| 摘要 |
A foliage trimmer has a housing centered on an axis, rotatable thereabout in a direction, and formed with a radially open eye. A spool rotatable in the housing carries a supply of a cutting line having a free end extending from the housing through the eye thereof. The spool has an outer periphery formed with at least one radially outwardly open recess or notch. A latching pawl has one end pivoted in the housing adjacent the eye about an axis parallel to the housing axis and an opposite end radially engageable in the notch and angularly offset from the pivoted end relative to the housing rotation direction. This element is displaceable as described above between an inner position with the opposite end in the notch to inhibit rotation of the spool and an outer position with the opposite end clear of the notch and the spool being rotatable. The line passes radially outward around the opposite end and radially inwardly engages same. A drive motor rotates the housing in one direction about the axis to extend the free line end radially from the eye and for urging the opposite end centrifugally outward by direct action of centrifugal force on the opposite end and for urging the opposite end radially inward by centripetal force tightening the line and pressing it radially inward against the pawl. Alternately the notch has relative to the direction a downstream flank facing at least partially radially inward. Rotation of the head urges the opposite pawl end radially inward by camming action of the notch flank against the opposite end.
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