Method for controlling a gripper

A gripper for removing a blank from a web of material lying flat, comprising:

• a frame having gripping elements that are distributed in a reference plane defined by the gripping elements, wherein the gripping elements are separately actuatable and are displaceable independently of one another between an extended operating position and a retracted release position perpendicularly to the reference plane with the aid of separate actuating drives for each of the gripping elements;
• and
• a control device that actuates the actuating drive for each of the gripping elements and the actuating drives as a function of a predetermined contour line of the blank, wherein a subset of the gripping elements form downholders which are actuated by the control device as a function of the contour line of the blank.

A gripper for removing a blank from a web of material lying flat, comprising:

• a frame having gripping elements that are distributed in a reference plane defined by the gripping elements, wherein the gripping elements are separately actuatable and are displaceable independently of one another perpendicularly to the reference plane with the aid of separate actuating drives;
• and
• a control device that actuates the gripping elements and the actuating drives as a function of a predetermined contour line of the blank, wherein a subset of the gripping elements form downholders which are actuated by the control device as a function of the contour line of the blank, wherein the gripping elements are—suction heads and wherein the suction heads include a suction cylinder which is displaceably mounted in a frame, opens into a suction box and interacts with a coaxial control cylinder, which is fixed to the frame and sealed with respect to the suction box and wherein the suction cylinder is displaceable with the aid of the actuating drive between an extended operating position against the force of a loading spring into a release position in which the suction cylinder engages sealingly in the control cylinder.