Patent ID: 6684974
Filing Date: 2004-02-03
Classification: B62D

Abstract:
A four-wheel steering system for a utility vehicle, comprising:a frame; a pair of front pivotal wheel support assemblies carried by said frame and adapted to be pivotal about turning axes for steering; a pair of front wheels rotationally mounted to said pair of front pivotal wheel support assemblies; a pair of rear pivotal wheel support assemblies carried by said frame and adapted to be pivotal about turning axes for steering; a pair of rear wheels rotationally mounted to said pair of rear pivotal wheel support assemblies; a front axle tie rod pivotally connected at opposite ends thereof to each of said front pivotal wheel support assemblies at a radial distance from its respective turning axis; a hydraulic cylinder operatively connected at opposite ends thereof between said frame and one of said front pivotal wheel support assemblies at a radial distance from its respective turning axis, and operable to expand and contract to pivot said one front pivotal wheel support assembly with respect to said frame; a linkage assembly operatively connected between one of said front pivotal wheel support assemblies and said rear pivotal wheel support assemblies to transform pivoting motion of said front pivotal wheel support assemblies to pivoting motion of said rear pivotal wheel support assemblies in a direction opposite to the pivoting motion of said front pivotal wheel support assemblies, wherein said linkage assembly includes a longitudinal rod operatively connected between said front pivotal wheel support assemblies and said rear pivotal wheel support assemblies, pivoting of said front pivotal wheel support assemblies causing a longitudinal shifting of said longitudinal rod which in turn causes pivoting of said rear pivotal wheel support assemblies.