Patent ID: 6402862
Filing Date: 2002-06-11
Classification: B62D,C21D,Y02P

Abstract:
A method of hardening a work piece having (i) an outer surface, (ii) an inner surface which defines a passageway extending through said work piece, and (iii) an end, comprising the steps of:advancing said work piece through a first induction coil such that a first hardened area is formed on said work piece; advancing a second induction coil into said passageway of said work piece such that a second hardened area is formed on said work piece; and positioning a third induction coil adjacent to said end of said work piece such that a third hardened area is formed on said work piece, wherein said positioning said third induction coil step is performed after (i) said advancing said work piece through said first induction coil step and (ii) said advancing a second induction coil into said passageway step.