GB1314031A - Air cushion vehicle propelled by linear induction motor - Google Patents

Abstract

1314031 Air cushion vehicles; tracked hovercraft TRACKED HOVERCRAFT Ltd 16 March 1970 [21 March 1969 (2)] 15137/69 and 15138/69 Headings B7K and B7L [Also in Division H2] An air cushion vehicle 1 for operation along a track 2 comprises a linear induction motor stator 7 for propelling the vehicle by electromagnetic co-operation with a generally vertical and electrically conductive reaction plate 10 forming part of a reaction rail 11 mounted on the track, means formed by a linkage 19 for connecting the stator to the vehicle body for independent movement with respect thereto except in a substantially longitudinal direction, guide means, such as wheels 32, for maintaining the stator 7 substantially at a predetermined lateral position relative to the reaction plate 10, support means, such as air cushion pads 35, for supporting the stator substantially at a predetermined vertical position relative to the reaction rail and roll control means (also 35) for providing the stator with stability in roll. The stator 7 includes magnetic structures 8 which are held in a carriage formed by backing members 13 secured together by yokes 14. The stator guide wheels 32 are mounted on levers 33 pivoted at the ends of the carriage, the wheels being biased into engagement with a thickened portion 39 of the reaction rail by springs 34 and being incapable of transmitting any stator rolling moment to the rail. The air-cushion pads 35 are resiliently mounted at 36 on two yokes 14 and co-operate with track surfaces 4. The linkage 19 connecting the stator to a cross-member 17 of the vehicle body includes drag links 18, arms 23, 26, pivot spindles 24 and a cross-link 29. The linkage transmits the tractive force, which acts in the direction of the arrow T, to the vehicle body, but accommodating movements of the drag links, which are pivotally mounted at both ends prevent movements of the vehicle body, e.g. pitching and heaving, being transmitted to the stator. During braking a second linkage 31, which is a mirror image of the linkage 19, becomes operable and transmits a force, in the opposite sense to the arrow T, from the stator to the vehicle body. In an alternative embodiment the stator is supported from the vehicle body by four hydraulic jacks, which jacks may be controlled by a servo system either in unison or differentially to maintain the stator at a constant height above the track and to prevent roll (Figs. 4 and 5, not shown). The vehicle body is supported and guided by air cushion pads 3, 5 co-operating with the track 2. Reference has been directed by the Comptroller to Specification 1,203,025.