EP3617357B1 - Warp knitting needle and method for producing a warp knitted net - Google Patents

Description

The invention relates to a knitting needle for a warp knitting machine with a shaft and with a needle hook, the needle hook forming a catching space for catching a warp thread, the needle hook having a stem section adjoining the stem, a transition section adjoining the trunk section and an end section adjoining the transition section wherein a first interface between the shaft and the stem portion of the needle hook lies in a first plane, wherein a second interface between the stem portion of the needle hook and the transition portion of the needle hook lies in a second plane, a third interface between the transition portion of the needle hook and the end section of the needle hook lies in the second plane, wherein the first plane is oriented perpendicular to a longitudinal axis of the knitting needle and is tangent to the end section, and wherein the second plane is oriented perpendicular to the longitudinal axis of the knitting needle and a P. rofilkurve is tangent, which in a profile view of the knitting needle runs between the catching space and the needle hook, the end section having a first diameter which forms a maximum diameter of the end section, the transition section having a second diameter which forms a minimum diameter of the transition section, and wherein the second diameter is at least 1.3 times as large as the first diameter.

Knitting needles are used to form loops in warp knitting machines. Warp knitting machines have knitting tools that process the warp threads in a knitting process into a textile surface, a so-called knitted fabric. Since a large number of knitting tools can be moved simultaneously by means of a bar, a large number of stitches are created in the knitting process formed at the same time. Common knitting tools include knitting needles and guide needles. The guide needles feed the warp threads to the knitting needles, while the knitting needles catch the warp threads and cause the loop formation.

Using the technique of warp knitting, a large number of different textile materials can be produced. Among other things, it is possible to produce knitted mesh. These can serve as basic materials for insect protection nets, sun protection nets and the like. The knitting needles are exposed to very great forces, which in the long term can lead to damage to the knitting needles.

Warp knitting machines with a relatively coarse needle pitch are used in the manufacture of knitted nets. This means that the distances between adjacent knitting needles are relatively large. Inferior warp threads are often used that have flaws. The flaws can be, for example, thick places, thin places, hard places or knots. In the area of a thick point or a knot, the warp thread can, for example, have a thread thickness that is threefold. The thread thickness of the warp thread is reduced in the area of a thin point. In the area of a hard spot, the warp thread is not limp. In addition, when warping partial warp beams to provide the warp threads, there may be errors due to jamming points when the warp threads run off, since the warping process often has a poor process quality. The flaws must be passed through the knitting elements and can particularly stress the knitting needles. Knitting needles are particularly heavily stressed by hard spots, since the needle hooks of the knitting needles sometimes have to exert great deformation forces on the hard spots so that the hard spots can pass the knitting needles.

The pamphlet US 761 831 A describes a point needle. This has a reinforced end section to make it more resistant. The pamphlet DE 30 36 309 A1 describes compound needles whose hooks are designed differently. This results in different tee depths and, accordingly, different mesh sizes. The pamphlet U.S. 2,685,787 A describes a reinforced needle that is also suitable for use at increased machine speed. The pamphlet US 2010/229605 A1 describes a tulle fabric. This is particularly robust because it has several interlining threads per wale.

The invention is therefore based on the object of providing a knitting needle which withstands continuous loads even when used with warp threads of inferior thread quality and is suitable for the production of various types of knitted fabrics, including netting.

The object is achieved by providing a knitting needle of the type described at the outset, with a trap chamber depth of the trap chamber, which is defined by a distance between the first plane and the second plane, being at least as great as the second diameter. As has been found, knitting needles of this type are particularly resilient due to the reinforced transition section. The diameter of the transition section falls below the second diameter according to the invention not. An undesired bending up of the knitting needle and thus an expansion of the catching space is avoided by the increased material thickness in the transition section. The trap area has a depth that may be necessary for some layings. This minimum depth may be required, especially when producing some types of knitted mesh.

According to the invention, the first level and the second level are imaginary levels which allow the needle hook to be subdivided into the stem section, the transition section and the end section. The respective interfaces between these sections of the needle hook lie in the first and in the second plane. The subdivision is preferably merely an imaginary subdivision of the needle hook and the needle hook is formed in one piece. The profile curve is preferably an imaginary curve which, in a profile view of the needle hook, lies between the catching space and the needle hook.

According to the invention, the longitudinal axis of the knitting needle can be an imaginary longitudinal axis. According to the invention, the longitudinal axis can be aligned parallel to a longitudinal direction of the knitting needle.

The first diameter can be determined by determining a longest possible chord which connects two points of a surface of the end section with one another, which intersects a profile center line of the needle hook and which forms a right angle with the profile center line. The profile center line is an imaginary line that follows a curvature of the needle hook and runs centrally in the needle hook. The second diameter can be determined by determining a longest possible chord which connects two points of a surface of the transition section with one another, which intersects the profile center line of the needle hook and which forms a right angle with the profile center line.

The second diameter is preferably at least 1.4 times as large as the first diameter. This leads to an additional reinforcement of the needle hook. This has proven to be useful in particular with particularly strong tensile forces that the warp thread exerts on the needle hook in a direction parallel to the longitudinal axis of the knitting needle.

The second diameter is preferably at most twice as large as the first diameter. If the diameter exceeds this, there are no significant reinforcement effects that would be of importance in the knitting process. In addition, the material consumption and the weight of the knitting needle increase, which should be avoided.

It is advantageous if the second diameter is at least 0.5 mm. With this minimum diameter, the previously described reinforcement effects. It is particularly advantageous if the second diameter is at most 0.8 mm.

It is preferred if the trunk section has a third diameter which forms a minimum diameter of the trunk section, the third diameter being at least 1.3 times as large as the first diameter. This leads to a reinforcement of the needle hook against forces in a direction transverse to the longitudinal axis of the knitting needle. It is particularly preferred if the third diameter is at least 1.4 times as large as the first diameter. The needle hook is thus reinforced extremely well. The third diameter can be determined by determining a longest possible chord which connects two points of a surface of the stem section with one another, which intersects a profile center line of the needle hook and which forms a right angle with the profile center line.

It can further be provided according to the invention that a trap area access width of the trap area, which is defined by a distance between the trunk section and the end section of the needle hook at a height of the first level, is at least as large as the first diameter. This defines a minimum width of the trap area in an opening area of the trap area. This minimum width of the catch space in the opening area makes it easier to catch the warp thread and may be necessary in some knitting processes. In particular, this minimum width can be required for the production of knitted meshes. The trap area access width is preferably at least as large as the second diameter.

The knitting needle is preferably made of steel. This leads to a high stability and wear resistance of the knitting needle. According to the invention, however, the knitting needle can also be made of other materials.

It is advantageous if the needle hook has, at least in sections, a circular or an elliptical cross-sectional area. The warp thread can then more easily slide along the needle hook. It is also preferred if the knitting needle is a punched needle. Alternatively, however, the knitting needle can also be produced in a different manner. According to one embodiment, the needle can furthermore be coated. According to the invention, a chrome coating can be provided. The needle hook preferably has a conical cross section and / or a cross section that tapers towards one end of the needle hook. Particularly preferably, a surface of the needle hook does not have any steps, projections or the like on which a warp thread could get caught.

According to a particular embodiment of the invention, the knitting needle is a compound needle. The compound needle has a groove in which a slide can be guided. The slide enables the trap area to be opened and closed, which is necessary for the formation of the loop. According to the invention, however, it is also possible that the needle according to the invention is a Another type of needle is, for example, a latch needle or a pointed needle.

The invention also relates to a method for producing a knitted netting by means of a warp knitting machine. In the method according to the invention, knitting needles are used for stitch formation in the warp knitting machine, which are designed like the knitting needle according to the invention described above. This makes it possible to produce a knitted netting by means of a warp knitting machine without premature damage to the knitting needles due to tensile loading of the knitting needle or other wear effects due to the use of inferior warp threads. According to the invention, at least one further knitting tool such as a locating needle, a slide and / or a hold-down device can also participate in the formation of the loop.

According to one embodiment of the method according to the invention, at least one warp thread is used which, in sections, has a thread thickness that is at least three times greater than an average thread thickness of the warp thread. According to the invention, the thread thickness which is at least three times greater can be due to a knot or a thick point. A thick point is to be understood as a section of a warp thread in which the warp thread is thickened, for example due to irregularities in an extrusion process for producing the warp thread. According to the invention, the warp thread used can be a warp thread made of a plastic. However, it is alternatively possible that the warp thread is made of cotton, sheep's wool or some other material.

A tulle layer is preferably used as the laying in the production of the knitted netting. So is using a first Tulle variant (square), a second tulle variant (satin weave) or a third tulle variant (three-mesh hexagonal tulle) are possible according to the invention. However, other types of tulle can also be used. In addition, it is also possible, in principle, to use other layers with which knitted meshes can be produced. The properties of the textile surface obtained are determined by the respective laying. The person skilled in the art is familiar with these layers, but can produce knitted meshes with these layers according to the method according to the invention with a greatly reduced needle failure rate.

• Fig. 1 eine schematische Darstellung einer erfindungsgemäßen Wirknadel in einer Profilansicht,
• Fig. 2 eine schematische Darstellung eines Nadelhakens der erfindungsgemäßen Wirknadel in einer Profilansicht,
• Fig. 3 eine weitere schematische Darstellung des Nadelhakens in einer Profilansicht,
• Fig. 4 eine schematische Darstellung der erfindungsgemäßen Wirknadel in einer Ansicht von vorne,
• Fig. 5 eine schematische Darstellung eines mit einer ersten Tülllegung (Viereck) hergestellten Netzgewirks,
• Fig. 6 eine schematische Darstellung eines mit einer zweiten Tülllegung (Atlasbindung) hergestellten Netzgewirks, und
• Fig. 7 eine schematische Darstellung eines mit einer dritten Tülllegung (Drei-Maschen-Sechsecktüll) hergestellten Netzgewirks.

An advantageous embodiment of the knitting needle according to the invention is shown in the drawings. It shows:

• Fig. 1 a schematic representation of a knitting needle according to the invention in a profile view,
• Fig. 2 a schematic representation of a needle hook of the knitting needle according to the invention in a profile view,
• Fig. 3 another schematic representation of the needle hook in a profile view,
• Fig. 4 a schematic representation of the knitting needle according to the invention in a view from the front,
• Fig. 5 a schematic representation of a mesh fabric produced with a first tulle layer (square),
• Fig. 6 a schematic representation of a mesh fabric produced with a second tulle layer (satin weave), and
• Fig. 7 a schematic representation of a knitted mesh fabric produced with a third layer of tulle (three-mesh hexagonal tulle).

Fig. 1 shows a schematic representation of the knitting needle 1 according to the invention in a profile view. the Knitting needle 1 has a needle hook 2 and a shaft 3. An imaginary longitudinal axis 10 of the knitting needle 1 is shown by a dashed line.

Fig. 2 shows a schematic representation of the needle hook 2 of the knitting needle 1 according to the invention in a profile view. The needle hook 2 forms a catching space 4 which can accommodate a warp thread. The needle hook 2 is divided into three sections. The needle hook 2 has a stem section 5 adjoining the shaft 3, a transition section 6 adjoining the trunk section 5, and an end section 7 adjoining the transition section 6. A first interface between the shaft 3 and the stem section 5 of the needle hook 2 lies in a first plane 8. A second interface between the stem section 5 of the needle hook 2 and the transition section 6 of the needle hook 2 lies in a second plane 9. A third interface between the The transition section 6 of the needle hook 2 and the end section 7 of the needle hook 2 is also located in the second plane 9. The viewing direction of the Fig. 2 runs parallel to the first plane 8 and to the second plane 9. The first plane 8 and the second plane 9 are represented by dashed lines.

The first plane 8 is oriented perpendicular to the longitudinal axis 10 of the knitting needle 1. The first plane 8 is tangent to a tapering end 11 of the end section 7. The second plane 9 is oriented perpendicular to the longitudinal axis 10 of the knitting needle 1 and is tangent to a profile curve 12 which runs between the catching space 4 and the needle hook 2. The profile curve 12 is shown at a slight distance from the needle hook 2 only for better visibility. In fact, there is no distance between the profile curve 12 and the needle hook 2 formed, but the needle hook 2 directly adjoins the profile curve 12.

The end section 7 has a first diameter 13 which forms a maximum diameter of the end section 7. The transition section has a second diameter 14 which forms a minimum diameter of the transition section 6. The second diameter 14 is more than 1.3 times as large as the first diameter 13. The needle hook 2 is therefore particularly stable and is not damaged even under continuous load by a warp thread with high tensile forces.

The trunk section 5 has a third diameter 15 which forms a minimum diameter of the trunk section 5. The third diameter 15 is more than 1.3 times as large as the first diameter 13. This leads to a reinforcement of the needle hook 2 with respect to forces in a direction transverse to the longitudinal axis 10 of the knitting needle 1.

The trap chamber 4 has a trap chamber depth 16 which is defined by a distance between the first plane 8 and the second plane 9. The trap chamber depth 16 is dimensioned such that it is greater than the first diameter 13. The trap chamber 4 is therefore suitable for use in the most varied of laying operations. The trap area 4 also has a trap area access width 17 which is defined by a distance between the stem section 5 and the end section 7 of the needle hook 2 at a height of the first plane 8. The trap area access width 17 is larger than the first diameter 13 of the end section 7. This makes it easier to catch warp threads easily through the trap area 4.

Fig. 3 shows a further schematic representation of the needle hook 2 in a profile view. It is shown by way of example where the first diameter 13 and the second diameter 14 and the third diameter 15 are located. The diameters 13, 14 and 15 each lie on chords which each intersect the profile center line 21 of the needle hook 2 at a right angle and connect two points on a surface of the needle hook 2 with one another. The profile center line 21 is represented by a dashed line. The profile center line 21 is an imaginary line which follows a curvature of the needle hook 2 and which runs centrally in the needle hook 2. The first diameter 13 is dimensioned exclusively within the end section 7. The second diameter 14 is dimensioned exclusively within the transition section 6. The third diameter 15 is dimensioned exclusively within the trunk section 5.

Fig. 4 shows a schematic representation of the knitting needle 1 according to the invention in a view from the front, wherein the needle hook 2 and the shaft 3 can be seen. It can be seen that the knitting needle 1 is a compound needle, because the knitting needle 1 has a groove 18 in which a slide can be guided up and down. As a result, the trap space formed by the needle hook 2 can be opened and closed. This is necessary for stitch formation.

Fig. 5 shows a knitted mesh 19 produced with a lay-up according to a first tulle variant (square), Fig. 6 shows a knitted mesh fabric 19 and 19 produced with a lay-up according to a second tulle variant (satin weave) Fig. 7 shows a knitted mesh 19 produced with a lay-up according to a third tulle variant (three-mesh hexagonal tulle). Depending on the lay-ups used, different properties result in terms of size and the shape of holes 20 in the knitted mesh 19 and the extensibility and stability of the knitted mesh 19.

REFERENCE LIST

• 1. Knitting needle
• 2. Needle hook
• 3. Shank
• 4. Trapping area
• 5th trunk section
• 6th transition section
• 7th end section
• 8. First level
• 9. Second level
• 10. Longitudinal axis
• 11th end
• 12. Profile curve
• 13. First diameter
• 14. Second diameter
• 15. Third diameter
• 16. Catch depth
• 17. Catch access width
• 18. Groove
• 19. Knitted mesh
• 20th hole
• 21. Profile center line

Claims (13)

1. Warp knitting needle (1) for a warp knitting machine having a shank (3) and having a needle hook (2), wherein the needle hook (2) forms a catch space (4) for catching a warp yarn, wherein the needle hook (2) has a stem portion (5) adjoining on the shank (3), a transition portion (6) adjoining on the stem portion (5), and an end portion (7) adjoining on the transition portion (6), wherein a first interface between the shank (3) and the stem portion (5) of the needle hook (2) lies in a first plane (8), wherein a second interface between the stem portion (5) of the needle hook (2) and the transition portion (6) of the needle hook (2) lies in a second plane (9), wherein a third interface between the transition portion (6) of the needle hook (2) and the end portion (7) of the needle hook (2) lies in the second plane, wherein the first plane (8) is aligned perpendicularly to a longitudinal axis (10) of the warp knitting needle (1) and is tangent to the end portion (7), and wherein the second plane (9) is aligned perpendicularly to the longitudinal axis (10) of the warp knitting needle (1) and is tangent to a profile curve (12) which runs in a profile view of the warp knitting needle (1) between the catch space (4) and the needle hook (2), wherein the end portion (7) has a first diameter (13) which forms a maximum diameter of the end portion (7), wherein the transition portion (6) has a second diameter (14), which forms a minimum diameter of the transition portion (6), and wherein the second diameter (14) is at least 1.3 times as great as the first diameter (13), characterised in that a catch space depth (16) of the catch space (4), which catch space depth is defined by a distance between the first plane (8) and the second plane (9), is at least as great as the second diameter (14).
2. Warp knitting needle (1) according to claim 1, characterised in that the second diameter (14) is at least 1.4 times as great as the first diameter (13).
3. Warp knitting needle (1) according to any of the preceding claims, characterised in that the second diameter (14) is at most twice as great as the first diameter (13).
4. Warp knitting needle (1) according to any of the preceding claims, characterised in that the second diameter (14) is at least 0.5 mm.
5. Warp knitting needle (1) according to any of the preceding claims, characterised in that the stem portion (5) has a third diameter (15) which forms a minimum diameter of the stem portion (5), wherein the third diameter (15) is at least 1.3 times as great as the first diameter (13).
6. Warp knitting needle (1) according to claim 5, characterised in that the third diameter (15) is at least 1.4 times as great as the first diameter (13).
7. Warp knitting needle (1) according to any of the preceding claims, characterised in that a catch space access width (17) of the catch space (14), which catch space access width is defined by a distance between the stem portion (5) and the end portion (7) of the needle hook (2) on a level of the first plane (8), is at least as great as the first diameter (13).
8. Warp knitting needle (1) according to any of the preceding claims, characterised in that the warp knitting needle (1) is made of steel.
9. Warp knitting needle (1) according to any of the preceding claims, characterised in that the needle hook (2) has at least in portions a circular or an elliptical cross-sectional surface.
10. Warp knitting needle (1) according to any of the preceding claims, characterised in that the warp knitting needle (1) is a slide needle.
11. Method for producing a warp knitted net (19) by means of a warp knitting machine, characterised in that for stitch formation in the case of the warp knitting machine, warp knitting needles (1) are used which are designed according to the claims 1 to 10.
12. Method according to claim 11, characterised in that for producing the warp knitted net (19) at least one warp yarn is used which in portions has a yarn thickness which is at least three times greater than an average yarn thickness of the warp yarn.
13. Method according to claim 11 or 12, characterised in that a lapping used in the production of the warp knitted net (19) is a tulle lapping.

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