GB548572A - Improvements relating to members consisting of a frame covered with sheet metal - Google Patents

Abstract

548,572. Aircraft wings. ELLIOTT, A. June 19, 1941, No. 7746. [Class 4] [Also in Group XXII] The metal coverings of the wings, tail planes, flaps and like parts of aircraft, or other framed structures covered with sheet metal, are stiffened where necessary by means of channels, depressed therein, which are completely closed at the surface of the covering or have gaps which are small compared with the crosssectional dimensions of the channels, at least one of the channels being of a different length of metal in cross section, at one part of its length than at another in order to shape the covering. A wing is described in which the covering is formed with parallel longitudinal channels pressed in from the surface and of open rectangular or dovetail form or of the shapes shown in Figs. 5, 6, and 7. The channels may hold nuts or tapped strips for use in securing the covering to the ribs, or the channels may be filled with plastic and the gap closed before the plastic has set. Where the covering crosses a spar, the channel may be bent over and flattened or the metal may be slit at those places so as to form a flat lap joint when the channels at opposite ends of the slit are formed. Fig. 11 shows a tool for forming a rectangular channel, the metal sheet 30 being moved by lower and upper blocks 28, 29 against a former 31, lateral movement of the blocks being effected by links 34 and sloped surfaces 33. To form a closed channel, undercut grooves are formed in the upper blocks 29 and the former 31 is removed before the blocks are completely pressed together laterally.