US2977937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Once-through vapor generator
Assignee: Duerrwerke AG
•
Filing: 1958-01-08
•
Granted: 1961-04-04
•
Expires: 1978-01-08
Abstract
No abstract record available.
Inventors
- 👤 Deitlhauser Karl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:49
CPC Classifications
F; F22; F22G; F22G5/00; F22B; F22B29/00; F22B29/06; Y; Y10; Y10S; Y10S122/00; Y10S122/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1930455A
Cited
US2557569A
Cited
US2709424A
Cited
US2781746A
Cited
FR1112486A
Cited
GB750484A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-03 | 1964-10-03 | 1965-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-03 | 1968-10-03 | 1969-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-03 | 1972-10-03 | 1973-04-04 | $7700.00 | Window Closed / Lapsed |