US2642991A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal classifier
Assignee: Individual
•
Filing: 1949-09-22
•
Granted: 1953-06-23
•
Expires: 1969-09-22
Abstract
No abstract record available.
Inventors
- 👤 Davis John Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:56
CPC Classifications
B; B04; B04C; B04C5/00; B04C5/08; B04C5/103
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) | 1956-06-22 | 1956-12-22 | 1957-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-22 | 1960-12-22 | 1961-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-22 | 1964-12-22 | 1965-06-23 | $7700.00 | Window Closed / Lapsed |