Apparatus for working surface of metal pipe

An apparatus for working inner and outer surfaces of a metal pipe comprising:

• means for drawing the metal pipe to reduce a diameter thereof;
• means for working the inner and outer surfaces of the metal pipe to form at least one of the inner and outer surfaces thereof into a predetermined configuration;
• and
• said working means including a rolling unit and a driving mechanism therefor, said rolling unit including a housing having end members each provides with a central bore, a plurality of rolling rolls rotatably disposed within said housing and outside the metal pipe so that said rolling rolls have their respective axes extending at an inclination angle with respect to an axis of the metal pipe and are in pressure contact with the metal pipe, and support shafts each having axial opposite ends thereof rotatably supported by said housing through thrust bearing means, said rolling rolls being respectively mounted on said end members on said driving mechanism and driven by said driving mechanism to revolve said rolling rolls around the metal pipe, said working means further including a plug floatingly disposed within the metal pipe at a position corresponding to said rolling rolls, said driving mechanism comprising an outpput shaft having a free end and having therein an axial bore for allowing the metal pipe to pass therethrough, a connecting flange mounted on said free end of said output shaft for rotating therewith, said connecting flange having formed therein a recess, and a cap member threadedly engaging with said connecting flange for securing said rollng unit within said recess so that said axial bore in said output shaft is in coaxial communication with the respective central bores in said end members of said housing;
• said recess in said connecting flange having a peripheral wall surface tapering so as to diverge away from the free end of said output shaft, said cap member having a tapered surface tapering so as to diverge toward the free end of said output shaft, said driving mechanism further comprising a split sleeve having an inner peripheral surface thereof and an outer peripheral surface comprising a first tapered surface and a second tapered surface, said first tapered surface tapering so as to diverge toward the free end of said output shaft, said second tapered surface tapering so as to diverge away from the free end of said output shaft, said split sleeve being disposed in position with said first tapered portion being engaged with the peripheral wall surface of said recess in said connecting flange while said second tapered portion is engaged with the tapered surface of said cap member, so that the split sleeve is deformed into a shape of a reduced diameter to be brought into firm engagement with the outer peripheral surface of the rolling unit, thereby securing the rolling unit in position.