APPARATUS AND METHOD FOR SOIL CULTIVATION

APPARATUS AND METHOD FOR SOIL CULTIVATION

The present invention relates to an apparatus and method for soil cultivation. Known are apparatus with a surface cutter with which for instance a top layer of a ground surface is cut away, wherein the top layer is removed. This takes place for instance to replace vegetation that is present. A drawback of such apparatus is that the removal of the layer entails high transport and processing costs.

It is an object of the present invention to obviate this drawback. The invention provides for this purpose a ground-working apparatus, comprising: - a cutter for cutting a layer from the ground surface at a predetermined height adjustment, wherein the cutter is adapted to force the cut material over the cutter by means of cutting members rotatable about a rotation shaft, - a discharge conveyor arranged substantially parallel to the axial direction of the cutting device on the side thereof to which the cut material is forced, wherein

- the discharge conveyor comprises separating means for separating the cut material into a fraction of ground material which is returned by the separating means to the ground surface and a fraction of waste material which is discharged by means of the discharge conveyor. Such an apparatus has the advantage that only a fraction of the soil, such as remnants of vegetation, stones, waste and the like, is discharged and that useful parts are returned directly to the ground surface. This results in considerable savings in respect of transport costs and waste-processing costs, such as waste separation.

In a first preferred embodiment according to the present invention the ground-working apparatus comprises a cutter with a drive shaft having mounted rotatably thereon a number of cutting members, each provided with a connecting element extending from the drive shaft to a knife, wherein the connecting element has an offset form such that the successive knives display an overlap. Owing to the combination of a plurality of connecting elements and this offset form, the whole ground surface is worked over the whole width of the apparatus.

The connecting elements are preferably designed such that the knives are oriented in one direction, i.e. only knives directed to the left or right need be used in the apparatus. The production of the knives is hereby simplified, and therefore cheaper. It is also possible for maintenance purposes to suffice with stocking only one embodiment of the knives, with left or right-hand orientation. Assembly of the knives also becomes simpler, whereby fewer errors can occur.

In a further preferred embodiment the discharge conveyor comprises a star sieve. Such a star sieve can function with a dual action. On the one hand it has a transporting action and on the other the reusable material can fall back to earth through openings in the sieve during this transport. The application of this sieve above the area of the ground surface being cut away provides the effect that the reusable material is carried back to the ground surface substantially without a displacing operation.

The cutting device in the ground-working apparatus preferably comprises height-adjusting means for setting the height per side of the device at the front and rear thereof by means of one operating member, wherein the operating member is connected to height-adjusting means which define the height of a cutter shaft relative to a vehicle. This has the advantage that the person performing operations with the apparatus can set the height in relatively simple manner. In known surface cutters four spindles are applied per cutter, whereby it is awkward to adjust the cutter correctly as a whole. It now suffices to set the cutter at the correct height on the left and right, and the correct outcome hereof can be checked by viewing from the front .

Such an arrangement makes a possible motor height adjustment more advantageous since it is possible to suffice with two motors on either side of the apparatus. Operation of the height adjustment from the cab hereby becomes possible.

In a further embodiment of the ground-working apparatus the height-adjusting means comprise per connection thereof to the vehicle a rotation arm which rotates about a rotation shaft, which rotation shaft is connected on one side to the vehicle and on the other side to a member. With such a construction a relatively advantageous embodiment which is simple to maintain and operate becomes possible.

In this ground-working apparatus the rotation shaft of the cutting device is preferably positioned substantially transversely of the direction of travel. A large number of mutually adjacent knives with the combined action of a wide knife is hereby realized over substantially the width of the apparatus. The residual fraction to be discharged or waste fraction of the ground layer which is cut away can hereby be discharged laterally in practical manner. In such an arrangement the star sieve is further situated in practical manner behind the cutter, whereby the return fraction comes to lie precisely in the processing strip of the apparatus. No displacement operation is hereby required in order to position the return fraction on the ground surface.

A further aspect of the present invention relates to a cutting device for cutting a layer from a ground surface, comprising a drive shaft with cutting members rotatable therearound, wherein the cutting members comprise a knife and a connecting element extending from the shaft to the knife, wherein the connecting element is designed such that two knives, which in terms of operation thereof in the cutter are successive, work at least the whole ground surface or display an overlap.

Such a cutting device has the advantage that simple, for instance L-shaped knives can be applied, wherein an overlap (0) can be realized during operation of the knives. Soil, stones and vegetation for instance are hereby cleared away evenly.

During use the knives are heavily loaded as they are pushed through the ground which is scattered with for instance roots, stones and waste. The above mentioned overlap is realized in existing cutters by means of expensive bends in the knives. These bends are expensive, among other reasons, because they have to withstand the loads and must therefore be very robust. A further advantage of the present invention is that the knives, fitted both to the right and left on the connecting elements, can be of identical form, which simplifies assembly and for instance reduces stock costs.

In an embodiment of the cutting device two connecting elements which are mounted substantially opposite each other on the shaft preferably have two bends in opposite directions. The overlap is hereby realized in relatively simple manner, wherein identical connecting elements can for instance be applied on either side of the rotation shaft. The present invention will be further explained hereinbelow on the basis of an embodiment and with reference to the accompanying figures, in which:

- Figure 1 shows a partly cut-away perspective view of the embodiment;

- Figure 2 is a view of an embodiment with an alternative adjusting mechanism;

- Figure 3 is a view of the knives and knife holders; - Figure 4 is a view of a detail of figure 3,-

- Figure 5 is a side view of an embodiment; and

- Figure 6 is a rear view of an embodiment.

An embodiment (fig. 1) according to the present invention is a soil cutter 10 with a partial discharge, which has the advantage that a reusable fraction of the ground layer for cutting away falls back directly onto the ground. Costly transport and waste processing, such as separation of types of waste, is hereby reduced considerably. The ground cutter comprises a surface cutter 14 which can be adjusted in the height by means of only two operating members 32,36 of height-adjusters 20. These are shown as hand-operated members, but an electrical operation can also be arranged. Mounted at the rear of the surface cutter is a star sieve 12, all shafts of which rotate in the same direction, whereby waste is discharged in the rotation direction. A collecting hood is arranged on the top of this star sieve so that the scooped-up soil layer reaches the star sieve in controlled manner.

Height adjusters 20 are each provided with a spindle 34 operated by means of handles 32. Situated on the underside of spindle 34 is a T-rod 26 extending to two sides. Both the front side and rear side of the cutter are hereby adjusted in the height by means of a control operation. Tilting arms 22,28 are mounted rotatably on yoke 41 of the cutter by means of shaft or bolt 23, 25 respectively. Connecting rods 24 connect the T-rod to the two tilting arms 22,28- Moving of the T-rod 26 up or downward by means of the spindle causes a rotation of tilting arms 22,28, whereby yoke 41 of the cutter, and thereby the operating height of the cutter, is varied. For locking purposes the handles 32,36 are secured by means of respective clamps 42,43. In an alternative embodiment of height adjuster 20 (fig. 2) the height is adjusted by means of spindle arm 60. Arm 64 is set simultaneously to the correct height by means of connecting rod 62.

The assembly of knives 44 is shown in fig. 3 in combination with the connecting elements or knife holders 45, whereby the ground is worked over the whole width of the apparatus.

The cutter is driven by means of drive belt 47 which is driven in the direction of arrow A. The drive power herefor is obtained from the tractor by means of for instance a power take-off shaft. The rotor 49 of the cutter is hereby set into rotation. The soil is scooped up and inside hood 42 transported upward and rearward by means of knives 44 and, due to the speed at which this takes place, thrown onto star sieve 12. The shafts of the star sieve rotate in the direction of arrow B (fig. 5) for lateral discharge of the waste fraction (fig. 6) .

Knife holders 45 are mounted on rotor 49 of the cutter by means of for instance welding or other method suitable for the purpose. A first part 46 of knife holders 45 extends straight relative to the rotor. The knife holders then have a transition part 47 for the purpose of obtaining a translation in lateral direction of the knife. On the end of the knife holder is situated a straight part 48 for the right-angled knives. If knives with another angle are applied, a different angle can be used in this part of the knife holder. The result is a horizontal cutting plane of the knife, wherein the knives display an overlap for the purpose of level cutting-away of the soil.

The present invention is not limited to the above described embodiment. Within the subject-matter of this text the skilled person can make many modifications within the scope of protection defined by the appended claims.