US2936851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air purifier
Assignee: Individual
•
Filing: 1957-06-07
•
Granted: 1960-05-17
•
Expires: 1977-06-07
Abstract
No abstract record available.
Inventors
- 👤 Richard R Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:52
CPC Classifications
F; F24; F24F; F24F8/00; F24F8/10; F24F8/192; B; B01; B01D; B01D45/00; B01D45/04; B01D45/08; Y; Y02; Y02A; Y02A50/00; Y02A50/20
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) | 1963-05-17 | 1963-11-16 | 1964-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-17 | 1967-11-16 | 1968-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-17 | 1971-11-16 | 1972-05-17 | $7700.00 | Window Closed / Lapsed |