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Nov. A_12, 1946.
w. A. l-:AToN'
2,410?,966
BRAKE MECHANISM
Filed April 29, 1943
wigfred A. Eatøw.
W*
71. „Q 62W
2,41`0,966
Patented Nov. 12, 1946
UNITED STATES PATENT OFFICE
2,410,966
BRAKE MECHANISM
Wilfred A. Eaton, Elyria, Ohio, assignor to
Bendix-Westinghouse Automotive Air Brake
Company, Elyria, Ohio, a corporation of Dela
Ware
Application April 29, 1943, Serial No. 485,054
8 Claims. (Cl. 303-54)
1
.
This invention relates to control mechanisms
and more particularly to remotely controlled
?uid pressure operated mechanisms especially
adaptable for use in connection with motor ve
hicles.
2
o
ence being had for this purpose to the appended
claims.
i
'
In the drawing, a fluid pressure control system
embodying the features of the present invention
is illustrated as including a ?uid pressure reser
voir 4, a fluid pressure actuator indicated gen
It has heretofore been proposed to employ fluid
erally as 5, and a control valve mechanism 6 of
pressure operated, remotely controlled mecha
the so-called self-lapping graduating type, which
nism for controlling and actuating various of
is preferably constructed in accordance with the
the control elements of automotive Vehicles, and
apparatus of this charaoter is especially suitable 10 principles set forth in the patent to W. J. Andres,
and R. S. Sanford No. 2,133,275, dated October
and adaptable to motor Vehicles of the type
18, 1938. The actuator 5 is provided with a cyl
wherein the elements to be controlled are posi
inder 'l and a piston 8 slidably mounted therein,
tioned at a considerable distance from the opera
the piston being providedwith a piston rod 9
tor of the vehicle. Dif?culty has been experi
ada-pted to impart motion from the piston to a
15
enced in many of the mechanisms previously
vehicle controlling element IO.
proposed, however, in view of the fact that the
The control valve mechanism 6 is provided
time required to supply the required degree of
with
a casing l I provided with aninlet chamber
?uid pressure to the remotely positioned actua
|2, an outlet Chamber 13 and a'diaphragm cham
tor has 'been excessive, and it is accordingly one
the inlet and outlet ehambers being sepa
of the objects of the present invention to provide 20 ber'M,
rated
by
means of a partition |5 provided with
means for overcoming this diñiculty.
a port IB therein, and the'outlet Chamber being
A further object of the invention is to provide
separated from the diaphrag'm chamber' by
a control valve mechanism so constituted as to
means of a partition ll, the only connection'be
permit a substantially unrestrícted connection
25 Vtween the latter chambers being through the
between the source of fluid pressure and the actu
medium of a restricted passage or choke 18. The
ator during substantially the entire period dur
upper end of the chamber |4 is closed by means
ing which the source and actuator are connected
of a pressure responsive member or diaphragm
by the operation of the control valve mecha
|9 clamped 'between the upper end of the casing
nism.
Yet another object of the inventionris to pro
Vide, in a self-lapping control valve mechanism,
means for preventing lapping action of the valve
from occurring until the pressure in the actua
'tor is substantially that for which the valve has
been adjusted by the operator.
.
A still further object of the invention is to pro
vide control valve mechanism of the so-called
self-lapping and graduating type, so constituted
| I and a closure member 20 suitably bolted there
to, the upper portion of the closure member 20
being provided With a bore 2| and an operator
controlled -plunger 22 slidably mounted therein.
A valve Operating element 23 is slidably mounted
,in a bore 24 formed in partition Il, the valve op
eratíng element being attached to the pressure
responsive member l9 at its center, as shown,
for movement therewith, a sealing device 25 posi
tioned in the 'bore 24 serving toprevent com
as to permit the establishment of a substantially 40 munication between the outlet Chamber |3 and
the diaphragm chamber M between the outer
unrestricted connection between the source of
surface of the element 23 and the surface of the
fluid pressure and the actuator without in any
bore 24. The valve operating element 23 is
way interfering with the operation of the self
thus positioned by means of the bore 24 and the
lapping and graduating features of the valve
when the operation of the system requires the 45 pressure responsive member IS, and is adapted.
v to be operated by movement of the plunger 22l
satisfactory and normal operation of these fea
through the medium 'of a graduating spring 25
tures.
interposed between the upper face of a washer
These and other objects and novel features ofŸ
21 mounted on the element and a washer 28 slid
the invention will appear more fully hereinafter
from the following detailed description when 50 ably mounted at the upper end of the valve op
erating element and adapted to engage a shoul
taken in connection with the accompanying
der 23a formed on the plunger. In order that
drawing. It is to be expressly understood, how
the 'plunger 22 may Ibe readily controlled by the
ever, that the drawing is forwarded for purpose
vehicle operator, the closure member 20 is pro
of illustration only, and is not designed as a
de?nition of the limits of the invention, refer 55 vided at its upper end with a suitable pivot pin
'
›
e
i
2,410,966
3
4
ing a substantially unrestricted connection be
tween the reservoir and the actuator. In valves
control pedal 30, the latter having a connection
of this general type, however, it is well known
with the upper end of the plunger 22 through
that during this type of operation, as the pres
the medium of a roller 3| pivotally mounted on
sure in the outlet chamber approaches that for
the pedal by means of a pivot pin 32.
which the graduating spring has been adjusted,
In order that the valve mechanism may oper
the upward pressure on the diaphragm increases,
ate to control the flow of fluid pressure from
with the result that the valve actuating element
the reservoir 4 to the actuator 5 and from the
moves upward to permit gradual closing of the
actuator 5 to atmosphere, the inlet chamber |2`
is connected with the reservoir through the me 10 inlet valve under the action of the Valve spring
42, the connection between the conduits 33 and
dium of conduit 33, while the outlet chamber
34, gradually becoming more restricted until a
l3 is connected with the actuator through the
point is reached where the passage between the
medium of a conduit 34, the outlet chamber in
29 on which is pivotally mounted an operator's
inlet and outlet chambers is fully closed and
turn being connected with atmosphere through
the medium of a bore 35 formed in the element 15 further passage of ?uid pressure is prevented.
This has resulted in a relatively slow applica
23, a port 36 formed in the wall of said bore, and
tion of fluid pressure to the actuator, and a
an exhaust outlet 31 which serves to connect with
consequent delayed operation of the actuator in
atmosphere a chamber 38 formed between the
the past, and the present invention contemplates,
upper surface of the pressure responsive mem
ber |9 and the closure member 20. Communica 20 in connection with a control valve meohanism
of the above type, the inclusion of means for
tion between the chambers I 2 and I 3 through the
maintaining the inlet valve in substantially wide
port I 6 is normally prevented by means of an
open'position until the pressure delivered to the
inlet valve 39, an exhaust valve 40 connected
actuator is substantially equal to that for which
thereto by means of a Stem 4| being adapted to
close the lower end of the bore 35 in the element 25 the graduating spring has been adjusted by the
operator, and such means include, in the present
23 on downward movement of the latter. In
instance, a permanent magnet 43, which may be
order that the inlet valve may normally be main
of the horse shoe type, preferably mounted on
tained in closed position, a suitable spring 42 is
the casing as shown by means of suitable screws
interposed between the upper surface of the par
tition |5 and the lower face of the exhaust valve 30 44 'and provided with a bore 44a to provide clear
ance for the valve spring 42. The valve actuating
40. Thus it will be apparent that with the parts
element 23 is also provided with a suitable arma
in the positions shown, communication between
reservoir 4 and the actuator 5 is prevented by
ture 45 of magnetic metal, which may be
means of nonnally closed inlet valve 39, while
communication between the actuator and atmos
threadedly mounted on the lower end of the ele
ment as shown, the result being that on opera
phere is permitted through the conduit 34, outlet
tion of the control pedal to move the valve actuat
ing element 23 downward to move the inlet valve
chamber l3, bore 35, port 36, chamber 38 and ex
to fully open-position, the armature 45 carried
by the element approaches the poles 46 of the
of the valve Operating element 23, the lower end
of the bore 35 ?rstcontacts the exhaust valve 40 magnet, the armatura when in contact With the
upper end of the poles tending to adhere thereto
40 to'prevent communication between the outlet
and maintain the Valve Operating element in its
chamber and atmosphere, further movement
downward position so that the intake valve is
opening the intake valve against the force ex
fully open to permit the unrestricted flow of
erted by the spring 42 to permit communication
between conduits 33 and 34, thus allowing ?uid 45 fluid pressure between the inlet and outlet cham
bers,V and thence to the actuator. It is desirable,
pressure to be supplied from the reservoir to' the
haust outlet 31, while on downward movement
i
actuator.
It will be understood from the foregoing, and
on reference to the above referred to patent, that
on downward movement of the operatons pedal 50
30, the graduating spring 26 will be compressed
however, that the valve be permitted to move to
lapped position as soon as the pressure in the
outlet chamber and in the actuator approaches
that for which the graduating spring has been
adjusted, and the magnet is accordingly so de
signed in connection with the armature as to
to exert a downward force on the valve Operating
provide a holding force which will be overcome
element 23 to close the exhaust valve and open
by the fluid pressure acting on the diaphragm
the intake valve, and that as the pressure builds
up in the outlet chamber |3 and in the actuator 55 E9, when the force resulting from this pressure
exceeds that exerted in a downward direction
5, this pressure will also be supplied to the dia
phragm chamber |4 through the restricted port
|8,› with the result that the upward force on the
by the graduating spring by a small predeter
mined amount, the strength of the magnet being
preferably so chosen as to exert a force somewhat
diaphragm due to the pressure in the chamber |4
will eventually overbalance the downward force 60 on the order of the force necessary to compress
exerted by the spring and permit the element 23
the graduating spring by an amount necessary
to permit the inlet valve to move from fully open
to move upward to a point where both the inlet
to fully closed position. Thus with the inlet valve
and exhaust valves are in closed position, this
held in open position by means of the magnet
being considered as the lapped position in the
valve, as will be readily understood by those 65 as above described, andrwith the pressure build
ing up in the outlet chamber of the valve and
skilled in the art. It is to be pointed out, how
ever, that on initial operation of the pedal 30 to
the chamber below the diaphragm IS, it will be
adjust the valve mechanism to deliver a substan
understood that the pressure acting on the dia
phragm can increase su??ciently to overcome the
tially high pressure to the actuator 5, the fluid in
the chamber |4 will be substantially at atmos 70 lforce exerted by the graduating spring and the
pheric pressure, and consequently no pressure will
force exerted by the magnet and start upward
initially be exerted on the member |9 to oppose
movement of the valve Operating element to
downward movement of the valve actuating ele
move the valve to closed position, and that if
ment, the result being that the inlet valve 39 will
the force of the magnet is chosen as described,
be moved to its fully open position, thus establish 75 this additional force exerted on the diaphragm
5
willbe'substantially dissípated, or, in other Words,
absorbed by compression of the graduating spring
26, with the result that there will be no tendency
for the diaphragm to'exert` an over-Controlling.
action on the element 23,`with 'a resultant se
tion between said chambers, a valve Operating
element for moving said valve in one direction to
open the valve and establishl a connection be
tween said chambers, a member responsive to the
ressure in': the outletV Chamber and 'associated
with said'element for moving'the element in the
quential closing of the inlet valve and opening
other ldirection to permit closing ofv the valve,
of the exhaust valve to Åunnecessarily exhaust
and means including a magnet Vcooperating with
?uid pressure from the outlet Chamber l3 and
said valve 'Operating element and effective when
from the aotuator 5. It will also be clearly under
stood that the magnet force Chos'encan be any de 10 the latter is moved to valve-opening position for
maintaining said element in said position, until
sired amount less than that .above described, and
the f force exerted by the pressure responsive
that under certain circumstances of operation,
member/'to move the valve Operating element to
it may also be desirable' to usev a magnet exert
valve-Closing position exceeds the force tending
ing a larger force, it being understood that the
to move said valve Operating element to valve
foregoing description is merely illustrative of the
opening position by a predetermined amount.`
preferred mode of operation. As soon as the force
2. The combination in a fluid pressure control
exerted in an upward direction by the diaphragm
HQ exceeds the force exerted in a downward direc
valve mechanism having an inlet Chamber, an
outlet Chamber, and a valve for controlling the
tion by the graduating spring 25 by an amount
equal to or slightly greater than that exerted by 20 ?ow of'fluid between said chambers, of means
the magnet, it will be readily understood that
for moving said valve to one position to permit
the element 2-3 will be movedrapidly upward
> the ?ow of fluid from said inlet Chamber to said
outlet Chamber, means for moving said valve to
in an upward direction by the ?uid pressure force
a second position to prevent the ?ow fluid be
acting upward on the diaph-ragm, and that the
tween said chambers, and means including a
Valve spring 42 will then move the valve assembly
magnet for maintaining the valve in said one
upward to move the valve 39 to Closed position
position in vopposition to the action of said last
and prevent further communication between the
named means.
inlet and outlet chambers.
3. The combination in a fluid pressure control
With reference to the mode of operation de 30 valve mechanism having an inlet Chamber, an
scribed in the preceding paragraph, this type of
outlet Chamber and a valve for ,Controlling the
operation is particularly desirable under condi
?ow of ?uid from said inlet Chamber to said
tions such that the operator wishes to supply a
outlet Chamber, of means for applying a force
to the valve to move it to one position to estab
predetermined degree of pressure to the actuator
in the shortest possible period of time, but it is 35 lish communication between said lchambers,
means including a member responsive to the
pointed out that when it is desired to so operate
pressure in the outlet Chamber for applying a
the Control valve mechanism å as to establish
force to said valve to move it to another position
small increments or decrements of pressure in
to prevent communication between said Cham-`
the actuator 5, operation of the magnet to hold
the intake valve in open position might seriously 40 bers, and means including a magnet effective
on movement of said valve to said one position
interfere with the Sensitive operation of the Valve,
for maintaining the valve in said position until
and the mechanism is therefore preferably con
the force exerted by the second named means
structed as above described, in such a manner
exceeds that exerted by the ?rst named means
that the magnet becomes effective only when the
operator's Control pedal is operated to move the 45 by a predetermined value.
4. The combination in a ?uid pressure control
intake valve to fully open position, In the event
valve mechanism having a valve movable to open
the operator has already' adjusted the valve to
and closed positions for controlling the ?oW of
provide a desired pressure in the actuator, and
fluid therethrough, of force applying means for
then desires to further depress the control pedal
in order to obtain a slight increase of pressure in 50 moving the valve to open position, force apply
ing means for moving the valve to Closed posi
the actuator, it is to be understood that the Cor
tion, and means including a magnet operable
responding pressure increase which will occur in
when the valve is in open position for maintain
the outlet Chamber E3 and in Íthe diaphragm
ing the latter in said position until the force
Chamber lll Will occur with su?ioient rapidity to
prevent the additional force exerted by the grad 55 exerted by said second named means exceeds that
exerted by the ?rst named means by a prede
uating spring from forcing the valve actuating
termined amount.
.
element 23 and the armature ll? downward suni
under the action of the excess force accumulated
5. The combination in a ?uid pressure control '
ciently to be attracted by the poles of the magnet,
valve mechanism having a casing provided With
the result being that under this condition of op
eration the valve mechanism Will have a mode 60 inlet and outlet chambers, a port between said
chambers, and a valve movable for opening and
of operation comparable with that of the ordi
closing said port, of a spring adjustable for ex
nary and Well known self-lapping graduating
erting a force to move said valve to open posi
type control valve.
tion, means including a member responsive to'
While the invention has been described and
illustrated herein with Considerable particularity, 65 the pressure in the outlet Chamber for opposing
the force exerted by said spring and moving the
it is to be understood that the same is not limited
valve to closed position, and means including a
to the form shown, but may receive a variety of
magnet for holding said valve in open position,
mechanical expressions as will readily appear to
the holding force exerted by said magnet being
those skilled in the art. Reference will, there
fore, be had to the appended claims for a de?ni 70 substantially equal to the force required to Com
press the spring during movement of said valve
tion of the limits of the invention.
from open to closed position in response to the
What is Claimed is:
force exerted by said pressure responsive mem
1. In a ?uid pressure control valve of the-self
ber.
lapping type having an inlet Chamber, an outlet
6. The Combination in a self-lapping control
Chamber, and a valve for controlling the connec
'Z
_
valve mechanism having a pair of valves for con
trollingthe flow of ?uid pressure therethrough,
8
until the pressure in the outlet chamber exceeds
a, predetermined value, said means permitting
unrestricted movement of said element to effect
lapping of said valves when said pressure exceeds
means for normally maintaining one of said
valves in open position and the other valve in
closed position, and a valve Operating element
said predetermined value.
for moving said one valve to closed position and
8. In a control valve mechanism having a cas
said other valve to open position, of means for
ing provided with an inlet chamber, an outlet
applying a force to said element for moving said
Chamber, a port connecting said chambers, and
valves to one of said positions, means responsive
a valve for normally closing said port, means in
to the pressure in said valve mechanism for ap 10 cluding a graduating spring for moving said valve
plying a force to said element for moving the
in one direction to fully open position, means in
valves to said otherV position, and means includ
ing a magnet for holding said element and main
taining the valves in one of said positions when
difference in the forces applied to said element
cluding a member responsive to the pressure in
the outlet chamber for opposing the operation
of the moving means and moving the valve in the
opposite direction to closed position, and means
including a part supported by the pressure re
by said force applying means is less than a pre
sponsive member and a part supported by the
determined value.
'7. In a self-lapping valve of the type having
casing, and arranged to contact with each other
only when the valve is moved to substantially
an outlet chamber adapted to be connected with
an actuated device, inlet and outlet valves for 20 fully open position, said parts being so con
controlling the flow of ?uid pressure to and from
structed and arranged as to hold the valve in
fully open position until the force exerted by the
said Chamber, lmeans including a, pressure-re
sponsive- element adapted to be subjected to the
pressure responsive member to_ close the valve
exceeds the force exerted by the moving means
pressure of the fluid in the outlet chamber for
controlling the opening, lapping and exhaust 25 to open the valve by a predetermined value.
movements of said valves, and means including
a magnet for preventing lapping of said valves
WILFRED A. EATON.
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