GB439407A - Improvements in the manufacture of screw propellers - Google Patents

Abstract

439,407. Screw propellers. SOC. DU DURALUMIN, 23<bis>, Rue de Balzac, Paris. May 10, 1935, No. 13788. Convention date, May 14, 1934. [Class 114] Screw - propeller blades are constituted by a mono - block framework or skeleton with ribs extending over the whole length of the blade connected by a continuous sheet. A screw propeller blade f is formed with ribs l<1>, l<2>, united by the continuous surface forming the driving face of the blade. The rear face is completed by a metal sheet t which rests on the apices n<1>, n2, n3 and is riveted to the following edge of the blade and anchored at the front edge in a filler material o. Instead of maintaining hollow spaces between the ribs a suitable filler of material such as a resin product may be utilized and the cover t then rests upon this filler material. In an alternative form the ribs are disposed toward the leading and following edges only and the intermediate ribs are dispensed with. The ribs may in section be broader at the tips than at the roots thereof and the spaces a, b between the ribs l<1>, l<2>, l<3>, may be wider at the middle and narrow toward the tip and root of the blades.