42 by suitable means such as an interference fit or fasteners at respective locations adjacent the transverse ends of the carriage block 30 are a pair of equal diameter roller discs 44 the discs 44 each define circular peripheral surfaces 46 the selection and utilization of a pair of roller discs 44 or alternatively a single elongate roller or a greater plurality of roller discs 44 on each stub shaft 42 will generally be dictated by the application of the roller conveyor 10 thus it should be apparent that the configuration illustrated is exemplary and that the invention should be construed to include all functionally equivalent roller arrangements the stub shaft 42 defines a cylindrical surface 50 about which an overrunning or one way clutch assembly 52 is concentrically disposed the overrunning clutch assembly 52 may be a sprag or roller type and preferably extends axially along a significant portion of the cylindrical surface 50 in order to evenly distribute bending moments associated with the mechanical configuration this may of course be achieved by the utilization of plural narrow overrunning clutch mechanisms 54 as illustrated or alternatively a lesser number of wider mechanisms in either event the overrunning clutch assembly 52 is deemed to be well known in the art and due to this fact.