Patent Description:
Agricultural balers are used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. For example, when the crop is hay a mower-conditioner is typically used to cut and condition the crop material for windrow drying in the sun. As another example, when the crop is straw an agricultural combine discharges non-grain crop material from the rear of the combine defining the straw which is to be picked up by the baler. The cut crop material is usually dried, and a baler, such as a large square baler or round baler, straddles the windrows and travels along the windrows to pick up the crop material and form it into bales.

On a large square baler, pickup apparatus at the front of the baler gathers the cut and windrowed crop material from the ground. The pickup apparatus includes a pickup roll, and optionally may include other components such as side shields, stub augers, a wind guard, etc. A rotor cutter apparatus is then used to move the crop material from the pickup apparatus to a pre-compression chamber or duct. The rotor cutter apparatus forms a so-called 'wad' of crop within the pre-compression chamber which is then transferred to a main bale chamber.

Stuffer apparatus transfers the wad of crop material in charges from the pre-compression chamber to the main bale chamber. Typically, the stuffer apparatus includes stuffer forks which are used to move the wad of crop material from the pre-compression chamber to the main bale chamber, in sequence with the reciprocating action of a plunger within the main bale chamber.

In the main bale chamber, after the wad is injected into the bale chamber, the plunger compresses the wad of crop material into a so-called 'flake' against previously formed flakes to form a bale and, at the same time, gradually advances the bale towards the outlet of the bale chamber. Pressure exerted by the walls of the bale chamber dictates the frictional force needed to overcome friction and shift the flakes in the chamber. An increased force to shift the flakes causes the plunger to compact the flakes tighter, and thereby produce a higher-density bale.

The bale chamber typically has three moving walls (a top wall and two side walls), which may be positioned by two hydraulically controlled actuators connected to a cam mechanism. When enough flakes have been added and the bale reaches a full (or other predetermined) size, a number of knotters are actuated which wrap and tie twine, cord, or the like around the bale while it is still in the main chamber. The twine is cut and the formed bale is ejected out the back of the baler as a new bale is formed.

Returning to the rotor cutter apparatus, typically this includes a rotor assembly having a rotor shaft and a number of rotor tines arranged on the rotor shaft. The tines rotate with the rotor shaft and engage with the crop to move the crop material from the pickup unit towards a knife rack with knives for cutting the crop into smaller pieces and then on to the pre-compression chamber. The rotor cutter apparatus also typically includes a scraper behind the rotor assembly and in the vicinity of the input or entrance to the pre-compression chamber. The scraper includes a number of scraper tines extending or pointing generally back towards the rotor assembly. As the rotor shaft rotates about its axis, the rotor tines intersect the scraper tines to remove crop material from the rotor tines and further direct the crop material towards the knives and the pre-compression chamber. The rotor tines therefore need to be designed so that they both: provide an effective means for delivering the crop material to the pre-compression chamber; and, allow the scraper to effectively remove crop from the rotor tines as they intersect with the scraper tines.

It is an aim of the present invention to provide an arrangement that is designed to provide the above effects.

Patent Publication No. <CIT> discloses a straw cutting machine including a number of knives that are combined to form a body and have two cutting edges that form an acute angle with one another, and which are attached to a rotatable and lockable shaft. A cutting edge of the body is in operation in each case, so that with the exception of the knife to which this cutting edge belongs, all knives can be exchanged without the machine having to be put out of operation.

US Patent Publication No. <CIT> discloses tines of a baler pre-cutter rotor that each include a plate having a plurality of points disposed at equally spaced locations about a rotation axis of the rotor. Each point has a leading region reinforced by a pair of straps fixed in sandwiching relationship to the point. The pair of straps may also be applied to opposite sides of a trailing region bordering a circular mounting hole of the plate. A second pair of straps may abut each first pair of straps and reinforce a leading region bordering the circular mounting hole. Instead of the second pair of straps, a ramp may be provided on a side surface of the plate for deflecting crop towards a pre-cutter stationary cutting knife. Instead of including separate straps, the tines can be cast or forged as identical sections including a tine point.

According to an aspect of the invention there is provided a rotor cutter apparatus for an agricultural baler. The rotor cutter apparatus comprises a rotor shaft. The rotor cutter apparatus comprises a plurality of tine plates arranged axially along the rotor shaft. The tine plates are for moving crop material collected by the agricultural baler as the rotor shaft rotates. Each tine plate comprises at least one first tine and at least one second tine spaced angularly from the at least one first tine. A length of the at least one first tine is greater than a length of the at least one second tine. The at least one first tine of a first one of the tine plates is adjacent to the at least one second tine of at least one of the tine plates adjacent to the first one of the tine plates. The length of the at least one first tine of the first one of the tine plates is different from the length of the at least one first tine of another one of the tine plates. Alternatively, or in addition, in some embodiments the length of the at least one second tine of the first one of the tine plates is different from the length of the at least one second tine of another one of the tine plates.

Prior art arrangements may provide a tine plate with short tines between tine plates with longer tines. Longer tines may be regarded as providing a greater cleaning effect when used in conjunction with a scraper. In addition, the provision of short tines next to longer tines may be considered to provide a higher intake of crop material to a pre-compression chamber. The prior art is disadvantageous in that only the swept area of the tine plates having the longer tines benefits from increased cleaning efficiency, whereas the swept area of the tine plates having the shorter tines does not. The present invention is advantageous in that not only are short tines arranged next to, or beside, longer tines when the tine plates are arranged on the rotor shaft (so as to maintain the higher intake of crop material), but as each of the tine plates includes both long and short tines the cleaning efficiency is increased. This is because the swept area of each and every tine plate benefits from increased cleaning efficiency compared with the swept area of only alternate tine plates along the rotor shaft as in the prior art.

The rotor cutter apparatus may also be referred to as a pre-cutter apparatus or, in the case where no further cutting or chopping of crop is performed, a rotor assembly.

The at least one first tine of the first one of the tine plates may be adjacent to the at least one second tine of each of the two tine plates adjacent to the first one of the tine plates.

The plurality of tine plates may be spaced equally along the rotor shaft.

The plurality of tine plates may be arranged parallel to one another.

In some embodiments, each of the first and second tines has a tip, and the tips of the first and second tines of the plurality of tines plates define one or more curves axially along the rotor shaft.

In some embodiments, the tips of the first tines along a row of the plurality of tines plates define one or more curves axially along the rotor shaft. Alternatively, or in addition, the tips of the second tines along a row of the plurality of tines plates define one or more curves axially along the rotor shaft.

The rotor cutter apparatus may comprise a scraper including a plurality of spaced apart scraper tines. The first and second tines of the tine plates may be arranged to intersect the scraper tines as the rotor shaft rotates.

The scraper tines may be spaced equally apart.

Each tine plate may be generally circular shaped. A tine may also be referred to as a prong, sharp peak, protrusion, point or other suitable term. The at least one first tine may also be referred to as a long tine, and the at least one second tine may also be referred to as a short tine. Prior art arrangements provide tine plates with tines of the same size around their circumference. Advantageously, by providing a tine plate with tines of different size around its circumference, the cleaning efficiency and the crop conveying efficiency of an area to be swept by the tine plate as the rotor shaft rotates increases and may be maximised.

The length of one of the tines may be regarded as the distance from a tip or point of the tine to a body of the tine plate, for example to an inner edge of the tine plate. In such a case, the length of the tines is equal to their thickness in a radial direction. Alternatively, the length of one of the tines may be regarded as the length of one of the sides or edges of the tines.

The length of the at least one second tine may be greater than half of the length of the at least one first tine. The relative difference in length between each of the first and second tines may be any suitable difference.

Each tine plate may comprise an inner edge and an outer edge. The inner edge may be arranged for mounting to the rotor shaft of the rotor cutter apparatus. Each of the first and second tines may be at the outer edge.

The angular spacing between the first and second tines may be less than or equal to <NUM> degrees.

Each tine plate may comprise two first tines and two second tines. This may increase the efficiency of the tine plate as the cleaning frequency and the amount of crop that may be moved towards a pre-compression chamber by the tines increasing over a single rotation of the rotor shaft of the rotor cutter apparatus.

The two first tines may be arranged opposite each other. The two second tines may be arranged opposite each other. Advantageously, this allows for alternate sweeps of the crop by the long and short tines to improve cleaning and crop conveying efficiency.

Each tine plate may comprise two tine plate segments. This may facilitate mounting the tine plate to, and removing the tine plate from, the rotor shaft of the rotor cutter apparatus. This may also facilitate manufacture of the tine plate.

The rotor cutter apparatus may comprise a knife rack including a plurality of spaced apart knives. The first and second tines of the tine plates may be arranged to direct crop material collected by the agricultural baler towards and over the plurality of knives.

According to another aspect of the present invention there is provided an agricultural baler comprising a rotor cutter apparatus as described above.

<FIG> shows an agricultural baler <NUM> in the form of a large square baler. In particular, <FIG> is a perspective cutaway view illustrating the inner workings of the large square baler <NUM>. The baler <NUM> has a pickup unit or apparatus <NUM> for lifting crop material from windrows. The pickup apparatus <NUM> has a rotatable pickup roll (or rotor or cylinder) <NUM> with a number of pickup tines <NUM> to move the collected crop rearward towards a rotor cutter apparatus <NUM>. Optionally, a pair of stub augers (one of which is shown, but not numbered) is positioned above the pickup roll <NUM> to move the crop material laterally inward.

The rotor cutter apparatus <NUM> has a rotor assembly with rotor tines <NUM> that push the crop towards a knife rack with knives for cutting the crop and into a pre-compression chamber <NUM> to form a wad of crop material. The tines <NUM> intertwine the crop together and pack the crop within the pre-compression chamber <NUM>. The pre-compression chamber <NUM> and the rotor assembly with the tines <NUM> function as a first stage for crop compression. The rotor assembly and the tines <NUM> will be discussed in greater detail below.

Once the pressure in the pre-compression chamber <NUM> reaches a predetermined sensed value, a stuffer unit or apparatus <NUM> moves the wad of crop from the pre-compression chamber <NUM> to a bale chamber <NUM>. The stuffer apparatus <NUM> includes stuffer forks <NUM> which thrust the wad of crop directly in front of a plunger <NUM>, which reciprocates within the bale chamber <NUM> and compresses the wad of crop into a flake. The stuffer forks <NUM> return to their original state after the wad of material has been moved into the bale chamber <NUM>. The plunger <NUM> compresses the wads of crop into flakes to form a bale and, at the same time, gradually advances the bale toward an outlet <NUM> of the bale chamber <NUM>. The bale chamber <NUM> and plunger <NUM> function as a second stage for crop compression.

When enough flakes have been added and the bale reaches a full (or other predetermined) size, the knotters <NUM> are actuated which wrap and tie twine around the bale while it is still in the bale chamber. Needles <NUM> bring the lower twine up to the knotters <NUM> and the tying process then takes place. The twine is cut and the formed bale is ejected from a discharge chute <NUM> as a new bale is formed.

<FIG> shows a perspective view of the pickup apparatus <NUM> and the rotor cutter apparatus <NUM>, and <FIG> shows a partial rear view of the rotor cutter apparatus <NUM> at the entrance or input to the pre-compression chamber <NUM>. Referring to <FIG> and <FIG>, the rotor cutter apparatus <NUM> includes a rotor assembly <NUM> having a cylindrical rotor shaft <NUM> rotatable about its axis. The rotor assembly <NUM> also includes a number of tine plates <NUM> on the rotor shaft <NUM>, where the tine plates <NUM> include the rotor tines <NUM>.

The tine plates <NUM> are arranged and spaced axially along the length of the rotor shaft <NUM>. The tine plates <NUM> are spaced equally apart and are parallel relative to each other. The tine plates <NUM> extend circumferentially all the way around the rotor shaft <NUM> and have a central circular mounting opening in which the rotor shaft is located. The tine plates <NUM> are formed from metal and are planar. There may be any suitable number of tine plates <NUM> on the rotor shaft, for example approximately <NUM> tine plates <NUM>. The tine plates <NUM> will be discussed in greater detail below.

At a rear side of the rotor assembly <NUM> at an entrance to the pre-compression chamber <NUM> is a knife plate <NUM> including a number of blades or knives <NUM>. In particular, the knife plate <NUM> is positioned at a lower side of the entrance to the pre-compression chamber <NUM>. The knives <NUM> project upwardly from the knife plate <NUM>. When the rotor shaft <NUM> rotates, crop material from the pickup apparatus <NUM> is collected and dragged or forced by the tines <NUM> towards and over the knives <NUM>. The knives <NUM> cut the crop material into smaller pieces before it enters the pre-compression chamber <NUM>. With reference to <FIG>, the rotor tines <NUM> rotate in a direction towards the knives <NUM>.

Also at the rear side of the rotor assembly <NUM> at an entrance to the pre-compression chamber <NUM> is a scraper <NUM>. In particular, the scraper <NUM> is positioned at an upper side of the entrance to the pre-compression chamber <NUM>. The scraper <NUM> includes a number of scraper tines <NUM> in a fork-like arrangement along the entire length of the entrance to the pre-compression chamber <NUM>. The scraper tines <NUM> project or extend back towards the rotor assembly <NUM>, i.e. away from the pre-compression chamber <NUM>. Note that only an upper side of the pre-compression chamber <NUM> is shown in <FIG>. In the described embodiment, the scraper tines <NUM> are equally spaced and the spacing between each scraper tine <NUM> is sufficient to allow one of the rotor tines <NUM> intersect and pass therethrough.

As may be seen in <FIG>, as the rotor assembly <NUM>, and therefore the rotor tines <NUM>, rotate about the axis of the rotor shaft <NUM> the rotor tines <NUM> intersect the scraper tines <NUM> of the scraper <NUM>. For example, the number of scraper tines <NUM> may be substantially equal to the number of rotor tines <NUM> so that a single rotor tine <NUM> intersects each gap or space formed between the scraper tines <NUM>.

When the rotor shaft <NUM> rotates, crop material that has been collected by the rotor tines <NUM> is removed or shredded or scraped from the rotor tines <NUM> by the scraper <NUM> as the rotor tines <NUM> intersect the scraper tines <NUM>.

As will be understood with reference to <FIG>, the rotor tines <NUM> intersect the scraper tines <NUM> from below to above the scraper tines as the rotor assembly <NUM> rotates. As such, the crop material that is removed from the rotor tines <NUM> by the scraper <NUM> will remain at a lower side of the scraper <NUM> and be directed towards and into the pre-compression chamber <NUM>. In this way, the crop material is prevented from being returned to the ground from which it was initially collected and is instead provided to the pre-compression chamber <NUM> to form a wad.

The rotor tine plates <NUM> and rotor tines <NUM> are now discussed with reference to <FIG>. In the present embodiment each tine plate <NUM> is formed from two tine plate segments <NUM>, one of which is shown in <FIG>. In the present embodiment, the tine plate segments <NUM> are semi-circular in shape, with an inner edge 66a matching an outer surface of the rotor shaft <NUM> to which it is to be attached. The tines <NUM> are located at an outer edge 66b of the tine plate <NUM>. When the two tine plate segments <NUM> are brought together around the rotor shaft <NUM> they form the central circular mounting opening in which the rotor shaft <NUM> is located.

<FIG> shows that the tine segment <NUM> includes two rotor tines <NUM>. In the described embodiment, the rotor tines <NUM> are spaced apart angularly by approximately <NUM> degrees; however, any suitable angular spacing may be chosen. The rotor tines <NUM> on the segment <NUM> are not of equal length in a radial direction. In particular, a first one 20a of the rotor tines <NUM> has a length greater than that of a second one 20b of the rotor tines <NUM>. As such, the first tine 20a may also be referred to as a long tine 20a, and the second tine 20b may also be referred to as a short tine 20b. The length of the short tine 20b is only slightly less than that of the long tine 20a, and in any case the length of the short tine 20b is greater than half of the length of the long tine 20a.

In the described embodiment, the two segments <NUM> forming the tine plate <NUM> are of similar configuration. That is, each tine plate <NUM> includes two long tines 20a and two short tines 20b. Furthermore, when the segments <NUM> are positioned around the rotor shaft <NUM> to form the tine plate <NUM> the two long tines 20a are on opposite sides of the rotor shaft <NUM>, i.e. spaced apart by an angle of <NUM> degrees in the described embodiment. Similarly, the two short tines 20b are on opposite sides of the rotor shaft <NUM>, i.e. spaced apart by an angle of <NUM> degrees in the described embodiment. That is, each tine plate <NUM> includes four tines <NUM> each spaced apart by approximately <NUM> degrees in the described embodiment.

As illustrated in <FIG> and <FIG>, when the tine plates <NUM> are arranged in parallel along the rotor shaft <NUM>, the tines <NUM> of adjacent tine plates <NUM> are positioned substantially adjacent to one other. As such, four rows or lines of tines <NUM> are formed along the rotor assembly <NUM> (because each tine plate <NUM> has four tines <NUM>), each row being spaced apart by approximately <NUM> degrees. Note that each row of tines <NUM> is not a straight line, but instead forms a pattern or shape. Specifically, the shape of each row is defined by the tips or points of each of the tines <NUM>. In the described embodiment, each row of tines <NUM> forms an approximate 'V-shape', with each side of the 'V' being slightly curved.

As the rows formed by the tines <NUM> along the rotor shaft <NUM> are not in the form of straight lines then either the tine plates <NUM> are formed with the tines <NUM> at slightly different positions in a circumferential or angular direction, and/or the tine plates <NUM> are positioned on the rotor shaft <NUM> at different angular positions. In any case, the difference in angular position between adjacent tines <NUM> on adjacent tine plates <NUM> is relatively small such that the tines <NUM> may indeed still be regarded as being adjacent to each other.

As mentioned above, each of the tine plates <NUM> includes four tines: two long tines 20a and two short tines 20b. As best seen in <FIG>, the tine plates <NUM> are arranged on the rotor shaft <NUM> such that the long tines 20a of one of the tine plates <NUM> are positioned adjacent to the short tines 20b of the tine plates <NUM> on either side of said one tine plate <NUM>. Expressed differently, along a row of tines <NUM> on the rotor shaft <NUM> the tines <NUM> alternate between long and short tines 20a, 20b. As each tine plate <NUM> has both long and short tines 20a, 20b then adjacent rows of tines <NUM> on the rotor shaft <NUM> will also alternate between long and short tines 20a, 20b, but for a given tine plate <NUM> a short tine 20b will replace a long tine <NUM>, and vice versa.

Many modifications may be made to the above-described embodiments without departing from the scope of the present invention as defined in the accompanying claims.

In the above-described embodiment, each tine plate is formed by two tine plate segments. In different embodiments, each tine plate may be formed from a single piece, or may be formed by more than two plate segments.

In the above-described embodiment, each tine plate has four tines: two long tines and two short tines, with one of each on each of the two plate segments. In different embodiments, each tine plate may have a different number of tines as appropriate, for example a single long tine and a single short tine. In such an example, the long tine may be on one plate segment and the short tine on the other plate segment. Equally, each tine plate may have more than four tines in different embodiments.

In the above-described embodiment, the long tines on each of the tine plates along the rotor are of equal length, and this is also the case for the short tines. In different embodiments, the long tines may vary slightly in length between different tine plates (but still be longer than the short tines). Similarly, in different embodiments from the one described above, the short tines may vary slightly in length between different tine plates (but still be shorter than the long tines).

Claim 1:
A rotor cutter apparatus (<NUM>) for an agricultural baler (<NUM>), the rotor cutter apparatus (<NUM>) comprising:
a rotor shaft (<NUM>); and,
a plurality of tine plates (<NUM>) arranged axially along the rotor shaft (<NUM>) and being for moving crop material collected by the agricultural baler (<NUM>) as the rotor shaft rotates, each tine plate (<NUM>) comprising at least one first tine (20a) and at least one second tine (20b) spaced angularly from the at least one first tine (20a), wherein a length of the at least one first tine (20a) is greater than a length of the at least one second tine (20b),
wherein one of the at least one first tines (20a) of a first one of the tine plates (<NUM>) is adjacent to one of the at least one second tines (20b) of at least one of the tine plates (<NUM>) adjacent to the first one of the tine plates (<NUM>)
characterised in that :
the length of the at least one first tine (20a) of the first one of the tine plates (<NUM>) is different from the length of the at least one first tine (20a) of another one of the tine plates (<NUM>), and/or the length of the at least one second tine (20b) of the first one of the tine plates (<NUM>) is different from the length of the at least one second tine (20b) of another one of the tine plates (<NUM>).