GB2142511A - Agricultural tilling - Google Patents

Abstract

Rotary cultivating tines A', B', C', D', are secured to non-planar polygonal flanges (1, 2, 3, etc) equally spaced apart and mounted on a horizontal shaft 10. Each flange consists of a flat, ring-shaped, circular central part which is welded perpendicularly to the axis of the shaft (10) and of a non-planar polygonal peripheral part, the corners (A,B,C,D) of which form different angles in relation to the perpendicular to the axis of the shaft passing through the centre of gravity of the flange. <IMAGE>

Description

SPECIFICATION Soil Cultivating Tools This invention relates to soil-cultivating tools.

Agricultural rotary cultivators having a horizontai shaft extending parallel to the ground have been proposed, in which flanges supporting soilcultivating tools are fixed at intervals on this shaft.

The shaft is driven by conventional means.

Rotary cultivators serve to till the soil after ploughing or they may replace this operation, and this tilling acts to break up the soil so that it becomes loose and level.

Broadly two different types of machine have been proposed: the first one includes tool-supporting flanges arranged on the rotary shaft perpendicularly to its rotational axis; the second type includes tool-supporting flanges arranged at an angle differing from 90 in relation to the shaft. The type with flanges that are perpendicular to the shaft involves soil-cultivating tools which are connected to the periphery of each flange, inclined at a certain angle in their attachments and with a bent or "L" shape in their terminal cutting part. This achieves the result that, even with flanges set at intervals, all the soil is tilled.One drawback of this construction is that the action of these blades or tines or hoes creates a limit "surface" at a certain depth, below which the soil becomes compacted and compressed, due to the flattening action which the L-shape of these tools generates. This "surface" causes a low permeability of the soil and, therefore, the stagnation of the irrigation waters with ensuing damage to cultivation conditions. The other type of previously proposed construction with angled tooi-supporting flanges and with suitably shaped soil-cultivating tools avoids the disadvantage of soil compacting, but this system also presents some drawbacks, both in the construction phase and in the working phase of the operating machine.In the construction phase the welding of the angled flanges to the main shaft is rather difficult and costly, since it is not possible to perform the welding by means of the conventional automatic welding machines, due to the inclination of the surfaces to be welded. In the working phase, whenever the tools which are secured at the corners of the flanges find an anomalous resistance in the soil, this may cause deformation of the corresponding flange. It is obvious that, while a deformed or broken tool can easily be replaced, the deformation of a flange involves maintenance which is much more complicated, more difficult and which, above, all cannot normally be performed by the operator in charge of the agricultural machine.According to the present invention there is provided a rotary cultivating or tilling tool for incorporation in a machine for driving the tool, said tool comprising flanges of the same shape and size and arranged at an equal distance from one another on a shaft on the corners of each of which soil-cultivating tools are secured, each flange having a central, annular, zone secured perpendicularly to the transmission shaft and a peripheral non-planarzonewith a polygonal perimeter, the two zones being connected to one another at arcuate ribs, and diagonals passing through the corners and through the centre of gravity of the flange and the normal to the axis of the shaft, also passing through the centre of gravity, forming angles, which are different for each corner of the flanges.A rotary cultivating tool embodying the invention will now be described by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure lisa fragmentary perspective view of the rotary cultivator shaft assembly, having flanges which support soil-cultivating tools; Figure 2,3,4,5 show the various angles formed both by the corners of one flange supporting the soil-cultivating tools and by the soil-cultivating tools connected to it; Figure 6shows one flange in side elevation with the soil-cultivating tools secured to it; Figure 7shows the shape of each flange; and Figure 8 shows the angle of incidence in relation to the soil of the various soil-cultivating tools belong ing to flanges which are adjacent to one another and it emphasizes the substantially equidistant passage of the soil-cultivating tools in the soil.

With reference first to Figure 7 a flange 1 has a central part la shaped as a plane ring and peripheral part 1b of polygonal outline which is non-planar and which has corner portions lying in different planes and such that the diagonal passing through the corner and the centre of gravity of the flange forms for each corner portion different angles with the normal to the axis of the shaft, which also passes through the centre of gravity of the flange.

Parts la and 1b are connected together by two ribbed zones 1 C and ld which strengthen the flange and allow it to withstand high stresses at the corner portions, even with a reduced material thickness.

The ribbed zones extend in circular arcs centred on the axis of rotation of the shaft.

In the case represented in Figure 7 the flange is quadrilateral and each of the four corner portions A,B,C,D has three holes i.e., for securing the soilcultivating tools. In Figures 2,3,4,5 the same flange 1 is represented with part la welded on shaft 10 perpendicularly in relation to the axis of the shaft, and the various Figures represent the angular positions, in relation to the normal to the axis of the shaft, of the corners of the flange and of the soil-cultivating tools secured to these corners.

As is best seen in Figure 7, the corner portions A,B,C,D, lie at a small angle 2"-3" to those edge portions of the flange member which extend between the corners. This angular relationship is best shown between corner portions B and C and it will also be apparent that the angular relationship is opposite at corner B in comparison with that at C.

In Figure 2, the plane of corner A forms an angle of 8" with the vertical, in Figure 3 the angle formed by the plane of corner B and the vertical is 6 ; in Figure 4 the angle formed between the plane of corner C and the vertical is 11 ; in Figure5 the angle formed between the plane of corner D and the vertical is 7 .

Since all the soil-cultivating tools are the same and are squally bent with their cutting edges forming an angle of approx, 23 in relation to the plane of the corner to which they are secured, as can be seen in Figure 3, and since the soil-cultivating tools are secured to the corners of the flanges, as can be seen in the Figures, it follows that the angles formed by the soil-cultivating tools in relation to the vertical are differentiated in the following manner: soilcultivating tool A' in Figure 2 has an inclination of 15 in relation to the vertical; soil-cultivating tool B' in Figure 3 has an inclination of 29 in relation to the vertical-soil-cultivating tool C' in Figure 4 has an inclination of 34 in relation to the vertical; soilcultivating tool D' in Figure 5 has an inclination of 16 in relation to the vertical.

With reference to Figure 6, which shows a view of the soil-cultivating tools, each secured by three bolts to the corner portions of flanges 1, it is seen that these tools have a profile of their cutting edge which forms a constant angle Z of approximately 25 with the diagonals which join two opposite corners of the corresponding flange. This is done in order to make the penetration of the soil-cultivating tool in the soil easier. This Figure also makes clear that alternate tools are mounted on opposite faces of the flange 1 and tool at diagonally opposite corners are inclined in the same sense.

Figure 1 shows a perspective view of the shaft of the tool which will be incorporated in an agricultural machine. For the sake of simplicity, the soilcultivating tools fastened at the corner portions of each flange have been left out of this illustration. With reference to flange 1 welded in the central position, a selected corner portion forms an angle awith the normal to the axis of shaft 10 passing through the centre of gravity of the flange; more precisely, angle a is the angle formed between the plane containing normal a and axis b of the shaft and the plane containing corner portion C of flange 1 and axis b of the shaft.Flange 2 is welded to the shaft in such a way that the corresponding corner portion C forms an angle ss = awl+27"; this angle is defined in the same manner as angle a that is, it is the angle formed by the plane containing normal a and axis b and the plane containing corner portion C and axis b. In the same way flange 3 which follows flange 2 has corner portion C forming with normal a an angle w =vex+(2 x 27 ).

The flange 4, assuming that it is the third flange to right of flange 1 (since the shaft is interrupted between 1 and 4) - has corner portion C forming an angle 3 in the clockwise sense in relation to the perpendicular; the size of this angle is 3 = a -(3 x 27 ). In this way the following flange 5 has corner portion C forming an angle = a-(4 x 27 ). The arrangement of each flange staggered by 27 in relation to its adjacent flange, in the clockwise sense in relation to the flange arranged at its left, and in the anti-clockwise sense in relation to the flange arranged at its right, combined with the angling of the corners and the shape of the soil-cultivating tools, allows the soil to be penetrated by the soil-cultivating tools at a distance which is practically constant. This appears clearly in Figure 8. In this Figure the soil-cultivating tools marked with A', B', C', D' belong to flange while the soil-cultivating tools marked with A2, B2, C2, D2 belong to flange 2, soil-cultivating tools D3 and CO belong to flanges which are not shown in the Figures.

By examining Figure 8 it can be seen that soilcultivating tools each belonging to different flanges, cross their respective fields of action in the soil; specifically soil-cultivating tool C' of flange 1 enters the field of action of soil-cultivating tools fastened to flange 2, in the same way soil-cultivating tool D2 operates in the field of action of the soil-cultivating tools of flange 1. In this way the tools are made to work in the soil at close spacings and the different angling of the various soil-cultivating tools allow soil-cultivating tools at corners A and C of each flange to lift and transfer the soil transversely in one direction, while soil-cultivating tools at corners B and D lift and transfer it transversely in the opposite direction.In this manner the soil is constantly mixed transversely and alternatively in both directions and this provokes a very fine crumbling of the clods and an optimal levelling of the soil. This action is further refined and assisted by the small angle relationship of corner portions A,B,C and D hereinbefore de scribedwith reference to Figure 7.

The tool embodying the invention hereinbefore described reaches the aim of avoiding the deformaton of the flanges in the case of an anomalous resistance in the soil. Another achievement is that no compacted layer is produced under the cultivated surface, so that the soil becomes permeable to irrigation water. One further aim is that of provoking an action of the soil-cultivating tools in the soil, such that it can be lifted, cut and transferred in a sense transverse to the direction of progress of the associated machine and that it is further treated by other soil-cultivating tools secured to adjoining flanges, which produce the same effect and which again transfer the so;id already moved transversely, in the direction opposite to the first, so as to obtain a kind of fan-like displacement and an operation which breaks the soil into very small fragments.

Another aim, and not the least one, is that of constructing an agricultural machine which is simple and economic, particularly concerning the simplicity of manufacture of the flanges and the welding thereof to the shaft.

The different orientations of the corners of each flange and, as a consequence, the different angles which the soil-cultivating tools form in relation to the vertical, combined with the spatial arrangement off-set in a helicoidal manner, give rise to working of the soil with displacement of the clods in a transverse and alternative sense in relation to the progress of the machine. Besides, the various soilcultivating tools of the flanges enter the soil at close and almost constant distances, such that a homogeneous work and clods of very small sizes are obtained.

Claims (10)

1. A rotary cultivating or tilling tool for incorporation in a machine for driving the tool, said tool comprising flanges of the same shape and size and arranged at an equal distance from one another on a shaft, on the corners of each of which soil-cultivating tools are secured, each flange having a central, annular, zone secured perpendicularly to the transmission shaft and a peripheral non-planar zone with a polygonai perimeter, the two zones being connected to one another at arcuate ribs, and diagonals passing through the corners and through the centre of gravity of the flange and the normalsto the axis of the shaft, also passing through the centre of gravity, forming angles, which are different for each corner of the flange.

2. A tool according to claim 1 wherein the flanges supporting the soil-cultivating tools take on a peripheral shape having four corner portions (A,B,C,D) each of which sequentially forms an angle of 8 , 6 , 110 and 7" with the vertical, each of these angles being defined by the straight line passing through the corner and the centre of gravity of the flange and by the normal to the axis of the shaft passing through the same centre of gravity of the flanges.

3. A tool according to claim 1 or claim 2 wherein the flanges are secured in an off-set arrangement of one in relation to the other, so that the corresponding corners belonging to two different flanges secured to the main shaft are arranged sequentially in a substantially heliciodai disposition, the corner of each flange being rotated in relation to the corresponding corner of the preceding or of the succeeding flange by an equal angle.

4. A tool according to claim 3 wherein the angle formed by corresponding corners, belonging to adjacent flanges, coincide with the angle formed by the plane containing the corner and the axis of the shaft and by the plane containing the axis of the shaft and the normal to said axis passing through the centre of gravity, is increased by substantially 27 for each flange in relation to the preceding one.

5. A tool according to any one of the preceding claims wherein the soil-cultivating tools are fastened to respective corner portions of each flange by means of three-non-aligned bolts, these soilcultivating tools having along their terminal protruding part a cutting zone and these tools being equally angled in relation to the plane containing the fastening bolts.

6. A tool according to claim 5, wherein the cutting edge of each soil-cultivating tool forms an angle (Z) of approximately 25 in relation to the median line (X) passing through two opposite corners.

7. A tool according to any one of the preceding claims, wherein the shape and the geometrical arrangement of the flanges and of the soilcultivating tools permit an incision of the soil following close lines and at a practically constant distance, each field of action of the soil-cultivating tools belonging to one flange being interested by the action of two soil-cultivating tools, one belonging to the preceding flange and the other one belonging to the flange succeeding the flange being taken into consideration.

8. A tool according to any one of the preceding claims, wherein the geometrical arrangement of the soil-cultivating tools penetrate the soil at an angle, such that the soil is moved transversely in relation to the direction of progress of the machine, such displacement occurring in one direction for half of the soil-cultivating tools and in the opposite direction for the other half.

9. A rotary cultivating or tilling tool subtantially as hereinbefore described with reference to the accompanying drawings.

10. A rotary cultivator including a rotary cultivating or tilling tool according to any one of the preceding claims.