Patent US2877834A successfully refreshed from Google Patents.
US2877834A
Expired / Lapsed
US
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Air control apparatus for boiler
Assignee: Eclipse Fuel Engineering Co
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Filing: 1957-01-09
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Granted: 1959-03-17
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Expires: 1977-01-09
Abstract
No abstract record available.
Inventors
- 👤 Donald A Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:46
CPC Classifications
F; F23; F23L; F23L11/00; F23L11/005; F23L3/00; F24; F24H; F24H15/00; F24H15/30; F24H15/305; F24H15/31; F24H15/33; F24H9/00; F24H9/20; F24H9/2007; F24H9/2035; F23J; F23J2211/00; F23J2211/10; F23J2211/101
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) | 1962-03-16 | 1962-09-15 | 1963-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-03-16 | 1966-09-15 | 1967-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-03-16 | 1970-09-15 | 1971-03-17 | $7700.00 | Window Closed / Lapsed |