US2674442A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Envelope type radial seal for regenerative heat exchangers
Assignee: Alstom Power Inc
•
Filing: 1950-10-12
•
Granted: 1954-04-06
•
Expires: 1970-10-12
Abstract
No abstract record available.
Inventors
- 👤 William E Hammond
- 👤 John A Lidford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:07
CPC Classifications
F; F28; F28D; F28D19/00; F28D19/04; F28D19/047; Y; Y10; Y10S; Y10S165/00; Y10S165/009; Y10S165/013; Y10S165/016; Y10S165/026
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1652025A
Cited
US2229691A
Cited
US2287777A
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US2428041A
Cited
US2517512A
Cited
US2471995A
Cited
US2549656A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-04-05 | 1957-10-05 | 1958-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-04-05 | 1961-10-05 | 1962-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-04-05 | 1965-10-05 | 1966-04-06 | $7700.00 | Window Closed / Lapsed |