US2990907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic filter
Assignee: Individual
•
Filing: 1959-06-11
•
Granted: 1961-07-04
•
Expires: 1979-06-11
Abstract
No abstract record available.
Inventors
- 👤 Wilhelm S Everett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:16
CPC Classifications
F; F04; F04B; F04B39/00; F04B39/16; F01; F01N; F01N1/00; F01N1/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
FR664331A
Cited
US2058932A
Cited
US1796441A
Cited
US2323955A
Cited
US1934463A
Cited
US2020903A
Cited
US2037884A
Cited
US2164365A
Cited
GB493538A
Cited
US2869671A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-03 | 1965-01-02 | 1965-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-03 | 1969-01-02 | 1969-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-03 | 1973-01-02 | 1973-07-04 | $7700.00 | Window Closed / Lapsed |