GB2584835A

GB2584835A - Agricultural harrow

Info

Publication number: GB2584835A
Application number: GB1908256.9A
Authority: GB
Inventors: Martin Lole Christopher
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-10
Filing date: 2019-06-10
Publication date: 2020-12-23
Also published as: GB201908256D0

Abstract

An agricultural harrow 6 that preferably comprises a plurality of rows of tines 64 and is attachable to a drawbar 4, preferably through a pivotable coupling 68. The pivotable coupling may comprise a floating link assembly, preferably a planar quadrilateral linkage having four rotating joints. In a particularly preferred arrangement, one linkage (68c, Fig 6A) is pivotably fixed to the rear of the drawbar and front of the harrow, one linkage extends between two pivots on the harrow, and another linkage (68b, Fig 6A) extends from the rear of the harrow to a floating linkage attached to the drawbar by a crank (68a, Fig 6A). A pair of wheels 66 may further be connected to the harrow by means of an adjustable mounting (65a,b, Fig 7A), the mounting allowing for the position of the wheels with respect to the harrow to be varied. The drawbar may further be provided with support wheels 42 at a rear thereof. The harrow may further be connected to a trailing mower 2 by means of the drawbar.

Description

Agricultural Harrow

Field of the Invention.

The present invention relates to an improved agricultural harrow, particularly not exclusively a tine harrow that is trailed behind a tractor.

Background

A harrow is an implement for breaking up lumps of soil, breaking up crop residues, uprooting weeds and covering seed. A harrow may be attached to the rear of a tractor for pulling around a field thereby enabling large areas of vegetation to be tilled. However, the direct attachment of the harrow to the tractor can result in poor performance, with the harrow being unable to cope with the uneven ground surface.

It is beneficial to a farmer to be able to harrow large areas of land, particularly to reduce pest infestation without the use of chemicals. In this respect, turning over crop residues brings pests, such as slugs to the surface which results in their eggs being exposed to the sun, preventing them hatching. Thus, it is desirable to provide an improved trailing harrow that is able to operate effectively on very uneven ground.

Large agricultural mowers that attach behind a tractor are also well known in the art and are used for mowing large expanses of vegetation, such as agricultural fields of grass or hay, grassed areas surrounding airport runways and parkland. Generally, a drum or disc mower is attached to the back of the tractor, the mower having rotating blades, attached to a series of drums or discs, whereby the blades rotate perpendicularly to the grass to cut the grass as they spin. A protective skirt normally surrounds the blades and the rear of the mower may have a series of wheels. The mower may be provided with appropriate hydraulics to enable it to be lifted vertically behind the tractor when not in use for easy transportation behind the tractor.

These types of mower are entirely fit for purpose. However, the mowers leave the cut vegetation behind without any aeration of the soil. This can result in poor re-growth of the vegetation and may also provide conditions that favour pest multiplication and survival unless chemicals, such as pesticides, are applied to the land. It is desirable to minimise or even eliminate the use of such chemicals on the land but without a corresponding increase in pest survival.

It is the aim of the present invention to provide an improved agricultural harrow that overcomes, or at least alleviates, the abovementioned problems.

It is a further aim of the present invention to provide an improved agricultural mower that overcomes, or at least alleviates, the abovementioned problems.

Summary of the Invention

According to a first aspect of the present invention there is provided a harrow for attachment to a tractor, the harrow comprising a plurality of rows of tines, a pivotable coupling for attachment to a drawbar, and at least a pair of wheels, the wheels being attached to the harrow by an adjustable mounting to vary the position of the wheels with respect to the harrow.

According to a second aspect of the present invention there is provided a harrow and drawbar assembly for attachment to a tractor, the harrow comprising a plurality of rows of tines and at least a pair of wheels, preferably wherein the wheels are attached to the harrow by an adjustable mounting to vary the position of the wheels with respect to the harrow, the harrow being attached to the drawbar through a pivotable coupling, the drawbar having support wheels at a rear thereof.

Preferably the pivotable coupling comprises a linkage assembly having multiple pivot points. In a preferred embodiment, the linkage assembly comprises a floating linkage assembly, more preferably a planar quadrilateral linkage having four rotating joints, two being connected to the drawbar and two being connected to the harrow. In a preferred embodiment, one linkage is pivotably fixed to the rear of the drawbar and front of the harrow, one linkage extends between two pivots on the harrow, and another linkage extends from the rear of the harrow to a floating linkage attached to the drawbar by a crank. In this manner, a parallelogram arrangement is provided to allow the harrow to rise and fall independently relative to the tractor and drawbar which tow the harrow.

In a preferred embodiment, two such linkage arrangements are provided, one on each side of the central drawbar.

According to a third aspect of the present invention there is provided a combined trailing mower and harrow comprising a trailing mower having a rear hitch, a drawbar attachable to the rear hitch and a harrow attachable to the drawbar.

Preferably, the combined trailing mower and harrow according to the third aspect of the present invention incorporates a harrow and drawbar assembly according to the second aspect of the present invention.

Any suitable type of hitch may be fitted to the rear of a conventional trailing mower that is attachable to the rear of a tractor for towing. Preferably, the hitch allows pivoting about a vertical axis.

A drawbar comprising a rigid rod-like member is provided between the trailing mower and the harrow, the drawbar having a first coupling at one end thereof for attachment to the rear hitch of the mower and a second coupling at the other end thereof for attachment to the front of the harrow. Preferably, the second coupling is adapted to allow pivotable movement of the harrow with respect to the drawbar.

The trailing mower and the harrow of the present invention may be any type of a variety of existing trailing mowers and harrows adapted to enable their simultaneous towing and operation behind a tractor. Preferably, both the mower and the harrow are foldable and liftable to allow their easy transportation when not in use.

Preferably, the harrow comprises multiple rows of tines, preferably wherein multiple rows of tines are provided on two adjacent foldable wings wherein the wings may be lifted upwardly over a central portion when not in use. Preferably, the central portion of the harrow may pivot about a transverse axis of the drawbar so that the harrow with folded wings may sit on the drawbar for transportation.

The drawbar is preferably provided with a fixed rear axle having at least one wheel mounted on the axle either side of the drawbar. An upwardly extending support member may also be provided on the drawbar, spaced apart from the rear axle and the second coupling, for supporting a part of the harrow when it is folded for transportation.

In a preferred embodiment, the rod-like member of the drawbar is provided in at least two sections, preferably comprising a front and a rear section connected at a pivot point having a transverse axis, wherein an adjustable linkage is attached to the pivot point to alter the orientation of the two sections with respect to each other. Preferably, the adjustable linkage comprises a hydraulic piston. The drawbar may also be telescopically extendable to vary the distance provided between the mower and the harrow.

Preferably, the second coupling that is adapted to allow pivotable movement of the harrow with respect to the draw bar comprises a linkage assembly having multiple pivot points. In a preferred embodiment, the linkage assembly comprises a floating linkage assembly, especially a planar quadrilateral linkage having four rotating joints, two being connected to the drawbar and two being connected to the harrow. In a preferred embodiment, one linkage is pivotably fixed to the rear of the drawbar and front of the harrow, one linkage extends between two pivots on the harrow, and another linkage extends from the rear of the harrow to a floating linkage attached to the drawbar by a crank. In this manner, a parallelogram arrangement is provided to allow the harrow to rise and fall relative to the position of the mower and drawbar independently of the mower and drawbar.

Additionally, the harrow is preferably provided with at least two wheels at the front end thereof, preferably being provided equidistant from the centre of the harrow on either side thereof. It is preferable for the height of these wheels to be adjustable, for example, by attaching the wheels to the harrow by an adjustable mounting. Preferably, a bracket is attached to the harrow and an axle of each wheel is mounted on a rod which is fixable at variable positions relative to the harrow by suitable fixing means being placed manually within the bracket. However, it is to be appreciated that other types of adjustable mounting may be used and that the height of these wheels could be adjusted pneumatically or hydraulically.

It is to be appreciated that the different types of movement of the component parts of the mower, drawbar and/or harrow, such as folding, lifting, rotating etc are achieved by suitable actuation means. Preferably, hydraulic means is provided, ideally being controlled from within the tractor.

Brief Description of the Drawings

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings in which: Figure 1 is a perspective view of a combined mower, drawbar and harrow according to an embodiment of the present invention, shown in the extended position for use; Figure 1A is an expanded view of area A in Figure 1; Figure 2 is a top view of the combined mower, drawbar and harrow of Figure 1; Figure 2A is a perspective view of the combined mower, drawbar and harrow of Figure 1, shown with the mower and harrow in their folded positions for transportation; Figure 2B is a top view of Figure 2A; Figure 2C is a side view of Figure 2A; Figure 3 is a side view of the combined mower, drawbar and harrow of Figure 1; Figure 4 is a rear view of the combined mower, drawbar and harrow of Figure 1; Figures 5A to 5C illustrate different positions of a floating linkage between a drawbar and harrow according to an embodiment of the present invention; Figures 6A and 6B are expanded perspective views of the floating linkage of Figures 5A to 5B from each side of the drawbar and harrow; Figures 7 and 7A show a side view and expanded view of the drawbar and harrow illustrating an adjustable wheel of the harrow, shown in a raised position; Figures 8 and 8A show a side view and expanded view of the drawbar and harrow illustrating an adjustable wheel of the harrow, shown in a lowered position; and Figures 9A to 9C illustrate different positions of an adjustable linkage between a drawbar and harrow according to an embodiment of the present invention;

Detailed Description

The present invention provides a novel harrow and drawbar assembly for attachment to a tractor, as well as combining a conventional trailing mower with a harrow to provide a novel trailing mower and harrow combination. Preferably the harrow has multiple sets of tines wherein each set of tines is rotated on a vertical axis and tills the soil horizontally. This provides a combined machine that not only cuts the vegetation but simultaneously tills the soil and turns over the cut vegetation. This provides a number of advantages over the prior art machines that have to be towed separately behind a tractor, including scarifying the land to promote grass growth at the same time as the land is being mowed, thereby significantly reducing the overall time spent working the land. Scarification is desirable since it in enables lush, strong grass to be grown in parkland and at airports, with the latter deterring birds from landing in the area surrounding the runway. More significantly, the combined procedure can assist in reducing infestation of the vegetation with pests, such as slugs. For example, certain chemicals, such as slug bait, that are currently in use may be banned in the future for environmental reasons and thus, alternative methods need to be found to combat these pests without the use of such chemicals. Slugs are a particular problem with oil seed rape and the combination of a mower and a harrow according to the invention serves to prevent the slugs reproducing by cutting the stalks and turning over the cuttings to expose slug eggs to the sun and prevent them hatching.

It is not possible to simply attach an existing harrow to an existing mower to provide a satisfactory working machine due to the different weights of the parts and the undulating land that the parts need to be able to navigate. The present invention overcomes this problem by the provision of a drawbar between the mower and the harrow. The accompanying drawings illustrate an embodiment of a combined mower and harrow according to a preferred embodiment of the present invention.

Referring in particular to Figures 1 to 4 of the accompanying drawings, the combined system is shown comprising a trailing mower 2, a drawbar 4 and a harrow 4. The trailing mower may be any type of conventional power mower that is attachable by an appropriate coupling 21 to the rear of a tractor (not shown). For example, in the embodiment shown, the mower has blades (not visible) protected by a skirt 22, behind which are a plurality of wheels 26 on suspensions to move the mower across the land. The mower has three hinged sections 23 and hydraulic arms 25 which enable the two outer sections to be moved upwardly about the hinge 24 for storage and transportation (see, in particular Figures 2A to 2C). The mower is adapted by the provision of a rear hitch 28 (see Figure 1A) which allows attachment of the drawbar 4 and allows pivoting about an upright axis.

The drawbar 4 has couplings at either end for attachment to the hitch 28 of the mower 2 at one end and to the harrow 6 at the other end, further details of which will be described later. Additionally, the drawbar has a fixed rear axle 44 provided with two wheels 42. These support the drawbar and the harrow when it is raised for transportation (see Figures 2A to 2C). Furthermore, the wheels reduce the loading on the wheels of the mower and make the combination more stable when the mower and harrow are being transported.

A harrow 6 is attachable to the rear of the drawbar 4. In the illustrated example, the harrow has folding wings 62 each having multiple rows (five in the illustrated embodiment) of tines 64, with each of the rows being rotatable by hydraulic means about a transverse axis to enable the angle at which the tines work to be adjusted. The wings 62 are able to pivot upwardly about a longitudinal axis when not in use and the central portion of the harrow pivots around a transverse axis at the rear of the drawbar 4, thereby enabling the wings to be folded upwardly and the harrow to pivot to rest on supports 48 provided on the top of the drawbar for transportation (see Figures 2A to 2C). Pivoting is accomplished by hydraulic means which ideally are connectable to controls provided in the tractor to which the mower, drawbar and harrow are attached.

A simple single fixed or pivot attachment connecting the harrow to the drawbar does not allow the harrow to move and work effectively whilst being towed behind the tractor and mower. Therefore, a floating linkage assembly 68 is provided between the drawbar and the harrow, as illustrated in Figure 5A to 6B. The linkage assembly comprises a planar quadrilateral linkage having four rotating joints A, B, C and D, two being connected to the drawbar and two being connected to the harrow. One linkage 68c is pivotably fixed to the rear of the drawbar and front of the harrow, one linkage extends between two pivots on the harrow, another linkage extends from the rear of the harrow to a floating linkage 68b that is attached to the drawbar by a crank 68a. In this manner, a parallelogram arrangement is provided to allow the harrow to rise and fall relative to the position of the mower and drawbar independently of the mower and drawbar. A simple pivot about a transverse axis would allow the rear of the harrow to be at a different level to the front of the harrow, causing some of the tines to be lower than others resulting in unsatisfactory operation. In the preferred embodiment shown, two such linkage arrangements 68 are provided, one on each side of the central drawbar 4 (see Figures 6A and 6B illustrating different sides respectively) to allow for an amount of tilting of the harrow relative to the drawbar (and hence mower) to allow for uneven ground. The floating linkage arrangement allows the harrow to rise and fall while maintaining the orientation of the harrow as it is pulled alomng behind the mower and drawbar.

Additionally, the front of the harrow 6 is provided with adjustable depth wheels 66 which allow adjustment of the height of the tines 64 relative to ground level. In the illustrated embodiment, these depth wheels are manually adjustable (see, in particular, Figures 7, 7A, 8 and 8A) wherein each wheel axle is mounted on a rod 65a which is fixable at variable positions within a bracket 65b mounted on the harrow by suitable fixing means. Other types of adjustable settings may be provided to allow adjustment of the height of the wheels and it is to be appreciated that the height of these wheels could also be adjusted hydraulically.

A further adjustable linkage 46 is provided on the drawbar 4, see Figures 9A to 9C. A pivot point 46a having a transverse axis is provided between front and rear portions of the drawbar 4 across which is mounted a hydraulic piston 46. Adjustment of the piston enables tilting of the front portion of the drawbar with respect to the rear portion about the pivot axis, as shown in the drawings. This further improves the weight distribution between the parts of the system and allows improved movement and operation of the combined system across the land to enable efficient mowing and raking to take place.

It is to be appreciated that the actual type of mower and harrow could differ to those shown in the illustrated example, with different types of blades, mode of operation, tines and so on. However, it is important to modify the mower with a rear hitch and provide a drawbar, ideally with wheels, for supporting the harrow. A floating linkage should preferably attach the drawbar to the harrow, which may also be provided with support wheels, the depth of which may be adjustable. These adaptations provide a combined mower and harrow system having multiple benefits over the prior art machines that are towed separately behind a tractor.

In another embodiment of the present invention (not shown), only a harrow is attached to the tractor via the drawbar as hereinbefore described. Thus, the harrow and drawbar assembly shown in Figures 5A to 5C and 7A to 9C is attached directly to a tractor rather than to a mower 2. Features already described in relation to the harrow and drawbar of the combined mower and harrow apply equally to this assembly. The drawbar again comprises a rod with a rear axle supporting a pair of wheels, the drawbar having a front coupling for attachment to the ram of a tractor and a rear pivotable coupling for attachment to the front to the harrow. The pivotable coupling comprises a floating linkage assembly such as the planar quadrilateral linkage 68 illustrated in Figures 5A to 6B, with one linkage 68c pivotably fixed to the rear of the drawbar and front of the harrow, one linkage extending between two pivots on the harrow, another linkage extending from the rear of the harrow to a floating linkage 68b that is attached to the drawbar by a crank 68a. This arrangement enables the harrow to 'float independently behind the tractor and drawbar resulting in the harrow being able to operate effectively across the undulating contours of the land. The harrow may also provided with depth wheels at the front thereof which may be adjusted in height and ideally the drawbar includes the further adjustable linkage across a pivot point provided in the drawbar. This arrangement has been found to work more effectively than fastening the harrow directly to the rear of a tractor.

Claims

Claims 1. A harrow for attachment to a tractor, the harrow comprising a plurality of rows of tines, a pivotable coupling for attachment to a drawbar, and at least a pair of wheels, the wheels being attached to the harrow by an adjustable mounting to vary the position of the wheels with respect to the harrow.
2. A harrow and drawbar assembly for attachment to a tractor, the harrow comprising a plurality of rows of tines and at least a pair of wheels, the harrow being attached to the drawbar through a pivotable coupling, the drawbar having support wheels at a rear thereof.
3. The harrow and drawbar assembly as claimed in claim 2 wherein the wheels are attached to the harrow by an adjustable mounting to vary the position of the wheels with respect to the harrow.
4. The harrow and drawbar assembly as claimed in claim 2 or claim 3 wherein the pivotable coupling comprises a linkage assembly having multiple pivot points.
5. The harrow and drawbar assembly as claimed in claim 4, wherein the linkage assembly comprises a floating linkage assembly.
6. The harrow and drawbar assembly as claimed in claim 5 wherein the linkage assembly comprises a planar quadrilateral linkage having four rotating joints, two being connected to the drawbar and two being connected to the harrow.
7. The harrow and drawbar assembly as claimed in claim 6 wherein, one linkage is pivotably fixed to the rear of the drawbar and front of the harrow, one linkage extends between two pivots on the harrow, and another linkage extends from the rear of the harrow to a floating linkage attached to the drawbar by a crank.
8. The harrow and drawbar assembly as claimed in any one of claims 4 to 7 wherein two linkage arrangements are provided, one on each side of the drawbar.
9. A combined trailing mower and harrow comprising a trailing mower having a rear hitch, a drawbar attachable to the rear hitch and a harrow attachable to the drawbar.
10. The combined trailing mower and harrow as claimed in claim 9 wherein the rear hitch allows pivoting about a vertical axis.
11. The combined trailing mower and harrow as claimed in claim 9 or claim 10 wherein the drawbar comprises a rigid rod-like member provided between the trailing mower and the harrow, the drawbar having a first coupling at one end thereof for attachment to the rear hitch of the mower and a second coupling at the other end thereof for attachment to a front of the harrow, the second coupling being adapted to allow pivotable movement of the harrow with respect to the drawbar.
12. The combined trailing mower and harrow as claimed in claim 11 wherein the second coupling comprises a linkage assembly having multiple pivot points.
13. The combined trailing mower and harrow as claimed in 12, wherein the linkage assembly is a quadrilateral linkage having four rotating joints, two being connected to the drawbar and two being connected to the harrow, wherein one linkage is pivotably fixed to a rear of the drawbar and front of the harrow, one linkage extends between two pivots on the harrow, and another linkage extends from the harrow to a floating linkage attached to the drawbar by a crank thereby providing a parallelogram arrangement.
14. The combined trailing mower and harrow as claimed in claim 12 or claim 13 wherein two linkage assemblies are provided, one on either side of the drawbar.
15. The combined trailing mower and harrow as claimed in any one of claims 9 to 14 wherein the drawbar is provided with fixed rear axle having at least one wheel mounted on the axle either side of the drawbar.
16. The combined trailing mower and harrow as claimed in any one of claims 9 to 15 wherein an upwardly extending support member is provided on the drawbar.
17. The combined trailing mower and harrow as claimed in any one of claims 9 to 16 wherein the drawbar is provided in at least two sections connected at a pivot point having a transverse axis, wherein an adjustable linkage is attached to the pivot point to alter the orientation of the two sections with respect to each other.
18. The combined trailing mower and harrow as claimed in claim 17 wherein the adjustable linkage comprises a hydraulic piston.
19. The combined trailing mower and harrow as claimed in any one of claims 9 to 18 wherein at least one or both the trailing mower and the harrow are foldable and liftable to allow their easy transportation when not in use.
20. The combined trailing mower and harrow as claimed in claim 19 wherein the harrow comprises multiple rows of tines, the multiple rows of tines being provided on two adjacent foldable wings wherein the wings may be lifted upwardly towards a central portion of the harrow when not in use.
21. The combined trailing mower and harrow as claimed in claim 20 wherein the central portion of the harrow pivots about a transverse axis of the drawbar so that the harrow with folded wings rests on the drawbar for transportation.
22. The combined trailing mower and harrow as claimed in any one of claims 9 to 21 wherein the harrow is provided with at least two wheels at a front end thereof.
23. The combined trailing mower and harrow as claimed in claim 22 wherein the position of the wheels with respect to the harrow is adjustable by means of an adjustable mounting.
24. The combined trailing mower and harrow as claimed in claim 23 wherein an axle of each wheel is mounted on a rod which is fixable at variable positions by suitable fixing means within a bracket attached to the harrow.
25. The combined trailing mower and harrow as claimed in claim 9 incorporating the harrow and drawbar assembly as claimed in any one of claims 2 to 8.