| 摘要 |
PCT No. PCT/DE86/00459 Sec. 371 Date Jul. 10, 1987 Sec. 102(e) Date Jul. 10, 1987 PCT Filed Nov. 12, 1986 PCT Pub. No. WO87/03310 PCT Pub. Date Jun. 4, 1987.For piecing to a spinning device operating with a pneumatic torsion element, yarn is fed back through the torsion element into a readiness position alongside a drafting mechanism, while the roving is stopped before the end of the drafting zone. The roving is then released, whereby the forward roving end which is leaving the drafting mechanism, and which typically is rendered unsuitable for piecing due to stoppage of the roving, is sucked off. When a roving segment which remained in the drafting mechanism during the prior roving stoppage has been taken away, the roving and the yarn end are brought together and are simultaneously fed to the torsion element so as to be combined. To carry out this process, the drafting mechanism preferably includes before the end of its drafting zone at least one roving stopping device which may be controllable with feedback from a yarn monitor located adjacent the path of yarn being conveyed to a yarn take-up mechanism, such as a bobbin. Furthermore, a suction nozzle can be selectively situated and activated between a pair of exit rolls of the drafting mechanism and the torsion element, for removing controllably the forward end of a roving rendered unsuitable for piecing by stoppage of such roving. |
