US Patent 7625001 Single and tandem shunted torsion bar suspensions

A vehicle suspension utilizes a shunt linkage assembly between first and second torsion springs to change effective lengths of the first and second torsions springs in jounce and roll modes of operation. A first lever arm couples the first torsion spring to a first wheel and a second lever arm couples the second torsion spring to a second wheel component. The shunt linkage assembly acts as a tension-compression link between the opposed first and second lever arms. During jounce the first and second torsion springs would have one effective length, and during roll the first and second torsion springs would have a shorter effective length to provide roll stiffness that is greater than jounce stiffness.