US 7,320,239 B1
Forming tool for multiple-thickness blanks
Gary A. Kruger, Troy, Mich. (US); and James G. Schroth, Troy, Mich. (US)
Assigned to GM Global Technology Operations, Inc., Detroit, Mich. (US)
Filed on Mar. 28, 2007, as Appl. No. 11/692,440.
Int. Cl. B21D 26/02 (2006.01); B21D 22/22 (2006.01)
U.S. Cl. 72—350  [72/60; 72/57] 14 Claims
OG exemplary drawing
 
5. An apparatus for forming a metal blank characterized by two thicknesses, the apparatus comprising:
a first tool defining a first binder surface;
a second tool defining a second binder surface;
one of said first and second tools defining a forming surface and the other of said first and second tools defining a pressure chamber;
said first and second tools being selectively movable with respect to one another to a closed position in which the first binder surface opposes the second binder surface to grip the metal blank; and
said first binder surface being characterized by a step, a first region on a first side of the step, a second region on a second side of the step, and a bead segment having an upper surface contiguous with the second region.