Yarn knotter for creating a knot in yarn strands

Abstract

Yarn knotter for creating at least one knot in yarn strands (25, 25'), comprising: a knotter hook (26) rotatable about a knotter hook axis (27), with a knotter hook tongue (42) for clamping the yarn strands (25, 25') between the knotter hook tongue (42) and a hook section (39), wherein the knotter hook tongue (42) is arranged pivotably relative to a hook section (39) on the knotter hook (26) and has a retaining lug (47) projecting in the direction of the hook section (39), a driver (23) rotatable about a driver axis (31) with at least one driver disk (35) for temporarily clamping the yarn strands (25, 25'), wherein the driver axis (31) and the knotter hook axis (27) form an angle (51) of 45° to 90° and wherein the at least one driving disc (35) is arranged perpendicular to the driving axis (31), a knife lever (19) pivotable about a knife lever axis (18),with which a knife (20) arranged on the knife lever (19) can be pivoted in a knife plane (32), wherein the knife plane (32) is arranged between the knotting hook (26) and the driver (23), and a drive disk (12) which can be driven to rotate about a drive axis (30) and which is drivingly connected to the knotting hook (26), to the driver (23) and to the knife lever (19), characterized in that a ratio of a distance (49) between the retaining lug (47) of the knotting hook tongue (42) and the knotting hook axis (27) to a distance (40) between the knife plane (32) of the knife (20) and the knotting hook axis (27) of the knotting hook (26) along the yarn strands (25, 25') between the knotting hook (26) and the driver (23) has a value of at least 1.5 or at least 1.6 or at least 1.9.

Description

[0001] The invention relates to a twine knotter for creating at least one knot in twine strands, for example for use in large balers. The twine knotter comprises a knotter hook rotatable about a knotter hook axis, a driver rotatable about a follower axis, a knife lever pivotable about a knife lever axis, and a drive disk rotatable about a drive axis, which is drive-connected to the knotter hook, the follower, and the knife lever. The knotter hook has a knotter hook tongue for clamping the twine strands between the knotter hook tongue and a hook portion. The knotter hook tongue is pivotably mounted relative to a hook portion on the knotter hook and has a retaining lug projecting toward the hook portion.The driver has at least one driver disk for temporarily clamping the yarn strands, wherein the driver axis and the knotter hook axis form an angle of 45° to 90° when viewed in the direction of the drive axis, and wherein the at least one driver disk is arranged perpendicular to the driver axis. A knife arranged on the knife lever is pivotable in a knife plane by means of the knife lever, wherein the knife plane is arranged between the knotter hook and the driver.

[0002] Twine knotters are used in large bale presses for straw, hay, silage, and similar materials, as well as in recycling applications, e.g., for bundling paper, textiles, thin sheet metal, and the like. Binding or bundling devices equipped with such twine knotters can also be part of packaging systems for tying packs, bales, or bundles made of suitable materials.

[0003] In stationary or mobile large bale presses, the baled material is fed into a bale chamber with at least a rectangular cross-section and pressed into a rectangular bale. This bale is divided into cuboid-shaped bales – also commonly called square bales – whose top, bottom, and front sides are strapped lengthwise through the bale chamber with several twine strands, which are then knotted before the bale is ejected. Depending on the width of the bale and its compression density, two or more twine knotters are mounted side by side on the knotter drive shaft of a baler. The selection of twine knotters and the press elements that support the knotting process is determined by the number of straps required for a bale.

[0004] A knotter drive shaft is located either above or below the baling chamber, which is usually arranged at least approximately horizontally, and usually parallel to it. In other baling chambers, the drive shaft is arranged to the side.

[0005] To increase the pack weight and make better use of available transport capacity, the goal is to increase the compaction of the baled material. Knot strength is particularly important here, as it is lower than twine strength. Thus, the strength of a strapping can be achieved by increasing knot strength without having to use thicker twine, which would increase material usage.

[0006] In agricultural technology, there are basically two types of twine knotters: twine knotters that operate according to the Deering principle and create a strand knot with the knot ends pulled through, and twine knotters that operate according to the McCormick principle and create a loop knot. Loop knots have been shown to have higher knot strength than strand knots when using the same twine.

[0007] WO 2022 / 023530 A1 shows a twine knotter in the form of a double knotter, which forms two knots consecutively with one rotation of the drive disk. To ensure that both knots are formed as loop knots, it is proposed, among other things, that the length of the twine between the cut end and the knotter hook axis be at least 1.3 times the length of the knotter hook from the knotter hook axis to a tip of the knotter hook. However, this value can lead to a large variance in the length of the whole end, depending on the length of the knotter hook relative to the tip of the knotter hook.If the length of the knotting hook is to be adapted to conditions other than the length of the yarn between the cut end and the knotting hook axis, such as the ability to pull the knot off the knotting hook, it may happen that the length ratio specified in WO 2022 / 023530 A1 can no longer be maintained or that lengths of the yarn do not reliably lead to a loop knot.

[0008] The object of the present invention is to provide a yarn knotter which creates loop knots safely with a simple structure.

[0009] The problem is solved by a twine knotter for creating at least one knot in twine strands, wherein the twine knotter comprises a knotter hook rotatable about a knotter hook axis, a driver rotatable about a carrier axis, a knife lever pivotable about a knife lever axis, and a drive disk rotatably driven about a drive axis, which is drive-connected to the knotter hook, the driver, and the knife lever. The knotter hook has a knotter hook tongue for clamping the twine strands between the knotter hook tongue and a hook section, wherein the knotter hook tongue is pivotably arranged relative to a hook section on the knotter hook and has a retaining lug projecting toward the hook section.The driver has at least one driver disk for temporarily clamping the yarn strands, wherein the driver axis and the knotter hook axis enclose an angle of 45° to 90° viewed in the direction of the drive axis and wherein the at least one driver disk is arranged perpendicular to the driver axis. With the knife lever, a knife arranged on the knife lever can be pivoted in a knife plane, wherein the knife plane is arranged between the knotter hook and the driver. In this case, a ratio of a distance between the retaining lug of the knotter hook tongue and the knotter hook axis to a distance between the knife plane of the knife and the knotter hook axis of the knotter hook along the yarn strands between the knotter hook and the driver has a value of at least 1.5 or at least 1.6 or at least 1.9.

[0010] The knot formation zone is the section of yarn that is wrapped around the knotting hook by the rotation of the knotter's hook to create a knotted loop for forming the knot. The knotter's hook grips the ends of the yarn strands that are to be knotted together and which are ultimately cut off to form knotted ends, and holds them tight. To form the knot, the knotted loop is then pulled over the knotted ends held on the knotter's hook. In order to create a loop in the pulled-through knot ends after the knotted ends have been partially pulled through the knotted loop, the knotted ends must not be pulled completely through the knotted loop. This would otherwise result in a strand knot (Deering knot). The knotted ends must therefore be released from the clamp on the knotter's hook early enough. Furthermore, the knotted ends must be long enough to ensure that a loop is securely formed in the knotted ends.

[0011] According to the invention, the length of the knot ends, from a knot formation zone in the yarn to the yarn end where the yarn is cut, is measured as a function of the distance between the retaining lug of the knotter's tongue and the knotter's axis. Reference to the position of the retaining lug is essential, as this is the point at which the knot ends are held when the knot loop is slipped over. For the secure formation of a loop knot, the length of the knot ends up to the cutting plane is crucial.

[0012] This also has the advantage that the hook section of the knotting hook can be made as long as desired, for example to optimize the pulling behavior of the knot from the hook section, since the pulling behavior, i.e. how tightly the knot tightens, how easily it can be pulled off, etc., can be influenced by the length and shape of the hook section of the knotting hook, among other things.

[0013] The carrier axis and the knotter hook axis form an angle of 45° to 90° in the direction of the drive axis. The carrier has at least one carrier disc perpendicular to the carrier axis. The fewer carrier discs that can be used, the closer the knife plane can be moved to the carrier. This allows the distance between the knife plane and the knotter hook to be increased, enabling longer knot ends. In one embodiment, the carrier can, for example, have two carrier discs.

[0014] This arrangement of the driver discs also ensures that the yarn is clamped on the driver close to the knife plane, resulting in a compact design.

[0015] The carrier axis and the blade plane can form an angle of 80° to 90°. The blade plane and the carrier can be positioned as far away from the knotter hook as possible without colliding with other components on the side of the carrier facing away from the knotter hook, thus increasing the length of the knot ends.

[0016] The twine knotter is preferably designed as a single knotter, which is designed such that with one complete rotation of the drive disk the knotter hook rotates once around the knotter hook axis to create a knot.

[0017] In one embodiment, the twine knotter has a driver drive shaft rotatable about a driver drive axis and drivingly connected to the drive pulley and the driver. The driver drive axis and the knotter hook axis, viewed in the direction of the drive axis, form an angle of greater than 23.5° or of at least 25.75° or of greater than 30° or of at least 34.3°. This increases the distance between the driver and the knotter hook compared to a conventional twine knotter with a 23.5° spread angle, resulting in longer knot ends.

[0018] According to an exemplary embodiment, the driver axis and the knotter hook axis enclose an angle of 55° to 90° or 65° to 90° when viewed in the direction of the drive axis.

[0019] An exemplary embodiment is explained in more detail in the drawings. Herein: Fig. 1 a schematic side view of a baler with a twine knotter, Fig. 2 an enlarged view of the twine knotter according to Fig. 1 in the area of the knotter hook, Fig. 3 a perspective view of the twine knotter according to Fig. 1 and Fig. 4 a side view of the knotter hook of the twine knotter according to Fig. 1,

[0020] Fig. 1 shows a side view of a baler with a twine knotter 10. Fig. 2 shows an enlarged view of the twine knotter 10 according to Fig. 1. The Fig. 1 and Fig. 2 are described together below. In Fig. 1 shows a press channel 1 of a baling press, which is defined by a floor 2 and a top cover as well as corresponding side walls. A press piston 4 is arranged in the press channel according to Fig. 1 movable to the right, one in the Fig. 1 not shown left area into the press channel 1, the quantity of material to be pressed, for example straw, is pressed with a previously introduced quantity in several strokes in the direction of arrow 50 to form a bale 5. The bale 5 moves according to Fig. 1 to the right out of the press channel 1 and is ejected after completion.

[0021] To ensure that the bale 5 retains its cohesion, it is bound with loops of yarn 6 in vertical planes parallel to the direction of movement. The yarn 6 is taken from a yarn supply 7 and maintained under a certain tension by a clamping device 8. The strand 25' of the yarn 6 runs through an eyelet of a so-called press needle 9, then under the bale 5 to the right front until Fig. 1 right front side of the bale 5, along the front side upwards and on the top side of the bale 5 back to the twine knotter 10 arranged above the press channel, which holds the twine 6 taut and tight against the pressure of the press piston 4 during the formation of the bale 5. There are consistently two or more twine knotters 10 spaced apart in the direction perpendicular to the plane of the drawing of the Fig. 1 are provided next to each other, which form a corresponding number of mutually parallel yarn loops around the bale 5.

[0022] On a base plate 3 arranged above the upper cover of the press channel 1, a drive shaft 11 (often also called knotter shaft or knotter shaft) is provided, running horizontally transversely to the press channel 1, to which drive disks 12 (often also called knotter disks or knotter disks) of several twine knotters 10 are connected in a rotationally fixed manner. The drive disks 12 have toothed segments 13 and cam segments 14 for actuating the functional parts of the twine knotter 10. Furthermore, bearing eyes 15 of knotter frames 16 of the twine knotters 10 are mounted on the drive shaft 11. However, these bearing eyes do not rotate, but are supported at their free end against rotation on a bearing block 17.

[0023] A knife lever 19 with a knife 20 is pivotally mounted on the knotter frame 16 about a knife lever axis 18 which is substantially perpendicular to a drive axis 30 of the drive shaft 11. The knife 20 moves in a knife plane which does not exactly, but approximately, pass through the drive axis 30 of the drive shaft 11 and accordingly lies on the plane of the drawing of the Fig. 1 is vertical.

[0024] Furthermore, a driver drive shaft 21 in the form of a so-called worm shaft is rotatably mounted on the knotter frame 16 about a driver drive axis 33, which is driven by one of the toothed segments 13 and acts via a worm on a pinion 22, which is mounted on a driver shaft of the driver 23, which is in Fig. 1 is arranged to the right of the blade plane 32 of the blade 20. A driver axis 31, about which the driver 23 is driven in rotation, extends at least approximately perpendicular to the blade plane 32 of the blade 20. The blade 20 moves relatively close to the driver 23, which consists of two coaxial driver disks 35. It is a Fig. 1 not visible yarn holder is provided, which engages between the driver discs 35 of the driver 23 and has a transverse to the driver 23 through one of its edge recesses 24 ( Fig. 3) in the driver 23.

[0025] On the according Fig. 1 On the left side of the knife plane 32 of the knife 20, the knotting hook 26 is provided, the knotting hook axis 27 of which runs at least approximately through the drive axis 30 of the drive shaft 11 and which is driven by a pinion 28 which cooperates with one of the toothed segments 13 of the drive disk 12.

[0026] In the Fig. 1, the upper end of the twine 6, ie the strand 25, is held in the driver 23 and runs over the knotting hook 26 to the right around the bale 5. When the bale 5 is completed, the press needle 9 pivots upwards in the direction of the arrow 29 into the vicinity of the knotting hook 26 and beyond this into the vicinity of the driver 23. The knotting hook 26 thereby grasps the lower twine strand 25' of the twine 6 and brings it together with the upper twine strand 25, so that the knotting hook 26 can form the knot. The lower twine strand 25' is pulled out according to Fig. 1 to the right so that it can be caught by the driver 23. If the knife lever 19 with the knife 20 is then Fig. 1 pivots forward from the plane of the drawing, the fully formed knot is severed and the lower yarn strand 25' of the yarn 6 is gripped in the driver 23. After the knot has been severed, the yarn loop around the bale 5 is closed and the bale can be ejected to the right out of the press channel 1. New pressing material is then fed in by the press piston 4, whereby the yarn strand 25 running from the press needle 9, which has meanwhile been retracted downwards again, to the driver 23 is carried along to the right as the bale formation progresses.

[0027] As in Fig. 2, the driver axis 31 and the knotter hook axis 27, viewed in the direction of the drive axis 30, form an angle 51 of 45° to 90°. In addition, the driver disks 35 are arranged perpendicular to the driver axis 31. The knife plane 32 is thus arranged approximately parallel to the driver disks 35. The angle 52 between the driver axis 31 and the knife plane 32 is 80° to 90°. Thus, the maximum deviation from parallelism between the knife plane 32 and the driver disks 35 is 10°. This allows the knife plane 32 to be structurally brought as close as possible to the driver disks 35 in order to make the distance between the knife plane 32 and the knotter hook axis 27 as large as possible and to enable the formation of the longest possible knot ends.

[0028] In order to further increase the structural distance between the knife plane 32 and the knotter hook axis 27 compared to conventional twine knotters, the driver drive axis 33 and the knotter hook axis 27 are structurally arranged in such a way that, viewed in the direction of the drive axis 30, they enclose an angle 53 of greater than 23.5° (the spread of conventional twine knotters), for example of at least 25.75° or of greater than 30° or of at least 34.3°.

[0029] The twine knotter 10 is in Fig. 3 is shown again in perspective. It shows the phase shortly before the twine strands 25, 25' leading from the knotter hook 26 to the driver 30 are severed. The knotter hook 26 has formed the knot, and the twine strands 25, 25' extend through one of four edge recesses 24 of the driver disks 35 of the driver 23. The knife 20 moves forward on the knife lever 19 and severes the twine strands 25, 25' at a point located at a distance 40 from the knotter hook axis 27 of the knotter hook 26.

[0030] The distance 40 is at least 1.5 times or at least 1.6 times or at least 1.9 times the distance 49 from a retaining lug 47 of a knotter hook tongue 42 ( Fig. 4) to the knotter hook axis 27. This ensures that the projecting ends of the yarn strands 25, 25' remaining outside the knot, ie between the knotter hook 26 and the knife 20, the so-called knot ends 34, are long enough that the knot can be completely tightened by pulling in some of these knot ends 34, without one of the knot ends 34 being completely pulled through the knot.

[0031] A pivotable yarn bar 36 is arranged parallel to the upper side 3 of the press channel 1, which can be moved by means of a link 37 in time with the yarn knotter 10 and feeds the yarn strand 25' conveyed up by the press needle 9 to the knotter hook 26.

[0032] Fig. 4 shows the knotter hook 26 in a side view. It comprises a cylindrical shaft 38 with the knotter hook axis 27, around which the knotter hook 26 is mounted on the knotter frame 16 ( Fig. 1) is rotatably mounted. A hook section 39, which projects from the knotter hook axis 27, is firmly connected to the shaft 38. A pivot pin 41 extending perpendicular to the knotter hook axis 27 is arranged approximately in the region of the bend. The knotter hook 26 has a recess through which a knotter hook tongue 42 extends, which is designed as a two-armed lever, the front tongue part 43 of which extends approximately parallel over the hook section 39 and the rear tongue part 44 of which runs approximately in a direction that forms an angle of less than 90°, approximately 70°, with the knotter hook axis 27. At a free end of the rear tongue part 44, a tongue roller 45 is rotatably arranged for cooperation with a closer (not shown) for a closing movement of the knotter hook tongue 42. The closer exerts on the knotter hook tongue 42 in certain phases of the knot formation a counterclockwise Fig. 4 directed torque, under which the yarn strands 25, 25' are clamped in the knotting mouth 46 formed by the hook section 39 and the front tongue part 43.

[0033] The distance 49 between the retaining lug 47 of the knotter hook tongue 42 and the knotter hook axis 27 is measured from a nose tip 48 of the retaining lug 47, which has the smallest distance from the hook section 39 and is the first to come into contact with the hook section 39 during a closing movement of the knotter hook tongue 42. This is also the point at which the yarn strands 25, 25' are last to be held back by the retaining lug 47 during an opening movement of the knotter hook tongue 42.

[0034] In order to make it easier to pull out the loop in the knot ends 34, the holding lug 47 has a holding surface directed towards the knotter mouth 46, which forms an acute angle with the hook section 39 or with the direction in which the knot ends 34 are pulled out of the knotter mouth 46. The holding surface thus forms a type of ramp, so that when the knot ends 34 or the yarn strands 25, 25' are pulled out of the knotter mouth 46, a torque in a clockwise direction according to Fig. 4 is exerted on the knotting tongue 42 and the knotting tongue 42 is thus urged in the direction of assuming an open position. List of reference symbols 1 press channel 2 floor 3 Base plate 4 press pistons 5 bales 6 yarn 7 Yarn stock 8 clamping device 9 press needle 10 yarn knotters 11 Drive shaft 12 drive pulley 13 tooth segment 14 curve segment 15 Bearing eye 16 knotter frames 17 Bearing block 18 Knife lever axis 19 Knife lever 20 knives 21 Drive shaft 22 pinions 23 drivers 24 Edge recess 25, 25' yarn skein 26 knotter hooks 27 Knotting hook axis 28 pinions 29 Arrow 30 drive axle 31 Driving axle 32 knife level 33 Carrier drive axle 34 Node end 35 drive plate 36 yarn bars 37 handlebars 38 shaft 39 Hook section 40 distance 41 pivot pin 42 knotter hook tongue 43 front part of the tongue 44 rear part of the tongue 45 Tongue roll 46 knotter mouth 47 Retaining lug 48 Nose tip 49 distance 50 arrows 51 Angle between driver axis and drive axis 52 Angle between driver axis and knife plane 53 Angle between driver drive axis and knotter hook axis QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 023530 A1

[0007]

Claims

[1] Yarn knotter for producing at least one knot in yarn strands (25, 25') comprising: a knotter hook (26) rotatable about a knotter hook axis (27), with a knotter hook tongue (42) for clamping the yarn strands (25, 25') between the knotter hook tongue (42) and a hook section (39), wherein the knotter hook tongue (42) is arranged pivotably relative to a hook section (39) on the knotter hook (26) and has a retaining lug (47) projecting in the direction of the hook section (39), a driver (23) rotatable about a driver axis (31) with at least one driver disc (35) for temporarily clamping the yarn strands (25, 25'), wherein the driver axis (31) and the knotter hook axis (27) enclose an angle (51) of 45° to 90° when viewed in the direction of the drive axis (30), and wherein the at least one driver disc (35) is arranged perpendicular to the driver axis (31), a knife lever (19) pivotable about a knife lever axis (18), with which a knife (20) arranged on the knife lever (19) can be pivoted in a knife plane (32), wherein the knife plane (32) is arranged between the knotting hook (26) and the driver (23), and a drive disk (12) which can be driven to rotate about a drive axis (30) and which is drivingly connected to the knotting hook (26), to the driver (23) and to the knife lever (19), characterized by , that a ratio of a distance (49) between the retaining lug (47) of the knotter hook tongue (42) and the knotter hook axis (27) to a distance (40) between the knife plane (32) of the knife (20) and the knotter hook axis (27) of the knotter hook (26) along the yarn strands (25, 25') between the knotter hook (26) and the driver (23) has a value of at least 1.5 or at least 1.6 or at least 1.

9. [2] Yarn knotter according to claim 1, characterized bythat the twine knotter (10) is designed such that with one complete rotation of the drive disk (12) the knotter hook (26) rotates once around the knotter hook axis (27) to create a knot. [3] Yarn knotter according to claim 1 or 2, characterized by that the driver (23) has two driver discs (35). [4] Yarn knotter according to one of claims 1 to 3, characterized by that the driver axis (31) and the knife plane (32) enclose an angle (52) of 80° to 90°. [5] Yarn knotter according to one of claims 1 to 4, characterized by a driver drive shaft (21) rotatable about a driver drive axis (33) and drivingly connected to the drive disk (12) and to the driver (23), wherein the driver drive axis (33) and the knotter hook axis (27) enclose an angle (53) of greater than 23.5° or of at least 25.75° or of greater than 30° or of at least 34.3° when viewed in the direction of the drive axis (30). [6] Yarn knotter according to one of claims 1 to 5, characterized by that the driver axis (31) and the knotter hook axis (27) enclose an angle (51) of 55° to 90° or 65° to 90° when viewed in the direction of the drive axis (30).

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