AU2021101411A4

AU2021101411A4 - Improved Seed Destroying Impact Mill Assemblies

Info

Publication number: AU2021101411A4
Application number: AU2021101411A
Authority: AU
Inventors: Ben Matthew Crane
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-25
Filing date: 2021-03-18
Publication date: 2021-06-10
Anticipated expiration: 2029-03-18

Abstract

A seed destroying impact mill assembly (10) comprising a mill shaft (12), a driven pulley (14), and an impact mill (16), wherein the driven pulley (14) is fixedly attached to the mill shaft (12) such that rotational drive may be transferred therebetween, the impact mill (16) further comprising a plurality of impact means (30) and an impact mill housing (32), the impact means (30) are fixed directly or indirectly to the mill shaft (12) and positioned within the mill housing (32), the mill housing (32) providing for the rotational mounting of the mill shaft (12) therethrough and further comprising an inlet (34) by which seed enters the impact mill (16) directly and a screened portion (36) by which impacted seed may leave the impact mill (16). s 4'y 0 0s0

Description

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"Improved Seed Destroying Impact Mill Assemblies"

FIELD OF THE INVENTION

[0001] The present invention relates to improved seed destroying impact mill assemblies.

[0002] More particularly, the impact mill assemblies of the present invention are intended to be mounted substantially horizontally at the rear of a combine harvester and in an orientation substantially perpendicular to the longitudinal orientation of the combine harvester.

[0003] The present invention further relates to a combine harvester comprising a seed destroying impact mill assembly as described herein.

BACKGROUND TO THE INVENTION

[0004] When harvesting grain, combine harvesters cut the whole plant off near the base of the stalk, which is taken into the machine for threshing. The threshing process inside the combine separates the good or target grain from the chaff (secondary seeds and fine materials) and the straw (the stalk of the plant).

[0005] The good grain is kept inside the combine, and the straw and chaff are discharged from the back of the combine through a set of rotating knives that cut the straw into a finer product and spread it back onto the field. As part of the harvesting process, weed plants and their seeds are also taken into the combine. These weed seeds are passed through the machine and discharged back onto the field. Weed seeds can then germinate in following growing seasons and continue to contaminate future crops.

[0006] Unwanted plants or weeds in grain crops compete with the desired plants for water and nutrients resulting in lower yields and contamination of the final product. Typically, farmers will control these weeds by spraying herbicides onto the field multiple times throughout the year. However, the predominant weeds (such as ryegrass) are developing significant resistance to all the available herbicides. Herbicide resistance is becoming a significant issue in Australia, and over time the impact of herbicide resistance is expected to become more significant internationally.

[0007]The process by which most of the plant material is collected by the combine harvester presents an opportunity to destroy the weed seeds prior to discharge from the machine, by which they would preferably be rendered inert and prevented from germination in subsequent seasons. Such an approach provides a method by which a farmer might control weeds in cereal crops, particularly those plants that have developed herbicide resistance.

[0008] One system requires that a bin be towed behind the combine and all the chaff material collected. The towing of the bin and collection of chaff is cumbersome and draws power. The chaff material is taken to an area of the field and burnt in piles, which is time consuming. It is understood that burning the chaff removes nutrients from the soil when compared with letting it decompose naturally.

[0009]Another prior art system uses a mechanical mill to physically impact the weed seeds and destroy them. Early examples required that a separate machine be towed behind the combine. Subsequently, mills have been incorporated into the back of the combine, rather than having a separate machine towed behind it. Both options have included two cage mills, which utilise a series of concentric rotating cages, or a combination of rotating cages and stationary bars or screens. The chaff/seed mix is fed into the centre of the spinning cages, and is flung out of the cages, through the rotating bars. A series of impacts as the chaff/seed is flung from the cages is sufficient to destroy the majority of weed seeds.

[0010]Attempts to control weed growth utilising cage mills have, to date, provided two cage mills mounted on a vertical shaft at the rear of the combine harvester, such that the cage mills rotate around the vertical shaft in a horizontal plane. The drive for such cage mills is provided by a drive pulley mounted toward the rear of all combine harvesters. This pulley is mounted so as to sit in a substantially vertical plane and is driven by a horizontally oriented shaft normally used to drive straw choppers. As the drive pulley is mounted in a different orientation to the cage mills, it cannot be used to directly drive the mills. Other drive systems are required to transfer power to the cage mills, such as a right-angle gearbox and a series of belts, or using hydraulic pumps and motors. Both of these arrangements are costly, require significant maintenance, and gearboxes and hydraulic pumps can generate heat. Anything that presents a fire risk, such as an overheating gear box, is a significant risk in an agricultural environment, particularly one amongst dry chaff and straw.

[0011] The present Applicant has previously filed Australian Patent Application 2019202177 directed to "Improvements in Seed Destroying Impact Mill Assemblies". The impact mill assembly described therein utilises a pair of cage mill assemblies mounted horizontally on a single mill shaft. A chute directs seed material to a pair of conveyors that feed the material outwardly, or laterally, toward respective mill assemblies. The mill assemblies comprise a plurality of concentric or co-axial stationary screens located about the mill shaft. Between the screens are provided rotating impact components, such as impact bars or cages. Each of the cage mill assemblies has an outlet provided in a shroud thereof, the outlet being positioned at an upper level therein, at a point above a horizontal plane described by, and that intercepts, the mill shaft. The apparatus described is defined by the need to provide a pair of conveyors to convey seed material from a central point toward the laterally located cage mill assemblies. In addition, the concentric nested screens of the mill assemblies are relatively complex, are expensive to manufacture, need to be accurately balanced, and present a particular challenge during maintenance thereof.

[0012] One object of the present invention is to provide a seed destroying impact mill assembly that overcomes substantially the abovementioned problems of the prior art, or at least provides a useful alternative thereto.

[0013] The preceding 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 formed part of common general knowledge as at the priority date of the application.

[0014] 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 integer.

[0015] The term "seed destroying" is to be understood to refer to a physical impact or effect imparted on an unwanted seed, including weed seeds, or other unwanted organic material, unless the context clearly requires otherwise.

[0016] The terms "vertical" and "horizontal", or variations thereof used herein, are to be understood to be relative to a plane described by the or each axle of the wheels supporting the combine harvester on which the present invention may be provided. By extension, the terms will also be generally relative to a surface over which the combine harvester may be working.

SUMMARY OF THE INVENTION

[0017] In accordance with the present invention there is provided a seed destroying impact mill assembly comprising a mill shaft, a driven pulley, and an impact mill, wherein the driven pulley is fixedly attached to the mill shaft such that rotational drive may be transferred therebetween, the impact mill further comprising a plurality of impact means and an impact mill housing, the impact means are fixed directly or indirectly to the mill shaft and positioned within the mill housing, the mill housing providing for the rotational mounting of the mill shaft therethrough and further comprising an inlet by which seed enters the impact mill directly and a screened portion by which impacted seed may leave the impact mill.

[0018] Preferably, the mill shaft is arranged so as to be oriented and to extend substantially horizontally.

[0019] Preferably, the driven pulley is positioned in a substantially vertical plane, whereby the driven pulley may be driven directly or indirectly by a drive pulley also positioned in a substantially vertical plane.

[0020] Preferably, the impact means rotate with the mill shaft. Still further, the impact means are preferably rotatably mounted on or about the mill shaft whereby the impact means extend radially as the mill shaft rotates under the influence of centrifugal force.

[0021]Still preferably, the plurality of impact means are positioned along at least a portion of the length of the mill shaft within the housing, with a number of impact means being provided circumferentially about the mill shaft along the length thereof also.

[0022] In one form of the present invention a series of fixed flanges are provided circumferentially about the mill shaft along at least a portion of the length thereof within the housing, and between each adjacent pair of flanges is affixed, in a rotatable manner, a plurality of elongate impact means. The elongate impact means are mounted in a rotatable manner such that they may rotate at least to some extent about an axis extending substantially in parallel to that described by the mill shaft.

[0023] Preferably, the series of fixed flanges and associated impact means are provided with apertures therein whereby a number of elongate pins may be passed through the fixed flanges such that each pin locates a single elongate impact means between adjacent flanges.

[0024] In a preferred form of the present invention four impact means are provided evenly spaced circumferentially between each pair of flanges. The impact means of adjacent pairs of flanges are preferably off-set about the circumference of the mill shaft in a substantially even manner.

[0025] In one form of the present invention one or more fans may be provided to assist the passage of material through the impact mill. The one or more fans may draw or suck material through or from the impact mill depending upon the arrangement adopted.

[0026] The present invention further provides an impact mill assembly and combine harvester combination, wherein the impact mill assembly is as described hereinabove, the drive pulley being provided on the combine harvester.

[0027] The present invention still further provides a mounting arrangement for an impact mill assembly on a combine harvester, wherein the impact mill assembly is as described hereinabove, the drive pulley being provided on the combine harvester.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will now be described with reference to one embodiment thereof and the accompanying figures, in which:

Figure 1 is an upper rear perspective view of an impact mill assembly in accordance with the present invention, showing a pulley arrangement, and a portion of a mounting therefor, and by which a mill shaft of the impact mill assembly is driven from a combine harvester on which it is mounted;

Figure 2 is a side elevational view of the impact mill assembly of Figure 1, again showing a pulley arrangement, and a portion of a mounting therefor, and by which a mill shaft of the impact mill assembly is driven from a combine harvester on which it is mounted;

Figure 3 is an upper perspective view of the impact mill assembly of Figure 1, again showing a pulley arrangement, and a portion of a mounting therefor, and by which a mill shaft of the impact mill assembly is driven from a combine harvester on which it is mounted, and on which a portion of a shroud of the impact mill assembly has been removed revealing rotationally mounted impact bars and disks thereof;

Figure 4 is an upper perspective view of the impact mill assembly of Figure 1, again showing a pulley arrangement, and a portion of a mounting therefor, and by which a mill shaft of the impact mill assembly is driven from a combine harvester on which it is mounted, and on which the entirety of a shroud of the impact mill assembly has been removed revealing rotationally mounted impact bars and disks thereof;

Figure 5 is a rear elevational view of the impact mill assembly of Figure 1, shown without the pulley arrangement and portion of a mounting therefor, and with section line A-A;

Figure 6 is a sectional view of the impact mill assembly of Figure 1, defined by line A-A of Figure 5;

Figure 7 is a rear elevational view of the impact mill assembly of Figure 1, shown without the pulley arrangement and portion of a mounting therefor, and with section line C-C;

Figure 8 is a sectional view of the impact mill assembly of Figure 1, defined by line C-C of Figure 7;

Figure 9 is a sectional side view of the impact mill assembly of Figure 1, showing stator bars provided on an inside surface of the shroud;

Figure 10 is a sectional side view of the impact mill assembly of Figure 9, showing an additional venturi fan provided thereon; and

Figure 11 is a sectional top plan view through the drive shaft of the impact mill assembly of Figure 1, showing a fan mounted on the drive shaft.

DESCRIPTION OF PREFERRED EMBODIMENT

[0029] Embodiments of the present invention will now be described with reference to the accompanying Figures. The inventive concepts of the present invention may be embodied in different forms and should not be construed as limited to the embodiments described in this specification. The terminology used in this specification is for the purpose of describing particular embodiments and is not intended to be limiting of the invention. The singular forms 'a', 'an' and 'the' are intended to include plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms 'comprises', 'comprising', 'includes', and/or 'including' specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

[0030] The present invention provides a seed destroying impact mill assembly, a drive and mounting arrangement for impact mills that are positioned at the rear of a combine such that the axis of rotation is substantially horizontal and perpendicular to the intended direction of travel of the combine. The present invention also provides a combine harvester (or 'combine') that incorporates a seed destroying impact mill assembly as described herein.

[0031]A combine discharges the waste products from the rear of the machine, typically consisting of straw, unsuitable seeds, weed seeds and chaff. This discharge is intercepted by the present invention in or on the combine harvester prior to discharge, such that the unsuitable seeds and weed seeds can be separated from the straw and diverted into a seed destroying impact mill.

[0032] The impact mill destroys the majority of unwanted seeds by mechanical action and thereby hinders future germination thereof that would contaminate fields and crops. The destroyed product is discharged from the impact mill assembly of the present invention back onto the field.

[0033] The impact mill is provided about a horizontal shaft that is mounted on bearings along the rear of the combine harvester, perpendicular to the direction of machine travel and parallel to the axles of the combine. This mounting arrangement allows for a greatly simplified drive arrangement compared to other mill orientations. The shaft, and therefore the impact mill, can be driven by a belt arrangement that connects to existing pulleys on the combine harvester, without having to turn that drive through 900.

[0034] In Figures 1 and 2 there is shown a seed destroying impact mill assembly comprising a mill shaft 12, a driven pulley 14, and an impact mill 16. The driven pulley 14 is fixedly attached to the mill shaft 12 such that rotational drive may be transferred therebetween. The mill shaft 12 is, in use, oriented substantially horizontally, generally parallel to the axles of a combine on which it is provided (not shown), and substantially perpendicular to a direction of travel of that combine.

[0035] The driven pulley 14 has provided thereabout an endless loop belt 18 that is also provided about a first intermediate pulley 20. The intermediate pulley 20 is rotatably mounted on a support structure 22, shown in part, that is provided on the combine. A second intermediate pulley 24 rotates on the same shaft as the first intermediate pulley 20, whereby rotation or drive is transferred from one to another. The second intermediate pulley 24 has provided thereabout an endless loop belt 26 that is also provided about a drive pulley 28. The drive pulley 28 is provided on the combine and is arranged so as to be in a substantially vertical plane, being a plane that is at least substantially perpendicular to an axis of rotation of the mill shaft 12. The intermediate pulleys and 24, and the driven pulley 14, are similarly in a vertical plane, being a plane that is either coincident with that of the drive pulley 28 or is substantially parallel thereto. In this manner there is no requirement to turn or rotate the plane of rotation when imparting or transferring drive to the mill shaft 12.

[0036] The pulley pair 14 and 20 are of the same diameter, and the pulley pair 24 and 28 are of the same diameter. The diameter ratio between the intermediate pulleys 20 and 24 is selected by a user (not shown) to provide the desired speed of rotation in the mill shaft 12.

[0037] This arrangement allows the impact mill 16 to be fixed to the mill shaft 12 such that its axis of rotation is substantially horizontal and generally perpendicular to the direction of travel of the combine harvester on which it is provided. The orientation of the mill shaft in the present invention significantly simplifies the drive arrangement necessary to rotate the impact mill 16 when compared with most arrangements of the prior art that position the mill assemblies with their axis of rotation in a vertical orientation.

[0038] The impact mill 16 further comprises a plurality of impact means, for example elongate impact bars 30 best seen in Figures 3, 4, 6, 9, 10 and 11, and an impact mill housing 32. The impact bars 30 are fixed indirectly, in a rotatable manner, to the mill shaft 12, and are positioned within the mill housing 32. The mill housing 32 providing for the rotational mounting of the mill shaft 12 therethrough and further comprising an inlet 34 by which seed enters directly the impact mill, and a screened portion 36 by which impacted seed may leave the impact mill 16.

[0039] The housing 32 further comprises a first end 38 and a second end 40. Each end 38 and 40 has provided therein a bearing 42 through or into which is received and supported in a rotational manner the mill shaft 12. The housing 32 still further comprises an upper portion 44, shown in Figure 1, and positioned above and alongside the screened portion 36, that also extends alongside the inlet 34. In this manner the upper portion 44 is positioned between the screened portion 36 and the inlet 34. The housing 32 yet still further comprises a lower portion 46 positioned below and adjacent the inlet 34. The screened portion 36 also extends adjacent the lower portion 46, such that the lower portion 46 is positioned between both the inlet 34 and the screened portion 36.

[0040] The combine further generally comprises an internal product handling chute (not shown), whereby the chute and barriers (also not shown) inside the combine allow preferential selection of unwanted seeds and chaff, and the direction of this product into the chute that then feeds directly the inlet 34 of the housing 32 and impact mill 16. A straw product (also not shown) that does not contain seed material is separated and diverted in known manner, such that it bypasses the impact mill 16.

[0041] As is best seen in Figures 3, 4, 6, 8, and 11, the elongate impact bars are positioned about the circumference of the mill shaft 12 and along the length thereof, within the housing 32. The mill shaft 12 has a series of circumferential flanges 48 fixed thereto along the length thereof, and an inner end 50 of each impact bar 30 is positioned between adjacent pairs thereof. For example, each pair of adjacent flanges 48 has four evenly circumferentially spaced apart impact bars 30 provided therebetween. In this manner the impact bars are spaced apart by 900. The impact means 30 of adjacent pairs of flanges 48 are off-set about the circumference of the mill shaft 12 in a substantially even manner, for example by 45°. This arrangement is perhaps best illustrated in Figures 4 and 8.

[0042] The elongate impact means 30 are mounted in a rotatable manner such that they may rotate during use at least to some extent about an axis extending substantially in parallel to that described by the mill shaft 12. The series of fixed flanges 48 and associated impact bars 30 are provided with apertures therein whereby a number of elongate pins 52 may be passed through the fixed flanges 48 such that each pin 52 locates a single elongate impact bar 30 between adjacent flanges 48. In this arrangement each flange 48 is provided with 8 apertures evenly spaced thereabout. In use, the impact bars 30 extend radially under the influence of centrifugal force, as depicted in the Figures, as the mill shaft 12 rotates.

[0043] The screened portion 36 of the housing 32 has provided therein a plurality of apertures (not shown). Chaff, straw and unwanted seeds entering the impact mill 16 through the inlet 34 are subjected to the action of the rapidly rotating impact bars 30 and, in particular, their impact with same against the housing 32. The apertures of the screened portion 36 are sized so as to ensure the product is held within the impact mill 16 long enough to ensure sufficient damage to the seeds to render them infertile.

[0044] In one form of the invention a number of stator bars 54 are provided on the inside of the housing 32, extending between the ends 38 and 40 thereof, whereby static impact surfaces are provided that assist in the diversion of material away from the inlet 34.

[0045] It is envisaged that replaceable wear liners (not shown) may be provided within the housing 32 to provide improved longevity and less maintenance.

[0046] In Figure 10 there is shown the impact mill assembly 10 of the present invention in which a fan 56 is mounted adjacent the lower portion 46 of the housing 32. The fan 56 is provided with a fan housing 58 that extends rearwardly underneath the housing 32 of the impact mill 16 and past the screened portion 36. In this manner the operation of the fan 56 produces a venturi effect that assists in drawing material through the screened portion 36. In this arrangement no material is drawn through the fan.

[0047] In Figure 11 there is shown the impact mill assembly 10 of the present invention in which a fan 60 is mounted at or on the end of the mill shaft 12, within a fan housing 62. The fan housing 62 has an additional duct 64 provided extending to the screened portion 36. In this manner the fan 60 is able to draw air through the screened portion 36, thereby providing a relative increase in throughput, particularly when handling relatively light materials.

[0048] As can be seen from the above description, the impact mill assembly of the present invention, and a combined impact mill assembly and combine of the present invention, each allow drive to be transferred to the or each impact mill in a manner such that no right angle gearbox is required. Speaking generally, the drive for the mill shaft is not required to be tilted or rotated. Rather, the drive is passed directly, in the same or though a substantially parallel plane, from the drive pulley to the driven pulley, the driven pulley in turn passing that imparted rotational drive directly to the mill shaft, which is oriented so as to be substantially parallel with the axles of the combine, and substantially parallel with a shaft driving the drive pulley.

[0049] It is envisaged that the impact mill assembly of the present invention may provide lower power consumption when compared with impact mill assemblies of the prior art. This is understood by the Applicant to be important for mobile machines where power is limited to the installed engine power. Less power consumption means more power is available for harvesting the crop at a faster rate. Lower power consumption also translates to lower fuel consumption and therefore lower operating costs.

[0050] A significant portion of the envisaged power savings from the impact mill assembly of the present invention is thought to arise from the understanding that the impact mill assembly of the present invention does not pump as much air as prior art arrangements. The cage mill designs of the prior art act in the manner of a large fan and draws air in and blows it out centrifugally. This consumes power. The 'hammer mill' arrangement of the present invention does not operate like a fan impeller, and therefore does not consume energy moving air. As noted above, the impact mill assembly of the present invention also does not utilise gear boxes or other components in the drive train that can waste energy.

[0051] It is further envisaged that the impact mill assembly of the present invention may realise lower fabrication costs compared with the prior art. This is realised through the use of what are understood to be generally simpler components and assembly. The pin jointed and rotatable or swinging nature of the impact bars removes the need for high levels of balancing of spinning components. It also allows the rotating components to be lighter than those of the prior art as the pin joints do not transmit bending forces to the base of the bars, so the connections do not need to withstand bending loads. The impact mill of the present invention does not require tight tolerances to operate effectively. Again, the present invention does not require gearboxes or other complex components in the drive train due to the orientation of the mill.

[0052] It is yet still further envisaged that the impact mill assembly of the present invention may realise lower maintenance costs compared to those of the prior art. The rotating impact bars are arranged symmetrically and can be rotated four times before needing to be replaced. When replacement is required it is expected to be cheaper and simpler compared to cage mill technology of the prior art, in which the whole mill rotor needs to be replaced. For the impact mill assembly of the present invention, it is understood that only the rotating impact bars will need to be replaced, and this is achieved relatively simply by removing the elongate pins. The single screened portion of the present invention also allows much easier change out compared to the concentric nested screens of existing cage mills of the prior art.

[0053] It is again further envisaged that the impact mill assembly of the present invention provides a simplified design when compared to mills of the prior art, through provision of an inlet to the housing that feeds seed and chaff directly to the impact mill, without any requirement for conveying that seed and chaff laterally relative to direction of machine travel.

[0054] Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention.

Claims

The claims defining the invention as are follows:

1. A seed destroying impact mill assembly comprising a mill shaft, a driven pulley, and an impact mill, wherein the driven pulley is fixedly attached to the mill shaft such that rotational drive may be transferred therebetween, the impact mill further comprising a plurality of impact means and an impact mill housing, the impact means are fixed directly or indirectly to the mill shaft and positioned within the mill housing, the mill housing providing for the rotational mounting of the mill shaft therethrough and further comprising an inlet by which seed enters the impact mill directly and a screened portion by which impacted seed may leave the impact mill.

2. The seed destroying impact mill assembly of claim 1, wherein the mill shaft is arranged so as to be oriented and to extend substantially horizontally.

3. The seed destroying impact mill assembly of claim 1 or 2, wherein the driven pulley is positioned in a substantially vertical plane, whereby the driven pulley may be driven directly or indirectly by a drive pulley also positioned in a substantially vertical plane.

4. An impact mill assembly and combine harvester combination, wherein the impact mill assembly is as claimed in any one of claims 1 to 3, the drive pulley being provided on the combine harvester.

5. A mounting arrangement for an impact mill assembly on a combine harvester, wherein the impact mill assembly is as claimed in any one of claims 1 to 3, the drive pulley being provided on the combine harvester.

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