Agricultural mulching apparatus

Abstract

An agricultural stubble mulching machine comprising a roller assembly having at least three blade sets extending transversely side by side thereacross, each of said blade sets having a plurality of transversely disposed blades substantially evenly spaced around the circumference of said roller assembly, wherein the blades of at least some of said blade sets are disposed staggered relative to each other so as to alternately operate as said roller assembly rotates.

Description

Agricultural M ulching ApparatusField of the Invention

[0001] This invention relatesto agricultural mulching and in particular the mulching of stubble in broad acre farming.Background

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.

[0003] Current continuous cropping practises and in particular the development of new high yielding varieties that grow taller, producing lofty stubble heights, has created a stubble handling issues for farmers. As it is not possible to seed into high stubble loads, the stubble must be dealt with before seeding can take place.

[0004] Practises dealing with stubble have involved burning stubble, soil tillage, or slashing the stubble. Burning stubble is dangerous as it must be dry, which can lead to the risk of fire getting out of control. Apart from the risk of damage due to fire getting out of control, there is the risk of damage to the soil biota adversely affecting soil fertility, and damage to soil structure leading to wind erosion. Fire pollutes the environment, and its use utilises a lot of valuable time and resources.

[0005] Slashing is an expensive operation and requires maintenance of equipment uses in the slashing operations. Sashing also carries with it a high risk of starting fires.

[0006] Heavy soil tillage is a costly operation, causes so 11 erosion, and increased weed germination. It hasbeen found that soil tillage doesn't mulch stubble adequately, which causes seeding machines to block.

[0007] Alternatively, stubble could be harvested short, but this is very time consuming, and expensive due to the cost of machinery and fuel. In addition, harvesting in a manner that leaves stubble shorter doesn’t eliminate seeding machine blockage issues.

[0008] It is an object of the invention to provide a machine that can efficiently mulch stubble and provide a viable alternative to the practices referred to above.

[0009] Throughout the specification unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.Summary of Invention

[0010] In accordancewith the present invention there isprovided an agricultural stubble mulching machine including a roller assembly having at least three blade sets extending transversely side by side thereacross, each of said blade sets having a plurality of transversely disposed blades arranged radially and substantially evenly spaced around the circumference of said roller assembly, wherein the blades in each blade set are disposed linearly and parallel to a central axis of said roller assembly and parallel to each other, wherein the blades of at least some of said blade sets are disposed staggered relative to each other so as to alternately operate as said roller assembly rotates, and wherein the bladesof said at least three blade setsare arranged with mirror image symmetry about a radial plane normal to said central axis, said radial plane located at a center of the transverse extent of said blade sets.

[0011] The blades in said at least three blade sets being arranged with mirror image symmetry about a radial plane normal to said central axis, with said radial plane located at a center of the transverse extent of said blade sets results in the blades as they operate causing substantially equal drag on both sides of the radial plane. This balances the roller assembly and minimises transverse sway of the roller assembly, which minimises energy losses, which would otherwise result in increased fuel use by the motive vehicle..

[0012] Preferably the blades of adjacent said blade sets are disposed staggered relative to each other so as to alternately operate as said roller assembly rotates.

[0013] Preferably said roller assembly has three blade sets comprising a centrally located blade set extending across substantially half of thetransverse extent of said roller assembly and two outer blade sets each extending across substantially a quarter of the transverse extent of said roller assembly. The blades of said outer blade sets are disposed staggered relative to said blades of said centrally located blade set but not disposed staggered relative to each other. In this manner the blades on the blade sets are evenly staggered so that at any one time only half of the blades at the bottom of the roller assembly are in operational contact with the ground. This arrangement can be considered as a14- 4 - V+configuration with the outer blade sets being out of phase relative to the centrally located blade set. The same arrangement can be configured with the center half split into two to provide a 14 -14-14-14configuration with the two center blade sets being in phase (i.e. not staggered relative to each other) and the two outer blade sets being in phase with each other and out of phase with the two center blade sets (i.e. not staggered relative to each other but staggered relative to the two center blade sets). This has an advantage of saving manufacturing costs since identical length (width) bladescan be used for all of the blade sets. In all cases the blade sets extend ent I rely from one end of the roller assembly to the other end, with no gaps in coverage, so all stubble in the path of the roller assembly will be mulched.

[0014] Alternatively said roller assembly has five blade sets comprising a centrally located blade set extending across one sixth of the transverse extent of said roller assembly and two outer blade sets each extending across one sixth of the transverse extent of said roller assembly, and two intermediate blade sets each extending across one quarter of the transverse extent of said roller assembly, each intermediate blade set being located between the centrally located blade set and one of said two outer blade sets and each intermediate blade set. The blades of the intermediate blade sets are disposed staggered relative to the blades of the centrally located blade set and the two outer blade sets and the blades of the centrally located blade set and the two outer blade sets are not staggered relative to each other. Aswith the previous arrangement, thebladeson the blade sets are evenly staggered so that at any one time only half of the blades at the bottom of the roller assembly are in operational contact with the ground. This arrangement can be considered as a 1 / 6 -'A- 1 / 6 -1A- 1 / 6 configuration with the intermediate blade sets being out of phase relative to the centrally located blade set and the outer blade sets.

[0015] As another alternative, said roller assembly has seven blade sets comprising a centrally located blade set extending acrossone sixth of the transverse extent of said roller assembly and two outer blade sets each extending across one eighth of the transverse extent of said roller assembly, and two first intermediate blade sets each extending across one eighth of the transverse extent of said roller assembly, each first intermediate blade set being located next to the centrally located blade set on either side thereof, and two second intermediate blade sets each extending acrossone sixth of the transverse extent of said roller assembly and each located between one of said first intermediate blade sets and one of said two outer blade sets. The bladesof the first intermediate blade sets and outer blade sets are disposed staggered relative to the blades of the centrally located blade set and the second intermediate blade sets. The blades of the first intermediate blade sets and outer blade sets not staggered relative to each other and the blades of the centrally located blade set and the second intermediate blade sets are not staggered relative to each other. As with the previous arrangements, the blades on the blade sets are evenly staggered so that at any one time only half of the blades at the bottom of the roller assembly are in operational contact with the ground. This arrangement can be considered as a 1 / 8 - 1 / 6 - 1 / 8 - 1 / 6 - 1.8 - 1 / 6 - 1 / 8 configuration with the intermediate blade sets being out of phase relative to the centrally located blade set and the outer blade sets.

[0016] All of the above described arrangements have the blades of the alternate blade sets arranged half out of phase. Other arrangements are possible including for example, a 1 / 6 - 1 / 6 -1 / 3 - 1 / 6- 1 / 6 configuration with the bladesof adjacent blade sets being arranged one third out of phase, just as long as the mirror symmetry is maintained about the radial plane through the center of the transverse extent of said blade sets.

[0017] Preferably the blades are spaced circumferentially from 100mm to 150mm apart. This distance is as measured at the base of the blades as opposed to the cutting tips thereof.

[0018] Preferably the blades are spaced circumferentially from 110mm to 140mm apart.

[0019] Preferably the blades are spaced circumferentially from 120mm to 130mm apart.

[0020] Preferably the blades are spaced circumferentially about 125mm apart.

[0021] Preferably the blades are fitted to a cylindrical drum assembly.

[0022] Preferably said cylindrical drum assembly includes a plurality of radial blade mounts, for mounting each blade.

[0023] Preferably each said blade is mounted on one of said radial blade mounts by bolts, and preferably also with locking nuts, preferably so as to be detachable for replacement if necessary.

[0024] Preferably the blades have a radial height of from 80mm to 150mm.

[0025] Preferably the blades have a radial height of from 90mm to 140mm.

[0026] Preferably the blades have a radial height of from 100mm to 130mm.

[0027] Preferably the blades have a radial height of from 110mm to 120mm.

[0028] Preferably the blades are formed from a structural steel having wear resistance. A 450 grade steel such as Hardox ™450 is suitable. A blade thickness of from 8mm to 15mm is preferred, more preferably fro 10mm, and most preferably about 12mm. The edge of the blade is preferably formed with a bevel, preferably of from 40 degreesto 50 degrees, with the acute angle being the leading edge of the blades on the blade sets. The blade may be considered to have a forward face extending from the leading edge down to the base of the blade proximal to the cylindrical drum assembly, and a rearward face extending from the obtuse angle of the bevel down to the base of the blade proximal to the cylindrical drum assembly, The bevel is ideally 45 degrees in the most preferred arrangement, and this has been found in trials, to be self-sharpening. This is believed to be because as the roller assembly is moved forward, any retained soil falls off the back of the blade and across the bevel and over the leading edge, then falling to the ground. The thickness of the blade should be sufficient to allow the formation of the bevel, but not so thick as to impose additional fabrication costs.

[0029] Preferably the blade mounts are located with their central extents extending radially from the central axis of the roller assembly, and each of said blades is mounted to the back each blade mount. In this manner, the forward face of each blade extending between the base of each blade and the leading edge is disposed forward of the base at the face of each blade, with respect to the direction of travel. Thus, the blades lean slightly into the direction of travel.

[0030] Preferably said agricultural stubble mulching machine includes a towable frame to which said roller assembly is transversely mounted. The towable frame may comprise a central frame to which said roller assembly is mounted and include two outrigger frameseach mounting an outrigger roller assembly. Thus, in a preferred arrangement there is provided a central roller assembly and two outrigger roller assemblies, one each side of the central roller assembly. Still further, the outrigger frames are arranged in line, trailing the central frame.

[0031] The outrigger frames may each be disposed on pivoting mounts and may be hydraulically actuable between a folded stowed position in which the axis of the outrigger rollers lies transverse to the axis of said roller assembly, and an extended deployed position in which the axis of the outrigger rollers extends in the same direction asthe roller assembly axis.

[0032] Preferably the towable frame includes wheel assemblies which may be raised for deployment of the roller assembly and lowered to elevate said roller assembly to allow it to be transport ed.

[0033] Preferably said outrigger frames include a wheel assembly with awheel axis transverse to the outrigger roller axis, the outrigger frame wheel assemblies being arranged to be raised for deployment of each outrigger roller assembly and lowered to elevate each said outrigger roller assembly to allow it to be transported. When being transported, the outrigger frames will be disposed on pivoting mounts in thefolded stowed position. With the outrigger framesare arranged trailing the central frame, the width of the stowed outrigger frames and outrigger rollers may be substantially no wider than the width of the central frame and its roller assembly, which can be of a width suitable for road transport, towed behind a tractor of the like.

[0034] In accordance with a second aspect of the present invention there is provided an agricultural stubble mulching machine including a roller assembly having a blade set extending transversely, said blade set having a plurality of transversely disposed blades arranged radially and substantially evenly spaced around the circumference of said roller assembly, wherein the blades in said blade set are disposed linearly and parallel to a central axis of said roller assembly and parallel to each other, wherein each of said blades has a transverse edge formed with a bevel, preferably of from 40 degrees to 50 degrees, with the acute angle being the leading edge of the blades on the blade set.

[0035] Preferably the blades are fitted to a cylindrical drum assembly.

[0036] Preferably said cylindrical drum assembly includes a plurality of radial blade mounts, for mounting each blade.

[0037] Preferably each said blade is mounted on one of said radial blade mounts by bolts, and preferably also with locking nuts, preferably so as to be detachable for replacement if necessary.

[0038] Preferably the blades have a radial height of from 80mm to 150mm.

[0039] Preferably the blades have a radial height of from 90mm to 140mm.

[0040] Preferably the blades have a radial height of from 100mm to 130mm.

[0041] Preferably the blades have a radial height of from 110mm to 120mm.

[0042] Preferably the blades are formed from a structural steel having wear resistance. A 450 grade steel such as Hardox ™450 is suitable. A blade thickness of from 8mm to 15mm is preferred, more preferably from 10mm, and most preferably about 12mm. The edge of the blade is formed with a bevel of from 40 degrees to 50 degrees, with the acute angle being the leading edge of the blades on the blade sets. The blade may be considered to have a forward face extending from the leading edge down to the base of the blade proximal to the cylindrical drum assembly, and a rearward face extending from the obtuse angle of the bevel down to the base of the blade proximal to the cylindrical drum assembly, The bevel is ideally 45 degrees in the most preferred arrangement, and this has been found in trials, to be self-sharpening. This is believed to be because as the roller assembly is moved forward, any retained soil falls off the back of the blade and across the bevel and over the leading edge, then falling to the ground. The thickness of the blade should be sufficient to allow the formation of the bevel, but not so thick asto impose additional fabrication costs.

[0043] Preferably the blade mounts are located with their central extents extending radially from the central axis of the roller assembly, and each of said blades is mounted to the back each blade mount. In this manner, the forward face of each blade extending between the base of each blade and the leading edge is disposed forward of the base at the face of each blade, with respect to the direction of travel. Thus, the blades lean slightly into the direction of travel.Brief Description of Drawings

[0044] In order to provide a better understanding, a preferred embodiment of the present invention will be described, by way of example only, with reference to the accompanying drawings, in which:Figure 1 is an isometric schematic view of a towable agricultural stubble mulching machine according to the embodiment, shown in a stowed configuration for transport;Figure 2 is an isometric schematic view of the towable agricultural stubble mulching machine of figure 1, shown in a deployed configuration for towing to mulch stubble in a field, post harvest; Figure 3 is an isometric view of part the towable agricultural stubble mulching machine of figure 2, showing greater detail;Figure 4 is a side plan view of part the towable agricultural stubble mulching machine of figure 2; Figure 5 is a side plan view of Detail A of figure 4;Figure 6 is a side plan view of one stubble mulching roller, being a side roller part of the towable agricultural stubble mulching machine according to the embodiment;Figure 7 is an isometric view of the stubble mulching roller of figure 6 and 7;Figure 8 is a top plan view of the stubble mulching roller of figure 6;Figure 9 is a transverse cross-section view across section A-A of figure 6;Figure 10 is a cross-section view of the stubble mulching roller of figure 6 and 7, through section B-B;Figure 11 is a cross-section view of the stubble mulching roller of figure 6 and 7, through section C-C;Figure 12 is a cross-section view of the stubble mulching roller showing Detail Eof figure 10; Figure 13 is a cross-section view of the stubble mulching roller showing Detail D of figure 11; Figure 14 is a side view of part of the mount for the stubble mulching roller;Figure 15 is a cross-section view through section F-Fof figure 14:Figure 16 is a side view of another part of the mount for the stubble mulching roller;Figure 17 is a cross-section view through section G-Gof figure 16;Figure 18 is a side view of the axle mount for the stubble mulching roller;Figure 19 is a cross-section view through section H-H of figure 18;Figure 20 is an isometric view of another stubble mulching roller, being a central roller part of the towable agricultural stubble mulching machine according to the embodiment;Figure 21 is a top plan view of the stubble mulching roller of figure 20;Figure 22 is a transverse cross-section view of the stubble mulching roller of figure 21;Figure 23 is a third angle orthographic projection of the blades and blade mounts for the stubble mulching roller of figure 20; andFigure 24 is a third angle orthographic projection of the blades and blade mounts for the stubble mulching roller of figure 7.Description of Embodiments

[0045] Referring to figure 2, the towable agricultural stubble mulching machine 11 is shown in a deployed configuration for towing to mulch stubble in a field after a crop has been harvested. The stubble mulching machine 11 has a towable central frame 13 to which a roller assembly 15 is mounted for rotation about an axis 17 transverse to the tow direction. An A-frame draw bar 19 is pivotally mounted to the central frame 13, and has a towing point 21 at its apex 23, the towing point 21 provided for attaching to a tow hitch of a vehicle such as a tractor.

[0046] The central frame 13 has two pairs of wheel assemblies 2527 each pair of wheel assemblies 2527 being located either side of the center-line of the tow direction. The pairs of wheel assemblies 25 and 27 are each raised to a deployed position as shown in figure 2 and may be lowered as shown in figure 1 for transport. When lowered, the pairs of wheel assemblies 25 and 27 lift the roller assembly 15 clear of the ground, so that it does not contact the ground when being transported.Raising and lowering of the pairsof wheel assemblies 25 and 27 takes place under control of double acting hydraulic rams (not shown).

[0047] The central frame 13 includes on each side and trailing the roller assembly 15, a pivoting mount 29 with an upright / vertical axis to which of each is mounted an outrigger frame 31 33 each having an outrigger roller 35 37. The outrigger frames 31 33 may pivot between the extended deployed position as shown in figure 2 and a folded stowed position for transport as shown in figure 1, each under control by a double acting hydraulic ram (not illustrated) extending between each outrigger frame 31 and 33 and the central frame 13. The outrigger frames 31 and 33 are mirror imagesof each other, but in other respects are identical.

[0048] Located at the outer ends of the outrigger frames 31 33 are a pair of wheel assemblies 39 41 which may be pivoted to a raised position as shown in figure 2, when the stubble mulching machine is in use, and to a lowered position as shown in figure 1, to lift the outrigger rollers 3537 clear of the ground for transport. Ordinarily, the pair of wheel assemblies 39 41 would only be pivoted to the lowered position when the outrigger frames 31 33 are to be placed in the folded stowed position. Pivoting between the raised position and the lowered position takes place under control of double acting hydraulic rams4345.

[0049] Referring to figure 3, the stubble mulching machine 11 is shown in greater detail, in a deployed configuration for towing to mulch stubble in a field after a crop has been harvested. For clarity, some details have been omitted.

[0050] Referring to figures 7 and 8, the outrigger roller assemblies 35 37 are shown. These are identical to each other in their construction. The outrigger roller assemblies 33 and 35 comprise a cylindrical drum 47 of steel having a diameter of 610mm and wall thickness of 12mm. The outrigger roller assemblies 35 and 37 have three blade sets located radially therearound being a centrally located blade set 51 extending across substantially half of the transverse extent of the outrigger roller assembly 35, 37, and in the centre thereof, and two outer blade sets 53, 55 each extending across subst anti ally a quart er of the transverse extent of the outrigger roller assembly 3537 located at either side / end of the centrally located blade set 51, so that all three blade sets extend transversely side by side across the outrigger roller assemblies 35 and 37.

[0051] Each of said blade sets 51 5355 have a plurality of transversely disposed blades 59 61 63 located substantially evenly spaced around the circumference of the outrigger roller assembly 35 37. There are fifteen blades in each blade set 51, 53, 55, and the blades of each set are arranged radially at 24 degrees apart. The blades in each blade set are disposed linearly and parallel to a central axis of the roller assembly, and parallel to each other. The arrangement is such that the tips of the blades are nominally spaced at about 150 mm which is considered to result in an ideal stubble cut length for stubble from harvested crops grown in Western Australia. These dimensions may vary for stubble from different types of crop, necessitating different dimensions in the rollers and blades.

[0052] The blades 59 of the centrally located blade set 51 are disposed staggered by 12 degrees relative to the blades 61 and 63 of the outer blade sets 53 and 55 respectively. There is no staggering of the blades 61 of the outer blade set 53 compared with the blades 63 of the outer blade set 55. Figure 6 shows an end view of the outrigger roller assemblies 3537 with the nearer blades 61 of the outer blade set 53 and the blades 59 of the centrally located blade set 51 visible. In this view, the blades 63 of the outer blade set 55 are occulted by the blades 61 of the outer blade set 53, and so are not visible.

[0053] With the blades 59 of the centrally located blade set 51 disposed staggered by 12 degrees relative to the blades 61 and 63 of the outer blade sets 53 and 55 respectively, the blades 59 of the centrally located blade set 51 alternately operate relative to the blades 61 and 63 of the outer blade sets 53 and 55, as the outrigger roller assemblies 35 37 rotate. In this manner the blades on the blade sets are evenly staggered so that at any one time only half of the blades at the bottom of the roller assembly are in operational contact with the ground.

[0054] The outrigger roller assemblies 35 and 37 are mounted for rotation on axles 65 located along the central transverse axis of the drum 47. The axles 65 are mounted in spaced apart radial mounts 67 and 69 having locating bosses 71 located inside the drum 47. A pin 73 in the form of a bolt (and nut) located through an aperture 75 in the boss 71 and through an aperture 77 in the axle 65, secures the axle 65 to the outrigger roller assemblies 35 37.

[0055] Figure 10 is a view through section B-B of figure 8 and shows the blades 61 of the outer blade set 53 in greater detail. The blades 61 are made of 12mm x 114mm 450 grade steel and arefabricated with a 45 degree bevel 78 at the transverse edge. The blades 61 are each bolted 79 to a blade mount 81 formed of 50mm high x 16mm thick 300 grade steel which extends for the length of the blade 61 and is welded to the drum 47. The arrangement of the blades 61 is such that the tip 83 at the acute angle forms the leading edge of the stubble mulching machine 11 as it is towed during operation.

[0056] The arrangement of the blades 63 in the outer blade set 55 and their mounting to the drum 47 is identical to that of the blades 61 of the outer blade set 53.

[0057] Figure 11 is a view through section C-C of figure 8 and shows the blades 59 of the centrally located blade set 51 in greater detail. The mounting of the blades 59 to a blade mount 85 is identical to the manner in which the blade of the outer blade sets is mounted, save for rotational pitch difference, the length of the blade mounts 85 being longer commensurate with the length of the blades 59, and a larger number of bolts being used to secure the blades 59.

[0058] Referring to figures20 to 22, the roller assembly 15 of the central frame 13 is shown. This will be referred to as the central roller assembly 15, for brevity. Construction of the central roller assembly 15 is similar to that of the outrigger roller assemblies 33 and 35, apart from the length of the cylindrical drum 47 being 3130mm, compared with the drum length of the outrigger roller assemblies 33 and 35 being 4900mm. In view of this, like numbering is used for like parts.

[0059] The central roller assembly 15 has a cylindrical drum 47 of steel having a diameter of 610mm and wall thickness of 12mm. The central roller assembly 15 has three blade sets located radially therearound being a centrally located blade set 91 extending across substantially half of the transverse extent of the central roller assembly 15, and in the centre thereof, and two outer blade sets 93, 95 each extending across substantially a quarter of the transverse extent of the central roller assembly 15 located at either side / end of the centrally located blade set 91, so that all three blade sets extend transversely side by side across the central roller assembly 15.

[0060] Each of said blade sets 91 93 95 have a plurality of transversely disposed blades located substantially evenly spaced around the circumference of the central roller assembly 15. There are fifteen blades in each blade set 91, 93, 95, and the blades of each set are arranged radially at 24 degrees apart. The blades 59 61 63 in the blade sets 91, 93, 95, respectively, in the central rollerassembly 15 are identical save for their transverse length to the blades 59 61 63 in the blade sets 51, 53, 55, respectively, in the outrigger roller assemblies 3537.

[0061] The blades 59 of the centrally located blade set 91 are disposed staggered by 12 degrees relative to the blades 61 and 63 of the outer blade sets 93 and 95 respectively. There is no staggering of the blades 61 of the outer blade set 93 compared with the blades 63 of the outer blade set 95. Figure 6 referred to previously, shows an end view of the outrigger roller assemblies 3537 with the nearer blades 61 of the outer blade set 53 and the blades 59 of the centrally located blade set 51 visible. In this view, the blades 63 of the outer blade set 55 are occulted by the blades 61 of the outer blade set 53, and so are not visible. The arrangement of equivalent blades in the central roller assembly 15 is identical.

[0062] With the blades 59 of the centrally located blade set 91 are disposed staggered by 12 degrees relative to the blades 61 and 63 of the outer blade sets 93 and 95 respectively, the blades 59 of the centrally located blade set 91 alternately operate relative to the blades 61 and 63 of the outer blade sets 93 and 95, as the central roller assembly 15 rotates. In this manner the blades on the blade sets are evenly staggered so that at any one time only half of the blades at the bottom of the roller assembly are in operational contact with the ground.

[0063] The central roller assembly 15 is mounted for rotation on axles 97 located along the central transverse axis of the drum 47. The axles 97 are mounted to the drum 47 in the same manner as axles 65 are mounted to the drums 47 of the outrigger roller assemblies 3537.

[0064] The detail of the blades in the central roller assembly 15 is the same as shown in figures 10 to 13, and as described with respect to the outrigger roller assemblies 35 37.

[0065] In both the central roller assembly 15 and the outrigger roller assemblies 35 and 37, the blades 59, 61, and 63 are formed with a 45 degree bevel 78 at the transverse edge. The arrangement of the blades 61 is such that the tip 83 at the acute angle forms the leading edge of the stubble mulching machine 11 as it is towed during operation. Referring to figure 13, the blades 59, 61, and 63 may be considered to have a forward face 99 extending from the tip 83 at the leading edge down to the base 101 of the blades 59, 61, and 63 proximal to the drum 47 of the cylindrical drum assembly, and a rearward face 103 extending from the obtuse angle 105 of the bevel 47 down to the base 101 of the blades 59, 61, and 63 proximal to the drum 47 of the cylindrical drum assembly.The bevel 78 and tip 83 has been found in trials, to be self -sharpening. This is believed to be because as the roller assembly is moved forward, any retained soil falls off the backs 103 of the blades 59, 61, and 63 and across the bevel 78 and over the tip 83 at the leading edge, then falling to the ground.

[0066] The blade mounts 81 and 85 are located with their central extents (shown as line A-A in figure 6) extending radially from the central axis of the roller assembly, and each of said blades 59, 61, and 63 is mounted to the back of each blade mount 81, 85. In this manner, the forward face 99 of each blade extending between the base 101 of each blade 59, 61, and 63 and the leading edge 83 is disposed forward of the base 101 at the face 99 of each blade, with respect to the direction of travel. Thus, the blades 59, 61, and 63 lean slightly into the direction of travel.

[0067] While the blades in the embodiment are described as being made from 12mm thick 450 grade steel, depending on the nature of the soil, a thinner steel may be suitable (subject to the bevel edge being able to be maintained during operation), and in some cases 16mm thick steel sheet may be suitable, although lesspreferred due to increased fabrication costs.

[0068] The invention provides a heavy-duty agricultural stubble mulching machine that cuts stubble into 125mm pieces. This assists in processing the retained stubble to mulch so it can be returned to soil at a faster rate.

[0069] It is considered important, at least where the inventor has trialled the machine, that the blades, their location and spacings and staggering where they are bolted to the drums is important to operation of the machine. The blades are made of 12mm x 114mm 450 grade steel; they are laser cut and a 45-degree bevel is applied. This selection of material for the blades is important as it needsto be hard wearing, but not brittledue to the extreme conditionsthat the machine invariably needsto work in.

[0070] The 45-degree bevel is important as it needsto cut the stubble and retain its shape which is achieved by the following. The position the blade enters the ground is critical, with acute bevel edge entering the ground first and then exiting first. This allows for the soil to fall off the bevelled surface at the edge, which assists in maintaining the sharp edge at the tip of the blade edge, which has been found to impart self-sharpening properties, especially where the soil is very abrasive.

[0071] The blade tips are spaced at about 150mm spacings which has been found to be the maximum spacing, resulting in acut stubble length which allowsthe seeding machinesto be able to seed through efficiently. The blades are evenly staggered along the drum, so at any one time only half the bladesof the total width of the machine are in the ground. For example, in a 12.8 metre wide machine, only 6.4 meters of blade are in the ground at any time. This is important for two reasons, this increases the cutting weight applied to the bladesallowing it to be used in tougher conditions, used for longer periods of the day, and it has been found to make it better suited for all stubble types.

[0072] A further advantage provided by having staggered blades is that it eliminates most of the vibration that causeswear and tear to the overall machine. This is expected to reduce running costs and result in a machine that is efficient to run. The blade staggering and positioning allows the machine to be used at speeds from 2km per hour up to 20km per hour making the machine more efficient and being able to produce a low disturbance all the way through to full disturbance, depending on the operational speed.

[0073] The blade construction, the blade mounts and the cylindrical drum 47 construction provides a weight to the overall machine that suits efficient mulching of stubble. The cylinder diameter could be reduced and the blade mount and / or blade height increased with a view to maintaining the same weight in the overall machine, but the height of blade mount and blade described is considered to be ideal in terms of minimising bending stresses where the blade mounts are welded to the drums 47. The radial mounts 67 that support the axles 65 are provided with a circular aperture 107 fitted with a sealing closure 109 to seal the inside of the drum 47 from the outside environment. The closures 109 may be removed to allow filling of the drum 47 with water, in order to increase the drum weight and hence the overall machine weight, in order to assist with mulching particularly difficult and hard stubbles. The radial mounts 69 have flats 111 to allow flow of water therepast, inside the drums 47.

[0074] These stubble mulching drums in the machine are mounted to hydraulic folding and lifting frame which is towed by a tractor. Once the tractor folds out the frames it then lowers the stubble mulching drums to be in contact with the ground, allowing it go to work on chopping and mulching the stubble.

[0075] The machine according to the invention is expected to transform previous stubble handling options, a major one being to eliminate burning as a preferred stubble handling option. It allows crops to be harvested at a higher stubble height, reducing harvesting time, fuel use, and costs. It mulches stubble into 5 inch pieces, assisting in it breaking down and returning to the soil, increasing soil carbon, which is beneficial to soil nutrition and health, and water holding capacity. This in turn allows trouble free seeding of the following years crop, due to the mulch breaking down after the mulching operation. There is improved seed to soil contact, which improves crop germination. The application of fertiliser and other chemicals have better performance due to improved soil contact, rather than the stubble acting as a blanket cover. In addition, the improved breakdown of stubble from the previous season, reduces nitrogen tie-up, and reduces cross-crop contamination in the new crop.

[0076] The machine according to the invention is also expected to dramatically reduce the chances of erosion inherent in hitherto known tillage options and is expected to offer farmers a safer and environmentally better option. There is less risk of crop failure due to inclement weather, if soil integrity can be maintained. If through use of the invention, only soil erosion is reduced, that will be considered to be a massive achievement, but when you link the reduction of burning pollution to the atmosphere, improving soil health, increased efficiency, it is expected that this invention has the potential to provide a massive benefit to farmers.

[0077] It should be appreciated that the scope of the invention is not limited to the particular embodiment disclosed herein.

Claims

Claims1. An agricultural stubble mulching machine com prising a roller assembly having at least three blade sets extending transversely side by side thereacross, each of said blade sets having a plurality of transversely disposed blades arranged radially and substantially evenly spaced around the circumference of said roller assembly, wherein the blades in each blade set are disposed linearly and parallel to a central axis of said roller assembly and parallel to each other, wherein the blades of at least some of said blade sets are disposed staggered relative to each other so as to alternately operate as said roller assembly rotates, and wherein the blades of said at least three blade sets are arranged with mirror image symmetry about a radial plane normal to said central axis, said radial plane located at a center of the transverse extent of said blade sets.

2. An agricultural stubble mulching machine as claimed in claim 1 wherein the blades of adjacent said blade sets are disposed staggered relative to each other so as to alternately operate as said roller assembly rotates.

3. An agricultural stubble mulching machine as claimed in claim 1 or 2 wherein said roller assembly has three blade sets com prising a cent rally located blade set extending across subst antially half of the transverse extent of said roller assembly and two outer blade sets each extending across substantially aquarter of the transverse extent of said roller assembly.

4. An agricultural stubble mulching machine as claimed in claim 3 wherein said blades of said outer blade sets are disposed staggered relative to said blades of said centrally located blade set but not disposed staggered relative to each other.

5. An agricultural stubble mulching machine as claimed in claim 1 wherein the blades are spaced circumferentially from 100mm to 150mm apart, preferably from 110mm to 140mm apart, preferably from 120mm to 130mm apart and preferably about 125mm apart.

6. An agricultural stubble mulching machine as claimed in any one of the preceding claims wherein the blades are fitted to a cylindrical drum assembly.

7. An agricultural stubble mulching machine as claimed in claim 6 wherein said cylindrical drum assembly includes a plurality of radial blade mounts, for mounting each blade.

8. An agricultural stubble mulching machine as claimed in claim 1 wherein the blades have a radial height of from 80mm to 150mm, preferably from 90mm to 140mm, preferably from 100mm to 130mm, preferably from 110mm to 120mm.

9. An agricultural stubble mulching machine as claimed in any one of the preceding claims wherein the blades are formed from a structural steel having wear resistance.

10. An agricultural stubble mulching machine as claimed in any one of the preceding claims wherein the blades have a blade thickness of from 8mm to 15mm, and preferably from 10mm, and most preferably about 12mm.

11. An agricultural stubble mulching machine as claimed in any one of the preceding claims wherein the edge of the blade is formed with a bevel, preferably of from 40 degrees to 50 degrees, with the acute angle being the leading edge of the blades on the blade sets.

12. An agricultural stubble mulching machine as claimed in any one of the preceding claims including a towable frame to which said roller assembly is transversely mounted.

13. An agricultural stubble mulching machine as claimed in claim 11 wherein the towable frame comprises a central frame to which said roller assembly is mounted and includes two outrigger frames each mounting an outrigger said roller assembly.

14. An agricultural stubble mulching machine as claimed in claim 12 wherein the outrigger frames are each disposed on pivoting mounts and are hydraulically actuable between a folded stowed position in which the axis of the outrigger rollers lies transverse to the axis of said roller assembly, and an extended deployed position in which the axis of the outrigger rollers extends in the same direction asthe roller assembly axis.

15. An agricultural stubble mulching machine as claimed in claim 11, 12 or 13 wherein the towable frame includes wheel assemblies which may be raised for deployment of the roller assembly and lowered to elevate said roller assembly to allow it to be transported.

16. An agricultural stubble mulching machine as claimed in claim 12 wherein said outrigger frames include a wheel assembly with a wheel axis transverse to the outrigger roller axis, the outrigger frame wheel assemblies being arranged to be raised for deployment of each outriggerroller assembly and lowered to elevate each said outrigger roller assembly to allow it to be transport ed.

17. An agricultural stubble mulching machine including a roller assembly having a blade set extending transversely, said blade set having a plurality of transversely disposed blades arranged radially and substantially evenly spaced around the circumference of said roller assembly, wherein the blades in said blade set are disposed linearly and parallel to a central axis of said roller assembly and parallel to each other, wherein each of said blades has a transverse edge formed with a bevel, preferably of from 40 degrees to 50 degrees, with the acute angle being the leading edge of the blades on the blade set.

18. An agricultural stubble mulching machine as claimed in claim 17, wherein said roller assembly has a plurality of blade mounts located with their central extents extending radially from the central axis of the roller assembly, and each of said blades is mounted to a back of each blade mount.

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