| 摘要 |
1,033,925. Air cushion vehicles. HOVERCRAFT DEVELOPMENT Ltd. June 21, 1963 [July 2, 1962], No. 25285/62. Heading B7K. [Also in Division H2] A vehicle is associated with track 14 upon which it is supported by a cushion of pressurized air 12, driving motor 1 being of the linear type co-operating with continuous armature 13. A pole-changing unit 3 for the motor 1 is automatically controlled by a velocity detector 5 responsive to the speed of the vehicle. Upon failure of supply 2, the unit 3 sets the motor 1 for a synchronous speed below that at which the vehicle is travelling, the field of the motor being maintained by exciter 9 driven by prime mover 10. The motor 1 thereupon acts as a generator for supplying compressor motor 6 to maintain the supporting cushion for the vehicle. The unit 3 provides pole-changes as the motor decelerates to maintain re-generation until the speed has decreased to a safe value for use of wheeled or skid supports. In another arrangement, the pole-number of the motor 1 remains unchanged in the condition of power failure, the frequency of exciter 9 being reduced as the vehicle decelerates. The exciter 9 may be replaced by a reactive device which is automatically brought into use upon failure of the power supply, or by a battery-operated oscillator. |
