Abstract: A shock-absorbing wheel assembly having an annular cast iron core member disposed concentrically about an annular bearing seat in spaced relation thereto, with the core member having passageways extending radially therethrough. A continuous integral mass of moldably polyurethane is provided to cover the exterior surface of the core member with a predetermined thickness, to fill the passageways in the core member, and to fill the spacing between the core member and the bearing seat. A method of forming the wheel assembly is provided, which includes locating the core member and bearing seat within a cylindrical mold cavity, permitting flowable polyurethane to flow into the interconnected spacings and passageways, and allowing the polyurethane to cure.

Abstract: An improved caster assembly having a stationary base member, a wheel assembly having a rotatable load-supporting wheel, and a ball bearing arrangement supporting the wheel assembly on the base for swiveling rotation with respect thereto. The ball bearing arrangement includes respective generally arcuate raceway surfaces which extend annularly on the base and wheel assembly in spaced, facing relationship to form a ball bearing raceway therebetween. Each raceway surface including two generally arcuate end portions, a portion at one end of each raceway surface being spaced from a cylindrical plane through the centers of the ball bearings in the raceway and another portion at the other end of each raceway surface intersecting and extending beyond the cylindrical plane from the spaced portion.