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Patent US2678696A successfully refreshed from Google Patents.
US2678696A
Expired / Lapsed
US
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Paraffin scrapper for wells
Assignee: Shell Development Co
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Filing: 1951-04-24
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Granted: 1954-05-18
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Expires: 1971-04-24
Abstract
No abstract record available.
Inventors
- 👤 Wilfred S Crake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:22
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/02; E21B33/03; E21B33/068; E21B33/072; E21B37/00; E21B37/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US982652A
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US1662984A
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FR703369A
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US2182680A
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US2179814A
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US2278067A
Cited
US2294061A
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US2383934A
Cited
US2471198A
Cited
US2552939A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-05-17 | 1957-11-16 | 1958-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-17 | 1961-11-16 | 1962-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-17 | 1965-11-16 | 1966-05-18 | $7700.00 | Window Closed / Lapsed |