US Patent 7320239 Forming tool for multiple-thickness blanks

An apparatus for forming blanks having two thicknesses separated by a blank step includes a forming tool defining a binder surface that is characterized by a tool step, a first region on a first side of the tool step, a second region on a second side of the tool step, and a bead segment having a surface contiguous with the second region. The bead segment is configured to pinch material from a blank into any gap created between the tool step and the blank step caused by misalignment of the blank in the tool, thereby ensuring an effective seal to form the blank against a forming surface.