Moisture-detecting, switching device and a method of forming the same
AssigneeITT Flygt AB
InventorsHjalmar Fries, Per Hedmark
Life of this patent
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Abstract
One end of a dual-ended housing is closed off by a plug formed of a first constituent which is a water-soluble material and a second constituent which is a thermosetting resin and forms a readily-frangible structure in the plug. An electrical switch which has an actuating plunger is set, in the housing against the plug, so that the latter holds the plunger depressed/retracted. Moisture expands the water-soluble material which, in turn, destroys the plug integrity and, subsequently, the plug is so weakened that the plunger breaks through the frangible structure to actuate the switch.
Claims10
A moisture-detecting, switching device, comprising:
- a dual-ended housing having an inner surface;
- and
- an electrical switch confined in a tight fit manner within said housing;
- wherein
- said switch has an actuating plunger (a) biasingly extensible therefrom, and (b) disposed in adjacency to one end of said housing;
- and
- means fluid-sealing off said one end of said housing and restraining said plunger against extension;
- wherein
- said sealing means comprises a material formed of an admixture of a first, water-soluble constituent, and a second, non-water-soluble constituent;
- and
- said second constituent defines a structure within said sealing means which is readily frangible.
A method of forming a moisture-detecting, switching device, comprising the steps of:
- providing a dual-ended housing;
- forming a sealing means, for fluid-sealing off one end of said housing, within said one end;
- composing said sealing means of an admixture of a first, water-soluble constituent, and a second, non-water-soluble constituent which forms a readily-frangible structure within said sealing means;
- confining within said housing a switch which has a biasingly extensible, actuating plunger;
- and
- setting said switch against said sealing means so that said plunger is retractably held against extension by said sealing means.
A moisture-detecting, switching device, comprising:
- a dual-ended housing having an inner surface;
- and
- an electrical switch confined in a tight fit manner within said housing;
- wherein
- said switch has an actuating plunger (a) biasingly extensible therefrom, and (b) disposed in adjacency to one end of said housing;
- and
- means fluid-sealing off said one end of said housing and restraining said plunger against extension;
- wherein
- said sealing means comprises a material formed of an admixture of a first, water-soluble constituent, and a second constituent which defines a structure within said sealing means which is readily frangible.
A method of forming a moisture-detecting, switching device, comprising the steps of:
- providing a dual-ended housing;
- forming a sealing means, for fluid-sealing off one end of said housing, within said one end;
- composing said sealing means of an admixture of a first, water-soluble constituent, and a second constituent which forms a readily-frangible structure within said sealing means;
- confining within said housing in a tight fit manner a switch which has a biasingly extensible, actuating plunger;
- and
- setting said switch against said sealing means so that said plunger is retractably held against extension by said sealing means.
Dependencies are inferred from the claim text.