GB574177A - Improvements in aircraft control surface actuating means - Google Patents

Abstract

574,177. Controlling aircraft. HAWKER AIRCRAFT, Ltd., and PAGE, F. W. Jan. 10, 1944, No. 468. [Class 4] The actuating mechanism for an aircraft control surface of the kind provided with an auxiliary or servo surface operated with the main control surface, and in which the control transmitting mechanism incorporates a lever arm carried by the control surface and under the control of a restraining spring whose lostmotion is transmitted to the auxiliary surface, is so arranged that the lever arm is hinged to the control surface about an axis substantially parallel with the hinge axis of the control surface and displaced therefrom in the direction of the free end of the lever arm, the moment of the restraining spring being exerted about the first mentioned axis. In the construction according to Fig. 1, the main and auxiliary control rods 32, 34 are respectively connected to levers.24, 10 on a hollow shaft 12 carried in brackets 16 projecting from a block 18 secured to the main spar of the control surface, the axis of the shaft being displaced from but parallel to the axis of the hinge lug 22 for the control surface. The restraining spring comprises a torsion rod 26 within the hollow shaft 12, one end 28 being splined to one of the brackets 16, and the other, 30, to the end of the hollow shaft 12. Limit stops 48 are provided in order to prevent over-stressing of the torsion rod. According to a modification, Fig. 3 (not shown), the torsion rod is replaced by a coiled spring.