Patent ID: 7270334

Claim:
A wheel assembly that is arranged to support a load carrying platform and to roll on a surface, comprising: a generally planar primary wheel that is rotatable about a central axis, said primary wheel comprising a single planar member, said planar member having a plurality of stub axles at fixed locations extending perpendicularly outwardly from one side thereof, said locations being angularly equidistant apart and equidistant as well from the central axis; and an even number of secondary wheels, one wheel mounted on each stub axle, said secondary wheels being of equal diameter and equal width and configured as a generally cylindrical disk having a diameter greater than the distance between angularly adjacent stub axles, said axles and wheels arranged such that at least two angularly adjacent wheels are in rolling contact with said surface at any one time, each of said secondary wheels arranged to freely rotate independently of any other secondary wheel, and independently as well of said primary wheel, alternate ones of said wheels positioned along their respective axles by a spacer means mounted adjacent said planar member on alternate stub axles, said spacer means comprising a cylindrical element having an axial bore sized to fit over said stub axle, the height of each said cylindrical element being greater than is the width of a secondary wheel thereby causing each wheel of an angularly adjacent pair of wheels that is in contact with said surface to roll along a separate and parallel track.