Patent ID: 7200890

Claim:
An apparatus for preparing a welding region on an outer surface of a plastic pipe, comprising: anchoring means for anchoring to an inner surface of the pipe, which are fixed, in an active configuration thereof, to an end region of the pipe; a threaded pivot coupled to said anchoring means so as to be movable longitudinally with respect to the pipe by a rotary-translational motion; supporting means being jointly coupled to said pivot for at least one tool supported at said supporting means so as to be arrangeable to interfere with, and remove material from the outer surface of the pipe, and wherein said anchoring means comprise a central body, longitudinal sliding guides arranged at said central body, at least three rod-like elements mounted at said sliding guides so as to protrude partially from said central body, said rod-like elements laying and being slidingly movable in said sliding guides parallel to a cross-sectional plane that is perpendicular to said threaded pivot, feet elements provided at outer ends of said rod-like elements for resting against the inner surface of the pipe, and respective racks provided longitudinally at said rod-like elements, and a common actuation gear system to which said racks are kinematically connected, said central body being constituted by a cylindrical box-like container, on which said longitudinal sliding guides are provided, said guides comprising four lateral holes that extend through said box-like container so as to open on opposite parts of a peripheral wall of said box-like container, said lateral holes being shaped in cross-section complementarily with respect to a transverse cross-section of said rod-like elements and being located mutually equidistant on said peripheral wall of to box-like container, said longitudinal sliding guides further comprising through channels, which are coaxial to corresponding ones of said lateral holes and are formed in blocks that protrude from a bottom surface of said box-like container.