GB2033192A - Soil Cultivating Device - Google Patents

Abstract

A cultivating device (1) comprises sets of tines for working soil at different respective depths. Shallow leading sweep tines (5), intermediate chisel tines (6), and deep cutting sub- soiling tines (7) allow soil to be fully cultivated to sub-soil depths in a single pass and interact to produce more uniformly divided soil. <IMAGE>

Description

SPECIFICATION Cultivating Devices This invention relates to cultivating devices.

Agricultural cultivating devices usually comprise a set of tines arranged to work soil at a predetermined depth. Mostly, such devices are used in the upper few inches of soil to be worked.

There have been proposed some cultivating devices which are arranged to work soil at a level generally below the surface. Such devices are known generally as sub-soiling devices. If a farmer wishes to cultivate his soil thoroughly, using the known devices, he has to make several passes over a given piece of land, with different successive machines. For example, he may firstly carry out deep sub-soiling with a first machine, and then carry out surface cultivating with a second machine. This is evidently a rather timeconsuming process, and also somewhat inefficient as, when the farmer makes a second pass over the land, he inevitably recompacts the sub-soiling carried out in the first pass.

The present invention is concerned with the provision of a generally improved cultivating device.

According to one aspect of the present invention, there is provided a cultivating device comprising at least two sets of tines for working soil at different respective depths.

To assist in understanding the invention and to show how it may be carried out, a preferred embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a cultivating device; Figures 2 to 5 are respective perspective views of various tines of the device; Figure 6 is a perspective view of an arrangement for mounting a sub-soiling tine of the device; Figure 7 is a diagrammatic plan view showing the arrrangement of the tines of the device; and Figure 8 is a view similar to Figure 7, but showing an alternative device.

The cultivating device 1 shown in Figure 1 comprises a frame 2 of, for example, box-section steel. The frame 2 carries arrays of tines, and is arranged to be carried on a three-point linkage of a tractor. The frame 2 is provided with retractable road wheels 3, and retractable stands 4, two of which are illustrated. The arrangement of the various tines is illustrated diagrammatically in Figure 7. A set of first sweep tines 5 is provided for relatively shallow work, and each of these tines precedes a respective second chisel tine 6, for deeper work. It will be seen that the cutter tines 6 are arranged in two rows, and a respective sweep tine 5 and chisel tine 6 is disposed behind each land wheel 3. At the rear of the frame 2 there are situated two third tines 7 for yet deeper sub-soiling work.Each of these sub-soiling tines 7 is preceded by a respected fourth cutter tine 8 for shallower work than the sub-soiling tine 7.

All of the tines are so mounted on the frame 2 as to be moveable laterally thereof. The sweep tines 5, chisel tines 6 and cutter tines 8 are secured by respective clasp assemblies 9, which are tightened in position by four nuts. Each subsoiling tine 7 is mounted by means of a special clasp assembly 10, which is shown in more detail in Figure 6, to which particular reference will be made later.

The various tines will now be described individually in more detail.

A sweep tine 5 is illustrated in Figure 2. The purpose of each of these tines is to cut through the top soil at a depth that disrupts crop residues and leaves an acceptable size of clod. Such an action increases the effective depth of the chisel tines 6 that follow. The sweep tine 5 illustrated in Figure 2 has a leg 11 which is pivotally secured to the clasp 9 by means of a load-bearing bolt 12.

Two shear pins 13 and 14 pass through holes provided in the clasp 9. The leading shear pin 13 also passes through a respective hole at the top of the leg 11, and is therefore load bearing. An alternative hole is provided in the top of the leg 11 for location of the shear pin 1 3. By this means, it is possible to adjust the angle of the leg 11 to the horizontal. The rear shear pin 14 is used as a positioning means, and may also serve as a replacement load-bearing shear pin for emergency use. Should the sweep tine 5 be subjected to excessive load, the leading shear pin 13 will break, allowing the tine 5 to pivot about the bolt 12. Once the obstruction has been cleared, the tine 5 can be reset by pivoting about the bolt 12 until the rear of the leg 11 abuts against the rear shear pin 14.The respective holes in the clasp 9 and the leg 11 are then in register, permitting the insertion of a new shear pin 13.

Mounted at the lower end of the leg 11 is a sweep carrier 1 5. This is adjustable in height on the leg 11, by means of bolts 1 6 which engage in selected ones of respective series of holes in the leg 11 and sweep carrier 1 5. The sweep carrier 1 5 carries a forwardly extending sweep point (cutting (cutting point) 17, and two lateral sweep blades 18. Both the sweep point 1 7 and the sweep blades 18 extend forwardly and downwardly, and the angles at which they are inclined are particularly important. Adjustment of these angles can be made within the ranges given below, by appropriate selection of an appropriate hole in the leg 1 for the shear pin 13.The purpose of adjustment is to allow a steeper angle in dry conditions and to allow a flatter angle in moist soil conditions to avoid a bulldozing effect. The sweep point 1 7 is symmetrically reversible, having a central portion 1 9 and two end portions 20. The leading portion 20 is inclined downwardly at an angle of substantially 250 to the horizontal, and the central portion 19 is inclined downwardly at an angle in the range of 35 to 400 to the horizontal. The sweep blades 1 8 are inclined forwardly and downwardly at an angle in the range 130 to 18 to the horizontal, and have leading edges 21 which are raked back at an angle of substantially 1350 to the forwardly extending sweep point 17. The leading edges 21 of the sweep blades 18 are bevelled, and are substantially horizontal.The selected angles for the sweep point 1 7 ensure that the tine does sufficient,work, without any marked tendency to bulldoze. The selected angles for the sweep blades 18 allow the blades to cut both through soil and let the soil slip over the blades.

It will be seen that the leading edge of the sweep point 1 7 is also bevelled, to provide a selfsharpening effect. When the sweep point 1 7 has become worn, it may be simply unbolted from the sweep carrier 15, and turned through 1 800 to provide a new leading edge. When the sweep blades 18 have become worn, they may be readily detached by unscrewing countersunk bolts 22, for replacement.

The cutter tines 8 are essentially the same as the sweep tines 5, with the omission of the sweep blades 1 8 and mounting arrangements therefor.

Thus, as seen in Figure 3, a cutter tine 8 has a leg 11, a carrier 15, and a cutting point 1 7 mounted thereon. The angles and arrangement of the cutting point 1 7 are the same as those for the sweep point 1 7 of Figure 2. The carrier 1 5 is also adjustable for height, for example, by as much as four inches, on a leg 11, as in the figure 2 arrangement. Figure 3 shows a hole 23 through which the respective load-bearing shear pin 1 3 of a clasp 9 will pass. Sweep blades are not provided on the cutter tines 8 because they would provide virtually no additional effect to the combined effect of a cutter tine 8 and a following sub-soiling tine 7.There is a tendency for soil upheaved from below to be peeled back around the legs of the sub-soiling tines 7, which are themselves designed to cut quite cleanly. Each cutter tine 8 is arranged to cause shallow shattering ahead of a respective sub-soiling tine 7, to ensure that no large clods are rolled back from the sub-soiling tine 7.

Figure 4 shows a chisel tine 6, which comprises a leg 24 and a chisel point 26 mounted thereon. The leg 24 is adapted to be secured to a clasp 9, and to this end is provided with a hole 25 for the passage of a securing bolt 12, and a hole 23 for the passage of a load-bearing shear pin 13.

The leg 24 is parabolically curved. The chisel point 26 extends forwardly and downwardly at an angle of substantially 250 to the horizontal.

Again, this angle is important. The chisel point 26 is removable and reversible, comprising two generally straight portions which meet at an angle in the centre of the point. It will be noted that the position of the chisel point 26 is not adjustable on the leg 24. This is because the working depth of the chisel tines 26 is set by the position of the frame 2 above the ground. The relative depths of the remaining tines can then be adjusted by their respective adjusting means.

A sub-soiling tine 7 is shown in Figure 5, and its method of securing is shown in Figure 6. The tine 7 comprises a leg 27 of rectangular section steel, at the foot of which are mounted a forwardly extending cutting point 28 and two lateral wings 29. The point 28 and wings 29 are mounted on a frog 30. A bevelled shin blade 31 is fitted at the front of the leg 27.

The cutting point 28 extends forwardly and downwardly at an angle of substantially 250 to the horizontal. The point 28 is not made to be reversible, but it is removable and may be moved forward from a rear position to a forward position as it becomes worn. The wings 29 are inclined in two directions. Firstly, they are inclined forwardly and downwardly at an angle of substantially 350 to the horizontal. Secondly, they are inclined laterally and downwardly from the leg 27 at an angle of substantially 300 to the horizontal. The leading edge 32 of each wing 29 is bevelled, and the front thereof is positioned intermediate the front of the leg 27 and the front of the cutting point 28. The wings 29 are thus positioned to work at about the leading edge of the leg 27, which edge is defined by the shin blade 31.The purpose of the wings 29 is to give additonal upheaval to that caused by the cutting point 28, and in addition to creating vertical fissures in the soil, to give fissures branching out at, for example, 450, by pushing out the soil laterally from the sub-soiling tine 7. Thus, there may be produced a bigger shatter pattern than if there were no wings 29 at ali, or if the wings 29 were slanted only in one plane. The wings 29 are removable for replacement as they become worn. To this end, they are secured to the frog 30 by means of countersunk bolts 33. The leading edge 32 of each wing 29 is swept back at an angle of substantially 1450 to the forward extending cutting point 28.

The leg 27 itself is raked back at an angle of substantially 70 to the vertical, to assist its progress through the soil. The shin blade 31 is removable, and may be reversed by turning it upside down, as it becomes worn.

Referring now to Figure 6, the special clasp assembly 10 for securing the sub-soiling tine 7 in position comprises both clamping and wedging arrangement, which are so arranged that the effective height of the leg 27 is adjustable. A first plate 34 is secured to the frame 2 of the device 1 by various clamping arrangements such as 35, which are not shown in great detail. The arrangement is such that the plate 34 can be adjusted in position laterally of the frame 2, but once in a desired position, it is clamped firmly in place, such that it is effectively fixed relative to the frame 2. A second plate 36 is pivotally secured to the relatively fixed plate 34, by means of a pivot bolt 37. To inhibit pivotal movement of the plate 36 relative to the plate 34 in normal use, a shear bolt 38 engages in a hardened steel bush, to secure the two plates 34 and 36 together.

A channel clamp 39 is tightened by means of bolts 40 to clamp the leg 27 in position against the plate 36. In addition, a wedge 41 is inserted in position between the plate 36 and the leg 27 to assist in holding the leg 27 in position. The leg 27 is formed with a series of holes 42 in which a bolt 43 may engage, to assist in positioning the leg 27. Screw-adjustment means for adjusting the relative positions of the plates 34 and 36 comprises a first bolt 44 which engages the plate 36 and the head of which bears against the clamp 35, and a second bolt 45 which serves to lock the bolt 44.

Various adjustments of the leg 7 are carried out as follows.

If it is desired to lower the leg 27 from the position illustrated in Figure 6, the bolt 43 is removed from its present one of the holes 42 and placed in a desired higher one of the holes 42.

The holes 42 maybe at one inch spacings, for example. The clamp 39 is then slackened by means of the bolts 40, and the wedge 42 is also slackened. The leg 27 is then free to drop downwards to its new position, when the bolt 43 abuts against the top of the plate 34 to preposition the leg 27. The clamp 39 is then retightened by means of the bolts 40, and the wedge 41 is driven into position. Evidently, the leg 27 may be raised by resting the foot of the tine 7 upon the ground and then, with the clamp 39 and the wedge 41 slackened, lowering the frame 2 relative to the leg 27.

In the event of an undue obstruction, the shear bolt 38 will be subject to overload, and will shear to allow the plate 36 and the fixed tine 7 to pivot upwardly about the bolt 37. Once the obstruction has been cleared, the arrangement can readily be reset by lifting the cultivating device 1 out of work, whereupon the plate 36 and tine 7 pivot back into a rest position in which the head of the bolt 44 abuts against the clamp 35. The holes for the passage of a new shear bolt 38 should then be in register, to allow for ready replacement. Any necessary adjustment of the relative positions of the plates 34 and 36, to bring the respective holes into register, can be carried out by adjustment of the bolt 44 and locking bolt 45.

It may be appreciated that the 1 arrangement illustrated in Figure 6 provides a convenient means by which the position of the respective sub-soiling tine 7 may be readily adjusted to suit prevailing conditions. We have found it extremely important to carry out sub-soiling cultivation at the correct depth. In the past, we have found that farmers have tended to use sub-soiling tines as deep as possible, thinking that this would provide the best results. However, we have found that this is not the case, and additionally may constitute a significant waste of power. Thus, it is important to be able to adjust the depth of a sub-soiling tine in a ready manner. Another feature of the arrangement shown in Figure 6 for mounting the tine 7 is that both toe-in and camber may be provided to assist in the behaviour of the tine 7 in the soil.

Briefly, the device 1 is used as follows.

Firstly, it is necessary to determine the soil profile, by, for example, digging a pit or augering.

Then, there may be determined the depths at which it is necessary for the sub-soiling tines 7 and chisel tines 6 to operate. As explained above, the working depth of the chisel tines 6 determines the clearance of the frame 2 from the ground.

Knowing this clearance the sub-soiling tines 7 are then adjusted to their respective depths, as are the sweep tines 5 and cutter tines 8. Usually, the sweep tines 5 and cutter tines 8 will be adjusted to work the top four inches of soil.

Once the various tines have been adjusted to their correct relative positions, the frame 2 is lowered into its correct position, usually by means of the hydraulics of a tractor which is drawing the device 1. The land wheels 3 are adjusted in position to assist in taking the weight of the device 1. The device 1 is then drawn through the ground. The sweep tines 5 cut through the top soil at a depth that disrupts crop residues and leaves an acceptable size of clod, retaining the naturally developed tilth. The sweep tines 5 increase the effective depth of the chisel tines that follow. The cutter tines 8 cause shallow shattering ahead of the sub-soiling tines 7, to ensure that no large clods are rolled back from the sub-soiler blade.

Th.chisel tines 6 work under the top soil, breaking the soil by putting it under tension with minimum draught. They re-arrange the soil particles without bringing clods to the surface, and increase the effective depth of the sub-soiling tines that follow. The sub-soiling tines 7 cause a larger shatter pattern upwards and outwards from the foot of the tines. Shatter tends to occur first along the lines of natural fissures, then along the lines of weakness which in subsequent years will appear as natural fissures, resulting in an open soil structure eventually.

It should be appreciated that, as the device 1 is being drawn through the land, the effects of the individual tines interact to produce an overall effect which is considerably improved over the effect of successive passes through the land with tines of different type. A particular advantage is that work on the land can be completed in a single pass, saving cost and time, and recompacting of soil which has already been cultivated. It will be appreciated that each set of tines assists the progress of the set of tines behind it. That is, the sweep tines 5 reduce the ground resistance to the chisel tines 6, which in turn reduce the ground resistance to the subsoiling tines 7.In this way, considerably less power is required to draw the machine through the ground than the total of the individual powers which would be required to draw three successive machines through the land, in an attempt to achieve a similar result.

We have found that the use of cultivating device 1 as illustrated leads to greatly improved soil structure, controlled particle size, and better drainage and usage of water. As mentioned above, the tilth tends to be protected, and there is little tendency for clods to be formed. In view of the generally greatly improved soil condition which can be achieved with the cultivating device 1, correspondingly improved crop yields may be obtained.

It will be appreciated that, in the illustrated device 1, all wearing parts are readily removable for replacement. If it is desired to provide a substanially level finished surface, then levelling tines may be fitted at the rear of the frame 1.

The modified device illustrated diagrammatically in Figure 8 is generally similar to the device shown in Figures 1 to 7, but is of smaller dimensions and configuration. For example, where the device shown in Figures 1 to 7 may be three metres wide, the device shown in Figure 8 may be two metres wide. The device of Figure 8 has a frame 2, on which are mounted five sweep tines 5, four chisel tines 6, and one subsoiling tine 7. It will be noted that, for convenience, a sweep tine 5 rather than a cutter tine 8 is used to precede the sub-soiling tine 7.

Adjustable land wheels 3 are provided.

By way of a typical example, in the cultivating device 1 of Figures 1 to 7, and in the alternative device of Figure 8, the sweep and cutter tines 5 and 8 may work at depths between 3 and 5 inches, the chisel tines 6 may work at depths between 8 and 12 inches, and the sub-oiling tines 7 may work at depths between 14 and 24 inches.

Claims (37)

Claims

1. A cultivating device comprising at least two sets of tines for working soil at different respective depths.

2. A device according to claim 1, having a set of first tines for relatively shallow work and a set of second tines for deeper work and each preceded by a respective first tine.

3. A device according to claim 2, wherein the first and second tines are arranged to work at depths respectively in the ranges 3 to 5 inches and 8 to 12 inches.

4. A device according to claim 2 or 3, having at least one third tine for yet deeper work preceded by a respective fourth tine for shallower work than the third tine.

5. A device according to claim 4, wherein the third and fourth tines are arranged to work at depths respectively in the ranges 14 to 24 inches and 3 to 5 inches.

6. A device according to any preceding claim, including a frame on which the tines are mounted in rows.

7. A device according to claim 6, wherein at least some of the tines are adjustable in position laterally of the frame.

8. A device according to any preceding claim, wherein at least some of the tines are of adjustable depth.

9. A device according to any preceding claim, wherein at least some of the tines are mounted about respective pivot points and are secured by respective shear pins.

10. A device according to at least claim 2, wherein each first and/or fourth tine has a forwardly extending cutting point having a leading portion which is inclined downwardly at a first angle to the horizontal and a following central portion which is inclined downwardly at a second angle to the horizontal.

11. A device according to claim 10, wherein said first angle is in the range 350 to 400 and said second angle is substantially 250.

12. A device according to claim 10 or 11, wherein each first and/or fourth tine further carries lateral sweep blades which are inclined forwardly and downwardly at a third angle to the horizontal and have leading edges which are raked back at a fourth angle to the forwardly extending cutting point.

13. A device according to claim 12, wherein said third angle is in the range 130 to 180 and said fourth angle is substanially 1350.

14. A device according to at least claim 10, wherein said cutting point is removable and reversible.

1 5. A device according to at least claim 12, wherein said sweep blades are detachably mounted.

1 6. A device according to at least claim 2, wherein each second tine comprises a curved leg on which a forwardly extending cutting point is detachably mounted.

17. A device according to claim 15, wherein the cutting point of each second tine is inclined downwardly at an angle of substantially 250 to the horizontal.

18. A device according to 1 6 or 17, wherein the cutting point of each second tine is removable and reversible.

1 9. A device according to at least claim 4, wherein the or each third tine comprises a leg at the foot of which are mounted a forwardly extending cutting point and two lateral wings.

20. A device according to claim 19, wherein the cutting point of the third tine is inclined downwardly at an angle of substantially 250 to the horizontal.

21. A device according to claim 19 or 20, wherein the cutting point of the third tine is removable and may be moved forward to compensate for wear.

22. A device according to at least claim 19, wherein each of said wings is inclined forwardly and downwardly at an angle of substantially 350 to the horizontal and is inclined laterally and downwardly from the leg at an angle of substiantially 309 to the horizontal.

23. A device according to at least claim 19, wherein each of said wings has a leading edge which is swept back at an angle of substantially 1450 to the cutting point of the third tine.

24. A device according to at least claim 19, wherein the leg is provided with a leading bevelled shin blade which is removable and reversible.

25. A device according to at least claim 1 9, wherein the leg is raked back at an angle of substantially 70 to the vertical.

26. A device according to at least claim 19, where in the front of the leading edge of each said wing is positioned intermediate the front of the leg and the front of the cutting point of the third tine.

27. A device according to at least claim 19, wherein each said wing is detachably mounted.

28. A device according to at least claim 19, wherein the leg is secured in position by clamping and wedging arrangements, so as to be adjustable in height.

29. A device according to claim 28, wherein means for securing the leg in position comprises a first member which in use is fixed relative to the device, a second member which is pivotally secured to the first member, a shear bolt for securing the second member to the first member to inhibit relative pivoting therebetween, a clamp for clamping the leg to the second member, and a wedge for wedging the leg in position in the second member.

30. A device according to claim 29, comprising screw-adjustment means for positioning the second member relative to the first member for the replacement of said shear bolt.

31. A device according to at least claim 19, wherein means for securing the leg in position provides for toe in and/or camber of the leg.

32. A device according to any preceding claim, adapted for towing behind a tractor.

33. A device according to any preceding claim, provided with land wheels.

34. A device according to claim 33, wherein at least one tine is disposed behind each land wheel.

35. A device according to any preceding claim, provided at the rear thereof with levelling tines for providing a substantially level finished surface.

36. A cultivating device substantially as hereinbefore described with reference to Figures 1 to 7, optionally as modified by Figure 8, of the accompanying drawings.

37. A method of cultivating land, comprising drawing through the land a device according to any preceding claim.