| 摘要 |
<p>An air vortex spinning unit (3) is fed with sliver from a drafting system (4) through feed (11) and take-off (5) roller pairs driven by a motor (25). To piece up after an end break, yarn is pulled back from the package (23), the end joined to the sliver and quickly drawn forward again to commence spinning. The nip rollers (14, 29) are kept open while the motor (25) is accelerated and then closed rapidly at a set speed. Subsequently the other drive motors (26, 27) are started in a specified sequence. An independent claim is also included for an air vortex spinning arrangement including drives (25, 26, 27) and controller (28) to provide sequential start up of motors (25, 26) to a reduced intermediate speed and closure of the nip rollers (14, 29) before the second motor (26) is started. The nip rollers can have an intermediate position just before closure to give a rapid action. The third motor (27), which drives the wind-up, is started last and any yarn speed discrepancy during acceleration to spinning speed is taken up in a storage loop (24) supported by compressed air.</p> |
