Patent GB-260316-A (GB)
Title: Improvements in or relating to light metallic constructions more particularly for air-craft, boats and the like
IPC: B64C35/00
Filed: 1925-06-24
Abstract: 260,316. Hall, C. W. June 24, 1925. Planes, construction of; fuselages; framework.-A light metallic construction for aircraft wings and fuselages, hydroplanes, boats, &c. comprises a series of sheet metal frames with open lattice or solid webs, and open or closed hollow booms, and a series of intersecting hollow sheet metal stringers, the frames and stringers being banded together so that both booms or flanges of the frames and at least one boom or flange of each stringer are continuous, and the stringers are so positioned as to provide a backing for and to define the contour of a covering which encloses the framework. A hydroaeroplane body is shown having an arched upper surface and a V-shaped bottom the lateral slope of which increases towards the bow. A step with a reentrant angle at the rear is formed by plating 60 external to the main plating of the bottom. Fig. 4 shows a section and Fig. 5 a part section respectively on the lines 16, 13 of Fig. 1. A keel c is shaped from sheet metal with diagonal web members of open hollow section upset to prevent eccentric loading as described in Specifications 130,997 and 143,864 and has a separately formed tubular boom c<1>. Fixed on each side of this keel in pairs are lower series of transverse frames d<12>, d<13>, d<16> carrying arched upper members e<12>, e<16> having each a tubular boom and one flat flange. At the cockpit opening, these upper frames terminate at a tubular coaming j, Fig. 4, but elsewhere they are continuous from side to side. Intersecting these frames and secured thereto by rivets and bent metal clips 46 are sheet metal stringers f formed each with one tubular boom and one flat flange the flanges being cut at the intersections and upset so that the flanges of the stringer and frames are coplanar. A metal sheathing h, i is then secured to the frames and stringers. At the keel the sheathing h is flanged to lie parallel to the keel, and the joint, with interposed watertight packing, is embraced by a U-shaped piece 55. A similar joint is formed at the junction of the bottom and sides of the body around a chine fin g. This fin is vertical at the bow but turns outwards gradually until it becomes parallel to the bottom surface h amidships. The plating 60 of the step is secured to tapered side pieces 63 and false stringers 62, Fig. 5, with perforated webs. and to a false keel comprising two plates 61 bent to embrace the keel at the upper edge. The rear edges of the step are supported by transverse girders with perforated webs extending from the keel to the perforated side pieces so that the step is ventilated without perforating the main plating h. Where the surfaces h, 60 are too close to be secured to the false stringers by separate rivets, shouldered rivets 68, Fig. 16, are used. Where the wing spars are secured, the structure is stayed by struts 33, 34, 42, 40, Fig. 4, having flattened ends with internal reinforcing sleeves fitting over attachment lugs. To ensure a smooth surface the plating and the flanges of the stringers and frames are inwardly punched at intervals to take the heads of countersunk rivets. Stringers may be provided to support floor plating over the members d<12>, d<13>, d<16>. Fig. 18 shows a modified turtle deck for aircraft bodies in which arched members x having bent ends 71 secured around longerons z support stringers y by bent metal clips 73, the stringers and members x both being formed by bending sheet metal into flanged tubes.