US Patent 7775741 Apparatus and method for surface finishing cured concrete

A method and apparatus for finishing cured concrete floors using a riding trowel to which large diameter pans are rotationally secured, the pans having abraders releasably secured to their undersides. The individual abraders are preferably individually removably secured to the pans by hook-and-loop fasteners, wherein the fasteners are selectively disposed on the flat bottom surfaces of the pans or within shallow depressions in the bottom surfaces of the pans. The riding trowel further comprises a vacuum system in fluid communication with a contained space formed by a shroud having a rigid upper portion and a flexible lower portion where it contacts the finished cured concrete floor surface.