US2180839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Primary cell
Assignee: National Carbon Co Inc
•
Filing: 1937-06-17
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Granted: 1939-11-21
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Expires: 1957-06-17
Abstract
No abstract record available.
Inventors
- 👤 Erwin A Schumacher
- 👤 George W Heise
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:45
CPC Classifications
H; H01; H01M; H01M12/00; H01M12/04; H01M12/06; H01M12/065; H01M6/00; H01M6/50; H01M6/5077; H01M4/00; H01M4/02; H01M2004/026; H01M2004/029; H01M2300/00; H01M2300/0085; H01M6/42; H01M6/46; H01M6/48
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) | 1942-11-20 | 1943-05-22 | 1943-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-11-20 | 1947-05-22 | 1947-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-11-20 | 1951-05-22 | 1951-11-21 | $7700.00 | Window Closed / Lapsed |