GB2047062A - Tined soil working implement - Google Patents

Abstract

A tined soil working implement includes a rotary clod breaker(s) arranged behind tines (3, 4) to break open clods of earth formed by the tines. <IMAGE>

Description

SPECIFICATION Tined soil working implement This invention is concerned with soil cultivation, and relates particularly to a tined soil working implement.

One particular kind of tined soil-working implement used in cultivation is known as a "cultivator/ subsoiler". It comprises a frame which is towed behind a tractor, the frame carrying leading and trailing tines which dig into and lift the soil. The leading tines, which are known as "cultivators", operate at a relatively shallow depth of, for example, between 10 cms and 20 cms, whereas the trailing tines, known as "subsoilers", work at a depth of, for example, between 35 cms and 55 cms. The precise working depth of the various tines will be selected according to the type of soil, its moisture content etc.

and may on occasion be outside the ranges quoted above. As the tines lift the soil they create a considerable downward force on the frame of the implement, this force being supported by a pair of wheels at the back of the implement and by the tractor coupling point at the front of the implement.

After use of a cultivator/subsoiler, the worked soil may have large clods of earth which must be broken up, and this is conventionally achieved by towing further implements over the soil. A first implement to be towed over the soil may be cambridge rolls which consist of a number of rings about 8 cms.

wide which are freely rotatable on an axle. The rings rotate as they roll on the soil and they crush the clods. A second implement to be towed over the soil may be a spring-tired harrow which disturbs the crushed clods to produce soil suitable to be worked by a rotary cultivator prior to the seeding.

Thus, after an initial pass over the soil with a tractor towing a cultivator/subsoiler, two subsequent passes of the tractor are necessary towing other implements before the soil is ready for rotary cultivation.

It is an aim of the invention to provide a tined soil working implement which may avoid the necessity for the use of cambridge rolls and spring-tined harrows, and with this aim in view the invention provides a tined soil working implement which includes a rotary clod breaker arranged behind the tines to break open clods of earth formed by the tines.

Thus, by means of an implement according to the invention, clods are broken ratherthan being merely crushed as when cam bridge rolls are used.

Preferably, the clod breaker serves as a support for the implement, whereby the breaker is forced downwardly in use not only by gravity, but also by the downward force on the tines produced as the tines lift soil. In this case, the clod breaker may avoid entirely the need to provide conventional wheels, and the downward force needed to break the clods is generated by the tines.

Best clod breaking action is achieved if the clod breaker has clod breaking members comprised by plates having relatively narrow working edges able to cut into clods, the plates at an angle of between 20 and 40 relative to the radial as explained below.

The diameter of the breaker may be between 60 cms and 65 cms.

The tines may be of the kind used in conventional cultivator/subsoiler implements.

Desirably, each clod breaking member extends transversely for a distance at least equal to the distance between outermost tines.

In order that the present invention may be more readily understood, a preferred embodiment of a tined soil working implement according to the invention will now be described by way of example and with reference to the accompanying drawings in which Figure lisa plan view from above of the soil working implement; Figure 2 is a side view of the implement of Figure 1; Figure 3 is a perspective view of a clod breaker forming part of the implement of Figures 1 and 2; and Figure 4 is a view showing the approximate path of a single blade of the clod breaker of Figure 3 as the blade breaks a clod.

The implement shown in Figures 1 and 2 is similar to a known cultivator/subsoiler with the important difference that in place of wheels that support the known implement, the implement in the drawings is supported by a clod breaking device which is shown in detail in Figure 3.

The implement is designed to be towed behind a tractor in the direction of the arrow land comprises a main frame 2, mounting leading tines 3, trailing tines 4, and a clod breakerS. As best seen in Figure 1, the frame 2 consists of a pair of outer longitudinal frame members 6,7 extending parallel to the direction of the arrow 1, a pair of transverse frame members, 8, 9 extending between and connecting the outer longitudinal frame members, and a pair of inner longitudinal frame members 10, 11, disposed one on each side of the longitudinal centre line of the implement and connected to the two transverse frame members 8, 9. The frame members are welded to one another.

The frame member 8 carries three of the leading tines 3, whilst the frame member 9 carries six of the leading tines 3. These nine leading tines are known as "cultivators" and in use of the implement they operate in the soil at a depth of between 10 cms and 20 cms. There are two trailing tines 4, one mounted on the rear end of each of the frame members 10 and 11. The two trailing tines are known as "subsoilers" and they operate in the soil at a depth of between 35 cms and 55 cms. The front end of the implement has three points for connecting to a tractor, two of the points 12, 13, being disposed one on each of the frame members 10, 11, and the third point 14 being disposed at the top of a braced upright 15. The parts of the implement described above are similar to known cultivator/subsoilers.

However, in place of the conventional pair of wheels used on known implements, the implement shown in the drawings is supported by a clod breaker 5 mentioned above. As best seen in Figure 3, the clod breaker has an axle 16 on which a number of discs 17 are welded. There are four of the discs 17 equally spaced apart along the axle, with one disc near each end of the axle. Each of the discs has eleven equally spaced slots extending inwardly a short distance from the periphery of the discs. The slots in the four discs 17 are aligned with one another when viewed in a direction parallel to the axle 16 to provide eleven rows of slots, and eleven clod-cutting members in the form of plates 18 of oblong cross-section are disposed one in each row of slots and welded to the discs.

It can be seen from Figure 2 that the slots in the discs and thus the plates 18 are not disposed radially, each plate slanting at an angle x relative to a radial line extending through the plate. The clod breaker will, in use, rotate in the direction of arrow 19, and the direction in which each plate slants relative to the radial is such that each plate reaches a generally vertical position just before it reaches a lowermost position. This means that when a plate is in its lowermost position, it slants upwardly towards the front of the implement.

The axle 16 of the clod breaker is rotatably mounted by a pair of arms 20 which are pivotally connected at 21 one to the rear end of each longitudinal frame side member 6, 7. The angle which the arms 20 make with the frame members 6, 7, can be selectively varied by means of screw jacks 22. A lower end of each screw jack is pivoted to a bracket 22 fast on an arm 21, and the screw passes through a female threaded collar (not shown) mounted on a braced arm 23 welded to the frame 2.

Operation of the implement is as follows. The implement is hitched behind a tractor by means of its three connecting points. Then, in order to determine the depth at which the nine leading tines operate, the two screw jacks 21 are operated to swing the arms 20 up or down as required. The rear end of the implement is supported on the ground by way of the clod breaker 5, so that if the arms 20 and thus the breaker 5 are swung downwardly, the frame 2 will be raised from the ground and the tines 3 will operate at a shallower depth. The two subsoiler tines 4 are then adjusted to operate at the required depth in any suitable manner. For example, the leg 24 of each tine 4 may be arranged to slide in a fixed guide, and the end of leg 24 may have a series of vertically spaced holes 26. A bolt may then be passed through a selected hole 25 to bolt the leg 24 to a bracket fast on the frame 2.

The implement is then towed behind the tractor in the direction of arrows 1 over soil to be cultivated.

The tines 3 and 4 lift the soil and this creates a considerable downward force on the clod breaker 5 which runs over the soil behind the tines. The breaker is not power driven, but rotates due to its contact with the soil.

The soil lifted by the tines will have clods, and these clods are broken very effectively indeed by the clod breaker. It may well be that the soil will be ready for working by a rotary harrow after a single pass of the soil working implement shown in the drawings so that the need to use cambridge rolls and a spring tined harrow is avoided.

The effectiveness of the clod breaker may possibly be due to the twisting motion which the plates 18 undergo as they break a clod. Figure 4 shows successive positions of a single plate 18 as it enters and breaks a clod of earth 40. The plate 18 enters the clod from the right hand side of the Figure and exits towards the left hand side. The narrow edge of each plate 18 cuts into a clod rather like a blade, and the twisting motion then breaks the clod open.

Tests have shown that the slant anglexofthe plates is quite important, and that best results are achieved if the angle xis between 20 and 40 , the range 25 to 35 being preferably, and the angle 30 optimum. The preferable distance between plates is between 15 cms and 21 cms, between 17 cms and 18 cms being optimum. This means that the clod breaker shown in the drawings and having eleven plates will have diameter of about 62 cms. However, the diameter of the breaker is not particularly critical, and the diameter may be, for example between 45 cms and 80 cms. The number of plates will usually be chosen to give the preferred plate spacing of between 15 cms and 21 cms.

The above quoted figures relating to the breaker diameter, the number of plates, and the plate slant angles are given by way of example only, and it may be that values falling outside the ranges quoted might be necessary in certain types of soil, or when the size of clod produced by the tines requires a differently dimensioned breaker.

The implement described above uses "cultivator" tines and "subsoiler" tines but it should be understood that other types of tine can be used. The described implement has tines working at two depths, but the tines could instead work at, for example, five different depths, the tines working progressively deeper towards the rear of the implement. In this latter case, the clods produced may tend to be rather small, in which case the clod breaker might also be smaller, with plates closer together than 15 cms.

It will be noted that the traditional method of dealing with clods is to crush them by, for example, cam bridge rolls. In contrast to this, the device 5 tends to break open the clods, even if the clods are wet.

The term "tine" used in the following claims includes any soil working element producing clods.

It has been assumed above that the implement is to be towed behind a tractor. However, it is within the scope of the invention to provide the implement with its own engine. It is also within the scope of the invention to provide wheels for at least partly supporting the frame, in which case the breaker would engage the clods under the action of its own weight only, or with its weight augmented by the force generated by the tines. The breaker could be power driven.

The shape of the members 18 should be chosen to exert the action described where the members break the clods open by a twisting movement. Thus, it is believed that if the members 18 were not plates, but were bars of round or square cross-section, they would not be as satisfactory as the plates described.

The embodiment of invention described has one other important advantage not mentioned above.

When a conventional cultivator/subsoiler is towed behind a tractor, it often happens that one of the supporting wheels will drop into a hole or rut. This will cause the tines to suddenly dig deeper into the soil than intended, so that the tine shear bolts may go, or the implement will need more force to pull it.

However, because the clod breaker 5 spans the whole width of the tine array, it cannot drop into a hole or rut as a tyre would. Thus, a greater consistency of tine depth is achieved so that there will be no sudden peak loads on the tines or on the tractor.

Finaily, Figure 4 may show only an approximation of the true path of each plate 18. The reason for this is that, because the breaker digs into the soil, it may effectively roll on a smaller diameter than its actual diameter. Thus, each plate 18 may possibly execute a looping action in the soil, actually (for a short time) moving backwardly relative to the direction of arrow 1.

Claims (20)

1. A tined soil working implement which includes a rotary clod breaker arranged behind the tines to break open clods of earth formed by the tines.

2. An implement according to claim 1, in which the clod breaker serves as a support for the implement, whereby the breaker is forced downwardly in use not only by gravity, but also by the downward force on the tines produced as the tines lift soil.

3. An implement according to claim 1 or claim 2, in which the clod breaker has clod breaking members extending transverse to the direction of towing.

4. An implement according to claim 3, in which the clod breaking members comprise plates.

5. An implement according to claim 3 or claim 4, in which the clod breaking elements have relatively narrow working edges which tend to cut into clods rather than to crush them.

6. An implement according to claims 4 and 5, in which the plates are of oblong cross-section, with a narrower edge of each plate serving as a working edge to cut into a clod.

7. An implement according to claim 4, or any claim appendent to claim 4, in which the plates slant at an angle (marked x in Figure 2), which angle x is between 20 and 40 .

8. An implement according to claim 7, in which the angle xis between 25 and 35 .

9. An implement according to claim 8, in which the angle x is approximately 30 .

10. An implement according to claim 4, or any other claim when appendentto claim 4, in which the spacing between adjacent plates is between 15 cms and 21 cms.

11. An implement according to claim 10 in which the spacing between plates is between 17 and 18 cms.

12. An implement according to claim 4, or any other claim when appendentto claim 4, in which the diameter of the clod breaker is between 45 and 80 cms.

13. An implement according to claim 12, in which the clod breaker has a diameter between 60 cms and 65 cms.

14. An implement according to any one of claims 3 to 13 in which each clod breaking member extends transversely for a distance at least equal to the distance between outermost tines.

15. An implement according to any preceding claim, in which the tines include cultivator tines.

16. An implement according to any preceding claim, in which the tines include subsoiler tines.

17. An implement according to any preceding claim, in which the tines are mounted on a frame, and in which the clod breaker is rotatably mounted by a pair of arms carried by the frame.

18. An implement according to claim 17, in which the pair of arms are pivotally connected to the frame, and in which means are provided for varying the angle of the arms relative to the frame for controlling tine working depth.

19. An implement substantially as described herein with reference to the accompanying drawings.

20. For an implement according to claim 1, a clod breaker substantially as described herein with reference to the drawings.