Extendable shaft

摘要

An extendable shaft includes a first and a second shaft sections aligned on the same axis. External splines on an outer periphery of the first shaft section engage external splines on an inner periphery of the second shaft section. The first shaft section includes a slit extended from an opening end thereof for a predetermined length along an axial direction. A diametrically contractible portion adapted for elastic reduction in diameter is provided in a region ranging from the opening end of the first shaft section to place away therefrom by the predetermined length along the axial direction. A thin-wall portion is formed in a part of the diametrically contractible portion. A clamping member elastically clamps the diametrically contractible portion.