BLANKING AND FORMING TAPERED WALL ARTICLES

摘要

Elongated, thin wall shells are formed from substantially circular blanks cut from sheet material by steps including providing a blank in a blank holder on a die having an effective entrance and exit aperture, the entrance aperture having an extent substantially commensurate in size with the size of the blank to be drawn, the die having a cavity, the wall of which converges inwardly from the entrance aperture to the effective exit aperture. The wall connecting the entrance and exit apertures is defined by an arc of a sector of a circle, the sector having an angle in the range of 12 to 34.degree.. The thin wall shell is formed by displacing the blank through the die by action of a punch.