A metal blank or tin plate is drawn to form a cup, said cup is then subjected to ironing, trimming and flanging to produce a metallic container or can. However the final ironing is not effected at all on the upper part of the can body wall. For this purpose, a punch core is used which has the upper portion of smaller diameter and the rest portion of larger diameter, the latter constituting a substantial part of the core. The container thus produced has a thin walled center portion constituting a greater part of the body wall and a thick walled upper portion constituting a smaller part of the body wall.
A method and tool for drawing and ironing and bottom profiling a container in a single process operation is disclosed wherein the ironing does not take place during the bottom profiling operation and the precoating of the container side wall is not damaged during removal of the punch because of a specifically configured undercut portion of the punch wall.
A cup shaped stainless steel blank is deep drawn into a closed end hollow shape having a thickened bottom and a thickened rim at its open end. A ram for forcing the blank through a drawing die has a forward plunger portion and a conical body portion merging with and tapering rearwardly from the plunger portion. Axial forward thrust of the ram forces its plunger portion into the blank and pushes the latter through the drawing die, thereby transforming the blank into an elongated hollow shape having a uniform outside diameter from end to end and an inwardly projecting rim at its open end. Stripping of the elongated hollow shaped from the ram radially distends the inwardly projecting rim so that the stripped hollow shape will have the same inside diameter from end to end.
An open-ended cylindrical container body whose body wall marginal open end portion includes an annular body curl, and comprises metal less than about 0.0057 inch thick for a drawn and ironed container body, and less than about 0.002 inch for the metal foil liner of a composite container body, a method of securing a metal end closure to the curled container bodies by mechanical engagement and compression of end portion of the end closure cover hook substantially axially against the body curl, and the hermetic pressure-resistant containers formed therby.
A light-weight unitary can body for pressure packs, such as carbonated beverage containers, is produced from high tensile strength steel. Flat rolled container stock steel is double cold reduced without an intermediate anneal. This material is drawn and ironed, and a bottom profile is formed while the can body is mounted on the ironing mandrel. The bottom profile includes a rounded-bottom annular chime and recessed convex panel. Formation of the bottom profile breaks surface adhesion between the ironing mandrel and the interior of the can body facilitating removal of the can body. The open end of the can body is necked-in to accommodate a closure chime seam within the diameter of the main portion of the can body sidewall.
A deep drawn cup-shaped blank has a wall thickness substantially the same as the sheet metal blank from which it has been formed. The cup-shaped blank is subjected to a separate succession of die and punch members to perform individual forming stages one at a time to effect a decrease in the inside diameter and wall thickness of the cup-shaped blank at a working zone around the periphery of the blank. The working zone is moved along the length of the blank as the blank moves through the die. The punch member used to force the container through a die at each forming stage has an outside diameter that is smaller than the inside diameter of the cup-shaped blank being formed. Consequently, an annular gap is disposed therebetween to a point contiguous to the working zone. A fluid medium is introduced into the annular gap to effect cooling of the metal directly at the working zone. The same frequency of working stroke is effected for all of the punch members operating at each of the forming stages.
