Fluid handling – With leakage or drip collecting
Reexamination Certificate
2003-11-13
2004-09-21
Walton, George L. (Department: 3753)
Fluid handling
With leakage or drip collecting
C073S04050R, C073S046000, C122S504000, C122S507000, C137S067000, C137S068110, C251S074000, C251S294000, C285S013000
Reexamination Certificate
active
06792967
ABSTRACT:
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to a valve system that detects the presence of a water leakage and turns off an associated valve in order to stop the flow of the water, thus avoiding significant property damage. More particularly the invention pertains to such applications as clothes washing machines, dishwashing machines, toilets, sinks, and refrigerators equipped with ice cube makers, which occasionally are the source of water leaks due to broken hoses, faulty water level detectors, and the like.
Insurance companies have recently disclosed that water damage claims exceed fire damage claims. This emphasizes the need for the preventive measures that are provided by this invention. Since the invention does not require any electronic circuitry or complex mechanical devices to function, it provides a cost-effective and reliable means of turning off the source of water leakage.
2. Description of Prior Art
There are numerous water leak detection systems, most of which involve the use of an electronic means for sensing the presence of fluids such as water. The sensor elements of such systems typically involve measuring the conductivity of the water and use such a detection means to energize a solenoid or other such device to turn off an associated water valve. Not only does the electronic circuitry add cost and reduced reliability, it also requires the presence of electrical power to function. If a water leak occurs coincidentally with an electrical power outage, the valve will fail to accomplish its purpose, unless auxiliary power is supplied.
There are several prior art patents that provide water shutoff protection utilizing a water sensor that changes physical properties when placed in contact with water, thereby activating a valve shutoff device. Upon review it will become evident that these patents are intended for use on water heaters. Installation of such shutoff devices requires plumbing skills such as cutting into the existing water source pipe and soldering the new valve device in place or installing the necessary threaded fittings to accommodate the new valve. In many locations it would involve hiring a licensed plumber to comply with local building codes. The cost and complexity of such an installation often is a deterrent to undertaking the project. As will be seen by the following disclosure the proposed water shutoff system of the present invention is intended for use on the indicated appliances such as clothes washing machines, etc. and can be easily installed. Since no knowledge of plumbing skills is required, this invention would lend itself to do-it-yourself installation.
One device described in U.S. Pat. No. 2,798,503, dated Jul. 9, 1957, issued to Carver et al, utilizes a water softenable link that dissolves when coming in contact with water leaking from a water heater into an associated drip pan. As described, the cable attaching the water softenable link to the shutoff valve must be positioned directly beneath the shutoff valve so that the sofltenable link can be anchored in the drip pan. While appropriate for this installation it would not provide the flexibility to be applicable on other applications.
Another device described in U.S. Pat. No. 3,920,031, dated Nov. 18, 1975, issued to Maxfield provides a water shutoff device associated with a water heater application. The water detection means involves the use of a water-soluble material held in compression by a spring. The water detection means is placed in a drip pan that surrounds the base of the water heater such that, as water leaks from the faulty water heater, it will reach a level to dissolve the detection means which in turn releases a spring driven valve that is plumbed into the water supply line of the water heater.
Another device described in U.S. Pat. 5,632,302, dated May 27, 1997, and issued to Robert M. Lenoir, Jr. provides two different means of specifically dealing with water heater leakage. One means involves the use of an electrical sensor to detect the presence of water leakage specifically from a water heater in order to activate a solenoid to turn off an associated water valve located in the cold water input pipe of the water heater. A second described means involves the use of a thin, dissolvable strip, which is in tension, and dissolves in the presence of water thus releasing a spring mechanism which, in turn, activates a spring loaded valve specifically located in the cold water input pipe of a water heater. There are two basic drawbacks to this second means as described. First, the use of a standard ball valve in such an application requires the use of a spring-loaded valve with a very strong spring. Ball valves typically involve full contact seals such as O-rings on both the inlet and outlet sides of the rotating ball. These O-rings produce a great deal of pressure on the ball, thus requiring inordinate rotational torque to close the valve, making the valve reliability questionable. Second, the dissolvable strip as described in the invention is shown in tension. Most such materials, which might be used as described, are composed of a water soluble, crystalline structure that exhibits poor tensile strength, thus making it unreliable and subject to premature failure. As will be seen later, the present invention overcomes the above shortcomings and provides an easily installed system for water and, where applicable, non-water water systems.
Yet another U.S. Pat. No. 6,024,116, dated Feb. 15, 2000, issued to Almberg et al, again deals specifically with water leak detection in water heater applications. It provides a water softenable latch that, when exposed to water, will release a valve mechanism from its open to closed state thus turning off the water supply. In addition the invention turns off the gas supply to the water heater.
Most prior art found addresses the subject of water leak conditions as they pertain to water heaters. The following invention description pertains more specifically to use with clothes washing machines, dishwashing machines, toilets, sinks, and refrigerators equipped with ice cube makers that often use flexible hoses in their individual applications.
SUMMARY OF THE INVENTION
This invention provides a simple, reliable means of detecting and shutting off the source of most common water leaks involved with clothes washers, dishwashers, toilets, sinks, and refrigerators equipped with ice cube makers by utilizing a spring loaded shutoff valve in conjunction with a water sensor. Although the following invention description focuses primarily on those appliance applications listed above, which involve water leakage, it could likewise apply to other applications involving the use of other non-water fluids, where applicable. As will be seen later, the valve described in this invention utilizes a flow-through central element that allows water to flow through its central opening in normal operation but closes the water flow patly when activated to its closed condition. The use of this flow-through central element, in conjunction with a water sensor and activation mechanism, provides a compact, simple water shutoff device. The use of this valve does not preclude the use of other types of valves by those skilled in the art to accomplish the goals of this invention.
The water sensor described in this invention utilizes a water-soluble substance in a compression mode. Other methods for containing the water-soluble material, for example, in a bending, torsion, or tension mode, as devised by those skilled in the art, should not detract from the spirit of this invention. The water-soluble substance could be composed of such materials as sugar, salt, or the like. These materials exhibit relatively high strength in compression when dry and lose most if not all of that strength when exposed to a fluid such as water. As will be shown later with regard this invention, a spring maintains pressure against the water-soluble substance and will initiate a closure of the associated valve when the water-soluble substance dissolves. The substance used i
Hill Robert Charles
Walton George L.
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