B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21D43/00—Feeding, positioning or storing devices combined with, or arranged in, or specially adapted for use in connection with, apparatus for working or processing sheet metal, metal tubes or metal profiles; Associations therewith of cutting devices
B21D43/02—Advancing work in relation to the stroke of the die or tool
B21D43/04—Advancing work in relation to the stroke of the die or tool by means in mechanical engagement with the work
B21D43/10—Advancing work in relation to the stroke of the die or tool by means in mechanical engagement with the work by grippers
B21D43/11—Advancing work in relation to the stroke of the die or tool by means in mechanical engagement with the work by grippers for feeding sheet or strip material