US4256523A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the manufacture of a pipe
Assignee: Handelsbolaget Evaksystem Ekstrom and Co
•
Filing: 1978-10-27
•
Granted: 1981-03-17
•
Expires: 1998-10-27
Abstract
Abstract This disclosure relates to a method of manufacturing a pipe having a rubber lining within a layer of looped fabric and a resin layer. The method comprises placing a tubular layer of unvulcanized rubber on an expansible mandrel, then wrapping a layer of looped fabric on the rubber layer, with the loops outwardly directed. The mandrel is expanded to draw the looped fabric partially into the rubber, the protruding loops then being impregnated with uncured thermosetting resin, and glass fabric is then wrapped on the resin.
Inventors
- 👤 Stig O. M. Ekstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:25
CPC Classifications
B; B29; B29D; B29D23/00; B29D23/001; B29D30/00; B29D30/02; F; F16; F16L; F16L58/00; F16L58/02; F16L58/04; F16L58/10; F16L58/18; F16L58/185; F16L58/187; B29C; B29C35/00; B29C35/02; B29K; B29K2021/00; B29K2105/00; B29K2105/06; B29K2105/24; B29K2105/246; B29L; B29L2009/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
123 words
A method of manufacturing a pipe comprising: placing a tubular layer of unvulcanized rubber on an expansible elongate mandrel, wrappig on said rubber layer a layer of fabric having loops protruding therefrom with the said loops extending outwardly from said fabric layer, away from said rubber layer, expanding said mandrel, placing said mandrel in a heated zone to vulcanize said rubber, rotating said mandrel about its longitudinal axis while said mandrel is in said heated zone, removing the vulcanized rubber and fabric article thus formed from said heating zone, and with said loops protruding outwardly, impregnating said fabric with an uncured thermosetting resin, wrapping said resin with at least one layer of glass fibre impregnated with uncured thermosetting resin, and curing said resin.
Claim 2
Independent Claim
123 words
A method of manufacturing a pipe comprising: placing a tubular layer of unvulcanized rubber on an expansible elongate mandrel, wrappig on said rubber layer a layer of fabric having loops protruding therefrom with the said loops extending outwardly from said fabric layer, away from said rubber layer, expanding said mandrel, placing said mandrel in a heated zone to vulcanize said rubber, rotating said mandrel about its longitudinal axis while said mandrel is in said heated zone, removing the vulcanized rubber and fabric article thus formed from said heating zone, and with said loops protruding outwardly, impregnating said fabric with an uncured thermosetting resin, wrapping said resin with at least one layer of glass fibre impregnated with uncured thermosetting resin, and curing said resin.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1, wherein the looped fabric is formed by glass fibre roving.
Claim 4
Dependent Claim
32 words
A method as claimed in claim 1, wherein the looped fabric is formed by a ground fabric of tissue or knitted fabric and loops fixed to said ground fabric and protruding therefrom.
Claim 5
Dependent Claim
23 words
The method of claim 1, wherein the impregnating of said fabric comprises the impregnation of resin in surrounding relationship to said protruding loops.
References Cited (Backward Citations)
US2035660A
Cited
US2788804A
Cited
US2814313A
Cited
US2999780A
Cited
US2868257A
Cited
US2943009A
Cited
US2830622A
Cited
US2967796A
Cited
US3026223A
Cited
US3379591A
Cited
US3258384A
Cited
US3219738A
Cited
US3273978A
Cited
US3424220A
Cited
US4044799A
Cited
US3682201A
Cited
US3934064A
Cited
US4091063A
Cited
US4104095A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |