Patent US2641456A successfully refreshed from Google Patents.
US2641456A
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Heat recovery apparatus
Assignee: Individual
•
Filing: 1949-12-22
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Granted: 1953-06-09
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Expires: 1969-12-22
Abstract
No abstract record available.
Inventors
- 👤 William E Schmertz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:15
CPC Classifications
F; F28; F28D; F28D17/00; Y; Y10; Y10S; Y10S165/00; Y10S165/009; Y10S165/03; Y10S165/035
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR516065A
Cited
US1531648A
Cited
US1915880A
Cited
US1978191A
Cited
US2171353A
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US2185559A
Cited
US2259913A
Cited
FR885596A
Cited
US2492788A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-08 | 1956-12-08 | 1957-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-08 | 1960-12-08 | 1961-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-08 | 1964-12-08 | 1965-06-09 | $7700.00 | Window Closed / Lapsed |