Apparatus for machining pipe

Claim 1

A CUTTING TOOL FOR CUTTING A PIPE HAVING AN INNER LAYER AND AN OUTER LAYER, SAID TOOL COMPRISING A CLAMPING UNIT DESIGNED TO ENGAGE THE PIPE, SAID UNIT HAVING A PLURALITY OF JAWS AND MEANS FOR MOVING SAID JAWS GENERALLY RADIALLY TO CLAMP THE PIPE AND PREVENT ROTATIONAL AND LONGITUDINAL MOVEMENT OF SAID CLAMPING UNIT WITH RESPECT THERETO, A CENTERING AND MACHINING UNIT CONNECTED TO SAID CLAMPING UNIT FOR ROTATIONAL MOVEMENT ONLY WITH RESPECT THERETO, SAID CENTERING UNIT INCLUDING RADIALLY MOVABLE ROLLER MEANS POSITIONED TO BE ON DIAMETRICALLY OPPOSITE SIDES OF THE PIPE AND EQUALLY SPACED FROM AN AXIS WHICH EXTENDS THROUGH SAID TOOL AND IS CENTRALLY LOCATED WITH RESPECT TO SAID JAWS, MEANS FOR MOVING SAID ROLLER MEANS EQUAL DISTANCES TOWARD AND AWAY FROM THE AXIS OF THE CUTTING TOOL TO MAINTAIN THE PIPE COAXIAL WITH THE AXIS OF THE TOOL REGARDLESS OF THE DIAMETER OF THE PIPE, A CUTTER CARRIED BY SAID CENTERING UNIT, SAID CUTTER HAVING A PROJECTING CUTTING EDGE FOR CUTTING THE PIPE IN TWO AND A RETRACTED CUTTING EDGE FOR REMOVING A NARROW RING OF AT LEAST PART OF THE OUTER LAYER OF THE PIPE, AND MEANS FOR MOVING SAID CUTTER TOWARD AND AWAY FROM THE TOOL AXIS.