Patent ID: 6857304

Claim:
A bottle-shaped can manufacturing method or forming a shoulder portion and a neck portion integrally by working a bottom side of a bottomed cylindrical can formed thinner at a trunk wall than at a bottom wall by drawing and ironing a metallic sheet, comprising: a diametrically small cylindrical portion forming step of: drawing the bottom wall and a portion of the trunk wall adjacent to the bottom wall into (i) a diametrically small bottomed cylindrical shape having a diameter less than a diameter of a remaining portion of the trunk wall and (ii) a curved face of a lower part of the shoulder portion by applying pressure on a bottom corner portion with a forming pusher having an outer face shape corresponding to a shape of the curved face of the shoulder portion to be formed and a drawing die having an inner face shape corresponding to the shape of the curved face of the shoulder portion to be formed while holding the curved face of the shoulder portion with the forming pusher and the drawing die simultaneously; another diametrically small cylindrical portion forming step of: re-drawing the diametrically small bottomed cylindrical shape into a diametrically smaller bottomed cylindrical shape and holding the bottom corner portion with a blank holder having a tapered face, a re-drawing die having a tapered face, and a re-drawing punch; and a shoulder portion reforming step of: pushing and extending the shoulder portion formed by said diametrically small cylindrical portion forming steps after a diameter of the diametrically smaller bottomed cylindrical shape is substantially equal to a diameter of said neck portion by executing drawing working of the another diametrically small cylindrical portion forming step one or two more times.