| 摘要 |
A four-wheel drive work vehicle, e.g. an agricultural tractor, is selectively drivable in a standard four-wheel drive mode (4WD-I) in which all wheels are driven at the same speed, an accelerated four-wheel drive mode (4WD-II) in which the front wheels are driven faster than the rear wheels and in a two-wheel drive mode (2WD), by movement of a shift fork (17) which is biassed towards position 4WD-I and is shiftable linearly to the other positions. A cam (22), whose shaft (21) is connected to the steering input, is movable by a link mechanism (A) between an operative position, in which it pushes the shift fork (17) from 4WD-I to 4WD-II when a predetermined steering angle is exceeded, and an inoperative position clear of the shift fork (17). For greater operator convenience, the link mechanism (A) has a third condition in which the cam (22) is moved to its inoperative position and the shift fork (17) is moved to the 2WD position. The camshaft (21) may pivot with the steering pitman arm (50, Fig. 11). The driver's seat (29, Fig. 10) may be pivotable to act as a lid for an opening (32) in a floor panel (30). …<IMAGE>… |
