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Sept. 17, 1946.
E. s. COOK
VARIABLE LOAD BRAKE APPARATUS
Filed‘ Dec. 28, 1944
2,407,870
Patented Sept. 17, 194-6
1
2,407,870
‘UNITED, STATES PATENT‘ OFFICE
VARIABLE LOAD BRAKE APPARATUS
Earle S. Cook, Forest Hills, Pa., assignor to The
Westinghouse Air Brake Company, Wilmerding,
Pa., a corporation of Pennsylvania
Application December 28, 1944, Serial No. 570,053
V2s Claims. (01. 303-22)
1
2
This invention relates to variable load ‘brake
equipment for vehicles, and more‘ particularly to
that type of equipment which is constructed and
arranged to be automatically adjusted or condi~
tioned to vary the braking force according to the
position that the vehicle body, under various
plication of the standard freight brake equip
ment vavailable for use by the train operator.
Another object is to provide‘ a variable load
brake equipment of the type employing a single
brake cylinder device in which the ?uid pressure
may be varied according to the degree of brake
loads, assumes relative to a ?xed part of a truck.
application, the pressure for any given applica
The present trend toward the use of light
tion being proportioned according ‘to the weight
weight materials in the construction of railway
of the load carried by the vehicle.
freight cars has resulted in much higher ratios 10
To attain these objects the variable load brake
of gross weight to tare weight than ever before
mechanism embodying this invention employs a
encountered. Since the braking force with re
single brake cylinder device, which is preferably
lation to the weight of an empty car must be
of larger diameter than the standard device, for
such as to avoid wheel sliding and excessive train
providing the braking force for a fully loaded
shock, the braking force on lighter weight cars 15 vehicle. The lower degree of braking force
will consequently have'to be lower than hereto
which is necessary‘ for vehicles carrying lighter
fore. Because the gross weight of the car is lim
loads is obtained by the use of a relay valve
mechanism of‘the scale beam type which is ar
ranged to operate in response to the pressure of
be inadequate for proper control of such cars 20 ?uid in the brake cylinder device to spill or bleed
when loaded.
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‘
?uid under pressure from the brake cylinder de
The principal object of this invention, there
vice orbrake cylinderpipe into a volume reser
fore, is to provide a variable load brake equip
voir until the degree of pressure of ?uid in said
ment which will operate in conjunction with “the
reservoir is svu?'icient to balance‘with the brake
present type of ?uid pressure freight brake equip 25 cylinder pressure, thereby reducing the pressure
ment so that the braking force will be su?iciently
of ?uid inthe brake cylinder device according
low on an empty car to prevent wheel sliding and
to thefweight of the lading carried by the ve
will be increased in relation to any increase in
hicle as determined by the position of the ful
the gross weight of the car so'that a loaded or
crum along the scale beam. The fulcrum is po
partially loaded car may be‘properly controlled 30 sitioned, according to the weight of the load car
in a train.
'
ried, by a mechanism which‘ is responsiveto ?uid
under pressure supplied from the brake pipe when
Another object is to provide a variable load
the brake pipe is below a certain degree of pres
brake equipment which will require a ‘single
sure to initially actuate a measuring element in
standard auxiliarygreservoir and a single brake
cylinder device and which will operate in con 35 to engagement with the top of a vehicle axle and
thereafter to displace the fulcrum distances pro
junction with the standard ?uid pressure freight
gressively increasing as the weight of the lading
brake equipment to obtain the present applica
ited only by the load limit for the trucks, which
remains unchanged, the lower braking force will
tion and release time intervals on a car without
altering “the ?ow capacities of any passages in
the present‘standard freight brake equipment.
increases.
‘
i
A feature of this variable load brake mecha
40 nism is the use of an intercepting valve device
Another object is to provide a variable load
brake equipment which will prevent the producj
interposed in the communication between the
brake controlling valve device and the auxiliary
reservoir and operative to close off said commu
nication during a brake application if the pres
sure of ?uid in the auxiliary reservoir is reduced
reduction in brake pipe pressure and thereby 45 more
than a ?xed amount, such as twenty pounds,
tion of undesirably high braking forces on an
empty or a lightly loaded vehicle‘ by‘ an over- ~
provide for safer operation while at the‘same
time conserving the ?uid under pressure in‘ the
below that at the initiation of the brake applica
tion.‘ Upon r‘elease‘of the brakes the intercept
auxiliary reservoir for subsequent brake appli
ing valve device will reset to measure the ?xed
cations. As will appear later, particular impor 50 amount of twenty pounds reduction in ?uid pres—
tance attaches to this feature in the operation
sure from the pressure to which the auxiliary res
of train brakes on long descending grades.
ervoir has been recharged, and upon‘ a further
Another object is to provide a variable load
reduction of twenty pounds will again close off
brake equipment which will ‘always have a brak-‘
the communication.
'
ing force equivalent to a full service brake ap 55
Other objects and advantages will appear in
52,407,870
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variable load Ibrake equipment embodying the
invention.
As shown in the drawing, the variable load
?uid pressure brake equipment may comprise the
usual brake‘ pipe I', a branch pipe 2, a-brake con
trolling valve device 3, a cut-01f valve device 4,
a load measuring apparatus 5, a check valve de
vice 6, a locking mechanism 1, a variable load
valve mechanism 8, a service volume reservoir
9, an emergency volume reservoir‘ 18, an inter
I9 is open to the under side of the diaphragm
and at the other side of the diaphragm there is
a chamber 31] which is in constant open com-i
munication with the atmosphere by way of a
passage 3!. Contained in the chamber 39 and
interposed between and engaging the, valve cas
ing andv the diaphragm 28 is a spring 32 which
produces the loading force to hold the slide valve
2.6" on its seat.
The load measuring apparatus '5 may be'of
any desired construction but for illustrative pur
poses is shown as comprising a bracket 33 which
isrigidly secured by any suitable means to any
convenient part of the vehicle body such for in
cepting valve device I l, a brake cylinder device ~~
stance as to thellower cover plate of a center
I2, an auxiliary reservoir 13, an emergency reservoir l4, and a retaining valve device I5.
I
The brake controlling valve device 3 shown is
of the “AB” type but may be of any other de»
sired type. This device may be of substantially \
thewsame construction and have the same. oper
ating characteristics as the “AB” valve device
fully described in- the patent to .Clyde C. Farmer,
No; 2,031,213, issued, February. 18,. 193.6, and ,as
sill 34? of which only the bottom cover plate is
shown, The bracket includes the arms 35 and
36 on which are operatively mounted a linkage
the following more detailed description of the
invention.
In the accompanying drawing the single ?gure
is a diagrammatic view mainly in section of a
or measuring mechanism 3‘! comprising a meas
uring element 38 having a horizontal portion 33,
disposed above the central portion of an axle
40 and parallel to the bottom of the center sill
34, and having a downwardly depending pore
tion 4! which is normally spaced away from the
signed to theassignee of the, present invention,
axle a suf?cient distance so that it will not be
aridzin view of this it is deemed unnecessary to
engaged by ‘the axle 40 when the vehicle is sub
ject to the usual service shocks, Extending be
show and describe this devicein detail. It will,
of course, be understood that this device operates
tween the arms 35 and 36' and the measuring‘ele
ment 38 and operatively connected thereto are
upon a service. reduction in brake pipe pressure
to supply ?uid under pressure to effect a serv 30 vertically spaced links 42 and 43, link 42 having
one end pivotally connected by means of a pin
ice. applicationof the brakes, upon an emergency
44 to the arm35 and having the other end con
reduction‘in brake pipe pressure to e?ect an
nected by means of a pin 45 to the upper end
emergency applicationof the brakes,v and .upon an
of the portion 4| of the measuring element, 33.
increase inbrake pipe pressure to e?ect a re
One end of the link 43 is pivotally connected
by means of a pin 46 to the arm 36 and the other
lease of the brakes and the ohargingof the brake
equipment.
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.
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_
.
end is connected by means of a pin 41 to the
lower end of the depending portion 4! of the
The cut-01f valve device 4 may. comprise a'cas
ing in .which there is- mounted. a ?exible .dia
phragm £6, at one side of which is a chamber
measuring .element. The axes of the pivot points
.11 in constant .open communication with the at .40 at each end of thelinks 42 and 43 are in vertie
mosphere. by wayrof a passage-1.8. At..the . other ‘ " cal alignment and spaced apart equal distances
vertically was to maintain the portion ,39-sub
sideof the diaphragm is a valvechamber .i 9. which
stantially parallel with the center sill 34' in all
is in constant open communication (by Way‘ of a
positions of the‘ linkage. The links 42 and .43
connected pipe and passage :za withabrake pipe
are each provided with a series of corresponding
passage ‘2 I provided in the brake controlling valve
device .3.‘
Slidablymounted inchamber ll is a
" holes 48 and 49, respectively, for receiving the
pins 45 and 41, respectively, to obtain a di-?'ere
ent degree of total vertical travel of the wmeasur-'
ing‘element 38 to meet varied conditions, asset
ber1 to limitv the upward movement of theimem
her, or a ring. 24, expanded into an annular 50 forth in the copending patent application of
Claude A. Nelson et al., Serial No. 551,200, ?led
groovein said wall, tollimit the. downward move
August 25, 1944, now Patent ‘No. 2,402,434, issued
ment of said..member.. Interposed between and
June 18, 1946, and assignedto the assignee ofthe
operatively engaging ‘the member 22 and the top
present application, in which the load measuring
wall. of the chamber i1 is a spring '25 which, at
mechanism 5 is fully disclosed and claimed. 70p
all times, tends to move the‘ stop member down
erati-vely connected between a lug 53' on the ele
wardly. Contained in the chamber [.9 is a slide
valve 126 which is arranged tov be operated by .a
ment 38 and a lug 5!- on the centersill 34 is a
stop member 22 which is arranged to abut either
a» shoulder 23 formed on the wall of .the chain-.
notched stem or follower 21 operatively secured
tension spring 52 which, at all times, tends to
to the ?exible diaphragm I6 for controlling the
move the measuring element toward the position
operation of the locking mechanism 1 and the 60 in which it is shown and to normally hold the
element in this position-against accidental move
load measuring apparatus, 5', and for also control
ment therefrom. For limiting the upward travel
ling a communication to the emergency volume
reservoir It, as will hereinafter more fully ap
of the'elemen-t, 38, the horizontal p‘ortion‘is pro;
pea-.1‘.
.
.
.
The cut-off valve device 4 is provided with a
loadingrmechanism for the purpose of prevent
in-g; ?uid under pressure, acting on the under side
of the slide valve 26, from raising the valve from
its‘seat when the pressure of ?uid in the-valve
a
vided'with a stopmember 53 which engages the
bottom of center sill 34- and is adjustable'in the
portion 39 by screw-thread means. Archer-54
is mounted by means of" a pin 55 on one end of
a supporting member 56, which member is piv
otally mounted. at its other end to the arm 36
chamber I9 is reduced. This mechanism may 79 by means of the pin 46. ‘ For imparting move
ment to the element .38, the roller isvcoupled to
comprise a ?exible diaphragm 28 which is mount
the lower end of the portion 4| by means of a
ed in the cut-off valve device casing and which
operatively engages a rocking pin 29 through
strut member '51 which is mounted at vits one
which a loading force is adapted to be trans
end on the pin 55. and at its other end on the
mitted to the slide valve 26. 'Thefvalve chamber 75 other pin 41-- ..Thesirui member isprqvidedai
2,407,870
5
spring 99 which engages a casing .9I of the mech
anism 8 at one end and the lever 96 at the other
the .latterend with a series of holes 58 forad
justing the coupling between‘the roller 54 andthe
end so as to urge the leveryand thereby the bar
85, ‘and fulcrum member 89 of the mechanism
For actuating the roller 54, the load measur CI 8 toward the position in which they are shown.
ingapparatus 5 is a ?uid‘pressure controlled
The variable load valve mechanism 8 may com
mechanism comprising a casing which is integral
prise the casing 9I having a recess formed
with the bracket 33 and which is provided with
therein and having secured to the bottom. there- '
apiston 59 having at one side a chamber 69
of in any suitable manner a cap portion 92 which
which is in constant open communication with 10 closes the open end of said recess, the inner sur
the atmosphere by way ‘of. a passage 6|, which
faces of the recess and the cap portion de?ninga
chamber contains a spring 62 engaging a wall 63
chamber 93 which is constantly open at the left-v
of the chamber 69 and the non-pressurefside of
hand end to the atmosphere. 7 This chamber
the piston 59 so as to tend to move the piston
contains the fulcrum member 89 and a scale
toward the position in which it is shown; A stem
beam lever 94 arranged to rock on the fulcrum
64 of the piston 59 extends through chamber 69
member. Secured in any suitable manner to the
and an opening in the wall 63 and is pivotally
top of the casing 9I is a cap portion 95, there
being a sealing gasket 96 clamped between the
connected, by means of a pin 65 with a shiftable
casing SI and the cap portion.‘ This gasket96
lever,66'at a ‘point intermediate the ends of the
lever. For purposes which will more fully ap 20 comprises laterally spaced ?exible diaphragms
97 and 98 which are preferably‘of substantially
pear later, this lever 66 is located so that its lower
element 38 when a change is made. in the loca
tion of the pin 47 in the link 43.
'
end may be actuated into operative engagement
the same area.
with roller 54.
At one side of thediaphragm 91 there is a
chamber 99 Which is open at all times to the at:
mosphere by way of an opening I99 and the at
'
At the other side of the piston 59 is a chamber
B‘Iwhich is in constant open communication, by
way of pipe and passages 68, with a valve cham
ber 69 of the check valve device 6. This chamber
69 contains a ball check valve ‘I9, the under side
of which is connected to a locking mechanism ‘I
by way of pipe and passages ‘I I. The check valve 30
device 6 is ,further provided with a passage .12
which by-passes the ball check valve and is of
small ?ow capacity to insure the occurrence of
the locking operation of the mechanism 1. before
the chamber 61 is depleted of ?uid under pres
sure, as will hereinafter more fully appear.
The locking mechanism 1 comprises a casing
which is provided with a piston ‘I3 having atone
,
mospheric chamber 93 in the casing 9|. ,C‘on
tained in this chamber 99 and operatively en
gaged by the diaphragm 91 is a follower I9I hav
ing a stem I92 which extends throughjan opening
in the casing, and which, at its lower end, is piv
otally connected with the scale beam lever 94 at
a point located a short distance from its left
hand end. At the other side of the diaphragm
‘ 91 is a chamber I93 which is open to the under
side of a valve I94 by way of a ?uted stem‘ I95 .
of the .valve, which stem extends into chamber
I93 and is arranged to be engaged by the dia
‘ phragm 91 so that the valve may be operated to
control the ?ow of ?uid under pressure to said
communication with the cut-off valve device 4 40 chamber, whence it may ?ow to the service vol
ume reservoir 9 by way of a passage I95, a pipe
by way of a connected pipe and passage ‘I5. At
the other side of the piston is a chamber 16 which
I91, and a pipe I98.‘ The passage I96 is also open
to the under side of a ball check valve I99 and the
is in constant open communication‘with the at
pipe I9? is also open to the slide valve seat of
mosphere by way of a passage 11. This chamber
‘I6. contains a spring ‘I8 which operatively‘ en
the cut-off valve device 4.
gages the bottom surface of the chamber and
The valve I94 is contained in a‘ chamber II9
the piston ‘I3 so asto tend to move the piston
formed in the cap portion 95, which chamber is
toward the position in which it is shown. A stem
closed at the top by a cap nut III. This cham
"I9 attached to the piston ‘I3 extends downwardly
ber is in open communication with a chamber I I 2
through the chamber 16 and terminates in a ,, containing the ball check valve I99 by way of a
locking portion 89 which is slidably mountedin a
passage H3 and also is in open communication
guide opening BI formed in the bottom portion of
with the brake cylinder device I2 by way of a
the casing of the mechanism. The locking por
passage H4 and pipe II5. Interposed between
tion 89 of the piston stem has a transverse open
the cap nut III and the valve I94 is a spring IIB
ing 82 which is arranged to register with openings
which at all times urges said valve toward its
seating position.
83 formed in the wall of the opening 8!. The
upper surface of the bottom wall of the opening
At one side of the diaphragm 98 is a chamber
82 in the locking portion 99 is toothed for locking
III which is open at all times to atmosphere by
engagement with a correspondingly toothed por
way of an opening H8 in the casing 9| and the
tion 84 formed on one end of a fulcrum position (50 atmospheric chamber 93. Contained in this
ing bar 85, the opening 82 being large enough to
chamber I I1 and operatively engaged by the dia
provide su?icient clearance for moving the lookphragm 98 is a follower II9 having a stem I29
ing portion 89 of the stem ‘I9 downwardly out of
which extends through an opening in the casing
engagement with the bar.
and which, at its lower end, is pivotally connect
Intermediate its ends, the bar 85 is operably 6:3 ed with the right-hand end of the lever 94.‘ At
connected to the lever 66 by means of a pin 86
the other side of the diaphragm 98 is a chamber
which extends through a slot 81 formed in the
IZI which is in constant open communication
upper end of the lever 66, the slot providing for
with the passage I I4,
the necessary relative movement between , the
The intercepting valve device II comprises a
lever and the bar whenthey are operated. Ro
casing
and diaphragm I22 rigidly clamped around
tatably connected to the right-hand end of the 70 its periphery between two connected parts of the
bar 85 by means of a pin 88 is a fulcrum member
casing, and having, at one side, a chamber I429
89 which may be shifted in the variable load valve
which, as shown, may be connected with the aux
mechanism 8 in a manner to be more fully de
iliary reservoir I3 by way of a valve chamber I24,
side a chamber ‘I4- which is in constant open
scribedlater. Encircling the. bar 851s" a helical
passage '25 and pipe. I26- .At the ‘other side 0.4‘
2,407,870
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the diaphragm I 22 is a springchamber I21 which 7
is'inconstantopen communication with the ‘brake
controlling valve device 3v by way of a connected
pipe and a-passage I28 and is in valve‘controlled
8
V
V
pistons of the brake controlling valve device 3,
moving the pistons indue courseto ,‘release'a-nd
charging position. Fluid under pressure‘willthen
?ow to the several chambers of the brake con-,
communication with the auxiliary reservoir I3 by
wayof passages I29 ‘in a‘ wall I30 of the casing,
manner, to the auxiliary reservoir 13 bywayof
a'valve chamber I3I,w passage I25 and pipe I 25.
the “pipe I123, the chamber I21, passages I29,
trolling valve device 3, and thence in the usual
chamber I'3I, and passage I25 in the intercept
ing valve device I I, and pipe I26, and to the emer
through a'suitable bore in the casingrsev that’ its 10 gency reservoir I4 by way of a pipe I45“ Atthe
lower end may be operatively engaged by a por
same time, ?uid ‘under pressure will also .?ow
from “the v:brake pipe I through passage 21 ' and
tionof a follower‘ I34 secured to the diaphragm
connected ‘pipe and passage 20 to valve-chamber
I22. ‘ Interposed between and operatively engag
I9 in the cut-off valve device 4. Fromv'chamber
ing'a cap nut I35 at the topof the chamber I24
I9. ?uid under pressure ?ows through pipe and
and the valve I32 is a spring I33 which urges
passage 15 to chamber 14 of the .lockingmecha
said valve toward its seated position. 7
‘Contained in the valve [chamber I24 is a valve
I32 having a ?uted stem l>33 which extends
Contained in the chamber I3I is a valve I31
arranged to engage a valve seat I38 formed in the
bottom wall of the chamber and thereby inter
nism ,1.‘ Upon an increase in the pressure of. ?uid
in this chamber 14 to a predetermined. value, the
piston 13 is caused tomove downwardly against
rupt the communication between the auxiliary
reservoir I3 and the brake controlling valve de
vice 3 as will later more fully appear. For limit
the opposing pressure of the spring 18‘, thereby
moving; the toothed locking portion 80 out of
locking engagement with the toothed portion“ 84
ing ithe‘upward movement of the valve I31, said
of the bar 85, thus releasing the bar.
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The piston 13 as it moves downwardly passes
valve is provided with a ?ange I39 which normally
‘engages the bottom surface of the wall I30 be 25 the mouth of the passage 1I, thereby establishing
communication between chamber 14 of: the lock
tween chambers I21 and I3I. The valve I31. is
secured by- screw-thread or other suitable means
' ing mechanism and chamber 31 of the load meas
uring apparatus by way of said passage and
check‘ valve device 6. Fluid under pressure will
which sleeve portion is contained in chamber I21. 30 ?ow from chamber 14 through. pipeand. passage
Contained in chamber I21 and interposed be
H, and passage 12 to passage and pipe 68 and
tween the upper ?anged 'end of ‘the guide member
also past ball check valve 13 to chamber‘69 in
the check valve device 6, and thence byway of
I14” and the wall I39‘ is a coil spring 442- which
encircles the sleeve portion I M and the guide
pipe and passage '68 .to chamber Bland therefore
member I40 and constantly urges the ‘guide ‘mem 35 to the face of the piston. 59., In response to the
to a'gui'de member I 40 which ‘is slidably mounted
in a suitable sleeve portion M! of ‘the wall ‘I39
pressure of ?uid thus supplied to. chamber 61,
her, and thereby the valve I31, toward their up
per positions, in which position the ?ange I39 of
piston 59 will move to the right against the op
posing pressure of spring 62, effecting through
the valve I3?! abuts the wall I3B.- As explained
later, this spring I42 is a reduction limiting spring
the: medium of the stem 64 and pin. 65, the move
which determines when the valve I31 will be 40 ment of the lever 66. Since the upper endof the
moved into its lower seated position. Contained
lever 66 isheld in its left-hand position by the
pressure of the spring 93., the lever will be caused
in a recess 143 formed in the» guide member I40
is a spring I44, the upper end of which operative
ly engages the under side of the diaphragm fol
lower I34 and the lower end engages the bottom .
wall 'of' the recess. This spring exerts an upwardly
directed force on the follower I34 so as ‘to cause
the follower to normally engage the bottom of
stem I33 of the valvehl32 and hold the valve in
to‘ rock in a'counterclockwise direction- aboutthe
pin..86.' As the .lever' rocks in this manner ‘it an
gages the roller 54 of ‘the measuring mechanism
36; causing the connected members 56, roller. 54
and pin 55 to rock in a clockwise direction. about
the pin 46. The member 51, being coupled cdi!~
rectlyv to the \pinz55 and to the pin 41 ‘andthereby
its unseated position. as shown.‘
to member .56 and portion M of the measuring
OPERATION
element; will force the element 38 downwardly
against the opposing force of spring 52 until the
bottom surface of the portion 39 of the element
Initial charging of the equipment
Assuming the vehicle embodying the invention
to‘ be empty‘ or separated from a train, the brakes
on the vehicle released, the brake pipe 'I on the
vehicle depleted of ?uid under‘ pressure and the
fulcrum member 89 of the variable load valve
mechanism 8 temporarily disposed in the empty
engages the'periphery of the axle 40 at a point
located ‘substantially at the middleo'f its length,
the links 42 and '43 rotating in unison inaclocke '
wise direction to so control the element 'as to
maintain the bottom surface of the arm 39 there
of in. substantially parallel relation to the hori
position in which it is shown, the brake con 60 zontal plane of the adjacent surface of the cen- '
tral portioniof the axle 40‘.
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trolling valve device 3 will be in brake applied
I With ‘the vehicle empty, the movement of the
position and the several other‘ parts of the equip
piston 59' will be taken up entirely in actuating
ment will be in the‘ positions in which they are
the load measuring mechanism 36 and ‘therefore
shown.
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Now if the empty vehicle is placed in a train, 65 no- movement will be imparted to they fulcrum‘
positioning bar 85 by the piston 59. The: fulcrum
the brake‘ pipe I will of course be‘ connected at
member 89' of the load compensating valve mech
each end of the vehicle to the corresponding
an'ismIBv will therefore remain in the position in
brake pipe at the adjacent end of each-adja
which. lt'i‘s' illustrated; which is the positioni’or
cent vehicle of the train and as a result" the brake
’
equipment will be in condition'to ‘be charged with 70 braking an‘ empty vehicle.
?uid under pressure in the usual manner. In ini
tially charging the equipment fluid under pres
sure supplied in the usual manner to the brake
Now when the pressure of ?uid in the valve
‘chamber I9 of the cut-off .valve device 4Yhas1i1'i
creased ’ to approximately thirty pounds" per
pipe ‘ I ?ows through‘a branch pipe -2 to the cham
square inch, the diaphragm I3 will be caused to
‘bers at'the facesof the service‘ and emergency 75 de?ect upwardly against the opposing pressure
2,497,870
of the spring 25. The diaphragm,‘ as it is thus
de?ected, acts .through the medium of the stem
or follower 21 to shift the slide valve 26 to its
uppermost position, in which position a cavity
I46 in the valve connects pipe and passage 15 and
a pipe and passage I41 to a passage I48 which
leads to the atmosphere. With this connection
thus established, ?uid under pressure in piston
10
device 3 and brake cylinder pipe I49. At the same
time, ?uid under pressure ?ows from the brake
cylinder pipe I49 through pipe II5 andpassage
II4 to chamber I 2| in the variable load‘ valve
mechanism 8, and by way of passage I I4 to valve
chamber H0, and thence by way of passage II3
to checkvalve chamber H2. Fluid under‘pres
sure thus supplied to chamber ,I2I causes the
chamber 14 of the locking mechanism 1 will be
diaphragm 98 to ?ex downwardly, and the dia
vented to atmosphere by way of pipe and passage 10 phragm 98 as it is thus being ?exed acts through
15, cavity I46 and passage I48. Also, ?uid under
the medium of the follower H9 and follower
pressure will ?ow from chamber 61 of the load
stem I20 to rock the lever 94 about the fulcrum
measuring apparatus 5 through pipe and passage
member 89 in a clockwise direction, the lever 94
68, ‘passage 12 of the check valve device 6, pipe
as is thus operated acting through the medium
and passage H to chamber 14. Since passage 15 of the follower stem I02, follower ml, and dia
12 is of restricted ?ow capacity, the ?uid pres
phragm 91 to cause the valve I04 to be unseated
against the opposing pressure of the spring IIS
sure in chamber 14 will reduce much more rap
idly than in chamber 61.
and of the ?uid in chamber II 0 acting on the
When the pressure of ?uid in chamber 14 is
valve. With the valve I04 unseated, ?Ulid under
slightly less than that of the spring 18, said 20 pressure ?ows from the valve chamber IIO past
spring will act to shift the piston 13 upwardly,
the unseated valve I04 and its ?uted stem I05
bringing the locking portion 80, through the
into chamber I03, from whence it ?ows by way of
medium of the stem 19 into locking engagement
passage I06, pipes J01 and I08 to the service vol.
ume reservoir 9.
with the toothed portion 84 of the fulcrum shift
ing bar 85. With the piston 13 in its uppermost 25
It should here be noted that at this time the
slide valve 26 of the cut-off valve device 4 will be
position, pipe and passage ‘II are connected to
in its uppermost position, in which position com—
atmosphere by way of chamber 16 and a passage
munication between pipe I01 and emergency
11 in‘ the casing and leading from chamber 16
to the atmosphere. Fluid under pressure ?ows
volume reservoir I0 is closed, and there will
therefore be no flow of ?uid under pressure from
from chamber 61 through pipe 68, passage 12 and
the brake cylinder pipe to the emergency volume
pipe 1| .to chamber 16 and thence to atmosphere
by way of passage 11.
Whenthe ?uid pressure
in chamber 61 acting upon piston 59 is slightly
less than the opposing pressure of the spring 02,
said spring will cause the piston 61, stem 64 and
the lever 66 to return to the positions in which
they are shown. With the force of piston 59
which operates the measuring mechanism 31 re
moved, the spring 52' will act to retract the meas
uring mechanism to the position in which it ‘is
shown.
.
.
reservoir
I0.
‘
‘
.
When the pressure of ?uid in diaphragm cham
ber I93 of the variable load valve mechanism 8
and consequently in the reservoir 9 becomes su?le
cient to overcome the pressure of ?uid in chamber
I2I acting in the opposite direction on the lever
94, the diaphragm 91 will be caused to flex in a
downward direction and thereby permit ,the
spring ‘I Hi to seat the valve I04, closing off the
further ?ow of ?uid under pressure to‘ volume
reservoir 9. Since further build-up of pressure
From the preceding paragraph it will be ob;
in chamber I03 can not occur, the lever 94will
served that the locking mechanism ‘I is always
come to rest in the position in which it is shown.
operated to lock the fulcrum shifting bar 05, and
thereby fulcrum member 89 of the variable load 45 It will here be understood that the brake lever
age ratio and the brake cylinder volume will be
valve mechanism 0, beforethe measuring mech
such as to be able to attain with a single brake
anism 31 is retracted from contact with the axle.
cylinder the maximum braking required, or in
With the chambers 61 and 14 thus vented of ?uid
other words to attain the desired degree of brak
under pressure, lock controlling piston 13, meas
uring apparatus controlling piston 59, and lever _ 5 0 ing for a fully loaded vehicle. From the fore‘
going paragraph it is apparent that, when a serv
66 which had been previously displaced are now
ice application of the brakes is effected with the
returned to the position to which they are shown,
fulcrum member 89 in the position in which it is
and, with the cut-off valve device 4 being main
shown, the maximum amount of ?uid under pres
tained by ?uid at brake pipe pressure in the posi
tion to which it was previously moved, the equip 55 sure is spilled or bled from the brake cylinder
pipe I49 into‘the service volume reservoir 9 and
ment is now conditioned for braking an empty
consequently there ‘ is obtained the minimum
vehicle.
Service application of the brakes on an empty
vehicle
‘
When it is desired to effect an application of V
brake cylinder pressure for a given reduction in
brake pipe pressure. As will hereinafter more
fully appear the fulcrum member 89 is shifted
to the right from the position in which it is shown
in accordance with the added weight of any lad
ing placed on the vehicle, so that the leverage or
the brakes, the brake pipe pressure is reduced in
the usual manner, causing the brake controlling
mechanical advantage will be resolved in favor
valve device 3 to function to supply fluid under
of the diaphragm 91. Consequently the pres
65
pressure from the auxiliary reservoir I3 to the
sure
of ?uid in chamber I03 will not have to be
brake cylinder device I2 by way of the intercept
come as high as that in chamber I2I in order to
ing valve device I I in order to advance the usual
seat the valve I04 ‘and terminate the ?ow of
brake shoes, notshown, into frictional engage
?uid under pressure from the brake cylinder pipe
ment with the vehicle wheels. The flow of ?uid
I49 to the volume reservoir. Thus, as the weight
under pressure from the auxiliary reservoir I3 to 70 of the load carried by the vehicle is increased, the
the ‘brake cylinder device I2 is by way of a pipe
amount of ?uid under pressure that will. flow to
I26, passage I25 in the intercepting valve device
the ‘volume reservoir is decreased and as a con
II, past valve seat I33 and valve I31 into cham
sequence the force exerted by the brake cylinder
ber I3I‘, thence through passages I29 to chamber
device, forany degree of brake pipe reduction,
I21 andpipe I28,‘ through the brake control valve 75 will'increase as the load increases.
'
T
2,407,870
11
When, at the start of‘ the brake'applicationon
the empty vehicle; the: brake controlling valve
deviilejt‘ operates'in‘ the usual manner vto supply
brake cylinder pipe‘ I43‘, ?uid under pressure-will
?ow from these chambers to the atmospherewith
the'?uid under pressure ?owing from the brake
cylinder device I2. Valve chamber ‘I I2 being-con
?uid under pressure from the auxiliary reservoir
nected to Valve chamber III] by way of‘ passage
‘I3’ to the brake’ cylinder device I2, ?uid under
I I3, ?uid under pressure therein will also flowv to
pressure will ?ow from chamber I23 past the
atmosphere byv the same route. With the pres
?uted ‘valve stem I33 and‘ valve I32 into valve
sure of ?uid in chamber II2 reduced'dueto-the
‘chamber I24, and thence by way of passage I25
?ow of ?uid therefrom, the pressure of ?uid-be
past valve I31, through the chamber I3I, pas
sage ‘I23, chamber I21‘ and passage andpipe I28 10 neath the balllcheck valve I03 will lift the check
valve to permit the flow of ?uid‘from theeser-vice
to the brake controlling valve device 3. Because
volume reservoir 3 to atmosphere by wayofipipes
the volume of chamber E23 is larger than the
I38 and I31’, and-v passage I 33 past the'unseated
combined volume of. chambers I2‘! and I3I and
check valve I33 into chamber H2 which-isnovv
by, reason of ‘a choke I250, in passage I25 as
shown,,the.pressure of ?uid in chamber I27 will 15 connected to atmosphere byway of the‘rout'e
previously described. Fluid under pressure in
reducemore rapidly than that in chamber I23.
chamber I03 may also‘ ?ow by way'o‘f passaJge’lilS
Inresponse to the excess of ?uid pressure acting
and past ball check valve I09 intovalve chamber
on the upper side of the diaphragm I22 the dia
I I2 and thence to atmosphere.
phragm will be caused to de?ect. downwardly
The brake controlling valve device?’ also func
againstthe opposing pressure of the spring I44
tions at this time to supply ?uid under pressure
until the bottcmlof the follower I34 engages the
from the brake pipe- I ~ to the auxiliary and emer
top. of. ‘the guide member I43, the downward
gency reservoirs I3§and I4, respectively. As pre
movement Of said guide member being stopped
viously described in connection with‘ initial
at‘ this time by the action of the spring I42.
charging of the equipment, ?uid under pressure
However, this-movement of the follower I34 will
in brake pipe I will ?ow through branch pipe 2
be su?icient to-permitthe’spring I36 to actuate
to the brake controlling valve'device 3 and from
the valve.l'32ito its seated position. The pressure
thence by way of connected pipe and passage'IZIl
of. ?uid thus bottled up .in chamber I23 is now
to chamber I2‘! in the intercepting vvalve device
‘the. standard with. which‘ the. pressure ofv ?uid
II, through passages I29'to chamber I 3|‘. When
at reducedauxiliary reservoir pressure in cham
the pressure of ?uid inrchamber I21 located‘at
ber I21 will be compared.
>
the underside of the diaphragm I22 is within‘less
If the brake controlling valve device 3 con
than twenty pounds of that in- chamber I23; the
tinues- to operate tosupply ?uid under. pressure
spring I42 will act to move the guide member I43
from the. auxiliary. reservoir I3 to the brake cyl
inder. device 12 in theapplioation of the brakes 35 and thereby the valve I31, upwardly'until the
?ange I39 of said valve ‘engages-the bottom sur
justlpreviously. described, the pressure of ?uid
face of the wall I33 formed in the casing. With
in.the auxiliary reservoir I3, and consequently
the valve I31 thus positioned out of engagement
in the interconnected chamber I21, will continue
with the seat I38, as shown in the drawing, com
to decrease .untilthe pressuretherein is 20 pounds
munication
is established by which?uid under
40
less than that. in chamber{ I23, at which time the
pressure supplied from the brake pipe I to cham
diaphragm I22 willbecaused by the higher pres
ber I21 ?ows past valve seat I33, through passage
sure in- chamber I23 to de?ect downwardly‘
I25 and pipe I26 to auxiliary reservoir I3.
‘
against the opposing pressure of spring I42. The
The guide member‘ I 40 as'it is being moved up—
diaphragm, as‘ it is thus de?ected; acts through
the medium of the follower’ I 34 and guide -mem-. 45 wardly, effects,"through the medium of a follower
ber I431to move the valve I3‘! downwardly to its
lowermost position; in which position'said valve '
engages the valve seat I38“ ‘With-the valve- I3‘!
thus- seated, the ?ow- of ?uid under pressure 'from
the auxiliary reservoir ‘I3 to- the‘ valve device 3
occurring during, a. service application of the
brakes will be terminated for that brake applica
tion, regardlessw of the degree-of‘ brake pipe‘ re
duction.
Release of a service application of the brakes on \
I34, an ‘upward’ de?ection of the diaphragm I22. ‘
Upon a further build-up of ‘ pressure in chamber
I211, spring I 44 will be permitted to move'the dial‘
phra‘gm I22 upward, thereby moving ‘the follower
I34. out of engagement with the ,member I43’.
Thereafter a further increase'in the‘?uid‘pres
sure in chamber I21 will cause diaphragm I22't0
de?ect upwardly and act through the medium'of
the follower I34 and valve stem I33 to move the .
valve" I32 upwardly, against the opposing pres
valve device > 3- to' functionto establish communi
sure of a ‘spring I36, to its unseated‘ position.
With the valve I32 unseated, ?uid under pressure
supplied to passage I25 for ‘charging- the auxil
iary reservoir I3 will also ?ow through chamber
I24, past valve I32 and ?uted valve stem I33 into
chamber I23, charging chamber‘ I23 with ?uidat
cationfrom a brake cylinder device I2'to atmos-'
auxiliary reservoir pressure.
an empty vehicle
Whenit. is desired. to effect the release of the
brakes, the brake. pipe. pressure is ‘increased in
the usual manner, causing the brake controlling 60
‘
In‘ connection with‘the foregoing description
it should be mentioned that, with the" brake con
I 43 from the brake cylinder'device I2 to the vbrake 65 trolling valve device of the‘ standard?uid pres
sure.‘ brake equipment now in‘ use‘ operating in
controlling valve device 3 and from there byway
the usual manner in response to a full service
of pipe l?iltothe retaining-valve device I5‘ which
brake application, when the brake pipe pressure
connects‘ pipe I53 directly to- the: atmosphere
has. been reduced'from' seventy pounds to ap
when a'handle I51 " on ‘device ~I 5 is in the position
phere by'way'of the retaining valve device I5.
Fluid under pressurenow'?owsby way of pipe
inwhich it is shown. - The brake cylinder device
proximately ?fty pounds; the'auxiliary reservoir
I2 now’responds- to-the releaseof‘ ?uid under
will be in" open communication with the‘ brake
cylinder and‘as a consequence the auxiliary res
pressure therefrom in the usual manner‘ to effect
a‘rel'ease-ofthevehicle‘brakes.
’
Valve chamber 1 i il-‘and chamber "I 2 I 'being con
nected by waysofpassageII4'and_pipe' II5'to
ervoir: pressure will equalize with'the brake cyl
inder“ pressure at approximately ‘?fty pounds
whichcorresponds with the reduced'brakel pipe
2,407,870
13
pressure. Since the pressures of ?uid in the aux
iliary reservoir and‘ brake ‘cylinder are‘now equal,
a further reduction in brake pipe pressure can
not increase the pressure of ?uid in the brake
cylinder.
‘
14
operating parts in their emergency positions,
communication is established by which ?uid un
der pressure is supplied from both the auxiliary
reservoir I3 and the emergency reservoir I4
through pipe I49 to the brake cylinder device I2
It will be apparent to those familiar with the
to obtain greater brake cylinder pressure than
operation of the standard ?uid pressure brake
that obtained by a full service application.
equipment mentioned in the preceding paragraph
A5 previously described for a service applica
that if the intercepting valve II were omitted
tion of the brakes on an empty vehicle, ?uid
and the remaining features of the invention were 10 under pressure in pipe I49 also ?ows by way of
combined with the brake controlling valve device
pipe I I5 and passage II4 to chambers I2I and
3, certain undesirable operations may occur. For
III) in the variable load valve mechanism 8. In
example, when a full service reduction of twenty
response to the pressure of ?uid in chamber I2I
pounds in brake pipe pressure is effected, the
acting upon diaphragm 98, said diaphragm de
brake controlling valve device will of course 15 ?ects downwardly and acts through'the medium
move to application position and in this position
of follower I I9 and stem I253 to rock the lever
will supply ?uid under pressure from the auxil
94 about the fulcrum member 89 in a clockwise
iary reservoir to the brake cylinder, and to the
direction, the lever, as it is thus being rocked,
service’volume reservoir‘ 9 also if the vehicle is
acting through the medium of the stem I02, fol
empty or lightly loaded. The amount of ?uid 20 lower IIlI, diaphragm iii, and valve stem I05
?owing from the auxiliary reservoir will be sub
against the opposing pressure of spring II 6 to
stantially the same as in the standard brake
unseat the valve I04. Fluid under pressure sup
plied from the auxiliary and emergency reser
voirs I3 and Ill, respectively, to chamber IIO now
service volume reservoir, is greater than that‘ . ?ows past valve I94 and ?uted valve stem I05
of the standard brake cylinder, the pressure of
into chamber I03, whence it will ?ow to the serv
equipment. Since the volume of the brake cyl
inder, to which may be added the volume of the
the brake cylinder will be substantially less for
a full service reduction in brake pipe pressure.
When, due to the ?ow of ?uid from the auxil
iary reservoir to the brake cylinder and‘volume
reservoir 9, the auxiliary reservoir pressure re
duces slightly below the reduced brake pipe pres
sure (?fty pounds), the brake controlling valve
device will move to lap position and thereby out
oi? the ?ow of ?uid from the auxiliary reservoir.
In this position the brake controlling valve de
vice will bottle up the ?uid in the auxiliary res
ervoir at a higher pressure than has been at
tained in the brake cylinder, so that if a fur
ther reduction were effected the brake control
ling valve device would function to again supply
?uid under pressure from the auxiliary reservoir
to the brake cylinder and service volume reser
voir and thus effect an increase in the pressure
of ?uid in the brake cylinder beyond a safe or
desirable degree. As will hereinafter more fully
appear, such an undesirable condition is most
likely to occur in cycling the brakes in descend
ing a grade, that is to say, in alternately effect
ing an application of the brakes and then re
charging the equipment partially while a partial
release is taking place through the usual retain
ing valve device which has previously been set
to retain a predetermined pressure in the brake
cylinder. It will be apparent from the forego
ing description that by the use‘ of the intercept
ing valve device II this undesirable increasing
of brake cylinder pressure due to an over-reduc
tion in brake pipe pressure, which may be ef
ice volume reservoir 9 by way of passage I06, pipe
I01 and pipe I08.
In the description of the effecting of a service
application of the brakes on an empty vehicle,
it was noted that the flow of ?uid from the brake
cylinder device I 2 was terminated when the ?uid
pressure in the service‘ volume reservoir 9,‘ ‘and
therefore in chamber I54 acting upon diaphragm
35 91, was high enough to counterbalance the brake
cylinder pressure in chamber I2I acting‘upon
diaphragm 98 so as to permit valve I64 to seat.
Obviously, if the cubic content of the brake cyl
inder device I2 were greater, the brake ‘cylinder
pressure at the time when valve IE3‘ is seated
would be higher, or if the cubic content of the
reservoir 9 were greater, the brake cylinder pres
sure would be lower at the time When the valve
I M was seated. Since during an emergency ap
plication the brake cylinder pressure is increased
and also the auxiliary and emergency reservoirs
are both open to the brake cylinder device, there
by adding their volumes to the brake cylinder
volume, means are provided for connecting the
emergency volume reservoir I ii to reservoir 9 as
a supplementary volume in order to prevent the
occurrence of an unreasonably high or unsafe
brake cylinder pressure.
When an emergency reduction in brake ‘pipe
pressure is effected, the brake pipe I is depleted
of ?uid under pressure in the usual manner by
the brake controlling valve device 3. Since cham
ber I9 in the cutno? valve device £5 is connected
by way of pipe and passage 20, passage 2i and
fected in cycling the brakes, is entirely elim 60 branch pipe 2 to the brake pipe, it will‘ likewise
inated since the device functions in response to
be depleted of ?uid under pressure. The'result
a twenty pound reduction in auxiliary reservoir
ing reduction in the‘pressure of fluid in chamber
pressure from any pressure to which the reser
I9 to atmospheric pressure will‘permit the pres
voir is recharged to close the supply communi
sure of the spring 25 acting through the medium
cation from the auxiliary reservoir to the brake
of the stop member 22 and follower or stem 27
controlling valve device.
to actuate the slide valve 26 to its lowermost posi
tion, in which position it is shown. Cavity I46 in
Emergency application of the brakes on an empty,
the slide valve 26 which formerly connected the
vehicle
emergency volume reservoir It to atmosphere
When it is desired to effect an emergency ap
as previously noted now establishes communica
plication of the brakes,‘ an emergency reduction
tion between pipe MI and said reservoir.‘ Fluid
in brake pipe pressure is effected in the usual
under pressure now ?ows from chamber I03 in
Well known manner which causes the several
the variable load valve mechanism 8 through pas
parts of the brake controlling valve device 3 to
sage I06 to pipe IIi'I, whence it flows by way of
‘move to their emergency positions. With the
pipe I08 to service volume reservoir 9 and, by way
254075870
7
of cavity M?in slide valve 26 to_ pipe MT and
emergency volume reservoir l9. When the pres
sure of fluid in chamber “53 approximates that
in chamber iii the various operative parts of
the mechanism‘ 3 will'return to the position‘in
which they are shOWn and the brake cylinder
pressure will have been reduced to a degree com
patible with safe braking of an empty or partially
loaded vehicle.
Referring now to the intercepting valve 'de
vice ll, said device will function as hereinbefore
described in connection with a service brake ap
plication on an empty vehicle to cut o? the flow
of fluid under pressure from the auxiliary res
ervoir l3. to the brake controlling valve device
3 when, by reason of the operation of the variable
load valve mechanism 8 in this instance, the ?uid
pressure of the auxiliary reservoir is reduced
more thanrtwenty pounds below the pressure at
the initiation of the emergency brake applica
tion. Thus, if the initial pressure were seventy
pounds the auxiliary reservoir pressure will not
drop'below approximately ?fty pounds, thereby
conserving the ?uid under pressure in the aux
iliary reservoir and aiding in the prevention of
excessive brake cylinder pressures. It does not,
however, affect the how of ?uid under pressure
from the emergency reservoir for which the
emergency volume reservoir I5 and the function
of the cut-on valve device 4 described in the
preceding paragraph are provided.
Release of the brakes after an emergency ap
plication and automatic changeover operation
of the equipment from empty vehicle to a
loaded vehicle condition
When it is desired to effect the release of the
brakes after an emergency application on a ve
1'6
themeasuring element-31 and, the axle,~having
been shortened because of the yielding of the
springunder the in?uence of the-load, the portion
39'wil1 engage the axle ‘10 before piston‘ 59 has
completed its full stroke. As a result, the-pis
ton 59 ‘will now cause the lever 55 to rotate in a
clockwise direction about its lower end which
is now in engagement with the roller 54 of‘ the
now stationary mechanism 35, the ‘roller of
course, being stationary andserving as a fulcrum
for the lever. Movement of the upper end‘ of
the lever 55 in this direction will be yieldably op
posed by the force of the spring 5!! while the. pis~
ton completes its stroke. The lever 56 as=it-is
thus being moved‘ acts to shift the bar 85v and
the fulcrum roller 89- associated therewith toward
the right along the scale beam‘lever 94~ until
such time as the piston comes to‘a stopat-the
end of‘its stroke, the distance of travel of the
roller 89 being proportional to thedistance of‘
piston travel after the measuring element is
brought to a stop ‘by’ its engagement with the axle.
When the brake pipe pressure is increased to
the degree required to effect the’operation of cut‘
off valve device 4, this device will operate,‘ as
hereinbefore described, to'vent“ fluid under pres
sure from‘ chambers ‘M and 61', and emergency
volume reservoir N}. With'the chamber 14" thus
vented, the piston 13 and the stem 19 of the lock"
ing ‘mechanism 1 respond .to the force ofv the
spring 13 to move the locking portion 80 into on‘
gagement with the toothed port-ion 84* ofthe'bar
85' to hold the bar and vthereby the fulcrum mem
ber 89 in their newly‘ assumed positions.
'
With the chamber 61‘ of the load'measuring
apparatus 5 vented of ?uid under'pres'sure, the
spring 62 acts to return the piston 59 and‘pisto‘n
stem 64 to the position‘in which theylare shown.
In so doing, it will cause the lever 66-’to be rotated
hicle equipped with the described embodiment
of the invention, the brake pipe will be charged 40 clockwise about the pin 86 which‘is now'locke'd,
through'the medium‘ of the bar‘ 85 and‘portion
with ?uid under pressure in the same manner
80, in a position corresponding to the'degreei‘of
, as hereinbefore described in connection with the
initial charging of the equipment. As before de
lading on the vehicle. As the lower end of the
lever is withdrawn from engagement with‘ the
scribed, ?uid under pressure supplied to the brake
pipe I will flow by way of branch pipe 2 to the 45 measuring mechanism 31 the spring‘ 52 willlact‘lt‘o
brake controlling valve device 3, from whence it
retract the mechanism from engagement witl'i'the
will flow by way of passage 2| and pipe and pas
axle 40 to the position in which it is ‘shown.
sages 20 to cut-oiT valve device 4 and from valve
With the position of the fulcrum member 8'9’r'ela
chamber 19 therein to chamber 14 in the locking
tive to the scale beam lever 94 of the variable load
mechanism 1 by way of connected pipe and pas
valve mechanism 8‘ determined according to the
sages 15. In response to an increase in the fluid
amount of movement of‘ piston 59 transferred
pressure in chamber 14, piston 13 wil1 move
by the lever 66‘ from the mechanism to‘the ful
downwardly against the pressure of spring ‘18,
crum shifting bar‘ 85, and they transferoflmove
thereby causing the locking portion 80 to move
ment being‘determined according to the load on
out of locking engagement with the toothed por
the vehicle, the variable load valve mechanism
tion 84 of the bar 85 and also effecting by way
is now in condition for braking a partially or
of a check valve device 6 the supply of ?uid under
fully loaded vehicle as the case may be.
pressure to chamber ‘61 in the measuring ap
Fluid under pressure supplied to the ‘brake pipe
paratus 5. The pressure of ?uid thus supplied to
I also ?ows to the chambers at the faces of the
chamber 5'! will cause the piston 59 to effect the 60 service and emergency pistons of ‘the brake'con
downward movement of the measuring mechan
trolling valve device 3, moving the'pistons in due
ism 37 until stopped by portion 39 of the mech
course to release and charging position. Fluid
anism engaging the axle 4U.
under pressure wil1 then‘ ?ow‘ into‘ ‘the several
Insetting a car out of a train it is the usual
chambers of the ‘brake controlling valve device-3,
practice to effect an emergency application of the 65 and thence to the emergency reservoir 14 by way
brakes.
'
of pipe I45 and to chamber 121 in the intercept‘
Assuming now that while the car is thus set
ing valve device I I by way of connected pipe and
out and lading has been placed on the body of
passage !28. As previously described in connec
the car and under the in?uence of such addi
‘ tion with the release of the brakes after service
tional weight on the vehicle body, the center sill 70 application of an equipment conditioned for
empty braking, when the pressure of fluid in
34 wil1 have moved downwardly relative to the
chamber l2‘! at the under side of the diaphragm
axle 40 by reason of the usual truck springs (not
l22 rises to a pressure within less than ‘twenty
shown) yielding to the additional weight. The
pounds of that in chamber I23, that is, above ?fty
space between the center sill 34 and the axle
40, and consequently between the-portion” of 75 pound‘s,.in this instance, the pressure: or. the
2,407,870
17
spring I42 will operate to move the guide mem
18
pressure of spring IIS and of ?uid in diaphragm
chamber I03, and consequently in the reservoir
8, becomes su?icient to counterbalance the pres
ber I00 and thereby the valve I31 upwardly until
the ?ange N9 of said valve engages the lower
surface of the wall I30 formed in the casing.
sure of ?uid in chamber IZI acting on the lever
With the valve I31 out of engagement with the CH 94 said lever will be rotated counterclockwise,
seat I38, communication is established by which
thereby causing valve I04 to seat and close oil the
?uid under pressure supplied from the brake pipe
further ?ow of ?uid under pressure to the vol
I to chambers I2’! and I3I ?ows past valve seat
ume reservoir 9.
I38, through passage I 25 and pipe I 26 to auxiliary
Since the fulcrum member 89 has been ad
reservoir I3
justed to the right of the position shown, the
When the operative parts of the brake con
pressure in chamber I03 will not be as high as
trolling valve device 3 move to release position,
-that on an equipment conditioned for empty
said device functions to establish communica
braking and consequently the brake cylinder
tion from the brake cylinder device I2 to atmos
pressure will be higher for the additional load.
phere by way of the retaining valve device I5. 15 When the vehicle is fully loaded, ‘the fulcrum
Fluid under pressure will ?ow from the brake
member will be shifted to its extreme right-hand
cylinder device I2 to the atmospheric passage in
position, in which position it will prevent en
the retaining valve device I5 by way of pipe I49,
tircly the operation of the diaphragm 98 and. of
brake controlling valve device 3 and pipe I50.
the whole mechanism 8. Fluid in the brake cyl
The brake cylinder device I2 now responds to
inder device I 2 will then build up to its maximum
the release of ?uid under pressure therefrom in
pressure for any particular degree of brake pipe
the usual manner to effect a release of the ve
hicle brakes.
reduction.
‘
As previously stated, the operation of the in
Fluid under pressure also ?ows from chambers
tercepting valve device II becomes important in
I2I and H0 in the variable load valve mecha 25 controlling the brake when the vehicle is de
nism 8 to atmosphere. being connected to brake
scending a long grade. Preparatory to descend
cylinder pipe I49 by way of passage H4 and pipe
ing a grade, the retaining valve device I5 is set
H5.
luid under pressure in the service volume
by turning the handle I-5I from the position in
reservoir 9 ?ows by way of pipe I08, pipe‘Iil'I,
which it is shown in the drawing to a position to
passage I90, past back check valve I09 to cham
retain a predetermined pressure in the brake cyl
ber Ill’, and thence by way of passage H3 to
inder device I2 when recharging reservoirs I3
chamber H0 and to atmosphere by the same
and Ill after the initial application. It is to be
route. It should here be noted that when slide
understood that the pressure retained will be the
valve 26 of the cut-off valve device 4 was actu
minimum required to maintain the brake shoes
ated to its uppermost position upon the attain.
in engagement with the vehicle wheel. In con
ment of thirty pounds pressure in the brake pipe.
trolling the train on a descending grade it is cus
fluid under pressure in the emergency volume
tomary to cycle the brakes, that is, to effect an
reservoir {0 was connected to atmosphere by way
application of the brakes and recharge the equip
of pipe and passage I41, cavity I45 and passage
ment while a partial release of the brakes is
I48.
taking place through the adjusted retaining
valve device, and alternately applying and re
Application of the brakes on a partially loaded
leasing the brakes. It will be understood that it
vehicle
.
is highly desirable to have a brake equipment
When an application of the brakes is made on
that will provide selectivity of brake operation
a partially loaded vehicle by e?ecting a reduc 45 regardless of the operating pressures and one
tion in brake pipe pressure. the operation of the
that will also conserve the braking energy and
brake controlling valve device 3 will be identical
yet will retain a reasonably heavy brake appli
with‘the operation described for an empty ve_
cation available to the train operator.
hicle. From this it will be understood that ?uid
Attention is therefore directed to the fact that
under pressure will be supplied through pipe I49 50 the operator may obtain a brake application
to the brake cylinder device I2. from pipe I49 by
equivalent to a twenty pound brake pipe reduc
way of pipe H5 and passage IIA to chambers I2!
tion, so long as there is reserve ?uid pressure
and H0 in the variable load valve mechanism 8
in the equipment, by reason of the device II set
in the manner previously described for the ap-_
ting the pressure of ?uid in the auxiliary reser
plication of the brakes for an empty vehicle.
55 voir as a standard (in the closing of valve I32)
The pressure of ?uid in the chamber I2! de
and measuring a twenty pound reduction there- ,
?ects the diaphragm 98 and the follower H9
from by the weighing of spring I 42 and there
downwardly, thereby rocking lever 94 in a clock
after isolating the auxiliary reservoir (by the
wise direction about the fulcrum member 89,
seating of valve I31). By providing a reset for
which is now located at some point intermedi 60 each release operation (in the unseating of valve
ate the position in which it is shown and the
132) the operator may again effect a twenty
right-hand end of the lever 94. When the ?uid
pound reduction in auxiliary reservoir pressure
pressure in said chamber is suf?cient to outweigh
although the auxiliary reservoir has not been
the opposing pressure of spring I I6 acting upon
recharged to its initial pressure. By preventing
the left-hand end of lever 94. the resultant clock 65 an over-reduction in auxiliary reservoir pressure
wise rocking of the lever will cause the dia
the operator is compelled to conserve his reser
phragm 91 to de?ect upwardly against the stem
voir pressure and at the same time prevent ex
i055 and thereby against the opposing force of
cessive brake cylinder pressure ‘from being at
the swing I I5 to unseat the valve I04. With the
tained as a result of an. over-reduction in brake
valve unseated, ?uid under pressure from the 70 pipe pressure.
‘ brake cylinder pipe I49 ?ows through pipe I I5,
Summary
passage I I4, valve chamber H0, past the unseat
ed valve I04 and its ?uted stem I05, through
Thus, it will be seen from the foregoing that
chamber I03, passage I06, pipe I01 and pipe I08
there is provided a variable load brake equipment
to the service volume reservoir 9. When‘the -1 an of the type employing a single brake cylinder and
2,407,870
'20
which is automatically adjusted, during the
charging of the brake pipe I from atmospheric
vice. With the charged volume increased, it be
pressure, to vary the braking force exerted by
said brake cylinder for a given reduction in the
pressure in the brake pipe according to the weight
which the ?uid under pressure supplied from the
brake controlling valve device to the brake cyl
inder may be spilled. Therefore, when the pres
of the ‘load on the vehicle.’ As the pressure in
sure of ?uid in the brake pipe is reduced below '
the brake pipe is increased above atmospheric
pressure during the charging of the brake pipe,
the cut-off valve device 4 permits ?uid under
pressure to flow from the brake pipe I to the
locking mechanism 1 which mechanism operates
previously operated to cut-off the brake pipe from
the locking. mechanism, the cut-01f valve device
will not only operate to cut in the brake pipe but
will also operate to connect the emergency vol
comes necessary to increase the volume into
the pressure at which the cut-off valve device
ume Iii with the service volume reservoir t and
thereby establish that relation between pressures
and volumes which isv properior an emergency
in response to the pressure of ?uid thus sup-.
plied to unlock the load measuring apparatus ‘I
and then to supply ?uid under pressure from the
brake .pipe to. said apparatus. In response to
the pressure of ?uid thus supplied, the load meas
uring apparatus actuates the measuring element
38 into- engagement with the vehicle axle 4t and
positions the fulcrum member 89 in the variable
load valve mechanism 8 accordingly; When the ~“
pressure of ?uid in the cut-off valve device
reaches a predetermined degree the cut-off valve
device operates in response thereto to- cut off the
further ?ow of ?uid under pressure to the look
ing mechanism and the load measuring appara
tus and‘connects said mechanism’ and apparatus
to atmosphere so that ?rst the locking mecha
and then the load measuring apparatus
are vented.
'
'
>
The apparatus being thus adjusted, when a re
duction in the pressure of ?uid‘ in the brake pipe
is effected, the brakecontrolling valve device 3
will operates’in the usual manner to supply ?uid
under pressure to the brake cylinder and also to
the variable load valve mechanism 8. If the ve
hicle is" less than fully loaded, the mechanism 8
will operate in- response to» the pressure of ?uid
thus supplied from the brake controlling valve
device to spill or bleed a portion of this ?uid un
der'pressure into the service volume reservoir 9 ~
until‘ the scalev beam ‘lever 94 is balanced, thereby
reducing the braking power of the brake cylinder
accordingto the weight of the load as determined
by the adjusted‘position of the fulcrum member
*
application.
'
I
When the brake controlling valve device ‘3
moves to release position in response to an in
crease in the pressure of ?uid in the brake pipe,
said. device will function to vent ?uid under pres- ‘
sure from the brake cylinder device to atmos
phere by way of the retaining valve device :5.
From the foregoing it will be readily apparent
that since the standard volumes and passages
used in the “AB” freight brake equipment are
- retained in the use of‘ this invention, the brake
application and release times'will be the same as
those for the "AB”, equipment and therefore this
apparatus will operate in harmony with the
“AB” equip-ment, the response to, the e?ecting of
a brake application on the train will be the same
regardless of the load on the vehicle, and a brake
application equivalent to a 20 pound reduction
in the pressure in the brake pipe will always be
available to the operator.
Having now described my invention what I
claim as new and‘ desire to secure by Letters Pat
cut, is:
.
'
-
.
1. In a variable load ?uid pressure brake equip
ment for a vehicle, in combination,‘ a brake cyl
inder, a brake controlling valve device operative
to supply ?uid under pressure to the brake cylin
der to effect an application of the brakes, a res
ervoir arranged to receive ?uid supplied by the
brake controlling valve device to control the
88- in' the variable load valve mechanism 8. If 45 pressure of ?uid in the brake cylinder,_ valve
means subject to the opposing pressures of ?uid
the-vehicle is fully loaded the mechanism 3 will
be inoperative because the adjustment for the
in said reservoir and brake cylinder and operative
weight of the load on the vehicle will: be such that
in response to an increase in the pressure of ?uid
the fulcrum. member 89 will be directly underv the
in the reservoir for controlling the amount of
diaphragm til-so- that de?ection of thediaphragm 50 ?uid ?owing to the reservoir, and means opera~
to operate the mechanism will be prevented.
tive according to different weights of lading car
Now, if the reduction of brake pipe pressure
ried by the vehicle for variously conditioning said
should be of‘a' degree such that the pressure of
valve means for‘ response to di?erent reservoir
?uid’ in-the' auxiliary reservoir It would be re
pressures to provide the pressure of ?uid in the
duced more than 20 pounds below the pressure
brake cylinder for any given weight of lading car
present in the auxiliary reservoir at the initiation“
ried by the vehicle.
'
of the brake application, the intercepting valve
2. In a variable load ?uid pressure brake equip;
device I I will limit such reduction in the pressure
ment for a vehicle, in combination, a brake cyl
of ?uid in the auxiliary reservoir to 20 pounds by
inder, a ‘brake controlling valve device operative
operating in response'to such reduction to out off 60 to supply ?uid underrpressure to the brake cylin
the" further ?ow of ?uid under pressure from the
der to e?ect an application of the brakes, a res
auxiliary reservoir to the brake controlling valve
ervoir arranged to receive ?uid supplied by the
device. If the brakes are alternately applied and
brake controlling valve device to control the pres
released as in cycling on long‘descending grades,
sure ‘of ?uid in the brake cylinder, valve means
the intercepting valve device will automatically
subject to the opposing pressures of ?uid in said
reset so as to measure aZO-pound reduction from;
reservoir and brake cylinder and operative in re
the degree of pressure present in the auxiliary
sponse to an increase ‘in the pressure of ?uid in
reservoir at the initiation of that particular
the reservoir for controlling the amount of fluid
brake application.
?owing to the reservoir, and means operative ac
If the pressure of ?uid in the brake, pipe is,v
cording to different Weights of lading carried by
reduced to atmosphericpressrure at an emergency
the vehicle for variously conditioning said valve
rate, the brake controlling valve device will op
means for response to different reservoir pres
erate in the usual manner to effect an emergency
sures to provide the pressure of ?uid in the
application of the brakes by connecting the‘ emer
brake cylinder for any givenwveight of l’ading
gency reservoir I4 also: to the brake cylinder-de 75 carried by the vehicle, said means being operative
2,407,870,
21‘
22
when the vehicle is heavily loaded to render said
valve means ineffective to permit the ?ow of ?uid
from the brake cylinder to said reservoir and
thereby render the reservoir ineffective to control
the brake cylinder pressure.
3. A vehicle variable‘load ?uid pressure brake
equipment, in combination, a brake cylinder de
vice, a volume reservoir, a brake controlling valve
device operative to supply ?uid under pressure to
said brake cylinder device, valve means operative 10
to control the ?ow of ?uid under pressure from
said brake controlling valve device to said volume
reservoir and to thereby vary the pressure of ?uid
in said brake cylinder device, and means for ad
justing said valve means in accordance with the
creased braking power on the vehicle when the
vehicle is lightly loaded, means operative accord
ing to the load carried by the vehicle for condi
tioning said valve means for, operation in re
sponse to any increase in the pressure of ?uid in
said brake cylinder device to permit proportional
amounts of ?uid to ?ow to said volume reservoir,
the conditioning of said valve means being di?er
out for different loads carried by the vehicle so
as to render said valve means operative to provide
for the flow of di?erent amounts of ?uid under
pressure to said volume reservoir and thereby
control the braking power of said brake cylinder
device according to the load carried by the vehi
cle,
‘
weight of lading carried by the vehicle for op
, 7. The combination with a vehicle ?uid pres
eration in response to variations in the pressure
sure brake equipment of the type having a brake
cylinder device, a volume reservoir, and a brake
controlling valve device for supplying ?uid un
der pressure to said brake cylinder device and said
volume reservoir, of adjustable means operative
of ?uid supplied by said brake controlling valve
device to proportion the amount of ?uid under
pressure which may flow to said volume reservoir
inversely to the Weight of the load carried by the
vehicle.
4. A vehicle variable load ?uid pressure brake
equipment in combination, a brake cylinder de
vice, a volume reservoir, a brake controlling valve
device operative to supply fluid under pressure to
said brake cylinder device, a valve mechanism in
terposed between said brake controlling valve de
vice and said volume ‘ reservoir for permitting
?uid being supplied to the brake cylinder to ?ow
to the volume reservoir and operative in response
in response to variations in the pressure of ?uid
supplied by said brake controlling valve device for
varying. the amount of ?uid under pressure ?ow
ing from said brake controlling valve device to
said volume reservoir to thereby vary the pres
sure of ?uid in said brake cylinder device accord
ing to the adjustment of the adjustable means,
and means operative in accordance with different
30 weights of lading carried for adjusting said ad
justable means,
to an increase in pressure of ?uid in said reser
voir for cutting o? the ?ow of ?uid to the reser
voir according to the load carried by the vehicle
by causing a certain amount of the ?uid under
pressure being supplied to‘the brake cylinder de
vice to flow to said volume reservoir, the amount
of ?uid flowing to the reservoir varying inversely
to the load carried by the vehicle, and means for
adjusting said valve mechanism in accordance
with the weight of the load carried by the vehicle
for operation according to variations in the pres
sure of ?uid supplied to the brake cylinder de
vice to control the amount of ?uid under pressure
?owing to said volume reservoir.
5. In a vehicle variable load ?uid pressure
brake equipment, in combination, a brake cylin
der device, a volume reservoir, a brake control
ling valve device operative to supply ?uid under
pressure to said brake cylinder device, a conduit
through which ?uid under pressure may ?ow to
brake cylinder for diiferent weights of the lading
carried.
amounts varying inversely proportional to the
weights of the load carried by the vehicle, and
‘
i
inder, a brake controlling valve device operative
to supply fluid under pressure to the brake cylin
der, a volume reservoir, a conduit through which
?uid under pressure being supplied by the brake
controlling valve device may ?ow to said reser
voir, valve means interposed in said conduit con
ditioned according to the weight of the lading
carried by the vehicle for response to the pres
sure of the ?uid being supplied by the brake con
trolling valve device for metering the‘ amount of
?uid flowing to said reservoir or for preventing
the flow of ?uid. thereto to provide di?erent pres
sures of ?uid in the brake cylinder for different
“ weights of lading carried by the vehicle.
means operative as an incident to the charging
of the equipment with ?uid under pressure for
conditioning said valve means.
'
9. In a variable load ?uid pressure brake equip
ment for a vehicle, in combination, a brake cyl
said reservoir, and a valve mechanism operative
to control the ?ow of ?uid under pressure
through said conduit from said brake controlling
valve device to said volume reservoir and there
by control the pressure of ?uid in said brake cyl
inder device, said valve mechanism being condi
tionable when the vehicle is fully loaded to pre
vent the ?ow of ?uid under pressure to said vol
ume reservoir and for operation according to var
iations in the pressure of ?uid supplied by said
brake controlling valve device and being condi~
tionable when the vehicle is empty or partly
loaded to provide for metering the ?uid under
pressure admitted to said volume reservoir in
‘
8. "In a variable load ?uid pressure brake. equip
ment for a vehicle, in combination, a brake cylin
der, a brake controlling valve device operative to
supply ?uid under pressure to the brake cylinder,
a volume reservoir, a conduit through which ?uid
under pressure being supplied by the brake con
trolling valve device may ?ow to said reservoir,
valve means interposed in said conduit condi
tioned according to the weight of the lading car
ried by the vehicle for response to the pressure
of the ?uid being supplied by the brake control
ling valve device for e?ecting the ?ow of ?uid
through said conduit and for response to the
pressure of ?uid being supplied to said reservoir
for cutting off the ?ow of ?uid through said cone
duit to provide different pressures of ?uid in the
‘
10. In a, variable load ?uid pressure brake
equipment for a vehicle, in combination, a brake
cylinder, a brake controlling valve device opera
tive to supply ?uid under pressure to the brake
cylinder, a volume reservoir, a conduit through
6. In a vehicle variable load ?uid pressure brake
which ?uid under pressure being supplied by the
equipment, in combination, a brake cylinder de
vice for providing braking power on a heavily
loaded vehicle, a volume reservoinvalve means
arranged to be cut into operation to provide de 75
brake controlling valve device may ?ow to said
reservoir, valve means interposed in said conduit
conditioned according to the weight of the lad
ing carried by the vehicle for response to the pres;
2,407,870
23
sure of. the ?uid; being supplied by the brake con-‘
trolling valve‘ devicev for metering the amount
of ?uid ?owing tosaid reservoir to provide differ
ent: pressures of ?uid in the brake cylinder for
different weights of, lading carried by the vehicle. Si
11'. In a variable load ?uid pressure brake
equipment for a vehicle, in combination, a brake
cylinder, a brake controlling valve device opera
tive to supply ?uid under pressure to the brake
cylinder to effect an application of the brakes, a
?uid reservoir into which ?uid under pressure
supplied by the brake controlling valve device
?ows to control the pressure of fluid in the brake
cylinder, means subject to the opposing ?uid
pressures of the reservoir and brake cylinder
and operative upon an increase in the pressure of
?uid in the reservoir for limiting the amount of
fluid ?owing to the reservoir, and means adjusta
ble according to different Weights of lading car
ried by the vehicle for rendering said valve
means responsive to different ?uid pressures in
the reservoir.
24
a
sage connecting‘ said mechanism to the volume
reservoirs,‘ said variable load valve mechanism
being operative to vary the pressure of ?uid in
said brake cylinder according to variations in
the weight of the lading carried by the vehicle
byv permitting, ?uid under pressure being supplied
by the brake controlling valve device .to said
brake cylinder to flow to said pass-age in amounts
varying inversely to the Weight of the lading car
ried by the vehicle, and valve means interposed
in said passage and operative in response to a
subsequent increase the pressure of fluidv in the
brake pipe to effect a release of the brakes .to
close communication between said passage and
said emergency‘volume reservoir'and to vent ?uid
‘ under pressure from the emergency volume reser
voir.
15. A vehicle variable load ?uid pressure brake,
in combination, a brake pipe, an auxiliary reser
voir, an emergency reservoir, all normally
charged‘ with ?uid under pressure, a brake cylin
der, a brake controlling valve device operative in
12. In a variable load ?uid pressure brake
response to a service reduction in the pressure
equipment for a vehicle, in combination, a brake
of ?uid in said brake pipe to admit ?uid under
cylinder,v a brake controlling valve device opera 25 pressure from said auxiliary reservoir to said
tive to. supply ?uid under ‘pressure to the brake
brake cylinder and operative in response to an
cylinder to effect an application of the brakes, a
emergency reduction in the pressure of ?uid in
?uid receiver normally at atmospheric pressure
said brake pipe to admit ?uid under pressure
for receiving ?uid under pressure being supplied
from the auxiliary and emergency reservoirs to
to the brake cylinder, a conduit through which oil the brake cylinder, a service volume reservoir,
the ?uid under pressure flows to said ?uid re
an emergency volume reservoir, a variable load
ceiver.. valve means interposed in said conduit
valve mechanism interposed between said brake
conditioned according’ to the Weight of the lad
controlling valve and said servicevolume reser
ing carried by the vehicle for response to the pres
voir and operative to vary the pressure of ?uid
sure of the ?uid being supplied by the brake J; in said brake cylinder by permitting ?uid under
controlling valve device for either effecting the
pressure supplied from the brake controlling
?ow of ?uid to said receiver and for controlling
valve device to the brake cylinder to‘?ow to said
the amount of ?uid ?owing thereto or inhibiting
service volume reservoir in amounts varying in
the ?ow of ?uid thereto to provide the pressure
versely to the load carried by the vehicle, said
of ?uid inthe brake cylinder called for by the 40 valve mechanism being adjustable in accordance
weight of the lading carried by the vehicle.
with the Weight of the load carried by the vehicle
13; In a vehicle variable load ?uid pressure
for operation according to variations in the pres
brake equipment of the typev comprising a brake
sure of ?uid supplied to the brake cylinder to
pipe, an auxiliary reservoir, an emergency‘ reser~
permit proportional amounts of ?uid under pres
voir, a brake cylinder, and a brake controlling
sure to ?ow to said service volume reservoir, and
valve device operative in response to a service re“
valve means subject to the pressure of ?uid in
duction'; in the pressure of ?uid in said brake pipe
the brake pipe and operative in response to an
to connect said auxiliary reservoir to said brake
emergency reduction in the pressure of ?uid in
cylinder and operative in response to an emer
the brake pipe to connect said emergency volume
gency reduction in the pressure of ?uid in the Si) reservoir to said service volume reservoir.
brake pipe to open communication between both
16. In a vehicle variable load ?uid pressure
reservoirs and the brake cylinder to effect an ap~
brake equipment of the type comprising a brake
plication of the brakes, in combination, a service
pipe, an auxiliary reservoir, an emergency reser
volume reservoir; a variable load valve mecha
voir, a brake cylinder, and a brake controlling
nism. operative to vary the pressure of ?uid in a valve device operative to effect a service brake
said brake cylinder by effecting a ?ow of ?uid
application by admitting fluid under pressure
being supplied to said brake cylinder to said serv
from said auxiliary reservoir to said brake cylin
ice volume reservoir in amounts varying inverse
der and operative to effect an emergency brake
ly to‘ the load carried by the vehicle, an emer
application by admitting ?uid under pressure
gency volume reservoir, and means operative as
from the auxiliary and the emergency reservoirs
a result of an emergency reduction in the pres~
to the brake cylinder, in combination, a service
sure of ?uid in the brake pipe to establish’ a
volume reservoir, an emergency volume reser
communication through which ?uid under pres
voir, a variable load valve mechanism ‘operative
sure ?ows from‘ said service volume reservoir to
to vary the pressure of ?uid in said brake cylin
said emergency volume reservoir.
65 der by admitting ?uid supplied ‘thereto to ‘the
14. A vehicle variable load ?uid pressure brake,
volume reservoirs in amounts varying inversely
in'combination,‘ a brake pipe normally charged
to the load carried‘ by the vehicle, said mecha
, with ?uid under pressure, an auxiliary reservoir,
nism being adjustable in accordance with the
an emergency reservoir, a brake cylinder, a brake
weight of the load carried by the vehicle for op
controlling valve device operative in response to 70 eration according to variations in the pressure of
?uidv suppliedto. said brake cylinder to permit
an emergency reduction in the pressure of ?uid
proportional amounts of ?uid under pressure to
. in said‘ brake pipe to connect the auxiliary and
flow to the volume reservoirs, and valve means
emergency reservoirs to the brake cylinder, a
subject to ?uidt under pressure-in theibrake pipe.
service volume reservoir, an emergency volume
and normally closing communication between
reservoir; a» variable load valve mechanism, apas
2,407,870
25
26
said variable load valve mechanism and said
emergency volume: reservoir, said means being
receive ?uid under pressure being supplied to
the brake cylinder by said brake controlling valve
device, a second volume reservoir normally de
operative as an incident to effecting an emer
gency application to connect said emergency vol
ume reservoir to said variable load valve mecha
pleted of ?uid under pressure, means operative
in response to said emergency reduction in the
pressure of ?uid in the brake pipe for establish
nism.
17. In a fluid pressure brake equipment, in
combination, two ?uid pressure supply sources,
valve means operative to supply ?uid under pres=
ing a communication through which ?uid under
pressure being supplied by the brake controlling
valve device may ?ow to said second volume res-.
sure from one of said ?uid pressure supply sources 10 ervoir, and valve means operative according to
to effect aservice application of the brakes and
operative to supply ?uid under pressure from'said
various weights of lading carried by the vehicle
for variously measuring the amounts of ?uid
?owing to either said ?rst volume reservoir or
to both volume reservoirs.
two ?uid pressure supply sources .to eifect an
emergency application of the brakes, two volume
reservoirs normally depleted of ?uid under pres
20. In a vehicle variable load ?uid. pressure
sure and arranged for receiving ?uid under pres
brake equipment, a brake pipe normally charged
sure being supplied by the brake controlling valve
with ?uid under pressure, an auxiliary reservoir
normally charged with ?uid under pressure, an
- device, valve means functioning in response to
the pressure of ?uid being supplied by the brake
emergency reservoir normally charged with ?uid
controlling valve device to establish communica 20 under pressure, a brake cylinder, a brake control
tion through which ?uid under pressure being
ling valve device operative in response to a serv
supplied by the brake controlling valve device
ice reduction in the pressure of ?uid in the brake
may ?ow to one of said volume reservoirs, and
pipe for supplying ?uid under pressure from the
means normally isolating the other of said vol
auxiliary reservoir to said brake cylinder and
ume reservoirs from said one volume reservoir 25 operative in response to an emergency reduction
and operative as an incident to the effecting of
in the pressure of ?uid in the‘ brake pipe for
an emergency application of the brakes for open
supplying ?uid under pressure from both the
ing said other volume reservoir to said one vol
auxiliary and emergency reservoirs to the brake
ume ‘reservoir.
“
,
18. In a vehicle variable load ?uid pressure
brake equipment, in combination, two ?uid pres
sure supply sources, valve means operative to
supply ?uid under pressure from one of said
?uid pressure supply sources to effect a service
application of the brakes, and operative to sun
ply ?uid under pressure from said two ?uid pres- ‘
sure supply sources to effect an emergency appli
cation of the brakes, two volume reservoirs nor
mally depleted of ?uid under pressure and ar
ranged for receiving ?uid under pressure being
supplied by said brake controlling valve device,
valve means functioning in response to the pres
sure of ?uid being supplied by the brake con
trolling valve device to establish a communica
35
cylinder, a ?rst volume reservoir normally de
pleted of ?uid under pressure and arranged to
receive ?uid under pressure being supplied to the
brake cylinder by said brake controlling valve
device, a second Volume reservoir normally de
pleted of ?uid under pressure, means operative
in response to said emergency reduction in the
pressure of ?uid in the brake pipe for establish
ing a communication through which ‘?uid under
pressure being supplied by the brake controlling
valve device may ?ow to said second volume res
ervoir, and valve means operative according to
various weights of lading carried by the vehicle
for variously measuring the amounts of ?uid
?owing to either said ?rst volume reservoir or
to both volume reservoirs, said valve means being
tion through which ?uid under pressure being 45 subject to the opposing pressures of ?uidin the
supplied by the brake controlling valve device
brake cylinder and said first volume reservoir
may ?ow to one of said volume reservoirs, and
and operative upon an increase in the pressure
means normally isolating the other of said vol
of ?uid in the ?rst volume reservoir for control
ume reservoirs from said one volume reservoir,
ling the amount of ?uid under pressure ?owing
and operative as an incident to the e?ecting of 50
an emergency application of the brakes for open
21. In a vehicle variable load ?uid pressure
ing said other volume reservoir to said one vol
brake equipment, a brake pipe normally charged
thereto.
'
-
i
ume reservoir, said valve means being condi
with ?uid under pressure, an auxiliary reservoir
normally ‘charged with ?uid under pressure, an
ried by the vehicle for operation to correspond 55 emergency reservoir normally charged with ?uid
ingly vary the amount of ?uid ?owing to one or
under pressure, a brake cylinder, a brake con
both of said volume reservoirs for any given
trolling valve device operative in response to a
amount of ?uid under pressure supplied by the
service reduction in the pressure of ?uid in the
brake controlling valve device.
brake pipe for supplying ?uid under pressure
19. In a vehicle variable load ?uid pressure 60 from the auxiliary reservoir to said brake cyl
tioned according to various weights of lading car
brake equipment, a brake pipe normally charged
with ?uid under pressure, an auxiliary reservoir
normally charged with ?uid under pressure, an
emergency reservoir normally charged with ?uid
inder and operative in response to an emergency
reduction in the pressure of ?uid in the brake
pipe for supplying ?uid under pressure from‘ both
the auxiliary and emergency reservoirs to the
under pressure, a brake cylinder, a brake con 65 brake cylinder,‘ a ?rst volume reservoir normally
trolling valve device operative in response to a
depleted of ?uid under pressure‘and arranged to
service reduction in the pressure of ?uid in the
receive ?uid under pressure being supplied to
brake pipe ‘for supplying ?uid under pressure
the brake cylinder by said brake controlling valve
from the auxiliary reservoir to said brake cyl
device, a second volume reservoir normally de~
inder and operative in response to an emergency 70 pleted of ?uid'under pressure, means operative
reduction in the pressure of ?uid in the brake
‘inresponse ‘to said emergency reduction in the
pipefor supplying ?uid under pressure from both
pressure of ?uid in the brake pipe for establish
the auxiliary and emergency reservoirs to the
ing a communication through which ?uid under
brake cylinder; a ?rst volume reservoir normally
pressure being supplied‘by the brake controlling
depleted of ?uid ‘under pressure and arranged to 75 valve device may ‘ ?ow'to said second volume
12,407,876
27
reservoir, vand valve ‘means operative according
to various weights of the lading carried-bythe
vehicle for variously measuring the amounts of
?uid ?owing to either said ?rst volume reservoir
or to both volume reservoirs, said valve means
vbeing subject to the opposing pressures of ?uid
in the brake cylinder and said ?rst volume res"
ervoir and operative upon'an increase in the pres
sure of ?uid in the ?rst volume reservoir for
controlling the amount of ?uid under pressure
?owing thereto, and said means comprising
.28
a brake controlling valve device operative in re
sponse to a full ‘service reduction in brake pipe
pressure to supply ?uid :under ‘pressure from said
auxiliary reservoir ‘to said ‘brake cylinder and
service volume reservoir, the pressure of ?uid in
the auxiliary reservoir being reduced by such‘ sup
ply to a pressure substantially equal to there
duced ‘brake pipe pressure, and valve means op
erative in response _to the reduction in auxiliary
10 reservoir pressure for-inhibiting any further-sup
meansadjustable according to different weights
ply of ?uid from the auxiliary reservoir .t'olth‘e
brake cylinder in the event of Jafurther reduc
of 'lading carried by the vehicle for conditioning
tion'in brake pipe pressure.
the valve means for response to different pres~
sures ‘of ?uid in said ?rst volume reservoir.
22. The ‘combination in a vehicle variable load
brake equipment, of a brake pipe, an auxiliary
reservoir, a brake cylinder, a brake controlling
valve device operative upon a. reduction in brake
pipe pressure to establish communication through ~
(
'26. In a ?uid pressure brake equipment, in
combination, a brake pipe normally charged with
?uid under pressure, an auxiliary reservoir
charged with ?uid to a pressure substantially
equal to that of the ‘fluid in ‘the brake pipe, a
brake cylinder, a brake controlling 'valve'device
subject to the opposing pressures of ?uid in the
brake pipe and auxiliary reservoir and operative
which ?uid under pressure is supplied from said
in response to a full service reduction in brake
auxiliary reservoir to said brake cylinder to effect
pipe-pressure ‘to supply ?uid under pressure from
an application of the brakes, a volume reservoir,
said auxiliary reservoir to v‘the brake cylinder, -a
a variable load valve mechanism operative to vary
service volume reservoir into which‘ ‘fluid under
the-pressure of ?uid supplied to said brake cyl
pressure being supplied by the brake ‘controlling
inder by permitting ?uid under pressure being
valve device to the brake cylinder-‘also ?ows, said
supplied to the brake cylinder to ?ow to said
brake controlling valve device-‘being operative,
volume reservoir in amounts varying inversely to
when due to the flow of ?uid to‘ the‘ brake
the load carried by the'vehicle, said mechanism
being adjustable in accordance with the Weight 30 cylinder and service volume reservoir, the ‘aux
iliary reservoir pressure is reduced to- substan
of the load carried by the vehicle for operation ac
tially the reduced brake pipe pressure, ‘to cut-off
cording to variations in the pressure of ?uid sup
the ?ow of ?uid to the brake cylinder ‘and service
plied to said brake cylinder to permit propor»
volume reservoir, and meansre'spun‘sive to the re
tional amounts of ?uid under pressure to flow
to said volume reservoir, and valve means'respon- ' l duction in auxiliary reservoir pressure for inhib
iting any further supply of ?uid under pressure
sive to a predetermined decrease in the pressure
from the auxiliary reservoir vto the brake cylinder
of fluid in said auxiliary reservoir for closing said
in the event of a ‘further reduction in brake pipe
communication to limit the ?ow of ?uid from the
pressure.
'
auxiliary reservoir to the brake cylinder.
27. In a ?uid pressure brake equipment, in
23. In a ?uid ‘pressure brake, in combination,
combination, a brake pipe normal-1y charged with
a reservoir normally charged ‘with ?uid under
?uid under pressure, an auxiliary. reservoir
pressure, -a brake controlling valve device opera
tive to supply ?uid under pressure from said’ res
er-voir to effect anapplication of the brakes, and
valve means interposed between said reservoir
and said brake controlling valve device vand op
erative in response to a chosen reduction in the
‘pressure of ?uid in the reservoir and regardless
of the rate of such reduction for cutting off the
brake cylinder supply of ?uid under pressure from ' '
the reservoir.
7
24. In a ?uid-pressure brake, in combination,
a reservoir normally charged with ?uid under
pressure, a brake controlling valve device oper
ative to supply ?uid under pressure from-said res- l
ervoir to effect an application of the brakes, and
valve means interposed between said ‘reservoir
and said brake controlling valve device and op
erative in response to a predetermined reduction
in the pressure of ?uid in the reservoir for cut
ting off the brake cylinder supply of ?uid’ under
pressure from the reservoir, said valve means
being automatically‘conditioned, according to any
charged with ?uid to a pressure substantially
'equal'to that of the ?uid in the brake pipe, 7a
= brake cylinder, a brake controlling valve device
subject to the opposing pressures vof ?uid ‘in the
brake ‘pipe, and auxiliary reservoir and ‘operative
in response to a full service reductionin brake
pipe pressure tosupply ?uid .under pressure from
said auxiliary reservoir ‘to ’ the brake’ cylinder, a
service ‘volume reservoir into which ?uid under
pressure being supplied by the brake controlling
valve device to theibrake cylinder also ?owss'aid
brake, controlling valve ‘device ‘being operative,
when due to the f?ow of ?uid toithabrake
cylinder. and service volume reservoir, 'the auxil
iary reservoir ‘pressure is reduced tosubstantially
the reduced brake pipe pressure, to cut-elf the
flow of ?uid to the brake cylinder-and service
volume reservoir, the combined volumes of the
brake cylinder and service volume reservoir being
such‘ with relation to the ‘volume of the :auxiliary
reservoir vthat the brake cylinder pressure at
tained by ‘said reduction in vbrake pipe pressure
one of different pressures of ?uid to which the
reservoir may be charged, for operation'in re 65 will be lower than the pressure of ?uid-remaining ‘
in the auxiliary reservoir, and means responsive
sponse to said predetermined reduction in the
to the reduction in auxiliary reservoir- pressure
reservoir pressure below the particular pressure
for inhibiting any further supply of ?uid under
of ?uid carried in the reservoir. pressure from the {auxiliary reservoir to the brake
25. In a ?uid pressure brake equipment, in com
bination, a brake pipe normally charged with ?uid
cylinder in theevent of a further reduction'in
under pressure, an auxiliary reservoir normally
brake pipe pressure.
‘
'
-~
'
7
chargedwith ?uid from the brake pipe and to the
28. In a ?uid pressure brake equipmentyin
same pressure, a-brake cylinder, a service volume
combination, a brake pipe normally charged'with
?uid under pressure, an ‘auxiliary reservoir
reservoir normally at atmospheric pressure and
in open communication with said brake cylinder, 75 charged with ‘?uid to a pressure substantially
29
2,407,870
equal to that of the ?uid in the brake pipe, a
brake cylinder, a brake controlling valve device
subject to the opposing pressures of ?uid in the
brake pipe and auxiliary reservoir and operative
U
30
reservoir, the combined volumes of the brake cyl
inder and service volume reservoir being such
with relation to the volume of the auxiliary res~
ervoir that the brake cylinder pressure attained
in response to a full service reduction in brake Cir
by said reduction in brake pipe pressure will be
pipe pressure to supply ?uid under pressure from
lower than the pressure of ?uid remaining in the
said auxiliary reservoir to the brake cylinder, a
auxiliary reservoir, means responsive to the re
service volume reservoir into which ?uid under
duction in auxiliary reservoir pressure for inhib
pressure being supplied by the brake controlling
iting any further supply of ?uid under pressure
valve device to the brake cylinder also ?ows, said 10 from
the auxiilary reservoir to the brake cylinder
brake controlling valve device being operative,
in
the
event of a further reduction in brake pipe
when due to the ?ow of ?uid to the brake cylinder
pressure, and valve means operative according to
and service volume reservoir, the auxiliary reser
the weight of the lading carried by the vehicle
voir pressure is reduced to substantially the re
for
measuring the amount of ?uid under pressure
duced brake pipe pressure, to cut-off the ?ow of
flowing
to said service volume reservoir.
?uid to the 1crake cylinder and service volume
EARLE S. COOK.
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