Means for and method of controlling frame rise in vehicle suspensions

Abstract

Vehicles, notably heavy duty trucks, equipped with torque reactive suspensions, such as trailing arm air suspensions, are susceptible to driveline vibration and wheel hop due to engine produced torque. According to this invention such driveline vibration and wheel hop can be suppressed by preventing frame rise from occurring. Suppression can be accomplished by providing one of several forms of frame rise control means operative between the vehicle drive axle and the vehicle frame. One form of frame rise control means utilizes rebound control leaf springs on opposite sides of a vehicle. Another form utilizes shock absorbers each of which incorporates a spring mounted on the piston rod. Another form utilizes hydraulic cylinders, each having a source of pressurized hydraulic fluid connected to the chamber of the cylinder on the rebound side of the piston and the chamber on the opposite side of the piston vented to atmosphere. Another form utilizes hydraulic cylinders each having a source of hydraulic fluid connected to the chambers on opposite sides of the piston with a valve operative to block flow of hydraulic fluid from the chamber on the rebound side of the piston. Still another form utilizes an elongated endless elastic strap embracing the shock absorbers.