Patent ID: 6477963
Filing Date: 2002-11-12
Classification: B61F,B62D

Abstract:
A steering apparatus for a vehicle adapted to travel on a guideway having at least one guide rail extending parallel to the desired course of the vehicle, wherein the vehicle rests upon a support frame secured to a wheel assembly, wherein the wheel assembly has a guide frame adapted to pivot about a guide frame pivot point such that a guide frame longitudinal axis remains parallel to the guide rail when the guide frame is following a straight portion of the guide rail and remains tangential to the guide rail when the guide frame is following a curved portion of the guide rail, wherein the wheel assembly further includes a first steerable drive tire connected to a first axle which is supported by the support frame and pivotable about a pivot for turning the tire, wherein the steering apparatus comprises:a) a mechanical steering linkage comprised of a series of links connecting the guide frame to the first steerable drive tire of the wheel assembly for turning the first steerable drive tire parallel to the guide rail when the guide frame is following a portion of the guide rail that is straight and for turning the first steerable drive tire tangential to the guide rail when the guide frame is following a portion of the guide rail that is curved, thereby defining a neutral steering angle between a longitudinal axis extending through the tire and a central longitudinal axis extending through the vehicle body; wherein the length of one of the links is adjustable; and b) an actuator for increasing or decreasing the length of the adjustable link of the steering linkage thereby amplifying or reducing the amount the first steerable drive tire is turned in response to motion of the guide frame when the guide frame pivots along a curved guide rail and thereby introducing a compensation angle to the neutral steering angle and producing an adjusted steering angle to account for a slip angle of the steerable drive tire.