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US2689999A
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Apparatus for manufacturing prestressed concrete structural units
Assignee: CONCRETE PRODUCTS Co
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Filing: 1950-05-26
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Granted: 1954-09-28
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Expires: 1970-05-26
Abstract
No abstract record available.
Inventors
- 👤 Robert P Petersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:14
CPC Classifications
B; B28; B28B; B28B23/00; B28B23/02; B28B23/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2516453A
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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) | 1957-09-27 | 1958-03-29 | 1958-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-09-27 | 1962-03-29 | 1962-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-09-27 | 1966-03-29 | 1966-09-28 | $7700.00 | Window Closed / Lapsed |