Patent US1858508A successfully refreshed from Google Patents.
US1858508A
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Regenerative heating device
Assignee: Ljungstroms Angturbin AB
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Filing: 1925-10-09
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Granted: 1932-05-17
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Expires: 1945-10-09
Abstract
No abstract record available.
Inventors
- 👤 Kignell Erik Peder
- 👤 Kignell Erik Harald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:02
CPC Classifications
F; F28; F28D; F28D17/00; F28D17/02; Y; Y10; Y10S; Y10S165/00; Y10S165/009; Y10S165/037; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49357
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1935-05-17 | 1935-11-16 | 1936-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-05-17 | 1939-11-16 | 1940-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-05-17 | 1943-11-16 | 1944-05-17 | $7700.00 | Window Closed / Lapsed |