GB2151443A

GB2151443A - Soil cultivating implements

Info

Publication number: GB2151443A
Application number: GB08431180A
Authority: GB
Inventors: Der Lely Cornelis Van
Original assignee: C Van der Lely NV
Current assignee: C Van der Lely NV
Priority date: 1983-12-20
Filing date: 1984-12-11
Publication date: 1985-07-24
Also published as: NL8304356A; FR2556553A1; FR2556553B1; DE3446312A1; NL9400667A; GB8431180D0; DE3446312C2; FR2641934B1; NL193848C; GB2151443B; NL193848B; FR2641934A1

Abstract

Soil working members rotatable about upright axis each comprises a carrier 4 having a central hub 5 and two arms which project in opposite directions from that hub 5. Each arm of the carrier 4 defines a corresponding flat and recessed fastening surface that is inclined downwardly and forwardly with respect to the direction of rotation B of the corresponding soil working member and the fastening portion 11 of a soil working tool 12 or 23 can be firmly but releasably secured to the fastening surface by a single bolt 15 and a clamp 17. The tool 23 of Fig. 8 may quickly and easily be substituted for the blade-like tool 12 of Fig. 3, or vice versa, so that the soil working members may be adapted without difficulty to working soils of different natures and conditions as effectively as possible. The tool 12 is advantageously formed by pressing several tools simultaneously from a single strip of material. <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 supported by said frame portion so as to be power-rotatable about corresponding substantially vertical, or at least upwardly extending, axes, each such soil working member including a carrier upon which at least one soil working tool can be releasably mounted. The expression "implement(s) or machines(s)" is shortened to "implement(s)" alone throughout the remainder of this document for the sake of brevity.

Implements of this known kind are used for preparing seed beds and for other cultivation purposes but it will be apparent that they have to deal with many different types of soil in various conditions due to climatic and other seasons. To ensure optimum cultivation, it is desirable that the tools which actually work the soil should be adapted to the nature and condition of that soil as closely as possible and the present invention seeks to enable this readily to be brought about. The present invention provides a soil cultivating implement of the kind set forth, wherein each carrier is constructed and arranged so that either at least one blade-like soil working tool or at least one tine-like soil working tool can optionally be directly and releasably secured thereto.

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: Fig.1 is a plan view of a soil cultivating implement having soil working members constructed in accordance with the invention, the implement being shown connected to the rear of an agricultural tractor, Fig 2 is a section to an enlarged scale, taken on the line ll-ll in Fig.1, Fig.3 is an elevation of one soil working member of the implement as seen in the direction indicated by an arrow Ill in Fig.2, Fig.4 is a section taken on the line IV-IV in Fig.2, Fig.5 illustrates the way in which two bladelike soil working tools can be formed from a single metallic sheet, Fig.6 is an elevation illustrating an alternative form of blade-like soil working tool that may be employed, Fig.7 is a view as seen in the direction indicated by an arrow VII in Fig.6, Fig.8 is a similar view to Fig.6 but illustrates a tine-like soil working tool that may be employed, Fig.9 is a view as seen in the direction indicated by an arrow IX in Fig.8, Fig. 10 is a similar view to Fig.2 but illustrates an alternative soil working member construction, Fig.1 1 is a view as seen in the direction indicated by an arrow Xl in Fig.10, Fig.12 is a section taken on the line XII-XII in Fig.10, and Fig.1 3 illustrates the way in which two blade-like soil working tools for the embodiment of Figs. 10 to 1 2 of the drawings may be formed from a single sheet of metal.

Referring to the drawings, and particularly to Figs. 1 to 4 thereof, the soil cultivating implement that is illustrated is a rotary harrow that is intended primarily, but not exclusively, for the so-called secondary cultivation of soil to produce a seed bed in ground that has previously undergone primary cultivation by, for example, a plough. The implement is intended to produce a seed bed providing substantially optimum conditions for the germination of seeds that may be directly sewn therein and for the growing on of those seeds, with the thinning of the seedlings, where required, to give mature plants.

The implement comprises a hollow boxsection frame portion 1 that is elongate in a substantially horizontal direction that will usually, as illustrated in Fig.1, be perpendicular or substantially perpendicular to the intended direction of operative travel of the implement that is denoted in that Figure by an arrow A.

A plurality, of which there are twelve in the example that is being described, of normally substantially vertical, but at least Upwardly extending, shafts 2 are rotatably journalled in bearings carried by the upper and lower walls of the frame portion 1 so as to be rotatable about their own longitudinal axes, the twelve shafts 2 having their parallel longitudinal axes a (Figs. 2,3 and 4) spaced apart from one another at regular intervals along the transverse length of the frame portion 1 which intervals 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 by some distance and the downwardly projecting portion thereof has the hub 5 of a corresponding rotary soil working member 3 firmly but releasably secured thereto by a corresponding clamping ring or washer 6 (Fig.2) and a nut 7 that co-operates with a screw-threaded lower end region of the shaft 2 concerned, said region being formed with a transverse bore in which is received a split or other retaining pin that prevents the nut 7 concerned from loosening unless that retaining pin is removed.

The hub 5 of each soil working member 3 is integral with a substantially, although not exactly, horizontal carrier 4 which exhibits two arms that project in radially opposite directions from the central hub 5. In fact, as can be seen best in Fig.2 of the drawings, the lower surface of each arm of each carrier 4 is inclined downwardly and outwardly away from the bottom of the hub 5 concerned at an angle of substantially 25 to an imaginery plane that is perpendicular to the axis a of the shaft 2 to which said member 3 is secured.

The tops of the two arms of each carrier 4 define corresponding fastening surfaces to receive the fastening portions of soil working tools that will be described below, each such fastening surface extending to the radially outer end of the top of the carrier arm concerned at the rear of that arm, with respect to the intended direction of operative rotation B (Figs. 3 and 4) of the soil working member 3 under consideration, this downwardly and outwardly inclined upper surface or top of each carrier arm being in parallel or substantially parallel relationship with the downwardly and outwardly inclined lower surface of the same arm that has been referred to above.

It can be seen in Fig.3 of the drawings that each tool fastening surface slopes downwardly and forwardly to the leading edge (with respect to the direction of rotation B) of the carrier arm concerned, said surface being at an angle of substantially 20 to an imaginery plane that is perpendicular to the axis a of the corresponding shaft 2. Each fastening surface is principally afforded by the base of a shallow recess in the top of the corresponding carrier arm, this recess having a straight upright rim 10 at the rear of that surface with respect to the intended direction of operative rotation B.

The inner edge of each fastening surface that is closest to the corresponding hub 5 is in the form of a straight boundary that is perpendicular or substantially perpendicular to the longitudinal axis b (Fig.4) of the carrier 4 as seen projected onto a horizontal plane. The radially outer edge of each fastening surface extends up to the radially outer boundary of the corresponding carrier arm of the soil working member 3 concerned and is so disposed that, as can be seen in Fig.4, an imaginery plane A-A which contains the corresponding axis a and that is perpendicular to the flat outer boundaries of the carrier arms is inclined at an angle of substantially 9 to said axis b.

Considered in the intended direction of operative rotation B of each soil working member 3, the aforementioned axis b lies in front of the plane A-A but rearwardly of the front of the corresponding carrier arm in such a position that the distance between the axis a concerned and the leading corner of that carrier arm is greater than is the distance between said axis a and the rear corner thereof as seen in Fig.4 of the drawings. This is also true of the soil working portion of a soil working tool that may be fastened to one of the carrier arms as will be described below.

As previously mentioned, when the implement is assembled for use, the fastening portion 11 of a corresponding blade-like soil working tool 12 is firmly but releasably clamped against the fastening surface of each carrier 4, the tools 1 2 being formed from strip-shaped metallic material. The shallow recess whose base principally affords each fastening surface has a depth which is the same, or substantially the same, as is the thickness of each tool fastening portion 11, each such portion 11 being integrally joined by a relatively sharp downwardly directed bend to the upper end of a corresponding upright soil working portion 1 3 that is in parallel or substantially parallel relationship with the corresponding longitudinal axis/axis of rotation a.

As can be seen best at the right-hand side of Fig.2 of the drawings, an upper end region of each soil working portion 1 3 is in substantially surface-to-surface contact with the flat outer end or boundary of the corresponding carrier arm 4 throughout the upright height of that outer end or boundary.

The sharp bend which integrally interconnects the fastening and soil working portions 11 and 1 3 of each tool 1 2 corresponds to a fold line C (Fig.5) which is inclined at a little less than 60= to the longitudinal axis of the soil working portion 1 3 of the tool 1 2 concerned. The longitudinal axis in question is, as can be seen in Fig.3 of the drawings, inclined to the corresponding axis a at an angle of substantially 5 , each soil working portion 1 3 trailing downwardly and rearwardly from its upper end with respect to the corresponding intended direction of operative rotation B.

Each fold line C has a length with is substantially one and half times the perpendicular width of the strip-shaped material of the tool 1 2 concerned in the region of that fold line, the constructional arrangement being such that the fastening portion 11 at one side of each fold line C is of adequate size.

The rear edge of each soil working portion 13, with respect to the corresponding direction B, is straight and is in parallel or substantially parallel relationship with the longitudinal axis of that portion 1 3. The leading edge thereof, however, is initially, at its upper end, in parallel relationship with the rear edge, but then joins, by way of an obtuse angular bend, a downwardly and rearwardly inclined region that is at an angle of substantially 1 5, to the longitudinal axis of the portion 1 3 and, finally, at a location just below the upright centre point thereof, merges by way of an opposite obtuse angular bend into a lowermost rear edge region which is in parallel or substantially parallel relationship with the straight leading edge of the same soil working portion 1 3.

The lowermost edge of each soil working portion 1 3 is in substantially, although not exactly, perpendicular relationship with the corresponding axis a. Thus, each soil working portion 1 3 tapers downwardly to sme extent although it terminates towards its lower end in a region whose leading and rear edges, with respect to the corresponding direction B, are parallel or substantially parallel to one another.

In order to be able releasably to secure the fastening portion 11 of each tool 1 2 in a corresponding one of the recessed fastening surfaces, each arm of each carrier 4 is formed with a cylindrical opening 14 to receive the shank of a bolt 1 5 that is also entered through a hole 1 6 in the tool fastening portion 11 concerned, the openings 1 4 and holes 1 6 advantageously, but not essentially, having diameters of twenty millimetres.

It can be seen from Fig.4 of the drawings that the openings 1 4 and holes 1 6 are located in advance, with respect to the direction of rotation B, of the imaginery plane A-A which contains the corresponding axis a and that extends perpendicular or substantially perpendicular to the flat radially outer ends or boundaries of the arms of the carrier 4. The releasable fastening of the tools 1 2 in their appointed positions is reinforced by clamps 1 7 each of which has a shape that substantially corresponds, as seen in plan view, with the shape of one of the previously mentioned fastening surfaces.

However, the radially outer edge thereof and the leading edge thereof, with respect to the direction B, each extend beyond the corresponding edges of the carrier arm 4 concerned as view in a direction parallel to the corresponding axis a (Fig.4). Each clamp 1 7 thus itself defines a co-operating supporting surface that extends beyond the upper supporting surface of the adjoining arm of the carrier 4 under consideration.

The front of each clamp, with respect to the direction B, is formed with an upstanding partially curved shield or screen 1 8 that can be seen best in Figs. 3 and 4 of the drawings, the shape thereof being such that it partially surrounds the head of the corresponding bolt 15, said bolt being entered through a registering hole in the clamp 1 7 as well as through the hole 1 6 and opening 14.

It can be seen in Fig.3 of the drawings that the cylindrical opening 1 4 through each carrier arm is of stepped construction, having a larger diameter region at its lower end in which region a further fastening nut 7 that cooperates with the screwthread of the bolt 1 5 is recessed so as to shield it from impact damage and progressive wear during the use of the implement.The flat surface of the top of each shield 1 7 is formed with two upright ribs 1 SA between which the head of the corresponding bolt 1 5 is received, the distance between said ribs 1 5A substantially corresponding to the flat-to-flat diameter of the bolt head so that said bolt 1 5 cannot rotate around its own longitudinal axis when its head lies between the ribs 1 so. The two ribs 1 SA are, of course, parallel to one another and they extend rearwardly, with respect to the direction B, from the shield or screen 1 8 to which their leading ends are strengtheningly joined.

The fastening portion 11 of each soil working tool 1 2 has a rear edge, with respect to the direction B, which bears against the upright rim 10 at the rear of the corresponding fastening surface. The front of each clamp 17, with respect to the direction B, has a downwardly directed extension 1 9 that, when the bolt 1 5 concerned is tightened, prevents the corresponding soil working portion 11 from turning angularly about the axis of said bolt 1 5 whilst that bolt remains tightly installed.

Since each fastening surface slopes downwardly and forwardly with respect to the direction B, the carrier 4 of each soil working member 3 can reliably resist the forces which act upon it as the implement moves forwardly in the direction A and it revolves in the direction B. The single fastening bolt 1 5 for each tool 1 2 is so disposed that, in cooperation with the neighbouring parts, the tool 1 2 concerned remains reliably secured in its appointed position until the corresponding nut 7 is unscrewed.

Fig.5 of the drawings shows that the two soil working tools 1 2 corresponding to a single soil working member 3 can be produced from one oblong metal strip.

The leading edge of each tool 12, with respect to the direction B, is a cutting edge and this edge is formed by cutting obliquely at substantially 45 through the thickness of the strip that can be seen in Fig.5, this arrangement accounting for the central "overlap" between the leading edges of the two tools 1 2 which are produced from the strip shown in that Figure.

This way of producing the tools 1 2 enables them to be formed quickly and easily from strip-shaped material at relatively low cost and with substantially no wastage. The fact that each blade-like soil working tool 1 2 is of narrower fore-and-aft width in a lower region of its soil working portion 1 3 facilitates some flexible movement of the portions 1 3 and thus thorough crumbling of the soil through which those soil working portions 1 3 rapidly move.

Figs. 6 and 7 of the drawings illustrate an alternative form of blade-like soil working tool 20 which is again basically formed from stripshaped material and that is arranged to be secured to one arm of the carrier 4 of one of the soil working members 3 in the same way as has already been described above for the tools 1 2. The tools 20 are, however, formed by a pressing operation that gives the uniformly downwardly tapering soil working portion 21 thereof a central outwardly directed stiffening bulge 22 that is of elongate configuration extending from substantially the top to substantially the bottom of the soil-working portion 21 concerned whilst progressively tapering in width (as seen in Fig.6) in a downward direction.It will be evident from Fig.6 of the drawings, when compared with Fig.3 thereof, that the soil working portion 21 of each tool 20 will trail gently downwardly and rearwardly with respect to the corresponding direction B when the fastening portion 11 of that tool 20 is secured to one of the carrier arms of one of the soil working members 3.

The leading cutting edge of each soil working portion 21, with respect to the direction B, is straight but very gently inclined to the longitudinal axis of the portion 21 concerned whereas the rear edge thereof, with respect to the same direction, is again straight whilst being in parallel or substantially parallel relationship with said longitudinal axis thus producing the very gentle downward taper of the portion 21 that can be seen in Fig.6. The lowermost free edge of the portion 21 is substantially perpendicular to the longitudinal axis of that portion.

Figs. 8 and 9 of the drawings illustrate an alternative tine-like soil working tool 23 which is produced by a forging operation. The tool 23 has a fastening portion 11 which is constructed and arranged to be secured to one of the arms of the carrier 4 of one of the soil working members 3 in substantially exactly the same way as has already been described above. However, said tool 23 has a downwardly tapering externally ribbed soil working portion 24 whose upper end is integrally joined to a flattened portion 25 which flattened portion 25 merges, by way of a bend, into the corresponding soil working portion 11 but it will be seen from Figs. 8 and 9 that the upper end of the soil working portion 24 itself does not vanish until said bend is reached.Initially, just beneath the flattened portion 25, the soil working portion 24 is of substantially circular cross-section but, as progress is made downwardly towards the free end or tip thereof, that substantially circular cross-section progressively becomes a substantially rhomboid rectanqular cross-section whose larger corner-to-corner diagonal is substantially tangential to an imaginery circle centered upon the corresponding axis a.

At or near to its free end or tip, the lastmentioned dimension has a magnitude which is not less than substantially twice that of the other corner-to-corner diagonal thereof (compare Figs. 8 and 9 of the drawings). The ribs are formed at substantially the four corners of the substantially rhomboid cross-section towards the lower end of each soil working portion 24, two of those ribs thus being substantially radially disposed with respect to the corresponding axis a whilst the other two are substantially tangential to the aforementioned imaginary circle that is centered upon that axis a.

It will be evident by comparing Fig. 8 with Fig.3 of the drawings that, when the tine-like tool 23 is secured in its operative position in one of the soil working members 3, the soil working portion 24 thereof trails downwardly and rearwardly, with respect to the direction B, at an angle of substantially 8 to an imaginary substantially vertical plane containing the corresponding axis a.

The free end or tip of the portion 24 is then substantially, although not exactly, horizontally disposed. The soil working portion 24 of the tool 23 is. as mentioned above, formed with four ribs, except towards its upper end, and, between the ribs, the surface of the portion 24 is effectively recessed to provide a substantially symmetrically shaped cavity between each successive pair of ribs moving rotationally around the tool portion 24.

The whole tool 23 is very effective in crumbling soil and the lower end region of its soil working portion 24 breaks up hardened soil very efficiently.

Figs. 10 to 1 2 of the drawings illustrate an alternative form of soil working member 3A and an alternative way of mounting blade-like soil working tools 26 which tools, like the tools 1 2, are formed from metal strip In this case, the member 3A comprises a substantially horizontally disposed carrier 27 comprising two arms which radiate from the centrally disposed hub 5 thereof. It will be seen from Fig. 10 of the drawings that the hub 5 is firmly but releasably secured to the lower end of a corresponding one of the shafts 2 in the same manner as has already been described above with particular reference to Fig. 2 of the drawings.

The top of the carrier 27 is substantially horizontally disposed whilst that portion of the bottom thereof which is foremost with respect to the corresponding direction of rotation B initially extends outwardly and downwardly from the hub 5 to merge into a portion that is substantially horizontally parallel to the top of the carrier 27 (see the left side of Fig. 10 of the drawings).

This last mentioned portion terminates, at the outer end or boundary of the carrier arm concerned, in a junction with a plane that is parallel to the corresponding axis a.

The embodiment of Figs. 10 to 1 2 of the drawings comprises, for each carrier arm, a recessed substantially triangular fastening surface that lies between the central hub 5 and the outer end or boundary of that arm. One side of each triangle is located at the outer end or boundary of the corresponding arm which extends substantially parallel to the axis a, said fastening surface extending upwardly and rearwardly with respect to the direction B at an angle of substantially 60 to an imaginary plane that is perpendicular to said axis a.

The upper end of each fastening surface, that is formed on the bottom of the carrier 27, substantially reaches the top of the latter (see Fig. 11) and, at this location, said surface has a downwardly and rearwardly projecting rim 28. An opening is formed through each fastening surface approximately centrally of the latter and the longitudinal axis of this opening, which is of cylindrical configuration, is perpendicular to the general plane of the fastening surface concerned, the upper leading end, with respect to the direction B, of each opening being enlarged to form a funnelshaped recess in the material of the corresponding carrier arm in which recess is received the head of a corresponding fastening bolt 32.Each substantially funnel-shaped recess is formed in a forwardly (with respect to the direction B) directed bulge of the carrier arm concerned with the result that, as seen in plan view (Fig.12), each carrier 27 is very approximately S-shaped.

The blade-like soil working tools 26 are again made from metallic strip and each of them has a fastening portion 29 that is of a triangular shape which matches the shape of the fastening surface of one of the carrier arms. Each fastening portion 29 fits substantially exactly in the recess of the corresponding fastening surface, its rear edge bearing against the corresponding downwardly directed rim 28. A clamp 30 of triangular configuration sandwiches the fastening portion 29 of the corresponding soil working tool 26 between the clamp 30 and the recessed fastening surface of the corresponding carrier arm.

Each tool fastening portion 29 is formed substantially centrally with a hole 33 (Fig. 13) and each clamp 30 is formed with a registering hole. The shank of the corresponding bolt 32 passes downwardly and rearwardly, with respect to the direction B, through the cylindrical opening in the carrier arm and through the hole 33 and the aligned hole in the clamp 30 to receive, on its projecting screw-threaded end, a co-operating nut 31 that is preferably of a known kind incorporating a frictional insert designed to prevent the nut from accidentally working loose.

Fig. 1 3 of the drawings illustrates a length of metal strip from which two soil working tools 26 are formed. It can be seen in Fig. 1 3 that each fastening portion 29 is integrally connected by a fold-line C' to the soil working portion of the same tool 26. When bent to shape, the fastening portion 29 of the tool 26 is inclined to the soil working portion thereof at an angle of substantially 90 about the fold-line C' which fold line is inclined at substantially 60 to the longitudinal axis of the soil working portion of the tool 26 concerned.As can be seen in Fig. 11, the downwardly directed soil working portion of each tool 26 trails downwardly and rearwardly by a few degrees with respect to the direction B, an inclination of substantially 6" to an imaginary plane which contains the corresponding axis a being preferred. The rear edge of the soil working portion of each tool 26 is straight throughout its length and is parallel to the longitudinal axis of that soil working portion but the leading edge thereof comprises an upper more steeply downwardly and rearwardly inclined region which merges, by way of an obtuse angle, into a lower region which is parallel to the straight rear edge.

As can be seen best in Fig. 13, complementary obtuse angles interconnect rear edge regions of the leading edge, with respect to the direction B, of each tool 26. There are three of these leading edge regions, the upper and lower ones, when the tool is mounted, being parallel to the rear edge thereof and the central one being downwardly and rearwardly inclined, by said complementary obtuse angles, to interconnect the upper and lower parallel regions. The obtuse angles are located at approximately one third and approximately two thirds of the way along each leading edge from one end thereof.

It will be remembered that, when bent to shape, the fastening portion 29 of each tool 26 is inclined to the soil working portion thereof at substantially 90 about the corresponding fold-line C', that fold-line having a length which is substantially one and a half times the perpendicular width of the strip material from which the tools 26 are formed in a region of that material adjacent the foldline C'.

The soil working portions of the two tools 26 of each soil working member 3A are in substantially parallel relationship with the corresponding axis a and it will be evident from Fig. 1 2 of the drawings that the aforementioned imaginary plane A-A that contains the axis a concerned, and that is perpendicular to the end surfaces or boundaries of the corresponding two carrier arms, is to the rear of the longitudinal axis or centre-line b' in relation to the direction B, said longitudinal axis or centre-line b' being shown in Fig. 1 2 of the drawings as projected onto a horizontal plane.

The distance between the leading edge, with respect to the direction B, of one of the tools 26 and the corresponding axis a is again greater than is the distance between the rear edge of that tool and said axis a and this arrangement facilitates resilient movement of the soil working portions of the tools 26 in the ground and this tends to produce well crumbled soil. As seen in Fig.12, the angle between the imaginary plane A-A and the longitudinal axis or centre-line b' is substantially 25 .

Fig. 1 3 of the drawings, like Fig. 5 thereof, shows that the two tools 26 of a single soil working member 3A can be formed from a single length of metallic strip that is of rectangular, although not strictly oblong, shape. In fact, the shorter edges of the parallelogram are inclined at substantially 70' to the longer edges thereof and this has the result that, when one of the tools 26 is mounted in its operative position (Fig. 11), the free lower edge of its soil working portion is very nearly horizontally disposed. Moreover, one edge of the fastening portion 29 of each tool 26, with this shape, exactly fits an edge of the recessed fastening surface of the corresponding carrier arm.

The blade-like soil working tools which are formed from metal strip by a pressing operation in the way that has been described and the tine-like soil working tools that are produced by forging can, if desired, be shaped to co-operate with the substantially triangular fastening surfaces of the arms 27 of the carriers that have been described with reference to Figs. 10 to 1 2 of the drawings.

The opposite ends of the hollow box-section fray' portion 1 (Figs. 1 and 2) of the soil working implement are closed by side or end plates 34 which extend substantially vertically parallel to one another and to the direction A.

Upper leading corners, with respect to the direction A, of the side or end plates 34 are provided with substantially horizontally aligned pivots about which the leading ends of corresponding arms 35 are upwardly and downwardly turnable, said arms 35 extending generally rearwardly alongside the respective plates 34 from the corresponding pivots to locations well beyond the rear edges of said plates 34. The arms 35 are located at the sides of the plates 34 which face the centre of the implement.Setting means that does not form the subject of the present invention, and that may be of a construction which is know per se, is provided to maintain the arms 35 in chosen angular settings about the substantially horizontal axis afforded by the pivotal connections of those arms 35 to the plates 34 and a ground roller 36 is mounted in a freely rotatable manner between substantially horizontally aligned bearings carried by downwardly directed rear end regions of the arms 35. It will be apparent that manipulation of the setting means that has just been mentioned will either raise or lower the bodily level of the ground roller 36 relative to that of the remainder of the implement and is thus a principal factor in determining the maximum depth of penetration of the soil working tools of the members 3 or 3A into the ground that is possible when the implement is in use.The roller 36 is not illustrated in detail but may be an open-work, cage-formation roller comprising a plurality of elongate elements that are wound helically around a central tubular shape of the roller, in spaced relationship with that shaft, skeletally to define the cylindrical ground-engaging surface of the roller.

Shield plates 43 that are normally substantially vertically parallel to one another and to the direction A lie immediately beyond the opposite ends of the row of twelve soil working members 3 or 3A and act primarily to cooperate with the neighbouring members 3 or 3A at the ends of the row in working the soil to substantially the same thorough extent as is produced by co-operation between immediately adjacent members 3 or 3A at locations closer to the centre of the implement. Each shield plate 43 is carried by an arm which comprises a portion that is mounted so as to be turnable about a substantially horizontal axis disposed a short distance above the top of the hollow frame portion 1 and at a short distance inwardly from a corresponding end of that frame portion.This arrangement enables the shield plates 43, whose lower edges are shaped to slide forwardly over the ground surface, to move upwardly and downwardly, when required, to match undulations in the surface of the ground that is being dealt with by the implement. In addition, the shield plates 43 can be turned upwardly and inwardly through substantially 180" to bring them to inoperative positions, for transport purposes. in which they lie in inverted positions on top of the hollow frame portion 1.

Moreover, the shield plates 43 substantially prevent stones and other hard objects from being flung laterally of the path of travel of the implement so that the danger of any damage or injury being caused in this way is reduced to a minimum, if not entirely eiiminated.

Each rotary shaft 2 is provided. inside the hollow frame portion 1. with a corresponding straight- or spur-toothed pinion 37, the sizes of the twelve (in this embodiment) pinions 37 being such that each of them has its teeth in mesh with those of the or each immediately neighbouring pinion in the single row thereof.

One of the centre pair of shafts 2 in the single row thereof has an upward extension, through the top of the hollow frame portion 1, into a gearbox 38 that is mounted on top of said frame portion 1. Shafts and bevel pinions inside the gear box 38 place this upward shaft extension in driven connection with a rotary input shaft 40 of the gearbox 38 whose leading splined or otherwise keyed end projects forwardly from the front of that gearbox in substantially the direction A. The rear of the gearbox 38, with respect to the direction A, is provided with a change-speed gear 39 whose construction and operation is not the subject of the present invention. It suffices to say that splined or otherwise keyed shaft ends project into the change-speed gear 39, which latter has a readily removable cover, enabling a pair of co-operating pinions having matchingly splined or keyed hubs to be mounted on those shaft ends to give a corresponding transmission ratio therebetween. The two pinions can be interchanged on the shaft ends or be replaced by an alternative pair of co operating pinions of different sizes, to give any chosen one of a number of different transmission ratios so that the shafts 2 can be revolved at different speeds without it being necessary to vary the initiating speed of driv ing rotation that is applied to the rotary input shaft 40 of the gearbox 38.As can be seen in Fig. 1 of the drawings, the leading end of the rotary input shaft 40 of the gearbox 38 is intended to be placed in driven connection with the rear power take-off shaft of an agri cultural tractor or other operating vehicle by way of an intermediate telescopic transmission shaft 41, which is of a construction that is known per se, having universal joints at its opposite ends.

The top and front of the hollow frame portion 1 is provided with a coupling member or trestle 42 that is of substantially triangular configuration as seen in front or rear eleva tion, the coupling member or trestle 42 being constructed and arranged to connect the implement to the rear-mounted three-point lift ing device or hitch of a tractor or other operating vehicle in a manner that is generally known per se and that is shown somewhat diagrammatically in Figure 1. Downwardly and rearwardly divergent tie-beams strength eningly interconnect substantially the apex of the coupling member or trestle 42 and widely spaced apart locations at the top and rear of the hollow frame portion 1.

During the use of the implement that has been described, its coupling member or trestle 42 is connected to the three-point lifting de vice or hitch at the rear of the operating tractor or other vehicle and the intermediate transmission shaft 41 is employed to place the rear power take-off shaft of that tractor or other vehicle in driving connection with the rotary input shaft 40 of the gearbox 38.

Adjustments that ma". if necessary, be made before work commences include altering the transmission ratio in the change-speed gear 39 and raising or lower the bodily level of the ground roller 36 relative to that of the frame portion 1 and its rotary soil working members.

These adjustments will normally be made in the light of 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. As the imple ment moves operatively in the direction A, each soil working member 3 or 3A revolves in the direction B which direction is opposite to that of the or each immediately neighbouring member 3 or 3A due to the inter-meshing relationship of the pinions 37.Each member 3 or 3A works an individual strip of ground extending in the direction A but the relation ship between the spacing of the axes a of the shafts 2 and the effective working width of each member 3 or 3A is such that these strips of ground overlap, or at least adjoin, one another to produce a single broad strip of worked soil that will have a width of substantially, but not necessarily exactly, three metres when the dimensions that have been referred to above are employed. It will be apparent that the working width of the implement could be increased or decreased by providing it with a greater or lesser number of the soil working members 3 or 3A.

If the soil working members 3 or 3A are provided with the tine-like soil working tools 12, 20 or 26, those tools are so arranged, as mentioned above, that the leading edges of their soil working portions are further spaced from the corresponding axis of rotation a than are the rear edges thereof with respect to the direction of operative rotation B of the member 3 or 3A concerned. Resilient movement of the soil working portions as they move through the soil is thus facilitated and such movement tends to produce a well crumbled soil structure. The leading edges of the bladelike soil working tools are so constructed that those tools are particularly suitable for use in fields where the soil is very hard, such as is often the case after a harvest,or when the soil is badly contaminated by weeds, root remnants and the like.The blade-like soil working tool 1 2 of the first embodiment are particularly suitable for dealing with hard ground in which there are many weed and root remnants since, it will be remembered, the leading edges of the soil working portions 1 3 of the members 1 2 are formed as cutting edges.

These cutting edges tend to slice up large weed and root remnants and will penetrate without much difficulty into hard soil. Each tool 1 2 trails downwardly and rearwardly, with respect to the direction B, and an upper region of its leading edge is more steeply downwardly and rearwardly trailing than is a lower region thereof (see Fig.3) with the result that any weeds, root remnants, lengths of twine or the like that may temporarily adhere to the tools 1 2 tend quite quickly to be shed from those tools as they continue their rapid rotation through the soil.

The tools 20 of Figs 6 and 7 of the drawings have leading edges with respect to the direction B, that are straight throughout their lengths and these tools are accordingly more satisfactory for use in "cleaner" soil containing only a minimum of weeds, root residues and other plant refuse.

The tine-like soil working tools 23 may be substituted for blade-like soil working tools where the ground is wet and heavy, rather than being particularly hard, since the soil working portions 24 of these tools 23 have a greater soil displacing effect and therefore tend to break up such ground satisfactorily where blade-like tools would only "cut" through it without actually causing as much displacement as is desirable. In addition, the tools 23, having greater mechanical strength than the blade-like tools, may advantageously be used in ground which contains a lot of stones.

It will be apparent that the carriers 4 and 27 that have been described enable soil working tools of different constructions, appropriate for different soils and/or working conditions, quickly and easily to be mounted thereon employing only a single fastening bolt per soil working tool, no constructional alterations being required when one tool is to be substituted for another. Blade-like soil working tools can readily be formed in pairs from rectangularly shaped lengths of metal strip which strip may advantageously have a thickness of 1 2 mms. The way in which the tools are cut from said lengths of strip enables them to be formed quickly, easily and inexpensively with very little, if any, wastage of material other than where the holes 1 6 or 33 are made. In particular, producing such soil working tools by pressing operations performed on lengths of strip enables those tools to be mass-produced at a rapid rate and low cost.

Although certain features of the soil cultivating implement, carriers and soil working tools that have been described, and that are illustrated in the accompanying drawings, are 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 soil cultivating implement, each carrier and each soil working tool that has been described and/or that is illustrated in the accompanying drawings both individually and in various combinations.

Claims

1. A soil cultivating implement of the kind set forth, wherein each carrier is constructed and arranged so that either at least one bladelike soil working tool or at least one tine-like soil working tool can optionally be directly and releasably secured thereto.

2. An implement as claimed in claim 1, wherein a fastening portion of each soil working tool includes means to protect the fastening region from damage.

3. An implement as claimed in claim 2, wherein said means to protect the fastening region from damage includes a projecting rib or the like arranged to prevent the fastening portion of the tool concerned from being displaced relative to the carrier when that tool is operatively secured to the carrier.

4. An implement as claimed in any preceding claim, wherein each carrier defines at least one recessed fastening surface constructed and arranged to co-operate with a fastening portion or with said fastening portion of a corresponding soil working tool.

5. An implement as claimed in claim 4, wherein the fastening portion of each soil working tool is flat and has a shape which matches that of each recessed fastening surface.

6. An implement as claimed in claim 4 or 5, wherein each fastening surface is provided with a least one upright boundary which is located at the rear of that surface with respect to the intended direction of operative rotation of the corresponding soil working member

7. An implement as claimed in claim 6, wherein each fastening surface is located on top of the corresponding carrier and extends downwardly and forwardly relative to said intended direction of operative rotation from said upright boundary to substantially the front of the corresponding carrier relative to the same direction of rotation.

8. An implement as claimed in any one of claims 4 to 6, wherein each fastening surface is formed on the bottom of the corresponding carrier and is downwardly and forwardly inclined from its rear edge with respect to the intended direction of operative rotation of the corresponding soil working member.

9. An implement as claimed in any one of claims 4 to 7, wherein each fastening surface is in inclined relationship with a plane containing the intended axis of rotation of the corresponding soil working member and extends laterally to an outer end of the carrier concerned.

10. An implement as claimed in any preceding claim, wherein opposite ends or boundaries of each carrier are in substantially parallel relationship with the intended axis of rotation of the corresponding soil working member but are non-perpendicularly inclined to the longitudinal axis of that carrier when the latter is seen projected onto a horizontal plane.

11. An implement as claimed in claim 1 0, wherein the opposite ends of each carrier are substantially flat and an imaginary plane that is perpendicular to those ends and that contains the intended axis of rotation of the soil working member concerned is located rearwardly of said longitudinal axis of the carrier with respect to the intended direction of operative rotation of the soil working member in question.

1 2. An implement as claimed in claim 4 or in any one of claims 5 to 11 when read as appendant to claim 4, wherein a fastening portion, or said fastening portion, of each soil working tool is flat and, in use, is clamped to a corresponding one of the fastening surfaces by a single bolt or equivalent fastening member.

13. An implementas claimed in claim 2 or in any one of claims 3 to 12 when read as appendant to claim 2, wherein said protection means forms part of a clamp by which a fastening portion, or said fastening portion, of each tool is releasably secured to a corresponding one of the fastening surfaces.

14. An implement as claimed in claim 2 or in any one of claims 3 to 1 3 when read as appendant to claim 2, wherein said protecton means includes a rib or like extension which is arranged to co-operate with the front, with respect to the intended direction of operative rotation of the corresponding soil working member, of the respective carrier in such a way as to secure the fastening portion of a corresponding soil working tool releasably but immovably in its appointed operative position.

1 5. An implement as claimed in any preceding claim, wherein the blade-like soil working tools are strip-shaped and/or knife-edged.

16. An implement as claimed in claim 15, wherein an upper region of a soil working portion of each such tool is in abutting contact with a flat radially outer end of the corresponding carrier when that tool is mounted in its operative position.

1 7. An implement as claimed in claim 1 6, wherein the leading edge, with respect to the intended direction of operative rotation of the corresponding soil working member, of the soil working portion of each such tool trails downwardly and rearwardly with respect to said direction of rotation in an upper region of that edge and joins a lower region thereof that is less steeply trailing and in parallel or substantially parallel relationship with the rear edge of the same soil working portion.

18. An implement as claimed in any one of claims 1 5 to 17, wherein the leading edge of the soil working portion of each such tool is further spaced from the intended axis of rotation of the corresponding soil working member than is the rear edge of that tool when the latter is releasably secured in its operative position.

1 9. An implement as claimed in any one of claims 1 5 to 18, wherein a fold-line about which the soil working portion of each such tool is bent relative to the fastening portion of that tool has a length which is substantially one and a half times the width of the tool in the region of said fold-line.

20. An implement as claimed in any preceding claim, wherein the blade-like soil working tools are formed from strip material by a pressing operation.

21. An implement as claimed in claim 20, wherein the soil working portion of each blade-like tool is formed with a stiffening projection that extends lengthwise of said soil working portion.

22. A soil cultivating implement substantially as hereinbefore described with reference to Figs. 1 to 4 of the accompanying drawings or with reference to Figs. 1 to 4 as modified by Figs. 6 and 7, 8 and 9 or 10 to 12 of those drawings.

23. A blade-like soil working tool destined for use in a soil cultivating implement as claimed in any preceding claim, wherein said tool comprises a fastening portion and a soil working portion, these portions being bent over relative to one another about a fold-line whose length is substantially one and a half times the width of the strip material from which the tool is formed, considered in the region of said fold-line.

24. A soil working tool as claimed in claim 23, wherein the tool is so shaped that it can be cut from a parallelogram-shaped strip of material together with an identical end-for-end reversed tool.