Patent US2491952A successfully refreshed from Google Patents.
Patent US3535853A successfully refreshed from Google Patents.
US3535853A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air cleaner
Assignee: Vortox Manufacturing Co
•
Filing: 1968-06-18
•
Granted: 1970-10-27
•
Expires: 1988-06-18
Abstract
No abstract record available.
Inventors
- 👤 Jesse R Brown
- 👤 Charles W Hahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:17
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/24; B01D46/2403; B01D46/2411; B01D50/00; B01D50/20; B01D46/42; B01D46/48; B01D2279/00; B01D2279/60
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
BE517681A
Cited
US1864201A
Cited
US1712947A
Cited
US1870216A
Cited
US2193479A
Cited
US2378506A
Cited
GB761710A
Cited
US3360909A
Cited
US3216182A
Cited
US3429108A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-10-26 | 1974-04-27 | 1974-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-26 | 1978-04-27 | 1978-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-26 | 1982-04-27 | 1982-10-27 | $7700.00 | Window Closed / Lapsed |