Tractor, or german vehicle with an additional wheel set

摘要

962,615. Tractors. P. HALLSATER, D. DIAMANT, and J. PERSSON. Nov. 16, 1962 [Nov. 21, 1961], No. 43514/62. Headings B7D and B7H. In a tractor provided with additional wheels 9 which may engage an endless track or halftrack 28, the additional wheels 9 are mounted on levers 11, 12 pivoted on the tractor and coupled to the ends of a transverse balance beam 15 suspended from an hydraulically actuated power-lift linkage having a control mechanism 7 which maintains the lifting force exerted by the power-lift at a constant value selected by a control lever 8. The ground contact pressure exerted by the wheels 9 is thereby maintained at a constant value and the balance beam 15 ensures that this pressure is equally divided between the wheels. In another embodiment (Fig. 3, not shown), the levers carrying the wheels 9 are not coupled to the linkage of the power-lift but are each acted upon by one or more hydraulic cylinders connected to the hydraulic system of the power-lift and to a further cylinder actuating the control mechanism 7. Valves are provided to enable disconnection of the hydraulic cylinder acting on either of the levers if conditions require a ground contact pressure on only one of the wheels 9, and the cylinders may be used to raise the wheels by means of a reversing valve. The wheels 9 may each be replaced by a group of wheels.