GB431895A - Improvements in or connected with the construction of cantilever wings and other aircraft structures - Google Patents

Abstract

431,895. Aircraft structural members. SHORT BROS. (ROCHESTER & BEDFORD), Ltd., and GOUGE, A., Seaplane Works, Rochester, Kent. July 28, 1934, No. 22090. [Class 4] Framework.-A spar for cantilever wings or other aircraft parts comprises cruciform section booms A, B, C, D, Fig. 3, each having two horizontal flanges and a vertical web above and below, the booms being interconnected by bracing members. In each boom the inwardly extending web part a<3> is of greater length than the outer and provides attachment by gusset plates to tubular struts b, b<1>, as shown in side elevation in Fig. 1. Transverse and diagonal struts c, cl, Fig. 6, are similarly attached to inwardly extending flanges a, a<1>, Fig. 3. Each transverse panel is braced by crossed members d, d<1> secured as shown in Fig. 7. The booms which may be extruded sections of the material known under the Registered Trade Mark " Duralumin " or of other light alloy or steel may be progressively reduced in weight from root to tip of the spar by milling the corners of the sections in successive stages ; thus the boom section may be changed at e, Fig. 1, from that shown in Fig. 4 to that shown in Fig. 7. The length of the web or breadth of the flanges may also be varied. In a modification the booms are built up from two T -sections or four angle sections riveted together in such manner as to produce a cruciform boom. The arrangement of the diagonal members connecting the booms to each other, Figs. 1 and 6, is such that bending stresses on the spar due to lift forces and torsion due to aileron operation is taken in tension. Ribs f, Fig. 6, may be secured to outwardly extending web parts a<2>.