Chain saw with tool-less chain tensioner and guide bar lock

摘要

A chain saw (10) includes an engine (14), a chassis (12), and a clutch cover (22). A guide bar (18) is adjustable relative to the chassis (12) and the clutch cover (22), but stationary while in a secured position. An adjustment arrangement (50) moves the guide bar (18) to tension a chain (16), and includes a member (54) operatively connected to the bar (18), intermeshed drive components (58,60,62,68,74,76) to move the bar (18) and a manually engaged member (72) that is operated without use of any tool. A guide bar securing arrangement (36) has a knob (30) rotatable between a tightened and loosened position. In the loosened position, the guide bar (18) may be adjusted. A knob handle (38) of the securing arrangement (36) is pivotable between a stowed position and an operation position. A lock arrangement (40), associated with the knob (30) and knob handle (38), includes portions (44,46) that cooperate to prevent the knob (30) from rotating when the knob handle (38) is in the stowed position.