The present invention relates to improving the stability of a turning-track track-laying vehicle such as a snowmobile, in which vehicle such a track belt is used whose one edge can be stretched and whose other edge contracted by turning the end roll or rolls which guide the track belt so that the track belt can be bent to a curved position in order to steer the vehicle.
U.S. Pat. Nos. 3,934,664; 4,046,429; 3,938,607; 4,051,914; 4,119,356; and 4,188,076 and Finnish Patent Nos. 46708 and 51308 to the inventor describe turning-track track-laying vehicles and track belts used in such vehicles.
The object of the present invention is to further develop the turning-track vehicle known from patents mentioned above.
A turning-track vehicle is superior to snowmobiles or similar equipped with skis in that it is able to move in off-the-road conditions in the summer as well as in the winter.
A drawback of a turning-track vehicle has, when driving in soft snow, been that the vehicle is sideways unstable and unsteady, because it presses (treads) snow under its track in an obliquely upward direction, which means that, particularly at higher speeds, the variations in the properties of snow and various dynamic forces make the vehicle run unstably and particularly rock sideways. The first idea that may occur in order to avoid this drawback is that the center of gravity is placed as far front as possible. The results of this arrangement are not satisfying in practice, as the vehicle will dive into the snow even in the smallest mound. The same will happen when slowing down the vehicle.
In the known snowmobiles equipped and steered with skis said problems have been avoided by suitably locating and weighting the skis.