1. No category

Aug. 22, 1939-
c. c. FARMER ET Al.
2,170,237
BRAKE CONTROL MEANS
uw@cam.
ATTORN EY
I Àug- 22, 1939-
c. c. FARMER r-_T Al.
2,170,237
BRAKE CONTROL MEANS
Filed April 20, 1957
2 Sheets-Sheet 2
@om
om@@EN
o_om
BY
Patented Aug. 22, 1939
2,170,237
PATENT
UNITED STATES
2,170,237
BRAKE CONTROL MEANS
Clyde C. Farmer, Pittsburgh, and George W.
Baughman, Edgewood, Pa., assignors to The
Westinghouse Air Brake Company, Wilmer
ding, Pa., a corporation of Pennsylvania
Application April 20, 1937, Serial No. 137,954
39 Claims. (Cl. 303-21)
This invention relates to brake control means
and more particularly to brake control equip
ments for high speed trains whereby 'the brakes
are automatically controlled both according to
5 the speed of the train and according to the rate
of retardation of the train.
indicated in the ñrst mentioned object, a wheel- `
slip detecting means associated with one wheel
and-axle unit which’is more heavily braked than
the other wheel-and-brake units of the train, for
automatically controlling the brakes associated
with the other wheel-and-axle units on the train
to prevent the attainment of such a braking force
thereon as would induce a wheel-slipping or a
Present-day high »speed trains intended` to
travel normally at speeds in excess of one hundred
miles per hour, have presented numerous prob
wheel-sliding condition.
10 lems incidental to the adequate braking of the
The above objects and other and more speciñc 10
objects which will appear in the subsequent de
train whereby the train may be brought to a
stopfrom a high speed over stopping distances
scription of our invention, are attained by means '
substantially .the same as obtained in the case of
of illustrative embodiments hereinafter described
and shown in the accompanying drawings,
present-day, lower speed, trains. Various brake
15 control equipments for high speed trains have
been proposed for automatically controlling the
brakes on the trains, both according to the speed
of the train and according to the rate of retarda
wherein,
tion of the train, so as to bring the train to a I v
stop from avhigh speed within a reasonable stop
15
Fig. 1 is a simplified diagrammatic view, with
parts thereof in section, showing a brake control
equipment for one car of a train and constituting
one embodiment of my invention,
Fig. 2 is a fragmentary diagrammatic view, 20
>ping distance, comparable to stopping distances villustrating
one possible modified arrangement of
obtaining in the case of low speed trains, With
out causing undue sliding of the wheels.
One of such brake control equipments for high
25 speed trains is described and claimed in the co
pending application of George W. Baughman, one
n of the present joint applicants, now Patent
2,096,505 assigned to the assignee of the present
application.
'
It is an object of the present invention to pro
vide, in a brake control equipment for high speed4
trains of the character described in the copend
ing application just mentioned, additional fea
tures including means for detecting wheel. slip
f ping and for effecting automatically a reduction
in the degree of the application to guard against
and prevent a wheel sliding condition.’ It will
be understood that the term “slipping” and the
term “sliding”, as employed herein with respect
to vehicle wheels have definitely diiîerent mean
ings. As used herein, the term “wheel-slipping”
or “wheel-slip” refers to the condition wherein a
vehicle wheel is slowing down from 'a rotative
45
speed, corresponding to the speed of travel of
the vehicle, to zero speed corresponding to the
locked condition of the- wheel.
As used in the
present application, the term “wheel-sliding”
designates that condition of 'a vehicle wheel
wherein it is locked against rotation while the
50 vehicle continues to travel along the track rails.
Another object of our invention is to provide
novel means for detecting a wheel-slipping or a
wheel-sliding condition.
A further object'of our invention is to provide,
55 in a brake control equipment of the character
the control circuits shown in the embodiment
represented in Fig. 1.
.
Fig. 3 is a fragmentary diagrammatic view of
another embodiment of my invention which dif 25
fers from the embodiment shown in Fig.- 1
principally in the provision of a different type
of mechanism for detecting a wheel-slip condi
tion, and
Fig. 4 is a sectional view, taken on the line 4_4 30
of Fig. 3, showing in further detail the construc
tion of the wheel-slip detecting mechanism.
BRIEF DESCRIPTION or EQUIPMENT SHOWN 1N FIG. 1
Referring to Fig. 1, the brake control equipment 35
comprises at least one brake cylinder I0 for ap
plying and releasing the brakes associated with
one wheel-and-axle unit, indicated by the wheel
8 and axle 9, and at _least one brake cylinder Illa
for applying and releasing the brakes associated 40
with another wheel-and-axle unit of the car or
train and represented by the Wheel 8a vand axle
9a, a brake control valve mechanism II for con
trolling the supply of ñuid under pressure to and
the release of fluid under pressure from the brake 45
cylinders I0 and Illa, a speed-controlled or gov- '
ernor switch device I2, an inertia device herein
after called a retardation controller I3, an auto
matic valve device I4, a manually operated brake
valve device I5, and a fluid pressure operated 50
switch device I 'I for controlling electrical con
nections, hereinafter described, to a suitable
source of electrical energy such as a battery I8.
.Also included in the equipment are a main
reservoir I9 charged with ñuid under pressure in
2,170,237
2
well known manner'from a fluid compressor, not
shown, an auxiliary reservoir 2i, the supply of
fluid under pressure to and from which is con
trolled by the automatic valve device i4, a feed
valve device 25 of standard construction and
functioning in well known manner to regulate
the pressure of. ßuid supplied from the main
reservoir I9 into a pipe 26, hereinafterdesignated
the feed valve pipe, to a substantially uniform
10 pressure lower than that to which the reservoir
I9 is charged, and a double check valve device 21,.
Also provided are three pipes indicated as extend
ing through all the cars of the train and herein
.after designated the main reservoir pipe 22, the
control pipe 23 and the brake pipe 2d.
prising a valve section 5|, a diaphragm section 52
secured to the valve section 5l as by bolts, not
shown, two cover sections`53 and 54, respectively,
secured to the diaphragm section 52 as by bolts,
not shown, and a magnet valve section 55 secured
to the valve section 5l as by bolts, not shown.
Formed in the casing section 5l is a chamber
5B which is constantly connected to the main
reservoir pipe 22 through a branch pipe 51 and
which contains a valve of the poppet type, here
inafter designated supply valve 58. Also formed
in the casing section El is a chamber 59 which
communicates with the brake cylinders lll and lila
through a pipe -and passage 6| and which con
tains a valve of the poppet type,l hereinafter des
ignated the release valve S2, for controlling the
venting of fluid under pressure from the chamber
mediate wire and the low wire, and according to ' 59 and the brake cylinders i@ and lila through
.
our invention, energization and deenergization' of an exhaust port S3.
Operation of the supply valve and release valve 20
the
train
wires
3i,
32
and
33
is
effected
in
the
20
manner hereinafter described under the control is eii‘ected by rocking movement of s. lever 64
which is pivoted substantially intermediate the
of four electrical relay devices, hereinafter re
There are also three train wires 3|, 32 and 33,
hereinafter referred to as the high wire, the inter
spectively called the wheel-slip relay 35, the low»
retardation relay 36, the high-retardation relay
25 3l and the speed relay 38;
ends thereof as by a pin t5 on a slidable mem
ber t6.
,
The supply valve 58 - is normally yieldingly 25
The speed relay 3@ is controlled by the governor , urged into seated position on an associated valve seat by a biasing spring El, the inner end of the
switch device i2 in the manner to be hereinafter iluted
of the'supply valve 5t engaging one
described and the retardation relays @t and 3l end ofstem
a
iluted
spacer 58 slidable in the casing
are controlled by the retardation controller i3 in
section 5 l, the other end of the spacer 68 engaging 30
the
manner
.also
hereinafter
described.
The
30
wheel-slip relay 35 is controlled by a differential the lower end of the lever @d and _urging it into
_relay élB, which is in turn controlled according substantial contact with an adjustable stop screw
59. lThe slidable member @t is yieldingly urged
to the current supplied thereto from two gener
' ators ¿3d and 45 driven, as through a pulley and in the right-hand direction by a spring li so that
the lever t@ is pivoted about its lower end. which 35
35 belt arrangement in the manner shown, by >ro
is held between ,the stop screw t@ and the spacer
tation oí’ the axles t and 9a, respectively.
’in accordance with our invention, there are also' 53.
The release valve 62 is carried on a stem 'l2
provided a magnet valve device 4S for releasing
slidable
in the casing section 5l and having two
iìuid under pressure from the brake cylinder iii,
spaced shoulders connected by a reduced portion
and
a
signal
device,
represented
by
a
signal
lamp
40
ill, for indicating to the operator or engineman 'l0 which is straddled by the upper bifurcated
end of the lever $8 in such manner that the upper
the'occurrence of a wheelrslipping or a wheel“
sliding condition o_i’ the Wheels 8 and axle 9, both end of the lever til is free to pivot at the upper
the magnet valve device 46 and the signal lamp end thereof between the spaced shoulders.
With the lower end of the lever 6d held between
4.5 âil bgiang under thecontrol of the differential re
the spacer 58 and the stop screw GS, the shifting
The brake control equipment shown in Fig. 1 of the slidable member 66 in the right-hand di
is adapted for use on trains of either the articl rection by the spring ‘li causes a shifting of the
ulated or the non-articulated type and only so slidable stem i2 and the release valve -62 in the
much
of the` equipment is shown as illustrates right-hand' direction to unseat the valve 62 and 50
'so the operation
thereof, the control of the brakes permit fluid under presume in the chamber 59
associated with wheels and wheel-and-axle units and in the brake cylinders to exhaust toatmos»
ay
.
l
other than those shown being eifected in a man
ner similar to that described for the particular
55 wheel-and-axle units shown.
Dn'rArwo DESCRIPTION or EQUIPMENT SHOWN IN
.
F1o. l
(a) Brake control 'valve mechanism 11
The brake control valve mechanism il repre
sents, in simpliñed form, a type of valve device
described in detail and claimed in the copending
application oi. Ellis E. Hewitt, now Patent
2,140,624 -assigned- to the assignee of the
65 present application, certain parts of vthe valve
device shown and described in the patent being
omitted in the present application for the sake
of simplicity.
.
In view of the fact that the valve mechanism
70 ii is described in detail both as to construction
and operation- in Patent 2,140,624, the valve
mechanism .i i is _described herein only in a brief
manner suiiicient to offer comprehension of the
construction and operation thereof. Valve mech
75 anism il is embodied in a sectional casing com
phere through the exhaust port 63.
-
When a force is applied to the right-hand end
of the slidable member t6, as in the manner to 55
be hereinafter described, and the slidable mem
ber d@ is urged in the lett-hand direction from
the normal position shown, the spring tl 'holds
the supply valve 53 seated and the spring> ll
yields so that the lever 5t is pivoted‘ at its lower 60
end and .the upper end shifted ~in the left-hand
direction to cause the release valve 62 to engage
its lassociated valve seat to close off the connec
tion from the chamber 59 to atmosphere through
the exhaust port S3. Thereafter, as the slidable 65
member d@ is further shifted in the left-hand
direction, the lever t@ pivots at its upper bifur
cated end and the lower end is shifted in the
left-hand direction to eñect unseating of the
supply valve 58 against the force of the spring 61.'
When the force urging the slidable member
65 in the left-hand direction is relieved the spring
t1 acts to seat the supply valve 58 and thus rock
the lever 6&3 about the pin 55 to maintain the
release valve t2 seated. After the supply valve
2,170,237
58 is seated, the spring 61 is no longer effective
in rocking the lever 64 about the pin 65 and the
spring 1| then acts to rock the lever 64 in a
clockwise direction about the lower end thereof
which is held between the spacer 68 and the
stop screw 69 to effect unseating of the release
valve 62.
three electromagnet valve devices, hereinafter y
designated the high magnet valve device |_0|,
the intermediate magnet lvalve device |02 and
the low magnet valve device |03, which function
to control the supply and the release -of fluid
under pressure from the chambers 93, 94 and
_
95 respectively.
The high magnet valve device |0| comprises
Contained in the casing section 52 are a plu
rality of movable abutments or diaphragms 13,
a pair of oppositely seating valves, hereinafter
10 14, 15 and 16 of successively smaller effective
pressure areas in the order named, the dia
Dhragms being suitably clamped at the periphery
thereof and disposed inl spaced coaxial relation.
The arrangement of the diaphragms 13, 14, 15
15 and 16 is such as to form a chamber 93 between
the diaphragms 13 and '14, a chamber 94 between
the diaphragms 14 and 15, a chamber 95 between
the diaphragms 15 and 16 and a chamber 96
between the diaphragm 16 and the cover sec
20 tion 53, the latter chamber being constantly
connectœ to the control pipe 23 through a pipe
and passage 23a.
>
In order to maintain a minimum'spacing be
tween the successive diaphragms, a cup-shaped
25 spacer 11 is attached in suitable manner- to one
face of each of the diaphragms 14, 15 and 16
without perforating the diaphragm. The spacer
11 associated with the diaphragm 16 is adapted
to engage the diaphragm 15, spacer 11 associated
30 with the diaphragm 15 is adapted to engage the
diaphragm 14 and the spacer 11 associated withV
the diaphragm 14 is adapted to engagea fol
lower plate 83 suitably attached to one face _of
the largest diaphragm 13 in a manner not neces
sitating perforation of the diaphragm. The fol
lower plate 83 has an outwardly flared fiange or
skirt 84 thereon which engages -a stop shoulder
on the casing section 52 to limit the movement of
'the diaphragm 13 in the right-hand direction.
Associated‘with the face of the largest dia
phragm 13 opposite to the follower plate 83 is a
follower disc 18 which is slidably movable in a
bore ~19 in the casing section 5I, the bore 19
being open at the central portion thereof, through
45 an opening 60, to the chamber 59. The right
hand end of the slidable member 66 contained
in the valve section 5| engages the follower disc
18 'and the spring 1| urging the slidable mem
ber 66 in the right-hand direction is thus effec
50 tive to shift 'the diaphragms 13, 14, 15 and 16
in the right-hand direction until the flared flange
84 on the follower plate 83 engages the stop
shoulder on Lthe casing section 52.
It will be observed that thediaphragms 13, 14,
55 15 and 16 are unconnected and that they may be
moved collectively or individually.
_
'
Interposed between the chambers 93, 94 and 95
and the passage 23a are check valves 93a, 94a
and 95a, respectively, which are yieldingly urgéd
60 into seated relation on an associated valve seat
by lightly tensioned return springs |00.
The
check valves 93a, 94a and 95a are unseated to
effect substantial equalization of the pressure in
the chambers 93, 94 and 95 with the pressure
in the passage 23a and in the control pipe 23
upon a reduction of the pressure in the control
pipe 23 below the pressure in the chambers but
are actuated to seated position to prevent the
flow of fluid under pressure from the control
pipe 23 and passage 23a to the chambers 93, 94
and 95 therepast upon an increase in the pressure
in the control pipe 23. The purpose of the check
valve 93a, 94a and 95a will be understood more -
clearly from subsequent description.
75
The magnet valve casing section 55 contains
3
,
called the supply valve |05 and the release valve
|06, which are yieldingly urged by a spring |01 10
into seated and unseated positions, respectively,
and which are actuated against the force of the
spring |01 into unseated and seated positions,
respectively, upon energization of an electromag
net |08.
With the release valve _|06 unseated 15
as shown, communication is established from a
passage ||3, connected to the chamber 93 be
tween the diaphragms 13 and 14, to an atmos
pheric exhaust passage ||| containing a choke
fitting | | 2, this communication being closed when
the release valve- |06 is seated. When the supply
valve |05 is unseated communication is estab
lished from _the pasage 23a >to the passage I|3
to charge the chamber 93 with fluid under pres
sure from the control pipe 23, this communica
tion being closed when the supply valve |05 is
seated.
,
'I'he intermediate magnet valve device |02 is
identical in construction to the high magnet
valve device |0| and comprises a pair of oppo
sitely seating valves, hereinafter called the supply
valve ||5 and the release valve ||6, which are
^ yieldingly urged into seated and unseated posi
tions respectively by a spring | |1 and actuated
against the force ofthe spring i |1 into unseated
and seated positions, respectively, upon ener
gization of an electromagnet | |8. With the re
lease valve ||6 unseated, as shown, communica
tion is established from a pasage ||4, connected
to the chamber 94 between the diaphragms 14 40
and 15, to an atmospheric exhaust passage |2|
containing a choke fitting |22, this communica
tion being closed when the'release valve ||6 is
seated.
With the supply valve | I5 unseated, communi
cation is established from the passage 23a to the
passage ||4 leading to the chamber 94 so that
the chamber 94 is thus charged to the pressure
in the control pipe 23, this communication being 50
closed when the supply valve ||5 is seated.
The low magnet valve device |03 comprises ,a
double beat valve |26 which is urged to an upper
seated position by a spring |21 and to a. lower
seated position against the force of a spring |21
upon energization of an electromagnet |28. With
the double beat valve |26 in its upper seated po
sition, communication is established from the
passage 23a to a passage |25 leading to the
chamber 95 between the diaphragms'15'and 16,
so that the chamber 95 is charged with fluid
at the pressure established in the control pipe
23. With the double beat valve |26 in its lower
seated position, communication through which
the chamber 95 is charged is closed and another 65
communication is established through which the
passage |25 leading from the'chamber 95 is con
nected to an exhaust passage |31 containing a
choke fitting |32, this exhaust communication
being closed when `the double beat valve is in its 70
upper seated position.
(b) Governor switch device 12
lI’he governor switch device |2 -may be of any
siutable construction and is illustrated diagram
4
.
2,170,237
matically'in simplified form as comprising a con
tact bridging member |35 carried in insulated
relation on a stem |36 slidably mounted in a cas
ing |46, a portion of which is shown, the mem
ber |35 being adapted to engage a pair of in
sulated resilient contact fingers |31 in circuit
closing relation. ,A biasing spring |38, inter
posed between a collar or flange |39 fixed on the
stem |36 and a portion of the casing |46 yielding
urges the stem |36 in a direction to ei‘fectdis
10 ly
engagement of the contact bridging member |35
from the contact fingers |31. A centrifuge |4|
element |5|, the roller |59 is biased into contact
with the left-hand edge of the inertia element by
a lightly tensioned return spring |6| which is
connected at one end to the casing |48' and at
the opposite end to the inner end of the lever
|56. Upon an’application of the brakes, the
shiftingl of the inertia element |'5| in the left
hand direction causes a counterclockwise rota
tion of the lever |56.
'
In its normal or vertical position, the contact
finger |62 engages a stationary contact segment
|63'.
As the lever |56 is rotated in a counter
urges the stemv |36 in the opposite direction,
against the force of the spring |38, to eiîect en
clockwise direction, the contact finger |62 slides
along the contact segment |63, disengages the
gagement of the contact bridging member |35
16 with the contact fingers |31. The centrifuge iéli
comprises a rotary element |62 which is suitably
arc and then engages another contact segment
|66. The spring |54 may be suitably designed
segment |63, travels through a predetermined
journaled in a portion of the casing |66 and ro
tated according to the speed of travel of the
train as by a driving connection to a wheel
and tensioned, and the segments |63 and |615
` >(c) Retardation controller device 13
initial tension of the spring’lää so as to necessi
may be so arranged and disposed as to cause the
Contact finger |62 to disengage the segment |63 20
axle, such as the axle 6a, which driving connec- ' when> the rate of retardation of the train ex
tion is diagrammatically shown by the broken ceeds a certain uniform rate, such as two miles
line. Two or more 'levers |63 carrying fly-balls per hour per second, and so that the contact
finger |62 does not engage the contact segment
|65 at the outer ends thereof are so mounted on
the rotary element |62 that when the fly-balls |66 unless the rate of retardation of the train
exceeds another higher certain uniform rate of
|66 move outwardly under the iniiuence of cen
trifugal Jìorce, the inner ends of the levers exert retardation, such as three miles per hour per
an upward force on the flange |39 oi the stem second. >For simplicity, the range of retardation
|36. The spring |36, the levers |63, and fly-balls rates over which the contact ñnger |62..engages
|65 are so designed that upward movement of the contact segment |63 will hereinafter be 30
the stem |36, in opposition to the force of the termed range A of retardation rates, the range
spring |36, suiiìcient to cause engagement of the of retardation rates over which the contact fin
ger |62 engages neither the segment |63 nor
contact bridging .member |35 with the contact the
segment |64 will b_e termed range B, and the
ñngers i3? is not effected unless the speed of the
range of retardation rates over which the contact 35
train as reflected in the speed of rotation of the
rotary element |62 exceeds a certain uniform or `finger |62 engages the contact segment |66 will
be termed range C.
ï
- '
_
chosen speed, such as forty miles per hour.
Suitable means is provided-for increasing the
tate a higher rate of retardation of the train to
The retardation controller device i3 may com
produce a Agiven degree of movement of the con
prise a casing |66 having a chamber |69 con
tact finger |62 from its normal position and thus
taining an inertia element |5| in the form of aaffect the ranges A, B, and C
heavy weight, which is suitably mounted for correspondingly
of retardation rates. For example, a mechanism
v -horizontal movement in the casing, in a fric
such as is described and claimed in the copending
tionless manner, as by providing iianges |52 on application of Ellis E. Hewitt, now Patent 2,147,
opposite sides of the inertia element, only one of 295 and assigned to the assignee of the present
which flanges is shown, and supporting the in
application, may be provided. As shown in Fig,
ertia element by means of the flanges on fric
1, such mechanism may comprise a piston |61
tionless rollers |53 carried on the casing |66.
which is subject on one side to the pressure of `
The retardation controller device |3 is mount
69 ed on a car of the train in such manner that fluid in a chamber |66 constantly connected to
the brake pipe 26 by a branch pipe 26a., and sub
when the brakes are applied,.the inertia element ject on the opposite side to the opposing pressure
|6| shifts toward the head end of the train, cor- - of a spring |69.
The piston |61 has a stem |1|
responding to the'left-hand direction in Fig. l,A which-is pivotally connected to one end of a '
against the force of a yielding spring |56. When _
the ‘train is at rest or traveling at a substan
lever |12, the opposite end of which has pivotally
connected thereto a stem |14 carrying thereon
tially constant rate of speed, spring |56 urges in fixed relation a collar or ñange |15 against
the inertiaA element- in the right-hand direction ¿which the spring |56 presses.` The lever |12 is
into contact with a stop lug _|55 formed on or
pivoted intermediate the ends thereof, as on a
attached to the casing |68. The degree to which pin |13 carried by the casing |48, and when the
the inertia element |5| shifts in the >left-hand pressure in the chamber |66 exceeds _a certain _
direction away from the stop lug> |55 increases
predetermined pressure sufficient to overcome the ì
in proportion to the increase in the rate of re
spring |63 and shift the piston in the right-hand
tardation of the train, the maximum movement direction into engagement with a stop-shoulder
65 of -the inertia element |5| in the left-hand di
|16 formed on the casing, the iiange |15 is posi
rection being .determined by a stop shoulder |56 tioned as shown to determine the initial tension
on the casing which is engaged by the inertiaof the spring |56 for service applications of the
element.
.
f
ì
A lever |56 is pivotally mounted on the casing
70 |88 and extends through a slot or opening |58
in the wall of the casing |66. The inner end of
the lever |66, within the chamber |66, carries
a roller |66 andthe outer end of the lever has
secured thereto, in insulated relation, a contact
ñnger |62. in the normal position of the inertia
75
When a suiîicient reduction in the pres
sure of the fiuid inthe chamber |66 from the
normal brake pipe pressure carried therein is `
effected, as in the case of emergency applications
‘ brakes.
of the brakes, the spring |69 acts to shift the
piston |61 in the left-hand direction until the
piston strikes the cap or cover |18 closingthe
2,170,237
open end of the chamber |68, the stop ñange |15
being correspondingly shifted in the right-hand
direction to increase the initial tension of the
spring |54.
'
It will accordingly be readily apparent that by
suitably selecting the length of the lever |12 and
' the pivotal point of pin |13 intermediate the ends
of lever |12, any desired degree of increase in the
initial tension of the spring |54 as between serv
ice applications and emergency applications of
the brakes may be effected whereby the ranges
A, B and C of retardation rates may be corre
spondingly varied. For example, instead of the
previously given limits for ranges A, B and C, the
range A for emergency application of the brakes
may cover from zero to three miles per hour per
second, range B may cover from three 'to four and
one-half miles per hour per second, and range C
may cover retardation rates in excess of four and
20 one-nalil miles per hour per second.
(d) Automatic valve device 14
The automatic valve device I4 shown is pref
erably'of conventional design and representative
25 of any of the familiar standard types of automatic
valve devices, such as the well known triple valve
device, which is effective in response to reduc
tion in pressure in the brake pipe 24 at a service
rate or at an emergency rate, to supply fluid under
30 pressure from the auxiliary reservoir 2| to a pipe
|8I leading to one side of the double check valve
‘ device 21 and which is eiîective upon an increase
in brake pipe pressure to release iiuid under pres
sure from the pipe ISI and to eiTect charging oi'
the auxiliary reservoir 2| from the brake pipe 24.
(e) Brake valve device 15
The brake valve device I5 may be of any suit
able construction and for purposesvof the present
40 application there is illustratively employed a
brake valve device of the type described and
claimed in the copending application Serial No.
105,659, of Ellis E. Hewitt, ñled October 15, 1936,
and assigned to the assignee of the present ap
45 plication.
It is deemed unnecessary for purposes
of the present application to describe the brake
valve deviceI I5 in detail, it being necessary to
understand merely that -the single handle |83 of
the brake valve d_evice is operative over the same
50 zone or range of movement in a. horizontal plane
to effect straight-air applications of the brakes
or automatic applications of the brakes, depend
ing upon whether a manually operative selector
element |84 is vpositioned in a straight-airA appli
55 cation position or an automatic application posi
tion.
‘
With the selector element |84 in straight-air
position, the shitting of the operating handle I 83
of the brake valve device I5 from its normal re
5
in the pipe |85, and evenl though the operating
handle |83 is shifted beyond the full service posi
tion to an emergency position, no further increase
in the pressure in the pipe |85 occurs beyond the
maximum pressure for a full service application
of the brakes.
With the operating handle |83 of the brake
valve device I5 in its normal release position, and
with the selector element |84 'in either the
straight-air position or automatic position, the 10
pipe |85 is vented to atmosphere and the brake
pipe 24 is charged with iluid under pressure from
the feed valve pipe 26. During straight-air oper
ation of the brake valve device I5, connections are
maintained through the brake valve device so that 15
the brake pipe 24 remains charged to the normal
pressure therefor.
With the selector element |84 of the brake
valve device I5 in the automatic position thereof,
the operating handle |83-is operative to effect 20
reduction in the brake pipe pressure at a. service
rate and to a desired degree, for service applica
tions of the brakes. Shifting of the operating
'handle |83 to emergency position while the selec
tor element |84 is in automatic position, causes
reduction in brake pipe pressure at an emergency
rate and at the same time causes fluid under pres
sure to be supplied from the feed valve pipe 25
to the pipe |85 to the maximum degree of pressure
attainable therein, that is, to the degree of pres 30
sure corresponding to a full service application
of the brakes.
The double check valve device 21 is of standard
construction and includes a shiftable piston valve,
not shown, which is subject on- one side to `the 3.5'
pressure in the pipe |8| and on the opposite side
to the pressure in the pipe |85 and which is
effective to establish connection between either
the pipe I8I or the pipe |85 and the control pipe
23, depending upon the relation of the pressure 40
in the two pipes |8| and |85.
As will be hereinafter explained, the maximum
pressure established in the pipe I8| for emer
gency applications of the brakes exceeds the
maximum pressure established in the pipe |85 45
for straight-air applications of the brakes and
thus, 4although both pipes |8| and |85 are simul
taneously supplied with fluid under pressure, 'the
pressure in'the pipe |8| predominates and thus
causes the double check valve device 21 to be 50
conditioned to establish communication from
the pipe |8| to the control pipe 23.
(f) Additional equipment and control circuits
The fluid pressure operated switch device I1 55
may be of any suitable construction andy may
comprise a casing containing a piston`|9| sub
ject on one side to :duid under pressure in a cham
ber |32 connected by a branch pipe |93 to the
control pipe 23. When the pressure of the fluid 60
supplied to the control pipe 23 and acting in
the chamber |52 on the one side of the piston
hereinafter termed feed valve pipe 25, to _a pipe - I9| exceeds a predetermined low pressure, such
|85 leading to the side of the double check valve
one or two pounds per square inch, the piston
21 opposite to that to which the pipe |8| from as
ISI is moved against the force of a spring |94, 65
the automatic valve device I4 is connected. The which yieldingly opposes movement of the piston.
brake valve device I5 includes a .self-lapping valve The piston has a stem |85 carrying, in insulated
'i mechanism effective for straight-air operations,
and thus the pressure attained in the pipe |85 relation thereon, a contact membet'lß. The
70 is in proportion to the degree of movement of the contact member |35 engages a.V lower contact
member |31 when the pressure in the control
operating handlel |83 outfof its normal release pipe 23 and chamber |82 is less than the prede 70
position into the application zone. The con
termined pressure of one or two pounds per
struction >oi the brake valve device I5 _is such square inch, and is shifted out of engagement
that when the handle |83 reaches the full service with the contact member |31 and into engage
75 pœition thereof, a maximum pressure is attained ment with ~an upper contact member |88 when
75
60 lease position into the application zone, causes
fluid under pressure to be supplied from the pipe
25, leading from the feed valve device 25 and
2,170,237
6
the pressure of the ñuid in the control pipe and
chamber |92 exceeds the predetermined pressure.
The electrical relays 35, 3â, 3l and 39 are of
any suitable standard construction comprising
an electromagnet
an associated staf
tionary magnetic core, and a movable armature
actuated upon energization of the electromagnet.
For simplicity of description, the electrical relays
will be described as having “front-contact mem
which is actuated from the upper seated posi
tion to a lower seated position against the force
of the spring 222 by any electromagnet 223 when
the electromagnet 223 is energized. The double
beat valve 22| .is contained in a chamber 224
constantly connected to the brake cylinder i0
through a portion of the pipe Si and is effective
in the normal position shown, that is with the
electrcmagnet 223 deenergized, to establish com
bers" and “back-contact members”, and it will munication past the lower valve seat from the
be understood that, as employed herein, the term - chamber 224 to a chamber 225 which is connected
“front-contact member” designates a contact to another portion of the pipe Si leading to the
member which is actuated from a circuit-opening chamber 59 of the valve mechanism ||. Brake
cylinder ita is connected by a branch pipe Sla
to a circuit-closing position when the electro
to the portion of the pipe 5| leading from the 15
magnet
of
the
relay
is
energized,
and
the
term
15
“back-contact member” designates a contact magnet valve device 45 to the valve mechanism
il. Thus, with'the double beat valve 22| in its
member which is actuated from. a circuit-closing
position to a circuit-opening position when the upper seated position, fluid under pressure sup
plied into the pipe 6| from chamber 59 of the
v relay electromagnet is energized. The relay 35
is illustrated diagrammatically as comprising an valve mechanism || ñows to the brake cylinder 20
20 electromagnet 2M and a pair of front-contact
iii and the brake cylinder lila,
When the double beat valve 22| is in its lower
members 202 and 263. .
The relay 3d may comprise an electromagnet seated position, communication between the
264i and a pair of front-contact members 225 chambers 225 and 22d is cut-oí and communi 25
cation is opened from the chamber 22d to a
'
25 and 206.
The relay 3l may comprise an electromagnet chamber. 226 which is constantly open to atmos
phere through an exhaust port 22'i. Thus fluid
2d?, a back-contact member 2632, and a iront
under pressureis released to atmosphere solely
contact member 2%.
from the brake cylinder id.
' ' The relay 32 may comprise an. electromagnet
One of the terminals of the battery iii, here 30
2li, two front-contact members 282 and 2id,
inafter
referred to as the positive terminal,.is
respectively, and a back-contact member 2id.
The diderential relay E33 may >comprise two connected to the contact member it@ oí the
pressure switch |l by a wire 23|, and the oppo
separate electromagnet coils 2|@ and 2H., con
site terminal of the battery it, hereinafter called
nected respectively to the terminals of the gener
the negative terminal, is connected to ground.
ators
#lli
and
¿i5
as
shown,
a
back-contact
mem
35
ber 2id and a iront-contact member 2id. The The contact member itl of the pressure switch
il is connected to the back-contact member 2|?,l
electromagnet coils 2id and 2li or” the relay ¿i3
are so connected to the generators 636i and t5 that ' of the diñerentiai relay «i3 by a wire 232, and the
the direction of current flow in the two windings back-contact member 2id, in the circuit-closing 40
' position thereof, connects the wire 232 to a wire
40 is in opposite directions whereby the magnetic
233 to which one terminal of the eiectromagnet
flux set up by energization of the two eiectro
magnet coils is in opposite directions. The two _ 2ii| -of _relay 35 is connected. The opposite termi
generators 44 and t5 have substantially identical nal of the electromagnet Zûi of relay 35 is con
to the negative terminal of the battery it,
speed-voltage characteristics and, consequently, nected
as through a ground connection including a wire 45
if
the
wheels
t
associated
with
the
more
heavily
45
23d connecting the opposite terminal to ground.
braked axle 9 and the wheels'ta associated with
With
the contact member it@ ci the pressure
the less heavily braked axle @a rotate at the same
speed, the resultant magnetic ñux produced in switch il in engagement with the contact mem
the magnetic core associated with the electro-. ber |9l, and with _the back-contact member 2id 50
of differential relay d3 in circuit-closing posi
magnet'coils 2id, 2|'| of the relay ¿33 is substan
tion, it will thus be apparent that a circuit is
tially zero and as a result the back-contact mem
completed forenergizing the electromagnet 2d@
ber 2|8 and the front-contact member 2|@ are
normally in circuit-closing and circuit-opening
positions, respectively. Ii, due to the heavier
55 braking force exerted on the wheels t and axle 9,
slipping of the wheels t is initiated while the
wheels 3a, continue to rotate at a speed corre»
sponding to the >speed of travel of the train, the
current supplied from generator @d to the electro
60 magnet Winding 2|@ reduces rapidly from a value
corresponding to the current supplied from the
of the relay 35 so that the front-contact mem
bers 2M and 203 of the relay 35 are actuated to
circuit-closing position.
,
55
.
'The contact member 2ü2 of the relay 35 is con
nected by a branch wire 235, a wire 23d and wire
23| to the positive terminal of the battery i8 and,
in the circuit-closing position thereof connects
branch wire 235m- a wire 23"? which is con 60
nected to the wire 232. Thus with the front»
' generator 45 to the electromagnet winding 2|l on
» account of the decrease in voltage generated by
contact member 202 of relay 35 in circuit-closing
position, a holding circuit is established for
the generator ed at a decreased speed. Upon a
suñicient reduction in the rotational speed of the
wheels 8 and axle a during the _slipping interval,
the contact member |36 of pressure switch Il
the 'resultant magnetic ñux produced in the ìniag- l
netic core associated with the electromagnet coils
2|B and 2H is in a direction to cause shifting of
the back-contact member 2id and front-contact
member 2|9 to circuit-opening and circuit-clos
ing positions, respectively.
maintaining the electromagnet 20| of relay 35
energized independently of the separation of 65
from the contact member |91.
‘ *l
The front-contact member 249 of the diiîe'r
ential relay d3 is connected by a wire 239, wires
23B and 23| to the positive terminal of the bat 70
tery i3. and ~when. in circuit-closing position,
>connects the wire `239 to a wire 24| which is
The magnet valve device d6 may comprise a connected to one _terminal of the electromagnet
donne beat valve 22| which is yleiaingiy urged' 223 of the magnet valve device I6 and to one
terminal o1' the signal lamp Il. The opposite 'Il>
75 into an upper seatedposrtion by a spring 2_22 and
2,170,237
7
terminal of the electromagnet 223 and the op 'l magnet |03 vof the magnet valve device |0I is
posite terminal of the signal lamp 41 are respec
energized.
tively connected to the negative terminal of bat
Back-contact member 208 of relay- 31 is con
tery I8 as by connections to ground in the man-l stantly
connected to the positive terminal of the
ner shown. It will thus be seen that Whenever
battery I8 by a wire 264, Wires 235, 236 and 23|
the contact member 2|8 of relay 43 is in circuit
closing position the electromagnet 223 of the and in the circuit-closing position thereof con
magnet valve device 246 is energized and the nects the wire 264 to a wire 265 to which the
front-contact member 2|3 of the relay 38 is con
signal lamp 41 is illuminated.
nected. When the front-contact member 2|3
10
The contact member |98 of the pressure of the relay,38 is in circuit-closing position, it
10
switch I1 is connected„by a branch wire l243 and
a wire 244 including a flexible portion, to *thev connects the wire 265 to the intermediate train
wire 32. One terminal of the electromagnet |I8
Contact finger |62 of the retardation controller of the magnet valve device |02 of, the valve
I3.v The contact segment |63, associated with mechanism |I is connected to the intermediate
15 the contact ñnger I 62, has a Wire 245 connected
train wire 32 by a branch wire 262, the other
‘thereto~ which, in the circuit-closing position of terminal
being connected to the negative termi
the contact member 203 of the relay 35, is con
nal of the battery I8, as through a ground con
nected to a Wire 246 to which one terminal of
the electromagnet 204 of relay 36 is connected. nection in the manner shown. Thus, with the
member 208 of relay 31 and front
The opposite terminal of the electromagnet 204 back-contact
contact member 2| 3 of relay 38 both in circuit 20
is connected to the negative terminal of the bat
closing position, the electromagnet ||8 of the
tery i8 by a branch wire 241, wire 234, and magnet valve device |02 is energized.
through ground.
It will thus be seen >that with the contact
member |96 of the pressure switch |1 engaging
the contact member |08, with the contact linger
|62 of the retardation controller engaging the
contact segment' |63, and with the front-contact
nected. In the circuit-closing position thereof,
member 203 of the relay 35 in circuit-closing
back-contact member 2|4 of relay 38 connects
wire 261 to the wire 236 and thus to the positive 30'
terminal of the battery I8. Accordingly, it will
30 position, the electromagnet 204 of relay 36 is
energized.
One terminal of the electromagnet 201 of the
relay 31 is connected by a wire 249 to the con
tact segment |64 of the retardation controller I3
and the other terminal is connected to the nega
be seen that with the front-contact member 206
of relay 36 in circuit-closing position and with
the back-contact member 2| 4 of relay 38 in cir
cuit-closing position, electromagnet ||8 of the 35
tive terminal of the battery I8 through a ground
connection including a branch wire 25| and the
magnet valve device |02 is energized independ
ently of the circuit through back-contact mem
ber 208 of relay 21 and front-contact member
wire 234. Thus, with the contact member |86
of the pressure switch I1 engaging the contact
member |08 and with the contact finger |62 of
2|3 of. relay 38.
the retardation controller I3 engaging the con- l
tact segment |64, electromagnet 201 of relay 31
is energized.
.
~
One of the contact lfingers |31 of the gover
45 nor switch I2 has the Wire 244 connected thereto
and the other contact finger |31 is connected by
a wire 252 to one terminal of the electromagnet v
2I| of the relay 38.- The other terminal of the
clectromagnet 2|I of relay 38 is connected to the
50 negative terminal of the battery I8 as through a
ground connection including a branch wire 253
and wire 234. Thus, with the contact member
|96 of , pressure switch
I1 engaging contact
member |38 and with the contact member |35 of
55 the governor switch in circuit-closing engage
ment with the contact ñngers |31, electromagnet
2|| of relay 38 is energized.
Front-contact member 205 of relay 36 is con
stantly connected to the positive terminal of
60 battery I8 through a- branch Wire 254, wires 235,
236 and 23| and in the circuit-closing position
thereof connects the wire 254 to a Wire 255' which
is connected to the front-contact member 2I2 of
the relay 38. Contact member 2| 2 of relay 38,
when in circuit-closing position, connects the
wire 255 to the high train wire 3|. One terminal
o! the electromagnet ' |08 of the >magnet valve
device I 0| of the valve mechanism II is con
nected by a branch wire 26| to the high Wire 3|,
70 the opposite terminal of the electromagnet being
connected to the negative terminal of the bat
tery _I8 as through a ground connection in the
manner shown. Thus, with the front-contact
members 205 and 2I2 of the relays 36 and 38
75 respectively in circuit-closing positions, electro
Front-contact member 206 of relay 36 is con
nected to the intermediate train Wire 32 by a
wire 266 and in a circuit-closing position thereof 25
connects the wire 266 to a wire 261 to which the
back-contact member 2|4 of the relay 38 is con
Front-contact member 209 oi' the relay 31 is 40
connected by a branch wire 268 to the wire 261
and in the-circuit-closing position thereof con
nects the wire 268 to the low train wire 33. One
lterminal of the electromagnet |28 of the magnet
valve device |03 of the valve mechanism || is 45
connected to the train wire 33 by a branch wire
263, the other terminal being connected to the
negative terminal of the 'battery |8 as through a
ground connection in the manner shown. Thus,
with the front-contact member 208 of relay `31 50
and back-contact member 2|4 of relay 38 both
in circuit-closing position, the electromagnet |28
of the magnet valve device |03 is energized.
~Or'lrlza'rron or EQUIPMENT SHOWN 1N F1o. 1.
(a) Running condition
55
With the car or train running under power or
coasting, with the handle |83 of the brake valve
device I5 in the release position thereof, with
the selector element |84 in either straight-air
or automatic positions, and with the main reser
voir I9 fully charged with ñuid under pressure
in the usual manner, fluid under pressure is sup
plied to the main reservoir pipe 22 and to the
feed-valve pipe 26. As will appear hereinafter, 05
with the brake valve handle I 83 in release posi
tion, the supply valve 58 and the release valve
62 of _the valve mechanism || are respectively
in seated and unseated positions and, accord
ingly, the chamber 56 containing the supply valve 70
58 is charged with fiuid under pressure from the `
.main reservoir I8 throughv the main reservoir-
pipe 22 andbranch pipe 51 while brake cylinders
I0 and |0a are vented to atmosphere by way of
- Pipe and passage 6I, chamber 53 of valve mech- 1I
8
-
2,170,237
anism II past the unseated release valve 62 and
exhaust port 63 so that the brakes associated
with the wheels fixed to the axles 9 and 9a are
all released. Under the conditions assumed,
front-contact member 2I9 of the differential re
lay 43 is in circuit-opening position and, conse
quently, the electromagnet 223 of the magnet
valve device 46 is deenergized so that the -brake
cylinder I 0 is connected through the magnet
10 valve device 46 to the chamber 59 of the valve
mechanism Il.
_`
With the handle |83 of the brake valve device
I5 in release position, connections are estab
lished through the brake valve device whereby
15 fluid under pressure is supplied from the feed
valve pipe 26 into the brake pipe 24 so that it is
accordingly charged with fiuid under pressure as
regulated by the feed valve 25.
From the brake pipe 24 fluid under pressure
20 flows to the automatic valve device I4 where it
acts on the operating piston thereof to condi
tion the automatic valve device to establish com
munications through which the auxiliary reser
voir 2| is charged with fluid under pressure from
25 the brake pipe 24 and the pipe I8I is vented to
`
atmosphere.
-
A Brake pipe pressure acting in chamber |68 of.
retardation controller I3 shifts the piston» A|67
against the opposing force of the spring |69 into
30 engagement with the stop shoulder |16 so that
the stop flange |15 ris positioned to initially ten
sion the spring I5@ of the retardation controller
for service applications of the brakes.
_
In order to obtain some idea as to the relative
35 fluid pressures in the various pipes and other
parts of the equipment, let it be assumed that the
main reservoir i9 is maintained charged to a
pressure of one hundred and twenty-five pounds
per square inch, that the feed-valve 25 regulates ,
the pressure supplied to the feed-valve pipe 23
an thus the pressure in the brake pipe 24 to a
pressure of one hundred and ten pounds per
square inch, that the maximum pressure which
may be established in the pipe |85 and thus _in
A15 the control pipe 23 for straight-air applications
is seventy-five pounds per sq. in., that the maxi
mum pressure which is established in the control
pipe 23 for automatic service applications of the
brakes is seventy-five pounds per sq. in., and that
50 the maximum pressure established in the control
pipe 23 for emergency applications of the brakes,
that is the pressure of equalization between the
auxiliary reservoir 2| and the control pipe 23,
is one hundred pounds per sq. in.
55 (b) Application of the brakes initiated at train
speeds in excess of a certain uniform speed
For simplicity, no attempt will be made to
specifically describe a straight-air application- of
the brakes, an automatic service application _of the
brakes, or an emergency. application of the brakes,
since the application of the brakes for any of
these types of application is initiated by charging
the control pipe 23 with fluid under pressure and
since a complete description of the various types
of application of‘the brakes, for an equipment
similar to that shown and describedherein, is
I given in the copending application of George W.
70 Baughman, Serial No. 126,375, filed February 18,
brakes, and that unless otherwise specified, the
pressure in the control pipe remains unchanged.
Let it now be assumed that an application of
the brakes is initiated when the train is travel
ing at a speed of one hundred miles per hour,
the governor switch device I2 being correspond
ingly in circuit-closing position and the relay 38
energized upon _the shifting of the contact mem-_
ber |96 of the pressure switch Il into contact with
the contact member |98. As previously pointed
out, the relay 35 is maintained energized, over a
holding circuit including its own front-contact
member 202, independently of the separation of
the contact member |90 of the pressure switch
I1 from the contact member |91. -
In view of the fact that the Contact finger |02
of the retardation controller I3 engages the con
tact segment |63 at the time the application of the
brakes is initiated, the engagement of the con
tact member |95 with the contact member |98 20. .
of the pressure switch I'I completes the circuit
previously described for energizing the electro
magnet 203 of the relay 30.
` `
With the electromagnets of the relays 30 and
38 energized and the electromagnet of the relay
31 deenergized, the circuits, previously described,
for energizing the electromagnets M38 and H0
of the magnet valve devices I9| and> |02, respec
tively, are completed.
Accordingly, fluid under pressure is supplied 30
from the control'pipe 23 and branch pipe and
passage 23a to the diaphragm chambers 93, 94
and 95~ under the control of the magnet valve
devices IllI,‘I02'and |03, respectively. Chamber
93 at the right of the smallest diaphragm lt, being 35
directly connected to the passage 23a is likewise
simultaneously charged to the pressure estab
lished in the control pipe 23.
-
'
Accordingly, it will be seen that the fluid
pressure forces exerted on opposite sides of the 40
diaphragms lli, ‘I5 and 16 are balanced, only the
largest diaphragm ‘I3 having an unbalanced fluid
pressure force acting thereon in the chamber 93.
Thus the diaphragm 73 is flexed and the slidable
member 66 shifted in the left-hand direction to
effect operation of the release valve 02 and the
supply valve 58, in the manner previously de
scribed, to supply fluid under pressure from the
main reservoir pipe 22 to the brake cylinders
50*
I0 and I0a.
The pressure of the fluid supplied to the brake
cylinders I0 and AIlla acts in the chamber 59 on
the left-hand face `of the follower disc 'lâ as
sociated with the largest diaphragm 'i3 and,
when the force of the fluid pressure in the cham 55
ber 59 substantially balances the opposing force
of the fluid _pressure in the chamber 93, spring
'II becomes effective to shift the slidable member
66 sufficiently in the right-hand direction to op- '
erate the supply and release valves 58 and 62 to 60
lap or close both the supply and the release com
’ munications so that the pressure established in
the brake cylinders I0 and Illa is substantially
equal and in a substantially one-to-one ratio to
the pressure established in the "control pipe 23. 65
Since a pressure of seventy-five pounds per sq. in.
is assumed to be established in the control pipe,
the pressure established in the brake cylinders
I0 and Illa will accordingly be seventy-five
70
'
,
In- the event of leakage of fiuid under pressure
from the brake cylinders I0 and I0a past the re
application. For further simplicity, it will be as
»lease valve 62 or in the event of reduction of
sumed that a certain fluid pressure, such as sev
enty-flve' pounds per sq. in., is established in the the pressure in the brake cylinders for any other
35 control pipe 23 to initiate the application of the reason, the higher unbalanced pressure main 76
1937, and assigned to the assignee of the present
pounds per sq, in.
1v1/mms ¿sr-emmene,
_- vvv
Ilvlu‘ ullvu
2,170,237
tained in the chamber 83 again becomes ef
,fective to cause unseating of the supply valve
58 to replenish the supply of fluid under pressure
to the brake cylinders from the main reservoir
pipe 22. Upon the restoration of the pressure in
the brake cylinders to a pressure corresponding
to the pressure in the control pipe 23, the supply
valve 58 is again seated. It will thus be seen
that the valve mechanism II operates to main
10 tain the pressure in the brake cylinders against
leakage.
As the train speed reduces from the initial high
speed of one hundred miles per hour, the contact
finger |62 of the retardation controller I3 is
15 gradually shifted in a counterclockwise direction
because of the increase in the rate of retardation
with the reduction in speed. When the contact
finger |62 leaves the range A of retardation rates,
that is, disengages from contact segment |63,
20 and enters the range B of retardation rates, the
circuit previously described whereby the electro
magnet of the relay 36 is energized, is interrupted
and the contact members 205 and 206 of relay
36 shifted to circuit-opening position. Assum
25 _ing that the speed of the train is still in excess
of the certain uniform speed of forty miles per
hour and that the governor switch device I2 is
accordingly in circuit-closing position to main
tain the electromagnet of the relay 38 energized,
30 it will be seen that electromagnet I I8 of the mag
net valve device |02 is maintained energized
through a circuit including the back-contact
member 208 of relay 31 and front-contact mem
ber 2I3 of the relay 38, independently of the
35 operation of the front-contact member 206 of
relay 36 to circuit-opening position, but that
electromagnet |08 of the magnet valve device |0I
is deenergized because the circuit therefor is
interrupted due to the shifting of the contact
40 member 205 of relay 36 into circuit-opening po
sition. As in the previous instance, the electro
magnet |28 of the magnet valve device |03 is
deenergized because the front-contact member
209 of the relay 31 is in circuit-opening position.
As a result ofthe deenergization of the elec
tromagnet |08 thereof, the magnet valve device
IOI is actuated to cut off the supply of fluid
under pressure to the diaphragm chamber 83 and
to release fluid under pressure therefrom through
the choke fitting II2. The restricted passage
in the choke fitting II2 may be any desired size
so that the rate of release of fluid under pres
sure from the chamber 93 may be. timed to a
desired rate. Obviously, upon the release of
fluid under pressure from the chamber 83, the
force acting on the largest diaphragm 13 and
urging the slidable member 66 in the left-hand
direction is diminished, so that the higher brake
cylinder pressure in the chamber 59 tends to
60 shift the diaphragm 13 in the right-hand direc
tion. At the same time the reduction of the
pressure in the chamber 93 causes a differential
fluid pressure force to be exerted in the left
hand direction on the diaphragm 14. However,
the differential fluid pressure force on the dia
phragm 13 is larger than the differential fluid
pressure force on the diaphragm 14 and conse
quently as the pressure in the chamber 93 re
duces, the spring 1| becomes effective to unseat
the release valve 62 and thus effect the release
of fluid under pressure from the brake cylinders
I0 and |0a, the rate of reduction of pressure in
the brake cylinders I0> and I0a being determined
according to the rate of reduction of the pressure
75 in diaphragm chamber 93.Í
9
When the fluid under pressure in chamber 93
has been completely vented to atmosphere, the
pressure in the brake cylinders |0 and |011V will
obviously be determined according to the force
exerted by the ñuid under pressure in the cham
ber 94 on the diaphragm 14 and urging the slid
able member 66 in the left-hand direction. Ob
viously, since brake cylinder pressure always acts
on the follower disc 18 having an area corre
sponding to the effective area of the largest dia
phragm 13 to oppose any force in the opposite
direction, it will be seen that the pressure in the
brake cylinders is reduced, upon the deenergiza
tion of the electromagnet I 08 of the magnet valve
device IUI, to a pressure which bears a certain
15
uniform ratio to the pressure established in the
control pipe, which ratio is substantially the
ratio of the effective area of the diaphragm 14
to the effective area of the diaphragm 13.
'I'he diaphragms 13, 14, 15 and 16 may, of
course, be of any desired area and relative areas,
but for simplicity let it be assumed that the areas
20
of the diaphragms 13, 14, 15 and ‘I6 are l, 3A, 1/2,
and 1/3 units of area respectively. Assuming then
that the area of the diaphragm 14 is three- _
fourths of the area of the diaphragm 13, the
pressure established in the brake cylinders I0
and I0a, upon the deenergization of the electro
magnet |08 of the magnet valve device |0I in
the manner just described, is in ratio to the ,
pressure established in the control pipe 23 as
three is to four. With seventy-five pounds sq. in.
pressure established in the control pipe 23, the
brake cylinder pressure is reduced to approxi
mately 56 pounds per sq. in.
Now let it be assumed that with the train speed
still remaining above the certain uniform speed
of forty miles per hour and notwithstanding the
reduction in brake cylinder pressure as just de
scribed, the further reduction of speed of the lo
train causes an increase in the rate of retarda
tion of the train such that the contact finger
|62 of the retardation controller I3 is shifted
out of the range B of retardation rate and into
the range C, wherein the contact linger engages
contact segment |64.'
The engagement of the contact finger |62 with
the contact segment |64 of the retardation con
troller establishes a circuit, previously described.
for energizing the electromagnet of the relay 31.
Consequently, the back-contact member 208 and 50
front-contact member 200 of the .relay 31 are
shifted to circuit-opening and circuit-closing
positions, respectively.
l
The electromagnet |I8 of the magnet valve
device |02 is accordingly deenergized due to the
interruption of the circuit thereof by shifting of
the back-contact member 208 of relay 31 to
circuit-opening position. The shifting of the
front-contact member 208 of relay 31 to circuit
closing position is without effect at this time since
the back-contact member 2I4 of the relay 38 is
still held in circuit-opening position, relay 38
remaining energized for train speeds in excess
of the certain uniform speed.
It Will thus be seen that where previously the
electromagnet I I8 of the magnet valve device |02
was energized, now the electromagnets of all of
the magnet valve devices IOI, |02 and |03 are
deenergized. As a result of the deenergization 70
of the electromagnet of the magnet valve device
|02, communication for the supply of fluid under
pressure to the diaphragm chamber 94 is closed
and the exhaust communication through the
choke fitting |22 is opened, thereby effecting the 75
10
2,170,237
release of fluid under pressure from the chamber
94 at a rate determined by the size of the re
stricted passage in choke fitting |2`2. As in the
case of the reduction of fluid under pressure in
the chamber 93, reduction of the pressure of ñuid
in the chamber 94 results in reduction of the
pressure of fluid in the brake cylinders I0 and
|0a at a rate determined according to the rate
of reduction of the fluid under pressure in the
10 chamber 94.
When the fluid under pressure in the chamber
94 is reduced to atmospheric pressure, the pres
sure established in the brake cylinders I0 and
I 0a is in substantially the same ratio to the pres
15 sure established in the control pipe 23 as the
effective area of the diaphragm 15 is to the
effective area of the diaphragm 13, that is on the
basis of the assumed areas of the diaphragms,
in the ratio of one to two. With a pressure of
20 seventy-five pounds per sq. in. established in the
control pipe 23, the pressure established in the
brake cylinders I0 and Illa at this stage of the
operation is accordingly approximately thirty
25
seven and one-half pounds per sq. in.
Let it now be assumed that with the brake con
trol equipment conditioned as just described, that
is, With the contact finger |62 of the retardation
controller I3 in engagement with the contact
segment |64 and a pressure established in the
30 brake cylinder which has a one-to-two ratio to
the pressure established in the control pipe 23,
the speed of the train reduces below the certain
uniform speed of forty miles per hour so that the
governorI switch device I2 is shifted to circuit
35 opening position to cause deenergization of the
electromagnet 2II of the relay 38. The conse
quent shifting of the back-contact member 2I4
of relay 38 to circuit-closing position, completes
the circuit previously described for energizing
40 the electromagnet |28 of the magnet valve device
|03, energization of Which results in the closing
of the supply communication to the 'chamber 95
and the opening of an exhaust communication
for releasing fluid under pressure from the cham
45 ber 95 through the choke fitting |32.
Keeping in mind that the chambers 93 and 94
have been previously reduced to atmospheric
pressure. the reduction of the pressure in the
chamber 95 results in the reduction of the pres
50 sure in the brake cylinders I0 and I0a at a rate
determined by the rate of reduction in pressure
in the chamber 95, in a manner similar to that
described With respect to the reduction of pres
sure in the chamber 93.
55
When the pressure of the fluid in the chamber
95 is reduced to atmospheric pressure, the cor
responding pressure established in the brake cyl
inders I0 and I0a is in ratio to the pressure
established in the control pipe 23 as the effective
60 area of the diaphragm 16 is to the effective area
of the diaphragm 13. Such ratio being assumed
to be a one-to-three ratio, the pressure estab
lished in the brake cylinders I0 and I0a for a
control pipe pressure of seventy-five pounds per
sq. in. is twenty-five pounds per sq. in.
Let it now be assumed that the reduction of
brake cylinder pressure just effectedis such as
to reduce the rate of retardation of the car or
train sufficiently that the Contact ñnger |62 of
70 the retardation controller I3 recedes toward its
normal position out of range C into the rang B,
of the relay 31. Electromagnet |28 of magnet
valve device |03 is accordingly deenergized due
to the interruption of the energizing circuit there
for by the shifting of the front-contact member
209 of the relay 31 to circuit-opening position.
The shifting of the back-contact member 208 of
the relay 31 to circuit-closing position is ineffec
tive to cause energization of the electromagnet
I I8 of the magnet valve device |02 due to the fact
that the front-contact member 2| 3 of the speed 10
relay 38 is in circuit-opening position.
It Will thus be seen that the electromagnets of
the magnet valve devices IOI, |02 and |03 of
the valve mechanism I I are again all deenergized
simultaneously so that the diaphragm chambers 15
93, 94 are at atmospheric pressure and the cham
bers 95 and 96 are charged to the pressure estab
lished in the control pipe 23. Accordingly, it Will
be seen that the valve mechanism II is operated
to resupply fluid under pressure to the brake cyl 20
inders I0 and I 0a to build up the pressure therein
to a pressure having a one-to-two ratio to the
pressure established in the control pipe, or ap
proximately thirty-seven and one-half pounds
per sq. in.
25
Should the contact linger |62 of the retardation
controller I3 recede suiiiciently toward its nor
mal position as to enter the range A and thereby
engage the Contact segment |63, a further in
crease in brake cylinder pressure is effected. It 30
Will be seen that such is the case because the en
gagement of the Contact finger I 62 with the con
tact segment |63 of the retardation controller
completes a. lcircuit, previously described, for en
ergizing the electromagnet of the relay 36, thus 35
causing the circuit for energizing the electromag
net I I8 of the magnet valve device |02 to be com
pleted through the back-contact member 2I4 of
the relay 38 and the front-contact member 206
of relay 36. The circuit for energizing the elec
tromagnet of the magnet Valve device |0| is not
completed despite the shifting of the front-con
tact member 205 of relay 36 to circuit-closing po
sition, because the front-contact member 2I2 of
the relay 38 remains in circuit-opening position.
Thus, with only the electromagnet I I 8 of the mag
net valve device |02 energized, diaphragm cham
bers 94, 95 and 96 are charged to the pressure
established in the control pipe 23, while only the
chamber 93 is at atmospheric pressure. Accord 50
ingly, an increase in pressure in the brake cyl
inder pressure is effected to the degree that the
pressure in the brake cylinders bears a three-to
four ratio to the pressure established in the con
trol pipe 23, or approximately fifty-six pounds 55
per sq. in.
If as the speed of the train further reduces, the
rate of retardation increases suiìciently, so thatl
the contact ñnger |62 of the retardation con
troller again leaves the range A of retardation 60
rates and enters either of the other ranges B
or C of rates of retardation, brake cylinder pres
sures corresponding thereto and previously de
scribed are established in the manner previously
described.
When the car or train is brought to a complete
stop, the contact linger |62 of the retardation
controller automatically returns to its normal po
sition in engagement with the contact ñnger |63 70
and thus the pressure established in the brake
thereby disengaging contact segment |64. Dis-, cylinders to hold the car or train at a standstill
engagement of the contact ñnger |62 from the
contact segment |64 interrupts the circuit previ
75 ously described for energizing the electromagnet
will bear a three-to-four ratio to the pressure
established in the control pipe 23, or approximate
ly fifty-six pounds per sq. in.
75
2,170,237
(c) Applications of the brakes initiated at train
speeds below the certain uniform >speed
If an application of the brakes is initiated at
a time that the train is traveling at a speed below
the certain uniform speed of forty miles per hour
so that the governor switch I2 is in circuit-open
ing position and the relay 38 controlled thereby
is accordingly deenergized, it will be seen that
the maximum brake cylinder pressure established.
will bear a three-to-foiir ratio to the pressure
established in the control pipe, as compared to
the maximum- or one-to-one ratio established in
the case of an application of the brakesinitlated
at a time that the train was traveling at a speed
15 in excess of the 'certain uniform speed.
It will be apparent that such is the case for with
the contact finger |62 in engagement with the
contact segment |63 of the retardation controller
410
is maintained energized until the pressure in the
control pipe 23 is reduced to the relatively low
pressure of one or two pounds per sq. in. and
suiiicient to cause disengagement of the Contact
member |96 from the contact ñnger |98. In
order, therefore, to permit immediate reduction
in brake cylinder pressure upon reduction in the
pressure in the control pipe 23 and also reduction
of brake cylinder pressure independently of the
magnet valve devices |0|, |02 and |03 of the
valve mechanism ||, the check valves 93a., 94a
and 95a are provided.
Thus, it will be seen that
veven though the magnet valve devices .|0|, |02
and |03 are conditioned to supply fluid under
pressure to the diaphragm chambers 93, 94 and 15
85, reduction of pressure in the control pipe 23
causes the higher pressure previously established
in the chambers 93, 94 and 95 to respectively un
' seat the check valves and thus effect equalization
20 I3 and with the electromagnet of the relay 36 of the pressure in the diaphragm chambers with
accordingly energized, only the electromagnet
20
the pressure‘in the control pipe. It will be ap
||8 of thel magnet valve device |02 is ener
parent
that
the
check
valves
93a,
94a
and
95a
gized, the energizing circuit including the back
function at any time during an application o1' the
contact member 2|4 of the relay 38 and the front
brakes to vary the pressure in the diaphragm
contact member 206 of the relay 36. The electro
magnet |08 of the 'magnet valve device |0| is -chambers 93, 94 and 95 in accordance with a
variation in the pressure in the control pipe 23
not energized, despite the shifting of the front
contact member 205 `oi relay 36 to circuit-closing so as to correspondingly vary the pressure in the
position, because the front-contact member 2| 2 brake' cylinders -|0 and |0a, without, however,
causing variation of the particular ratio in effect
30 of the relay 38'is in circuit-opening position.' at the time between the pressure in the brake
Electromagnet |28 of the magnet valve device |03
is not energized because electromagnet 201 of the cylinder and the pressure in the control pipe' 23.
If the car or`train is withdrawn from service,
relay 31 is deenergized and, consequently, the
front-contact member 209 of the relay 31 is .in obviously .it is not desirable that the wheel slip
relay 35 be permitted to continue inthe ener
35 circuit-opening position to interrupt the- circuit gized condition overthe holding circuit previously
for energizing the electromagnet of the magnet.
described. Accordingly a suitable switch (not
valve device |03.
'
l
As in the case of the deceleration of the train shown) may be provided for effecting deenergiza
from a speedin excess of the certain uniform_ tion of the electromagnet of the wheel-slip relay
speed
of forty miles per hour, after havingl been 35 when the car or train is not in operation.
40
reduced to speeds below forty miles per hour, the -(e) Wheel-slipping occurring during application
ratio between the pressure established in the'
of the brakes initiated at a time that the
brake cylinders |0¢and |0a and the pressure es
train speed is in excess of a certain .uniform
tablished in the control pipe 23 is determined ac
speed
45 cording to the position of the Contact ñnger |62
lAs thus iar described, it has been assumed, for
of the retardation controller I3 in range A, range
‘ B or range C of retardation rates. Thus, as the simplicity, that the application of the brakes was
not attended by a slipping or a sliding of any of
speed of the train reduces following'an applica
tion _of the brakes initiated atfthe time the train the wheels of the car or train, and in such re
50 is traveling at a speed below forty miles per hour, spect, the operation of the equipment shown in
_valve mechanisml || is automatically controlled Fig- 1 is substantially identical to that described
to vary the ratio between the brake cylinder for the embodiment shown in Fig. l of the Patent
pressure and the pressure vestablished in _the con--v 2,096,505 of George W. Baughman, above re
.
trol pipe according to the retardation of the train ferred to.
According to our invention, however, additional
55 being within range A, range B or range C of re
equipment is included in the embodiment shown
tardation rates. '
in Fig. 1V of the present `application for guiding
against sliding of the car wheels.
(d) Release of the brakes.
Let it, therefore, now be assumed that the ini
'I‘he brakes may be released at any time-by 11e
60 ducing the pressure in the control pipe 23 to 'at' tial pressure established in the brake cylinder |0
mospheric pressure, In such case, with all of they upon the initiation of an application of the brakes
diaphragm chambers 93,.94, 95 and 96 reduced when the train is traveling at a speed, such as
to atmospheric pressure, the spring 1| causes one hundred miles per hour, causes the wheels 8
associated with the more heavily braked axle l to
shifting of the slidable member 66 in the right
65 hand direction and the consequent operation of - begin to slip, that is’reduce in speed from a. ro
tational speed corresponding to the speed of trav
. the release valve 62 to completely release iluid
el of the train to a zero rotational speed corre
25
'
85
40' ’
50
55
under pressure from the brake -cylinder's I0 and » spending to a locked condition of the wheel. The
|0a, the valve mechanism Il thus being returned - actual slipping time, that is, the time over which
to the vposition shown in Fig. 1.
l
the wheels 8 decelerate from a rotational speed,
70
Upon the reduction of the pressure in the con
corresponding to the speed of travel of the train, 70
trol pipe 23 to atmospheric pressure, the _pres
to zero rotational speed is of appreciable magni
sureswitch |1 is operated s'o that the .contact tude, being in many cases of the order of one sec
member |96 is shifted out of contact with con
ond. Therefore, during the slipping time, cur
tact iìnger |98 and into contact with the contact- rent supplied from the generator 44, driven from
75. ñnger |91. Thus the electromagnet of relay 36 the axle 9, to the electromagnet winding 2|4 of 15
12.
2,170,237 .
the differential relay 43 decreases suñiciently that
the front-contact member 2 I9 and the back-con
tact member 2I8 of the relay 43 are actuated, re
spectively, to circuit-closing position and circuit
opening position.
Upon the shifting of the front-contact member
2 I 9 of differential relay 43 to said closed position,
the signal lamp 41 and the electromagnet 223 of
the magnet valve device 46 are energized over cir
10 cuits previously described. With the double beat
valve 22| of the magnet valve device 46 accord
ingly shifted to its lower seated position, ñuid
under pressure is immediately and rapidly vented
to the rotational speed corresponding to the speed
of travel of the train so that, as far as the wheels
8 associated with the axle 9 are concerned, wheel
sliding does not occur.
~
,.
-
When the wheels 8 on the axle 9 again attain a
rotational speed substantially equivalent-to the
rotational speed of the wheels 3a associated with
the axle 9a, the magnetic fluxes set up by the
separate electromagnet coils r2I6 and 2I1 again
substantially counterbalance each other andthe
relay contact members 2 I8 and 2I9 are shifted to
circuit-closing and circuit-opening positions, re..
spectively. Accordingly, the signallamp 41 is ex
from brake cylinder I0 to atmosphere through tinguished and electromagnet 223 of the magnet
the
exhaust port 221 of the magnet valve device -valve device 46 is deenergized due to the shifting
15
of the contact member 2I9 to circuit-opening
Because the holding circuit for the wheel-slip position. It follows that the double beat valve
22| of the magnet valve device 46 is correspond
relay 35 is maintained only when >the back-con
tact member 2I8 of the diiîerential relay 43 is in _ ingly returned to its upper seated position and
communication between the brake cylinder I0
20 circuit-closing position, it will be apparent that and the brake cylinder I0a is restored, so that the
the wheel-slip relay 35 is deenergized when the
y contact member 2 I8 is shifted to circuit-opening reduced pressure established in the brake cylin
der I0a is also established in the brake cylinder
position.
,
Keeping in mind that under the circumstances I0.
The return of the back-contact member 2 I8 of
assumed,
that
is,
an
application
of
the
brakes
ini
25
tiated at a. time the train is traveling at a speed the differential relay 43 to circuit-closing position,
in excess' of the certain'> uniform speed (40 however, is without effect at this time in eiïecting
re-energization of the electromagnet 20| of the
M. P. H.), and that the relays 36 and 38 are ac
cordingly energized initially, and the relay 31 is wheel-slip relay 35 because the contact member
|96 of. the pressure switch~ I1 is maintained in 30
30 deenergized initially to cause the establishment of
a brake cylinder pressure having a one-to-one its upper position in contact with the contact
ratio to the pressure established in the control finger |98 and out of contact with the contact
finger |91. It will thus be seen that once the dif
pipe 23, it will be seen that shifting of the front
contact member 203 of the wheel-slip- relay 35 to ferential relay 43 is actuated during an applica
tion .of the brakes to effect deenergization of the 35
35 circuit-opening position as a result of the deener
electromagnet of the wheel-slip relay 35, the relay
gization of the wheel-slip relay 35 as just de
Áscribed, interrupts the circuit for energizing the 35 is locked out against further energization even
electromagnet of the relay 36. Deenergization of though the differential relay 43 subseqhently re
turns to its normal position.
relay 33 results in the deenergization of the elec
As will be seen hereinafter, the only Way in 40
tromagnet |09 of the magnet valve device IDI, due
to the interruption of the energizing circuit for which the wheel-slip relay 35 may be subsequently
reenergized and the holding circuit therefor
electromagnet |09 by the shifting of the front
through its own contact member 202 established,
contact member 205 of the relay 33 to circuit
is by'reducing the pressure in the control pipe 23
opening position.
substantially to atmospheric pressure, which in
The electromagnet IIB of the magnet valve de
vice |02 remains energized, however, because the turn amounts to complete release of the brakes.
With the wheel-slip relay 35 thus locked in its
back-contact member 208 of relay 31 and the
front-contact member 2|3 of the relay 38 are in dee’nergizing position, the circuit for energizing
circuit-closing positions. The electromagnet |28 the electromagnet of the relay 36 is maintained
open at the contact member' 203 of relay 35, 50
of the magnet valve device |03 is not energized be
cause both th‘e back-contact member 2I4 of the and unless the wheel slip relay 35 is reenergized in.
relay 33 and the front-contact member 209 of the the manner just indicatedgthe maximum pres
sure attainable in the brake cylinders thereafter
relay 31 are in circuit-opening position.
that determined by the condition of the valve
As in previously described instances, with only is
mechanism II wherein only the electromagnet 55
the
eleotromagnet
I
I8
of
the
magnet
valve
device
56
H8 of the magnet valve device |02 is energized,
|02 energized, the valve mechanism iI is condi
tioned to reduce the brake cylinder pressure from or in other words a three-to-four ratio» with re
spect to the pressure established in the control
the initially established degree to a degree hav
pipe 23.
ing the next lower ratio with respect to the pres
As in the previously described operation where 60
60 sure in the control pipe, that is, a three-to-four
ratio. Still maintaining the assumption that the in no wheel-sliding occurred, the retardation
controller I3 continues to exercise control of
pressure established in the control pipe 23 is sev
brake cylinder pressure dependent upon the rate
enty-ñve pounds per sq. in., brake cylinder pres
46.
’
'
-
sure in the brake cylinder IIJav is accordingly re
65 duced "from the initial pressure of seventy-tive
pounds per sq. in. to a pressure of approximately
fifty-six pounds per sq. in.
Due to the rapidity of the response of the dilîer
ential relay 43 and the magnet valve device 43 to
70 the initiation of a wheel-slipping condition of
Wheels 8 associated with the~ axle 9, the pressure
in the brake cylinder I0 is reduced at a suñicient
ly rapid rate that before attaining a zero rota
tional speed corresponding to the locked position
75 thereof, the wheels 8 on the axle 9 accelerate back
of‘ retardation of the train being within range A,
range B or range C. -In view of the fact that the 65
relays 31 and 38 are controlled by the retarda
tion controller I3 and the governor switch device
I2 independently of the Wheel-slip relay 35, it will
be seen that the occurrence of a wheel-_slipping
condition for the wheels 8 associated with the
axle 9 at a time that the train is being retarded
at a rate Within the range B or the range C does
not result in a reduction of brake cylinder pres
sure from the particular ratio with respect to
the >control pipe pressure established under the 75
2,170,287
control of the retardation controller I3 and the
governor switch I2.
-
It will thus be seen that the equipment which
We have provided functions automatically to re
duce the braking force, as represented by brake
cylinder pressure, on all of the vehicle wheels im
mediately upon the occurrence of a wheel-slipping
condition on a particular set of car wheels which
are more heavily braked than the other car
10 wheels.
Being less heavily braked as compared
to the vehicle wheels 8, it follows that the vehicle
wheels 8a and the other wheels on the train can
not attain a wheel-slipping condition until after
a Wheel-slipping Y condition is attained on the
15 wheels 8.
Since the equipment whichwe have
provided vfunctions to prevent actual sliding of
the wheels 8, it will be apparent that except in
rare instances, sliding of the Wheels 8a and other
similarly braked wheels of thetrain cannot occur.
In the event that the reduction of pressure in
20
the brake cylinders |0and |0a, as automatically
' effected upon the slipping of the wheels 8 associ
ated with the more heavily braked axle 3, is in
sufficient to prevent re-occurrence of the wheel
slipping condition of the wheels 8 upon the resto
ration of the reduced pressure in the brake cylin
der I0, no further automatic reduction in brake
cylinder pressure is eiîected since the relay 35 is
locked in deenergized position. However, the
30 driver or operator, observing the illumination of
signal lamp 41, may effect a desired reduction
in the pressure of the control' pipe 23 and thus
correspondingly eiîect a reduction in brake cylin
der pressure, so that sliding of the wheels other
than the wheels 8 may be prevented if the oper-l
ator is on the alert and reduces the control pipe
pressure immediately upon the illumination of the
signal lamp 41.
-
In a similar manner if slipping of the wheels
40 8 associated with the axle 9 occurs when the
contact finger |62 of the retardation controller
Iis either the range B or range C of rates oi’ re
tardation, the _operator may reduce the pressure
in the control pipe and accordingly prevent slid
45 ing of the wheels of the train.'
(f) Wheel-slipping occurringv during application
of the brakes initiated at a time that the train
speed is less 'than a certain uniform. speed
50
As will be recalled from previous description,
the maximum initial brake cylinder pressure
i which can be established in the case of an ap
plication of the brakes initiated at a time that
the train is traveling at a speed below the cer
55 tain uniform speed of forty miles per hour is
Ilower than at speeds above this value. In this
case the governor switch I2 is in circuit-opening
position and the relay 38 is deenergized, only the
electromagnet | I0 of the magnet valve device |02
60 of the valve mechanism || then being energized
13
circuit including the back-contact member 2|4
of the relay 38 and the front-contact member
206 of the relay 36~ Thus, when the relay 36 is
deenergized, following the deenergization of the
wheel-slip relay 35 as result of the slipping of
the Wheels 8, the circuit for energizing the elec
tromagnet ||8 of the magnet valve device |02is interrupted due to the sluiting of the front
contact member 206 of relay 36 to circuit-opening
position. The relays 31 and 38 being deener
gized at this time, it will be readily apparent that 10
the electromagnets |08 and |28 of the magnet
valve devices |0|.and |03 are deenergized at this
time so that upon the deenergization of thel elec
tromagnet of the magnet valve device |02, the
electromagnet of each of the magnet valve de 15
vices |0i, i02 and l03 is deenergized.
As will be remembered from previous descrip
tions, the ratio established between brake cylin
der pressure and the pressure in the control pipe
23 by the valve mechanism | | under such circum 20
stances is a one-to-two ratio, which is the next
lower ratio to the three-to-four ratio initially
established. Thus the pressure of the ñuid in
the brake cylinder iûa and in the other similarly
controlled brake cylinders associated with other 25
Wheels of the train is automatically reduced from
a three-to-four ratio to a one-to-two ratio, with
respect to the control pipe pressure.
At the same time and inthe same manner 80
as previously described for slipping of the Wheels
8 while the train was traveling at a speed in ex
cess of the certain uniform speed of forty-miles
per hour, the signal lamp 41 is illuminated and
the magnet valve device 46 is actuated to vent
fluid under pressure from the brake cylinder |0. 35
Uponthe return of the wheels 8 to a rotational
speed corresponding to the speed of travel of
the train and substantially equivalent to the
rotational speed of the wheels 8a associated with 40
the axle 9a, the differential relay 43 is returned
to its normal position wherein the signal lamp
41 is extinguished and the magnet valve device
46 again establishes communication between the
brake cylinder |0 and the brake cylinder |0a.
Likewise, the return of the back-contact mem
ber 2|8 of the differential relay 43 to circuit
closing position is ineffective to cause re-ener
gization of the Wheel-slip relay 35, and the relay
35 accordingly remains locked in deenergized
condition.
'
Thus, as in the previous case, upon the slipping
of the wheels 8 the v_alve mechanism || is condi
tioned to limit the brake cylinder pressure to the
next lower ratio with respect to the pressure in
the control pipe 23, so that re-occurrence of the
wheel-slipping condition on the wheels 8 isy un
likely.
and, consequently, the maximum initial brake
If a slipping of the wheels 8 should occur while
the train is traveling at a speed below the cer-_
tain uniform speed. that is, while the governor
cylinder pressure which can be established is one
which bears a three-to-four ratio to the pressure
the train is being retarded, at a rate within either
established in the control pipe. With seventy
65 five pounds per square inch pressure in the con
trol pipe 23, such brake cylinder pressure- is ap
proximately nity-six pounds per square inch.
In the event that such initial brake cylinder
pressure is sumciently high that the braking
70 force exerted on the more heavily braked wheels
8 associated with the axle. begin to slip, a re
duction in the brake cylinder pressure is im
mediately eii'ected. As will be recalled, under the
conditions assumed, the electromagnet ||8- of the -
75A magnet valve device |02 is energized through a
ss'
switch |2 is in circuit-opening position, and while ’
the range B or range C, the wheel-slipping con
dition of the wheels 8 is indicated by the signal
lamp 41 but no automatic reduction in brake cyl
inder pressure is effected. However, as previously
described, the operator may manually effect a re
duction in the pressure of the control pipe 23 and
thereby reduce the pressure in the brake cylin
ders sumciently rapidly to prevent sliding of the 70
_ wheels.
EMBODIMENT SHOWN 1N Fra. 2
The embodiment represented by Fig. 2 is sub
stantially identical to the embodiment shown in 75
ida
aimee?
Fig. 1 and diders therefrom in the substitution
Vof a wheel-slip relay tta in the place of the wheel
slip relay 3,5 shown in Fig. 1.
Wheel-slip relay 35a diiïers fromv the wheel
control pipe, the pressure in the brake cylinders
l0 and I0a is reduced and limited to a one-to
two ratio with respect to the pressure established
in the control pipe.
As in the case of the wheel slip relay 35, the C1
Wheel-slip relay 35a. is locked in deenergized posi
tion once the differential relay 43 operates to
interrupt the holding circuit therefor through the
front-contact member 202 of the wheel-slip relay
slip relay 35 in having, in addition to the two
front-contact members 202 and 203, a contact~
member 300 which, when the electromagnet 20|
of the relay is energized, is shifted vfrom a lower
circuit-closing position to an upper circuit-closing
position. In its upper circuit-closing position. ` 435m. and, accordingly, as described for the em, ic
contact member 300 connects a Wire 26911. which bodiment shown in Fig. 1, the Wheel-slip relay
is connected to the contact segment i618 of the 35a cannot again be energized unless the pressure
retardation controller £3, to a wire 24th which in the control pipe 23 is reduced substantially
is connected to the non-grounded terminal of to atmospheric pressure to permit the contact
the electromagnet 20'? of the relay 3l. In the member ISB of the pressure switch il to re -15
15 lower circuit-closing position, 'thereof the contact
establish the initial energizing circuit for the
'
member 30G of relay 35a. connects a wire Msc, wheel-slip relay 35a.
Assuming that the wheel-slip relay 35a is de
Whichis connected to the positive terminal of
the battery le through the wires 235 and 23%, to energized in response to a slipping of the wheels
S during an application of they brakes initiated at 20
the wire Zilgb.
’
20
In operation, therefore, it will be seen that a time that the' train is traveling at a speed below
should the more heavily braked wheels 3 on the the certainA uniform speed as determined by the
axle 9 begin to slip during an application or' the governor switch device l2, it will be seen that the
valve mechanism ll is changed from the initial
brakes, the resultant deenergization of the wheel
condition thereof, wherein only the elecromagnet
slip
relay
35a
‘not
only
interrupts
the
energizing
25
circuit for the relay 30 due to the shifting of the H8 of the intermediate magnet valve device lili’
contact member 2&3 to `circuit-opening position, is energized by' way of the back-contact 2id of
but also eiîects energization of electromagnet 201> speed relay 38 and the front-contact 20e of the
of relay 3l by completing-the circuit from the relay 36, to the >condition wherein only the elec
positive terminal of the battery i8 to the wire tromagnet |28 of'the low magnet valve device 30
~30 Zfiâb through contact member 300.
103 is energized. It will be apparent that the
The eüect oi energizing the >relay 3l at the shifting of the front-contact member 23S of the
same time that the relay ist is deenergized, as a relay 35 to circuit-opening position eiîects de
energization of the electromagnet M8 of the in
result of the Wheels t beginning to slip, is to con
termediate magnet valve .device 602 and that
dition
the
valve
mechanism
il
to
limit
the
maxi
35
mum brake cylinder pressure, thereafter efîected, „ the shifting of the front-contact member 2t@ of
to the second lower ratio, with respect to the the relay 3l to circuit-closing position completes
¿control pipe pressure, as compared t0 the first vthe circuit for energizing the electromagnet H25
lower ratio relative to maximum initial ratio at ofthe low magnet valve device iBS.
Since the-¿maximum initial ratio between brake 40
the time that the application of the brakes is
initiated eüected in the embodiment shown in cylinder pressure .and pressure established in
the control pipe 23 for applications of the brakes
Fig. 1.
initiated at train speeds less than the certain uni
Should the more heavily bralsed wheels ß as
sociated with the axle d begin to slip upon the form speed of forty miles per hour, is a three-tof
initiation of an application of the brakes at a four ratio, it follows that in the event of slipping
45 time that the .train is traveling at a speed in of the wheels â, the valve mechanism H is auto
excess of the certain uniform speed of which matically conditioned to limit the brake cylinder
the governor switch device l2 is in circuit-clos-- pressure to a one-to-three ratio with respect to
ing position, it will be Yseen that the shifting of the control pipe pressure.
In view of the fact that the embodiment of the 50
the contact member 205i of the relay d@ into cir
50 cuit-opening position interrupts the circuit for invention represented in Fig. 2 functions in other
energizing the electromagnet ldd of the' high respects as does the embodiment shown in Fig. 1,
magnet valve device §06 and that the shifting of such operation is not repeated herein.
the contact member 208 of the relay valto circuit
EMBODIMENT SHowN 1N Fics. 3 AND Ãi
opening position interrupts the circuit for ener
55
55
gizing the electromagnet l l0 of the magnet valve
The embodiment shown vin. Fig. 3 is identical
with the embodiment shown in Fig. 1A in many
device H32. In view of the fact that the back
contact member 2id of the speed relay 3@ is held respects and diii‘ers from the equipment shown
in circuit-opening position, the closing of the in Fig. 1 principally in employing a diñerent type
front-contact member 20@ of relay 3l is without of mechanism for detecting slipping of the more 60
heavily braked wheels â associated with the axle
effect and the electromagnet’igâ of the low mag
net valve device 803 is accordingly deeenergized. 0. The representation of the embodiment shown
in Fig. 3 is accordingly limited to only those ele
Thus, when the wheel-slip relay 35a, is de
energized in response to a slipping of the wheels ments which are required to point out the man
ner of application and operation of the different 65
65 8, the valve mechanism il is changed from the type of wheel-slip detecting means.
initial condition thereof wherein the electromag- .
The equipment employed in the embodiment
nets of the magnet valve devices lûl and db2 are
energized and the electromagnet of the magnet shown in Fig. 3 which is not employed in the
valve device' its is deenergized, to the condition embodiment shown in Fig. 1, includes a wheel
.wherein
the electrcmagnets of all the magnet slip detecting device 340, a so-called brake cyl 70
70
valve Vdevices lili, ldd and i03- are deenergized. inder pressure switch device 3H, and in place
Thus, assuming that the brake cylinder pressure of thewheel-slip relay 35, two relays 35h and
`
initially established in the brake cylinders l@ and 35e, respectively.
The wheel-slip detecting device 3l0 may com
. lila had reached its full initial one-»to-one ratio
prise an inertia element in the form of a .dy- «gg
75 with.v respect to the pressure established in the
9,170,237
wheel 3 I 5 mounted for rotation relative to a shaft
rotating with the wheels 3, such as the axle 3, by
15
the spring 336 is overcome and the piston 33| and
roller or ball bearings in the manner shown, a
the contact member 333 are shifted upwardly, the
suitable material and are secured at one end, as
a front contact member 233b, two back-contact
members 34| and 342 and a contact member 343.
contact member .333 disengaging the contact
pair of resilient contact fingers 3I6 and 3I6a ' member
engaging an upper contact mem
carried in insulated relation on the ily-wheel 3| 5, ber 331. 336 and
’
ì
-and a torque arm 3I1 fixed to the axle 3.
The
relay
35b
comprises
an
electromagnet
23'Ib,
The contact iingers 3I3 and 3I3a may be of any
by screws 3I3, to an insulating member 3I3 af
10 iixed to the ily-wheel 315 near the- periphery
Thel contact member 343 has a lower circuit- '
closing position when the electromagnet 2Mb is
thereof and extending in parallel relation to the deenergized,
an upper circuit-closing posi 10
axle 3. 'I'he contact lingers 3I6 extend in paral Vtion when theand
electromagnet
2Mb is energized.
lel spaced relation past opposite sides of the axle
The relay 35e comprises an electromagnet'~23lc,
3 and have ~suiiîlcient inherent vresiliency or -are
15 biased by spring means (not shown) so that the
free ends of the lingers engage in circuit-clos
ing contact.
.
The torque arm 3 I 1 comprises a hub portionv 32I
^ lilxed as by a key 326 to the axle 3 and a laterally
extending portion 322 of T-shape,- located in
alignment with and extending into the space
betweenthe contact _lingers 3I3 and 3I3a, the
width of the portion 322 conforming closely to
a iront-contact member 344 a'nd a back-contact
member 345.
_
'I'he centrifuge I 4I of governor switch device 15
I2 is driven according to the speed ‘of travel
of the car or train, as through gears_36I con
necting the centrifuge to any element which ro
tates according to the speed of the car or train,
such as the axle 9a to which are fixed the more
lightly braked wheels 3a.
The control circuits of the embodimentv repre
sented in Fig. 3 are substantially identical to the
control circuits of the embodiment shown in
The contact fingers 3I6 and 3`I_3a are so de- .
Fig. 1 and already described and for the sake
signed and so tensioned that as long as the >axle of simplicity, only the differences relative to the
3 is not ,rotatively accelerated or deceleratcd with embodiment shown in Fig. 1 will -be pointed out.
respect to the fly-wheel I5 at a rate in excess
of the brushes 326 associated with the col
of a certain rate, the contact fingers 3I6 and One
lector ring 323 on the axle l9,is connected by a
3I6a remain in contact with each other against' wire 352 to a wire 353 which is in turn connected 30
ythe torce exerted to cause rotation of the iiy
to the contact member |91 of the pressure switch
wheel 3I5 with the axle 3 and wheels 3, through
the medium of the torquevarm 3I1 and one of I1. The other brush 326, associated with> the
collector ring 323:1, is connected to one terminal
the contact lingers 3I6 or 3I6a. If the axle 3 is of
the electromagnet 2Mb _of the relay 35h by a
rotatively decelerated ata rate in excess of the wire_354 and tlie opposite terminal of the electro
certain rate, as when the wheels 3 ilxed to the magnet 2Mb is connected to the negative ter
axle 8 begin to slip, the .force exerted on one minal of the battery I3, as through a ground con
of the contact lingers' 3I6 and 3I3a by the torque nection including the wire 234. It will thus Vbe v,
arm 3I1 is suiiiciently great to cause separation seen, that with the contact fingers 3_I3 and' 3I6ay
of the contact lingers 3I6 and 3I3a and interrup
of the wheel-slip detector 3|@ in circuit-closing 40
tion of a circuit controlled thereby.
-contact and with 'the contact member |36 oi' the i
In view of the fact that contact lingers 3IIìv pressure switch I1 in engagement with the con
and 3 I6a rotate with the ily-wheel 3I5, it is neces
tact member |91, Va circuit is »established for en
sary to 4provide a pair of collector rings 323 and ergizing
the electromagnet -of the relay 35h.
323a mounted in insulated relation on the axle
The contact member 333 of the brake cylinder
9 and connected to the contact fingers 3I6 and pressure switch 3II is connected'to the positive
3I6a, respectively, as by wires 324 and 325, and , terminal of the battery I3 by a wire 366 and the
a pair of suitably mounted brushes 326' cooper
236 and 23|. 'The _contact member 336 of
ating respectively with the collector rings 323 and wires
the pressure switch 3II is connected by a wire to'
323a.
351 to the contact member 344 of .the relay- 35e
'I'he brake cylinder pressure switch 3II is sim
and to the contact member 34I of the relay 35h
ilar in construction to the pressure switch I1 by the wire 351- and a branch wire 356. The con
‘,andymay comprise a casing'containing a piston - tact member 331 of the pressure switch 3II is
33| having a stem 332 connected in insulated re
connected to the contact member 342v of the .re-I`
lation to a movable contact member 333. -The lay 35b by a Wire- 358.
.
piston 33I is subject at one side to the pressure
In its circuit-closing position, the contact mem
o1' i‘luid in a chamber 334 which is connected,
34| oi' the relay 35h connects the wire 353 to
through a branch pipe 3Ib,l to that portion of aberwire
to which lone terminal of the -electro
the pipe BI connecting the magnet valve device magnet36|
of the relay 35e is connected, the other
46' to the brake cylinder III associated with the terminal
of the electromagnet of the relay 36c
more heavily braked wheels 3. Movement ot the being connected to the negative terminal oi' >the
piston 33| by the pressure of the fluid'in thebattery I8 as by -a connection through ground in
chamber 334 is yieldingly resisted by a spring 335 the manner indicated. It will thus be seen that
at the opposite side of the piston. The tension
with the contact member 333 of the pressure
of the 'spring 335' is such that when the pres
switch
I engaging the contact member 336, and
sure in the chamber 334 and thus in the brake with the3|wheel-slip
relay 35h deenergized and the
cylinder I0 is below a certain uniform' pressure, l» contact -member 34| thereof in .circuit-closing
such as ilve pounds per square inch,- and sui!-v
a circuit is completed for energizing the
ficient to relieve slipping of the wheels 3- under position,
electromagnet
relay 36e. In its circuit
any condition, piston 33I is actuated downwardly closing position,ofthe
the contact member 344 ofthe
to the position shown wherein the contact mem
relay 36e connects the wire A351 to a wire 363
ber 333 engages a lower contact member 336. _
When the pressure of the Iluid in the chamber which is connected to the wire 236 and thus to
the positive terminal of the battery I3. 'Accord
334 exceeds the said certain uniform pressure, ingly,
it will be seen that once the electromagnet
the' distance between the inner faces of the con
(See Fig. 4.)
25 tact tlngers 3I6 and 3I3a.
l
r
,
A1 6
'
_
9,170,223?
oi relay 35e is energized, a holding circuit is /shown'in'
established for maintainingthe relay energized
independently of the pressure switch 3H, the
holding circuit extending from the positive ter
Wl minal of the battery I8 through the contact mem
ber 344 of the relay 35o, wires 351 and 358, con
tact member 34| of the relay 35h, electromagnet
of the relay 35e, and thence to the _negative ter
minal of the battery i3 through ground.
`
10 „ In itscircuit-closing position, the contact mem-
l to control the degree of the ap
plicationoi vthe brakes.
v
Keeping in mind that the holding circuit
through the contact member 343 of the relay
35h includes the contact fingers 3|3 and 3|6a of
the wheel-slip detector 3|0, it will be seen that A
should a separation of the contact lingers 3|3
and 3|5a occur as the result oi the initiation of
a slipping of the wheels 8 associated with the
axle 9, the relay 35h will be deenergized. Accord
ber 342 'of the relay 35h connects the wire 353 to , ingly, since the contact member 333 of the brake
a wire 365 which is, in turn, connected to the
back-contact member 345 of the relay-35e. lIn
its. circuit-closing position, the back-contact
' - member 345 of the relay 35o, 'connects the wire
335'to a' wire 358 to which one terminal of the '
'electromagnet oi the magnet valve device 46 is
connected, the otherv terminal of the electromag
net of the magnet valve device 46 being connected
cylinder pressure switch 3H is in its upper posi
tion engaging the contact member 331, the return
of the back contact member 342 of the relay 35h
to circuit-closing position completes a. circuit pre
viously described for energizing the electromagnet
of the magnet valve device 46, which is kaccord
ingly operated to immediately and rapidly vent
ñuid under pressure from the brake cylinder Il
applying the brakes to the wheelsB. At the same
through a- ground connection in the manner time, the shifting of the contact member 343,01'
shown. Thus, withA the contact member- 333 of - the relay 35h to its lower circuit-closing position
the pressure switch 3|| engaging the contact causes the signal lamp 41 to be. illuminated to in
_ member 331,’and with the back-contact members dicatethe slipping of theV wheels 3. .
25 342 and 346 o! the relays 35h and 35e, respec
At the Sametime also, the shifting of the iront
tively, both in circuit-closing position, it will be„ contact member 20317 of the relay 35h to circuit
seen thatI a circuit is completed for energizing the openingvpositicn, interrupts the circuit through
electromagnet of the magnet valve device 46.
the contact iìnger I 62 and contact segment |33 of >
go‘to the negative terminal ofthe battery i3, >as
Once the eleetromagnet 2Mb of_ the relay 35h _ the retardation controller i3 whereby the relay
36 was energized, ,thus effecting deenergization
is energized and the contact member 343 of relay
35h actuated toits upper circuit-closing position,
a holding circuit is established for maintaining
the relay 35h energized, independently -oi> the‘ 'separation of the-- contact member |33 of the pres
sure switch I1 `from-the contact member |91, it
of the high train wire 3| in the same manner as
previously described for shifting of the contact`
member 203 of thel relay 35 oi' Fig. l to circuit
opening position upon a slipping oi the wheels l.
Accordingly, the valve mechanism || is condi
beingapparent that in its circuit-closing position, -_tioned to’limit'the subsequent pressure for the
. the contact-memben343 of the relay 35h con
Vbrake cylinder Illa, as wellas the brake cylinder ì
' nects the wire 23E and thu's the «positive terminal
. oi the battery I3 to the wire 353 and thus to the
I0 to a degree corresponding to the next lower
ratio with respect to the pressure established in
the control pipe 23. On the basis of the ratios
between brake cylinder pressure and control pipe
pressure determined by the valve mechanism Il
as previouslyassumed, it will be seen that the
valve mechanism. Il is conditioned to limit the
subsequent maximum ratio between brake cyl
wire 352 leading to that one'oi the brushes 326
‘ associated with the collector ring 323 of the
, `wheel-slip detector device 3|0. When the electro
magnet of the relay 35h is deenergized and the
contact‘member 343 shifted to its lower circuit
closing position,- a circuit is completed from the
positive terminal'of the battery I8 through the
wire 238, contact member.l 343 of relay 35h, a
wire 388, signal lamp 41, a wire 339 which is con
inder premure and the pressure‘ in the control
pipe 23 to a three-to-four ratio insteadof themaximum or -one-to-one ratio.u
riected to ground, and back through ground to
When the reduction of the pressure ofthe fluid
5@ the negative terminal of the battery se. since ' in the brake cylinder Gd, as eñected by the mag
the relay 35h is normally energized, it will _be net valve device 6€, is sumcient to cause the
apparent that the signal lamp tl is normally ex- y wheels 8 to accelerate back toward a rotational
tinguished and that it is illuminated only upon speed corresponding to the speed of travel of the
the deenergization of the relay 35h as a result of train and the pressure switch 3M is correspond
'
separation of the contact fingers 3|@ and äiödof ingly actuated from its upper to its lower circuit
tine wheel-slip >'detector device 3m.
closing position wherein the Contact member 333
thereof engages contact member 333; the circuit
Operarios. or Ennonmnnr snows nv Fre. 3
through the back-contact member 34| oi the re
rt is deemed unnecessary to describe 1n emu lay 35h, previously described, is completed and
the operation of the embodiment represented in the electromagnet of the relay 35e is energized.
- @n
` Fig. 3, since this would in large measure repeat
-what has already-` been described inconnection
with the embodiment Ashown in Fig.' l. , So far
possible, therefore, onlyV those diüerenées .oi
ves as
operation rœulting from the employment of the
wheel-slip detector Si@ will be pointed out._
, therefore, that the train is traveling
at aspeed. or, for example, one hundred miles per
hour and that an application of the brakes has
- been initiated by supplying uuid lat _a pressure oi
,
@cv-.
At the same tmie, the electromagnet of the mag
net valve device 46 is voleenergizeda due to the in
terruption of the energizing' circuit therefor by
the separationof the contact member 333 of the
pressure switch 3H from the contact member
' 33?, and due-to the energization of the relay Sic
and the consequent establishment of the holding
circuit therefor through the contact member 344
of the relay 35e and the back-contact member 84B
of the relay 35h, previously described, the rmgnet
valve device 43 is prevented from being further
seventy-uve pounds per square inch to control
energized es long as the relay 35h remains deen- ~
pipe 23, it will be apparent that the valve mecha
ergized, due to'the back-contact member 345 of
nism li is controlled in identically the same man
P55 ner m previously described _for the embodiment
relay 35e being held in circuit-opening position.
Reengagement oi the contact ñngers3|6 and
2,170,237
3|6a of the wheel-slip detector 3|0, following the
return of the wheels 8 of the rotational speed
corresponding to the speed of travel of the train
is, however, ineffective to cause re-energization
of the relay 35h since with the seventy-live
17
two ratio with respect to the pressure established
in the control pipe 23.
AIt will be apparent that, upon the slipping of
the wheels 8, a two-step reduction in the ratio
between brake cylinder pressure and the pres
sure in the control pipe 23 may be effected in the
embodiment shown in Fig 3 instead of a one
step reduction by adding an additional contact
pounds per square inch pressure maintained in
the control pipe~23, the contact member |96 of
the pressure switch | 1 is out of engagement with
the contact member |91. Thus, the initial cir `member to the relay 35h, corresponding to the
cuit for energizing the relay 35h cannot be com
contact member 300 of the relay 35a shown in
pleted unless the pressure in the control pipe 23 is Fig. 2, whereby relay 31 will be energized at the l0
reduced substantially _to atmospheric pressure, same time that the relay 36 is deenergized.
and the brakes thereby substantially released, to
permit the Contact member |96 to reengage the
15 contact member |91, in which case the relay 35h
`is energized so that the holding circuit therefor is
again set up through the contact member 343 of
the relay 35h, and the signal lamp 41 is extin-l
guished.
20
If, upon a slipping of the wheels 8, the engine
man or operator of the car or train does not re
duce the pressure established in the control pipe
23, the relay 35h accordingly remains deenergized
and consequently the relay 35e remains energized
25 over the holding circuit including the front-con
tact member 344 of the relay 35e and the back
contact member 34| of the relay 35h, regardless
of the fact that the contact member 333 of the
brake cylinder pressure switch 3| | is again shift
ed, by the restoration of pressure in the brake
-cylinder I0 following the deenergization of the
magnet valve device 46, out of engagement with
the contact member 336. With the back-contact
member 345 of the relay 35e thus held in circuit
35 opening position, the reengagement oi’ the con
tact member 333 of the pressure switch 3| | with
the contact member 331, as a result of the resto
ration of the pressure in the brake cylinder I0, is
ineffective to complete the circuit for energizing
40 the magnet valve device 46. Thus, the magnet
valve device 46 remains deenergized for the re
mainder of the application of the brakes, assum
ADAPTION or INVENTION 'ro A TRAIN BRAKE CONTROL
SYSTEM
The manner in which our invention is adapted
to control the brakes on a train of cars of either
the articulated or the non-articulated type should.
be readily apparent. Obviously, the brake cylin
ders for applying the brakes on wheel-and-axle
units not shown in the drawings are respectively
under the control of valve mechanisms corres
ponding to the valve mechanism I |, the magnet
valve devices |0I, |02, and |03 of each valve
mechanism being respectively connected to the 25
train wires 3|, 32 and 33.
Furthermore, it should be obvious that addi
tional governor switch devices similar to the gov
ernor switch device |2 shown in the drawings may
be privided in _parallel connected relation for 30
insuring the proper control of the valve mechan
isms || in the event of failure of one of the gov
ernor switch devices.
It will be understood that instead of providing a
main reservoir pipe 22 in the manner shown, 35
local supply reservoirs may be provided at inter
vals along the length of the train, and charged in
any suitable manner either from the brake pipe
or from another supply pipe whereby an adequate
and immediately available supply of iiuid under 40
pressure is assured for each brake cylinder along
the length of the train.
~
‘ lng nor reduction in the established pressure in
45
the control pipe 23, so that the pressure reestab
SUMMARY
lished in the brake cylinder |0 bears thelnext
summarizing, it will be seen that we have dis
lower ratio from the maximum ratio with respect closed several embodiments of a brake control 45
to the pressure established in the control pipe equipment effective to control the application of
23
If slipping of the wheels 8 occurs upon an ap- ' ` the brakes automatically both according to the
50 plication of the brakes initiated at a time that speed of the train and according to the rate of
retardation of the train, and including means
the train is traveling at a speed less than the cer
whereby the degree of the application of the 60
tain uniform speed of forty miles per hour as
is automatically and rapidly decreased
determined bythe setting of the governor switch brakes
and limited to a reduced degree upon the occur
device I2, the deenergization of the relay 35h as rence of wheel-slipping, so as to prevent wheel
55 a result of the separation of the contact fingers
slipping and so as to render recurrence of wheel 55
3| 6 and 3|6a of the wheel-slip detector 3||J oper
'slipping unlikely.
altes',~ in the same manner as does the opening of
By associating wheel-slip detecting means with
the contact member 203 of the relay 35 of Fig. 1 a particular set of wheels which is more heavily
60 under the same condition, to so condition the braked than the remaining sets of wheels on the
valve mechanism | | as to limit the brake cylinder train, the automatic reduction and limitation of
pressure to the next lower ratio with respect to the degree of the brake application precedes the 60
~the pressure in the control pipe 23. As will be possible occurrence of the wheel-slipping or
recalled from the operation of the embodiment wheel-sliding condition on the sets of wheels
shown in Fig. l, the maximum initial ratio be
other than the -more heavily braked set' of wheels.
tween brake cylinder pressure and the pressure in
The embodiments shown in Figs. 1 and 3 effect 65
the control pipe 23 when the application of the a certain reduction- in brake cylinder pressure
brakes is initiated~ at a time that the train is from that established initially when a slipping of
the more heavily braked wheels occurs, While the
traveling at a speed less than said certain uni
embodiment shown in Fig. 2 causes a greater
70 form speed of forty miles per hour is a three-to.
vfour ratio. It will thus be seen that slipping oi’ ' reduction in brake cylinder pressure upon a slip
the wheels 8 in the embodiment shown in Fig. 3`
will similarly cause the valve mechanism || tobe
conditioned to limit brake cylinder pressure dur
75 ing the remainder of the application to a one-to
70
ping of the more heavily braked wheels.
It will be understood that while we have shown
and described our invention Illustratively in cer
tain speciñc forms, certain omissions, additions
or modifications may be effected in the embodi
75
i8
ments shown without departing from the spirit of
our invention. It is accordingly not our inten
tion to limit the scope vof our invention except as
it is necessitated by the scope of the prior art.
Having now described our invention, what we
claim as new and desire to secure by Letters »Pat
ent is:
_
l. In a vehicle or train brake system, in com
bination, brake control means for controlling the
10 degree of braking _force with which the brakes are
applied, means responsive to the speed of the
train, >means operatively responsive only to the
. slipping of a vehicle Wheel, the speed-responsive
means and the wheel-slip `responsive means being
l5
>
jointly eiîective‘to control
the operation -of 'the
_
brake control means.~
2. In a car or train brake-system, in combina
tion, brake control means adapted to control the
_supply and release of _fluid under pressure for
controlling the degree _of braking force with
ously conditioning the brake control means as
to cause it to eiîect one of said certain ratios at
one rate of retardation and a diiîerent one of
said certain ratios at another rate of retardation,
means responsive to variations in the speed of
the train for variously conditioning the brake con
trol means to cause it to establish different ones
of said certain ratios between the brake cylinder
pressure and the pressure inthe said pipe de
pendent upon the speed of _the train, and means l0
responsive to the slipping of a vehicle wheel for
also varying the condition of the brake control
means to cause it to establish diiîerent ratios be
tween the brake cylinder pressure and the pres- .
sure in the said pipe thanthat determined mere
ly-under the control of the retardation-respon
sive-means and the speed-responsive means. '
6. In a vehicle or train brake system, in com
bination, a ñrst brake cylinder for effecting-ap
’ plication of the brakes on one wheel of the train,
which >the-brakes are applied-means responsive to » a second brake cylinder for' eiîecting application
of the brakes on a second wheel of the train,
brake control meansior controlling the supply
sive to the speed of the train, and means opera
tively responsive only to the slipping of a car of ñuid under pressure to and the release of fluid'
wheel,
the retardation-responsive means, the under pressure from» both of said brake cylinders,
25
speed-responsive means, and the wheel-slip means responsive to the slipping oi said one train
responsive means all being effective to control the wheel, independent means controlled by the said
Wheel-slip responsive means and eiîective upon
operation of the brake control means.
the slipping of the said one wheel for rapidly re
3. In -a vehicle or train brake system, in com
ducing the pressure in only the said ñrst brake 30
bination,
a
brake
cylinder,
a
normally
uncharged
30
cylinder
to prevent sliding of ‘the said one wheel,
pipe chargeable with fluid under pressure, brake
control means variously conditionable to cause a said brake control means being controlled by
plurality of certain diiîerent uniform ratios the wheel-slip responsive means so as to reduce
between the pressure established in the said pipe ` the pressure in the second brake cylinder and to
. the rate of retardation of the train, means _respon
35 and the pressure in the brake cylinder, means
responsive to the rate of retardation of the train
for conditioning said brake controlmeans diiîer
ently for different rates of retardation of the'train
and thereby causing different r-atios between the
40 pressure established in the control pipe and the
pressure in the brake cylinder, and means opera
tively responsive only to the slipping of a vehicle
wheel for conditioning the said brake control
means to cause it to establish a lower ratio
45 between the pressure in the brake cylinder and
the pressure in the said pipe than that effected
under the sole control of the said retardation
responsive means.
4. In a vehicle or train brake system, in com
50 bination, a brake cylinder, a normally uncharged
pipe chargeable with fluid at different pressures,
limit the pressure obtainable in both the brake Y en
cylinders for the remainder of the -application
of the brakes after slipping of the said one wheel
ceases, to a maximum pressure which is less than
the brake cylinder pressure at the time that the
Ain
said one train wheel begins to slip.
7. In a vehicle or train brake system, in corn
Abination, a ñrst brake cylinder for eiïecting ap
plication of the brakes on one wheel of the train
with a certain degree of braking force for a given
pressure in the brake cylinder, a second brake
cylinder for eiîecting application of the brakes
on a diiîerent wheel of the train with a lesser
degree of braking force for the said given pres
sure of iluid therein, brake control means for
controlling the supply ñuid under pressure to r
and the release of fluid under pressure from both
of said brake cylinders, means responsive to the
brake control means veriously conditionable to
effect a plurality of certain different uniform slipping of the said one train wheel, independent
ratios between the pressure established in the means controlled by the said wheel-slip responsive
said pipe and the pressure in the brake cylinder. lmeans and effective upon the slipping of the
means responsive to the speed of the train for said one Wheel for rapidly reducing the pressure
variously conditioning said brake control means> in only the said first brake cylinder to reduce
to cause it to establish one of the certain uniform the degree of braking forcel on the said one wheel
ratios at one speed and another of said uniform and thus to prevent sliding of the said one wheel,
said brake control means being controlled by the
60 ratios at another speed, andmeans responsive to wheel-slip responsive means so as to reduce the
the slipping of a vehicle wheel for varying the
condition of the said brake control means to pressure in said second brake cylinder and to
effect a diiîerent ratio between the pressure in the limit the maximum pressure attainable in both
brake cylinder and the pressure established in the brake cylinders for the remainder of the ap
the said pipe than that determined solely under plication of the brakes after slipping of the said
the control of -the said speed-responsive means. one wheel ceases to a pressure which is less than
the maximum initially attainable prior to the
5. In a vehicle _or train brake system, in com
bination, a brake cylinder, a normally uncharged slipping of the said one train wheel.
8. In a vehicle or train brake system, in' com
pipe chargeable with fluid at diiîerent pressures,
bination, a brake cylinder for effecting appli
a
brake
control
means
variously
conditionable
to
70
cation of lthe brakes on a vehicle Wheel, brake
cause a plurality of certain different uniform
ratios between the pressure established in the control means variously conditionable to control
said pipe and the pressure established in the the degree of the pressure in the said brake cyl
brake cylinder, means responsive to variations inder, means operatively responsive to the slip
ping of the said vehicle wheel, independent means
75 in the rate of retardation of the train for vari