KNITTED NET FOR ENVELOPING ROUND BALES, AND METHOD AND DEVICE FOR THE PRODUCTION THEREOF

Abstract

A netting, knitted from fringes and weft threads is provided in which at least one fringe in at least one marginal region of the netting is shorter than the remaining fringes of the netting. The invention relates, furthermore, to a method for producing the netting on a knitting machine, during the knitting of the netting shorter loops for forming stitches from which the fringes are knitted being generated in at least one marginal region than in the remaining regions of the netting. Moreover, a knitting machine for producing a netting is described, which comprises a first lay bar for feeding the weft threads, a second lay bar for feeding the longitudinal threads, a needle bar with needles and a take-up device, at at least one position on the needle bar at which the marginal region of the netting is knitted the needle being positioned higher than the remaining needles.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a netting which is knitted from fringes and weft threads, to a method for producing the netting, to a knitting machine for producing the netting and to the use of the netting.

2. Description of the Background Art

Fringes are to be understood as meaning threads which, during the manufacture of the netting, run longitudinally in the production direction, and weft threads are to be understood as meaning threads which, during the manufacture of the netting, run in the transverse direction. Threads are in this context preferably to be understood as meaning film strips, that is to say strips which are generated by the longitudinal cutting of sheet-like films and which assume the character of a thread by drawing in the longitudinal direction.

Knitted nettings of such a type are employed, for example, in agriculture for the wrapping of round bales. The round bales are generally straw or hay bales. Furthermore, nettings of such a type are employed, for example, for the wrapping of silage bales, bales with chopped corn, bales with pressed pulp, bales with shredded plastic waste or bales with comminuted household garbage.

Nettings, such as are known from the prior art and are sold commercially, often contract when they are being wound around the round bales, so that the round bales are then not covered by the netting at their edges. The result of this is that the round bales may fray and become unstable at the margins. Also, for visual reasons, the customers for such nettings do not want the round bales to fray at the margins.

Edges of a generally cylindrical round bale are in this context to be understood as meaning the edges at which the surface area of the cylinder adjoins the circular base. In this case, the base and the surface area of the cylinder form, in general, an angle of about 90°.

Raschel nettings, as they are known, are often already employed for wrapping the round bales. These Raschel nettings are distinguished in that the fringes are connected to the weft threads, consequently running in a “zigzag” manner and diagonally in relation to the fringes, to form a netting. The construction of such Raschel nettings employed as round bale nettings is described, for example, in DE-U 200 08 520.

A netting which can be drawn around the edge of the round bale is known from EP-A 0 304 104, which corresponds to U.S. Pat. No. 4,917,008. In this round bale netting, an elastic marginal thread is used, by means of which the netting is drawn over the edge of the round bale. This avoids the situation where the netting contracts on the bale, which will lead to the margins of the round bale not being covered by the netting.

The round bale netting with an elastic marginal thread has the disadvantage that, during the production of the netting, an additional thread consisting of another material has to be provided in the marginal region. Also, due to aging, the elasticity of an elastic marginal thread may diminish. Moreover, the latter may become brittle and tear.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a netting which is knitted from fringes and weft threads and which, in practical use, lays itself around the edge of a round bale, so that a fraying of the round bale in the edge region is prevented. Further objects of the present invention are to provide a method and a device for producing the netting.

The object is achieved by means of a netting which is knitted from fringes and weft threads and in which at least one fringe in at least one of the two marginal regions of the netting is shorter than the remaining fringes of the netting. The at least one shorter fringe, that is to say the at least one fringe which is shorter than the remaining fringes of the netting, is preferably at least 0.5%, more preferably at least 1% and, in particular, at least 2% shorter than the remaining fringes of the netting. What is in this context considered to be a marginal region is in each case that 20% of the netting, preferably in each case that 10% of the netting, which forms the lateral margin running parallel to the fringes.

Furthermore, the object is achieved by means of a method for producing a netting on a knitting machine, during the knitting of the netting shorter loops for forming stitches from which the fringes are knitted being generated in at least one marginal region than in the remaining regions of the netting.

Finally, the object is achieved by means of a knitting machine for producing the netting, the knitting machine comprising a lay bar for feeding the longitudinal threads for knitting the fringes, a lay bar for feeding the weft threads, a needle bar with needles and a take-up device. At least one position on the needle bar at which the at least one shorter fringe in at least one marginal region of the netting is knitted, the needle is positioned higher than the remaining needles, and/or the take-up device comprises at least one take-up roller which has a region of smaller diameter at least one position at which a shorter fringe is knitted.

The at least one shorter fringe in at least one marginal region of the netting ensures that, when the marginal region having the shorter fringe is being wound around the round bale, the netting fits snugly around at least one of the edges of the round bale, and a contraction of the netting on the round bale and therefore a fraying of the round bale edge region are thus avoided.

In each case the marginal fringes, that is to say the fringes which form the lateral termination of the netting on each side, are preferred as shorter fringes. If more than one fringe in the marginal region is shortened, the shorter fringes preferably lie next to one another; one of the shorter fringes is in this case preferably the marginal fringe.

In an embodiment, the fringes are in each case produced from a longitudinal thread which can be knitted into stitches lined up with one another. The at least one shorter fringe is generated in that the stitches of the at least one shorter fringe are smaller than the stitches of the remaining fringes of the netting. As a result, even while the netting is being knitted, a shorter fringe is generated in a simple way in each case at the positions at which the fringes with smaller stitches are knitted.

In a further embodiment, the longitudinal threads from which the shorter fringes are knitted can have a greater cross section than the longitudinal threads from which the remaining fringes are knitted. This is achieved, for example, in that, when film strips are used, the strips from which the shorter fringes are knitted are cut wider than the film strips from which the remaining fringes are knitted, the thickness of the film being the same. Alternatively to this, even for the shorter fringes, strips may be used which consist of a thicker film and which are cut exactly as wide as the film strips from which the remaining fringes are knitted. It is also conceivable that both the thickness and the width of the film strip from which the shorter fringe is knitted are greater than the thickness and width of the film strip from which the remaining fringes are knitted. With an approximately circular cross section of the thread, preferably, the diameter of the thread from which the shorter fringe is knitted is greater than the diameter of the threads from which the remaining fringes are knitted. When a thread of greater cross section is used, smaller stitches arise during knitting because of the greater cross section, with the loop length being the same, since, on account of the greater cross section, the additional thread volume reduces the space surrounded by the loop.

Preferably polyolefin strips including, in particular, polyethylene, polypropylene or copolymers of these or of other co-components, are used as fringes and/or (in particular, and) as weft threads. By polyolefin strips being used, weather-resistant nettings are obtained which may be employed, for example, in agriculture for the wrapping of round bales.

Further suitable materials for producing the fringes and/or weft threads are, for example, plant fibers or starch-based threads and also mixtures of fibers and/or starch and polyolefins.

In another aspect, the shorter loops can be generated in that the netting is taken up from the knitting region of the knitting machine over a shorter distance at the positions at which the shorter fringes are knitted. Since the netting is taken up from the knitting region of the knitting machine over a shorter distance at the positions at which the shorter fringes are knitted, the longitudinal threads from which the fringe is knitted are drawn over a shorter distance through the stitch last knitted. Shorter loops are thereby generated.

The fact that the netting is taken up from the knitting region of the knitting machine over a shorter distance at the positions at which the shorter fringes are knitted is preferably achieved in that the knitting machine comprises a take-up device with a take-up roller which has a smaller diameter at the positions at which the shorter fringes are knitted.

In a further embodiment, to generate the shorter loops, needles are used which, at the position of the needle bar at which the shorter fringes are knitted, are positioned higher than the remaining needles. This is achieved, for example, in that longer needles are used.

Owing to the higher position of the needles, the longitudinal thread from which the shorter fringes are knitted is drawn over a shorter distance through the stitch already knitted. This gives rise to a shorter loop. The renewed drawing of the longitudinal thread through the shorter loop thus gives rise to a smaller stitch.

In the knitting machines, known from the prior art, for the knitting of nettings, the needles with which the fringes are knitted have a fastening nose. The needles are positioned at the fastening nose coming to abutment in a groove on the needle bar. By the height of the fastening nose being reduced, with the result that a lengthening of the effective needle length is achieved, a higher position of the needle is likewise achieved.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 shows a netting designed according to the invention with shorter fringes in the marginal region,

FIG. 2 shows a section through a knitting region of a knitting machine,

FIG. 3 shows a top view of the knitting region of a knitting machine with a take-up device,

FIG. 4 shows a needle,

FIG. 5 shows a fastening nose of a needle,

FIG. 6 shows the generation of a loop for a shorter fringe,

FIG. 7 shows the generation of a loop for an unshortened fringe,

FIG. 8 shows a top view of a needle bar with needles positioned at different heights, and

FIG. 9 shows a take-up roller with a smaller diameter at the positions at which the shorter fringes are knitted.

DETAILED DESCRIPTION

FIG. 1 shows a knitted netting having shorter fringes in a knitting region.

A knitted netting 1 comprises fringes 2 and weft threads 3. The fringes 2 are in this instance knitted in each case from a longitudinal thread. In a preferred embodiment, the longitudinal threads from which the fringes 2 are knitted and the weft threads 3 are polyolefin strips which are cut from a polyolefin film and subsequently drafted.

To produce the fringes 2, loops 4 are formed from the longitudinal thread, through which loops the longitudinal thread is drawn so as to form a new loop. A loop through which the longitudinal thread is drawn so as to form a further loop is designated in general as a stitch.

The netting 1 illustrated in FIG. 1 is what is known as a Raschel netting in which the weft threads 3 run in each case in a “zigzag” manner between two fringes 2. A fastening of the weft thread 3 and the fringe 2 takes place in that the weft thread 3 is drawn through a stitch of the fringe 2 during the knitting of the netting 1. The weft thread 3 is thereby connected to the fringe 2.

In order to achieve a stable wrapping of a round bale, in the embodiment illustrated in FIG. 1 fringes are knitted with shorter loops 4.1 in the marginal region. This gives rise to shorter fringes 2.1. Owing to the shorter fringes 2.1, the netting 1, when being wound around a round bale, is drawn over the edges of the round bale, thus achieving a wrapping of the round bale over the entire round bale width, without the netting 1 contracting and therefore without the round bale being capable of fraying in the edge region.

In addition to the embodiment illustrated in FIG. 1, in which in each case the two outer fringes 2.2 are shortened in relation to the remaining fringes 2 of the netting and form the marginal region, it is also possible that only the marginal fringe 26, that is to say the outermost fringe, more than in each case two fringes 2,2.2, 26 on each side or in any other fringe 2 in the marginal region of the netting is knitted shorter than the remaining fringes 2 of the netting 1.

FIG. 2 shows a section through a knitting region of a knitting machine for producing a netting.

A knitting region 5 of a knitting machine comprises a first lay bar 6 and a second lay bar 7. In the first lay bar 6, a weft thread, not illustrated here, is guided in an eye 8 which is arranged on that side of the first lay bar 6 which faces a needle 10.

A longitudinal thread, likewise not illustrated here, from which a fringe 2 is knitted, is guided in an eye 9 which is located on that side of the second lay bar 7 which faces the needle 10. For this purpose, the needle 10, by means of a hook 11 arranged at its end facing the eyes 8, 9, grips the longitudinal thread guiding the eye 9 and then moves away from the eye 9 in the direction of a knockover bit bar 12. The longitudinal thread gripped by means of the hook 11 is drawn through a loop 4 which has formed around the needle 10. A stitch of the fringe is thereby generated.

The needle 10 is fastened to a needle bar 13 which, to knit the netting, moves in the directions illustrated by the double arrow 14. The needle 10 has, at its end facing away from the hook 11, a fastening nose 15 which engages into a groove 16 in the needle bar 13. This prevents the needle 10 from slipping out of place during the knitting of the netting 1.

The fastening of the needle 10 in the needle bar 13 preferably takes place via a clamping connection. For this purpose, the needle 10 is pressed with a clamping shoe 17 against the needle bar 13. In the embodiment illustrated here, the fastening of the clamping shoe 17 takes place via a cramp 18 which is screwed into the needle bar 13 with the aid of a screw 19. However, any other possibility, known to a person skilled in the art, for fastening the needle may also be envisaged.

Furthermore, a slide bar 20 is arranged in a knitting region 5 of the knitting machine. By means of the slide bar 20, a slide, not illustrated here, in the needle 10 is controlled and closes or releases the hook 11. When the longitudinal thread is gripped, the hook 11 is released. The needle 10 moves in the direction of the knockover bit bar 12, with the result that a loop is drawn. As soon as the needle 10 moves back in the direction of the eye 9, the loop 4 formed is laid around the needle 10. The needle 10 grips the longitudinal thread once again with the hook 11 and moves in the direction of the needle bar 13 again. During this time, the loop 4 which lies around the needle 10 is displaced on the needle 10 in the direction of the hook 11. So that the longitudinal thread can be drawn through the loop 4, the slide closes the hook 11, so that the loop 4 is guided along the slide via the hook 11, and the longitudinal thread gripped by the hook 11 is drawn through the loop 4. A stitch is thereby formed.

The knitted netting is taken up from the knitting region 5 of the knitting machine by a take-up device. The take-up device preferably comprises at least one take-up roller 21. So that the netting 1 is taken up from the knitting region 5 of the knitting machine by means of the take-up roller 21 and does not slip off on the take-up roller 21, the take-up roller 21 is preferably provided with a coating to which the netting 1 adheres. A suitable coating is, for example, a polymer foam with a rough surface. The netting 1 is held on the surface of the take-up roller 21 by frictional force and is thus taken up from the knitting region 5 of the knitting machine.

FIG. 3 shows a top view of the knitting region of a knitting machine with a take-up device.

The knitted netting 1 is taken up from the take-up device 22 via the knockover bit bar 12. The netting 1 first runs along the underside of the take-up roller 21. It is deflected from there via a second roller 23 and led to a winding device where the knitted netting 1 is wound up.

In the knitting machine illustrated in FIG. 3, two nettings 1 are produced simultaneously, parallel to one another, on a knitting machine. The right marginal region in the production direction of the left netting 1 is designated by reference symbol 24. Reference symbol 25 designates the left marginal region of the right netting 1 in the production direction. In order in each case to obtain a shorter marginal fringe 26 of the nettings, the diameter of the take-up roller 21 is reduced in the region in which the marginal fringe 26 is taken up. A lower tensile force is thereby exerted on the marginal fringe 23 by the take-up roller 21, as a result of which, when the marginal fringe 26 is being knitted, shorter loops are obtained and therefore the marginal fringe 26 is shortened in relation to the remaining fringes 2.

FIG. 4 illustrates a needle, such as is used for knitting a netting.

A groove in which a slide 27 is received is formed in the needle 10. The slide 27 is connected to the slide bar 20 at the point identified by reference symbol 28. While the netting is being knitted, the slide bar 20 does not move. The needle 10 is moved in the direction identified by the double arrow 29. As soon as the needle 10 moves towards the eye 9 in which the longitudinal thread for producing the fringes is guided, the hook 11 opens since the slide 27 remains in its position. The hook 11 can grip the longitudinal thread. As soon as the hook 11 has gripped the longitudinal thread, the needle 10 moves in the other direction. The hook 11 is thereby closed by the slide 27. A loop 4 is thus formed on the hook 11. As soon as the needle 10 is moved again in the direction of the eye 9, not illustrated here, the loop 4 slips over the needle 10 in the direction facing away from the hook 11. The hook 11 once again grips the longitudinal thread, whereupon the needle 10 moves back again. In this case, the slide 7 closes the hook 11. The loop 4 previously formed during the operation slips over the slide 27 and over the hook 11. Thus, the longitudinal thread, which therefore forms a new loop 4, is drawn through the loop 4 previously formed during the operation. A chain of stitches is obtained.

In order to move the needle 10, the latter is fastened in the needle bar 13. With the aid of the fastening nose 15, the needle 10 is held in its position in the needle bar 13. For this purpose, the fastening nose 15 engages into the groove 16 in the needle bar 13.

In order to lengthen the working length of the needle, that is to say to position the needle higher in the needle bar 13, the fastening nose 15 can be reduced. By the region 30 illustrated by hatching in FIG. 5 being removed, the abutment edge 31 with which the needle 10 is positioned against an abutment in the needle bar 13 is positioned further away from the hook 11. After the needle 10 has been installed in the needle bar 13, therefore, the needles 10, the fastening noses 15 of which have been reduced by the amount of the surface 30, project further out of the needle bar 13 by the height h.

FIG. 6 shows a needle bar with needles positioned at different heights.

In the needle bar 13 illustrated in FIG. 6, in each case the two outer needles 10.1 are positioned higher than the remaining needles 10. By the two outer needles 10.1 in the marginal regions of the needle bar 13 being positioned higher, in each case two shorter fringes are generated in the marginal region of the netting 1 during the knitting of the latter. In each case the first and the second fringe in the left marginal region and the first and the second fringe in the right marginal region are shortened. The needles 10, 10.1 are in each case held in the needle bar 13 via a clamping connection with a clamping shoe onto which a cramp 18 fastened by means of a screw 19 presses.

FIG. 7 shows the generation of a loop for a shorter fringe and FIG. 8 the generation of a loop for an unshortened fringe, the needle 10 in each case being in its lower abutment position.

In the lower abutment position, the fringe 2 is drawn via the knockover bit bar 12, a loop 32 being formed. On account of a smaller knockover depth 33, with the needle 10.1 positioned higher, as illustrated in FIG. 7, a smaller loop 32 is generated than in the case of the greater knockover depth 33, such as is illustrated in FIG. 8, and such as is achieved by means of a needle 10 not positioned higher.

The knitted fringe 2 is taken up from the knitting region of the knitting machine by the take-up roller 21 via the bit bar 12 in the take-up direction illustrated by the arrow 34.

A take-up roller with different diameters for generating fringes of different length is illustrated in FIG. 9.

The fringes which are taken up in regions of smaller diameter 35 have a shorter length than the fringes 2 which are taken up in the region of larger diameter 36.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.

Claims

1. A netting that is knitted from fringes and weft threads, the netting comprising: a plurality of fringes; and at least one fringe that is provided in at least one of two marginal regions of the netting being shorter than the remaining fringes of the netting.

2. The netting as claimed in claim 1, wherein at least one fringe in the marginal region is shorter than the remaining fringes.

3. The netting as claimed in claim 1, wherein, for the fringes, in each case a longitudinal thread is knitted into stitches lined up with one another, and wherein the stitches of at least one fringe in at least one of the two marginal regions are smaller than the stitches of the remaining fringes of the netting.

4. The netting as claimed in claim 3, wherein the longitudinal threads from which the shorter fringes in the marginal regions are knitted have a greater cross section than the longitudinal threads from which the remaining fringes are knitted.

5. The netting as claimed in claim 3, wherein the longitudinal threads from which the fringes are knitted and the weft threads are polyolefin strips.

6. A method for producing a netting on a knitting machine, the method comprising: providing at least one fringe in at least one of two marginal regions of the netting; and generating, during the knitting of the netting, shorter loops for forming stitches from which the fringes are knitted in at least one marginal region than in the remaining regions of the netting.

7. The method as claimed in claim 6, wherein the shorter loops are generated, in that the netting is taken up from the knitting region of the knitting machine over a shorter distance at positions at which the shorter fringes are knitted.

8. A knitting machine for producing a netting having at least one fringe that is provided in at least one of two marginal regions of the netting, the at least one fringe being shorter than the remaining fringes of the netting, the knitting machine comprising: a first lay bar for feeding weft threads; a second lay bar for feeding longitudinal threads for knitting fringes; a needle bar with needles; and a take-up device having a take-up roller which has a region of smaller diameter at least one position at which the shorter fringes are knitted wherein at least one position on the needle bar at which at least one shorter fringe in at least one marginal region of the netting is knitted, and wherein the needle is positioned higher than the remaining needles.

9. The knitting machine as claimed in claim 8, wherein the higher position of the needles is achieved with longer needles.

10. The knitting machine as claimed in claim 8, wherein the higher position of the needles takes place by lengthening a height of a fastening nose on the needle.

11. The netting according to claim 1, wherein the netting is for wrapping agricultural products.

12. The netting as claimed in claim 11, wherein the agricultural products are round bales.

13. The netting as claimed in claim 1, wherein the netting wraps silage bales, bales with chopped corn, bales with pressed pulp, bales with shredded plastic waste or bales with comminuted household garbage.