US3630237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyester concrete pipe
Assignee: Concrete Development Corp
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Filing: 1970-02-09
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Granted: 1971-12-28
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Expires: 1990-02-09
Abstract
Abstract Concrete pipe is made from a mixture of polyester resin and aggregate, and may be wrapped with resin coated aluminum reinforcing wire in tension to increase the internal pressure which the pipe can withstand. The pipe may also be reinforced with longitudinally placed resin coated aluminum bars. Both the reinforcing wire and bars are coated with resin while at an elevated temperature to avoid any substantial detrimental reaction between the aluminum and polyester resin.
Inventors
- 👤 William R Varnell
- 👤 Mance R Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:55
CPC Classifications
F; F16; F16L; F16L9/00; F16L9/14; F16L9/08; F16L9/12; F16L9/121
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
27 words
A pipe according to claim 1 in which the wire and plastic resin concrete each have a thermal coefficient of expansion of about 0.000012 per degree F.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |