Needle body, sliding needle assembly and warp knitting machine

Abstract

A needle body for a slider needle assembly of a warp knitting machine comprises a shank and a hook. The lower edge of the hook is arranged opposite and facing away from a re-bent portion of the hook. The upper edge of the hook is arranged facing away from the lower edge of the hook on the re-bent portion of the hook. The claimed needle body is characterized in that the hook height, measured longitudinally at the point of maximum vertical distance between the lower and upper edges of the hook, is a maximum of 0.81 mm, and the cross-sectional height, measured in a cross-section of the shank in a mesh sliding section perpendicular to the thickness direction, is a maximum of 0.81 mm. A claimed slider needle assembly comprises a needle body according to the invention and a slider and has a wrap-around length of 2.3 mm or less between the hook and the slider.

Description

[0001] Warp knitting machines and their associated knitting tools are available in various designs. Warp knitting machines are cost-intensive capital goods. Likewise, many different types of warp-knitted fabrics are available for different applications. Not every type of warp knitting machine is suitable for the production of every warp-knitted fabric, so in some cases a new warp knitting machine must be purchased to produce a new type of warp-knitted fabric. Due to the associated high costs for the knitters, warp knitting machine manufacturers strive to offer machines that can be used for many different types of warp-knitted fabrics. Therefore, modern warp knitting machines are equipped with extensive control software that can be used to adjust a wide variety of warp knitting machine parameters.

[0002] US20150361603A1 discloses detailed procedures for designing and setting up a warp knitting machine for the production of a specific warp-knitted fabric. The size of the needle stitch can be influenced to a certain extent, for example, by the interaction of yarn supply and fabric take-off.

[0003] The geometric dimensions of the knitting tools, particularly the needles and sliders, sometimes have a direct influence, for example, on the size of the needle loops in the warp-knitted fabric and thus on the appearance of the warp-knitted fabric. Due to the special design of the drives on warp-knitting machines, certain dimensions of the knitting tools, such as the needles, sliders, and sinkers, are fixed by the drive movement or can only be partially changed independently of one another. For each generation of a machine type in a particular gauge, almost without exception, only one needle type has been available on the market. Surprisingly, the known knitting tools, particularly compound needles comprising the needle body and slider, have uniform values ​​for certain functional dimensions, regardless of the gauge of the warp-knitting machine in which they are used.

[0004] For very old, slow-running knitting machines, different knitting tool geometries have become known. For example, GB512850 shows a needle with a slider arranged below the needle body. This special arrangement imposes certain constraints on the geometry of the needle body. FR936411 shows a needle in which the needle body and slider are formed from a tubular base material. Compound needles shaped in this way cannot be used on modern, high-speed warp knitting machines because the tubular cross-sections do not have sufficient bending moment in the direction of load.

[0005] In contrast to warp knitting, attempts have been made to produce stitches of different sizes on a single machine using flat knitting machines or circular knitting machines by changing the dimensions of the needles—and especially the hooks. Due to the completely different conditions regarding the needle drives on warp knitting machines and flat or circular knitting machines, such approaches, as shown, for example, in EP1767679A1, are not transferable to warp knitting machines.

[0006] The aim of the present invention is to expand the possible applications of a warp knitting machine for producing different warp knitted fabrics by providing novel knitting tools and arrangements of knitting tools.

[0007] A needle body according to the invention comprises a shaft defined by two parallel, oppositely arranged flat sides, to which a thickness direction of the needle body is perpendicular, and by an upper edge and a lower edge. The needle body further comprises a hook for receiving yarn sections. The needle body is configured for a compound needle arrangement of a warp knitting machine. A drive section of the shaft is configured for attaching the needle body to a drive device of a warp knitting machine.Typically, the drive section of the shaft of a needle body in a warp knitting machine is held together with other, usually identically constructed needle bodies in a drive device of the warp knitting machine, for example, in a bar. It is clamped, in particular, between its upper and lower edges under screw pretension and supported by its opposite flat sides in a groove of a bar to prevent lateral tilting. The shaft advantageously has a rectangular contour with rounded edges in cross-section. The drive section can define a rear end of the needle body in a longitudinal direction.

[0008] A hook bottom edge is positioned opposite and facing away from a bent-back portion of the hook. Hooks of knitting tools are almost always bent by approximately 180°, resulting in a bent-back portion (approximately 180°) that is positioned opposite a non-bent portion. This structure does not have to be created by bending; the term "bent" is used merely to describe the geometry. The hook bottom edge extends at least in one longitudinal direction of the needle body. The hook bottom edge is generally approximately straight, at least in part, relative to the bent-back portion. Such a straight or nearly straight portion defines the longitudinal direction of the needle body. The longitudinal direction is perpendicular to the thickness direction and to a vertical direction of the needle body that is also perpendicular to the thickness direction. The hook top edge is located above the hook bottom edge in the vertical direction.According to this positional relationship to the vertical direction, "top" and "bottom" are to be understood in this document. The hook forms the front end of the needle body in the longitudinal direction. Since needles of warp knitting machines are generally not guided longitudinally in a tool carrier and generally do not perform a linear movement during the knitting process, the definition of a longitudinal direction and the vertical direction perpendicular to it is, at least to a limited extent, arbitrary if the lower edge of the hook does not have a clearly straight section. In this case, the longitudinal direction must be averaged at the bottom of the bent-back area. The shank of the needle body can run predominantly in the longitudinal direction but also in one or more angled sections.

[0009] An upper edge of the hook is arranged on the bent-back part of the hook, facing away from the lower edge. The upper edge of the hook can be partially straight and is preferably inclined by a few degrees, for example up to 5°, to the lower edge of the hook. This can be advantageous to prevent collisions with the slider. The slider can be supported on the upper edge of the hook or run contact-free just above it when it performs its relative movement to the needle body. The relative movement between the needle body and the slider can occur predominantly approximately in the longitudinal direction, although the movement of the needle body and the slider generally does not follow a straight path.

[0010] A needle body according to the invention is characterized in that a hook height, which is to be measured longitudinally at the point of maximum distance in height between the lower edge of the hook and the upper edge of the hook, is a maximum of 0.81 mm and a cross-sectional height, which is to be measured in a stitch sliding section perpendicular to the thickness direction, is a maximum of 0.81 mm. A hook height of 0.78 mm or less can be particularly advantageous. Likewise, a cross-sectional height in the stitch sliding section of 0.65 mm or less can be particularly advantageous. Due to the reduced hook height and the reduced cross-sectional height in the stitch sliding section, smaller needle stitches can be produced without parameters of the warp knitting machine such as the yarn feed or the fabric take-off having to be specifically adapted to the production of small needle stitches.Due to the low height of the shaft in the loop sliding section, on which a stitch regularly slides or comes to rest during knitting, the respective stitch is not widened too much and the reduced height of the hook can therefore significantly determine the size of the stitch. The cross-sectional height in the loop sliding section can be 0.7 mm or 0.75 mm, for example. The loop sliding section can extend longitudinally, measured from the front end of the needle on the hook to 15 mm at the rear on the shaft. This means that at least the above-mentioned parameters of the warp knitting machine can be specifically tailored to other requirements of the warp knitted fabric and thus new types of warp knitted fabric can be produced that could not be manufactured in this way before. In particular, it is also possible to avoid a grid-like warp knitted fabric due to small needle stitches, despite the small hook and shaft cross sections.The appearance of the warp-knitted fabric can be positively influenced by straighter needle stitches. Warp-knitted fabric can also be produced with a higher density or quality. The hook can have a maximum extension of 0.26 mm or less perpendicular to the thickness direction at any point or at least half of the hook bend in a cross-section. A cross-section of the hook or the shaft is to be formed as follows: The needle body, with its overall elongated extension, defines a local body center longitudinal axis at every point of its extension. A cross-section at any point is to be formed perpendicular to this local body center longitudinal axis. The body center longitudinal axis should generally be perpendicular to the thickness direction, which is determined by the two flat sides.Needle bodies of knitting tools are usually punched out of steel strip, the thickness direction of the needle body corresponds to the thickness direction of the steel strip from which the knitting tool is punched.

[0011] A central section of the upper edge of the shank of the needle body can be recessed in a central part of the drive section relative to the two adjacent support sections of the upper edge, and the two adjacent support sections of the upper edge can lie in a support plane. With such a designed upper edge, the needle body can have a stable and precisely definable positioning on a drive device. The central section can have a length of 5 mm or more. Advantageously, the upper hook edge of the needle body lies between 1.5 mm and 1.6 mm below the support plane of the drive section in the vertical direction.

[0012] The bent-back part of the hook of the needle body ends with a hook point. The hook point can be rounded and positioned eccentrically to the adjacent bent-back part of the hook. The distance between the hook point and the furthest point of the hook in the longitudinal direction is at least 1.15 mm. The upper edge of the hook, which is located on the bent-back part of the hook, ends longitudinally forward, i.e., facing away from the hook point, as soon as the upper edge of the hook forms an angle of more than 5° to the longitudinal direction. Likewise, the lower edge of the hook ends forward at the point where the angular deviation from the longitudinal direction is more than 5°.

[0013] The needle body can have a butt located in the drive section of the shank. The butt can serve to secure the needle body against displacement by resting a front edge of the butt against a counter-bearing surface of the drive mechanism. The working distance from this front edge of the butt to the point of the hook that is furthest away in the longitudinal direction can be between 45 mm and 49 mm.

[0014] The shank of the needle body has a slotted section between the drive section and the hook, in which a slot is provided in the upper edge of the shank. The slot can be used to guide a slider under a stitch lying or sliding on the upper edge of the slotted section. The slotted section can therefore also include the stitch sliding section. A slot base of the slot can be aligned, at least in sections, with the nearest point on the upper edge of the hook or can lie below a longitudinal line that is tangential to the nearest point on the upper edge of the hook. This creates free space above the hook tip for a pivoting movement of the slider, so that a collision of the slider with the hook tip is unlikely.The point on the hook's upper edge closest to the slot is often not a point on the rounded hook point, but rather the last point on the hook's upper edge adjacent to the rounded hook point. The slot base is curved along its length to optimally accommodate the pivoting movement of the slider and thus avoid unnecessarily weakening the needle body's shank.

[0015] The compound needle assembly according to the invention comprises a needle body according to the invention and a slider. The compound needle assembly is specially designed for use in a modern warp knitting machine. The slider is arranged relative to the needle body such that a slider lower edge is positioned opposite the hook upper edge. The compound needle assembly is characterized in that a wrap length is 2.3 mm or less. The wrap length is to be measured in a cutting plane that is perpendicular to the longitudinal direction and in the longitudinal direction at any point where the hook upper and lower edges are opposite each other. The wrap length corresponds to the length of the shortest closed curve that encloses the cut contour of the hook and the slider.Due to the shorter wrap length compared to the prior art, a warp-knitted fabric can be produced with smaller needle stitches than was possible with previously known warp-knitted fabrics, because the wrap length, together with the cross-sectional height in the stitch sliding section, significantly determines the size of the needle stitch when the stitch slides over the hook and slider for knock-off. The claimed compound needle arrangement therefore relates to an arrangement of needle body and slider as it occurs at or around the time within a stitch formation cycle at which a stitch is knocked off. Due to the movement sequences occurring during the knitting process, it is not possible to produce corresponding needle stitches with the previously known wrap lengths of 2.4 mm or greater by selecting certain parameters for, for example, fabric take-up or yarn feed.A new type of warp-knitted fabric can, for example, have a new look due to straighter needle stitches or a greater density due to closer-spaced rows of stitches.

[0016] In a compound needle arrangement, the needle body and slider can be arranged so that there is a safety distance between the top edge of the hook and the bottom edge of the slider. Since both the needle bodies and the sliders in a warp knitting machine are usually permanently attached to a drive device, contact between the needle body and slider, for example for mutual guidance, is not necessary. Since contact would also result in wear, the needle body and slider often do not touch in an optimally adjusted compound needle arrangement. The amount of the mutual distance is incorporated accordingly into the degree of wrap. The distance can be influenced and, in particular, reduced by tension applied to the yarn sections.

[0017] The lower edge of the slider may be adjacent to the upper edge of the hook. Contact between the upper edge of the hook and the lower edge of the slider can usually occur at a point. The wrap length of the slider needle arrangement can then advantageously be 2.14 mm or less. The wrap length is to be measured in a cutting plane that is perpendicular to the longitudinal direction and in the longitudinal direction at any point where the upper and lower edges of the hook are opposite each other. The wrap length corresponds to the length of the shortest closed curve that encloses the cut contour of the hook and the slider.

[0018] A warp knitting machine according to the invention is characterized by a plurality of compound needle assemblies according to the invention. At least one compound needle assembly can be arranged in the warp knitting machine such that the at least one hook lower edge lies a maximum of 0.81 mm below a theoretical line for the hook upper edge, which is determined by the gear arrangement of the warp knitting machine. Particular advantages can result if the at least one compound needle assembly is arranged in the warp knitting machine such that the at least one hook lower edge lies a maximum of 0.78 mm below a theoretical line for the hook upper edge. This ensures that the warp knitting machine can operate at high productivity.At least two needle bodies of the plurality of needle bodies can be fixed to a first drive device of the warp knitting machine so as to be immovable relative to one another and / or at least two sliders of the plurality of sliders can be fixed to a second drive device of the warp knitting machine so as to be immovable relative to one another. Fig. 1 Figure 1 shows a symbolic representation of a needle body in a view in the thickness direction. Fig. 2 Figure 2 shows a cross section of the drive section of the shaft of the needle body of the Figure 1 . Fig. 3 Figure 3 shows in an enlarged, symbolic view a central section and support sections of the drive section of the needle body of the Figure 1 . Fig. 4 Figure 4 shows in an enlarged, symbolic view the hook and part of the slotted section of the needle body of the Figure 1 . Fig. 5 Figure 5symbolically shows a compound needle arrangement comprising the needle body of the Figure 4 and part of a slider. Fig. 6Figure 6 shows a cross section through the hook and slider of the slider needle assembly of the Figure 5 .

[0019] Figure 1 shows a symbolic representation of a needle body 1 in a view in the thickness direction D. In the view of the Figure 1 and the other figures, only the lines that define the outline of the needle body are shown. The needle body extends in the longitudinal direction L and the height direction H. The shaft 2 of the needle body 1 has in its Figure 1 The drive section 8 arranged on the right has a foot 19 with a front edge 18 which can be applied to a drive device of a warp knitting machine. The view in the thickness direction D is directed perpendicularly to the flat side 3, the opposite flat side 4 is in the cross-sectional view of the Figure 2The shaft 2 is limited in the height direction H by an upper edge 5 and in the height direction H by a lower edge 6. The shaft 2 has a rectangular cross-section with slightly rounded edges, which in turn Figure 2 can be seen.

[0020] In Figure 1On the left, the needle body 1 has a hook 7 with a bent-back part 10, a hook upper edge 11 and a hook lower edge 9. The front edge 18 of the butt 19 has a working distance 20 in the longitudinal direction L to the point of the hook 7 furthest away in the longitudinal direction L. A slotted section 21 is arranged between the drive section 8 and the hook 7. The slotted section 21 comprises the stitch sliding section 32, which is designed to support and guide stitches on the slotted edges of the slotted section 21. The shaft 2 is designed to be significantly lower in the stitch sliding section 32 in the height direction H compared to the drive section 8 so that the stitches are not widened.

[0021] Figure 3 shows in an enlarged, symbolic view a central section 13 and support sections 14 of the drive section 8 of the needle body 1 of the Figure 1. In this enlarged view, two features can be seen on the shaft, which are Figure 1 not emerge. Figure 3 shows a central section 13 of the drive section 8, which is set back in the height direction H compared to two adjacent support sections 14 of the shaft 2. The two support sections 14 are flat and lie in a uniform support plane 15, which is shown as a broken line. The central section 13 is shown as a trough-shaped design. This trough-shaped design is exemplary, and any desired designs are conceivable in which the central section 13 does not touch or penetrate the support plane 15 defined by the adjacent support sections 14 in the height direction H.

[0022] Figure 4 shows in an enlarged, symbolic view the hook 7 and large parts of the slotted section 21 of the needle body 1 of the Figure 1. The lower edge 9 of the hook is straight and runs in the longitudinal direction L. The upper edge 11 of the hook is inclined towards the lower edge 9 of the hook in the direction of the hook tip 16. The hook height 12 is thus the maximum distance in the height direction H between the lower edge 9 of the hook and the upper edge 11 of the hook. The hook tip 16 has a tip distance 17 in the longitudinal direction L to the point on the hook 7 which is furthest away from the hook tip 16 in the longitudinal direction L. The slot 22 is indicated by dashed lines. The slot base 23 of the slot 22 lies, at least in the vicinity of the hook 7, in the height direction H below the upper edge 11 of the hook and in particular below the line 24 which is applied tangentially from above to the hook tip 16 in the longitudinal direction L. A cross-sectional height 25 measured in a cross-section of the shaft 2 in the slot section 21 and in a direction perpendicular to the thickness direction D is 0.65 mm in the present example.

[0023] Figure 5symbolically shows a compound needle arrangement 26 comprising the needle body 1 of the Figure 4 and a slider 27. The slider 27 is in Figure 5only partially shown. In the vertical direction H upwards, the slider 27 is cut off because the further geometry of the slider 27 is irrelevant for this invention and thus any known geometry can be chosen. The dashed lines show that the slider 27 is recessed in the slot 22. The lower edge 28 of the slider 27 is arranged above the upper edge 11 of the hook in the vertical direction H. In this position of the compound needle arrangement 26, a stitch lying on the slider 27 could be knocked off. Between the lower edge 28 of the slider and the upper edge 11 of the hook there is a safety distance 29 which can be seen even more clearly in Figure 6. The theoretical line 30 indicates that the upper edge 11 of the hook, when installed in a warp knitting machine, lies on a target line predetermined by the gear and the associated drive device of the warp knitting machine.

[0024] Figure 6 shows a cross section through hook 7 with bent-back part 10 and slider 27 of the slider needle arrangement 26 of the Figure 5 . The closed line 31 drawn from the outside shows the curve whose length corresponds to the wrap length. List of reference symbols 1 needle body 2 shaft 3 Flat side 4 Flat side 5 top edge 6 bottom edge 7 Hook 8 Drive section 9 Hook bottom edge 10 bent back part 11 Hook top edge 12 Hook height 13 Middle section 14 Support section 15 Support level 16 Hook point 17 Tip distance 18 leading edge 19 Foot 20 Working distance 21 Slot section 22 slot 23 Slot base 24 line 25 Cross-sectional height 26 Slide needle arrangement 27 slider 28 Slider bottom edge 29 Safety distance 30 theoretical line 31 closed line 32 Mesh sliding section D Thickness direction H Altitude direction L Longitudinal direction

Claims

1. Needle body (1) for a compound-needle assembly of a warp knitting machine, comprising a shank (2), which is bounded by two mutually parallel flat sides (3, 4) to which a thickness direction (D) is perpendicular, and by an upper edge (5) and a lower edge (6), and a hook (7) for receiving yarn, wherein a drive portion (8) of the shank (2) is configured for attachment of the needle body (1) to a driving device of a warp knitting machine, wherein a loop-sliding portion (32) of the shank (2) is configured for guiding a loop to be knocked over, a lower hook edge (9) is disposed opposite to and facing away from a bent-back part (10) of the hook (7), and the lower hook edge (9) extends at least in a longitudinal direction (L) of the needle body (1), and the longitudinal direction (L) is perpendicular to the thickness direction (D) and to an elevational direction (H) of the needle body 1, which is perpendicular to the thickness direction (D), and an upper hook edge (11) is disposed at the bent-back part (10) of the hook (7) and faces away from the lower hook edge (9), between the drive portion (8) and the hook (7), the shank (2) has a slotted portion (21) in which a slot (22) with a slot bottom (23) is sunk in the upper edge (5) and the slot bottom (23) is curved lengthwise, characterised in that a hook height (12), which is to be measured at the point in the longitudinal direction (L) where the distance in the elevational direction (H) between the lower hook edge (9) and the upper hook edge (11) is greatest, is a maximum of 0.81mm and a cross-sectional height (25), which is to be measured perpendicular to the thickness direction (D) in a cross section of the shank (2) in a loop-sliding portion (32), is a maximum of 0.81mm.

2. Needle body (1) according to claim 1, characterised in that, in a central section of the drive portion (8), a central portion (13) of the upper edge (5) of the shank (2) is recessed in comparison with the two adjacent bearing portions (14) of the upper edge (5) and the two adjacent bearing portions (14) of the upper edge (5) lie in one bearing plane (15).

3. Needle body (1) according to claim 2, characterised in that, in the elevational direction (H), the upper hook edge (11) lies, at least section-wise, between 1.5mm and 1.6mm beneath the bearing plane (15) of the drive portion (8).

4. Needle body (1) according to any one of the preceding claims, characterised in that the bent-back part (10) of the hook (7) ends with a hook tip (16) and the tip distance (17) from the hook tip (16) to the point of the hook (7) which, in longitudinal direction (L), is most remote therefrom is at least 1.15mm.

5. Needle body (1) according to any one of the preceding claims, characterised in that a front edge (18) of a butt (19), which is disposed in the drive portion (8) of the shank (2), has a working distance (20) of 45mm to 49mm to the most distant point of the hook (7) in longitudinal direction (L) from this front edge (18).

6. Needle body (1) according to claim 1, characterised in that, in the elevational direction (H), the slot bottom (23) of the slot (22) is aligned, at least section-wise, with the nearest point of the upper hook edge (11) or lies beneath a line (24), which runs in longitudinal direction (L) and contacts the nearest point of the upper hook edge (11) tangentially.

7. Compound-needle assembly (26) for a warp knitting machine, which comprises a needle body (1) according to claim 1 and a closer (27), the closer (27) being disposed relative to the needle body (1) in such a way that a lower closer edge (28) is disposed opposite the upper hook edge (11), characterised in that a looping length has a value of 2.3mm or less, wherein the looping length must be measured in a sectional plane which is at right angles to the longitudinal direction (L) and which, in longitudinal direction (L), is at an arbitrary point at which the upper hook edge (11) and the lower hook edge (9) are mutually opposite, and wherein the looping length corresponds to the shortest closed curve surrounding the sectional contour of the hook (7) and the closer (27).

8. Compound-needle assembly (26) according to claim 7, characterised in that the needle body (1) and the closer (27) are disposed in such a way that a safety gap (29) exists between the upper hook edge (11) and the lower closer edge (28).

9. Compound-needle assembly (26) according to claim 8, characterised in that a looping length has a value of 2.14mm or less, wherein the looping length must be measured in a sectional plane which is at right angles to the longitudinal direction (L) and which, in longitudinal direction (L), is at an arbitrary point at which the upper hook edge (11) and the lower hook edge (9) are mutually opposite, and wherein the looping length corresponds to the shortest closed curve surrounding the sectional contour of the hook (7) and the closer (27), and the lower closer edge (28) borders on the upper hook edge (11).

10. Warp knitting machine, characterised by a multiplicity of compound-needle assemblies (26) according to claim 9.

11. Warp knitting machine according to claim 10, characterised in that at least one compound-needle assembly (26) is disposed in the warp knitting machine in such a way that the at least one lower hook edge (9) is a maximum of 0.81mm beneath a theoretical line (30) for the upper hook edge (11), which is defined by the warp knitting machine's transmission.

12. Warp knitting machine according to either of claims 10 or 11, characterised in that at least two of the multiplicity of needle bodies (1) are fixed, non-relocatably with respect to each other, to a first driving device of the warp knitting machine and / or at least two of the multiplicity of closers (27) are fixed, non-relocatably with respect to each other, to a second driving device of the warp knitting machine.

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