Patent · US Expired

Blade with swept-back tip for the rotary wings of an aircraft

US6000911A · kind A · utility

46Cited by
5References
10Claims
0Family size

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Key dates

Filing dateNov 18, 1997
Grant dateDec 14, 1999
Priority date
Expiry dateNov 18, 2017

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S416/05
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

The present invention relates to a blade with a swept-back tip for a rotary wings of an aircraft, a blade being formed of successive elemental cross sections. The blade is divided into different regions, with the chord length L and the offset y'f of the center of pressure from the pitch-change axis and the relative thickness of each elemental section are optimized for high-speed flight. The first region has a linearly increasing chord length, the second region has the maximum and constant chord length, the third region has a linearly decreasing chord length and the fourth region has a decreasing chord length according to a parabolic function. The offset of the aerodynamic center is positive and increases in proportional to the distance in the first region, is at its maximum and constant in the second region, and decreases linearly and become negative in the third region.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.