Patent US3958309A successfully refreshed from Google Patents.
Patent US2884135A successfully refreshed from Google Patents.
US2884135A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precoated filters for liquids
Assignee: BERKEFELD FILTER GES und CELLE
•
Filing: 1955-05-20
•
Granted: 1959-04-28
•
Expires: 1975-05-20
Abstract
No abstract record available.
Inventors
- 👤 Nowak Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:12
CPC Classifications
B; B01; B01D; B01D25/00; B01D25/12; B01D25/19; B01D37/00; B01D37/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US594013A
Cited
US2065263A
Cited
US2065384A
Cited
US2132770A
Cited
US2643772A
Cited
FR1019011A
Cited
GB703752A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-27 | 1962-10-27 | 1963-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-27 | 1966-10-27 | 1967-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-27 | 1970-10-27 | 1971-04-28 | $7700.00 | Window Closed / Lapsed |