US2981369A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vortical whirl separator
Assignee: Bituminous Coal Research Inc
•
Filing: 1951-11-23
•
Granted: 1961-04-25
•
Expires: 1971-11-23
Abstract
No abstract record available.
Inventors
- 👤 John I Yellott
- 👤 Peter R Broadley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:57
CPC Classifications
B; B04; B04C; B04C5/00; B04C5/08; B04C5/103
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US407598A
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US769808A
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GB190402792A
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US1035988A
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US1928702A
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GB390053A
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US2080147A
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FR851413A
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GB555908A
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US2370629A
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US2494465A
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AT164520B
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US2553175A
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US2582423A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-24 | 1964-10-24 | 1965-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-24 | 1968-10-24 | 1969-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-24 | 1972-10-24 | 1973-04-25 | $7700.00 | Window Closed / Lapsed |