Patent Description:
It is known to provide a baler for pressing bales with a reciprocal plunger, whereby the bale is bound by tying a plurality of twine loops around the bale.

The twine for binding the bale is supplied by two supplies per twine loop, one for the top side and one for bottom side of the bale. The closing of the loop around the finished bale is done by tying two knots. The basic principle of such a bale binding system is well described in <CIT> and <CIT>. The binding system described in <CIT> uses only one bill hook per twine loop, which produces the two knots sequentially. The binding system described in <CIT> uses two bill hooks per twine loop that produce one knot per bill hook per cycle and produce the knots simultaneously. The first system described in <CIT> is more compact and less complicated than the second described in <CIT>.

It is known from prior art that the knots can be of a conventional type or a loop type, as depicted in <FIG>. In a conventional knot as depicted in <FIG> the cut ends <NUM> of the twines extend outwards from the knot. In a loop knot as depicted in <FIG> the cut ends <NUM> of the twines are turned back on themselves and caught by the turns of the knot, forming short twine loops <NUM> on top of the knot. <CIT> is an example of a binding system as described above in which the twines are tied with a conventional knot. <CIT> is an example of a binding system as described above in which the twines are tied with a loop knot. Conventional knots as well as loop knots are also known from binding systems where there is only one twine supply per (bale binding) loop, and the binding loop is closed by one knot. Binding systems with one twine supply/knot are less favourable because passing the single twine around the bale puts a lot of tension on the twine while baling and during knotting of the twine, which can break the twine or deform the knot.

The binding of the bale is necessary to hold the bale under compression; the expansion of the bale as it is ejected from the baling channel puts a lot of tension on the binding twine. The breaking resistance of the binding twine and the knot(s) in the twine determine the maximum possible compression of the material in the bale. A high compression is desirable as the higher the compression the more efficiently the bale material can be stored and transported.

It is known that the breaking force for breaking the twine in or near the knot is less than the breaking force of the twine away from the knot, so if the expanding material of the bale puts too much tension on the binding loop the twine is likely to break in or directly adjacent to the knot, for example at the locations <NUM> indicated in <FIG>. This because the twine in and directly adjacent the knot is bent over a small radius and the fibers in the outer part of the bend are subjected to a greater strain and are likely to break first. When the outer fibers break the rest of fibers will also then break.

Further it is known that the binding twine is twisted and in practice it is always twisted in the same direction, called a Z-twist, as illustrated in <FIG>.

A knot can be made "right-handed" or "left-handed" depending on the turning direction of the bill hook. In <CIT> both knots are tied as right-hand knots (the bill hook is turned clockwise when seen from the drive side, and the twine loop from the finished bale is laid from the left over the bill hook). In <CIT> right-hand knot and a left-hand knot are formed; the lower bill hook that closes the loop on the finished bale turns clockwise (seen from the drive side) to make a right-hand knot and the other bill hook turns counterclockwise to make a left-hand knot.

It has been noticed that with currently available binding twine left hand knots have a lower breaking resistance than right hand knots. This is due to the interaction between the bends of the twine within the knot and the twist of the twine. With left hand knots the outer fibers are over-stretched at a lower tension/force. When the outer fibers break the rest of fibers will also break. With right hand knots the tension is spread more evenly between the fibres, giving the twine loop a higher breaking force.

Further, it is noticed that loop knots tend to break at a higher force than conventional knots. The twine ends that form the loops are doubled in the turn of the knot, and as a result the bend in the twine has a larger radius. Therefore, there is less strain on the outer fibers in the turns of the twine within the knot. The tension in the fibers in the outer part of the twine is thus reduced in comparison with the conventional knot. Therefore, the loop knot will have a substantially higher twine load breaking strength.

A problem with existing double-knot binding systems is that the binding twines tend to break adjacent the knots at a force that is significantly lower than the ultimate breaking strength of the binding twine.

<CIT> describes a knotter system for a baler in which the forces are regulated in the twine holder during formation of the first knot. The twine holder is partially released during formation of the knot, allowing the twine strands to pull through the twine holder so that these strands are not under high tension. When the knife engages the strands the strands bend and pull extra twine through the twine holder. The twine holder is then tightened again so that the knife cuts the twine. As a result, the knotter is able to form either a loop knot in which both ends of the twine are caught in the knot, or a half loop knot in which only one of the twine ends is longer and forms a loop.

A disadvantage of the system descripted in <CIT> is that the amount of twine pulled through the twine holder depends on numerous variables such as the sharpness of the knife, the physical properties of the twine (for example, its slipperiness) and the thickness of the twine. Furthermore, timing of the steps of the operation is critical and the mechanism to regulate the holding force is complicated. These factors all affect the reliability of the system.

It is an object of the present invention to provide a solution to one or more of the problems set out above, thereby allowing the compression of the bale to be increased without causing the twine loops to break and/or avoiding or mitigating one or more of the disadvantages of the system descripted in <CIT>.

Other known systems are disclosed in <CIT>, <CIT>, <CIT> and <CIT>. <CIT> discloses a knotter system that is capable of producing first and second loop knots. The solution disclosed is to adapt the drive system to cause the bill hook to perform an additional movement. The drive system includes a recess and an obstacle arranged to move a pinion into a recess. The recess and obstacle are arranged to rotate the pinion over a determined angle and back in order to move an upper lip of the billhook away from a lower lip and back after at least one of a first full rotation and a second full rotation. By rotating the pinion over a determined angle and back in order to move the upper lip of the billhook away from the lower lip and back after the first full rotation and/or after the second full rotation the forming of a first and second loop knot can be achieved.

According to one aspect there is provided a baler according to claim <NUM>.

Optionally, the twine holder comprises a rotary disk with a plurality of clamping notches, a retainer adjacent a periphery of the rotary disk, and a drive for rotating the rotary disk to clamp twines in at least one of the clamping notches against the retainer, and wherein the clamping notches are arranged asymmetrically around the periphery of the rotary disk.

Optionally, the twine holder comprises a rotary disk with a plurality of clamping notches, a retainer adjacent a periphery of the rotary disk, and a drive for rotating the rotary disk to clamp a twine in at least one of the clamping notches against the retainer, wherein the retainer is configured so that the twine can be guided across the retainer in two different positions depending on the rotational position of the rotary disk, comprising a first position in which the twine can be cut by the twine cutter and a second position in which the twine cannot be cut by the twine cutter.

Optionally, the bill hook is rotatable between a first position in which the bill hook engages the twines and a second position in which a knot formed by the knotter is stripped from the bill hook by the stripper element, wherein the bill hook includes a catching element that is configurable in a closed configuration to retain a twine to the bill hook and in an open configuration to release the twine from the bill hook, wherein the catching element is configured to adopt the open configuration to release a retained twine from the bill hook after a knot formed by the knotter is removed from the bill hook by the stripper element, so that the cut end of the twine is not pulled through the knot, and wherein the catching element is biased by a resilient biasing element towards the closed configuration and is moved to the open configuration by an opening element that acts against the resilient biasing element, without rotating the bill hook beyond the second position.

The first knot and the second knot are both loop knots.

The twine cutter is configured to cut the twine to provide a cut end, and wherein the twine cutter is displaced from the bill hook to provide a length L of twine between the cut end and the rotational axis of the bill hook, wherein the length L fulfils the following definition: L is at least <NUM> times the length of the bill hook from the rotational axis to the tip of the bill hook.

Optionally, the length L fulfils one or more of the following definitions:.

Optionally, the binding system further comprises a twine guide located between the twine holder and the bill hook.

Optionally, the twine cutter is located between the twine guide and the twine holder.

According to another aspect there is provided a method according to claim <NUM>.

Optionally, the twine holder comprises a rotary disk with a plurality of clamping notches arranged asymmetrically around a periphery of the rotary disk, and a retainer adjacent the periphery of the rotary disk, the method comprising driving rotation the rotary disk to clamp twines in at least one of the clamping notches against the retainer.

Optionally, the twine holder comprises a rotary disk with a plurality of clamping notches, a retainer adjacent a periphery of the rotary disk, and a drive for rotating the rotary disk to clamp a twine in at least one of the clamping notches against the retainer, the method comprising guiding the twine across the retainer in two different positions by adjusting the rotational position of the rotary disk, said positions comprising a first position in which the twine can be cut by the twine cutter and a second position in which the twine cannot be cut by the twine cutter.

Optionally, the method further comprises rotating the bill hook between a first position in which the bill hook engages the twines and a second position in which a knot is stripped from the bill hook by the stripper element, resiliently biasing the catching element towards a closed configuration to retain a twine on the bill hook while a knot is formed, and moving the catching element to an open configuration by operation of an opening element that acts against the resilient biasing element, without rotating the bill hook beyond the second position, to release the retained twine after the knot has been removed from the bill hook, so that the cut end of the twine is not pulled through the knot.

The first knot and the second knot are both tied as loop knots.

The method comprises cutting the twine to provide a length L of twine between a cut end of the twine and the rotational axis of the bill hook, wherein the length L fulfils the following definition: L is at least <NUM> times the length of the bill hook from the rotational axis to the tip of the bill hook.

Various embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:.

A binding system for baler and a method for binding a crop bale are described in <CIT>.

The baler shown in <FIG> is similar in many respects to the baler described in <CIT> and includes a bale case <NUM> that defines a bale chamber <NUM>. Bale material is introduced into the bale chamber <NUM> through a feed duct <NUM>. A plunger <NUM> compresses bale material in the bale chamber to produce a bale B. As the bale is produced, two twines <NUM>,<NUM> are drawn from twine sources <NUM>,<NUM> and laid along the upper and lower sides of the bale, as shown in <FIG>. Upon completion of the bale, the twines <NUM>, <NUM> are brought together by a needle <NUM> and the two twines <NUM>,<NUM> are tied together by a knotter <NUM>, which is driven via a clutch <NUM>, to form a twine loop <NUM> that is stretched around the bale B to maintain the bale material in compression after the bale is ejected from the bale case <NUM>.

In this example, the knotter <NUM> includes a rotary bill hook <NUM>, which is configured to tie two knots successively during each complete operating cycle. As illustrated in <FIG>, a first knot <NUM> is tied to complete the twine loop <NUM> around the completed bale B and a second knot <NUM> is then tied to start a new twine loop 62a for the next bale. The twines are severed between the two knots <NUM>, <NUM>. In this example, the first and second knots <NUM>,<NUM> are both right-handed knots and they are tied successively by the same bill hook. Also, in this example, the second knot <NUM> is a loop knot, whereas the first knot <NUM> is a conventional knot. The strength of the twine loop is therefore limited by the strength of the conventional first knot <NUM>, which has a lower breaking strength than the loop knot that forms the second knot <NUM>. Alternatively, in certain embodiments of the invention, the first knot <NUM> and the second knot <NUM> may both be loop knots.

The binding system and the method for binding a bale according to the present invention are similar in most respects to the binding system and the method for binding a bale described in <CIT>. However, in certain embodiments of the present invention, the first knot and the second knot are both loop knots. Optionally, the first knot and the second knot are also both right-handed knots and optionally they are tied successively by the same bill hook. In these embodiments the inherent weakness of a conventional knot is avoided, providing a twine loop that has a greater breaking strength. This is turn means that the bale material can more highly compressed, leading to storage and transportation efficiencies, while the risk of the twine loop bursting is reduced. In certain other embodiments, the second knot <NUM> is a loop knot and the first knot <NUM> is a conventional knot.

A knotter <NUM> according to an embodiment of the present invention is shown in more detail in <FIG>. The knotter <NUM> is similar in many respects to the knotter described in <CIT> and therefore will not be described in full detail.

The knotter <NUM> comprises a circular drive disk <NUM> that is attached through a hub <NUM> to a drive shaft <NUM>. The knotter <NUM> also comprises a frame <NUM>, a rotary bill hook <NUM> mounted on an end of a shaft 82a for rotation about an axis <NUM>, and a multi-disk twine holder <NUM> that has a plurality of notches <NUM> in its perimeter for holding the twines against a retainer <NUM>. A release arm <NUM> is pivotable to release the twines from the twine holder <NUM>. The release arm <NUM> carries a cutter <NUM> for severing the twine strands and a stripper arm <NUM> for stripping a knot from the bill hook <NUM>. Pivoting movement of the release arm <NUM> is controlled by a cam follower <NUM> that engages a cam track <NUM> in the drive disk <NUM>.

The rotary bill hook <NUM>, which is shown in more detail in <FIG> and <FIG>, includes a fixed lower lip 83b and a pivotable upper lip 83a that moves between open and closed configurations and is controlled by a cam follower <NUM>, which engages a cam track <NUM> provided on a collar <NUM> that surrounds the bill hook shaft 82a. Rotation of the bill hook <NUM> about the axis <NUM> is driven by a pinion <NUM> that engages first and second gear stretches <NUM>,<NUM> on the drive disk <NUM>. The disks of the twine holder <NUM> are driven by a worm gear <NUM>, a worm screw <NUM> and a bevel gear <NUM> that engages third and fourth gear stretches <NUM>, <NUM> on the drive disk <NUM>. Operation of the knotter <NUM> is substantially as described in <CIT>, except as described below.

In one embodiment of the invention, the knotter <NUM> is modified to provide an increased length L of twine between the bill hook <NUM> and the cut end of the twine in order to create two loop knots, so that the first knot <NUM> and the second knot <NUM> are both loop knots. This is achieved by placing the cutter <NUM> further from the bill hook <NUM>, as described below. The twine holder <NUM> is also preferably located further away from the bill hook <NUM>, so that it can hold the cut ends of the twines after the first knot <NUM> has been tied and the twines have been cut. Because the twines are severed further from the bill hook <NUM> and close to the twine holder <NUM>, this ensures that there is an increased length of twine L between the bill hook and the cut end of the twine.

In one embodiment of the invention the twine cutter <NUM> is configured to cut the twine to provide a cut end, and wherein the twine cutter is displaced from the bill hook to provide a length L of twine between the cut end and the bill hook.

The length L is at least <NUM> times the length of the bill hook from the rotational axis to the tip of the bill hook.

Optionally, the length L is at least at least <NUM> times, or at least <NUM> times the length of the bill hook from the rotational axis to the tip of the bill hook.

Optionally, the length L is at least <NUM> times, or at least <NUM> times, or at least <NUM> times the length of twine needed to wrap circumferentially around the bill hook.

Optionally, the length L is at least <NUM> times, or at least <NUM> times, or at least <NUM> times the diameter of the twine when tied around a bound bale.

Optionally, the length L is at least <NUM>, or at least <NUM>, or about <NUM>.

In one embodiment, the invention provides a baler with a reciprocal plunger, a method and system that combines the advantages of binding a bale from two supplies per binding loop and binding the bale with two knots per binding loop whereby the knots are:.

Preferably, the knots are both right-handed.

The key to forming a loop knot with a knotter <NUM> of the type described above is to have sufficient length of twine between the bill hook <NUM> and the position where the twine ends are severed from the twines held by the twine holder. Because the twine ends are severed near to the twine holder, the twine holder must also be placed substantially further from the bill hook.

The twine strands that form the loop of the loop knot are preferably released from the bill hook after the knot has been pulled off the bill hook. In one embodiment this is achieved by actively or passively releasing/opening a catching element <NUM> (also called a tongue or an upper lip 83a) that retains the twine on the bill hook <NUM> until just after the moment the knot is pushed/pulled off the bill hook by the stripper element <NUM>. This prevents the risk that the loop will be stuck between the catching element <NUM> and the base of the bill hook <NUM>, or that the ends of the twine will be pulled completely through the knot so that a conventional knot will be formed.

In one embodiment of the invention illustrated in <FIG>, the catching element <NUM> comprises the upper lip 83a of the bill hook <NUM>, which is biased by a resilient biasing element <NUM> towards the closed configuration. The catching element <NUM> can be moved actively or passively to the open configuration.

In the system illustrated in <FIG> the catching element <NUM> comprises the upper lip 83a, which is moved actively to the open configuration. Opening of the catching element <NUM> is driven by an opening element <NUM> that acts against the resilient biasing element. In one embodiment, the opening element <NUM> comprises the cam track <NUM> that is provided on the collar <NUM>.

In a conventional knotter the collar <NUM> is fixed to the frame <NUM> of the knotter. As the bill hook <NUM> rotates relative to the collar <NUM> the cam follower <NUM> runs along the cam track <NUM> and the catching element <NUM> opens when the cam follower encounters a part 91a of the cam track <NUM> that projects radially outwards from the collar.

In an embodiment of the invention illustrated in <FIG> and <FIG>, the collar <NUM> is modified so as to be rotatable relative to the frame <NUM>, as indicated in <FIG> by a curved arrow D. An actuator (not shown) may be provided to control rotary movement of the collar <NUM>, or rotation may be driven mechanically from the drive disk <NUM>. By rotating the collar <NUM> the catching element <NUM> (upper lip 83a) can be opened without rotation of the bill hook <NUM> relative to the frame <NUM>.

The bill hook <NUM> is rotatable between a first position in which the bill hook engages the twines and a second position in which a knot formed by the knotter is stripped from the bill hook <NUM> by the stripper arm <NUM>. The catching element <NUM> can be configured in a closed configuration to retain a twine to the bill hook <NUM> or an open configuration to release the twine from the bill hook <NUM>. The catching element <NUM> is configured to adopt the open configuration to release the retained twine from the bill hook <NUM> after the knot is removed from the bill hook <NUM> by the stripper arm <NUM>, so that the cut end of the twine is not pulled through the knot. In this embodiment the catching element <NUM> is biased by the resilient biasing element <NUM> towards the closed configuration and is moved to the open configuration by the opening element <NUM>, which comprises the collar <NUM> and the cam follower <NUM>. The catching element <NUM> can thus be opened to release the twine without rotating the bill hook <NUM> beyond the second position.

In another embodiment of the invention, also illustrated in <FIG>, the collar <NUM> is modified so that it can move relative to the frame <NUM> in a linear direction, parallel to the axis <NUM> of the bill hook <NUM>, as indicated by a straight arrow E. An actuator (not shown) may be provided to control linear movement of the collar <NUM>, or linear movement of the collar <NUM> may be driven mechanically from the drive disk <NUM>. For example, an actuator (not shown) connected to the collar <NUM> can be activated to push the collar <NUM> downwards so that a bevelled portion 93a of the collar engages the cam follower <NUM> at the rear end of the upper lip 83a, causing the catching element <NUM> to open. The catching element <NUM> can therefore be opened either with or without rotation of the bill hook <NUM> relative to the frame <NUM>. If an actuator is used, the actuator can comprise a linear actuator, for example an electric or hydraulic actuator, or it can be driven mechanically on basis of the rotation of the disk <NUM>.

In each of the above embodiments opening of the catching element <NUM> can be controlled to release the twines from the bill hook after the knot has been formed, to increase the length L of twine between the bill hook and the cut ends of the twines. As illustrated in <FIG>, the length L of twine between the bill hook and the cut ends of the twines can be equal to the distance between the axis <NUM> of the bill hook <NUM> and the position of the cutter <NUM> when it cuts the twines.

Alternatively, the catching element can be moved passively to the open configuration. For example, opening of the catching element can be achieved by inactivating the resilient biasing element or reducing/counteracting the biasing force, so that the catching element is moved to the open configuration by the tension in the twine. Inactivating the resilient biasing element or reducing/counteracting the biasing force can be achieved for example by modifying the configuring the resilient element <NUM> so that only at the position of the bill hook <NUM> where the knot is stripped off (and not if it is turned to form the knot) the catching element 83a is not affected by the resilient biassing element <NUM> and the catching element 83a is free to move (partly) upward. When the knot is formed and not yet stripped off the bill hook <NUM> the twine that is wound around the bill hook <NUM> will hold the catching element 83a down. As soon as the knot is stripped off the bill hook <NUM> the catching element 83a is then free to move upward. The upward movement of the catching element 83a may result as a reaction to the pulling force of the twine loop but could also be assisted by an additional counter-biasing resilient element.

If the bill hook <NUM> is turned for forming the loop the resilient biassing element <NUM> will force the catching element down.

The process of producing the knot is well described in text and pictures of <CIT>.

Conventionally, the twine holder <NUM> is mounted next to the bill hook <NUM>. In another embodiment of the invention illustrated in <FIG> the severing knife <NUM> and twine holder <NUM> are placed further away from the bill hook <NUM>, i.e., significantly further than the distances found in a conventional knotter.

In an embodiment of the present invention the twine holder <NUM> may be modified to provide a twine guide 86a, for example by removing or modifying the retainer <NUM>, so that the notches <NUM> in the periphery of the guide disk serve only to bring the twines into a correct position in relation to the bill hook <NUM> and the opened tongue/catching element 83a. An alternative twine holder 86b is then provided a short distance away from the bill hook <NUM> and the cutter <NUM> is repositioned so that it is located between the twine guide 86a and the twine holder 86b. The twine is held by the twine holder 86b, which is positioned further away from the bill hook <NUM> than the twine guide 86a and the twine is severed between the twine guide 86a and the twine holder 86b. As a result, the twine is severed beyond the position of a conventional disk/twine holder (seen from the bill hook) to provide an increased length L of twine between the bill hook <NUM> and the cut ends of the twines.

In this embodiment, the severing device or cutter <NUM> is optionally not mounted directly on the stripper arm <NUM> that strips the knot from the bill hook <NUM>, but comprises a separate cutter mechanism located further from the bill hook. By comparison, in a conventional knotter the cutter <NUM> is fixedly connected to the stripper arm <NUM>.

In another embodiment of the invention, the twine holder <NUM> is configured to release the twines just after the bill hook <NUM> has finished its second turn to complete the knot and before or at the moment the knot is pushed/pulled off the bill hook <NUM> by the stripper arm <NUM>. This helps to prevent the possibility that there will be loose twine ends or "tails" (waste) that will pollute the fodder or the environment. By releasing the twines the loop of the second knot of the binding cycle will have longer ends.

For example, in an embodiment of the invention, the releasing of the twine ends by the twine holder <NUM> is done by positioning the notches 87a, 87b in the twine holder disk <NUM> asymmetrically (not at <NUM> degrees), as illustrated in <FIG>, so as to have the twines held for the first knot between the first notch 87a and the retainer <NUM> and to have the second notch 87b positioned (at rest) just beyond the clamping retainer <NUM>. For example, the notches 87a, 87b may be displaced at angles of approximately <NUM>-<NUM> degrees and <NUM>-<NUM> degrees, as illustrated in <FIG>.

In another embodiment, as illustrated in <FIG>, the releasing of the twine ends by the twine holder can also be done by moving the worm screw <NUM> axially along its turning axis at the end of the second turn, so as to give the holding disk <NUM> an extra forward rotary movement and to release the twine ends just before the second knot is pushed/pulled off the bill hook <NUM>, so that the twine will not be cut during stripping off of the second knot. Axial movement of the worm screw <NUM> is shown in <FIG> by a straight double-headed arrow A, and the resulting additional rotation of the worm gear <NUM>, which drives rotation of the holding disk <NUM>, is shown by a curved double-headed arrow C. Axial movement of the worm screw <NUM> may be driven by another component of the knotter, for example the stripper arm <NUM>. After formation of the second knot the worm screw <NUM> will be positioned axially back to its original position, for example by a spring or other resilient component.

In another embodiment, as illustrated in <FIG> & <FIG>, the retainer <NUM> may be configured so that the twine <NUM> is guided across the retainer <NUM> in two different positions, depending on the rotational position of the guide disk <NUM>. For example, as shown in <FIG> in a first position of the guide disk <NUM> for tying the first knot the twine <NUM> is guided across the retainer <NUM> in a high position, where it can be contacted by the cutter <NUM>. As a result, the twine <NUM> is cut when the cutter <NUM> is activated. Alternatively, as shown in <FIG> in a second position of the guide disk <NUM> for tying the second knot the twine <NUM> is guided across the retainer <NUM> in a low position, where it cannot be contacted by the cutter <NUM>. As a result, the twine <NUM> is not cut by the cutter <NUM>, allowing it to be pulled through the guide disk <NUM>. The retainer <NUM> does not have a cutting edge and does not cut the twine <NUM>.

Claim 1:
A baler comprising a bale forming channel (<NUM>), a reciprocating plunger (<NUM>) configured to compress bale material in the bale forming channel (<NUM>) to form a bale (B), and a binding system for binding a bale in the bale forming channel (<NUM>) with a pair of twines (<NUM>,<NUM>) that pass around opposite sides of the bale (B), the binding system comprising a knotter (<NUM>) that includes a rotary bill hook (<NUM>) that has a rotational axis (<NUM>), a twine holder (<NUM>) and a twine cutter (<NUM>), wherein the binding system is configured to tie a first knot (<NUM>) and a second knot (<NUM>) successively in the twines (<NUM>,<NUM>) during one full operating cycle of the binding system, wherein:
- the first and second knots (<NUM>,<NUM>) are tied successively by a single bill hook (<NUM>), and
- the first knot (<NUM>) and the second knot (<NUM>) are both loop knots,
wherein the twine cutter (<NUM>) is configured to cut the twine (<NUM>) to provide a cut end, and wherein the twine cutter (<NUM>) is displaced from the bill hook (<NUM>) to provide a length L of twine between the cut end and the rotational axis (<NUM>) of the bill hook, characterised in that the length L fulfils the following definition:
- L is at least <NUM> times the length of the bill hook (<NUM>) from the rotational axis (<NUM>) to the tip of the bill hook.