a combination punching and binding machine for gang punching a stack of sheets and binding the sheets with a pre - curled plastic comb - binding element . the machine is electrically operated by energizing a reversible motor which , when operated in one mode actuates the punches , and when operated in a second mode , laterally moves a comb upon which the binding element is placed and then actuates a plurality of hook elements to uncurl the curled splines of the binding element for receiving the punched sheets .