Device and Method for Thread Positive Feeding

Abstract

The invention relates to a control unit for thread feeding devices, such as those associated with knitting machines and the like. The control unit generates pattern or switch data control signals based on a pattern memory, or otherwise, for the thread feeding devices. In an embodiment of the invention, the control unit adds to or subtracts from the pattern data any advance or lag angles as necessary to account for the structure of the machine and to thus assure effective thread feeding.

Description

FIELD OF THE INVENTION[0001]The invention relates to a control device for at least one thread feeding device of a thread processing machine, especially a knitting machine. The invention also relates to a method for positive thread feeding to a textile machine, especially a knitting machine with changing thread requirements.BACKGROUND OF THE INVENTION[0002]Circular knitting machines and flat knitting machines are known, which are designed for stitching patterned goods. With respect to patterned goods, different stitching positions must be supplied with thread intermittently rather than continuously.[0003]One example of a circular knitting machine for creating patterned goods is seen in EP 0 724 033 A1. The circular knitting machine has a cutting device in order to cut away unnecessary thread. If thread of the corresponding color is needed again, the previously cut thread is fed again to the stitching position.[0004]In addition, a so-called striping attachment for a circular knitting ...

AI Technical Summary

Benefits of technology

[0008]The goal of the invention is to present a system, as well as a method, with which thread-processing machines, especially circular knitting machines, can be fed with thread in a way that allows increased stitch quality despite changing thread requirements.

[0012]“Machine data” is, for example, a number of angular steps of the stitch cylinder or a number of other machine cycles that are executed after receiving a pattern command until the thread requirements actually change according to the pattern. Thus, the machine interpreter accesses both the pattern data memory and also the machine data memory and links these together (for example, through addition or subtraction of the advance angle or lag angle from the data of the pattern memory) and ensures that the feed wheel mechanisms are activated or deactivated at the correct point of the rotation of the needle cylinder. Instead of the access to the pattern memory, the machine interpreter can also be connected to a line that carries the pattern switching signals. Such lines are, for example, lines controlling switching elements of the knitting machine for activating or deactivating stitching positions. Thus, easily detectable control signals can be used that are used for controlling switching elements. In addition, signals of sensors that poll switching elements, needles, or other mechanical parts for executing pattern-specific actions can be used.

[0014]For a simple embodiment, the advance and lag angles can be determined beforehand and programmed by service personnel or the machine manufacturer or the feed wheel mechanism manufacturer. However, it is also possible to provide an input interface, by means of which corresponding data, for example, screen masks, can be input. It is thus possible to test certain start and stop points relative to the rotation of the machine cylinder, and in this way to optimize the quality of the stitching to be created. It has also been found to be useful to establish positive thread feeding for jacquard circular knitting machines, wherein the thread feeding is not dependent on the current thread tension.

[0015]In addition, it is possible to provide thread tension sensors for simplifying the gathering of the machine data and to monitor the thread tension in a test operating mode as well as to activate the thread feeding devices only when tension appears in the thread. The rotational angle of the needle cylinder at which the thread tension appears can be compared to the associated pattern data. The angle differences between the pattern data and the rotational angles at which tension appears in the thread can be stored as advance angles or lag angles. After completing the test run, the thread tension sensor can be deactivated and pure positive operation can be performed with reference to the obtained data. If necessary, however, thread tension monitoring can be continuous or intermittent, e.g., in order to identify error states.

Problems solved by technology

Knitting machines used to create patterned goods cannot be supplied with thread with such positive feed wheel mechanisms.

Unlike positive feeding devices, however, they do not directly create a uniform mesh size.

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