GB191220751A - Improvements in or relating to Propelling Mechanism of Aeroplanes and Air Ships. - Google Patents

Abstract

20,751. ViÙtor, A. Sept. 11. Screw propellers.-Screw propellers for aeroplanes are made up with two metal rims b connected by tension wires with the boss a. These wires intersect to form an hyperboloidal surface, which can be covered with fabric. Within this casing, the blades form a continuous screw, the outer edge being at 1, 2, 3 ... 30, 31, and the inner edge at 1<1>, 2<1>, &c. The inner edge may. however, be at some distance from the boss. The blades are of fabric or sheet metal and attached to spokes which are perpendicular to the shaft at the narrowest part of the casing and are increasingly inclined as the edges are approached. The inner ends of these spokes may be fixed to a sleeve loose on the shaft instead of the shaft itself. At the middle of the cage, a third ring is sometimes used to which the tension wires are fastened. This. centre ring may be made in two parts, the adjacent rings being distanced by set - screws whereby the tension of the wires can be adjusted. The blades may also be formed in sections instead of as a continuous screw. When used for lifting an aeronautical vessel, the rims are heavy, and when for propelling the rims are hollow and light.