GB165548A - Improvements in screw-propellers - Google Patents

Abstract

165,548. Leitner, H. April 1, 1920. Screw propellers.-Relates to laminated blades detachably and adjustably secured to the hub, and consists in making the cylindrical stem integral with one or more of the laminµ in forming the boss in two parts which are clamped or bolted together, in providing an outer shell for the blade shanks with an annular flange engaging inner flanges on the boss, also in providing serrated members for setting the blades at the desired pitch. The blades, made as described in Specification 151,693, have cylindrical sockets h, Figs. 1 and 2, with shoulders h<3> which engage the recess i<3> in the divided boss i. Each blade has a serrated rim h<4> with which engages a serrated locking member i<4> on the boss. The boss is attached to the shaft b<1> by a tapered sleeve b<2> keyed in the boss and secured by a shoulder b<3> and nut b<4>, the tapered portions of the shaft and sleeve have keys be and a tightening nut b<5>. In a modification, the blade is secured to the hub socket by a through bolt which prevents endwise movement, but by reason of the hole in the boss being elongated permits of pitch adjustment, a serrated fitting maintaining the setting as before. Alternatively, the blade socket may surround the hub socket. The blade socket may be reinforced by one or more external laminµ q which are secured by a clamping-ring p, Fig. 15, or may extend down and around the cylindrical shank. The blade socket may be made in two parts split longitudinally. When the socket has a shoulder adapted to engage a recess in the split boss, the sleeve s with its flange t, Fig. 22, and an inner sleeve r are riveted to the 'blade laminµ c which are continued around a base piece u and finally secured by a flange t<1> and nut v. The base piece u may be formed integrally with the inner sleeve r. In one construction, the boss sockets only are split, the boss centre being in one piece. For pitch adjustment, bolts w, Fig. 20, pivoted to lugs w<1> on the blades, pass through holes in lugs x on the hub sockets, and have adjusting nuts y.