Seat frame structure and method for forming

摘要

The present invention provides a method of forming a transversely extending passage through a tubular seat frame for receiving a headrest guide tube and includes the steps of: (i) forming first and second diametrically opposed axially aligned openings through the tubing; (ii) flowing metal from around the first opening through the tube and through the second opening while expanding the first opening to form at least part of an inner wall of the passage; (iii) flowing metal from around the second opening outwardly from the tube while expanding the second opening to form an outer wall of the passage extending about the inner wall.