Device for collecting yarns on conical reels with compensation of the fluctuations of the yarn take-up speed

#1. Description of Related Art

#The present invention refers to the collection of the yarn produced or processed by textile machines to be wound onto reels. In industrial practice, the technique generally adopted is that of collecting the yarns by rotating a tube, carried idle by the spindles of a reel-carrying arm and taking up the yarn arriving from a feeding organ to wind it onto itself. The reel is thus formed by pulling and winding the yarn onto its surface, being rotated in turn with a driving roller underneath; the reel rests on this and winds the yarn at a substantially constant linear speed, irrespective of the dimensions assumed by the reel as winding proceeds, and depending only on the rotating speed of said driving roller. The yarn is thus wound in spirals onto the rotating reel and distributed with a backward and forward movement on its surface by a thread-guiding device.

#For most of the subsequent uses of the yarn wound onto the reel in downstream processes, it is necessary for the reel to be conically shaped, this is typical when it is required to unwind the yarn axially from the fixed reel, placed on creels or similar supports.

#To illustrate more clearly the characteristics and the advantages of the present invention, it is described with reference to some of its typical embodiments shown in the figures from 1 to 5, as an example without limitation.

#These figures refer to an embodiment of the device according to the invention for collecting the thread produced by an open-end spinning machine, of which is shown only the system of the yarn extraction roller, to illustrate the characteristics and the benefits deriving from the present invention.

#FIG. 1 indicatively illustrates the trend of the pulsating take-up speeds of the conical reel in every point of the transverse stroke of the thread guide, to highlight the problem to be tackled.

#FIGS. 2 and 3, respectively with front and side view, illustrate the yarn collecting device in the path from upstream to downstream, from the outlet of the open-end spinning machine to the wound conical reel.

#The open-end yarn 1 comes from below and is fed to the collecting device above by a pair 2 of extraction rollers. Generally one of this pair of rollers is a drive roller activated with a constant speed and the other is an idle counter-roller. They grip the open-end yarn between them and feed it at a predetermined constant speed, extracting it from the spinning rotor. If the yarn 1 is picked up by the device above at an instantaneous linear speed higher than that of the rollers 2, it is clear that there will be some inconveniences anyway; if there are no remedies for this discrepancy in speed and for compensating the increased take-up by the reel, the thread will break when the take-up exceeds the stretching allowed by the elasticity of the thread itself.

#From the rollers 2 the yarn 1 goes up, passes over a transmission roller 3, and continues on its route, passing through the thread presence sensor 4, inserted under a plate 5 which supports it, corresponding to its V-shaped insertion slot.