Abstract: A workpiece W to be machined by a rotating cutting tool 32 is carried by a rotary workhead 22 which is in turn mounted on a rotary table 16 for movement relative thereto both rotationally about a first axis perpendicular to the rotation axis of the table 16 and rectilinearly along second and third mutually perpendicular axes. The plane of interpolation between the second and third axes lies perpendicularly to the first axis, irrespective of the angular setting of the table 16. Using a combination of movements, the machine tool is able to produce on the workpiece W an arcuate surface whose radius of curvature is different from the distance of that surface from the workhead rotation axis.

Abstract: A workpiece W to be machined by a rotating cutting tool 32 is carried by a rotary workhead 22 which is in turn mounted on a rotary table 16 for movement relative thereto both rotationally about a first axis perpendicular to the rotation axis of the table 16 and rectilinearly along second and third mutually perpendicular axes. The plane of interpolation between the second and third axes lies perpendicularly to the first axis, irrespective of the angular setting of the table 16. Using a combination of movements, the machine tool is able to produce on the workpiece W an arcuate surface whose radius of curvature is different from the distance of that surface from the workhead rotation axis.