Die-cutting device for performing slots perpendicular to the feeding direction of box-forming paperboard sheets

A paperboard die-cutting device for making paperboard boxes which is adapted for connection as an independent operating unit to an output of a paperboard sheet slotting machine having a slotting machine frame and feeding paperboard slotted sheets in a longitudinally feeding direction, wherein said die-cutting device is mounted on a cross-sliding supporting framework, which is transversely slidingly driven by a gear motor unit also mounted on said supporting framework and cross-sliding on cross slides applied to said slotting machine frame and cross arranged with respect to said longitudinal feeding direction, said gear motor unit rotatively driving a gear motor unit worm screw engaging with a female thread of a bush supported by said supporting framework, said framework further supporting two first driven shafts supporting a pair of roller supported cross-cutting means for making, in said paperboard sheets, two cross-slots, and two second driven shafts each idly rotatively supporting an abutment polyurethane ring element allowing said cross-cutting means to operate at different cutting portions to prevent said abutment ring elements from being quickly worn, and three brushless motors, a first of said three brushless motors driving said two second driven shafts, and the second and third motors driving said two first driven shafts, and wherein said two second driven shafts are driven by said first motor through a toothed pulley thereon is entrained a drive belt and by a pair of two further pulleys that are rigid with said two second driven shafts, thereby causing said polyurethane ring elements to operate with a speed synchronized with a feeding speed of said paperboard sheets, said cross-cutting means comprising two cross-cutting blades both driven by said first driven shafts.