Guide bar fastening device for chain saw
AssigneeMakita Corporation
InventorsYoshiaki Takayanagi, Masashi Sugiyama
Life of this patent
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Abstract
To provide an operation lever including a first lever that has a base end portion swingably supported to a peripheral portion of a nut member for fastening a guide bar in a chain saw, and a second lever that is engaged with the first lever in a manner slidable in an axial direction. The operation lever can be placed in a receiving portion of the nut member with an axial length thereof shortened, and can be manipulated to rotate the nut member by being gripped on an outer end portion of the second lever in a state in which the operation lever is lifted out from the receiving portion and the axial length is lengthened. Thus, a sufficient fastening force for the guide bar can be obtained, and operability can be improved.
Claims10
A guide bar fastening device for a chain saw, comprising:
- a chain cover that covers a part of a chain saw body of the chain saw;
- a bolt member that is secured to the chain saw body and configured to penetrate through an end portion of a guide bar and the chain cover;
- a circular rotatable nut member provided on the chain cover and configured to fasten the guide bar between the chain saw body and the chain cover by rotating a central screw portion of the nut member on a screw portion of the bolt member, the screw portion protruding toward an outside of the chain cover;
- and
- an operation lever that includes:
- a first lever that extends in a diametral direction of the nut member, and that has a base end portion that is supported to a peripheral portion of the nut member, so that the first lever is swingable on a plane perpendicular to a rotation plane of the nut member;
- and
- a second lever that slidably engages with the first lever in an axial direction of the first lever, wherein the operation lever is movable between a shortened state and a lengthened state by a sliding movement of the second lever relative to the first lever, wherein
- when the operation lever is in the shortened state, the operation lever is swingingly disposed in a receiving portion of the nut member formed along the diametral direction of the nut member, and
- when the operation lever is swung out of the receiving portion and the operation lever is lengthened outward to the lengthened state, the operation lever is configured to rotate the nut member via a rotation force acting on an outer end portion of the second lever.
Dependencies are inferred from the claim text.