Patent ID: 8286921
Filing Date: 2012-10-16
Classification: B64C

Abstract:
1. A high-lift system on a lifting surface of an aircraft, comprising a main wing which has a curved main wing nose and comprising a leading-edge flap which is disposed retractably on the main wing by means of an arrangement of several levers so that said leading-edge flap can be moved from a retracted position to a fully extended position which expands a profile of the lifting surface in the chord direction, increases the curvature of the lifting surface and creates a gap which guides energetic air from an underside of the leading-edge flap to an upper side of the main wing, wherein the lever arrangement is configured in the form of a four-bar linkage and comprises a first lever and a second lever, of which the first lever is connected at one end to a first point on the main wing in an articulated manner and the second lever is connected at one end to a second point on the main wing in an articulated manner at a distance from the first point, and the first and second levers are each connected at a respectively other end in an articulated manner to ends of a third lever which is part of and defines extending movements of the leading-edge flap, characterised in that the length and the mutual position of the levers and the curvature of the main wing nose are matched to one another such that during a first part of the extending movement from the retracted position to an intermediate position sufficient to substantially increase lift for take-off the trailing edge of the leading-edge flap substantially blocks the gap between the leading-edge flap and the main wing and that during a further part of the extension movement following the intermediate position, the trailing edge of the leading-edge flap increasingly exposes the gap.