GB280641A - Improvements in or connected with aerial machines - Google Patents

Abstract

280,641. Drury, C. A., and Drury, J. E. Aug. 18, 1926. Machines supported by rotary propellers; planes, construction of; propelling; steering and balancing. - Blades of the form shown in Figs. 5 and 2, tapered in thickness from the fuselage to the tips and either parallel edged or tapered in width towards the tips are freely mounted on transverse axes d. Fig. 12, so as to rotate automatically in the airstream. The curvature of both concave and convex parts increases towards the edges of the blades. The blades are of high aspect ratio which is at least 7 : 1. The bearings of the blades are constructed to allow a certain amount of oscillation subject to the control of the pilot and the fore and aft position and inclination of the blades axes relative to the centre line of the machine may be adjusted or the rotation of the blades may be retarded or accelerated for steering and balancing purposes. Instead of adjusting the fore and aft position of the blades, a tractor propeller V may be so moved. A tail plane W<1> with elevators W is provided. Blades of this form may be placed in superposed staggered relationship or arranged in tandem the diameters of successive blades being graded, the larger towards the rear. Where the blades are separated by the machine body, a blade preferably of the form shown in Fig. 2 may be placed above the gap in the draught from the tractor propeller. Two tractor propellers abreast or on concentric shafts may be used. Each blade may be built up on a tube or box girder and covered with plywood or sheet metal and may be slotted as shown in Fig. 5 to oscillate across a shaft K passing through it. The extent of the oscillation may be controlled by a flat sided cone L, Fig. 6, adapted to be moved along the shaft to penetrate to a varying extent into the slot end. Alternatively an enlarged circular hole in the blade end may bear loosely on an axially movable cone. For adjusting the inclination and position of the blade and for controlling the direction of the oscillatory movement, each end of a shaft N, Fig. 10, fixed to the blade has a bush O sliding in a slot t in a plate T which has a ring T<1> on its surface sliding in guides u on the frame. Two control cords R, R<1> opposed to a spring S enable the plate T and slots t to ba tilted or the plate moved backwards and forwards in the guide u. A modified bearing is described in which a bush on the shaft N bears within an enlarged ring subject to the constraint of a sickle-shaped plate hinged to the ring and movable by the pilot.