US4246575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture detector
Assignee: Individual
•
Filing: 1979-02-02
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Granted: 1981-01-20
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Expires: 1999-02-02
Abstract
Abstract A compressed dehydrated cellulose sponge wafer has conductive plates attached to opposing faces. A bridging conductor electrically connects the two plates together upon swelling of the wafer responsive to its contact with moisture. One edge of the sponge is treated with adhesive so as to form a hinge. The wafer opens like a book upon contact with moisture forcing the extending plates into contact.
Inventors
- 👤 Jack L. Purtell
- 👤 Rufus J. Purtell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:56
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/42; G; G08; G08B; G08B21/00; G08B21/18; G08B21/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
In a water leak alarm system having a. a source of electrical energy, b. an alarm, c. a detector including a two faced expansion wafer which expands upon contact with water, d. a connection means for connecting the source of electrical energy and alarm to the detector; the improved method of detecting moisture comprising: e. hinging said wafer at one edge, f. attaching a plate to one face of the wafer which plate extends beyond the hinged edge, g. attaching an opposing plate to an opposing face of the wafer which plate extends beyond the hinged edge, h. opening the plates by expansion of the wafer, and thereby j. levering the extensions into contact.
Claim 2
Dependent Claim
114 words
In a water leak alarm system having a. a source of electrical energy, b. an alarm, c. a detector including a two faced expansion wafer which expands upon contact with water, d. a connection means for connecting the source of electrical energy and alarm to the detector; the improved method of detecting moisture comprising: e. hinging said wafer at one edge, f. attaching a plate to one face of the wafer which plate extends beyond the hinged edge, g. attaching an opposing plate to an opposing face of the wafer which plate extends beyond the hinged edge, h. opening the plates by expansion of the wafer, and thereby j. levering the extensions into contact.
Claim 3
Dependent Claim
120 words
In a water leak alarm system having a. a source of electrical energy, b. an alarm, c. a detector including an expansion substance which expands upon contact with water, d. a connection means for connecting the source of electrical energy and alarm to the detector; the improved moisture detector comprising: e. a first electrical conductor plate adhered to one face of said expansion substance, f. an opposing plate adhered to an opposing face of said expansion substance, g. a bridging conductor attached to said opposing plate and extending proximate the first plate conductor h. so that expansion of the substance causes the bridging conductor to electrically connect the conductor plates, j. said expansion substance means is compressed dehydrated cellulose sponge.
Claim 4
Dependent Claim
120 words
In a water leak alarm system having a. a source of electrical energy, b. an alarm, c. a detector including an expansion substance which expands upon contact with water, d. a connection means for connecting the source of electrical energy and alarm to the detector; the improved moisture detector comprising: e. a first electrical conductor plate adhered to one face of said expansion substance, f. an opposing plate adhered to an opposing face of said expansion substance, g. a bridging conductor attached to said opposing plate and extending proximate the first plate conductor h. so that expansion of the substance causes the bridging conductor to electrically connect the conductor plates, j. said expansion substance means is compressed dehydrated cellulose sponge.
Claim 5
Dependent Claim
182 words
In a water leak alarm system having a. a source of electrical energy, b. an alarm, c. a detector including an expansion substance which expands upon contact with water, d. a connection means for connecting the source of electrical energy and alarm to the detector; the improved moisture detector comprising: e. a first electrical conductor plate adhered to one face of said expansion substance, f. an opposing plate adhered to an opposing face of said expansion susbstance, g. a bridging conductor attached to said opposing plate and extending proximate the first plate conductor h. so that expansion of the substance causes the bridging conductor to electrically connect the conductor plates, j. said substance being in the form of a two faced wafer, k. one edge of said wafer being hinged so the two faces of the wafer along said edge cannot move apart along that edge, m. said conductor plates extending beyond said hinge thus forming said bridging conductor whereby expansion of said wafer causes the wafer to fan open causing said conductor plates to be levered together on the briding conductor.
Claim 6
Dependent Claim
182 words
In a water leak alarm system having a. a source of electrical energy, b. an alarm, c. a detector including an expansion substance which expands upon contact with water, d. a connection means for connecting the source of electrical energy and alarm to the detector; the improved moisture detector comprising: e. a first electrical conductor plate adhered to one face of said expansion substance, f. an opposing plate adhered to an opposing face of said expansion susbstance, g. a bridging conductor attached to said opposing plate and extending proximate the first plate conductor h. so that expansion of the substance causes the bridging conductor to electrically connect the conductor plates, j. said substance being in the form of a two faced wafer, k. one edge of said wafer being hinged so the two faces of the wafer along said edge cannot move apart along that edge, m. said conductor plates extending beyond said hinge thus forming said bridging conductor whereby expansion of said wafer causes the wafer to fan open causing said conductor plates to be levered together on the briding conductor.
Claim 7
Dependent Claim
18 words
The invention as defined in claim 3 wherein n. said expansion substance means is compressed dehydrated cellulose sponge.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |