Patent ID: 6672121
Filing Date: 2004-01-06
Classification: B21D,Y10T

Abstract:
A method of forming an integral hem flange on an aluminum alloy sheet panel, said method comprisingforming an aluminum alloy sheet into a panel of desired configuration with fluid pressure against a forming tool, said panel being intended for assembly with a separately formed second panel and attached to said second panel at least in part by said hem flange; and during said forming of said sheet panel, forming said hem flange by bending a portion of said sheet over a portion of said forming tool, said portion of said tool having a radius no larger than about four times the thickness of said sheet before forming, to form a bend the length of said hem flange, and stretching the portion of said sheet in the bent material adjacent to said bend to form a hemline along and adjacent to said bend, the thickness of said hemline being less than the thickness of adjacent sheet material in said flange.