Overhead rail conveyor system with improved traction having elastically deforming wheel or rail portions

A conveyor system for moving loads, comprising an overhead rail, at least one carriage adapted to run along said rail, said carriage having a frame that extends between an upperside and a lower side of the rail, a drive wheel rotatably supported in an upper part of the frame, means for driving said drive wheel along the upperside of said rail and means for supporting a load on a lower part of said frame that extends beneath the lower side of said rail, said drive wheel having on a portion of its peripheral surface at least one rolling surface in rolling contact with a corresponding rolling surface on the upperside of the rail and in another portion of the drive wheel's peripheral surface a gripping surface that grips a corresponding gripping surface on the upperside of the rail as the drive wheel rolls along said rail, one of said gripping surfaces having rigid gripping teeth while the other of said gripping surfaces is made of an elastically pliable material that receives and adopts an imprint of the rigid gripping teeth as the drive wheel rolls along said rail and then resiliently returns to its original shape once the wheel has passed, said corresponding rolling surfaces of said wheel and of said rail being elastically less pliable than said other of said gripping surfaces.