Twine knotter for producing a knot in twine strands

Abstract

The invention relates to a twine knotter comprising: a knotter hook (26) which can be rotated about a knotter hook axis (27) and has a pivotable knotter hook tongue (42) and a hook portion (39), wherein the knotter hook tongue (42) has a retaining lug (47) protruding towards the hook portion (39); a driver (23) which can be rotated about a driver axis (31) and has a driver plate (35) for temporarily clamping the twine strands (25, 25'), wherein the driver axis (31) and the knotter hook axis (27), viewed in the direction of a drive axis (30), enclose an angle (51) of 45° to 90° and the driver plate (35) is arranged perpendicularly to the driver axis (31); a blade lever (19) which can be pivoted about a blade lever axis (18) and by means of which a blade (20) arranged on the blade lever (19) can be pivoted in a blade plane (32); and a drive plate (12) which can be driven in rotation about the drive axis (30) and is drivingly connected to the knotter hook (26), the driver (23), and the blade lever (19); wherein 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 blade plane (32) of the blade (20) and the knotter hook axis (27) of the knotter hook (26) along the twine 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.

Description

[0001] Yarn knotter for creating a knot in chamois strands

[0002] Description

[0003] 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 on the knotter hook relative to the hook portion 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.

[0004] Twine knotters are used in large bale presses for straw, hay, silage, and similar materials, as well as in recyclable materials recycling, e.g., for bundling paper, textiles, thin sheet metal, and the like. Tying 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. In stationary or mobile large bale presses, the material to be pressed is filled into a press channel with at least a rectangular cross-section and pressed into a rectangular strand of material. This strand is then divided into cuboid-shaped packs—also commonly called square bales—whose top and bottom sides, as well as their front sides, are strapped lengthwise along the press channel with several strands of twine, which are then knotted before the pack is ejected.Depending on the width of the pack and its compression density, two or more twine knotters are mounted side by side on the knotter drive shaft of a press. The selection of twine knotters and the press elements supporting the knotting process are determined by the number of straps required for a pack.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] 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 yarn 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 knotter hook is to be adapted to conditions other than the length of the yarn between the cut end and the knotter hook axis, such as the ability to pull the knot off the knotter 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.

[0009] DE 3607694 A1 addresses the problem of baling presses tending to produce larger bales. This results in thicker yarn being used due to the higher pressure required when tying the bales. Thicker yarn results in fuller knots, which tend to contract slightly when tension is applied to the bale, with yarn material being drawn in from the free ends of the knots. This can lead to very short knot ends, posing a risk of knots coming undone. To solve this problem, it is proposed that the distance, measured along the twine strand, between the center plane of the knotter hook and the pivot plane of the knife be at least 40 mm.The increase in distance has the effect that the distance from the knot formed in the knotting hook to the cutting plane at the knot ends becomes larger and thus the knot ends themselves become longer, so that more yarn is available at the knot, which can be pulled in when the knot is tightened without the risk of the knot coming loose.

[0010] The object of the present invention is to provide a yarn knotter which creates loop knots safely with a simple structure.

[0011] 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 portion, wherein the knotter hook tongue is pivotably mounted on the knotter hook relative to the hook portion 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 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. A knife arranged on the knife lever can be pivoted in a knife plane using the knife lever, wherein the knife plane is arranged between the knotter hook and the driver. 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.

[0012] 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 tying the knot. The knotter's hook grips and holds the ends of the yarn strands that are to be knotted together, which are ultimately cut off to form knotted ends. 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] This arrangement of the drive discs also ensures that the clamping of the chamois on the drive is arranged close to the knife plane, which leads to a compact design.

[0017] 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.

[0018] The twine knotter is preferably designed as a single knotter, which is configured such that with one complete rotation of the drive disk, the knotter hook rotates once around the knotter hook axis to create the knot. In one embodiment, the twine knotter has a driver drive shaft rotatable about a driver drive axis and drivingly connected to the drive disk and the driver, wherein the driver drive axis and the knotter hook axis, viewed in the direction of the drive axis, enclose an angle of greater than 23.5° or of at least 25.75° or of greater than 30° or of at least 34.3°. As a result, the distance between the driver and the knotter hook is increased compared to a conventional twine knotter with a 23.5° spread angle, which leads to longer knot ends.

[0019] 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.

[0020] An exemplary embodiment is explained in more detail in the drawings. Herein:

[0021] Figure 1 is a schematic side view of a baler with a twine knotter,

[0022] Figure 2 is an enlarged view of the twine knotter according to Figure 1 in the area of ​​the knotter hook,

[0023] Figure 3 is a perspective view of the twine knotter according to Figure 1 and

[0024] Figure 4 is a side view of the knotting hook of the twine knotter according to Figure 1,

[0025] Figure 1 shows a side view of a baler with a twine knotter 10. Figure 2 shows an enlarged view of the twine knotter 10 according to Figure 1. Figures 1 and 2 are described together below. Figure 1 shows a press channel 1 of a baler, which is defined by a floor 2 and an upper cover as well as corresponding side walls. In the press channel, a press piston 4 according to Figure 1 is movable to the right, which press piston 4 compresses a quantity of baling material, for example straw, introduced into the press channel 1 in the left-hand area not shown in Figure 1 with a previously introduced quantity in several strokes in the direction of arrow 50 to form a bale 5. The bale 5 moves to the right out of the press channel 1 according to Figure 1 and is ejected after completion.

[0026] To ensure that the bale 5 retains its cohesion, it is tied 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 held 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 side of the bale 5 (see Figure 1), upwards along the front side and on the top side of the bale 5 back to the yarn knotter 10 arranged above the press channel, which holds the yarn 6 taut and secure against the pressure of the press piston 4 during the formation of the bale 5. Two or more yarn knotters 10 are consistently provided next to one another at a distance in the direction perpendicular to the plane of the drawing in Figure 1, forming a corresponding number of mutually parallel yarn loops around the bale 5.

[0027] 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.

[0028] On the knotter frame 16, a knife lever 19 with a knife 20 is pivotally mounted about a knife lever axis 18 that is essentially perpendicular to a drive axis 30 of the drive shaft 11. The knife 20 moves in a knife plane that passes not exactly, but approximately, through the drive axis 30 of the drive shaft 11 and is accordingly perpendicular to the plane of the drawing in Figure 1. 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. The drive shaft 21 is driven by one of the toothed segments 13 and acts via a worm on a pinion 22 that is located on a driver shaft of the driver 23, which in Figure 1 is arranged to the right of the knife plane 32 of the knife 20. A driver axis 31, around which the driver 23 is driven in rotation, extends at least approximately perpendicular to the knife plane 32 of the knife 20.The knife 20 moves relatively close to the driver 23 consisting of two coaxial driver disks 35. A yarn holder, not visible in Figure 1, is provided, which engages between the driver disks 35 of the driver 23 and clamps a yarn strand 25 running transversely to the driver 23 through one of its edge recesses 24 (Figure 3) in the driver 23.

[0029] On the left side of the knife plane 32 of the knife 20 according to Figure 1, 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.

[0030] In the working phase shown in Figure 1, the upper end of the yarn 6, i.e. 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 finished, the press needle 9 pivots upwards in the direction of 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 yarn strand 25' of the yarn 6 and brings it together with the upper yarn strand 25 so that the knotting hook 26 can form the knot. The lower yarn strand 25' is displaced to the right as shown in Figure 1 until it can be grasped by the driver 23. When the knife lever 19 with the knife 20 pivots forward from the plane of the drawing as shown in Figure 1, the finished knot is severed and the lower yarn strand 25' of the yarn 6 is gripped in the driver 23.After the knot is severed, the twine loop around the bale 5 is closed, and the bale can be ejected to the right out of the press channel 1. New press material is then fed through the press piston 4, whereby the twine strand 25, which runs from the press needle 9, which has meanwhile been retracted downwards, to the driver 23, is carried to the right as the bale formation progresses.

[0031] As can be seen in Figure 2, 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. 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°. The maximum deviation from parallelism between the knife plane 32 and the driver disks 35 is thus 10°. This allows the knife plane 32 to be structurally brought as close as possible to the driver disks 35 in order to maximize the distance between the knife plane 32 and the knotter hook axis 27 and to enable the formation of knot ends that are as long as possible.

[0032] 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°.

[0033] The twine knotter 10 is shown again in perspective in Figure 3. This 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.

[0034] 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 (Figure 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.

[0035] Parallel to the upper side 3 of the press channel 1, a pivotable yarn bar 36 is arranged, which is movable by means of a link 37 in time with the yarn knotter 10 and which conveys the yarn strand 25' conveyed upwards by the press needle 9 to the knotter hook

[0036] 26.

[0037] Figure 4 shows the knotting hook 26 in a side view. It comprises a cylindrical shaft 38 with the knotting hook axis 27, about which the knotting hook 26 is rotatably mounted on the knotting frame 16 (Figure 1). A hook section 39, which projects from the knotting hook axis 27, is firmly connected to the shaft 38. A pivot pin 41 extending perpendicular to the knotting hook axis 27 is arranged approximately in the region of the bend. The knotting hook 26 has a recess through which a knotting 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 coincides with the knotting hook axis.

[0038] 27 forms an angle of less than 90°, approximately 70°. 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 a torque on the knotter hook tongue 42 in certain phases of knot formation, directed counterclockwise as shown in Figure 4, under which torque the yarn strands 25, 25' are clamped in the knotter mouth 46 formed by the hook section 39 and the front tongue part 43.

[0039] 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.

[0040] In order to facilitate the pulling out of 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 withdrawal direction of the knot ends 34 from 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 (see Figure 4) is exerted on the knotting tongue 42 and the knotting tongue 42 is thus urged towards assuming an open position.

[0041] List of reference symbols

[0042] 1 press channel

[0043] 2 floor

[0044] 3 Base plate

[0045] 4 press pistons

[0046] 5 bales

[0047] 6 yarn

[0048] 7 Yarn stock

[0049] 8 clamping device

[0050] 9 press needle

[0051] 10 twine knotters

[0052] 11 Drive shaft

[0053] 12 drive pulley

[0054] 13 tooth segment

[0055] 14 curve segment

[0056] 15 Bearing eye

[0057] 16 knotting frames

[0058] 17 Bearing block

[0059] 18 Knife lever axis

[0060] 19 Knife lever

[0061] 20 knives

[0062] 21 Drive shaft

[0063] 22 pinions

[0064] 23 drivers

[0065] 24 Edge recess

[0066] 25, 25' yarn skein

[0067] 26 knotter hooks

[0068] 27 Knotting hook axle pinion

[0069] Arrow

[0070] drive axle

[0071] Driving axis

[0072] Knife level

[0073] Driver drive axle

[0074] Node end

[0075] Drive plate

[0076] Yarn bar

[0077] handlebar

[0078] shaft

[0079] Hook section

[0080] Distance

[0081] pivot pin

[0082] Knotting hook tongue front tongue part rear tongue part

[0083] tongue roll

[0084] knotted mouth

[0085] retaining nose

[0086] tip of the nose

[0087] Distance

[0088] Arrow

[0089] Angle between driver axis and drive axis

[0090] Angle between driver axis and knife plane

[0091] Angle between driver drive axis and knotter hook axis

Claims

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 the 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 the 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.

2. Yarn knotter according to claim 1, characterized in that the yarn 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 the knot.

3. Yarn knotter according to claim 1 or 2, characterized in that the driver (23) has two driver discs (35).

4. Twine knotter according to one of claims 1 to 3, characterized in that the driver axis (31) and the knife plane (32) enclose an angle (52) of 80° to 90°.

5. Twine 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. Twine knotter according to one of claims 1 to 5, characterized in 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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