Abstract: In a collapsible steering shaft a collapse load is decreased while assuring the heat resistance of a coupling portion between an outer shaft and an inner shaft. In addition, a time during which a great collapse load is needed is also decreased. Female serration grooves on an inner surface of the outer shaft are engaged with male serration grooves on an outer surface of the inner shaft. A recess is formed on the outer surface of the inner shaft and is aligned with a root in the male serration grooves, and a steel ball is set in the recess. A part of this steel ball intrudes into a top part of a thread in the female serration grooves. A flat portion is formed by removing a part of the male serration grooves, whereby the top part crushed by the steel ball can be prevented from frictionally engaging with the male serration grooves.

Abstract: An energy absorbing member is constructed of a main body including a base and a belt portion having first and second folded portions and an interconnecting plate welded to the main body. A middle portion of the belt portion is confined between an upper surface of the base and a lower surface of the interconnecting plate. Thus, the energy absorbing member itself provides two surfaces for guiding the belt portion. Assembly of a shock absorbing steering column apparatus is thereby facilitated and a compact apparatus can be realized.