Microcellular Urethane Technology Applied to Automobile Suspension Systems

The use of microcellular urethane jounce bumpers in McPherson type suspension systems has increased in the last few years primarily because they offer improved comfort, more sound absorption, lighter weight, and smaller size than rubber bumpers. The McPherson strut type of suspension means that a much longer deflection of the shock absorber can occur; and consequently, the elastomeric bumper, which is situated on the top of the suspension, requires a correspondingly greater deflection in order to prevent discontinuity of reaction during the deformation of the suspension system. Under these conditions, the deflection/reaction characteristics of rubber require rubber bumpers with overall dimensions and weight greater than that desired for lighter, smaller automobiles.