Shaping by press-cutting Perforating

BPERFORMING OPERATIONS TRANSPORTING B21Mechanical metalworking B21DWORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL PUNCHING METAL

B21D28/00Shaping by press-cutting Perforating

B21D28/002Drive of the tools B21D28/005Adjustment of the punch stroke for compensating wear B21D28/007Explosive cutting or perforating B21D28/02Punching blanks or articles with or without obtaining scrap Notching B21D28/04Centering the work Positioning the tools B21D28/06Making more than one part out of the same blank Scrapless working B21D28/08Zig-zag sequence working B21D28/10Incompletely punching in such a manner that the parts are still coherent with the work B21D28/12Punching using rotatable carriers B21D28/125with multi-tools B21D28/14Dies B21D28/145with means for slug retention B21D28/16Shoulder or burr prevention B21D28/18Yieldable B21D28/20Applications of drives for reducing noise or wear B21D28/22Notching the peripheries of circular blanks B21D28/24Perforating B21D28/243in profiles B21D28/246Selection of punches B21D28/26in sheets or flat parts B21D28/265with relative movement of sheet and tools enabling the punching of holes in predetermined locations of the sheet B21D28/28in tubes or other hollow bodies B21D28/285punching outwards B21D28/30in annular parts B21D28/32in other articles of special shape B21D28/325using cam or wedge mechanisms B21D28/34Perforating tools Die holders B21D28/343Draw punches B21D28/346length adjustable perforating tools B21D28/36using rotatable work or tool holders