Patent ID: 6021864
Filing Date: 2000-02-08
Classification: B62D

Abstract:
The servo valve for a power assisted steering gear, comprising:an input member;an output member;a torsion bar having opposite ends respectively connected to the input member and the output member, said torsion bar having a plunger-containing hole formed in a radial direction of the torsion bar and in an intermediate part of the torsion bar between opposite ends of the torsion bar;a sleeve member surrounding the torsion bar and having first and second ends, the sleeve member being provided with an opening which penetrates the second end thereof in a radial direction of the sleeve member, an edge of the opening constituting means for holding the intermediate part of the torsion bar so as to increase an effective torsional rigidity of the torsion bar in a predetermined torsional angle range of the torsion bar;a plunger contained in the plunger-containing hole and being movable in a radial direction of the torsion bar and elastically engaged with the edge of the opening;a spring member for urging the plunger in a radially outward direction of the torsion bar; andmeans for preventing the first end of the sleeve member from being rotated with respect to the torsion bar.