cross section arranged in a triangular pattern or centrally located the columnar part can also include a threaded surface to engage the female part an intermediary part can also be provided to connect a ratchet type of part to the female part application_number US 201313827515 A description in the drawings like reference numerals or characters if applicable designate identical or corresponding parts throughout the several views fig1 illustrates an end of an opc drum 11 having a columnar male part provided by three circular cross section projections 21 these projections 21 may be formed by pins integral with or separate from the end of the opc drum rotation is provided by engagement of projections 21 within a twisted hole various cross section shapes can be used including circular ellipsoidal and polygonal the three projections 21 can be a frustum of a circular cone and or a frustum of a pyramid as shown in fig2 these projections 21 are aligned so as to correspond to available axial recess shape here a hexagonal outline provided by the solid line in a manner that corresponds to a twisted triangular hole these projections are shown as a series of three pins however other cross sectional shapes such as quadrilateral and elliptical can be used further the arrangement of the pins is not necessarily equilateral as shown in fig2 by such an arrangement a transmission is provided for rotational movement between the twisted triangular female part and the columnar male part also female parts other than a twisted triangular shape may be used fig3 4 illustrate a further implementation.