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US3401682A
Expired / Lapsed
US
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Regenerative tube-bundle heat exchanger having screw-like flat-tened tubes helicallywound in spaced-apart relationship
Assignee: Linde GmbH
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Filing: 1966-09-12
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Granted: 1968-09-17
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Expires: 1986-09-12
Abstract
No abstract record available.
Inventors
- 👤 Jakob Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:34
CPC Classifications
F; F28; F28D; F28D20/00; F28D20/0056; F28D7/00; F28D7/02; F28F; F28F1/00; F28F1/02; F28F1/025; Y; Y02; Y02E; Y02E60/00; Y02E60/14
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) | 1971-09-17 | 1972-03-18 | 1972-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-09-17 | 1976-03-18 | 1976-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-09-17 | 1980-03-18 | 1980-09-17 | $7700.00 | Window Closed / Lapsed |