US3988412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making pipe having a liner layer of mixed resins
Assignee: FOC Corp A DE CORP
•
Filing: 1975-05-13
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Granted: 1976-10-26
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Expires: 1995-05-13
Abstract
Abstract Method of making a plastic pipe and method of making same, having an outer shell of reinforced thermo-setting resin and an inner shell of thermo-setting and thermo-plastic resins.
Inventors
- 👤 Charles S. Woodson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:12
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/30; B29C70/32; B29C70/323; B29C70/326; B29C41/00; B29C41/02; B29C41/04; B29C41/042; B29C41/22; B29K; B29K2101/00; B29K2101/10; B29K2101/12; B29K2105/00; B29K2105/06; B29K2105/08; B29K2105/0854
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
103 words
A method of producing reinforced plastic pipe consisting essentially of positioning a reinforcing cylinder of fibrous material in a cylindrical mold, introducing thermo-setting resin into the mold and spinning the mold to form the outer shell of a pipe, said thermo-setting resin being of a quantity to just cover said fibrous material, then introducing into the said outer shell of a pipe a dispersion of thoroughly mixed thermo-setting and thermo-plastic resins and rotating the pipe to evenly spread the dispersion over the previously formed shell while maintaining the thermo-plastic resin dispersed throughout the thermo-setting resin to form the inner shell of the pipe.
Claim 2
Independent Claim
103 words
A method of producing reinforced plastic pipe consisting essentially of positioning a reinforcing cylinder of fibrous material in a cylindrical mold, introducing thermo-setting resin into the mold and spinning the mold to form the outer shell of a pipe, said thermo-setting resin being of a quantity to just cover said fibrous material, then introducing into the said outer shell of a pipe a dispersion of thoroughly mixed thermo-setting and thermo-plastic resins and rotating the pipe to evenly spread the dispersion over the previously formed shell while maintaining the thermo-plastic resin dispersed throughout the thermo-setting resin to form the inner shell of the pipe.
Claim 3
Dependent Claim
45 words
The method of claim 1, wherein the fibrous material is fiberglas, the thermo-setting resin is a vinyl ester, the thermo-plastic resin is powdered polyethylene at least as small as 35 mesh, and the thermo-plastic resin provides at least 15 percent by weight of said dispersion.
References Cited (Backward Citations)
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US2994919A
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US2887728A
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US3256362A
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US3338271A
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US3397169A
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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) | 1979-10-26 | 1980-04-26 | 1980-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-26 | 1984-04-26 | 1984-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-26 | 1988-04-26 | 1988-10-26 | $7700.00 | Window Closed / Lapsed |