| 摘要 |
PURPOSE:To decrease a turning radius under automatic control, by rotating front wheels faster than rear wheels in an all-wheel driven tractor of two-axle four- wheel type. CONSTITUTION:At rapid turning operation, either one of a handle 4 or brake pedal is operated for steering, and a control valve 32 is selectively operated to apply pressurized oil from a pump P in the direction to engage a clutch element 28 through a feed fluid pipe 35. If the valve is selected in this way, the element 28 causes a speed increase gear system 24 to interlock to a propeller shaft 20 of front wheels, and the front wheels 2 are rotated faster than rear wheels 3 to cause a tractive state by the wheels 2, here a tractor 1 can be moved turning in a small turning radius. Further if a steering means 10 is returned to a straight running position, a low speed gear system 25 is reset to interlock. |
