GB2082034A - Agricultural implement - Google Patents

Abstract

A soil cultivating implement comprising mounting means and at least one soil working tool supported on the mounting means for movement through the soil, the tool having an elongate blade 1 arranged to extend downwards and at an acute angle to the vertical, the blade having a sloping leading edge surface to lift soil over the blade during passage through the soil provided by a movable, or rigid, plate member 9 secured, preferably releasably, to the leading edge 6 of the blade or to the top surface of the blade at a position between the leading and trailing edges of the blade. <IMAGE>

Description

SPECIFICATION Agricultural implement This invention relates to an improved agricultural implement. More specifically, it relates to an improved implement for preparing the soil prior to growing crops.

For hundreds of years, agricultural land has been prepared for the sowing of seed by the use of the mould-board plough. The prime function of the plough is to kill weeds; but it also can have the effect of breaking up the soil, making it less compact, and creating a tilth in which seeds may be buried. Generally ploughing is followed by further operations for breaking up the soil, e.g. discing and harrowing, prior to sowing. However, ploughing uses substantial amounts of energy, in principle unnecessarily, in turning over the soil. Millions of tons of earth are lifted and inverted by the plough every year, using in nearly every case tractors powered by fossil-based fuels, a non-renewable resource.

In the 1950's the discovery of the herbicide paraquat opened the way to novel methods of establishing crops, without the use of the plough. Paraquat was the first herbicide (killing all green growth) to be discovered which was totally inactivated in contact with the soil. Experiments with this new herbicide showed that it could replace the weed-killing function of the plough: that stubble or grassland could be sprayed with paraquat; and that shortly thereafter seed could be drilled direct into the uncultivated ground; and that, in suitable circumstances, such seed would germinate as well as (sometimes better than) seed planted in ploughed land afterconventional tilling techniques. During the 1960's this technique of "direct drilling" was developed for use in agriculture. Seed-drills capable of making a seedfurrow in untilled ground had to be designed (see for example U.K.Patents Nos. 1150723 and 1274219) and manufactured; and the limitations ofthetechni- que explored, so as to be able to predict when the technique would work and when it would fail. This development has been succeeded by widespread adoption of the technique in the 1970's, with savings to farmers in fuel, in manpower and in time.

In the foregoing techniques the soil-inactivated total herbicide is preferably paraquat on account of its rainfastness and rapid kill. It is conveniently sprayed from a tractor-mounted boom at rates of about 0.75 to about 1.5 kilograms ion per hectare, depending on the weed cover on the soil to be treated. Glyphosate is another effective soil-inactivated herbicide, useful at approximately similar rates, and other suitable herbicides will no doubt be discovered in the future. Drilling may be carried out with a variety of specially designed drills, for example the drill described in U.K. 1274219, commonly known as the "triple disc" drill. Drilling may be carried out at any time from several hours to several weeks after spraying.

One limitation of the technique as it has been practised up to now is the type of soil on which it can be used. For success, the soil must be reasonably dry, light and porous. On heavy land, the grooves cut for the seed by the drills frequently become waterlogged, and establishment of seed is patchy. Much agricultural land (perhaps half the land farmed in Britain today) is to heavy to allow the direct drilling technique to be used on it with success. Land may also, by the passage of heavy machinery, become too compacted to be suitable for the technique.

It is known from U.K. Patent No. 1,493,346 to use knives or blades to break up compacted soil. This patent describes a sub-soil breaking soil cultivation implement comprising one or more blades extending downwardly and sideways into the soil and having a leading cutting edge (preferably sloped forwardly and downwardly) which is bevelled to raise soil over the blade and to avoid compression of soil underthe blade as it cuts. The invention is described for use in the improvement of grassland, or in the improvement of arable land in conjunction with the plough, or for use in establishing drainage channels which are simultaneously filled with sand, or for use in laying flexible pipe.

The device of U.K. Patent No. 1,493,346 may be used in not very heavy soils which are fairly dry and friable, provided the blades are mounted parallel to the direction of forward motion of the vehicle impelling them. Then, provided the soil is of just the right type, the blade causes just sufficient break-up of the soil to improve porosity without substantially disturbing the surface, and subsequent drilling can be carried out effectively in accordance with the invention. However, on many heavier and less friable soils, the blade so set will not break up the soil sufficiently. Attempts have been made to increase break-up by setting the plane of the blades at a slight angle to the direction of forward motion, so as to increase the displacement of the soil by the blades.

This however has generally proved impractical. The slight divergence between the plane of the blades and the direction of forward motion considerably increases the load on the tractor and moreover drags it off course. Also, the surface of the soil is considerably broken up.

In UK Patent Applications Nos. 7941175 and 8011376 there is described and claimed a cultivating implement comprising mounting means and at least one soil working tool supported on the mounting means for movement through the soil, the tool having an elongate blade arranged to extend downwards and at an acute angle to the vertical, the blade having a leading edge bevelled so as to lift soil over the blade during passage through the soil, the tool having at the trailing edge of the blade a movable extension which is adjustable between a position directly behind the trailing edge and a position projecting upwardly from the trailing edge, in the latter position the extension increasing the lifting action on soil passing over the blade.

It has now been found that a further effective implement can be produced which omits the movable extension at the trailing edge of the blade and modifies, instead, the construction of the leading edge of the blade.

According to the present invention, therefore, there is provided a cultivating implement compris- ing mounting means and at least one soil working tool supported on the mounting means for move ment through the soil, the tool having an elongate blade arranged to extend downwards and at an acute angle to the vertical, the blade having a lead ing edge bevelled and upwardly extended so as to lift soil overthe blade during passage through the soil.

In a further aspect the invention provides a cultivating implement comprising mounting means and at least one soil working tool supported on the mounting means for movement through the soil, the tool having an elongate blade arranged to pass edgewise through the soil and to extend downwards at an acute angle to the vertical, characterised by the blade having a sloping leading edge surface to lift soil over the blade during passage through the soil provided by a movable, or rigid, plate member secured, preferably releasably, to the leading edge of the blade orto the top surface of the blade at a position between the leading and trailing edges of the blade.

In a preferred aspect the invention provides a cultivating implement as defined above, characterised by having a movable plate member adjustable to be selectively located so as to provide a soil lifting surface edge sloped to a greater or lesser extent with respect to the plane of the blade to increase or decrease, respectively, the lifting action on soil passing over the blade. The movable member is preferably pivotally attached to the blade, and may conveniently be hingedly attached to the blade about an axis extending parallel to the plane of the blade.

In a still further aspect the invention provides a cultivating implement characterised in thatthe movable member is located in the selected upwardly projecting position by adjustable fixing means.

In a yet further aspect the invention comprises an implement as defined above for use in the improvement of land porosity wherein the blade is supported by mounting means for carrying it on a vehicle and, for example by hydraulic or other powered mechanism, is capable of being lowered into and, preferably aided by an adjustable depth wheel running over the ground surface and secured to the mounting means, held in an operative position for movement through the soil by traction from the vehicle, with the plane of the blade sloping sideways and downwardly so asto make a diagonal cut in the soil and to lift soil over the sloping leading edge surface of the blade as it passes through, without substantially compacting it beneath the blade.Preferably a separate plate, or plates, are secured (e.g. by bolts so as to be detachable and easily replaced when worn) to the bevelled edge of the blade. Preferably, also, the blade in the operative position is supported with its plane parallel to the direction of motion of the vehicle. Preferably the implement comprises a gang of such blades mounted adjacently, in rank or in echelon; and preferably each blade in the gang is mounted with its bottom edge approximately vertically below the top edge of its neighbour. Mechanical vibration of the blades can, if desired, be provided. Preferably, also, in front of each blade is independently mounted a flat, flexible cutting disc, the plane thereof lying in the same plane as the blade behind it. Such discs are preferably pivotally mounted on the mounting means, e.g. framework, carrying the blades, and are loaded, e.g. by spring action.Preferably they are fitted with scrapers.

As an optional feature the tool of the invention may further be provided with rollers, e.g. crumble rollers, located between adjacent blades, such crumble rollers not having a continuous arcuate surface but consisting of a plurality of parallel or spirally arranged rods or bars disposed bt a circumference, as viewed from the side, so as to present, as it were, an interrupted roller surface. Preferably such a roller, or crumble roller, is disposed in such a position relative to the blades that the surface, orthe rods or bars, successively impact upon and/or exert pressure on the soil art a point above or just rearward of the trailing edge of the blade.As an alternative to crumble rollers, angled blades mounted on rotatable shafts may be deployed to provide further fissuring of the soil structure downwardly from above ground level. These shafts are preferably biassed towards the soil e.g. by springs and the same applies to the crumble rollers. Both rollers and cutting knive shafts can be friction driven, or power driven from the power take-off shaft of the tractor pulling the tool or device. The axes of the crumble rollers or shafts are preferably disposed to lie horizontally of the soil surface and at right angles to the direction of pull of the tool or device as a whole.

It is found that a tool of this type may be used to improve soil porosity in many types of heavy soil, without substantial disturbance of the soil surface.

Provided the displacement of the bevelled leading edge which is extended upwardly is appropriate to the soil type (i.e. by length and angle in relation to the blade), the load on the tractor is not excessive, nor is it diverted from its course, then, nevertheless, an appropriate degree ofsoilfissuring may be obtained.

The (or each) blade is preferably of uniform thickness over its working surface, though it may, if desired, increase somewhat in thickness from upper to lower edge, or vice versa, or from front to rear. Its lower edge is preferably horizontal in the operative position, and may conveniently carry a shoe projecting forwardly and downwardly where the lower and leading edges meet. This shoe helps to draw the blade down into the soil.

The blades may be hollow and holed lo serve as distributors for liquid fertiliser during fissuring.

Alternatively separate fertiliser distributing tubes may be used, for example located between, or behind, the blade. These tubes may be perforated. If desired these tubes, or furthertubes, may be used to introduce materials into the fissures,whsch will, or can be made to, explode to providofurtherdisrup- tion of the soil structure.

Embodiments of the invention will now be described with reference to the drawings, in which: Figure 1 is a side view of a blade for use in the invention shown with operative position, mounted on a tractor drawbar; Figure 2 is a top view of the blade of Figure 1, viewed edgewise to the plane of the blade; Figure 3 is a rear view of a gang of blades of the kind shown in Figures 1 and 2 being drawn through the soil.

Figure 4 is a perspective view of a crumble roller.

Figure 5 is a plan view of a pair of rotatable cutting rollers with blades which may be used in the place of a crumble roller.

Figure 6 is illustrative of a further embodiment of the invention and shows, schematically in plan view, an implement having an arrangement on a framework of blades of the kind shown in figures 1 and 2 but with a modified, slimmer, and more sharply pointed nose and shoe portion to each 'blade'.

Figure 7 is a side elevation of the implement shown in figure 6 on the line I-I thereof.

Figure 8 is a larger scale view of a blade and disc as illustrated in Figure 7 and shows details of an assembly for mounting the disc upon the implement framework.

Figure 9 is a view similar to that of figure 8 but from the opposite side to the side used in figure 8.

With reference first to Figures 1 and 2, a parallelsided blade 1 is shown fastened by bolts 11 to an elbow 12, the other end of which is secured to a collar 13 mounted for rotation on a transverse bar 14 carried by a tractor (not shown). The elbow 12 projects sideways at about 45" to the axis of bar 14, holding the blade 1 at the same angle. The elbow also orients the blade 1 in the fore-and-aft position so that its sides are closely aligned with the forward motion of the tractor. The blade 1 has parallel edges, the upper and lower edges 7 and 8 being horizontal and the leading and trailing edges sloping forwardly and downwardly. The leading edge is provided with a downwardly sloping bevel 6 to which is secured, by bolts (not shown), a soil lifting plate 9 which serves as a soil-lifting surface.The lower edge 8 is fitted with a shoe 3, the front of which is turned downwards to form a nose 15 terminating in a cutting edge.

The use of the device will now be described with particular reference to figures 1,2 and 3.

Figure 3 shows a gang 40 of three blades, of the type shown in figures 1 and 2, mounted on a tractor 43. For transport, the gang 40 is rotated upwardly about the bar 14 by a hydraulic ram 41 until the lower edges 8 of the blades 1 are vertical. When the tractor 43 is positioned to begin working, the ram 41 lowers blades 1 into a position in which the noses 15 dig into the earth.

The tractor then moves forward, and the blades 1 and plates 9 are forced into the soil by the combined action of the ram 41 and the soil acting on the noses 15 and shoes 3. In the operative position the blades 1 cut diagonally through the soil, lifting the soil over their upwardly extending plates 9 without significant compression on the under sides. The total amount of lifting depends on the size of the plate fitted and its angle to the blade, and by this means the degree of fissuring in the soil is controlled as required. As the tool is carried along, the surface of the land lifts up and subsides like a wave, but apart from parallel trenches along the lines of entry of the blades 1, the surface of the soil is afterwards remarkably free from disturbance.

Figure 4 shows a crumble roller having circular side plates 44 having mounting shafts 45 and cross bars 46 for pressing upon the soil surface. The shafts 45 are rotatably mounted on each elbow 12 by way of extension arms (not shown) therefrom. In an alternative embodiment (not shown) the shafts 45 are rotatably mounted on arms extending separately from the transverse bar 14 or from another frame member of the tool. The action of crumble rollers is to further disrupt and break up the soil structure near the soil surface, where there may be trash and/or matted roots or compression of the soil by animal hooves.

Figure 5 shows a pair of cutting rollers 47 with angled blades 48 disposed circumferentially around shafts 49. A pair of these rollers may be deployed in the place of a crumble roller. The shafts 49 are rotatable and may be friction driven by contact with the soil surface; or they may be rotated by a suitable mechanical linkage (not shown) from the power take-off shaft of the tractor. The blades of the second cutting roller are angled in a different direction to those of the first roller and the shafts 49 can be variably biassed, for example by spring loading, so that the blades are forced into the soil to a greater or lesser degree depending upon the required amount of penetration of the soil.

The foregoing treatment of the soil may then be followed by herbicidal spraying, e.g. of paraquat at a rate of 1 Kg ion per hectare sprayed in 200 gallons of water from a boom sprayer, followed at an interval of a few days by drilling e.g. with barley seed, using a triple disc drill. A suitable drill is the Hestair Bettinson "3D" drill.

Figures 6, 7, 8 and 9 show a further implement according to the invention. In this device, the plan view of Figure 6 shows three blades 52,53, 54 mounted on a framework 51 of metal girders and are bolted to girders 55, 56, 57 thereof. The framework 51 has tow bars 58, 59 for connection to a tractor (not shown). Discs 60,61,62 are located in front of the blades and are mounted on the girders 55,56,57 by a mechanism (not shown) which is illustrated in detail in Figures 8 and 9. A ground or depth wheel 63, which is adjustable in height by a raising and lowering mechanism 64 (Figure 7) is set to regulate the depth to which the blades penetrate below the soil surface when the device is in use.

Figure 7 shows the implement of figure 6 in side elevation viewed on the line I-I of Figure 6. The slit cutting discs 60, 61, 62 lie in substantially the same plane as the blades 52, 53, 54 and in use the discs cut a slit in the soil which assists the penetration and movement of the fissuring blades into, and through, the soil.

Figures 8 and 9 show, in enlarged fashion, blade 52 and its associated disc 60 and illustrate mechanisms for the mounting of the discs on the framework 51 of the implement. A cranked rod 65 is adjustably held at one end by a clamp 66 to the girder 55 and to its other end is pivotally clamped a second clamp 67 having an integral abutment 68 in which is pivotally mounted an elongated flat metal bar 69. The clamp 67 and abutment 68 can pivot around the bar 65 in a bush 70 and the bar 69 can pivot around the abut ment 68 in a bush 72. Interposed between 68 and 69 is a rubber disc 71 to provide a cushioning resilience between them. Pivotal movement of the elongated flat bar 69 in the bush 72 is restricted by a pin 73 attached to the bar lying within a trough on the clamp 67 having raised edges 74,75 which act as stops.

Pivotal movement of the elongated bar 69 (by pivoting of the clamp 67 about the rod 65 in the bush 70) in the plane at right angles to the foregoing plane of pivotal movement is restricted by a retaining spring 76 extending between a loop 77 on the bar 69 and an attachment loop 78 to the girder 56, that is the girder adjacent to the girder 55 and on which is mounted the adjacent blade 53.

By this mechanism the flat, flexible, metal disc 79, which is rotatably mounted by a bush 80 on the elongated bar 69, is enabled to pivot bodily to a limited degree in two planes at right angles to each other. The first of these planes is the plane in which the disc itself normally lies (and the associated blade) and the other is at right angles to this. These degrees of freedom of movement assist the disc in penetrating and cutting through the soil without damage to its edges or mounting, e.g. by stones or other obstacles.

The disc 79 is equipped with a scraper 81 which is pressed against the surface of the disc buy a spring concealed within its point of pivotal attachment 82 to a cranked extension 83 of the elongated bar 69.

The implement shown in Figures 5,6,7,8 and 9 may incorporate one or more rollers of the kind hereinbefore described, for example as shown in Figure 4, or one or more pairs of shafts with rotating cutting knives, for example as shown in Figure 5.

Claims (7)

1. A cultivating implement comprising mounting means and at least one soil working tool supported on the mounting means for movement through the soil, the tool having an elongate blade arranged to pass edgewise through the soil and to extend downwards at an acute angle to the vertical, characterised bythe blade having a sloping leading edge surface to lift soil over the blade during passage through the soil provided by a movable, or rigid plate member secured, preferably releasably, to the leading edge of the blade or to the top surface of the blade at a position between the leading and trailing edges of the blade.

2. A cultivating implement according to claim 1 characterised by having a movable plate member adjustable to be selectively located so as to provide a soil lifting surface sloped to a greater or lesser extent with respect to the plane of the blade to increase or decrease, respectively, the lifting action on soil pas sing over the blade.

3. A cultivating implement according to claim 2 characterised in that the movable member is pivot ally attached to the blade.

4. A cultivating implement according to claim 3 characterised in that the member is hingedly attached to the blade about an axis extending paral lel to the plane of the blade.

5. 5. A cultivating implement according to claim 2, 3 or4 characterised in that the movable member is selectively located by adjustable fixing means.

6. Acultivating implement comprising mounting means and at least one soil working tool supported on the mounting means for movement through the soil the tool having an elongate blade arranged to extend downwards and at an acute angle to the vertical, the blade having a leading edge bevelled and upwardly extended so as to lift soil over the blade during passage through the soil.

7. An implement as claimed in any of the preceding claims wherein the blade is supported by mounting means for carrying it on a vehicle and, forexample by hydraulic, or other powered mechanism, is capable of beinlowered into and, preferably aided by an adjustable depth wheel running over the ground surface and secured to the mounting means, held in an operative position for movement through the soil by traction from the vehicle, with the plane of the blade sloping sideways and downwardly so as to make a diagonal cut in the soil and to lift soil over the sloping leading edge surface of the blade as it passes through, without substantially compacting it beneath the blade.