Appliance leak detector and inline shutoff

• US 20050138990A1
• Filed: 12/24/2003
• Published: 06/30/2005
• Est. Priority Date: 12/24/2003
• Status: Active Grant

• Current Assignee: Xylem Ip Holdings LLC (Xylem, Inc.)
• Original Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Inventors: Walls, James C., Cain, Jeffrey A., Phillips, David L.
• Granted Patent: US 6,978,659 B2
• Time in Patent Office: Days
• US Class Current: 73/40
• CPC Class Codes: G01M 3/16 using electric detection means G01M3/045, G01M3/06, G01M3/12, G01M3/20, G01M3/24, G01M3/26 take precedence
• CPC Class Codes: G01M 3/18 for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators
• CPC Class Codes: G08B 21/20 responsive to moisture

Abstract

A leak sensor apparatus (10) and flow control equipment (16) for sensing a leak from a machine using a supply of water (or other fluid) or from connecting hoses supplying the water, and for turning off the supply when a leak is detected, with the leak sensor (10) itself including in particular two conductors (10a-b) held in spaced apart relation in a fluid-permeable insulating material (10c), and the flow control equipment (16) for providing a voltage difference between the two conductors (10a-b) and for sensing the presence of a fluid based on the fluid providing an electrical path between the two conductors (10a-b) and so allowing current to flow between the two conductors (10a-b) under the urging of the voltage difference provided by the flow control equipment (16). In some embodiments, the two conductors (10a-b) are configured so as to wrap about one or more of the connecting hoses.

Claims

1. A system for detecting when a fluid is leaking from a machine or from one or more connecting hoses providing and removing the fluid from the machine, the system comprising:

a leak sensor apparatus (10) having two conductors (10a-b) held in spaced apart relation in a fluid-permeable insulating material (10c), responsive to an impressed voltage causing a voltage difference between the two conductors (10a-b), for providing a leak detection current when fluid from the machine leaks through the fluid-permeable membrane (10c); and

a flow control device (16), for providing the impressed voltage, for stopping the flow of the fluid to the machine in response to the sensor response signal.

2. A system as in claim 1, wherein further in response to the leak detection current, the flow control device (16) stops providing the impressed voltage.

3. A system as in claim 1, wherein the leak sensor apparatus (10) also includes a leak sensor detection component (10d) completing a circuit path for an alternating or radiofrequency current of a higher frequency than the leak detection current, and wherein the flow control device (16) is configured to provide an impressed voltage corresponding to the higher-frequency current and to detect the higher-frequency current in order to determine if the leak sensor apparatus (10) is coupled to the flow control device (16).

4. The system as in claim 1, wherein the two conductors (10a-b) are provided in a configuration adapted so as to be disposed on a surface beneath the machine.

5. The system as in claim 1, wherein the two conductors (10a-b) are configured so as to wrap about one or more of the connecting hoses.

6. A system as in claim 1, wherein the flow control apparatus (16) includes:

a sensor stimulus interface module (16d) for impressing a voltage across the pair of conductors (10a-b);

a sensor response interface module (16c), for providing a sensor response signal in response to the leak detection current;

a controller (16a), responsive to the sensor response signal, for providing a flow control signal for stopping the flow of the fluid to the machine upon receiving the sensor response signal; and

a flow control valve (16b), responsive to the flow control signal, for stopping the flow of the fluid upon receiving the flow control signal.

7. The system as in claim 6, wherein the flow control valve includes a valve apparatus having a valve disposed in-line with a supply of the fluid to the machine and including a solenoid to open and close the valve.

8. A system as in claim 1, wherein at least one of the two conductors (10a-b) is made of a spring wire.

9. A system as in claim 1, wherein at least one of the two conductors (10a-b) is made of a aluminum, steel, a conductive polymer, an alternative metal, or a carbon-based material.

10. A system as in claim 1, wherein a grounded portion of a connecting pipe or connecting hose or a grounded portion of the machine is used as a return path for the sensor output current and so serves as one of the two conductors (10a-b).

11. A system as in claim 1, wherein the two conductors (10a-b) are disposed so as to form a double helix.

12. A system as in claim 1, wherein the fluid-permeable insulator material (10c) is a water-permeable cloth.

13. A system as in claim 1, further comprising additional hoses and respective additional pairs of conductors (10a-b) wrapped around the additional hoses.

14. A system as in claim 1, wherein the pair of conductors (10a-b) are attached to a mechanically formative component to direct or fix the shape of the leak sensor apparatus (10).

15. A system as in claim 1, wherein the fluid-permeable insulating material (10c) is a sheathing on at least one of the conductors (10a-b).

16. A system as in claim 1, wherein the fluid-permeable insulating material (10c) is a sheathing having enhanced environmental robustness.

17. A system as in claim 1, wherein the fluid-permeable insulating material (10c) is a sheathing having enhanced usability attributes including a fast-drying or slow-drying or self-drying characteristic.

18. A system as in claim 1, wherein the permeability of the fluid-permeable insulating material (10c) is provided by one or more of the following characteristics:

hydrophilicity;

porosity;

open construction;

membrane action; and

capillary action.

19. A system as in claim 1, wherein the fluid-permeable insulator material (10c) includes one or more of the following materials:

woven fibers of natural or synthetic material including woven glass polyesters and cotton;

flexible natural or synthetic solids, such as rubber, latex or plastic; and

rigid or semi-rigid materials including fiberglass and composites.

20. A system as in claim 1, wherein the two conductors (10a-b) are provided as a solid or stranded metal wire or are a material impregnated with solid or stranded metal wire, such as a flexible material.

21. A system as in claim 1, wherein the two conductors (10a-b) are provided in one of the following forms:

helical;

circular;

straight;

patterned;

or free-form.

22. A system as in claim 1, wherein the two conductors (10a-b) are provided having proximate distal ends and are terminated at their distal ends by either elastic bands, flexible bands or rigid fasteners.

23. A machine having a hose for receiving or discharging a fluid, characterized in that:

electrical conductors (10a-b) separated from each other by a fluid-permeable insulating material (10c) are arranged in fixed proximate relation to the hose or the machine, and adapted so as to be responsive to a first signal and to fluid leaking from the hose, and so as to provide a second signal to a flow control device (16) that determines whether there is a possible leak in the hose.

24. A machine according to claim 23, wherein the electrical conductors (10a-b) are helically wrapped or intertwined in the insulating porous material (10c).

25. A machine according to claim 23, wherein the electrical conductors (10a-b) are helically wrapped around the hose.

26. A machine according to claim 23, wherein the electrical conductors (10a-b) are either a formed spring wire or a helical formed spring wire.

27. A machine according to claim 23, wherein the electrical conductors (10a-b) are helically wrapped end-to-end around the hose.

28. A machine according to claim 23, wherein the control device (16) provides a signal that stops the flow of the fluid to the machine.

29. A machine according to claim 23, wherein the fluid-permeable insulating material (10c) is a fluid-permeable cloth.

30. A machine according to claim 23, wherein the fluid-permeable insulating material (10c) holds the electrical conductors (10a-b) in spaced apart relation.

31. A machine according to claim 23, wherein the machine has a sensor stimulus module (16d) for providing the first signal.

32. A machine according to claim 23, wherein the machine is a washing machine.

33. A kit for adapting on a machine having a hose for receiving or discharging a fluid, characterized in that the kit comprises:

electrical conductors (10a-b) separated from each other by a fluid-permeable insulating material (10c), for arranging in fixed proximate relation to the hose or the machine, and adapted to respond to a first signal and to fluid leaking from the hose by providing a second signal; and

a flow control device (16), responsive to the second signal, for determining whether there is a possible leak in the hose.