US1621689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oil-well-drilling apparatus
Assignee: Individual
•
Filing: 1922-10-04
•
Granted: 1927-03-22
•
Expires: 1942-10-04
Abstract
No abstract record available.
Inventors
- 👤 Sheldon Waldo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:04
CPC Classifications
E; E21; E21B; E21B19/00; E21B19/08; E21B19/086
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1930-03-21 | 1930-09-20 | 1931-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1934-03-21 | 1934-09-20 | 1935-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1938-03-21 | 1938-09-20 | 1939-03-22 | $7700.00 | Window Closed / Lapsed |