Method of manufacturing a ball member usable in ball valves and other flow control devices

A method for manufacturing a ball member from a workpiece, the method comprising:

• connecting the workpiece to a rotating apparatus at a first connection point of the workpiece and at a second connection point of the workpiece;
• rotating the workpiece along a first axis;
• moving a rotating cutting tool along a second axis toward the workpiece;
• cutting the workpiece partially between the first connection point and the second connection point, thereby:
• forming a first surface extending partially between the first connection point and the second connection point;
• forming a portion of a first protrusion on a first side of the first surface;
• and
• forming a portion of a second protrusion on a second side of the first surface;
• moving the rotating cutting tool along the second axis away from the workpiece;
• further rotating the workpiece along the first axis;
• further moving the rotating cutting tool along the second axis toward the workpiece;
• further cutting the workpiece partially between the first connection point and the second connection point, thereby:
• forming a second surface extending partially between the first connection point and the second connection point;
• forming an another portion of the first protrusion on a first side of the second surface;
• and
• forming an another portion of the second protrusion on a second side of the second surface;
• and
• cutting a bore through the workpiece, wherein the bore extends through the first surface and through the second surface.

A method for manufacturing a ball member usable in a flow control valve, the method comprising:

• connecting a workpiece to a rotating apparatus along an axis of rotation of the workpiece;
• simultaneously rotating the workpiece about the axis of rotation and moving a rotating cutting tool toward the axis of rotation along a second axis to form a first curved surface having a progressively shorter radius with respect to the axis of rotation, wherein the second axis is generally oriented perpendicular to the axis of rotation, and the progressively shorter radius extends from a point on the second axis that is offset from an intersection of the second axis and the axis of rotation;
• moving the rotating cutting tool along the second axis away from the workpiece;
• further simultaneously rotating the workpiece about the axis of rotation and moving the rotating cutting tool toward the axis of rotation along the second axis to form a second curved surface having a progressively shorter radius with respect to the axis of rotation;
• and
• cutting a bore through the workpiece, wherein one end of the bore extends through the first surface and the other end of the bore extends through the second surface.