| 摘要 |
A cutting attachment for a chain saw which substantially reduces the problems of kickback, lubrication and maintenance, is described. The attachment comprises a guide bar, a saw chain and a drive sprocket. The guide bar is smoothly and symmetrically convexly curved along both its longitudinal edges with a first radius of curvature and is provided with a nose portion with a second and smaller radius of curvature. The edge of each of the cutter and balancing links in contact with the bar is provided with two curved surfaces, one surface having a radius of curvature corresponding to the radius of curvature of the nose portion of the bar, and the other surface having a radius of curvature corresponding to the radius of curvature of the longitudinal edge of the bar. The height of the cutter links is chosen in relation to the length of the cutter to prevent rearing of the cutter links. The depth of the groove in the bar is made equal to the depth of the drive links, to provide a zero clearance between the bottom of the groove and the lowest point of the drive links. The chain oil hole is positioned in the bottom groove and sloped to inject oil in the direction of chain motion. The size of the oil hole is reduced to prevent clogging during cutting and to inject oil directly onto the chain links.
|
