Patent ID: 7278509

Claim:
A counterbalanced forklift truck comprising: a driver's cab; front and rear wheels, where the rear wheels are steerable; a steering wheel in the driver's cab to be turned about an axis and coupled with an electric steering transmitter, the maximum of the steering wheel to both sides of a neutral position is smaller than 180° and is limited by fixed stops, the steering transmitter generating a first steering signal in response to the angle of the steering wheel relative to the neutral position; a speed measuring device for the forklift truck which provides a speed signal; an electric or electro-hydraulic steering mechanism for the rear wheels to actuate the steerable wheels in response to a position signal generated by a steering control, the steering control being supplied by an input signal which is formed by a comparison of a feedback signal corresponding to the actual angle of the rear steerable wheels and a desired steering signal, and a steering transmission ratio device having two ratio means to modify the first steering signal to achieve the desired steering signal, one ratio means effects a progressive characteristic to achieve small steering angles when the steering wheel is rotated in the range about its neutral position, the other ratio means being supplied by the speed signal to modify the first steering signal such that the steering angle decreases with increasing speed so that the maximum steering angle which is reached when the steering wheel is moved against one of the fixed stops is decreased with increasing speed.