Patent ID: 8020268

Claim:
A precision roll turning lathe, comprising: a bed; a headstock, mounted on the bed, having a main spindle for rotating a cylindrical workpiece while holding one end of the cylindrical workpiece by means of a chuck; a tail stock, mounted on the bed and disposed opposite the headstock, for rotatably supporting the other end of the cylindrical workpiece; a carriage including a saddle mounted on the bed movably in the longitudinal direction (Z-axis direction) of the cylindrical workpiece, and a table mounted on the saddle movably in a direction (X-axis direction) perpendicular to the longitudinal direction of the cylindrical workpiece; a tool swivel mounted on the table; a tool post mounted on the tool swivel and having a plurality of turning lathe cutting tools attached thereto; a C-axis controller coupled to the headstock and constructed and arranged to selectively carry out workpiece-indexing by sequentially indexing machine start positions in the circumferential direction when the lathe is machining longitudinal grooves, and selectively carry out continuous rotating of the main spindle at a predetermined rotating speed when the lathe is machining transverse grooves; a switch coupled to the C-axis controller and constructed and arranged to cause the C-axis controller to selectively cause workpiece-indexing control and to selectively cause continuous rotation of the main spindle; and a fly cutter spindle device that cuts longitudinal grooves on the cylindrical workpiece when the C-axis controller is indexing the start positions, the fly cutter spindle device having a fly cutter and mounted to the tool post.