GB2029183A - Rotary soil cultivator with protective plate - Google Patents

Abstract

A soil cultivating implement comprising a plurality of soil working members (6) that are rotatable about the axes of corresponding non-horizontal shafts (5), the shafts (5) being rotatably supported in a row from a hollow box-section frame (1). Denting or other damage to a lower part (2) of the frame (1) and damage to drive transmission members (5, 26) contained inside the frame (1) is greatly reduced when working in stony ground by the provision of at least one protective plate (17) that is releasably arranged between the bottom part (2) of the frame (1) and the rotary soil working members (6). Guide ribs (19) are arranged on the downwardly facing surface of the or each protective plate (17) to act as scrapers that will guide any stone or the like jammed between the protective plate (17) and a shield plate (10) of one of the soil working members (6) outwardly away from the corresponding shaft (5) to a position where it will be released. <IMAGE>

Description

SPECIFICATION Improvements in or relating to soil cultivating implements This invention relates to soil cultivating implements or machines which are of the kind that comprise a frame portion rotatably carrying a plurality of non-horizontal shafts which embody the axes of rotation of rotary soil working members, said frame portion also accommodating parts of a drive transmission to said soil working members. The expression "soil cultivating implement(s) or machine(s)" is shortened to "soil cultivating implement(s)" alone throughout the remainder of this specification for the sake of brevity.

In the use of known soil cultivating implements of the kind set forth, the frame portion, and particularly the bottom thereof, is spaced by a relatively short distance above the surface of the soil that is being cultivated and there is a tendency, particularly when working in stony soil, for stones at or near the ground surface to strike the bottom of the frame portion and this can cause denting or other damage to the bottom of the frame portion, especially if the stones concerned are large and/or firmly embedded in the soil. In the case of a deep dent or other local deformation of the frame portion bottom, parts of the drive transmission that are contained inside the frame portion may be damaged or at least displaced to some extent so that the implement may not be able to continue to operate or may have its operating efficiency impaired.

The present invention seeks to overcome, or at least very markedly to reduce, the shortcoming of known soil cultivating implements of the kind set forth that has been discussed above and accordingly one aspect of the invention, provides a soil cultivating implement of the kind set forth, wherein at least one protective plate is provided between the bottom of said frame portion and the rotary soil working member. The or each protective plate is releasably mounted in such a way that in the event of that plate itself being dented or otherwise damaged to a serious extent, it can be replaced.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure lisa plan view of a soil cultivating implement in accordance with the invention connected to the rear of a n an agricultural tractor, Figure 2 is a section, to an enlarged scale, taken on the line ll-ll in Figure 1, and Figure 3 is a section taken on the line Ill-Ill in Figure 2.

Referring to the accompanying drawings, the soil cultivating implement that is illustrated therein is in the form of a rotary harrow which comprises a hollow box-section frame portion 1 that extends substantially horizontally transverse, and usually (as illustrated) substantially horizontally perpendicular, to the intended direction of operative travel of the implement that is indicated by an arrow A in Figure 1. The frame portion 1 comprises a lower troughshaped part 2 (Figure 2) that is of broad substantially U-shaped cross-section although the limbs of the "U" diverge upwardly away from the broad substantially horizontal base thereof. The upper edges of said limbs of the trough-shaped part 2 are formed with horizontally disposed rims that project forwardly and rearwardly, respectively, relative to the direction A.A horizontal or substantially horizontal cover plate 4 of the frame portion 1 is releasably secured to the upper surfaces of the rims that have just been mentioned by a plurality of short vertically or substantially vertically extending bolts 3, a gasket being interposed between the upper surfaces of the rims and the lower surfaces of edge regions of the cover plate 4to prevent the leakage of oil from the interior of the hollow frame portion 1 and the contamination of oil within that frame portion by external dirt.

A plurality (in this case, twelve) of substantially vertically, or at least non-horizontally, disposed shafts 5 are rotatably journalled in the hollow frame portion 1 and lie in a single row with their longitudinal axes (axes of rotation) spaced apart from one another at intervals which preferably, but not essentially, have magnitudes of substantially 250 millimetres. Each shaft 5 projects downwardly beneath the bottom of the trough-shaped part 2 of the frame portion 1 and there has a corresponding soil working member, that is generally indicated by the reference 6, firmly but releasably secured to it. Each rotary soil working member 6 comprises a substantially horizontally disposed support or carrier 7 having a central internally splined hub that co-operates with matching external splines on a lower end region of the shaft 5 concerned.The opposite ends of each support 7 are integrally or rigidly provided with corresponding sleeve-like tine holders 8 whose longitudinal axes are substantially parallel to one another and to the longitudinal axis of the shaft 5 concerned. It will be seen from Figure 2 of the drawings that each carrier 7 is in perpendicular or substantially perpendicular relationship with the longitudinal axis of the respective shaft 5. The top and front of each tine holder 8 with respect to the intended direction of operative rotation of the soil working member 6 concerned (see the small arrows in Figure 1 of the drawings) is provided with a shield plate 10 which thus lies in advance of a corresponding fastening nut that co-operates with a short screwthreaded upper end part of a fastening portion of a rigid soil working tine 9.The shield plates 10 thus guard the fastening nuts and the screwthreaded parts of the tine fastening portions from direct impacts against stones and other potentially damaging items which the soil working members 6 may meet during their progress through the ground. As can be seen in Figure 2 of the drawings, each tine 9 also includes a downwardly tapering soil working portion that projects downwardly from the lower The drawing(s) originally filed were informal and the print here reproduced is taken from a laterfiledformal copy.

end of the corresponding holder 8 into the soil when the implement is in operation.

Each shaft 5 is rotatably supported from the bottom ofthetrough-shaped part 2 of the frame portion 1 by a corresponding substantially vertical ball bearing 11 that is accommodated in a corresponding bearing housing 12. Each bearing housing 12 has an upwardly directed flange by which it is located in a corresponding hole in the bottom of said troughshaped part 2 and the housing is positively maintained in its appointed position by three substantially vertically extending bolts 13 whose cooperating nuts are mounted internally of a ring 13A that is of channel-shaped cross-section and that is located internally of the hollow frame portion 1 in concentrically surrounding relationship with the shaft 5 concerned.The channel-shaped crosssection of the ring 13A opens upwardly and it will be seen in Figure 2 of the drawings that the upper edges of the ring are deformed inwardly in the regions of the three nuts that co-operate with the corresponding bolts 13 so as to prevent those nuts from being lost from their appointed positions. The upper end of each shaft 5 is rotatably supported from the cover plate 4 of the frame portion 1 buy a corresponding substantially vertical ball bearing 14 that is arranged in a respective bearing housing 15. Each bearing housing 15 fits closely in a corresponding hole in the cover plate 4 and has lugs which co-operate with substantially vertically disposed bolts 16 positively to secure the housing 15 in its appointed position.

The downwardly facing external surface of the troughshaped frame portion part 2 is provided, between that bottom and the soil working members 6, with a protective plate 17 which plate, as shown in the drawings, extends throughout the width of the frame portion 1 in a direction that is parallel to the direction A and throughout the length of that frame portion in a direction that is substantially perpendicular to the direction A. The protective plate 17 is shaped to match the configuration of the part 2 and thus has, at its upper leading and rear edges, substantially horizontally disposed rims which lie beneath those of said part 2.The rims of the protective plate 17 are fastened to those of the trough-shaped part 2 by approximately half of the number of bolts 3 but, as can be seen in Figure 3 of the drawings, the rims of the plate 17 are alternately formed with smaller holes for co-operating with corresponding bolts 3 and larger holes 17A which larger holes 17A are of greater diameter than the maximum diameter of the nuts which co-operate with the respective bolts 3.

Thus, it is only necessary to remove alternate bolts 3 to enable the protective plate to be released from the frame portion 1, these being the bolts 3 that do not register with the holes 17A. The remaining bolts 3 which do register with the holes 17A maintain the cover plate 4 of the frame portion 1 in fastened relationship with the underlying trough-shaped part 2 and avoid breaking the lubricant seal between those parts 4 and 2.

The protective plate 17 is formed with a plurality (in this case, twelve) of circular holes 18 (Figure 3) which holes 18 closely surround circular fastening flanges of the corresponding lower bearing housings 12. The downwardly facing surface of the protective plate 17 is provided at diametrically opposite sides of each hole 18 with a corresponding pair of guide ribs 19.Each guide rib 19 extends away from the edge of the corresponding hole 18 in a direction that is non-perpendicularly transverse to the intended direction of operative travel A and the end thereof that is remote from the respective hole 18 is just short of, but very close to, either the front or the rear (with respect to the direction A) edge of the flat bottom of the protective plate 17 that corresponds to the immediately overlying flat bottom of the trough-shaped part 2 of the frame portion 1. Each rib 19 is of oblong or other polygonal cross-section (see Figure 2) and has a gently curved length which is such that the side thereof which is remote from the corresponding hole 18 is convex.The two ribs 19 that correspond to each hole 18 are arranged in a symmetrically similar manner with respect to that hole 18 with their inner ends located at points which are diametrically opposite to the centre of the hole 18 concerned. As can be seen in Figure 3 ofthedraw- ings, the two points which correspond to these inner ends both intersect a straight line a that extends diametrically across the hole 18 under consideration, the line a being at an angle a to a further diametrically disposed line b which is parallel to the intended direction of operative travel A.The angle a preferably has a value of 45" or substantially 45 . It can also be seen in Figure 3 of the drawings that each guide rib 19 has a curved length which is equal or substantially equal to the diameter of one of the holes 18, each pair of ribs 19 being so disposed with respect to the corresponding hole 18 that they become prog ressively further from the centre of the hole 18 concerned considered lengthwise therealong from their inner to their outer ends in a direction which is the same as the intended direction of operative rotation of the corresponding soil working member 6. The intended directions of operative rotation of two neighbouring soil working members 6 are indicated by curved arrows in Figure 3 of the drawings.

The opposite ends of the hollow frame portion 1 are closed by substantially vertically disposed sector-shaped plates 20 that are parallel to one another and parallel or substantially parallel to the direction A. The tops and fronts, with respect to the direction A, of the end plates 20 are provided with substantially horizontally aligned stub shafts 21 about which corresponding arms 22 are upwardly and downwardly turnable alongside the respective plates 20, the arms 22 being directed generally rearwardly with respect to the direction A from their stub shafts 21. Rear end regions of the sector-shaped plates 20 project behind the remainder of the frame portion 1 and each of them is there provided with a curved row of holes in which each hole is at the same distance from the substantially horizontal axis that is defined by the stub shafts 21. Each arm 22 is formed with at least one hole at the same distance from said axis as the holes in the corresponding end plate 20 and horizontal locking pins 23A, or equivalent bolts, can be entered through these holes to retain the arms 22 in chosen angular settings relative to the frame portion 1 about the substantially horizontal axis that is defined by the stub shafts 21. The arms 22 project rearwardly by some distance beyond the end plates 20 of the hollow frame portion 1 and their rearmost ends are provided with substantially horizontally aligned bearings between which a rotatable supporting member and soil crumbling member, in the form of an open-work roller 23, is mounted so as to be freely rotatable about the substantially horizontal axis that is defined by said bearings.It is not necessary to describe the construction of the roller 23 in detail for the purposes of the present invention and it suffices to say that it comprises a plurality of relatively spaced elongate groundengaging elements 24 that all extend generally parallel to the axis of rotation of the roller but that are wound helically around that axis to a small extent.

The elongate elements 24 are the principal parts which skelletally define the cylindrical groundengaging surface of the roller 23. It will be apparent that the depth to which the tines 9 of the soil working members 6 can penetrate into the ground during the operation of the implement will be dependent to a large extent upon the level of the axis of rotation of the roller 23 relative to that of the frame portion 1 and this level can be changed, to adjust the working depth of the tines 9, by turning the arms 22 upwardly or downwardly about the stub-shafts 21 as may be required, employing the locking pins 23A, or equivalent bolts, temporarily to maintain any chosen setting.

Two substantially vertically disposed shield plates 25 are disposed at locations which are short distances beyond the opposite ends of the row of twelve rotary soil working members 6, each shield plate 25 having a lower edge which is shaped to slide forwardly over the ground surface in the direction A or rearwardly relative to that direction during manoeuvring. Each shield plate 25 is connected by a corresponding pair of arms to a pair of pivots that are mounted on top of the hollow frame portion 1 at a short distance inwardly towards the centre thereof from the corresponding end plate 20. The two pivots of each pair define an axis that is substantially horizontally parallel to the direction A and this allows each shield plate 25 to turn upwardly and downwardly during operative progress in the direction A to match undulations in the surface of the soil that may be met with.The shield plates 25 co-operate with the soil working members 6 at the opposite ends of the row thereof in working the soil and act to reduce the danger of injury of damage to bystanders, livestock and property by preventing the rapidly rotating members 6 from flinging loose stones and the like laterally of the path of travel of the implement.

Each of the twelve shafts 5 is provided, inside the hollow frame portion 1, with a corresponding straight-toothed or spur-toothed pinion 26, the sizes of the identical pinions 26 being such that the teeth of each of them are in mesh with those of the or each immediately neighbouring pinion in the single row of pinions. It will accordingly be realised that, during operation, each pinion 26 and the corresponding soil working member 6 will revolve in a direction which is opposite to the direction of rotation of the or each immediately neighbouring pinion 26 and soil working member 6. These directions of rotation are indicated by the aforementioned arrows in Figures 1 and 3 of the drawings.The shaft 5 that corresponds to one of the central pair of soil working members 6 has an upward extension through the cover plate 4 of the hollow frame portion 1 into a gear box 27 that is fastened to the top of the hollow frame portion 1.

The parts of the drive transmission to the rotary soil working members 6 that are contained within the gear box 27 comprise bevel pinions and two shafts that extend substantially horizontally parallel to one another and to the direction A, said two shafts being located one above the other. The rearmost ends of said two shafts project through the back of the gearbox 27 into a change-speed gear 28 that it is not necessary to describe in detail for the purposes of the present invention. However, briefly, the ends of the two shafts which project into the change-speed gear 28 are both splined for the reception of the matchingly splined hubs of exchangeable and interchangeable pairs of straight-toothed or spur-toothed pinions which are of different sizes.The particular pair of pinions that is chosen for use in the changespeed gear 28, and the arrangement thereof that is selected on the splined shaft ends, dictates the transmission ratio between the upper one of said two substantially horizontal shafts in the gear box 27, which shaft is referenced 29 in Figure 1 of the drawings, and the underlying and parallel shaft which cannot be seen in that Figure thus enabling the twelve rotary soil working members 6 to be revolved at any chosen one of a number of different speeds without having to vary the initiating speed of rotation that is applied to the leading splined or otherwise keyed end of the shaft 29 which projects forwardly from the front of the gear box 27 as a rotary input shaft of that gear box.The leading splined end of the shaft 29 is intended to be placed in driven connection with the rear power take-off shaft of an agricultural tractor or other operating vehicle of the implement by way of an intermediate telescopic transmission shaft 30, which is of a construction that is known per se, having universal joints at its opposite ends. The front of the frame portion 1, with respect to the direction A, is provided, mid-way between the general planes of its two end plates 20, with a coupling member ortrestle 31 that is of substantially triangular configuration as viewed in front or rear elevation.The coupling member or trestle 31 is employed in a manner which is knownperse, and which is illustrated somewhat diagrammatically in Figure 1 of the drawings, in connecting the implement to the three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle and it will be noted that, for strengthening purposes, locations towards the apex of the coupling member or trestle 31 are rigidly connected to well spaced apart anchorages at the top and rear of the frame portion 1 by downwardly and rearwardly divergent tie beams.

In the use of the soil cultivating implement that has been described, its coupling member or trestle 31 is connected to the three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle as discussed above and the telescopic transmission shaft 30 is employed to place the rotary input shaft 29 of the gear box 27 in driven connection with the rear power take-off shaft of the same tractor or other operating vehicle. Adjustments that may, if required, be made before work commences include setting the speed at which the soil working members 6 will be indirectly driven from the shaft 29 by changing the transmission ratio in the change-speed gear 28 as discussed above.The depth to which the tines 9 of the soil working members 6 can penetrate into the soil may be adjusted by raising the level of the axis of rotation of the roller 23 relative to the level of the frame portion 1 employing the locking pins 23A, or equivalent bolts, to maintain any chosen depth setting as long as may be required. As the implement is moved operatively in the direction A over land that is to be cultivated thereby, the twelve rotary sail working members 6 work a single broad strip of land that will have a width of substantially 3 metres since the distance between the soil working portions of the two tines 9 of each member 6 is a little greater than the preferred spacing (250 millimetres) between the axes of rotation of neighbouring member 6 as a result of which the strips of land that are worked by the individual members 6 successively overlap one another.The protective plate 17 that is releasably secured to the bottom of the hollow frame portion 1 so as to lie between that bottom and the soil working members 6 gives a high degree of protection to said bottom against denting and like damage by large stones and the like that may be turned up by the members 6 and the danger of the trough-shaped part 2 of the frame portion 1 itself being dented or otherwise damaged to any significant extent is thus very greatly reduced, if not entirely eliminated, so that the consequent danger of breakage of parts of the drive transmission to the members 6 that are contained inside the frame portion 1, or efficiency reducing disturbance of those parts, is also very greatly reduced.

Due to the provision of the pairs of guide ribs 19 at diametrically opposite sides of each hole 18 in the bottom of the protective plate 17, any stone or like hard object that may temporarily become trapped between the top of the support or carrier 7 or one of the shield plates 10 of one of the soil working members 6 and the downwardly facing surface of the bottom of the protective plate 17 will tend to be urged outwardly along one of the corresponding pair of guide ribs 19 away from the respective shaft 5 as the member 6 under consideration continues its rotation. Such a stone or the like will fall back to the ground after it has reached the outer end of the guide rib 19 against which it has been pressed because it will then become clear of contact with the soil working member 6 concerned and will no longer be trapped between that member 6 and the bottom of the protective plate 17.It will be appreciated that the guide ribs 19 co-operate with the tops of the soil working members 6, and particularly with the shield plates 10 thereof, in the manner of scrapers. If, exceptionally, the protective plate 17 should become dented or otherwise damaged to a serious extent, it can be removed from the hollow frame portion 1 by undoing the bolts 3 that do not register with the holes 17A, leaving the bolts 3 which do register with the holes 17a in a tightened condition. The whole protective plate 17 can then be released from the remainder of the implement without breaking the seal between the rims of the trough-shaped part 2 and the registering rims of the cover plate 4.

It the protective plate 17 is constantly to be used with the hollow frame portion 1,then the troughshaped part 2 of that frame portion may be made from thinner gauge material than would otherwise be desirable. It will be appreciated that, when the implement is to be employed in the working of soil which is substantially stone-free, the protective plate 17 may be removed. Such use is, of course, outside the scope of the present invention. Conversely, the protective plate 17 may be separately supplied for use with an existing implement whose frame portion 1 is particularly liable to receive damage by being used in stony ground.Although it is preferred to employ a single protective plate 17, it will be realised that this is not essential and that, if desired, two or more separate plates could be provided along the length of the frame portion 1 (in a direction transverse to the direction A) provided only that each portective plate registers with sufficient of the alternate fastening bolts 3 to enable itto be maintained reliably in its working position. With such a construction, any protective plate that became damage could be replaced without having to disturb the other protective plates. It is also noted that, although the invention has been described in relation to a soil cultivating implement having twelve of the rotary soil working members 6, this number of members 6 is by no means mandatory and the invention is equally applicable to implements having a greater or lesser number of rotary soil working members.

Although certain features of the soil cultivating implement hat have been described and/or that are illustrated in the accompanying drawings will be set forth in the following claims as inventive features, it is emphasised that the invention is not necessarily limited to those features and that it includes within its scope each of the parts of the soil cultivating implement that has been described, and/or that is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (23)

1. A soil cultivating implement of the kind set forth, wherein at least one protective plate is provided between the bottom of said frame portion and the rotary soil working members.

2. An implement as claimed in claim 2, wherein a single protective plate is provided that extends ihroughoutthe length of said frame portion.

3. An implement as claimed in claim 1 or 2, wherein the or each protective plate extends throughout the width of the frame portion.

4. An implement as claimed in any preceding claim, wherein the or each protective plate is secured to said frame portion at both substantially the front and substantially the rear thereof with respect to the intended direction of operative travel of the implement.

5. An implement as claimed in any preceding claim, wherein the or each protective plate is secured to a rim of a lower part of said frame portion, said lower part being substantially trough-shaped and being closed, at the top, by a cover plate.

6. An implement as claimed in claim 5, wherein bolts that are employed for securing the cover plate and the lower part of the frame portion to one another also serve for securing the or each protective plate to the frame portion.

7. An implement as claimed in claim 6, wherein the or each protective plate is formed, at locations between holes which co-operate fasteningly with said bolts, with holes that are of larger diameter than said bolts and their co-operating nuts whereby the or each protective plate can be removed from the frame portion without releasing the bolts which register with said larger diameter holes.

8. An implement as claimed in any preceding claim, wherein the or each protective plate is shaped to bear abuttingly against the lower surface of the bottom of said frame portion throughout substantially the whole of its area.

9. An implement as claimed in any preceding claim, wherein the or each protective plate is formed with holes which are arranged to have said shafts that embody the axes of rotation of the rotary soil working members entered therethrough.

10. An implement as claimed in claim 9, wherein said shafts are rotatably supported from the bottom of the frame portion by bearings arranged in bearing housings which fit in said holes in the protective plate or plates.

11. An implement as claimed in any preceding claim, wherein the lower surface of the or each protective plate is provided with spaced scrapers for co-operation with the rotary soil working members.

12. A soil cultivating implement of the kind set forth, wherein scrapers are arranged between the bottom of said frame portion and the rotary soil working members for co-operation with the latter.

13. An implement as claimed in claim 11 or 12, wherein each scraper is in the form of a rib and is located in close proximity to a hole, or to one of said holes, through which a corresponding one of said shafts is rotatably entered.

14. An implement as claimed in claim 13, wherein each rib is elongate in a direction that is transverse to the intended direction of operative travel of the implement.

15. An implement as claimed in claim 13 or 14, wherein each rib extends, from the edge of the respective hole, towards either the front or the rear of the bottom of said frame portion with respect to the intended direction of operative travel of the implement.

16. An implement as claimed in any one of claims 13 to 15, wherein said ribs are provided in pairs, the two ribs of each pair being located respectively in front of, and behind, the corresponding hole relative to the intended direction of operative travel of the implement.

17. An implement as claimed in any one of claims 13 to 16, wherein each rib is of elongate curved configuration, the convex side of said curve being remote from the corresponding hole.

18. An implement as claimed in any one of claims 13 to 17, wherein each rib extends away from the corresponding hole in such a way that, moving along that rib from said hole, the distance between the axis of rotation of the corresponding soil working member and said rib progressively increases considered in the intended direction of operative rotation of that soil working member.

19. An implement as claimed in claim 16 orin either claim 17 orclaim 18 when read asappendant to claim 16, wherein the two ribs of each pair meet the edge of the corresponding hole at points which are diametrically opposite with respect to the centre of the hole.

20. An implement as claimed in claim 19, wherein a straight line containing said two points is inclined at an angle of 45" or substantially 45" to a further diametrically disposed straight line that is parallel to the intended direction of operative travel of the implement.

21. An implement as claimed in any one of claims 13 to 20, wherein each rib has a length which is substantially equal to the diameter of the corresponding hole.

22. An implement as claimed in any one of claims 13 to 21, wherein each rib is of oblong or other polygonal cross-section.

23. Asoil cultivating implement of the kind set forth substantially as hereinbefore described with reference to the accompanying drawings.