GB2345627A

GB2345627A - Disc harrow

Info

Publication number: GB2345627A
Application number: GB9825710A
Authority: GB
Inventors: Kenneth Frederick Taylor; Anthony Gent
Original assignee: Knight Farm Machinery Ltd
Current assignee: Knight Farm Machinery Ltd
Priority date: 1998-11-25
Filing date: 1998-11-25
Publication date: 2000-07-19
Also published as: GB9825710D0

Abstract

A disc harrow having a frame supporting first and second (leading 3 and trailing 4) rows of soil cultivating discs in mutually opposed orientation and with each row divided into mutually opposed halves, characterised by an additional opposed pair of discs 6 disposed at or adjacent to the centre line between the opposed halves of the rows, which cultivate the soil between the halves of the rows. Each half of each row may be arranged at an angle to form an "X" configuration (figure 3) or arranged to form a "V" configuration (figure 8). There may be press rolls 9 to consolidate the soil and a tine 10 to cultivate soil along the centreline of the harrow. Several shapes of disc maybe used (figure 10).

Description

TITLE: DISC HARROW DESCRIPTION TECHNICAL FIELD The invention relates to soil cultivators for use in agriculture and more particularly to disc harrows.

BACKGROUND TO THE INVENTION Following the harvesting of a crop it is then necessary to cultivate the soil prior to planting of the next crop. Typical cultivation operations are ploughing, harrowing and sub-soiling, and one form of harrowing is disc-harrowing, which can be used for primary cultivation, i. e. the first operation to break the ground after harvesting the crop, or for secondary cultivation.

It is known for a disc harrow to comprise leading and trailing rows of discs, with the discs in the front or leading row opposing the discs in the rear or trailing row whereby soil moved laterally in one direction by a disc in the front row is moved laterally in the opposite direction by a corresponding but opposed disc in the rear row, and with each row divided into opposed halves about a longitudinal centre line of the harrow, and in which halves the discs are disposed to move soil in mutually opposed directions. In such a disc harrow, the forces acting to move the harrow laterally in use are, as far as is practicable, balanced so that the harrow is not deflected sideways.

Another form of disc harrow is known and comprises leading and trailing rows of discs arranged in a Vformation and with the discs in the leading row arranged to move soil laterally in one direction and the discs in the trailing row arranged to move soil laterally in the opposite direction.

According to one aspect the invention is a disc harrow having a frame supporting first and second (leading and trailing) rows of discs in mutually opposed orientation and with each row divided into mutually opposed halves, characterised by an opposed pair of discs disposed at or adjacent to the centre line between the opposed halves of the rows.

The pair of discs may be arranged side by side or may be disposed wholly or partly one behind the other. Where the discs are side by side, a further cultivating device, e. g. a tine, may be positioned at the centre line. The further cultivating device may be positioned immediately behind the said pair of discs. Each disc may overlap the said centre line. The pair of discs may be disposed in front of the leading row of discs, or alternatively one or both of the pair of discs may be disposed between the leading and trailing rows of discs.

The disc harrow may comprise discs with deep cut-outs in their peripheral edge to improve soil penetration. A press-roll may be provided in the same frame as the disc harrow. This may assist in preventing leaving the soil in an open and cloddy condition and avoids the requirement for a separate cultivation operation. In addition the weight of the press on the frame stabilises the disc harrow and acts both to improve soil penetration by the discs and as a depth control.

The press roll may be detachable from the frame and in this case depth control means, e. g. land wheels, may be provided between the leading and trailing rows of discs.

One advantage of depth control means in this position is that, unlike transport wheels, they can be of a wide track to improve the stability of the apparatus.

Any or all of the discs may be adjustable for depth and/or angling and/or for axial position. The press roll (s) may be adjustable for depth and/or for axial position.

From another aspect the invention is a disc harrow having a frame supporting at least one row of soil cultivating discs and at least one press roll integral with the frame. Any or all of the discs may have deep cut-outs in their periphery to aid soil penetration.

The disc harrow may include leading and trailing rows of discs. The rows of discs may be disposed in a Vformation. The press roll may be detachable from the frame in which case depth control means may be provided between the leading and trailing rows of discs.

The invention is diagrammatically illustrated, by way of example in the accompanying drawings, in which: Figure 1 is a side view of a first embodiment of disc harrow of the present invention in a folded, inoperative, position; Figure 2 is a side view of the disc harrow of Figure 1 in an unfolded, operative condition ; Figure 3 is a plan view of the disc harrow of Figure 1 in the operative position; Figure 4 is a rear view of the disc harrow of Figure 1 in the operative condition; Figure 5 is a rear view of the disc harrow of Figure 1 in an inoperative folded condition; Figure 6 is a side view of a second embodiment of disc harrow of the invention in a folded, inoperative position; Figure 7 is a side view of the disc harrow of Figure 6 in an unfolded operative condition; Figure 8 is a plan view of the disc harrow of Figure 6 in its operative condition; Figure 9 is a schematic diagram showing six different arrangements for the discs of a disc harrow in accordance with the present invention, and Figure 10 illustrates four different forms of disc for a disc harrow in accordance with the invention.

In the drawings, and referring more particularly to Figures 1 to 5, a disc harrow 1 comprises a frame 2 having a front end 12 formed with a tow bar 11 by which the disc harrow can be trailed behind an agricultural tractor (not shown). The frame 2 carries leading and trailing rows, 3,4 respectively, of harrow discs 5 each of which is a dished member mounted for rotation on an axle 14.

The leading and trailing rows 3,4 of discs are each divided into opposed halves 7,15 respectively about the centre line 16 of the disc harrow (see Figure 3) with the respective axles 14 in each half row disposed at an obtuse angle relative to one another and with each of the halves in the front row at an acute angle with respect to the corresponding half in the trailing row whereby the respective rows together define an X'configuration.

A pair of transport wheels 8 which might also be used for depth control are retractably mounted on the frame 2 behind the rows of harrow discs and at the rear end 13 of the frame 2 is integrally mounted a double interleaved row of press rolls 9 to consolidate soil cultivated by the harrow discs. The integral press rolls also add weight to the frame which in turn adds stability to the disc harrow and provides a degree of depth control.

An additional opposed pair 6 of harrow discs is disposed at the front 12 of the frame so as to be positioned in front of the leading row 3 of harrow discs and symmetrically about the centre line 16 of the frame to improve cultivation at the centre position. Further to improve the cultivation at the centre position a cultivator tine 10, best seen in Figures 1 and 2, is positioned on the centre line 16 of the frame immediately behind the additional pair of cultivator discs 6. If desired more than one pair of additional discs and/or more than one tine may be provided.

As shown in the drawings, the frame of the disc harrow is folded for storage and transport, but it will be appreciated that a fixed frame device is also possible.

Additional depth control wheels 17 can be mounted between the leading and trailing rows of discs and mounted on foldable parts of the frame at a wide spacing, compared to the transport wheels, to assist the stability of the harrow in use. Such additional depth control wheels might also be useful if, for any reason, the disc harrow were used with the press rolls removed.

In Figures 6 to 8 of the drawings there is shown an embodiment of disc harrow 1'comprising a frame 2 having a front end 12 formed with a tow bar 11 by which the disc harrow can be trailed behind an agricultural tractor (not shown). The frame 2 carries leading and trailing rows, 3,4 respectively, of harrow discs 5 each of which is a dished member mounted for rotation on an axle 14, with the respective rows arranged in a V-formation and with the discs in the leading row arranged to move soil laterally in the opposite direction to those of the trailing row.

Additional depth control wheels 17 can be mounted on the foldable part of the frame in front of the respective trailing ends of the leading and trailing rows of discs and thus at a wide spacing compared to the transport wheels to assist the stability of the machine. Such additional depth control wheels might be useful if, for any reason, the disc harrow were used with the press rolls removed. As shown, the frame of the disc harrow is folded for storage and transport, but it will be appreciated that a fixed frame device is also possible.

Referring to Figure 9 the disposition of the harrow discs in the arrangement of Figures 1 to 5 is substantially as shown in arrangement'A'. If desired one of the discs in the pair of discs 6 may be arranged slightly ahead of the other disc in the pair to minimise any lateral gap between the discs. The lateral gap between the discs in the pair 6 may be completely eliminated by adopting the arrangement shown at C'in which the discs in the pair are disposed substantially one behind the other and each overlapping the other to cover the mid position. In such an arrangement, the need for the tine 10 may be eliminated.

As shown in arrangement D'the pair of discs 6 may be disposed between the leading and trailing rows 3,4 of discs. Alternatively as shown in arrangement E'one of the pair of discs 6 may be disposed in front of the leading row 3 and the other of the pair of discs 6 may be disposed between the rows 3,4. If desired two pairs of the additional discs may be provided, e. g. as shown in arrangement F'.

Figure 10 illustrates four different forms of concave disc including a plain disc of circular configuration, a notched disc having a periphery formed with a number of cut-out portions, a lobed disc having a periphery formed as a plurality of convexly curved portions and a so-called flail in which the periphery of the disc is formed with deep notches.

The invention thus provides a disc harrow of improved cultivation capability both in terms of evenness of cultivation and in terms of providing cultivation by way of disc harrowing and, if desired, by way of press rolling in one machine.

Claims

CLAIMS 1. A disc harrow having a frame supporting first and second (leading and trailing) rows of soil cultivating discs in mutually opposed orientation and with each row divided into mutually opposed halves, characterised by an additional opposed pair of discs disposed at or adjacent to the centre line between the opposed halves of the rows.
2. A disc harrow according to claim 1, wherein the additional discs are arranged side by side or are disposed wholly or partly one behind the other.
3. A disc harrow according to claim 2, wherein the additional discs are side by side and comprising a further cultivating device, e. g. a tine, positioned at the centre line.
4. A disc harrow according to claim 3, wherein the further cultivating device is positioned immediately behind the said additional pair of discs.
5. A disc harrow according to any preceding claim, wherein each disc in the additional pair overlaps the said centre line.
6. A disc harrow according to any preceding claim, wherein the additional pair of discs is disposed in front of the leading row of discs, or alternatively one or both of the pair of discs is disposed between the leading and trailing rows of discs.
7. A disc harrow according to any preceding claim, wherein any or all of the discs comprise deep cut-outs in their peripheral edge to improve soil penetration.
8. A disc harrow according to any preceding claim, comprising a press-roll integral with the frame.
9. A disc harrow according to claim 8, wherein the press roll is made removable from the frame, and comprising depth control means between the first and second rows of discs.
10. A disc harrow having a frame supporting at least one row of soil cultivating discs and at least one press roll integral with the frame.
11. A disc harrow according to claim 10, wherein any or all of the discs have deep cut-outs in their periphery to aid soil penetration.
12. A disc harrow according to claim 10 or claim 11, wherein the disc harrow includes leading and trailing rows of discs.
13. A disc harrow according to claim 12, wherein the press roll is detachable from the frame and comprising depth control means between the leading and trailing rows of discs.
14. A disc harrow substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.