GB1592634A - Soil cultivating implements or machines - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO SOIL CULTIVATING IMPLEMENTS OR MACHINES (71) We, TEXAS INDUSTRIES INC., of Willemstad, Curacao, The Netherlands Antilles, a Limited Liability Company organised under the laws of The Netherlands Antilles, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to soil cultivating implements or machines of the kind which comprise at least one soil working member that is drivably rotatable about a vertical or substantially vertical axis, said soil working member being provided with at least one freely rotatable cultivating tool. The term "implement(s) or machine(s)" is shortened to "implement(s)" alone throughout the remain der of this specification for the sake of brevity.

According to the invention, there ispro- vided a soil cultivating implement of the kind set forth, wherein the or each freely rotatable cultivating teol comprises at least two soil working elements that extend substantially perpendicular to a member that embodies the axis of rotation of that tool, which axis is inclined to the axis of rotation of that soil working member.

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 1 is a plan view of a soil cultivating implement in accordance with the invention connected to the rear of an agricultural tractor, Figure 2 is a plan view, to an enlarged scale, illustrating the construction and arrangement of two neighbouring soil working members of the implement of Figure 1, Figure 3 is a part-sectional elevation as seen in the direction indicated by an arrow III in Figure 2, and Figure 4 is an elevation as seen in the direction indicated by an arrow IV in Figure 3.

Referring to the accompanying drawings, the soil cultivating implement which is illu strated therein has a frame which comprises a hollow box-section frame portion 1 that extends substantially horizontally transverse, and usually (as illustrated) substantially perpendicular, to the intended direction of operative travel of the implemnt which is indicated in Figure 1 by an arrow A. A plurality of vertical or substantially vertical shafts 2 are rotatably mounted in the hollow frame portion 1 and are arranged in a single row with their axes of rotation spaced apart from one another at regular intervals which advantageously, but not essentially, have magnitudes of substantially 375 millimetres. There are eight of the shafts 2 in the embodiment which is being described but it is emphasised that there could be a greater or lesser number thereof. The lowermost end of each shaft 2 projects downwardly from beneath the hollow frame portion 1 and is there provided with a corresponding soil working member 3 whose construction and arrangement will be further described below. Each shaft 2 is provided, inside the hollow frame portion 1, with a corresponding straight-toothed or spurtoothed pinion 4, the size and arrangement of the pinions 4 being such that the teeth of each of them are in mesh with those of the or each immediately neighbouring pinion 4 in the row of eight such pinions. A shaft 5 that is in substantially vertically parallel relationship with the shafts 2 is provided at substantially the rear of the hollow frame portion 1, with respect to the direction A, and substantially midway across the width of the frame portion 1 in a direction that is perpendicular to the direction A. The shaft 5 has a portion that is located inside the hollow frame portion 1 and also a portion which projects above the top of the latter.

The shaft 5 carries, inside the hollow frame portion 1, a pinion 6 whose teeth are in driving mesh with those of one of the centre pair of larger pinions 4 in the single row of those pinions. The portion of the shaft 5 that extends above the top of the hollow frame portion 1 projects into a gear box 7 that is secured in position on top of the frame portion 1 substantially midway across the width thereof. A bevel pinion (not illustrated) on the portion of the shaft 5 that is located inside the gear box 7 is in driven mesh with a further bevel pinion (also not shown) carried by a substantially horizontally disposed rotary input shaft 8 of the gear box 7 which shaft 8 has a splined or otherwise keyed portion which projects forwardly from the front of the gear box 7 in substantially the direction A. The forwardly projecting splined or otherwise keyed portion of the rotary input shaft 8 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, that is of a construction which is known per se, having universal joints at its opposite ends. Part of such a transmission shaft is illustrated somewhat diagrammatically in Figure 1 of the drawings. The opposite ends of the hollow box-section frame portion 1 are closed by side plates 9 that are substantially vertically parallel to one another and parallel or substantially parallel to the direction A.

Each of the soil working members 3 comprise a substantially horizontally disposed support or carrier 10 which has a central internally splined hub 11 whose splines co-operate with matching external splines on the portion of the associated shaft 2 which projects downwardly from beneath the bottom of the hollow frame portion 1. Moreover, each shaft 2 has a lowermost screwthreaded end part of reduced diameter which end part receives a washer and a co-operating fastening nut 12 which, when tightened, prevents the soil working member 3 concerned from becoming detached from its driving shaft 2. Each nut 12 is preferably provided, as diagrammatically illustrated in Figure 3, with a split pin or other means which is designed to prevent it from working loose when the implement is in use. The support or carrier 10 of each soil working member 3 comprises two arms 13 which are both straight and of equal lengths, said arms 13 projecting from diametrically opposite sides of the corresponding hub 11.

The two arms 13 of each support or carrier 10 extend radially with respect to the longitudinal axis/axis of rotation of the corresponding shaft 2, such axes being denoted by the reference a in the drawings. The outer ends of the two arms 13 of each pair either integrally (as illustrated) or at least rigidly carry corresponding substantially cylindrical sleeve-like holders 14, the longitudinal axes b of the two holders 14 of each soil working member 3 being coplanar with the corresponding axis of rotation a but, as will be evident from Figure 3 of the drawings, being in non-parallel relationship with that axis a.

The stepped interior of each sleeve-like holder 14 rotatably receives the also stepped upper end 15 of a corresponding straight shaft 16 which projects obliquely downwardly from the lowermost end of the holder 14 concerned.

Each freely rotatable shaft 16 is so disposed that its longitudinal axis is coincident with the longitudinal axis b of the holder 14 in whose interior the upper end 15 of that shaft is rotatably received. Figure 3 of the drawings shows that, in the plane which contains the axis of rotation a and the corresponding two axes b for each soil working member 3, each axis b is inclined to a line which is parallel to the corresponding axis a at an angle sc that advantageously has a magnitude of substantially 100. The two shafts 16 of each pair are downwardly convergent towards one another so that their upper ends 15 are further spaced apart from one another than are their lower ends. It will be apparent from Figure 3 of the drawings that, due to the coplanar relationship of each axis of rotation a and the corresponding pair of axes b, there will be a point, for each soil working mem her 3, where the three axes a and b concerned all intersect.

The upper end 15 of each shaft 16, which upper end 15 is in the nature of a stub shaft, is rotatably received in the corresponding holder 14 by opposed and relatively spaced lower and upper tapered roller bearings 17 and 18 that are of different diameters, the lower bearing 17 of each pair 17/18 being the bearing which is of larger diameter. The inner race of each lower bearings 17 abuts, at its lower end, against a step or shoulder of the corresponding upper shaft end 15 whereas the lower end of the outer race of the corresponding upper bearing 18 abuts against an internal step or shoulder of the surrounding holder 14. The upper end of each holder 14 is closed by a corresponding cover or cap 19 whose recessed centre is releasably secured to the upper extremity of the upper shaft end 15 concerned by the head of a bolt 20 whose shank is screwed axially into said upper end 15. The recess in the top of each cover or cap 19 completely re ceives the head of the corresponding bolt 20 so that said head does not project above the cover or cap. It will be seen from Figure 3 of the drawings that a rotary seal is provided between a convex cylindrical wall of each cover or cap 19 and the surrounding concave cylindrical wall of the respective holder 14. The bottom of each holder 14 is closed by an annular ring 21 whose inner edge region abuts against an underlying step or shoulder 22 of the upper shaft end 15 concerned. It will also be seen in Figure 3 of the drawings that a second lower rotary seal is provided immediately above each ring 21 so as to extend between that ring and the lower end of the corresponding lower tapered roller bearing 17.

The step or shoulder 22 of each shaft 16 constitutes a boundary between the upper end 15 of that shaft and a lower portion 23 thereof which latter portion is provided with a plu rality of soil working elements of which, in the embodiment that is being described, there are three elements 24, 25 and 26 per shaft portion 23. The portion 23 of each shaft 16 has a polygonal cross-section which advantageously, as illustrated, is a square one.

The elements 24, 25 and 26 are spaced apart from one another along the shaft portion 23 concerned and both the upper element 24 and the central element 25 are of straight strip-shaped configuration, the strip material from which they are made having a width of substantially 60 millimetres and a thickness of substantially 10 millimetres, both elements 24 and 25 being disposed perpendicular or substantially perpendicular to the corresponding axis b. The uppermost element 24 of each group of three has a length which may advantageously be substantially 300 millimetres and said length is greater than that of the underlying central element 25 which latter, in the embodiment that is being des cribed, has a length of substantially 240 millimetres. The lowermost element 26 of each group of three elements is of polygonal configuration and is advantageously, as illustrated, square or substantially square, each edge of the square having a length of substantially 180 millimetres and being bevelled so as to constitute a cutting edge. The general plane of each lower element 26 is also perpendi cular of substantially perpendicular to the corresponding axis b and said element 26 is formed from material of substantially the same thickness as that which is employed for the companion elements 24 and 25, i.e., a mat serial~~ having a thickness of~ substantialIy 10 millimetres. Each of the elements 24 and 25 is formed, midway along its length, with a hole and each lower element 26 is similarly formed with a central hole, said holes matching the polygonal configuration of the shaft portion 23 with which they are to co-operate and thus, in this embodiment, all being square in shape. The elements 24 25 and 26 are slid onto the corresponding shaft portion 23 from its lower end and are kept in their appointed spaced apart relationship by spacing sleeves 27 whose cross-sectional shapes match those of the shaft portion 23. The sleeves 27 which extend between the upper and cen tral elements 24 and 25 preferably have the same axial lengths as do the sleeves which lie between the central and lower elements 25 and 26. Bolts 28 have their shanks screwed axially into the lower ends of the shaft por tions 23 and the heads of said bolts 28 co operate with washers in clamping the groups of elements 24, 25 and 26, and the inter vening spacing sleeves 27, between those heads and the steps or shoulders 22 of the shaft 16 concerned. It can be seen in Figures 2 to 4 of the drawings that the central ele ment 25 of each group is arranged to project from opposite sides of the corresponding axis b in directions which are perpendicular, or substantially perpendicular, to the direction in which the associated upper element 24 projects from the same axis b. Due to the inclination tr of the axes b to lines which are parallel to the substantially vertical axes of rotation a, the upper and lower flat surfaces of the elements 24, 25 and 26 are all signifi cantly inclined to the horizontal and the flat outer surfaces of the polygonal spacing sleeves 27 are all significantly inclined to the vertical.

The fronts of the two frame portion side plates 9, with respect to the direction A, are provided with substantially horizontally aligned stub shafts 29 and corresponding arms 30, which extend rearwardly from said stub shafts 29 with respect to the direction A, are turnable upwardly and downwardly about said stub shafts 29 alongside the respective plates 9. Rear edge regions, with respect to the direction A, of the side plates 9 that project behind the remainder of the hollow frame portion 1 are formed with curved rows of holes at the same distances from the substantially horizontal axis which is defined by the stub shafts 29. The arms 30 are formed with holes at the same distance from said axis and bolts 31 are provided for entry through the holes in the arms 30 and chosen of the curved rows of holes in the side plates 9 so that, when tightened, said bolts 31 will retain the arms 30 firmly but releasably in chosen angular positions about the axis which is defined by the substantially horizontally aligned stub shafts 29. The arms 30 project rearwardly behind the side plates 9 with respect to the direction A and their rearmost ends have an open-work cage formation ground roller 32 mounted between them in a freely rotatable manner so that said roller 32 extends throughout the combined working width of the eight soil working members 3. The roller 32 has a central, preferably tubular, axially extending carrier 35 and a plurality, such as five, of support plates 34 are secured to said carrier 35 at regularly spaced apart intervals along the length thereof, two of said plates 34 being located close to the opposite ends of the carrier 35. The support plates 34 are of substantially circular con figuration and are in parallel substantially vertically - disposed relationship with one another and parallel or substantially parallel relationship with the direction A. Each support plate 34 is formed at regular intervals around its periphery with a plurality of holes and elongate elements 33 of rod-shaped or tubular formation are entered lengthwise through said holes in the successive plates 34 so as to extend helically around the central carrier 35 to some extent and so as to form the skeletal ground-engaging cylindrically curved surface of the roller 32.

Two supports 36 that both extend sub stantially horizontally parallel to the direction A are arranged on top of the hollow frame portion 1 at short distances inwardly from the opposite ends of that frame portion. That side of each support 36 which faces towards the adjacent end of the frame portion 1 is provided with two pairs of projecting lugs 37, said pairs of lugs 37 being spaced apart from one another along the length of the support 36 concerned. The two pairs of lugs 37 that correspond to each support 36 carry aligned pivct pins which define an axis that is substantially horizontally parallel to the direction A and the ends of two arms 38 are mounted on said pivot pins, in a freely turnable manner, between the lugs 37 of the two pairs. The two arms 38 that correspond to each support 36 extend, in convergent relationship, towards, and over, the adjacent end of the hollow frame portion 1 where they are both bent over downwardly to be secured to a corresponding shield plate 39 which will usually be substantially vertically disposed in parallel or substantially parallel relationship with the direction A. The lower edges of the two shield plates 39 are shaped to make sliding progress over the soil in the direction A during the operation of the implement and in the reverse direction during manoeuvring and it will be apparent that both shield plates 39 are turnable upwardly and downwardly about the axes that are defined by the corresponding pivot pins which connect the arms 38 to the pairs of lugs 37 so that said shield plates can match undulations in the surface of the soil over which the implement travels in the use thereof. The shield plates 39 co-operate with the soil working members 3 at the opposite ends of the row of those soil working members in ensuring that the soil is worked by the implement to substantially the same intensity as occurs at locations which are further from the edges of the path of operation thereof. Moreover, the shield plates substantially prevent stones and like hard objects from being flung laterally of the path of travel of the implement when it is in use thus very greatly reducing the danger of injury or damage to bystanders, property and so on. The front of the hollow frame portion 1, with respect to the direction A, is provided, midway between the general planes of the two side plates 9, with a coupling member or trestle 40 which is of substantially triangular configuration as seen in front or rear elevation. Lower parts of the coupling member or trestle 40 are secured to the leading ends of two further supports 41 which, like the supports 36, extend substantially parallel to the direction A at two locations on top of the hollow frame portion 1 which locations are spaced by equal distances from the midpoint of said frame por ticn. A location at substantially the apex of the generally triangular coupling member or trestle 40 is connected by two downwardly and rearwardly divergent strengthening tie beams 42 to points which are on top of the two further supports 41 and close to the rearmost ends of those supports 41 with res pect to the direction A. The coupling mem ber or trestle 40 is constructed and arranged for connection to the free ends of the lifting links of a three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle of the implement, such form of connection being well known per se and being illustrated only diagrammatically in Figure 1 of the drawings.

In the use of the soil cultivating implement that has been described, its coupling member or trestle 40 is connected to the three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle and the rear power take-off shaft of the same tractor or other vehicle is placed in driving connection with the forwardly projecting splined or otherwise keyed end of the rotary input shaft 8 of the gear box 7 by way of the previously mentioned known telescopic transmission shaft that has universal joints at its opposite ends. Adjustments that may need to - -be made, before work commences, include setting the maximum depth to which the soil working members 3 of the implement will be able to penetrate into the ground by moving the freely rotatable roller 32 bodily upwards, or downwards, relative to the hollow frame portion 1 by turning the arms 30 about the axis which is defined by the stub shafts 29 in the manner previously described, using the bolts 31 to maintain any newly chosen level of the roller 32 relative to the frame portion 1 for as long as may be required.

As the implement makes operative progress in the direction A, it is partially supported from the ground by the roller 32 which thus functions as a rotatable supporting member of the implement. Due to the intermeshing relationship of the pinions 4 inside the hollow frame portion 1, those pinions 4, together with the corresponding shafts 2 and soil work ing members 3, will be rotated about the respective axes a in the directions which are indicated by small arrows in Figure 1 of the drawings and by arrows at the right-hand side of Figure 2. Thus, each soil working member 3 is positively rotated in a direction which is opposite to that of its neighbour, or to those of both of its neighbours, in the single row of eight such members 3. It will be evi dent from the upper part of Figure 1 of the drawings and from Figure 2 thereof that the strips of soil which are worked by the indi vidual members 3 considerably overlap one another so as, in effect, to cultivate a single broad strip of land which, in the embodiment that has been described, where the eight axes of rotation a are spaced apart from one another by distances of substantially 375 milli metres, will have a width of substantially 3 metres. The drive which is applied to the shaft 8 is, of course, transmitted to the pinions 4 by way of the bevel pinions (not illustrated) inside the gear box 7, the shaft 5 and the pinion 6. Each assembly which comprises a group of three soil working elements 24, 25 and 26, together with the intervening spacing sleeves 27, may be considered as affording a cultivating tool which is generally indicated in the drawings by the reference 16A. It will be appreciated that each tool 16A is freely rotatable relative to the corresponding holders 14 about the respective axis b and, since the two axes b which correspond to each soil working member 3 are in downwardly convergent relationship with each other and with the axis of rotation a of the soil working member 3 concerned, the two tools 16A of each member 3 will tend to revolve about the corresponding axes b in the directions which are indicated by arrows in Figure 2 of the drawings, it being noted that these directions are opposite to the direction of positively driven rotation of the soil working member 3 of which said two cultivating tools 16A form parts. Each tool 16A attacks the soil at three different vertically spaced apart levels and, due to the inclinations of the elements 23, 24 and 25 to the horizontal, said tools 1 6A tend to displace the soil which they attack upwardly. The result is that the soil is well crumbled and mixed and this action is enhanced by the considerably overlapping relationship of the successive soil working members 3 along the row thereof. In addition to performing its supporting and depth control functions, the roller 32 which lies behind the members 3 with respect of the direction A performs a gentle levelling and consolidating action upon the soil that has been worked by the members 3 and will tend to crush any stubborn lumps of soil that may remain unbroken at or near the surface thereof, said roller 32 thus also acting as a soil working member in its own right. The cutting edges of the lower soil working elements 26 will tend to cut through the roots of any growing weeds and other unrequired plants so that such plants will usually be killed by the cultivating action d the implement. The free rotatability about the axes b of the tools 1 6A enables the elements 24, 25 and 26 of those tools to deflect readily to avoid being damaged by embedded stones and the like but, nevertheless, damage to the element does sometimes occur and, of course, inevitable wear eventually reduces their effectiveness to below an acceptable minimum standard. When one or more of the elements needs to be replaced, the corresponding bolt or bolts 28 is or are temporarily removed whereupon it is only necessary to slide the separate parts of the tool 16A concerned downwardly off the corresponding lower shaft portion 23 and to replace the worn and/or damaged element or elements with fresh elements, the latter being inexpensive to replace because of their very simple formation. It is only then necessary to re-assemble the or each removed tool 16A and to replace and tighten the or each corresponding clamping bolt 28. It has been found that the use of strip-shaped soil working elements that project from opposite sides of the axes b about which they are freely rotatable, said elements being arranged in groups that project from said axes b by progressively decreasing distances, considered downwardly along said groups from top to bottom, considerably reduces the power input that is required to drive the soil working members 3 as compared with, purely for example, soil working members which have rigid and fixedly mounted tines.

The soil cultivating implement and the soil working members thereof that have been described also form the subject of our copending Patent Application No. 7540/78 (Serial No. 1,592,635) to which reference is directed.

WHAT WE CLAIM IS:- 1. A soil cultivating implement of the kind set forth, wherein the or each freely rotatable cultivating tool comprises at least two soil working elements that extend substantially perpendicular to a member that embodies the axis of rotation of that tool, which axis is inclined to the axis of rotation of tha; soil working member.

2. An implement as claimed in claim 1, wherein said two soil working elements have different shapes.

3. An implement as claimed in claim 1 or 2, wherein said soil working elements are formed with holes that co-operate slidably, for installation and removal purposes, with said member which embodies, or said members which embody, the axis of rotation of the tool or corresponding tool.

4. An implement as claimed in claim 3, wherein said member which embodies the axis of rotation of the or each tool is in the form of a shaft or sleeve having a polygonal cross-section, the corresponding soil working elements being rendered non-turnable relative to the or each such shaft or sleeve by the cc-operation of said holes which are formed therein with said polygonal crosssection.

5. An implement as claimed in any preceding claim, wherein the axis of rotation of the or each cultivating tool is a nonhorizontally disposed axis.

6. An implement as claimed in any preceding claim, wherein the axis of rotation of the or each cultivating tool of said soil working member is inclined to a line whch is parallel to the axis about which the mem

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (18)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   3 metres. The drive which is applied to the shaft 8 is, of course, transmitted to the pinions 4 by way of the bevel pinions (not illustrated) inside the gear box 7, the shaft 5 and the pinion 6. Each assembly which comprises a group of three soil working elements 24, 25 and 26, together with the intervening spacing sleeves 27, may be considered as affording a cultivating tool which is generally indicated in the drawings by the reference 16A. It will be appreciated that each tool 16A is freely rotatable relative to the corresponding holders 14 about the respective axis b and, since the two axes b which correspond to each soil working member 3 are in downwardly convergent relationship with each other and with the axis of rotation a of the soil working member 3 concerned, the two tools 16A of each member 3 will tend to revolve about the corresponding axes b in the directions which are indicated by arrows in Figure 2 of the drawings, it being noted that these directions are opposite to the direction of positively driven rotation of the soil working member 3 of which said two cultivating tools 16A form parts. Each tool 16A attacks the soil at three different vertically spaced apart levels and, due to the inclinations of the elements 23, 24 and 25 to the horizontal, said tools 1 6A tend to displace the soil which they attack upwardly. The result is that the soil is well crumbled and mixed and this action is enhanced by the considerably overlapping relationship of the successive soil working members 3 along the row thereof. In addition to performing its supporting and depth control functions, the roller 32 which lies behind the members 3 with respect of the direction A performs a gentle levelling and consolidating action upon the soil that has been worked by the members 3 and will tend to crush any stubborn lumps of soil that may remain unbroken at or near the surface thereof, said roller 32 thus also acting as a soil working member in its own right. The cutting edges of the lower soil working elements 26 will tend to cut through the roots of any growing weeds and other unrequired plants so that such plants will usually be killed by the cultivating action d the implement. The free rotatability about the axes b of the tools 1 6A enables the elements 24, 25 and 26 of those tools to deflect readily to avoid being damaged by embedded stones and the like but, nevertheless, damage to the element does sometimes occur and, of course, inevitable wear eventually reduces their effectiveness to below an acceptable minimum standard. When one or more of the elements needs to be replaced, the corresponding bolt or bolts 28 is or are temporarily removed whereupon it is only necessary to slide the separate parts of the tool 16A concerned downwardly off the corresponding lower shaft portion 23 and to replace the worn and/or damaged element or elements with fresh elements, the latter being inexpensive to replace because of their very simple formation. It is only then necessary to re-assemble the or each removed tool 16A and to replace and tighten the or each corresponding clamping bolt 28. It has been found that the use of strip-shaped soil working elements that project from opposite sides of the axes b about which they are freely rotatable, said elements being arranged in groups that project from said axes b by progressively decreasing distances, considered downwardly along said groups from top to bottom, considerably reduces the power input that is required to drive the soil working members 3 as compared with, purely for example, soil working members which have rigid and fixedly mounted tines.

   The soil cultivating implement and the soil working members thereof that have been described also form the subject of our copending Patent Application No. 7540/78 (Serial No. 1,592,635) to which reference is directed.

   WHAT WE CLAIM IS:- 1. A soil cultivating implement of the kind set forth, wherein the or each freely rotatable cultivating tool comprises at least two soil working elements that extend substantially perpendicular to a member that embodies the axis of rotation of that tool, which axis is inclined to the axis of rotation of tha; soil working member.
2. 2. An implement as claimed in claim 1, wherein said two soil working elements have different shapes.
3. 3. An implement as claimed in claim 1 or 2, wherein said soil working elements are formed with holes that co-operate slidably, for installation and removal purposes, with said member which embodies, or said members which embody, the axis of rotation of the tool or corresponding tool.
4. 4. An implement as claimed in claim 3, wherein said member which embodies the axis of rotation of the or each tool is in the form of a shaft or sleeve having a polygonal cross-section, the corresponding soil working elements being rendered non-turnable relative to the or each such shaft or sleeve by the cc-operation of said holes which are formed therein with said polygonal crosssection.
5. 5. An implement as claimed in any preceding claim, wherein the axis of rotation of the or each cultivating tool is a nonhorizontally disposed axis.
6. 6. An implement as claimed in any preceding claim, wherein the axis of rotation of the or each cultivating tool of said soil working member is inclined to a line whch is parallel to the axis about which the mem

   ber is drivably rotatable at an angle of substantially 100.
7. 7. An implement as claimed in any preceding claim, wherein at least one of the soil working elements of the or each member is of elongate formation and has a straight or substantially straight configuration.
8. 8. An implement as claimed in any preceding claim, wherein the or each rotatable cultivating tool comprises more than two of said soil working elements which elements are in spaced superposed relationship with one another.
9. 9. An implement as claimed in claim 8, wherein the superposed soil working elements of the or each rotatable cultivating tool are spaced apart from one another by equal or substantially equal distances.
10. 10. An implement as claimed in claim 8 or 9, wherein the distances by which the spaced superposed soil working elements of the or each cultivating tool project from the axis d rotation of that tool progressively decrease from the upper to the lower element thereof.
11. 11. An implement as claimed in any preceding claim, wherein the at least two soil working elements of the or each tool are elongate and, when viewed in a direction parallel to the axis of rotation of the tool of which they form parts, are angularly offset relative to one another about that axis.
12. 12. An implement as claimed in claim 11, wherein the angle of offset about said axis is 900 or substantially 900.
13. 13. An implement as claimed in any preceding claim, wherein at least one of the soil working elements of the or each rotatable cultivating tool is formed from strip material and is arranged so that the width of the strip extends perpendicular or substantially perpendicular to the axis of rotation of the tool.
14. 14. An implement as claimed in any one of claims 1 to 3, wherein each soil working element of the or each rotatable cultivating tool is connected at substantially its centre to a shaft or sleeve embodying the axis of rotation of that tool.
15. 15. An implement as claimed in claim 8 or in any one of claims 9 to 14 when read as appendant to claim 8 wherein spacing sleeves are arranged between the superposed soil working elements of the or each cultivat ing tool so as substantially to fix the positions of said elements lengthwise of the axis of rotation of the tool.
16. 16. An implement as claimed in claim 15, wherein a shaft embodying the axis of rotation of the or each cultivating tool has its upper end freely rotatably mounted in a holder or corresponding holder, a lower portion of the or each shaft which projects downwardly from said holder or correspond ir.g holder being of polygonal cross-section and having said superposed soil working elements mounted therein together with at least one intervening spacing sleeve.
17. 17. An implement as daimed in any preceding claim, wherein a plurality of the soil working members are arranged in a row with the axes about which they are drivably rotatable spaced apart from one another at regular intervals of substantially 375 millimetres, the soil working members of said row being constructed and arranged so that their rotatable cultivating tools will work overlapping strips of soil when the implement is in operation.
18. 18. An implement as claimed in any preceding claim, wherein the or each soil working member comprises two of said freely rotatable soil cultivating tools that are located at diametrically opposite sides of the axis about which that member is itself drivably rotatable.