KR20200047327A - Compound needle for a warp knitting machine - Google Patents

Abstract

Disclosed is a complex needle (1) for a warp knitting machine having a needle head (2), a transition area (4), and a stem (5). The needle head (2) has a hook (3). The transition area (4) is adjacent to the hook (3) and a cross section thereof increases in a distancing direction from the needle head (2). When a yarn difficult to be processed is used, reliable operation of the warp knitting machine is possible. In order to achieve the above-mentioned purpose, provided are edge profilings (14, 15) where the transition area (4) continuously changes between the hook (3) and the stem (5).

Description

Compound needle for a warp knitting machine}

The present invention relates to a compound needle for a warp knitting machine, the compound needle having a needle head, a transition region and a stem, wherein the needle head With a hook, the transition region is adjacent to the hook and its cross section increases in a direction away from the needle head.

Such a composite needle for warp knitting machines is known from DE 25 # 37 502 A1, for example.

During the operation of the warp knitting machine, the compound needles must absorb force during loop formation. For example, the compound needles are bent to the side under load by thread tension and fabric take-down in the longitudinal and transverse directions and by the rise of the compound needles due to the transport of threads, In the meantime, the compound needle causes the biasing that must slide from the area of the hook onto the stem to receive a compressive load on the longitudinal axis.

Composite needles are made from sheet metal, for example, by punching or from wires, by hammering. After punching, burrs must be removed, which can be done, for example, by vibratory grinding. In addition, all sharp edges are rounded to some extent in the machining.

The above-mentioned loads received by the composite needle also depend, inter alia, on the yarns used for the manufacture of knitted articles. The load is generally greater as the yarn is more inflexible. For example, if a mosquito net is to be produced, a relatively stiff monofilament is used in the yarn. Even if the fineness is relatively low, the load received by the compound needle during operation of the warp knitting machine is very large, and failures are more and more, which may even extend to the destruction of the compound needle.

The present invention is based on the object that the warp knitting machine can be reliably operated even when a thread difficult to process is used.

This object is achieved in the case of the complex needle for warp knitting machines of the type mentioned initially, in that the transition region has continuously varying edge profiling between the hook and the stem.

Thus, the design of the composite needle may remain essentially unchanged. The composite needle may have a design that is strengthened to a certain limit, in particular to allow it to absorb the load caused by the thread being processed. However, predetermined edge profiling, which can be produced, for example, by a machining step, is provided to the composite needle in a targeted manner. Alternatively to this, edge profiling can also be produced by pressing. The effect that can be achieved by edge profiling is that the deviation formed in the hook can slide more easily onto the stem as the compound needle rises.

Edge profiling is preferably in the form of rounding. Therefore, the movement of the shift from the hook to the stem becomes easier.

The rounding preferably has an increasing curvature in a direction away from the hook. The transition region has an increasing cross-section from the hook to the stem. In parallel with the cross-section increase, the curvature of edge profiling also increases in a direction away from the hook, so that the transition region becomes more " angular ". However, sharp edges are not actually formed.

Alternatively or additionally, edge profiling can be in the form of a bevel. Rounding and mixing of slopes is possible. Then, the increasing curvature corresponds to the decreasing slope width.

In a preferred embodiment, the ratio between the area determined by the width and depth of the transition region and the cross-sectional area of the transition region from hook to stem increases. This condition applies at any distance from the hook. That is, the closer to the hook, the larger the area of the area determined by the width and depth of the transition area remains free by edge profiling. Here, the width is the direction in which the composite needles are arranged next to each other in the bar of the warp knitting machine. The depth is perpendicular to it and is perpendicular to the longitudinal extent of the compound needle.

The ratio at the first end of the transition region adjacent the hook is preferably up to 0.8. That is, the actual cross-sectional area of the transition region occupies only 80% of the actual available area by the product of the width and depth of the transition region.

It is also advantageous that the ratio at the second end of the transition region adjacent the stem is at least 0.85. Here, edge profiling has the effect that up to 15% of the area determined by the width and depth of the transition region is not covered by the cross section of the transition region.

Preferably, the front side of the composite needle has a first edge profiling, the rear side of the composite needle has a second edge profiling, and the first edge profiling and the second edge profiling have different designs. Therefore, this takes into account the fact that a groove is formed on the front side of the compound needle, and the slider moves during the operation of the warp knitting machine therein.

The first edge profiling preferably has a maximum first radius of curvature that is smaller than the thickness of the wall defining the slider groove. Thus, edge profiling ends before it reaches the slider groove. Therefore, the geometry of the slider groove can be maintained unchanged.

In a preferred embodiment, it is provided that the second edge profiling has a maximum second radius of curvature that is within the range of 10% to 30% of the width of the composite needle. Therefore, the maximum second radius of curvature is relatively large.

It is also advantageous that edge profiling continues at the stem. It can, for example, gradually become smaller in the stem, ie it does not have to be stopped at the very end of the transition region.

In addition, it is advantageous that edge profiling is limited to the area of formation of the ring of the compound needle. The area of formation of the circular ring basically corresponds to the lift or lifting height of the compound needle during operation of the warp knitting machine. Edge profiling beyond this is not required.

The invention will be described below with reference to the preferred exemplary embodiments in conjunction with the drawings.

1 shows a perspective view of a composite needle for warp knitting machines from two viewing directions,
FIG. 2 shows an enlarged view of the composite needle in areas A and B according to FIG. 1 between the needle head and the stem,
3 shows a side view and two cross-sectional views of a composite needle.
In all figures, the same reference signs are provided to the same elements. Here, FIGS. 1A and 2A show the composite needle from the left rear, while FIGS. 1B and 2B show the composite needle from the right front.

The composite needle 1 for warp knitting machine has a needle head 2 having a hook 3.

The hook 3 is adjacent to the transition region 4 and the cross section of the transition region 4 increases in a direction away from the needle head 2. The transition region 4 is adjacent to the stem 5 and a needle butt 6 is arranged at the end of the stem facing away from the needle head 2. The stem 5 has a bar support surface 7 adjacent the needle base 6.

1A shows the back side 8 of the needle, and FIG. 1B shows the front side 9 of the needle. The slider groove 10 is formed on the front side 9. During operation of the warp knitting machine, the slider groove serves to receive the slider, and by using the slider, the trapping space when the needle pulls the thread through the previously formed knitting on the knitting forming region 12 during the knitting forming operation (catching space; 11) is closed.

As can be seen, the cross section of the transition region 4 increases from the needle head 2 towards the stem 5. Thus, in turn, when the composite needle 1 ascends for the subsequent formation of the yaw to pull the warp thread through the previously formed yaw on the composite needle, the yaw formed in the region of the needle head 2 is It should be widened. This is generally known.

For example, in the case of yarns that are difficult to process because the yarns are relatively stiff, a large force acts on the compound needle 1 during this circular forming operation. The transfer of the thread causes the composite needles 1 to be bent in the lateral direction, that is, in the width direction under load. The composite needles 1 are loaded in the longitudinal and depth directions by thread tension and winding the fabric. The shape of the compound needle 1 causes the compound needle 1 to undergo compressive stress in the longitudinal axis due to the sliding slip from the needle head 2 onto the stem 5 as it rises. The processing material, i.e. the yarn or the resulting formation, is also subject to severe stress during ascension, as the deviation must slide from the needle head 2 onto the stem 5 and widens greatly in the processing. The widening can take up to three times the size of the ring.

The stress can be absorbed only in a limited range by the reinforcement of the composite needle 1. The reinforcing portion of the width of the composite needle 1, that is, the reinforcing portion parallel to the bar support surface 7, has a thickness of the composite needle 1 that can be affected by such reinforcing portions, often of fineness, ie of the composite needle per inch. Since it is already determined by number, it is possible only in a limited range. The reinforcement in the depth direction, ie in the direction between the rear side 8 and the front side 9, is also possible only in a limited range. In addition, the transition between the needle head 2 and the stem 5 cannot be performed at a very short distance, since in such a case, the shifting should be widened very quickly.

Now, another way to keep the load of the compound needle 1 low during the widening of the shift is selected. The composite needle 1 is provided with a continuously varying edge profiling between the hook 3, ie the needle head 2 and the stem 5. Here the continuous change need not take place over the entire distance between the needle head 2 and the stem 5. However, this must take place in the baffle formation region 12 where the baffle must be widened during operation. This part extends from the needle head 2 to approximately the position 13. However, the position 13 can also be located at different points for different types of compound needles 1. The baffle forming portion 12 typically has a length of 7 mm to 17 mm.

Edge profiling consists of a first edge profiling 14 on the anterior side 9 of the composite needle 1 and a second edge profiling 15 on the rear side 8 of the composite needle 1. . The first edge profiling 14 and the second edge profiling 15 have different designs.

The first edge profiling 14 and the second edge profiling 15 may be in the form of rounding, for example. Rounding follows a circular line in cross section, although this is not absolutely necessary. The circular line is used for the purpose of simplifying the explanation. That is, the radius of curvature can be defined here. More generally, each of the edge profilings 14 and 15 has a rounding, where a special feature is that each rounding in each case has an increasing curvature in a direction away from the hook 3. This means that with regard to the curvature in the form of a circular line, the radius of curvature decreases in the direction away from the needle head 2.

Alternatively to rounding, the first edge profiling 14 and the second edge profiling 15 can also be in the form of a slope. One of the edge profilings 14, 15 is in the form of rounding, and the other edge profiling 14, 15 is in the form of a slope, or in one or both edge profiling 14, 15, the rounding is sloped Or vice versa. Then, the increasing radius of curvature corresponds to the decreasing width of the slope, ie then the edge profiling becomes "sharper".

Now, the area formed by the product of width (i.e., the distance between the left side 16 and the right side 17) and depth (i.e., the distance between the front side 7 and the rear side 8) will be defined. You can. The area can be set as the ratio of the cross-sectional area of the transition region 4 at the same location. Now the ratio increases from hook 3 towards stem 5.

Thus, the ratio at the first end of the transition region 4 adjacent the hook 3 can be up to 0.8, ie the cross-sectional area is 80% of the area defined by the product of width and depth. At the other end of the transition region 4, the ratio can be at least 0.85, ie the cross-sectional area occupies at least 85% of the area formed from the product of width and depth.

As can be seen in the figure, the second profiling 15 has a smaller curvature on the rear side 8, ie more than the first edge profiling 14 on the front side 9 of the composite needle 1. It has a large radius of curvature.

The radius of curvature of the first edge profiling, in particular, is defined by the slider groove 10. The slider groove 10 is formed between the two walls 18,19. The first edge profiling 14 in each case has a maximum first radius of curvature that is smaller than the thickness of the walls 18, 19 defining the slider groove 10.

In contrast, the second edge profiling has a maximum second radius of curvature that is within the range of 10% to 30% of the width of the compound needle 1, that is, the distance between the left side 16 and the right side 17.

In a manner not specifically illustrated, edge profiling 14, 15 may continue on stem 5. However, as described above, this is sufficient when the edge profilings 14 and 15 are limited to the circular formation area 12 of the composite needle 1.

The hook 3 often has a circular cross section. At least, the hook 3 also has edge profiling with a corresponding curvature. Now, it can be ensured that the first edge profiling 14 and especially also the second edge profiling 15 are continuously changing on the hook 3.

3 shows a side view of the composite needle 1, where two sectional views C-C and D-D can be seen. 3B shows a cross-sectional view of the compound needle 1 along line C-C. 3C shows a cross-sectional view of the compound needle 1 along line D-D. The change in edge profiling can be clearly seen by comparing FIG. 3B with FIG. 3C.

Claims (12)

A compound needle (1) for a warp knitting machine having a needle head (2), a transition region (4) and a stem (5), comprising: the needle head (2) Has a hook (3), the transition area (4) is adjacent to the hook (3), its cross section increases in a direction away from the needle head (2), the transition area (4) is A composite needle (1) for warp knitting machines, characterized by having continuously varying edge profiling (14, 15) between the hook (3) and the stem (5). The composite needle according to claim 1, characterized in that the edge profiling (14, 15) is in the form of rounding. 3. A composite needle according to claim 2, characterized in that the rounding has a curvature that increases in a direction away from the hook (3). The composite needle according to claim 1, characterized in that the edge profiling (14, 15) is in the form of a bevel. 5. The area according to claim 1, which is determined by the width and depth of the transition region (4) and the cross-sectional area of the transition region (4) from the hook (3) to the stem (5). A compound needle characterized in that the ratio between the teeth increases. 6. Complex needle according to claim 5, characterized in that the ratio at the first end of the transition region (4) adjacent to the hook (3) is at most 0.8. 6. The complex needle according to claim 5, characterized in that the ratio at the second end of the transition region (4) adjacent to the stem (5) is at least 0.85. 5. The front side (9) of the composite needle (1) has a first edge profiling (14) and the rear side (8) of the composite needle (1). A composite needle characterized by having a second edge profiling (15), wherein the first edge profiling (14) and the second edge profiling (15) have different designs. 9. The method of claim 8, characterized in that the first edge profiling (14) has a maximum first radius of curvature that is smaller than the thickness of the walls (18, 19) defining the slider groove (10). Compound needles. 9. The composite needle according to claim 8, characterized in that the second edge profiling (15) has a maximum second radius of curvature within a range of 10% to 30% of the width of the composite needle (1). The compound needle according to any one of the preceding claims, characterized in that the edge profiling (14, 15) continues on the stem (5). The composite needle according to any one of claims 1 to 4, characterized in that the edge profiling (14, 15) is limited to a loop forming region of the composite needle (1).

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