GB833055A - Improvements in or relating to press tools - Google Patents

Abstract

833,055. Making closure caps; flanging; beading. HOPTON, H. J. W. Aug. 12, 1958 [May 14, 1957], No. 15259/57. Classes 83 (2) and 83 (4). A press tool for forming circular, rectangular or other shape closure caps from sheet metal and comprising a top assembly having a top inner former or knock-out pad 12 moving within a top ring 11 and a bottom assembly having a centre block 19 surrounded by a pressure-ring 21, is provided with a pressure-ring adapted to form a beaded edge on the flange of the cap and with means for holding down the knock-out pad so as to prevent the cap flank from rising after the flange has been formed and whilst the pressure ring and the top ring are rising and the beaded edge is being formed. A spring-loaded buffer pad 15 rests upon a shoulder formed inside the top ring 11. The centre block 19 and a cutting ring 20 is supported on a base 17. The pressure ring 21 which is provided with an annular beading groove 23 is resiliently supported on a rubber buffer 18 through pins 22. In operation, on downward movement of the top assembly a blank is cut out by co-operation of the top ring 11 and the cutting ring 20 and the top ring depresses the pressure ring 21 to form a flange on the blank and is eventually arrested by buffer pad 15 engaging the top member 10. As the top ring rises the spring- loaded buffer pad 15 ensures that the knock-out pad 12 remains pressing against the cap blank whilst the pressure ring 21 rises under the force of the rubber buffer 18 and beads the end of the cap flange. The inner edge of the top ring is rounded to initiate and facilitate the beading. In a modification the top inner former 12 is concave (Fig. 4), and a resilient pad 30 is provided between the former and the buffer pad 15. In another modification (Fig. 5), the top inner former is screwed to the buffer pad a packing 35 being inserted between the parts. Also a separate knock-out pad 33 is provided. Fig. 6 shows a buffer arrangement for transmitting the press force to the top member 10 of the tool the press ram acting against the top surface of the pot 41 and the top member 10 acting against the lower surface of the lower plate 46.