Sheet workpiece manipulating device for a bending press

A device for gripping a sheet workpiece having opposed surfaces, comprising:

• a pair of opposed arms;
• and
• a pair of sheet workpiece gripping means, each gripping means provided on each of the opposed free ends of the opposed arms for adhering to the opposed surfaces of a sheet workpiece;
• wherein each arm comprises means for detachably attaching said gripping means thereto;
• wherein the attaching means include a permanent magnet and an electrical coil associated with the permanent magnet for generating a magnetic flux opposite to that generated by the permanent magnet,
• wherein the attaching means comprises an engaging member capable of moving between a position where it engages with the engaging seat formed in the gripping means and a position where it disengages therefrom;
• and
• means for moving the engaging member between the engaging position and disengaging position.

A device for gripping a sheet workpiece having opposed surfaces, comprising:

• a pair of opposed arms;
• and
• a pair of sheet workpiece gripping pads each provided on each of the opposed free ends of the opposed arms, the gripping pads being respectively provided with suction cup means opposing each other for adhering to the opposed surfaces of a sheet workpiece;
• wherein each arm comprises means for detachably attaching the gripping pad thereto, and
• wherein the gripping pad is formed with a coupling member having a sealing ring, for coupling a pneumatic chamber with a vacuum source.

A device for gripping a sheet workpiece having opposed surfaces, comprising:

• a pair of opposed arms;
• and
• a pair of sheet workpiece gripping pads each provided on each of the opposed free ends of the opposed arms, the gripping pads being respectively provided with suction cup means opposing each other for adhering to the opposed surfaces of a sheet workpiece;
• wherein the suction cup means respectively have air tight bearing surfaces for adhering to the opposite surfaces of the sheet workpiece, the bearing surfaces respectively define perimeters of respective pneumatic chambers which are connected to a vacuum source in use, and the perimeters of the respective pneumatic chambers have a substantially identical closed loop shape;
• the pair of gripping pads being provided on the pair of the opposed arms in a manner such that when the sheet workpiece is being gripped, corresponding sections of the perimeters of the pneumatic chambers are disposed to be adjacent to each other with the sheet workpiece being interposed therebetween.