Portable power tool for milling tube ends

DETAILED DESCRIPTION An aspect of the present invention is to eliminate the need for reduction gears in air-operated, portable milling tools which are utilized to mill beveled surfaces on the ends of tubes, pipes, and the like.
The construction is generally compact and less complex than heretofore constructions.
Moreover, the time required to mill the beveled surface is drastically reduced.
The tool of the present invention is specifically adapted to mill or grind a frustoconical beveled surface on the end of a tubular, cylindrical workpiece (i.
e.
, pipe or tube end) having a longitudinal axis.
The tool has a housing that defines a central axis and that contains a rotary air motor mounted in its rearward end, the motor having a shaft that rotates about the central axis.
A fitting is provided for supplying air under pressure through the housing to the rotary motor.
Located at the forward end of the housing is a tool coupler assembly or collet that includes a spindle journaled therein and connected at its rearward end to the rotary shaft of the air motor.
Located on the arbor of the spindle is a rotary milling head attachable to the coupler for rotation about the central axis.
The milling head has a central guide pin extending forwardly thereof and adapted to be inserted with close tolerances in the open end of the tube or pipe to be milled and to position the cutting head in proper axial alignment with the tube or pipe during the milling operation.
The housing is also provided with handles or other holding means so that the tool may be positioned by an operator with the central axis of the tool in alignment with the longitudinal axis of the workpiece, whereby rotation of the milling head mills a frustoconical beveled surface on the workpiece.