INDEXING APPARATUS AND METHOD FOR DRIVING THE SAME FOR INDEXING THE SAME

摘要

Provided between a base (10) and a turret (11) are a pair of positioning engagement members (27) which engage with each other to prevent rotation of the turret (11), and a screw feed mechanism comprising a ball screw (21) and a nut (25) converts the rotation of the ball screw (21) or nut (25) into rectilinear movement of the turret (11) to cause engagement/disengagement of the positioning engagement members (27). The screw feed mechanism is driven by a first motor (24), and the turret (11) is made to index a work by a second motor (32). When the second motor (32) is actuated to rotate the turret (11) for indexing, the first motor (24) is rotated in a predetermined rotational direction at a predetermined ratio of rotational speed to that of the second motor (32) whereby relative rotation between the ball screw (21) and the nut (25) of the screw feed mechanism is made zero to prevent rectilinear movement of the positioning engagement members (27).