IMPROVEMENTS INTRODUCED IN THE TRANSMISSION OF A VEHICLE WITH FRONT AND REAR TRACTION.

摘要

The prime mover of the vehicle drives a gearbox which, in turn drives two pairs of driven wheels via respective drive trains. The gear box (13) includes a gear wheel which is axially slidable to effect a ratio change in the gearbox and an axially fixed gear which meshes with the slidable gear. A disconnecting mechanism such as a multi-plate clutch is provided in one of the drive trains to disconnect the drive connection with the associated pair of driven wheels during a ratio change which involves sliding of a gear wheel. This arrangement eliminates inter-tooth friction between the slidable gear wheel and the fixed gear wheel caused by transmission wind-up. The disconnecting mechanism may be actuated in response to movements of a selector means which effects ratio changes in the gearbox or, when a main clutch is provided between the prime mover and gearbox, in response to operation of a main clutch control such as a pedal.