Machines for machining workpieces, namely, machining centers; machining tools for the cutting and forming of material; workpiece and tool clamping devices, namely, metal clamps used for holding piece parts on machine tool tables; power driven clamping instruments, namely, electrically and/or hydraulically operated clamping tools for holding workpieces in machines or on machine tool tables; power driven gripping implements, namely, electrically and/or hydraulically operated gripping tools for ...