Patent US2936043A successfully refreshed from Google Patents.
US2936043A
Expired / Lapsed
US
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Cyclonic dust collector
Assignee: Research Cottrell Inc
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Filing: 1957-01-09
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Granted: 1960-05-10
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Expires: 1977-01-09
Abstract
No abstract record available.
Inventors
- 👤 John A Armstrong
- 👤 Alan B Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:55
CPC Classifications
B; B04; B04C; B04C5/00; B04C5/12; B04C5/13; B04C5/02; B04C5/06; B04C2005/136
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1723427A
Cited
US2506298A
Cited
FR1074255A
Cited
DE914701C
Cited
US2731102A
Cited
US2771157A
Cited
FR1069071A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-10 | 1963-11-09 | 1964-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-10 | 1967-11-09 | 1968-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-10 | 1971-11-09 | 1972-05-10 | $7700.00 | Window Closed / Lapsed |