Patent US4888455A successfully refreshed from Google Patents.
US4888455A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water leak detector and method therefor
Assignee: Individual
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Filing: 1989-02-27
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Granted: 1989-12-19
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Expires: 2009-02-27
Abstract
Abstract In the absence of moisture, a separation between a pair of electrical contacts is maintained by a material that becomes frangible when moistened. When the material becomes moist, it breaks and the contacts close.
Inventors
- 👤 James B. Hanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:44
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/42
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
324 words
A water leak detector comprising: a spring loaded switch comprising: a pair of metal plates having a first electrical contact means for providing a first electrical contact mounted on a front edge of one of said pair of metal plates and having a second electrical contact means for providing a second electrical contact aligned with said first electrical contact means and mounted on a front edge of the other of said pair of metal plates, said first and second electrical contacts are normally open; a spring and shaft means for rotatably securing and forcing said front edges of said pair of metal plates together comprising: a cylindrical shaft upon which said pair of metal plates are mounted; a compressed coil spring coaxially disposed on said shaft having a first end of said spring in contact with a first distal portion of a surface of one of said pair of metal plates and a second end of said spring in contact with a second distal portion of a surface of said other of said pair of metal plates, said first and second ends of said spring pushing said first and second distal portions away from each other and said front edges of said pair of metal plates towards each other; and means mounted on said front edges of said pair of metal plates opposite said first and second electrical contacts for maintaining a separation between said first and second electrical contacts of said switch in the absence of moisture said means for maintaining comprising a moisture responsive frangible material overlying one of said pair of metal plates, having a hole, the other of said metal plates having a puncturing means for puncturing said frangible material, said hole located in one of said pair of metal plates and aligned with said puncturing means mounted on said other of said pair of metal plates, said puncturing means punctures said frangible material when said frangible material becomes moistened.
Claim 2
Dependent Claim
324 words
A water leak detector comprising: a spring loaded switch comprising: a pair of metal plates having a first electrical contact means for providing a first electrical contact mounted on a front edge of one of said pair of metal plates and having a second electrical contact means for providing a second electrical contact aligned with said first electrical contact means and mounted on a front edge of the other of said pair of metal plates, said first and second electrical contacts are normally open; a spring and shaft means for rotatably securing and forcing said front edges of said pair of metal plates together comprising: a cylindrical shaft upon which said pair of metal plates are mounted; a compressed coil spring coaxially disposed on said shaft having a first end of said spring in contact with a first distal portion of a surface of one of said pair of metal plates and a second end of said spring in contact with a second distal portion of a surface of said other of said pair of metal plates, said first and second ends of said spring pushing said first and second distal portions away from each other and said front edges of said pair of metal plates towards each other; and means mounted on said front edges of said pair of metal plates opposite said first and second electrical contacts for maintaining a separation between said first and second electrical contacts of said switch in the absence of moisture said means for maintaining comprising a moisture responsive frangible material overlying one of said pair of metal plates, having a hole, the other of said metal plates having a puncturing means for puncturing said frangible material, said hole located in one of said pair of metal plates and aligned with said puncturing means mounted on said other of said pair of metal plates, said puncturing means punctures said frangible material when said frangible material becomes moistened.
Claim 3
Dependent Claim
15 words
The leak detector of claim 1 wherein said frangible material comprises a water absorbent paper.
Claim 4
Dependent Claim
23 words
The leak detector of claim 1 wherein said frangible material includes a tablet selected from the group consisting of aspirin, salt and sugar.
Claim 5
Dependent Claim
23 words
The leak detector of claim 2 wherein said frangible material includes a tablet selected from the group consisting of aspirin, salt and sugar.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |