Patent ID: 7775308
Filing Date: 2010-08-17
Classification: B62D

Abstract:
1. A payload-carrying motor vehicle comprising a frame, a steer axle, tandem drive axles, at least one pusher axle located between the steer axle and drive axles, a tag axle, said axles each having wheels with tires, a steer axle suspension system suspending the steer axle from the frame, a drive axle suspension system suspending the drive axles from the frame, a pusher axle suspension system including gas springs suspending the pusher axle from the frame, a tag axle suspension system including a primary tag axle suspension and a secondary tag axle suspension suspending the tag axle from the frame, said primary tag axle suspension adapted to suspend the tag axle for pivotal movement about a first axis parallel to the other axles, said primary tag axle suspension including actuators incorporating a gas spring adapted to apply a predetermined force on the tag axle urging pivotal movement of the tag axle about the first axis in a direction forcing the tag axle tires to bear against a road surface at a remote location rearward of the drive axles to aid in supporting the frame together with the other axles, said secondary tag axle suspension adapted to support the tag axle for pivotal movement about a second axis located equidistant from the tag axle wheels and laying in a plane at right angles to the first axis, and said secondary tag axle suspension including gas springs having a significantly higher gas charging pressure and significantly less spring compliance than the gas springs in said pusher axle suspension system operatively arranged on opposite sides of the second axis between the primary tag axle suspension and the tag axle so as to support only lateral loads acting on the frame.