similar to those of FIGS. 8 and 9 but illustrating the completed fourth embodiment wheel construction.DETAILED DESCRIPTION OF INVENTIONFirst EmbodimentReferring in more detail to the accompanying drawings, particularly FIGS. 1 and 2, the first embodiment 20 of a wheel assembly in accordance with the invention as illustrated therein comprises a metallic wheel 22 including a wheel disc 24 and adrop