Patent ID: 7861624

Claim:
A method of working a structure with a working apparatus at least having three rectilinear drive spindles orthogonal to each other and a rotary spindle rotationally driving a workpiece by cutting said workpiece in a state rotated about a C-axis employed as the axis of rotation with a cutting tool driven in directions X and Y while relatively adjusting a desired depth of cut with respect to said workpiece in a direction Z thereby forming a cavity of a desired shape in said workpiece, comprising the steps of: driving said cutting tool in said directions X and Y and synchronously rotating said cutting tool in the same rotational direction as said C-axis rotation; and cutting a desired position of said workpiece with said cutting tool thereby forming said cavity of said desired shape in said workpiece, wherein said step of cutting said desired position of said workpiece with said cutting tool includes the step of generating elliptical vibration on the cutting edge of said cutting tool thereby elliptically vibrating/cutting and working said workpiece at a relative desired cutting speed.