US1903440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter device
Assignee: Individual
•
Filing: 1931-12-30
•
Granted: 1933-04-11
•
Expires: 1951-12-30
Abstract
No abstract record available.
Inventors
- 👤 Walter R Cambridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:12
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1936-04-10 | 1936-10-10 | 1937-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-04-10 | 1940-10-10 | 1941-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-04-10 | 1944-10-10 | 1945-04-11 | $7700.00 | Window Closed / Lapsed |