US2933838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic depth control for an implement
Assignee: Allis Chalmers Corp
•
Filing: 1957-04-29
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Granted: 1960-04-26
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Expires: 1977-04-29
Abstract
No abstract record available.
Inventors
- 👤 Harvey W Rockwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:21
CPC Classifications
E; E02; E02F; E02F3/00; E02F3/04; E02F3/76; E02F3/80; E02F3/84; E02F3/844
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-04-26 | 1963-10-26 | 1964-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-26 | 1967-10-26 | 1968-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-26 | 1971-10-26 | 1972-04-26 | $7700.00 | Window Closed / Lapsed |