Improvements relating to the construction of dies for stamping sheet metal

1,044,614. Making built-up dies. TOOLMASTERS Ltd. Oct. 18, 1963, No. 41329/63. Headings B3A and B3W. In a press tool including a punch and a sectional die, the die sections are provided with formed faces which taper away from the path of the punch solely in the direction normal to the respective general plane of each formed face. The tool comprises a bottom bolster 10 which has a circular depression 11 in its top surface and an opening 12 passing through the bolster. Within the depression are a loosely fitting apertared thrust plate 14 and a tool-steel disc 13 which is an interference fit. The disc 13 has a central generally rectangular aperture 17 the sides of which taper out downwardly at 0À004 inch per inch. Tungsten carbide die sections 40-44, Fig. 4 (not shown), are secured by screws 19 to the thrust plate 14 with the intervention of a packing plate 20. The die sections 40-44 have faces 45 which form the cutting edges and which taper away from the path of the punch solely in the direction normal to the respective general planes of the formed faces. The outer walls 46 have the same taper as the disc aperture 17, so that when due to grinding of the top face the clearance between the punch and die becomes too great material can be removed from the faces 48 to bring the formed surfaces 45 of the die sections closer together. When reassembled in the disc 13 a thicker plate 20 will be necessary to bring the die sections into close contact with the tapered surfaces of aperture 17.