| 摘要 |
The driving device includes a pair of coaxial driving pulleys, of respective different diameters, driven directly by the motor of the vehicle, and a driven pulley connected to a shaft in turn connected, by respective coupling means, to a pair of rear driving wheels. The vehicle includes a dirigible front steering wheel. Each driving pulley has a respective endless belt trained therearound and arranged to drive the driven pulley. A single control lever is pivoted, intermediate its ends, for swinging about mutually perpendicular first and second axes, the first axis extending transversely of the vehicle and the second axis extending longitudinally of the vehicle. The lower, or operating, end of the single control lever is connected to a pair of tensioning pulleys each cooperable with a respective endless belt. When the lever is swung, from a neutral position, in one direction about the first axis, one endless belt is tensioned to drive the driven pulley and, when the lever is swung in the opposite direction about the first axis, the other endless belt is effective to drive the driven pulley. On one embodiment of the invention, each endless belt drives the driven pulley at a respective different forward speed and, in another embodiment of the invention, one endless belt drives the driven pulley at a respective forward speed and the other endless belt drives the driven pulley at a respective reverse speed. A cable, trained over pulleys, connects the operating end of the control lever to the dirigible wheel so that, as the control lever is swung in either direction about the second axis, the dirigible wheel is steered in a corresponding direction. Link means connect the single control lever to the driven axle to shift the same paraxially and, responsive to the control lever being swung to make a tight turn, the linkage means, through the driven shaft, disengages the coupling means connecting the driven shaft to the rear driving wheel then on the inside of the tight turn.
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