| 摘要 |
<p>The present invention relates to a chain saw comprising a chain arranged on a saw flange or guide bar (5). The chain saw is usually arranged in a multi-purpose head of forestry machinery by a mounting flange (1) immobile in regard to the multi-purpose head, whereby the chain is rotated by a chain wheel (4) controlled by a power unit. In order to tighten the chain, the saw flange, or a relevant part of the chain saw comprising the same, is arranged to move parallel with the longitudinal axis (A) of the saw flange in regard to the chain wheel. This is achieved by a tightening device and at least one supporting guide therein which are attached to the mounting flange of the chain saw or a structure arranged therein. By arranging the supporting guide in the tightening device to extend onto both sides of the centre of the chain wheel parallel with the longitudinal axis of the saw flange, the saw flange is made to move in a completely supported manner parallel with its longitudinal axis in regard to the chain wheel. <IMAGE></p> |
