GB952126A - Improvements in or relating to ground effect machines - Google Patents

Abstract

952,126. Air cushion vehicles. WESTLAND AIRCRAFT Ltd. Nov. 13, 1962 [Nov. 21, 1961; Jan. 26, 1962; Feb. 3, 1962], Nos. 41542/61, 3148/62 and 4254/62. Heading B7K. An air cushion vehicle has a main gas system discharging pressurized gas from the bottom of side, end, or peripheral downwardly extending walls or skirting to generate and contain the gas cushion, and downwardly extending walls or keels partitioning the cushion area, pressurized gas being discharged from the bottom of such walls or keels, so as to cause, during pitching or rolling, a pressure differential within the cushion area to produce a righting moment on the vehicle, at least the parts of the walls or skirting and the partitioning walls or keels which are likely to be subject to wave or obstacle impact being of flexible construction. Fig. 1 is a perspective view from above of peripheral skirting 1, having inner and outer flexible walls 2, 3 of rubberized material reinforced by canvas or nylon mesh. Diaphragms 4 divide and shape the skirting and form jet nozzles 5, fed from gas ducts surrounding the main platform (not shown) of the vehicle. Flexible keels 8 and 9, of construction similar to the skirting, also depend from the platform, and discharge stabilizing jets downwardly. The depth of the keels should be not less than the depth of the skirting less half the ground clearance during hover, nor more than the depth of the skirting, plus the ground clearance. During pitching or rolling, the pressure in the various compartments 20 is varied by the stabilizing jets from the keels in the sense to right the vehicle. Gaps 21 between the keels and between the keels and skirting determine the degree of damping in pitch and roll, and this may be varied by inflatable conical members 11, one being shown in Fig. 4, located between the inner skirting wall 2 and a keel 9, and attached to the former. The pressure in the member 11, and hence the gap between the keel and the member, is varied by control of an individual gas supply, or by inflating the member through an aperture 12 from the gas supply to the nozzles 5. A further vehicle is described, Fig. 5 (not shown), in which the side parts of the peripheral skirting are rigid, and the forward and rear parts are flexible. A central fore-and-aft extending stabilizing keel is flexible only at its forward part. According to the first Provisional Specification, the keels may be of H, X or Y formation seen in plan.