Month in the Patent Office: A Selection from Important Recently Published Aircraft and Aero Engine Specifications

Framework.—Aircraft wings, fuselages, and other light structures comprising tubular members built up from two or more metal strips with out‐turned flanges and continuous from end to end of the member, have gusset plates secured to adjoining flanges on the tubular members, and bracing members are secured to the gusset plates so that the line of action of each member of the structure passes through the centroid of that member. The tubular members are formed from two, three, or four metal strips extending the whole length of the member, as described in Specification 264,626. Figs. 7 and 8 show a joint for a fuselage wherein a gusset plate 34 is secured between the flanges of a tubular boom 33 and also between the flanges of two tubular bracing members 37, 42. A bracing member 41 is similarly secured to the boom 33. A plate 44, having bent flanges 45, 46 is secured to the flanges of the members 37, 41, and the flanges of a diagonal member 43 are secured thereto on opposite sides. Alternatively, the flanges of the boom may be embraced by pairs of gusset plates secured between the flanges of the bracing members. Fig. 15 shows a modification in which two bracing members 81, 82 are secured to a single gusset plate having a bent portion 84 resting against the boom 83. The ends of the bracing members may be reinforced internally or externally by sleeves, or by flat plates butted against the edges of the gusset plates and riveted between the flanges. For building up irregular outlines, the gusset plates or the flanges of the boom may be bent into the plane of the bracing member. Specification 24948/96 is referred to.