Power roller accumulating conveyor

Claim 1

A conveyor comprising a frame, a plurality of spaced apart power rollers positioned on said frame and operable to propel articles along said conveyor, each of said power rollers comprising a roller member terminating at opposite ends and having a longitudinal passageway extending between and through said ends, at least a portion of said passageway forming a radially inwardly facing cylindrical surface of substantially uniform diameter, drive means for imparting rotational movements to each of said power rollers, said drive means comprising a drive shaft rotatably mounted on said frame and extending through and beyond the ends of the passageway of an associated power roller, a friction drive member mounted on said drive shaft and positioned in said passageway portion, co-acting means on said drive shaft and on said friction drive member providing for the conjoint rotational movement of said drive shaft and said friction drive member, said friction drive member having a generally cylindrical outer surface of substantially uniform diameter which is sufficiently less than the diameter of said cylindrical surface in said passageway to provide for a space between the bottom sides of said cylindrical surfaces when the top sides thereof are in frictional engagement, said friction drive member being frictionally engaged with said roller member to transmit the rotational movement of said drive shaft to said roller member to propel the articles along said conveyor, said friction drive member being formed of a powdered metal and being impregnated with a lubricating agent enabling said friction drive member to slip in said passageway relative to said roller member when an article on said roller member is restrained from movement.