Note: Descriptions are shown in the official language in which they were submitted.
CA 02429531 2008-11-21
TOILET FLUSHER WITH NOVEL VALVES AND CONTROLS
Field of the Invention
The present invention is directed to toilet flushing. It finds particular, al-
though not exclusive, application in automatic tank-type flushers.
s Background Information
The art of toilet flushers is an old and mature one. (We use the term toilet
here in its broad sense, encompassing what are variously referred to as
toilets,
water closets, urinals, etc.) While many innovations and refinements in this
art
have resulted in a broad range of approaches, flush systems can still be
divided
into two general types. The first is the gravity type, which is used in most
Ameri-
can domestic applications. The gravity type uses the pressure resulting from
wa-
ter stored in a tank to flush the bowl and provide the siphoning action by
which the
bowl's contents are drawn from it. The second type is the pressurized flusher,
which uses line pressure more or less directly to perform flushing.
Some pressure-type flushers are of the tank type. Such flushers employ
pressure tanks to which the main water-inlet conduit communicates. Water from
the main inlet conduit fills the pressure tank to the point at which air in
the tank
reaches the main-conduit static pressure. When the system flushes, the water
is
driven from the tank at a pressure that is initially equal to that static
pressure,
without reduction by the main conduit's flow resistance. Other pressure-type
flushers use no pressure tank, and the main conduit's flow resistance
therefore re-
duces the initial flush pressure.
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-2-
While flush-mechanism triggering has historically been performed manually,
there is also a long history of interest in automatic operation. Particularly
in the
last couple of decades, moreover, this interest has resulted in many practical
in-
stallations that have obtained the cleanliness and other benefits that
automatic
operation affords. As a consequence, a considerable effort has been expended
in
providing flush mechanisms that are well adapted to automatic operation. Auto-
matic operation is well known in pressure-type flushers of the non-tank
variety, but
gravity-type flushers and pressurized flushers of the tank variety have also
been
adapted to automatic operation.
European Patent Publication EPO 0 828 103 Al illustrates a typical gravity
arrangement. The flush-valve member is biased to a closed position, in which
it
prevents water in the tank from flowing to the bowl. A piston in the valve mem-
ber's shaft is disposed in a cylinder. A pilot valve controls communication
between
the main (pressurized) water source and the cylinder. When the toilet is to be
flushed, only the small amount of energy required for pilot-valve operation is
ex-
pended. The resultant opening of the pilot valve admits line pressure into the
cyl-
inder. That pressure exerts a relatively large force against the piston and
thereby
opens the valve against bias-spring force. Pilot valves have similarly been em-
ployed to adapt pressure-type flushers to automatic operation.
Summary of the Invention
According to another aspect, a tank-type flusher includes an intake valve
(i.e., a fill valve), a diaphragm-operated flush valve, and a pressure control
mechanism. The intake valve is connected to an external water source and is
con-
structed to close water flow to a water storage tank at about a predefined
water
level in the water tank. The diaphragm-operated flush valve is constructed to
con-
trol a flush valve member between a seated state and an unseated state
allowing
water discharge from the water tank into a toilet bowl. There is a diaphragm,
separating a flush-valve chamber and a pilot chamber, arranged to seal the
flush-
valve chamber and thereby maintain pressure forcing the flush valve member to
the seated state preventing the water discharge from the water storage tank to
the
toilet bowl. The pressure control mechanism is constructed and arranged, upon
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-3-
actuation, to reduce pressure in the pilot chamber of the diaphragm-operated
flush
valve to cause deformation of the diaphragm and thereby reduce pressure in the
flush-valve chamber causing the water discharge.
Preferred embodiments of this aspect include one or more of the following
features: The intake valve includes a float constructed and arranged without
any
fixed coupling to any valve member. The intake valve includes a float that
freely
floats within a float cage. The intake valve includes a float arranged to
float within
a float cage and to block a relief orifice at the predefined water level.
The pressure control mechanism is controlled by a solenoid. The flush
valve member is constructed to move linearly within a flush valve housing. The
flush-valve chamber is arranged to receive water pressure from the external
source and being arranged to prevent the water discharge utilizing at least a
por-
tion of the water pressure.
According to another aspect, a tank-type flusher includes an intake valve
1s (i.e., a fill valve), and a diaphragm-operated flush valve. The intake
valve is con-
structed to close water flow from an external water source to a water storage
tank
when there is a predefined water level in the water tank. The intake valve
includes
a float constructed and arranged to freely float within a float cage. The
diaphragm-
operated flush valve includes a flush-valve chamber, wherein the diaphragm-
operated flush valve is constructed to open upon actuation to discharge water
into
a toilet bowl from the water tank.
According to yet another aspect, a tank-type flusher includes an intake
valve, and a diaphragm-operated flush valve. The intake valve is connected to
an
external water source and is constructed to close water flow to a water
storage
tank at about a predefined water level in the water tank. The flush valve is
con-
structed to control position of a flush valve member movable between a seated
state and an unseated state allowing water discharge from the water tank into
a
toilet bowl, wherein the flush valve member is biased to the unseated state by
a
bias member and is forced to the seated state by at least a portion of water
pres-
sure from the external source.
Preferred embodiments of this aspect include one or more of the following
features: The intake valve and the flush valve are located within a single
housing.
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-4-
The flush-valve chamber is arranged to receive a water pressure from the
external
source and is arranged to prevent the water discharge utilizing at least a
portion of
the water pressure.
The diaphragm-operated flush valve may be controlled by a solenoid. The
water tank may be an exposed water tank or a concealed water tank located be-
hind a wall. The intake valve enables a variable water level in the tank.
The tank-type flusher may include a vacuum breaker arranged to prevent
transfer of water from the tank to a water supply.
The tank-type flusher may includes a manual actuator constructed and ar-
ranged to actuate the flush valve. The manual actuator may be a push button ac-
tuator. The push button actuator is constructed to actuate the flush valve
enabling
a dual water volume flush. The push button actuator is constructed to actuate
hy-
draulically the flush valve.
The tank-type flusher may include an automatic actuator constructed and
arranged to actuate the flush valve. The automatic actuator is constructed to
be
triggered by a sensor. The sensor may register presence of an object or move-
ment of an object. The sensor may be an optical sensor. The automatic actuator
may be constructed to actuate the flush valve enabling a dual water volume
flush.
The automatic actuator may be located outside of the water tank and is con-
structed to actuate hydraulically the flush valve.
The tank-type flusher may include a check valve arranged to reduce varia-
tion of closing pressure depending on water line pressure. The tank-type
flusher
may include a pressure compensated flow regulator. The tank-type flusher may
includes a viper seal co-operatively arranged with the flush valve to prevent
water
leaking into the toilet bowl. The tank-type flusher may include a vent for
controlling
odor.
We have invented novel gravity-type and pressure-type flush mechanisms.
In the case of the gravity-type flush valve, we have recognized that operation
can
be made more repeatable by simply employing a configuration that is the
reverse
of the one described in the above-mentioned European patent publication. Spe-
cifically, we bias our flush valve to its unseated state, in which it permits
flow from
the tank to the bowl, and we use line pressure to hold the flush valve shut
rather
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-5-
than to open it. We have recognized that this approach makes it very simple to
have a repeatable valve-opening profile. Also, high line pressure actually
aids in
preventing leakage through the flush valve, rather than tending to reduce the
ef-
fectiveness of the flush-valve seal. Since the toilet's suction generation is
princi-
pally dependent on that profile, and since our approach makes the bias mecha-
nism essentially the sole determinant of that profile, our approach enables
this as-
pect of flush operation to be largely independent of line pressure.
We have also recognized that pressure-type flush systems adapted for
automatic operation can be simplified by providing a pressure-relief passage
that
extends through the flush-valve member itself, Specifically, part or the
entire valve
member is disposed in a pressure chamber, into which line pressure is
admitted.
This pressure overcomes a bias force and holds the valve member in its seated
position, in which it prevents flow from the pressurized-liquid source into
the bowl.
To open the flush valve, it is necessary to relieve the pressure in the
pressure
chamber by venting it into some unpressurized space. Rather than follow the
con-
ventional approach of providing an additional pressure-relief exit from the
flush
mechanism, we use the flush outlet for pressure relief by providing a pressure-
relief conduit that extends from the pressure chamber through the flush-valve
member itself. A pressure-relief mechanism ordinarily prevents flow through
this
pressure-relief conduit, but it permits such flow when the toilet is to be
flushed.
In both pressure- and gravity-type systems, much of the mechanism em-
ployed to operate the flush valve is typically local to the wet region. That
is, it is
inside the pressure vessel in the case of a pressure-type system, and it is in
the
tank below the high-water line in case of a gravity-type.system. For automatic
op-
eration, though, at least some part, such as a lens used as part of an object
sen-
sor to collect light reflected from the object, is disposed at a remote
location. So
there is some communication between the local and remote regions. This com-
munication may be totally hydraulic, wherein a pressure-relief line extends
from
the local region to a remote region outside the pressure vessel or outside the
part
of the tank interior. A remote valve controls a pressure-relief line for
controlling the
flush valve's operation. In this embodiment, there is no need for a sealed
enclo-
sure for the electrical components.
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-6-
Brief Description of the Drawings
Fig. 1 is a sectional view of a toilet tank illustrating its float and gravity-
type
flush valves.
Fig. IA is a more-detailed cross section of the gravity-type flush valve in
its
closed state.
Fig. I B is a similar view of the gravity-type flush valve, but in its open
state.
Fig. 1 C is a cross-sectional view depicting Fig. 1's gravity-type flush valve
in
more detail.
Fig. I D is a cross-sectional view of an alternative flush-valve arrangement,
in which solenoid-control circuitry is located remotely from a solenoid
located in
the flush-valve assembly.
Fig. 2 is a cross-sectional view that illustrates an embodiment in which the
float- and flush-valve assemblies share common elements.
Fig. 2A is a cross-sectional view of another embodiment, one in which the
solenoid as well as the solenoid-control circuitry is located remotely from
the flush-
valve assembly.
Fig. 3 is a cross-sectional view of a pressure-type embodiment.
Fig. 3A is a more-detailed cross-sectional view of a pilot-valve for the pres-
sure type embodiment.
Fig. 4 is a sectional view of a toilet tank illustrating its float and gravity-
type
flush valves.
Fig. 4A is a more-detailed cross section of the gravity-flush valve in its
ciosed state.
Fig. 4B is a similar view of the gravity-type flush valve, but in its open
state.
Fig. 5 is a cross-sectional view of the push-button valve of Fig. 4.
Fig. 5A is a cross-sectional view taken at line 5A-5A in Fig. 5.
Fig. 6 is a sectional view of the toilet tank illustrating its float and
gravity-
type flush valves.
Fig. 6A is a more-detailed cross section of the flush-valve mechanism.
Fig. 6B is a cross-sectional view of a remote actuator valve and push but-
ton.
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-7-
Fig. 6C is a top isometric view of one of the push-button members in the
push-button assembly of Fig. 3.
Fig. 6D is an isometric view of the button frame in Fig. 3's push-button as-
sembly.
Fig. 6E is an isometric view of another button member from the push-button
assembly of Fig. 6B
Fig. 7 includes Figs. 7A and 7B wherein Fig. 7A is a more detailed cross
sectional view of Fig. 6's float-valve assembly and Fig. 7B is a cross-
sectional
view of the flush-vaive assembly showing a fill tube and a flow diverter.
Fig. 8 is a cross-section of a valve that employs the present invention's
teachings.
Fig. 8A is an isometric view of a stop member employed in an alternative
embodiment of the present invention.
Fig. 8B is a plan view of the Fig. 8A embodiment with parts removed.
1s Fig. 8C is an isometric view of the inner button member employed in the
Fig. 8A embodiment.
Detailed Description of Illustrative Embodiments
Referring to Fig. 1, a gravity-type flush mechanism includes a fill valve
mechanism 5 and a flush-valve mechanism 10 located in a toilet tank 16. Toilet
tank 16 is an exposed tank traditionally used in the US, or a concealed tank
fre-
quently used in the EU countries. Fig. IA shows flush-valve mechanism 10 in a
closed state wherein flush-vaive member 12 is seated in a flush-valve seat 14
formed in the bottom of toilet tank 16. In that seated position, the valve
member
12 prevents water from the tank 16 that has entered through flush ports 18 in
a
flush-valve housing 20 from flowing through a flush outlet 21 and a flush
conduit
22 to a toilet.
The flush mechanism includes a bias spring 24, which exerts a force that
tends to urge flush-valve member 12 off its seat 14. That is, flush-valve
member
12 is biased to an unsealed state but remains seated between flushes due to wa-
ter line pressure. This pressure that normally prevails in a flush-valve (or
piston)
chamber 25 because of its communication with a (pressurized-) water source con-
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-8-
duit 26. The flush-valve housing 20's cap 27 provides this chamber, and the
flush-
valve member is slidable within a cylinder 28 that the cap forms.
Referring to Figs. 1A and 1B, operation of flush valve mechanism 10 is con-
trolled by pressure in chamber 25 using a pilot valve diaphragm 30. The valve
member's seal ring 29 cooperates with diaphragm 30 to prevent escape of the
pressurized water from piston chamber 25 through a pressure-relief outlet 31
in
chamber 25's narrowed passage portion 32. Diaphragm 30 is resiliently deform-
able so pressure within passage 32 tends to lift it from engagement with a
pilot-
valve seat 34 and a similar pressure within a pilot chamber 36 acts on
diaphragm
30 in the opposite direction over a greater area. There is a small orifice 38
through which a pilot-vaive pin 40 extends, and orifice 38 permits water to
bleed
into it (through a relatively high flow resistance) to equalize the pressure.
Due to a
greater surface area of diaphragm 30 in chamber 36 there is a net force that
keeps
diaphragm 30 seated at seat 34.
To cause the system to flush, a solenoid 42 withdraws a second pilot-valve
member 44 from a seat to enable flow through a passage 46 that leads from
chamber 36 to a further passage 48 that leads to an outlet 50. The flow
resistance
through passages 46 and 48 is much lower than that through bleed orifice 38,
so
the pressure within chamber 36 drops. This pressure drop creates an opposite
force due to pressure within passage 32 to raise diaphragm 30 off its seat, as
Fig. 1 B shows. Diaphragm 30 serves as a pressure-relief valve that lowers the
water pressure within passage 32 (and thus within chamber 25) through a
plurality
of openings such as opening 51. As a consequence, the bias spring 24 can over-
come the force exerted by the pressure within chamber 25. The flush-valve mem-
ber 12 therefore rises, lifting its 0-ring seal 52 off the main valve seat 14
and
thereby allowing the tank to empty as shown in Fig. 1 B.
Importantly, 0-ring 52 may be replaced by a rubber or plastic seal having a
viper-shaped blade. The viper-shaped blade is designed both to provide a seal
on
seat 14 and to clean or remove any deposits located on the surface of seat 14.
The design and the action of the viper-shaped blade further helps in
preventing
water leaks.
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-9-
Gravity flush mechanisms are used with toilets that operate by way of suc-
tion created when the rising liquid level in the bowl drives water to the turn
in a ver-
tical conduit bend, where the pull of gravity then draws fluid down the
reverse
bend to siphon bowl contents out. The effectiveness of the desired suction de-
pends significantly on the profile of flush-valve movement as the flush valve
opens. In the present embodiments, the flush valves have a repeatable opening-
movement profile achieved by employing bias spring 24, which causes the valve-
opening motion. This repeatable motion is then essentially independent of line
pressure so long as the pressure-relief path has much less flow resistance
than
the path by which the chamber is repressurized.
Referring again to Fig. 1, after tank 16 is emptied, solenoid 42 seats valve
member 44 to close flow in passages 46 and 48 again. At least when the system
is battery-operated, it is preferable for the solenoid to be of the latching
variety as
described in US Patent 6,293,516 (but non-latching solenoid described in US
Pat-
ent 6,305,662 may also be used). That is, it is preferable for the solenoid to
re-
quire power to change state but not to require power to remain in either state
to
increase battery longevity. With valve member 44 seated, the pressure above
diaphragm 30 can again build to equal that below it, so diaphragm 30 again
seats
to cause pressure in chamber 25 to produce enough force to close this main
flush
valve 12 again. As a result, flow from Fig. 1's main line 59 fills the tank
through
float-valve assembly 5 best seen in Fig. 1 C.
Referring to Fig. 1 C, float valve assembly 5 uses diaphragm 63 to control
water filling tank 16. Specifically, water from line 59 flows through main
valve pas-
sage 60 formed by a valve cap 61 sealingly secured in a float-valve frame 62.
Fill-
valve diaphragm 63 is heid between valve cap 61 and a valve plug 64 threadedly
secured to the valve cap 61 and also sealed to the float-valve frame 62. At
rest,
resilient diaphragm 63 seats against a valve seat 65 that valve cap 61 forms.
Float valve assembly 5 also includes a ball float 66 freely floating in a
float cage
67. So long as ball float 66 does not plug a pressure-relief orifice 68, the
pressure
within passage 60 causes such a deformation of the resilient diaphragm 63 as
to
leave a clearance between it and the valve seat 65. Thus, water from a passage
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-10-
60 can flow around the valve seat 65 through a valve-cap opening 69 and open-
ings 70 in the float-valve frame 62.
The height of pressure relief orifice 68 is designed (or selected) to close
the
fill valve at a predefined water level. The resultant rising water in tank 16
eventu-
s ally lifts float 66 into a position in which it blocks pressure-relief
orifice 68. This
prevents the escape of water that has bled through a high-flow-resistance
orifice
71 into a chamber 72 formed by diaphragm 63 with valve plug 64. Thus, the pres-
sure within that chamber approaches that within passage 60. Moreover, that
pressure acts on the diaphragm 63's lower surface over a greater area than the
same pressure does on the diaphragm's upper surface. The resultant upward
force presses diaphragm 63 against its seat 65 and prevents further flow from
the
high-pressure line 59 into the tank. In the illustrated embodiment, the water
level
at which this occurs can be adjusted by adjusting the height within frame 62
of cap
61, plug 64, and parts connected to them.
A user can trigger a solenoid cycle manually by, for instance, using a push
button. Alternatively, the solenoid operates automatically in response to
sensed
user activity. For instance, a control circuit 84 mounted in a water-tight
enclosure
86 and powered by batteries 88 provides the solenoid drive current. To
determine
when to drive the solenoid, control circuit 84 generates and transmits
infrared light
through optic fibers 90 to a lens 92 and thereby irradiates a target region.
Another
lens 94 collects light that a target has reflected, and optic fibers 96
conduct that
light to a detector in control circuit 84. Typically, control circuit 84
assumes an
"armed" state when a target is detected. From that armed state, the subsequent
absence of a target will, possibly after some delay, result in the solenoid's
causing
the flush valve to open and close in the manner described above.
Fig. I D illustrates an embodiment of a tank type flusher having a solenoid
control circuitry mounted on the tank. For example, an electronics enclosure
98
may be mounted on the tank wall, above the tank's high-water line. Lenses 100
and 102 have the same functions as those shown in Fig. l's. In the Fig. 1 ar-
rangement, the object-sensor lenses are disposed at the tank's exterior; all
of the
control circuitry is disposed inside the tank and inside a water-tight
enclosure dis-
posed below the tank's high-water level. Lenses 92 and 94 can be mounted in
the
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-11-
same enclosure as control circuitry 104 so there is no need for optic fibers
to con-
nect the lenses to the control circuitry. However, the control circuitry is
now re-
mote from solenoid 42, which remains in the watertight enclosure 86. Operator
wires 106 lead from control circuit 104 to solenoid 42 to enable the control
circuit
to operate solenoid 42.
An alternative, wireless approach would be a hybrid of the approaches that
Figs. 1 and 1 D illustrate. Push-button or sensing circuitry in such an
approach
would be located remotely, as in Fig. I D, but the solenoid-drive circuitry
would be
local, as in Fig. 1. The remote circuitry would additionally include a
wireless
transmitter, and the local circuitry would include a wireless receiver
responsive to
the transmitter. For example, the transmitter and receiver may communicate by
way of Iow-frequency-say, 125 kHz-electromagnetic waves. Such electro-
magnetic waves may be modulated by pulse trains so encoded as to minimize the
effects of spurious reception from other sources. It may be preferable in
wireless
approaches for at least the local receiver to be located above the water line,
but
this is not required.
Whereas the Fig. 1 D arrangement employs the operator wires 106 to cou-
ple the remote control elements to the local ones, Figs. 2 and 2A illustrate
an ar-
rangement in which diaphragm 30 is controlled by a hydraulic line 108 (or a
pneu-
matic line). In the embodiment of Fig. 2A, the passage 46 by which the pilot
valve's upper chamber 36 is relieved communicates through an appropriate
fitting
110 with the hydraulic line 108. Another fitting 112 on a control-circuit
housing 114
places the hydraulic line 108 into communication with a valve passage 116
through which a solenoid 118 controls the flow.
In one state, solenoid 42 holds a valve member 120 in the position in which
it prevents flow from passage 116 to a further passage 122. The pressure in
the
pilot valve's upper chamber 36 would otherwise be exhausted to the tank
interior
by way of an exhaust hose 124 secured to another fitting 126 on the control-
circuit
housing 114. Exhaust hose 124 is provided for those installations in which the
control-circuit housing 114 is disposed outside the tank; such installations
would
need an exhaust hose to return water to the tank. If the housing 114 is
instead
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-12-
mounted inside the tank (above the high-water line), such an exhaust hose is
un-
necessary.
In the embodiment of Fig. I float-valve assembly 5 is provided separately
from flush-valve assembly 10. Alternatively, the embodiment of Fig. 2 has the
s float- and flush-valve assemblies located in a single unit. Frame 130 is
mounted
on the float-valve pilot assembly just as watertight enclosure 86 of Fig. 1.
Hydrau-
lic line 108 provides communication with the remote elements, so frame 130
does
not need to provide watertight protection to any local elements. Frame 130
serves
the same function as Fig. 1C's float-valve frame 62. In other embodiments
where
it is necessary to protect local elements from water in the tank, frame 130
can be
arranged to provide watertight protection.
According to another embodiment, Fig. 3 illustrates a pressure-type flusher
135 of the tank variety. Pressure-type flusher 135 includes a pressure vessel
136,
a flush valve assembly and a fill valve assembly. Pressure vessel 136 is
always
is under pressure introduced from main pressure line 142. A flush-valve member
140 controls flow from flush valve outlet 138 into the toilet bowl. Flush-
valve
member 140 is moveable within a cylinder 144 supported by fins 146 that extend
upward from the base of the pressure vessel 136. A bias spring 148 acting be-
tween a ledge 150 provided by cylinder 144 and a piston head 152 formed by
valve member 140 tends to lift valve member 140 off its seat 154. The pressure
in
a chamber 156 formed by cylinder 144 between piston head 152 and a cap 158
keeps the flush-valve member 140 in the illustrated position, in which it
squeezes
an 0-ring seal 160 against the valve seat 154. Seals 162 on the piston head
and
164 on the cap help to prevent the escape from the chamber 156 of pressurized
water that has been introduced into it by way of an input pressure line 166.
To cause the mechanism to flush, pressure in chamber 156 is relieved by
way of a pressure-relief conduit comprising a pilot-valve inlet passage 168, a
pilot-
valve outlet chamber 170, guide-tube inlet passage 172, a guide tube 176
secured
to the cap 158 by a collar 178 that the cap forms, and a bore 180, formed by
the
flush-valve member 140, that receives the guide tube 176. Seals 182 on the
guide
tube prevent escape of fluid from chamber 156.
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-13-
A pressure-relief valve 184 operates similarly to pilot valves previously de-
scribed to control flow through the pressure-relief conduit just described.
Specifi-
cally, fluid from the pilot-valve inlet passage 168 is ordinarily prevented by
dia-
phragm 186 from flowing around an annular valve seat 188 though valve-cap
openings 190 into the pilot-valve outlet chamber 170. When the pressure-relief
mechanism's solenoid 192 raises a valve member 194 so as to relieve the pres-
sure above diaphragm 186 through passages 196 and 198, pressure below the
diaphragm 186 lifts it off the valve seat 188 and permits relief of chamber
156's
pressure through the pressure vessel 136's flush opening 138. By thus
relieving
the chamber pressure through the valve member itself, the illustrated flush
mechanism avoids the need for a separate passage to the pressure-vessel exte-
rior.
The pressure type flusher of Fig. 3 includes control circuitry for controlling
solenoid 192 located locally. According to another embodiment, solenoid 192
may
1s be provided remotely, in a manner similar to that depicted in Fig. 2A. The
pres-
sure-relief passage could include conduits that are similar to Fig. 2A's hoses
108
and 124 but communicate with the embodiment of Fig. 3 passages 196 and 198.
Fig. 4 illustrates another embodiment of a gravity-type flush-valve system
200. Similarly as shown in Figs. 1A and 1B, gravity-type flush valve system
200
includes flush valve member 12 seated in flush-valve seat 14 formed in the
bottom
of toilet tank 16. In the seated position, the valve member 12 prevents water
in
tank 16 that has entered through flush ports 18 in flush-valve housing 20 from
flowing through flush outlet 21 and flush conduit 22 to a toilet.
As Fig. 4A shows, the flush mechanism includes bias spring 24. Bias
spring 24 exerts a force that tends to urge flush-valve member 12 off its seat
14.
But pressure that normally prevails in chamber 25 because of its communication
with pressurized- water source conduit 26 keeps the flush-valve member seated
between flushes. The flush-valve housing 20's cap 27 provides this chamber,
and
the flush-valve member is slideable within a cylinder 28 that the cap forms.
The valve member's seal ring 29 cooperates with a pilot-valve diaphragm
30 to prevent escape of the pressurized water from the piston chamber 25
through
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-14-
a pressure-relief outlet 31 in chamber 25's narrowed passage portion 32. The
pi-
lot-valve diaphragm 30 is resiliently deformable, so the pressure that
prevails
within passage 32 would tend to lift it from engagement with the pilot-valve
seat 34
if a similar pressure did not prevail within pilot chamber 36 and act on the
dia-
phragm 30 over a greater area. The reason why this pressure prevails within
chamber 36 is that a small orifice 38 through which pilot-valve pin 40 extends
permits water to bleed into it (through a relatively high flow resistance).
In this embodiment, 0-ring 52 may again be replaced by a rubber, polymer
or plastic seal having a viper-shaped blade. The viper-shaped blade is
designed
both to provide a seal on seat 14 and to clean or remove any deposits located
on
the surface of seat 14. The design and the action of the viper-shaped blade
fur-
ther helps in preventing water leaks.
To cause the system to flush, the user depresses Fig. 4's push button 202.
As will be explained in more detail below, this causes a remote pressure-
relief
valve 204 to permit flow to its outlet 206 from a pressure-relief tube 208
that com-
municates with pilot chamber 36 through passages 49 (Fig. 4A). This relieves
pressure in chamber 36. The flow resistance through that path is much lower
than
the bleed orifice 38's flow resistance, so the pressure within chamber 36
drops
and permits that within passage 32 to raise diaphragm 30 off its seat, as Fig.
4B
shows. Diaphragm 30 serves as a pressure-relief valve. Specifically, it
permits
the pressure within the passage 32 and thus within chamber 25 to be relieved
through a plurality of openings such as opening 53. As a consequence, bias
spring 24 can overcome the force exerted by the pressure within chamber 25.
Flush-valve member 12 (Fig. 4) therefore rises, lifting its 0-ring seal 52 off
the
main valve seat 14 and thereby allowing the tank to empty.
After the tank empties, remote valve 44 closes, as will be explained below
in more detail, to prevent any further flow out of chamber 36. The pressure
above
diaphragm 30 can therefore again build to equal that below it, so diaphragm 30
again seats to cause pressure in chamber 25 to produce enough force to close
the
main flush valve 12 again. As a result, flow from main line 59 fills the tank
through
a float-valve assembly best seen in Fig. 4. Specifically, as described above,
water
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-15-
from line 59 flows through main valve passage 60 formed by a valve cap 61 seal-
ingly secured in a float-valve frame 62 (Fig. 1 C).
Referring to Fig. 1 C, at rest, resilient diaphragm 63 seats against a valve
seat 65 that the valve cap 61 forms. At low water level, the pressure within
pas-
sage 60 causes such a deformation of the resilient diaphragm 63 as to leave a
clearance between it and the valve seat 65. Thus, water from passage 60 can
flow around the valve seat 65 through a valve-cap opening 69 and openings 70
in
the float-valve frame 62. The rising water in the tank eventually lifts the
float 66
into a position in which it blocks the pressure-relief orifice 68. This
prevents the
escape of water that has bled through a high-flow-resistance orifice 71 into a
chamber 72 that the diaphragm 63 forms with the valve plug 64. Then, the pres-
sure within that chamber approaches that within the passage 60. Moreover, that
pressure acts on the diaphragm 63's lower surface over a greater area than the
same pressure does on the diaphragm's upper surface. The resultant upward
force presses the diaphragm 63 against its seat 65 and prevents further flow
from
the high-pressure line 59 into the tank.
Referring to Fig. 5, remote valve 204 includes a movable valve member 205
actuated by button 202, for releasing pressure in tube 208. The relief tube
208
terminates in a valve inlet 210 and communicates with a main-valve entrance
chamber 212. Cooperating threads on a seal frame 214 and a valve core 216 se-
cure the latter to the former, which in turn is threadedly secured to the
housing
220's interior. A net 222 threadedly secured to the end of the valve core 216
bears against a washer 218 that holds a screen 224 in place. By flowing
through
the screen, water from the entrance chamber 212 can enter an annular space 232
sealed by an 0-ring 234 that seal frame 214 holds in place against housing
220's
inner surface.
A lip seal 234 mounted on seal frame 214 acts as a valve seat. In the illus-
trated, closed valve state a movable valve member 205 seats against that lip
seal.
When the valve is thus closed, a second lip seal 102 mounted on the valve mem-
ber 205 cooperates with lip seal 234 to prevent water from flowing from an
outlet-
passage entrance chamber 236, with which a core port 238 provides annular
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-16-
space 232 communication, through an annular outlet passage 240 and out the
valve outlet port 206.
The resultant pressure in the outlet-passage entrance chamber 236 exerts
a force against the lower lip seal 242 that would tend to unseat the valve
member
205, but the valve member remains seated because equal pressure in another,
seating-pressure chamber 244 acts over a greater area and thereby exerts a
greater, countervailing force. Pressure prevails in that seating-pressure
chamber
because, as Fig. 5A illustrates, the valve core forms a pin passage 246 in
which a
fluted core pin 248 is disposed to form a high-flow-resistance flow path from
main
valve entrance chamber 212 through a further screen 250 into the seating-
pressure chamber 244. Acting against the core pin's enlarged head 252, an
inter-
nal lip 254 retains the core pin.
The push button 202 is threadedly secured to an actuator rod 256 whose
stop surface 258 bears against a valve-member shoulder 260 that acts as a sta-
1s tionary stop. When depressing button 202, the user overcomes the force of
bias
spring 262 located in a spring recess 264 formed by the valve housing 220.
Spring 262 exerts return force on a collar 266 formed by the actuator rod.
When a user manually depresses push button 202, the actuator rod 256
bears against valve member 205, and the user overcomes fluid-flow resistance
(explained below) and the force from the seating-pressure chamber 244 to dis-
place the valve member 205 downward. This both unseats the valve member
from the upper lip seal 234 and draws water out of the seating-pressure
chamber
244 through passage 212. By unseating the valve, the user opens communication
between the outlet-passage entrance chamber 236 and the outlet passage 240.
That is, pressure in the pressure-relief tube is relieved through a valve flow
path
that includes the main entrance chamber 212, the annular space 232, core port
238, the annular outlet passage 240, and the main valve outlet port. An 0-ring
seal 266 mounted in an annular seal groove 268 that the actuator rod 256 forms
prevents leakage through the spring recess 264.
Actuator rod 256 and valve member 205 are cooperatively constructed and
arranged to relieve pressure in tube 208 and cause delay in pressure buildup
after
actuation. The actuator rod's end shaft 270 is slideable within the valve
member's
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-17-
central passage 272, so the bias spring 262 can urge that actuator-rod's stop
sur-
face 258 out of engagement with the valve member 205 when the user releases
the push button 202. The user usually releases the push button while most of
the
water has yet to drain from the flush tank. Therefore, there is a delay during
which
remote valve 204 remains open so that flush valve 205 also remains open. In re-
mote valve 204, valve member 205's movement from its unseated position to its
seated position increases the seating-pressure chamber's volume and thus ne-
cessitates flow into seating-pressure chamber 244 in order to return its
pressure to
the value that prevails at the inlet 210 and thus in the space 236 whose
pressure
tends to keep the valve member 205 unseated. However, the flow resistance of
the passage 246 (Fig. 5A) by which that make-up must flow into the seating-
pressure chamber 244 is so great that this flow causes a simplified pressure
drop
for several seconds. As a consequence, the force on the valve member 205
caused by the pressure within the seating-pressure chamber 244 is not great
enough to overcome the force from space 236s pressure, so the valve member
205 remains unseated for that length of time.
The precise duration of the delay between the user's release if the push
button 202 and the valve member's seating - and thus of the flush valve's
closing
- depends to a great extent on the difference between the seating-pressure
chamber's volumes in the two states. This in turn depends on the travel
permitted
by the illustrated valve-closed distance between the push button 202's stop
sur-
face 280 and the housing's end lip 282. A setscrew 284 enables installation
per-
sonnel to adjust that distance and thereby the length of time for which the
flush
valve is open. Therefore, remote valve 204 can vary flush duration by
adjustably
selecting the time flush valve 10 is opened.
Figs. 6 and 6A illustrate another embodiment of a gravity type flush 300 in-
cluding a fill valve 302 and a flush valve 304 constructed in a unitary
structure.
Flusher 300 is actuated by actuator 306. Flush valve 304 includes a bias
spring
310 keeps a gravity-type flush mechanism's flush-valve member 312 separated
from a flush-valve seat 314 formed on the inlet of a flush conduit 316
disposed in
the bottom of a toilet tank 318. As Fig. 6A shows in more detail, a lower main
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-18-
housing half 320 mounted by struts 322 on the flush conduit 316 forms a
pressure
chamber 324 above the valve member 312. Pressure chamber 324 includes a cyl-
inder 326 within which a piston portion 328 of the valve member 312 is
slideable.
Chamber 324 is ordinarily under pressure because of fluid communication that a
pressure line 330 provides between it and a pressurized-water supply connected
to passage 448. When that pressure prevails, it holds the valve member 312 in
a
seated position.
Pressure chamber 324's pressure ordinariiy prevails because a pilot-valve
diaphragm 332 secured in housing half 320 by a pilot-valve cap 333 ordinarily
co-
operates with the valve member's seal ring 334 to prevent escape of
pressurized
water from the chamber. The pilot-valve diaphragm 332 is resiliently
deformable,
so the pressure that prevails within chamber 324 would tend to lift it from
engage-
ment with a pilot-valve seat 336 and thus allow pressure relief if a similar
pressure
did not prevail within a pilot chamber 338 and act on the diaphragm 332 over a
greater area. The reason why this pressure prevails within the pilot chamber
338
is that a small orifice 340 through which a pilot-valve pin 342 formed by cap
333
extends permits water to bleed (through a relatively high flow resistance)
into the
pilot chamber. Thus, vaive member 312 remains in the seated position (not
shown) between flushes.
To cause the system to flush, the user depresses a push button 344 (Fig.
6B). As will be explained in more detail below, this causes a remote pressure-
relief valve 346 to permit flow to its outlet 348 from a pressure-relief tube
350 se-
cured at its other end by a fitting 352 to a plug member 354 mounted on cap
333.
This places remote valve 346's outlet 348 in communication with a plug member
354's interior passage 356 (Fig. 2) and thereby with the pilot chamber 338
through
passage 358. This relieves pressure in that chamber. The flow resistance of
the
path is much lower than that of the bleed orifice 340, by which the pilot
valve's
pressure is replenished, so the pressure within chamber 338 drops and permits
pressure chamber 324s pressure to raise diaphragm 332 off its seat.
Diaphragm 332 permits the pressure within the pressure chamber 324 to be
relieved through a plurality of openings such as opening 360. As a
consequence,
the bias spring 310 can overcome the force exerted by the now-reduced pressure
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-19-
within chamber 324. The flush-valve member 312 therefore rises to its open
posi-
tion (Fig. 6A), lifting its 0-ring seal 362 off the main valve seat 314 and
thereby al-
lowing water from the bank to flow out through the flush conduit 316.
The user typically doesn't keep the push button 344 depressed long enough
for the required flush volume to flow from tank 16 to the toilet bowl.
However, re-
mote valve 346 nonetheless remains open long enough. Referring to Fig. 6B,
push button 344 actually is a compound button consisting of outer and inner
button
members 364 and 366 held in a button frame 368 by a button cap 370. A flexibie
diaphragm 372 secured to button frame 368 by an actuator-chamber housing 374
biases inner bufiton 366 to the illustrated rest position, in which it
additionally holds
the outer button member 364 in its rest position.
Fig. 6C is a top isometric view of inner button member 366 co-operatively
arranged with outer button member 364, shown in Fig. 6E. Button member 366
includes a central land 376 extending from a generally disk-shaped layer 378
from
which four keys 380 extend radially. Button frame 368 (Fig. 6D) forms a set of
six-
teen partitions 382 extending radially inward. Those partitions 382 cooperate
to
define sixteen key guides, within any four of which keys 380 can slide. The
button
frame 368 also forms stop surfaces 384 at the bases of the key guides thus
formed. The stop surfaces 384 in the key guides occupied by the four keys at
any
one time are all arranged at the same level so that they stop all four keys
simulta-
neously. However, different sets of four stops are disposed at different
levels so
that placing the keys in different sets of the key guides results in different
amounts
of permitted button travel.
Referring again to Figs. 6C and 6E, each of the four keys 380 includes a
passage 386 therethrough. Outer button member 364 is generally annular but
forms four radially extending tabs 388 from which respective legs 390 extend.
Legs 390 register with passages 84 in a sliding arrangement shown in Fig. 6B.
When the user operates push button 344, he most often presses against
outer button member 364 and thereby depressed that member until its legs 390
reach the respective key guides' stop surfaces. Outer button member 364 bears
against inner button member 366 (moving it to the right in Fig. 6B causing it
to de-
form flexible diaphragms 372 from its illustrated position, to which it is
biased. A
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-20-
valve housing 392 secured to the actuator-chamber housing 374 holds in place a
second flexible diaphragm 394, which cooperates with diaphragm 372 and actua-
tor-chamber housing 374 to form an actuator chamber. The actuator chamber is
filled with an incompressible fluid, and button member 366's deformation of
dia-
phragm 372 forces the fluid through four angularly spaced openings 396 in a di-
vider wall 398 that the actuator-chamber housing 374 forms. In flowing through
openings 396, the fluid lifts the lip of an umbrella-type check-valve member
400
snap fit in a central divider-wall opening.
Referring still to Fig. 6B, umbrella-type check valve 400 and openings 396
and 398 are designed for fast expulsion and slow return of ejected fluid. The
fluid's motion urges diaphragm 394 against the force of a bias spring 401 and
thereby pushes to the right a valve member 402 slidably disposed in a valve
chan-
nel 404 formed by valve housing 392. Valve member 402 forms two annular re-
cesses in which respective 0-ring seals 406 and 408 are disposed, and
rightward
motion causes 0-ring 408 to extend into a widened portion 410 of channel 404
and thereby break the seal that it had theretofore maintained with the channel
wall.
Pressure theretofore prevailing in tube 350 is thereby relieved through
channel
404 and outlet passage 348. When the user depresses only the outer button
member 364, the point at which that members' legs 390 encounter their
respective
lands 384 determines how far into the widened channel portion 410 valve member
402 extends.
When the user releases button, flexible diaphragms 372 and 394 tend to
resume the rest positions to which spring 401 biases them, so they act to
return
the valve 346 to its closed state. To resume the rest positions, they must
move
the actuator chamber's fluid back through the dividing wall 398. But check
valve
400 prevents fluid from flowing through openings 396, and the only route
through
the wall that remains is therefore a bleed orifice 412, which imposes
significant
flow resistance and therefore a delay between the user's releases of the
button
and valve 346's closure.
The duration of the delay depends on the amount of diaphragm deformation
that occurred, and this in turn depends on how far button member 364 traveled.
The amount of that travel is determined by the selection of the key guides
into
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-21-
which that button member's keys 380 were placed; different-level stop surfaces
384 result in different amounts of travel of legs 390 before they encounter
those
stop surfaces, but the resultant delay is usually at least two seconds.
The delay imposed as a result of the user's depressing only the outer but-
ton member 366 is usually so selected as not to permit the tank to empty com-
pletely but still to permit enough flushing flow for most purposes. If the
user de-
sires a fuller flush, he instead depresses the inner button member 366's land
376
(Fig. 6C). Button member 366 can travel farther than member 364; it can travel
until it keys 380 reach respective stop surfaces 384. As a consequence, its
opera-
tion causes more of the incompressible fluid to flow through the divider wall
398,
and it thus requires more of the fluid to return upon the button's release
before the
valve 346 returns to its closed position. More of the tank's contents
therefore flow
into the toilet bowl to flush it.
Figs. 7A and 7B provide an enlarged view of flusher 300. When the water
zs level in the tank has fallen significantly below a full-tank level, a
freely floating float
410 (Fig. 7A) permits float valve 412 to open. That valve is mounted in an
upper
main-housing half 414 supported on the lower main-housing half. The main hous-
ing is provided in two halves so that the float-valve assembly 412's height,
and
thus the level to which the tank is allowed to fill, can be adjusted by means
not
shown.
A main pressure-inlet manifold 416, which feeds the conduit 330 by which
pressure chamber 324 is pressurized, forms a further outlet 418. Through this
out-
let it feeds a conduit 420 mounted on the upper main housing half 414 and
forming
at its lower edge a float-valve seat 422. Formed integrally with the conduit
420 is a
generally annular mouth portion 424 in which a pilot-chamber base 426 is
thread-
edly secured. That base cooperates with the conduit 420's mouth portion 424 to
form a float-valve pilot chamber 428 and secure within it a resiliently
deformable
float-valve diaphragm 430 that tends to seal against the float-valve seat 422.
However, a bleed orifice in which is disposed a positioning pin 434 formed by
the
pilot-chamber base 426 permits fluid from the conduit 420 to enter the pilot-
valve
chamber 428. When a pilot-valve member 436 is held by the float 410 against
the
outlet of a pressure-relief passage 438, the pressure in the pilot-valve
chamber
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-22-
428 can build up to equal the pressure in the conduit 420 and, prevailing over
a
larger area than the pressure from the conduit 420, hold the float-valve
diaphragm
430 seated so that it prevents the liquid in conduit 420 from flowing around
the
float-valve seat 422 through mouth-portion openings 440 and a port 442 to a
tank-
fill tube 444.
Referring still to Fig. 7A, when the tank level is low float 410 does not stop
pressure-relief passage 438, so pressure in the pilot-valve chamber 428 is
relieved
faster than it can be restored through the bleed orifice 432. The pressure in
con-
duit 420 therefore unseats the float-valve diaphragm 430, so water from
conduit
420 can flow into the fill tube 444.
Fill tube 444 is designed for filling the tank, and the tank-filling flow
tends to
reduce the manifold pressure (i.e. line pressure). Since that pressure is what
closes the flush valve, significant tank-filling flow might impair that
valve's closing
performance. Therefore, there is a flow restrictor 416 so that when the flush-
valve
member 312 is in its fully unseated position, water cannot flow at any
significant
rate from the fill tube 444 into the tank. Flow restrictor 446 is mounted on
the
flush-valve member and protrudes into the fill tube's outlet as to restrict
the tube's
flow area greatly. This has the beneficial effect of maintaining high pressure
in the
manifold 416 and thus the pressure line 430 by which, through bleed orifice
440,
the manifold pressure closes the pilot valve and thus imposes on the flush
valve
the pressure that closes it. In other words, the flow restrictor ensures that
there is
enough pressure to close flush valve 304 with significant speed. When flush
valve
302 does close, it retracts flow restrictor 446 from the fill tube 444 and
thereby al-
lows the tank to fill rapidly.
The flow-restrictor operation just described tends to make the flush valve's
operation more predictable in duration than it would otherwise be; tank
filling does
not adversely affect the pressure that operates to close the flush vaive.
However,
the pressure from the water source can vary, and this, too, could result in
unde-
sired variations in the delay between the remote valve's closing and that of
the
flush valve. Referring to Fig. 6, flush valve 304 includes a flow-rate
controller 448
interposed in the flow path by which the flush-valve-closing pressure is
supplied.
The particular type of flow controller 448 is not critical, but Fig. 7B
depicts one of
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-23-
the deformable-ring variety. A flow restrictor 450 disposed in the conduit
cooper-
ates with a resiliently deformable ring 452 to restrict the flow area through
which
pressurized water must flow to enter the pressure chamber that applies the
closing
force to the flush valve. If the supply pressure is relatively low, it does
not greatly
deform the ring, and the resultant flow area is relatively low, it does not
greatly de-
form the ring, and the resultant flow area is relatively great: the already-
low pres-
sure is not reduced much in flowing through the restrictor. If the supply
pressure is
high, on the other hand, it deforms the ring by a greater amount and thereby
re-
stricts the flow area more significantly. So a greater pressure drop from the
origi-
nally high pressure occurs. The flow-rate controller therefore reduces the
pres-
sure variation that the flush valve would otherwise experience. This reduces
varia-
tion in the speed at which the flush valve closes.
Plumbing installations can experience not only pressure variation but also
total pressure loss. In the absence of the present invention, such a pressure
loss
would permit the flush valve to open, causing an unintended flush. But a check
valve 454 is provided in pressurizer conduit 330 so that the pressure holding
the
flush valve closed is not lost when the line pressure is.
Fig. 8 illustrates another embodiment of a remote actuator used with flusher
300. Remote actuator 500 includes a valve 510, which controls flow from its
inlet
511 to its outlet 512. The user depresses a push button 513 to open valve 510.
The user typically will not keep the button depressed long enough for the
required
flush volume to flow. But the valve 510 nonetheless remains open long enough,
as will now be explained.
In the illustrated embodiment, push button 513 actually is a compound but-
ton consisting of outer and inner button members 514 and 516. Those button
members are disposed within an operator housing 518 that includes an outer
housing member 520 and an inner housing member 522 threadedly secured to it.
The outer housing member 520 forms a flange 524 that cooperates with an end
cap 526 to secure the valve assembly to some support such as a toilet-tank
wall.
An actuator frame 528 is threadedly secured to the inner operator-housing mem-
ber 522 and cooperates with it to clamp a flexible diaphragm 530 into
position.
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-24-
Flexible diaphragm 530 urges the inner button member 516 upward in Fig. 8, but
a
knee 532 that the outer operator-housing member 520 forms so engages a shoul-
der 534 formed by the outer button member 514 as to retain the inner button
member 522 within the housing.
A nut 535 that threadedly engages the actuator housing 528 secures a
valve housing 536 to the actuator housing 528 and thereby clamps into a fixed
po-
sition an annular lip 538 formed at the end of a second flexible diaphragm
540.
Together with the actuator housing 528, the first and second flexible
diaphragms
530 and 540 form an actuator chamber divided into first and second chamber
segments 542 and 544 separated by a divider wall 546 that the actuator housing
528 forms.
The inner and outer button members 516 and 514 are so sized that a user
depressing button 513 will ordinarily depress the outer button member unless
he
takes care to concentrate on the inner member only. When the outer button
member 514 is depressed, it in turn presses down on the inner member's plate
portion 547, and this causes the first flexible diaphragm 530 to deform in
such a
manner as to reduce the volume of the first chamber segment 542. But the actua-
tion chamber that segments 542 and 544 form is filled with an incompressible
fluid
such as distilled water, and a reduction in the first chamber segment 542s
volume
causes the second segment 544's volume to increase. Specifically, the incom-
pressible fluid flows from the first chamber segment 542, through openings
548,
past the lips of a flexible check-valve member 550, and into the second
chamber
segment 544. As a result, the second flexible diaphragm 540 deforms downward:
the second chamber segment grows in volume.
This deformation of the second flexible diaphragm 540 occurs against the
force of a compression spring 552, which is disposed within a spring chamber
554
that the second flexible diaphragm 540 cooperates with the valve housing 536
to
form. That spring bears against an actuator head 556 that in turn bears
against
the second flexible diaphragm 540 to bias it into the illustrated position. In
that po-
sition, an 0-ring 557 mounted on the actuator's shaft 558, which is disposed
within
a guide 560 that the valve housing 536 forms, keeps water in the inlet 511
from
flowing to the outlet 512. A second 0-ring 562 prevents inlet water from
flowing
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-25-
into the spring chamber 554. The just-explained downward deformation of the
second flexible diaphragm 540 in response to a user's pressing the push button
moves the lower 0-ring 557 into an expanded region 564 and thus breaks its
seal.
This permits flow from the valve inlet 511 to the valve outlet 512.
When the user releases the push button, spring 552 causes the second
flexible diaphragm 540 to return to the illustrated rest state. For that
return to oc-
cur, the incompressible fluid has to flow back from the second chamber segment
544 to the first chamber segment 542. Check-valve member 550 prevents that
return flow from occurring through the low-flow-resistance path that the
relatively
large divider-wall openings 548 provide. Instead, the returning fluid must all
flow
through a small divider-wall bleed orifice 572, so the return flow is slow,
requiring
at least two seconds before the actuator shaft 558 can reach a position in
which
the lower 0-ring re-seals against the guide 560's wall and again prevents main
valve flow.
Of course, the actual closure delay depends on the orifice size, the incom-
pressible fluid's viscosity, and the actuation-chamber size. But it
additionally de-
pends upon the degree of deformation from which the flexible diaphragms need
to
recover, and this in turn depends on the length of button travel. When the
user
pushes the outer button, outer-button legs 574 move downward through plate-
portion holes 575 until they meet a stop surface provided by an annular stop
member 576. The distance from legs 574's rest position to the position of the
stop
member 576 thus determines the button travel when the user pushes the outer
button member. If the user instead pushes only on the inner button member,
though, that button member can travel a little farther, since it does not stop
until
the inner button member's plate portion 547 encounters stop member 576. This
feature of enabling the user to choose between closure delays is of particular
utility
when the valve controls toilet flushing; pressing the outer button results in
a nor-
mal flush, while pressing only on the inner button results in a fuller flush.
In both
cases, it is the stop member 576s position that determines the button travel
and
thus the closure delay.
Stop member 576's position depends in turn on the valve's inlet pressure,
as will now be explained. The inner operator-housing member 522 and the stop
CA 02429531 2003-05-20
WO 02/42670 PCT/US01/43273
-26-
member 576 cooperate with a tension spring 580, which is secured to them, to
form a resiliently expandable stop. The stop defines an internal stop chamber
582, which 0-rings 583 and 584 seal. A check valve 585 allows fluid to flow
from
a pressurizer conduit 586 into chamber 582 from a pressurizer port 587. That
port
communicates with the inlet 511 by way of the clearance between the actuator
shaft 558 and the actuator guide 560's wall. Pressure at the valve inlet 511
thus
can pressurize the stop chamber 582. The tension spring 80 tends to urge the
stop member 576 toward the inner operator-housing member's lower end and
thereby reduce the stop chamber's size. But the force that the inlet pressure
ex-
erts on the stop member 576 acts against the spring force and thus tends to ex-
pand the expandable stop.
The degree of stop expansion depends on the inlet pressure: the greater
that pressure is, the more the actuator stop expands. Greater stop expansion
re-
sults in the button travel's being more limited and thereby in less delay
before the
main valve closes. This shorter closure delay tends to compensate for the
greater
main-valve flow rate that a higher pressure causes. That is, it reduces
pressure-
caused variations in the volume of liquid that a single push-button operation
allows
to pass through the main valve.
Now, the outlet pressure typically undergoes a sudden reduction when the
user operates the valve and thus permits flow from the valve inlet 11 through
the
valve outlet 512. But the pressurizer check valve 585, which readily permits
fluid
flow from the valve outlet 511 through the pressurizer conduit 585 to the stop
chamber 576 to pressurize it, retards flow through conduit 586 in the other
direc-
tion. It thereby tends to keep the stop expanded to the size that the inlet
pressure
dictated before the valve was opened. So the stop remains expanded throughout
the duration of a closure delay, i.e., throughout the time when the valve is
open.
The stop chamber pressure will nonetheless adjust to inlet-chamber pressure re-
ductions that occur while the valve is closed, because a bleed slot 588 formed
in
the valve member 590's seat permits depressurization over a longer time scale.
Other embodiments may instead provide a bleed passage 591 through the valve
member rather than around it.
CA 02429531 2008-11-21
-27-
Although, for the sake of simplicity, Fig. 8 depicts the stop member 576 as
providing a single-level stop surface, it may be advantageous to have it
provide
several levels of stop surface so that a choice of closure-delay range can be
made
while the valve is being assembled or installed. A stop member such as Fig.
8A's
stop member 576' may be employed for this purpose. That stop member is pro-
vided with a generally cylindrical extension 594, from which partitions 596
extend
radially inward to form key ways 598. Fig. 8B, which is a stop view of the
valve
assembly with its end plate 526 and outer operator-housing member 520 removed,
show that the outer button in such an embodiment forms keys 602 that fit into
four
to key ways spaced by equal angles from each other. As Fig. 8C shows, the
inner
button similarly forms keys 104 that fit into those key ways.
Fig. 8A shows that the different key ways have different-height stop sur-
faces 600. The heights repeat so that each key in any set of four key ways
spaced by 900 from each other, such as the set that keys 604 of Fig. 8C
occupy,
have the same height. When the button is assembled, the assembler chooses the
closure-delay range by selecting the 1 st of four key ways into which he
inserts the
outer-button and inner-button keys 602 and 604.
Having described various embodiments and implementations of the present
invention, it should be apparent to those skilled in the relevant art that the
forego-
ing is illustrative only and not limiting, having been presented by way of
example
only. There are other embodiments or elements suitable for the above-described
embodiments. The functions of any one element may be carried out in various
ways in alternative embodiments. Also, the functions of several elements may,
in
alternative embodiments, be carried out by fewer, or a single, element.
What is claimed is:
