GB141141A - Improvements in or relating to metal spars and the like for aviation - Google Patents

Abstract

141,141. Mooney, D. J., and Emby, D. H. Jan. 15,1919. Framework. - Metal spars, longerons, &c. of box-girder form for aircraft comprise two longitudinally corrugated, channel members united by top and bottom flange members, the channel members having outwardly - turned corrugations adjacent to each flange, and the flange members a deep central corrugation and two inwardlyturned side corrugations forming abutments for the channel members. Fig. 1 shows a spar comprising two channel members a having bent flanges b, corrugations c near each flange, and a part d curved outwards, and top and bottom members having deep curves f, side curves g, and edges h overlapping the flanges b. The flanges b may be of semicircular form and the part d curved inwards, or the part between the corrugations c may be straight and the flanges may be flat, and a reinforcing-strip may be inserted between the flanges and the edges of the flange members. Fig. 6 shows one form in which an L-section reinforcing-strip r is used and the webs strengthened at intervals by bolts s and distance-pieces t. The webs may be bent outwards near the flanges as shown in Fig. 6<*>. U-shaped strips may be clamped over the edges of the flanges and flange members, and the bend of the, U may be bulbed. The web members a may have three equal corrugations.