US2804171A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combination reverse flow vortical whirl separator and classifier
Assignee: Bituminous Coal Research Inc
•
Filing: 1955-02-07
•
Granted: 1957-08-27
•
Expires: 1975-02-07
Abstract
No abstract record available.
Inventors
- 👤 John I Yellott
- 👤 Peter R Broadley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:13
CPC Classifications
F; F23; F23J; F23J15/00; F23J15/02; F23J15/022; F23J15/027; B; B04; B04C; B04C5/00; B04C5/14; Y; Y10; Y10S; Y10S55/00; Y10S55/37
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US418836A
Cited
US769808A
Cited
US1761627A
Cited
FR947478A
Cited
US2451755A
Cited
US2582423A
Cited
US2681124A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-08-26 | 1961-02-25 | 1961-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-08-26 | 1965-02-25 | 1965-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-08-26 | 1969-02-25 | 1969-08-27 | $7700.00 | Window Closed / Lapsed |