Patent ID: 6446337
Filing Date: 2002-09-10
Classification: F28F,Y10T

Abstract:
A method of forming slots in a sheet of material having a cladding layer on at least one surface, comprising the steps of:pre-forming the material by forming depressions in the sheet, each of the depressions having a bottom wall having the approximate dimensions of a desired slot, each of the depressions also having sidewalls with the cladding thereon, the sidewalls extending from the bottom wall to the sheet which has not been pre-formed, each of the depressions also having end walls with the cladding thereon, the end walls extending from the bottom wall to the sheet which has not been pre-formed, the end walls extending between the side walls; and removing the entire bottom wall of the depressions in a piercing operation without deforming the sidewalls, forming a slot in the sheet where the bottom wall was, and leaving the slot with clad sidewalls and clad end walls.