1. Field of the Invention
This invention relates to a light endless track vehicle, especially to its steering and supporting wheel arrangement as well as the endless track bands or tracks for use in this arrangement.
In endless track vehicles the power for operating and steering the vehicle is transmitted via driving wheels to the tracks. The tracks can consist in light vehicles for example of two endless edgechains interconnected by means of transverse blocks. The tracks surround two or more wheels on either side of the vehicle. The driving wheels usually support also the rear end of the vehicle. In the front end of the vehicle is provided corresponding freely rotating wheels, so called running wheels, over which the tracks run in the front part of the vehicle. Especially in cross-country vehicles these running wheels have a smaller diameter than the driving wheels. Between the rear driving wheels and the front running wheels are provided supporting wheels. Often several in a row, which have a smaller diameter than both the driving and the running wheels. The running wheels are so arranged that the lower part of the tracks forms, between the running wheels and the front supporting wheels, a upwardly slanting part, which facilitates the movements of the vehicle in terrain and e.g. in snow. The supporting wheels can also be of the same size as the driving wheels, whereby in the case of light vehicles only one supporting wheel is needed in the front part. Also in this case it is possible to use the afore mentioned running wheels which are positioned somewhat ahead of the supporting wheels and the axis of which is higher than the axes of both the supporting wheels and the driving wheels in order to accomplish the slanting part of the tracks in the front part of the vehicle.
2. Description of the Prior Art
In this type of supporting wheels, which are rigidly mounted on the vehicle and comprise either several small or one single bigger wheel, the wheels exert on the track construction a substantial, non-flexible resistance, against which the obstructions in the terrain, such as stones and tree stumps, hit rather hard irrespective of the upwardly deflecting front part of the tracks. In order to soften such an impact it is possible to provide the front supporting wheels with a spring system, but this solution has its own disadvantages as regards the operation of the tracks. When the driving power acts on the tracks also the supporting wheels will be pressed inwardly with a slackening of the tracks as a result, which fact, especially when turning the vehicle by operating the tracks in different directions, can lead to the tracks falling off the respective driving and running wheels.