Patent US2631013A successfully refreshed from Google Patents.
US2631013A
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Hole digging apparatus
Assignee: Darin and Armstrong Inc
•
Filing: 1948-04-19
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Granted: 1953-03-10
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Expires: 1968-04-19
Abstract
No abstract record available.
Inventors
- 👤 Peter C Darin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:26
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/002; E21B7/003
Claims Analysis
Total Claims: 0
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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) | 1956-03-09 | 1956-09-08 | 1957-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-03-09 | 1960-09-08 | 1961-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-03-09 | 1964-09-08 | 1965-03-10 | $7700.00 | Window Closed / Lapsed |