US2822989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for prestressing concrete pipe
Assignee: Cen-Vi-Ro Pipe Corp
•
Filing: 1954-02-15
•
Granted: 1958-02-11
•
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 01:30
CPC Classifications
B; B28; B28B; B28B21/00; B28B21/56; B28B21/60; B28B21/62; B28B21/64
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US704574A
Cited
US1356226A
Cited
FR835177A
Cited
US2242435A
Cited
US2348765A
Cited
US2639864A
Cited
US2469706A
Cited
US2643068A
Cited
US2573793A
Cited
US2668670A
Cited
US2601961A
Cited
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 |