EP2270270A1 - Drawing-free method for circular knitting of wires, device for drawing-free circular knitting of wires and hose made of knitted wires - Google Patents

Abstract

The method involves detecting a loosened end of wires by a needle (16) of a circular knitting machine (10) during a knitting process. The wires are transformed to a meandering stitch course by needles. A released section of the stitch course of conveying elements (24) arranged between the needles is detected and conveyed away internally from the needles. The wires are cut at end of the knitting process. The knitting process is continued until the tube section is not detected by the needles and the conveying elements. An independent claim is also included for a device for drawing-free circular knitting of wires to a wire mesh tube.

Description

The invention relates to a method for circular knitting at least one wire to a tube section with multiple courses. Furthermore, the invention relates to a device for circular knitting and a hose section of wire mesh.

For a long time it has been known to knit wire with the help of a circular knitting machine to an endless tube of knitted wire. In this case, the at least one wire of the circular knitting machine is fed continuously, wherein the guided in a common needle carrier needles to form the new stitches of a course pull the wire through the stitches of the previously formed course, while the needles strip the previously held stitches of the previously formed row of stitches and release them in sections. The term needles is understood in this context knitting needles, which are particularly well suited for the entanglement of wires.

Due to the high rigidity of the wire material, the finished knitted tube must be continuously conveyed away by means of a so-called withdrawal device, since otherwise the previously formed courses will not be transported away from the needles and the knitting process would be interrupted. As a take-off often come two intermeshing toothed rollers used, between which the finished knitted hose is guided and capture the hose with the help of their teeth and pull away with high force from the knitting machine.

Since the use of an endless tube makes little sense, the tube is cut by means of a separator, such as a cutting knife, in hose sections of defined length. Since the courses at the Circular knitting show a helical course, it is impossible in the cutting process, especially in very fine-meshed wire knit to separate the courses so that not sections of several courses are cut simultaneously. This has the consequence that immediately after the cutting of the knitted wire a plurality of separated stitch residues, the so-called chaff, remain in the tube section. Since the use of hose sections with chaff hanging in it is undesirable, the chaff hanging in the hose section must be removed with great effort, either mechanically for example by everting or manually as completely as possible.

Not only that the hose sections must be freed from the chisels with great effort, there is also the problem that the already falling out during cutting chaff incurred directly in the knitting machine and possibly can affect the knitting process.

Another major disadvantage of the known method is the very high loss of material. Thus, the material content of chaff is related to the total amount of entangled wire at up to 10%, so that a material loss of 10% must be taken into account, which especially in wires made of very high quality materials, such as precious metals, the cost of the final product additionally increased. Finally, another problem with the known knitting method is that neither a clearly defined length of the tube section nor a clearly defined weight of the tube section can be predetermined by the inaccurate cutting process. Rather, relatively large tolerances must be specified so that the manufactured tube sections can be used at all to a sufficient extent.

Furthermore, the effort in the so-called Anstrickvorgang in which a knitting machine is to knit a new tube after the knitting process of the previous tube is completed, extremely high. Thus, the wire must be fed by hand and the newly formed courses as long as manually removed with the aid of tools until the trigger can detect the beginning of the newly knitted tube, which may take several hours, depending on the material and diameter of the hose, to the machine is running properly.

Based on this prior art, it is an object of the invention to provide a method and apparatus for circular knitting at least one wire to a tube section with multiple courses that works without deduction and with the hose sections defined length in a simple manner without cutting can be made. Furthermore, it is an object of the invention to provide a tubular section of knitted wire, which is made without cutting.

According to the invention, this object is achieved by a method having the features of claim 1. Furthermore, the object is achieved by a device having the features according to claim 7 and by a hose section made of wire mesh with the features of claim 11.

An essential idea of the invention is that, unlike previously customary, already the first row of stitches as well as all other subsequent rows of stitches which are produced during the knitting process are grasped with the aid of conveying elements arranged between the needles and conveyed away inwards from the needles. This makes it possible, on the one hand, to end the knitting process by separating or capping the wire at any time and to promote the knitted tube section from the circular knitting machine, on the other hand, the knitting process can be restarted again without much effort. So only a loose end of the Detected wire from one of the needles of the circular knitting machine and the wire from the other needles to a meandering first row of stitches are transformed. In the further knitting process, the further fed wire is entangled by the needles with the previously formed first course to a subsequent course of stitches, as usual, pulling the needles to form the new stitches of the subsequent course the wire through the stitches of the previously formed first course. In this case, the needles strip the previously held stitches of the previously formed first row of stitches and release them in sections, the respective released portion of the previously formed first row of stitches being grasped by the conveying elements arranged between the needles and being conveyed inwardly away from the needles. This process is also continued in the other courses to be formed, wherein the already knitted hose section is continuously transported away by the conveying elements from the region of the needles. By conveying away the respectively released sections of the previously formed row of stitches, a stagnation of the stitches, which are inherently stiff, in the needle carrier is prevented, so that the knitting process can be continued without problems, whereas in the prior art, as already described, the stiff courses are made by hand with the aid of assistance Tools must be pulled out of the needle carrier until the trigger device can detect the hose. This is precisely not the case with the method according to the invention, so that the hitherto necessary extraction device can be dispensed with. The knitting operation is then continued until the tube portion obtains the desired length, for example, based on experience, based on the weight or calculations of the supplied length of wire material, the wire is cut and the knitting process continues until the tube section is no longer from the needles and the conveyor elements is detected.

Thereafter, only the end of the capped wire must again be fed to the circular knitting machine so that it can be grasped by one of the needles of the circular knitting machine. Then the knitting process is continued, wherein the other needles reshape the wire into a meandering row of stitches and continue to knit in the manner described above.

In the method according to the invention, it is possible for the first time to dispense with the withdrawal device customary in the prior art. Furthermore, it is possible for the first time to dispense with the problematic cutting of the tube made of wire mesh, as is usual and necessary in the prior art. Also eliminates the usual in the art elaborate Anstricken.

In the method according to the invention, no chaff is produced. The length of the tube section is determined only by capping the wire at a predetermined length and continuing the knitting operation. In this way, it is possible for the first time by the invention to manufacture tube sections with a precisely defined length or precisely defined weight in hitherto unreachable tolerance ranges. The mentioned material loss of up to 10% of the wire material to be entangled is completely eliminated. Even complex extraction devices or cutting devices are obsolete.

Furthermore, it is possible to entangle several wires at the same time depending on the application. It is also possible to entangle not only mono-form wire, but also multi-filament wire, stranded wire or stranded wires.

Further advantages and advantageous developments will become apparent from the following description and the dependent claims.

Thus, in a particularly preferred embodiment of the method, it is proposed that the conveying elements release the previously conveyed previously formed row of stitches only when they grip the row of stitches formed below and convey it inwards away from the needles. This ensures that due to the stiffness of the wire material already formed and from the conveyor elements weggeförderte stitch row does not jump back and hinders the knitting process.

In particular, in wires with a comparatively thick wire cross-section is also proposed to preform the supplied wire to support the stitch formation, for example by the wire is passed immediately before the entanglement through a corresponding preforming device and then handed over to the needles for entangling.

In order to facilitate the discharge of finished tube sections, it is further proposed to detect the first formed end of the tube section by means of a handling device and to remove after completion of the knitting process from the circular knitting machine. As a handling device, for example, a robot is suitable.

According to a further aspect, the invention relates to a device for the deduction-free circular knitting of at least one wire to a Drahtgestrickschlauch. As in the prior art, the device comprises a needle carrier on which a plurality of identical needles are guided, which are controlled by means of a needle control according to a predetermined knitting movement. Furthermore, a feed device for feeding the at least one wire and a device for removing the hose is provided.

According to the invention, the device for removing the hose as a discharge device is formed of a plurality of conveying elements movably guided between the knitting needles on the needle carrier, which for detecting the respectively immediately before released from the knitting needles of the previously formed course and for conveying away the released sections inwardly away from the Serve knitting needles. With the help of these conveying elements, it is now possible for the knitted tube without deduction, ie to promote without the use of a trigger device, from the device and at the same time to ensure that there is no jamming of the courses in the needle carrier during the knitting process.

The conveying elements are preferably moved by a control device coupled to the needle control of the needles in accordance with a predetermined sequence of movements. The needle control is designed so that the conveying elements detect the respectively released sections according to the knitting movements of the needles and transport them away inwards into the needle carrier. The conveying elements are preferably actuated by a respective actuator associated with each conveying element. It is also conceivable, however, a common control by a common actuator, such as a control disc with control grooves.

In order to ensure the most uniform possible removal of the released sections, preferably between each two adjacent needles each have a conveyor element is provided so that each web mesh between each two shared mesh can be detected by a conveyor element.

Each conveyor element is advantageously designed in each case as at least one at least approximately at right angles with respect to the direction of movement of the knitting needles movable slider.

According to a third aspect, the invention relates to a tubular section made of knitted wire, which is knitted from at least one wire section, wherein the tube section has a predetermined defined length, which results exclusively by capping the wire section during the feeding of the wire section during knitting. According to the invention, the hose section is chopper-free immediately after the knitting process and has only one separate permanent wire end open at each of its two ends per wire section.

Preferably, the wire of the wire knit forming the tube section is deformed at least in sections between the stitches. This deformation is generated in particular by the conveying elements, which detect the wire mesh during the circular knitting defined.

The hose section may consist of a monoform wire, a multi-filament wire, a stranded wire or stranded wires depending on the application. The wire section may have a round, oval, flat or even polygonal cross-sectional shape.

It is also advantageous if the mesh shapes and / or the number of stitches per row of stitches and / or the mesh size in the wire mesh varies, in order to optimize the wire mesh for specific applications.

The tube section produced in this way can be converted into any type of molded part, for example in filter inserts for gas generators of airbags.

Fig. 1

eine geschnittene Seitenansicht einer erfindungsgemäßen Vorrichtung zum abzugsfreien Rundstricken von Drähten; und

Fig. 2

eine perspektivische Ansicht, in der aus einem Blickwinkel oberhalb der Vorrichtung ein Abschnitt der Vorrichtung aus Fig. 1 dargestellt ist.

The invention will be explained in more detail with reference to an embodiment with reference to the accompanying drawings. It shows:

Fig. 1

a sectional side view of a device according to the invention for non-triggering circular knitting of wires; and

Fig. 2

a perspective view in which from a viewing angle above the device, a portion of the device Fig. 1 is shown.

Fig.1 shows a sectional side view of an apparatus 10 according to the invention for the trigger-free circular knitting of wires. The device 10 has a substantially hollow cylindrical needle carrier 12 having on its outer peripheral surface 14 a plurality of straight, identical guide grooves (not shown). The guide grooves are uniformly spaced from one another on the outer peripheral surface 14 and extend parallel to the longitudinal axis of symmetry of the needle carrier 12. In each guide a needle 16 for entangling wires is guided longitudinally displaceable. The needles 16 are controlled in a known manner by a needle control 18, which is in the form of a pushed onto the needle carrier 12, rotatable relative to this control cylinder 20, in its peripheral surface corresponding control grooves (not shown) are formed, which cooperate with the needles 16 ,

Furthermore, between each two guide grooves on the in Fig. 1 shown upper end face of the needle carrier 12 each have an adjusting groove 22 is formed. In particular Fig. 2 shows, in which a portion of the device 10 is shown in a perspective view, the parking grooves 22 extend radially with respect to the longitudinal axis of symmetry of the needle carrier 12 and serve to guide each of a slide 24 formed as a conveying element. Each slide 24 has on its the needle carrier 12 end facing a gripping portion 26, whose function will be explained later.

The slides 24 are actuated by a slide control 28 designed in the form of a control ring provided with control grooves and coupled to the needle control 18 of the needles 16. Each slider 24 is, depending on the position of each adjacently arranged needles 16 by means of the slider control 28 between a radially outwardly disposed position in which the slider 24 is arranged with its gripping portion 26 radially further out than the respectively adjacent needles 16, and a radially inwardly disposed position in which the slider 24 protrudes with its gripping portion 26 in the needle carrier 12, displaced in the adjusting groove 22.

If now a new hose section of wire to be knitted, the free end of the wire is fed to the needle carrier 12 by means of a feeding device, not shown, until one of the needles 16 detects the wire. Subsequently, the wire is continuously supplied in a conventional manner by either the feeder is rotated about the needle carrier 12 or the Needle carrier 12 rotates about its longitudinal axis of symmetry, the other needles 16 detect the wire in a conventional manner, while forming the wire to a meandering course row due to the shape of the needle carrier 12 and the shape of the needles 16.

Once the wire has been completely guided around the needle carrier and grasped by the needles 16, the actual knitting operation begins, in which the needles 16 entangle the further fed wire with the previously formed first course to form a subsequent course of stitches. This is done by the needles 16 to form the new stitches of the subsequent courses pull the wire through the stitches of the previously formed first course, while the needles 16 strip the previously held stitches of the previously formed first courses and continuously release the previously formed first course series sections , The respective released portion of the previously formed course is now continuously detected by the sliders 24 by the slides 24 are moved from its radially outer position to the radially inner position, wherein the gripping portions 26 detect the released portions and inwardly of the needles 16 away in the hollow cylindrical needle carrier 12 promote.

During the further knitting process, the sequence described above is repeated, whereby the released sections of the previously formed stitch row are respectively grasped by the slides 24 and conveyed inwards into the needle carrier 12 during stitch formation of the following row of stitches. In this case, the portion held by the slides 24, which has already been conveyed away beforehand, is released and pressed downwards into the needle carrier 12 by the section subsequently detected. This stripping movement is additionally assisted by a rounded edge 30 extending over the entire circumference, which forms the transition of the end face of the needle carrier 12 into the inner peripheral surface of the hollow cylinder of the needle carrier 12.

At the end of the knitting process, only the wire supplied by the feeding device is cut off and the knitting process is continued until the tube section is no longer caught by the needles 16 and the sliders 24.

Subsequently, it is possible to start again with the above-described coating.

With the method according to the invention and the device 10 according to the invention, it is possible for the first time to easily apply wires, since the hitherto required removal of the already knitted tube section is completely eliminated. Furthermore, with the method according to the invention and the device 10 according to the invention, it is possible for the first time to produce a hose section of defined length and defined weight in very tight manufacturing tolerances, without the hose section having to be shortened to the desired length after knitting by appropriate cutting devices. Rather, to form a defined length of a hose section only the supplied wire must be cut and the knitting process continued until the fabricated tube section of the device 10 can be removed or falls out of this by its own weight. In this way, the problem of occurring in the usual cutting cutting chaff is avoided because in the invention such chaff do not occur at all. The product produced by the process according to the invention neither has to be freed of chaff by hand or by machine, as is inevitably required in the state of the art, nor is the material loss of up to 10% supplied wire previously considered in the prior art to be taken into account.

LIST OF REFERENCE NUMBERS

10

contraption

12

needle carrier

14

Outer circumferential surface

16

needles

18

needle control

20

control cylinder

22

control grooves

24

pusher

26

cross section

28

slider control

30

rounded edge

Claims (16)

A zero-draft method of circularly knitting at least one wire into a multiple-course tube section, the method comprising: during the painting process, a loose end of the wire is grasped by one of the needles (16) of the circular knitting machine (10) and the wire is converted from the other needles (16) into a meandering row of stitches, in the further knitting operation, the needles (16) entangle the further fed wire with the previously formed course of stitches to form a subsequent course of stitches, by the needles (16) pulling the wire through the stitches of the previously formed course to form the new stitches of the subsequent course while the needles (16) strip the previously held stitches of the previously formed stitches and release the previously formed stitches in sections, wherein the respective released portion of the previously formed course of between the needles (16) arranged conveying elements (24) detected and inwardly of the Needles (16) is conveyed away, and cut off the supplied wire at the end of the knitting process and the further knitting process is continued until the tube section is no longer detected by the needles (16) and the conveying elements (24). The method of claim 1, wherein the conveying elements (24) release the previously conveyed previously formed row of stitches only when they capture the stitch row formed below and convey away from the needles (16) inwardly. A method according to claim 1 or 2, wherein the supplied wire is preformed to aid in stitch formation, preferably immediately prior to knitting. A method according to claim 3, characterized in that the wire is preformed meandering, wherein the meandering preform of the shape of the stitch pattern is approximated. Method according to one of claims 1 to 4, wherein the first formed end of the tube section is detected by means of a discharge device and removed from the circular knitting machine. Method according to one of claims 1 to 5, in which the loose end of the wire is formed into a hook shape for the application process. Apparatus for the deduction-free circular knitting of at least one wire to a wire knit hose, with
a needle carrier (12) on which a plurality of identical needles (16) are guided for entangling the wire,
a needle control (18) for driving the needles (16) according to a predetermined knitting movement,
a feed device for feeding the at least one wire, and means (24) for removing the tube knitted from the wire, characterized
in that the device for removing the hose is a discharge device comprising a plurality of conveying elements (24) movably guided between the needles (16) on the needle carrier (12), which are used to grasp the sections of the previously formed course row and immediately released from the needles (16) for conveying away the released portions inwardly away from the needles (16). Apparatus according to claim 7, characterized by a control device (28) coupled to the needle control of the needles (16) for moving the conveying elements (24) in accordance with a predetermined sequence of movements. Device according to claim 7 or 8, characterized in that between each two adjacent needles (16) in each case a conveying element (24) is provided. Apparatus according to claim 7, 8 or 9, characterized in that each conveying element is at least one at least approximately at right angles with respect to the direction of movement of the needles (16) movable slide (24). Tubular section of knitted wire knitted from at least one wire section, in particular using one of the methods defined in claims 1 to 6,
characterized,
in that the at least one wire section from which the finished tube section is formed has a predetermined defined length, which results exclusively by capping the wire section during the feeding of the wire section during knitting, and that the tube section is free of chaff immediately after the knitting operation and at each of its ends has two ends per wire section only in each case a separate insoluble open wire end. Hose section according to claim 11, characterized in that the wire section of the wire knit forming the hose section is deformed between the stitches at least in sections by the withdrawal process Hose section according to claim 11 or 12, characterized in that the wire section consists of a mono-formed wire, a multi-filament wire, a strand-shaped wire or stranded wires. Hose section according to claim 11, 12 or 13, characterized in that the wire section has a round, oval, flat or polygonal cross-sectional shape. Hose section according to one of claims 11 to 14, characterized in that the mesh shapes and / or the number of stitches and / or the mesh size varies in the knitted wire. Hose section according to one of claims 11 to 15, characterized in that the hose section has been formed into a molded part.

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