US2840351A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature equalizing means for regenerative air preheater structure
Assignee: AIR PRCHEATER Corp
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Filing: 1953-09-10
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Granted: 1958-06-24
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Expires: 1973-09-10
Abstract
No abstract record available.
Inventors
- 👤 Holm Sven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:46
CPC Classifications
F; F28; F28D; F28D19/00; F28D19/04; F28D19/041; F23; F23L; F23L15/00; F23L15/02; F28D15/00; F28D15/02; F28D15/0275; Y; Y02; Y02E; Y02E20/00; Y02E20/34
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) | 1961-06-23 | 1961-12-23 | 1962-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-23 | 1965-12-23 | 1966-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-23 | 1969-12-23 | 1970-06-24 | $7700.00 | Window Closed / Lapsed |