US2796703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for sharpening drills
Assignee: UNION TWIST DRILL Co
•
Filing: 1951-12-28
•
Granted: 1957-06-25
•
Expires: 1971-12-28
Abstract
No abstract record available.
Inventors
- 👤 Esmonde J Bushey
- 👤 John N Engelsted
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:41
CPC Classifications
B; B24; B24B; B24B3/00; B24B3/24; B24B3/245
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-06-24 | 1960-12-24 | 1961-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-06-24 | 1964-12-24 | 1965-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-06-24 | 1968-12-24 | 1969-06-25 | $7700.00 | Window Closed / Lapsed |