GB226301A - Improvements in airscrews - Google Patents

Abstract

226,301. Leitner, H. Oct. 2, 1923. Screw propellers.-Screw propeller blades are formed with an internal foundation of high tensile material such as a steel tube around which a light metallic material is cast to form the exterior surface.. A tube a, of uniform or taper gauge, is flattened at the tip c, and carries transverse tubes d with closed ends which act as keys for the outer skin b, which is cast or moulded about the foundation. In place of the tubes d, a series of projecting studs may be riveted to the main tube. At the butt end of the tube rings f and g are formed, the part between forming a journal for fitting to the boss. One flange cnly may be used, the skin being formed with a similar flange adjacent thereto. Alternatively the butt end may have an internal thread into which a plug having a flange is screwed. The tube may extend across the boss to form a common foundation for two blades. When a box foundation is used, the plates l, Fig. 6, are riveted across the lugs m, which are staggered to form keys. Corrugated plates n, Fig. 7, riveted together as at o may be used. The girder may be made up with two semi-cylindrical members p, Fig. 8, with splayed lips which are secured by a ring q and rod r. When casting the outer surface, a core is used extending to the position s. Specification 165,548 is referred to.