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Patent US2221871A successfully refreshed from Google Patents.
US2221871A
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Fluid heat exchange apparatus
Assignee: Babcock and Wilcox Co
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Filing: 1935-09-28
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Granted: 1940-11-19
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Expires: 1955-09-28
Abstract
No abstract record available.
Inventors
- 👤 Howard J Kerr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:17
CPC Classifications
F; F22; F22G; F22G7/00; F22G7/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1943-11-19 | 1944-05-20 | 1944-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-11-19 | 1948-05-20 | 1948-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-11-19 | 1952-05-20 | 1952-11-19 | $7700.00 | Window Closed / Lapsed |