from tube I' to cock I by a block 1, attached to the tube and stepped into a
recess in the end of the cock, and from tube l' to handle 1' by a block I, attached to
the tube and fitting into a recess in the under side of the handle. Immediately above
the block I the upper surface of the handle is recessed, as shown at . A curved
plate J extends from tube J up over recess ³, and a screw-bolt J³, screwing down
through said arm, fits into the recess and serves to regulate the friction of cock I
against its conical seat, or, in other words, to resist the tendency of the train-pipe
pressure to loosen cock I in its seat. By this provision the cock is made to work
with very little friction, and yet is kept perfectly air-tight, and it may at any time be
readily and conveniently adjusted in these respects. 1 prefer a tubular to a solid
rod 1, merely because it is less liable to bend or buckle under the force of the
adjusting-screw. An indicating-plate T is attached to the overhanging end of the
curved plate J, so as to lie in a horizontal position just above the shank of the handle 13,
and a retairing-spring T', attached to the under side of the handle, comes up through
a slot therein and bears against the inner edge of the indicating-plate, which is
provided with suitable notches or shoulders to mark the several operative positions
of the handle and properly retain it therein. The peculiar arrangement described
exposes the indicating notches or shoulders at the upper side of the plate and outside
of the spring, and thus enables the engineer to see them much more readily and
easily than when arranged as heretofore.
Whether the brakes be held set or released the handle will normally be carried at
the feed position, (marked w, Fig. 11,) where it automatically refills the auxiliary
reservoirs to their allowed maximum without disturbing the brakes. One point to the
right, at w it will apply the service-stop or grade up the brake pressure at will without
applying the emergency-stop. At the extreme right w it will apply the emergency-
stop. At u, one point to the left of the normal position, it will grade down the
brake-pressure at will and incidentally increase the auxiliary-reservoir pressure
without releasing the brakes. At u¹, two points to the left, it will release and refill,
and at u, the extreme left, it will quickly release and refill. If the train should
contain cars not adapted to the refilling of the auxiliary reservoirs, with the brakes
held set, the handles can be carried while the brakes are set at the sinall notch
marked v immediately at the right of the normal position w, in which case the feed-
port in will be held closed and out of action. It will be observed that all positions
which decrease the train-pipe pressure and apply the brakes are at the right of the

page_text: notch v, (as the engineer stands.) in the order of the violence of their action, and all
positions which increase the train-pipe pressure and refill or release, or both, are at
the left of said notch, in similar order, so that, without gross negligence, no mistake
can occur, either as to the direction or extent of the movement of the handle in the
practical operation of the system for the different purposes herein referred to. The
extreme simplicity and certainty of operation will be appreciated when it is observed
that at its normal position the handle bolds the brakes in whatever position they may
have assumed, while if moved one point to the right it gradually raises their pressure,
and if moved one point to the left it gradually lowers their pressure, the amount of
increase or decrease depending entirely upon the length of time during which it is
so held.
I prefer to use the auxiliary reservoir of the tender to supply air to chambers F1,
because it is always with the engine, and therefore available. In such case the brake
mechanism of the tender should preferably be of the same dimensions as those of the
other cars, in order to insure uniformity of action, and if, when so constructed, its
brake force be too great for the tender, a resisting-spring may be arranged to take up
a portion of such force, as shown at Q, Fig. 1.
In the refilling feed-passage in a further principle comes into operation. The
amount of air which ought to be fed to the train per second necessarily depends upon
the number of auxiliary reservoirs to be simultaneously refilled along the train, and
the amount of air that will be fed per second through a passage of any given size
depends upon the head of pressure forcing the air through said passage; hence, in
order to feed a full supply without danger of accidentally releasing the brakes, both
the capacity of the feed-port and the head of pressure feeding through it should be
capable of regulation. With the differential regulating-valve N applied as described,
both of these objects are attained, the valve automatically adjusting the capacity of
the feed-passage at the engine to the capacity of the aggregato number of refilling-
ports in operation along the train, and the head of pressure being rendered uniform
whether the difference between the train-pipe pressure and main-reservoir pressure be
great or little.
In case any or all of the three regulating-valves should accidentally get out of
order, the brake system can be temporarily operated for applying and releasing the
brakes and refilling the auxiliary reservoirs by the other way-cock ports. In such
case it may be desirable to cut off communication between the auxiliary reservoir and
the defective regulating-valve or valves. To this end I arrange in the line of such
communication a valve-casing A2, Fig. 12, having a port a to the pipe A¹, and
ports a¹ as a to branches A AA, which lead to the several regulating-valves, and adjust
within the casing a conical cock A, provided with a handle A7, and having a segmental
valve-surface A³, adapted to close any one of the four ports, leaving the other three
open, or to stand between two of the ports when in its normal position, leaving them
all open, as shown in the drawings. A cock r is placed in the pipe R for adjusting the
capacity of the feed-passage.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In a railway-air-brake system, in combination with the main reservoir, train-pipe,
connecting-passage, and engineer's valve, a limiting-valve actuated by variations of
train-pipe pressure independently of the pressure in the main reservoir, and so arranged
that the superior force of the latter pressure tends to hold the valve to its seat when
closed, substantially as described.
2. In a railway-air-brake system, the combination of the main reservoir, train-pipe,
connecting-passage, and engineer's valve with a valve-seat having a suitable port or
ports which, when open, vent air from the main reservoir to the train-pipe, a valve
interposed between said valve-seat and the main reservoir, and so constructed and
arranged with relation to its port or ports that the main-reservoir pressure tends to
B

page_text: hold it to its seat when closed, a diaphragm actuated by train-pipe pressure against
the resistance of a spring, and a connection from the diaphragm to the valve, whereby
the latter is actuated by variations of train-pipe pressure acting upon the diaphragm,
substantially as described.
3. In a railway-air-brake system, the combination of a main reservoir and
train-pipe with a connecting-passage controlled by the engineer's valve, and with a
limiting-valve device consisting of a diaphragm, valve, and spring, said spring being
supplemented in its action by fluid-pressure independent of the main-reservoir pressure,
combined and operating substantially as described, whereby the spring, aided by its
coacting fluid-pressure, tends to hold the valve-port open, and the train-pipe pressure
at a predetermined limit above said coacting fluid-pressure closes it.
4. In a railway-air-brake system, the combination of the main reservoir, train-pipe,
connecting-passages, engineer's valve, and auxiliary reservoir with a limiting-valve
device consisting of a diaphragin, spring, valve, and air-passage from an auxiliary
reservoir, which is independent in its pressure from the main air-reservoir to the back
of the diaphragm, combined and operating substantially as described, whereby the
spring and auxiliary-reservoir pressure coact to hold the valve-port normally open and
the train-pipe pressure at a predetermined limit above the auxiliary-reservoir pressure
closes it.
5. In a fluid-pressure-brake system, the combination of the engineer's valve with
a differential valve governed by the pressure of the auxiliary reservoir of oue of the
brake mechanisms, substantially as and for the purposes described.
6. In a fluid-pressure-brake system, the combination, with the train-pipe or other
air-receptacle the pressure of which is to be regulated, of a separate air-chamber and a
diaphragm interposed between them and actuated in opposite directions by the two
fluid-pressures, a passage communicating. with the train-pipe or air-receptacle the
pressure in which is to be regulated, an engineer's valve to open and close said passage
at will, a valve controlled by said diaphragm to automatically govern said passage
when it is opened by the engineer's valve, and a spring to aid one of said pressures in
holding the valve-port open against the opposition of the other, substantially as
described.
7. In a fluid-pressure-brake system, the combination, with the train-pipe or other
air-receptacle the pressure in which is to be regulated, of a separate air-chamber the
pressure in which corresponds to the pressure in the auxiliary reservoirs of the brako
mechanism, and a diaphragm interposed between them and actuated in opposite directions
by the two fluid-pressures, a passage communicating with the train-pipe or air-
receptacle the pressure in which is to be regulated, an engineer's valve to open and
close said passage at will, a valve controlled by said diaphragm to automatically govern
said passage when it is opened by the engineer's valve, and a spring to aid one of said
pressures in holding the valve-port open against the opposition of the other, substan-
tially as described.
8. In a fluid-pressure-brake system having governing-valves provided or combined
with refilling-passages to permit the refilling of the auxiliary reservoirs from the
train-pipe while the brakes are set without releasing them, the combination of the
main reservoir and train-pipe with a feed-passage leading from the source of the fluid-
pressure to the train-pipe, an engineer's valve to open and close the same, and means
for independently adjusting the capacity of the feed-passage, substantially as
described.
9. In a fluid-pressure-brake system having governing-valves provided or combined
with refilling-passages to permit the refilling of the auxiliary reservoirs from the
train-pipe while the brakes are set without releasing them, the combination of the
following elements, viz.: a feed-passage leading from the source of fluid-pressure to
the train-pipe, an engineer's valve to open and close said feed-passage at will, and
means for limiting the head of feed-pressure to a predetermined amount above the
train-pipe pressure, substantially as des ribed.
10. In a fluid-pressure-brake system having governing-valves provided or combined

page_text: with refilling-passages to permit the refilling of the auxiliary reservoirs from the
train-pipe while the brakes are set without releasing them, the combination of the
following elements, viz. : a feed-passage leading from the source of fluid-pressure to
the train-pipe, an engineer's valve to open and close said feed-passage at will, means
for independently adjusting the capacity of the feed-passage, and means for limiting
the head of feed-pressure to a predetermined amount above the train-pipe pressure,
substantially as described.
11. In a fluid-pressure-brake system, the combination of the train-pipe with an
expansion chamber arranged between the engineer's valve and the governing-valves,
and located at or near the engineer's valve, substantially as and for the purpose
described.
12. In a railway-air-brake system, the combination of a way-cock and its casing
adapte to be arranged at or beneath the floor of the cab, with a tubular standard
extending upwards from the engineer's valve-casing, an operating-shaft extending
upward from the way-cock through the tubular standard and provided with a handle
at its upper end, a curved plate extending from the standard up over the upper end of
the shaft, and a screw supported by said plate, and bearing down upon the end of the
shaft for the purpose of holding the cock to its seat, substantially as described.
13. In a railway-air-brake system, the combination of a way-cock, a curved
indicating plate or rim, a handle so arranged as to leave the upper surface of the plate
or rim entirely exposed, and a retaining-spring engaging with the inner or concave
edge of the plate or rim to retain the handle in its several positions, substantially as
lescribed.
14. In a railway-air-brake system, the combination of a way-cock casing, a tubular
standard enlarged at its lower end to scrow into the top of the casing, a screw or pin
to retain the standard in proper relation to the casing, a way-cock arranged in the
casing, a shaft extending up from the engineer's valve and provided with a handle, a
curved plate extending from the standard up over the top of the shaft and held in
proper relation to the standard by a screw or pin, a screw extending through the
curved plate and bearing downward upon the upper end of the shaft, and an indicating-
plate or retaining-spring, substantially as described.
15. In a railway-air-brake system provided with means for applying the auxiliary-
reservoir pressure of the tender to regulate the flow of air to or from the train-pipe at
the engine, the combination of the brake-applying rods and levers of the tender with a
spring to reduce the effective force of the air-pressure upon the brakes, substantially as
and for the purposes described.
16. In a railway-air-brake system provided with means for applying the auxiliary-
reservoir pressure of the tender to regulate the flow of air to or from the train-pipe at
the engine, the combination of a pipe leading from said auxiliary reservoir, a valvo-
casing connected to said pipe, branch pipes or passages leading from said valve-casing
to the regulating devices, and a cock arranged in said casing adapted to open all the
pipes and passages communicating with the casing, or to close any one of them and
leave the others open, substantially as described.
17. In a railway-air-brake system, the combination of a valve-casing having a
tapering internal chamber circular in cross-section, a pipe A¹, leading from the
auxiliary reservoir of the tender to said chamber, branch pipes or passages leading
from said chamber to devices for regulating the flow of air to and from the train-pipe,
to open all
and a cock arranged in said chamber, provided with a handle and adapted
the ports of the chamber or to close any one of them and leave the others open,
substantially as described.
18. In a railway-air-brake system operated by varying, by movements of the
engineer's brake-valve, the relation between the air-pressure in the train-pipe and the
air-pressure in the auxiliary reservoirs along the train, and provided with a valve
controlled by a piston or diaphragm for automatically limiting the extent of such
variation, the herein-described method of governing the action of said valve, consisting,
essentially, in subjecting said piston or diaphragm on one side to an air-pressure whose
variations substantially coincide with those of the train-pipe and on the other side to

page_text: an air-pressure whose variations substantially coincido with those of the auxiliary
reservoirs along the train.
19. In an engineer's brake-valve, the combination of a piston or diaphragm and a
connected discharge-valve controlling the exhaust of air from a brake-pipe, said piston
or diaphragm being adapted to close the discharge-valve by a disturbance of equilibrium
of pressure to a predetermined extent on its opposite sides and to open and maintain
the opening of the discharge-valve by a restoration of such equilibrium, whereby, when
the engineer's valve is opened, the flow of air from the brake-pipe is automatically
regulated, substantially as described.
20. In an engineer's brake-valve, the combination of a piston or diaphragm and a
connected supply-valve controlling the supply of air from the main reservoir to the
brake-pipe, said piston or diaphragin being adapted to close the supply-valve by a
disturbance of equilibrium of pressure to a predetermined extent on its opposite sides
and to open and maintain the opening of the supply-valve by restoration of such
equilibrium, whereby, when the engineer's valve is opened to the reservoir-port, the
flow of air into the brake-pipe is automatically regulated, substantially as described.
21. In a railway-air-brake system, the combination of a brake-pipe or other air-
receptacle whose pressure is to be reduced, an exhaust-passage therefrom controlled at
one point by a hand-valve and at another point by an automatic valve, and a piston or
diaphragm connected to the automatic valve and adapted to close the same by a
disturbance of equilibrium of pressure to a predetermined extent on its oppozite sides
and to open and maintain the opening of the same by a restoration of such equilibrium,
whereby, when the engineer's valve is opened, the flow of air from the brake-pipe is
automatically regulated, substantially as described.
22. In a railway-air-brake system, the combination of a brake pipe or other air-
receptacle whose pressure is to be increased, a supply-passage leading from the main
reservoir to said brake-pipe or receptacle, controlled at one point by a hand-valve and
at another point by an automatic valve, and a piston or diaphragm connected to the
automatic valve and adapted to close the same by a disturbance of equilibrium of
pressure to a predetermined extent on its opposite sides and to open and maintain
the opening of the same by a restoration of such equilibrium, whereby, when the
engineer's valve is opened to the reservoir-port, the flow of air into the brake-pipe
is automatically regulated, substantially, as described.
23. In an engineer's brake-valve, the combination of a piston or diaphragm and a
connected discharge-valve controlling the exhaust of air from a brake-pipe, with a
spring or its equivalent to oppose the closing of the valve, said piston or diaphragm
being adapted to close the discharge-valve by a disturbance of equilibrium of pressure
on its opposite sides sufficient to enable it to overcome the resistance of the spring and
to permit the spring to open and maintain the opening of the discharge-valve upon the
restoration of such equitibrium, substantially as described.
24. In an engineer's brake-valve, the combination of a piston or diaphragın and a
connected supply-valve controlling the supply of air from the main reservoir to the
brake-pipe, with a spring to oppose the closing of the valve, said piston or diaphragm
being adapted to close the supply-valve by a disturbance of equilibrium of pressure on
its opposite sides sufficient to enable it to overcome the resistance of the spring and to
permit the spring to open and maintain the opening of the supply-valve upon the
restoration of such equilibrium, substantially as described.
25. In a railway-air-brake system, the combination of a brake-pipe or other air-recep-
tacle whose pressure is to be reduced, an exhaust-passage therefrom controlled at one point
by a hand-valve and at another point by an automatic valve, and a piston or diaphragm
connected to the automatic valve, with a spring to resist the closing of said valve, said
pton or diaphragm being adapted to close the automatic valve by a disturbance of
equilibrium of pressure on its opposite sides sufficient to. enable it to overcome the
resistance of the spring and to permit the spring to open and maintain the opening of
said valve upon the restoration of such equilibrium, substantially as described.
26. In a railway-air-brake system, the combination of a brake-pipe or other air-
receptacle whose pressure is to be increased, a supply-passage leading from the main

page_text: reservoir to said brake-pipe or receptacle, controlled at one point by a hand-valve and
at another point by an automatic valve, and a piston or diaphragm connected to the
automatic valve, with a spring to resist the closing of said valve, said piston or
diaphragm being adapted to close the automatic valve by a disturbance of equilibrium
of pressure on its opposite sides sufficient to enable it to overcome the resistance of
the spring and to permit the spring to open and maintain the opening of said valve
upon the restoration of such equilibrium, substantially as described.
27. In an engineer's brake-valve, the combination of an automatic discharge-valve
controlling the exhaust of air from a brake-pipe or other air-receptacle whose pressure
is to be reduced, a piston or diaphragm connected to said valve, adapted to close the
same by a disturbance of equilibrium of pressure to a predetermined extent on its
opposite sides and to open and maintain the opening of the same by a restoration of
such equilibrium, and a valve actuated by hand for effecting an exhaust of air through
the passage controlled by the automatic valve at one side of the piston or diaphragin,
and for causing by the same movement a slower exhaust of the air at the opposite side of
the piston or diaphragm, substantially as described, whereby, when the hand-actuated
valve is open, the automatic valve is so controlled by the two varying air-pressures
as to initially permit the one to reduce to the predetermined extent below the other,
and then to allow both to reduce together without any substantial disturbance of the
difference thus initially established.
28. In an engineer's brake-valve, the combination of an automatic supply-valve
controlling the admission of air from the main reservoir to a brake-pipe or other air-
receptacle whose pressure is to be increased, a piston or diaphragm connected to said
valve, adapted to close the same by a disturbance of equilibrium of pressure to a
predetermined extent on its opposite sides and to open and maintain the opening of
the same by a restoration of such equilibrium, and a valve actuated by hand for effecting
an increase of pressure through the passage controlled by the automatic valve at one sido
of the piston or diaphragm, and for causing by the same movement a slower increase
of pressure at the opposite sides of the piston or diaphragm, substantially as described,
whereby, when the hand-actuated valve is open, the automatic valve is so controlled
by the two varying air-pressures as to initially permit the one to rise to the pre-
determined extent above the other, and then to allow both to rise together without any
substantial disturbance of the difference thus initially established.
29. In a railway-air-brake system, the combination of a brake-pipe or other air-
receptacle whose pressure is to be reduced, an exhaust-passage therefrom controlled at
one point by a hand-valve and at another point by an automatic valve, a piston or
diaphragm connected to the automatic valve, adapted to close the same by a disturbance
of equilibrium of pressure on its opposite sides sufficient to enable it to overcome the
resistance of the spring and to permit the spring to open and maintain the opening of
the same upon the restoration of such equilibrium, and an air-passage, effecting a
communication between the auxiliary reservoir of one of the brake mechanisms and
that side of the piston or diaphragm which is most remote from said exhaust-passage,
substantially as described.
30. In a railway-air-brake system, the combination of a brake-pipe or other air-
receptacle whose pressure is to be increased, a supply-pipe leading from the main
reservoir to said brake-pipe or receptacle, controlled at one point by a hand-valve and
at another point by an automatic valve, a spring to resist the closing of the automatic
valve, a piston or diaphragm connected to the automatic valve, adapted to close the
same by a disturbance of equilibrium of pressure on its opposite sides sufficient to
enable it to overcome the resistance of the spring and to permit the spring to open and
maintain the opening of the same upon the restoration of such equilibrium, and an
air-passage effecting a communication between the auxiliary reservoir of one of the
brake mechanisms and that side of the piston or diaphragm which is most remote from
said supply-passage, substantially as described.
31. In a railway-air-brake system operated by varying the relation between the
air-pressure in the train-pipe and the air-pressure in the auxiliary reservoirs along the
train, a controlling-valve for automatically limiting such variation, said valve being so

page_text: connected as to be operated by the differences of pressure in the train-pipe and
auxiliary reservoirs, substantially as and for the purpose set forth.
32. In a railway-air-brake system, the combination of a train-pipe, an engineer's
valve, a controlling-valve connected to the engineer's valve, and a pipe or passage
connecting the controlling-valve with one of the auxiliary reservoirs of the train,
substantially as and for the purpose set forth.
33. In a railway-air-brake system, the combination of a train-pipe, an engineer's
valve, a controlling-valve regulating the flow of air through a port or passage leading
into the train-pipe, and a pipe or passage connecting the controlling-valve with one
of the auxiliary reservoirs of the train, substantially as and for the purpose set forth.
Dated this 18th day of February 1890.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.