Patent US2520743A successfully refreshed from Google Patents.
US2520743A
Expired / Lapsed
US
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Break-back implement attachment for tractors
Assignee: Allis Chalmers Corp
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Filing: 1946-10-24
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Granted: 1950-08-29
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Expires: 1966-10-24
Abstract
No abstract record available.
Inventors
- 👤 Willard H Tanke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:06
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/02; A01D34/03; A01D34/032; A01D34/035
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USRE21734E
Cited
US843993A
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US917603A
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US2198910A
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US2375025A
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US2284003A
Cited
US2332719A
Cited
US2331863A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-08-28 | 1954-02-27 | 1954-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-08-28 | 1958-02-27 | 1958-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-08-28 | 1962-02-27 | 1962-08-29 | $7700.00 | Window Closed / Lapsed |