Eye needle with a symmetrical hole

Abstract

Guide needle (1) for use in warp knitting machines with the following features - a shaft (2) extending in a longitudinal direction (x), - a yarn guide area (3) which adjoins one end of the shaft (2) in the longitudinal direction (x) and forms the end of the guide needle (1) in the longitudinal direction (x), - a hole (4) which completely penetrates the guide needle (1) in the yarn guide area (3) in a width direction (z) perpendicular to the longitudinal direction (x) - wherein the hole (4) has a contour (5) in a plane perpendicular to the width direction (z), - and wherein the contour (5) is symmetrical to a plane of symmetry (9), characterized by that the contour (5) is substantially straight at least in a first straight section (6), and that the first straight section (6) encloses an angle (7) to the longitudinal direction of 5 to 60 degrees, but preferably 10 to 45 degrees.

Description

Needles for many years have been used in warp knitting machines to feed a yarn to the needles of warp knitting machines. Needles have a shaft extending in a longitudinal direction and a yarn guide region which adjoins the shaft and terminates the needle in the longitudinal direction. In the yarn guiding region, a hole penetrates the perforated needle completely in a width direction which runs perpendicular to the longitudinal direction, so that during operation in a warp knitting machine yarn can be guided through the hole. The hole has a contour in a plane perpendicular to the width direction, which contour is usually symmetrical to a plane of symmetry. The most common design of perforated needles has a circular contour. The plane perpendicular to the width direction is a plane spanned by the longitudinal direction and a depth direction, the depth direction being perpendicular to the longitudinal direction and the width direction.DE1736224U shows, by way of example, a perforated needle of this type having a circular hole. Needles with a circular hole have the disadvantage that the yarn is deflected in the hole at a very small (acute) angle during operation due to the contour of the hole. As a result, high yarn tensions are produced in the yarn at the deflection, which can damage the yarn. This can lead to production errors during warp knitting, in particular in the case of yarns with low strengths, such as natural fiber yarns, for example.EP1273688A1 already describes this problem in connection with perforated needles and proposes to remedy this the use of a perforated needle which is simulated in the construction of a conventional sewing machine needle having a thread groove and a hole (eye). The hole should have an elongated oval shape. In combination with the thread groove, the deflection or deflection of the yarn is thereby to be significantly reduced. In addition, it is proposed to use the pin punch rotated through 90 degrees relative to the usual installation position of pin punches in warp knitting machines. The construction of the perforated needle is substantially more complex due to the thread groove than in conventional perforated needles, and the perforated needle also requires more space due to the installation rotated through 90 degrees. Such needles are therefore expensive to produce and are not suitable for the production of very fine knit goods.DE2226000 also addresses the problem that deflecting the yarn in a perforated needle at an angle which is too small leads to damage to the yarn. In order to deflect the yarn in a relatively large arc and to avoid a "kink" in the yarn, it is therefore proposed to provide the contour of the hole of a perforated needle with a constriction on the side facing the yarn deflection. The constriction leads to a convex contour directed into the interior of the hole, which is asymmetrical. However, this has the disadvantage that the yarn is correctly guided only when it is introduced into the hole from the correct side of the perforated needle. However, it has been found that, during operation of a warp knitting machine, knitting defects can frequently be eliminated by rethreading the yarn into the perforated needle at the location of the knitting defect and in the process exchanging the side from which the yarn is introduced into the perforated needle. This measure is not possible with asymmetrical needles.Starting from the prior art, it is therefore the object of the present invention to specify a perforated needle which can be produced cost-effectively, is suitable for producing fine knitted goods and can be used in a particularly wide variety of ways in a knitting machine.The object is achieved by a perforated needle having the features of claim 1. the perforated needle according to the invention for use in warp knitting machines comprises a shaft which extends in the longitudinal direction. The main extension direction of the shaft is thus the longitudinal direction. At one end of the shaft in the longitudinal direction is a yarn guide region which forms the termination of the perforated needle in the longitudinal direction. During operation of the perforated needle in a warp knitting machine, the yarn guide region usually has at least phase-wise contact with the yarn. The pin punch also includes a hole that completely penetrates the pin punch in the yarn guide portion in a width direction perpendicular to the longitudinal direction. The hole is thus a through hole. For operation in a warp knitting machine, a yarn is passed through the hole from one side of the pin to the other side of the pin. The yarn can then be guided by the movement of the perforated needle and laid around a needle of the warp knitting machine. The hole has a contour in a plane perpendicular to the width direction-i.e. in a plane spanned by the longitudinal direction and the depth direction-which contour is symmetrical to a plane of symmetry. The contour is preferably closed, i.e. it is not broken through. Due to the symmetry of the hole, the perforated needle can be used in a great variety of ways in a chain machine. In particular, in the case of a symmetrical perforated needle, the yarn can be passed through the hole of the perforated needle from both sides without changing the function of the perforated needle depending on the selected side. The perforated needle can thus be used in a particularly wide variety of ways in warp knitting machines. According to the invention, the contour runs substantially straight in a first straight section. A section is essentially straight within the meaning of the teaching according to the invention if it is either exactly straight within the production technology options or has a large radius which is greater than 2 mm, preferably greater than 3 mm. Given hole diameters of usually 1-2 mm, such large radii result in curvatures that are hardly perceptible to the naked eye at the hole of the perforated needle. The first straight portion encloses an angle of 5 to 60 degrees with respect to the longitudinal direction. The first straight section is thus inclined obliquely to the longitudinal direction. When the perforated needle is used in a warp knitting machine, the yarn can then be deflected at the oblique first straight section. The deflection takes place because of the oblique first straight section in a larger arc than is the case with conventional needles with a circular hole contour. The yarn is thus guided in a substantially more gentle manner and lower tensions are produced in the yarn, for which reason damage to the yarn can be avoided. A twisted installation position of the perforated needle is not necessary for this purpose, and the structural design also does not require a greater material thickness. The perforated needle according to the invention can therefore also be used for producing very fine knit goods.Further advantages result if the plane of symmetry of the contour is a plane which is spanned by the longitudinal direction and the width direction. In this way, an improved yarn guidance can be ensured regardless of from which side of the perforated needle a yarn is guided through the hole.It is particularly advantageous if the plane of symmetry runs centrally through the shaft in the longitudinal direction. This also ensures improved yarn guidance regardless of from which side of the perforated needle a yarn is guided through the hole.Further advantages result if the contour comprises a second straight section, in which the contour runs substantially straight, and which encloses an angle to the longitudinal direction of 5 to 60 degrees, but preferably 10 to 45 degrees. In this second straight section too, an optimized deflection of a yarn can then take place. In this way, an improved deflection of the yarn can be achieved with the perforated needle in even more different configurations of a warp knitting machine. It can therefore be used in even more varied ways in a warp knitting machine.Further advantages result if the first straight section and the second straight section are symmetrical to one another. The yarn deflection at the first straight section and at the second straight section is then identical. Thus, with the perforated needle, a comparable yarn deflection is always achieved independently of the current configuration of the warp knitting machine.An even better and gentler deflection of the yarn can be achieved if the contour has rounded edges. Thus, an even gentler deflection of the yarn can be achieved. Yarn damage due to excessively high yarn tensions can thus be prevented even better.Further advantages result if the first straight section and the second straight section are connected at their ends in each case via a curved section, so that a drop-shaped contour results. A yarn-preserving transition between the first straight section and the second straight section is provided by the bent section. Damage to the yarn can thus be avoided. The drop-shaped contour has surprisingly proven to be the contour that offers the most diverse possible uses in a warp knitting machine. It is particularly advantageous if the bent sections each transition tangentially into the first straight section and the second straight section.A perforated needle according to the invention having a combination of the features described above can be used in a perforated needle module. The perforated needle module then comprises a plurality of such perforated needles, wherein the perforated needles are cast, aligned next to one another in the width direction, into a module body of the perforated needle module. The module body may be cast from a metal such as lead, tin, antimony, aluminum, copper, iron, or a metal alloy containing at least one of the foregoing metals. The module body can also be cast from a plastic, for example by plastic injection molding. The needles are preferably arranged next to one another at regular intervals in the width direction. Thus, a uniform knitted fabric can be produced with the perforated needle module. The yarn guiding region of the needles protrudes from the module body so that a yarn can be guided by the needles without being affected by the module body. The perforated needles are thus cast with their end, which is opposite the yarn guide region, in the module body. FIG. 1 shows a three-dimensional view of a perforated needle module ( 13) FIG. 2, FIG. 2 shows an overall view of a perforated needle ( 1) according to the invention in the viewing direction of the width direction (z) FIG. 3 shows a detailed view of the yarn guide region ( 3) of the perforated needle ( 1) from FIG. 2.FIG. 1 shows a three-dimensional view of a perforated needle module 13 having a multiplicity of perforated needles 1 according to the invention. The perforated needles 1 each have a shank 2 which extends in a longitudinal direction x and is cast with its end into a module body 14. The plurality of needles 1 of the needle punch module 13 is firmly connected to each other by the module body 14 such that the plurality of needles 1 are fixed relative to each other in the needle punch module 13. At the front end of the shaft 2 in the longitudinal direction x, i.e. the end facing away from the module body 14, a yarn guide region 3 which forms the termination of the perforated needle 1 in the longitudinal direction x, adjoins the shaft 2. During operation of the perforated needle 1 in a warp knitting machine, the yarn guide region 3 functionally interacts with the yarn and is in direct contact with the yarn at least in phases. In the pin hole module 13, the pin holes 1 are arrayed side by side at regular intervals in the width direction z. Therefore, very uniform warp knit goods can be produced with the perforated needle module 13. For the sake of better clarity, only one perforated needle 1 is provided with reference symbols in FIG. 1. All the needles 1 shown in FIG. 1 are, however, of identical construction.FIG. 2 shows an overall view of a perforated needle 1 according to the invention in the direction of view of the width direction z. In contrast to the illustration of FIG. 1, the perforated needle 1 is not yet cast into a module body 14 of a perforated needle module 13. The perforated needle 1 is shown enlarged for this purpose, so that the yarn guide region 3 can be better seen. In the yarn guide portion 3, the needle punch 1 includes a hole 4 which completely penetrates the needle punch 1 in the width direction z. In the drawing plane shown, which is spanned by the longitudinal direction x and the depth direction y and is perpendicular to the viewing direction (i.e. the width direction z), the perforated needle 1 has a contour 5 which delimits the hole 4 inward. The entire perforated needle 1 including the contour 5 is in itself symmetrical to a plane of symmetry 9 spanned by the longitudinal direction x and the width direction z. The plane of symmetry 9 extends in the longitudinal direction x exactly centrally through the shank 2.In order to be able to describe the features of the hole 4 in a better manner, FIG. 3 shows a detailed view of the yarn guide region 3 of the perforated needle 1 from FIG. 2, the contour 5 of the hole 4 can be divided into four subareas: a first straight section 6, a second straight section 8 and two bent sections 10. The ends of the first straight section 6 and the second straight section 8 are connected to one another via two bent sections 10, so that a closed, drop-shaped contour 5 is formed. The two bent sections 10 pass tangentially, i.e. without any kink in the contour 5, into the first straight section 6 and the second straight section 8. This ensures a secure and gentle guiding of the yarn in the hole 4. Due to the symmetry of the contour 5 along the plane of symmetry 9 and the angle 7, the first and the second straight section 6, 8 are inclined to one another like the legs of a triangle. This results in the first and second straight portions 6, 8 being closer to each other at one of their ends than at their other end. The two bent portions 10 are therefore rounded with radii 11, 12 of different sizes in order to connect the ends of the first and the second straight portions 6, 8 to one another. The bent portion 10 connecting the ends closer to each other is rounded with a small radius 11 while the other bent portion 10 connecting the ends farther from each other is rounded with a large radius 12. In the context of the teaching according to the invention, the terms small and large indicate only the ratio of the small radius 11 to the large radius 12, namely that the small radius 11 is smaller than the large radius 12.List of reference characters1 Perforated needle 2 Shaft 3 Yarn guide region 4 Hole 5 Contour of the hole 4 6 First straight section 7 Angle 8 Second straight section 9 Plane of symmetry 10 Bent section 11 Small radius 12 Large radius 13 Perforated needle module 14 Module body x Longitudinal direction y Depth direction z Width directionReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 1736224U

[0002] EP 1273688A1

[0003] DE 2226000

[0004]

Claims

Perforated needle (1) for use in warp knitting machines, having the following features - a shaft (2) which extends in a longitudinal direction (x), - a yarn guide region (3) which adjoins an end of the shaft (2) in the longitudinal direction (x) and forms the termination of the perforated needle (1) in the longitudinal direction (x), - a hole (4) which completely penetrates the perforated needle (1) in the yarn guide region (3) in a width direction (z) perpendicular to the longitudinal direction (x), - wherein the hole (4) has a contour (5) in a plane perpendicular to the width direction (z), - and wherein the contour (5) is symmetrical to a plane of symmetry (9), characterized in that the contour (5) runs substantially straight at least in a first straight section (6), and that the first straight section (6) encloses an angle (7) to the longitudinal direction of 5 to 60 degrees, but preferably 10 to 45 degrees.Perforated needle (1) according to the preceding claim, characterized in that the plane of symmetry (9) of the contour (5) is a plane which is spanned by the longitudinal direction (x) and the width direction (z).Perforated needle (1) according to one of the preceding claims, characterized in that the plane of symmetry (9) runs centrally through the shank (2) in the longitudinal direction (x).Perforated needle (1) according to one of the preceding claims, characterized in that the contour (5) comprises a second straight section (8), in which the contour (5) runs substantially straight, and which encloses an angle (7) with respect to the longitudinal direction of 5 to 60 degrees, but preferably 10 to 45 degrees.The puncture needle (1) according to the preceding claim, characterized in that the first straight portion (6) and the second straight portion (8) are symmetrical to each other.Perforated needle (1) according to one of the preceding claims, characterized in that the contour (5) has rounded edges.Perforated needle (1) according to one of the preceding claims 4 to 6da, characterized in that the first straight section (6) and the second straight section (8) are each connected at their ends via a curved section (10), so that a drop-shaped contour (5) results.Perforated needle module (13) comprising a plurality of perforated needles (1) according to one of the preceding claims, wherein the perforated needles (1) are cast, aligned side by side in the width direction (z), into a module body (14) of the perforated needle module (13).

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