US2773602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter apparatus
Assignee: Specialties Development Corp
•
Filing: 1953-02-02
•
Granted: 1956-12-11
•
Expires: 1973-02-02
Abstract
No abstract record available.
Inventors
- 👤 Walter G Sylvester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:32
CPC Classifications
B; B01; B01D; B01D29/00; B01D29/44; B01D29/46; B01D25/00; B01D35/00; B01D35/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1076128A
Cited
US1955903A
Cited
US2108798A
Cited
US2359475A
Cited
US2480108A
Cited
US2507125A
Cited
GB656494A
Cited
US2598131A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-12-11 | 1960-06-11 | 1960-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-12-11 | 1964-06-11 | 1964-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-12-11 | 1968-06-11 | 1968-12-11 | $7700.00 | Window Closed / Lapsed |