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 tine plates arranged axially along the rotor shaft and which rotate with the rotor shaft. Each of the tine plates has one or more tines which, as the rotor shaft rotates, engage with the crop to move the crop material from the pickup unit towards a knife rack. The knife rack typically has knives for cutting the crop into smaller pieces before it reaches the pre-compression chamber.

As well as simply moving the crop towards the pre-compression chamber, it is desirable for the rotor assembly to arrange the collected crop so that the crop is equally distributed as it is loaded into the pre-compression chamber. This ensures that the entire pre-compression chamber is filled, which assists in allowing a desired bale rate of the baler to be reached. In order to distribute the crop, typically the tine plates are arranged on the rotor shaft such that the tines form a particular pattern or shape. For example, it is known to arrange the tine plates so that the tines form or define a 'V'-shape or profile with a corner at a central or middle portion of the rotor shaft and two straight lines extending out towards end or side portions of the rotor shaft. However, such a rotor shape may not provide equal distribution of the crop in certain cases. For instance, for relatively wide-windrow crop collection the amount of crop filling at the sides of the pre-compression chamber can be too high to provide an optimal or desired bale shape. Also, for relatively narrow-windrow crop collection the V-rotor transports the crop to the pre-compression chamber with little or no spreading, which leads to unequal crop distribution in the pre-compression chamber.

European Patent Publication No. <CIT> discloses a pre-cutter rotor that includes a central longitudinal core having a central rotation axis and having a plurality of tines fixed to said core at longitudinally spaced locations, with each of said tines including a plurality of substantially radially extending points spaced equal-angularly from each other about said axis (<NUM>). Each point has a leading working surface having a wide profile for engaging crop when the rotor is rotated in a direction for moving crop rearward. The working surface is oriented at an angle relative to a vertical plane making a right angle with said rotation axis.

German Patent Publication No. <CIT> discloses a loading wagon with a loading device for crop consisting of stalks or leaves. The wagon comprises a pick-up device with a working width which the crop is equipped with pick-up prongs from the ground, a pressing device downstream of the receiving device for forwarding the harvested crop, a loading space downstream of the pressing device. The pressing device comprises a pressing channel in which an integral rotor is arranged. The integral rotor has two outer working widths with screws and a middle working width with pressing tines. The augers and the outer press tines have an overlap area.

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. In one embodiment, the pair of straps is also applied to opposite sides of a trailing region bordering a circular mounting hole of the plate. In another embodiment, a second pair of straps abuts each first pair of straps and reinforces 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.

European Patent Publication No. <CIT> discloses rotor strippers that are sized and shaped to securely fit between adjacent rotor fingers on a rotor shaft of a rotor for stripping crop material and for conveying the crop material inside an agricultural machine. Each rotor stripper is formed of a segment comprised of two opposing side walls with an interior section extending between the two opposing side walls. A first end portion has a curved hook section shaped to securely fit around a majority portion of the rotary shaft for secure engagement therewith; a second end portion is secured to a backbone portion of the rotor allowing the segment to remain fixed with respect to rotation of the rotary shaft; and a middle portion extends between the first (<NUM>) and second (<NUM>) end portions in a curved manner.

European Patent Publication No. <CIT> discloses a cutting unit for agricultural machines, comprising a rotor carrying on a base body spaced apart tine arrangements with circumferential phase shifts in between adjacent tine arrangement. Each tine arrangement has at least one tine with a base secured to a base body of the rotor and an outwardly protruding triangular tine tip, the tine tip forming a conveying flank leading in the direction of rotation of the rotor and extending from the tine end to a transition into the base, a cutting unit bottom forming a lower boundary of a conveying channel, cutting blades protruding from the cutting unit bottom through the conveying channel besides moving paths of the tine tips, and scrapers placed in conveying direction through the conveying channel behind the rotor, a compression surface is provided at the base of the tine ahead of the conveying flank in the direction of rotation of the rotor, the compression surface gradually ascending at least substantially up to the transition into the conveying flank.

US Patent Publication No. <CIT> discloses a combine harvester has a straw chute with a straw conveyor which comprises a conveyor rotor which can be set into rotation and has dogs distributed helically around the conveyor rotor.

It is an aim of the present invention to address one or more disadvantages associated with the prior art.

According to an aspect of the present invention there is provided a rotor assembly for an agricultural baler in accordance with claim <NUM>. The rotor assembly comprises a rotor shaft having a central portion and first and second end portions either side of the central portion, the rotor shaft defining a first shaft section between the first end portion and the central portion, and the rotor shaft defining a second shaft section between the central portion and the second end portion. The rotor assembly comprises a plurality of tine plates to be arranged axially along the rotor shaft. Each of the tine plates comprises a tine. The tine plates are arranged such that there is an angular spacing between the tines of adjacent ones of the tine plates. In the first shaft section a magnitude of the angular spacing is greater or smaller at the central portion than at the first end portion. In the second shaft section a magnitude of the angular spacing is greater or smaller at the central portion than at the second end portion. In the first and second shaft sections, the magnitude of the angular spacing is greater at the central portion than at the first and second end portions and decreases from the central portion to the first and second end portions, or, in the first and second shaft sections, the magnitude of the angular spacing is smaller at the central portion than at the first and second end portions and increases from the central portion to the first and second end portions. The central portion may be regarded as the central point or simply the vicinity of a central portion of the rotor assembly or shaft. Likewise, the first and second end portions may be regarded as being in the vicinity of the first and second end portions. The section of the rotor shaft between the central portion and the first end portion is referred to as a first shaft section, and the section of the rotor shaft between the central portion and the second end portion is referred to as a second shaft section. The 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 angular spacing between tines may be regarded as an angle between the tines relative to the rotor shaft or a point of the rotor shaft, for example the axis of rotation of the rotor shaft. In particular, the angular spacing between tines may be the angular spacing between respective tips of the tines.

By having an angular spacing between tines that is greater at the centre of the rotor shaft compared with the ends or sides means that tine spacing may be regarded as being more aggressive at the centre and less aggressive at the ends or sides. By having more aggressive tine spacing at the centre, crop is distributed or spread by the rotor assembly from the centre out towards the side portions of the rotor shaft. This is particularly useful when collecting crop in relatively narrow windrows, e.g. windrows having a width less than that of the rotor shaft. Also, by having less aggressive angular spacing of the tines at the end portions ensures that sufficient crop remains towards or at the side portions of the rotor shaft, and therefore the sides of the pre-compression chamber are filled with a sufficient amount of the collected crop. This may be particularly useful when collecting crop in relatively wide windrows. In both cases this helps to ensure that the crop is more evenly distributed when it is moved into a pre-compression chamber of the baler, in particular that the crop that fills the sides of the pre-compression chamber is optimal. By having the crop more evenly distributed in the pre-compression chamber means that a desired bale shape and bale rate may be more readily achieved. Alternatively, by having an angular spacing between tines that is smaller at the centre of the rotor shaft compared with the ends or sides means that tine spacing may be regarded as being less aggressive at the centre and more aggressive at the ends or sides. By having less aggressive tine spacing at the centre, crop may be moved by the rotor assembly towards the centre from one or more of the side portions of the rotor shaft. This may be particularly useful, for example, if the baler is not correctly lined up with the windrow of crop it is collecting.

The decrease or increase in the angular spacing may be monotonic. Advantageously, this ensures a consistent direction of spreading of the collected crop to ensure even distribution in the pre-compression chamber.

The tines may define a first curve between the central portion and the first end portion. That is, the tines may define the first curve in the first shaft section, with the first curve spanning some or all of the first shaft section. The tines may define a second curve between the central portion and the second end portion. That is, the tines may define the second curve in the second shaft section, with the second curve spanning some or all of the second shaft section. Each of the tines of the respective first and seconds tines may therefore be regarded as being 'in-phase' with one another. Arrangement of the tines to define such a curve or smooth shape/pattern helps to ensure more predictable and even spreading or swathing of the collected crop. The tines have tips or pointed ends and, in particular, it may be the tips or tops of the tines that define the first and second curves.

The first and/or second curves may be quadratic curves. This is a particularly advantageous smooth shape to provide an even distribution of crop.

The first curve may have no extrema between the central portion and the first end. The second curve may have no extrema between the central portion and the second end. That is, there is no change in the direction of the angular spacing in the first shaft section or in the second shaft section.

The first and/or second curves may form a corner at the central portion. Alternatively, a smooth meeting point may be defined by the tines in the vicinity of the central portion.

There may be a phase difference between the first and second curves at the central portion. The phase difference is an angular spacing between the respective tines of the first and second curves at the central portion, i.e. the first and second curves do not meet at the central portion, either in a smooth manner or otherwise. That is, there is a discontinuity between the first and second curves at the central portion. A phase difference between the first and second curves may be referred to as the first and second curves being 'out of phase' with each other. This helps to ensure that no crop blockage develops in the vicinity of the central portion of the shaft. In addition, such a phase difference may help to ensure that the rotor assembly distributes or spreads crop evenly towards both sides of the rotor shaft and does not favour distribution to just one of the sides.

The tines may define a plurality of first curves between the central portion and the first end portion in a circumferential segment of the rotor shaft. The tines may define a plurality of second curves between the central portion and the second end portion in the circumferential segment of the rotor shaft.

Each of the tine plates may comprise a plurality of tines spaced angularly apart. The tine plates may be arranged such that the tines define a plurality offirst curves and/or a plurality of second curves in an axial segment of the rotor shaft. 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.

The rotor assembly may comprise first and/or second end plates at the first and/or second ends, respectively, of the rotor shaft. The first and/or second end plates may each comprise a tine. The first and/or second end plates may be arranged such that their respective tine is adjacent to the tines of the adjacent tine plates.

The tine plates may be spaced equidistantly along the rotor shaft.

The tines of adjacent ones of the tine plates may be of different length. This helps to ensure a balance between the amount of crop being collected and moved by the rotor assembly, and cleaning of the tines by scraper apparatus adjacent to the rotor assembly. 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 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.

An angular orientation of the tine plates may be adjustable to adjust the angular spacing between the tines of adjacent ones of the tine plates. Advantageously, this allows for the aggressiveness of the tine spacing to be changed or altered at one or more points along the width of the rotor shaft. This means that the tine spacing may be optimised to convey and spread crop depending on the type of crop and width of the windrows.

According to another aspect of the present invention there is provided an agricultural baler comprising a rotor assembly 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> and <FIG> show perspective and side views of the rotor assembly <NUM> of the rotor cutter apparatus <NUM> in <FIG>. The rotor assembly <NUM> has 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>. In the described embodiment, 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 <NUM> is located. In the described embodiment, 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 fifty six tine plates <NUM>.

In the described embodiment each tine plate <NUM> is formed from two tine plate segments <NUM> that are semi-circular in shape, with an inner edge 56a 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 56b 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. 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 a particular segment <NUM> are of equal length in a radial direction in the described embodiment; however, this need not be the case. The two segments <NUM> forming the tine plate <NUM> are of similar configuration. That is, each tine plate <NUM> includes four tines <NUM> each spaced apart by approximately <NUM> degrees in the described embodiment.

The radial length of the tines <NUM> is not equal on each of the tine plates <NUM> along the length of the rotor shaft <NUM>. In particular, the tine plates <NUM> have tines <NUM> of either a first radial length or a second, shorter, radial length. The tine plates <NUM> are arranged along the rotor shaft <NUM> such that alternate tine plates <NUM> have tines <NUM> of the first length and alternate tine plates <NUM> have tines <NUM> of the second length. That is, on either side of a tine plate <NUM> that has tines <NUM> of the first length is a tine plate <NUM> that has tines <NUM> of the second length, i.e. adjacent tine plates <NUM> have tines <NUM> of different length.

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, rows or lines of tines <NUM> are formed along the rotor assembly <NUM>. 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>. 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 plate segments <NUM> are positioned on the rotor shaft <NUM> at different angular positions. In the described embodiment, the latter is the case. Irrespective of this, 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 referred to as being adjacent to each other.

The pattern or shape formed by the tines <NUM> along the rotor shaft <NUM> is now described in greater detail. The rotor shaft <NUM> is split into two axial segments or sections: a first shaft section 52a between a first end 60a and a central portion <NUM> of the rotor shaft <NUM>; and, a second shaft section 54b between the central portion <NUM> and a second end 60b of the rotor shaft <NUM>. The first and second ends 60a, 60b are opposite ends of the rotor shaft <NUM>, with the central portion <NUM> being located therebetween.

Focussing firstly on the first shaft section 52a, the tines <NUM> form four shaped rows between the first end 60a and the central portion <NUM> of the rotor shaft <NUM>. There are four rows around the circumference of the rotor shaft <NUM> as each tine plate <NUM> has four tines <NUM>. The rows of tines <NUM> in the first shaft section 52a form a curved shape. This is achieved by arranging the tine plates <NUM> such that there is an angular spacing <NUM> between the tines <NUM> of adjacent ones of the tine plates <NUM> in the first shaft section 52a. In accordance with a first alternative of the present invention, in order to achieve the curved pattern, a magnitude of the angular spacing <NUM> between the tines <NUM> of adjacent ones of the tine plates <NUM> varies from the central portion <NUM> to the first end 60a of the rotor shaft <NUM>, i.e. across the length of the first shaft section 52a. More specifically, the magnitude of the angular spacing <NUM> between adjacent tines <NUM> in the first shaft section 52a decreases from the central portion <NUM> to the first end 60a of the rotor shaft <NUM>.

In the described embodiment, the magnitude of the angular spacing <NUM> varies such that the resulting curve formed by the row of tines <NUM> is a quadratic curve. The magnitude of the gradient of the quadratic curve is greatest at the central portion <NUM> and smallest at the first end portion 60a. In the described embodiment, the angular spacing <NUM> between the tines <NUM> at the central portion <NUM> is <NUM> degrees and the angular spacing <NUM> between the subsequent pair of tines <NUM> is <NUM> degrees. The angular spacing <NUM> reduces by <NUM> degree for each pair of tines along the row from the central portion <NUM> to the first end portion 60a until the pair of tines at the first end portion 60a, which has an angular spacing <NUM> of <NUM> degrees. That is, the angular spacing <NUM> along the row of tines <NUM> follows quadratic behaviour proportional to <NUM>. It will be understood that any suitable angular spacing <NUM> between the tines <NUM> may be selected. However, it is noted that the magnitude of the angular spacing <NUM> between adjacent tines <NUM> decreases from the central portion <NUM> to the first end 60a and, in particular, this decrease is monotonic.

In the described embodiment, the direction of the angular spacing <NUM> between tines <NUM> is the same for each pair of adjacent tines <NUM> in the first shaft section 52a, i.e. between the central portion <NUM> and the first end portion 60a. That is, the shape or pattern formed by the tines <NUM> in the first shaft section 52a is curved but has no extrema, i.e. no maximum or minimum between the central portion <NUM> and the first end portion 60a. The curve defined by the tines <NUM> may be considered to have its maximum at the first end 60a and its minimum at the central portion <NUM>. In addition to the curve formed by the tines <NUM> having no extrema, the decrease in angular spacing <NUM> from the central portion <NUM> to the first end 60a is monotonic.

As noted above, in the first shaft section 52a the magnitude of the angular spacing <NUM> between the tines <NUM> is greater at the central portion <NUM> than at the first end 60a. The tine spacing or pattern at the central portion <NUM> may in this case be referred to as being more aggressive than at the first end 60a. That is, the greater the angular spacing <NUM>, the more aggressive the tine pattern is. Expressed differently, the magnitude of the gradient of the curve defined by the tines <NUM> is greater at the central portion <NUM> than at the first end 60a.

The curve formed by the tips of the tines <NUM> in the first shaft section 52a may be referred to as a first curve. As noted above, each of the tine plates <NUM> has four tines <NUM> spaced apart by <NUM> degrees in the angular direction. As such, the first shaft section 52a has four first curves around the circumference of the shaft <NUM>, spaced apart by <NUM> degrees in the angular direction.

Referring now to the second shaft section 52b, the tines <NUM> of the tine plates <NUM> in the second shaft section 52b form a similar shape or pattern to that in the first shaft section 52a, namely, a quadratic curve. In particular, the magnitude of the angular spacing <NUM> between adjacent tines <NUM> in the second shaft section 52b decreases from the central portion <NUM> to the second end 60b of the rotor shaft <NUM>.

The curve formed by the tips of the tines <NUM> in the second shaft section 52b may be referred to as a second curve. As noted above, each of the tine plates <NUM> has four tines <NUM> spaced apart by <NUM> degrees in the angular direction. As such, the second shaft section 52b has four second curves around the circumference of the shaft <NUM>, spaced apart by <NUM> degrees in the angular direction.

<FIG> shows that the first curves do not meet the second curves at the central portion <NUM> of the rotor shaft <NUM>. Instead, there is a phase difference (<NUM>) between the tine <NUM> of the first curve at the central portion <NUM> and the tine <NUM> of the second curve at the central portion <NUM>. In the described embodiment, the phase difference (<NUM>) or angular spacing between these tines <NUM> is <NUM> degrees; however, any suitable phase difference may be used. In the described embodiment in which each tine plate <NUM> has four tines <NUM> spaced apart equally in the angular direction, the phase difference of <NUM> degrees at the central portion <NUM> may be regarded as the first and second curves being completely out of phase. More generally, for tine plates having k tines spaced apart equally in the angular direction, the first and second curves are completely out of phase if the phase difference therebetween is <NUM>/k degrees. Such a phase difference may be optimal for crop distribution.

When referring to the angular spacing <NUM> between a pair of tines <NUM>, or adjacent tines <NUM>, this may refer to the angular spacing <NUM> between tines <NUM> of directly adjacent tine plates <NUM> or, alternatively, this may refer to the angular spacing <NUM> between tines <NUM> of the same length, i.e. the angular spacing <NUM> between tines <NUM> of alternate tine plates <NUM> in the described embodiment. This second alternative may also be understood as a first pair of adjacent tine plates, one with first tines <NUM> and one with second tines <NUM>, being spaced angularly from a second pair of adjacent tine plates <NUM> themselves adjacent to the first pair of tine plates <NUM>, the second pair also having one with first tines <NUM> and one with second tines <NUM>.

<FIG> shows a partial perspective view of the rotor assembly <NUM>, also including an end plate <NUM> at the second end 60b of the rotor shaft <NUM>. Note the first end 60a also includes an end plate (not shown). The end plates <NUM> have end plate tine segments <NUM> with tines <NUM> similar to the tine plate segments <NUM> with the tines <NUM>. The end plate tine segments <NUM> may rotate as the rotor shaft <NUM> rotates or may remain stationary. In the described embodiment there is a phase difference between the tines <NUM> of the end plates <NUM> and the tines <NUM> of the adjacent tine plates <NUM>. In different embodiments the tines <NUM> of the end plates <NUM> may be adjacent to the tines <NUM> of the adjacent tine plates <NUM> and, in particular, the tines <NUM> of the end plates may be a continuation of the first and second curves at the respective first and second ends 60a, 60b.

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 of equal length, with two tines on each of the two plate segments. In different embodiments, each tine plate may have a different number of tines as appropriate, for example two tines, with one tine on each plate segment. Equally, each tine plate may have more than four tines in different embodiments.

In the above-described embodiment, the first curves do not meet the second curves at the central portion <NUM> of the rotor shaft <NUM>, i.e. there is a phase difference therebetween. In different embodiments, the first curves do meet the second curves at the central portion of the rotor shaft to form a continuous curve defined by the tines all the way along the rotor shaft. The first and second curves may meet in a manner that the resulting curve is smooth at the central portion, or the first and second curves may meet such that there is a corner formed by the tines at the central portion. When the first and second curves meet at the central portion then the tines may be considered to define a single continuous curve or shape along the entire axial length of the rotor shaft <NUM>.

In the above-described embodiment, the rotor shaft <NUM> is split into two axial shaft segments or sections 52a, 52b, where the tines <NUM> in the first shaft section 52a define a number of first curves and the tines <NUM> in the second shaft section 52b define a number of second curves. In particular, in a given circumferential segment of the rotor shaft <NUM> of the described embodiment, for example approximately equal to or less than <NUM> degrees, there is a single first curve in the first shaft section 52a and a single second curve in the second shaft section 52b. The resulting pattern may be considered to be a 'quadratic V shape' or 'offset quadratic V shape'. In different embodiments, the given circumferential segment may include more than a single first curve and a single second curve arranged in series along the rotor shaft. In particular, the circumferential segment may include a number of first curves and a number of second curves between the first and second ends of the rotor shaft, for example two first curves and two second curves, alternating between the first and second curves from the first end to the second end. Such a pattern may be considered to be a 'quadratic W pattern or 'offset quadratic W pattern'.

In the above-described embodiment, the tine plates <NUM> are fixed relative to the rotor shaft <NUM> and to one another such that the angular spacing <NUM> between the tines <NUM> of the tine plates <NUM> is also fixed. In different embodiments, this need not be the case. In particular, the tine plates <NUM> may be rotatable around the rotor shaft such that the angular spacing <NUM> between adjacent tines is adjustable. This would allow the aggressiveness of the tine spacing to be adjusted (and the shape defined by tines to be changed) as needed, for example during use of the agricultural harvester or between uses of the agricultural harvester.

Claim 1:
A rotor assembly (<NUM>) for an agricultural baler (<NUM>), the rotor assembly (<NUM>) comprising:
a rotor shaft (<NUM>) having a central portion (<NUM>) and first and second end portions (60a, 60b) either side of the central portion (<NUM>), the rotor shaft (<NUM>) defining a first shaft section (52a) between the first end portion (60a) and the central portion (<NUM>), and the rotor shaft (<NUM>) defining a second shaft section (52b) between the central portion (<NUM>) and the second end portion (60b); and,
a plurality of tine plates (<NUM>) to be arranged axially along the rotor shaft (<NUM>), each of the tine plates (<NUM>) comprising at least one tine (<NUM>), and
wherein the tine plates (<NUM>) are arranged such that there is an angular spacing (<NUM>) between the at least one tine (<NUM>) of adjacent ones of the tine plates (<NUM>),
wherein in the first shaft section (52a) a magnitude of the angular spacing (<NUM>) is greater or smaller at the central portion (<NUM>) than at the first end portion (60a), and wherein in the second shaft section (52b) a magnitude of the angular spacing (<NUM>) is greater or smaller at the central portion (<NUM>) than at the second end portion (60b)
the rotor assembly (<NUM>) being characterised in that
in the first and second shaft sections (52a, 52b) the magnitude of the angular spacing (<NUM>) is greater at the central portion (<NUM>) than at the first and second end portions (60a, 60b) and decreases from the central portion (<NUM>) to the first and second end portions (60a, 60b), or
in the first and second shaft sections (52a, 52b) the magnitude of the angular spacing (<NUM>) is smaller at the central portion (<NUM>) than at the first and second end portions (60a, 60b) and increases from the central portion (<NUM>) to the first and second end portions (60a, 60b).