Pinch valve element for plumbing fixture flush valve

The present invention discloses a pinch valve for replacing a diaphragm valve in a plumbing fixture. The plumbing fixture includes an inlet chamber defining a fluid inlet and in fluid communication with an inside chamber defining a fluid outlet. The pinch valve includes a cartridge member with a fluid inlet opening, a fluid outlet opening and a cartridge chamber defined by a cartridge chamber wall and in fluid communication with the fluid inlet opening and the fluid outlet opening. A flexible sealing member is positioned at least partially within the cartridge chamber and includes a wall with an inner surface defining an inner chamber and an outer surface defining an outer chamber between the outer surface of the flexible sealing member wall and the cartridge chamber wall. The inlet chamber of the plumbing fixture is in fluid communication with the inner chamber and the outer chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to flush valves used in connection with plumbing fixtures, such as toilets, urinals and the like, and in particular, to a replacement for a diaphragm valve in such a plumbing fixture.

2. Description of Related Art

Valves are used throughout many fluid transfer systems and in various applications, such as in the transfer and control of water conduit systems, and in particular in connection with plumbing fixtures in both residential and commercial settings. For example, flush valves are typically used for control and operation of toilets, urinals and the like, such that when a user actuates a handle, water flows through the flush valve into a basin portion and out the drain.

Presently, a common type of flush valve is a diaphragm flush valve. For example, such a diaphragm flush valve is disclosed in U.S. Pat. No. 4,327,891 to Allen et al. The Allen patent discloses the use of a diaphragm in a flush valve, where the diaphragm is made of molded rubber and serves to effectuate the flow of water from a water inlet, through the valve and to a water outlet. Further, the Allen patent sets forth the various components and sub-components of the flush valve according to the prior art.

Such diaphragm flush valves have several drawbacks. For example, the relatively small seal area in the diaphragm can become clogged with debris, which causes the flush valve to remain open, resulting in constant water flow. In addition, since the flush valve is pressurized, a small bleed hole is used in order to allow enough volume to flow through the valve in order to flush the toilet or urinal. This small bleed hole is easily clogged, which can also result in the malfunction of the valve. Still further, the flushing cycle of the diaphragm flush valve takes approximately seven seconds to complete, depending upon the flow rates and water pressure entering the valve, due to the design of the diaphragm of the flush valve. Since an upper chamber fills slowly, the valve is slowly “shutting off”. Therefore, a significant amount of water is wasted through the trap and sewer line during the sealing process. The trip lever seal area can also be blocked with debris, which causes the valve to flow continuously. Yet another drawback is that conventional diaphragm flush valves only work at water pressures greater than 35 psi, which is due to the difference in the diaphragm surface area and the diameter of the bleed hole.

Pinch valves have found use in various valve applications other than a diaphragm-type valve. For example, U.S. Pat. No. 4,111,391 to Pilolla discloses a pinch valve including a distortable rubber-like valve member in a generally cylindrical form. As disclosed in the Pilolla patent, the valve member has uniformly spaced projections and grooves enabling it to collapse upon itself and form a complete closure between opposite ends. Heretofore, however, the use of such a pinch valve as a replacement valve in the application of flush valves for plumbing fixtures has not been effective due to the different sealing arrangement bound in pinch valves in comparison to diaphragm valves. Therefore, there remains a need for an effective valve for replacing a diaphragm flush valve in a plumbing fixture.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a valve replacement for a diaphragm valve that overcomes the deficiencies of the prior art. It is another object of the present invention to provide a valve replacement for a diaphragm valve that has a decreased failure rate and, therefore, an increased cost efficiency. It is a further object of the present invention to provide a valve replacement for a diaphragm valve that has a larger seal area, such that small debris cannot be trapped in the seal area and hold the valve open. It is a still further object of the present invention to provide a valve replacement for a diaphragm valve that has a decreased flush time with a high flow rate and velocity, thereby being more water efficient. It is yet another object of the present invention to provide a valve replacement for a diaphragm valve that is capable of resetting at low pressure, such as when a facility loses mainline pressure.

The present invention is directed to a pinch valve for use in a plumbing fixture, and is particularly adapted for replacement of a diaphragm valve in a plumbing fixture. The plumbing fixture includes an inlet chamber defining a fluid inlet, which is in fluid communication with an internal chamber defining a fluid outlet. The pinch valve includes a cartridge member having a fluid inlet opening, a fluid outlet opening and a cartridge chamber defined by a cartridge chamber wall. The cartridge chamber is in fluid communication with the fluid inlet opening and the fluid outlet opening. A flexible sealing member is positioned at least partially within the cartridge chamber and has a wall with an inner surface defining a flow chamber and an outer surface defining a pressure chamber between the outer surface of the flexible sealing member wall and the cartridge chamber wall. The inlet chamber of the plumbing fixture is in fluid communication with the flow chamber and the pressure chamber.

In an undisturbed state, fluid force in the pressure chamber is at least equal to fluid force in the flow chamber. In this situation, the wall of the flexible member constricts inwardly and pinches, thereby preventing fluid flow through the flow chamber. However, when the pressure chamber is relieved of pressure, the fluid force in the pressure chamber is less than the fluid force in the flow chamber. When this occurs, the wall collapses to an unpinched position, thereby permitting fluid flow through the flow chamber and causing water to flow through the flush valve for flushing of the fixture.

The present invention is also directed to a plumbing fixture. The plumbing fixture includes an inlet chamber defining a fluid inlet in fluid communication with an internal chamber defining a fluid outlet. The plumbing fixture also includes a pinch valve having a cartridge member with a fluid inlet opening, a fluid outlet opening and a cartridge chamber defined by a cartridge chamber wall and in fluid communication with the fluid inlet opening and the fluid outlet opening. The pinch valve further includes a flexible sealing member positioned at least partially within the cartridge chamber and having a wall with an inner surface defining a flow chamber and an outer surface defining a pressure chamber between the outer surface of the flexible sealing member wall and a cartridge chamber wall. The inlet chamber of the plumbing fixture is in fluid communication with the flow chamber and the pressure chamber as described above.

The present invention, both as to its construction and its method of operation, together with the additional objects and advantages thereof, will best be understood from the following description of exemplary embodiments when read in connection with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to flush valves, and in particular to an improved valve insert for use in such valves. The valve insert is particularly useful for replacement of a traditional diaphragm-type valve insert for flush valves. Such traditional diaphragm-type valves are shown in U.S. Pat. No. 4,327,891, as depicted inFIG. 1herein. In such diaphragm-type flush valves, the flush valve2has a general hollow body10which includes an inlet connection12, an outlet connection15and a handle coupling connection16. The top of the valve body is closed by an outer cover18and an inner cover20. The inlet portion of the valve is separated from the outlet portion by a central throat22which is attached to the inside walls of the valve body10. A main valve seat24is formed on the top of the throat.

The valve is actuated by an operating handle26which is fastened to the valve body10by means of coupling nut28. The handle is connected to a plunger30which extends to the interior portion of the valve body. The plunger30is guided and supported by a bushing32and restored by a spring34. A rubber sealing cap or packing36is snapped on the end of bushing32and prevents leakage outward from the handle opening.

The annular valve seat24is normally closed by a diaphragm38. The diaphragm extends across the body10and defines an upper chamber40. The diaphragm has a by-pass42which provides fluid communication between the inlet side of the valve and the upper chamber40. A filter44may be provided to prevent clogging of the by-pass42.

The diaphragm38is attached at its outer edge to the valve body. The outer cover18clamps the diaphragm between a shoulder on the valve body and the inner cover20. The center of the diaphragm has an opening which allows fluid communication between the upper chamber40and the outlet14. A relief valve shown generally at46is attached to the diaphragm and normally closes the opening at the center of the diaphragm. The relief valve46includes a guide portion48having wings49. The wings49fit closely against the inside diameter of the throat22. The guide48also has a lip50. The lip supports a collar52. The relief valve46includes a clamping member54which is threadedly engaged with the guide portion48. The clamping member54clamps the inner edge of the diaphragm38between the member54and the collar52. The clamping member54has a hole in the middle which is normally closed by an auxiliary valve member56. This member is connected to a depending stem58which extends to a point opposite the actuating plunger30. The clamping member54may have a rubber liner to improve the sealing contact between the auxiliary valve member56and the clamping member.

The operation of this prior art valve is as follows. In the normally-closed position shown inFIG. 1, water pressure at the valve inlet is communicated to the upper chamber40through the by-pass42. Since the surface area subjected to the water pressure is greater on the upper side of the diaphragm, the water pressure forces the diaphragm down onto the valve seat24. This prevents water from flowing to the outlet14. When a user rotates the handle26in any direction the plunger30moves inwardly, tilting the stem58and moving the auxiliary valve member56out of the sealing engagement with the clamping member54. This relieves the pressure in the upper chamber40by allowing water to flow through the guide member48. With the upper chamber pressure relieved the inlet water pressure forces the diaphragm upwardly, off of the main valve seat24. Water then flows directly from the inlet, through the throat22and to the outlet14. When the diaphragm38and relief valve46move upwardly the auxiliary member56reseats, closing off the upper chamber, forcing the diaphragm back onto the main valve seat24to close the valve46. The guide48and its associated wings49contact the throat22to provide stability to the diaphragm as it moves. The guide keeps the diaphragm level as it closes and thus prevents chattering. Should the operating lever26be held overly long, the valve46will still operate as the stem58has a telescoping part which will allow it to return to its normal position even though obstructed by the plunger30.

As discussed in detail hereinabove, flush valves incorporating such a diaphragm38have numerous drawbacks and other deficiencies.

Accordingly, the present invention is directed to a valve element as a replacement for the diaphragm in a conventional valve body. More particularly, with specific reference toFIGS. 2–8, the valve element of the present invention includes a pinch valve replacement element100which is provided for use with a conventional flush valve body such as previously described in terms of the prior art including flush valve2′, a hollow body10′, an inlet connection12′, an outlet connection14′, and a handle coupling connection16′. In the present invention, pinch valve replacement element100replaces the diaphragm valve mechanism used in prior art valve bodies, and as such sits directly within hollow body10′ on main valve seat24′ in direct communication with central throat22′, providing a mechanism for regulating water flow through the valve body by way of central throat22′, as will be discussed in more detail herein.

Pinch valve replacement element100generally includes a cylindrical cartridge member102and a dynamic pinch-type flexible sealing member130provided within the cartridge member102. Cartridge member102is defined by a tubular cartridge chamber wall110extending between a first open end102forming a fluid inlet opening and a second open end104forming a fluid outlet opening, and further defining an internal chamber108extending therethrough. The internal chamber108provides direct fluid communication between the fluid inlet opening defined by first open end104and the fluid outlet opening defined by second open end106. A fluid channel120extends through the cartridge chamber wall110, desirably at a position adjacent first open end104. Such fluid channel120includes a fluid inlet opening122, which may be present on the top surface of cartridge member102adjacent first open end104thereof. Desirably, a plurality of fluid channels120are provided through the cartridge chamber wall110and may be spaced from each other, such as depicted inFIGS. 6A–6B.

The fluid inlet opening preferably has a diameter which is less than the diameter of the fluid inlet established through fluid channel156of upper clamping member150. In use, this fluid channel120provides a mechanism for fluid flow from the upper chamber40′ of the valve body into the pinch valve replacement element100, which fluid flow regulates sealing of the valve for operation of the valve, as will be described in more detail herein. Fluid channel120may further be provided with a filter device (not shown) which prevents solid or semi-solid material from flowing through or clogging the fluid channel120.

The pinch valve replacement element100further includes a flexible sealing member130positioned within the internal chamber108of the cartridge member102. The flexible sealing member130includes a flexible tubular wall132extending between a first open end132positioned adjacent first open end104of cartridge member102, and a second open end134positioned adjacent second open end106of cartridge member102. As such, the flexible sealing member130is positioned at least partially within the cartridge member108, and extends substantially between first open end104and second open end106of cartridge member102.

More particularly, the first open end134of the flexible sealing member130is fixed upon an upper annular rim112defined within the first open end104of the cartridge member102. In a similar manner, the second open end136of the flexible sealing member130is fixed upon a lower annular rim114defined within the second open end106of the cartridge member102. Any means of affixing the ends of the flexible sealing member130to the ends of the cartridge member102may be employed. Desirably, this is accomplished through a mechanical securement, such as through upper clamping member150and lower clamping member160, as best depicted inFIGS. 4 and 5.

Upper clamping member150desirably includes a generally disc-shaped cylindrical body extending between an upper, external surface152and a lower, internal surface154, with an internal fluid channel156extending therethrough. The outer cylindrical surface of upper clamping member150is threaded with external threads158for threaded engagement with internal threads105which extend within the inner surface of first open end104of cartridge member102. By threading such external threads158of upper clamping member150with the internal threads105of cartridge member102, the first open end134of the flexible sealing member130can be effectively trapped between the internal surface154of upper clamping member150and the upper annular rim112of cartridge member102, thereby effectively securing the entire annular rim of the first open end134of flexible sealing member130therebetween. In a similar manner, lower clamping member160desirably includes a generally disc-shaped cylindrical body extending between a lower, external surface162and an upper, internal surface164, with an internal fluid channel166extending therethrough. The outer cylindrical surface of lower clamping member150is threaded with external threads168for threaded engagement with internal threads107which extend within the inner surface of second open end106of cartridge member102. By threading such external threads168of lower clamping member160with the internal threads107of cartridge member102, the second open end134of the flexible sealing member130can be effectively trapped between the internal surface164of lower clamping member160and the lower annular rim114of cartridge member102, thereby effectively securing the entire annular rim of the second open end136of flexible sealing member130therebetween. As such, both of the ends134,136of the flexible sealing member130are statically sealed with respect to cartridge member102. Cartridge member102and upper and lower clamping members150,160may be constructed of any rigid material, for example a metallic material such as stainless steel, or a rigid polymeric material, such as polyethylene terephthalate.

With upper clamping member150and lower clamping member160secured to opposing ends of cartridge member102, fluid channel156of upper clamping member150defines an inlet opening for fluid flow into cartridge chamber108, and fluid channel166of lower clamping member160defines an outlet opening for fluid flow out of cartridge chamber108, as will be discussed in more detail herein.

Moreover, with flexible sealing member130secured as such within cartridge member102, the tubular wall132separates cartridge chamber108into two separate chambers. In particular, a first chamber is provided as pressure chamber142, defined between the inner wall surface of cartridge chamber wall110and the outer wall surface140of tubular wall132of flexible sealing member130. A path for fluid flow between this pressure chamber142and the external area of the pinch valve replacement element100(namely, upper chamber40′ of the valve body) is provided through the fluid channel120which extends through the cartridge chamber wall110of cartridge chamber102adjacent the first open end104thereof. A second chamber is provided as flow chamber144, defined as the interior chamber within inner wall surface138of tubular wall132of flexible sealing member130. The fluid channels156,166of upper clamping members150,160are in fluid communication with this flow chamber144. As will be discussed in more detail herein, fluid flow through the pinch valve replacement element100, and therefore fluid flow through the valve body itself, is regulated by the fluid pressure within pressure chamber142which regulates the pinching or collapsing of the flexible sealing member130to close or open this flow chamber144, thereby regulating fluid flow between fluid channel156and fluid channel166.

The flexible sealing member130is constructed of an elastomeric material, such as rubber, a polymeric material or other synthetic material having elastomeric properties. Further, in order to reduce the chances of failure and reduce the costs of maintenance, a portion or all of the walls of the flexible sealing member130may be reinforced with a semi-rigid material. Flexible sealing member130is moveable between a collapsed state as shown inFIG. 6A, in which the tubular wall132is collapsed, defining flow chamber144therein, and a constricted or pinched state as shown inFIG. 6B, in which the tubular wall132is pinched or gathered to form a closed structure in which flow chamber144is entirely closed off. In particular, flexible sealing member130is capable of folding to form a plurality of folded walls which mate with each other and meet together at the center of the pinched sleeve to form a generally complete closure. This folding may be assisted by providing a plurality of grooves148on the outer wall surface140to act as a weakened portion of tubular wall132of flexible sealing member130. Desirably, three grooves148are provided such that flexible sealing member130pinches off to form three pairs of mating wall structures which meet at a center point, closing off flow chamber144. It is contemplated that the inner wall surface138of tubular wall132may include protrusions at a point corresponding to each of grooves148such that, upon pinching off, the protrusions meet at a center point to ensure complete closing of flow chamber144.

Pinch valve replacement element100is positioned within the hollow body10′ of the flush valve2′, and in particular, within central throat22′. The cylindrical shape of the cartridge member102is dimensioned such that cartridge chamber wall110has an outer diameter which is substantially the same size, or only slightly smaller than, the internal diameter of central throat22′, such that a snug fit is achieved with little or no annular space therebetween. The cartridge member102may also include a rim portion116with a rim portion undersurface118. The rim portion undersurface118is sized and shaped so as to engage with and form a seal with the upper edge defining the main valve seat24′ of the central throat22′ of the plumbing fixture. For example, the undersurface118of the rim portion116may include a layer capable of forming a seal, desirably an elastomeric layer or other layer such as a coated layer, a bonded layer, or other similar seal area.

Cartridge member102further includes a plunger channel124extending through the cartridge chamber wall110at a location between the upper annular rim112within first open end104and the lower annular rim114within second open end106. In this manner, plunger channel124establishes a path for fluid flow between pressure chamber142and the external environment, namely outlet connection14′, through the cartridge wall110. When pinch valve replacement element100is positioned within central throat22′of the flush valve body, the lower end of the cartridge member102adjacent second open end106must be properly positioned such that the plunger channel124is aligned with plunger30′, which is interconnected with operating handle26′ and extends through hollow body10′ through coupling nut28′, bushing32′, spring34′ and packing36′ as described above in connection withFIG. 1with reference to the prior art. Desirably, plunger30′ may be positioned so as to extend slightly within plunger channel124, which extends through cartridge chamber wall110. As such, plunger channel124is desirably larger in diameter than plunger30′ to provide sliding movement of plunger30′ therein and to permit fluid to flow around plunger30′ through plunger channel124.

Moreover, plunger channel124includes a sealing member, and preferably a spherical sealing member such as ball seal180, for closing fluid channel120to prevent fluid flow therethrough. Desirably, such a sealing member is a ball seal180positioned within pressure chamber142and adapted to seal against the inner surface of the cartridge chamber wall110at the interior opening forming plunger channel124, as shown inFIG. 5. This sealing member may be constructed of any material capable of sealing fluid channel120for fluid flow, and is desirably an elastomeric material such as rubber. It is also contemplated that plunger30′ may be provided with an enlarged end surface to act as such a sealing member. Also, in embodiments wherein pinch valve replacement element100is provided as an integral unit for replacement of a diaphragm-type valve element for retrofitting an existing flush valve, a separate extension piece can be provided for attachment to the end of plunger30′ so as to extend within plunger channel124and seal off the opening and prevent fluid flow therethrough.

Assembly of flush valve2′ including pinch valve replacement element100is as follows. Flush valve2′ is provided with hollow body10′, and may be appropriately connected to a water source through inlet connection12′, and to a plumbing fixture such as a toilet, a urinal, or the like, through outlet connection14′. Also, operating handle26′, as well as the corresponding plunger30′, bushing32′, spring34′ and packing36′ components, may be connected to handle coupling connection16′ through coupling nut28′. Pinch valve replacement element100is provided within central throat22′, with rim portion116resting on main valve seat24′ in a sealing engagement. Pinch valve replacement element100is positioned such that plunger channel124is aligned with plunger30′, and desirably, such that plunger30′ slightly extends within plunger channel124. Inner cover20′, if provided, may then be placed over flush valve2′, with outer cover18′ thereafter threaded onto hollow body10′ to enclose flush valve2′. In this manner, pinch valve replacement element100provides a valve element for regulating fluid flow, in particular water flow, between inlet connection12′ and outlet connection14′.

As noted, the present invention is directed to a flush valve including the pinch valve element therein, as well as to the pinch valve element for use as a replacement or retrofit for a diaphragm-type valve. Accordingly, in use as a replacement or retrofit application, assembly of the flush valve2′ may first involve removing the outer and inner covers, and removing a diaphragm-type valve, such as the diaphragm38and all corresponding parts described in connection with the prior art with reference toFIG. 1. After removal of such diaphragm parts, the pinch valve replacement element100can be placed within the central throat22′ of hollow body10′ as described above, with plunger30′ aligned with plunger channel124, and with the inner and outer covers20′,18′ replaced onto hollow body10′.

In operation, flush valve2′ including pinch valve replacement element100therein is connected to an appropriate source of water through inlet connection12′ and to an appropriate fixture through outlet connection14′. Pinch valve replacement element100is sealed off because flexible sealing member130is pinched. This is achieved by the fluid force in the pressure chamber142being at least equal to the fluid force in the flow chamber144. In particular, water flows into upper chamber40′ of flush valve2′ from inlet connection12′, and passes into fluid inlet opening122and through fluid channel120into pressure chamber142. When sufficient water is present within pressure chamber142, the flexible tubular wall132of flexible sealing member130pinches and/or folds along grooves148, closing off flow chamber144and forming a closed structure as seen inFIG. 6B. In this state, the tubular wall132of the flexible sealing member130folds inwardly and pinches the inner wall surface138of the flexible sealing member138against itself. Accordingly, this prevents fluid flow through the flow chamber144.

To operate the valve, i.e., to provide water to the fixture, water flow must be established through cartridge chamber108, which is dynamically sealed off through flexible sealing member138as described above. Accordingly, the pressure which forces flexible sealing member138pinched closed must be relieved. This is achieved by activation of the operating handle26′ of the flush valve2′. More particularly, rotational movement of operating handle26′ in any direction causes the plunger30′ to moves inwardly. Such movement causes the end of plunger30′ to pass through plunger channel124and to contact and displace ball seal180from sealing engagement with plunger channel124. As such, water flows from within the pressure chamber142through the plunger channel124and out through outlet connection14′ to the plumbing fixture connected thereto. This outflow of water from within the pressure chamber142relieves the pressure within the pressure chamber142, which reduces the fluid force in the pressure chamber142to less than the fluid force in the flow chamber144. With this reduction in pressure, tubular wall132of the flexible sealing member130relaxes or collapses to an unpinched position, thereby permitting fluid flow through the flow chamber144. As such, water is then free to flow directly from the inlet12′, through upper chamber40′, and down through the cartridge chamber108, more particularly down through fluid channel156, through flow chamber144, out through fluid channel166and to the outlet14′ for delivery to the associated plumbing fixture.

Plunger channel124cannot remain permanently open or sufficient pressure cannot build in the pressure chamber142. Accordingly, during this water flow through flush valve2′, sufficient water passes through the flush valve2′ through cartridge chamber108to flush the fixture, while water is simultaneously passing through fluid inlet opening122and through fluid channel120into pressure chamber142. This flow of water into pressure chamber142gradually increases the fluid pressure within pressure chamber142, and causes, the sealing member, which is provided for example through ball seal180, to re-engage and re-seal the opening to plunger channel124to prevent any further fluid flow therethrough. When the plunger channel124is sealed by the ball seal180as such, fluid can collect in the pressure chamber142at a more rapid pace. As such, the fluid force within pressure chamber142increases to a level at which it is greater than the fluid force within flow chamber144. At this point, tubular wall132of flexible sealing member130once again constricts or pinches, thereby closing off flow chamber144from further fluid flow therethrough.

As noted, when the seal between the ball seal180and the plunger channel124is disengaged or broken, the ball seal180must be re-engaged with the plunger channel124in order to stop the fixture from running continuously. There are several manners of accomplishing this result. For example, a sloped surface186may be provided immediately adjacent and be sloped toward the inner wall opening at plunger channel124. In this manner, when the plunger30′ pushes and disengages the ball seal180, and after the fluid is finished exiting through the plunger channel124, the ball seal180slides or rolls back down the sloped surface186and to re-engage with the opening at plunger channel124.

As indicated, pinch valve replacement element100can be provided as an integral unit with flexible sealing member130secured within cartridge member102as described. In this manner, the pinch valve replacement member100can be easily inserted into the central throat22′ of hollow body10of a flush valve body, and serves as an easy replacement for a removed diaphragm valve element. Accordingly, the present invention is directed not only to a pinch valve as described hereinabove, but also to a plumbing fixture, such as a flush valve assembly, which includes such a pinch valve in combination with a flush valve assembly.

FIG. 8depicts a pinch valve replacement element200in a further embodiment of the present invention. In particular, in the embodiment depicted inFIG. 8, the cartridge member is substantially identical to the previously described embodiment, with the exception that the fluid channel does not extend through the cartridge chamber wall. Instead, in the present embodiment, a different type of upper clamping member250is provided for securing the flexible sealing member within the cartridge member, which upper clamping member250includes a fluid channel220including a fluid inlet opening222. Also, the flexible sealing member includes a bleed hole226extending through the wall thereof at a position adjacent and aligned with the fluid channel220. The pinch valve replacement element200works in a similar manner as in the previous embodiment, except that in order for the flexible sealing member to constrict and pinch the valve closed, water enters into the pressure chamber through the upper clamping member250as opposed to through the cartridge chamber wall of the cartridge chamber, that is, through the fluid inlet opening222, through the fluid channel220, and through the bleed hole226, as shown inFIG. 8. It is noted that a plurality of fluid channels220may be provided through the upper clamping member, and may be properly spaced thereabout.

FIG. 9depicts a further embodiment of the present invention, in which the mechanical activation mechanism for the flush valve is substituted or replaced with an electronic activation mechanism, such as a solenoid mechanism. In particular, in the embodiment ofFIG. 9, the flush valve2′ including the pinch valve replacement element100is identical to the embodiment described in connection withFIGS. 1–7, but substituting the previously described operating handle with a solenoid assembly190. Solenoid assembly190may be any assembly capable of providing a linear movement upon activation, as is known in the art. Upon activation, solenoid assembly190causes a linear movement of plunger30′, which in turn causes activation of the pinch valve assembly for water flow through the flush valve for flushing of the fixture, as previously described. Activation of the solenoid assembly may be accomplished in any known manner, such as through contact with a push button192which activates the solenoid assembly190. Alternatively, an electronic sensor assembly (not shown) may be associated with solenoid assembly190to cause automatic activation thereof, as is known in the art.

FIG. 10depicts a further variation on the embodiment ofFIG. 9, with the solenoid element acting as a flow regulator as opposed to merely providing a linear actuator for activation of a plunger element. More particularly, as with the embodiment ofFIG. 9, the flush valve2′ including the pinch valve replacement element100is identical to the embodiment described in connection withFIGS. 1–7, but substituting the previously described operating handle with a solenoid assembly390and eliminating the need for a ball seal. Instead, sealing of the pressure chamber142is achieved through water flow through the solenoid assembly390.

For example, the solenoid assembly390may be interconnected to the pinch valve replacement element100through a flow channel394extending through the cartridge wall110, thereby establishing fluid communication between pressure chamber142and the solenoid assembly390. Solenoid assembly390includes a housing which defines an interior flow chamber391therein, with a flow port392extending through the housing and providing a path for fluid communication between the interior flow chamber391and outlet14′, and with flow channel394in fluid communication with interior flow chamber391. Solenoid assembly390further includes a solenoid coil393which surrounds a plunger395biased by spring396to the right, as illustrated in the drawings, or toward a position closing the flow port392. The solenoid assembly390is attached to the valve body10′ through a coupling nut28′, and is interconnected with pinch valve replacement element100through a tubing such as flow channel394. Solenoid assembly390may further be interconnected with an electronic sensor element for activation thereof.

In operation, the plunger395is biased through spring396to a position closing and sealing flow port392. In this position, a sealed environment is established such that pressure chamber142can fill with water as described previously, thereby constricting flexible wall132of flexible sealing member130and closing or pinching off the flow chamber144. When the solenoid assembly390is activated, such as through an infrared sensor (not shown), electric power is applied to the solenoid coil393, causing the plunger395to move away from flow port392. Water which is contained within pressure chamber142is then released and can then flow through flow channel394into interior flow chamber391and out through flow port392where it is released into outlet14′. This releases the pressure within pressure chamber142which in turn causes the flexible wall132of flexible sealing member130to collapse, thereby opening flow chamber144and permitting water flow therethrough.

After the solenoid assembly390has been activated for a predetermined time period, such as five seconds, the electric power to the solenoid coil393is cut off, and the spring396with again bias plunger395against flow port392, thereby closing it off and sealing off interior flow chamber391. Pressure can then accumulate therein, and water will again flow through fluid inlet opening122and fluid channel120into pressure chamber142, and will once again pinch off flow chamber144when sufficient pressure is established to constrict flexible wall132.

FIG. 11depicts yet a further embodiment of the present invention, in which the pinch valve replacement element400includes a pressure chamber442which is designed to be pressurized through an external air source as opposed to water flowing through the flush valve. More particularly, the activation mechanism of the previously described embodiment ofFIG. 1–7is replaced with an activation mechanism including a pressure source P. Cartridge wall410does not include any fluid channel extending therethrough, nor any plunger channel extending therethrough. Instead, an air channel494extends from pressure source P through the cartridge wall410and into pressure chamber442. Pressurized air can therefore be provided from pressure source P through air channel494and into pressure chamber442. When the air pressure within pressure chamber442is sufficient, flexible wall132of flexible sealing member130constricts to pinch off the flow chamber144. To activate the valve, an activation mechanism, such as push button492, causes the pressure source P to release the air pressure provided within pressure chamber442, such as through an air bleed hole (not shown). This causes a decrease in the air pressure within pressure chamber442, and once the pressure falls below a predetermined threshold, the water pressure acting upon the flexible wall of flexible sealing member130will overcome the air pressure and collapse flexible wall132, thereby opening flow chamber144for water flow therethrough. After a predetermined period of time, pressure source P will once again provide air pressure through air channel494to re-pressurize pressure chamber442, which in turn will cause the flexible wall132of flexible sealing member130to constrict and again pinch off flow chamber144, stopping the flow of water therethrough. In such an embodiment, it is important to ensure that pressure source P, as well as air channel494and pressure chamber442, are appropriately sealed from both the external environment as well as to the internal water flow within the valve assembly, so as to be able to maintain proper pressure regulation therein and prevent water from entering the pressure source P.

The present invention provides a more durable flush valve requiring less maintenance through the use of the pinch valve element as opposed to a standard conventional diaphragm-type valve. Due to the large seal area established by the wall132of the flexible sealing member130closing in on itself, even if debris is trapped or engaged in the pinched area, a seal is still realized. Also, the large diameter secondary fluid inlet opening established by fluid channel156is not easily clogged. In addition, the present invention provides a valve element that has a single static seal area as opposed to multiple sealing areas as in the diaphragm valve12according to the prior art.

The pinch valve replacement element100of the present invention is capable of achieving flush flow-through times of about 3.5 seconds with a very high flow rate velocity when used in connection with a standard flush valve. Moreover, the pinch valve element is capable of being reset at very low fluid pressures, and therefore can reseal itself and close off water flow even when a facility loses mainline pressure.

This invention has been described with reference to the preferred embodiments. Various modifications and alterations will be apparent upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations.