EP0926286B1 - Method for making knitwear on a flat bed knitting machine - Google Patents

Description

The invention relates to a method for producing a knitted fabric on a flat knitting machine with a sled at least one lock system that tracks the movements of the needles according to a sample program for the knitted fabric to be manufactured controls.

In modern high-performance flat knitting machines they are Lock systems that control needle movements are designed to that the control of the needles is no longer the maximum possible Limited carriage speed. The sled speed is now rather through the processed knitting thread limited, which can tear when the forces that the needles on exercise it, get too big. The acceleration jerk, too a knitting thread finds out when the associated thread guide passes through the carriage moving at high speed can break the knitting thread. This Acceleration jerk occurs especially at the knitted edges with certain knitting patterns, for example intarsia, also occur within a row of knitting. Most on knitted fabrics produced in a flat knitting machine are inherent patterned so that individual needle groups in each row of knitting form different structures. For example formed in a row of stitches and / or tuck handles, stitches and tentacles piled up in one section, floats inserted, Stitches shifted laterally on the same needle bed or but from a needle bed to the opposite needle bed be transmitted. Depending on the activity of the needles the knitting thread experiences at different points different forces within a row. This ensures error-free production on the flat knitting machine can be reached, the sled at that speed moved over the row of knitting that just barely is permissible so that the knitting thread at the most critical point the row of knitting, that is, at the point where the Needles still exert the greatest forces on the knitting thread does not tear. Are only a few critical points within one Knit row available, so are large areas of the knitted fabric produced at a sled speed that for this Areas is actually unnecessarily small.

A flat knitting machine is known from EP 0 276 383 A2, where the stroke of the carriage is adjusted to the width of the knitted fabric so that the sled does not travel unnecessarily got to.

GB 2 195 360 A describes a sled control that the Deceleration and acceleration of the carriage when changing direction depending on the carriage speed regulates.

In GB 2 201 167 A there is a switch-on and switch-off device described a flat knitting machine in which the carriage speed depending on the position of an engagement rod is controlled. The more the engagement bar The closer to its "on" position, the closer it gets Carriage speed their predetermined maximum value, and each the engaging rod approaches its "off" position, the lower the sled speed.

To enable an even more rational production of knitted pieces on a flat knitting machine than ever since was the case, the present invention proposes a method with the features of claim 1. The highest possible speed of the sled in a particular section of a Knitting row is of the type of material of the knitting thread and of it depending on how the knitting thread is processed by the knitting needles , that is, whether it is normal, large or small stitches or Form tuck loops, pile tuck loops, transfer stitches or take over etc. In the regulation of the sled speed therefore go for information on the type of knitting thread as well as sample data from which it can be seen which Knitting needles which form structures from the knitting thread. Out the data about the knitting thread or threads used can be determine a thread-specific maximum speed. from that will also be the greatest possible acceleration jerk for the thread calculated. The sample data is then used to determine which Set the thread-specific maximum speed within the knitting row must be reduced. If within the Knitted sections exist where there are no needle movements are necessary, the sledge can be placed in these Sections are moved at speeds up to that possible maximum speed according to its drive device can be enough, because in these sections too no forces are exerted on the knitting thread. This is a further increase in the production speed of the Knits possible. In addition, the carriage speed be reduced in places of a row of knitting where the Sled a mechanical circuit on an auxiliary unit must make. Such an additional unit can, for example be a decker device, the course of movement of curves is controlled on the sled. The area of the diminished Speed as well as the amount of speed reduction is determined by the sample data. Compared to the more well-known methods for producing a knitted fabric A flat knitting machine ensures that the invention Processes a much more rational production, because the Carriage speed always for a faultless production of the knitted fabric is still allowed. The Knitting row is no longer with that sled speed formed based on the most critical case in the knitting course is determined.

The invention also includes a flat knitting machine for performing a method according to one of claims 1 to 3 with a sled with at least one lock system that the Movements of the needles according to a sample program for controls the knitted fabric and with a control device, the drive unit of the sled according to data about the parameters of the knitting thread or threads used as well that generated by the individual needles or groups of needles Controlled pattern types during the formation of a knitting course in such a way that the carriage is at every point in the knitting course moved at the highest possible speed. For this can the control device expediently with a sample program memory connected to the machine.

A drawing according to the invention is described below with reference to the drawing Process for producing a knitted fabric on a flat knitting machine based on the speed diagrams of the Carriage described a flat knitting machine.

Fig. 1

einen Schlittengeschwindigkeitsverlauf über eine Strickreihe nach dem Stand der Technik;

Fig. 2

einen ersten Schlittengeschwindigkeitsverlauf über eine Gestrickreihe eines Gestricks;

Fig. 3

einen zweiten Schlittengeschwindigkeitsverlauf über eine Strickreihe eines Gestricks;

Fig. 4

einen dritten Schlittengeschwindigkeitsverlauf über eine Strickreihe eines Gestricks;

Fig. 5

einen vierten Schlittengeschwindigkeitsverlauf über eine Strickreihe eines Gestricks;

Fig. 6

einen fünften Schlittengeschwindigkeitsverlauf über eine Strickreihe eines Gestricks.

Show it:

Fig. 1

a carriage speed curve over a row of knitting according to the prior art;

Fig. 2

a first carriage speed curve over a row of knitted fabrics of a knitted fabric;

Fig. 3

a second carriage speed curve over a row of a knitted fabric;

Fig. 4

a third carriage speed curve over a row of a knitted fabric;

Fig. 5

a fourth carriage speed curve over a row of a knitted fabric;

Fig. 6

a fifth carriage speed curve over a row of a knitted fabric.

Fig. 1 shows the course of a carriage speed Vs over a row of knits of a knitted fabric with the width B according to a manufacturing method according to the prior art. The row of knits is formed from the same knitting thread in the entire width B of the knitted fabric. Vs _max denotes the maximum speed of the carriage, which depends on the material of the knitting thread, if all needles form stitches of normal size. In the example shown _, however, the actual maximum speed Vs _tat shown by the solid line is lower than the maximum speed Vs _max , since the knitted fabric has a section at least at one point within which the needles exert such great forces on the knitting thread that a speed reduction is necessary, to avoid tearing the knitting thread. As the diagram according to FIG. 1 clearly shows, in the methods according to the prior art the entire row of knits is knitted at a uniform speed of the carriage, with the exception of the start and end regions in which the carriage accelerates and before after the reversal of the knitting direction 10 the renewed reversal of the knitting direction 10 must be braked.

FIG. 2 shows a first profile of the speed Vs of a carriage in a manufacturing method according to the invention. Here, too, the entire row of knits of width B is formed by a knitting thread which is fed with a thread guide FF1. The direction of knitting is again indicated by an arrow 10. In a starting area A of the knitting course, the carriage is accelerated from the knitted edge. The acceleration in a section 11 of the curve of the speed Vs is lower than later, as a result of which the acceleration jerk on the knitting thread is reduced. The knitting course has a first section S ₁ , in which all needles form stitches of normal size, so that here the carriage can be moved with its maximum possible speed Vs _max . In the adjoining section S _{2 of} the knitting course, enlarged stitches are formed, which is why the carriage speed must be reduced. The deceleration phase required for the speed reduction is marked with Vz2. In the subsequent section S _{3 of} the knitting course, all needles knit normal-sized stitches again, that is to say the speed can be accelerated again in the area Bs3 to the maximum speed Vs _max . In the subsequent section S ₄ , the knitting thread is floated over several needles. To do this, the thread must be inserted with a low internal tension, which is only possible if the carriage speed is reduced. Consequently, the course of the carriage speed Vs at the transition between section S ₃ and section S _{4 has} a delay section Vz4. In the following section S ₅ all needles of normal size are knitted again so that the carriage can be accelerated again to the maximum speed Vs _max . In section S ₆ stitches are transferred from one needle bed to the other needle bed, which also requires a lowering of the carriage speed Vs before the carriage in the last section S ₇ , in which all needles knit normal-sized stitches again, on the Maximum speed Vs _{max is} accelerated. In section E towards the end of the knitting course, the carriage is decelerated to a complete standstill before the reversal of the carriage direction 10, the deceleration being increased again in an area 12 shortly before reaching the standstill, so that the knitting thread that passes from the edge stitch to the thread guide FF1 runs, has the lowest possible tension and thus does not narrow the edge stitch. In the example shown in FIG. 2, the maximum speed Vs _max in the knitting area between the initial acceleration A and the end deceleration E is reached to 41% of the sled path. In comparison to the course of the carriage speed shown in FIG. 1, this means a significant reduction in the production time for the knitting course.

3 shows a further example of a speed profile Vs of a carriage over a row of knitting of width B. This row of knitting is formed by three different knitting threads made of different materials M1, M2 and M3. The first knitting thread of material M1 knits in the first section S ₁ , the knitting thread with material M2 in the second section S ₂ and the third knitting thread made of material M3 in the third section S ₃ . Due to the different materials M1 to M3 of the knitting threads, there are also three different maximum speeds VsM1 _max , VsM2 _max , VsM3 _{max of} the carriage, with which the carriage can move before the respective thread breaks, provided the needles form stitches of normal size. The start and end sections A, E are identical to those shown in FIG. 2. In section S ₁ stitches of normal size are formed by the first thread, which is why the slide is accelerated to the associated permitted maximum speed VsM1 _max . In section S ₂ the more robust second knitting yarn is knitted with the material M2, so that the carriage can be accelerated to the higher maximum speed VsM2 _max (Bs2). In section S ₃ the third knitting thread is knitted with the material M3, whereby also only stitches of normal size are produced, so that the carriage is now set to the permissible maximum speed for the third thread VsM3 _max . The material M1 of the first knitting thread could for example be a mohair thread, the material M2 an acrylic mixture and the material M3 for example new wool.

FIG. 4 shows a speed curve Vs of a carriage over a row of knitting which is formed in the three sections S ₁ , S ₂ and S ₃ with the same threads made of different materials M1, M2 and M3 as the row of knitting in FIG. 3. In sections S ₁ and S ₂ , however, there are now needle areas S ₁ . and S ₂ , in which either larger stitches are formed by the respective knitting threads or stitches are transferred to the opposite needle bed. In both areas S ₁ and S ₂ , a reduction in the carriage speed is therefore necessary, as FIG. 4 clearly shows. In section S ₃ , normal-sized stitches are again formed from all needles. So here the carriage can maintain its maximum speed up to the end section E.

FIG. 5 shows the example of a speed profile Vs of a carriage when moving over a knitted fabric of width B, but no stitches are formed. However, there is a section S ₂ in the central area of the knitted fabric, in which stitches are transferred into the opposite needle bed. In the other two areas S ₁ and S ₃ , however, there are no needle movements. Therefore, the carriage in the initial area A, which is very short, can be accelerated to the maximum possible speed VsH of its drive device. He maintains this speed until shortly before reaching section S ₂ , where he is braked in an area Vz _max , so that the stitch transfer in area S ₂ can be carried out safely. The carriage is then accelerated again in the area Bs _max to the maximum permissible speed VsH and decelerated to a standstill only in the end area E before the direction of the carriage 10 reverses. Should it make sense for certain reasons not to move the sled at maximum speed in the areas S ₁ and S ₃ , then of course all possible speeds below VsH can be selected.

FIG. 6 shows a profile of a carriage speed Vs over a knitted fabric of width B, the knitted row shown being formed continuously with a knitting thread. The knitting course has several different sections S ₁ to S ₇ , wherein sections S ₁ , S ₃ , S ₅ , S ₇ each form stitches of normal size, so that in these areas the carriage reaches its maximum permissible speed from the thread material can be brought. In section S ₂ , enlarged stitches are formed, so the knitting thread is subjected to a greater load, so that the sled must be reduced in speed in this area. In section S ₄ the slide performs a mechanical switching function. To do this, the carriage speed must be reduced in accordance with the kinematic concerns of the switched apparatus. This apparatus can, for example, be a decker device, the movement of which is controlled by curves on the carriage. In section S ₆ , a stitch transfer takes place from one needle bed to the other, so that here again the carriage speed must be reduced compared to the maximum speed applicable in sections S ₅ and S ₇ . The areas Vz2, Vz4 and Vz6 respectively indicate areas in which the carriage is braked, while the areas Bs3, Bs5 and Bs7 are areas in which the carriage is accelerated to its maximum speed which is permitted according to the thread material.

Claims (5)

1. A process for making a knitted fabric on a flat bed knitting machine having a carriage with at least one carriage system which controls the movements of the needles in accordance with a pattern program for the knitted fabric to be made, characterised in that the carriage speed (Vs) is continuously regulated by means of a control device triggering the drive unit of the carriage within a row of knitting in dependence on data relating to the properties of the knitting thread or threads used, from which a thread-specific maximum speed and a maximum possible acceleration jolt for the thread or threads are calculated, and relating to the types of pattern created by the individual needles or groups of needles, such that at each point on the row of knitting the carriage is moved at the maximum possible speed at which there is a guarantee that no knitting thread will break.
2. A process according to Claim 1, characterised in that, in sections (S₁, S₃) within the knitted fabric in which no needle movements are required, the carriage is moved at speeds which can attain as much as the maximum speed (VsH) possible in accordance with its drive device.
3. A process according to Claim 1 or 2, characterised in that the carriage speed (Vs) is reduced at the points on a row of knitting at which the carriage has to perform mechanical switching to an additional unit.
4. A flat bed knitting machine for carrying out a process according to one of Claims 1 to 3, having a carriage with at least one carriage system which controls the movements of the needles in accordance with a pattern program for the knitted fabric to be made, characterised in that it has a control device which triggers the drive unit of the carriage in accordance with data relating to the parameters of the knitting thread or threads used and the types of pattern created by the individual needles or groups of needles while a row of knitting is being formed such that at each point on the row of knitting the carriage moves at the maximum possible speed.
5. A flat bed knitting machine according to Claim 4, characterised in that the control device is connected to a pattern program memory of the machine.

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