GB2135163A - Soil cultivating implements - Google Patents

Abstract

A soil cultivating implement comprises a row of power-driven soil working members that are rotatable about the upright axes of corresponding shafts 2 and a ground roller 12 which sustains the implement from the ground surface and governs the working depth of said soil working members. The ground roller 12 is positively rotated about its axis a by a drive transmission comprising a telescopic transmission shaft 35 having universal joints 34 at its opposite ends, the rotary power being derived from the power take-off shaft of an agricultural tractor or other operating vehicle of the implement. The shaft 35 and a change-speed gear 33 which governs the speed of rotation of the roller 12 are so arranged as not to hinder adjustments of the level of the roller 12. The surface of a cylinder 13 of the roller 12 comprises groups of projecting cutting tines or blades 14. An alternative construction is described in which the drive to the roller 12 is derived from the ground wheel axle of the tractor. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines of the kind comprising a frame portion that is movable over the ground and that supports a row of power-drivable soil working members, the frame portion and soil working members being sustained from the ground surface, at least when the implement or machine is in use, by a ground roller whose axis of rotation extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement or machine. The term "implement(s) or machine(s)" is shortened to "implement(s)" alone throughout the remainder of this document for the sake of brevity.

Implements of the kind set forth usually require a very powerful tractor or other vehicle to move and operate them if a good quality seedbed is to be prepared, particularly if the implements have to work heavy soil. One object of the present invention is to apply some of the available power to positive rotation of said ground roller without, however, the required drive transmission to the ground roller being positioned so that it will hinder upward and downward adjustments of the bodily level of the roller relative to that of the frame portion to increase or decrease the effective working depth of the soil working members.Accordingly, one aspect of the invention provides a soil cultivating implement of the kind set forth, wherein a drive transmission is provided for the positive rotation of said ground roller, the drive transmission comprising at least one shaft having universal joints at its ends and being arranged to revolve said roller from one axial end thereof.

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 shown connected to the rear of an agricultural tractor, Figure 2 is a side view as seen in the direction indicated by an arrow II in Figure 1, Figure 3 is a section taken on the line Ill-Ill in Figure 1, Figure 4 is a plan view of a second embodiment of a soil cultivating implement in accordance with the invention shown connected to the rear of an agricultural tractor.

Figure 5 is a section taken on the line V-V in Figure 4, Figure 6 is a plan view of a third embodiment of a soil cultivating implement in accordance with the invention shown connected to the rear of an agricultural tractor, and Figure 7 is a side elevation as seen in the direction indicated byan arrowVII in Figure 6.

The soil cultivating implements which will be described, and that are illustrated in the accompanying drawings, are intended primarily, but not exclusively, for use in preparing seedbeds from previously worked soil in which seedbeds seeds can germinate and, after appropriate thinning of the seedlings, if required, can grow on to maturity. Referring now to Figure 1 to 3 of the accompanying drawings, the soil cultivating implement that is illustrated therein is in the form of a rotary harrow and comprises a hollow box-section frame portion 1 of elongate configuration whose longitudinal axis extends substantially horizontally transverse and usually, as illustrated, substantially horizontally perpendicular, to the intended direction of operative travel of the implement that is indicated throughout the drawings by an arrow A.A plurality, of which there are twelve in the example that is being described, of substan tialiy vertical, or at least upwardly extending, shafts 2 are rotatably journalled in bearings carried by upper and lower walls of the frame portion 1 so as to lie in a single rowthat is parallel to the transverse length ofthe hollow frame portion 1,the longitudinal axes/axes of rotation of the twelve shafts 2 being parallel to one another and being spaced apart at regular intervals which advantageously, but not essentially, each have a magnitude of substantially 25 cms. Each shaft 2 projects downwardly from beneath the bottom of the hollow frame portion 1 and is there provided with a corresponding soil working member that is generally indicated by the reference 3 (Figure 2).Each soil working member 3 comprises a substantially horizontally disposed support or carrier 4 defining arms that project in diametrically opposite directions from the shaft 2 concerned and whose outer ends terminate in corresponding sleeve-like tine holders. Fastening portions of rigid soil working tools in the form of tines 5 are firmly by releasably received in the holders that have just been mentioned and soil working portions of the tines 5 project downwardly into the ground, when the implement is in use, to an extent that is adjustable in a manner which will be described below.

The opposite ends of the hollow frame portion 1 are closed by corresponding side plates 6 which extend substantially vertically parallel to one another and to the direction A. As will be evident from Figure 2 of the drawings, the side plates 6 project vertically above the remainder of the hollow frame portion 1 and also both forwardly and rearwardly thereof relative to the direction A, upper leading portions of the two side plates 6 being provided with horizontally aligned pivots 7 about which respective arms 8 are upwardly and down wardlyturnable alongside said plates and against the surfaces of those plates 6 which face the centre of the implement.Each arm 8 extends generally rearwardly, with respect to the direction A, from the corresponding pivot and is of a downwardly and rearwardly offset construction which is such that longer leading and shorter trailing portions of each arm 8 are parallel to one another. Atransverse connection in the form of a tie beam 15 of square cross-section and hollow construction rigidly interconnects the rearmost ends of the two arms 8 and the outer surfaces of those two arms 8 have the upper ends of corresponding rearwardly and steeply downwardly inclined plates 9 rigidly secured to them. Lower portions of the two plates 9 carry substantially horizontally aligned bearings in which co-axial stub shafts 10 and 11 at the opposite ends of a ground roller 12 are rotatably journalled.The bearings in which the stub shafts 10 and 11 are rotatably mounted are carried by corresponding bearing housings releasably bolted to the lower portions of the corresponding plates 9 (see Figure 2).

The ground roller 12 comprises a cylinder 13 of circular cross-section, the opposite ends of the cylinder being provided with corresponding end plates which carry the stub shafts 10 and 11 whose common longitudinal axis a (Figures 1 and 3 of the drawings) coincides with the longitudinal axis of the cylinder 13 itself.

The outer surface of the roller cylinder 13 carries a plurality of cutting tines or blades 14 which tines or blades 14 are arranged in groups of three with the three tines or blades 14 in each such group being spaced apart from one another at 120 interval around the axis a and said three tines or blades 14 being contained in a corresponding single vertical or substantially vertical plane that is perpendicular to the axis a and parallel or substantially parallel to the direction A. The groups of tines or blades 14 are parallel to one another and are spaced apart at regular intervals along the length of the roller cylinder 13, each group being angularly displaced about the axis a, in the embodiment that is being described, by 90 as compared with the or each of its immediate neighbours.It is not, of course, essential that the groups of tines or blades 14 should comprise three such tines or blades and, if preferred, each group may comprise two, four or more thereof and it is possible to replace the groups by single tines or blades contained in corresponding substantially vertical planes that are substantially parallel to the direction A, such single tines or blades preferably being successively offset around the axis a so that the tines or blades 14 extend in a helical row around that axis a. Each cutting tine or blade 14 is of plate-like formation and has a rear edge, with respect to the intended direction of operative rotation B of the roller 12 concerned, which extends radially or substantially radially with respect to the axis a.Each cutting tine or blade 14 also has a leading edge, with respect to the same direction of rotation B, and an imaginary rectilinear extension of this leading edge is in tangential relationship with an also imaginary circle centered upon the axis a. The two leading and rear edges of each cutting tine or blade 14 that has just been mentioned are interconnected, at the radially outermost extremity of that tine or blade 14, by a curved edge whose centre of curvature also coincides with the axis a (see Figures 2 and 3 of the drawings).In the embodiment that is being described, the roller cylinder 13 has a diameter of substantially 40 cms and each cutting tine or blade 14 projects from the outer surface of the cylinder 13 by substantially 5 cms, it being preferred that each cutting tine or blade 14 should not project radially from the outer surface of the cylinder 13 buy a distance which is greater than one fifth of the diameter of that cylinder 13.

The top of the tie beam 15 which rigidly interconnects the rearmost ends of the two arms 8 is provided, mid-way along the length of that beam, with a pair of upwardly projecting and horizontally spaced apart lugs 16 between which one end of a rod mechanism 17 of known construction isturnably mounted by a pivot that extends substantially horizontally parallel to the axis a. The opposite end of the rod mechanism 17 is turnably connected, by a relatively parallel pivot pin, to a horizontally spaced apart pair of lugs 18 which project rearwardly, with respect to the direction A, from the apex of a coupling member our trestle 19 that is of substantially equilateral triangular configuration as seen in either front or rear elevation.The known mechanism 17 comprises two axially aligned rods formed with oppositely screw-threaded end portions that are entered into the opposite ends of a central sleeve which, at its opposite ends, has matching internal screw-threads. Thus, upon rotating the central sleeve in one direction about its longitudinal axis, the length of the mechanism 17 will be increased whereas a rotation thereof in the opposite direction will decrease the length of the mechanism 17.

The coupling member or trestie 19 is arranged at the front of the frame portion 1 with respect to the direction A and substantially mid-way accross the working width of the implement, being provided at the front with means for connection to the single upper lifting link of a three-point lifting device or hitch carried at the rear of an agricultural tractor or other operating vehicle and also with horizontally spaced apart means for connection to the free ends of the two lower lifting links of the same lifting device or hitch.It will be apparent from Figure 2 of the drawings that increasing or decreasing the effective length of the rod mechanism 17 in the manner that has been described above will either lower or raise the level of the ground roller 12 relative to that of the hollow frame portion 1 and the row of soil working members 3 which it rotatably suports with the result that the maximum depth to which the tines 5 can penetrate into the soil when the implement is in operation will be correspondingly decreased or increased. The use of the known rod mechanism 17 for this purpose is by no means essential. A manually operable screw spindle of known construction could be substituted for the rod mechanism 17 or the arms 8 could be individually angularly adjustable about the corresponding pivots 7 by respective manuaully operable screw spindles.

These two possible alternatives to the use of the rod mechanism 17 are not exhaustive and still further ways of maintaining the bodily level of the ground roller at any chosen one of a number of different levels relative to that of the frame portion 1 and rotary soil working members 3 may be employed.

Each shaft 2 is provided, inside the hollow frame portion 1, with a corresponding straight- or spurtoothed pinion 20 which is of such a size that its teeth are in mesh with those of the or each immediately neighbouring pinion 20 in the single row thereof.

The shaft 2 which corresponds to one of the centre pair of soil working members 3 in the single row thereof has an upward extension through the top or cover plate of the hollow frame portion 1 into a gear box 21 that is mounted on top of said frame portion 1 between the upwardly convergent sides of the coupling member or trestie 19. The upward extension of the shaft 2 that has just been mentioned is provided, inside the gear box 21, with a bevel pinion 22 whose teeth are in driven mesh with those of a smaller bevel pinion 23 mounted on a substantially horizontal shaft 24 that is rotatably journalled in the gear box 21 so as to extend substantially parallel to the direction A, the leading end of the shaft 24 projecting forwardly in substantially the direction A from the front of the gear box 21 to serve as a splined or otherwise keyed rotary input shaft of that gear box 21.This splined or otherwise keyed leading end of the shaft 24 is intended to be placed in driven connection with the rear power take-off shaft of the tractor or other operating vehicle which moves and operates the implement by way of a telescopis transmission shaft 25, which is of a construction that is known perse having universal joints at its opposite ends. The rearmost end of the shaft 24 projects from the back of the gear box 21 into a second gear box 26 where it is provided with a bevel pinion 27. The bevel pinion 27 has its teeth in driving mesh with those of a somewhat larger bevel pinion 28 mounted on a substantially horizontal rotary shaft 29 that is parallel or substantially parallel to the length of the row of soil working members 3 and to the axis a of the ground roller 12.The substantially horizontal shaft 29 is rotatably journalled in the second gear box 26 and projects from both lateral sides of that second gear box 26. A rotary shaft 30 whose position can be seen best in Figure 2 of the drawings is located substantially vertically beneath the shaft 29 inside the second gear box 26, the shafts 29 and 30 being parallel to one another and the opposite ends of both of them being arranged to protrude beyond the walls of the second gear box 26. A housing or cover is mounted at the right hand side of the second gear box 26 when the implement is viewed from the rear in the direction A and this housing or cover is readily releasablefromthe second gear box 26 to give access to the splined ends of the upper and lower shafts 29 and 30.

Co-operating pairs of toothed pinions 31 and 32 can be mounted on these splined shaft ends beneath the housing or cover, the pinions 31 and 32 being interchangable between the shaft ends and being exchangable for other pairs of pinions of different sizes to give a tranmission ratio between the shafts 29 and 30 which will depend upon the particular pair of pinions which interchangably interconnects them.

This whole assembly constitutes a change-speed gear 33. The end of the lower shaft 30 which is remote from the change-speed gear 33 projects from the second gear box 26 and is connected by a universal joint 34 to one end of a telescopic transmission shaft 35 whose other end, in turn, is connected by a second universal joint 34 to a substantially horizontally extending shaft 36 that is parallel or substantially parallel to the axis a. A hollow casing 37 is carried by that one of the two arms 8 towards which the transmission shaft 35 is directed (see Figure 1) and at the side of said arm 8 which faces the centre of the implement. The shaft 36 is rotatably journalled in the casing 37 and carries, inside that casing, a sprocket wheel 38.A second and larger sprocket wheel 40 is also mounted in the casing 37 on the stub shaft 11 at the corresponding end of the ground roller 12, the smaller and larger sprocket wheels 38 and 40 being drivingly interconnected by a transmission chain 39.

In the use of the soil cultivating implement that has been described with reference to Figures 1 to 3 of the drawings, the coupling member or trestle 19 is connected to the lifting links of the three-point lifting device or hitch at the rear of the agricultural tractor or other vehicle which both moves and operates the implement and the forwardly projecting input end of the shaft 24 of the gear box 21 is placed in driven connection with the rear power take-off shaft of the same tractor or other vehicle by way of the known telescopic shaft 25 which has universal joints at its opposite ends.The bevel pinions 22 and 23 transmit drive to the soil working members 3 by way of the pinions 20 and it will be apparent that, as the implement moves operatively over the ground in the direction A, each pinion 20, shaft 2 and soil working member 3 will revolve in the opposite direction to that of the or each immediately neighbouring similar assembly in the single row of twelve, in this embodiment, such assemblies, these direction of rotation being indicated by small arrows in Figure 1 of the drawings for two immediately neighbouring assemblies.Each soil working member 3 works an individual strip of ground whose width is equal to, or a little greater than, 25 cms so that these individual strips of ground overlap or at least adjoin one another to produce a single broad strip of worked soil that will have a width of substantially, although not necessarily exactly, 3 metres when there are twelve of the soil working member 3. It will readily be apparent that greater or smaller working widths are possible by increasing or decreasing the number of rotary soil working members 3.The maximum depth to which the tines 5 of the soil working members 3 can penetrate into the soil is dependent primarily upon the horizontal level of the powerdriven ground roller 12 relative to that of the soil working members 3 and this level can be changed by increasing or decreasing the length of the rod mechanism 17 in the manner briefly described above.

The ground roller 12 is positively driven to rotate in the direction B (Figure 2) by the transmission that has been described above, the speed of such rotation being dependent upon the transmission ratio that is established in the change-speed gear 33 by a suitable selection and arrangement of the pinions 31 and 32 or of another co-operating pair of pinions of different sizes. It will be seen from Figure 2 of the drawings that the direction B corresponds to the direction of travel A and a speed of rotation of the ground roller 12 in the direction B may be chosen which is such that the circumferential speed of rotation of the roller 12 substantially corresponds to the speed of travel of the implement in the direction A.Alternatively, the circumferential speed of rotation B of the roller 12 may be arranged, by an appropriate adjustment of the change-speed gear 33, either significantly to exceed or to be significantly less than, the speed of travel in the direction A.

Since imaginary extensions of the straight leading edges of the cutting tines or blades 14, with respect to the direction B, are in substantially tangential relationship with also imaginary circles centered upon the axis a, a useful treatment of the soil surface after cultivation thereof by the tines 5 is obtained and it will be apparent that, since the tines or blades 14 penetrate into the soil surface, rotation of the roller 12 in the direction B tends to assist forward travel of the implement and its propelling tractor or other vehicle in the direction A.Particularly if the speed of rotation of the roller 12 in the direction B does not match the speed of travel in the direction A, self-cleaning of the roller 12 is facilitated by the positive rotation thereof and the risk of long-term adhesion of mud, clods of earth, weed remnants and the iike to the roller 12 is still further reduced by the fact that each group of cutting tines or blades 14 is angularly offset around the axis a relative to the or each neighbouring group and by the fact that the number of tines or blades 14 in each such group is limited.

It will be apparent that a proportion of the power required to drive the implement and tractor or other vehicle combination in the direction A is exerted by the roller 12 which derives its positive drive from the power take-off shaft of said tractor or other vehicle by way of the adjustable transmission that has been described and that is illustrated in Figures 1,2 and 3 of the drawings.The telescopic transmission shaft 35 which has universal joints 34 at its opposite ends drivingly interconnects the second gear box 26 and the hollow casing 37 and extends substantially horizontally perpendicular to the direction A at a horizontal level substantially corresponding to that of the top of the hollow frame portion 1 and this arrangement enables the roller 12 to be moved bodily upwards or downwards to increase or decrease the maximum depth of penetration of the tines 5 into the soil that is possible without interfering in any way with the positive rotary drive of the ground roller 12. Slippage of the drive transmission to the ground roller 12 cannot occur and the whole assembly is relatively compact.The change-speed gear 33 is readily accessible whenever the implement is not in operation so that an alteration of the transmission ratio which is determined thereby can quickly and easily be made merely by releasing the housing or cover thereof and interchanging the positions of the pinions 31 and 32 or replacing those pinions by an alternative pair and subsequently replacing the housing or cover.

Figures 4 and 5 of the drawings illustrate a second embodiment in which, however, many parts are similar or identical to parts that have already been described with reference to Figures 1 to 3 of the drawings. Such parts will not be described in detail again and are indicated by the same references as are used in Figures 1,2 and 3. This is also true of a third embodiment which will be described below with referene to Figures 6 and 7 of the drawings. In the embodiment of Figures 4 and 5 of the drawings a second gear box 26A replaces the second gear box 26 of the first embodiment and contains a smaller bevel pinion secured to the rearmost end of the shaft 24 and a larger bevel pinion 28 secured to the substantially horizontal shaft 29 that extends parallel or substantially parallel to the axis a defined by the stub shafts 10 and 11.The second gear box 26A is mounted at the rear of the gear box 21 with respect to the direction A, but does not comprise a changespeed gear. A change-speed gear 33A is, however, mounted alongside the arm 8 towards which the telescopic transmission shaft 35 is directed at that side of said arm 8 which is remote from the centre of the implement. The change-speed gear 33A comprises an upper shaft 39A directly connected to the telescopic transmission shaft 35 by one of the two universal joints 34 and, inside the casing of the change-speed gear 33A, the interchangable pinions 31 and 32 are mounted on splined shaft ends so as to establish a chosen transmissin ratio between the splined end of the shaft 39A that is remote from the end thereof connected to one of the universal joints 34 and the splined end of the shaft 36 upon which the sprocket wheel 38 is mounted.The arrangement of the change-speed gear 33A at that side of one of the two arms 8 which is remote from the centre of the implement still further increases the ready accessability of the change-speed gear 33A, for adjustment purposes, without detracting from the compact arrangement of the positive drive transmission to the ground roller 12.

Referring now to the third embodiment that is illustrated in Figures 6 and 7 of the drawings, a gear box 41 which is mounted on top of the hollowframe portion 1 replaces the gear box 21 of the first and second embodiments, the gear box 41 being provided at the rear thereof, with respect to the direction A, with a change-speed gear 42 by adjustment of which the speed of rotation of the soil working members 3 can be increased or decreased, as may be required, in response to a substantially fixed speed of driving rotation applied to the rotary input shaft of the gear box 41. The construction of the change-speed gear 42 is not the subject of the present invention but it is basically similar in arrangement to the change-speed gears 33 and 33A that have been described above.The particular speed of rotation of the soil working members 3 that is chosen for any soil cultivating operation, and the maximum depth of penetration of the tines 5 into the soil which is established for that operation, will depend primarily upon the nature and conditions of the soil that is to be dealt with and the particular purpose, such as the sowing of seeds, for which the cultivated ground is required after treatment by the implement.

In the embodiment of Figures 6 and 7 of the drawings, the ground roller 12 is again positively power-driver but, instead of drive being derived from the rear power take-off shaft of the cooperating tractor or other vehicle, said drive is derived from the rear axle of that tractor or other vehicle. A hollow casing 43 is mounted on that surface of one of the two plates 9 which is remote from centre of the implement and, inside the casing 43, a transmission chain 45 drivingly interconnects sprocket wheels 46 and 44 that are of substantially the same size.The sprocket wheel 44 is carried by the stub shaft 10 at one end of the ground roller 12 and the sprocket 46 is mounted at one end of a shaft 47 that extends substantially horizontally parallel to the longitudinal axis of the roller 12 to have its opposite end rotatably journalled in a gear box 48 that is mounted on top of the tie beam 15. The end of the shaft 47 that lies inside the gear box 48 carries a bevel pinion 49 whose teeth are in driven mesh with those of a larger bevel pinion 50 carried by a substantially horizontal shaft 51 which is rotatably journalled in the gear box 48 so as to extend substantially parallel to the direction A. The forwardly projecting leading end of the shaft 51 is in driven connection with a rearwardly directed output shaft 54 of a gear box 55 by way of a telescopic transmission shaft 53 having universal joints 52 at its opposites ends.

The gear box 55 is mounted at one end of the rear axle of the tractor or other vehicle which moves and operates the implement and the shaft 54 is provided, inside the gear box 55, with a bevel pinion 56 whose teeth are in driven mesh with those of a larger bevel pinion 57 carried by a shaft 58 that is preferably of hollow construction arranged, as shown somewhat diagrammatically in Figure 7 of the drawings, so that it can be mounted on the outer end of the appropriate half-shaft 59 of the tractor or other vehicle back axle. The housing of the gear box 55 is rotatable relative to the tractor or other vehicle wheel, so that it will not revolve with that wheel, but is maintained axially in position by a surrounding flange bolted or otherwise secured to the wheel.An elongate support 60 has one end bolted to the top of the gear box 55 and projects forwardly therefrom to have its leading end entered movably through an opening in a bracket 61 fastened to the top of the casing of the gear box 48. This arrangement prevents the gear box 55 from revolving with the rear axle of the tractor or other operating vehicle.

The implement of Figures 6 and 7 of the drawings operates in substantially the same manner as has been described with reference to Figures 1 to 5 of the drawings but the positive rotation of the ground roller 12, which again revolves in the direction B (Figure 7), can be influenced in any one of three different ways. Firstly, the drive transmission of the tractor or other operating vehicle itself will influence the speed of rotation of the roller 12 in the direction B; secondly, an appropriate transmission ratio can be established in the gear box 55 and/or; thirdly, an appropriate transmission ratio can be established in the gear box 48. In this embodiment, the universal joints 52, the telescopic transmission shaft 53 and the gear box 55 provide a simple but effective positive drive to rotate the ground roller 12 in the direction B.The speed of rotation in the direction B can, once again, substantially correspond to the speed of travel in the direction A or can significantly exceed, or be significantly less than, that speed of travel in the direction A. As already mentioned above, self-cleaning of the surface of the roller cylinder 13 is facilitated, particularly when the speed of rotation of the ground roller 12 does not match the speed of travel in the direction A. A speed of rotation of the roller 12 in the direction B which is greater than that required to match the speed of travel in the direction A is particularly advantageous as regards self-cleaning of the roller 12, the form and disposition of the cutting tines or blades 14 also being a significant contributory factor.It will be understood that a tractor or other vehicle having at least one of its ground wheel axles provided with a gear box such as the gear box 55 that has been described with reference to Figures 6 and 7 of the drawings could be employed as a source of drive for moving parts of implements, machines and tools other than the rotary soil working members of soil cultivating implements.

Although certain features of the implement embodiments and agricultural tractor or other operating vehicle that 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 emphasized that the invention is not necessarily limited to those features and that it includes within its scope each of the parts of each implement embodiment and tractor or other vehicle that has been described, and/orthat 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 a drive transmission is provided for the positive rotation of said ground roller, the drive transmission comprising at least one shaft having universal joints at its ends and being arranged to revolve said roller from one axial end thereof.

2. An implement as claimed in claim 1, wherein the drive transmission to said ground roller comprises a change-speed gear.

3. An implement as claimed in claim 1 or 2, wherein said at least one shaft having universal joints at its ends is arranged to be driven, when the implement is in use, from a ground wheel axle of a tractor or other vehicle to which the implement is operatively connected at such time.

4. An implement as claimed in claim 1 or 2, wherein said at least one shaft having universal joints at its ends is drivably connected to a transmission by which, in the use of the implement, said soil working members are operatively rotated.

5. An implement as claimed in claim 4, wherein said at least one shaft having universal joints at its ends interconnects a central region of the implement and transmission mechanism at one axial end of the ground roller.

6. An implement as claimed in claim 4 or 5, wherein said at least one shaft having universal joints at its ends is located at substantially the same horizontal level as is said frame portion.

7. An implement as claimed in any one of claims 4, 5 or 6, wherein said at least one shaft having universal joints at its ends is substantially horizontally disposed and extends substantially horizontally perpendicular to the intended direction of operative travel of the implement.

8. An implement as claimed in any preceding claim, wherein a transmission mechanism, or said transmission mechanism, interconnecting said at least one shaft and the ground roller at one axial end of the latter comprises a transmission chain.

9. An implement as claimed in claim 1 or claim 2 or any one of claims 4 to 8 when read as appendant to claim 1 or claim 2, wherein, in the use of the implement, the transmission between the power take-off shaft of a tractor or other vehicle moving and operating the implement and said ground roller comprises a shaft interconnecting that power takeoff shaft and a change-speed gear of the implement and said at least one shaft having universal joints at its ends, the latter being disposed between said change-speed gear and a transmission mechanism or said transmission mechanism at one axial end of the ground roller.

10. An implement as claimed in claim 8, wherein a change-speed gear or said change-speed gear interconnects said at least one shaft having universal joints at its ends and the transmission mechanism which includes a transmission chain.

11. An implement as claimed in claim 2 or in any one of claims 3 to 10 when read as directly or indirectly appendant to claim 2, wherein said change-speed gear comprises at least one pair of interchangable toothed pinions that are operatively connectable to respective shafts disposed one above the other, and wherein the upper one of said two shafts is arranged to be driven from the power take-off shaft of a tractor or other vehicle which moves and operates the implement in the use thereof and the lower one of said two shafts is drivingly connected to said at least one shaft having universal joints at its ends.

12. An implement as claimed in claim 3, wherein a gear box is provided that is constructed and arranged to be drivably mounted on the ground wheel axle of a tractor or other vehicle which moves and operates the implement in the use thereof, said gear box being disposed alongside one ground wheel and comprising a rotary output shaft drivingly connected to said at least one shaft having universal joints at its ends.

13. An implement as claimed in claim 12, wherein said gear box comprises a rotary input shaft of hollow formation arranged to surround the end of said axle in such a way that the axle will, during use, rotatably drive that input shaft.

14. An implement as claimed in claim 13, wherein said gear box is rotatable relative to the immediately neighbouring ground wheel.

15. An implement as claimed in claim 14, whrein said gear box comprises a support which can be arranged so that, during use of the implement, it is connected to said frame portion of the implement in such a way that rotation of the gear box about said axle is prevented.

16. An implement as claimed in any preceding claim, wherein said ground roller comprises a plurality of cutting tines or blades arranged in respective planes of rotation that are substantially perpendicular to the axis of rotation of said roller.

17. An implement as claimed in claim 16, wherein each of said tines or blades projects radially from the surface of the remainder of the roller by a distance which does not substantially exceed one fifth of the diameter of the latter.

18. An implement as claimed in claim 16 or 17, wherein each cutting tine or blade is of substantially flat formation and is contained in a plane that is substantially perpendicular to the axis of rotation of the roller.

19. An implement as claimed in claim 18, wherein the cutting tines or blades are arranged in groups in corresponding planes of rotation and each group is angularly offset about the axis of rotation of the roller by substantially 90 relative to the or each immediately neighbouring group.

20. An implement as claimed in any one of claims 16 to 19, wherein each cutting tine or blade has one edge which is substantially radial with respect to the axis of rotation of the roller and an edge which is so disposed that an imaginary rectilinear extension thereof is in substantially tangential relationship with an also imaginary circle centered upon said axis of rotation.

21. An implement as claimed in claim 20, wherein the non-radial edge of each cutting tine or blade is located at the front thereof with repect to the intended direction of operative rotation of the roller.

22. A soil cultivating implement of the kind set forth, substantially as hereinbefore described with reference to any of the embodiments that are illustrated in the accompanying drawings.

23. An agricultural orothertractoror other vehicle that is constructed and arranged to as to be suitable for moving and operating an implement as claimed in any preceding claim, wherein the ground wheel axle of at least one ground wheel of said tractor or other vehicle is provided with means by which a source of rotary drive for at least one moving part of the implement can be derived from said axle.