Patent US2269461A successfully refreshed from Google Patents.
US2269461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Respirator
Assignee: American Optical Corp
•
Filing: 1939-11-02
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Granted: 1942-01-13
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Expires: 1959-11-02
Abstract
No abstract record available.
Inventors
- 👤 William H Lehmberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:31
CPC Classifications
B; B01; B01D; B01D46/00; A; A62; A62B; A62B23/00; A62B23/02
Claims Analysis
Total Claims: 0
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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) | 1945-01-12 | 1945-07-14 | 1946-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-01-12 | 1949-07-14 | 1950-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-01-12 | 1953-07-14 | 1954-01-13 | $7700.00 | Window Closed / Lapsed |