GB1143383A - Improvements in or relating to aerodynamic slots in flexible membranes - Google Patents

Abstract

1,143,383. Parachutes, sails and other air sustained membranes. O. W. NEUMARK. 25 May, 1966 [31 May, 1965], No. 22980/65. Headings B7G, B7K, B7V and B7W. Flexible fabric used in parachutes, kites, sails and for the skirts of ground-effect machines is provided with an aerodynamic slot 6 having edges 4. 5 interconnected at a plurality of positions by webs 3 to thereby ensure that the width of the slot is uniform. The webs are integrally woven into main webs 1, 2 to which the edges 4, 5 of the slot are sewn. The webs may be in a single central or offset row, or in two mutually staggered rows. A parachute of generally wing-shaped configuration. Fig. 7, has a number of slots 6 formed in the above manner distributed over its upper surface. The surface has an air-filled bulbous leading edge 10 and is constrained to an aerofoil configuration in side elevation by downwardly extending fabric webs 11, the lower edges of which are provided with tension cords 12 which are extended to form fore-and-aft rigging lines 13. To close each slot the edges 4, 5 may be drawn together by cords (17), Fig. 9 (not shown), passing through eyelets in an adjacent web 11 and the resulting nick which occurs in the surface of the parachute may be smoothed out by tensioning a cord 20 which passes through a tunnel 21 provided on the web 11. A groundeffect machine, Fig. 10 (not shown), has a skirt comprising inner and outer skins (22, 23) separated by flexible webs (25) to define a passage through which air passes through slots (6) of the above described form and disposed in the lower part (22a) of the outer skin. The skins (22, 23) are held in an inwardly curved position by cables (23a, 26).