This application discloses a novel process in the manufacture of two-piece metal cans and the like wherein a predrawn cup is produced at the mill rather than by the can manufacturer. The predrawn cup is flanged and tapered. The predrawn cups are stacked in nested relation and a plurality of stacks are packaged at the mill for shipment to the can manufacturer. The can manufacturer then need only redraw and wall-iron the cups and trim, flange, wash and decorate them in order to complete the manufacture of the can. By this procedure scrap loss to the can manufacturer is avoided, making it also easier for a manufacturer to enter the can manufacturing business with less capital investment.
A nestable can and method of manufacture is described wherein a blank cut from sheet metal stock is drawn into a tapered die with a tapered drawhorn to form a first stage cup having a bottom, a tapered cylindrical sidewall and a peripheral flange. Care is taken to avoid coining of the sidewall in the first stage of manufacture. The partially formed can is then reformed by expanding the sidewall while maintaining its taper, thereby removing wrinkles and forming a second stage cup having smooth interior and exterior sidewall surfaces. The nestable quality of the cup is dependent upon a novel profile created while reforming the first stage cup. In that operation the upper end of the cup is reshaped to form an upper rim that is offset from a tapered sidewall and having convex contact surfaces that support one cup within another. The location of the contact surfaces is such that adjacent sidewalls of two nested cups are spaced apart by at least 0.0015 inch, the peripheral rims being vertically spaced by at least 0.140 inch to facilitate cup separation.
In a method for the manufacture of substantially cylindrical pressurized or liquefied gas tanks first and second portions deformable to open-ended cylindrical shape are stamped out of a same metal sheet, the cylindrical portions then being welded together by their free edges which mated in the sheet. A machine for automatically carrying out the method comprises means for stamping, shaping and assembling the portions.
A method and apparatus for forming nestable two-piece containers includes forming a cup from a metal blank; redrawing the cup thus formed to approximately one-half its final height while imparting a tapered sidewall thereto by use of a tapered die center; redrawing the container thus formed to its full height while continuing the taper by use of a second tapered die center while simultaneously profiling the bottom of the container thus drawn. The apparatus includes at least two redraw stations, each including a tapered redraw die center and corresponding die. The second of said stations also includes bottom profiling tooling.
A method of forming a drawn and redrawn container body which includes forming an inwardly projecting annular bead in the end wall of a drawn cup to be redrawn in order to prevent wrinkling in the end wall when it is subsequently formed into a pressure-resistant profile.
An installation for making and treating cans of metal, in which the individual working operations such as deep-drawing, ironing, trimming of the can rim and the forming of the can bottom, the washing, drying, inside coating and decorating the cans as well as the necking of the can rim and the flanging are carried out in individual working stations which are interconnected by a conveying device that feeds the raw cans in a predetermined rhythm and arrangement and in a predetermined spaced relationship to each other to the individual working stations.
