US3177936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluted heat exchange tube with internal helical baffle
Assignee: Individual
•
Filing: 1963-06-05
•
Granted: 1965-04-13
•
Expires: 1983-06-05
Abstract
No abstract record available.
Inventors
- 👤 Walter Gustave
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:38
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/02; F28F1/06; F28F13/00; F28F13/06; F28F13/12; F28F9/00; F28F9/02; F28F9/04; F28F9/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US493376A
Cited
US2079144A
Cited
US2258526A
Cited
US2847953A
Cited
US2864405A
Cited
US2960114A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-04-12 | 1968-10-12 | 1969-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-04-12 | 1972-10-12 | 1973-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-04-12 | 1976-10-12 | 1977-04-13 | $7700.00 | Window Closed / Lapsed |