US2823670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Underwater breathing apparatus
Assignee: HOPE PAGE ENGINEERING CORP
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Filing: 1954-03-29
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Granted: 1958-02-18
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Expires: 1974-03-29
Abstract
No abstract record available.
Inventors
- 👤 Rory E Page
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:49
CPC Classifications
B; B63; B63C; B63C11/00; B63C11/02; B63C11/18; B63C11/22; B63C11/2209
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) | 1961-02-17 | 1961-08-19 | 1962-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-17 | 1965-08-19 | 1966-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-17 | 1969-08-19 | 1970-02-18 | $7700.00 | Window Closed / Lapsed |