GB895057A - Improvements relating to vehicles or craft which are supported on air cushions - Google Patents

Abstract

895,057. Vehicles supported by gaseous cushions. BRITTEN, F. R. J., NORMAN, N. D., and BRENNAN, M. J. Jan. 12, 1961 [Oct.20, 1959], No. 35528/59. Class 4. [Also in Group XXVI] In a vehicle which in operation is supported on a cushion of air maintained by a fan or compressor having an impeller supplying a downwardly directed annular jet extending round at least part of the vehicle, the impeller is mounted in an annular air duct extending around at least part of the vehicle above the annular jet and comprises a series of blades mounted on an annular carrier which moves around the duct on one or more guides. In the Figures, the body 1 is constructed of plywood sheeting, and reinforeed by bulkheads, as at 2, 3. The underside of the body is inwardly curved as at 4, Fig. 3, and the annular air duct 6 is formed between the body 1 and a ring 5 also formed from plywood sheeting reinforced by bulkheads. The ring is attached to the body by struts 7, Fig. 1, and tie rods 9 and 10, Figs. 1 and 3. Fixed compressor blades 8 form further struts. The annular carrier comprises a box section girder 11 carried by sets of three rollers 12, 13 and 14. A shroud ring 18 at the tips of the blades 17 forms part of the inner wall of ring 5. The girder and rollers are enclosed by a cowl 19. Three castoring wheels 20, (one shown, Fig. 1) are located in recesses 21 in the body 1, for towing on the ground when the vehicle is inoperative. Adjacent the cockpit 22 is an engine 24 which drives variable pitch propellers 31, 32, used for propulsion and steering, and drives the carrier 11 through frictional contact with a pneumatically tyred wheel 37 connected to gear box 30 through a shaft 38 universally jointed at each end. The force with which wheel 37 bears against the carrier is adjustable by a rigging screw (not shown). In modifications, the air duct 6 may be of inverted U- section, the inlet being at the bottom of the vehicle and radially outside the outlet, so that recirculation of air takes place. The impeller may be in either limb of the U, or may be in the connecting bend, in which case it is of the radial flow type. If the air duct is elliptical, oval, or otherwise non-circular in plan, the carrier 11 is flexible or articulated, and further rollers bear on the outer face of the carrier or on a flexible or articulated shroud 18. Instead of a single annular duct, there may be two ducts, each extending around half the vehicle. The carrier may be driven by a belt or flexible steel wire which passes around the outside of the carrier and round an engine driven pulley. According to the Provisional Specification, there may be a row of fixed blades in the duct on both sides of the impeller blades. The impeller may have more than one row of blades, with fixed blades between, and the rows may be on contra-rotating carriers. Two parallel jets one within the other may be provided, by dividing the duct outlet by a partition of aerofoil section, or by having two annular ducts each with its own impeller. The impeller may be driven by a gear wheel engaging a rack on the carrier, or the carrier may have cups or vanes driven by an air blast from an engine driven compressor. There may be two or more annular jets arranged side by side, their total area extending over substantially the whole area of the vehicle, in which case the body may be articulated between the different jets to facilitate travel over irregularities in the land or sea surface.