US2571631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchange element
Assignee: MW Kellogg Co
•
Filing: 1947-02-26
•
Granted: 1951-10-16
•
Expires: 1967-02-26
Abstract
No abstract record available.
Inventors
- 👤 Paul R Trumpler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:20
CPC Classifications
F; F28; F28F; F28F3/00; F28F3/02; F28F3/025; F28F3/027; Y; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/356; Y10S165/373
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US937380A
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US1220745A
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US1734274A
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US1834604A
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US1899080A
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US2018085A
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US2222721A
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GB477276A
Cited
US2396208A
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GB574949A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-10-15 | 1955-04-16 | 1955-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-10-15 | 1959-04-16 | 1959-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-10-15 | 1963-04-16 | 1963-10-16 | $7700.00 | Window Closed / Lapsed |