Compound needle for stitch-forming knitting machine, stitch-forming knitting machine, and stitch-forming method

Abstract

The present invention relates to a compound needle (1) for a stitch-forming knitting machine, a stitch-forming knitting machine, and a stitch-forming method. In order to reduce the intrusion of dirt and fiber debris into the groove (6) of the compound needle (1), the compound needle (1) according to the present invention is configured in a stitch-forming knitting machine so that a force (13) acts downward in the vertical direction (y) during operation, thereby pressing the slider (10) against the groove bottom (8) of the groove (6).

Description

[Background Technology]

[0001] Compound needles for stitch-forming knitting machines have been known to textile engineers for many years. Examples of stitch-forming knitting machines using compound needles include circular knitting machines, flat knitting machines, and warp knitting machines. Compound needles for stitch-forming knitting mainly comprise two separate parts: a slider and a needle body, both of which extend primarily in the longitudinal direction. The slider is arranged to be movable relative to the needle body. A hook having an open hook space at the front end of the needle body is arranged. By appropriate relative movement of the slider, this hook space can be opened or closed relative to the needle body depending on the slider's position. Thus, compound needles differ from other needles for stitch-forming knitting machines primarily in the way the hook's hook space is closed. During operation of the stitch-forming knitting machine, a stitch is formed using the compound needle. For this purpose, a yarn is first inserted into the hook space, and a half stitch is formed by the retraction movement of the compound needle. Then, as the compound needle moves upward, the slider moves relative to the needle body, opening the intra-hook space and allowing the half stitch to slide out of the intra-hook space along the needle shaft of the compound needle. The yarn is then reinserted into the open intra-hook space. In the subsequent retraction movement, the slider moves relative to the needle body, closing the intra-hook space and forcing the previously formed half stitch out of the compound needle and past the hook. The yarn in the intra-hook space is then pulled through the previous half stitch, forming a new half stitch. This turns the previous half stitch into a knit stitch. Half stitches and knit stitches differ in the number of join points. A join point is a point where a (half) stitch contacts the previous (half) stitch and / or the following (half) stitch. A half stitch only contacts the previous stitch at two points, so it has two join points at the foot of the stitch. On the other hand, a knit stitch contacts the previous (half) stitch and the following (half) stitch at two points each. Therefore, a stitch has four join points. A detailed description of stitches, half stitches and other joining elements in knitting can be found in Chapter 01.1.4 of "Circular Knitting Machines: Theory and Practice of Knitting Technology" (Iyer; Mammel; Schach, ISBN: 3-87525-132-6).In this document, half stitches are referred to as stitch loops.

[0002] European Patent Application Publication No. 131709 discloses a typical compound needle for a stitch-forming knitting machine, in which a U-shaped groove is formed in the needle shaft, opening upward in the vertical direction. The groove is bounded laterally by two needle shaft walls and downward by a groove bottom. A slider is housed in the groove and is movable longitudinally, sliding on the groove bottom. The upper surface of the groove is at least partially closed by a guide web. It is known that during knitting, fiber debris and dirt particles enter the groove of the compound needle, increasing the power requirement of the knitting machine and accelerating wear of the compound needle. To ensure the removal of fiber debris, an additional opening is provided in the groove bottom or one of the needle shaft sides. However, this additional opening reduces the stability of the needle. Such compound needles do not meet the increasing demands resulting from current increases in knitting speed. Although such compound needles can repeatedly remove lint and dirt from the grooves, they do nothing to reduce the amount of lint and dirt that initially enters the grooves. Summary of the Invention

[0003] Starting from the prior art, the object of the present invention is to provide a compound needle for a high-speed stitch-forming knitting machine, which is easy to manufacture, has high stability and has a low amount of lint and dirt particles that get into the groove during the knitting operation.

[0004] This object is achieved by a compound needle having the characteristics of claim 1. The compound needle according to the present invention comprises a needle body having a needle shaft extending primarily in the longitudinal direction. The needle shaft may have a substantially rectangular cross section, preferably with rounded corners. However, the needle shaft may also have a substantially oval or circular cross section. A hook is adjacent to the needle shaft at the front end of the needle body, and the hook is formed so as to enclose an internal space of the hook that is open upward in a height direction perpendicular to the longitudinal direction. The needle shaft has a groove, which is an elongated recess formed in the needle shaft and has an opening that is open upward in the longitudinal direction. The groove is limited downward in the height direction by a groove bottom. The groove may have a U-shaped cross section in a plane spanned by the height and width directions. The width direction extends perpendicular to the longitudinal and height directions. The slider of the compound needle is supported on the groove bottom and guided movably in the longitudinal direction within the groove, and its front end in the longitudinal direction is configured to open and close the internal space of the hook in the height direction. The slider is supported in the height direction relative to the groove bottom. In many cases, it is preferred that the slider only contacts the groove bottom or is supported in the height direction. In either case, the slider has a working area that at least partially defines the slider in the upper height direction and allows the half stitches to be transported and pushed out during the knitting operation. Transporting the half stitch refers, for example, to the half stitch sliding along the longitudinal direction of the compound needle. For those skilled in the textile technology field, pushing out the half stitch means that the half stitch slides downward from the compound needle beyond the closed intra-hook space and no longer comes into contact with the compound needle. The pushed out half stitch or stitch does not wrap around the compound needle. The working area is the area of ​​the slider that comes into direct contact with the half stitch during the knitting operation. The working area of ​​the slider therefore includes the part of the slider that can close the intra-hook space. To reduce the ingress of lint and dirt into the groove, the slider is guided in the groove in such a way that the knitting half stitches exert a downward vertical force on the working area of ​​the slider, reinforcing the pressing force of the slider against the groove bottom, preferably by direct contact between the half stitches and the working area of ​​the slider.As a result, the slider is reliably guided over the groove bottom, preventing the formation of a gap between the slider and the groove bottom through which a large amount of fiber debris and dirt can penetrate and remain. This force can preferably be applied to the slider's longitudinal extension area of ​​the groove. The direction of force application has a point that intersects with the groove bottom. As a result, the pressing force can be very efficiently increased. However, if the force could only be applied to the slider's longitudinal extension area of ​​the hook space, the increase in the pressing force acting on the groove bottom by the slider would not be achieved. In this case, the slider would only tilt around its widthwise axis. As a result, the pressing force acting on the groove bottom by the slider would actually be reduced. The force is preferably applied to the slider when the hook space is open as the half stitch slides along the needle axis during knitting. When the hook space is open, the slider moves the maximum distance in the longitudinal direction away from the hook relative to the needle body. Even in this position, the half stitch can apply force to the slider. As a result, when the hook interspace is open, the intrusion of fiber debris and dirt into the groove is prevented. Typically, the slider does not have any protrusions or ridges in the working area that would prevent the half stitches from sliding or widen the width of the half stitches. Furthermore, the slider does not have any protrusions or ridges in the working area that would apply a longitudinal control force to the slider to control its longitudinal movement. Stitch-forming knitting machines typically have a needle tack separated in the width direction by a groove wall. The needle body and slider of the compound needle are preferably guided together in the needle tack of the stitch-forming knitting machine so as to be longitudinally movable. In this case, the needle body and slider are also longitudinally movable relative to each other. The compound needle of the present invention can be operated to form a half stitch with a yarn in the hook interspace. To this end, the yarn is typically inserted when the hook interspace is open. The formed half stitch moves longitudinally along the needle axis away from the hook and leaves the hook interspace. During operation of the stitch-forming knitting machine, the compound needle preferably performs an upward movement, and the hook of the compound needle moves longitudinally outside the needle hook. The half stitches that have previously slipped out of the hook space exert a downward vertical force on the working area of ​​the slider, increasing the pressing force of the slider against the groove bottom.This increased pressure ensures that the slider is guided particularly firmly on the groove bottom, so that no gaps form between the slider and the groove bottom during operation. This makes it possible to particularly effectively reduce the ingress of lint, dust, dirt, etc. into the grooves in the stitch-forming knitting machine. Furthermore, a particularly uniform stitch pattern is achieved.

[0005] In a preferred embodiment, the needle body has at least one, preferably two, axial walls on both sides that define the groove along the entire length of the groove in a width direction perpendicular to the longitudinal direction and perpendicular to the height direction. The axial walls allow the slider to be fixedly positioned in the width direction. Therefore, the slider cannot move in the width direction relative to the needle body. In the case of a groove having a U-shaped cross section, the axial walls are two parallel legs of the U, which are connected together at the end of each leg by a groove base. At least a portion of the cut end of the groove base extends perpendicular to the cut end of the axial walls.

[0006] Further advantages are achieved when recesses are provided in at least two axial walls of the compound needle, and the slider's working area protrudes beyond the recesses in the height direction or ends flush with the recesses in the height direction. Preferably, the slider's working area protrudes beyond the recesses or ends flush with the recesses when the hook space is in the open position. At this time, the slider is in a retracted state. In this case, the slider is maximally displaced in the longitudinal direction away from the hook relative to the needle body. When the half stitch slides along the axis in the recess area, it can apply particularly large forces to the slider that protrudes from the recesses or ends flush with the recesses. This further significantly reduces the intrusion of fiber waste, dirt, and dirt into the groove of the stitch-forming knitting machine. It is particularly preferred if the slider's working area protrudes from the recesses in the height direction. This increases the magnitude of the force that the half stitches exert on the slider. This further enhances the above-mentioned advantages.

[0007] To prevent damage to the yarn during operation of the compound needle in the stitch-forming knitting machine, at least two shaft walls of the compound needle may be provided with at least one protrusion. This protrusion protrudes in the height direction from the working area of ​​the slider. The working area of ​​the slider preferably protrudes from the recess at least when the slider is in the retracted state. If a recess is also provided on the shaft wall, the protrusion is arranged so as to be located between the recess and the hook in the longitudinal direction.

[0008] The compound needle may have a guide web connected to at least one axial wall and at least partially closing the opening of the groove in the height direction. If the axial wall of the compound needle is provided with a recess, the guide web advantageously adjoins the recess in the longitudinal direction away from the hook. The guide web is preferably an integral part of the needle body. It is particularly advantageous if the guide web is part of at least one of the axial walls bent in the width direction. The guide web increases the stability, in particular the rigidity, of the compound needle. Compound needles with such a guide web are particularly suitable for stitch-forming knitting machines operating at high speeds.

[0009] The half stitches formed by a compound needle typically spread or stretch as they slide from the hook space onto the needle shaft. To achieve a particularly uniform knitted fabric, the compound needle may be configured to minimize spreading. To this end, the needle breast, which defines the upper height boundary of the needle body and is adjacent to the hook, may have a longitudinal profile that rises obliquely away from the hook. This obliquely rising profile allows the stitch to be continuously stretched in the initial stage as it slides along the needle breast. This prevents excessive and sudden stretching of the half stitches. To prevent excessive stretching of the half stitches, the compound needle may further have a throat. The throat is a recess in the needle back that longitudinally overlaps the working area of ​​the slider. Those skilled in the art will generally understand the needle back to refer to the area that defines the needle body below the height of the compound needle. The needle back is typically adapted to be placed on the bottom of the needle chuck of a stitch-forming knitting machine. To improve the guiding of compound needles in needle tricks, the throat may be arranged to extend only longitudinally in the working area of ​​the slider, i.e., the throat may be arranged to completely overlap the working area in the longitudinal direction. Increasing the width of the half stitches affects the magnitude of the downward vertical force that the half stitches exert on the slider. It has been shown that reducing the width of the half stitches can reduce the friction between the slider and the needle body. This reduces the power requirements for operating the compound needle, thereby saving energy.

[0010] Compound needles are typically driven by engagement with a stitch-forming cam of a stitch-forming knitting machine. For this purpose, the cam has at least one groove-like recess along the cam track. The drive feet of the compound needles project into these groove-like recesses and are driven to move longitudinally according to the profile of the cam track during knitting. For this purpose, the needle body has, at its rear end away from the hook of the needle shaft, a needle drive protrusion that projects in height beyond the peripheral region of the needle shaft and is adapted to engage with at least one groove-like recess of the cam. The needle body may have multiple needle drive protrusions. Preferably, the slider of the compound needle has, at its rear end away from the working area, a slider drive protrusion that projects in height beyond the peripheral region of the slider and is adapted to engage with at least one groove-like recess of the cam. The slider may have multiple slider drive protrusions. The slider drive protrusion and the needle drive protrusion typically engage with different groove-like recesses of the cam. The needle drive protrusion and the slider drive protrusion are adapted to receive a drive force of the stitch-forming knitting machine for driving the compound needle. The drive force is provided by a cam on the stitch-forming knitting machine and is transmitted to a drive foot.

[0011] Compound needles are typically suitable for being guided in a groove-shaped needle tack for forming stitches in a stitch-forming knitting machine. To ensure particularly stable guidance of the compound needle according to the present invention in the needle tack, it is advantageous for both the needle body and the slider to be supported by at least a portion of their longitudinal extension on the walls of the needle tack. For this purpose, the slider has a slider shaft that is longitudinally adjacent to the working area and has the same width as the needle shaft. In this case, the working area of ​​the slider is tapered in width relative to the width of the slider shaft and can be inserted into the groove of the needle body so that the slider is guided longitudinally movably between the two shaft walls in the U-shaped groove of the needle body. Therefore, the slider shaft is wider than the working area of ​​the slider. The stability of the slider is further improved by the wider slider shaft. Such compound needles are particularly advantageous in stitch-forming knitting machines operating at high speeds. Typically, the width of the working area of ​​the slider is at most equal to the width of the groove or the widthwise distance between the shaft walls.

[0012] When the compound needle of the invention is inserted into a stitch-forming knitting machine, the compound needle advantageously engages with another groove-shaped recess of the cam, and this cam is suitable for transmitting a longitudinal driving force to the slider. The compound needle is preferably movable in the width direction relative to the cam. As a result, the compound needle slides along the groove-shaped recess and moves longitudinally according to the profile of the groove-shaped recess. In this manner, the movement of the compound needle can be controlled by the cam. Preferably, at least the slider is configured to engage with the groove-shaped recess of the cam. As a result, the movement of the slider can be controlled by the cam. Furthermore, when the needle body engages with the groove-shaped recess of the cam, other advantages are obtained. In this case, the movement of the needle body can also be controlled through the cam portion. It is particularly advantageous when the slider and the needle body engage with different groove-shaped recesses of the cam. The movement of the slider and the movement of the needle body can be controlled independently of each other and can move relative to each other.

[0013] In particular, when the slider is retracted and the interior space of the hook is fully open in the height direction, fiber waste and dirt may enter the groove of the compound needle. Therefore, it is particularly advantageous for the half stitches to exert a force on the working area when the interior space of the hook is fully open in the height direction. This significantly reduces the amount of fiber waste and dirt entering the groove.

[0014] Further advantages can be obtained by inserting the yarn again into the inner space of the hook while the previously formed half stitch is exerting force on the working area. This can particularly effectively prevent the intrusion of fiber debris into the needle tip, especially during yarn insertion. When the compound needle is retracted, another half stitch can be formed with the yarn still in the inner space of the hook, and the previously formed half stitch becomes a knit stitch. By repeating this procedure, stitches can be formed sequentially. Advantageously, the yarn is inserted when the inner space of the hook is completely open in the height direction, while the previously formed half stitch simultaneously exerts force on the working area. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing a compound needle 1. As shown in FIG. [Figure 2] FIG. 2 shows the compound needle 1 in place in a stitch-forming knitting machine 27 and the different positions 30, 31, 32 that the compound needle 1 assumes during operation. [Figure 3] FIG. 3 is an enlarged view of the front end of the compound needle 1 of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line AA in FIG. [Figure 5] FIG. 5 is a view showing a cross section taken along the line BB in FIG. [Figure 6] FIG. 6 is a view showing a cross section taken along line CC in FIG. [Figure 7] FIG. 7 is a view showing a cross section taken along the line DD in FIG. [Figure 8] FIG. 8 shows another embodiment of the compound needle 1 in an enlarged view similar to that shown in FIG. [Figure 9] FIG. 9 is a view showing an E-E cross section of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] FIG. 1 shows a compound needle 1 having a needle body 2 and a slider 10. The needle body 2 has a needle shaft 3 whose extension direction is the longitudinal direction z. The needle body 2 has a hook 4 at its front end in the longitudinal direction z, which surrounds an intra-hook space 5. The hook 4 is suitable for forming a half stitch 12 during knitting using a yarn. The half stitch 12 can apply a downward force 13 in the height direction y to the slider 10. The intra-hook space 5 opens upward in the height direction y. However, the slider 10 is movably guided within a groove 6 in the longitudinal direction z of the needle body 2 (see FIGS. 4-6 ), allowing the intra-hook space 5 to be opened or closed depending on the relative position of the slider 10 to the needle body 2. To control the relative positions of the slider 10 and the needle body 2, the slider 10 and the needle body 2 each have a drive protrusion. The drive protrusion of the slider 10 is referred to as a slider drive protrusion 21, and the drive protrusion of the needle body 2 is referred to as a needle drive protrusion 20. A driving force acts on the needle body 2 and the slider 10 in the longitudinal direction z via a driving foot, respectively, so that the movements of the needle body 2 and the slider 3 can be controlled independently of each other.

[0017] Three positions 30, 31, and 32 of the compound needle 1 are shown in FIG. 2, which are positions in which the compound needle 1 typically occurs during operation in a stitch-forming knitting machine. To simplify the illustration, common mechanical elements known in the prior art (e.g., sinkers, etc.) have been omitted. Such elements may be advantageously employed in a stitch-forming knitting machine in combination with the compound needle 1 of the invention, particularly for holding down and lowering stitches. During operation, the compound needle 1 of the invention passes through the positions 30, 31, and 32 shown in FIG. 2 in order from left to right to form stitches. The sequence between each of the positions 30, 31, and 32 is symbolically indicated by arrows 28. Because the same compound needle 1 is shown in all positions, for clarity, not all components of the compound needle 1 at each position are labeled with reference numerals. The mode of operation of the compound needle 1 and the method of forming stitches using the compound needle 1 are described below starting from the raised position 30, in which the compound needle 1 projects a maximum distance in the longitudinal direction z from the needle tip 23. That is, at this position, the distance in the longitudinal direction z between the hook 4 and the needle tack 23 is at its maximum. In the raised position 30, the half stitch 12 previously formed by the compound needle 1 is located outside the inter-hook space 5 of the needle shaft 3 or wraps around the needle shaft 3. The half stitch 12 contacts the slider 10 in the working area 11 of the slider 10. The slider 10 is partially hidden by the shaft wall 9. Therefore, the hidden portion is shown with a dashed line for illustrative purposes. At the point of contact with the slider 10, the half stitch 12 exerts a downward force 13 on the slider 10 in the height direction y. This force 13 further presses the slider 10 into the groove 6 of the needle body 3 (see Figures 4-6). In the raised position 30, the inter-hook space 5 opens, and the yarn 24 is inserted into the inter-hook space 5. From the raised position 30, the compound needle 1 performs a retraction movement 29 in the longitudinal direction z to retract the compound needle 1 further into the needle tack 23. During this retraction movement 29, the slider 10 moves relative to the needle body 2 so that the front end of the slider 10 closes the intra-hook space 5 in the longitudinal direction z. The half stitch 12 slides along the needle shaft 3 and slider 10 past the closed intra-hook space 5 during the retraction movement and moves downwards from the compound needle 1, which is shown in the intermediate position 31 shown in Figure 2.The sliding of the half stitch 12 from the compound needle 1 is referred to by those skilled in the art as "pushing out," since the half stitch 12 is no longer in direct contact with the compound needle 1. The yarn 24 previously inserted into the inter-hook space 5 is pulled through the half stitch 12, forming a loop, thereby forming a new half stitch 12'. The previously formed half stitch 12 then becomes a stitch 26. The new half stitch 12' and stitch 26 are shown in the drawing in the retracted position 32. In the retracted position 32, the compound needle 1 is retracted deepest into the needle tack 23. That is, the distance between the hook 4 moving in the longitudinal direction z and the needle tack 23 is the shortest at this position. At this position, the new half stitch 12' still resides within the inter-hook space 5. Starting from the retracted position 32, the compound needle 1 performs an upward movement 33 in the longitudinal direction z from the needle tack 23. During the upward movement 33, the slider 10 moves relative to the needle body 2, opening the inter-hook space 5. The compound needle 1 continues its upward movement 33 until it again reaches the raised position 30. During this time, a new half stitch 12' slides out of the open inter-hook space 5 onto the needle shaft 3. At this point, the stitch formation method described above begins from the front. In this way, stitches are formed one after the other to produce a knitted fabric.

[0018] FIG. 3 shows an enlarged view of the front end of the compound needle 1 of FIG. 1 , showing the hook 4 and the working area 11 of the slider 10. The slider 10 is partially hidden by the shank wall 9. Its hidden outline is shown by a dashed line for illustrative purposes. The intra-hook space 5 of the compound needle 1 is shown closed. That is, the working area 11 of the slider 10 is positioned relative to the needle body 2 so as to completely cover the opening of the intra-hook space 5. The hook 4 is adjacent to the obliquely rising needle breast 17 in the longitudinal direction z. In this case, the needle breast 17 is the surface that defines the upper boundary of the needle body 2 in the height direction y. The obliquely upward profile of the needle breast 17 ensures a continuous, gradual expansion of the half stitch 12 as it slides out of the intra-hook space 5 onto the needle shank 3. The needle body 2 has a throat 19 in the needle spine 18 that defines the lower boundary of the needle body 2 in the height direction y. The throat 19 is a recess in the needle spine 18 that reduces the height of the needle body 2 in the height direction y. The throat 19 overlaps the slider working area 11 and the diagonally rising part of the needle breast 17 in the longitudinal direction z. The throat 19 prevents excessive spreading of the half stitches 12 during the knitting action. The diagonally rising part of the needle breast 17 ends in a protrusion 15 of the needle body 2 that protrudes beyond the slider 10 in the height direction y. The protrusion 15 covers the tip of the slider 10 when it is retracted.

[0019] FIG. 4 shows a cross section AA of the compound needle 1 of FIG. 3. This cross section shows the groove 6 of the needle body 2, along which the slider 10 is guided. The groove 6 is bounded on both sides in the width direction x by a respective axial wall 9. Both axial walls 9 include the aforementioned protrusions 15. The protrusions 15 protrude in the height direction y above the slider 10 by a height 25 corresponding to the distance in the height direction y between the apex of the protrusion 15 and the apex of the slider 10. The height 25 is greater than zero if the protrusion 15 protrudes above the slider 10 in the height direction y. During the knitting operation, the half stitches 12 shown can slide over the protrusions 15 without coming into contact with the slider 10. This is particularly advantageous when the inter-hook space 5 is open, as it prevents the half stitches 12 from coming into contact with the tip of the slider 10 and being damaged.

[0020] As can be seen further in Figure 3, the protrusion 15 is followed by a recess 14 in the needle body 2. Figure 5 shows a cross section along the line B-B in the area of ​​this recess 14. The slider 10 ends flush with the recess 14 in the axial wall 9 of the needle body 2 in the height direction y. As a result, the half stitch 12 rests on the slider 10 when it is located in the area of ​​the recess 14. The half stitch 13 thus exerts a force 13 on the slider 10, gradually pressing it against the groove bottom 8 of the groove 6. This prevents a gap from forming between the groove bottom 8 and the slider 10 during operation, which could allow dirt and lint to enter.

[0021] In the compound needle 1 shown in FIG. 3, the guide web 16 adjoins the recess 14 in the longitudinal direction z, away from the hook. In the region of the guide web 16, the height of the needle shaft 3 increases in the height direction y. This region is therefore unsuitable for contacting the half stitches 12 during knitting, which would otherwise result in excessive spreading of the half stitches 12. FIG. 6 shows a cross section CC of the compound needle 1 in the region of the guide web 16 in the position shown in FIG. 3. In contrast to the cross section BB of FIG. 5, it can be seen that the shaft wall 9 protrudes from the slider 10 in the height direction y. The end of the shaft wall 9 is bent laterally inward above the groove 6 in the width direction x, at least partially closing the groove 6 in the height direction y. In the exemplary embodiment of FIG. 6, the opening 7 of the groove 6 remains, but its size is extremely small, preventing the slider 10 from removing from the groove 6 in the region of the guide web 16. The guide web 16 increases the stability of the compound needle 1 and therefore its service life.

[0022] In another embodiment not shown, the guide web 16 may be continuous, such that the grooves 6 are free of openings 7 in the region of the guide web 16 .

[0023] As shown in FIG. 3, the groove 6 ends behind the guide web 16 in the longitudinal direction z. The slider 10 is arranged on the needle body 2 without being laterally supported or guided by the shank wall 9 in the region extending behind the guide web 16 in the longitudinal direction z. FIG. 7 shows a cross section DD of FIG. 3, in the region behind the guide web 16 or behind the groove 6 in the longitudinal direction z. In this region, the needle body 2 has a substantially rectangular cross section without any grooves or recesses. The slider 10 is supported on the needle body 2. In the cutaway, the tapered portion of the slider 10 is cut out and is shown hatched. It can be seen that the slider shank 22 extends in the width direction x to the width of the needle body 2 behind the interaction surface (the unhatched part of the slider 10). The slider 10 and the needle body 2 can therefore be used together in a conventional needle chuck 23 of a stitch-forming knitting machine 27 and are guided independently of each other through the needle chuck 23 in the width direction x. 7 shows a conventional needle trick 23 in a stitch-forming knitting machine 27, in addition to the slider 10 and the needle body 2. Other mechanical components of the stitch-forming knitting machine 27 have been omitted from the drawing. Therefore, only a small portion of the stitch-forming knitting machine 27 is shown, as indicated by the dashed lines in FIG. 7.

[0024] Figure 8 shows an enlarged view of another embodiment of a compound needle 1'. The illustrated compound needle 1' largely corresponds to the compound needle 1 partially shown in Figure 3. Therefore, only the differences from the compound needle 1 of Figure 3 will be described below. Unlike the compound needle 1 of Figure 3, the compound needle 1' of Figure 8 has a deep recess 14 in the height direction y in the axial wall 9 of the needle body 2.

[0025] Figure 9 shows the E-E section of figure 8. It can be seen that as a result of the deeper recess 14, the slider 10, in the region of its longitudinal extension, protrudes in the height direction y beyond the recess 14 or beyond the needle body 2 and its axial wall 9. In the region of its longitudinal extension, the half stitches 12 sliding along the needle axial 3 are thereby in contact with the slider 10 only and exert a force 13 on the slider 10 which acts in the height direction y. [Explanation of symbols]

[0026] 1,1' compound needle 2 Needle body 3 needle shaft 4 Hooks 5. Space inside the hook 6 Groove 7 Opening of groove 6 8 Groove bottom 9 Axial Wall 10 Sliders 11 Working area 12,12' half stitches 13 Power 14 Recess 15 Protrusion 16 Guide Web 17 Needle chest 18 needle back 19 Throat 20 Needle drive protrusion 21 Slider drive protrusion 22 Slider axis 23 Needle Trick 24 Thread 25 height 26 stitches 27 Stitch forming knitting machine 28 Arrow 29 Retraction 30 ascending position 31 Intermediate position 32 Retracted position 33 Upward movement x width direction y Height direction z Longitudinal direction

Claims

1. A compound needle (1) for a stitch-forming knitting machine, a) a needle body (2) having a needle shaft (3) extending mainly in the longitudinal direction (z); b) a hook (4) adjacent to the needle shaft (3) at the front end of the needle body (2) and surrounding an inner space (5) of the hook that is open upward in a height direction (y) perpendicular to the longitudinal direction (z); c) a groove (6) which is an elongated recess formed in the needle shaft (3), having an opening (7) which opens upward in the height direction (y) and which is bounded below in the height direction (y) by a groove bottom (8); d) a slider (10) supported on the groove bottom (8) and movably guided in the groove (6) in the longitudinal direction (z), the front end of the slider (10) in the longitudinal direction (z) being capable of opening and closing the hook inner space (5) in the height direction (y); e) said slider (10) has a working area (11) extending in a width direction (x) and a length direction (z), said working area (11) at least partially delimiting said slider (10) in an upper height direction (y) and allowing half stitches (12) to be transported and pushed out during the knitting operation; the slider (10) is guided in the groove (6) in such a way that the half stitches (12) during the knitting operation can exert a downward force (13) in the height direction (y) on the working area (11) of the slider (10), increasing the pressing force of the slider (10) against the groove bottom (8); A compound needle (1) characterized by:

2. 2. The compound needle (1) according to claim 1, characterized in that at least two axial walls (9) of the needle body (2) delimit the width direction (x) of the groove (6) over its entire length in the longitudinal direction (z), the width direction (x) extending perpendicular to the longitudinal direction (z) and the height direction (y).

3. 3. The compound needle (1) according to claim 2, characterized in that the at least two axial walls (9) have recesses (14), and the working area (11) of the slider (10) protrudes beyond the recesses (14) in the height direction (y) or ends flush with the recesses (14) in the height direction (y).

4. 4. The compound needle (1) according to claim 3, characterized in that the at least two axial walls (9) have at least one protrusion (15) protruding in a height direction (y) from the working area (11) of the slider, the protrusion (15) being arranged between the recess (14) and the hook (4).

5. 5. The compound needle (1) according to claim 3 or 4, characterized in that a guide web (16) is adjacent to the recess (14) in the longitudinal direction (z) away from the hook (4) and is connected to at least one of the at least two axial walls (9) and at least partially closes the opening (7) of the groove (6) in the height direction (y).

6. a) a needle chest (17) that defines the upper boundary of the needle body (2) in the height direction (y), the needle chest (17) being adjacent to the hook (4) and having a profile that extends obliquely upward in the longitudinal direction (z) away from the hook (4); b) a needle spine (18) that defines a lower boundary in the height direction (y) of the needle body (2); c) a recess formed in the needle back portion (18) and having a throat portion (19) overlapping the working area (11) of the slider in the longitudinal direction (z).

7. a) The needle body (2) has a needle drive part (20) that protrudes in the height direction (y) from the surrounding area of ​​the needle shaft (3) at the rear end of the needle shaft (3) in a direction away from the hook (4), b) and the slider (10) has a slider drive protrusion (21) at a rear end portion thereof away from the working area (11) that protrudes in a height direction (y) from the surrounding area of ​​the slider (10); c) A compound needle (1) according to any one of claims 1 to 6, characterized in that the needle drive lug (20) and the slider drive lug (21) are suitable for receiving a drive force of a stitch-forming knitting machine to drive the slider needle (1).

8. The slider (10) has a slider shaft (22) adjacent to the working area (11) in the longitudinal direction (z), and the slider shaft (22) has the same width as the needle shaft (3) in the width direction (x); The compound needle (1) according to any one of claims 1 to 7, characterized in that the working area (11) of the slider (10) is tapered in the width direction (x) relative to the width of the slider shaft (22) and can be inserted into the groove portion (6) of the needle body (2).

9. A stitch-forming knitting machine (27) comprising a compound needle (1) according to any one of claims 1 to 8, The stitch-forming knitting machine (27) is characterized in that the needle body (2) and the slider (10) are guided so as to be movable together in the longitudinal direction (z) in a needle trick (23) of the stitch-forming knitting machine, and the needle body (2) and the slider (10) are also movable relative to each other in the longitudinal direction (z).

10. 10. The stitch-forming knitting machine (27) according to claim 9, characterized in that the compound needle (1) is engaged in a groove-like recess of a cam, the cam being suitable for transmitting a driving force acting in the longitudinal direction (z) to the compound needle (1).

11. 11. The stitch-forming knitting machine (27) according to claim 10, characterized in that the compound needle (1) engages in a groove-like recess of a cam, the cam being suitable for transmitting a driving force acting in the longitudinal direction (z) to the slider (10).

12. A method for forming stitches using the compound needle (1) according to any one of claims 1 to 8, comprising: a) forming half stitches (12) in the inter-hook space (5) using a yarn (24); b) the formed half stitch (12) sliding out of the inter-hook space (5) along the needle axis (3) in a direction away from the hook (4) in the longitudinal direction (z); c) applying a force (13) acting downward in the height direction (y) to the working area (11) of the slider (10) by the half stitches (12), thereby increasing the pressing force acting on the groove bottom (8) of the slider (10); How to perform each step in the order listed.

13. 13. The method according to claim 12, wherein the force (13) is applied to the working area (11) in a state where the hook inner space (5) is completely opened in the height direction (y).

14. 14. The method according to claim 12 or 13, characterized in that the thread (24) is reinserted into the inter-hook space (5) while a previously formed half stitch (12) is exerting the force (13) on the working area (11).

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