GB1356462A - Manufacture of can bodies - Google Patents

Abstract

1356462 Making cans; bending; seaming METAL BOX CO Ltd 25 April 1972 [11 May 1971] 14152/71 Headings B3A B3E and B3J An end neck and an end flange merging therewith are formed simultaneously on a can body while rigidly supported internally by relative rolling motion between the body and an external necking tool. A can end is subsequently seamed onto the flange, while reforming of the neck takes place. In Fig. 5, the can body 20 is shown gripped by an expandable mandrel 21 shown contracted in section in Fig. 4. First jaws 22<SP>1</SP> are movable radially outwardly against springs 45 by axial movement of a chamfered sleeve 40. Smaller second jaws 49 are simultaneously moved radially outwardly against springs 50 to fill in the circumferential gaps between jaws 22<SP>1</SP>. The expanded jaws together with a non-expandable part 28 of the mandrel offer surfaces on which the neck 23 and flange 24 are formed by necking rollers 26. Preferably two diametrically opposite rollers are used, moved radially inwardly together but at different distances from the mandrel axis 25. The mandrel may be driven, or the rollers 26 may be driven and circle about the mandrel, or the necking tool may be a fixed bar of suitable profile. The diameter of the flange may be greater than, equal to, or less than that of the body, and in the first case the non-expandable part of the mandrel may be movable of smaller diameter than the neck and be movable transversely of its axis towards the necking tool, Fig. 7 (not shown). In another form, the mandrel jaws 86, Fig. 14, are mounted on a member which includes an annular ring 92 radially outside the can body offering a surface 105 on which the can body initially abuts. Neck and flange formation by tool 26 is constrained by a surface 96 on ring 92 which intersects the path 107 which would be taken by the flange end in the absence of such constraint. Fig. 16 shows a first seaming operation, in which a can end member 80 with seaming flange 110 is partly seamed on by a seam forming profile 123 of a first seaming roll 108, while a further profile 111 on the roll simultaneously reshapes the neck profile from 23 to 23<SP>1</SP>. Similarly in a final seaming operation a second seaming roll completes the seam while simultaneously reshaping the neck profile still further. The can body may be open at one or both ends, necking, flanging, and seaming taking place at the or both ends.