GB302277A - Improvements in airplanes having a variable lifting surface - Google Patents

Abstract

302,277. Gerin, J. Dec. 13, 1927, [Convention date]. Aeroplanes; planes, arrangement and construction of ; steering and balancing.-The fixed planes of an aeroplane are varied in area by flexible strips reinforced by ribs running on slides arranged on the planes or other fixed parts of the machine and adapted to be wound on and unwound from drums sheltered from the wind. To compensate for the reduced efficiency of the lateral control at the reduced speed resulting from the strips being in use, pivoted wing tips are used which become coupled to the strips when the latter are extended so that the ends of the strips are warped when the wing tips are moved. The flexible strips are secured to H-shaped members 3 which are connected together by chains 10, the rollers 12 of which run in guides 5, 6 secured to the front spar 2 and the ribs of a fixed plane 1. The lower rear part of the covering 17 is sprung to allow the passage of the members 3 when the strips are extended. The outer member 3 is connected to cables 18 led over pulleys 20 and wound on a spiral drum as the strip is wound off a conical drum. A torsion spring connects the two drums so as to maintain the cable always in tension. The drums on the two sides of the machine are geared together and can be moved by an electro-motor or by pedal mechanism. Instead of the members 3 being guided only at the front end, they may span the space between two tandem planes, and in the case of large surfaces may be centrally supported by guides on a third plane. The rear ends of the members 3 in the form shown in Figs. 7, 8 may be flexible. Fig. 18 shows an aileron 39 tiltable about a pin 40 on the end of the fixed wing by means of cables 47 bell-crank lever 45 and arm 48. An extension 39<a> on the aileron engages the end rib 3 of the strip when extended, the end sections 5a, 6<a> of the guides 5, 6 being ball-jointed to permit the end of the strip to be warped as the aileron moves. To compensate for changes in the centre of pressure when the strips are extended the tail plane may be simultaneously tilted by lever and link or cable and pulley gear. Alternatively the forward spars of the wings may be moved about pivots 70, Fig. 30, together with the rollers 51 for carrying the flexible strips, by means of arms engaging nuts 71 on screwed shafts 72, 73 turned by gearing 75. Various types of machine are described including a biplane with a fixed upper wing fitted with flaps and a fixed lower wing having extensible strips the rollers for which are housed in the fuselage, or, in the case of a seaplane, in the floats. A machine with three fuselages also is described having three planes in tandem with extensible strips as described adapted to be drawn across the gaps and another pair of strips adapted to be extended along the trailing edge of the tail plane, Triplanes also are described with extensible strips on the top and bottom planes, the rollers for the upper strips being arranged in one or more engine nacalles. Tanks, arrangement of.-Fuel tanks are arranged in the engine nacelles above or above and below the rollers for the extensible strips.