US2431228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchange unit
Assignee: Individual
•
Filing: 1945-06-04
•
Granted: 1947-11-18
•
Expires: 1965-06-04
Abstract
No abstract record available.
Inventors
- 👤 Burgess Russell Harvey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:21
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/10; F28F1/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE178245C
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US443220A
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FR466371A
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US1797535A
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GB309798A
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US1874009A
Cited
US1895755A
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US1957292A
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US1975925A
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US2109270A
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US2257558A
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US2232568A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-11-17 | 1951-05-19 | 1951-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-11-17 | 1955-05-19 | 1955-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-11-17 | 1959-05-19 | 1959-11-18 | $7700.00 | Window Closed / Lapsed |