GB2053634A - Agricultural subsoiling tool - Google Patents

Abstract

An agricultural subsoiler tool for breaking up and aerating the subsoil without bringing it to the surface. It comprises a leg portion 1 for extending downwards from a mounting frame and penetrating into the ground, and a tapering foot portion 2 having a downwardly sloping top surface extending forwardly of the leg portion, the top surface in use being inclined at an angle of 15 DEG to 30 DEG to the horizontal. One or more of the subsoiler tools can be suspended from a frame having points for attachment to a tractor forward of the tool or tools. Such an assembly may be combined with a cultivator. The invention also includes an adjustable framework, for example for providing adjustable depth wheels on an agricultural implement. <IMAGE>

Description

SPECIFICATION Agricultural subsoiling tool This invention relates to an agricultural subsoiling tool. A subsoiler is an agricultural implement for breaking up and loosening the subsoil as an aid to drainage and aeration, but without bringing subsoil (e.g. large stones, solid lumps of clay) to the surface.

Conventional subsoilers are mounted on a single beam frame which can be attached to the back of a tractor. The subsoiler tool itself comprises a leg which in use penetrartes into the ground. At the bottom of the leg is a short tapered foot portion with a pointed end and a sloping top surface. In use, the subsoiler tool is pulled through the soil with the foot portion facing forwards. One problem with known subsoilers is that a very powerful four-wheel-drive tractor is needed to pull them, owing to the resistance of the ground to the passage of the tool. I have now discovered that this high resistance is caused largely by the passage of the vertical leg portion of the tool through ground that has not already been loosened by the foot. My new subsoiler overcomes this problem by ensuring that the subsoil has been largely broken up before the leg portion reaches it.

According to one aspect of this invention I provide an agricultural subsoiler tool, comprising a leg portion for extending downwards from a mounting frame and penetrating into the ground, and a tapering foot portion having a downwardly sloping top surface extending forwardly of the leg portion, the top surface in use being inclined at an angle of 15"to 300 to the horizontal.

The angle between the top surface of the foot portion and the horizontal is preferably about 20 .

The distal end of the foot portion is preferably curved downwards to assist in penertation of the foot portion into the ground.

Certain working surfaces of the foot and leg portions are particularly prone to wear, and these surfaces are preferably on replaceable wear members.

Thus, the leg portion preferably has a replaceable tapered leading edge, the whole of the distal end of the foot portion is preferably detachable and thus replaceable, and the foot portion preferably also includes a replaceable shoe plate providing an upper wear surface on the foot portion. The working surfaces of these wear members may be ceramic coated.

The total length of the subsoiler from the back of the leg to the tip of the foot is preferably from 26 to 40 inches, more preferably about 32 inches. This contrasts sharply with conventional subsoilers, where the total length is only about 12 to 14 inches.

Moreover, in a conventional subsoiler the angle between the top surface of the foot and the horizontal is only about 10 .

According to a further feature of the invention, I provide a subsoiler assembly comprising a frame, means on a forward portion of the frame for attachment to the rear of a tractor, and at least one sub- soilertool according to the invention depending from a rearward portion of the frame with its foot portion facing towards the tractor. The subsoiler assembly preferably includes two or more subsoiler tools laterally spaced apart. Where there are three or more, these may for example be in line, or arranged on a chevron with the point of the chevron facing forwards.

The frame preferably includes horizontal transversely and longitudinally-extending beams. The use of a frame which is attachable to the tractor well ahead of the subsoiler tool or tools as opposed to a frame which comprises only a single transverse beam which is both attachable to the tractor and carries the subsoiler tools, is that it ensures that the distal end of the foot portion is clear of the tractor wheels. The arrangement according to the invention also improves the traction of the tractor.

According to another feature of the invention, I provide an adjustable framework comprising a pair of members pivotally attached together, wherein each of the members is fixed to one of a pair of plates and the two plates are connected by a fastener device freely slideable in both slots to permit releative pivotai and sliding movement between the plates, the fastener means being operable to prevent further relative movement between the plates and thus to fix the members in a desired configuration relative to one another.

In one embodiment, one of the members is part of a frame of an agricultural implement, and the other member is an arm carrying a ground-engaging wheel. Thus, the height of the ground wheel relative to the frame can be adjustably set as desired.

The fastener means is preferably a nut and bolt, and the bolt can be tightened to claimp two plates together when the ground wheel is at the desired height relative to the frame. The agricultural implement may, but need not be, a subsoiler assembly as described herein.

The subsoiler assembly according to the invention may be combined with a cultivator of known type, such as a cultivator fitted with flexitines and spring tiens. The cultivator is fixed behind the subsoiler assembly and smoothens out the ground after the subsoiler assembly has passed.

Embodiments of the invention are described below by way of example and with reference to the accompanying drawings in which: Figures 1,2 and 3 show a subsoilertool according to the invention in side elevation plan, and front elecation, respectively, Figure 4 shows in perspective a subsoiler assembly having two subsoiler tools, Figure 5 shows in perspective a subsoiler assembly having five subsoiler tools, Figure 6 shows in side elevation an adjustable framework which allows adjustment of the height of the subsoiler assembly relative to the groundengaging wheels, Figure 7 shows in plan part of a subsoiler assembly having five tools, in combination with a cul The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy.

tivator, and Figures is a side elevation of the combination shown in Figure 7.

The subsoiler tool shown in Figures 1 to 3 comprises a strong leg portion 1, the upper end of which is fixed to a frame unit (see Figure 4) by shear bolts so that the leg portion projects vertically downwards from it. Integral with the bottom part of the leg portion 1 is a forwardly-projecting tapered foot portion 2 with a sloping top surface. The direction of travel of the tool through the soil is indicated by the arrow 3 in Figure 1. The wear surface portions of the tool are replaceable and comprise a tapered cutting member 4 for the leading edge of the leg portion, a shoe plate 5 for the top surface of the foot portion 2, and a toe member 6 for covering and projecting beyond the forward end of the foot portion 2. The toe member 6 has a slightly down-turned leading edge 12.

The shoe plate 5 projects laterally beyond the foot portion 2, and the top-parts of the shoe plate 5 and the toe portion 6 are aligned to form a continuous upper working surface. The cutting member4 locates on a pin 7 projecting vertically upwards from the rear of the foot portion 2, and is held in place by a fixing pin 8 having a bent-over top end, and a cotter pin 9, arranged on either side of a small plate 31 welded to the leg portion. The toe portion 6 is fixed to the foot portion 2 by means of a dowell pin 10 rather than by bolts, which tend to become damaged.

The shoe plate 5 is located by the rear upper part of the toe portion 6 and by the bottom ofthe cutting member 4. The leg portion 1 is bolted to a subsoiler frame by means of the four holes 11 using shear bolts (not shown) which can break if the tool encounters an immovable obstacle such as a large rock, thus preventing further damage to the equipment.

The angle X between the horizontal base 13 of the foot portion, and the surface formed by the top of the toe portion 6 and the shoe plate 5, is 20 . This angle X, which can in fact be varied between 15 and 30 to suit different types of soil (the heavier the soil, the smaller must be the angle) is much greater than in conventional subsoilertools where the angle is usually only about 10 . The foot portion is furthermore much longer than in conventional subsoilers. With this design, the soil is lifted and broken up by the toe portion and the top surface of the shoe plate before the vertical leading edge of the leg portion reaches it.

The resistance of the soil to the movement of the tool is thus greatly reduced, so that the subsoiler assembly can be pulled behind a much less powerful tractorthan can conventional ones (the tractor may be up to one-third less powerful) and, furthermore, a four-wheel-drive tractor is no longer essential.

Figure 4 shows a subsoiler assembly 13 fitted with two of the subsoiler tools of the type illustrated in Figures 1 to 3. This comprises a frame which is gen erally rectangular in plan, and includes rearward, intermediate, and forward transverse beams 14, 15, and 16 respectively. The rearward and intermediate transverse beams 14, 15 are relatively close together and the subsoiler tools are suspended from between them. The forward transverse beam unit 16 com prises attachment points 32 which enable it to be fixed to the conventional 3-point hitch on the rear of a tractor (not shown). The arrow 17 shows the direction of travel.

The subsoilertools are aboutfourfeet apart and are arranged to penetrate to a depth of about 18 to 20 inches into the ground. Subsoiling is often carried out with this arrangement prior to ploughing, for example in the case of a field which has been used to graze animals anywhere the soil has thus become highly compacted.

Figure 5 shows a generally similar subsoiler assembly 13', except that it comprises only forward and rearward transverse beams 16', 14' respectively, and that it is fitted with five subsoiler tools. These are hung from the rearward transverse beam 14', and this is V-shaped so that the subsoiler tools are in chevron formation, with the centre tool 1', leading.

The arrow 17' shows the direction of travel. The tools are spaced about 2 feet apart, and the stagger in the direction of travel between adjacent tools is about 9 inches.

The assemblies shown in Figures 4 and 5 can be fitted with height-adjustable ground-engaging depth wheels, to ensure that the subsoiler tools do not penetrate too deeply into the ground. One depthwheel unit according to the invention is shown in Figure 6, which shows the depth wheel in its lowermost position in full lines, and in its uppermost position in broken lines. This comprises a supporting arm 18, one end of which is pivotally connected to a lateral beam 19 of an assembly 13 or 13'. The other end of the arm 18 carries a rotatable groundengaging depth wheel 20.

Rigidly fixed to the arm 18 and extending upwards at right angles to it a longitudinally-slotted plate 21 having a bolt 22 which is free to slide in the slot. This bolt, which is fitted with a nut (not shown) passes through the slot in a second plate 23 which is rigidly fixed relative to the frame member 19. The plates 21 and 23 are thus joined together by the bolt 22, but can slide and pivot relative to one another. Thus, the height of the wheel relative to the assembly 13 or 13' can be adjusted between its two extreme positions shown in the drawing by pivoting the suspension arm 18 about its pivot on the frame member 19, the plates 21 and 23 pivoting and sliding relative to one another to permit such movement of the wheel. The wheel is locked in the desired position simply by tightening up the nut on the bolt 22, thus locking the plates 21 and 23 togther.

The subsoiler assembly shown in Figure 5 is specially suited for use with a cultivator unit as shown in Figures 7 and 8. The cultivator unit 24, which incorporates a pair of depth wheels 33, is pivotally attached to each side of the assembly 13' by means of a parallel linkage 25 which allows relative vertical movement, but not angular displacement, between the cultivator unitandthesubsoiler assembly. This is controlled by a single-acting hydraulic jack 26.

This jack allows the cultivator unit to "float" relative to the subsoiler assembly, i.e. to ride up and pass over any irregularities on the ground over which it is travelling, but prevents it from penetrating more deeply into the ground than a desired depth, which can be preset on the cultivator's depth wheels 33.

The cultivator unit comprises two rows 27, 27' of flexitines 28, and the tines 28 in the two rows are staggered. Behind the two rows of flexitines 28 is a single row 29 of spring tines 30. Both flexitines and spring tines are well known. The fiexitines are of heavier gauge metal and are intended to work below the surface of the soil, e.g. about four inches below ground level. The spring tines are ofthinnerspring- ier steel and are not intended to penetrate below the surface.

In the case of a combined subsoiler and cultivator, the subsoiler tools are preferably about two feet apart and are arranged to penetrate the soil to a depth of about 12 to 16 inches. Subsoiling alone would leave the field rough and uneven, but the addition of a cultivator with flexitines penetrating to about 4 inches, followed by spring tines working on the surface, results in a smooth surface which is ready for drilling without further treatment. However, the use of a subsoiler penetrating as deep as 12 to 16 inches is bet ter forthe ground in the long term than conventional modern pre-drilling treatments which do not penetrate so deeply.

Claims (17)

CLAIMS:

1. An agricultural subsoiler tool, comprising a leg portion for extending downwards from a mounting frame and penetrating into the ground, and a tapering foot portion having a downwardly sloping top surface extending forwardly of the leg portion, the top surface in use being inclined at an angle of 15"to 300 to the horizontal.

2. An agricultural subsoiler tool according to Claim 1, wherein the said angle is 20 .

3. An agricultural subsoiler tool according to Claim 1, wherein the distal end of the foot portion is inclined downwardly relative to the remainder of the foot portion.

4. An agricultural subsoiler tool according to Claim 1, including a detachable tapered wear member on the leading edge of the plate, and wherein the foot portion includes a detachable shoe plate and a detachable distal end portion, the top surfaces of the shoe plate and the distal end portion forming a continuous wear surface.

5. An agricultural subsoiler tool according to Claim 1, having a total length of 26 to 40 inches, from the back of the leg portion to the distal end of the foot portion.

6. An agricultural subsoiler assembly, comprising a frame, means on a forward pdrtion of the frame for attachment to the rear of a tractor, and at least one subsoiler tool according to Claim 1 depending from a rearward portion of the frame with its foot portion facing towards the tractor.

7. An agricutural subsoiler assembly according ta Claim 6, including two or more subsoiler tools laterally spread apart.

8. An agricultural subsoiler assembly according to Claim 7, including three or more subsoiler tools arranged in line or in a chevron with the point of the chevron facing forwards.

9. An adjustable framework comprising a pair of members pivotally attached together, wherein each of the members is fixed to one of a pair of plates having a slot, the two plates being connected by a fastener means freely slidable in both slots to permit relative pivotal and sliding movement between the plates, the fastener means being operable to prevent further relative movement between the plates and thus to fix the members in a desired configuration relative to one another.

10. An adjustable framework according to Claim 9 wherein one of said members is part of an agricultural implement frame, and the other of said members carries a ground-engaging wheel.

11. An adjustable framework according to Claim 10, wherein said agricultural implement is an agricultural subsoiler assembly according to any of Claims 6 to 8.

12. An agricultural subsoiler assembly according to any of Claims 6 to 8, in combination with a cul tivatorfastened behind it and arranged to smoothen the ground over which the subsoiler assembly has passed.

13. An agricultural subsoiler assembly according to Claim 12, wherein the cultivator includes at least one row of flextines arranged to work beneath the surface of the ground, and at least one row of spring tines arranged to work on the surface of the ground.

14. An agricultural subsoiler assembly according to Claim 1, wherein the cultivator is attached to the frame by a linkage which allows relative vertical movement but not angular displacement between the cultivator and the subsoiler assembly, the linkage being controlled buy a single action hydraulic jack which allows the cultivator to ride up over surface irregularities, but not to penetrate into the soil deeper than a pre-set depth.

15. An agricultural subsoiler tool, substantially as hereinbefore described, with reference to Figures 1 to 3 ofthe accompanying drawings.

16. An agricultural subsoiler assembly, substantially as hereinbefore described, with reference to Figure 4, or FigureS, or Figures 7 and 8 of the accompanying drawings.

17. An adjustable framework, substantially as hereinbefore described, with reference to Figure 6 of the accompanying drawings.