GB613288A - Rotor blade - Google Patents

Abstract

613,288. Rotor blades. ROTARY RESEARCH CORPORATION. June 17, 1946, No. 18166. Convention date, June 21, 1945. [Class 4] A rotor blade for rotating wing aircraft, including an elongated envelope having a leading edge and a trailing edge has means connected with the envelope for adjusting the relative lengths of the two edges. The blade shown in Fig. 1 has, as the result of shrinkage warping of the envelope 12, the locus line 17 of centres of pressure swept back from the torsional axis 18 (which is in line with attachment spar 13); by means of the above adjustment such a blade may be flexed to bring the line 17 into coincidence with line 18; according to one form of the invention a blade may be originally produced with a forward swept centre-ofpressure line 17 when at rest but which, as the result of drag-forces, become straightened in flight; the adjustment device according to the invention may also be used for obtaining such a forward-swept line which becomes straightened in flight. In Fig. 5 is shown a blade, with a tubular attachment spar 13 near the leading edge and to which the envelope 12 is secured, and having an adjustment device comprising a threaded rod 19 screwed into blade tip 14 and received at its inner end in a clamp 22 bolted on the spar 13; a nut 26 is screwed up on the threaded rod to provide the adjusting tension. In a modification an adjusting thrustrod is placed near the trailing edge of the blade.