Patent US2581747A successfully refreshed from Google Patents.
US2581747A
Expired / Lapsed
US
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Combined heat exchange system and auxiliary power plant for internal-combustion engines
Assignee: Individual
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Filing: 1950-09-18
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Granted: 1952-01-08
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Expires: 1970-09-18
Abstract
No abstract record available.
Inventors
- 👤 Carl H Block
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:06
CPC Classifications
F; F02; F02N; F02N19/00; F02N19/02; F02N19/04; F02N19/10; F01; F01P; F01P11/00; F01P11/14; F01P2011/205
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) | 1955-01-07 | 1955-07-09 | 1956-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-01-07 | 1959-07-09 | 1960-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-01-07 | 1963-07-09 | 1964-01-08 | $7700.00 | Window Closed / Lapsed |