US2789805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for recovering fuel from subterraneous fuel-carrying deposits by heating in their natural location using a chain heat transfer member
Assignee: Svenska Skifferolje AB
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Filing: 1953-05-26
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Granted: 1957-04-23
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Expires: 1973-05-26
Abstract
No abstract record available.
Inventors
- 👤 Ljungstrom Fredrik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:29
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24
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) | 1960-04-22 | 1960-10-22 | 1961-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-22 | 1964-10-22 | 1965-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-22 | 1968-10-22 | 1969-04-23 | $7700.00 | Window Closed / Lapsed |