Patent US2881540A successfully refreshed from Google Patents.
US2881540A
Expired / Lapsed
US
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Land leveling machine
Assignee: Individual
•
Filing: 1953-07-06
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Granted: 1959-04-14
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Expires: 1973-07-06
Abstract
No abstract record available.
Inventors
- 👤 Frank N Sprague
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:44
CPC Classifications
E; E02; E02F; E02F3/00; E02F3/04; E02F3/76; E02F3/7663; E02F3/7672; A; A01; A01B; A01B31/00; A01B63/00; A01B63/14; A01B63/16; E02F3/80; E02F3/84; E02F3/841
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1388266A
Cited
US1845324A
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US2189962A
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US2254414A
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US2283744A
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US2503638A
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US2722067A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-13 | 1962-10-13 | 1963-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-13 | 1966-10-13 | 1967-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-13 | 1970-10-13 | 1971-04-14 | $7700.00 | Window Closed / Lapsed |