Patent US2451A successfully refreshed from Google Patents.
US2451A
Expired / Lapsed
US
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Machine for screening or sifting coal
Assignee: —
•
Filing: —
•
Granted: 1842-02-07
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Expires: 1859-02-07
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:42
CPC Classifications
B; B07; B07B; B07B1/00; B07B1/18; B07B1/22; B07B1/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1845-02-06 | 1845-08-08 | 1846-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1849-02-06 | 1849-08-08 | 1850-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1853-02-06 | 1853-08-08 | 1854-02-07 | $7700.00 | Window Closed / Lapsed |