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Patent US2640481A successfully refreshed from Google Patents.
US2640481A
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Exhalation valve
Assignee: American Optical Corp
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Filing: 1950-02-14
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Granted: 1953-06-02
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Expires: 1970-02-14
Abstract
No abstract record available.
Inventors
- 👤 Thomas A Conley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:23
CPC Classifications
A; A62; A62B; A62B18/00; A62B18/08; A62B18/10; F; F16; F16K; F16K15/00; F16K15/14; F16K15/144; Y; Y10; Y10S; Y10S137/00; Y10S137/908
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) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |