US Patent 7926833 All-wheels steer trailer

An all-wheel steer trailer is disclosed which includes front and rear axle beams which are pivotally mounted, above vertical axes, to the forward and rearward ends of a frame. In normal operation, the front and rear axle beams are interconnected so that the rear axle beam will pivot in an opposite direction to pivotal movement of the front axle beams so that the rear wheels of the trailer will track the front wheels of the trailer as the trailer is being turned. The trailer includes a convenient locking assembly which may be quickly utilized to prevent pivotal movement of the rear axle beam with respect to the frame when it is desired to pull the trailer on a highway or roadway.