GB1306616A - Air cushion vehicle - Google Patents

Abstract

1306616 Air cushion vehicles R V TAYLOR 30 Dec 1970 61875/70 Heading B7K [Also in Division F2] In an air cushion vehicle 10, Fig. 1, in which an airscrew 27 and a centrifugal fan 26 are both coupled to an engine 25, a plenum chamber is formed by a bag skirt 13 and a wall 14 containing louvres 23 which are adjustable in order to control the pressure distribution between the skirt enclosure and the cushion space 16. Fan 26 and screw 27 are arranged to be efficient only at relatively low and high speeds respectively, the fan providing sufficient air to fill skirt 13 before the airscrew can develop substantial thrust; thus the vehicle 10 is lifted almost to take-off point with louvres 23 closed, then take-off is achieved when they are opened. As the fan efficiency drops with higher speeds the louvres are closed to a position which is just sufficient to ensure that the air cushion exists; the fan is then partially choked so that additional engine power is mostly available for the airscrew. A lever and pedal arrangement connected to the engine throttle by means of the outer and inner parts of a Bowden cable (Fig. 2, 3, not shown) may be used to control the engine speed, the lever determining the minimum speed which will inflate the skirt with the louvres closed and the pedal serving to increase the speed beyond this point.