Chain saw

Abstract

A chain saw includes a housing, a sprocket wheel which is provided in the housing for driving a saw chain, and a chain guide for guiding the movement of the saw chain. The chain guide extends out longitudinally from the housing and is movable longitudinally relative to the housing. The chain saw includes a chain tensioning device. The chain tensioning device comprises a driven member arranged on the chain guide, a driving member which drives the driven member to move the chain guide longitudinally, a rotating device rotating the driving member, a clutch device arranged between the rotating device and the driving member, and an elastic component which is disposed between the rotating device and the clutch device. The chain tensioning device presses the chain guide while it tensioning the saw chain. Thus it prevents effectively the chain guide from loosing after the saw chain is tensioned.

Dependencies are inferred from the claim text.