Abstract: For motor-driven chain saws, there is the danger that the chain saw will be kicked back if the reaction forces suddenly increase intensely in response to the forward thrust. This kickback effect and the danger of accident associated therewith are intended to be reduced by means of a special configuration of the saw chain. The saw chain has drive links which have an approximately triangular shape and which engage the tooth gaps of the nose sprocket with inclined flanks. The drive links are configured to be asymmetrical with respect to a partition line running between the two pivot axes of the link so that the forward flank angle is greater than the rearward flank angle referred to the partition line. The two flank angles together are greater than the opening angle of the V-shaped tooth gap of the nose sprocket.

Abstract: 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.

Abstract: 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 saw chain 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 of the saw chain which engage into 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 .alpha. of the cutting teeth is reduced.

Abstract: This disclosure is directed to a saw chain sharpener for a motor-driven chain saw having a guide bar assembly that includes a guide bar and a saw chain guidingly mounted thereon. The saw chain sharpener includes an elongated chain guard casing for removably receiving the guide bar assembly therein. The chain guard casing defines a cavity in the forward end thereof adjacent the nose of the guide bar. A sharpening device is mounted in the cavity for sharpening the saw chain whereby the device is contained within the casing.

Abstract: The invention is directed to a saw chain for a motor-driven chain saw which includes cutting links, side connecting links, driving links and safety links. Each safety link has an upper edge defining a wave-like contour that prevents chips from accumulating during the cutting action. The cutting links and safety links of the saw chain are arranged with respect to each other so that overlap is avoided between the tail end of the rearward projection of the safety link and the forward projection of the depth limiter of the cutting tooth. This affords the advantage that cutting chips do not become jammed therebetween.