a conveyor system is provided including a modular link conveyor belt forming an endless loop and requiring no inverted return run . the conveyor belt is comprised of a plurality of modular links with at least one of the modular links having an angled cleat depending downwardly therefrom . a screw driving means is provided for engaging the angled cleat . specifically , the screw driving means includes a screw having a thread wherein the thread advantageously engages the angled cleat for providing a positive driving force to the conveyor belt .