Enhanced draining and drying cycles for an automatic dishwasher

• US 5,806,541 A
• Filed: 05/09/1997
• Issued: 09/15/1998
• Est. Priority Date: 04/12/1995
• Status: Expired due to Term

• Current Assignee: Maytag Corporation (Whirlpool Corporation)
• Original Assignee: Maytag Corporation (Whirlpool Corporation)
• Inventors: Corbett, Mitchell N., Cooper, Randall L., Cracraft, Mark A.
• Primary Examiner(s): Stinson, Frankie L.
• Application Number:
  US08/853,529
• Time in Patent Office: 494 Days
• Field of Search: 134/56 D, 134/57 D, 134/58 D, 134/105, 134/102.3, 134/113
• US Class Current: 134/57.00D
• CPC Class Codes: A47L 15/0031 Water discharge phases
• CPC Class Codes: A47L 15/0034 Drying phases, including dripping-off phases
• CPC Class Codes: A47L 15/4297 Arrangements for detecting or measuring the condition of the washing water, e.g. turbidity
• CPC Class Codes: A47L 2401/023 Quantity or concentration of the consumable product
• CPC Class Codes: A47L 2401/08 Drain or recirculation pump parameters, e.g. pump rotational speed or current absorbed by the motor
• CPC Class Codes: A47L 2401/10 Water cloudiness or dirtiness, e.g. turbidity, foaming or level of bacteria
• CPC Class Codes: A47L 2401/12 Water temperature
• CPC Class Codes: A47L 2401/24 Spray arms status, e.g. detection of spray arm rotation
• CPC Class Codes: A47L 2501/01 Water supply, e.g. opening or closure of the water inlet valve
• CPC Class Codes: A47L 2501/02 Water discharge, e.g. opening or closure of discharge valve
• CPC Class Codes: A47L 2501/12 Air blowers
• CPC Class Codes: A47L 2501/30 Regulation of machine operational steps within the washing process, e.g. performing an additional rinsing phase, shortening or stopping of the drying phase, washing at decreased noise operation conditions

Abstract

An automatic dishwashing machine includes enhanced drying and draining cycles. Toward the end of the rinse and hold cycle when the water is draining, a second quantity of water is added to the machine resulting in a purging action which reduces the concentration of soil in the wash pump. During the normal wash cycle, if the dishwashing machine determines that the water is sufficiently dirty, a second drain is initiated to remove any dirty water that is present in the bottom of the pump after the first drain. During the dry cycle, the machine senses the temperature of the water and the presence of a rinse aid to select an appropriate dry cycle. The possible dry cycles include a delayed dry cycle and a pulsed dry cycle.

Claims

1. An electronic control system for an automatic dishwashing machine for washing articles having a drying cycle with at least a first and second drying sequence comprising:

a controller for controlling the operation of the dishwashing machine;

a heat source for providing heat to the articles during at least a portion of the drying cycle; and

a water temperature sensor for sensing the temperature of the water in the dishwashing machine, wherein the predetermined time can be modified by the controller depending on the sensed temperature of the water and wherein one of said first and second drying sequences is selected depending on the sensed temperature of the water.

2. The electronic control system of claim 1 wherein the first drying sequence is selected if the sensed temperature is greater than a certain temperature and the second drying sequence is selected if the sensed temperature is less than the certain temperature.

3. The electronic control system of claim 1 wherein the second drying sequence is a delayed dry sequence initiated when the temperature of the water exceeds a predetermined temperature.

4. The electronic control system of claim 3 wherein the heat source is activated after a delay period following the beginning of the dry cycle.

5. The electronic control system of claim 4 wherein the delay period is 400 seconds.

6. The electronic control system of claim 1 wherein the first drying sequence is a pulsed dry sequence.

7. The electronic control system of claim 6 wherein the heat source is pulsed on and off during the dry cycle.