Patent Number: 
Section: claims

1. A method of manufacturing a container comprising:the upsetting step of placing a pressurizing platform into a ring-shaped die having a first opening at a first end of the ring shaped die and a second opening at the second end of the ring shaped die, the second opening being smaller than the first opening, and putting a metal billet into a mold composed of the die and the pressurizing platform from the first end of the die so as to pressurize the metal billet by means of a boring punch; andthe metal billet drawing step of supporting the die by means of a drum-shaped spacer and pushing the metal billet by means of the boring punch. 2. A method of manufacturing a container comprising:the upsetting preparation step of stacking a plurality of ring-shaped dies formed with an opening on its inner end portion and stacking a plurality of pressurizing platforms respectively in the dies and putting a metal billet into a mold composed of the die and the pressurizing platform;the upsetting step of pressurizing the metal billet from above the mold using a boring punch to be operated by a pressing machine;the receding step of allowing the boring punch and the whole metal billet including and the upper die to recede;the drawing preparation step of removing the used pressurizing platform and placing a drum-shaped spacer onto the next die and placing the receded whole metal billet including the die onto the spacer;the drawing step of pushing the metal billet by means of the boring punch and drawing the metal billet by means of the die; andthe repeating step of repeating the above-mentioned steps on the next pressurizing platform and die using a spacer of a length according to deformation of the metal billet.