US2556539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtering device
Assignee: Individual
•
Filing: 1946-07-22
•
Granted: 1951-06-12
•
Expires: 1966-07-22
Abstract
No abstract record available.
Inventors
- 👤 Carl W Hellberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:09
CPC Classifications
A; A47; A47J; A47J31/00; A47J31/04; A47J31/043
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2366951A
Cited
US1927287A
Cited
US2058136A
Cited
US2291427A
Cited
US2387322A
Cited
US2392656A
Cited
US2376410A
Cited
US2390269A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-06-11 | 1954-12-11 | 1955-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-11 | 1958-12-11 | 1959-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-11 | 1962-12-11 | 1963-06-12 | $7700.00 | Window Closed / Lapsed |