Note: Descriptions are shown in the official language in which they were submitted.
DUAL FLOW RATE VALVE
This invention relates to valves for controlling the flow of
liquids, and more par~icularly to such a valve capable of providiny
two diffexent rates of flow, as well as shutting off flow com-
pletely.
In certain installations, such as automatic liquid dispensing
equipment, large but precise metered amounts of liquid must be
delivered within a relatively short time. An example of such equip-
ment is that used at self-service gasoline pumps. A customer will
pre-pay for a particular amount of fuel, and then operate the pump
which has been set to deliver the exact quantity paid for. Typ-
ically, two separate valves are used in this operation: a large
orifice valve for rapidly delivering most of the gaso]ine, and a
smaller orifice, or "topping off", valve for accurately completing
delivery of the remaining portion. The large flow rate valve is
closed during the final fillin~ operation through the slower flow
rate valve. If only a large orifice valve were used, it would be
very dificult to deliver the exact quantity of liquid desired, and
if only a small orifice valve were used, delivery would take too
long.
While these two~valve arrangements operate satisfactorily, they
are relatively expensive. Usually, the valves are solenoid op-
erated. Thus, in addition to requiring two valves, two separate
electrical solenoid operators must be furnished, as well as l
associat~d wiring for two solenoids and piping for two valves.
It is an object of the presen~ invention -to provide a slngle
two-way valve which can automatically provide two different flow
ra~es, and thus take the place of the conventional high and low
flow rate pair of valves.
It is another object of the invention to provide a dual 10w
rate valve having two flow c~nditions, one in which the valve is in a
stable open position, and the o~her in which the valve member is
oscillated to permit only restricted flow through the valve~
It is a further object o~ the invention to provide such a
valve operated by a single solenoid, the solenoid being ene.rgized
by half-wave rectified ~C power ~o cause oscillation of the valve
me~ber, and having full wave AC power applied to it to produce
the stable open position of the valve.
It i5 an additional object of the invention to provide a dual
flow rate, two-way, pilot-operated valve. When the pilot valve is
fully opened, th~ main valve opens to provide a large flow rate.
When the valve member of the pilot valve is oscillated , the main
valve remains closed and ~low takes place, at a low rate, only ~hrough
the pilot valve.
Additional objects and featuxes of the invention will be ap-
parent from the following description, in which reference is made to
~ the accompanying drawings.
In the drawings:
Fig~ a cross-sectional view of a pilot-operated valve,
according to the invention, in completely closed condition;
~ ig. 2 is a cross-sectlonal view of the valve in fully opened
condition;
Fig~ 3-is a cros~-sectional view of the valve showing the main
valve closed and the pilot valve in its vibratory open condition;
Fig~ 4 is a schematic di.ayram showing one electri.cal circuit
for energizing the solenoid of the pilot valve; and
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Fig. 5 is a schematic diagram showing an alternative circuit
for energizing the solenoid of the pllo~ valve.
The valve chosen to illustra~e the p~esent invention
includes a valve body 10 having a main inlet port 11, a main out-
let port 12, and an orifice 13 between the ports surrounded by a
circular valve seat 14. Mountecl upon body 10 is a bonnet 15, the
body and bonne-t being secured together by bolts (not shown).
Sandwiched between body ].0 and bonnet lS is the margin of a
flexible diaphragm 18, seals 19 also being present to insure a
liquid-tight seal between the parts. Sesured to the lower ace
of aiaphragm 18 is a main valve member 20 movable into engagement
with valve seat 14 (Fig. 1), tv close the main valve, and out
of engagement with the valve seat (Fig. 2), to open the main
valve, A compression spring 21, arranged between bonnet 15 and
a support plate 22 carried by the upper surface of diaphragm 18,
continuously urges the diaphragm and main valve member 20 toward
valve seat 14.
Bonnet 15 and diaphragm 18 define a chamber 23 between them.
Chamber 23 is i~ constant communication with main inlet port 11
2Q through a bleed hole 24 defined by a grommet passing through a
hole in diaph.ragm 18.
The right side of bonnet 15 (as seen in Figs. 1-3) constitutes
the body 15' of a pilot valve. Pilot valve body 15' includes a
pilot inlet port 27, communicating with chamber 23, a pilot outlet
port 28, communicating with main outlet port 12 through a hole 29
i~ a diaphragm 18, and a.pilot orifice 30, b2tween the two pilot
port~, surrounded by a circular pilot valve seat 31. Threaded into
pilot valve body 15' is a bonnet 32 carrying a tube 33 within which
an armature 34 is lonyitudinally slidable. At its lower end,
armature 34 carries a resilien~ pi.lot valve member 35 rnovable into
engagement with pilot valve seat 31 (E~iy. 1), to close the pilot
valve, and out of engagement with ~he valve seat 31 (Fig. 2), to
open the pilot valve. A compression spring 36 continuously urges
armature 34 and hence valve member 35 toward v~lve seat 31. Valve
body 15' ancl bonnet 32 de~ine a pilot valve chamber 37 between them,
which constantly communicates with chamber 23 through pilot valve
inlet port 27.
A solenoid coil (not shown in Figs. 1-3, but indicated by the
reference numeral 40 in ~igs. 4 and 5) surrounds tube 33 and is
enclosed within a housing 41~ When coil 40 is ene~gized, armatu.re
34 xises .i~ tube 33, against the force of spring 36, and engages
a stationary armature 42 located within the upper nd of the tube
(Fig. 2). In this condition, the pilot valve is fully open. IJpon
deenergi,~ation of the solenoid coi.l, spring 36 returns armature 34
to the position in which valve member 35 engages valve seat 31
~Fig. 1) so a~ to close the pilok valve~
According to the present invent.ion, solenoid coil 40 can be
energized by what amount tG two distinct power sources, an ex~m~le .
of whic~ is shown in Fig. 4. ~rminal.s 45 and 46 are connectable
to a sour~e of electric power, 5uch as 120 volt~ 60 cycle, alter-
nating current. A movable switch member 47 may be brought alter-
natively into engagement with either of two terminals 48 or 49.
Terminal 48 i5 connected in series with solenoid coil 40 and
terminal 46. Thus, when switch member 47 i8 in its solid line
position engaging terminal 48, ~ull wave current is applied to
coil 40, and armature 34 moves lnto a skable condition engaging
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stationary armature 42. Terminal ~9 is connected in series with a
diode 50, coil 40, and terminal 46~ Thus, when switch member 47
is shifted to its broken line positi.on engaginy terminal 49, hal~
wave rec~i~ied current is appliec~ -~o coil 40. This causes armature
34 to oscillate toward and away from valve seat 31, the range o~
vibratory mov~ment heing indicated by the distance 51 in Fig. 3.
Operation of the valve will now be explained. Assume that
solenoid coil 40 is deenergized, i.e., terminals 45 and 46 are
disconnected from a source of power, and the valve is in the condi.~ion
shown in Fig. 1. Fluid at inlet pressure, from inlet port 11,
fills chamber 23 through bleed hole 24, this fluid also filling
chamber 37 through port 27. The ~orce on the upper face of dia-
phragm 18 produced by th.is fluid pressure, together with the force of
spring 21, hold main valve member 20 against seat ].4 to close the
main valve~ Spring 36 hold~ pilot valve member 35 agalnst seat 31
to alose the pilot valve.
If terminals 45 and 46 are now connected to a source o AC
power, by means of a switch (not shown), and switch member 47 contacts
terminal 4a, full wave power is applied to solenoid coi.l 40. As a
xesult, armature 34 rises to the position shown in Fig. 2, opening
the pilot valve. Pressurized fluid within pilot chamber 37 flows
through pilot outlet port 2g to ma~n outlet port 12. Pressurized
fluid in chamber 23 flows through pilot inlet port 27 into chamber
37, and then th~ough port 28 to main outlet port 12. As a result, the
pressure above diaphragm 18 is relieved, and inlet pressure acting
on the lower ace o the diaphragm and valve member 20 in the area
surrounding valve s~at 14 cause the diaphragm and valve member to
ri~e to the position shown in Fig. 2~ thereby opening the main valve.
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Although high pressure fluicl continues to enter chamber 23
through bleed hole 24, pressure does not huild up in the chamber
~ince the cross-sectional flQw areas of pilot por~s 27 and 28, and
pilot orifice 30 are larger than the cro~s-sectional flow area of
bleed hole 24. Thus, as long as the pilot valve remains in its stahle
open condit.ion ~Fig. 2), ~he mai.n valve remains open, and liquid
~lows ~ugh the valve at a rapid rate.
When the volu~e of liquid dispensed nears the quantity desired,
switch memb~r 47 i5 automa~ically shifted from ten~nal 48 to ten~nal 49.
As a result, solenoid coil ~0 i.s no longer energized with full wave
AC power, but instead with hal wave rectified AC power, since diode
50 prevents every alternate hal wave of current from reaching coil
40. Half wave power is not sufficient to hold armature 34 in the
stable condition shown in Fig. 2. Instead, the half wave current
causes the armature to oscillate toward and away rom valve seat
31, as illustrated in Fig~ 3~ Oqcillation of pilot valve me~er 35,
carried by armature 34, in the region adjacent to valve seat 31
permits some liquid flow rom chamber 37 through orifice 30 to
outlet port 12. However, the rate of this flow is smaller than
when the pilot valve is fully open ~Fig. 2~. In fact, the flow rate
through orifice 30 when valve member 35 oscillates is smaller than or
about equal to the flow rate o inlet liquid through bleed hole 24
into chamber 23. Consequently, fluid pressure builds up in chamber
23 which, t~gether with the force of spriny 21 moves, valve member
20 into engagement with valve ~eat 14 to close the main valve, and
discontinue high rate flow through the valve. Liquid fl~w continues
.
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through the valve, at a low rate, from main inlet port 11, through
b].eed hole 24, chamber 23, pilo~ inlet port 27, pilot chamher 37,
and pilot outlet port ~8 to main outlet port 12. This low rate flow
continues until the prescribed quantity of liquid has been dis-
pensed, at which point power to terminals 45 and 46 is automatically
switched off. Solenoid coil 40 i5 then completely deenergized, and
the pilot valve closes (Fig. l).
An alternative circuit for energlzing solenoid coil 40 is
shown in Fig. 5. Terminals 45' and 46', like terminals 45 and
46 of Fig. 4, are connectable to a source of conventional AC power.
Terminal 45' is connected in series with a diode 53, coil 40, and
terminal 46'. Connected in parallel with coll 40 are series-
connected diode 54 and switch 55. When power is applied to terminals
45' and 46', and switch 55 is closed, half wave power is applied
to coil 40; however, current flow through coil 40 is through diode
54, and the valve is fully open ~Fig. 2) delivering high rate flow.
Opening of switch 55 causes half wave power to be applied to coil
40, whereby armature 34 oscillates (Fig. 3~, and low rate flow passes
through the valve.
Although in the example described above the pilot valve of
a pilot-operated valve is oscillated to provide reduced rate flow,
tne invention could be applied to a single orifice valve wherein
the solenoid armature directly operates the main valve member of
the valve. In such a case, when full wave current i5 applied to
the solenoid coil, the armature holds the valve open in stable
condition for full rate flow~ When half wave current is applied
to the coil, the armature and hence the valve member oscillate
to permit only a more restricted flow -through the valve.
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The invention has been shown and described .in preferred form
only, and by way of example, and many variations may be made in
the invention which will still be comprised within its spirit.
It is undarstood, therefore, that the invention is not limited
~o any specific form or embodiment except insofar as such limitat.ions
are included in the appended claims.
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