GB2158685A - Soil cultivating implements - Google Patents

Abstract

In a soil cultivating implement comprising a hollow frame portion 1 that extends transversely to the intended direction of operative travel of the implement and supports a row of power-rotatable soil working members 2, a shield plate 11 is provided at least one end of the row. The maximum depth to which tines 5 of the members 2 can penetrate into the soil is adjustable and, in order to enable the plate 11 to maintain its substantially vertical dispostion for full co-operation with the neighbouring member 2 at any chosen working depth of the tines 5, a portion 14 of an arm 12 which carries said plate 11 can be entered through any appropriate pair of circular openings 17 in a front bracket 15 and a rear bracket that are both mounted on top of the hollow frame portion 1. The plate 11 can yield outwardly to release a momentarily trapped stone or the like before damage is caused by temporarily compressing the spring 24 of a resilient mechanism 18. Other constructions of the resilient mechanism are both described and illustrated. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines of the kind which comprise a row of power-drivable soil working members that extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement or machine with each soil working member rotatable about a substantially vertical, or at least upwardly extending, axis, at least one plate being provided to co-operate in working the soil with one of said members at one end of said row and said plate being arranged so as to be capable of angular displacement about an axis during the use of the implement or machine. The expression "implement(s) or machine(s)" is shortenet to "implement(s)" alone throughout the remainder of this document for the sake of brevity.

Implements of this known kind usually operate very satisfactorily as regards the soil working cooperation between the or each of said plates and the immediately neighbouring soil working member(s) but sometimes, upon considerably increasing or decreasing the maximum depth to which the soil working members can penetrate into the ground, the or each plate is turned about the corresponding axis to such an extent that the efficiency of the cooperation between it and the neighbouring soil working member is very significantly reduced.

An object of the present invention is to provide a simple but effective construction that can enable the or each plate to co-operate correctly with the immediately neighbouring soil working member whatever maximum depth setting for the row of such members has been adopted and, accordingly, one aspect of the invention provides a soil cultivating implement of the kind set forth, wherein means which defines the axis about which the or each plate is angularly displaceable is constructed and arranged so that the or each such axis can be located at any chosen one of a plurality of different levels relative to that of said soil working members.

The term "plate" is used throughout this document in respect of each part bearing the reference "11" but it is possible for such a part to be comprised by a plurality of bars, strips, rods or the like which together function in the manner of one of the plates 11 that will be described below. Accordingly, the word "plate" is to be interpreted, throughout this document, as including such constructions within its scope when used in regard to the or each item referenced "11".

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure lisa 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 front view, to an enlarged scale, as seen in the direction indicated by an arrow II in Figure 1, Figure 3 is a section, to an enlarged scale, taken on the line Ill-Ill in Figure 2, Figure 4 is a similar view to that of Figure 2 but shows an alternative embodiment, Figure 5 is a plan view as seen in the direction indicated by an arrow V in Figure 4, Figure 6 is again a view as seen in the direction indicated by the arrow II in Figure 1 but illustrates a further alternative embodiment, Figure 7 is a plan view as seen in the direction indicated by an arrow VII in Figure 6, Figure 8 is another view as seen in the direction indicated by the arrow II in Figure 1 but illustrates a fourth embodiment, Figure 9 is a plan view as seen in the direction indicated by an arrow IX in Figure 8, and Figure 10 corresponds to Figure 8 but illustrates an alternative working position of some of the parts in Figure 8.

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 that is intended principally, but not exclusively, for the preparation of seed beds in previously worked agricultural soil. The implement has a hollow box-section frame portion 1 that extends substantially horizontally transverse and usually, as illustrated, substantially horizontally perpendicular, to the intended direction of operative travel of the implement that is indicated in Figures 1 and 5 of the drawings by an arrow A.The top and bottom of the hollow frame portion 1 carry bearings in which a plurality, of which there are twelve in the Example that is being described, of substantially vertical, or at least upwardly extending, shafts 3 are rotatably mounted with the axes of rotation of the twelve shafts 3 parallel to one another and spaced apart at regular intervals which advantageously but not essentially, each have a magnitude of substantially 25 cms.

Each shaft 3 has a portion which projects downwardly from beneath the bottom of the hollow frame portion 1 and this downwardly projecting portion has the hub of a corresponding soil working member, that is generally indicated by the reference 2, fastened to it in a secure but releaseable manner.

Each soil working member 2 comprises a substantially horizontal carrier 4 exhibiting arms which project substantially radially in opposite directions from the hub of that member 2. The outer ends of these carrier arms are integrally or rigidly provided with substantially vertically extending sleeve-like holders in which upper fastening portions of soil working tools in the form of rigid metallic tines 5 are firmly but releaseably secured. As can be seen best in Figure 2 of the drawings, each tine 5 also has a downwardly tapering soil working portion that trails rearwardly from top to bottom by a few degrees with respect to the intended direction of operative rotation of the soil working member 2 in question.

The opposite ends of the hollow frame portion 1 are closed by corresponding side plates 6 which are substantially vertically parallel to one another and to the direction A, each side plate 6 being larger in area than the otherwise open end of the hollow frame portion 1 with which it co-operates and being arranged to project both vertically above the substantially flat top ofthe hollow frame portion 1 and rearwardly behind that frame portion 1 with respect to the direction A.

Upper leading regions of the two side plates 6 are provided with corresponding strong pivots 7 which are substantially horizontally aligned in a direction parallel to the transverse aligned in a direction parallel to the transverse length of the hollow frame portion 1 and each pivot 7 has the leading end of a corresponding arm 8 turnably mounted on it in such a way that said arm 8 extends generally rearwardly, with respect to the direction A, from the pivot 7 concerned at that side of the corresponding plate 6 which faces the centre of the implement, the rearmost ends of the two arms 8 being located well behind the frame portion 1 and behind the rear edges of its frame portion side plates 6.

Means which is not shown in detail in the drawings, and that may be of a construction which is known per se, inter-connects each arm 8 and the top and rear of the hollow frame portion 1 at one end of the latter, said means conveniently, as illustrated, comprising a manually operable screw-threaded spindle 9 having a crank handle at its uppermost end. This spindle 9 or other means is operable to adjust the angular setting of the corresponding arm 8 about the axis defined by the aligned pivots 7 and incorporates parts (not shown) firmly to retain any such chosen angular setting for as long as may be required. The rear ends of the two arms 8 carry substantially horizontally aligned bearings between which a ground roller 10 is mounted so as to be freely rotatable about a substantially horizontal axis that is substantially parallel to the transverse length of the frame portion 1.When it is in operation, the implement is supported from the ground surface principally by the roller 10 and it will therefore be appreciated that the bodily level of that roller 10 relative to that of the frame portion 1 and soil working members 2 is the principal factor which determines the maximum depth of penetration of the tines 5 of those members 2 into the soil that is possible. When this maximum possible working depth should be increased or decreased, the level of the ground roller 10 is either raised or lowered by manual operation of the screw-threaded spindles 9 or other adjusting mechanisms to turn the arms 8 either upwardly or downwardly about the corresponding pivots 7.

A plate 11 is arranged immediately beyond the opposite ends of the single row of twelve, in this embodiment, soil working members 2, the plates 11 being arranged to co-operate with the immediately neighbouring soil working members 2 at the opposite ends of said row in cultivating the soil to substantially the same thorough extent at these locations as is produced closer to the centre of the implement by the co-operation of soil working members 2 with their neighbours. In addition, the plates 11 serve as shield plates inasmuch as they prevent stones and other hard objects displaced by the tines 5 from being flung laterally of the path of travel of the implement so that the danger of damage or injury being caused in this way is very greatly reduced, if not entirely eliminated.Each plate 11 normally extends substantially vertically parallel to the other plate 11 and to the direction A, each plate 11 being connected, at its top, to a corresponding shaped arm 12 that is initially inclined upwardly and forwardly, with respect to the direction A, from said plate 11 after which it is integrally connected, by a bend, to a laterally inwardly extending oblique portion 13 whose inner end, in turn, is connected by a further substantially 90 bend to the leading end of a straight portion 14 that is substantially horizontally parallel to the direction A.

The lateral portion 13 of each arm 12 has a length which preferably at least equals, but is not less than, one and a half times the perpendicular distance between the axes of rotation of the shafts 3 which carry two immediately neighbouring soil working members 2. Thus, in the case of the embodiment that is being described, this length is preferably 37.5 cms.The turnability of each straight arm portion 14 is provided by entering the rear end thereof through an opening in the upright part of a bracket 16 and by entering substantially the front thereof through the base of a bracket 15 that is channel-shaped as seen in plan view (Figure 1). in fact, each pair of vertically extending front and rear brackets 15 and 16 is formed with three pairs of circular holes 17 that are located at different vertical levels, Figure 2 of the drawings showing one arm portion 14 entered through the lowest hole 17 in the upright base of the corresponding front bracket 15. As can be seen in both Figures 1 and 3 of the drawings, the two limbs of each front bracket 15 project forwardly from its upright base, with respect to the direction A, to locations which are vertically in register with the front edge of the frame portion 1.

Each arm 12 carries, at a location on the portion 14 thereof which is between the limbs of the corresponding front bracket 15 and thus close to the bend interconnecting that arm portion 14 and the corresponding lateral arm portion 13, a resilient mechanism that is generally indicated by the reference 18.

Retaining pins 19 and 19Awhich extend perpendicularly through the portions 14 of the arms 12 at locations immediately in front of, and immediately behind, with respect to the direction A, the upright limbs of the two brackets 15 and 16 concerned, act to prevent significant axial displacement of the arms 12 in directions parallel to the lengths of the portions 14 of those arms, the retaining pins 19 and 19A freely allowing rotational movements about the longitudinal axes of the arm portions 14 and being readily removable, when required, to allow the arm portions 14 to be entered through different pairs of the circular holes 17 in the brackets 15 and 16.

Each resilient mechanism 18 is welded (see Figure 2) or otherwise rigidly secured to the respective arm portion 14 and includes a pin generally indicated by the reference 20, said pin 20 having a domed head 21 at one end and a rubber, artificial rubber or resilient synthetic plastics plug 22 at its opposite end, Each pin 20 displaceably carries a stop washer 23 (Figure 3) and a helical compression spring 24 is wound, with some clearance, around the pin 20 to bear between its domed head 21 and the stop washer 23 concerned, said spring 24 being installed with an initial degree of compression that is adjustable in the manner that can be seen in Figure 3 of the drawings by changing the distance between the head 21 and the plug 22 as may be required.The plug 22 carries a screw-threaded shaft which is entered into a matchingly screw-threaded bore formed axially in the end of the pin 20 remote from its head 21 and a sleeve 25 surrounds these interengaging parts between the corresponding stop wahser 23 and a metal or other rigid base of the plug 22 concerned. Thus, rotation of the plug 22 in an appropriate direction relative to the headed pin 20 will increase or decrease the distance between the head 21 and the plug 22 and will thus decrease or increase the initial degree of compression of the spring 24.

Each sleeve 25 is welded or otherwise rigidly secured (Figure 2) to one end of a lever 26 of the resilient mechanism 18 which lever 26 is the part of that mechanism 18 which is also, at its other end, welded or otherwise rigidly secured to the respective arm portion 14. In the position shown in full lines in Figure 2 of the drawings, the lever 26 extends generally upwardly from the arm portion 14 to the sleeve 25. The pin 20 of each mechanism 18 extends more or less horizontally between the two limbs of the corresponding front bracket 15 with the domed head 21 contacting, or very close to, one of those limbs whilst the resilient plug 22, which has a flat end surface, bears against, or is located very close to, the other limb of the same bracket 15.It will be appreciated that, as well as co-operating in the function of each resilient mechanism 18, the limbs of the front brackets 15 protectively enclose the pins 20 and associated parts of the mechanisms 18.

Each shaft 3 is provided, inside the hollow frame portion 1, with a corresponding straight- or spurtoothed pinion 27, the size of each pinion 27 being such that its teeth are in mesh with those of the or each immediately neighbouring pinion 27 in the single row of twelve, in this embodiment, such pinions. One of the centre pair of shafts 3 in the single row thereof has an upward extension through the top of the hollow frame portion 1 into a gear box 28 that is releaseably mounted on top of the frame portion 1.The gear box 28 has a rotary input shaft 30 which projects substantially horizontally forwards from the front thereof in substantially the direction A where it is splined or otherwise keyed to enable it to be placed in driven connection with the rear power take-off shaft of an agricultural tractor or other operating vehicle by way of an intermediate telescopic transmission shaft 31, which is of a construction that is known per se, having universal joints at its opposite ends. Shafts and bevel pinions (not visible) within the gear box 28 place the rotary input shaft 30 thereof in driving connection with the upwardly extension of said one of the shafts 3 and this driving connection is by way of a change-speed gear 29 that is mounted at the back of the gear box 28.

The change-speed gear 29 is not the subject of the present invention and it suffices to say that, beneath a readily removable cover thereof, the splined or otherwise keyed ends of two parallel shafts are accessible and receive a co-operating pair of straight- or spur-toothed pinions whose meshing relationship with one another established a predetermined transmission ratio between the two shafts. The two pinions can be interchanged on the shaft ends or be exchanged for at least one alternative pair of co-operating pinions of different sizes to give any chosen one of a number of different sizes to give any chosen one of a number of different transmission ratios.The particular transmission ratio which is established in the change-speed gear 29 determines the speed at which all of the soil working members 2 will revolve in response to a substantially fixed speed of rotation applied to the rotary input shaft 30 of the gear box 28. A coupling member or trestle 32 that is of substantially isosceles triangular configuration as seen in front or rear elevation is mounted at the top and front, with respect to the direction A, of the hollow frame portion 1 at a location mid-way between the side plates 6 and, as illustrated somewhat diagrammatically in Figure 1 of the drawings, is employed, in the use of the implement, in connecting that implement to the three-point lifting device or hitch at the rear of an agricultural tractor or other propelling and operating vehicle.Tie rods which diverge steeply downwardly and rearwardly from a location close to the appex of the coupling member or trestle 32 strengtheningly interconnect the latter and widely spaced apart locations at the top and rear of the frame portion 1.

In the use of the soil cultivating implement that has been described with reference to Figures 1 to 3 of the drawings, its coupling member or trestle 32 is connected to the three-point lifting device or hitch at the rear of the tractor or other vehicle which is both to move and operate the implement and the rear power take-off shaft of that tractor or other vehicle is placed in driving connection with the rotary input shaft 30 of the gear box 28 by way of the known telescopic transmission shaft 31 which has universal joints at its opposite ends.Adjustments which may, if required, be made before work commences include altering the transmission ratio established in the change-speed gear 29 and increasing or decreasing the maximum depth to which the tines 5 can penetrate into the ground by raising or lowering the bodily level of the ground roller 10 relative to that of the frame portion 1 and soil working members 2, using the screw-threaded spindles 9 or other adjusting mechanisms for this latter purpose. If a significant change in the bodily level of the ground roller 10 is effected, a change in the disposition of the previously described shield plates 11 may also be required and the way in which this is brought about will be described below. The adjustments that have been mentioned below. The adjustments that have been mentioned will usually be made, if required, in the light of the nature and condition of the soil that is to be dealt with by the implement and the particular purpose for which that soil is required after its cultivation. As the implement is moved operatively in the direction A by the tractor or other operating vehicle, all of its soil working members 2 will be revolved at a speed which is dependent upon the transmission ratio established in the change-speed gear 29 with their tines 5 penetrating into the soil to a depth which is principally dependent upon the bodily level ofthefollowing ground roller 10 relative thereto.Each individual member 2 works a corresponding strip of ground extending in the direction A but, since the effective working width of each such member 2 is the same as, or a little greater than, the distance between the axes of rotation of immediately neightbouring members 2, these individual strips of ground overlap, or at least adjoin, one another to produce a single broad strip of worked soil that extends in the direction A. In the case of the implement that is being described, this broad strip of ground will have a width of substantially, but not necessarily exactly, three metres. It will be readily apparent that the effective working width of the implement could be increased or reduced by either increasing or reducing the number of rotary soil working members 2 in the single row thereof.Due to the inter-meshing relationship of the toothed pinions 27, each soil working member 2, shaft 3 and pinion 27 will revolve in the opposite direction to the or each immediately neighboring similar assembly and the following ground roller 10 acts in its own right as a soil working member, tending to crush any lumps or clods of soil exeptionally missed by the members 2, spreading the worked soil substantially uniformly throughout the working width of the implement and gently compressing the soil surface to form, usually, a seed bed ready for the subsequent reception of seeds.

The soil working members 2 at the opposite ends of the single row thereof co-operate, as mentioned above, in working the soil with the closely neighbouring plates 11 which, for many purposes, will be disposed substantially as shown in Figures 1 and 2 of the drawings. This co-operation ensures that the soil is thoroughly worked to substantially the same extent at the margins of the broad strip of cultivated land which is produced by the implement as it is at locations closer to the centre of that broad strip where the cultivation is effected by working cooperation between immediately neighbouring pairs of the soil working members 2.Each plate 11 tends to maintain substantially an optimum position for co-operation with the neighbouring soil working member 2, being able to turn outwardly away from that neighbouring member 2 about the axis of the corresponding arm portion 14that is entered turnably through an aligned pair of the circular holes 17 in the front and rear brackets 15 and 16. Any outward displacement takes place, however, against the action of the corresponding spring 24 which spring 24 resists further compression and thus tends to maintain substantially the position visible in Figures 2 and 3 of the drawings.

If the ground roller 10 should be displaced bodily upwards to a significant extent to increase the maximum depth of penetration of the tines 5 into the ground which is possible, then, to maintain correct co-operation between the plates 11 and the neighbouring soil working members 2, those plates 11 should also be moved bodily upwards to approximately the same extent. This is effected in a simple manner merely by temporarily removing the rear retaining pins 19, withdrawing the arm portions 14 forwardly through the aligned holes 17 with all of the parts that are directly or indirectly connected to those arm portions 14 and subsequently replacing said arm portions 14 rearwardly through appropriate alternative pairs of aligned holes 17 and finally replacing the temporarily removed rear retaining pins 19.The upward displacement of the arm portions 14 into fresh pairs of aligned holes 17 brings the plates 11 back into positions in which they are both substantially vertically parallel to the direction A, the resilient mechanisms 18 again tending to keep the plates 11 in positions, at an appropriate level, in which they are substantially vertically parallel to one another and to the direction A but the plates 11 being displaceable outwardly about the axes of the arm portions 14 against the resilient restoring action of the springs 24.The springs 24 are sufficiently strong to ensure that the soil working co-operation between the plates 11 and the neighbouring members 2 will normally be maintained without interruption but should, for example, a large stone get momentarily trapped between one of the plates 11 and the neighbouring soil working member 2, the action of the corresponding spring 24 will readily be overcome to allow the plate 11 concerned to yield temporarily outwardly to release the stone or other object without causing damage, the spring in question immediately restoring the normal working position of the plate 11 under consideration as soon as the stone orthe like has been released.

When the implement is to undergo inoperative transport, the plates 11 are advantageously turned inwardly through substantially 180 about the axes of the corresponding arm portions 14 to bring the arms 12 to substantially symmetrical positions of which one is shown in broken lines in Figure 2 of the drawings. This is effected by temporarily removing the rear retaining pins 19, withdrawing the arm portions 14forwardlyfrom the aligned holes 17, turning the arm portions 14 and the parts connected thereto through substantially 180 and replacing those arm portions 14 rearwardly through the uppermost pairs of aligned holes 17 in the front and rear brackets 15 and 16, the removed retaining pins 19 then being replaced.It is necessary to use the uppermost aligned pairs of holes 17 to ensure that, when inversion into the inoperative transport position has taken place, there will still be room for the resilient mechanism 18 between the limbs of the front brackets 15 and 16. Although not illustrated, the upright limbs of the rear brackets 16 and the upright bases of the front brackets 15 may, instead of being formed with the holes 17, be constructed so that a substantially infinitely variable level of the axis of turnability of each arm portion 14 may be attained. Purely for example, the arm portions 14 could be provided with front and rear plain bearings whose housings were slidable upwardly and downwardly along vertical slots formed in the bracket parts that have just been referred to, means also being provided to clamp said bearing housings at any required levels and such levels being indicated by pointers, carried by the bearing housings, mov able along scales marked close to the edges of the slots. Alternatively, only two holes 17, or more than three of them, may be formed in each bracket 15 and 16.

Figures 5 and 6 of the drawings illustrate an alternative construction in which the top of each plate 11 is provided with two relatively spaced supporting arms 33 each comprising an initial portion extending upwardly from the plate 11 concerned and the top of the initial portion being integrally connected by a bend of more than 90 to a lateral portion that extends over the top of the respective side plate 6 and then obliquely downwardly and inwardly to terminate, through the intermediary of a 90 bend, in a horizontal front portion 35 and a horizontal rear portion 36, respectively, which portions are horizontally aligned and are entered through the holes 17 in the upright limb of the rear bracket 16 and the upright base of the front bracket 15, respectively.The arm portions 35 and 36 are each fixedly provided with a collar 37 and, as will be immediately evident from Figure 5 of the drawings, the arm portions 35 and 36 can be disengaged from the brackets 15 and 16 merely by temporarily removing a retaining pin 19 that cooperates with the corresponding front bracket 15 immediately to the rear thereof, the arm portions 35 and 36 then being readily capable of re-engagement in alternative pairs of aligned holes 17. Once the removed retaining pins 19 are replaced, the plates 11 will be maintained in their appointed positions by resilient mechanisms l8Athataresimilartothe previously described mechanisms 18 except that each end of each pin 20 is provided with one of the resilient plugs 22 instead of one end thereof carrying the domed head 21.Figure 4 of the drawings includes the reference 14to denote generally the aligned arm portions 35 and 36 which serve the same purpose as one of the arm portions 14 in the first embodiment. It will be noted from Figure 5 that the arm portion 35 is of significantly greater axial length than is the corresponding arm portion 36.

After the removal of the retaining pin 19 which co-operates with the front arm portion 35, this arrangement enables the plugs 22 to be disengaged from the opposed limbs of the front brackets 15 before the arm portion 35 is completely out of the hole 17 through which it was entered. Conversely, the initial entry of the arm portion 35 through one of the holes 17 in the front bracket 15 assists in subsequently correctly locating the resilient mechanism 18A between the opposed limbs of the bracket 15 concerned. The plates 11 themselves are identical to the plates 11 of the first embodiment and these plates can be bodily displaced upwardly or downwardly, as may be required, substantially to match the working depth of the tines 5 that is dictated by the bodily level of the ground roller 10 relative to that of the soil working members 2.

Figures 6 and 7 of the drawings illustrate another alternative construction in which, again, parts that are similar or identical to parts which have been described in connection with Figures 1 to 3 of the drawings are denoted by the same references as are employed in those earlier Figures. Figures 6 and 7 show the employment of a front bracket 1 5A which serves substantially the same purpose, but whih is of a different construction, to the previously described front bracket 15. An upright portion of the front bracket 15A is again formed with three circular holes 17 which are spaced apart vertically from one another at regular intervals and a rear bracket, equivalent to one of the previously described rear brackets 16, is provided with holes that are in alignment with the holes 17, this rear bracket not being illustrated.The pivotable portion 14 of the illustrated arm 12 is again entered lengthwise through a chosen pair of front and rear holes 17 and one of the retaining pins 19 is entered perpendicularly through said arm portion 14 immediately in front of the base of the bracket 15A in which said holes 17 are formed. A collar comprising a projecting lug 38 is welded or otherwise rigidly secured to each arm portion 14 a little in front of the portion of each front bracket 15A that is formed with the holes 17 and the tip of said lug 38 has welded or otherwise rigidly secured to it a sleeve 39 which is substantially equivalent to one of the previously described sleeves 25.A screw-threaded rod provided at one end with a nut is entered lengthwise through the sleeve 39 and the opposite end of that rod carries a rubber or other resilient plug 40 substantially equivalent to one of the previously described plugs 22. The plug 40 normally bears against an upright portion of the front bracket 1 5A that extends substantially vertically parallel to the direction A and perpendicular to the portion of that bracket 15A in which the holes 17 are formed. The front bracket 15A has a foot, as do the previously described brackets 15 and 16, that is secured to the top of the hollow frame portion 1 and, in this case, said foot carries a horizontal pivot pin 41 about which a lever 42 is turnable.

The axis defined by the pivot pin 41 extends substantially horizontally parallel to the direction A and is located at the opposite side of the portion of the bracket 1 SA against which the plug 40 normally bears from the upright portion of the same bracket in which the holes 17 are formed. A lug 45 is perpendicularly secured to the leading edge of the portion of the bracket 1 5A that is substantially vertically parallel to the direction A, said lug 45 lying immediately behind the lever 42 with respect to the direction A.

The lug 45 is carried by an upper region of the bracket 1 SA at a significant distance from the pivot pin 41 and is formed with two relatively spaced holes 44 either one of which can register with a single hole in the lever 42, depending upon the angular position of that lever about the pivot pin 41. A horizontal locking pin 43 is provided for entry through the chosen hole 44 in the lug 45 and through the single hole in the lever 42.

A lower end region of the lever 42 is forked by the provision of a bracket and a block is mounted between the limbs of the fork, the block being formed with a transverse bore through which the screw-threaded shank or an eye 46 is entered, said shank carrying a pair of co-operating lock nuts that can be tightened together to retain them at any chosen setting lengthwise along said shank. A helical tension spring 47 is stretched between the eye 46 and a hole in a lug 48 which is welded or otherwise rigidly secured to the lateral portion 13 or the corresponding arm 12 at a location on the lower surface of that portion 13 and close to the bend which integrally connects said portion to the further portion therefore that is actually secured to the corresponding plate 11.It will be apparent that it is the spring 47 which normally maintains the illustrated plate 11 in the position in which it extends substantially vertically parallel to the direction A, this position being defined by abutment of the plug 40 against the co-operating portion of the front bracket 15A. If a change in the level of the illustrated plate 11 is required substantially to match a change in the maximum working depth of the members 2, the locking pin 43 is first withdrawn so that the spring 47 is no longer tensioned and the illustrated retaining pin 19 is then temporarily removed to allow the arm portion 14to be withdrawn from one of the aligned pairs of holes 17 after which the arm portion 14 is replaced in the required fresh pair of aligned holes 17, the removed retaining pin 19 is replaced and the locking pin 43 is again installed to keep the spring 47 stretched to the required extent. It may be necessary to use the alternative hole 44 in the lug 45 for this purpose having regard to the changed level of the plate 11 and its arm 12 and, should the tension in the spring 47 require to be significantly increased or decreased, the effective position of the eye 46 can be changed by moving the lock nuts lengthwise along the screw-threaded shank of that eye 46. Once again, whatever maximum depth setting for the soil working members 2 is adopted, it is possible to arrange the two plates 11 at a corresponding level which will substantially match that depth setting and maintain the soil working co-operation between the plates 11 and the neighbouring members 2 at the ends of the single row of those members.Should a stone or other hard object become momentarily jammed between one of the plates 11 and the neighbouring member 2, that plate 11 can yield outwardly to allow release of the stone or the like, against the action of the corresponding spring 47, before any damage occurs, the spring 47 immediately restoring the normal position of the displaced plate 11 once the stone or the like has gone.

In the embodiment of Figure 8 to 10 of the drawings, a relatively short arm is welded or otherwise rigidly secured to the top of the illustrated plate 11, adjacent to the front thereof, with respect to the direction A, said arm initially extending upwardly and then being bent over forwardly through 90" to form a portion 48A that is entered turnably through a circular hole in one end of a displaceable support49.

A retaining pin 50A is entered perpendicularly through the arm portion 48A adjacent the leading end of the that portion 48A and just in front of the support 49. One end of a plate 50 surrounds the arm portion A immediately to the rear, with respect to the direction A, of the support 49 and is welded or otherwise rigidly secured to said arm portion 48A.

As can be seen best in Figure 10 of the drawings, the plate 50 is of progressively increasing vertical height towards the centre of the implement away from the point at which it is rigidly secured to the arm portion 48A. The end of the elongate support 49 which is remote from the arm portion 48A is welded or otherwise rigidly secured to the leading end of a shaft 51 that extends substantially horizontally parallel to the direction A, said shaft 51 being turnably mounted in the upright triangular limbs of two brackets of which only the front bracket 52 is visible in the drawings. The corresponding rear bracket, which is not illustrated, is located at the top and rear of the hollow frame portion 1 and are corresponds to the rear bracket 16 of the first embodiment.A radially extending lug 53 is welded or otherwise rigidly secured to the shaft 51 immediately in advance of the upright limb of the front bracket 52 and projects generally upwardly from said shaft 51 to carry, at its upper end, a sleeve in which a screw-threaded pin, provided with a fastening nut, is mounted, said pin carrying a rubber or other resilient plug 54 which corresponds to one of the previously described plugs 22 or 40. Upon turning the support 49 angually about the axis of the shaft 51 through substantially 1200 in an anti-clockwise direction as seen in Figure 8 of the drawings, the flat surface of the plug 54 will come into contact with the top of the hollow frame portion 1 at a location close to the leading edge of that frame portion.

A bracket 55 of forked configuration has one limb thereof secured to the support 49 immediately alongside the plate 50, the two limbs of said forked bracket 55 guidingly supporting a pin 56 which is urged axially towards the plate 50 by a helical compression spring 55A. The tip of the pin 56 can thus be retained, by the spring 55A, in either a lower and larger hole 57 or an upper and smaller hole 58 which are both formed in the plate 50. A stop plate 59 having opposite downwardly inclined edges is welded or otherwise rigidly secured to the upper edge of the plate 50 at a location which, as seen in Figure 8 of the drawings, is vertically above the pin 56.The stop plate 59 is arranged to co-operate with a further rubber, synthetic rubber, synthetic plastics or other resilient plug 60 carried on the top of an arched bracket that is fastened by bolts to the top and front of the hollow frame portion 1. An anchorage 61 is fastened to the base of the forked bracket 55 and has one end of a helical tension spring 62 hookingly engaged therewith, the opposite end of the tension spring 62 being connected to a lug or other anchorage (not shown) at the front of the hollow frame portion 1.

By entering the spring-loaded pin 56 into either the hole 57 (Figure 10) orthe hole 58 (Figure 8), the illustrated plate 11 will occupy either a higher or a lower position relative to the frame portion 1 and soil working members 2, the plate 11 being turned angularly about the axis of the arm portion 48A during a displacement from one of these positions to the other to maintain its substantially vertically parallel relationship with the direction A. Figure 8 shows the position in which the illustrated plate 11 is at the lower possible level relative to the frame portion 1 and soil working members 2 whilst Figure 10 shows the position in which said plate 11 is at the higher possible position relative to those parts. In the former position shown in Figure 8, the resilient plug 60 bears against the lower surface of the stop plate 59.In either working position, the spring 62 will normally maintain the illustrated plate 11 in substantially vertically parallel relationship with the direction A but will allow that plate to yield outwardly, to avoid damage, should a stone or other hard object become momentarily jammed between the plate and the neighbouring soil working member 2, such yielding taking place about the axis of the shaft 51 and against the restoring action of the spring 62.

When an inoperative transport position of the implement is required, the plate 11 is turned upwardly and inwardly about the axis of the shaft 51, from either the position of Figure 8 or the position of Figure 10, through substantially 120 until the plug 54 contacts the top of the hollowframe portion 1.The arrangement is such that, in the inoperative transport position, the spring 62 will tend to keep the plug 54 in contact with the frame portion 1 so that vibration during transport will not shake the plate 11 back into its "working" position. The tip of the pin 56 is stepped (see Figure 9) so that said pin can move further axially into the lower and larger hole 57 in the plate 50 than it can into the upper and smaller hole 58.The reason for this is to enable the pin 56, when entered through the larger hole 57 in the position of Figure 10 of the drawings, to bear downwardly on the top of the rubber or other resilient plug 60 carried by the arched bracket mounted on top of the hollow frame portion 1.

It will, of course, be realised that, like the embodiment of Figures 1 to 3 of the drawings, all of the embodiments of Figures 4 to 10 thereof are substantially symmetrically duplicated at the opposite end of the hollow frame portion 1 from that which is illustrated, a description of the symmetrically similar or identical construction therefore being unnecessary. However, the invention includes within its scope the provision of one of the described mountings of a plate 11 at only one end of the frame portion 1.

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 implementembodimentthat has been described, and/or that is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (25)

1. A soil cultivating implement of the kind set forth, wherein means which defines the axis about which the or each plate is angularly displaceable is constructed and arranged so that the or each such axis can be located at any chosen one of a plurality of different levels relative to that of said soil working members.

2. An implement as claimed in claim 1, wherein the or each plate is displaceable from its normal position of co-operation with the neighbouring soil working member against the resilient opposition of a resilient mechanism which is constructed and arranged to exert substantially the same positionrestoring effect upon the plate or corresponding plate whatever chosen level of the axis of turnability of that plate has been adopted.

3. A soil cultivating implement of the kind set forth, wherein the or each plate is united with a resilient mechanism and is releaseably attachable to the remainder of the implement.

4. An implement as claimed in claim 2 or 3, wherein the or each resilient mechanism is united with the means which is constructed and arranged so that or each axis of turnability can be located at any chosen one of a plurality of different levels.

5. An implement as claimed in any preceding claim, wherein the or each axis of turnability extends substantially horizontally parallel to the intended direction of operative travel of the implement and always at a level above that of the top of a frame portion of the implement which rotatably supports said soil working members.

6. A soil cultivating implement of the kind set forth, wherein the or each axis about which the or each plate is angularly displaceable during the use of the implement extends substantially horizontally parallel to the intended direction of operative travel of that implement, the or each plate being capable of being arranged in any chosen one of a plurality of different working positions relative to the soil working members by turning it about said axis or corresponding axis.

7. An implement as claimed in any one of claims 1 to 5, wherein at least one support bracket is provided relative to which the means defining the axis, or one of the axes, is bodily displaceable, said means co-operating with parts which will retain it at any chosen bodily level.

8. An implement as claimed in claim 7, wherein a frame portion, or said frame portion, which rotatably supports the row of soil working members is provided with at least one pair of front and rear support brackets that are spaced apart from one another in the intended direction of operative travel of the implement, the brackets of the or each such pair being formed with vertically or substantially vertically spaced apart openings that receive the or each means which defines the axis about which said plate, or one of said plates, is angularly displaceable.

9. An implement as claimed in claim 2 or in any one of claims 3 to 8 when read as appendent to claim 2, wherein the or each resilient mechanism is combined with the or each means defining the axis of turnability of the plate or one of the plates, said latter means co-operating turnably with a support bracket or with said support bracket.

10. An implement as claimed in claim 8 or in claim 9 when read as appendent to claim 8, wherein the leading one of said support brackets with respect to the intended direction of operative travel of the implement is substantially channel-shaped having limbs which project forwardly with respect to the same direction from the base thereof, and wherein the resilient mechanism is arranged, with a mini mum of clearance, between said support bracket limbs, and wherein the means which defines the axis of turnability of the plate or corresponding plate is entered through the rear support bracket and is there provided with a retaining pin arranged substantially to prevent significant axial displacement of said means whilst the retaining pin remains installed.

11. An implement as claimed in claim 10, wherein the or each resilient mechanism comprises a horizontally or substantially horizontally disposed pin which is arranged, with a minimum of clearance, between the limbs of the front support bracket, and wherein said pin is surrounded by a coiled spring against the resilient opposition of which a sleeve that surrounds said pin is displaceable, the sleeve being connected to an angularlyturnable arm carrying the plate or corresponding plate.

12. An implement as claimed in claim 1 1,wherein the or each sleeve is spaced laterally, with respect to the intended direction of operative travel of the implement, from the plate or corresponding plate and at leas one end of the ore each pin is provided with a quantity of resilient material.

13. An implement as claimed in any preceding claim, wherein the means which defines the axis about which the or each plate is angularly displaceable includes a portion of an arm, or of said arm, which carries the plate or corresponding plate, the or each of said arm portions extending substantially horizontally parallel to the intended direction of operative travel or the implement and being integrally of rigidly connected to a further arm portion that extends laterally of said direction of travel and that is located, as seen in plan view, in advance of a frame portion, or of said frame portion, which rotatably supports the soil working members.

14. An implement as claimed in claim 1, wherein the means which defines the axis about which the or each plate is angularly displaceable comprises a portion of an arm which carries the plate or corresponding plate, said arm portion extending substantially horizontally parallel to the intended direction of operative travel of the implement and being integral ly or rigidly connected at its leading end, relative to said direction of travel, to a laterally extending arm portion and also being connected, by way of a tension spring, to a pivotally mounted lever that is constructed and arranged to occupy a fixed position when the plate or corresponding plate is operatively disposed.

15. An implement as claimed in claim 14, where in said arm portion corresponding to the or each plate extends substantially horizontally parallel to the intended direction of operative travel of the implement in such a way that the tension spring or corresponding tension spring can be relaxed upon turning the arm and plate, or corresponding arm and plate, aboutthe longitudinal axis of said portion of the arm.

16. An implement as claimed in claim 15, where in the or each arm portion defining the axis of turnability of the plate or of one of the plates is located towards one end of an elongate frame portions, or said frame portion, that rotatably sup ports the row of soil working members.

17. An implement as claimed in claim 16, wherein said arm portion, or each arm portion, is arranged on a support that extends tranverse to the intended direction of operative travel of the implement, that support itself being connected to said frame portion so as to be turnable relative thereto about an axis that is substantially horizontally parallel to the intended direction of operative travel of the implement.

18. An implement as claimed in claim 17, wherein the or each plate is carried by an arm which is pivotable relative to said support, means being provided to retain the arm in any chosen one of at least two different positions relative to that support.

19. An implement as claimed in claim 18, wherein a leading portion of the or each arm, with respect to the intended direction of operative travel of the implement, carries a plate which is displaceable relative to the support and which is formed with openings for the reception of a locking pin that is also entered through the support itself.

20. An implement as claimed in claim 19, wherein a lower opening in said plate is of larger diameter than is an upper opening in that plate whereby a stepped tip of said locking pin can move axially further into said lower opening than into said upper opening to serve, in the former case, as a stop defining the downward limit of displaceability of the plate, or corresponding plate, which co-operates with one of the soil working members.

21. An implement as claimed in claim 20, wherein, when said locking pin is entered through said lower opening of larger diameter, it will co-operate with a quantity of resilient material mounted on the top of said frame portion which rotatably supports the row of soil working members.

22. An implement as claimed in any one of claims 17 to 21, wherein the axis about which the or each support is itself pivotable is spaced from the corresponding end of the frame portion which rotatably supports the row of soil working members by a distance which is substantially half that between the axes of rotation of two immediately neighbouring soil working members in said row.

23. An implement as claimed in any one of claims 17 to 22, wherein the or each support and said frame portion which rotatably carries the row of soil working members are interconnected by a tension spring that bears between locations that are both spaced from the axis of turnability of the support itself.

24. An implement as claimed in claim 23, where in the or each tension spring extends transverse to the intended direction of operative travel of the implement and is located wholly or principally at a level beneath that of the axis about which the plate or corresponding plate is angularly displaceable.

25. A soil cultivating implement of the kind set forth substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings or with reference to Figures 1,4 and 5, Figures 1,6 and 7 or Figures 1,8,9 and 10 of those drawings.