GB2130862A - Soil cultivating implements - Google Patents

Abstract

In a soil cultivating implement, such as a rotary harrow, of the kind which comprises a frame portion 1 supporting a row of rotary tines 5 soil working members 3 that extends substantially horizontally perpendicular to the intended direct of operative travel A of the implement and that also comprises a rear ground roller 17 that is upwardly and downwardly adjustable relative to the frame portion 1 by way of mechanisms 11 to control the maximum possible depth of penetration of the tines 5 into the ground, a screen 24A which comprises regularly spaced apart resilient tines 24 is arranged rearwardly of the soil working members 3 with respect to the direction A and between those members 3 and the ground roller 17 in said direction A. When the implement is in use, tines 24 of the screen 24A lie above the ground surface and the whole screen 24A is upwardly and downwardly adjustable relative to the soil working members 3 about an axis defined by pivot bolts 20. The screen 24A tends temporarily to accumulate cultivated soil for further soil crumbling by the tines 5 and progressively to release the worked soil rearwardly relative to the direction A at a uniform rate. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines, such as rotary harrows, of the kind which comprise a frame portion movable over the ground and a plurality of soil working members power-drivable to rotate about substantially vertical, or at least upwardly extending, axes, such implements or machines being particularly intended for use in the production of seedbeds.

The term "implement(s) or machine(s)" is shortened to "implement(s)" alone through the remainder of this document for the sake of brevity.

An object of the invention is to enable the implement temporarily to accumulate cultivated soil for progressive and uniform release rearwardly of the direction of travel of the implement, the accumulated soil being subject to further crumbling action by the rotary soil working members and, accordingly, the invention provides a soil cultivating implement of the kind set forth, wherein a screen which comprises tines is arranged rearwardly of the rotary soil working members with respect to the intended direction of operative travel of the implement so as to lie above the ground surface during such operation, the screen being upwardly and downwardly adjustable in level relative to the soil working members.

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 somewhat diagrammatic 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 section, to an enlarged scale, taken on the line I1--II in Figure 1, and Figure 3 is a section taken on the line Ill-Ill in Figure 2 at one lateral side of the implement.

Referring to the accompanying drawings, the soil cultivating implement that is illustrated therein is in the form of a rotary harrow and comprises an elongate hollow 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 in Figures 1 and 2 of the drawings by an arrow A.

A plurality, of which there are twelve in the example that is being described, of substantially 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 row that is parallel to the transverse length of the 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 cm. 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 having two arms that project in substantially diametrically opposite directions from a central hub of the carrier which hub has internal splines arranged to co-operate with matching external splines on a downwardly projecting portion of the corresponding shaft to prevent the carrier 4 and the shaft 2 from being rotationaliy displaceable relative to one another.

Axial displacement of each carrier 4 relative to the corresponding shaft 2 is prevented in a known manner that is not the subject of the present invention but which includes providing a screwthreaded lowermost end portion of each shaft 2 with a co-operating retaining nut that, when installed, is prevented from becoming loose by the provision of a split pin or the like entered through a transverse bore in the screw-threaded shaft portion and through aligned openings in the nut itself.

The outer ends of the arms of each support or carrier 4 are integrally or rigidly supplied with corresponding sleeve-like tine holders in which upper fastening portions of diametrically opposed soil working tines 5 are firmiy but replaceably secured. The tines 5 are of rigid formation and have downwardly tapering soil working portions that project into the ground that is to be cultivated by the implement to an adjustable extent.These soil working portions are spaced apart from one another by an effective distance which is a little greater than is the spacing between the longitudinal axes/axes of rotation of the shafts 2 so that, during operative progress of the implement in the direction A, the individual strips of ground that are worked by the twelve (in this example) soil members 3 overlap one another to produce a single broad strip of worked soil which, with the dimensions that are mentioned above, will have a width of substantially, but not necessarily exactly, 3 metres.

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, the lowermost edge of each side plate 6 being at substantially the same horizontal level as is the bottom of the hollow frame portion 1 (see Figure 2) and each side plate 6 having a portion which projects some distance rearwardly behind the hollow frame portion 1 with respect to the direction A.

Moreover, as can also be seen in Figure 2 of the drawings, the vertical extent of each side plate 6 is such that more than half of that plate 6 is above the top of the hollow frame portion 1. That portion of each side plate 6 which projects above the top of the hollow frame portion 1 carries a corresponding substantially horizontal pivot bolt 7 at a location which is close to the leading edge of the plate 6 with respect to the direction A and substantially mid-way between the upper edge of the same plate and the level of the top ofIhe hollow frame portion 1.The two substantially horizontal pivot-bolts 7 that correspond to the two frame portion side plates 6 are in alignment with one another and define a substantially horizontal axis that is parallel to the transverse length of the frame portion 1 and perpendicular or substantially perpendicular to the direction A. each pivot bolt 7 has the leading end, with respect to the direction A, of a more or less horizontal portion 9 of a corresponding arm 8 turnably mounted thereon at that side of the corresponding plate 6 which faces the centre of the implement.The portion 9 of each arm 8 extends generally rearwardly from its pivot bolt 7 and the rear end thereof merges by way of a substantially 600 angular bend into a shorter downwardly inclined portion whose lower end merges by way of a further oppositely directed substantially 600 angular bend into a short rear portion 10 that is consequently parallel to the longer more or less horizontal portion 9. The relatively inclined portions of each arm 8 are all of straight configurafion.

Each arm 8 is provided, at substantially the rearmost end of its more or less horizontal portion 9, with a bracket at that side thereof which faces the centre of the implement, said bracket supporting a substantially horizontal stub 12 through which an internally screw-threaded transverse bore is formed that extends substantially perpendicular to the straight length of the arm portion 9. Each bore receives the matchingly screw-threaded spindle of a corresponding adjusting mechanism 11 having a foldable crank handle at its upper end.A lower unthreaded end of the screw-threaded spindle of the mechanism 11 is entered through a hole formed in a corresponding lug 1 3 which is secured to a rear edge region of the hollow frame portion 1 so as to project rearwardly beyond that edge region by a short distance. The hole in each lug 13 is of larger diameter than is the portion of the adjusting mechanism spindle which projects therethrough and, immediately above the lug 13, a thick resilient washer 1 5 surrounds the plain spindle portion and is maintained in position by a small bracket connected to said spindle portion by an upper retaining pin 14 entered through a transverse bore in the plain spindle portion.A second washer surrounds the same spindle portion at a level spaced by a short distance beneath that of the corresponding lug 13, the underneath surface of this second washer bearing against a lower retaining pin 14 which is similarly entered through a transverse bore in the plain spindle portion.Upon using the crank handle at the upper end of either adjusting mechanism 11 to rotate the spindle of that mechanism 11 in an appropriate direction, the arm 8 concerned will be turned either upwardly or downwardly about the axis defined by the pivot bolts 7, the parts 1 3, 1 4 and 1 5 accommodating tilt of each mechanism 11 relative to the frame portion 1 and thus enabling the mechanism 11 to be operated in any possible position of the arm 8 concerned.

The short rear portion 10 of each arm 8 has the upper end of a corresponding downwardly directed plate 16 firmly but releasably bolted to it, each plate 1 6 being rearwardly inclined from the corresponding arm portion 10 in most positions of adjustment of each arm 8. Lower inwardly offset portions of the two plates 1 6 carry corresponding horizontal bearings between which an open-work, cage-formation ground roller 17 is mounted so as to be freely rotatable about its own longitudinal axis which axis is parallel or substantially parallel to the hollow frame portion 1 and to the axis defined by the pivot bolts 7.The roller 17 comprises a plurality, such as five, of regularly spaced apart support plates which are substantially vertically parallel to one another and to the direction A, the shape of each support plate being visible in Figure 2 of the drawings and it being evident from both Figures 1 and 2 that each support plate has six projections spaced around its periphery at 600 intervals and that these projections are interconnected by elongate tubular elements 1 8 which extend helically around the central axis of rotation of the roller 1 7.It will be evident from Figure 2, in particular, of the drawings that, during operation of the implement, the ground roller 17 bears supportingly against the ground surface and usually projects into that surface by a short distance to assist the roller 1 7 in also performing a soil working function in its own right as well as its supportion function. The adjusting mechanism 11 can be rotated in appropriate directions to turn the arms 8 about the pivot bolts 7 and consequently to raise or lower the frame portion 1 and the soil working members 3 relative to the ground surface and it is accordingly this adjustment which principally determined the maximum depth of penetration of the tines 5 into the soil which is possible whilst the implement is in use.

In addition to carrying the ground roller 17, the plates 1 6 support corresponding arms 1 9 that project generally forwardly from the plates 1 6 relative to the direction A. A rear end region of each arm 1 9 is turnably connected to a rear region of the corresponding plate 1 6 by a substantially horizontal pivot bolt 20, it being noted from Figure 2 of the drawings that the pivot bolts 20 are located at substantially the same horizontal level as is the top of the ground roller 17 and substantially vertically above the relatively parallel axis of rotation of that roller 17. Each plate 1 6 is formed, towards the front edge thereof, with a corresponding arcuate slot 21 whose centre of curvature coincides with the axis defined by the corresponding pivot bolt 20. A retaining bolt 22 is entered through each slot 21 and through a simple hole in the corresponding arm 1 9 and thus, upon loosening the retaining bolt 22, each arm 19 can be turned upwardly or downwardly about the axis defined by the pivot bolt 20 concerned within the limits dictated by the opposite ends of the corresponding slot 21 , any desired position of each arm 1 9 relative to the corresponding plate 1 6 being maintained, as long as required, merely by tightening the appropriate retaining bolt 22 once the required position has been attained. The parts 20, 21 and 22 comprise angular setting mechanisms for the arms 19.

The arms 19, like the plates 16, comprise portions that are angularly offset relative to other portions thereof and, in the case of the arms 1 9, the leading ends thereof, relative to the direction A, are angularly offset inwardly towards one another from the rear ends thereof that are adjustably connected to the plates 1 6. The angularly offset leading ends of the two arms 1 9 have the opposite ends of a carrier 23 welded to them (Figure 3) in such a way that said carrier 23 extends substantially horizontally parallel to the transverse length of the hollow frame portion 1 and to the axis of rotation of the roller 17, said carrier 23 being in the form of an angular bar of substantially inverted L-shaped cross-section having its upright limb projecting downwardly from its substantially horizontal limb at the leading end of the latter with respect to the direction A.

The limbs are respectively substantially vertically and substantially horizontally disposed when the implement is on horizontal ground but their precise dispositions will, of course, depend upon the particular settings of the arms 19 about the pivot bolts 20 that have been adopted. Spring steel or other resilient tines 24 project downwardly behind the leading substantially vertical limb of the carrier 23 at substantially regularly spaced apart intervals which, it is preferred should not be less than 5 cm. The resilient tines 24 are conveniently, as illustrated, formed in integral pairs from corresponding lengths of spring steel or other resilient material having a circular cross-section with a diameter of substantially 9 mm.Each tine 24 comprises a substantially straight soil engaging portion whose upper end merges, by way of a coil 25, into a single substantially U-shaped fastening portion 26 that is firmly but releasably secured to the substantially horizontal limb of the carrier 23 by an upright bolt 28 and a shaped clamping plate 27. As will be entirely clear from Figure 3 of the drawings, each clamping plate 27 and the corresponding bolt 28 co-operate with the substantially U-shaped fastening portion 26 that integrally interconnects the coils 25 corresponding to an integral pair of tines 24.The clamping plates 27 and bolts 28 are located in a rear edge region of the substantially horizontal limb of the carrier 23, relative to the direction A, and it will be evident from Figures 2 and 3 of the drawings that the substantially vertical limb of the same carrier 23 lies immediately in front of the coils 25 relative to the direction A and thus shields those coils 25 against striking obstacles which may be met with during forward progress of the implement in the direction A when it is in use.In any possible setting of the arms 1 9 about the pivot bolts 20 relative to the plates 16, the free ends or tips of the resilient tines 24 are always at a horizontal level which is beneath that of the axis of rotation of the ground roller 17 and, when the arms 1 9 are turned downwardly about the pivot bolts 20 as far as it is possible, the free ends or tips of the resilient tines 24 are beneath the level of said axis of rotation by a distance which is not less than substantially two-thirds of the radius of the cylindrical figure generated by the roller 1 7 during its rotation.The resilient tines 24 together afford a screen that is generally indicated by the reference 24A which screen 24A lies between the soil working members 3 and the ground roller 1 7 with the resilient tines 24 thereof in proximity to the paths traced by the rigid tines 5 of the soil working members 3 during rotation of those members 3 about the axes of the shafts 2. The term "proximity" is to be interpreted in this specification as meaning that the resilient tines 24 are spaced from the figures traced by rotation of the rigid soil working tines 5 and the sleeve-like tine holders which carry those tines 5 by a distance which is equal to a value between substantially onethird and substantially one-half of the diameter of one of those figures. The distance in question advantageously has a mgnitude of between 10 and 20 cm inclusive.

Each shaft is provided, inside the hollow frame portion 1, with a corresponding straight- or spurtoothed pinion 34, the sizes of the pinions 34 being such that each of them has its teeth in mesh with those of the or each immediately neighbouring pinion 34 in the single row of twelve (in this embodiment) such pinions. With this arrangement, each pinion 34, shaft 2 and soil working member 3 will revolve, during use of the implement, in a direction opposite to that of the or each immediately neighbouring similar assembly as is indicated by small arrows in Figure 1 of the drawings for some of the assemblies. One of the centre pair of shafts 2 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 35 mounted immediately above that top or cover plate.Shafts and pinions (not visible in the drawings) inside the gear box 35 place the upward extension of said one of the shafts 2 in driven connection with a rotary input shaft 37 of the gear box that projects substantially horizontally forwards from the front of the latter in substantially the direction A to enable it to be placed in driven connection with the rear power take-off shaft of an agricultural tractor or other operating vehicle through the intermediary of a telescopic transmission shaft 29 which is of a construction that is known per se having universal joints at its opposite ends. The rear of the gear box 35, relative to the direction A, carries a changespeed gear 36 which is not illustrated, nor will be described, in detail since it is not the subject of the present invention.It suffices to say that the splined ends of two shafts project into the interior of the change-speed gear 36 which has a removable cover. Pairs of toothed pinions of different sizes can be mounted on these splined ends, by way of the correspondingly splined hubs of those pin ions, to co-operate with one another to change the transmission ratio between the two shafts and thus enable all of the soil working members 3 to be rotated at a chosen faster or slower speed without having to alter the speed of rotation that is applied to the rotary input shaft 37 from the rear power take-off shaft of the tractor or other operating vehicle.

A leading central region of the top of the hollow frame portion 1 is provided with a coupling member or trestle 30 that is of substantially triangular configuration as seen in front or rear elevation. The coupling member or trestle 30 defines two horizontally spaced apart lower coupling points for pivotal connection to the rear ends of the lower lifting links of a rear-mounted three-point lifting device or hitch of the operating agricultural tractor or other vehicle and a single upper coupling point for pivotal connection to the upper adjustable-length lifting link of the same three-point lifting device or hitch.A location adjacent to the apex of the coupling member or trestle 30 is connected to widely spaced apart locations at the top and rear of the hollow frame portion 1 by two downwardly and rearwardly divergent tie bars (Figure 1) in order to strengthen the connection of the coupling member or trestle 30 to the frame portion 1.

Substantially vertically disposed shield plates 32 lie immediately beyond the opposite ends of the single row of soil working members 3 so as to extend substantially parallel to one another and to the direction A. The shield plates 32 co-operate with the neighbouring soil working members 3 at the opposite ends of the row in working soil at the margins of the broad strip of ground that is dealt with by the implement to substantially the same thorough extent as occurs by co-operation between neighbouring members 3 at locations closer to the center of the implement. In addition, the shield plates 32 prevent the rapidly moving tines 5 of the members 3 from flinging stones and other hard object laterally of the path of travel of the implement and thus greatly reduce the possibility of injury or damage that might otherwise be caused in this way.A lower region of each shield plate 32 is shaped to slide over the ground surface and each shield plate 32 is carried by a corresponding arm 31 which arm includes a portion that extends substantially horizontally parallel to the direction A, being turnably mounted in brackets located on top of the hollow frame portion 1. This arrangement enables the shield plates 32 to move upwardly and downwardly during operative progress in the direction A to match the particular working depth of the implement that has been adopted and also undulations in the ground surface that are met with during such progress.In addition, when the implement is to undergo inoperative transport, the shield plates 32 can be turned upwardly and inwardly through substantially 1 800 about the arm portions that are turnably mounted in said brackets to bring the shield plates 32 to inverted positions in which they lie on top of the hollow frame portion 1.

In the use of the soil cultivating implement that has been described, its coupling member or trestle 30 is connected to the rear three-point lifting device or hitch of an agricultural tractor or other operating vehicle and the rotary input shaft 37 of its gear box 35 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 transmission shaft 29 having universal joints at its opposite ends. If required, the speed of rotation of the soil working member is increased or decreased, before work commences, by an appropriate adjustment of the change-speed gear 36 and the maximum depth of penetration of the soil working tines 5 which can take piace is increased or decreased by raising or lowering the level of the ground roller 1 7 relative to that of the remainder of the implement using the adjusting mechanisms 11.Clamps 33 (Figures 1 and 2) are provided to secure the arms 88 rigidly to the frame portion side plates 6 in any chosen bodily setting of the roller 1 7 to ensure a rigid assembly and relieve the adjusting mechanisms 11 of supporting stresses. The adjustments which have just been mentioned are carried out in the light of the nature and condition of the soil that is to be cultivated and the particular purpose for which the cultivated soil is required. In addition to these adjustments, the screen 24A which comprises the regularly spaced apart resilient tines 24 can be moved upwardly or downwardly by turning the arms 19 about the pivot bolts 20 and using the retaining bolts 22 to maintain any chosen setting as long as may be required.As shown in Figure 2 of the drawings, the free ends or tips of the resilient tines 24 will normally be spaced above the ground surface but the actual spacing is, of course, adjustably variable.

The screen 24A engages a proportion of the soil crumbled and displaced by the immediately preceding rotary members 3 which soil is usually ejected rearwardly from those members 3 in fanlike patterns and in more or less horizontal directions. The screen 24A acts in several advantageous ways. It temporarily retains some of the displaced soil and allows any remaining lumps or clods thereof to be further crumbled by the rigid tines 5 for subsequent progressive release towards the following ground roller 1 7 which, in addition to performing a gentle levelling and compressing action, also acts in its own right as a soil working member in crushing any stubborn lumps or clods of soil that have defied being broken up by the rigid tines 5 or the resilient tines 24. The screen A releases crumbled soil from a temporary accumulation thereof at a substantially uniform rate and this has the advantage that, should the implement be travelling over unuduiating or other ground where the well broken top-soil is relatively shallow at the peaks thereof, the implement tends to accumulate soil in the troughs and to release it at the peaks thus improving the uniformity of topsoil depth. The screen 24A is readily adjustable to a position in which excess soil will not accumulate in front of it, relative to the direction A where, particularly in abrasive soil, it could cause the rigid soil working tines 5 to become worn too quickly.The resilient formation of the tines 24 makes their action more intensive than it would be if they were rigid and this effect is particularly noticeable in regard to the further crumbling and uniform rearward distribution of the worked soil. When the implement is set for relatively deep penetration of the tines 5 into the ground surface, it is necessary to move the screen 24A upwardly about the axis defined by the pivot bolts 20 and it will be seen from Figure 2 of the drawings that this action moves the screen 24A closer to the figures traced by rotation of the tines 5 than when the screen 24A is turned further downwardly about the pivot bolts 20.The intensity of co-operation between the resilient tines 24 and the rotary soil working members 3 is thus still greater when the implement is set for deep penetration of the rigid tines 5 into the ground, provided only that the screen 24A is substantially correctly adjusted in position. Generally speaking, the implement that has been described is capable of bringing previously cultivated agricultural land to a condition suitable for use as a seedbed, and/or for use in growing on seedlings to maturity, after thinning out when so required, in a single traverse of the ground and the use of the screen 24A has been found significantly to improve the degree of fineness of the worked soil and the uniformity of depth thereof.

Although certain features of the implement 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 in not necessarily limited to those features and that it includes within its scope each of the parts of the implement that has been described, and/or that is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (21)

1. A soil cultivating implement of the kind set forth, wherein a screen which comprises tines is arranged rearwardly of the rotary soil working members with respect to the intended direction of operative travel of the implement so as to lie above the ground surface during such operation, the screen being upwardly and downwardly adjustable in level relative to the soil working members.

2. An implement as claimed in claim 1, wherein the screen is located between the rotary soil working members and a ground roller that is also located rearwardly of those soil working members with respect to the intended direction of operative travel of the implement.

3. An implement as claimed in claim 1 or 2, wherein the screen is upwardly and downwardly adjustable in level relative to the soil working members about an axis which is substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement.

4. An implement as claimed in claim 3, wherein said axis is located rearwardly of the screen with respect to the intended direction of operative travel of the implement.

5. An implement as claimed in claim 2 or in either claim 3 or claim 4 when read as appendant to claim 2, wherein both the screen and the ground roller are bodily pivotable relative to said frame portion.

6. An implement as claimed in either claim 4 or claim 5 when read as appendant to claim 2, wherein the screen is pivotable about an axis which is located at substantially the same horizontal level as is the top of the ground roller.

7. An implement as claimed in claim 6, wherein said axis is in substantially vertical register with the axis of rotation of the ground roller.

8. An implement as claimed in 2 or in any one of claims 3 to 7 read as appendant to claim 2, wherein the screen is carried by arms which extends parallel or substantially parallel to the intended direction of operative travel of the implement, rear end regions of said arms, with respect to the same direction, being pivotably connected to supports of the ground roller.

9. An implement as claimed in claim 8, wherein setting mechanisms are arranged in advance of the pivots of said arms, with respect of the intended direction of operative travel of the implement, said setting mechanisms enabling the arms to be placed, and retained, in chosen angular positions about their pivots.

10. An implement as claimed in claim 9, wherein each setting mechanism comprises an arcuate slot along which, when not tightened, a retaining bolt is movabie.

11. An implement as claimed in any preceding claim, wherein said screen comprises a plurality of tines arranged in a row that extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement, said row coinciding with substantially the whole of the working width of the implement.

12. An implement as claimed in claim 11 when read as appendant to any one of claims 8, 9 or 10, wherein said tines are mounted on a carrier arranged between said arms.

13. An implement as claimed in claim 12, wherein said carrier is located at substantially the same horizontal level as the tops of the rotary soil working members.

14. An implement as claimed in claim 11, wherein the tines of said screen are resilient and are mounted on a carrier in such positions that the fastening locations thereof on that carrier are shielded by the carrier when the implement is moving in its intended direction of operative travel.

1 5. An implement as claimed in claim 14, wherein the carrier is afforded by a bar of substantially right-angled cross-section, one limb of the bar extending downwardly, and the other limb of the bar extending rearwardly, from the junction between those limbs, with respect to the intended direction of operative travel of the implement, and wherein the locations at which the tines of the screen are fastened to the carrier bar are disposed between said limbs thereof.

16. An implement as claimed in claim 14 or 15, wherein the locations at which the tines of said screen are fastened to the carrier are adjacent to the rear edge of the rearwardly extending limb of.

the bar which principally affords that carrier, and wherein the fastening of each such tine is connected to the tine, proper, by a resilient support located protectively behind the downwardly extending limb of said bar withrespect.to the intended direction of operative travel of the implement.

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17. An implement as claimed in Claim 1.6, wherein each resilient support is in the form of a coil that is integral with the corresponding tine, proper

18. An implement as claimed in claim 11 or in any one of claims 12 to 17 when read as appendant to.claim 11, wherein the tines of said screen extend substantially perpendicularly downwards towards their free ends or tips.

19. An implement as claimed in claim 11 or in any one of claims 12 to 1 8 when read as appendant to claim 11, wherein each screen tine, proper, has a length which is not less than half the effective diameter of the ground roller.

20. An implement as claimed in claim 11 or in any one of claims 12 to 1 9 when read as appendant to claim 11, wherein immediately neighbouring tines of said screen are formed in integral pairs from single lengths of spring steel or other resilient material.

21. A soil cultivating implement of the kind set forth, substantially as hereinbefore described with reference to the accompanying drawings.