Apparatus for calibrating and surfacing tubes

In a calibrating and surfacing machine for tubes having a fixed frame, means for holding a tube on said frame, an internal tool carrying stem for said tube mounted from said frame for movement internally with respect to said tube, a tool removably fixed to one end of said stem for working the internal surface of said tube, said tool having a working surface which is limited for part of its external surface at least by a surface of revolution with a profile which increases in a constant manner from a first end plane of the tool, which corresponds to the point of entry into contact of the tool with the tube, to a second end plane of said tool, which corresponds to the place at which the contact of the tool with the tube ends, with a maximum depth from said point of entry to the point where the contact of the tool with the tube ends greater than the maximum depth of the defects on the interior surface of the tube but small enough to insure displacement of the tool along the axis of the tube by a force which does not exceed the mechanical resistance of the tube, a piston movable axially with respect to said tube, the improvement comprising means including an externally threaded flanged end on said tool carrying stem removably connecting an outer end of said piston with the end of said stem opposite the end removably fixed to said tool, means forming an internal passageway running axially through said stem from said flanged end and terminating internally of said stem adjacent the point where said tool is attached, one or more passageways extending outwardly from said internal passageway to the surface of said stem adjacent said tool and means to introduce a lubricant into said internal passageway at said flanged end of said tool carrying stem.