Metal containers and their manufacturing method and apparatus

摘要

A cylindrical metal container with a relatively large holding capacity has triple seams having a vertically long, generally elongate rectangular cross section, the top and bottom parts of the seam having a convex substantially semi-elliptical or semi-circular profile. The outer face of the seam bulges outward adjacent its top, or its top and bottom, and the middle part between the top and bottom constitutes a pressed groove between the top and bottom and substantially parallel to the axis of the container. The body and end plate flanges are held in strong and direct contact with each other, overlapping each other in the center of the seam. A sealing compound is sealed in a void left between the edge of one flange and the curved portion of the other flange. The seam is formed by nip-bending the edge of the end plate flange with the first (entry-side) corner of a forming groove in a nip-bending and press-forming roll, seaming together the body and end plate flanges with the forming groove in a seaming roll, then, upon completion of seaming, press forming the seam thus formed into a desired shape with the forming groove in the afore-mentioned nip-bending and press-forming roll. A special nip-bending recess is provided at the first or entry side corner of the forming groove in the nip-bending and press-forming roll.