US2854220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air heater
Assignee: Combustion Engineering Inc
•
Filing: 1956-11-09
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Granted: 1958-09-30
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Expires: 1976-11-09
Abstract
No abstract record available.
Inventors
- 👤 Paul H Vaughan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:36
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/08; F28D7/082; F28D7/085; F28D7/087; F22; F22B; F22B31/00; F22B31/08; F23; F23M; F23M20/00; Y; Y10; Y10S; Y10S165/00; Y10S165/921
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) | 1961-09-29 | 1962-03-31 | 1962-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-29 | 1966-03-31 | 1966-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-29 | 1970-03-31 | 1970-09-30 | $7700.00 | Window Closed / Lapsed |