Wheeled vehicle with rotatable endless track

A wheeled vehicle having a source of driving power, a chassis extending longitudinally in said vehicle, a propeller shaft connected to the source of driving power, rear wheels drivably connected to the source of driving power through the propeller shaft, and an auxilliary drive means comprising:

• a pair of rotatable endless track means disposed between a pair of front and rear wheels;
• means for selectively raising and lowering said pair of endless track means with respect to the road surface;
• and
• means for drivably connecting said endless track means with said source of driving power when said endless track means is lowered and brought into contact with the road surface, said connecting means comprising first and second rotatable shafts for driving said pair of endless track means, said first and second shafts extending parallel to the axis of said propeller shaft, first pulley means fixedly mounted on said propeller shaft and rotatable therewith, second and third pulley means fixedly mounted on said first and second rotatable shafts, respectively, first endless belt means stretched between said first pulley means and said second pulley means, second endless belt means stretched between said first pulley means and said third pulley means and first actuating means for moving said second pulley means closer to and away from the axis of said propeller shaft, and second actuating means for moving said third pulley means closer to and away from the axis of said propeller shaft, said first and second actuating means being independently operable from one another to move said second and third pulley means relative to the axis of said propeller shaft independently of one another.