Abstract: A flap folding assembly for engaging a work piece, such as a paperboard carton flap, and moving that flap into a desired position. The flap folding apparatus can be used in a continuous motion packaging machine to engage a sleeve type carton flap as the carton is transported downstream through the package machine. The apparatus is operated in timed relationship with the machine's carton conveyor either by mechanically interlinking the apparatus to the main machine drive, or by the use of a servo drive operated from and controlled by the packaging machine's main controller. The flap folding apparatus includes a vacuum cup driven in a circular path by a drive mechanism comprised of two spaced gears which are driven in the same direction of rotation.