Patent US4655076A successfully refreshed from Google Patents.
US4655076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture measuring apparatus
Assignee: Tyco International Ltd Bermuda
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Filing: 1984-01-23
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Granted: 1987-04-07
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Expires: 2004-01-23
Abstract
Abstract An apparatus for measuring the moisture content of soil includes a chamber having a water-swellable material in the chamber, the chamber being sized so that the water-swellable material can swell to its fully swollen state, with the external resistance, if any, against the swelling being substantially constant. The device includes a device for transmitting water to the water-swellable material so that it is in equilibrium with the environment. A sensor responsive to the volume of the water-swellable material is provided to indicate the water content of the environment exterior of the apparatus. The preferred sensor is a magnet moveable by the water-swellable material and a Hall effect sensing device.
Inventors
- 👤 Gary R. Weihe
- 👤 Roger D. Lion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:47
CPC Classifications
G; G01; G01N; G01N19/00; G01N19/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
An apparatus for measuring humidity comprising: (a) a rigid, porous, cylindrical substrate, the substrate being capable of passing water therethrough; (b) a tube of water-swellable polymer in contact with the cylindrical substrate, the water-swellable polymer having a fully swollen volume when in its fully swollen state in equilibrium with water at least about 2 times its dry volume, said tube and substrate being substantially completely contained in a chamber, the volume of the chamber being sufficiently large to accomodate the tube in its fully swollen state; and (c) sensing means responsive to the volume of the water-swellable polymer for producing a signal that varies with the water content of the environment exterior to the chamber.
Claim 2
Independent Claim
115 words
An apparatus for measuring humidity comprising: (a) a rigid, porous, cylindrical substrate, the substrate being capable of passing water therethrough; (b) a tube of water-swellable polymer in contact with the cylindrical substrate, the water-swellable polymer having a fully swollen volume when in its fully swollen state in equilibrium with water at least about 2 times its dry volume, said tube and substrate being substantially completely contained in a chamber, the volume of the chamber being sufficiently large to accomodate the tube in its fully swollen state; and (c) sensing means responsive to the volume of the water-swellable polymer for producing a signal that varies with the water content of the environment exterior to the chamber.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 in which the substrate is a porous ceramic material.
Claim 4
Dependent Claim
11 words
The apparatus of claim 1 in which the substrate is tubular.
Claim 5
Dependent Claim
17 words
The apparatus of claim 3 including a water wicking material in the interior of the tubular substrate.
Claim 6
Dependent Claim
38 words
The apparatus of claim 1 wherein (a), (b) and (c) are arranged such that the external resistance, if any, to swelling of the water-swellable polymer remains substantially constant as the water-swellable polymer swells to its fully swollen state.
Claim 7
Dependent Claim
32 words
The apparatus of claim 1 including sensing means responsive to the volume of the water-swellable polymer for producing a signal proportional to the water content of the environment around the water-swellable polymer.
Claim 8
Dependent Claim
17 words
The apparatus of claim 1 which the water-swellable polymer is shrunk into contact with the cylindrical substrate.
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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) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |