Abstract: This invention relates to a track unit intended for endless tracked cross-country vehicles, for example forestry working machines, comprising at least one driven track driven from a driven axle of the vehicle. In order to render possible the driving of forestry working machines with tracks of rubber, which are much more sparing for the ground than steel tracks, but do not possess the tensile strength of steel tracks, the present track unit of bogie type distributes the driving force on several tracks and comprises two track stands (9), each of which comprises a track (8) supported on two wheels (38,39) and driven via of these wheels (38,39), which track stands (9) are mounted between the axles (40,41) of their wheels each at one end of a rocker arm (5), which in its turn is located freely pivotally between its ends on the drive axle (4) of the vehicle, between which drive axle and the drive wheel axle (40) of each track stand a chain transmission (12,13,14,37) is located.

Abstract: A forestry cultivation instrument, particularly a scarifier, is attached to a telescoping carrier. In operation, the carrier is connected to a vehicle and, when an obstacle is encountered, the carrier may telescope outwardly thereby reducing shock loading to both the vehicle and the scarifier. The telescoping members are held contracted by fluid pressure with the telescoping occurring, after the obstacle is encountered, when the obstacle causes fluid pressure to increase beyond the pressure which would occur from normal drawing resistance of the scarifier. The fluid pressure may then be used to aid the operator in clearing the scarifier from the obstacle. Various other forms of forestry equipment may be substituted for the scarifier.