| 摘要 |
<p>During piecing on an open-end spinning machine the yarn has to be accelerated suddenly and to provide the necessary friction, the nip roller (12b) of the draw-off roller pair has a rubber surface. To extend the roller life, the yarn is moved by a yarn guide (18a) to a different part of the roller surface. The motion is performed by a traverse drive mechanism (19) at every operation of the nip roller. An independent claim is included for the corresponding equipment to move the yarn. This can involve a reciprocating guide (18a) or alternatively, a drive to move the position of the nip roller (12b). The nip roller action can be assisted by a pneumatic cylinder. The traverse drive can be taken from the rotation of the nip roller or it can be an independent drive. The rubber surface of the nip roller can be structured, e.g. ribbed.</p> |
