초록 ▼

A method of hardening a work piece having (i) an outer surface, (ii) an inner surface which defines a passageway extending through the work piece, and (iii) an end. The method includes the steps of (A) advancing the work piece through a first induction coil such that a first hardened area is formed

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

대표청구항 ▼

1. 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

1. 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.