Patent ID: 8251384

Claim:
An apparatus, comprising: an axle; mounting structure effective to couple said axle to a conveyance, a portion of said mounting structure being configured and arranged to permit oscillation of said axle in substantially a single plane; and a support surface having an area with a profile configured and arranged to variably contact a working surface associated with said axle as said axle oscillates such that a location of a theoretical pivot axis, about which axis said axle instantaneously rotates with respect to said mounting structure; is disposed at a locus of substantially line contact between said support surface and said working surface during a portion of an axle oscillation cycle; from a local frame of reference with respect to said support surface, is displaced back and forth in a direction generally parallel to a length axis of said axle during said axle oscillation cycle; and wherein, from said local frame of reference, said instantaneous theoretical pivot axis disposed at a max-right turn configuration is parallel to said theoretical pivot axis disposed at a max-left turn configuration.