Patent Description:
This invention relates to agricultural balers and, more particularly, to a baler for forming rectangular bales having a bale knotting system using twine to bind the bales.

Agricultural balers for binding bales of crop materials with strands of a binding material, such as twine, are well known in the art. Typically, balers are equipped with means to wrap twine around the formed bale and tie off the twine to secure the bale. This includes a knotter assembly having a knotter disc rotated by a powered drive shaft that controls a rotational movement of the components of the knotter assembly. Agricultural balers, utilizing knotter assemblies that form two knots on every loop for binding a bale have been available for many years. For example, <CIT>, assigned to Hesston Corporation, which is now part of the assignee of the present application, discloses a knotter assembly of the double knotter type. Referring to <FIG>, the knotter assembly forms a loop <NUM> made from two strands of binding material, i.e., one strand <NUM> from a first supply of binding material <NUM> along the normally top side of the bale and a second strand <NUM> from a second supply of binding material <NUM> along the normally bottom of the bale and its two opposite ends. The two strands <NUM>, <NUM> thus fully circumscribe the bale and are circumferential complements of one another. Two knots <NUM> and <NUM> appear in the loop <NUM> at those locations where the strands <NUM> and <NUM> are substantially end-to-end. Such a knotter assembly uses a bill hook for forming the knot, a twine disc in combination with a retainer for retaining the strands when forming the knot, and a wiper arm with an integrated cutter for stripping the formed knot from the billhook in combination with the separation of the knot from the retained strands. When a bale reaches its desired length, a knot tying cycle is initiated. During this tying cycle, two knots are formed, the first knot <NUM> for closing the loop of the finished bale and the second knot 68a for starting the loop for the next bale.

In use, such conventional knotters, while being effective in binding bales with twine, result in small pieces of twine <NUM>' and <NUM>', commonly known as twine tails, being cut off after each knotting operation. These twine tails <NUM>', <NUM>' are obtained after the second knot 68a is formed and stripped of the billhook by the wiper arm. Although the amount of twine wasted is not great, the twine tails may build up in the vicinity of the knotter and ultimately cause knotter-tying problems. Typically, the twine tails fall onto the formed bale and are removed from the baler when the formed bale is pushed out of the bale. The twine tails then may drop on the field where they may cause or contribute to environmental pollution. Today, many farmers use synthetic twine instead of natural fibers. Unlike natural fibers, synthetic twine will not be broken down by atmospheric influences, and therefore, the synthetic twine tails remains longer on the field and may be picked up the next harvesting season by a baler. Twine tails picked up with the baled material may be eaten by livestock, potentially causing harm to the animals' heath. Additionally, these off-cuts limit the ability for balers to be used in certain conditions where foreign material isn't permitted in the bales.

While some knotter assemblies have been designed to operate with a knotting cycle that does not produce these twine tales, these design use a mechanical solution that increases the complexity to the knotter assembly. It would be desirable to have an improved knotter assembly that could function in substantially the same manners as conventional double knotters while eliminating the production of twine tales during the knotting operation.

<CIT>) discloses a knotter assembly having the features of the precharacterising portion of claim <NUM>.

In one embodiment, the invention is directed to a knotter assembly for use with a baler, the knotter assembly configured to form knots in strands of a binding material used to secure a formed bale. The knotter assembly is operable to produce two successive knots in a pair of strands of binding material during one full operating cycle of the knotter assembly to secure a formed bale. The knotter assembly includes a billhook configured to perform at least a first full rotation around its rotation axis during formation of a first one of the two successive knots and a second full rotation around its rotation axis during formation of a second one of the successive knots. The knotter assembly includes a twine holder for maintaining the pair of strands throughout the formation of the first one of the successive knots and to continue to maintain the pair of strands in a suitable position during the initial stage of the formation of the second one of the successive knots, and a cutter co-operating with the twine holder for severing the pair of strands during formation of the first one of the successive knots. The knotter assembly includes a twine disc assembly having a plurality of parallel discs mounted for rotation on shaft, wherein each disc of the plurality of discs has a plurality of notches spaced around the outer circumference of the twine disc, the plurality of notches including a first set of notches having a first shape and a second set of notches having a second shape different than the first shape. The first set of notches has a U shape and the second set of notches has a long J-hook shape.

These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.

The above mentioned and other features of this invention will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:.

Corresponding reference characters indicate corresponding parts throughout the views of the drawings.

Although the invention is described with reference to these specific preferred embodiments, it will be understood that the invention is not limited to these preferred embodiments and is instead defined by the appended claims.

Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms "left" or "right" are used as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already by widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail. In the description which follows and in certain passages already set forth, the principles of the present invention will be described in terms of "twine" and "knots" formed in such twine. While twine is used in the exemplary embodiment, the term binding material is intended to mean not only twine made from natural or synthetic fibers, but may also include metallic wire or other strapping material.

Turning to the figures, wherein like reference numerals represent like elements throughout the several views, <FIG> shows a baler <NUM> with a fore- and-aft extending baling chamber <NUM> mounted on a baler frame <NUM> within which bales of crop material are prepared. Crop material is collected with a pickup <NUM> below and slightly ahead of baling chamber <NUM> and then loaded up into the bottom of the chamber <NUM>. Baler <NUM> may be hitched to a towing vehicle (not shown) by a tongue <NUM>, and power for operating the various mechanisms of the baler may be supplied by the towing vehicle, such as the vehicle's power takeoff shaft.

Turning now to <FIG>, the bale chamber <NUM> receives material though a curved duct <NUM>. A plunger <NUM> reciprocates within the bale chamber <NUM> to intermittently pack fresh charges of material from the duct <NUM> rearwardly in the chamber <NUM> in the direction of the arrow <NUM>. When the bales reaches a predetermined size (this is determined by an appropriate bale length sensor (not shown)), a trigger engages a suitable clutch understood by one skilled in the art which in turn is connected to a knotter assembly <NUM> and a set of needles <NUM>. As will be appreciated, the knotter assembly <NUM> comprises a set of individual knotters <NUM> provided crosswise on top of the bale chamber <NUM> at spaced intervals. Each knotter <NUM> has an associated needle <NUM> for assisting in forming an individual loop around a finished bale. When the bale needs tying, the knotter <NUM> and its respective needle <NUM> is connected to a source of driving power to initiate the tying operation. As the individual knotters <NUM> all operate in an identical manner, it suffices to describe the present invention in relation to only one such knotter <NUM>. The needle <NUM> is swingably mounted on the bale chamber <NUM> and is swung back and forth across the bale chamber <NUM> by a linkage <NUM>. The needle <NUM> has an "at-home" or rest position fully below the bale chamber <NUM> as illustrated in <FIG> and a "full-throw" position extending completely across the bale chamber <NUM>.

<FIG> shows the binding loop <NUM> for a completed bale as already known for many years in the prior art. To the left of loop <NUM> is a partial loop 62a which is in the process of being formed. The top strand 64a emanates from a source of twine supply <NUM>, while the bottom strand 66a emanates from an entirely separate, second source of twine supply <NUM>. At the particular point in the sequence chosen for illustration, the knot 68a is in existence, and the bale is approaching that length where the needle <NUM> is ready to swing into operation and present the strands 64a and 66a to the knotter <NUM> to complete the first knot 70a (not shown in <FIG>). It is also shown in <FIG> that twine tails <NUM>' and <NUM>' are obtained between the last knot <NUM> of a first bale and the first knot 68a of a next bale.

In contrast therewith, <FIG> shows the binding loop <NUM> formed without the formation of twine tails <NUM>' and <NUM>' as obtained by the knotter assembly <NUM> of the present invention. In a finished bale, and still comparable to the prior art, the loop <NUM> is made from two strands of binding material, i.e., one strand <NUM> along the top side of the bale and a second strand <NUM> along the bottom side of the bale and its two opposite, vertical ends. The strands <NUM> and <NUM> together form the continuous loop <NUM>. Together, they fully circumscribe the bale and are circumferential complements of one another. The two knots <NUM> and <NUM> appear in the loop <NUM> at those locations where the strands <NUM> and <NUM> are substantially end-to-end. This is typically in the area of the top corners of the bale. However, in contrast with the prior art, the first knot <NUM> of a bale according to the present invention, is desirably a so called loop-knot. This means that the ends of the strands <NUM> and <NUM> of the knot <NUM> are released from a retained position (to be described further) to form a small loop on top of the knot <NUM>. The knot <NUM> itself, thus holds the ends of the strands <NUM> and <NUM> so twine tails need not be cut off and dropped on the bale.

With this short explanation in mind, the details of the embodiment according to the present invention and as illustrated primarily in <FIG> will now be described. The knotter assembly <NUM> is similar in many respects to the knotter assembly shown in <CIT>. Turning now to <FIG>, the knotter assembly <NUM>, which is mountable to the frame <NUM> of the baler <NUM>, is configured to take strands of twine, broadly binding material, looped around a finished bale and bind the strands with the two knots <NUM> and <NUM>. The knotter assembly <NUM> comprises a generally circular knotter disc <NUM> that is secured to a drive shaft (not shown) for rotation with the latter. The knotter assembly <NUM> includes a frame <NUM> that supports a rotary bill hook <NUM> for rotation about an inclined axis <NUM> and a twine disc assembly <NUM> comprising a plurality of individual discs is positioned rearwardly adjacent the bill hook <NUM> for holding strands 64a and 66a in position for engagement by the bill hook <NUM> during rotation of the latter. The strands 64a and 66b are held in the twine disc assembly <NUM> by a retainer or twine holder <NUM>. As known previously, a wiper arm <NUM> pivotably mounted to the frame <NUM> by a bolt <NUM> releases the connected strands from the twine disc assembly <NUM>. The lower end of the wiper arm <NUM> is forked, defining a crotch <NUM> that opens away from the twine disc assembly <NUM> beneath the bill hook <NUM>. The crotch <NUM> carries a cutter <NUM> between the bill hook <NUM> and the twine disc assembly <NUM> for severing the strands 64a, 66a in response to swinging movement of the wiper arm <NUM> in the proper direction. Such movement of the wiper arm <NUM> to operate the cutter <NUM> also serves to engage the proximal areas of the crotch <NUM> with a knot formed on the bill hook <NUM> for stripping such knot off of the bill hook <NUM>.

In order to transmit driving power from the knotter disc <NUM> to the bill hook <NUM>, the latter is provided with a pinion gear <NUM> which is disposed for meshing engagement with a pair of circumferentially spaced gear stretches <NUM> and <NUM> on the knotter disc <NUM>. Similarly, driving power is transmitted to the discs of the twine disc assembly <NUM> through a worm gear drive <NUM> and a bevel gear <NUM> in position for sequential meshing engagement with a pair of circumferentially spaced gear sections <NUM> and <NUM> on the knotter disc <NUM>. Power to swing the arm <NUM> about the pivot bolt <NUM> is obtained through a cam follower <NUM> at the upper end of the arm <NUM> beyond the pivot bolt <NUM> which is disposed within a cam track <NUM> on the knotter disc <NUM>. A pair of circumferentially spaced cam shoulders <NUM> and <NUM> in the track <NUM> are positioned to sequentially engage the follower <NUM> to operate the latter. As many aspects of the knotter assembly <NUM> are well known in the art, further details about known aspects of the knotter assembly <NUM> need to be explained herein.

Turning now to <FIG>, the twine disc assembly <NUM> comprises a plurality of parallel discs <NUM> mounted for rotation on shaft <NUM>. Desirably, the shaft <NUM> is driven by the worm gear drive <NUM> and bevel gear <NUM> shown in <FIG>. Each disc <NUM> has a plurality of notches <NUM> spaced around the outer circumference <NUM> of the twine disc <NUM>. According to the invention, the plurality of notches <NUM> includes a first set of notches labeled 200A having a first shape and a second set of notches labeled 200B having a second shape different than the first shape. The first set of notches 200A has a U shape and the second set of notches 200B has a long J-hook shape. Desirably, in the U shape of the first set of notches 200A, each side <NUM> of the notch 200A approaches the outer circumference <NUM> at an angle α<NUM> of between about <NUM> and <NUM> degrees, more desirably between about <NUM> and <NUM> degrees, and in the illustrated embodiment at an angle α<NUM> of about <NUM> degrees. In one embodiment the angles α<NUM> for the two sides of the notch 200A are the same, however one skilled in the art will understand that there could be slight variations in the angles. Desirably, in the J-hook shape of the second set of notches 200B, a first side <NUM> of the notch 200B approaches the outer circumference <NUM> at an angle α<NUM> of between about <NUM> and <NUM> degrees, more desirably between about <NUM> and <NUM> degrees, and in the illustrated embodiment at an angle α<NUM> of about <NUM> degrees. In one embodiment α<NUM> is the same as α<NUM>, however one skilled in the art will understand that there could be slight variations in the angles. A second side <NUM> of the notch 200B approaches the outer circumference <NUM> at an angle β of between about <NUM> and <NUM> degrees, more desirably at an angle of between about <NUM> and <NUM> degrees.

In the illustrated embodiment, there are two notches in the first set of notches 200A and they are positioned on the disc <NUM> so as to be on opposite sides of the disc <NUM> from each other, and there are two notches in the second set of notches 200B and they are positioned on the disc <NUM> so as to be on opposite sides of the disc <NUM> from each other. The twine disc assembly <NUM> is timed such that one of the first notches 200A is configured to retain the twines 64a and 66a when the knotter assembly <NUM> is forming the knot <NUM> which is tied first in the tying cycle, and one of the second notches 200B is configured to be used when holding the twines 64a and 66a when the knotter assembly <NUM> is forming the knot <NUM> which is tied second in the tying cycle.

Turning now to <FIG>, the twine holder <NUM> has a pressing portion <NUM> that slopes continually downward from a mid hump <NUM> to a distal end <NUM> of the twine holder <NUM>. However, the shape of the pressing portion <NUM> is such that when the second notch 200B is holding the twines 64a and 66b to form the knot <NUM> and the twine disc <NUM> reaches the end of its rotation, there is very little tension on the twines 64a and 66b and all tension can easily be removed when twines are pulled by the wiper arm <NUM>. This allows the components to release the twines 84a, 86a from the disc <NUM> without requiring a mechanical release mechanism. Desirably, the twine holder <NUM> has a base portion <NUM> that is substantially similar to those used in conventional knotter assemblies such as the one shown in the <CIT> patent, but the pressing portion is re-profiled to work with the J-shaped notches 200B in the twine disc <NUM> so that no mechanical device is required to release twines.

Turning now to <FIG>, the billhook <NUM> is illustrated. The billhook <NUM> includes billhook casting <NUM> and a lower lip <NUM>, and a billhook tongue <NUM> connected around a pivot point with the lower lip <NUM>. During a tying cycle, the billhook <NUM> performs at least a first full rotation around its rotation axis <NUM> during a first knot forming cycle and a second full rotation around its rotation axis <NUM> during a second knot forming cycle. When the billhook <NUM> rotates around its axis <NUM>, the cam follower <NUM> will push the upper lip <NUM> away from the lower lip <NUM>. The billhook tongue <NUM> is provided at a free end thereof with a downwardly protruding end part <NUM>, and the lower lip <NUM> is provided with an end recess <NUM> for receiving the protruding end part <NUM>. In that way the billhook tongue <NUM> can be placed against or very close to the lower lip <NUM>. The protruding end part <NUM> has a reverse tip angle µ between the trailing edge <NUM> and a lower surface <NUM> of the billhook tongue <NUM> that is greater than <NUM> degrees, and desirably greater than <NUM> degrees. While the billhook <NUM> can use the same billhook casting <NUM> as what is used in conventional knotter assemblies, such as shown in the <CIT> patent, the angle µ causes the protruding end part <NUM> of the billhook tongue <NUM> to have a more rounded shape than conventional end parts on billhooks.

The knotter assembly <NUM> performs first knotting cycle in which the notch 200A of the twine disc <NUM> holds the twine to tie the knot <NUM> to finish the bale like a conventional double knotter such as the one shown in the <CIT> patent. In presenting the twines 64a and 66a, the needle <NUM> drapes the twines across the billhook <NUM> and thence into one of the notches 200A of the twine disc assembly <NUM>. Upon rotation of the twine disc assembly <NUM>, in combination with the pressing twine holder <NUM>, causes the twines 64a, 66a to be firmly griped preventing their escape as the billhook <NUM> begins its rotation. Typically, the twine disc assembly <NUM> rotates a quarter of a turn and clamps the twines 64a and 66a firmly together in one of the notches 200A. The needle <NUM> then moves downward. During the down travel of the needle <NUM>, the two twines 64a, 66a on the back of the needle are placed in the next adjacent notch 200B of the twine disc assembly <NUM> for the second knot <NUM>. During formation of the first knot <NUM>, the wiper arm <NUM>, and hence the cutter <NUM>, swings across that portion of the twines 64a, 66a between the billhook <NUM> and the twine disc assembly <NUM>, thereby severing the same. To complete the knot formation, the wiper arm <NUM> engages the twines 64a and 66a which are retained in a twisted manner around the billhook <NUM>. But on the second knot <NUM>, when it is time when the cut would have happened on a conventional knotter assembly, the twine 64a, 66a is released from the disc assembly <NUM> by the geometry of the notch 200B in the discs <NUM> and the profile of the lower portion of the twine holder <NUM>. The cutter <NUM> of the wiper arm <NUM> pulls the twine 64a, 66a from the disc assembly <NUM> instead of cutting it. The shape of the billhook tongue <NUM> allows the twine 64a, 66a to slip out of the billhook <NUM> without having to pull the end of the tail back through the knot <NUM>. The second knot <NUM> on this knotter design can be either a McCormick or Deering style without leaving an off-cut of twine. This can depend on how the tensions of the knotter assembly <NUM> are adjusted.

Claim 1:
A knotter assembly (<NUM>) for use with a baler (<NUM>), the knotter assembly operable to produce two successive knots (<NUM>, <NUM>) in a pair of strands (<NUM>, <NUM>) of binding material during one full operating cycle of the knotter assembly (<NUM>) to secure a formed bale, the knotter assembly (<NUM>) comprising a billhook (<NUM>) configured to perform at least a first full rotation around its rotation axis (<NUM>) during formation of a first one (<NUM>) of said two successive knots and a second full rotation around its rotation axis (<NUM>) during formation of a second one (<NUM>) of said successive knots, a twine holder (<NUM>) for maintaining said pair of strands throughout the formation of the first one (<NUM>) of said successive knots and to continue to maintain said pair of strands in a suitable position during the initial stage of the formation of the second one (<NUM>) of said successive knots, a cutter (<NUM>) co-operating with said twine holder (<NUM>) for severing said pair of strands (<NUM>,<NUM>) during formation of said first one (<NUM>) of said successive knots, and a twine disc assembly (<NUM>), the twine disc assembly (<NUM>) comprising a plurality of parallel discs (<NUM>) mounted for rotation on shaft (<NUM>), wherein each disc of the plurality of parallel discs (<NUM>) has a plurality of notches (<NUM>) spaced around the outer circumference (<NUM>) of the disc, characterised in that the plurality of notches (<NUM>) includes a first set of notches (200A) having a first shape and a second set of notches (200B) having a second shape different than the first shape, the first set of notches (200A) consisting of two notches that are positioned on each disc (<NUM>) so as to be on opposite sides of the outer circumference (<NUM>) of the disc (<NUM>) from each other, and the second set of notches (200B) consists of two notches that are positioned on each disc (<NUM>) so as to be on opposite sides of the outer circumference (<NUM>) of the disc (<NUM>) from each other.