Improvements in or relating to piercing and blanking dies

摘要

1,018,870. Making piercing and blanking dies. G. E. WHITECOTTON. May 1, 1964, No. 18283/64. Headings B3A and B3W. In a method of making matching piercing and blanking dies, the male die blank is coated with a hardenable resin layer and the female die is impressed in the resin which is then hardened and the blank formed to the hardened impression. A steel rule blade 26 is fixed in a plywood block which is bored to receive piercing punches 28 and to provide dowel holes 22 thereby forming a die 20. A die blank 31 is fixed to a die plate 33 and a layer 38 of epoxy resin is coated on the blank 31. The plate 33 is placed on an assembly jig 40 and the die 20 is lowered on the jig until the blade 26 is impressed in the resin layer 38. When the resin is cured the die 20 is removed so that the blank 31 may be formed into a punch 39 (Fig. 6, not shown) preferably of slightly smaller size than the impression on the blank. The punch 39 and die 20 are replaced on the jig 40 and the punch has a thin overlapping coating 46 (Fig. 6) of partially cured resin applied. The die is lowered and a layer 47 of resin forms in the clearance between the blade 26 and punch 39. The resin is cured and the clearance is checked by measuring the thickness of the layer.