US4489603A
Expired / Lapsed
US
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Moisture sensitive element
Assignee: Soken Inc
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Filing: 1982-09-07
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Granted: 1984-12-25
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Expires: 2002-09-07
Abstract
Abstract A moisture sensitive element including a sheet made from a mixture of electrically insulating fibers having the property to expand upon adsorbing the moisture (e.g., cellulose fiber) and electroconductive fibers (e.g., activated carbon fiber). The moisture sensitive element is capable of sensing the humidity of the air by determining the electric resistance which varies according to the change of the humidity of the air, and can also be applied as a condensation sensor which can sense, for example, dew condensation on windowpanes.
Inventors
- 👤 Akira Fukami
- 👤 Kunio Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:49
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/121
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
70 words
A moisture sensitive element, comprising: a sheet made from a mixture of electrically insulating fibers having a property of expanding upon absorbing moisture and electroconductive fibers having a length of 1-5 mm, the ratio of the electrically insulating fibers being 30% or more of the total fiber mixture in the sheet, and the ratio of the electroconductive fibers being 10% or more of the total fiber mixture in the sheet.
Claim 2
Dependent Claim
70 words
A moisture sensitive element, comprising: a sheet made from a mixture of electrically insulating fibers having a property of expanding upon absorbing moisture and electroconductive fibers having a length of 1-5 mm, the ratio of the electrically insulating fibers being 30% or more of the total fiber mixture in the sheet, and the ratio of the electroconductive fibers being 10% or more of the total fiber mixture in the sheet.
Claim 3
Dependent Claim
24 words
The moisture sensitive element according to claim 1, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are cellulose fibers.
Claim 4
Dependent Claim
32 words
The moisture sensitive element according to claim 1, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are a mixture of cellulose fibers with polyvinyl alcohol (PVA) fibers.
Claim 5
Dependent Claim
15 words
The moisture sensitive element according to claim 1, wherein: the electroconductive fibers are carbon fibers.
Claim 6
Dependent Claim
16 words
The moisture sensitive element according to claim 1, wherein: the electroconductive fibers are activated carbon fibers.
Claim 7
Dependent Claim
38 words
The moisture sensitive element according to claim 3, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are a mixture of cellulose fibers with PVA fibers, and the electroconductive fibers are activated carbon fibers.
Claim 8
Dependent Claim
29 words
The moisture sensitive element according to any one of claims 1-6, wherein: at least one side of said sheet is covered with a layer not containing the electroconductive fibers.
Claim 9
Dependent Claim
116 words
A moisture sensitive element, comprising: a sensor unit composed of a sheet made from a mixture of electrically insulating fibers having a property of expanding upon absorbing moisture and electroconductive fibers having a length of 1-5 mm, the ratio of the electrically insulating fibers being 30% or more of the total fiber mixture in the sheet, and the ratio of the electroconductive fibers being 10% or more of the total fiber mixture in the sheet, said unit being held on its both sides by air-permeable and rigid plate-like insulators; a pair of electrodes disposed between said sensor unit and said insulators; and securing members for securing said sensor unit, insulators and electrodes as an integral assembly.
Claim 10
Dependent Claim
116 words
A moisture sensitive element, comprising: a sensor unit composed of a sheet made from a mixture of electrically insulating fibers having a property of expanding upon absorbing moisture and electroconductive fibers having a length of 1-5 mm, the ratio of the electrically insulating fibers being 30% or more of the total fiber mixture in the sheet, and the ratio of the electroconductive fibers being 10% or more of the total fiber mixture in the sheet, said unit being held on its both sides by air-permeable and rigid plate-like insulators; a pair of electrodes disposed between said sensor unit and said insulators; and securing members for securing said sensor unit, insulators and electrodes as an integral assembly.
Claim 11
Dependent Claim
39 words
The moisture sensitive element according to claim 8, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are cellulose fibers and polyvinyl alcohol fibers, and the electroconductive fibers are carbon fibers and activated carbon fibers.
Claim 12
Dependent Claim
23 words
The moisture sensitive element according to claim 8 or 9, wherein: the air-permeable and rigid plate-like insulators are comprised of plate-like ceramic material.
Claim 13
Dependent Claim
59 words
A moisture sensing unit, said unit comprising: a moisture sensitive element according to any one of claims 8-13, said element being held on its both sides by air-permeable and rigid plate-like insulators; a pair of electrodes disposed between said sensitive element and said insulators; and securing members for securing said sensitive element insulators and electrodes as an integral assembly.
Claim 14
Dependent Claim
31 words
The moisture sensitive element according to claim 8, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are cellulose fibers, and the electroconductive fibers are carbon fibers.
Claim 15
Dependent Claim
32 words
The moisture sensitive element according to claim 8, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are cellulose fibers, and the electroconductive fibers are activated carbon fibers.
Claim 16
Dependent Claim
35 words
The moisture sensitive element according to claim 8, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are cellulose fibers, and the electroconductive fibers are carbon fibers and activated carbon fibers.
Claim 17
Dependent Claim
32 words
The moisture sensitive element according to claim 8, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are polyvinyl alcohol fibers, and the electroconductive fibers are carbon fibers.
Claim 18
Dependent Claim
33 words
The moisture sensitive element according to claim 8, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are polyvinyl alcohol fibers, and the electroconductive fibers are activated carbon fibers.
Claim 19
Dependent Claim
36 words
The moisture sensitive element according to claim 8, wherein: the electrically insulating fibers having a property of expanding upon absorbing moisture are polyvinyl alcohol fibers, and the electroconductive fibers are carbon fibers and activated carbon fibers.
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) | 1987-12-25 | 1988-06-25 | 1988-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-25 | 1992-06-25 | 1992-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-25 | 1996-06-25 | 1996-12-25 | $7700.00 | Window Closed / Lapsed |