| 摘要 |
In a cutting head for a yarn cutting device driven by an electric motor, the automatic adjustment of the yarn length effected segment-wise by means of a rotary motion between a yarn bobbin (36) and a sleeve (24) which is axially displaceable and wherein the bobbin is housed. The sleeve (44) is provided on the outside with locking tappets while the yarn bobbin is provided inside with tappets co-operating with the locking tappets. The sleeve (24) may be inserted by sliding with the hand in response to a spring force in order to press the locking by segments. A centrifugal displacement is provided for an automatic adjustment of the yarn. To this effect, at least two spherical radial slots (40) are provided between the casing part (14) and a radial extension (48) of the sleeve (24); in the spherical slots balls (44) are conducted and are pushed to the outside by the centrifugal force. The modification of the spherical slot height on an inclined plane (42) causes, upon a radial outward motion of the balls (44), the spacing apart of the two parts (48, 14), thereby causing a segment-wise unlocking. The various rotation angle segments are limited by lower, respectively upper tappets, with which co-operates a counter tappet controlled by the displacement motion and alternatingly co-operating with one tappet or the other, the segment-wise angular displacement being due to the repeated starts and stops of the motor. |
