Infinite temperature control

• US 5,978,995 A
• Filed: 06/17/1998
• Issued: 11/09/1999
• Est. Priority Date: 06/17/1998
• Status: Expired due to Fees

• Current Assignee: Maytag Corporation (Whirlpool Corporation)
• Original Assignee: Maytag Corporation (Whirlpool Corporation)
• Inventors: Bruntz, Jordan S., Griffith, Scott E.
• Primary Examiner(s): Coe, Philip R.
• Application Number:
  US09/098,910
• Time in Patent Office: 510 Days
• Field of Search: 8/158, 8/12.19, 8/12.21, 8/12.22, 8/12.27, 8/207, 236/12.12
• US Class Current: 8/158
• CPC Class Codes: D06F 2103/16 Washing liquid temperature
• CPC Class Codes: D06F 34/24 Liquid temperature

Abstract

An infinite temperature control system is used to control the temperature of wash and rinse water in a washing machine. The invention includes a temperature selection switch which operates the water valves for controlling the temperature of water entering the washing machine. The switch has an infinite number of possible temperature settings and includes various contacts for affecting various aspects of the water temperature control.

Claims

1. A temperature control system for a washing machine having at least one water valve for allowing the washing machine to be filled with water comprising:

a user adjustable temperature selection switch operatively coupled to the at least one water valve for controlling the temperature of water entering the washing machine, wherein the temperature selection switch has a substantially infinite number of possible temperature settings.

2. The apparatus of claim 1, wherein the temperature selection switch further comprises a variable resistor.

3. The apparatus of claim 2, further comprising:

a relay operatively connected to the at least one water valve for controlling the operation of the water valve; and

a timing circuit electrically connected to the variable resistor and to the relay for controlling the operation of the relay depending on the value of the variable resistor.

4. The apparatus of claim 3, wherein the relay receives a control signal from the timing circuit which determines the temperature of the water entering the washing machine.

5. The apparatus of claim 4 wherein the control signal is a pulse width modulated signal.

6. The apparatus of claim 1 wherein the control system includes a substantially infinite number of wash temperature settings between hot and cold.

7. The apparatus of claim 1 wherein the control system includes a substantially infinite number of rinse temperature settings between warm and cold.

8. The apparatus of claim 1 wherein the temperature selection switch includes at least one secondary switch which allows full hot and full cold temperature settings.

9. The apparatus of claim 1 wherein the temperature selection switch includes at least one secondary switch which prevents a hot or warm rinse if a hot wash is selected.

10. The temperature control system of claim 1, further comprising:

a temperature sensor for sensing the temperature of water in the washing machine; and

a circuit operatively connected to the temperature sensor for adjusting the temperature of the water entering the washing machine.

11. The temperature control system of claim 10 wherein the temperature sensor is comprised of a thermistor.

12. The temperature control system of claim 1 wherein the selection switch includes a secondary switch which prevents hot wash water from entering the washing machine when the selection switch is positioned to select a warm or cold wash temperature.

13. A method of controlling the temperature of water used by a washing machine comprising the steps of:

providing at least one water valve for allowing hot and cold water to fill the washing machine;

providing a control switch having a substantially infinite number of operating positions;

selecting a desired temperature by actuating the control switch to a desired position; and

adjusting the at least one water valve to fill the washing machine with water having a temperature determined by the desired position of the control switch.

14. The method of claim 13 further comprising the step of providing the control switch with a variable resistor, wherein the adjustment of the water valve is made depending on the value of the variable resistor.

15. The method of claim 13 further comprising the steps of:

electrically connecting a relay to at least one water valve for controlling the operation of the water valve;

electrically connecting a timing circuit to the relay for controlling the operation of the relay; and

controlling the timing circuit based on the position of the control switch.

16. The method of claim 15, further comprising the step of sending a pulse width modulated signal from the timing circuit to the relay to control the operation of the relay.

17. The method of claim 13 further comprising the step of preventing a hot or warm rinse if a hot wash is selected.