US3222850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter
Assignee: Cambridge Filter Corp
•
Filing: 1961-05-11
•
Granted: 1965-12-14
•
Expires: 1981-05-11
Abstract
No abstract record available.
Inventors
- 👤 Charles G Hart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:32
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/02
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-13 | 1969-06-14 | 1969-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-13 | 1973-06-14 | 1973-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-13 | 1977-06-14 | 1977-12-14 | $7700.00 | Window Closed / Lapsed |