The present invention relates to improvements in or relating to chain saws. In particular, it relates to chain saw switching mechanisms. We describe a chain saw comprising a run-down brake function and a kick-back brake function, wherein the kick-back brake function is provided by a switchable one-way directional drive assembly, characterised in that the switchable one-way directional drive assembly also acts to provide the run-down brake function. A cutting chain is carried on a chain bar and driven by means of a chain sprocket rotated by a prime mover through the switchable one-way directional drive assembly. Suitably, the switchable one-way directional drive assembly is a freewheel or clutch mechanism; preferably a wrap-spring clutch arrangement. |