Patent US3979569A successfully refreshed from Google Patents.
US3979569A
Expired / Lapsed
US
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Water level sensing device having rupturable hygroscopic-type switch actuator
Assignee: Individual
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Filing: 1975-07-28
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Granted: 1976-09-07
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Expires: 1995-07-28
Abstract
Abstract A water level sensing device includes a housing having a bottom opening and a micro-switch mounted in the housing above its bottom and provided with a spring loaded horizontally projecting actuating arm. An upper support arm depends from the actuating arm and terminates in a horizontal leg and a bottom horizontal arm is vertically adjustably supported on a wall of the housing below the horizontal leg. A loop of water absorbent paper is engaged and stretched between the horizontal arm and leg and retains the switch arm in actuated position until the loop is wetted and weakened to rupture and releases the switch arm to a deactuated position.
Inventors
- 👤 Michael Bilgrei
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:16
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/42
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
136 words
A water level sensing device comprising a housing having a bottom opening therein, a microswitch disposed in said housing and including a horizontally extending actuating arm swingable between advanced depressed and raised retracted positions and resiliently urged to its retracted position, a loop formed of a material having relatively low wet and relatively high dry strengths, and means for supporting said loop in said housing in a vertically extending position between said actuating arm and an underlying point to retain said arm in its advanced position, the stress of said actuating arm being imparted to said loop and exceeding the wet strength and being less than the dry strength of said loop whereby to rupture said loop when wet, and effect the switch actuating retraction of said actuating arm only with the rupture of said loop.
Claim 2
Dependent Claim
136 words
A water level sensing device comprising a housing having a bottom opening therein, a microswitch disposed in said housing and including a horizontally extending actuating arm swingable between advanced depressed and raised retracted positions and resiliently urged to its retracted position, a loop formed of a material having relatively low wet and relatively high dry strengths, and means for supporting said loop in said housing in a vertically extending position between said actuating arm and an underlying point to retain said arm in its advanced position, the stress of said actuating arm being imparted to said loop and exceeding the wet strength and being less than the dry strength of said loop whereby to rupture said loop when wet, and effect the switch actuating retraction of said actuating arm only with the rupture of said loop.
Claim 3
Dependent Claim
15 words
The sensing device of claim 1 wherein said loop material comprises a water absorbent paper.
Claim 4
Dependent Claim
15 words
The sensing device of claim 1 including means for adjusting the level of said loop.
Claim 5
Dependent Claim
35 words
The sensing device of claim 1 wherein said loop supporting means comprises a horizontally extending arm engaging the inside lower part of said loop and mounted in said housing vertically below said switch actuating arm.
Claim 6
Dependent Claim
39 words
The sensing device of claim 1 wherein said loop supporting means comprises an upper arm depending from said switch actuating arm and terminating at its bottom in a horizontally projecting leg engaging the inside upper part of said loop.
Claim 7
Dependent Claim
23 words
The sensing device of claim 1 including a junction box mounted on a wall of said housing and communicating with the interior thereof.
References Cited (Backward Citations)
US3123687A
Cited
US2191630A
Cited
US3115557A
Cited
US3142610A
Cited
US3091674A
Cited
US3163729A
Cited
US3243536A
Cited
US3288961A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |