Patent ID: 8567224
Filing Date: 2013-10-29
Classification: B21D

Abstract:
1. A method of forming a stretched metal workpiece having a reinforced terminal wall comprising the steps: providing a die body defining a first longitudinal axis, and a complementary cylindrical drawing punch defining a second longitudinal axis; orienting a planar metal blank orthogonal to said first longitudinal axis; constructing a first annular wall transitioning immediately to a closed end orthogonal to said first longitudinal axis by stretching said planar metal blank against said die body along said first longitudinal axis; forming an intermediate opening in said closed end circumscribed by a second annular wall extending radially away from said first annular wall by removing a portion of said closed end; and folding said second annular wall against said first annular wall to form said reinforced terminal wall by moving said complementary cylindrical drawing punch against said second annular wall along said second longitudinal axis collinear with said first longitudinal axis.