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US1822216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Underreamer
Assignee: Individual
•
Filing: 1927-02-26
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Granted: 1931-09-08
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Expires: 1947-02-26
Abstract
No abstract record available.
Inventors
- 👤 Earl S Hartson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:54
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/26; E21B10/32
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) | 1934-09-07 | 1935-03-09 | 1935-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-09-07 | 1939-03-09 | 1939-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-09-07 | 1943-03-09 | 1943-09-08 | $7700.00 | Window Closed / Lapsed |