DE3619105A1 - Thread-changing method for textile machines - Google Patents

Abstract

The thread change no longer takes place, as is customary, at the work station of a textile machine by means of a thread-guide change, but in front of the work station by means of knotting or splicing. Storage feeders with a stepping-motor drive serve as thread stores for an uninterrupted working of the machine. The control of the thread store, thread selector and knotting operation takes place by microcomputer.

Description

According to the prior art, working threads on textile machines, for. B. Round Knitting machines, each assigned to a thread guide directly at the knitting point. The number of threads to be processed (= colors) is determined by the number of threads existing thread guide limited.

When the threads are changed, a second one becomes the active first thread guide laid, both threads knitted together on a few needles, the first thread leader laid out, the thread cut and held. The thread change is done directly at the knitting point.

Disadvantages of this process are thickening, color mixing and not ab tied thread ends in goods. The knitting point itself is determined by the An organization of several thread guides in a narrow space with their actuation, cutting and holding mechanism and their thread feed lines are confusing. Devices of this type are potential sources of error because cleaning and maintenance-intensive.

The invented method has the task of avoiding these disadvantages and the following Gain advantages:

The thread change point in the item is made using a special knot or splice replaced, which remains practically invisible on the front of the goods. The An knotting point can be computer controlled and preprogrammed to any needle the knitting machine and thus on any stitch in the item be placed. This enables a new pattern technology: inlaid pattern without cross-binding on machines without any pattern setup.

The thread changing device is spatially separated from the knitting point and in the proximity of the creel advanced where there is enough space for a larger Thread selection is. The thread feed to the knitting point takes place under exactly defi Protected and monitored voltage by selfthread pipes (steel pipes) until just in front of the needles.

The task is solved as follows:

An automatic knotter or splicer, as known from automatic dishwashers operated by an electromechanical thread selector at the right time, the threads coming from the creel on a selectable selection Summarizes rail.  

During the knotting or splicing (hereinafter referred to as "tie-on process") the running thread must be stopped. To continuous production a thread supply must not be interrupted. This is ensured by storage Suppliers with stepper motor drives (hereinafter referred to as "thread stores"), which can take up and deliver a precisely predictable thread supply. A microcomputer uses sensor signals for needle position and row number synchronizes with the knitting machine and runs a program in which all thread change points including the associated thread selection are defined.

The control of the thread store is determined by

• a) machine-specific data such as machine pitch, number of needles, digi Talized expiry time of the tying process, etc. (constants),
• b) work-specific data such as current work speed, Mesh density desired position of the connection point etc. (variable).

Based on this data, the microcomputer calculates a lead point at which chem the tying process must be triggered.

For example, suppose row 11 of a piece of knitwear is said to be different colored stripes can be worked from needle No. 21 to needle No. 45.

In this example, the microcomputer could, due to the corresponding machine-specific constants then already change thread activities guide if the machine is still working in row 10. He gets the variables which he has continuously updated in the meantime, from his data storage and

• 1. calculates the lead point for thread change on needle No. 21 / row 11,
• 2. gives impulse to thread selector according to program,
• 3. controls thread store according to lead point,
• 4. When the lead point is reached, it triggers the connection process,
• 5. calculates the lead point for thread change on needle No. 45 / row 11,
• 6. like 2.,
• 7. like 3. etc. etc.

Claims (3)

1. A method for changing the working threads on textile machines, here using the example of circular knitting machines, characterized in that the thread change takes place without interrupting the machine by knotting or splicing a second one onto a first working thread and the thread changing point thus created by microcomputer at any desired and preprogrammable point of the goods can be placed with great accuracy. 2. The method according to claim 1, characterized in that color stripes and marquetry patterns without on the right side of the goods visible color transitions and blends in the item be worked. 3. The method according to claim 1, characterized in that threads different materials, different elasticity and different thicknesses within a row of stitches be changed often.