Patent US2521895A successfully refreshed from Google Patents.
US2521895A
Expired / Lapsed
US
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Earth boring attachment for tractors
Assignee: Ferguson Harry Inc
•
Filing: 1945-08-23
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Granted: 1950-09-12
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Expires: 1965-08-23
Abstract
No abstract record available.
Inventors
- 👤 Ernest V Bunting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:39
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/02; E21B7/021; Y; Y10; Y10T; Y10T74/00; Y10T74/17
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US515731A
Cited
US1220949A
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US1674189A
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US1641926A
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US1921812A
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US2321680A
Cited
US2320775A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-09-11 | 1954-03-13 | 1954-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-11 | 1958-03-13 | 1958-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-11 | 1962-03-13 | 1962-09-12 | $7700.00 | Window Closed / Lapsed |