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

• US 20040255988A1
• Filed: 06/17/2003
• Published: 12/23/2004
• Est. Priority Date: 06/17/2003
• Status: Abandoned Application

• Current Assignee: Emerson Electric Company
• Original Assignee: Emerson Electric Company
• Inventors: Scott, Charles E., DuHack, Michael R.
• Application Number:
  US10/462,991
• Publication Number:
  US 20040255988A1
• Time in Patent Office: Days
• US Class Current: 134/57D
• 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 2401/06 Water supply, circulation or discharge information water level A47L2401/09; water pressure or flow rate A47L2401/14
• 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 2501/05 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 13/006 measuring volume in function of time
• CPC Class Codes: G01P 13/0006 of fluids or of granulous or powder-like substances
• CPC Class Codes: G01P 13/002 with electrical coupling to the indicating devices
• CPC Class Codes: G01P 13/006 by using thermal variables
• CPC Class Codes: G01P 13/0066 by using differences of pressure in the fluid
• CPC Class Codes: G05D 7/0688 by combined action on throttling means and flow sources G05D7/0694 takes precedence
• CPC Class Codes: H01H 2009/0083 using redundant components, e.g. two pressure tubes for pressure switch
• CPC Class Codes: H01H 35/405 the switch being of the reed switch type

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

a flow element configured to be pushed in a flow direction by the water flow;

a biasing device configured to bias the flow element in a second direction substantially opposite to the flow direction; and

a sensing device configured to sense movement of the flow element in the flow direction in opposition to the biasing device; and

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

2. The dishwasher of claim 1, wherein the flow element includes a magnet.

3. The dishwasher of claim 2, wherein the sensing device includes a proximity switch.

4. The dishwasher of claim 3, wherein the proximity switch includes a reed switch.

5. The dishwasher of claim 2, wherein the sensing device includes a coil substantially surrounding at least a portion of the magnet.

6. The dishwasher of claim 5, further comprising a current sensing device coupled to the coil and configured to sense current in the coil.

7. The dishwasher of claim 1, wherein the flow element includes a sleeve.

8. The dishwasher of claim 7, wherein the sleeve is magnetically coupled to said sensing device.

9. The dishwasher of claim 1, wherein the sensing device is configured to sense movement of the flow element in the second direction, the movement resulting from the bias of the biasing device.

10. A dishwasher, comprising:

a water inlet connectable to a water source;

a dishwasher element operable on water received through said inlet;

a flow element disposed within said inlet for movement in response to a flow of the water through said inlet;

a sensing device configured to generate a control signal as a result of the movement of the flow element; and

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

11. The dishwasher of claim 10, wherein said flow element is configured to be pushed in a flow direction by the flow of the water, said dishwasher further comprising a biasing device configured to bias the flow element in a second direction substantially opposite to the flow direction.

12. The dishwasher of claim 11, wherein the sensing device is configured to sense movement of the flow element in the flow direction and sense movement of the flow element in the second direction, the movement in the second direction resulting from the bias of the biasing device.

13. The dishwasher of claim 12, wherein the control apparatus is configured to determine, based upon a status of the sensing device, at least one time duration of the water flow, said time duration being between the movement of the flow element in the flow direction and the movement of the flow element in the second direction.

14. The dishwasher of claim 13, wherein the control apparatus is configured to terminate a dishwasher cycle dependent upon the at least one time duration.

15. The dishwasher of claim 13, further comprising an indicator configured to indicate to a user whether a sufficient amount of the water has flowed through said inlet based on the at least one time duration.

16. The dishwasher of claim 11, wherein at least a portion of the biasing device is fixed relative to the inlet.

17. The dishwasher of claim 11, wherein the sensing device is configured to sense movement of the flow element in the second direction, the movement resulting from the bias of the biasing device.

18. The dishwasher of claim 10, wherein said control apparatus includes a timer.

19. The dishwasher of claim 10, wherein the flow element includes a magnet.

20. The dishwasher of claim 19, wherein the sensing device includes a coil substantially surrounding at least a portion of the magnet.

21. The dishwasher of claim 20, further comprising a current sensing device coupled to the coil and configured to sense current in the coil.

22. The dishwasher of claim 10, wherein the sensing device includes a proximity switch.

23. The dishwasher of claim 22, wherein the proximity switch includes a reed switch.

24. The dishwasher of claim 10, wherein the flow element includes a sleeve.

25. The dishwasher of claim 24, wherein the sleeve is magnetically coupled to said sensing device.