Overflow protection for a washing machine
First Claim
1. An improvement for an overflow protector of a control circuit of a liquid supply portion of a fillable tub that interrupts a supply of liquid to the tub in response to a sensed failure of the control circuit, regardless of a liquid level of the fillable tub, the improvement comprising:
- an electrically controlled liquid valve;
a liquid level sensing circuit;
a controller operatively coupled to the liquid level sensing circuit and the electrically controlled liquid valve, the controller emitting a regularly varying control signal that is operatively received by the liquid level sensing circuit;
the liquid level sensing circuit emitting a regularly varying sensor signal indicative of a level of liquid in the tub in response to the regularly varying control signal; and
a lockout circuit operatively coupled to the liquid level sensing circuit and the electrically controlled liquid valve, the lockout circuit interrupting power to the liquid valve in response to an interruption in the regularly varying sensor signal, the presence of the regularly varying sensor signal being indicative of the proper operation of both the liquid level sensing circuit and the controller.
2 Assignments
0 Petitions
Accused Products
Abstract
Improved overflow protection for washing machines and other applications in which a liquid from a controllable valve fills a tub is achieved by a circuit in which a single pulse train generated cooperatively by a pressure sensor and a controller is monitored by a lockout timer. If an interruption in the train of pulses occurs that is longer than a predetermined time-out period indicating a failure of either the pressure sensor or the controller that would otherwise prevent the valve from shutting off the flow of liquid into the tub, the lockout timer will cause the valve to turn off. The controller is also able to override the lockout timer and cause a relay to shut off power to the controllable valve to force it off if the pressure sensor detects a continued rise in liquid level after the controller has signalled the controllable valve to shut off.
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Citations
32 Claims
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1. An improvement for an overflow protector of a control circuit of a liquid supply portion of a fillable tub that interrupts a supply of liquid to the tub in response to a sensed failure of the control circuit, regardless of a liquid level of the fillable tub, the improvement comprising:
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an electrically controlled liquid valve; a liquid level sensing circuit; a controller operatively coupled to the liquid level sensing circuit and the electrically controlled liquid valve, the controller emitting a regularly varying control signal that is operatively received by the liquid level sensing circuit; the liquid level sensing circuit emitting a regularly varying sensor signal indicative of a level of liquid in the tub in response to the regularly varying control signal; and a lockout circuit operatively coupled to the liquid level sensing circuit and the electrically controlled liquid valve, the lockout circuit interrupting power to the liquid valve in response to an interruption in the regularly varying sensor signal, the presence of the regularly varying sensor signal being indicative of the proper operation of both the liquid level sensing circuit and the controller. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An improvement for an overflow protector of a control circuit of a liquid supply portion of a fillable tub that interrupts a supply of liquid to the tub in response to a sensed failure of the control circuit, regardless of a liquid level of the fillable tub, the improvement comprising:
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an electrically controlled liquid valve; a liquid level sensing circuit; a controller operatively coupled to the liquid level sensing circuit and the electrically controlled liquid valve, the liquid level sensing circuit emitting a regularly varying sensor signal indicative of a level of liquid in the tub, the regularly varying sensor signal being operatively received by the controller; the controller emitting a regularly varying control signal in response to receiving the regularly varying sensor signal; and a lockout circuit operatively coupled to the controller and the electrically controlled liquid valve, the lockout circuit interrupting power to the electrically controlled liquid valve in response to an interruption in the regularly varying control signal, the presence of the regularly varying control signal being indicative of the proper operation of both the liquid level sensing circuit and the controller. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for preventing liquid overflow in a fillable tub in response to a sensed failure of a control circuit of a liquid supply portion of the fillable tub, regardless of a liquid level of the fillable tub, the method comprising:
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providing the control circuit with a controller, a liquid level sensing circuit for sensing a level of liquid in the tub, and at least one electrically controlled liquid valve for controlling a supply of liquid to the tub; generating a regularly varying control signal at an output of the controller; generating a regularly varying sensor signal at an output of the liquid level sensing circuit in response to the regularly varying control signal, the regularly varying sensor signal being indicative of a level of liquid in the tub; and interrupting power to the at least one electrically controlled liquid valve in response to a variation of the regularly varying sensor signal indicative of a failure of at least one of the controller and the sensor. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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25. A method for preventing liquid overflow in a fillable tub in response to a sensed failure of a control circuit of a liquid supply portion of the fillable tub, regardless of a liquid level of the fillable tub, the method comprising:
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providing the control circuit with a controller, a liquid level sensing circuit for sensing a level of liquid in the tub, and at least one electrically controlled liquid valve for controlling a supply of liquid to the tub; generating a regularly varying sensor signal at an output of the liquid level sensing circuit, the regularly varying sensor signal being indicative of a level of liquid in the tub; generating a regularly varying control signal at an output of the controller in response to the regularly varying sensor signal; and interrupting power to the at least one electrically controlled liquid valve in response to a variation of the regularly varying control signal indicative of a failure of at least one of the controller and the sensor. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32)
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Specification