초록 ▼

Method and apparatus are disclosed for fabricating a one-piece can body, with profiled closed end, from flat rolled steel of selected thickness gauge and tensile strength. Such steel substrate is electrolytically metal plated to facilitate sidewall ironing into an elongated sidewall can body for pre

Method and apparatus are disclosed for fabricating a one-piece can body, with profiled closed end, from flat rolled steel of selected thickness gauge and tensile strength. Such steel substrate is electrolytically metal plated to facilitate sidewall ironing into an elongated sidewall can body for pressurized beverage packs. An axially-recessed bead is formed in the endwall of a drawn cup by pulling sidewall metal for movement into such endwall. That preformed bead being symmetrically positioned in the drawn cup such that a bodymaker redraw of the drawn cup positions sheet metal of the preformed bead so as to constitute a closed end angled portion, which extends from a circular configuration base support toward contiguous sidewall. Following subsequent sidewall ironing of the bodymaker redrawn cup, a substantially-planar endwall panel, radially inward of such base support, is formed into a concave dome by moving sidewall sheet metal into the closed end of the sidewall ironed can body, thus substantially avoiding thinning of closed end sheet metal and providing desired bulge and implosion resistance. Also, reforming steps for such closed end, subsequent to can body fabrication, are eliminated.

대표청구항 ▼

[ What is claimed is:] [1.]1. Process for fabricating a one-piece sheet metal can body, of predetermined internal diameter, with a closed-end configuration defining a base support for a two-piece can for use in a pressurized-beverage pack, comprisingA. providing a planar blank of flat-rolled sheet m

[ What is claimed is:] [1.]1. Process for fabricating a one-piece sheet metal can body, of predetermined internal diameter, with a closed-end configuration defining a base support for a two-piece can for use in a pressurized-beverage pack, comprisingA. providing a planar blank of flat-rolled sheet metal having tensile strength above a selected level,a circular-configuration cut edge of predetermined diameter, anda substantially uniform starting thickness gauge throughout such planar sheet metal blank area;B. draw forming such flat-rolled sheet metal blank into a shallow-depth cylindrical configuration one-piece drawn cup having a closed end and an open end with a centrally-located axis extending therebetween,(i) a substantially-planar circular configuration endwall, of predetermined diameter at such closed end, in which sheet metal is at such preselected starting gauge,(ii) a cylindrical-configuration sidewall in which sheet metal gauge does not exceed such preselected starting gauge, withsuch sidewall sheet metal extending toward the open end of the drawn cup in symmetrical relationship to such centrally-located axis, and(iii) a unitary juncture, extending between such planar endwall and cylindrical-configuration sidewall at the closed end of such cup, in which sheet metal does not exceed such preselected starting gauge; then,after completion of such cup sidewall,C. preforming a bead, having a circular-configuration in plan view, in such cup endwall, by(i) selecting tensile strength of such sheet metal such that preforming such bead pulls sheet metal from such sidewall into such endwall producing a uniformly axially-recessed bead internally of such drawn cup, with(ii) such endwall and such circular configuration bead, as formed, being substantially free of decrease in thickness gauge of sheet metal, and with(iii) such circular-configuration axially-recessed bead being preformed:to have a predetermined diameter, and so as to be predeterminedly located uniformly spaced radially-inwardly from a projection of such cylindrical-configuration sidewall onto a plane defined by such planar endwall of such drawn cup; thenD. directing such drawn cup, with such predeterminedly-located axially-recessed bead, into bodymaker apparatus having a single elongated plunger for carrying out redrawing of such cup and sidewall ironing in a single work stroke forcarrying out redraw of such drawn cup in such bodymaker apparatus to form a circular configuration redrawn cup of decreased diameter and increased height with respect to such drawn cup, by(i) positioning such single elongated plunger of such bodymaker apparatus to project axially inwardly internally of such drawn cup,(ii) locating clamping ring means coaxially with respect to such plunger internally of such drawn cup, and(iii) locating redraw die means externally of such drawn cup; withsuch bodymaker plunger, as projecting axially inwardly within such drawn cup, presenting:(a) a cylindrical configuration outer wall of predetermined diameter establishing such predetermined internal diameter for both such redrawn cup and such can body being prepared for assembly of a two-piece can, and(b) closed-end shaping tooling, disposed internally of the drawn cup, to project in confronting relationship to such drawn cup endwall on its internal surface;E. symmetrically disposing such internal closed-end shaping tooling coaxially with such centrally-located axis of such drawn cup, so as to present(i) an axially protruding portion having a nose-like configuration in a radially-oriented cross-sectional plane which includes such central axis,such axially protruding portion presenting:(ii) a distal end of circular configuration in plan view for defining such base support, for such pressurized-beverage can pack, in such can body being fabricated, and(iii) a surface which is disposed radially outwardly of such distal end, in such cross-sectional plane,such circular-configuration distal end within such nose portion diameter presenting a concave dome-shaped curved surface for confronting the endwall surface internally of such drawn cup,such dome-shaped curved-surface being symmetrical in plan view with respect to such centerline axis of such distal end;F. preselecting diameters of such circular-configuration preformed bead and such circular-configuration distal end of such internal closed-end shaping tooling such that the distal end internal tooling contacts such drawn cup endwall surface radially inward of, and contiguous to, such axially-recessed bead at a location where sheet metal of such recessed bead returns to a substantially-planar configuration end wall panel of circular-configuration located radially inwardly of such bead;G. (i) carrying out redraw of such drawn cup in such bodymaker apparatus by decreasing endwall diameter of such drawn cup and increasing sidewall height,(ii) producing a unitary redrawn cup having an open end and closed end and a decreased-diameter cylindrical configuration sidewall of increased height in relation to such first drawn cup sidewall which is symmetrically disposed with relation to a centrally-located longitudinal axis extending between such open end and closed end, while(iii) locating such internally-disposed closed-end shaping tooling so as to enable buckle-free unfolding of sheet metal of such recessed bead during forming of a diameter-decreased redrawn cup sidewall in such bodymaker, and in which(iv) such unfolding bead sheet metal extends, in angled relationship to such central axis, from contact with such closed-end axially-protruding circular-configuration distal end toward such redrawn cup sidewall,(a) an axially-directed component directed toward such open-end of the redrawn cup, and(b) a radially-directed component directed toward such redrawn cylindrical sidewall for contact with such redrawn sidewall at a location contiguous to such closed end; with such redrawn cup presenting:a substantially-planar closed endwall panel located radially inwardly of contact of such circular-configuration distal end of such redrawn cup, anda cylindrical sidewall having an internal diameter substantially equal to such predetermined internal diameter cylindrical sidewall for such can body being prepared for assembly of such two-piece can; then, whileH. maintaining positioning of such internally-disposed closed end shaping tool with its centrally located axis coextensive with such centrally located axis of such bodymaker redrawn cup,I. ironing sidewall sheet metal of such bodymaker redrawn cup to a can body of desired height, bypassing such redrawn cup, while mounted on such single elongated bodymaker plunger, through sidewall ironing ring means of selected internal diameter less than such diameter of such bodymaker redraw die cavity and greater than the external diameter of such bodymaker plunger, and then,after such ironing step is completed, andsuch ironed sidewall is free of such ironing ring means,J. finishing shaping of such closed end of such ironed-sidewall can body by:providing for solely axial movement of externally-mounted closed end shaping tooling, including(a) shaped-surface tooling for such sheet metal extending radially outwardly in angled relationship from such endwall contact with circular-configuration distal end contact toward such sidewall, and(b) profiling tooling presenting a uniformly-curved convex dome-shape, havinga circular-configuration periphery which, as disposed in an axial direction, is radially inwardly and contiguous to such curved surface at such circular-configuration distal end of such internally-disposed tooling, with suchaxial relative movement of such externally-mounted closed-end shaping tooling establishing contact with such substantially-planar closed endwall panel sheet metal, on its external surface, so as to form such sheet metal of such planar endwall panel into a concave dome of uniformly-curved configuration disposed radially inwardly of such circular-configuration distal end diameter,such shaping of the substantially-planar closed endwall panel sheet metal of such ironed sidewall can body taking place while such ironed sidewall is free of any contact with such ironing ring means, so as to provide for(i) facilitating movement of sheet metal, from such ironed sidewall into such closed end of such ironed sidewall work product,(ii) diminishing ironed sidewall adhesion with such bodymaker plunger, and(iii) conforming such closed end configuration of such sidewall-ironed can bodyto such externally-mounted closed-end shaping tooling, includingsuch bodymaker plunger closed-end shaping tooling.