Patent US3521431A successfully refreshed from Google Patents.
US3521431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particle separator for engine air inlets
Assignee: Avco Corp
•
Filing: 1969-04-28
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Granted: 1970-07-21
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Expires: 1989-04-28
Abstract
No abstract record available.
Inventors
- 👤 Harold D Connors
- 👤 Fred D Buckley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:31
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/04; F02C7/05; F02C7/052
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3371471A
Cited
US3421296A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |