WO1994028702A1

WO1994028702A1 - Plough and tilling unit

Info

Publication number: WO1994028702A1
Application number: PCT/GB1994/001213
Authority: WO
Inventors: Peter Douglas Temple Topham
Original assignee: Topham Peter D T
Priority date: 1993-06-04
Filing date: 1994-06-03
Publication date: 1994-12-22
Also published as: AU6852894A; GB2278766B; GB9311568D0; GB2278766A

Abstract

A plough comprising a plurality of tilling units, each comprising a main rotary tilling member (36) with a skimmer member (78) provided rearwardly thereof. The skimmer, during ploughing, raises and turns the upper soil surface layer containing the stubble to be buried, the main tilling member of a following tilling unit serving to lift and turn clean soil over on top of the initially turned material. The skimmer member (78) can be a blade or a further rotary disc which can be swung from side to side in order to be inclined appropriately to the direction of movement of the tilling apparatus, depending upon the direction of inclination of the main tilling member (36). A further aspect of the invention provides in each tilling unit for a downwardly depending leg (12) carrying a soil penetration member (13) to be connected at its lower end with support structure for the main rotary tilling member (36). The edge of the connecting structure is so shaped as progressively to reduce the gap between the edge of the connecting structure and the edge of the inclined main tilling member (36) from a minimum at ground level at the leg to minimise the tendency for stones and debris to jam rotation of the main rotary tilling member (36).

Description

"PLOUGH AND TILLING UNIT"

This invention relates to rotary ploughs and to tilling units for use in rotary ploughs.

Farmers are currently faced with the prospect of a complete ban on straw and stubble burning. This represents a considerable problem for arable farmers since the volume of straw produced by grain crops is far more than is required for animal bedding purposes and like uses. Moreover, the cost of transporting straw in bulk for other uses is prohibitive, even if such uses could be found. Accordingly, there is a need to incorporate straw into the ground from whence it has grown.

Many proposals have been made for straw incorporation, including the use both of ploughs and of harrows. The success of these proposals depends very much on the conditions prevailing when the straw is to be incorporated into the soil. Generally speaking, problems are much less acute on light soil. The present invention provides a process which is particularly useful for dealing with the problems which arise in the case of heavy land and/or wet and dry conditions although it is efficient over a very wide range of ground conditions.

In the case of heavy land, mouldboard ploughs are found to be of somewhat limited utility. When the ground is hard and dry, penetration is a problem and wear of all soil-engaging parts of the plough is excessive and thus costly, when the land is wet, the mouldboard plough causes an unacceptable level of soil compaction, arising from the dynamic effect of the moving soil engaging the relatively stationary mouldboard. Disc ploughs have been tried. While the rotary action of the disc reduces the compaction effect mentioned above, there, nevertheless, remains, particularly in the case of heavy straw burying conditions, the problem of achieving effective straw burial. Disc ploughs and disc harrows tend to produce a mixing action which does not bury the straw fully and this leads to problems in wet conditions.

In my earlier GB-A-2 254 232, I have disclosed a plough comprising a main or primary concave rotary tilling member with a smaller secondary tilling member being mounted within the concavity of the primary tilling member and more greatly inclined to the direction of forward movement to act as a skimmer to displace a sliver of soil, together with stubble and straw, off the surface of the ground, before the primary tilling member is operative to roll clean soil from the underside of the sliver over to cover the sliver of soil, stubble and straw initially displaced. While this prior arrangement has been effective, I have found that efficient and reliable burying can be obtained if the skimmer or secondary soil tilling means are mounted in a position spaced behind and to one side of the primary rotary tilling member.

With this arrangement, the skimmer is clear of, or less affected by, disturbance of the ground caused by the action of the main ploughing or soil tilling mechanism, with the result that the surface layer of soil can be lifted and turned in a consolidated manner while it is in part held together by the roots of the stubble being buried, each skimmer turning the surface layer of the ground for burial by soil turned over by the main tilling member of the following tilling unit. The layer turned over by the last skimmer will be buried by soil turned over by the leading tilling unit in the return run of the plough across the field being ploughed. During use of rotary ploughs, I have found that a preferred structure comprises a downwardly extending forward leg carrying a soil penetration member which can be made very strongly, the rotary tilling member being supported by support structure provided rearwardly of the leg and strengthening structure being provided between the lower ends of the support structure and the leg so as to provide a very strong and rigid support for the ploughing member. Whilst this structure with the rotary ploughing member being received in a longitudinally enclosed space, whilst having the advantages provided by rigidity and strength, can have problems arising from larger stones or other debris which may be in the soil becoming jammed between the structure and the periphery of the rotary ploughing member. This problem is accentuated where the rotary ploughing member itself comprises a number of teeth about its periphery. In order to overcome this problem, I am proposing, in a second aspect of the present invention to provide for shaping of the edge of the structure surrounding the space receiving the main rotary tilling member, in order to avoid this possibility of jamming. According to a first aspect of the present invention, there is provided a tilling unit for a plough comprising a frame member; fixed structure comprising a forward leg downwardly depending from said frame member and having a bottom end, a forwardly facing soil penetrating member carried by said leg near the bottom end thereof, a landslide extending rearwardly of said leg adjacent the bottom end thereof, and a support structure extending between the frame member and the landslide; and a rotary tilling member carried by said support structure in the space between the leg and the support structure for rotation about a substantially horizontal axis and for swinging movement about a substantially vertical axis whereby the inclination of the plane of the tilling member to the longitudinal extent of the landslide may be varied, the tilling member being inclined during ploughing so as to have a leading edge portion nearer the leg and a trailing edge portion nearer the support structure, wherein the transition edge from the rear of the leg back towards the support structure is so-shaped that with the tilling member inclined, the distance between the periphery of the tilling member and the fixed structure is substantially at a minimum at a location at, or close to, ground level between said periphery and the leg and progressively increases along said periphery towards said support structure. The transition edge may be progressively curved although for simplicity of construction, I have found that it will work avoiding the possibility of jamming even when it is formed as a series of straight edges, progressively inclined relative to each other. The tilling unit of the first aspect of the present invention may further comprise an upper soil surface turning means or skimmer adapted to extend downwardly into the ground during ploughing to part only of the depth of the rotatory tilling member to lift and turn the upper surface of soil prior to a main full depth ploughing and turning action of the rotary tilling member, said skimmer being mounted in said unit in a trailing, laterally displaced, position, relative to the rotary tilling member, whereby, during ploughing, the portion of the upper surface of the ground turned by the skimmer will be buried by soil turned by a tilling member of a following tilling unit.

The upper soil surface turning means, or skimmer, preferably is mounted for swinging movement about the same substantially vertical axis as said rotary tilling member in order to be similarly inclined to the direction of movement of the plough. This provides for particularly simple reversing of the plough since a single control will, at the same time, cause both the main tilling member and the skimmer to be swung from a position for one hand of ploughing to the opposite hand. The skimmer may comprise a swingable blade but, preferably, comprises a rotatable disc of smaller diameter than the main rotatable tilling member. Preferably, the skimmer is mounted by means including shear bolts or resettable retention means, to protect the skimmer upon engagement with an obstruction during use of the tilling apparatus.

It should be noted that we have referred herein to the tilling members as being rotatable about a substantially horizontal axis for the purposes of convenience when considering the geometry of the arrangement. While, more usually, the tilling member will be rotatable in a substantially vertical plane about the substantially horizontal axis during its tilling action, it should be appreciated that in some cases there may be a substantial variation in order to vary the angle of attack and angle of the wheel from the vertical plane to change the ploughing characteristics. Such variations are intended to be covered by the reference to a substantially horizontal axis.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which:-

Figure 1 is a side view of a tilling unit with the structure shaped to prevent jamming of the rotary tilling member;

Figure 2 is a detailed cross-sectional view of part of the structure of Figure 1;

Figure 3 is a forward view of the structure of Figure 1;

Figure 4 is a diagrammatic view showing the tilling member in its inclined, operative, position, as occupied during ploughing;

Figure 5 is a view similar to Figure 1 but showing the provision of a rearwardly mounted skimmer; and

Figure 6 is a view similar to Figure 5 but showing an alternative skimmer arrangement; and

Figure 7 is a diagrammatic top plan view showing three tilling units arranged to form a plough. Figure 1 illustrates in side view, a tilling unit comprising a forward frame portion 10 adapted to be trailed behind an inclined beam towed by a plough and a frame comprising a horizontal portion 17 and a vertical portion 16, the vertical portion 16 providing a strong and rigid support for a forward leg 12 secured to the portion 16 by bolts 14. The bolts 14 can provide some adjustability of the height of the leg 12 with the leg 12 itself comprising at its forward end a soil penetration member having a point 13 and secured to the lower end of the leg 12 by bolts 15, again this positioning of the soil penetration member being adjustable by utilising different holes in the leg 12 for the bolts 15. Rearwardly of the leg 12, there is provided support structure for a rotary tilling member 36 comprising an axle member 18 extending vertically and fixed at its lower end to a bracket 20 which provides a bolted support for the rear end of structure 22 extending rearwardly from the leg 12. The structure 22 can be considered as being the forward end of the landslide which is continued by the main landslide portion 24 bolted thereto. In general, the bottom edge of the landslide will be substantially horizontal and located at a height above the level of the point 13. The landslide itself may be replaceable or have replaceable wear-plates secured thereto.

A tube 26 is mounted for rotation about a vertical axis on the axle 18, supported by bearings 19. At the top end of the tube 26 there is provided a flange member 28 provided with adjustable stops 49 for engaging a stop member 52 for limiting rotation of the tube 26 about the axle 18. Also provided on the flange member 28 is a mounting 30 for the end of a piston of a hydraulic unit 32 secured to the frame 17.

At the lower end of the tube 26, there is provided an axle 34 for the rotary tilling member 36, this axle being provided with a cylindrical mounting portion 35 encompassing, and fixed to, the tube 26 whereby operation of the hydraulic cylinder 32 will cause the tube 26 to be rotated with consequent swinging movement of the axle 34 about the axis of the axle 18. The rotatable tilling member 36 (partially omitted in Fig. 2) comprises a central planar portion 38, secured to a hub 37, rotatable about the axis 34, the hub 37 being supported by bearings 42, seals 44 being provided to protect the bearings from contamination. Mounted on the end of the axle 34, projecting through the centre of the rotary tilling member 56, is a support 46, to the upper end of which there is secured a scraper 48 (omitted in Fig. 2) by means of bolts 50. Grease nipples 21 are shown in Figure 2 for supplying lubricant to the bearings 19 and to the bearings 42.

As can be seen in Figure 3, the tilling member 36 is a soil inversion wheel which comprises a substantially planar central portion 38 to which are secured teeth 40 by bolts 41, the teeth 40, in essence, providing a frustoconical flange portion to the tilling member. While an inversion wheel is preferred, in some cases a more conventional concave disc may be used. Figure 4 diagrammatically illustrates the main ploughing member in its ploughing position, inclined relative to the direction of movement C of the unit. As shown, the bottom-most portion of the tilling member or inversion wheel 36 will be below the level of the top of the connecting structure 22 with the edge of the inversion wheel 36 extending through the substantially U-shaped space between leg 12 and tube 26 shown in Figure 4. During ploughing, stones and other debris at ground level can tend to fall into the gap between the rearward edge of the leg 12 and the peripheral edge of the frustoconical flange portion of the inversion wheel 36. This peripheral edge may be a continuous edge where the flange portion itself is continuous or may simply be the locus of the tips of the lugs or teeth 40 in the structure as actually shown in the Figures 1 to 4. Clearly, it is important that such debris does not jam rotation of the rotary ploughing member 36 and in the structure as illustrated in Figure 4, the minimum distance between the edge of the leg 12 and the tips of the lugs 40 defining the peripheral edge of the inversion wheel 36 is at, or close to, ground level during normal operational use of the plough. Thus, the position of minimum gap will be higher when the tilling member is less steeply inclined to the direction of extent of the landslide and lower when more inclined to the direction of extend of the landslide. In order to prevent such jamming, the space between the transitional rearward edge of the structure defined by the leg 12, the connecting part 22 and the supporting structure for the rotary tilling member should increase progressively. Whilst a continuous curve may be used, it has been found to be particularly advantageous for such a curve to be approximated by a series of straight lines, as illustrated in the various Figures. Such a construction is easy to fabricate and has been found, in practice, to work well. In a particular example, the distance or gap between the peripheral edge of the inversion wheel 36 and the transitional edge of the supporting structure at the point B at ground level is about 1^M (2.54 cm) with the distance or gap between the point A and the nearest point of the periphery of the inversion wheel 36 suitably being at least 6 to 8" (15 to 20 cm) when measured horizontally. In general terms, the gap between the inversion wheel periphery and the transitional edge of the structure can be thought of as increasing progressively from a point of minimum separation at ground level to the most rearward point of the periphery of the inversion wheel. While the transitional edge can be, as illustrated, a simple right- angled edge of the thickness of the plate metal from which it has been formed, preferably it has a V-shaped cross- section to reduce further the chance of jamming of the inversion wheel against rotation. The inversion wheel 36 is swingable about the substantially vertical axis of axle member 18 between a first position and a second oppositely facing position, in which two positions the angle of inclination of the plane of the inversion wheel 36 to the longitudinal extent of the landslide 24 is of similar magnitude. In both of the first and second positions the distances between the periphery of the inversion wheel 36 and the structure is substantially similar. It will be appreciated that the bottom edge of the inversion wheel 36 will be below the normal position of the top of the connecting structure 22 so that when the inversion wheel is moved from its inclined position to one side of the direction of extent of the landslide to the oppositely inclined position on the other side of the direction of extent of the landslide, it will need to rise to pass over the structure 22. This is permitted by allowing the tube 26 to rise up on the axle 18 as it is moved by the action of the hydraulic cylinder 32, the lifting force being given by the inversion wheel 36 as it climbs up and walks over the structure 22. During ploughing the main rotary member 36 can be retained in its lower position prevented from rising simply by mounting a part-circular blocking member between the top of the tube 26 and the bottom of the frame portion 17 so as to prevent lifting of the tube 26. Similarly, the tube 26 can be held in its raised position by inserting a blocking member between the lower end of the tube 26 and the bracket 20. Sometimes the plough may be operated in this way to provide the soil turning action more shallowly and above the depth of penetration of the soil penetrating member or of the landslide.

Figure 5 shows a skimmer 78 mounted to the rear of the main rotary member 36. A lug 70 is mounted to the exterior of the tube 26 and includes a hollow section 72 through which extends a support strut 74, carrying at its lower end a rotary disc 78 which acts as a skimmer in use of the plough. The height of the skimmer 78 can be adjusted by use of the bolt 76 engaging different holes in the strut 74. As shown, the axle 74 is tilted in relation to the axis of the tube 26. Means may be provided for adjusting the angle of inclination of the strut 74 to the axis of the tube 26. With this arrangement, when the inversion wheel 36 is in its inclined ploughing position, principally to one side of the direction of extent of the landslide 24, the skimmer 78 will be provided on the other side of the direction of extent of the landslide 24 so that during use of the plough the inversion wheel of a particular tilling unit will carry out a ploughing action and behind that ploughing action the skimmer 78 will operate to lift a sliver of soil away from the surface and turn it over for burial by the inversion wheel of the or a subsequent tilling unit. Generally, the skimmer 78 will have a depth of penetration which is a minor proportion only of the depth of penetration of the main rotatable tilling member or inversion wheel 36. A scraper and/or deflector can be provided adjacent the skimmer 78 for scraping or deflecting material away therefrom. Instead of having a rotary skimmer as shown in Figure 5, a soil turning blade can be used for turning the top layer of soil, stubble etc. Preferably, shear bolts or resettable retention means are provided to mount the skimmer in order to prevent it from damage upon engagement with an obstruction during use of the plough. Some play may be provided in the mounting of the skimmer so that in use it will drop down to a position which is not quite parallel with the soil inversion wheel. It will have alternative positions to drop into depending upon whether right- or left-hand ploughing is required.

Figure 6 illustrates a structure similar to Figure 5 with the exception that the skimmer 78' is generally arranged in a vertical plane for rotation about a horizontal axis, the skimmer 78' being mounted upon a strut 74' carried by a member 72' to which it is adjustable secured by a bolt 76'.

Figure 7 is a diagrammatic top plan view of three tilling units of the form described previously. To aid clarity only certain items of the tilling units have been shown and the beam 100 has been shown in dotted lines. In general, in use of the plough, a plurality of the tilling units trail behind the beam 100 which is swingable about a headstock pivot between oppositely inclined positions, relative to the direction of forward movement of the plough denoted by arrow C, depending upon whether a left-hand or a right-hand furrow is required. Generally, the swinging movement of the beam and the swinging movement of the tilling units relative to the beam will be controlled by opposite hydraulic jacks although alternative means may be used where convenient. Similarly, alternative means, for example mechanical, electrical or pneumatic, may be used instead of the hydraulic piston and cylinder arrangement 32 referred to previously for controlling inclination of the tilling and skimming means. Whilst figure 7 shows 3 tilling units, other numbers of tilling units may be provided.

Claims

C L A I M S

1. A tilling unit for a plough comprising a frame member; a fixed structure comprising a forward leg downwardly depending from said frame member and having a bottom end, a forwardly facing soil penetrating member carried by said leg near the bottom end thereof, a landslide extending rearwardly of said leg adjacent the bottom end thereof, and a support structure extending between the frame member and the landslide; and a rotary tilling member carried by said support structure in the space between the leg and the support structure for rotation about a substantially horizontal axis and for swinging movement about a substantially vertical axis whereby the inclination of the plane of the tilling member to the longitudinal extent of the landslide may be varied, the tilling member being inclined during ploughing so as to have a leading edge portion nearer the leg and a trailing edge portion nearer the support structure, wherein a transition edge from the rear of the leg back towards the support structure is so-shaped that with the tilling member inclined, the distance between the periphery of the tilling member and the fixed structure is substantially at a minimum at a location at, or close to, ground level between said periphery and the leg and progressively increases along said periphery towards said support structure.

2. A tilling unit according to claim 1, wherein the transition edge is progressively curved.

3. A tilling unit according to claim 1, wherein the transition edge is formed as a series of straight edges, progressively inclined relative to each other.

4. A tilling unit according to any preceding claim, wherein the bottom end of the leg has a rearwardly extending portion connected directly to the support structure, said landslide having a forward end mounted on said rearwardly extending portion.

5. A tilling unit according to any preceding claim, wherein the tilling member is a rotary inversion wheel having a central, substantially planar, portion and a frustoconical flange-like tilling portion.

6. A tilling unit according to claim 5, wherein the rotary inversion wheel comprises a plurality of lugs or teeth mounted, preferably detachably, to the periphery of the central portion to form said flange-like tilling portion.

7. A tilling unit according to any preceding claim, wherein the support structure comprises means for supporting the tilling member for vertical displacement thereon, whereby the tilling member can rise when being swung from an inclined position to enable it to climb over the connection between the leg and the support structure.

8. A tilling unit according to any preceding claim, wherein the tilling member is rotatable about an axis carried by the support structure, a fixed scraper being carried by the axle for cooperation with the forward side of said tilling member.

9. A tilling unit according to any preceding claim, wherein said minimum distance between the periphery of the inclined tilling member and the fixed structure is about 2.5 cm (1 inch).

10. A tilling unit according to any preceding claim, wherein the distance between the periphery of the inclined tilling member and the fixed structure increases to at least about 15-20 cm (6-8 inches) , when measured horizontally at, or close to, ground level and from the nearest point of the periphery.

11. A tilling unit according to any preceding claim, wherein the distance between the periphery of the inclined tilling member and the fixed structure is at a maximum at approximately the most rearward point of the periphery of the inversion wheel.

12. A tilling unit according to any preceding claim, wherein at least part of the transition edge is generally V-shaped in cross-section.

13. A tilling unit as claimed in any preceding claim, wherein the rotary tilling member is swingable about said substantially vertical axis between a first position and a second oppositely facing position, in which two positions the angle of inclination of the place of the tilling member to the longitudinal extent of the landslide is of similar magnitude, the distances between the periphery of the tilling member and the fixed structure being substantially similar in both said positions of the tilling member.

14. A tilling unit as claimed in any preceding claim, further comprising an upper soil surface turning means or skimmer adapted to extend downwardly into the ground during ploughing to part only of the depth of the rotatory tilling member to lift and turn the upper surface of soil prior to a main full depth ploughing and turning action of the rotary tilling member, said skimmer being mounted in said unit in a trailing, laterally displaced, position, relative to the rotary tilling member, whereby, during ploughing, the portion of the upper surface of the ground turned by the skimmer will be buried by soil turned by a tilling member of a following tilling unit.

15. A tilling unit according to claim 14, wherein the rotatory tilling member in ploughing position is positioned at least principally to one side of the landslide and the skimmer is positioned to the other side of the landslide.

16. A tilling unit according to claim 14 or 15, wherein the skimmer is carried by the same structure as is used to support the rotary tilling member.

17. A tilling unit according to any one of claims 14 to 16, wherein the skimmer is swingable simultaneously with the rotary tilling member from side to side of the direction of extent of the landslide.

18. A tilling unit according to claim 16, wherein both a support for the skimmer and the axle of the main rotatable tilling member are connected for conjoint movement about a common vertical axis bearing.

19. A tilling unit according to any one of claims 14 to 18, wherein means are provided whereby the vertical height of the skimmer is adjustable.

20. A tilling unit according to any one of claims 14 to 19, wherein means are provided for selectively varying the angle of inclination of the skimmer relative to the direction of ploughing and/or to the horizontal.

21. A tilling unit according to any one of claims 14 to 20, wherein the depth of penetration of the skimmer is a minor proportion only of the depth of penetration of the main rotatory tilling member.

22. A tilling unit according to any one of claims 14 to 21, wherein the skimmer is swingable about the same substantially vertical axis as the tilling member in order to be similarly inclined to the direction of ploughing.

23. A tilling unit plough according to any one of claims 14 to 22, wherein the skimmer comprises a second rotatable tilling member of smaller diameter than said rotatory tilling member and itself rotatable about a substantially horizontal axis.

24. A tilling unit according to claim 23, wherein a scraper and/or deflector is provided adjacent the second rotatable tilling member for scraping or deflecting material away therefrom.

25. A tilling unit according to any one of claims 14 to 22, wherein the skimmer comprises a soil turning blade.

26. A tilling unit according to any one of claims 14 to 25, wherein the skimmer is mounted by means including shear bolts or resettable retention means to protect the skimmer upon engagement with an obstruction during use of the plough.

27. A plough comprising a plurality of tilling units as claimed in any preceding claim, wherein each tilling unit is trailed behind a beam with the beam being swingable between positions oppositely inclined to the direction of travel of the tilling apparatus for left- and right-hand ploughing, said rotary tilling members being swingable between their oppositely inclined positions upon movement of the beam between its oppositely inclined positions for left- and right-hand ploughing.