Patent EP0160790A2 successfully refreshed from Google Patents.
Patent US2822989A successfully refreshed from Google Patents.
US2822989A
Expired / Lapsed
US
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Means for prestressing concrete pipe
Assignee: Cen-Vi-Ro Pipe Corp
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Filing: 1954-02-15
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Granted: 1958-02-11
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Expires: 1974-02-15
Abstract
No abstract record available.
Inventors
- 👤 Stephen R Hubbard
- 👤 Carl W Chanlund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:19
CPC Classifications
B; B28; B28B; B28B21/00; B28B21/56; B28B21/60; B28B21/62; B28B21/64
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US704574A
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US1356226A
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FR835177A
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US2242435A
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US2348765A
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US2639864A
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US2469706A
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US2643068A
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US2573793A
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US2668670A
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US2601961A
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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) | 1961-02-10 | 1961-08-12 | 1962-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-10 | 1965-08-12 | 1966-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-10 | 1969-08-12 | 1970-02-11 | $7700.00 | Window Closed / Lapsed |