A straw spreader for a combine harvester

Abstract

A spreading system for a combine harvester has first and second oscillatory spreading arrangements, for distributing material to follow a first and second oscillatory paths which are interleaved with each other. This provides improved spread of material.

Description

A STRAW SPREADER FOR A COMBINE HARVESTERCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of the filing date of U. K. Patent Application2313090.9, "A Straw Spreader for a Combine Harvester," filed August 29, 2023, the entire disclosure of which is incorporated herein by reference.FIELD

[0002] Embodiments of the present disclosure relate generally to combine harvesters, and in particular to a straw spreader used within a combine harvester.BACKGROUND

[0003] A combine harvester typically includes a threshing system for detaching grains of cereal from material other than grain, such as cobs, stems and seed pods, a separating apparatus downstream of the threshing system, and a grain cleaning apparatus (known as the cleaning shoe) for receiving grain from the separating apparatus. A stratification pan aims to stratify the material into a layered structure of grain at the bottom and light chaff and other material other than grain (MOG) at the top. The grain is collected in a grain bin, and from the grain bin the grain can be unloaded, for example to a trailer pulled by a tractor which runs alongside the combine harvester.

[0004] It is well known to install chaff spreaders for collecting and distributing MOG (i.e., chaff) ejected from the rear of the cleaning shoe. A chaff spreader for example comprises a pair of fan modules which eject the chaff at a tangent to a fan rotation axis.

[0005] It is also well known to install a straw chopper behind the threshing and separating apparatus for cutting straw, and to use a straw spreader to distribute the cut straw over the field. The straw spreader comprises rotary spinners (impellers) which drive the material into an output channel with a desired output direction. For example, a typical straw spreader hasa pair of spinners, to actively accelerate the chopped straw and spread it at the back of the combine.

[0006] It is also known to enable the chaff from the chaff spreader to be fed into the straw chopper and / or straw spreader. For example, in a first mode, the chaff may be delivered to the straw chopper so that the chaff is spread together with the chopped straw, across the full cutting width. The straw spreading system provides a better distribution over the harvested field than a typical chaff spreader. In a second mode, a straw swath is formed, and the chaff spreader can be slowed down to mix the chaff with the straw swath to maximize the quantity and quality of straw. In a third mode, the chaff is spread before entering the straw chopper or spreader, by directing the chaff to the sides using deflectors. The deflectors are for example coupled together with a hinge arrangement so that a single actuator drive may be used to adjust the positions of the set of deflectors.

[0007] In known straw spreaders, it is usually a challenge to achieve an even spread of material. It is known to provide an an oscillating or swinging movement of the deflectors of a straw spreader, such as the so-called "SwingFlow" tailboard of the IDEAL combine harvester. By moving the deflectors in an oscillatory manner, a more even distribution of material is achieved, as well as a wider width across which the material is spread (to correspond to the header width). This will be described as an "oscillatory spreading arrangement" in this document. An example is disclosed in WO 2021 / 099633.

[0008] The result of the oscillating movement is to create a serpentine S-shaped spreading track (when viewed from above). There may however be a non-even spread in some areas, with a lack of material.

[0009] There is therefore still a need for a straw spreader which can achieve a more uniform distribution of MOG.BRIEF SUMMARY

[0010] The invention is defined by the claims.

[0011] According to examples in accordance with the invention, there is provided a spreading system for a combine harvester, comprising:

[0012] a first oscillatory spreading arrangement for distributing material from a first output to follow a first oscillatory path; and

[0013] a second oscillatory spreading arrangement for distributing material from a second output to follow a second oscillatory path, wherein the first and second oscillatory paths are interleaved with each other.

[0014] By interleaving the oscillatory paths along which residue material is distributed it is possible to increase the uniformity with which material is distributed. Each oscillatory path is for example a serpentine S-shaped track, which oscillates between laterally outermost and laterally innermost positions (wherein "lateral" refers to the width direction of the combine).

[0015] The first and second oscillatory spreading arrangements are for example driven180 degrees out of phase with respect to each other. Thus, the oscillatory paths are 180 degrees out of phase. When one path is at its laterally outermost position, the other path is at its laterally innermost position, so that material is added by one spreading arrangement to the locations where the material density delivered by the other spreading arrangement is a minimum.

[0016] In a first example, the first oscillatory spreading arrangement comprises a straw spreader and the second oscillatory spreading arrangement comprises a chaff spreader.

[0017] In this example, a straw spreader and a chaff spreader are operated in a coordinated (and out of phase) way to deliver a more uniform combined flow. The straw spreader for example comprises a pair of fan units and a straw spreader deflector arrangement, wherein the straw spreader deflector arrangement is driven with an oscillatory movement, and the chaff spreader also comprises a pair of fan units.

[0018] The fan units of the chaff spreader may have outputs which are driven to face different directions with an oscillatory movement. Thus, the oscillatory path created by the chaff spreader is made by steering the fan units themselves.

[0019] The chaff spreader may instead comprise a chaff spreader deflector arrangement which is driven with an oscillatory movement. Thus, a deflector may instead by used to adjust the chaff spreader output direction.

[0020] In a second example, the first oscillatory spreading arrangement comprises a first straw spinner arrangement of a straw spreader and the second oscillatory spreading arrangement comprises a second spinner arrangement of the straw spinner.

[0021] In this example, a single straw spreader provides the two separate material flows by having two separate spinner arrangements. They are for example stacked one above the other, so can rotate on the same axis.

[0022] The straw spreader may then comprise a pair of fan units, each having a first spinner and associated first deflector arrangement and a second spinner and associated second deflector arrangement. The two first spinners thus form the first spinner arrangement and the two second spinners form the second spinner arrangement. Thus, separate spinners and deflectors are used.

[0023] The invention also provides a combine harvester comprising:

[0024] a crop cutting head;

[0025] a threshing and separating system;

[0026] a grain cleaning apparatus;

[0027] a straw chopper for cutting MOG received from the threshing and separating system; and

[0028] the spreading system defined above (with a straw spreader and chaff spreader) for receiving a straw flow from the straw chopper and receiving a chaff flow from the grain cleaning apparatus and distributing the cut straw and the chaff.

[0029] The invention also provides a combine harvester comprising: a crop cutting head; a threshing and separating system; a straw chopper for cutting MOG received from the threshing and separating system; and the spreading system defined above (with two spinners of the straw spreader) for receiving a straw flow from the straw chopper and distributing the cut straw.

[0030] Within the scope of this application it should be understood that the various aspects, embodiments, examples and alternatives set out herein, and individual features thereofmay be taken independently or in any possible and compatible combination. Where features are described with reference to a single aspect or embodiment, it should be understood that such features are applicable to all aspects and embodiments unless otherwise stated or where such features are incompatible.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] One or more embodiments of the invention / disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0032] Figure 1 shows a combine harvester which may be adapted in accordance with the invention;

[0033] Figure 2 shows one example of threshing system and grain cleaning apparatus in more detail;

[0034] Figure 3 shows a conventional active straw spreader, viewed from beneath;

[0035] Figure 4A shows the output from a conventional active straw spreader;

[0036] Figure 4B shows the output from a known oscillatory straw spreader;

[0037] Figure 5 shows the material distribution generated by a known oscillatory straw spreader;

[0038] Figure 6 shows the material distribution generated by the spreading system of the invention;

[0039] Figure 7 shows a first implementation of the spreading system of Figure 6;

[0040] Figure 8 shows a second implementation of the spreading system of Figure 6;

[0041] Figure 9 shows a first possible implementation of the spreading system ofFigure 8 in more detail; and

[0042] Figure 10 shows a second possible implementation of the spreading system ofFigure 8 in more detail.DETAILED DESCRIPTION

[0043] The invention will be described with reference to the Figures.

[0044] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0045] This disclosure provides a spreading system for a combine harvester that has first and second oscillatory spreading arrangements, for distributing material to follow a first and second oscillatory paths which are interleaved with each other. This provides improved spread of material.

[0046] This disclosure relates to the design of the residue distribution system of a combine harvester, namely the straw spreader and chaff spreader. However, a general outline of a combine harvester will first be provided.

[0047] Figure 1 shows a known combine harvester 10 to which the invention may be applied. The combine harvester includes a threshing system 20 for detaching grains of cereal from the ears of cereal, and a separating apparatus 30 which is connected downstream of the threshing system 20. The threshing system comprises one or more threshing units, in particular rotors, and associated concaves. In the example shown, the separating apparatus 30 includes a plurality of parallel, longitudinally-aligned, straw walkers 32, and this is suitable for the case of a so-called straw-walker combine. The grains after separation by the separating device 30 pass to a grain cleaning apparatus 40.

[0048] The grain cleaned by the grain cleaning apparatus is delivered to a grain bin 80 by a filling auger 70. Grain from the grain bin is removed from the combine harvester by an unloading tube 84.

[0049] The combine harvester has a front elevator housing 12 at the front of the machine for attachment of a crop cutting head (known as the header, not shown). The header when attached serves to cut and collect the crop material as it progresses across the field, thecollected crop stream being conveyed up through the elevator housing 12 into the threshing system 20.

[0050] In the example shown, the threshing system 20 is a tangential-flow'conventional' threshing system, i.e., formed by rotating elements with an axis of rotation in the side-to-side direction of the combine harvester and for generating a tangential flow. For example, the 'conventional' threshing system includes a rotating, tangential-flow, threshing cylinder and a concave-shaped grate. The threshing cylinder includes rasp bars (not shown) which act upon the crop stream to thresh the grain or seeds from the remaining material, the majority of the threshed grain passing through the underlying grate and onto a stratification pan (also sometimes known as the grain pan).

[0051] There are also axial threshing systems, i.e., formed by rotating elements with an axis of rotation in the longitudinal direction (direction of travel). For example, the threshing section may have axially-aligned rasp bars spaced around the front section whilst the separating section has separating elements or fingers arranged in a pattern, e.g., a spiral pattern, extending from the rasp bars to the rear of the rotor.

[0052] The MOG (material other than grain), in particular chaff, exits the combine harvester at the back. This invention relates to the residue management system 90 provided at the back of the combine harvester.

[0053] As mentioned above, instead of tangential flow threshing (and separating), axial threshing (and separating) is also known, and the invention may be applied to any type of combine. For completeness, Figure 2 shows an axial threshing and separating system 20, together with a more detailed view of the cleaning apparatus 40.

[0054] The threshing system 20 in this case comprises an axial rotor 22 beneath which is mounted the concave 24. The concave may have different sections along its length, and the first section to receive the crop material (to the left in Figure 2) may have a releasable concave, or else the whole length of the concave may be releasable. The separating function for this type of combine involves conveying the crop stream rearwardly in a ribbon passing along a spiral path.

[0055] No matter what type of threshing is performed, the initial threshing creates a flow of grain to a stratification pan 42. The separating function further downstream of thethreshing system serves to separate further grain from the crop stream and this separated grain passes through a grate-like structure onto an underlying return pan 44. The residue crop material, predominantly made up of straw, exits the machine at the rear. Although not shown in Figure 1, a straw spreader and / or chopper may be provided to process the straw material as required.

[0056] The threshing apparatus 20 does not remove all material other than grain,"MOG", from the grain so that the crop stream collected by the stratification pan 42 and return pan 44 typically includes a proportion of straw, chaff, tailings and other unwanted material such as weed seeds, bugs, and tree twigs. The remainder of the grain cleaning apparatus 40 is in the form of a grain cleaning unit 50. The grain cleaning unit 50 removes this unwanted material thus leaving a clean sample of grain to be delivered to the bin.

[0057] The grain cleaning unit 50 comprises a fan unit 52 and sieves 54 and 56. The upper sieve 54 is known as the chaffer.

[0058] The stratification pan 42 and return pan 44 are driven in an oscillating manner to convey the grain and MOG accordingly. Although the drive and mounting mechanisms for the stratification pan 42 and return pan 44 are not shown, it should be appreciated that this aspect is well known in the art of combine harvesters and is not critical to disclosure of the invention. Furthermore, it should be appreciated that the two pans 42, 44 may take a ridged construction as is known in the art.

[0059] The general flow of material is as follows. The grain passing through the concave24 falls onto the front of stratification pan 42 as indicated by arrow A in Figure 2. This material is conveyed rearwardly (in the direction of arrow B in Figure 2) by the oscillating motion of the stratification pan 42 and the ridged construction thereof. Material passing through the concave further back falls onto the return pan 44 and is conveyed forwardly by the oscillating motion and ridged construction thereof as shown by arrow C.

[0060] It is noted that "forwardly" and "rearwardly" refer to direction relative to the normal forward direction of travel of the combine harvester.

[0061] When the material reaches a front edge of the return pan 44 it falls onto the stratification pan 42 and is conveyed as indicated by arrow B.

[0062] The combined crop streams thus progress rearwardly towards a rear edge of the stratification pan 42. Whilst conveyed across the stratification pan 42, the crop stream, including grain and MOG, undergoes stratification wherein the more dense grain sinks to the bottom layers adjacent stratification pan 42 and the lighter and / or larger MOG rises to the top layers.

[0063] Upon reaching the rear edge of the stratification pan 42, the crop stream falls onto the chaffer 54 which is also driven in a fore-and-aft oscillating motion. The chaffer 54 is of a known construction and includes a series of transverse ribs or louvers which create open channels or gaps therebetween. The chaffer ribs are angled upwardly and rearwardly so as to encourage MOG rearwardly whilst allowing the grain to pass through the chaffer onto an underlying second sieve 56.

[0064] The chaffer 54 is coarser (with larger holes) than second sieve 56. Grain passing through chaffer 54 is incident on the lower sieve 56 which is also driven in an oscillating manner and serves to remove tailings from the stream of grain before being conveyed to the on-board bin by the filling auger 70 which resides in a transverse trough 72 at the bottom of the grain cleaning unit 50. Tailings blocked by sieve 56 are conveyed rearwardly by the oscillating motion thereof to a rear edge from where the tailings are directed to the returns auger 60 for reprocessing in a known manner. The grain is for example smaller and denser and generally more aerodynamic than MOG, therefore, less susceptible to being conveyed rearward by the chaffer / sieve and / or blown out of the rear of the machine by the air stream of the cleaning fan, passing upward and rearward, through the chaffer.

[0065] All material which has not been collected by the filling auger 70 or returns auger exits the back of the combine harvester and passes to a chaff spreader. The chaff spreader receives the rejected material from the cleaning shoe. It is also known to provide a straw chopper and straw spreader for the straw output by the separating apparatus, such as the straw walker. The chaff spreader and straw chopper and spreader are shown schematically in Figure 1 as the residue management unit 90. This disclosure relates in particular to the design of the spreader of the residue management unit.

[0066] Figure 3 shows a conventional straw spreader, viewed from beneath. The straw spreader is downstream of a straw chopper, which is not shown.

[0067] The straw spreader has an an inlet area 100 for receiving MOG, in particular chopped straw from a straw chopper, but it may also receive chaff from a chaff spreader downstream of the cleaning shoe of the combine. First and second rotary spinners 102, 104 are provided at opposite lateral sides of the straw spreader for receiving MOG from the input area 100 and distributing the MOG from an outlet area 110. The spinners 102, 104 rotate in opposite directions, to accelerate the straw and deliver it along an output channel 102a, 104a. Each output channel is defined by a respective deflector 112b, 112a.

[0068] Each of the deflectors 112a, 112b in this example has an inlet portion 120 and an outlet portion 122 (labelled only for the deflector 112a). The two portions are coupled by a hinge. The inlet portion is fixed but the angle between the two portions may be adjusted so that the direction faced by the outlet portion is adjustable. The deflector may be fixed in the chosen shape by fixing bolts. The adjustment of the shape is enabled by guide slots 124 which follow an arcuate path centered on the hinge point.

[0069] Figure 3 also shows four further deflectors between the deflectors 112a, 112b, which define between them (and the outer deflectors 112a, 112b) five further channels. These provide a flow of material towards a central area, but without the assistance of the spinners. The central channel splits into two, so that there are six outlet channels between the deflectors 112a, 112b, and one laterally outermost flow channel for each of the spinners. The divider for the central channel is also adjustable, so that the angle between the two ramp surfaces in the center can be adjusted.

[0070] The four further deflectors may also be adjusted. In the example shown, they pivot about their inlet end, and guide slots are again shown along which the deflectors are moved and clamped into their desired positions.

[0071] It is known to enable adjustment of the deflectors into desired static positions, to implement a desired output spread of material. It is also known to provide an actively driven adjustment of the deflector positions, to implement what is described in this document as an "oscillatory spreading arrangement". Such oscillatory driving may be applied to deflectors of a straw spreader or to deflectors of a chaff spreader, or indeed the output direction faced by fans of a chaff spreader may be adjusted (instead of adjusting deflector positions).

[0072] Figure 4A shows the output flow directions from an active straw spreader such as shown in Figure 3. Channels between adjacent deflectors provide an output flow in a particular direction, and in combination these channels aim to provide an even (static) distribution of material.

[0073] Figure 4B shows the output flow directions from an active straw spreader with an oscillatory spreading arrangement. As shown, a simpler deflector arrangement is used in this example. Active control of the deflector arrangement creates a dynamic oscillatory output distribution as represented by arrows 130.

[0074] Figure 5 shows the material distribution generated by the known oscillatory straw spreader. Figure 5 shows a straw chopper 200 that delivers chopped straw to a straw spreader 202. The straw spreader has two spinners 204,206 each feeding a deflector arrangement. The deflector arrangement is driven with an oscillatory drive so that two serpentine paths 210 of material are formed. The two paths are directed to the left and to the right at the same time. This design results in areas 212 where the distributed material density is lowest, and the uniformity may be lower than desired.

[0075] Figure 6 shows the material distribution generated by the spreading system 300 of the invention. The spreading system 300 has a first oscillatory spreading arrangement for distributing material from a first output to follow a first oscillatory path 310 and a second oscillatory spreading arrangement for distributing material from a second output to follow a second oscillatory path 312. The first and second oscillatory paths 310, 312 are interleaved with each other.

[0076] Each path 310, 312 comprises two path portions, one at each side and created by a respective fan unit. Each path portion is a serpentine track, for example an S-shaped track. The interleaving means that residue material is distributed with increased uniformity. In this arrangement, each oscillatory path comprises two serpentine S-shaped tracks, which each oscillate between laterally outermost (i.e., left or right) and laterally innermost (i.e., central) positions.

[0077] The path portions (i.e., tracks) of each individual path are in phase with each other in this example.

[0078] The first and second oscillatory spreading arrangements are however preferably driven 180 degrees out of phase with respect to each other. Thus, the oscillatory paths are 180 degrees out of phase. When one path portion is at its laterally outermost position, a corresponding path portion of the spreading arrangement is at its laterally innermost position, so that material is added by one spreading arrangement to the locations where the material density delivered by the other spreading arrangement is a minimum.

[0079] The spreading system may be implemented in various ways, based on a modification to a straw spreader or based on the combination of a straw spreader and a chaff spreader.

[0080] Figure 7 shows a first implementation of the spreading system of Figure 6. The spreading system comprises a straw chopper 200, a straw spreader 202 and a chaff spreader 400.

[0081] In this example, the first oscillatory spreading arrangement comprises a straw spreader 202 and the second oscillatory spreading arrangement comprises a chaff spreader 400. The straw spreader delivers chopped straw to a first output and the chaff spreader delivers chaff to a second output. Thus, the spreading system combines a straw spreader and a chaff spreader, and they are both driven in an oscillatory manner each to deliver a serpentine distribution of residue material. The straw spreader may then be a conventional oscillatory straw spreader, and the chaff spreader is also driven in an oscillatory way. The two units are operated in a coordinated (and out of phase) way to deliver the more uniform combined flow.

[0082] The straw spreader for example comprises a pair of fan units 204, 206 and a straw spreader deflector arrangement. The straw spreader deflector arrangement is driven with an oscillatory movement. The chaff spreader for example also comprises a pair of fan units 402, 404.

[0083] In one implementation of the chaff spreader, the fan units 402, 404 of the chaff spreader have outputs which are driven to face different directions with an oscillatory movement. In this way, the entire chaff spreader housing can be rotated using an actuator, and the actuator can be driven to move continuously, thereby providing an oscillatory movement. The actuator may be electric or may use hydraulic cylinders or a hydraulic motor combined with a crankshaft mechanism.

[0084] In another implementation of the chaff spreader, the chaff spreader comprises a chaff spreader deflector arrangement which is driven with an oscillatory movement (in a similar manner to the straw spreader explained above).

[0085] Figure 8 shows a second example in which the first oscillatory spreading arrangement comprises a first straw spinner arrangement 204a, 206a of a straw spreader 202 and the second oscillatory spreading arrangement comprises a second spinner arrangement 204b, 206b of the straw spreader.

[0086] In this example, a single straw spreader 202 provides the two separate material flows by having two separate spinner (and associated deflector) arrangements. They are for example stacked one above the other, so they can rotate on the same axis and be driven by a shared drive.

[0087] The straw spreader may again comprise a pair of fan units. A first fan unit 204 comprises a first spinner 204a and a second spinner 204b, and a second fan unit 206 comprises a first spinner 206a and a second spinner 206b. The first spinner arrangement (which delivers the first serpentine material flow) thus comprises the combination of the two first spinners 204a, 206a and the second spinner arrangement (which delivers the second serpentine material flow) comprises the combination of the two second spinners 204b, 206b.

[0088] Figure 9 shows a first example of an implementation of the spreading system ofFigure 8 in more detail and shows only the first fan unit. The first fan unit has a first spinner 204a and a second spinner 204b. They are stacked so rotate about a common drive axis.

[0089] The first spinner 204a delivers material to a first deflector arrangement 208a and the second spinner 204b delivers material to a second deflector arrangement 208b. The two deflector arrangements are driven in the out-of-phase oscillatory way explained above. The first deflector arrangement defines a first output and the second deflector arrangement defines a second output.

[0090] A linkage system couples the deflector arrangements, so that a single oscillatory drive signal can be used to control the overall spreading system. Each spinner thus has its own associated deflector arrangement, so the system is in the form of two straw spreaders stackedone above the other. A linkage system is for example used so that only one oscillatory drive signal can control both straw spreaders in out-of-phase manner.

[0091] The example of Figure 9 has an upper spinner 204a that spreads the chopped straw from the chopper 200, and a lower spinner 204b that spreads the chaff (fed by the chaff spreader).

[0092] Figure 10 shows a second example of an implementation of the spreading system of Figure 8 in which the upper and lower spinners 204a, 204b each receive a flow comprising a mix of chopped straw and chaff. Thus, the combined chopped straw and chaff flow is split into upper and lower regions.

[0093] The invention may be applied to any design of combine harvester. Thus, it does not rely on any particular threshing, separating or cleaning design, and the examples above are only given to aid overall understanding.

[0094] Within the scope of this application it should be understood that the various aspects, embodiments, examples and alternatives set out herein, and individual features thereof may be taken independently or in any possible and compatible combination. Where features are described with reference to a single aspect or embodiment, it should be understood that such features are applicable to all aspects and embodiments unless otherwise stated or where such features are incompatible.

[0095] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0096] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0097] Any reference signs in the claims should not be construed as limiting the scope.

[0098] All references cited herein are incorporated herein in their entireties. If there is a conflict between definitions herein and in an incorporated reference, the definition herein shall control.

Claims

CLAIMSWhat is claimed is:

1. A spreading system for a combine harvester, comprising: a first oscillatory spreading arrangement (204,206; 204a, 206a) for distributing material from a first output to follow a first oscillatory path (310); and a second oscillatory spreading arrangement (402,404; 204b, 206b) for distributing material from a second output to follow a second oscillatory path (312), wherein the first and second oscillatory paths are interleaved with each other.

2. The spreading system of claim 1, wherein the first and second oscillatory spreading arrangements are driven 180 degrees out of phase with respect to each other.

3. The spreading system of claim 1 or 2, wherein the first oscillatory spreading arrangement comprises a straw spreader (202) and the second oscillatory spreading arrangement comprises a chaff spreader (400).

4. The spreading system of claim 3, wherein the straw spreader comprises a pair of fan units (204, 206) and a straw spreader deflector arrangement, wherein the straw spreader deflector arrangement is driven with an oscillatory movement, and wherein the chaff spreader comprises a pair of fan units (402, 404).

5. The spreading system of claim 4, wherein the fan units of the chaff spreader have outlets which are driven to face different directions with an oscillatory movement.

6. The spreading system of claim 4, wherein the chaff spreader comprises a chaff spreader deflector arrangement which is driven with an oscillatory movement.

7. The spreading system of claim 1 or 2, wherein the first oscillatory spreading arrangement comprises a first straw spinner arrangement (2041a, 206a) of a straw spreader and the second oscillatory spreading arrangement comprises a second spinner arrangement (2204b, 206b) of the straw spinner.

8. The spreading system of claim 7, wherein the straw spreader comprises a pair of fan units, each having a first spinner (204a) and associated first deflector arrangement (208a) and a second spinner (204b) and associated second deflector arrangement (208b).

9. A combine harvester comprising: a crop cutting head; a threshing and separating system; a grain cleaning apparatus; a straw chopper for cutting MOG received from the threshing and separating system; and the spreading system of any one of claims 3 to 6 for receiving a straw flow from the straw chopper and receiving a chaff flow from the grain cleaning apparatus and distributing the cut straw and the chaff.

10. A combine harvester comprising: a crop cutting head; a threshing and separating system; a straw chopper for cutting MOG received from the threshing and separating system;and the spreading system of any one of claim 7 or 8 for receiving a straw flow from the straw chopper and distributing the cut straw.

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