Patent US3055437A successfully refreshed from Google Patents.
US3055437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture proof helicopter blade
Assignee: Doman Helicopters Inc
•
Filing: 1957-10-15
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Granted: 1962-09-25
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Expires: 1977-10-15
Abstract
No abstract record available.
Inventors
- 👤 George R Stack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:35
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46; B64C27/473
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
77 words
AN AERODYNAMIC PORTION OF A HELICOPTER BLADE COMPRISING A LAMINATED SPAR OF MOISTURE ABSORBING MATERIAL AND HAVING AN EXTERIOR UPPER SURFACE AND LOWER SURFACE, A TRAILING PORTION ATTACHED TO THE SPAR OF MOISTURE ABSORBING MATERIAL AND HAVING EXTERIOR SURFACES, A THIN FILM OF TRIFLUOROCHLORETHYLENE OF APPROXIMATELY 5 TO 10 MILS THICKNESS HAVING ITS INNER SURFACE A BONDING SURFACE, AND THE FILM BEING BONDED TO ALL EXPOSED EXTERIOR SURFACES OF THE SPAR AND TRAILING PORTION WITH AN ADHESIVE.
Claim 2
Dependent Claim
77 words
AN AERODYNAMIC PORTION OF A HELICOPTER BLADE COMPRISING A LAMINATED SPAR OF MOISTURE ABSORBING MATERIAL AND HAVING AN EXTERIOR UPPER SURFACE AND LOWER SURFACE, A TRAILING PORTION ATTACHED TO THE SPAR OF MOISTURE ABSORBING MATERIAL AND HAVING EXTERIOR SURFACES, A THIN FILM OF TRIFLUOROCHLORETHYLENE OF APPROXIMATELY 5 TO 10 MILS THICKNESS HAVING ITS INNER SURFACE A BONDING SURFACE, AND THE FILM BEING BONDED TO ALL EXPOSED EXTERIOR SURFACES OF THE SPAR AND TRAILING PORTION WITH AN ADHESIVE.
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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) | 1965-09-24 | 1966-03-26 | 1966-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-09-24 | 1970-03-26 | 1970-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-09-24 | 1974-03-26 | 1974-09-25 | $7700.00 | Window Closed / Lapsed |