US2456485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter with coaxial rotors
Assignee: HELICOPTERS Inc
•
Filing: 1943-11-23
•
Granted: 1948-12-14
•
Expires: 1963-11-23
Abstract
No abstract record available.
Inventors
- 👤 Bendix Vincent
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:15
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/08; B64C27/10
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-12-14 | 1952-06-14 | 1952-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-12-14 | 1956-06-14 | 1956-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-12-14 | 1960-06-14 | 1960-12-14 | $7700.00 | Window Closed / Lapsed |