Patent US3503572A successfully refreshed from Google Patents.
US3503572A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vertical take-off and landing aircraft
Assignee: Westland Group PLC
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Filing: 1967-12-04
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Granted: 1970-03-31
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Expires: 1987-12-04
Abstract
No abstract record available.
Inventors
- 👤 Raoul Hafner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:13
CPC Classifications
B; B64; B64C; B64C29/00; B64C29/0091; B64C29/0008; B64C29/0016; B64C29/0033
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-30 | 1973-09-29 | 1974-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-30 | 1977-09-29 | 1978-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-30 | 1981-09-29 | 1982-03-31 | $7700.00 | Window Closed / Lapsed |