Patent GB-1162150-A (GB)
Title: Improvements in or relating to the Formation of Containers
IPC: B21D26/025
Filed: 1966-12-14
Abstract: 1,162,150. Shaping metal foil containers. KAISER ALUMINUM & CHEMICAL CORP. 14 Dec., 1966 [27 Dec., 1965], No. 56069/66. Heading B6J. An apparatus for forming a foil blank into a smooth walled container comprises a reciprocable ram and co-operating platen each having certain surface portions for engaging and clamping the outer marginal portion of the blank to seal the inner portion of the blank from the atmosphere and other surface portions which smooth the outer peripheral edge of the outer marginal portion and bend this edge relative to the remainder of the portion, the platen further having associated means for directing fluid at high pressure and high velocity against one side of and against the inner portion of the blank during the clamped engagement of ram and platen to force the inner portion of the blank into backup means on the ram and complete the formation of the container. A die 10 is provided with a ram 12, movable to co-operate with a platen 16 by fluid actuated piston 22, containing a female die section 14. Die section 14 is mounted for limited axial movement in draw ring 27 and preferably comprises outer draw ring 42 having a frusto-conical forming surface 64 mounted for slidable movement relative to a central section 44 having a planar forming surface 62, the ring 42 being slidable in turn on surface 36 of ring 27. Die element 44 is resiliently suspended from plate 50 by cap screws 56 slidable in bores 54 and carrying coil springs 60. Pressure chamber 74 carries a piston 76 interconnected with draw ring 42 by freely mounted pins 82 such that ring 42 may be yieldably maintained in a position with flange 68 abutting shoulder 38. Platen 16 includes bed 92, outer ring 94, inner plate 96 and an elevatable intermediate ring 98 which co-operates with forming ring 27. Ring 98 is movable by actuator 102 containing piston 105 such that in its uppermost position surface 116 is co-planar with surfaces 100 and 104. The advancing ram 12 clamps the outer marginal portions of a blank between surface 66 and the periphery of surface 104, ring 27 then passes into space 107, forcing ring 98 downwards and severing the blank from intermittently fed strip material S<SP>11</SP> between cutting edges 28 and 115. As ring 28 passes into the space previously occupied by ring 98 the outer periphery of the blank is bent downwards and smoothed out by sliding between surfaces 32 and 116, and surfaces 36 and 120. Passage 122 then admits a compressed gaseous fluid which is directed explosively against the underside of the blank forcing the latter against surface 62. When draw ring 42 moves into contact with flange surface 20, ring 42 and element 44 define the shape of the container to be formed and mould the explosively expanded blank. Vents V allow the escape of pressurized fluid. On withdrawal of ram 12 upwardly biased ring 98 maintains contact between surfaces 32 and 116 in order to curl the edge of the container between torroidally complementary surfaces 118 and 40. The mechanism is controlled by a series of cams 130, 132, 134 rotating on shaft 124 to operate in timed sequence the valves 136, 138 and 140 controlling the supply of pressurized fluid to pistons 105, 22, 76 and to supply line 122. In a modified apparatus (Figs. 6 and 7) a one-piece die 14<SP>1</SP> is used in place of element 14 and ring 42.