Automatic temperature control for clothes washer
First Claim
1. An automatic temperature control system for a washing machine including a mixing nozzle in flow communication with a wash tub, a hot water conduit and a cold water conduit in flow communication with the-mixing nozzle, a cold water valve controlling flow of water from the cold water conduit to the mixing valve, and a hot water valve for controlling flow of hot water from the hot water conduit to the mixing valve, said system comprising:
- a microprocessor;
a temperature sensor configured to sense the temperature of water supplied to the wash tub and electrically coupled to said microprocessor;
a cold water relay configured to be coupled to the cold water valve, said cold water relay electrically coupled to said microprocessor;
a hot water relay configured to be coupled to the hot water valve, said hot water relay electrically coupled to said microprocessor;
said microprocessor programmed to control operation of said cold water relay and said hot water relay so that a desired water temperature is provided in the mixing nozzle, said microprocessor further programmed to perform a pretreater function.
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0 Petitions
Accused Products
Abstract
An automatic temperature control system which limits the total number of valve cycles for the cold and hot water valves to, for example, a total of ten cycles yet also provides the desired temperature control of water supplied to the wash tub is described. To limit the number of valve cycles, and in one embodiment, the automatic temperature control (ATC) system includes a microprocessor which integrates the temperature of the water provided to the wash tub over time to predict the length of the time period required for the next water valve cycle. The integration balances the energy input on the “OFF” cycle with the energy input during the “ON” cycle. Such balancing limits the number of valve cycles thereby reducing the possibility for premature valve failure and facilitating reduced noise. The ATC control system also provides a pre-treater function. When the pre-treater function is selected, e.g., by depressing a momentary switch mounted on the control panel, and provided that the lid is open, the control system energizes the cold water valve for 7 seconds. As a result, cold water flows into the wash tub. The system provides temperature control yet limits the number of valve cycles during a fill even with extreme water temperatures. Even with such cycle limitations, the control provides the desired temperature control.
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Citations
16 Claims
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1. An automatic temperature control system for a washing machine including a mixing nozzle in flow communication with a wash tub, a hot water conduit and a cold water conduit in flow communication with the-mixing nozzle, a cold water valve controlling flow of water from the cold water conduit to the mixing valve, and a hot water valve for controlling flow of hot water from the hot water conduit to the mixing valve, said system comprising:
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a microprocessor;
a temperature sensor configured to sense the temperature of water supplied to the wash tub and electrically coupled to said microprocessor;
a cold water relay configured to be coupled to the cold water valve, said cold water relay electrically coupled to said microprocessor;
a hot water relay configured to be coupled to the hot water valve, said hot water relay electrically coupled to said microprocessor;
said microprocessor programmed to control operation of said cold water relay and said hot water relay so that a desired water temperature is provided in the mixing nozzle, said microprocessor further programmed to perform a pretreater function. - View Dependent Claims (2, 3)
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4. A washing machine comprising:
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a wash tub;
a mixing nozzle in flow communication with said tub;
a hot water conduit in flow communication with said mixing nozzle;
a cold water conduit in flow communication with said mixing nozzle;
a cold water valve controlling flow of water from said cold water conduit to said mixing valve;
a hot water valve for controlling flow of hot water from said hot water conduit to said mixing valve; and
an automatic temperature control system comprising a microprocessor, a temperature sensor configured to be located in said mixing nozzle and electrically coupled to said microprocessor, a cold water relay configured to be coupled to the cold water valve, said cold water relay electrically coupled to said microprocessor, a hot water relay configured to be coupled to the hot water valve, said hot water relay electrically coupled to said microprocessor, said microprocessor programmed to control operation of said cold water relay and said hot water relay so that a desired water temperature is provided in the mixing nozzle, said microprocessor further programmed to perform a pretreater function. - View Dependent Claims (5, 6)
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7. A method for controlling a flow of hot and cold water to a wash tub in a washing machine during a fill operation, the washing machine including a mixing nozzle, a hot water conduit and a cold water conduit in flow communication with the mixing nozzle, a cold water valve controlling flow of hot water from the cold water conduit to the mixing valve, and a hot water valve for controlling flow of hot water from the hot water conduit to the mixing valve, the washing machine further including a control panel having a pretreater switch mounted thereto, said method comprising the steps of:
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determining a temperature of the water flowing to the tub;
if the water temperature is not within a desired range, then cycling at least one of the hot water valve and the cold water valve;
if an operator selects the pretreater switch, then performing a pretreater operation. - View Dependent Claims (8, 9)
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10. A pretreater control system for a washing machine including a mixing nozzle in flow communication with a wash tub, a cold water conduit in flow communication with the mixing nozzle, a cold water valve controlling flow of water from the cold water conduit to the mixing valve, and a pretreater selection control actuatable by an operator, said system comprising:
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a microprocessor;
a cold water relay configured to be coupled to the cold water valve, said cold water relay electrically coupled to said microprocessor;
said microprocessor programmed to execute a pretreater control routine upon actuation of the pretreater selection control. - View Dependent Claims (11, 12, 13)
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14. An automatic temperature control system for a washing machine including a mixing nozzle in flow communication with a wash tub, a hot water conduit and a cold water conduit in flow communication with the mixing nozzle, a cold water valve controlling flow of water from the cold water conduit to the mixing valve, and a hot water valve for controlling flow of hot water from the hot water conduit to the mixing valve, said system comprising:
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a microprocessor;
a temperature sensor configured to sense the temperature of water supplied to the wash tub and electrically coupled to said microprocessor;
a cold water relay configured to be coupled to the cold water valve, said cold water relay electrically coupled to said microprocessor;
a hot water relay configured to be coupled to the hot water valve, said hot water relay electrically coupled to said microprocessor;
said microprocessor programmed to control operation of said cold water relay and said hot water relay so that a desired water temperature is provided in the mixing nozzle and said microprocessor configured to integrate the water temperature sensed by said temperature sensor to predict a length of a time period required for a subsequent water valve cycle.
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15. A washing machine comprising:
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a wash tub;
a mixing nozzle in flow communication with said tub;
a hot water conduit in flow communication with said mixing nozzle;
a cold water conduit in flow communication with said mixing nozzle;
a cold water valve controlling flow of water from said cold water conduit to said mixing valve;
a hot water valve for controlling flow of hot water from said hot water conduit to said mixing valve; and
an automatic temperature control system comprising a microprocessor, a temperature sensor configured to be located in said mixing nozzle and electrically coupled to said microprocessor, a cold water relay configured to be coupled to the cold water valve, said cold water relay electrically coupled to said microprocessor, a hot water relay configured to be coupled to the ;
hot water valve, said hot water relay electrically coupled to said microprocessor, said microprocessor programmed to control operation of said cold water relay and said hot water relay so that a desired water temperature is provided in the mixing nozzle, said microprocessor configured to integrate a water temperature sensed by said temperature sensor to predict a length of a time period required for a subsequent water valve cycle.
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16. A method for controlling a flow of hot and cold water to a wash tub in a washing machine during a fill operation, the washing machine including a mixing nozzle, a hot water conduit and a cold water conduit in flow communication with the mixing nozzle, a cold water valve controlling flow of water from the cold water conduit to the mixing valve, and a hot water valve for controlling flow of hot water from the hot water conduit to the mixing valve, said method comprising the steps of:
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reading a temperature sensor located in the mixing valve;
if the water temperature is not within a desired range, then cycling at least one of the hot water valve and the cold water valve; and
integrating the water temperature sensed by the temperature sensor to predict a length of a time period required for a subsequent water valve cycle.
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Specification