Appliance leak detector and inline shutoff
View Patent ↗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 ( 10 a–b ) held in spaced apart relation in a fluid-permeable insulating material ( 10 c ), and the flow control equipment ( 16 ) for providing a voltage difference between the two conductors ( 10 a–b ) and for sensing the presence of a fluid based on the fluid providing an electrical path between the two conductors ( 10 a–b ) and so allowing current to flow between the two conductors ( 10 a–b ) under the urging of the voltage difference provided by the flow control equipment ( 16 ). In some embodiments, the two conductors ( 10 a–b ) are configured so as to wrap about one or more of the connecting hoses.
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 ( 10 a–b ) held in spaced apart relation in a fluid-permeable insulating material ( 10 c ), responsive to an impressed voltage causing a voltage difference between the two conductors ( 10 a–b ), for providing a leak detection current when fluid from the machine leaks through the fluid-permeable membrane ( 10 c ); 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 leak detection current;
wherein the leak sensor apparatus ( 10 ) also includes a leak sensor detection component ( 10 d ) 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 ).
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. The system as in claim 1 , wherein the two conductors ( 10 a–b ) are provided in a configuration adapted so as to be disposed on a surface beneath the machine.
4. The system as in claim 1 , wherein the two conductors ( 10 a–b ) are configured so as to wrap about one or more of the connecting hoses.
5. A system as in claim 1 , wherein the flow control apparatus ( 16 ) includes:
a sensor stimulus interface module ( 16 d ) for impressing a voltage across the pair of conductors ( 10 a–b );
a sensor response interface module ( 16 c ), for providing a sensor response signal in response to the leak detection current;
a controller ( 16 a ), 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 ( 16 b ), responsive to the flow control signal, for stopping the flow of the fluid upon receiving the flow control signal.
6. The system as in claim 5 , 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.
7. A system as in claim 1 , wherein at least one of the two conductors ( 10 a–b ) is made of a spring wire.
8. A system as in claim 1 , wherein at least one of the two conductors ( 10 a–b ) is made of a aluminum, steel, a conductive polymer, an alternative metal, or a carbon-based material.
9. 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 ( 10 a–b ).
10. A system as in claim 1 , wherein the two conductors ( 10 a–b ) are disposed so as to form a double helix.
11. A system as in claim 1 , wherein the fluid-permeable insulator material ( 10 c ) is a water-permeable cloth.
12. A system as in claim 1 , further comprising additional hoses and respective additional pairs of conductors ( 10 a–b ) wrapped around the additional hoses.
13. A system as in claim 1 , wherein the pair of conductors ( 10 a–b ) are attached to a mechanically formative component to direct or fix the shape of the leak sensor apparatus ( 10 ).
14. A system as in claim 1 , wherein the fluid-permeable insulating material ( 10 c ) is a sheathing on at least one of the conductors ( 10 a–b ).
15. A system as in claim 1 , wherein the fluid-permeable insulating material ( 10 c ) is a sheathing having enhanced environmental robustness.
16. A system as in claim 1 , wherein the fluid-permeable insulating material ( 10 c ) is a sheathing having enhanced usability attributes including a fast-drying or slow-drying or self-drying characteristic.
17. A system as in claim 1 , wherein the permeability of the fluid-permeable insulating material ( 10 c ) is provided by one or more of the following characteristics: hydrophilicity; porosity; open construction; membrane action; and capillary action.
18. A system as in claim 1 , wherein the fluid-permeable insulator material ( 10 c ) 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.
19. A system as in claim 1 , wherein the two conductors ( 10 a–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.
20. A system as in claim 1 , wherein the two conductors ( 10 a–b ) are provided in one of the following forms: helical; circular; straight; patterned; or free-form.
21. A system as in claim 1 , wherein the two conductors ( 10 a–b ) are provided having proximate distal ends and are terminated at their distal ends by either elastic bands, flexible bands or rigid fasteners.
22. A machine having a hose for receiving or discharging a fluid, characterized in that:
electrical conductors ( 10 a–b ) separated from each other by a fluid-permeable insulating material ( 10 c ) 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;
wherein the machine also includes a leak sensor detection component ( 10 d ) completing a circuit path for an alternating or radiofrequency current of a higher frequency than the second signal, and wherein the flow control device ( 16 ) is configured to provide an impressed voltage corresponding to the higher-frequency signal and to detect the higher-frequency signal in order to determine if the electrical conductors ( 10 a–b ) are coupled to the flow control device ( 16 ).
23. A machine according to claim 22 , wherein the electrical conductors ( 10 a–b ) are helically wrapped or intertwined in the insulating porous material ( 10 c ).
24. A machine according to claim 22 , wherein the electrical conductors ( 10 a–b ) are helically wrapped around the hose.
25. A machine according to claim 22 , wherein the electrical conductors ( 10 a–b ) are either a formed spring wire or a helical formed spring wire.
26. A machine according to claim 22 , wherein the electrical conductors ( 10 a–b ) are both helically wrapped around the hose.
27. A machine according to claim 22 , wherein the control device ( 16 ) provides a signal that stops the flow of the fluid to the machine.
28. A machine according to claim 22 , wherein the fluid-permeable insulating material ( 10 c ) is a fluid-permeable cloth.
29. A machine according to claim 22 , wherein the fluid-permeable insulating material ( 10 c ) holds the electrical conductors ( 10 a–b ) in spaced apart relation.
30. A machine according to claim 22 , wherein the machine has a sensor stimulus module ( 10 d ) for providing the first signal.
31. A machine according to claim 22 , wherein the machine is a washing machine.
32. A kit for adapting a machine having a hose for receiving or discharging a fluid, characterized in that the kit comprises:
electrical conductors ( 10 a–b ) separated from each other by a fluid-permeable insulating material ( 10 c ), for arranging in fixed proximate relation to the hose or the machine, and adapted to respond to a first signa arid to fluid leaking from the hose by providing a second signal;
a flow control device ( 16 ), responsive to the second signal, for determining whether there is a possible leak in the hose; and
a leak sensor detection component ( 10 d ) completing a circuit path for an alternating or raido frequency current of a higher frequency than the second signal, and wherein the flow control device ( 16 ) is configured to provide an impressed voltage corresponding to the higher-frequency signal and to detect the higher frequency signal in order to determine if the electrical conductors ( 10 a–b ) are coupled to the flow control device ( 16 ).