US2877991A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchangers
Assignee: Individual
•
Filing: 1957-09-12
•
Granted: 1959-03-17
•
Expires: 1977-09-12
Abstract
No abstract record available.
Inventors
- 👤 Jr William A Warrington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:39
CPC Classifications
F; F24; F24F; F24F5/00; F24F5/0007; F24F5/001; F28; F28D; F28D7/00; F28D7/10; Y; Y10; Y10S; Y10S165/00; Y10S165/228; Y10S165/302; Y10S165/314
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) | 1962-03-16 | 1962-09-15 | 1963-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-03-16 | 1966-09-15 | 1967-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-03-16 | 1970-09-15 | 1971-03-17 | $7700.00 | Window Closed / Lapsed |