Patent ID: 8201428

Claim:
A multipart punch for forming an aperture in a hydroformed member, comprising: a first punch segment moveable between retracted and extended positions, the first punch having one of a recess and a boss; a second punch segment having the other of the recess and the boss, wherein the boss is positioned within the recess with a clearance therebetween to allow the second punch segment to move relative to the first punch segment a predetermined amount, the first punch segment being moveable toward the extended position at least partially through the hydroformed member prior to the second punch segment moving from the retracted position; a stop restricting the second punch segment from moving away from the hydroformed member further than the retracted position; and, a ram fixed to the first punch segment and moveable relative to the second punch segment, the ram operable to move the first punch segment at least partially through the hydroformed member prior to contacting the second punch segment, wherein the first and second punch segments each include a distal end surface adapted to contact the hydroformed member, the distal ends being substantially aligned along a common plane when the first and second punch segments are in their retracted positions, and wherein the boss is clear from sides of the recess when the ram is in contact with the second punch segment.