Method and apparatus for sensing water flow through a dishwasher including a vacuum switch

• US 20040255976A1
• Filed: 06/17/2003
• Published: 12/23/2004
• Est. Priority Date: 06/17/2003
• Status: Active Grant

• Current Assignee: Nidec Motor Corporation (Nidec Corporation)
• Original Assignee: Emerson Electric Company
• Inventors: Schloot, Andrew F., Clouser, Michael T., DuHack, Michael R., Slocum, Laurence S.
• Granted Patent: US 7,163,590 B2
• Time in Patent Office: Days
• US Class Current: 134/18
• CPC Class Codes: A47L 15/0049 Detection or prevention of malfunction, including accident prevention arrangements to prevent clogging of filters A47L15/4208; safety arrangements for preventing water damage A47L15/421
• CPC Class Codes: A47L 15/4217 Fittings for water supply, e.g. valves or plumbing means to connect to cold or warm water lines, aquastops
• CPC Class Codes: A47L 15/46 Devices for the automatic control of the different phases of cleaning ; Controlling devices A47L15/449 takes precedence
• CPC Class Codes: A47L 2401/06 Water supply, circulation or discharge information
• CPC Class Codes: A47L 2401/14 Water pressure or flow rate
• CPC Class Codes: A47L 2401/30 Variation of electrical, magnetical or optical quantities
• CPC Class Codes: A47L 2401/34 Other automatic detections
• CPC Class Codes: A47L 2501/01 Water supply, e.g. opening or closure of the water inlet valve
• CPC Class Codes: A47L 2501/05 Drain or recirculation pump, e.g. regulation of the pump rotational speed or flow direction
• CPC Class Codes: A47L 2501/06 Water heaters
• CPC Class Codes: A47L 2501/26 Indication or alarm to the controlling device or to the user
• CPC Class Codes: A47L 2501/32 Stopping or disabling machine operation, including disconnecting the machine from a network, e.g. from an electrical power supply
• CPC Class Codes: G01F 1/28 by drag-force, e.g. vane type or impact flowmeter
• CPC Class Codes: G01F 1/44 Venturi tubes
• CPC Class Codes: G01F 1/68 by using thermal effects
• CPC Class Codes: H01H 35/346 in which the movable contact is formed or directly supported by the diaphragm

Abstract

A dishwasher includes a water inlet connectable to a water source. A dishwasher element is operable on water received through the inlet. A flow sensor is in fluid communication with the inlet and is operable to generate a control signal indicative of water flow through the inlet. A control apparatus is connected between the dishwasher element and the flow sensor and is operable to inhibit operation of the dishwasher element in response to the control signal.

Claims

1. A dishwasher, comprising:

a water inlet connectable to a water source;

a dishwasher element operable on water received through said inlet;

a flow sensor in fluid communication with said inlet and operable to generate a control signal indicative of water flow through said inlet; and

a control apparatus connected between said dishwasher element and said flow sensor and operable to inhibit operation of said dishwasher element in response to said control signal.

2. The dishwasher of claim 1, wherein the flow sensor includes a vacuum switch.

3. The dishwasher of claim 2, wherein said flow sensor includes a conduit and a venturi opening in communication between said conduit and said vacuum switch.

4. The dishwasher of claim 1, wherein the control apparatus includes a cycle controller configured to initiate timed operation of said dishwasher element, said control apparatus being configured to remove power from the cycle controller if the water is not flowing through the flow sensor.

5. The dishwasher of claim 4, further comprising a valve in fluid communication with and disposed upstream from the flow sensor, the cycle controller being configured to cause the valve to open to thereby allow water into the flow sensor.

6. The dishwasher of claim 4, wherein said cycle controller is digital and configured to bypass the application of power to the dishwasher element in response to the control signal.

7. The dishwasher of claim 1, wherein the control apparatus includes a cycle controller having a timer module configured to initiate timed operation of said dishwasher element, said control apparatus being configured to remove power from the timer module if the water is not flowing through the flow sensor.

8. The dishwasher of claim 7, wherein the timer module includes a switch configured to selectively apply power to said dishwasher element, said control apparatus including a relay configured to electrically connect said switch to a voltage source dependent upon said control signal.

9. The dishwasher of claim 1, wherein said control apparatus is configured to remove power from the dishwasher element in response to said control signal.

10. The dishwasher of claim 1, further comprising a fault light connected to said flow sensor to illuminate in response to said control signal for indicating that water is not flowing through the flow sensor.

11. The dishwasher of claim 1, wherein said flow sensor is disposed downstream of said inlet.

12. A method of operating a dishwasher, comprising:

sensing a flow of water through the dishwasher; and

inhibiting an operation of the dishwasher dependent upon said sensing step.

13. The method of claim 12, wherein the inhibiting step includes inhibiting operation of at least one of a heater and a water pump of the dishwasher if the water does not flow through the dishwasher.

14. The method of claim 13, comprising the further step of using a timer to selectively apply power to the at least one of a heater and a water pump.

15. The method of claim 14, comprising the further step of providing the dishwasher with a venturi in the flow of water, said sensing step including using a vacuum switch to sense the flow of water past the venturi.

16. The method of claim 15, comprising the further step of using a signal through the vacuum switch to disable the timer.

17. The method of claim 12, comprising the further step of operating a fault light to indicate an absence of water flowing through the dishwasher.

18. The method of claim 12, wherein said inhibiting step includes one of cutting power to a heater and bypassing a heating cycle while allowing the dishwasher to continue.