US4020229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-cavity filaments
Assignee: Hercules LLC
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Filing: 1975-08-07
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Granted: 1977-04-26
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Expires: 1995-08-07
Abstract
Abstract Multi-cavity filaments having improved resilience and anti-soiling properties have continuous cavities along their length with each cavity having a vertex angle formed by two sides or legs of the cavity of between about 65° and 140°. The vertex angle of each cavity points substantially toward the center axis of the filament. The cavities are spaced from each other and from the periphery of the filament in a manner producing a filament having good physical and aesthetic properties.
Inventors
- 👤 Paul R. Cox, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:16
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/24; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2927; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
62 words
A polypropylene filament having a substantially round cross-section, the cross-section at any point along the length of the filament having three or more cavities of substantially equal cross-section therein, each of said cavities having two legs forming a vertex angle therebetween of between about 65° and 140°, with said vertex angle being pointed substantially directly toward the center axis of the filament.
Claim 2
Dependent Claim
62 words
A polypropylene filament having a substantially round cross-section, the cross-section at any point along the length of the filament having three or more cavities of substantially equal cross-section therein, each of said cavities having two legs forming a vertex angle therebetween of between about 65° and 140°, with said vertex angle being pointed substantially directly toward the center axis of the filament.
Claim 3
Dependent Claim
55 words
A polypropylene filament as set forth in claim 1 wherein said cavities are spaced from the periphery of the filament by a distance no less than one-tenth the radius of the filament and the distance between adjacent cavities at the outer points of said legs being no less than two-tenths the radius of the filament.
Claim 4
Dependent Claim
21 words
A polypropylene filament as set forth in claim 1 wherein said filament has spherulites of 8 microns or smaller in diameter.
Claim 5
Dependent Claim
16 words
A polypropylene filament as set forth in claim 2 wherein said cavities are quadrilateral in shape.
Claim 6
Dependent Claim
15 words
A polypropylene filament as set forth in claim 2 wherein said cavities are sector shaped.
References Cited (Backward Citations)
US3562374A
Cited
US3745061A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |