Patent US2180544A successfully refreshed from Google Patents.
Patent US1535633A successfully refreshed from Google Patents.
US1535633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Submarine contact mine
Assignee: Individual
•
Filing: 1917-11-08
•
Granted: 1925-04-28
•
Expires: 1937-11-08
Abstract
No abstract record available.
Inventors
- 👤 Elmer A Sperry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:25
CPC Classifications
F; F42; F42B; F42B22/00; F42B22/10; F42B22/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1928-04-27 | 1928-10-27 | 1929-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1932-04-27 | 1932-10-27 | 1933-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1936-04-27 | 1936-10-27 | 1937-04-28 | $7700.00 | Window Closed / Lapsed |