| 摘要 |
<p>In a scrub-clearing tool, of the type comprising a tube (2), a blade (3) supported for rotation at one end of the tube, a motor (3a) for driving the blade (3) and a transmission shaft for connecting the drive motor (3a) to the blade (3), a disc (6) is provided for protecting the blade and is mounted for rotation on the shaft of the blade (3) with the interposition of a bearing (16). The protective disc (6) has a diameter larger than the outer diameter of the blade (3) and has a plurality of recesses (7) around its periphery, the inner edges whereof are spaced from the centre of the disc by a distance less than the radius of the outer circumference of the blade (3). The protective disc (6) is normally rotated together with the blade (3). It stops when it comes into contact with the ground or with some obstacle, whilst the blade (3) can continue to rotate by virtue of the presence of the bearing (16). The disc (6) therefore protects the blade (3) from impacts with obstacles, protects the operator from accidental direct contact with the blade (3), and finally prevents the cutting of woody stems of a diameter greater than the width of the recesses. In fact, larger stems cannot penetrate these recesses (17) and hence are not cut by the blade.</p> |
