Miniaturized valve

Miniaturized valves having fast response time and characterized by low power requirements and minimal fluid consumption. A main valve member, which is movable and determines the state of the valve, is responsive to the state of a control member which may be a solenoid operated pilot valve.

BACKGROUND OF THE INVENTION 
(1) Field of the Invention 
The present invention relates to miniaturized valves and particularly to 
such valves which have a fast response time and very low power 
consumption. More specifically, this invention is directed to exercise of 
control over the flow of fluids and especially to controlling fluid flow 
directly from the output of solid state electronic circuitry. Accordingly, 
the general objects of the present invention are to provide novel and 
improved apparatus and methods of such character. 
(2) Description of the Prior Art 
Advances in fluid handling devices have not kept pace with advances in 
micro-electronics. Accordingly, there is a long-standing desire for a 
reliable, comparatively inexpensive miniature control valve which has a 
fast response time. Since control applications generally require that such 
a valve be used in conjunction with a piston-type actuator, such valves 
should preferably be of the three-way type. In addition, in order to 
permit such valves to be mounted directly on circuit boards, and thus 
operated directly by the micro-electronics, the desired compatible valve 
must be characterized by very low electrical power requirements. 
The typical prior art approach to control valve miniaturization has been 
simply to attempt to scale down existing valves. These attempts to reduce 
valve size, however, have been largely unsuccessful and the devices 
resulting therefrom have been characterized by slow response time and/or 
unduly high electrical power requirements and/or a high rate of fluid 
consumption. 
A major disadvantage of prior art miniaturized valves resides in the need 
to constantly bleed fluid when one of the fluid passage-ways controlled by 
the main valve member is in the closed condition. If the fluid which is 
employed is contaminated with dirt, this constant bleeding may lead to a 
clogging of passage-ways which, as the valve becomes physically smaller, 
become more susceptible to such clogging. Further, miniaturized valves are 
often used to regulate the flow of expensive fluids such as oxygen and the 
constant bleeding of the fluid is thus expensive and can, with a flamable 
fluid, be dangerous. 
SUMMARY OF THE INVENTION 
The present invention overcomes the above-discussed and other deficiencies 
and disadvantages of the prior art by providing a novel and improved 
miniaturized valve. 
A valve in accordance with the present invention defines three main fluid 
flow paths and has two flow modes. The inlet to a first of these paths is 
permanently connected to a source of a pressurized operating fluid. A 
second path, which is controllably interrupted or opened by a main valve 
member, establishes fluid communication between a two-way port and a 
discharge port. When this second flow path is in the interrupted state, 
communication is established between the two-way port and the source of 
pressurized operating fluid. The third path, which is also controllably 
established or interrupted, directs the pressurized operating fluid to the 
first side of a power diaphragm disposed in a chamber formed within the 
valve housing. The power diaphragm functions as the actuator for the main 
valve member which controls the state of the second fluid flow path. 
In accordance with a preferred embodiment the power diaphragm drives a 
valve spool, which comprises the main valve member, between opposite 
limits wherein seals carried by the spool are seated against cooperating 
valve seats. Thus, in a first mode of pressurization of the power 
diaphragm communication will be established between the source of 
operating fluid and the two-way port and the second fluid path will be in 
the interrupted state. In the second mode of pressurization of the power 
diaphragm the two-way port will be isolated from the source of operating 
fluid and communication will be established between the two-way port and 
the discharge port. It is to be noted that the power diaphragm functions 
as a differential area piston. 
Also in accordance with the preferred embodiment, the means for controlling 
the state of the third flow path is a solenoid operated valve assembly 
which is mounted within a separate housing which may be mated with the 
housing of the three-way valve. Alternatively, this pilot valve 
subassembly may be in the form of a fluidic actuator. In either event, the 
state of the pilot valve determines the state of actuation of the power 
diaphragm. A principal advantage of the present invention resides in the 
fact that only a minute volume, substantially the volume of the chamber 
behind the power diaphragm, is vented when the valve is switched from one 
state to the other. Thus, when the pressurization of the chamber behind 
the power diaphragm is terminated, through operation of the pilot valve, 
the operating fluid will act on the main valve spool thus switching the 
valve and moving the diaphragm in the chamber. This movement is permitted 
because the closing of the pilot valve will establish a vent path, through 
the pilot valve housing, to the ambient atmosphere.

DESCRIPTION OF THE DISCLOSED EMBODIMENTS 
Referring jointly to FIGS. 1 and 2, a valve in accordance with a first 
embodiment of the present invention is indicated generally at 10. All of 
the components of valve 10, unless otherwise specifically noted, may be 
comprised of anodized aluminum. The device of FIGS. 1 and 2 includes a 
valve subassembly, indicated generally at 14, and an actuator or pilot 
valve subassembly, indicated generally at 12. The actuator subassembly 12 
is removably mounted on the valve subassembly 14 by means of a coupling 
nut which has been indicated generally at 16. Nut 16 has an internal 
thread which engages an external thread on the valve body 22. Nut 16 
further has an inwardly extending flange 18 which engages an annular 
projection 20 on the housing of the actuator subassembly 12. 
The valve subassembly 14 includes the valve body 22, a spool 24 and an 
insert 26 which, among other purposes, defines a first or upper valve 
seat. The insert 26 cooperates with a nozzle plate 28 to support a power 
diaphragm 52 and define a chamber 42 in which that diaphragm moves. The 
diaphragm 52 is connected to the spool 24 as will be described below. The 
valve subassembly further includes a coupling member 30 which is received 
in body 22, for example, by means of a press fit. Coupling 30 defines, at 
its upper end, a second or lower valve seat which cooperates with the 
spool 24. Leakage around the coupling 30 is prevented by means of sealing 
rings 32 positioned between coupling 30 and the wall of the aperture in 
valve body 22 which receives the coupling. 
The coupling member 30 defines an inlet port 34 which is permanently 
connected to a source of pressurized operating fluid. The valve body 22 
defines a two-way port 36 and a discharge port 38. With the valve in the 
position depicted in FIG. 1, wherein a pilot valve or actuator is in the 
energized state, the operating fluid will be delivered from port 34, 
through the valve seat at the upper end of coupling 30, through the 
chamber 40 in which the spool 24 moves to the passage which extends from 
the two-way port 36. The discharge port 38 will be in constant 
communication with the chamber 42. When the actuator is deenergized, the 
valve switches to the state shown in FIG. 2 and sealing ring 44, carried 
by a member 46 mounted on spool 24, will contact the seat defined by the 
upper end of coupling 30. Communication between inlet port 34 and chamber 
40 will thus be interrupted. The seal carrying member 46 is press fit on 
an extension 48 of spool 24, this arrangement being in the interest of 
facilitating assembly of the valve. The second seal, in this case an 
O-ring 50, is mounted on spool 24 and cooperates with the upper valve seat 
defined by insert 26. Thus, with the valve in the state depicted in FIG. 1 
the sealing ring 50 prevents fluid flow between two-way port 36 and 
discharge port 38 whereas, when the valve switches to the state shown in 
FIG. 2, fluid may flow between port 36 and port 38 through the valve 
defined by spool 24 and insert 26. 
The position assumed by valve spool 24 within the chamber 40 is a function 
of the state of pressurization of a diaphragm 52. Diaphragm 52 is affixed, 
in any suitable manner, to a spider 54. Spider 54 may be in the form of an 
annular plate which extends outwardly in a transverse direction with 
respect to the axis of spool 24. The spider 54 cooperates with an integral 
flange 56 to define an annular groove which receives the inner edge of 
diaphragm 52. The outer periphery of diaphragm 52 is captured, with the 
aid of a projection 58, between nozzle plate 28 and insert 26. The 
diaphragm 52 thus divides the valve subassembly chamber 42, defined by 
nozzle plate 28 and insert 26, into an upper portion 60 and a lower 
portion. The lower portion of this chamber, as noted above, is in constant 
fluid communication with discharge port 38 and, with the valve in the 
state depicted in FIG. 2, also in communication with two-way port 36. The 
diaphragm 52 is effectively a differential area piston since the upper 
side thereof, as the device is shown in FIGS. 1 and 2, has a greater 
reaction surface area than the area of the lower side of spider 54. The 
spool 24 is caused to reciprocate, in the axial direction, by varying the 
pressure at the opposite sides of diaphragm 52 in the manner to be 
described below. 
Operation of the main valve, i.e., the position of spool 24, is a function 
of whether the upper chamber portion 60 is in communication with port 34 
or vented to the ambient atmosphere. Thus, the delivery of the pressurized 
operating fluid to upper chamber 60 results in the spool 24 moving to the 
position shown in FIG. 2 where two-way port 36 is isolated from port 34 
but is in communication with port 38 via the lower portion of chamber 42. 
Venting of pressure from upper chamber 60, in the manner to be described 
below, will result in the valve returning to the state depicted in FIG. 1 
under the influence of the pressurized operating fluid acting on the 
underside of spider 54 and the lower end of spool 24. 
The state of pressurization of upper chamber 60 is a function of the state 
of energization of the actuator subassembly 12. With the actuator in the 
deenergized state as shown in FIG. 2, port 34 is in fluid communication 
with upper chamber 60 via a passageway 64 defined by apertures formed in 
coupling 30, housing 22, and nozzle plate 28. The flow passage in nozzle 
plate 28 includes an orifice 66 which provides communication between a 
blind transverse passage and a small valve chamber 68. The flow passage in 
nozzle plate 28 also includes an aperture 70 which extends from the 
chamber 68, at the downstream side of orifice 66, to upper chamber portion 
60. The end of a plunger, indicated generally at 72, which forms part of 
the actuator extends into chamber 68 and is preferrably coaxial with 
orifice 66. The position of plunger 72 will be a function of the state of 
energization of a solenoid coil indicated generally at 90. The plunger 72 
is, in the embodiment of FIGS. 1 and 2, of five-piece construction. Thus, 
plunger 72 comprises a pair of head portions 76 and 78 which are of 
increased diameter with respect to the remainder of the plunger. Head 
portion 76 will typically be integral with a post or rod 86 and will be 
provided with a recess which receives a sealing member 80 which may, for 
example, be comprised of rubber. The plunger will also be comprised of a 
sleeve member 84 which is provided with a blind hole for receiving post 
86, the post being split at its upper end to insure insertion and capture 
in sleeve member 84. Sleeve member 84, at its upper end, is provided with 
a recess which receives a disc 82 of rubber or other similar resilient 
material. The head portion 78 is a split ring comprised of soft iron. 
Plunger 72 is caused to reciprocate between the positions shown in FIGS. 1 
and 2 by delivering current to or discontinuing the supply of current to 
the solenoid coil 90. Coil 90, in the disclosed embodiment, is wound on a 
frame 92 comprised of a suitable non-conducting material such as nylon. 
The solenoid coil and its supporting frame are positioned within a casing 
94 which is formed of a suitable magnetic material. The frame 92 is 
provided with at least a first longitudinal slot, as indicated at 96, so 
that gas may flow, in the direction indicated by the arrows in FIG. 2, 
between plunger 72 and the solenoid coil. 
The actuator subassembly also includes an upper housing extension 102 in 
which is received an insert 104. Insert 104 defines a vent port 100. A 
sealing ring 106 is provided to insure against gas leakage between insert 
104 and housing 102. In the disclosed embodiment the vent port 102 tapers, 
in steps, to a nozzle 110 defined by a projection which cooperates with 
the disc 82 carried by plunger 72. 
In operation, when the coil 90 is energized, head 78 is attracted to the 
casing 94 thus causing the plunger 72 to move from the position shown in 
FIG. 2 to that shown in FIG. 1. With the plunger in the FIG. 1 position 
the orifice 66 will be closed by sealing disc 80 and the source of 
pressurized operating fluid will thus be isolated from the upper chamber 
portion 60 and, accordingly, from upper side of diaphragm 52. 
Simultaneously, fluid in upper chamber portion 60 will be vented, via 
aperture 70, chamber 68, the slot or slots 96, the split (not shown) in 
ring 78, nozzle 110 and port 100. This relief of the pressure from the 
upper side of diaphragm 52 will result in the operating fluid acting on 
the end of spool 24 and the underside of plate 54 causing the valve spool 
to move to the FIG. 1 position wherein fluid communication between ports 
36 and 38 is interrupted through the cooperation of sealing ring 50 with 
its associated valve seat. It will be recognized that, because of the 
closing of orifice 66, the only fluid which will be vented to the ambient 
atmosphere in the manner described above is that very minute quantity in 
upper chamber 60 and the passages downstream thereof, in the direction of 
port 100, at the time the solenoid is energized. 
When the solenoid is deenergized, the fluid acting on disc 80, i.e., the 
fluid at the discharge end of orifice 66, will force plunger 72 to move 
from the FIG. 1 position to the FIG. 2 position whereupon the nozzle 110 
will be sealed by disc 82 while fluid communication between port 34 and 
upper chamber portion 60 will be reestablished. Accordingly, since the 
diaphragm 52 functions as a differential area piston as noted above, the 
diaphragm will deflect and thus will move spool 24 from the position of 
FIG. 1 to that of FIG. 2. Accordingly, communication will be reestablished 
between ports 36 and 38 while communication between ports 34 and 36 will 
be interrupted. In one reduction to practice of the embodiment of FIGS. 1 
and 2 the solenoid required to operate the pilot valve, i.e., to move the 
plunger 72, required only 0.08 watts with a five volt direct current 
source. This is a much lower power consumption when compared to prior art 
valves and permits direct operation of the valve of the present invention 
from low gain solid state electronics. 
Referring now to FIG. 3, a fluidically controlled pilot valve, which may be 
substituted for the solenoid operated pilot valve of the embodiment of 
FIGS. 1 and 2, is indicated generally at 112. The fluidic actuator 112 is 
attached to and cooperates with the main valve in the same manner as the 
previously described solenoid actuator. Accordingly, the main valve will 
not be described and it should suffice it to merely note that like 
reference numerals refer to like elements in FIG. 3 and in FIGS. 1 and 2. 
The fluidic pilot valve 112 comprises an outer housing 104 which defines a 
recess 116. The recess 116 receives a pair of members 118 and 120 which 
cooperate to define a chamber 144. A plunger or poppet, indicated 
generally at 122, is disposed for movement in chamber 144 and is suspended 
by means of diaphragms 128, 130 and 132. Poppet 122 carries, at its upper 
end, a sealing disc 126 and, at its lower end, a sealing disc 124 which 
cooperates with orifice 66. The outer periphery of diaphragm 130 is 
captured, in the manner shown, between the upper chamber defining member 
118 and housing 104. The diaphragm 132, which divides chamber 144 into 
upper and lower portions, is captured at its outer periphery between 
members 118 and 120. Upper diaphragm 132 is affixed, at its inner 
periphery, to a flange or spider which is shown as being integral with and 
extending from poppet 122. Lower diaphragm 132 is similarly affixed to a 
flange or spider 138 which is also shown as being integral with poppet 
122. The third diaphragm 128 is captured, about its outer periphery, 
between the lower housing member 120 and the nozzle plate of the main 
valve. The inner periphery of diaphragm 128 is affixed to a flange or 
spider 134 which is also integral with poppet 122. 
The lower portion of chamber 144, as defined by diaphragm 132, is in 
constant communication with the ambient atmosphere via a vent port 148. 
The chamber portion at the other side of diaphragm 132 is coupled to a 
source of control pressure, which is connected to a port 146 in the main 
housing 104, via an aperture 152 in upper housing member 118. 
In operation, the poppet 122 is shifted between the position shown in FIG. 
3 to the position therein disc 126 seals nozzle 110 and orifice 66 is 
opened to permit the pressurized operating fluid to act on the upper side 
of diaphragm 52 of the main valve. The movement of poppet 122 results from 
the selected application of control pressure at inlet port 146. With the 
control valve in the "energized" position of FIG. 3, the operating fluid 
will be vented from the upper chamber portion 60 of the main valve via 
aperture 70, chamber 68, a passage 150 in poppet 122 and nozzle 110. When 
the control pressure at port 146 is removed, the pressure of the operating 
fluid against sealing disc 124 will cause poppet 122 to move upwardly 
until nozzle 110 is sealed by disc 126 and the operating pressure is again 
applied, via orifice 66, to the upper side of main valve control diaphragm 
52. The diaphragms 128 and 130 serve merely support poppet 122, to prevent 
leakage of operating fluid from either end of poppet 122 into chamber 144 
and also to prevent the control fluid from leaking from the upper portion 
of chamber 144 to the vicinity of nozzle 110. The application of a very 
small control pressure at port 146 will be sufficient to move poppet 122 
to the FIG. 3 position and hold it in this position whereby the main valve 
will move to the position depicted in FIG. 1. 
A preferred embodiment of a solenoid operated valve in accordance with the 
present invention is shown in FIG. 4. The valve of FIG. 4 has a main valve 
housing 200 which defines an operating fluid inlet port 202, an exhaust or 
discharge port 204 and a two-way port 206. Housing 200 further defines an 
irregularly shaped chamber in which the main valve or poppet member 208 
moves. This irregularly shaped chamber in housing 200 includes a pair of 
oppositely disposed valve seats 210 and 212 which cooperate with a sealing 
ring 214 mounted in an annular groove in, and thus carried by, poppet 208. 
The main or power diaphragm 216 is affixed to the upper end of poppet 208 
and is partly supported by a spider 218 which is press fit on a reduced 
diameter section at the upper end of poppet 208. The outer periphery of 
diaphragm 216 is captured, in the manner shown, between a projection 220 
on housing 200 and the nozzle plate defining member 222. 
The nozzle plate defining member 222 corresponds to nozzle plate 28 of the 
embodiment of FIGS. 1 and 2 and thus defines an orifice 224 and an 
aperture 226 which provides communication between the downstream side of 
the orifice and the upper side of diaphragm 216. The orifice 224 and 
aperture 226 communicate via a chamber 228 which, in part, is defined by 
the housing of the solenoid operated pilot valve. 
The actuator or pilot valve comprises a solenoid coil 230 which is wound on 
a frame, for example a nylon frame 232. Frame 232 is positioned within a 
casing 234 comprised of an appropriate magnetic material. In the disclosed 
embodiment the solenoid, including the coil and casing, is positioned 
within an aluminum shell 236 which is caused to engage valve housing 200 
in the manner shown. 
The actuator or pilot valve further includes a plunger, indicated generally 
at 240, which assumes a position determined by the state of energization 
of the solenoid coil 230. In the disclosed embodiment plunger 240 
comprises a steel tube 242 having both ends thereof split. The lower end 
of this tube is collapsed and a brass "tack" 244 is inserted therein. The 
tack 244 has a recess in the head portion thereof which receives a sealing 
disc 246 which cooperates with the orifice 224 to perform a valving 
action. A rubber insert, having a head portion and a shank portion, is 
inserted in the upper, expanded end of tube 242 and, subsequently, a soft 
iron washer 250 is forced over the upper end of tube 242. The split in the 
upper end of tube 242 is indicated at 252. 
The valve of FIG. 4 operates in substantially the same manner as the 
above-described embodiments of the invention. The solenoid coil 230 is 
normally deenergized and thus the valve will be in the condition shown in 
FIG. 4. In this position the venting of the operating fluid, which is 
acting on the upper side of diaphragm 216, will be prevented by virtue of 
the cap 248 sealing an exhaust port 254 in shell 236. When the solenoid 
coil is energized, and the washer 250 attracted against the casing 234, 
the orifice 224 will be closed and exhaust port 254 will be opened. With 
port 254 opened, fluid will be vented from the region at the upper side of 
diaphragm 216 via aperture 226, chamber 228, the clearance between tube 
242 of plunger 240 and frame 232, the split 252 in tube 242 and port 254. 
It is to be noted that the valve of FIG. 4 is provided with a pair of 
bayonnet type plugs 260 and 262 whereby the valve may be easily installed 
on a circuit board, the plugs 260 and 262 establishing both the electrical 
and mechanical connections to the board. Thus, the housing 220 will be 
provided with a pair of passages 264 and 266 by which the electrical 
connections to solenoid coil 230 will be made through plugs 260 and 262 
respectively. 
While preferred embodiments have been shown and described, various 
modifications and substitutions may be made thereto without departing from 
the spirit and scope of the invention. Accordingly, it is to be understood 
that the present invention has been described by way of illustration and 
not limitation.