Abstract: A steering apparatus steers a steerable road wheel in response to turning movement of a steering wheel with a variable steering angle ratio therebetween. The steering apparatus includes a first member operatively coupled to either one of the steerable road wheel and the steering wheel, and a second member operatively coupled to the other of the steerable road wheel and the steering wheel. The first member has a portion engaging the second member at a variable engaging position that is movable on a predetermined path. The steering angle ratio varies when the engaging position varies. When the steering angle ratio varies with the first and second members in their respective neutral positions, the first and second members remain completely still, and their neutral positions are kept in alignment with each other.

Abstract: A variable ratio steering system on a motor vehicle can vary the ratio of the angle through which the steerable road wheels are steered to the angle through which the steering wheel is turned by the driver. The variable ratio steering system includes an input shaft coupled to the steering wheel, a first ball screw mechanism including a first nut threaded through balls over the input shaft, an output shaft coupled to the steerable road wheels, a second ball screw mechanism including a second nut threaded through balls over the output shaft, and a steering angle ratio adjusting mechanism, mechanically coupled to the first and second nuts, for varying the ratio of an axial displacement of the second nut to an axial displacement of the first nut.