GB124935A - Improvements in Self Setting Sails or Blades of Windmills or of Tractor Screws or of Pusher Screws of Aeroplanes or Dirigibles. - Google Patents

Abstract

124,935. Drzewiecki, S., and Rey, J. April 30, 1918. Blades &c.-Relates to self-adjusting screw blades for windmills and aircraft propellers adapted to allow a substantially constant speed to be obtained in spite of variations in the speed of the wind or the aircraft. A socket c mounted on the end of a shaft d carries in a transverse sleeve e a rod f freely pivoted therein and fitted at one end with the screw blade g and at the other end with a counterweight h. The weight h not only balances the centrifugal pull of the blade g, but, by reason of its inclination to the shaft, exerts a torsional action on the rod f opposite to, and greater than, that exerted by the blade g. This torsional action tends to increase the pitch of the screw and is effective only when it overcomes the opposite tendency of springs j, j<1>, stops k, L limiting the movement in each direction. The blade assumes an inclination the pitch of which multiplied by the predetermined speed corresponds to the speed of the wind or the aeroplane. In place of one counterweight, several may be used; Fig. 6 shows one weight M for balancing the centrifugal pull of the blade, and two N<1>, N<2> for producing the torsion couple. The position of these weights N<1>, N<2> may be varied; for example, they may be placed at N', N''. Screw devices P, Q, R, Fig. 7, may be provided for adjusting the positions of the weights on the rod f. A propeller having two intergeared blades is shown in Fig. 8; and Fig. 9 shows two blades connected by one or more flexible members T to balance one another centrifugally.