Steering system for non-tracked motor vehicles

A steering system for a non-tracked motor vehicle, comprising a steering handle operatable by the driver;

• a steering adjusting drive for steering adjustment of steerable vehicle wheels;
• a steering-angle desired-value generator operable by the steering handle;
• a steering-angle actual-value generator operable by the steerable vehicle wheels;
• an automatic control system configured and arranged to control the steering adjusting drive as a function of a comparison of the desired and actual values of the steering angle and to continuously monitor itself as well as a sensor system interacting therewith for determining malfunctioning;
• and a mechanical or hydraulic forced coupling arranged between the steering handle and the steerable vehicle wheels and opened up or remaining open in an inoperative normal condition when the automatic control system operates correctly and is automatically closed when the automatic control system is defective during an operative special condition, wherein the automatic control system is further configured to analyze or detect a parameter which is correlated with forces or torques transmitted between the steering adjusting drive and the steerable vehicle wheels and, with a certain loading of the adjusting drive, switches the forced coupling to be operative in an assisting manner and parallel to the steering adjusting drive, so that a manual force acting upon the steering handle is able to assist the adjusting drive.