Cutting chain for a hand-operated implement and a hand-operated implement

摘要

A cutting chain 10 for a hand-operated implement for cutting metal and mineral materials has central links 44, 46 connected to one another by lateral links 42. The central links comprise first central links 44 which each have a drive tooth 45, and second central links 46 which may have a volume and surface area smaller than the volume and surface area of the first links by at least 25%. The drive teeth of the second central links 46 are shaped or spaced differently to those of the first links, or are not present. The cutting chain 10 is driven around the periphery of a guide bar 9 by a drive sprocket 24, the guide bar having a nose sprocket 53, around which the cutting chain passes. The nose sprocket 53 has first area 70 comprising a first recesses 54 in which the drive teeth 45 of the first links 44 are adjacent to and engage with. The nose sprocket 53 further comprises a second area 71 which the second links 56 area adjacent to and a blocking contour 55 which prevents the first link 44 drive teeth 45 from fully engaging. The first and second areas 70, 71 may extend over approximately identical angles, and the nose sprocket may have at least two second areas. The drive sprocket 24 may have the same circumferential features as the nose sprocket 53. The sprocket is intended to prevent an incorrect cutting chain from being fitted to the cutting implement in error.