Helicopter blade
Patent 4142837 Issued on March 6, 1979. Estimated Expiration Date: 
November 11, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 11, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3728045 3822105 Composite tip weight attachment Patent #: 3999888 InventorApplicationNo. 05/850765 filed on 11/11/1977US Classes:416/223R, SPECIFIC BLADE STRUCTURE (E.G., SHAPE, MATERIAL, ETC.)416/226, Formed with main spar416/228Tined or irregular peripheryExaminersPrimary: Powell, Everette A. Jr.Attorney, Agent or FirmInternational ClassesB64C 27/32 (20060101)B64C 27/46 (20060101) B64C 27/467 (20060101) AbstractA helicopter blade of improved airfoil shape which reduces or eliminates retreating blade stall by reducing the magnitude of the upper airfoil blade surface peak pressure and distributes it over a greater chord section of the blade to thereby reduce flow separation and drag. | |
