Vehicle suspension with an axle having two steering wheels, particularly for four-wheel lift trucks

摘要

The axle (1) is provided integrally in its centre line with a transverse appendix (14) hinged by means of a strong lever (23) to the lower end of an inverted "L"-shaped support (10) pivoted on the truck frame and to the upper portion (210) of which there is hinged the end of a hydraulic cylinder (12) which by its opposite end is securely fixed to the said appendix (14) of the axle. The amplitude of the oscillation of the lower lever (23) with respect to the horizontal and the relative position and the dimensions of the various parts of the suspension, are such that the steering axes (4) located on the ends of the axle, remain always in substantially vertical position. The hydraulic cylinder (12) is electronically controlled in such a manner that when the truck travels at normal speed or very slowly, the suspension is extended and in the first case it can be dampened by the accumulator (30) while in the second case is becomes rigid. Upon variation of the load applied to the forks, the controller can maintain the truck always in almost horizontal position. Whenever the truck exceeds a maximum predetermined speed, the suspension can automatically be retracted and lower the truck to increase its stability. <IMAGE>