US3763338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polypyrrolidone fiber for activating sensor means in a humidity responsive device
Assignee: Alrac Corp
•
Filing: 1972-01-06
•
Granted: 1973-10-02
•
Expires: 1992-01-06
Abstract
Abstract A device responsive to changes in humidity is provided in which at least one strand of polypyrrolidone fiber is disposed between a stanchion and spring means, changes in the humidity being detected by means responsive to contraction and expansion of the polypyrrolidone strand.
Inventors
- 👤 J Tozer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:27
CPC Classifications
G; G01; G01N; G01N19/00; G01N19/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
77 words
A humidity responsive device according to claim 1 wherein said polypyrrolidone is a melt extruded fiber of a polymer of 2-pyrrolidone having an inherent viscosity of at least about 2.5 d1/g obtained through the polymerizaton of 2-pyrrolidone in the presence of an alkaline polymerization catalyst and the presence of carbon dioxide. 3 A humidity responsive device according to claim 2 wherein a plurality of strands of polypyrrolidone fiber are disposed between sAid spring means and said stanchion.
Claim 2
Dependent Claim
28 words
A humidity responsive device according to claim 3 wherein the said sensor means operable to detect expansion and contraction of said polypyrrolidone strands is a dial and pointer.
Claim 3
Dependent Claim
26 words
A humidity responsive device according to claim 3 wherein said sensor means operable to detect expansion and contraction of said polypyrrolidone strands is an electrical switch.
Claim 4
Dependent Claim
26 words
A humidity responsive device according to claim 3 wherein said sensor means operable to detect expansion and contraction of said polypyrrolidone strands is an inductive transducer.
Claim 5
Dependent Claim
26 words
A humidity responsive device according to claim 3 wherein said sensor means operable to detect expansion and contraction of said polypyrrolidone strands is a capacitive transducer.
Claim 6
Dependent Claim
26 words
A humidity responsive device according to claim 3 wherein said sensor means operable to detect expansion and contraction of said polypyrrolidone strands is a pneumatic sensor.
Claim 7
Dependent Claim
26 words
A humidity responsive device according to claim 3 wherein said sensor means operable to detect expansion and contraction of said polypyrrolidone strands is a hydraulic sensor.
Claim 8
Dependent Claim
57 words
A humidity responsive device according to claim 1 further characterized in that a swing lever is pivotably mounted on said base, and a plurality of strands of polypyrrolidone fiber are disposed between said swing lever and said stanchion, said spring means being operative to urge said swing lever in tensional opposition to said stanchion through said strands.
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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) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |