US2439570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric contact
Assignee: Duracell Inc USA
•
Filing: 1942-11-10
•
Granted: 1948-04-13
•
Expires: 1962-11-10
Abstract
No abstract record available.
Inventors
- 👤 Franz R Hensel
- 👤 Earl I Larsen
- 👤 Earl F Swazy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:59
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/02; H01H1/021; H01H1/023; H01H1/0233; H01B; H01B1/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1181742A
Cited
GB345171A
Cited
US1979372A
Cited
US2049317A
Cited
US2281446A
Cited
US2313070A
Cited
US2289708A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-04-13 | 1951-10-13 | 1952-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-13 | 1955-10-13 | 1956-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-13 | 1959-10-13 | 1960-04-13 | $7700.00 | Window Closed / Lapsed |