Patent US2620722A successfully refreshed from Google Patents.
US2620722A
Expired / Lapsed
US
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Ventilating and air conditioning apparatus
Assignee: Individual
•
Filing: 1950-04-03
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Granted: 1952-12-09
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Expires: 1970-04-03
Abstract
No abstract record available.
Inventors
- 👤 Owens George Erwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:32
CPC Classifications
F; F24; F24F; F24F6/00; F24F6/02; F24F6/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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Cited
US679587A
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US1543760A
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US1808935A
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US2083905A
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US2055958A
Cited
US2137905A
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US2197004A
Cited
US2311155A
Cited
US2247276A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-12-09 | 1956-06-09 | 1956-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-12-09 | 1960-06-09 | 1960-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-12-09 | 1964-06-09 | 1964-12-09 | $7700.00 | Window Closed / Lapsed |