Method and apparatus for complete machining of a shaft-shaped workpiece

A method of operating a machining apparatus having:

• a frame defining an input station, an output station, and first and second machining stations;
• respective first and second workpiece holders in the first and second machining stations capable of retaining a workpiece therein;
• a first pivotal turret movable vertically and horizontally on the frame between the input station and the first machining station and carrying at least one machining tool and a first grab;
• and
• a second pivotal turret movable vertically and horizontally on the frame between the first and second machining stations and the output station and carrying at least one machining tool and second and third grabs, the method comprising the steps of:
• taking a semifinished workpiece out of the first machining station with one of the grabs of the second turret and generally simultaneously taking an unfinished workpiece out of the input station with the grab of the first turret;
• thereafter
• placing the unfinished workpiece in the first station with the grab of the first turret;
• taking a finished workpiece out of the second machining station with the other grab of the second turret;
• and thereafter placing the semifinished workpiece in the second machining station with the one grab of the second turret;
• and
• placing the finished workpiece in the output station with the other grab of the second turret.