Patent US3537019A successfully refreshed from Google Patents.
US3537019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical filter apparatus utilizing analog signal processing techniques
Assignee: Princeton Applied Research Corp
•
Filing: 1966-11-14
•
Granted: 1970-10-27
•
Expires: 1986-11-14
Abstract
No abstract record available.
Inventors
- 👤 Harry S Reichard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:17
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/369; A61B5/377; A61B5/72; A61B5/7225; H; H03; H03H; H03H19/00; H03H19/002
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US3087487A
Cited
US3234472A
Cited
US3154747A
Cited
US3229212A
Cited
US3344262A
Cited
US3412338A
Cited
US3445685A
Cited
US3390377A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-10-26 | 1974-04-27 | 1974-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-26 | 1978-04-27 | 1978-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-26 | 1982-04-27 | 1982-10-27 | $7700.00 | Window Closed / Lapsed |