U.S. Patent Specifications

Mechanism for actuating the control surfaces of aircraft, including a flap mounted so that it is lowered bodily from its normal retracted position to a position below the wing level and turned to a desired extent about a transverse axis at or near the centre of pressure, the bodily lowering and turning movements of the flap being effected independently and either successively or simultaneously, wherein a lever by which the flap is moved to its lowered position is pivoted at its front end on the aircraft wing and is part of a link and lever mechanism comprising said lever, a second lever parallel therewith and also pivoted at its front end on the aircraft wing, and a link connecting the free ends of said levers, said second lever and said link together constituting a toggle or knuckle jointed strut, the elements of which, when the flap is moved to its lowered position, are straightened out to form one side of a triangulated structure, a second side of which is formed by the first lever, and the third side of which is constituted by the wing structure between the pivotal axes of the first and second levers.