Patent US1721004A successfully refreshed from Google Patents.
US1721004A
Expired / Lapsed
US
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Rotary well-drilling apparatus
Assignee: Individual
•
Filing: 1928-04-23
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Granted: 1929-07-16
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Expires: 1948-04-23
Abstract
No abstract record available.
Inventors
- 👤 Albert S Debose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:29
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/10; E21B17/1057
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) | 1932-07-15 | 1933-01-14 | 1933-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1936-07-15 | 1937-01-14 | 1937-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1940-07-15 | 1941-01-14 | 1941-07-16 | $7700.00 | Window Closed / Lapsed |