A valve assembly including a main body, a gate and an actuator. The main body defines a fluid chamber, with an inlet fluidly coupled to the fluid chamber, and an outlet also fluidly coupled to the fluid chamber. The gate has a first portion and a second portion connected to one another and both are subjected to a fluid pressure within the fluid chamber. The first portion is configured to close the outlet when the fluid chamber is pressurized due to a closing fluid force acting on the first portion. The second portion provides a counter-acting fluid force to the closing fluid force when the fluid chamber is pressurized. The actuator is coupled to the first portion or the second portion and is configured to provide a net opening force on the gate to open the outlet.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to fluid controlling valves, and, more particularly to, valves that control the flow of fluids using pressure of the fluid to balance the force needed to open the valve.

2. Description of the Related Art

Numerous patents have issued dealing with problems associated with pilot operated valves, with a focus on how to reduce valve failures due to contaminants becoming lodged in the pilot and diaphragm apertures. Pilot valves operate on the principle of opening and closing an output pilot aperture that is part of a flexible diaphragm assembly, which in turn opens and closes the main fluid passage between the valve input and an output port. The valve input port is normally connected to the source of fluid, such as a pressurized water source. The valve output port is normally connected to a water consuming portion of an appliance, such as a clothes washing machine or dishwashing machine. An input pilot aperture allows fluid to enter a pilot chamber for the purpose of supplying fluid necessary to force the flexible diaphragm to a valve closed condition. This occurs when the output pilot aperture is closed to fluid flow by the de-energizing of a solenoid-controlled plunger. As with all pilot operated valves, the input pilot aperture (typically in the diaphragm) is always smaller in area than the output pilot aperture to allow a larger volume of fluid to escape through the output pilot aperture than can flow through the input pilot aperture. The blocking of the input pilot aperture(s) by contaminants can result in failure of the pilot valve to properly close, resulting in possible property damage. With this in mind, many design improvements have been patented to reduce the possibility of pilot aperture clogging by contaminants that may exist in the fluids that are being controlled by the pilot valve.

U.S. Pat. No. 3,593,957 issued to Dolter et al on Jul. 20, 1971 describes a pilot operated valve that utilizes small filter holes incorporated in the flexible diaphragm assembly to reduce the possibility of contaminants lodging in the input pilot aperture of the valve. This feature, or variations thereof, have been incorporated extensively in pilot valves that are in use today. Although it does offer an advantage over previous designs, experience has indicated that, because of the size of the filter holes and the limited number of holes provided, the contamination of the filter holes can lead to the failure of the pilot valve to close properly. One variation incorporates twelve holes molded into the rubber diaphragm, each hole being on the order of twenty-five thousandths of an inch in diameter. In such designs, when the pilot valve is in an open condition, allowing fluid to flow between its input and output ports, there will be continuous fluid flow through the filter holes and both the input and output pilot apertures. This continuous flow provides the opportunity for any fluid contaminants to clog the filter holes.

Richmond, in U.S. Pat. No. 5,269,333 issued Dec. 14, 1993 addresses the above problem by partially blocking fluid flow through the pilot apertures when the pilot valve is in an open condition, allowing fluid to flow from the input to the output ports. To accomplish this partial blocking of fluid flow through the input pilot aperture, an actuation chamber opening is molded into the diaphragm valve seat. When the diaphragm valve seat is pushed against the surface of the guide tube it substantially closes the pilot aperture to fluid flow. As described in the patent, the surface that the diaphragm valve seat encounters is slightly roughened to allow a micro-flow of fluid through the input pilot aperture. This micro-flow is necessary to allow the valve to change from an open condition to a closed condition when the solenoid is de-energized and the associated plunger closes the output pilot aperture.

There are two problems that become apparent when observing the design of Richmond. The first problem is the fact that a micro-flow is required, which allows continuous fluid flow through the pilot apertures when the pilot valve is open to fluid flow. Although the flow rate is small it still presents the opportunity for contaminants to clog the pilot apertures.

A difficulty with prior art technologies is their reliance on orifices or small apertures and their vulnerability to clogging with small contaminates.

What is needed in the art is a valve that has the advantage of small actuation forces, yet not being vulnerable to orifice clogging.

SUMMARY OF THE INVENTION

The present invention is directed to a valve, and more particularly a fluid flow control valve using balanced pressure to reduce the energy required to open and close the valve.

The present invention provides a fluid control system having a housing and a connected valve assembly including a main body, a gate and an actuator. The main body defines a fluid chamber, with an inlet fluidly coupled to the fluid chamber, and an outlet also fluidly coupled to the fluid chamber. The gate has a first portion and a second portion connected to one another and both are subjected to a fluid pressure within the fluid chamber. The first portion is configured to close the outlet when the fluid chamber is pressurized due to a closing fluid force acting on the first portion. The second portion provides a counter-acting fluid force to the closing fluid force when the fluid chamber is pressurized. The actuator is coupled to the first portion or the second portion and is configured to provide a net opening force on the gate to open the outlet.

In another embodiment of the present invention there is provided a valve assembly including a main body defining a fluid chamber, a gate and an actuator. The gate has a first portion and a second portion connected to one another and both subjected to a fluid pressure within the fluid chamber. The main body has an inlet fluidly coupled to the fluid chamber and an outlet fluidly coupled to the fluid chamber. The gate controls fluid flow from the inlet to the outlet, the first portion being configured to maintain the gate in a closed position thereby preventing fluid flow from the inlet to the outlet when the fluid chamber is pressurized due to a closing fluid force acting on the first portion. The second portion providing a counter-acting fluid force to the closing fluid force when the fluid chamber is pressurized. The actuator is coupled to the first portion or second portion and is configured to provide a net opening force on the gate to open the outlet.

An advantage of the present invention is that the valve controls a large fluid flow with a reduced size actuator.

Another advantage of the present invention is that it avoids the problems with orifice clogging of pilot valves.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly toFIGS. 1 and 2, there is shown a water consuming appliance10in the form of a washing machine10including a fluid control system12in the form of a water vacuum break assembly12connected to washing machine10. Vacuum break assembly12includes a housing14, a temperature sensor16, a valve assembly18and a valve assembly20. Temperature sensor16is adjacent to a mixing cavity in which water from both the hot and cold supply are mixed and the temperature is controlled by a control device, not shown. Valve assemblies18and20are respectively assigned to cold and hot water supplies that are coupled in a conventional manner by way of a hose to hot and cold water supplies. Valve assemblies18and20are substantially similar and for all practical purposes are identical in every respect. For the sake of convenience only valve assembly18will be discussed, with the understanding that the attributes of valve assembly18are also included in valve assembly20. Although a washing machine10is depicted the present invention may be utilized to control the flow of any fluid, whether or not it is included in a household appliance.

Valve assembly18includes a solenoid22for operative activation by a control system, not shown. Although solenoid22is depicted, it is understood that a control mechanism other than a solenoid may be utilized in operating valve assembly18. Hot and cold water is mixed in a mixing chamber contained in vacuum break assembly12, the chamber exists between valve assemblies18and20. A control system variously activates valve assemblies18and20to control the temperature of water that travels through the mixing chamber of vacuum break12.

Now, referring toFIG. 3is shown details of a prior art valve assembly118, which can be understood as being used in a prior art assembly12to control water in appliance10. Valve assembly118includes a housing120with a fluid chamber122, an inlet124, an outlet126, a diaphragm128with orifices130, an actuator132, an actuator chamber134, and a pilot orifice136. Here diaphragm128also serves as a seal keeping fluid from passing from inlet124to outlet126. Pressure from the fluid in chamber134that has passed through orifices130and the spring of actuator132serve to keep fluid from flowing to outlet126. When actuator132is activated then it retracts upward removing its seal of orifice136. The size of orifice136is larger than the combined size of orifices130. When the fluid in chamber134passes through orifice136there becomes a pressure differential on the two sides of diaphragm128causing diaphragm128to lift upward and unseal allowing the fluid to flow from inlet124to outlet126. When actuator132is deactivated then diaphragm128is moved toward the sealing position and since orifice136is sealed the fluid that passes through orifices130equalizes the pressure on each side of diaphragm128so that the fluid pressure itself holds diaphragm128in the sealed position.

As mentioned earlier, valve assemblies118, known as pilot valves, are vulnerable to clogging that can cause failure of the valve to open or close depending upon the extent of clogging of orifices130and/or136. Another problem with pilot valves is that they are dependent upon fluid pressure to move the diaphragm, and if the fluid pressure is low the pilot valve will not function properly. The present invention will now be discussed to illustrate the inventive nature of still being able to use a small actuating force to control a pressurized valve, as with a pilot valve, but not having the vulnerabilities of the pilot valves that are widely used.

Now, additionally referring toFIG. 4there is illustrated in a cross sectional view of an embodiment of a valve assembly200of the present invention. Valve assembly200includes a main body202defining a fluid chamber204, an inlet206fluidly coupled to the fluid chamber204, and an outlet208fluidly coupled to the fluid chamber204. There is a gate210having a first portion212and a second portion214connected to one another and both subjected to a fluid pressure within the fluid chamber204

First portion212, is in the form of a sealing member212is configured to close the outlet208when the fluid chamber204is pressurized due to a closing fluid force (as in a downward directed pressure) acting on the first portion212holding sealing member212in a closed position. Second portion214, in the form of a diaphragm214, provides a counter-acting fluid force (as in an upward or opposite force) to the closing fluid force when the fluid chamber204is pressurized.

An actuator216is coupled to first portion212or second portion214of gate210and actuator216is configured to provide a net opening force on gate210to open outlet208allowing fluid flow from inlet206/chamber204. Actuator216can be in the form of a solenoid216having an electromagnetic coil218a thin walled housing220, a biasing member222, a plunger224, and a coupling member226. Electromagnetic coil218is coupled to a controller, not shown, and is activated as in the prior art. Housing220is coupled to main body202in a fluid tight manner. Biasing member222can be in the form of a spring located within housing220. Plunger224has a magnetic property, being attracted to an electromagnetic field provided by coil218so as to move against spring222and to pull gate210. Coupling member226is connected to a distal end of plunger224allowing a convenient coupling to gate210as detailed later.

The size of sealing member212and the size of diaphragm214are selected so that the counter-acting fluid force is optimized relative to the closing fluid force to thereby provide a balancing force to the closing fluid force. This optimized counter-acting force may be selected by defining the effective areas of members212and214, such that the counter-acting force is less than the closing force, more than the closing force, or generally the same as the closing force, thus allowing other biasing elements to provide the controlling aspect of the valve. This allows for the opening and closing of valve200with a smaller activation force, supplied by actuator216, than would be needed to overcome the closing fluid force. In the illustrated embodiment biasing member222is arranged to bias the gate210to a closed position with a biasing force. Actuator216, when activated, overcomes the biasing force of spring222less any net opening force, which is supplied by the combination of the pressure against diaphragm214less the closing fluid pressure. When gate210is in an open position the closing fluid force and the counter-acting fluid force are reduced.

Diaphragm214is coupled to main body202and to gate210in a fluid tight manner, with no openings or orifices therein. Diaphragm214is illustrated as being symmetrical about a perpendicular axis established as the direction in which plunger224moves, although other configurations are also contemplated.

Actuator216includes an actuator chamber portion228, with diaphragm214defining a part of the actuator chamber228boundary. Actuator chamber portion228is fluidly coupled to outlet208by way of a passageway230that allows actuator chamber portion228to be fluidly coupled to outlet208. Passageway230is an opening that passes through gate210, and more specifically through sealing member212.

Plunger224is a moving member224within the actuator chamber portion228that is coupled to the gate210. Moving member224is coupled to gate210by coupling member226in part of the passageway230. This allows passageway230to serve both a coupling function but also allowing fluid flow therethrough to equalize pressure in actuator chamber228with outlet208.

Now, additionally referring toFIG. 5, valve200is illustrated in an open position with gate210separated from outlet208. Coil218is activated to overcome the bias of spring222with an upward force having been supplied by the fluid pressure against diaphragm214to help overcome the closing force of water pressure on gate210. Once lifted the pressure differential across diaphragm214is lessened due to the presence of passageway230, which is another advantage of the present invention, since the opening force is not then needed to overcome the closing force.

Now, additionally referring toFIG. 6, there is shown a more robust illustration of valve assembly200. Housing220is coupled to main body202by a threaded member232that serves to also compress and seal diaphragm214to main body202. Coupling member226is seen in passageway230as previously discussed. Additionally, details of gate210can be seen where sealing member212is shown coupled to diaphragm214by way of compression of a first part234and a second part236. Second part236has an elastomeric seal238that interacts with a sealing profile240of outlet208.

It should be appreciated that the terms “inlet” and “outlet” are used herein for convenience of description and not intended to be limiting, since fluid pressure in the fluid chamber will flow in a direction from high pressure to low pressure when the fluid chamber is pressurized and thus determine which port is the inlet and which port is the outlet. Inlet206can have a screen, such as a filter, associated therewith and be connected to a pressurized fluid source, such as a water feed line, to provide pressurized fluid within fluid chamber204. In some embodiments, the inlet206can have threads formed on an outer surface of the inlet206for connecting to the pressurized fluid source. The outlet208, on the other hand, can be fluidly coupled to a relatively low pressure destination so fluid can flow through fluid chamber204to the low pressure destination from the pressurized fluid line. In some embodiments, the outlet can be barbed to connect to a hose fluidly coupled to the low pressure destination. The valve assembly200described herein may be used, for example, in washing machines10, dishwashers, oil and gas transmission lines, or any other application where selective pressurized fluid feed is used. It should therefore be appreciated that the valve assembly200described herein can be used in many different applications.

To selectively control fluid flow through outlet208, valve assembly200, gate210is formed with the first portion212and the second portion (here a diaphragm)214defined about a gate210centerline which usually is coaxial with an outlet208centerline, the first portion212having a first diameter about the gate centerline connected to the second portion214having a second diameter about the gate centerline which is less than the first diameter. The effective areas of the first portion and the second portion being established by the diameters. As can be seen, the first portion can be an enlarged diameter portion of the gate and the second portion214can be another enlarged diameter portion of the gate in the form of diaphragm214and connected to the first portion212by a rod, the second portion having a smaller diameter than the first portion. The relative effective areas of the first portion212and the second portion214can be configured so that either the closing force or the counter-acting force is larger to provide an inherent net force. It is also contemplated to closely balance the forces so that an active control selectively holds the valve in the desired position. When the first portion212has a larger effective area than the second portion214and is positioned adjacent to the outlet208, the first portion212is configured to close the outlet when the fluid chamber is pressurized due to a closing force acting on the first portion212which is greater than a counter-acting fluid force acting on the second portion214. In other words, the closing force acting on the first portion212due to the fluid pressure, biases the first portion212toward the outlet208to cover the outlet208, with the opposing counter-acting force acting on the second portion214due to the fluid pressure, being less than the closing force. In this sense, the gate210is mechanically/fluidically “normally closed” when the fluid chamber204is pressurized. For certain applications, a spring222can provide the necessary closing force to bias the gate210into the closed position.

To open the gate210, actuator216is coupled to gate210and is configured to provide a net opening force, which, when combined with the opposing counter-acting force caused by the fluid pressure, overcomes the closing force acting on the first portion212to move the first portion212away from the outlet208to thereby open outlet208, allowing pressurized fluid to escape via outlet208. The actuator may be, for example, a solenoid or other construction coupled to the second portion214via the enlarged diameter portion at an end of the second portion214which is diaphragm214or other sealing element. Once the actuator216is activated to provide the net opening force, the first portion212of the gate moves away from the outlet208, allowing pressurized fluid in the fluid chamber to flow through the outlet and out the fluid chamber. Once the net opening force is removed by, for example, deactivating the actuator, the first portion can move back toward the outlet and seal the outlet, preventing further fluid flow through the outlet from the fluid chamber.

As can be seen, the diaphragm214can fluidly separate the fluid chamber from an additional chamber (chamber228). A runoff channel230is formed which fluidly couples the additional chamber228to the outlet208so the fluid pressure formed “behind” the diaphragm214in the additional chamber228provides the counterbalancing fluid pressure on the first portion212opposed to the fluid pressure within the fluid chamber, reducing the amount of opening force which needs to be provided by the actuator216to open the gate210. The runoff channel230can also pressurize the additional chamber228after the outlet opens to reduce the amount of net force needed to close the gate210. Further, the runoff channel230can safely prevent fluid leakage out of the valve assembly in the event that the diaphragm214bursts or otherwise fails by fluidly coupling the additional chamber to the outlet. By counterbalancing the pressures in the additional chamber228and the fluid chamber204, the magnitude of the opening force generated by the actuator216to produce the net opening force can be reduced so actuators216of relatively small size can be used to open the gate and uncover the outlet while being less prone to failure from contamination.

From the foregoing, it should be appreciated that the previously described valve assembly200benefits from having both the first portion212and the second portion214subjected to the same fluid pressure within the fluid chamber, combined with assistance from the use of the runoff channel or otherwise. Such a configuration can minimize the effect that fluid pressure variations have on the operation of valve assembly200. The fluid pressure variations may be, for example, due to differences in local service water pressures in water utility lines. Further, since the openings in the valve assembly, as in passageway230, can be dimensioned to be relatively large, as opposed to typical pilot valves which have small apertures, the previously described valve assembly200is less prone to failure caused by particles entrapped in the pressurized fluid than typical pilot valves. Even further, balancing the fluid forces as previously described reduces the effect of high fluid pressure on the net opening force the actuator must provide to open the outlet, which allows for reasonably sized actuators to be used even when the fluid pressure in the fluid chamber is relatively high.

Referring now toFIG. 7, an alternative embodiment of a valve assembly300formed according to the present invention is shown (with similar elements having the same numbers of the previous embodiment, but increased by100) which includes a fluid chamber304with an inlet306, an outlet308, and a gate310including a first portion312and a second portion314subjected to a fluid pressure within fluid chamber304. As can be seen, first portion312and second portion314are pivotally connected to one another at a pivot350defining a pivot axis so the gate has a “see-saw” action. First portion312can define a first pivot length L1between a first end of the first portion and a second end of the first portion and the second portion314can define a second pivot length L2between a first end of the second portion and a second end of the second portion, the second pivot length can be different than the first pivot length so the fluid force acting on the first portion and second portion due to the fluid pressure can be the same or tend to bias the “see-saw” toward either end. As can be seen inFIG. 7, the first portion312of the gate and the second portion314of the gate are both placed within the fluid chamber304so the gate310can be biased by the spring with the balance of the fluid forces being biased or neutral. In this embodiment first portion312and second portion314are not in-line, but are angled relative to one another. Such an arrangement allows an actuator316connected to the second portion314to produce a net opening force extending in a direction which is generally parallel to a first portion312axis of the first portion312in order to open the outlet308, and may be useful to meet space requirements in certain applications. The valve assembly300has an additional fluid chamber328on a side of diaphragm314opposite the fluid chamber304, with the additional fluid chamber328being fluidly coupled to the outlet308by a runoff channel330, similarly to the previously described valve assembly.

In any of the previously described embodiments, certain measures can be included to reduce the risk of valve assembly malfunction. For example, in some embodiments the valve assembly may incorporate a “cage” assembly around the first portion of the gate in the event that the first portion and the second portion separate from one another in a manner that might uncontrollably leave the outlet opened, with the cage assembly keeping the first portion of the gate in an area adjacent the outlet and oriented so the vacuum formed at the outlet can pull the first portion to the outlet and close the outlet. In other embodiments, the valve assembly can incorporate motion limiting stops at, for example, the first portion and second portion of the gate to prevent excessive movement of either portion during operation. In other embodiments, the valve assembly can incorporate motion guides at any of the moving parts, including but not limited to the portions of the gate and the actuator, to direct motion in a desired manner to promote desired operation and/or reduce the risk of wear and breakage of any of the moving parts. The foregoing measures are exemplary only, and other measures are contemplated as being included in valve assemblies formed according to the present invention.

From the foregoing, it should be appreciated that exemplary embodiments of the present invention can take advantage of counter-balancing forces provided by fluid pressure, either directly or indirectly, acting on the previously described first portions and second portions of gates to reduce the effect that varying fluid pressures have on the opening force required to open an outlet. The counter-balancing forces can act on a gate with the first portion and the second portion connected directly in-line with one another, or a gate with the first portion and the second portion pivotally connected to one another in a “see-saw” arrangement. In either arrangement, the relative diameters, lengths, thicknesses, etc. of the first portion and second portion can be adjusted to produce desired respective forces from the fluid pressure acting on the first portion and second portion, with the fluid pressure forces acting on the first portion, which can close the outlet, being countered by the fluid pressure forces acting on the second portion, so an actuator can exert a relatively small net opening force on the second portion to open the outlet from the normally closed position of the first portion.

Now, additionally referring toFIGS. 8 and 9, there is illustrated three parts of gate210and how they are assembled. First part234is inserted through an opening in diaphragm214and inserted through second part236. While first part234is pressed toward second part236a shaped heated tool is used to form end242as shown inFIG. 9, changing a cylindrical shape to that shown to thereby form gate210as an integrated assembly. A notch244in first part234is used so that coupling member226can slide into part234.

Now, additionally referring toFIG. 10, there is shown an exploded perspective view of valve200, which here additionally has a screen and flow regulator assembly246insertable into inlet206. Threaded member232is separate from thin wall metal housing220allowing the assembly to thereby eliminate scrubbing that would otherwise occur between the face of diaphragm214and member232. Additionally, the thin wall housing220improves the efficiency of solenoid216.

Now, additionally referring toFIGS. 11A and 11Bthere are illustrated two versions of sealing profiles240, here referred to as240A and240B. Sealing profiles240A and240B provide a distinct diameter for seal238to contact as gate210closes. Seal238can be made from EPDM or some other flexible resilient material. Seal profile240and flat seal238provide for initial contact at exactly the desired diameter, to ensure consistency of the force and provides a large enough contact area to protect the seal material from exceeding its maximum recommended stress or specific pressure.