GB563319A - Improvements in or relating to air brakes and/or lift increasing devices for aircraft - Google Patents

Abstract

563,319. Controlling aircraft. FAIREY AVIATION CO., Ltd., and BOOTH, J. P. March 26, 1943, No. 4930. [Class 41 A flap or the like constituting an air-brake and/or lift increasing device for aircraft, is adapted to be set in varying positions by means of a bellows which is subdivided into a number of sections each arranged to be connected to sources of positive and negative pressure derived from a venturi tube situated in the air stream whereby the bellows sections may be actuated cumulatively in succession. As shown, a wing a has a flap b hinged at g and actuated by a bellows divided into sections c, d, e by walls f also hinged at g, the expansion of the sections being limited by cords connected to the outer wall h. Pipes k, m, n extend from the sections to ports o, p, q in a slidable valve plate r operable by the pilot and controlling groups of ports 11-13 and 14-16 in valve chambers u, v connected respectively by pipes 19, 22 to a Pitot-tube 20 arranged in a venturi tube 21 and to an annular passage 23 connected by ports with the throat of the venturi tube. When the aircraft is travelling, the chambers u. v are thus respectively under positive and negative pressure. Normally, the valve plate v is at its extreme right-hand position with its ports in register respectively with ports 14-16 so that all the bellows sections are connected to the chamber v and the flap is thus held in its retracted position. As the valve plate is moved to the left the ports o, p, q successively register with ports in the pressure chamber u so that the bellows sections are also expanded successively. Movement of the valve plate to the right similarly effects the retraction of the flap step-by-step by connecting the sections to the chamber v. Specification 562,365 is referred to.