Variable camber leading edge for an airfoil

A variable camber leading edge assembly for an airfoil, comprising:

• a forward suspension link pivotably coupled at a first end to a portion of said airfoil;
• an aft suspension link coupled at a first end to a portion of said airfoil aft of said first end of said forward suspension link;
• a bullnose;
• a variable camber panel hingedly coupled at a first end to said bullnose;
• a first extension link coupled at a first end to said bullnose and at a second end to said aft suspension link;
• a support link fixedly secured adjacent a trailing edge of said variable camber panel;
• a second extension link coupled at a first end to said bullnose and at a second end to said support link, and at an intermediate point to said aft suspension link;
• a scissors linkage assembly having:
• a first scissors link pivotably coupled at a first point to an intermediate point of said forward suspension link;
• a second scissors link pivotably coupled at a first point to said support link;
• and a third scissors link pivotably coupled at a first end to second ends of each of said first and second scissors links, and at a second end thereof pivotably to a second end of said aft suspension link;
• wherein said bullnose and said variable camber panel are movable by rotational movement of said aft support link from a cruise position retracted within a lower surface of said airfoil to a landing position, wherein in said landing position said second end of said variable camber panel is spaced apart from a leading edge of said airfoil to form a gap therebetween, and when in said cruise position said variable camber panel forms a first arc;
• wherein said variable camber panel is moveable from said cruise position to a takeoff position extending forwardly of said airfoil, wherein said scissors linkage operates to flex said variable camber panel to form a second arc and wherein said second end of said variable camber panel engages flush with said leading edge of said airfoil to form a smooth, aerodynamic transition therebetween;
• and
• wherein retracting movement of said variable camber panel from said takeoff position to said cruise position is accomplished by rotating said variable camber panel and said bullnose attached thereto about a lower end of said forward main support link such that said variable camber panel and said bullnose do not operate to scoop air into a lower area of said airfoil when moving from said takeoff position to said cruise position.

A variable camber leading edge assembly for an airfoil, comprising:

• an aft suspension link assembly having an upper link and a lower link pivotably coupled together, wherein said upper link thereof is pivotably coupled at a first end thereof to a portion of said airfoil;
• a forward suspension link pivotably coupled at a first end to a portion of said airfoil forward of said first end of said aft suspension link;
• an actuator having a torque shaft operably coupled to said first end of said upper link of said aft suspension link;
• a bullnose;
• a variable camber panel hingedly coupled at a first end to said bullnose;
• a first extension link coupled at a first end to said bullnose and at a second end to said lower link of said aft suspension link;
• a second extension link coupled at a first end to said bullnose and operatively coupled at a second end thereof to a second end of said variable camber panel, and at an intermediate point to said lower link of said aft suspension link;
• a scissors linkage assembly having:
• a first scissors link pivotably coupled at a first point to an intermediate point of said forward suspension link;
• a second scissors link pivotably coupled at a first point to said second end of said variable camber panel;
• and a third scissors link pivotably coupled at a first end to second ends of each of said first and second scissors links, and at a second end thereof pivotably to said second end of said aft suspension link;
• and
• wherein said bullnose and said variable camber panel are movable by rotational movement of said aft support link by said actuator from a cruise position, wherein said variable camber panel assumes a first arc, from within a lower surface of said airfoil to a landing position, wherein in said landing position said second end of said variable camber panel is spaced apart from a leading edge of said airfoil to form a gap therebetween, and said variable camber panel forms a second arc;
• wherein said variable camber panel is moveable from said cruise position to a takeoff position extending forwardly of said airfoil, wherein said scissors linkage assembly operates to flex said variable camber panel to form said second arc and wherein said second end of said variable camber panel engages flush with said leading edge of said airfoil to form a smooth, aerodynamic transition therebetween, and wherein said second arc is greater than said first arc;
• and
• wherein retracting movement of said variable camber panel from said takeoff position to said cruise position is accomplished by rotating said variable camber panel and said bullnose attached thereto about a lower end of said forward main support link such that said variable camber panel and said bullnose do not operate to scoop air into a lower area of said airfoil when moving from said takeoff position to said cruise position.

A method of controlling a variable camber panel disposed within a lower area of an airfoil when the panel is in a cruise position such that said panel is extended forwardly of said airfoil into a landing position in a manner to avoid scooping air during movement between said cruise and landing positions, said method comprising the steps of:

• suspending said variable camber panel from within a recess point disposed within said airfoil by a linkage assembly;
• using said linkage assembly to cause a forward edge of said variable camber panel to being rotating at a greater rate of travel than a trailing edge of said panel when said panel is moved initially out of said cruise position;
• using said linkage assembly to continue rotating said variable camber panel while also moving said panel forwardly of said airfoil such that said trailing edge is maintained close to a leading edge surface of said airfoil as said panel is moved to and beyond an intermediate position between said cruise and landing positions;
• and
• continuing to rotate said variable camber panel beyond said intermediate position to said landing position, wherein said panel forms a relatively continuously curving forward section of said airfoil.