GB2124063A - Soil cultivating implements - Google Patents

Abstract

In a soil cultivating implement of the kind which comprises, or at least includes, a soil cultivating packer roller 14, said roller 14 has a convex surface afforded by a plurality of sleeves 22 which are secured to a central tubular support 15 that they closely surround. The convex surface defined by the sleeves 22 has a diameter that does not exceed 200mm and the bottom of said surface, at any instant, co-operates with scrapers 27 that are located between groups or crowns of tine-like or tooth- like projections 20. The restricted diameter of the surface defined by the sleeves 22 ensures that continuous rotation of the roller 14 is not significantly opposed by the scrapers 27. Slippage of the roller 14 is also substantially prevented by each projection 20 having a blunt rear edge, with respect to the intended direction of operative rotation B of the roller, that strongly resists forward progress through the soil and thus urges the roller to rotate about its central axis a. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines of the kind which comprise, or at least include, at least one soil cultivating roller that is arranged to co-operate, during use, with at least one soil-shedding scraper. The term "implement(s) or machine(s)" will be shortened to "implement(s)" alone throughout the remainder of this document for the sake of brevity.

Such known implements are often employed in producing good quality seed beds but the problem of mud and other soil adhering tenaciously to the roller frequently has to be faced, which problem can very adversely affect the quality of the seed bed actually formed. The scrapers are, of course, intended to shed such mud and other soil but it has been found that, since the central tubular support of such a roller, with which the scrapers co-operate, invariably has a diameter of more than 200mm, the scrapers often tend to prevent the roller from rotating properly and will cause it to slip under unfavourable operating conditions, again adversely affecting seed bed production.

An object of the invention is to overcome, or at least very significantly to reduce, the problems discussed above and, accordingly, one aspect of the invention provides a soil cultivating implement of the kind set forth, wherein the or each scraper is arranged to co-operate with a convex surface of the roller which convex surface has a diameter that does not exceed 200mm.

For a better understanding of the invention, and to show how the same is 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 constructed in accordance with the invention shown connected to the rear of an agricultural tractor, Figure 2 is a part-sectional plan view, to an enlarged scale as compared with Figure 1, showing futher details of the construction and mounting of a packer roller of the implement at, and adjacent to, one end of that packer droller, Figure 3 is a section taken on the line Ill-Ill in Figure 2, Figure 4 is a similar view to Figure 2, but to a futher enlarged scale, illustrating the employment of an alternative form of packer roller, Figure 5 is a section taken on the line V-V in Figure 4, Figure 6 is again similar to Figure 2, but to the same scale as Figure 4, and illustrates a third form of packer roller in an implement in accordance with the invention, and Figure 7 is a section taken on the line VII-VII in Figure 6.

Referring firstly to Figures 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 elongate boxsection 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 of the drawings.A plurality, of which there are twelve in the example that is illustrated, of upwardly extending and usually vertically or substantially vertically disposed shafts 2 are rotatably carried by bearings in upper and lower walls of the frame portion 1 so as to extend in a single row that is parallel to the transverse length of that frame portion with the longitudinal axes of the shaft 2 spaced apart from one another at regular distances which advantageously, but not essentially, have magnitudes of substantially 25cm.Each shaft 2 projects downward lyfrom beneath the bottom of the hollowframe portion 1 and is there provided with a corresponding soil working member (not visibie) comprising a central hub that is firmly but releasably secured to the lowermost end of the shaft 2 concerned, two arms which extend in opposite directions from said hub, sleeve-like holders mounted at the outer ends of the arms and two rigid tines or other soil working tools whose fastening portions are firmly but releasably secured in the holders and whose soil working portions project downwardly into the ground when the implement is in use.

The opposite ends of the hollow frame portion 1 are closed by substantially vertical side plates 6 that extend substantially parallel to one another and to the direction A. The side plates 6 extend vertically above the remainder of the frame portion 1 and project some distance rearwardly thereof with respect to the direction A. Each side plate 6 carries, adjacent to its leading uppermost corner, a corresponding strong pivot 7 that is substantially horizontally disposed and in alignment with the pivot7 that corresponds to the other one of the two side plates 6.

An arm 8 is turnably mounted on each pivot 7 so as to be movable upwardly and downwardly about that pvot 7 immediately alongside the corresponding plate 6. Each arm 8 extends generally rearwardly from the corresponding pivot 7 alongside the inner surface of the corresponding side plate 6, that is to say, alongside that surface thereof which faces the centre of the implement. Two shield plates 9 that both extend substantially vertically parallel to the direction A are provided immediately beyond the opposite ends of the single row of twelve (in this embodiment) rotary soil working members.The shield plates 9 are upwardly and downwardly turnable about axes that extend substantially horizontally parallel to the direction A, these axes being formed by portions of carrying arms that are turnably mounted in brackets located on top of the hollow frame portion 1 at short distances from its opposite ends. The principal function of the shield plates 9 is to co-operate with the immediately neighbouring soil working members in cultivating the soil to substantially the same thorough extent as is effected by the co-operation of neighbouring pairs of those members at locations closer to the centre of the implement.The shield plates 9 can move upwardly and downwardly to match undulations in the surface of the soil over which the implement moves and also prevent stones and other potentially injurious objects from being flung laterally of the implement by the rapidly moving tines or other tools of its soil working members.

Each of the shafts 2 is provided, inside the hollow frame portion 1,with a corresponding straighttoothed or spur-toothed pinion 3, the sizes of the pinions 3 being such that the teeth of each of them are in mesh with those of the or each immediately neighbouring pinion 3 in the single row of twelve such pinions 3 that are provided in the example that is being described. It will readily be apparent that, with this arrangement, each pinion 3, shaft 2 and corresponding soil working member (not visible) will revolve in the opposite direction to that of the or each immediately neighbouring similar assembly as indicated by small arrows in Figure 1 of the drawngs.

The shaft 2 that corresponds to one of the centre pair of rotary soil working members is upwardly extended through the top of the hollow frame portion 1 into a gear box 10 mounted on top of said frame portion 1. Bevel pinions and shafts (not shown) within the gearbox 10 place the upward extension of said shaft 2 in driven connection with a rotary input shaft 12 of the gearbox 10 whose leading end projects substantially horizontally forwards from the front of the gearbox in substantially the direction A. The transmission between the rotary input shaft 12 and the upward extension of said shaft 2 includes a change-speed gear 11 that is mounted at the rear of the gearbox 10. The change-speed gear 11 does not form the subject of the present invention and will not be described in detail.It suffices to say that it can be employed to change the transmission ratio between the input shaft 12 and the upward extension of said one of the shafts 2 so that the twelve (in this embodiment) rotary soil working members can be caused to revolve at a faster or slower rate without having to change the driving speed that is applied to the leading end of the rotary input shaft 12. The speed of revolution of the rotary soil working members will, of course, be chosen in accordance with the nature and condition of the soil that is to be cultivated and the particular purpose for which that soil is required after cultivation.

A telescopic transmission shaft 4 which is of a construction that is known per se, having universal joints at its opposite ends, is employed to place the leading splined or otherwise keyed end of the rotary input shaft 12 in driven connection with the rear power take-off shaft of a n an agricultural tractor or other moving and operating vehicle. A coupling member or trestle 13 that is of substantially triangu- lar configuration as seen in front or rear elevation is mounted at the front of the hollow frame portion 1, with respect to the direction A, at a location mid-way across the working width of the implement, the apex of this coupling member or trestle 13 being strengtheningly connected to widely spaced apart locations at the rear of the hollow frame portion 1 buy a pair of tie beams.

The two arms 8 project rearwardly behind the frame portion side plates 6 and their rear ends carry the rotary mountings of a soil-contacting packer roller 14 which roller 14 also serves as a soil cultivating member. The roller 14 comprises a central tubular support 15 whose external diameter is not less than substantially 100mm nor more than substantially 150mm. The opposite ends of the central tubular support 15 have corresponding circular plates 16 welded to them, each plate 16 carrying a corresponding outwardly projecting stub shaft 17 in such a way that the two aligned stub shafts 17 together define the intended axis of rotation a of the roller 14.Each stub shaft 17 is received in a freely rotatable manner in a corresponding substantially horizontal bearing whose housing is carried at the lower end of a corresponding downwardly and rearwardly inclined support 19, the upper end of that support 19 being releasably secured to a rear end region of a corresponding one of the two arms 8 by a group of three bolts (Figure 3).

The external surface of the central tubular support 15 of the roller 14 carries a plurality of groups or crowns oftine-like or tooth-like hollow projections 20, each group or crown comprising six such projections 20 that are spaced apart from one another at regular angular intervals of 60O around the axis a.When the central support 15 of the roller 14 has its diameter within the preferred magnitude range mentioned above, it is also preferred that the general planes of the groups or crowns of projections 20 should be spaced apart from one another by distances of substantially 120mm and it will be clear from Figure 2 of the drawings that the general planes of the two groups or crowns of projections 20 that are closest to the opposite ends of the roller 14 are spaced from those ends by distances which are substantially half the spacing between the general planes of two immediately neighbouring groups or crowns of projectionms 20.

The successive groups or crowns of projections 20 are substantially identical to one another but are mounted on the central support 15 of the roller 14 in such a way that each of them is angularly staggered around the axis a by substantially 6 as compared with the or each of its immediate neighbours, the direction of stagger always being the same so that the projections 20 are arranged in six helical rows around the axis a considered lengthwise of the roller 14. Each projection 20 extends from the surface of the central support 15 by a maximum distance of substantially 90mm and has a tip which, as can be seen in Figure 3 of the drawings, is of substantially right-angled configuration. The rearmost edge of each projection 20, with respect to the intended direction of operative rotation B of the roller 14 is straight and nearly, although not strictly, radially disposed relative to the axis a and it will therefore be apparent that, where the projections 20 enter the soil in a lower region of the roller 14, those edges are foremost with respect to the direction of travel A.

The tips of the six projections 20 of each group or crown each extend for a significant distance substantially along an imaginary circle whose centre coincides with the axis a and the diameter of this imaginary circle is substantially twice that of the central tubular support 15 of the roller 14. The tip of each projection 20 includes a recess 20A of sawtoothed configuration, the leading edge of each recess 20A with respect to the intended direction of operative rotation B of the roller 14, being substantially radially disposed, in relation to the axis a, whereas the rear edge of said recess is approximately tangentially disposed relative to an imaginary circle centred upon the axis a.A front region of the tip of each projection 20, with respect to the direction of rotation B, includes a short substantially straight portion, adjoining the corresponding recess 20A, that extends substantially tangentially with respect to an imaginary circle centred upon the axis a and, immediately in advance of this short substantially straight portion, with respect to the direction B, each projection 20 has a much longer regularly curved edge that is directed generally inwardly towards the surface of the support 15 from the leading end of the short substantially straight portion concerned.

Each group or crown of projections 20 is formed from two symmetrically identical pressed metal plates 21 that advantageously, but not essentially, have thicknesses of 4mm. Each plate 21 comprises a sleeve 22 which surrounds the external surface of the central tubular support 15 with a limited degree of clearance, each sleeve 22 terminating at the end thereof which is closest to the companion sleeve 22 in a disc 23 which extends perpendicular or substantially perpendicular to the axis a. The two discs 23 of each group or crown of projections 20 comprise those six projections 20 themselves, the projections being incised in the plates 21, and also radial ring portions of the plates 21 that interconnect the sleeves 22 and the shaped projections 20.The discs 23 are all perpendicular or substantially perpendicular to the axis a and the distance between the two discs 23 that correspond to a single group or crown of projections 20 is advantageously substantially 12mm in a region where those discs 23 are close to their integral junctions with the sleeves 22.At their outer edges, in which the projections 20, proper, are formed, the two discs 23 are welded or otherwise rigidly secured to one another, the contacting edges of the discs 23 in the projections 20 becoming further spaced apart, to form the ring portions of those discs 23, by way of contour fold lines whose positions are apparent from a study of Figures 2 and 3 of the drawings from which, in particular, it will be apparentthat said contour fold lines are much closer to one another adjacent the rear edge, with respect to the direction of rotation B, of each projection 20 than they are in the leading generally curved edge thereof. With this construction, the rear edge, with respect to the direction of rotation B, of each projection 20 will be foremost relative to the direction of travel A when that projection 20 penetrates into the soil during the use of the implement.The leading edges, with respect to the direction of travel A, of the projections 20 where they penetrate into the soil in a lower region of the roller 14 presents relatively blunt surfaces to that soil which strongly resist forward penetration therethrough whereas the rear edges, in the same region of the roller, of the projections 20 have their contour fold lines much further apart and therefore present to the soil relatively sharply inclined surfaces which will cut through the soil much more easily. The result is that the penetration of the projections 20 into the soil tends very positively to cause rotation of the roller 14 around its axis a.The shape of each group or crown of projections 20 is thus such that said projections 20 will penetrate relatively easily into the soil but present to that soil, where there is actual penetration into the ground, surfaces that are strongly resistant to progress in the direction A so that rotation of the roller 14 will cause its projections 20 to have a strong cultivating effect upon an upper iayer of the soil.

When the roller 14 is being assembled, the ends of the sleeves 22 of the groups or crowns of projections 20 are spot welded to the surface of the central support 15 (see Figure 2). Each arm 8 has a downwardly and rearwardly inclined extension 5 that is secured to the arm 8 concerned by the same group of bolts as fastens the corresponding support 19 to that arm. The lowermost and rearmost ends of the two extensions 5 are perpendicularly interconnected by a carrier 24 that extends parallel or substantially parallel to the axis a and that is of channel-shaped cross-section having outwardly directed co-planar rims at the free ends of its two limbs. The carrier 24 is welded to the two extensions 5 and a cover plate 25 is releasably secured to the rims thereof by a plurality of substantially regularly spaced apart bolts 26.The 26 also serve to secure scrapers 27 to the carrier 24 and the cover plate 25 and it will be seen from Figures 2 and 3 of the drawings that each scraper 27 extends downwardly and forwardly, with respect to the direction A, from the carrier 24 to bear against the curved surfaces of the sleeves 22 of two neighbouring, but separate, groups or crowns of projections 20, each scraper 27 being of such a width in a direction parallel to the axis a that its opposite edges are close to the two discs 23 that correspond to those two sleeves 22.

Each scraper 27 is strip-shaped and is preferably formed from a resilient material which is advantageously spring steel. As can be seen in Figure 3 of the drawings, the leading end of each scraper 27, with respect to the direction A, is cylindrically curved to match the curvature of the external surfaces of the sleeves 22, its leading extremity in the direction A being in advance of a vertical plane A-A which contains the axis of rotation a of the roller 14.A further plane which contains the axis a and the leading end of each scraper 27 is inclined at an angle (3to the plane A-A, said angle p advantageously having a magnitude of substantially 15 . The cylin dricallycurved leading portion of each scraper 27 subtends an angle or at the axis a which advantageously has a magnitude of substantially 45 .

Although not illustrated, the scrapers 27 may cooperate with their fastening bolts 26 by way of slots to enable the scrapers to be adjusted to a limited extent in directions that are substantially parallel to their own lengths and, instead of the carrier 24 being welded to the arm extensions 5, it may be connected thereto by way of slotted brackets and those brack etsthemselves may, if desired, be turnable to a limited extent about an axis that is substantially parallel to the axis a. Such an arrangement enables the scrapers 27 to be adjusted in position to some extent in a direction that is substantially parallel to the axis a and for their inclinations to the horizontal also to be adjusted.

Figures 4 and 5 of the drawings illustrate the use of an alternative packer roller 28 in which the stub shafts at its opposite ends are afforded by opposite end regions of a continuous shaft 29 that extends substantially horizontally throughout the whole of the length of the roller. A plurality of groups or crowns of tine-like or tooth-like hollow projections 30 are spaced apart from one another at regular intervals along the length of the shaft 29, each group or crown comprising six of the projections 30 that are spaced apart from one another at 60 intervals around the axis of rotation a of the roller 28 which axis coincides with the longitudinal axis of the shaft 29.Once again, the distance between the general planes of two immediately neighbouring groups or crowns of projections 30 is substantially 120mm and each group or crown is staggered in the same direction around the axis a by substantially 6" with respect to the or each of its immediate neighbours.

In this embodiment, each projection 30 has a substantially straight rear edge, with respect to the intended direction of operative rotation B of the roller 28, which is inclined at an angle of substantially 150 to a strictly radial line, the direction of inclination being forwardly relative to the direction B as considered outwardly towards the tip of each projection 30. Again, the tips of the projections 30 of each group or crown thereof substantially coincide with an imaginary circle whose centre coincides with the axis a.Each tip includes a saw-toothed recess, as in the embodiment of Figures 1 to 3 of the drawings, and the leading edge of each projection 30, with respect to the direction of rotation B, comprises a first shorter straight portion and a second longer straight portion which portions are inclined to one another at only a very small angle and both of which are directed generally inwardly from the projection tip concerned with respect to the axis a.

As in the preceding embodiment, each group or crown of projections 30 is afforded by a co-operating pair of symmetrically identical pressed plates 31, each plate 31 comprising a circular disc 32 that extends perpendicularly with respect to the axis a from the shaft 29, the outer edge of each disc 32 being integrally connected by a 90".bend to a corresponding sleeve or shoulder 33 and the opposite edge of each sleeve or shoulder 33 being integrally connected by a 90" bend to a further disc 34 in which latter one side of each of the six projections 30, proper, is formed by incision. The two plates 31 of each pair are welded or otherwise rigidly secured to one another at the contacting outer edges of the projections 30 and centre regions of the discs 32 are welded or otherwise rigidly secured to the shaft 29.It can be seen in Figures 4 and 5 of the drawings that, in a similar manner to the first embodiment, said further discs 34 merge into the projections 30, proper, by way of pairs of contour fold lines and that, once again, the contour fold lines at the rear of each projection 30, with respect to the direction of rotation B, provide bluntly inclined surfaces that strongly resist forward progress through the soil in the direction A whereas the rear of each projection 30, with respect to the direction B, provides much more acutely inclined surfaces that will penetrate relatively easily into the ground. Thus, once again, the roller 28 will be caused very positively to rotate about the axis a when its projections 30 penetrate into the ground surface during operative progress in the direction A.The distance between the two further discs 34 of each group or crown of projections 30 is substantially 12mm and this is substantially one tenth of the distance between the general planes of two immediately neighbouring groups or crowns of those projections.

The sleeves or shoulders 34 of the successive symmetrically identical plates 31 provide a substantially cylindrically surfaced support portion of the roller 28 which support portion is of greater diameter than the central tubular support 15 in the first embodiment having a diameter which is preferably between substantially 150 and 190mm, inclusive.

The tip of each projection 30 is spaced from the cylindrical support portion defined by the sleeves or shoulders 33 at a maximum distance of substantially 80mm and, once again, the plates 31 are advantageously formed from sheet metal having a thickness of substantially 4mm. Scrapers 27 are again provided between the successive groups or crowns of projections 30 and co-operate with the curved surfaces of the sleeves or shoulders 33. However, in this case, the angle ss' (Figure 5) which corresponds to the angle ss shown in Figure 3 has a magnitude that is preferably only substantially 5 since the diameter of the cylindrical support portion of the roller 28 that is afforded by the sleeves or shoulders 33 is greater than in the first embodiment.The angle a which the cylindrically curved leading portion of each scraper 27 subtends at the axis a has a magnitude which is preferably substantially three times that of the angle ss'.

Figures 6 and 7 illustrate a further alternative construction in which a packer roller 35 is provided comprising a central tubular support 36 whose opposite ends are closed by circular plates 37 to the outer surfaces of which aligned stub shafts 38 are welded or otherwise rigidly secured to define the longitudinal axis a of the roller 35 which axis is also its intended axis of rotation. The roller 35 may be freely rotatably mounted in a similar manner to that which has briefly been described above. The groups or crowns of projections that are provided in this embodiment have substantially the same form as the projections 30 of the preceding embodiment and are therefore again designated in Figures 4 and 5 by the reference 30. Their general planes are spaced apart from one another in the direction of the axis a by distances of substantially 100mm and, in this embodiment, each group or crown comprises three identical integral pairs of projections 30 each of which subtends 1200 at the axis a, said pairs being welded to the surface of the support 36 at the junctions between them as somewhat diagrammatically illustrated in Figures 6 and 7 of the drawings.

Each integral pair of projections 30 comprises two co-operating symetrically identical pressed plates 39, a minimum of welding being required to connect the two plates 39 together and to secure them in their appointed positions on the support 36. As in the preceding embodiment in which the cylindrical support is afforded by the sleeves or shoulders 33, the central tubular support 36 in this embodiment preferably has a diameter of not less than substantially 1 50mm and not more than substantially 190mm, inclusive. Scrapers 27 which are constructed and deployed in the same manner as in the embodiment of Figures 4 and 5 of the drawings are, once again, provided.

During the use of the implement that has been described, whichever of the three different packer rollerconstructions 14, 28 or35 is employed, the coupling member or trestle 13 is used in a manner which is generally known perse to connect the frame of the implement to the three-point lifting device or hitch at the rear of a tractor or other moving and operating vehicle.The known telescopic transmission shaft 4, having universal joints at its opposite ends, is employed to place the splined or otherwise keyed rotary input shaft 12 of the gearbox 10 in driven connection with the rear power take-off shaft of the same tractor or other vehicle so that, as described above, the rotary soil working members that are secured to the lowermost ends of the shafts 2 will be revolved, as the implement moves forwardly in the direction A, in the directions indicated by the small arrows in Figure 1, the speed of rotation being determined by the prior setting of the change-speed gear 11.Each rotary soil working member cultivates a corresponding strip of land that extends in the direction A but, since the effective spacing between the tines or other soil working tools of each member is greater than is the distance between the axes of rotation of neighbouring shafts 2, these strips of land overlap one another to produce a single broad strip of worked spoil that will have a width of substantially 3m in the case of the example that is being described. The depth to which the tines or other soil working tools of the rotary soil working members can penetrate into the soil is preferably adjustable and is governed by the bodily level of the packer roller 14, 28 or 35 relative to that of the frame portion 1 and the rotary soil working members themselves.

To this end, means (not illustrated) is provided to enable the arms 8 to be retained in chosen angular settings about the substantially horizontal axis that is defined by the pivots 7, this means being well known per se.

During operation, the projections 20 or 30 penetrate into the surface of the ground to such an extent that, as shown in Figures 3, 5 and 7, those projections are, when in a lowermost region of the roller concerned, substantially completely beneath the ground surface. It is the leading edge, with respect to the direction of rotation B, of each projection 20 or 30 that first contacts the soil surface during rotation of the roller 14,28 or 35 about the axis a and, since this edge is relatively sharp, it will penetrate into the ground without difficulty. The rearmost, with respect to the direction B, edges of some of the projections 20 or 30 will also be in the soil at the same time and, since these edges are rather blunt, as discussed above, they strongly resist forward progress in the direction A thus strongly urging the roller concerned to revolve about its axis a.This "pushing" effect that is produced by the "blunt" edges of the projections 20 or 30 also, it will be realised, considerably assists in forcing the much sharper edges of the projections 20 and 30 downwardly into the ground surface. A very effective rotation of the roller 14, 28 or 35 is thus produced and, even when working with heavy soil in a wet condition, slipping of the packer roller over the surface of that soil is reduced to a minimum, if not completely eliniinated. The scrapers 27 between the projections 20 or 30 keep the roller 14,28 or 35 substantially free of significant accumulations of adhering mud and themselves assist the roller concerned in crumbling and gently consolidating the worked soil to produce, in many instances of use of an implement in accordance with the invention, a seed bed giving optimum conditions for the germination and onward growth of seedlings.It is greatly preferred that the central tubular supports of the described packer rollers that are afforded by the parts 15,33 and 36, respectively, should have diameters which do not exceed substantially 200mm and positive and continuous rotation of each roller 14,28 or 35 around the corresponding axis a is ensured, under almost all normal operating conditions, by the drive to the packer roller concerned that is derived from the penetration of the projections 20 or 30 into the soil during operative progress in the direction A. Any adhering mud or other soil is scraped off the packer roller substantially immediately in the region where it first stuck to that roller and little resistance to forward progress in the direction A is attributable to adhering mud and the like.Since shedding of mud and other material adhering to each packer roller takes places at the bottom of the central support thereof, that mud or other adhering material will not be displaced upwardly or otherwise to any significant extent and will therefore not adversely affect the preparation of any seed bed that is being produced. The formation of the projections 20 and 30 from pre-fabricated pressed metal plates enables the described rollers to be quite quickly and easily constructed in a relatively inexpensive manner whilst still being strong and of relatively light weight.

It is noted that, whilst the packer rollers 14,28 and 35 have all been described as being employed in combination with a row of rotary power-driven soil working members, it is within the scope of the invention to provide an implement in which such rotary power-driven soil working members are not used and which cultivates the soil by the use of such a roller alone. Moreover, if desired, two or more such soil cultivating packer rollers may be provided one behind the other in the direction A whether or not in combination with at least one row of rotary power-driven soil working members.

The soil cultivating implement embodiments that have been described also form the subject of our co-pending patent application No. 83 (Serial No.

to which reference is directed.

Although certain features of the soil cultivating implement embodiments 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 soil cultivating implement embodiment 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 the or each scraper is arranged to co-operate with a convex surface of the roller which convex surface has a diameter that does not exceed 200mm.

2. An implement as claimed in claim 1, wherein the or each scraper contacts, or is disposed in close proximity to, the lowermost extremity, at any instant, of said convex surface of the roller.

3. A soil cultivating implement of the kind set forth, wherein the or each scraper contacts, or is disposed in close proximity to, the lowermost extremity, at any instant, of said convex surface of the roller.

4. An implement as claimed in any preceding claim, wherein the or each scraper extends into a space between two immediately neighbouring groups or crowns of roller projections.

5. A soil cultivating implement of the kind set forth, wherein the or each scraper extends into a space between two hollow circumferential projections of the roller.

6. An implement as claimed in claim 5, wherein said hollow projections are arranged in side-by-side relationship in groups or crowns.

7. An implement as claimed in any preceding claim, wherein the or each scraper is located principally rearwardly of said roller with respect to the intended direction of operative travel of the implement but extends forwardly to a location in advance of a vertical plane containing the intended axis of rotation of the roller.

8. An implement as claimed in any preceding claim, wherein the free end of the or each scraper is contained in a plane that also contains the intended axis of rotation ofthe roller, said plane being inclined to a vertical plane that also contains that intended axis of rotation at an angle of not less than 5 and not more than 15".

9. An implement as claimed in any preceding claim, wherein a portion of the or each scraper is shaped to match the curvature of a convex surface, or said convex surface, of the roller and to contact, or extend in close proximity to, that surface, said matchingly shaped portion of the or each scraper subtending an angle of substantially 45" at the intended axis of rotation of the roller.

10. An implement as claimed in any preceding claim, wherein the roller is provided with a plurality of projections, the rear of which, relative to the intended direction of operative rotation of the roller, exhibits a relatively blunt surface that is resistant to forward progress through the soil whereby, during use, said relatively blunt surface facilitates constant rotation of the roller.

11. A soil cultivating implement of the kind set forth, wherein said roller is provided with a plurality of circumferential projections arranged so that at least one scraper extends into a space formed axially along the roller between such projections, and wherein, in the use of the implement, said roller is caused to revolve by its contact with the ground, a such projection having a rear edge, with respectto the intended direction of operative rotation of the roller, which exhibits a relatively blunt surface that is resistant to forward progress through the soil and that consequently facilitates constant rotation of the roller.

12. An implement as claimed in claim 10 or 11, wherein the leading edge of each projection, with respect to the intended direction of operative rotation of the roller, exhibits a relatively sharp surface that is designed to penetrate into the ground.

13. An implement as claimed in any one of claims 9 to 12, wherein groups of said projections are afforded by two juxtaposed plates having at least parts thereof in contact with one another.

14. An implement as claimed in any one of claims 9 to 13, wherein pluralities of said projections are formed in groups or crowns from two juxtaposed pressed plates having at least portions thereof in contact with one another.

15. An implement as claimed in any preceding claim and comprising a plurality of circumferential projections of which at least some each have a free end or tip that extends throughout a significant distance at least substantially along an imaginary circle centred upon the intended axis of rotation of the roller, said free end or tip also being formed with a recess of saw-toothed configuration.

16. An implement as claimed in any one of claims 9 to 15, wherein the leading edge of each of at least a plurality of the projections is of curvilinear configuration when viewed in a direction parallel to the intended axis of rotation of the roller.

17. An implement as claimed in any one of claims 9 to 15, wherein the leading edge of each of at least a plurality of the projections comprises two relatively inclined straight portions when viewed in a direction that is parallel to the intended axis of rotation of the roller.

18. An implement as claimed in claim 12 or in any one of claims 13 to 17 when read as appendant to claim 12, wherein said pairs of pressed plates engage one another circumferentially to produce said projections and define contour lines which are significantly closer to one another adjacent the rear edge of each projection, with respect to the intended direction of operative rotation of the roller, than they are adjacent the leading edge thereof.

19. An implement as claimed in any preceding claim wherein the diameter of a convex surface, or said convex surface, of the roller is substantially half that of the circular paths traced by the free ends of circumferential projections, or said circumferential projections, during rotation of the roller.

20. An implement as claimed in any preceding claim, wherein, when the roller is viewed in a direction parallel to its intended axis of rotation, it comprises a plurality of circumferential projections, or of said circumferential projections, each of at least a plurality ofwhich has a substantially radial rear edge and an at least partially tangential leading edge with respect to the intended direction of operative rotation of the roller.

21. An implement as claimed in any preceding claim, wherein, as seen in a direction parallel to the intended axis of rotation of the roller, each of at least a plurality of circumferential projections, or of said circumferential projections, defines, at and adjacent its free end or tip, an angle of substantially 90".

22. An implement as claimed in any preceding claim, wherein each of at least a plurality of circumferential projections, or of said circumferential projections, of the roller has a maximum radial extent from a convex surface, or said convex surface, of the roller of substantially 90mm.

23. An implement as claimed in any preceding claim, wherein circumferential projections, are spaced apart from one another axially of the roller by substantially 120mm.