US2428884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric blasting cap
Assignee: Hercules Powder Co
•
Filing: 1942-04-17
•
Granted: 1947-10-14
•
Expires: 1962-04-17
Abstract
No abstract record available.
Inventors
- 👤 Edward K Lefren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:07
CPC Classifications
F; F42; F42B; F42B3/00; F42B3/10; F42B3/103
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US408096A
Cited
US1306641A
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CH37332A
Cited
US1577539A
Cited
US1503420A
Cited
GB246727A
Cited
FR40035E
Cited
US2083733A
Cited
US2129439A
Cited
US2178723A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-10-13 | 1951-04-14 | 1951-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-10-13 | 1955-04-14 | 1955-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-10-13 | 1959-04-14 | 1959-10-14 | $7700.00 | Window Closed / Lapsed |