US3383840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dust collecting system
Assignee: Research Cottrell Inc
•
Filing: 1966-05-10
•
Granted: 1968-05-21
•
Expires: 1986-05-10
Abstract
No abstract record available.
Inventors
- 👤 Bob R Johnson
- 👤 Robert V Mccabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:20
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/66; B01D46/70; B01D46/02; B01D46/04; B01D46/42; B01D46/4272
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2821262A
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US3078646A
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US2964129A
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US3146080A
Cited
GB939641A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-05-21 | 1971-11-20 | 1972-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-05-21 | 1975-11-20 | 1976-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-05-21 | 1979-11-20 | 1980-05-21 | $7700.00 | Window Closed / Lapsed |