Method and device for the constant-tension feed and take-up of a yarn fed to a textile machine

Abstract

A device for controlling the feeding of yarn (2) into a textile machine (3) which intermittently consumes the yarn in successive discrete time periods, said Broken from periods in which the yarn is at rest and not used for the production of textiles, said yarn is withdrawn from a bobbin (B) and fed into the textile machine (3) at its own speed, said device Provided are: a sensor device (16) for detecting the tension of the yarn (2) and a device (5, 12, 13) for measuring and changing the yarn speed, the sensor device (16) and the measuring and changing device ( 5, 12, 13) are all connected to a control and adjustment device for said tension and speed parameters, said control and adjustment device continuously measuring said two during the feeding of yarn (2) to the textile machine (3) parameter value, thereby acting on the speed changing device (5) to change the tension of the yarn (2) when needed. The speed changing device is a rotating element (5), which is connected to the textile machine. The conveyed yarn (2) contacts or is wound at least once around said rotating element, said rotating element (5) being driven by its own drive controlled by a control and regulating device, characterized in that, The rotating element (5) can be moved in a controllable manner in two opposite directions of rotation, in a first direction when the yarn (2) is fed into the textile machine and in a first direction when the yarn (2) is fed into the textile machine. The rotational element moves in a second rotational direction when the thread is in a resting state, that is, during each period of time when the yarn is not used, the second movement enables the yarn (2) to be pulled and wound to on the rotating element (5) to prevent its accumulation on the corresponding textile machine, during the feeding of the yarn to said textile machine and when the taken-up yarn is at rest or is re-wound on the rotating element (5) , the yarn tension is maintained at constant tension (T, R).

Description

technical field [0001] The present invention relates to a device for feeding yarn into a textile machine which consumes yarn in an intermittent manner, i.e. the yarn is used in successive periods of time which are separated by a number of Where the time periods in which the textile machine is not using the yarn are spaced, said yarn feeding being performed at constant tension, said device is of the type described in the preamble of the independent claim. [0002] The invention also relates to a yarn control method implemented by the above-mentioned device. Background technique [0003] Devices for controlling the feeding of yarn at constant tension into textile machines are already known. In general, these devices consist of a yarn tension sensor connected to a measurement and processing circuit capable of controlling an electric motor (such as a stepper motor or a brushless motor) on a closed-loop basis. motor) which feeds the yarn under constant tension by braking or acc...

AI Technical Summary

Problems solved by technology

This is due to dust and yarn debris collecting on the take-up arms which prevents them from moving properly (as they do not slack down)

Moreover, since said take-up arms cannot be finely adjusted for the force they exert on the yarn, they cannot ensure a good take-up of the yarn controlled by them, especially due to the high production flexibility and Yarn type

[0011] Finally, there is the disadvantage that said tension take-up devices are often not able to stop the textile machine if the yarn is not completely and completely gone, in which case if the yarn breakage is located downstream of the take-up device, then For thick and fuzzy yarns it will probably also come into contact with the take-up device so that there will not be enough yarn slack for the take-up device to stop the loom

[0012] Moreover, the known "constant tension" yarn control devices are not used in this type of textile machines, nor can they be used in them, because their existing structure and mode of operation make in some cases false signals, each The yarns controlled by them for the first time will stop running, which will cause obvious inconvenience

In other cases, known devices of the type mentioned above will prevent the gathering or relaxation of the yarn in the textile machine, which requires the machine to have mechanical elements or take-up; if this take-up is not carried out, it will lead to unacceptable work question

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