Patent ID: 7810601

Claim:
An all-terrain or utility vehicle, comprising: left and right front wheels; left and right rear wheels; a differential rotationally variably coupling said left and right front wheels together with a variable coupling torque; and said coupling torque being relatively stronger when a speed of said vehicle is relatively slower and being relatively weaker when said speed of said vehicle is relatively faster; a source of motive power being selectively coupled to said left and right rear wheels in a first configuration and coupled to said left and right front wheels as well as to said left and right rear wheels in a second configuration; and said second configuration being selectable from said first configuration while said vehicle is in motion only when (1) a rotational difference in speed exists between at least one of said left and right front wheels and at least one of said left and right rear wheels and (2) a rotational speed of at least one of said left and right rear wheels exceeds a rotational speed of at least one of said left and right front wheels.