GB2146213A - Agricultural implements - Google Patents

Abstract

An agricultural implement, such as a soil cultivating implement which comprises a row of rotary soil working members 3 that extends substantially horizontally perpendicular to the intended direction of operative travel A of the implement, has a coupling frame 6 defining an upper coupling point 8 and two horizontally spaced apart lower coupling points 7 arranged for co-operation with a three-point lifting device or hitch 11A, 26A at the rear of an agricultural tractor or other operating vehicle. Each lower coupling point 7 is afforded by a fork 26 at the leading end of an arm which is pivotally sandwiched between parallel spaced upright support plates 24. Upper regions of the support plates 24 also have sandwiched between them pairs of strips 23 which afford stops limiting upward pivotal movements of said arms and the rear ends of the strips 23, with respect to the direction A, define lower rear coupling points by which lower arms 33 of a rear coupling member 34 can be pivotally mounted when an additional implement as a seed drill 37, is to be connected to the soil cultivating implement. <IMAGE>

Description

SPECIFICATION Agricultural implements This invention relates to agricultural implements (or machines) of the kind which com- prise a coupling frame defining coupling points constructed and arranged for connection to a three-point lifting device or hitch carried by a tractor or other vehicle.

Such agricultural implements, and particularly soil cultivating implements, are often used in combination with other implements, machines or tools, such, for example, as seed drills, planting machines or artificial fertilizer spreaders, so that, again for example, land can be cultivated and sown with seed in a single operation. However, such operation in combination, and inoperative transport of the combination, exerts heavy forces on the coupling frame of the soil cultivating implement which many coupling frames cannot reliably withstand without expensive and complicated reinforcement.It is an object of the present invention to avoid, or at least very significantly to reduce, this disadvantage of many known coupling frames and the invention accordingly provides an agricultural implement of the kind set forth, wherein at least one lower coupling point of the coupling frame comprises a part sandwiched between two substantially planar support plates which support plates also have secured to them a rear coupling point for the connection to the implement of an additional implement, machine or tool which may be used in combination therewith.

For a better understanding of the invention, and to show how ihe same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a plan view of an agricultural implement in accordance with the invention in the form of a soil cultivating implement, that implement being shown in combination with an additional implement in the form of a seed drill and the combination being shown connected to the rear of an agricultural tractor, Figure 2 is a side elevation as seen in the direction indicated by an arrow II in Fig. 1, Figure 3 is a section, to an enlarged scale, taken on the line Ill-Ill in Fig. 1, Figure 4 is a front view as seen in the direction indicated by an arrow IV in Fig. 3, Figure 5 is a section taken on the line V-V in Fig. 3, Figure 6 is a scrap plan view illustrating a quick-action coupling piece that may be added to lower coupling points of the implement, and Figure 7 is a side view as seen in the direction indicated by an arrow VII in Fig. 6.

Referring to the accompanying drawings, the agricultural implement which is illustrated as a good example of one to which the present invention can advantageously be applied is a soil cultivating implement that is primarily, but not exclusively, intended for the preparation of seed beds on previously worked agricultural land. The implement has a hollow elongate 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 Figs. 1 to 3 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 mounted in upper and lower walls of the hollow frame portion 1 so as to extend parallel to one another in a single row with their longitudinal axes spaced apart from one another at regular intervals which advantageously, but not essentially, each have a magnitude of substantially 25 cms. Each shaft 2 projects downwardly from beneath the bottom of the hollow frame portion 1 and the downwardly projecting portion thereof has firmly but releasably secured to it a corresponding soil working member 3 (Figs. 2 to 4 of the drawings).

Each soil working member comprises a substantially horizontally disposed support or carrier 4 which has arms that radiate in opposite directions from a central hub thereof that is fastened to the shaft 2 concerned. The outer ends of these arms carry sleeve-like holders in which upper fastening portions of rigid soil working tools in the form of metallic tines 5 are firmly but releasably secured. The tines 5 have downwardly projecting soil working portions that penetrate into the soil (see Fig. 2) to an adjustable extent when the implement is in use.

A central region of the top of the hollow frame portion 1 is provided with a coupling frame 6 which defines two horizontally spaced apart lower coupling points 7 and a single upper coupling point 8 which are so disposed as to enable them to co-operate readily with the three-point lifting device or hitch at the rear of an agricultural tractor or other vehicle which both moves and operates the implement when the latter is in use. Reference may be made to Figs. 1 and 2 of the drawings where this arrangement is somewhat diagrammatically illustrated.An upper region of the coupling frame 6 includes a substantially horizontally disposed elongate main frame beam or carrier 9 that is formed so as to be highly resistent to torsional deformation, the beam 9 extending transverse, and usually substantially horizontally perpendicular, to the direction A, being of hollow formation and advantageously having a quadrilateral or other angular crosssection which, as illustrated, is preferably a square one measuring, in cross-section, not less than 100 mms. by 100 mms. and prefer ably 120 mms. by 120 mms. or more. The opposite ends of the main frame beam 9 are closed by corresponding plates 9A which are substantially vertically parallel to one another and to the direction A.It will be noted from Figs. 2 and 3 of the drawings that the main beam or carrier 9 of the coupling fame 6 is so disposed about its own longitudinal axis that diagonals of its square cross-section respectively extend substantially although not exactly vertically and substantially although not exactly horizontally.

The main beam or carrier 9 of the coupling frame 6 is connected to the top of the hollow frame portion 1 by two frame parts or supports 10 which extend substantially vertically downwards between locations towards the opposite ends of the beam or carrier 9 and locations on the top of the frame portion 1 which latter locations extend throughout substantially the fore and aft width of the frame portion 1 measured in the direction A. The lower edge of a side region 14 of each supporting frame part 10 is, in fact, secured by bolts 1 3 between juxtaposed strips 23 at the top of a corresponding elongate box which houses a double arm 25 whose leading end is divided to form a fork 26 which principally affords the corresponding lower coupling point 7.

The top of the main beam or carrier 9 of the coupling frame 6 is provided, centrally along its length, with two plates 11 carrying parallel but relatively spaced upright portions that are of identical size and substantially, although not exactly, triangular shape (see Figs. 2 and 3 of the drawings). Each plate 11 has a perpendicularly bent-over rim 1 2 that extends towards a corresponding end of the beam 9 and which rim 12 is secured to the upwardly and forwardly facing surface of the beam 9 by a group of four of the bolts 1 3 whose positions can be seen best in Fig. 4 of the drawings.Each rim 1 2 extends throughout substantially the whole of the length of the lower rear edge of the substantially vertical portion of the corresponding plate 11 but it will be seen from Fig. 4 of the drawings that a rear region, with respect to the direction A, of each rim 1 2 has an upwardly and rearwardly bevelled edge that, at its leading end, merges into an edge which is contained in a substantially vertical plane that is perpendicular to the longitudinal axis of the beam 9.

This latter edge registers with the upper leading surface of the beam or carrier 9 (see Figs.

3 and 4 of the drawings). The rims 1 2 and the upper leading surface of the beam 9 are preformed with holes for reception of the bolts 13, each group of bolts 1 3 comprising three bolts whose longitudinal axes arse contained in a plane that is substantially vertically perpendicular to the longitudinal axis of the beam 9 and one bolt 1 3 whose longitudinal axis is co-planar with the uppermost bolt in the corresponding row of three, this imaginary latter plane being parallel to the lower leading and upper rear surfaces of the beam 9. Each row of three bolts is closely adjacent to the substantially vertical portion of the corresponding plate 11 whereas the single bolt 1 3 that is not in said row is further spaced from that substantially vertical portion.

Forwardly projecting regions of the substantially vertical portions of the two plates 11 are formed with horizontally aligned pairs of holes 14A, one pair of holes 14A being further advanced, with respect to the direction A, than is the other pair. Either pair of holes 1 4A may be used to co-operate with the free end of the upper lifting link 1 1A (Fig. 2) of the three-point lifting device or hitch to which, during operation, the implement is connected, it being a matter of choice as to which pair of holes 1 4A is used having regard to the construction and dimensions of the particular lifting device of hitch that is to co-operate therewith.

Each supporting frame part 10 includes, in addition to its side region 14, a rear region 1 5 and a front region 17, these front and rear regions being produced by making 90 folds about corresponding lines a and b. The single sheet of steel or other metal from which the regions 14, 1 5 and 1 7 are produced preferably as a thickness of substantially 6 mms. The side region 14 of each supporting frame part 10 has substantially, but not exactly, the shape of a right-angled triangle, the disposition thereof being such that the 90 corner of the triangle is lowermost and foremost with respect to the direction A.Both the rear region of 1 5 of each supporting frame part 10 and the front region 1 7 thereof are of substantially, although not exactly, triangular configuration, being arranged so that they taper downwardly from relatively broad uppermost bases. The side region 14 of each supporting frame part 10, however, whilst being of substantially, although not exactly right-angled triangular configuration, has its base at the bottom thereof from which it tapers upwardly towards the main beam or carrier 9 of the coupling frame 6.It can be seen in Fig. 4 of the drawings that the uppermost base of each rear region 1 5 has substantially twice the width of the uppermost base of each leading region 1 7. Edges of the rear and front regions 1 5 and 1 7 that are remote from the corresponding side region 14 are each bent over respectively forwardly and rearwardly through 90 to form strengthening rims 16 and 18 that are both parallel or substantially parallel to the direction A.

The rear and front regions 1 5 and 1 7 of each supporting frame part 10 are formed at their upper ends with corresponding broad fastening lugs 1 9 and 20, each lug 1 9 being substantially co-planar with the corresponding rear region 1 5 and each fastening lug 20 being bent-over obliquely upwardly and forwardly relative to the direction A to match the disposition of the leading lower surface of the beam or carrier 9.Each lug 1 9 is fastened to the upper rear surface of the beam or carrier 9 by four of the bolts 1 3 and each lug 20 is fastened to the lower leading surface of the frame beam or carrier by three of the bolts 1 3. It will be seen from Figs. 3 and 4 of the drawings that each lug 1 9 extends throughout substantially the complete width of the surface of the beam 9 against which it abuts whilst each lug 20 extends throughout only substantially the lower half of the surface of the beam 9 with which it is in contact.Three of the four bolts 1 3 by which each broad lug 1 9 is secured to the upper rear surface of the beam or carrier 9 are arranged in a triangular group and also fasten to that beam or carrier 9, adjacent one end thereof, the bent-over foot of an approximately square supporting tag 21 that projects upwardly and rearwardly from the beam or carrier 9 in a substantially vertical plane that is parallel or substantially parallel to the direction A. Each substantially square tag 21 is formed with an approximately central hole 22. The three bolts 1 3 by which each lug 20 is secured to the leading lower surface of the beam or carrier 9 are arranged in a single substantially horizontal row.

As previously mentioned, the lower edge of the side region 1 4 of each supporting frame part 10 is sandwiched between a pair of strips 23 by some of the bolts 13, the strips 23 and the lower edge of the side region 14 also being fastened by those bolts 1 3 to upper edges of juxtaposed substantially planar support plates 24, each of the two pairs of these plates 24 extending substantially vertically parallel to one another and to the direction A in sufficiently spaced apart relationship to have the parts which have just been mentioned located between them. Lower regions of each pair of plates 24 define the elongate boxes mentioned above and it will be seen from Fig. 3 of the drawings that the height of each plate 24 slowly but progressively decreases in a rearward direction opposite to the direction A.It can also be seen in the same Figure, and in Fig. 5, that the two strips 23 of each pair project both forwardly in front of, and rearwardly behind, the leading and rear edges, respectively, of the corresponding pair of plates 24. Their lower edges are at a slightly lower level than that of the bottom extremity of the corresponding side region 14 of one of the supporting frame parts 10. Each plate 24 is formed at both the front and the rear thereof, with respect to the direction A, with a horizontally bent-over foot 25A which foot is firmly and reliably secured to a front or rear edge region of the top of the hollow frame portion 1 by still further bolts 1 3.

Each double arm 25 is of strip formation and is arranged in the corresponding elongate box in sandwiched relationship between the corresponding pair of plates 24, the rear end thereof with respect to the direction A being formed with a transverse hole into which a strong horizontal pivot 28 can be entered so as turnably to couple that arm to the wall plates 24 of the corresponding box, the pivot 28 also being entered through a horizontally aligned pair of holes 29 formed in said plates 24 by a punching operation. The punching operation is carried out in such a way as to form each hole 29 with a corresponding outwardly directed punched rim 30 whose axial extent is greater than the thickness of the plate 24 concerned.The rims 30 act as plain bearings for the corresponding strong pivots 28 and it will be seen from Figs. 3 and 5 of the drawings that the juxtaposed support plates 24 of each elongate box are each formed with a row of four of the rimmed holes 29 with each hole 29 at a different distance from the rear end of the box concerned. The pivot 28 that can be seen in Fig. 3 of the drawings is shown as occupying the rearmost pair of rimmed holes 29, with respect to the direction A, and it will be readily apparent that, upon pivotally mounting the corresponding double arm 25 in its box by the use of an aiternative pair of the holes 29, the fork 26 at the leading end of that double arm will project further forwardly from the remainder of the implement than it does in the position actually illustrated.The fork 26 at the leading end of each double arm 25 is formed with two pairs of aligned holes 27 that are at different distances from the base of the fork 26 concerned, either pair being capable of co-operating with the free end of one of the two lower lifting links 26A (Fig. 2) when the implement is in use, depending upon which pair is most convenient having regard to the constructon of the particular three-point lifting device or hitch concerned. It is the fork 26 at the leading end of each double arm 25 that principally defines each lower coupling point 7 of the coupling frame 6.

It has already been mentioned, and is evident from Fig. 3 of the drawings, that each double arm 25 is upwardly and downwardly turnable to a limited extent in its box about the substantially horizontal axis which is afforded by the corresponding strong pivot 28.

When turned upwardly as far as possible about that pivot 28, the upper edge of each double arm 25 comes into contact with a stop formed by the lower edges of the corresponding pair of strips 23. The rearmost ends of each pair of strips 23 are formed with horizontally aligned holes 31 and these holes 31 serve to receive horizontal pivots 32 (Fig. 2) by which the leading ends of lower lifting arms 33 are turnably coupled to the remainder of the implement when an additional implement, machine or tool, such as the seed drill 37 which is illustrated in Figs. 1 and 2 of the drawings purely by way of example, is to be used in combination with the soil cultivating implement. The rear ends of the arms 33 are pivotally connected to coupling lugs projecting forwardly from a lower region of the seed drill 37.Similarly, the holes 22 in the supporting tags 21 receive further horizontal pivots 32 by which the leading ends of upper lifting arms 35 are turnably connected to the remainder of the implement. The rear ends of these arms 35, which are longer than the arms 33 because of the relative dispositions of the tags 21 and the rear ends of the strips 23, are pivotally connected to upper coupling lugs projecting forwardly from an upper region of the front of the seed drill 37. Setting means in the form of substantially vertically disposed hydraulic jacks 36 have their cylinders mounted on top of the rear feet 25A, the free ends of their piston rods being connected to the corresponding upper arms 35 at locations spaced rearwardly from the upper pivots 32.The hydraulic jacks 36, which may be connected by hydraulic ducts (not shown) to the hydraulic system of the operating tractor or other vehicle, enable the level of the seed drill 37 readily to be governed relative to that of the soil cultivating implement. It is noted that the arms 33 and 35 and the jacks 36 together form a rear coupling member 34 and that the rear ends of the arms 33 and 35 could, when required, carry a three-point hitch for co-operation with a three-point coupling member at the front of some implement other than the seed drill 37 which is described and illustrated purely by way of example.

Figs. 6 and 7 of the drawings illustrate the provision on the fork 26 at the leading end of each double arm 25 of a corresponding coupling piece 38 that may advantageously be used in the quick-action connection and release of the lower coupling point 7 to the free ends of the lower lifting links 26A of the three-point lifting device or hitch at the rear of an agricultural tractor or other operating and propelling vehicle.Each coupling piece 38 is formed in its lower edge with an inverted Ushaped slot 39, the slot 39 being provided at both sides of the coupling piece 38 with a matchingly shaped supporting rim 40 that, at one side, projects from the coupling piece 38 by a much greater distance than it does from the opposite side thereof, it being preferred that the magnitude of the projection of the rim 40 at one side thereof should be substan tiaily ten times the extent of its projection at the other side. It can be seen in Fig. 6 of the drawings that the total length of each rim 40 in a horizontal direction that is perpendicular to the general plane of the corresponding coupling piece 38 is considerably greater than half the distance between the inner surfaces of the two limbs of the corresponding fork 26.

Each coupling piece 38 is readily mounted, in a readily releasable manner, between the two limbs of the corresponding fork 26 by enter ing headed pins 42 through the two pairs of aligned holes 27 in the limbs of that fork 26, each pin 42 being surrounded, between said limbs, by a sleeve 41 which projects from each side of a corresponding hole in the coupling piece 38 concerned. The two cou pling pieces 38 provide the required quick action engagement and release of the lower coupling points 7 with the free ends of the lower lifting links 26A carried by the operat ing tractor or other vehicle when those free ends are, as is often the case, interconnected by a substantially horizontal rod.Under such circumstances, opposite end regions of the rod will readily enter, or be released from, the slots 39 in the coupling pieces 38, the inverted U-shaped rims 40 of those slots 39 acting effectively to spread any high loads exerted on the rod and also functioning as positioning guides for that rod.

The opposite ends of the hollow frame portion 1 are closed by corresponding side plates 43 which extend substantially vertically parallel to one another and to the direction A.

An upper leading region of each side plate 43, with respect to the direction A, lies above the remainder of the hollow frame portion 1 and is provided with a horizontal pivot 44 around which an arm 45 is upwardly and downwardly turnable about the substantially horizontal axis defined by the aligned pivots 44. The arms 45 extend rearwardly from the pivots 44 alongside the outer surfaces of the plates 43, locking bolts or the like that are visible in Fig. 2 of the drawings being provided for entry through holes in the arms 45 and chosen aligned holes in rear edge regions of the side plates 43 so that, upon tightening these bolts or the like, the angular settings of the arms 45 about the pivots 44 are fixed for as long as may be required.The arms 45 project behind the rearmost edges of the frame portion side plates 43 and, at their rear ends, carry downwardly directed supports which supports, in turn, carry substantially horizontally aligned bearings between which an open-work, cage-formation roller 46 is mounted in a freely rotatable manner. The roller 46, which acts to level the soil worked by the members 3 and to crush any lumps thereof exceptionally missed by those members, bears firmly against the ground surface during the operation of the implement and it will be apparent that its bodily level relative to that of the frame portion 1 and soil working members 3 governs the maximum depth of penetration of the tines 5 of those members 3 into the ground which is possible.

Each shaft 2 is provided, inside the hollow frame portion 1, with a corresponding straight- or spur-toothed pinion 47, each of the twelve, in this embodiment, pin ions 47 having its teeth in mesh with the or each immediately neighbouring pinion 47 in the single row of twelve such pinions. One of the centre pair of shafts 2 in the single row of twelve shafts has an upward extension through the top of the hollow frame portion 1 into a gear box 48 that is fastened in position on top of the hollow frame portion 1. Shafts and bevel pinions within the gear box 48 place the upward extension of the shaft 2 that has just been mentioned in driven connection with a rotary input shaft 50 of the gear box 48 which projects substantially horizontally forwards from the front of that gear box in substantially the direction A.The rear of the gear box 48, with respect to the direction A, is provided with a change-speed gear 49. The change-speed gear 49 is not the subject of the present invention and it suffices to say that two splined shaft ends project into the change-speed gear 49 where they were drivingly interconnected by a pair of straight- or spur-toothed pinions of different sizes whose hubs are internally splined to match the external splines of the shaft ends. The transmission ratio between the two shafts can be altered by interchanging the two pinions on the shaft ends or, alternatively, by removing them and substituting another pair of pinions of different sizes. This is readily accomplished merely by temporarily removing a cover of the change-speed gear 49.The change-speed gear 49 allows the rotary soil working members 3 to be revolved at a faster or slower speed without having to change the substantially standard speed of rotation that is applied to the leading end of the rotary input shaft 50 of the gear box 48 by drive derived from the rear power take-off shaft of an agricultural tractor or other operating vehicle through the intermediary of a telescopic transmission shaft 51 of known construction having universal joints at its opposite ends. The forwardly projecting rotary input shaft 50 of the gear box 48 is splined or otherwise keyed for cooperation with the universal joint at the rear end of the transmission shaft 51.It is noted that the gear box 48 is secured to the top of the frame portion 1 inside the space which is enclosed by that frame portion and the main beam or carrier 9 and supporting frame parts 10 of the coupling frame 6 (see particularly Fig. 4 of the drawings).

In the use of the soil cultivating implement or machine that has been described, the coupling points 7 and 8 of the coupling frame 6 are connected to the three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle in the manner which has been described above and that is illustrated somewhat diagrammatically in Figs. 1 and 2 of the drawings. If necessary, the double arms 25 are moved forwardly until the pivots 28 can be entered through the holes at the rear thereof and through alternative pairs of the rimmed holes 29 in the juxtaposed support plates 24 of the boxes which accommodate said double arms 25. As mentioned above, the forks 26 will project forwardly from the leading ends of the boxes to an extent determined by the particular pair of rimmed holes 29 in each box which is chosen for cooperation with the corresponding pivot 28.Either pair of holes 14A in the upright portions of the plates 11 can be used to cooperate with the free end of the upper lifting link 11A. The known telescopic transmission shaft 51 is arranged drivingly between the rear power take-off shaft of the same tractor or other vehicle and the forwardly projecting end of the rotary input shaft 50 of the gear box 48. Other adjustments which may, if necessary, be made before work commences include moving the ground roller 46 bodily upwards or downwards using the locking bolts or the like carried by the arms 45 to maintain any chosen bodily level as long as may be required, this adjustment determining the maximum depth of penetration of the tines 5 into the soil which is possible.The speed of rotation of the members 3 may be increased, or decreased, by an appropriate adjustment of the change-speed gear 49 without it being necessary to change the substantially standard speed of driving rotation that is applied to the rotary input shaft 50 of the gear box 48.

These adjustments are made primarily with regard to the nature and condition of the soil that is to be cultivated by the implement and the particular purpose for which that soil is required after its cultivation. When, as illustrated, the seed drill 37 is to be used in combination with the implement, the hydraulic jacks 36 may require alteration in length to adjust the level of the seed drill 37 relative to that of the soil cultivating implement and to enable the rear coupling member 34 to cooperate correctly with the forwardly projecting coupling lugs of the seed drill 37.

As the implement moves forwardly in the direction A, the inter-meshing relationship of the pinions 47 causes each assembly of one pinion 47, one shaft 2 and one soil working member 3 to revolve in the opposite direction to the or each immediately neighbouring similar assembly. Each soil working member 3 cultivates an individual strip of ground that extends in the direction A but, since the effective distance between the soil working portions of the tines 5 of each member 3 is the same as, or a little greater than, the distances between the longitudinal axes of immediately neighbouring shafts 2, the strips worked by the individual members 3 overlap, or at least adjoin, one another so that a single broad strip or worked soil is produced.When the preferred dimensions that are referred to above are used, this broad strip of worked soil will have a width of substantially, but not necessarily exactly, 3 ms. It will be realised that a broader or narrower strip could be produced by increasing or decreasing the number of rotary soil working members 3 in the single row thereof.

The coupling frame 6 which is afforded principally by the main beam or carrier 9 and the supported frame parts 10 can readily be manufactured from lengths of hollow beam and folded sheet steel or other sheet metal, all of the various connections being made releasably by employing the fastening bolts 1 3 all, or most, of which may be of the same size and type. Expensive welding is thus very greatly reduced, if not entirely eliminated, in producing and mounting the coupling frame 6 and any part of that frame 6 which may become seriously damaged can be replaced alone merely by releasing the appropriate bolts 1 3 and substituting a fresh undamaged part.The double arms 25 at whose leading ends the lower coupling points 7 are formed lie between the corresponding pairs of plates 1 4 and, at least in the position illustrated in the drawings, extend throughout the fore and aft width of the hollow frame portion 1, their upper edges usually being in contact, when the implement is in operation, with the stops that are afforded by the lower edges of the corresponding pairs of strips 23. These strips 23, as previously described, have the lower edges of the side regions 14 of the supporting frame parts 10 firmly but releasably sandwiched between them.

The pairs of strips 23 that are formed at their rearmost ends with the holes 31 and the tags 21 which are formed with the holes 22 constitute means by which the rear coupling member 34 is, when required, connected to the remainder of the implement to enable an additional implement, machine or tool, such as the seed drill 37 which is illustrated in Figs. 1 and 2 of the drawings by way of example, to be used in combination with the soil cultivating implement. When the soil cultivating implement is used in combination with the seed drill 37 or with a fertilizer spreader or some other implement, machine or tool, the pairs of strips 23 effectively transmit the heavy forces which are involved, when the whole combination is lifted, to the lower lifting links 26A by way of the double arms 25 at whose leading ends the lower coupling points 7 are principally defined.The coupling frame 6 can reliably support an additional implement, machine or tool, such as the seed drill 37, under such circumstances.

Since the rear regions 1 5 of the supporting frame parts 10 are relatively broad in width, and since that width progressively increases from bottom to top, the broad fastending lugs 1 9 at their upper ends very effectively support the main frame beam or carrier 9 of the coupling frame 6, particular since said lugs each extend lengthwise of the carrier 9 for a significant distance and extend throughout the width of the surface of the carrier 9 against which they abut and to which each of them is secured by four relatively spaced bolts 1 3 arranged in the pattern that has been described above and that can be seen best in Fig. 4 of the drawings.This strong and reliable support is important because, both during operation and during inoperative transport of the implement alone or in combination with a further implement, machine or tool, strong forces are exerted upon the beam or carrier 9 which forces must not deform that beam nor displace it relative to the other parts of the coupling frame 6. The connections of the lower edges of the side regions 1 4 of the frame parts 10 to the pairs of strips 23, in sandwiched relationship between those strips.

have been found to be an excellent way of transferring forces from the frame parts 10 to the support plates 24 without deformation or displacement.

It is emphasized that a soil cultivating implement has been described purely as a good example of an agricultural implement to which the present invention may advantageously be applied and that other agricultural implements having coupling means for cooperation with three-point lifting devices or hitches carried by agricultural tractors and other operating vehicles may equally well employ the present invention with considerable advantage.

Although certain features of the soil cultivating agricultural implement that has 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 the implement that has been described, and/or that is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (11)

1. An agricultural implement of the kind set forth, wherein at least one lower coupling point of the coupling frame comprises a part sandwiched between two substantially planar support plates which support plates also have secured to them a rear coupling point for the connection to the implement of an additional implement, machine or tool which may be used in combination therewith.

2. An implement as claimed in claim 1, wherein said rear coupling point is part of at least one strip which strip extends throughout the length of the corresponding support plates considered in the intended direction of operative travel of the implement.

3. An implement as claimed in claim 2, wherein two of said strips are provided for each lower coupling point, said strips being arranged in side-by-side relationship with one another.

4. An implement as claimed in claim 2 or 3, wherein the strip constitutes, or the strips constitute, a stop limiting pivotal movement in one direction of said part which is sandwiched between the support plates, that part being in the form of an arm at one end of which said lower coupling point is principally defined.

5. An implement as claimed in any preceding claim, wherein a lower edge region of a supporting frame part that is wholly or principally of plate formation is also sandwiched between said support plates, the supporting frame part interconnecting an upper coupling point and a corresponding lower coupling point of the coupling frame.

6. An implement as claimed in claim 4 or in claim 5 when read as appendent to claim 4, wherein the leading end of said arm is forked, the limbs of the fork being formed with pairs of aligned holes which are spaced apart from one another in the intended direction of operative travel of the implement, said fork being constructed and arranged for connection to the lower lifting link of the threepoint lifting device or hitch of a tractor or other operating vehicle.

7. An implement as claimed in claim 6, wherein a coupling piece is provided for optional fastening between the limbs of said fork by at least one pin, said coupling piece being formed with a guide slot for connection to the three-point lifting device or hitch of a tractor or other operating vehicle.

8. An implement as claimed in claim 7, wherein said coupling piece is of substantially planar formation, said guide slot opening downwardly and being flanked by outwardly projecting guide rims.

9. An implement as claimed in claim 8, wherein the guide rims project laterally of the substantially planar coupling piece by a combined distance which is not less than half the distance between the internal surfaces of the limbs of said fork.

10. An implement as claimed in any preceding claim, wherein said coupling frame comprises an elongate hollow carrier that extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement, said carrier being of quadrilateral cross-section with each side thereof measuring, in crosssection, not less than 100 mm. in length.

11. An implement as claimed in claim 10 when read as directly or indirectly appendent to claim 2, wherein the coupling point at the rear of the or each strip and coupling points defined by supports located adjacent the opposite axial ends of said hollow carrier define means by which corresponding arms can be turnably connected thereto to constitute a rear coupling member or lifting device for cooperation with coupling means carried by an additional implement, machine or tool that may be used in combination with the soil cultivating implement.

1 2. An implement as claimed in any preceding claim, and being in the form of a soil cultivating implement comprising a plurality of soil working members that are arranged in a row which extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement with each such member rotatable about a corresponding upwardly extending axis.

1 3. An agricultural implement of the kind set forth and comprising a coupling frame constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

1 4. A soil cultivating implement substantially as hereinbefore described with reference to the accompanying drawings.