US3239011A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter rotor blade spar structure
Assignee: Parsons Corp
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Filing: 1964-11-23
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Granted: 1966-03-08
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Expires: 1984-11-23
Abstract
No abstract record available.
Inventors
- 👤 Winston E Brownlee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:28
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46; B64C27/473
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
116 words
IN AN IMPROVED HELICOPTER ROTOR BLADE STRUCTURE, A SPAR AND REINFORCEMENT THEREFOR COMPRISING A STEEL SPAR EXTENDING SPANWISE FROM THE BLADE ROOT END AND HAVING AN OUTER SURFACE CONTOURED TO FORM A SURFACE PORTION OF THE AIRFOIL SECTION OF SUCH BLADE, A STEEL DOUBLER HAVING AN UNDERSURFACE FORMED COMPLEMENTARY TO SAID CONTOURED OUTER SURFACE OF SAID STEEL SPAR, SAID DOUBLER HAVING A SMOOTH-FINISHED, UNINDENTED OUTER SURFACE AND ITS SAID UNDERSURFACE HAVING A PLURALITY OF INTEGRAL EMBOSSED ROUNDED SPACING PROJECTIONS EXTENDING THEREFROM THE DISTANCE EQUAL TO A DESIRED BRAZE JOINT THICKNESS, AND A BRAZING ALLOY FORMING A BRAZED JOINT OF SUCH THICKNESS BETWEEN THE OUTER SURFACE OF SAID STEEL SPAR AND THE UNDERSURFACE OF SAID METAL DOUBLER.
Claim 2
Dependent Claim
116 words
IN AN IMPROVED HELICOPTER ROTOR BLADE STRUCTURE, A SPAR AND REINFORCEMENT THEREFOR COMPRISING A STEEL SPAR EXTENDING SPANWISE FROM THE BLADE ROOT END AND HAVING AN OUTER SURFACE CONTOURED TO FORM A SURFACE PORTION OF THE AIRFOIL SECTION OF SUCH BLADE, A STEEL DOUBLER HAVING AN UNDERSURFACE FORMED COMPLEMENTARY TO SAID CONTOURED OUTER SURFACE OF SAID STEEL SPAR, SAID DOUBLER HAVING A SMOOTH-FINISHED, UNINDENTED OUTER SURFACE AND ITS SAID UNDERSURFACE HAVING A PLURALITY OF INTEGRAL EMBOSSED ROUNDED SPACING PROJECTIONS EXTENDING THEREFROM THE DISTANCE EQUAL TO A DESIRED BRAZE JOINT THICKNESS, AND A BRAZING ALLOY FORMING A BRAZED JOINT OF SUCH THICKNESS BETWEEN THE OUTER SURFACE OF SAID STEEL SPAR AND THE UNDERSURFACE OF SAID METAL DOUBLER.
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) | 1969-03-07 | 1969-09-06 | 1970-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-07 | 1973-09-06 | 1974-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-07 | 1977-09-06 | 1978-03-08 | $7700.00 | Window Closed / Lapsed |