GB2191375A - Subsoiler - Google Patents

Abstract

A tine (10) for a subsoil cultivator comprises a depending leg (20) fitted with a shin (22) and point (28). At the heel of the leg there is a pair of wings (34) which are pivotable about respective bolts (36) between a raised substantially horizontal position which they adopt when the leg is travelling through the soil and a substantially vertical position which they adopt when the tine is being lifted out of the soil. The displacement movement is caused solely by the shape and orientation of the wings and soil pressure against them. Subsoil is therefore not brought to the surface when the tine is raised. <IMAGE>

Description

SPECIFICATION Agricultural implements This invention relates to a tine for use with an agricultural implement, and also to agricultural implements incorporating or equipped with such tines. The invention is particularly concerned with sub-surface cultivators, and more particularly with the design and construction of tines for such cultivators which are used to break up compacted soil and sub-surface pans.

Existing sub-surface cultivators are known which have fixed wings at the heel of each tine. Such cultivators have the disadvantage that when the tines are lifted from the soil at the headland the projecting wings lift up the subsoil to the surface as the tines are raised, thereby bringing clods or subsoil to the surface and causing lumps of subsoil to be deposited on the surface. Not only are these clods and lumps of subsoil difficult to break down, but it is also extremely undesirable to deposit subsoil on the surface where new seeds or plants are to be planted. Lifting of subsoil to the surface is particularly undesirable if one wishes to carry out sub-surface cultivation of grassland where it is important that the grass is left relatively undisturbed and should not have subsoil deposited on it.

It is an object of the present invention to overcome this problem and to provide a tine for a sub-surface cultivator which, in use, will not lift subsoil to the surface when the cultivator is raised and the tine is lifted out of the soil.

It is a further object of the present invention to provide a sub-surface cultivator, especially for use in grassland, which avoids the ripdamage which can occur with conventional sub-surface cultivators which have fixed wings.

It is yet another object of the present invention to provide a tine for agricultural implements, especially sub-surface cultivators, which is provided with a novel design of wing such that the implement can be lifted out of work with minimum soil heave.

In accordance with the present invention there is provided a tine for use with an agri cuitural implement, the tine comprising a leg which has the lower portion thereof arranged to travel through the soil, wherein the lower portion of the leg is fitted with a wing extending to each side of the leg and displaceable in dependence upon the forces exerted upon them in use.

Preferabiy, the wings on each side of the tine are displaceable between a substantially horizontal position which they adopt when the leg is travelling through the soil and a substantially vertical position which they adopt when the tine is lifted from the soil.

The wings are preferably pivotable through about 90 from a raised attitude when the tine is performing its cultivating function to a downwardly extending attitude when the tine enters and leaves the soil.

It is an important preferred feature of the invention that each wing is pivotable about a pivot axis which extends at an inclined angle to the vertical plane which includes the direction in which the tine travels. The axes of pivotal movement preferably also lie at an inclined angle to the horizontal when the leg is performing its cultivating function. By virtue of the angled pivots each wing "unfolds" as the tine enters the soil. Soil flow then holds the wings out until forward movement ceases.

Lifting causes the wings to fold back parallel to the leg.

With the tine of the present invention the displaceable wings hang substantially vertically until contact is made with the soil, whereupon they move outwards and upwards into a substantially horizontal attitude in work, in which position they are able to break and shatter compacted layers of soil. As the tine is lifted out of the soil the wings are forced to return to their vertical position and are therefore unable to bring clods or subsoil to the surface.

In order to ensure that the wings will move up to the raised attitude as the tine is lowered into the soil, the leading edge portion of each wing is preferably suitably shaped so that an upward force is exerted on each wing by the soil as the tine enters the soil. This can be achieved for example by chamfering the underside of the leading edge portion of each wing and/or by appropriately tapering the leading edge of the wing from root to tip.

The underside of the leading edge portion of each wing may be provided with suitable projecting means, either integral with the wing or secured to the wing, such as a wedge, which will generate a lifting force and ensure that the wings are raised to the working attitude as soon as they enter the soil.

The tine is preferably rearwardly angled, in use, i.e. so that the bottom of the tine is positioned rearwardly of the top of the tine.

The actual shape and configuration of the wings, and the orientation of the wings, will be determined by various factors, some of which are dependent upon the particular operative conditions under which the agricultural implement is to be used. However, these considerations do not affect the broad principle of the present invention which is the provision of displaceable wings on the tine or tines.

The displaceable wings are preferably, although not necessarily, provided at the heel of the leg. Alternatively, one could for example position the wings forward from the heel of the tine to a position substantially midway along the foot of the tine. The present invention is also not limited just to a simple pivotal movement of the wings, but is intended also to include embodiments of tine in which the wings have a more complex pattern of movement and are displaceable between their operational attitude and their inactive attitude through a more complex path.

One presently preferred embodiment of tine in accordance with the invention will now be described by way of example and with reference to the accompanying drawings, in which: Fig. 1 is a side view of the tine, shown clamped to a cultivator toolbar; Fig. 2 is a schematic exploded view of the tine; Fig. 3 is a front view of the tine with the wings shown in their raised, working attitude; Fig. 4 is an underneath plan view of a slightly modified tine, with the wings shown in their raised, working attitude; and, Fig. 5 is a rear view of the tine with the wings shown in the attitude which they adopt as the tine is lifted from the soil.

Referring first to Fig. 1 of the drawings, there is shown a tine, indicated generally at 10, which is mounted by means of shear bolts 12 to a clamping plate 14 which is coupled by bolts 16 to a box-section toolbar 18 of an agricultural implement, especially a sub-surface cultivator. The mounting mechanism for the tine may incorporate means to permit swivelling of the tine relative to the clamp.

As will be appreciated from Fig. 1, the tine 10 is designed to travel from right to left as shown in Fig. 1, which means that the tine 10 is rearwardly angled, i.e. the bottom of the leg of the tine is positioned rearwardly of the top of the leg so that the longitudinal axis 11 of the leg of the tine extends downwards and rearwards from the mounting plate 14.

As shown most clearly in Fig. 2, the tine comprises a leg portion 20 which is provided adjacent to its upper end with holes to receive the shear bolts 12. A replaceable shin 22 is bolted to the leading edge of the leg 20 in order to assist in cutting through the soil. The shin 22 is made of an appropriate hard-wearing material and is replaceable. At the bottom of the leg portion 20 is a foot portion 24 which projects forwardly from the leg portion and which is provided with bolt holes 26. A point 28 which is replaceable and self-sharpening is fitted over the projecting portion of the foot 24 and bolts 30 are used to connect the point 28 to the foot 24. The point 28 is shaped to assist in breaking up the sub-surface soil.The heel portion of the foot 24 is provided with recesses 32 which are dimensioned to receive projecting portions of a pair of wings 34 which, as can be seen most clearly from Figs. 3 and 4, are positioned one at each side of the tine. The wings 34 are secured in place on the foot of the tine by bolts 36 which serve as pivot bolts and define the axes of pivotation for the respective wings. In the embodiment shown in Fig. 2 the pivot axes 37 of the bolts 36 are parallel to the vertical plane which includes the direction A in which the tine travels. However, the pivot axes 37 of the bolts 36 lie at a small angle of downward forward inclination to a line extending perpendicular to the main longitudinal axis 11 of the leg 20. In use, as will be apparent from Fig. 1, the axes of pivotation 37 of the bolts 36 lie at an angle of about 30 to the horizontal.The wings 34 are each pivotable about the bolts 36 through approximately 90" from a raised position when the tine is travelling through the soil, downwards and backwards to a substantially vertical, backwardly angled position, as shown in Figs. 1 and 5, when the tine is out of the soil or is being lifted from the soil.

In order to ensure that the wings 34 adopt the correct attitude during the various phases of use of the agricultural implement, the leading edge portions of the wings are appropriately shaped and constructed to achieve that effect. In particular, in order to ensure that the wings move up from a downward attitude to a raised attitude as the tine is lowered into the soil at the beginning of cultivation, the underside of the leading edge portion of each wing 34 is preferably chamfered or tapered or otherwise shaped so that as the wing enters the soil there is a force exerted upwards in a direction which assists the lifting of the wing up into its raised attitude. The underside of the leading edge portion of each wing 34 is preferably rounded or chamfered at an angle of the order of 30 in order to achieve this effect.In a preferred construction, the upper side of the leading edge portion of each wing 34 is also tapered, again preferably at an angle of the order of 30 , as indicated at 38 in Figs. 1, 2 and 3. One can alternatively, or additionally, provide a projecting wedge 40 (Fig. 4) or rib or other deflector at the underside of each wing 34, at its leading edge portion, in order to assist in the deflection movement of the wings. As shown in Fig. 4, the wedges 40 are here positioned over the outer half of each wing, viewed from root to tip, and extend rearwardly of each wing over about 75% of the wing width. The wedges 40 may be tapered or otherwise shaped to achieve the necessary lifting force. Such projecting wedges or ribs or other deflectors can be an integral part of the wing or designed to be bolted on or otherwise secured to the wing. The wings 34 may also be tapered from root to tip and/or vary in thickness from root to tip. Moreover, although the wings 34 are shown in the drawings, as in Fig. 4, as extending substantially at 90 to the direction of advance A, and in alignment with the leg axis 11, the wings may alternatively be swept back in "delta" fashion.

Fig. 4 shows a slightly modified arrangement for the mounting of the wings 34 on the foot 24 of the tine. Here, the axes of pivotal movement as defined by the bolts 36 do not extend parallel to the direction of advance A of the tine, but lie at an angle of inclination to that direction. As will be seen from Fig. 4, the projecting portions of the wings 34 which are provided with the bolt holes are appropriately angled so that the bolts can be fitted through the foot and wings to lie at an angle of the order of 10-15 to the direction of travel A. This angled pivotal mounting of the wings again assists in the displacement movement of the wings into their raised attitude, in work.

In use, as mentioned above, as the tine 10 is lowered into the soil, so the configuration and orientation of the wings will cause the soil beneath the wings to force them up into a raised attitude. When the tine is travelling forward through the soil the force which is exerted by the soil on the tines, in motion, holds the wings back and up and maintains them in their raised attitude. When the agricultural implement is brought to a standstill at the headland for example, and the tine is lifted from the soil, the upward force exerted by the soil on the underside of the wings will be reduced and the force exerted downwards on the upper surface of the wings will be increased, thus causing the wings to pivot downwards into their vertical attitude, as shown in Fig. 5, enabling them to be withdrawn from the soil without dragging the subsoil up with them.

Although the wings are shown in the drawings as being pivotable about simple pins or bolts 36, any alternative method of securing the wings to the tine may be used which will permit the wings to execute a displacement movement appropriate to give the desired result.

The tines of the present invention are of heavyduty, rigid construction and the shins 22, points 28 and wings 34 are all replaceable. The tines can be used in multiples on an appropriate toolbar, or used singly. The tines of the present invention are particularly appropriate for working at depths of 20-40cm (8-16 inches).

Claims (16)

1. A tine for use with an agricultural implement, comprising a leg which has the lower portion thereof arranged to travel through the soil, wherein the lower portion of the leg is provided with at least one wing on each side of the leg and displaceable in dependence on the forces exerted upon them in use.

2. A tine as claimed in claim 1, in which the wings are displaceable between a raised position which they adopt when the leg is travelling through the soil and a substantially vertical position which they adopt when the tine is lifted from the soil.

3. A tine as claimed in claim 1 or 2, in which the wings are pivotally movable.

4. A tine as claimed in claim 3, in which each wing is pivotable through substantially 90".

5. A tine as claimed in claim 3 or 4, in which each wing is displaceable about a pivot axis which extends at a forwardly outwardly inclined angle to the vertical plane which includes the direction in which the tine travels.

6. A tine as claimed in any of claims 3 to 5, in which each wing is displaceable about a pivot axis which lies at a forwardly downwardly inclined angle to the horizontal when the leg travels forward through the soil.

7. A tine as claimed in any of claims 3 to 6, in which each wing is displaceable about a pivot axis which extends at a forwardly downwardly inclined angle to a line perpendicular to the longitudinal axis of the leg.

8. A tine as claimed in any preceding claim, in which the leading edge of each wing is chamfered on its upper and/or lower side.

9. A tine as claimed in any preceding claim, in which each wing is provided on its underside with deflector means.

10. A tine as claimed in claim 9, in which the deflector means comprises a wedge at the outer end of the wing.

11. A tine as claimed in any preceding claim, in which the wings are provided at the heel of the leg.

12. A tine as claimed in any preceding claim, which includes a replaceable shin and a replaceable point fitted to the leg.

13. A tine as claimed in any preceding claim, arranged in use to be angled rearwardly so that the lower end of the leg is rearward of the upper end of the leg.

14. A tine substantially as hereinbefore described with reference to the accompanying drawings.

15. An agricultural implement fitted with one or more tines as claimed in any preceding claim.

16. An agricultural implement as claimed in claim 15, which is a subsoil cultivator.