The present invention relates to a device for adjusting the tension in the saw chain of a chain saw. The device comprises a clamping means, a tensioning means in the form of a rotatable cam, and elongate rod which interacts with the rotatable cam at a first end, and a blade, upon which the saw chain is driven, at a second end. The chain is driven by a sprocket and rotation of the cam causes the elongate rod to longitudinally extend or retract, relative to the sprocket, to adjust the tension in the saw chain. The present invention also relates to a chainsaw including such a tensioning device. |