Abstract: Improvement in a mechanism for guiding a belt on a conveyor comprising a belt guide having a roller and belt guide members at opposite ends of the roller, a hanger for hanging the roller from a conveyor so that the roller pushes upon the slack side of the conveyor belt, an arrangement providing a pivot axis by which the roller can rotate in respect to the hanger during operation of the conveyor, the device utilizing the left or right sideways movement of the belt to engage one of the guide members and rotate the roller about the pivot axis so that the belt is automatically moved by the device toward the position from which it originally commenced to move, the improvement comprising a roller frame for the roller, an axle made fast to the roller frame, the roller rotatably carried on the axle, the belt guide members carried on the axle and made fast to the roller frame, the belt guide members having belt-contacting surfaces for engaging opposite edges of the belt, each belt-contacting surface disposed at an obt