US3109670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air duct installations
Assignee: Individual
•
Filing: 1960-10-17
•
Granted: 1963-11-05
•
Expires: 1980-10-17
Abstract
No abstract record available.
Inventors
- 👤 Charles F Engel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:08
CPC Classifications
F; F24; F24F; F24F13/00; F24F13/02; F24F13/0209; F16; F16L; F16L11/00; F16L11/14; F16L9/00; F16L9/02; F24F13/0218; Y; Y10; Y10S; Y10S138/00; Y10S138/11
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US471266A
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US529216A
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US631376A
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US1106542A
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US1303098A
Cited
US1902763A
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US2544120A
Cited
US2741496A
Cited
US2821896A
Cited
US2726682A
Cited
US2722237A
Cited
US2824575A
Cited
US2861598A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-11-04 | 1967-05-06 | 1967-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-11-04 | 1971-05-06 | 1971-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-11-04 | 1975-05-06 | 1975-11-05 | $7700.00 | Window Closed / Lapsed |