Patent ID: 8272296

Claim:
A screw fastener, comprising: a rotary tool that has a rotary shaft and a main body in which to fasten a screw to a workpiece; a linear motion robot unit that is composed of an X-axis linear motion robot, a Y-axis linear motion robot, and a Z-axis linear motion robot, the X-axis linear motion robot, the Y-axis linear motion robot, and the Z-axis linear motion robot being connected with one another and moving the rotary tool along directions of the X, Y and Z-axes, respectively, where the X, Y, and Z-axes each orthogonally cross; a supporting member that supports the main body of the rotary tool in a movable manner along each of the directions of the X, Y, and Z-axes and restricts rotation of the main body of the rotary tool around the rotary shaft so as to restrict the rotation of the main body around the rotary shaft; a reaction force supporting member that is composed of a parallel link that is disposed on a plane approximately orthogonal to the rotary shaft of the rotary tool and connects the main body of the rotary tool with the supporting member; a positioning device that positions the workpiece; and a floating table that is coupled to the linear motion robot unit and the positioning device and movable along a plane approximately orthogonal to the rotary shaft of the rotary tool.