| 摘要 |
<p>With motor-driven chain saws, there is the danger that the chain saw will be thrown upwardly and rearwardly when it is applied to wood by the user with a forward thrust. Serious injuries can then occur. The invention is directed to a motor-driven chain saw which is so configured that the cutting forces are automatically reduced in response to the occurrence of excessive reaction forces so that the reaction force is immediately reduced to a tolerable amount thereby eliminating the kickback effect. The drive links engaging the nose sprocket of the guide bar are so dimensioned that they can further pivot in the tooth gaps of the nose sprocket out of their normal position and, in this way, take the cutting links with them in such a manner that the free angle of the cutting teeth is reduced. The drive links are latched in the pivoted-in position on the nose sprocket in order to assure that the cutting links will retain the position with the reduced free angle over the entire turnaround region of the guide bar. For this purpose, latches are provided on the drive links and/or on the nose sprocket.</p> |
