Patent ID: 7563053

Claim:
A roller assembly for movement along the ground in a forward working direction; the assembly comprising: a frame member extending transversely to the forward working direction; a plurality of walking beams, each walking beam extending generally in the forward working direction between opposed ends; a roller rotatably supported at each end of each walking beam so as to be arranged for rotation about respective roller axes and arranged for rolling movement along the ground in the forward working direction; a pivot on each walking beam between the rollers at the opposed ends of said walking beam pivotally supporting the walking beam so as to be arranged for pivotal movement of the walking beam relative to the frame member about a respective generally horizontal pivot axis oriented transversely to the forward working direction; each of the rollers being arranged for rotation relative to the respective walking beam about a respective roller axis at a location spaced from the pivot axis of the walking beam; and a support mechanism supporting the pivots between the rollers at opposed ends of the walking beams on the frame member such that each of said pivots is movable generally upwardly and downwardly relative to the other ones of said pivots.