Actuation system for a control surface of an aircraft

Abstract

An actuation system for rotating a control surface mounted on an aircraft airfoil, the control surface being rotatable about a first axis at an acute angle to the longitudinal axis of the aircraft is disclosed. The invention comprises a first crank having a first end and a second end pivotally mounted to the airfoil and rotatable about a spanwise second axis substantially perpendicular to the longitudinal axis of the aircraft. A second crank is pivotally mounted at its first end to the first crank and is rotatable about a third axis which is substantially perpendicular to the second axis. The second end of the second crank is pivotally mounted to the control surface. The second end of the second crank is rotatable about a fourth axis substantially perpendicular to the second and third axes. An actuator, substantially aligned with the longitudinal axis of the aircraft, is coupled to the airfoil and to the first end of the first crank. Thus, upon extension or retraction of the actuator in a direction parallel to the longitudinal axis of the aircraft the first and second cranks rotate about the second axis, causing the control surface to rotate about the first axis, and further to rotate relative to each other to accommodate the motion of the second end of the second crank in a plane perpendicular to the first axis caused by its attachment to the control surface.

Dependencies are inferred from the claim text.