US2441920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary wing aircraft
Assignee: McDonnell Aircraft Corp
•
Filing: 1939-01-25
•
Granted: 1948-05-18
•
Expires: 1959-01-25
Abstract
No abstract record available.
Inventors
- 👤 Haviland H Platt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:28
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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GB274973A
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US1910520A
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US1830731A
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US1900689A
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US1849766A
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US1957813A
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US1942888A
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GB499073A
Cited
US2337570A
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US2321572A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-05-18 | 1951-11-17 | 1952-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-05-18 | 1955-11-17 | 1956-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-05-18 | 1959-11-17 | 1960-05-18 | $7700.00 | Window Closed / Lapsed |