US Patent 7104099 Center support punch assembly for hydroforming die

A center support punch assembly for a hydroforming die includes a center support member for fixed attachment to a die. The center support punch assembly also includes a button disposed about and space from the center support member for fixed attachment to the die. The center support punch assembly further includes a plunger movable relative to the center support member to allow fluid within a tubular member to force a wall portion of the tubular member outward against the center support member and be sheared by the button to produce an opening in the tubular member.