Fluid handling – With leakage or drip collecting
Reexamination Certificate
1999-07-06
2001-02-13
Walton, George L. (Department: 3753)
Fluid handling
With leakage or drip collecting
C122S504200, C122S507000, C137S554000, C251S129050, C251S129120, C251S129130, C251S251000, C251S249500, C307S118000, C340S605000, C340S636210, C361S178000
Reexamination Certificate
active
06186162
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to the problem of monitoring water leakages occurring in commercial and household water systems. In a more specific aspect the invention pertains to apparatus for automatically cutting off the water supply upon the detection of a leak.
A problem of great concern is that of water damage to carpeting, flooring, walls and furniture due to water leakage resulting from faulty water heaters, defective plumbing fixtures, appliances such as washing machines and dishwashers, as well as damage resulting from such unforeseen disasters as earthquakes and fires. The seriousness of this problem is evidenced by large a volume of patents.
By way of example U.S. Pat. No. 5,240,022 discloses an automatic shut-off. U.S. Pat. No. 4,845,472 provides an apparatus which responds to the sensing of water leakage from a water line of a hot water system. U.S. Pat. No. 5,190,069 utilizes wires embedded in insulation tape carrying leak detecting liquid sensing elements. U.S. Pat. No. 5,229,750 utilizes a float and solenoid valve combination to control a cut-off in the event of a water leak. U.S. Pat. No. 5,632,302 discloses an overflow protection shut-off device for use with a water heater.
An investigation of this prior art shows that most of the patents, such as U.S. Pat. No. 4,845,472, U.S. Pat. No. 5,428,347, and U.S. Pat. No. 5,655,561 generate audible alarms to signal a detected leak. Of these U.S. Pat. No. 4,845,472, U.S. Pat. No. 5,428,347, and U.S. Pat. No. 5,655,561 additionally disclose the use of solenoid-actuated valves in the water supply line. U.S. Pat. No. 5,229,750 and U.S. Pat. No. 5,632,302 also disclose the use of solenoid-actuated valves to cut off a water supply. U.S. Pat. No. 5,029,605 points out that deposits that accumulate in pipes and valves over a period of time may impede the actuation of solenoid-type valves. Also avoiding the use of solenoid actuated valves is U.S. Pat. No. 5,240,022, which incorporates a ball valve in the water supply line. To hold the ball valve in an open position it is coupled to a rotor and a spring is attached to the rotor exerting a counterclockwise torque on the rotor. The rotor is then locked in a valve-open position by a latching arm. The end of the latching arm contacts a trip arm that receives its retaining torque from a wire spring. A trip wire actuates the trip arm. This trip wire is a metallic memory alloy wire which contracts when heated. Heating is effected by a circuit actuated by the water detector. As a consequence the latch aim is released and the rotor rotates to a valve-closed position.
Also of interest for disclosing a ball valve is U.S. Pat. No. 5,334,973. This valve controls flow into a hot water tank by using a mechanical drive in conjunction with a multilayer moisture sensor which encases the water tank liner.
While U.S. Pat. No. 5,240,022 overcomes the problems of solenoids, it is subject to several disadvantages. In addition to requiring a rotor, a latching arm, a trip arm, a trip wire and various springs, allowances had to be made for the ball valve high rotational forces, primarily due to the friction between the valve ball and the O-ring seals. In addition the ball valve must be reset to its open position by turning a knob, which frequently is not always easy. The invention herein provides an improvement which permits the use of a ball valve without the problems encountered in U.S. Pat. No. 5,240,022. All of the above mentioned patents are incorporated herein by reference.
This leak detection and shut-off apparatus is an improvement over the known prior art apparatus.
SUMMARY OF THE INVENTION
The prior art describes a water shut-off system that incorporates a water shut-off valve adapted for installation in a water supply line, and for turning off a supply of water when a leaking condition exists. That system utilizes a device consisting of a pair of adjacently disposed electrodes which conduct an electric current when water is present. Also included with the device is a radio frequency transmitter adapted to transmit a digitally encoded signal when the said electric current is sensed. A receiving means receives that radio frequency signal. On the reception of the signal the receiving means actuates an electrical circuit so that the said electrical circuit can close the water supply line shut-off valve. By the invention herein such a water shut-off system is improved.
By this invention a timing logic is incorporated in the actuated electrical circuit. This timing logic causes current flow to a motor as electric pulses. The motor has a drive shaft which is geared down to provide a reducer output shaft which rotates slowly, and that output shaft is coupled to a ball valve. The ball valve requires a rotation of ninety degrees from open to closed, and a further ninety degree rotation from closed to open. A cam operated switch is also coupled to the output shaft. The cam switch prevents current flow to the motor after a ninety degree cycle, which either closes or opens the valve. When the valve closes a reset switch must be used to actuate the timing circuit to initiate the flow of current to reopen the ball valve.
It is an aspect of this invention to provide brake means adapted to prevent further drive shaft rotation when the cam switch prevents current flow.
It is an aspect of this invention to provide that a microprocessor timed signal prevents interruption of a valve operating cycle due to “close valve” signals being received from both manual and automatic inputs within a predetermined time interval, and another aspect to provide that the status of the ball valve is stored in the microprocessor in the event of the ball valve in the event of AC power failure.
It is another aspect of this invention that the cam means is provided with cam surfaces adapted to depress and release a double throw pushbutton cam switch so that said switch alternately cuts off current flow actuated by the receiving circuit and the reset switch.
It is yet another aspect of this invention to provide that the generated electric pulse is a five second pulse and the motor drive shaft speed is eight to ten rpm.
This leak detection and shut-off apparatus is relatively simple and inexpensive to manufacture, easy to install and efficient for its intended purpose.
REFERENCES:
patent: 3680831 (1972-08-01), Fujiwara
patent: 3770002 (1973-11-01), Brown
patent: 4252088 (1981-02-01), Frisby
patent: 4264901 (1981-04-01), Petersen et al.
patent: 4324268 (1982-04-01), Jacobson
patent: 4428398 (1984-01-01), Mito et al.
patent: 4754949 (1988-07-01), Fukamachi
patent: 4845472 (1989-07-01), Gordon et al.
patent: 5029605 (1991-07-01), Dowling et al.
patent: 5060859 (1991-10-01), Bancroft
patent: 5099867 (1992-03-01), Emery
patent: 5156190 (1992-10-01), Staley, Jr.
patent: 5190069 (1993-03-01), Richards
patent: 5229750 (1993-07-01), Welch, Jr. et al.
patent: 5240022 (1993-08-01), Franklin
patent: 5334973 (1994-08-01), Furr
patent: 5428347 (1995-06-01), Barron
patent: 5632302 (1997-05-01), Lenoir, Jr.
patent: 5655561 (1997-08-01), Wendel et al.
patent: 5713387 (1998-02-01), Armenia et al.
patent: 5877689 (1999-03-01), D'Amico
patent: 6003837 (1999-12-01), Raymond, Jr. et al.
Bryan, Jr. J. Rodney
Purvis Michael J.
Cohn, Powell & Hind
Walton George L.
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