MAKING ANNULAR METAL MEMBERS

摘要

Process and apparatus for making a metal annular member of precise tolerances and desired surface finish. An external die has a continuous die surface of the configuration desired for the external surface of the metal annular member and an annular ridge surrounding the inside of the die for seating one end of an annular sheet metal blank. A first punch engages the sheet metal blank and drives it into the external die so as to reduce the external diameter of the blank and seat it against the ridge. The precise tolerance of the die surface of the external die determines both the external and at least a portion of the internal dimensions produced in the annular sheet metal blank. The first punch is axially movable to an endmost position wherein substantially all of the blank has been forced into the die. An ejector punch is positioned inside of the external die and operates to provide a portion of the forming die surfaces as well as to eject the completed workpiece.