US2437489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air filter with heat exchange arrangements
Assignee: Vokes Ltd
•
Filing: 1944-03-15
•
Granted: 1948-03-09
•
Expires: 1964-03-15
Abstract
No abstract record available.
Inventors
- 👤 Vokes Cecil Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:36
CPC Classifications
F; F02; F02M; F02M35/00; F02M35/02; F02M35/04; F02M1/00; F02M2700/00; F02M2700/43; F02M2700/4302; F02M2700/434; F02M2700/4342; F02M2700/4357; F02M2700/4359
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2022463A
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US1452699A
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US1580291A
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US1855308A
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US1906984A
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US1881770A
Cited
US1914063A
Cited
US2105433A
Cited
US2353337A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-03-09 | 1951-09-08 | 1952-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-03-09 | 1955-09-08 | 1956-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-03-09 | 1959-09-08 | 1960-03-09 | $7700.00 | Window Closed / Lapsed |