Portable pipe end preparation machine tool

A portable machine tool for preparing pipe workpiece ends for welding comprising:

• a cutting head having axially forward and rearward sides, and including at least one cutter seat on the forward side thereof;
• a mandrel shaft extending axially through the cutting head;
• said cutting head supported on the mandrel shaft for relative rotation on and axial movement along the mandrel shaft;
• workpiece engaging elements movably carried by the mandrel shaft located towards the cutting head forward side and configured to be moveable relative to and to engage a workpiece located forwardly of and adjacent the cutting head;
• said workpiece engaging elements adapted to secure a workpiece and said mandrel shaft against relative rotation and axial motion when engaged with a workpiece;
• a feed mechanism carried by the mandrel shaft on the rearward side of the cutting head and cooperating with the mandrel shaft and cutting head to advance and retract the cutting head in axially forward and rearward directions along the mandrel shaft when actuated;
• a rotary drive coupling carried by the cutting head on its rearward side, said drive coupling drivingly connected to the cutting head for transmitting rotary motion to the cutting head;
• a drive motor unit including a housing and an annular drive head connected to the housing;
• said drive head including a rotary drive pawl within its annulus connected in driving relationship with said drive coupling, said drive coupling disposed at least in part within said annulus;
• said housing extending transversely of the mandrel shaft when the drive head is coupled to the rotary drive coupling;
• a drive torque reaction bar secured to the mandrel shaft rearwardly of the rotary drive coupling, the reaction bar non-rotatably coupled to the mandrel shaft and including a transversely extending first leg and at least one axially extending second leg, said axially extending second leg carried by said first leg and extending generally adjacent said mandrel shaft up to a position overlying and adjacent one side of the transversely extending drive motor unit housing, so that substantial relative rotation of the motor housing relative to the mandrel shaft is prevented by said first and second legs of said reaction bar.

A portable machine tool for preparing annular workpiece ends for welding, comprising:

• a rotary cutting head having a first outer diameter and axially forward and rearward sides, and including at least one cutter seat on the forward side thereof;
• said rearward side including a rearwardly axially projecting hub having a second outer diameter that is smaller than said first outer diameter;
• a mandrel shaft extending axially through the cutting head;
• said cutting head supported on the mandrel shaft for relative rotation on and axial movement along the mandrel shaft;
• a feed mechanism carried by the cutting head on the rearward side thereof and including internal threads;
• said mandrel shaft including external threads;
• said internal threads of said feed mechanism and said external threads of said mandrel shaft connected together so that rotation of the feed mechanism drives the cutting head axially along the mandrel shaft;
• an annular rotary drive coupling carried by the hub, said drive coupling drivingly connected to the hub and configured to receive an annular driving head of a rotary drive motor unit.