Chain saw sharpener

Abstract

A chain saw sharpener is provided for sharpening the teeth of a cutting chain during operation of the chain saw. The sharpening system includes a housing mounted in the chain saw engine shroud and projecting both interior of and exterior of that shroud. A bushing is splined within the housing and the arbor of a grinding stone is rotatably supported in the bushing. The bushing and grinding stone are movable with respect to the fixed housing between a first position in which the grinding stone is remote from the cutting chain teeth and a second position in which the grinding stone is positioned for contact with cutting edges of the chain teeth as they travel in their fixed path around a sprocket within the shroud. A manually depressable knob is threadably engaged with the bushing and includes a stop surface engagable with the housing to define the second position of the grinding stone. The positioning of that stop surface with respect to the housing is adjustable by the threaded engagement of the knob with the bushing. A chosen position is maintained by a free-floating detent member disposed around the bushing within the housing and engaging a serrated surface of the knob. The detent, and thus the knob, the bushing, and the grinding stone, are biased by a spring within the housing urging all those items toward a position in which the grinding stone is retracted from the cutting chain.

Dependencies are inferred from the claim text.