Patent ID: 7503264

Claim:
A side bearing assembly for a vehicle including a bolster and a car body disposed on the bolster, said side bearing assembly comprising: a cage for attachment to the bolster of the vehicle; a cap coupled to said cage and moveable relative to said cage for supporting a portion of the car body of the vehicle; and an insulator disposed between said cap and said cage for coupling said cap to said cage; said insulator formed of microcellular polyurethane for resiliently deforming and storing energy during compressive movement between the car body and the bolster through a range of temperatures between −40° C. and 80° C.; wherein said insulator includes an interior member extending along an axis and an exterior member including an inner surface defining a bore extending through said exterior member along said axis and receiving said interior member in said bore and wherein said interior member and said exterior member are formed of microcellular polyurethane.