US3528040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronically variable filter
Assignee: AEROSPACE RES
•
Filing: 1968-12-12
•
Granted: 1970-09-08
•
Expires: 1988-12-12
Abstract
No abstract record available.
Inventors
- 👤 Aaron A Galvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:45
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2989887A
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US3182271A
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US3202926A
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US3327210A
Cited
US3316341A
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US3281723A
Cited
GB1088131A
Cited
US3354316A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-09-07 | 1974-03-09 | 1974-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-09-07 | 1978-03-09 | 1978-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-09-07 | 1982-03-09 | 1982-09-08 | $7700.00 | Window Closed / Lapsed |