Linkage suspension system

Abstract

A vehicle suspension system particularly useful in the heavy duty truck and trailer industry is disclosed. The suspension features lower control rods that are pivotally connected at their leading ends to hangers attached to each side frame member. The rearward ends of the lower control rods are attached to axle seats, one at each end of the axle, which are connected to the axle of the vehicle. Air springs and shock absorbers or, alternatively, hydraulic cylinders with accumulators, are mounted between each axle seat and each side frame member. The lower control rods are in an inclined orientation with their forward ends above their trailing ends. Additionally, some embodiments of the suspension feature upper control rods with their forward ends pivotally attached to the two opposing truck side frame members. The rearward ends of the upper control rods are attached to the top center of the axle by either a bolt and bushing mount or a ball and socket mount so that the upper control rods form a 'V'. The upper control rods lay in a nearly horizontal plane. As an alternative to the 'V' configuration of the upper control rods, a single, nearly horizontal, longitudinal upper control rod mounted between the centers of the frame cross member and the vehicle axle may be used in conjunction with either a control rod or a Watt linkage transverse to the side frame members. The suspension eliminates the heavy and costly Z-springs commonly used in air or hydraulic suspensions. The suspension has a lower frequency and is not torque reactive. Both of these features reduce vibration and provide for a better vehicle ride. The suspension also offers improved vehicle traction.