GB249572A - Improvements in and connected with control surfaces for aeroplanes - Google Patents

Abstract

249,572. Hill, G. T. R. Sept. 29, 1924. Aeroplanes; planes, construction of; steering, balancing, and regulating altitude; stopping way.-Control surfaces for 'both elevating and balancing are located in free air beyond the ends of the wings and behind the centre of pressure of the total supporting area of the wing surfaces. In the arrangement shown, the tips E, D, Figs. 4, 5 and 6, of the bachwardly-swept main supporting surfaces B, A are pivoted on axes E<1>, D', approximately parallel to the leading edge, and are adjustable in the same or opposite senses for elevating and balancing. The surfaces E, D may be independently controlled, but preferably a single lever F, Fig. 4. is provided. mounted on a universal joint F<1> and carrying a hinge joint F<2> connected by a rod F<3> to one arm of a hell-crank lever G, fulcrumed on a universal joint G<2> and having a cross-head G<1> on its other end. The two arms of the cross-head G<1> are connected through rods and 'bell-cranks H - - H<5> to the controlling surfaces. Movement of the lever F fore and aft raises and lowers the cross-head G' and adjusts the surfaces E, D simultaneously in the same direction, whilst sideways movement rocks the cross-head G<1> and moves them in opposite directions. The surfaces E, D are provided with weighted forward balancing extensions E<2>, D<2>, Fig. 6, and, if desired, controllable relay surfaces O, Fig. 11, pivoted on beams O<1> extending from the main control surfaces, may be used instead of or in addition to the control on the main control surfaces. The relay surfaces O may alternatively be directly mounted in recesses in the trailing edges of the main control surfaces. In another modification, the main control surfaces are provided with a hinged trailing edge by means of which the rolling movement may be controlled without adjusting the main surfaces. Rudders K, K, Figs. 5 and 6, may be pivoted on axes K<1>, K<1> (inclined to the vertical) on the under surface of the wings A, B or of the controlling surfaces D, E. The rudders are connected by links L', L<1>, to the arms of a rudder bar L, Fig. 7, carried on a pivot M on the upper end of a pivoted arm M<1>, the other end of which is connected by a rod M<3> to a hand-lever M<4>. Steering control is effected by turning the foot bar L about its pivot M: both rudders may be turned outwardly to brake the machine by bodily moving forward the bar L by means of the lever M<4>. When the rudders are being used as an air brake they may still be controlled for steering by means of the foot bar L. Additional braking surfaces may be provided on the wings.