Patent US2719698A successfully refreshed from Google Patents.
US2719698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Earth boring apparatus
Assignee: Darin and Armstrong Inc
•
Filing: 1951-02-01
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Granted: 1955-10-04
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Expires: 1971-02-01
Abstract
No abstract record available.
Inventors
- 👤 Peter C Darin
- 👤 Le Roy E Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:11
CPC Classifications
E; E21; E21B; E21B7/00; 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) | 1958-10-03 | 1959-04-04 | 1959-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-03 | 1963-04-04 | 1963-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-03 | 1967-04-04 | 1967-10-04 | $7700.00 | Window Closed / Lapsed |