Crosswinding bobbin winder and process for the handling and control of the yarn in a crosswinding head of a crosswinding machine in bobbin doffing operations

Abstract

The invention relates to a device and a process for the handling and control of the yarn (1) in a crosswinding head of a crosswinding machine in bobbin (2) doffing operations, said crosswinding machine being equipped with a series of crosswinding heads and at least one service trolley (13), in which the yarn (1) run is moved to a definite position, near the end portion of its course from the pirnto the bobbin (2) and the yarn (1) is subsequently drawn from a handling device (12) of the service trolley (13), cut and, after removal of the bobbin (2), its end coming from the pirn, is arranged on a new winding tube.

Description

technical field [0001] The present invention relates to an apparatus and method for automatic doffing in a cross-winding winder; or such an apparatus and method for replacing bobbins reaching a predetermined size with new bobbins, from a yarn feed The yarn from the bobbin is wound on this new bobbin to form a new bobbin. Background technique [0002] It is known that the procedure for bobbin formation basically comprises the following steps: the unwinding operation of the yarn from the feed bobbin, the removal of possible defects of the yarn, and the cross-winding of the yarn on the bobbin, the winding of the yarn. Form and size vary according to the purpose of the yarn. If the yarn is destined to be fed to a high-speed machine, the bobbins are generally cylindrical, or frusto-conical with a slight taper, and conversely, if the yarn is destined to be fed to a low-speed machine, the bobbin is highly tapered Frusto-conical. The taper is chosen so as to ensure correct unwind...

AI Technical Summary

Problems solved by technology

In the described way, the intervention of the auxiliary trolley is facilitated according to the disclosure of the patent of Murata, since it is not necessary to extend the arm of the auxiliary trolley excessively, but the efficiency of the yarn exchange between the two suction nozzles is not guaranteed to be sufficiently successful , because the yarn exchange between the suction nozzles is by stopping the suction of the suction nozzle on the bobbin side, and this allows the suction nozzle on the bobbin side to suck the yarn end, considering the rather long The yarn has been engaged by the suction nozzle on the bobbin side, which can thus hinder the suction action of the suction nozzle on the bobbin side

This possibility of errors in the delivery of the yarn is highly undesirable, as it can jeopardize the restart of the crosswinder, thus producing a loss of production

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