Patent ID: 6266882
Filing Date: 2001-07-31
Classification: B21D,F28F,Y10T

Abstract:
A method for manufacturing a heat exchanger with a plate-fin design having a plurality of fin collars, wherein each of the fin collars having an elongated fin portion, a contact leg, a transition portion connecting the contact leg and the fin portion, and a curved contact leg tip, comprising the steps of:providing a tube and fin stock;forming a button in the fin stock;piercing the fin stock and forming a first working collar including a pre fin portion and a pre-contact leg having a first end with a tip;extruding said first working collar and substantially straightening said pre-contact leg;abutting said tip against a shoulder of reflaring tooling;finally straightening said pre-contact leg by pushing said pre-contact leg into said reflaring tooling and against said shoulder for forming the contact leg with a straight tube-contact portion and a curved tip portion, the contact leg having a collar leg height and a collar contact height; andexpanding said tube to form an interference fit with the fin collars for attaching the plurality of the fin collars to said tube.