US3021839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Underwater breathing apparatus
Assignee: Individual
•
Filing: 1956-08-31
•
Granted: 1962-02-20
•
Expires: 1976-08-31
Abstract
No abstract record available.
Inventors
- 👤 De Loss L Marsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:20
CPC Classifications
B; B63; B63C; B63C11/00; B63C11/02; B63C11/18; B63C11/22; B63C11/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-02-19 | 1965-08-21 | 1966-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-02-19 | 1969-08-21 | 1970-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-02-19 | 1973-08-21 | 1974-02-20 | $7700.00 | Window Closed / Lapsed |