Control circuit running open=end spinning machine - compensates for slip between larger yarn package and driving cylinder

摘要

In an open-end spinning machine with a number of units, each unit comprises a turbine with a feed roller for a strand of fibres; with a winding cylinder for drawing the yarn from the turbine and winding it on to a tube; with a winding tube holder in which the tube is free to rotate; with separate drives for feed roller and winding cylinder and with couplings for transmitting the drives. Detectors are provided to gauge the amt. of yarn wound on to the tube, and there are control devices with the help of which, a timed control of the feed roller and winding cylinder can be effected, dependent upon the amount of yarn wound on, by a timed engaging and disengaging of the couplings. The detectors work so as to gauge the amount of yarn wound on as a function of the degree to which the yarn tube holder has pivoted. A shaft turns together with the detector and the winding tube holder, and the angle through which the shaft turns is detected, for pref. by means of a number of limit switches, contacted by a tappet fixed on the shaft. Alternatively a potentiometer may be coupled to the shaft. Or photo-electric cells may be positioned on the arms of the fork holding the winding tube. Arrangement overcomes the difficulties with existing systems that when a large amt. of yarn is wound on to the tube, the inertia of the package causes slip. This has the result of distorting timing intervals. The feed back of the yarn when an end is broken does not coincide with the delivery of fibres from the opener to the turbine. When the drive is reversed slip causes winding on to commence a fraction of time later. On stopping, the slip imposes excessive tension on the yarn at the nip of the draw rollers and this may cause a breakage.