| 摘要 |
<p>A lawn and bush cutting device comprises a housing (1) mounted for rotation about an axis with a drive shaft (11) fixed to the housing and drivable by a motor for rotating the housing. A wire cylinder (27) is coaxially mounted in the housing and can be held fixed with respect to the housing (1) for rotation therewith. A supply of cutting wire (F1-F2 ) is wound on the wire cylinder, or on a reel rotatably fixed to the wire cylinder. A length of the wire (F1-F2) extends out of the housing (1) to act as a cutting tool when the housing rotates. A sleeve member (33) is axially movable in the housing and has helical coupling piece (35) which are coupled to helical piece in the cylinder (27). Axial movement of the sleeve (33) thus causes relative rotation between the wire cylinder (27) and housing (1), thus paying out additional lengths of wire from the housing. A ring (23) is axially movable but rotationally fixed to the sleeve (33) and can be moved downwardly by cable operated member. The ring has recesses which engage projections of the sleeve member so that, with the ring lowered, the sleeve member is engaged and can be forced further downwardly to cause relate rotation between the wire cylinder and the housing. The ring also includes teeth which engage the cylinder for holding the cylinder rotationally fixed with the shaft when the ring is disengaged from the sleeve member, and for disengagement from the cylinder when the ring is engaged with the sleeve member.</p> |
