Patent ID: 7347293

Claim:
A working vehicle comprising: a pair of right and left crawlers; a pair of right and left planetary gear trains; a speed change apparatus for outputting a step-less rotational driving force toward the pair of right and left planetary gear trains, the step-less rotational force being transmitted to the planetary gear trains so that the planetary gear trains are driven in a common direction; a speed change lever for controlling the speed change apparatus and thereby providing step-less altering of a running speed of the vehicle; a steering apparatus for outputting a step-less rotational driving force toward the pair of right and left planetary gear trains, the step-less rotational force being transmitted to the planetary gear trains so that the planetary gear trains are driven at in opposing directions with respect to each other; a steering wheel for controlling the steering apparatus and thereby altering a difference between velocities of the crawlers; the right and left planetary gear trains combining the driving force from the speed change apparatus and the driving force from the steering apparatus to produce combined driving forces, and outputting the combined driving forces to the pair of right and left crawlers, respectively; a first force routing mechanism for connecting between the speed change lever and the speed change apparatus so that a rotational speed of the driving force output by the speed change apparatus is decreased proportionally to an operated angle of the steering wheel; and a second force routing mechanism for connecting between the speed change lever and the speed change apparatus so that the rotational speed of the driving force output by the speed change apparatus is defined according to a operated amount of the speed change lever independently from the operated angle of the steering wheel; and wherein the first and second force routing mechanisms are alternately selectable.