Abstract: A plate positioning apparatus which determines the position of a plate workpiece for a processing machine by an aligning member which moves in the X-axis direction and an aligning member which moves in the Y-axis direction. The Y-axis aligning member is provided with a movable retainer which retracts toward the Y-axis side when it comes in contact with the X-axis side aligning member and comprises a base part and an extension member which is remountable on the base part. The aligning member for the X-axis is provided on its upper surface with at least one aligning bar which contacts the plate workpiece. The aligning members for both directions of X and Y axes are adapted to be guided by the base frame and their moving strokes are controlled by position detecting switches provided in the base frame, the base frame being closed at its upper side by the cover plate. The respective slits along which the aligning members move are covered with respective movable dust-proof belts.

Abstract: A plate positioning apparatus for use with a punch machine having a number one workpiece stopper that moves left and right along the direction of the X axis and a number two workpiece stopper that moves to and fro along the direction of the Y axis perpendicular to the X axis, each workpiece stopper having its own motor. The number one workpiece stopper moving left and right relative to the punch along the direction of the X axis structured with a corner cutout on its inner leading edge so as to allow the punch to pass through. The number two workpiece stopper moves to and fro relative to the punch along the direction of the Y axis structured with a cutout section in the middle of its leading edge so as to allow the punch to pass through, the two cutout openings meeting at the forwardmost point of intersection to allow the punch to pass through.