Compound needle for knitting textile machines, knitting textile machine and method for knit stitch formation

Abstract

The invention relates to a slider needle (1) for stitch-forming textile machines, a stitch-forming textile machine, and a method for stitch formation. To reduce the introduction of dirt and lint into the groove (6) of a slider needle (1), a slider needle (1) according to the invention is designed and operated in a stitch-forming textile machine such that, during operation, a force (13) acts downwards in the vertical direction (y) on the working area (11) of the slider (10) of the slider needle (1), pressing the slider (10) onto the groove base (8) of the groove (6).

Description

[0001] Compound needles for stitch-forming textile machines have been well known to those skilled in the field of textile technology for many years. Stitch-forming textile machines in which compound needles are used include circular knitting machines, flat knitting machines, and warp knitting machines. Compound needles essentially comprise two individual parts: a slider and a needle body, both of which extend primarily in a longitudinal direction. The slider is arranged so that it can be moved relative to the needle body. At the front end of the needle body is a hook with an upwardly open hook interior. By means of a suitable relative movement of the slider, this hook interior can be opened and closed depending on the position of the slider relative to the needle body. Compound needles therefore differ from other needles for stitch-forming textile machines primarily in the way in which the hook interior of their hook is closed.In the operation of loop-forming textile machines, stitches are formed with the help of compound needles. For this purpose, a yarn is first inserted into the interior of the hook and a half stitch is formed by the drawing-in movement of the compound needle. During a subsequent expulsion movement of the compound needle, the slider is then moved relative to the needle body in such a way that the interior of the hook is opened and the half stitch slides out of the hook along the shank of the compound needle. A new yarn is then inserted into the open interior of the hook. During the subsequent drawing-in movement, the slider is moved relative to the needle body in such a way that the interior of the hook is closed and the previously formed half stitch on the slider is thrown off the compound needle over the hook. The yarn in the interior of the hook is pulled through the previous half stitch and thus formed into a new half stitch.The previous half stitch becomes a stitch. A half stitch and a stitch differ in the number of their binding points, with binding points being the points where a (half) stitch touches the preceding and / or following (half) stitches. A half stitch is in contact with only one previous stitch at two points and therefore has two binding points on the stitch feet. A loop, on the other hand, is in contact with a preceding and a following (half) stitch at two points each. A stitch therefore has four binding points. A more detailed description of stitches, half stitches, and other knitting elements can be found in "Kundstricken: Theorie und Praxis der Maschentechnik" (Circular Knitting: Theory and Practice of Stitch Techniques), Iyer; Mammel; Schäch (ISBN: 3-87525-132-6), Chapter 1.1.4. Half stitches are referred to here as loops.

[0002] EP131709A1 shows a typical compound needle for stitch-forming textile machines, which has a needle shaft in which a U-shaped groove is formed that opens upwards in the vertical direction. The groove is bounded laterally by two shaft walls and downwards by a groove base. A slider is accommodated in the groove so that it can be displaced longitudinally, whereby the slider can slide on the groove base. At the top, the groove is at least partially closed by a guide web. It is known that lint and dirt particles can penetrate the groove of a compound needle during knitting operation, which leads to increased power consumption of the knitting machine and increased wear of the compound needle. To ensure the removal of lint, the groove therefore has an additional opening in its base or in one of the shaft cheeks. However, this additional opening weakens the stability of the needle.Such compound needles therefore fail to meet the increasing demands of rapidly increasing knitting speeds. While such a compound needle can remove lint and dirt from the groove, it cannot reduce the amount of lint and dirt particles that initially enter the groove.

[0003] US3229485A shows a compound needle for stitch-forming textile machines with a needle body, a hook, a groove, and a slider with a working area. The compound needle is said to have a longer service life than conventional latch needles and be usable at higher machine speeds. Lint and dirt can penetrate the groove of this compound needle, thus increasing the power requirements of the compound needle during knitting.

[0004] GB512850A shows a compound needle for a knitting machine with a groove and a slider that opens and closes the hook point, which is intended to enable more precise and efficient knitting. The groove has side walls which, together with a groove base that is closed upwards in the vertical direction, form a U-shaped cross-section. This is intended to provide improved stability and control during the knitting process, resulting in higher quality knitted goods. The use of this The speed and accuracy of the knitting machine is intended to be improved. Even with a compound needle in this design, large quantities of dirt and lint get into the groove during knitting, thus increasing the power requirements of textile machines with this type of compound needle.

[0005] US4109490A shows a compound needle for use in knitting machines, particularly circular and flat-bed knitting machines. Like conventional compound needles, it comprises a needle body and a slider that can slide in a groove in the needle body. The compound needle includes lugs and stops that control the movement of the compound needle and ensure precise opening and closing of the hook, resulting in more accurate and efficient knitting. Even with such a compound needle, large amounts of lint and dirt can enter the groove of the compound needle during knitting, thus increasing power requirements.

[0006] Based on the prior art, it is therefore the object of the invention to provide a compound needle for high-speed stitch-forming textile machines which is easy to manufacture, has great stability and in which fewer lint and dirt particles penetrate into the groove of the compound needle during knitting operation.

[0007] The object is achieved by a compound needle with the features of claim 1. A compound needle according to the invention comprises a needle body with a needle shaft which extends predominantly in a longitudinal direction. The needle shaft can have a substantially rectangular cross-section with preferably rounded edges. However, the needle shaft can also have a substantially oval or round cross-section. At the front end of the needle body, a hook adjoins the needle shaft, wherein the hook encloses a hook interior which is open upwards in a vertical direction perpendicular to the longitudinal direction. The needle shaft comprises a groove which is an elongated depression in the needle shaft which has an opening directed upwards in the vertical direction and is delimited downwards in the vertical direction by a groove base. In a plane spanned by the vertical direction and a width direction, the groove can have a U-shaped cross-section.The width direction runs perpendicular to the length direction and perpendicular to the height direction. A slider of the compound needle rests on the groove base and is guided in the groove so that it can be moved lengthwise in such a way that its longitudinally forward end can close and open the hook interior in the height direction. The slider is supported in the height direction on the groove base. It is often advantageous if the slider rests or is supported in the height direction only on the groove base. In any case, the slider has a working area which at least partially delimits the slider upwards in the height direction and which enables the transport and drop of a half stitch during knitting. The transport of a half stitch is understood to mean, for example, the sliding of a half stitch in the length direction of the compound needle.A specialist in textile technology understands the drop of a half stitch to mean the sliding of a half stitch over the closed interior of the hook and off the compound needle so that the half stitch no longer has contact with the compound needle. A dropped half stitch or loop does not wrap around the compound needle. The working area is the area of ​​the slider that has direct contact with the half stitch during knitting. The working area of ​​the slider therefore includes, among other things, the part of the slider with which the interior of the hook can be closed. To prevent lint and dirt from getting into the groove, the slider is guided in the groove in such a way that a half stitch during knitting can exert a force on the working area of ​​the slider that is directed downwards in height and leads to an increase in the pressure force of the slider on the groove base.The force is preferably exerted through direct contact of the half-stitch with the working area of ​​the slider. This guides the slider securely on the groove base and prevents the formation of a gap between the slider and the groove base, into which large amounts of lint and dirt could penetrate and remain. The force is preferably exerted on the slider in the area of ​​the longitudinal extension of the groove. The direction of action of the force then intersects with the groove base. This allows the pressure force to be increased very efficiently. However, an increase in the pressure force of the slider on the groove base is not achieved if the force can only be exerted on the slider in the area of ​​the longitudinal extension of the hook interior. In this case, at most a tilting of the slider about an axis lying in the width direction would be caused. The pressure force of the slider on the groove base would actually be reduced.The force can preferably be exerted on the slider when the hook interior is open and the half stitch slides along the needle shaft during knitting. When the hook interior is open, the slider is displaced as far as possible in the longitudinal direction away from the hook relative to the needle body. Even in this position, a force can be exerted on the slider with a half stitch. This prevents lint and dirt from getting into the groove, even when the hook interior is open. The slider usually has no projections or elevations in the working area that could prevent a half stitch from sliding along or cause a half stitch to widen. Furthermore, the slider usually has no projections or elevations in the working area via which a longitudinally acting control force with which the longitudinal movement of the slider can be controlled can be exerted on the slide.Stitch-forming textile machines typically have a needle channel that is delimited in the width direction by groove walls. The needle body and the slider of the compound needle can advantageously be guided together in the needle channel of a stitch-forming textile machine so as to be displaceable in the longitudinal direction, wherein the needle body and the slider are also displaceable relative to one another in the longitudinal direction. Compound needles according to the invention can be operated such that a half stitch is formed in their hook interior using a yarn. For this purpose, the yarn is usually inserted into the hook interior when the hook is open. The formed half stitch slides longitudinally away from the hook along the needle shank and out of the hook interior. When operated in a stitch-forming textile machine, the compound needle preferably performs a propulsion movement - the hook of the compound needle moves longitudinally out of the needle channel.The half stitch, which has previously slid out of the hook's interior, then exerts a downward force on the working area of ​​the slider, increasing the vertically directed pressure of the slider on the groove base. This increased pressure guides the slider particularly firmly against the groove base. This prevents a gap from forming between the slider and the groove base during operation. This makes it particularly effective in reducing the ingress of lint, dust, and dirt into the groove of a stitch-forming textile machine. Furthermore, a particularly uniform stitch pattern is achieved.

[0008] According to the invention, the needle body has two shank walls that delimit the groove over its entire longitudinal extension in the width direction, which runs perpendicular to the longitudinal direction and perpendicular to the height direction, at least on one side, but preferably on both sides. The shank walls enable the slider to be firmly positioned in the width direction. The slider is therefore not displaceable in the width direction relative to the needle body. In the case of a groove with a U-shaped cross-section, the shank walls are two parallel legs of the U-shape, which are connected to one another at their ends by the groove base, wherein the cutting edge of the groove base runs at least partially perpendicular to the cutting edge of the shank walls.

[0009] According to the invention, the at least two shaft walls of the compound needle have a recess and the working area of ​​the slide projects beyond the recess in the vertical direction or is flush with the recess in the vertical direction. Preferably, the working area projects beyond the recess or is flush with it when the slide is in a position in which the hook interior is open. The slide is then in a retracted state. The slide is thereby displaced to its maximum extent relative to the needle body in the longitudinal direction pointing away from the hook. A particularly great force can be exerted by a half stitch on a slide that projects beyond the recess or is flush with the recess if the half stitch slides along the shaft in the region of the recess. The ingress of lint, dust and dirt into the groove of a stitch-forming textile machine can thus be reduced even further.It is particularly preferred if the working area of ​​the slider extends vertically beyond the recess. This allows the amount of force that can be exerted by a half-stitch on the slider to be increased. The previously described advantages are thereby enhanced.

[0010] To prevent damage to the yarn during operation of the compound needle in a stitch-forming textile machine, the at least two shaft walls of the compound needle can have at least one elevation. The elevation projects vertically above the working area of ​​the slider. The working area of ​​the slider preferably projects above the recess, at least when the slider is in a retracted state. If the shaft walls also have a recess, the elevation is arranged longitudinally between the recess and the hook.

[0011] The compound needle can have a guide bar that is connected to at least one of the shaft walls and at least partially closes the opening of the groove in the vertical direction. If the shaft walls of the compound needle have a recess, the guide bar advantageously adjoins the recess in the longitudinal direction, pointing away from the hook. The guide bar is preferably an integral component of the needle body. It is particularly advantageous if the guide bar is a part of at least one of the shaft walls that is bent in the width direction. The guide bar increases the stability and in particular the rigidity of the compound needle. Compound needles with such a guide bar are particularly suitable for high-speed stitch-forming textile machines.

[0012] The half stitches formed with a compound needle are usually widened or stretched as they slide from the inside of the hook onto the needle shank. To achieve particularly even knitwear, the compound needle can be designed so that the widening is as small as possible. For this purpose, a needle breast, which limits the needle body in terms of height and is connected to the hook, can have a diagonally rising profile pointing away from the hook in the longitudinal direction. Due to the diagonally rising profile, the stitch is initially continuously stretched as it slides along the needle breast. This prevents the half stitch from stretching too quickly or abruptly. To counteract excessive stretching of the half stitch, the compound needle can also be designed with a groove. The groove is a depression in the back of the needle and overlaps the working area of ​​the slider in the longitudinal direction.The needle back is usually understood by those skilled in the art to be the surface of the compound needle that limits the needle body in the vertical direction downwards. The needle back is usually designed to rest on the floor of the needle channel of a stitch-forming textile machine. To improve the guidance of the compound needle in a needle channel, the groove can be arranged so that it extends longitudinally only within the working area of ​​the slider - i.e., it completely overlaps the working area in the longitudinal direction. The widening of the half stitch also influences the amount of force that can be exerted by the half stitch on the slider in the vertical direction downwards. It has been shown that by reducing the widening of the half stitch, the friction between the slider and the needle body can also be reduced. The compound needle then has a lower power requirement during operation and enables energy savings.

[0013] Compound needles are typically driven by engagement with a cam part of a stitch-forming textile machine. For this purpose, the cam parts have at least one groove-like recess along a cam curve. Drive butts of the compound needle protrude into these groove-like recesses and, during knitting, are driven to move longitudinally according to the course of the cam curve. For this purpose, the needle body preferably has a needle drive butt at the rear end of the needle shaft facing away from the hook. This needle drive butt projects vertically above the surrounding areas of the needle shaft and is suitable for engaging the at least one groove-like recess of a cam part. The needle body can also have more than one needle drive butt.Preferably, the slider of the compound needle has a slider drive butt at its rear end facing away from the working area, which projects vertically above the surrounding areas of the slider and is also suitable for engaging in a groove-like recess of a cam part. The slider can also have more than one slider drive butt. The slider drive butt and the needle drive butt usually engage in different groove-like recesses of the cam part. The needle drive butt and the slider drive butt are suitable for absorbing drive forces from a stitch-forming textile machine for driving the compound needle. The drive forces are advantageously provided by a cam part of a stitch-forming textile machine and transmitted to the drive butts.

[0014] Compound needles are typically designed to be guided in a groove-like needle channel of a stitch-forming textile machine. In order to guide a compound needle according to the invention particularly stably in a needle channel, it is advantageous if both the needle body and the slider can be supported on the walls of the needle channel, at least over sections of their longitudinal extent in the width direction. For this purpose, the slider can have a slider shaft that adjoins its working area in the longitudinal direction and has the same width in the width direction as the needle shaft. So that the slider can be guided longitudinally displaceably in the U-shaped groove of the needle body between the two shaft walls, the working area of ​​the slider is tapered in the width direction compared to the width of the slider shaft so that it can be inserted into the groove of the needle body.The slider shaft is therefore wider than the working area of ​​the slider. The wider slider shaft also increases the stability of the slider. Such compound needles are therefore particularly advantageous for use in high-speed, loop-forming textile machines. Typically, the working area of ​​the slider has a width that is at most equal to the width of the groove or the distance between the shaft walls in the width direction.

[0015] When a compound needle according to the invention is used in a stitch-forming textile machine, the compound needle advantageously engages in a further groove-like recess of a cam part, wherein the cam part is suitable for transmitting a drive force acting in the longitudinal direction to the slider. Advantageously, the compound needle can be moved in the width direction relative to the cam part. The compound needle slides along in the groove-like recess and is moved in the longitudinal direction depending on the course of the groove-like recess. In this way, the movement of the compound needle can be controlled with the cam part. Preferably, at least the slider engages in a groove-like recess of the cam part. The movement of the slider can then be controlled via the cam part. Further advantages arise if the needle body also engages in a groove-like recess of the cam part.The movement of the needle body can then also be controlled via the cam. It is particularly advantageous if the slider and the needle body engage in different groove-like recesses in the cam. The movement of the slider and the needle body can then be controlled independently of each other, allowing them to move relative to each other.

[0016] Especially when the slider is in a retracted position, with the hook interior fully open vertically, lint and dirt can penetrate the groove of the compound needle. It is therefore particularly advantageous if the half-stitch exerts a force on the working area while the hook interior is fully open vertically. This significantly reduces the amount of dirt and lint that penetrates the groove.

[0017] Further advantages arise when the yarn is inserted into the hook interior again while the previously formed half stitch exerts the force on the working area. This is a particularly effective way to prevent lint from entering the needle channel, especially while the yarn is being inserted. When the compound needle is then pulled in, another half stitch can be formed with the yarn in the hook interior, while the previously formed half stitch becomes a stitch. By repeating this procedure, one stitch can be formed after the other. Advantageously, the yarn is inserted into the hook interior while the hook interior is completely open in vertical direction and the previously formed half stitch simultaneously exerts the force on the working area. Fig. 1 Figure 1 shows a slide needle 1. Fig. 2 Figure 2shows the compound needle 1 in a stitch-forming textile machine 27, showing various positions 30, 31, 32 that the compound needle 1 assumes during operation. Fig. 3 Figure 3 shows an enlarged view of the front end of the slide needle 1 from Fig. 1 . Fig. 4 Figure 4 shows the section AA from Fig. 3 . Fig. 5 Figure 5 shows the cut BB from Fig. 3 . Fig. 6 Figure 6 shows the section CC from Fig. 3 . Fig. 7 Figure 7 shows the section DD from Fig. 3 . Fig. 8 Figure 8 shows an alternative embodiment of the slide needle 1 in an enlarged view as in Fig. 3 . Fig. 9 Figure 9 shows the cut EE from Fig. 8 .

[0018] The Figure 1shows a compound needle 1 with a needle body 2 and a slider 10. The needle body 2 has a needle shaft 3, the main direction of extension of which lies in a longitudinal direction z. At its front end in the longitudinal direction z, the needle body 2 has a hook 4, which encloses a hook interior 5. The hook 4 is suitable for forming half stitches 12 with a yarn during knitting. With the half stitch 12, a force 13 directed downwards in the vertical direction y can be exerted on the slider 10. The hook interior 5 is open upwards in the vertical direction y. The slider 10, however, is displaceable in the longitudinal direction z in a groove 6 (see Fig. 4-6) of the needle body 2 so that it can open and close the hook interior 5 depending on its relative position to the needle body 2. In order to control the relative position between the slider 10 and the needle body 2, both the slider 10 and the needle body 2 each comprise a drive butt, wherein the drive butt of the slider 10 is referred to as the slider drive butt 21 and the drive butt of the needle body 2 is referred to as the needle drive butt 20. A drive force acting in the longitudinal direction z can be exerted on the needle body 2 and the slider 10 via the drive butts in order to control the movements of the needle body 2 and the slider 10 independently of one another.

[0019] In Fig. 2Three positions 30, 31, 32 of the compound needle 1 are shown, which typically occur when used in a stitch-forming machine during operation of the compound needle 1. To simplify the illustration, the representation of conventional machine elements known from the prior art, such as sinkers, is omitted. Such elements can nevertheless be advantageously combined with the compound needle 1 according to the invention in stitch-forming machines, in particular for holding down and knocking off stitches. During operation, the compound needle 1 according to the invention passes through the Fig. 2illustrated positions 30, 31, 32 in the sequence from left to right to form stitches. The sequence is represented symbolically by arrows 28 between the individual positions 30, 31, 32. Since the same compound needle 1 is shown in all positions, for the sake of clarity not all components of the compound needle 1 have been provided with reference symbols in every position shown. The mode of operation of the compound needle 1 and a method for forming stitches with the compound needle 1 is described below starting from an extension position 30 in which the compound needle 1 protrudes as far as possible from the needle channel 23 in the longitudinal direction z. This means that the distance in the longitudinal direction z between the hook 4 and the needle channel 23 is greatest in this position.In the drive-out position 30, a half-stitch 12 previously formed with the compound needle 1 is located outside the hook interior 5 on the needle shaft 3 or rather wraps around the needle shaft 3. The half-stitch 12 is in contact with the slider 10 in the area of ​​the working area 11 of the slider 10. The slider 10 is partially covered by the shaft wall 9. Its covered edges are therefore shown in dashed lines for clarity. At the point of contact with the slider 10, the half-stitch 12 exerts a force 13 on the slider 10, directed downwards in the height direction y. The slider 10 is pushed into the groove 6 (see . Fig. 4-6) of the needle body 3. In the expulsion position 30, the hook interior 5 is opened and a yarn 24 is inserted into the hook interior 5. Starting from the expulsion position 30, the compound needle 1 makes a retraction movement 29 in the longitudinal direction z, by which the compound needle 1 is retracted further into the needle channel 23. During this retraction movement 29, the slider 10 is moved relative to the needle body 2 such that the slider 10 closes the hook interior 5 with its front end in the longitudinal direction z. The half stitch 12 then slides during the retraction movement 29 along the needle shaft 3 and the slider 10 over the closed hook interior 5 and off the compound needle 1, which Fig. 2The sliding of the half-stitch 12 off the compound needle 1 is also referred to by those skilled in the art as a drop, because the half-stitch 12 in question then no longer has direct contact with the compound needle 1. With the yarn 24 previously inserted into the hook interior 5, a loop is pulled through the half-stitch 12, thus forming a new half-stitch 12'. The previously formed half-stitch 12 thus becomes stitch 26. The new half-stitch 12' and stitch 26 are shown in the illustration of the insertion position 32. In the insertion position 32, the compound needle 1 is drawn furthest into the needle channel 23. This means that the distance between the hook 4 and the needle channel 23 in the longitudinal direction z is smallest in this position. In this position, the new half-stitch 12' is still located in the hook interior 5.Starting from the insertion position 32, the compound needle 1 makes a propulsion movement 33 in the longitudinal direction z out of the needle channel 23. During the propulsion movement 33, the slider 10 is moved relative to the needle body 2 such that the hook interior 5 is opened. The compound needle 1 continues its propulsion movement 33 until it has reached its propulsion position 30 again. Meanwhile, the new half stitch 12' slides out of the opened hook interior 5 onto the needle shaft 3. The previously described stitch formation process begins again at this point. In this way, one stitch after the other can be formed to produce a knitted fabric.

[0020] The Figure 3 shows an enlarged view of the front end of the slide needle 1 from Figure 1with the hook 4 and the working area 11 of the slider 10. The slider 10 is partially covered by the shank wall 9. Its covered contours are shown in dashed lines for clarity. The hook interior 5 of the compound needle 1 is shown closed. This means that the working area 11 of the slider 10 is positioned relative to the needle body 2 in such a way that it completely covers the opening of the hook interior 5. A diagonally rising needle breast 17 is connected to the hook 4 in the longitudinal direction z. The needle breast 17 is the surface that limits the needle body 2 upwards in the vertical direction y. The diagonally rising course of the needle breast 17 ensures a continuous, slow and therefore gentle widening of a half stitch 12 when it slides out of the hook interior 5 onto the needle shank 3. At its needle back 18, which limits the needle body 2 downwards in the height direction y, the needle body 2 has a groove 19.The groove 19 is a depression in the needle back 18 that reduces the height of the needle body 2 in the vertical direction y. The groove 19 overlaps in the longitudinal direction z with the working area 11 of the slider and the diagonally rising section of the needle breast 17. The groove 19 prevents excessive widening of a half stitch 12 during knitting. The diagonally rising section of the needle breast 17 ends in a raised portion 15 of the needle body 2 that projects beyond the slider 10 in the vertical direction y. The raised portion 15 covers the tip of the slider 10 when it is retracted.

[0021] In Fig. 4 is the section AA through the slider needle 1 from Figure 3shown. The section shows the groove 6 in the needle body 2, in which the slider 10 is guided at this point. The groove 6 is delimited on both sides in the width direction x by a shaft wall 9. Both shaft walls 9 have the previously described elevation 15. The elevation 15 projects beyond the slider 10 in the height direction y by the elevation height 25, which corresponds to the distance in the height direction y between the top side of the elevation and the top side of the slider 10. The elevation height 25 is greater than zero if the elevation 15 projects beyond the slider 10 in the height direction y. During knitting, a half stitch 12 can slide over the elevation 15, as shown, without coming into contact with the slider 10. This is particularly advantageous when the hook interior 5 is open, because it can prevent the half stitch 12 from touching the tip of the slider 10 and possibly being damaged by the tip.

[0022] As in Fig. 3As can be seen further, the elevation 15 is followed by a recess 14 in the needle body 2. Fig. 5 shows the section BB in the area of ​​this recess 14. The slide 10 is flush with the recess 14 in the shaft walls 9 of the needle body 2 in the vertical direction y. As a result, the half stitch 12 rests on the slide 10 when it is located in the area of ​​the recess 14. The half stitch 13 exerts a force 13 on the slide 10, which presses the slide 10 more strongly against the groove base 8 of the groove 6. This prevents a gap from forming between the groove base 8 and the slide 10 during operation, into which gap dirt and lint could penetrate.

[0023] In the longitudinal direction z pointing away from the hook, the Fig. 3In the slider needle 1 shown, a guide bar 16 is attached to the recess 14. In the area of ​​the guide bar 16, the height of the needle shaft 3 is increased in the vertical direction y. This area is therefore not suitable for contact with a half stitch 12 during knitting. The half stitch 12 would then be widened too much. Figure 6 shows the section CC through the slider needle 1 at the Fig. 3 marked point in the area of ​​the guide bar 16. In contrast to the section BB from Fig. 5 It can be seen that the shaft walls 9 protrude in the vertical direction y over the slide 10. The ends of the shaft walls 9 are bent laterally inwards over the groove 6 in the width direction x and at least partially close the groove 6 in the vertical direction y. In the embodiment of Fig. 6However, an opening 7 of the groove 6 remains, which is so small that the slider 10 cannot be removed from the groove 6 in the area of ​​the guide bar 16. The guide bar 16 increases the stability of the slider needle 1 and thus its service life.

[0024] In alternative embodiments, which are not shown, the guide web 16 can also be designed to be continuous, so that the groove 6 no longer has an opening 7 in the region of the guide web 16.

[0025] As in Fig. 3 As shown, the groove 6 ends in the longitudinal direction z behind the guide bar 16. The slide 10 rests on the needle body 2 in the area extending in the longitudinal direction z behind the guide bar 16, without being supported or guided laterally by the shaft walls 9. In Fig. 7 is the cut DD from Fig. 3which lies in the area in the longitudinal direction z behind the guide bar 16 or behind the groove 6. The needle body 2 has a solid, essentially rectangular cross-section without grooves or recesses in this area. The slider 10 rests on the needle body 2. In the area of ​​the section, a tapered area of ​​the slider 10 is cut and marked by hatching. It can be seen that the slider shaft 22 widens behind the cutting plane (non-hatched parts of the slider 10) in the width direction x to the width of the needle body 2. The slider 10 and the needle body 2 can thus both be inserted together in a conventional needle channel 23 of a stitch-forming textile machine 27 and guided independently of one another in the width direction x through the needle channel 23. For clarification, Fig. 7In addition to the slider 10 and the needle body 2, a conventional needle channel 23 in a stitch-forming textile machine 27 is also shown. The illustration of further machine parts of the stitch-forming textile machine 27 has been omitted. Therefore, only a very small section of the stitch-forming textile machine 27 is shown, which is also indicated by the break line in Fig. 7 is indicated.

[0026] The Figure 8 shows an alternative embodiment of the compound needle 1' in an enlarged view. The compound needle 1' and the illustration correspond to a large extent to the compound needle 1, which is partially Figure 3 Therefore, only the differences to the slider needle 1 from Figure 3 In contrast to the slider needle 1 from Figure 3 has the Schibernadel 1' from Figure 8 a recess 14 in the shaft walls 9 of the needle body 2 which is deeper in the height direction y.

[0027] The Figure 9 shows the cut EE from Figure 8 . It can be seen that, as a result of the deeper recess 14, the slider 10 projects beyond the recess 14 or the needle body 2 and its shaft walls 9 in the vertical direction y in the region of the longitudinal extension of the recess 14. A half stitch 12, which slides along the needle shaft 3 in the region of the longitudinal extension of the recess 14, thus rests only on the slider 10 and exerts a force 13 acting on the slider 10 in the vertical direction y. List of reference symbols 1, 1` Slide needle 2 needle body 3 needle shaft 4 Hook 5 Hook interior 6 Nut 7 Opening of the groove (6) 8 Groove base 9 shaft wall 10 slider 11 Workspace 12, 12' half stitch 13 Power 14 recess 15 Survey 16 Guide bridge 17 Needle breast 18 Needle back 19 throat 20 Needle drive foot 21 Slide drive foot 22 Slide shaft 23 Needle channel 24 yarn 25 elevation 26 mesh 27 Stitch-forming textile machine 28 Arrow 29 retraction movement 30 Expulsion position 31 Intermediate position 32 Feed position 33 sprouting movement x Latitude direction y Altitude direction z Longitudinal direction

Claims

1. Compound needle (1) for stitch-forming textile machines comprising a) a needle body (2) with a needle shank (3), that extends predominantly in a longitudinal direction (z), b) a hook (4), which adjoins the needle shank (3) at the front end of the needle body (2) and encloses an upwardly open hook inner space (5) in a vertical direction (y) perpendicular to the longitudinal direction (z), c) a slot (6) which is an elongate recess in the needle shank (3) which has an upwardly directed opening (7) in the vertical direction (y) and is delimited downwards in the vertical direction (y) by a slot base (8), d) a slider (10) that is guided displaceably in the slot (6) resting on the slot base (8) in such a manner in the longitudinal direction (z) that it can close and open the hook inner space (5) in the vertical direction (y) with its front end in the longitudinal direction (z), e) wherein the slider (10) has a working area (11) running in the width direction (x) and the longitudinal direction (z) which at least partially delimits the slider (10) upwards in the vertical direction (y) and enables a half-stitch (12) to be transported and pressed off during knitting operation, f) and wherein at least two shank walls (9) of the needle body (2) over their entire length of extension in the longitudinal direction (z) delimit the slot (6) in a width direction (x), wherein the width direction (x) runs perpendicular to the longitudinal direction (z) and vertical direction (y) characterized in that the slider (10) is guided in the slot (6) in such a manner that with a half-stitch (12) in knitting operation a force (13) can be applied onto the working area (11) of the slider (10) which is downwardly directed in the vertical direction (y) and results in a strengthening of the pressing force of the slider (10) on the slot base (8), and that the at least two shank walls (9) have a recess (14) , wherein the working area (11) of the slider (10) projects beyond the recess (14) in the vertical direction (y) or terminates flush with the recess (14) in the vertical direction (y).

2. Compound needle (1) according to the preceding claim, characterized in that the at least two shank walls (9) have at least one elevation (15) which projects beyond the working area (11) of the slider in the vertical direction (y) and is arranged between the recess (14) and the hook (4).

3. Compound needle (1) according to one of the preceding claims characterized by a guide web (16) which adjoins the recess (14) pointing away from the hook (4) in the longitudinal direction (z), which is connected to at least one of the at least two shank walls (9) and at least partially closes the opening (7) of the slot (6) in the vertical direction (y).

4. Compound needle (1) according to one of the preceding claims characterized in a) that the needle body (2) has a needle drive butt (20) at its rear end of the needle shank (3) pointing away from the hook (4) which projects beyond the surrounding areas of the needle shank (3) in the vertical direction (y) , b) and that the slider (10) has a slider drive butt (21) at its rear end pointing away from the working area (11) which projects beyond the surrounding areas of the slider (10) in the vertical direction (y), c) wherein the needle drive butt (20) and the slider drive butt (21) are suitable for receiving drive forces of a stitch-forming textile machine to drive the slider needle (1).

5. Compound needle (1) according to one of the preceding claims characterized in that the slider (10) has a slider shank (22) adjoining its working area (11) in the longitudinal direction (z) which has the same width as the needle shank (3) in the width direction (x) and that the working area (11) of the slider (10) is tapered in the width direction (x) in such a manner with respect to the width of the slider shank (22) that it can be inserted into the slot (6) of the needle body (2).

6. Stitch-forming textile machine (27) with a compound needle (1) according to one of Claims 1 to 5, characterized in that the needle body (2) and the slider (10) are guided jointly displaceably in a needle trick (23) of the stitch-forming textile machine in the longitudinal direction (z), wherein the needle body (2) and the slider (10) are also displaceable relative to one another in the longitudinal direction (z).

7. Stitch-forming textile machine (27) according to the preceding claim, characterized in that the compound needle (1) engages in a slot-like recess of a cam, wherein the cam is suitable for transferring a drive force acting in the longitudinal direction (z) onto the compound needle (1).

8. Stitch-forming textile machine (27) according to the preceding claim characterized in that the compound needle (1) engages in a slot-like recess of a cam, wherein the cam is suitable for transferring a drive force acting in the longitudinal direction (z) onto the slider (10).

9. Method for stitch formation using a compound needle (1) according to one of Claims 1 to 5 with the following process steps in the said sequence: a) a half-stitch (12) is formed in the hook inner space (5) with a yarn (24), b) the half-stitch (12) formed slides in the longitudinal direction (z) pointing away from the hook (4) along the needle shank (3) out from the hook inner space (5) characterized in that c) with the half-stitch (12) a force (13) is applied to the working area (11) of the slider (10) which is directed downwards in the vertical direction (y) and strengthens the pressing force of the slider (10) on the slot base (8).

10. Method according to the preceding claim characterized in that the force (13) is applied to the working area (11) whilst the hook inner space (5) is completely open in the vertical direction (y).

11. Method according to one of the preceding Claims 9 to 10 characterized in that the yarn (24) is again inserted into the hook inner space (5) whilst the previously formed half-stitch (12) applies the force (13) to the working area (11).

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