GB1043351A - Improvements relating to means for bounding a space for receiving pressurised gas - Google Patents

Abstract

1,043,351. Air cushion vehicles. HOVERCRAFT DEVELOPMENT Ltd. March 26, 1963 [March 27, 1962], No. 11645/62. Heading B7K. [Also in Division G3] The cushion of an air cushion vehicle is bounded at least partly by a wall comprising a plurality of separate downwardly extending flexible members each having an outer, cushionbounding portion, and side portions extending inwardly therefrom. Fig. 3 is a horizontal section through a wall depending from the periphery of a vehicle to contain a cushion in a plenum chamber. The portions 6 are outermost, and adjacent side portions 7 are pressed together by the pressure in the cushion. In vertical section, the portions 6 may extend downwardly and inwardly. When the flexible members bound the upper part of the cushion and the lower part is bounded by a curtain of fluid, such as air, the air issues from duct 25 and nozzle 31 down the inner face of the outer portion of each member, Fig. 11. The outer portion may be curved or bent, as shown, to deflect the air inwardly. In this case, the members at the rear of the vehicle may tend to act as scoops, so their inner ends are joined by a surface 48 acting as a screen, or a separate screen may be fitted. The air flow may be further guided by a surface 53, and apertures 51, 52 may be provided to maintain a suitable pressure between them. Fig. 12 shows a suitable fastening comprising a framework 60, the outer portion of a member being attached to rail 63, the side portions to rails 61, 62, and any screen to rail 64. The inner ends of rails 61, 62 pass through a fixed member 66, and a lug 65 is bolted to the vehicle structure 21. To prevent deflection of the member, on contact with the ground or water, from cutting off the curtain by covering the nozzle 31, Fig. 13 shows the member as pivoted to a fixed guide vane 75 located in an enlarged part 72 of duct 25, which part terminates in a lip 74 normally forming a seal against the outer portion 6. When the member is pressed up against the vehicle base 26 to cut off nozzle 31, the curtain is maintained by air flowing past lip 74. Fig. 15 shows a vehicle with two concentric curtains 22 and two walls of flexible members 5. The flow to either curtain can be decreased, and that to the other curtain augmented, by flaps 86, 87 pivoted at 88, 89, and connected to rod 90 by pin-and-slot couplings, so that flap 86 may be lowered as at 94, or flap 87 raised, as at 95. A spray deflecting screen may be attached to the upper outer edge of each member, the screen extending downwardly and outwardly, Fig. 19 (not shown). The bottom edges of the side portions preferably extend normal to the outer portions. but may be cut back if suitably stiffened, Figs. 20-21 (not shown). A ground or water contacting element may be arranged to retract or extend each member to maintain ground clearance through a fluid pressure servo system (see Division G3). Walls constructed as above may be used to divide cushions, with or without a fluid curtain. A vehicle may have walls as above without fluid curtains along its sides, and shorter walls with fluid curtains around its front and rear parts.