GB423709A - Improvements in or relating to head-wind brakes for aircraft - Google Patents

Abstract

423,709. Controlling aircraft. JUNKERS - FLUGZEUGWERK AKT.-GES., 40, Junkersstrasse, Dessau, Germany.- (Assignees of Junkers, H. ; 21, Hauptmann Loeper Platz, Dessau, Germany) June 27, 1934, No. 18995. Convention date, July 3, 1933. [Class 4] In a speed control or braking device for aircraft of the kind comprising transverse strips pivotally mounted on the under side of the wings and adapted to be swung into a braking or operative position, the strips 10, Figs. 1 and 2, which extend transversely for a distance c exceeding half the length of either wing, are disposed rearwards of the leading edge 12 of the plane a distance a which is not greater than 40 per cent of the chord t of the wing and in an operative position project a distance b that is not greater than 6 per cent of the chord, whereby the resistance to forward movement is considerably augmented when the lift is small or negative. Adjustment of the strips 10 may be effected either by the pilot or automatically on the aircraft attaining a predetermined speed. The strips may be in the form of flat plates or sectors or, as shown in Fig. 5, of arcs or scoops 20 controlled directly by bell-crank and link mechanism 22, 23 with means 26, 27 for retaining the strips in any adjusted position. If desired, springs may be incorporated for lessening the effort to be exerted by the pilot, or, as shown in Fig. 8, the two strips 30 may be interconnected by gearing 32 so that the wind-pressures thereon counterbalance, and each strip may be divided into a number of independently controlled shorter strips. In another modification, Fig. 12, (not shown), the wind pressure on an auxiliary vane is employed to lessen the effort of the pilot; or the atmospheric pressure acting on such an auxiliary surface or on the strip itself may be utilized alone to actuate the strip without any effort on the part of the pilot. Fig. 15 shows an arrangement in which the strips 30 are automatically actuated, when the speed exceeds a predetermined limit, by the pressure effect of air collected through a pipe 74 upon an adjustable control piston 71.