US1690446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Leaching process
Assignee: HOWARD M HANNA
•
Filing: 1925-03-31
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Granted: 1928-11-06
•
Expires: 1945-03-31
Abstract
No abstract record available.
Inventors
- 👤 Richard F Grant
- 👤 Franklin B Richards
- 👤 Herbert E Wetherbee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:33
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/28
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) | 1931-11-06 | 1932-05-07 | 1932-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1935-11-06 | 1936-05-07 | 1936-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1939-11-06 | 1940-05-07 | 1940-11-06 | $7700.00 | Window Closed / Lapsed |