Device for forming box joining flaps in a box splitting machine

An improved device, to be applied to a paperboard material splitting machine having paperboard material splitting and counter-splitting means, for forming box joining-flaps, comprising a supporting frame for supporting a first supported framework of a joining flap primary cutting assembly, said first supporting framework being driven transversely to a paperboard material feeding direction, by a worm screw in turn driven by an electronically controlled geared motor unit, and a second supporting framework supporting an auxiliary trimming assembly and also driven transversely of said paperboard material feeding direction.