GB2135162A - Seed placement and covering device - Google Patents

Abstract

A seed placement and covering device 10 for use in stubble-bearing soil and other uncultivated soil comprising a roll 12 for forming corrugations in the soil and an inclined helical-coll roller 14 for sidewardly displacing soil from the resulting ridges over seed deposited in the troughs by a conventional seed-broadcasting mechanism 13. The roll 12 differs from a conventional Cambridge roll in having powered cutter sections 16 (Figs. 2, 3, not shown) to cultivate and clear the furrow bottoms. Other devices for forming the corrugations are also described. <IMAGE>

Description

SPECIFICATION Seed placement and covering device The present invention relates to a seed placement and covering device.

Recent work broadcasting seed grain on uncultivated stubble and then lightly harrowing or rotovating the soil to cover the seed has produced encouraging results. However, existing systems for carrying out this work are unreliable in that the seed depth varies from the optimum value to zero.

Historically, horse ploughs produced narrow well set-up furrows so that the broadcast grain was channelled into the vee formed in the lea furrow bottoms. A good coverage of this seed was achieved by harrowing slightly diagonally along the line of the furrow. The success of this method of sowing can be attributed to the fact that the well-formed furrows trapped the seed and the diagonal harrowing gave good seed coverage without disturbance.

Currently there is a interest in reducing the amount of cultivation required for cereal growing and the present invention seeks to achieve this objective whilst at least to some extent retaining the advantages of the traditional method described above. Towards this end, the present invention comprises a seed placement and covering device comprising means for forming stubble-bearing soil and other uncultivated soilinto corrugations so that the majority of the seed broadcast over the soil will fall into the troughs so formed, and means for levelling the intervening soil ridges over the seed contained in the troughs thereby to give a substantially even seed coverage.

Conveniently, the corrugation-forming means comprises a Cambridge roll modified by the inclusion of powered cutting sections to cultivate and clear the furrow bottoms.

Conveniently, the cutting sections are separated by unpowered rolling sections adapted to form the ridge crests.

Conveniently, the powered and unpowered sections of the modified roll are contra-rotating. Alternatively, the powered sectons may rotate in the same direction as the unpowered sections but at a different, e.g. greater, speed.

Conveniently, the cutting sections have peripheral blades co-operating with one another two form soil ridges between adjacent cutting sections.

In one such embodiment, successive ones of the cutting sections have alternately right and left handed throw blades only, so that if one cutting section displaces soil to the right, say, its neighbour will displace soil to the left.

In an alternative embodiment, successive blades on each of the cutting sections are of right and left-handed throw so that if one blade displaces soil to the right, say, the neighbouring blades on the same section will displace soil to the left.

In alternative embodiments, the corrugationforming means comprises cutting sections e.g. with successive blades of each of the cutting ections of right and left-handed throw, and adjacent cutting sections are separated by vertically-extending party tion means. In operation of these embodiments, soil thrown against the partition means by the rotating cutting sections, slides down the partition means to form ridges between the troughs created by the cutting sections.

If desired, the shaft on which the various sections are mounted may be segmented or articulated for wide sowings.

The seed may be broadcast by any suitable commercially available mechanism e.g. a seed hopper floored with a contra-rotating double roller seed distributor mechanism as used by Ransomes Norsten or Sisis, or, as an alternative, any other seed drill with the delivery pipes suitably modified.

To achieve good seed covergage, soil movement at right angles to the direction of sowing and travel is desirable. For this purpose traditional methods of seed covering, usually based on some form of folowing tine or harrow, are inefficient.

According to a preferred feature of the present invention, however, suitable sideways soil movement is achieved by including in the device a soil-engaging roller formed as a single start helical coil. When towed behind a seeder with its shaft at right angles to the direction of travel, each pitch of the helical coil roller will make contact with the ground art a slight angle to the direction of travel, thus moving soil slightiy sideways to cover seed while at the same time levelling and rolling the soil surface.

Preferably, but not necessarily, the helical coil roller is arranged with its shaft at a slight angle e.g.

at about 18 to the width direction of the device thereby to increase the angle of each roller to the contacting soil and give a greater movement of soil than would otherwise be achieved. Other angles preferably within the range 10 -20 , may be used instead however.

Conveniently, the helical coil roller comprises two separate roller sections of opposite hand arranged on opposite sides of the centre-line of the device.

Conveniently, these two roller sections are interchangeable so as in operation each to move soil towards or away from said centre-line, as the case maybe.

Alternatively, or additionally, the device may, if desired, include means for powering the helical coil roller, this also serving to increase soil movement.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic plan view of a preferred embodiment of the invention; Figure 2 is a rear view (on an enlarged scale) of the soil preparation unit used in the embodiment of Figure 1; Figure 3 is a similar part-sectional view of an alternative embodiment; and Figures 4 and 5 are schematic plan and rear views of yet another embodiment.

Thus referring first to Figure 1, a seed placement and covering devic 10 comprises a corrugationforming roll 12 followed by a seed-broadcating mechanism 13 and a helical-coil levelling roller 14.

Details of alternative designs of roll 12 are appa rent from the scrap views of Figures 2 and 3 which each show two of the powered cutter sections 16 mounted on the driven shaft 19 of the roll.

In the embodiment of Figure 2, these sections 16 are made from a standard roll section gouged out to form cutting blades (not shown) on the periphery whereas in the embodiment of Figure 3, sections 16 are made by attaching generally triangular shape blades round the periphery of a plain disc.

In the embodiment of Figure 2, successive powered sections 16 will have alternately right and left-handed throw blades only so that in operation each section 16 displaces soil in the opposite direction to its neighbour so as to form a soil ridge between them. In the embodiment of Figure 3, on the other hand, successive blades on each section 16 are alternately of right and left-handed throw so as to displace soil first to one side and then to the other side of that section.

Conveniently, in either case, each blade lies at about 45 to the plane containing the tip of that blade and the rotation axis ofthe roll.

It is to be understood that if desired, the embodiment of Figure 2 can be modified to have the alternate throw blades of the Figure 3 embodiment.

Equally the embodiment of Figure 3 can be modified to have each section 16 displacing soil in one direction only as above described with reference to Figure 2.

Adjacent cutter sections 16 are separated by pairs of smaller-diameter ridge-forming sections 21, 22 free to freewheel on shaft 19 and bevelled to continue the tapering edges of the cutter sections 16.

The resulting ribbed contour of the soil surface is shown at 24.

The direction of rotation of shaft 19 is normally against the rolling motion of the free-wheeling sections 21, 22. However, if desired, the drive to sections 16 can be reversed so as to drive them in the same direction as sections 21, 22 but at a different, e.g. greater, speed.

Although if desired, the rotation axis of the helical coil levelling roller 14 can lie at right angles to its direction of travel A, in accordance with a preferred feature of the invention this axis is inclined at a small angle to the width direction ofthe device 10 e.g. at 18 degrees as shown in Figure 1. This increases the amount of sideways soil movement produced by roller 14.

The roller 14 is normally ground driven.

Reference numeral 13 in Figure 1 indicates any suitable commercially available mechanism for broadcasting the seed e.g. a seed hopper floored with a contra-rotating double-roller seed-distribution mechanism as used by Ransomes Norsten or Sisis or, as an alternative, any other drill with the delivery pipes suitably modified.

Although dimensions are not critical, the plan view of Figure 1 is roughly to scale and the sowing width of the device 10 is typically about 3,000 mm. A typical forward speed in average soil conditions might be about 2 metres per second in which case the shafts of items 12 might be driven at around 100 r.p.m. Clearly, however, these operational figures are only by way of example and may be varied at will to suit the conditions pertaining at the time.

Figures 4 and 5 show a third embodiment of the same or roughly the same size and operational characteristics as the embodiments of Figures 1,2 and 3.

In this third embodiment, the cutter sections 16 are similar to those of Figure 3 in so far as each is of alternately right and left-handed throw, but the free-wheeling roll sections 21 and 22 have been replaced by vertical stationary partition plates 26 positioned between and to the rear of the cutter sections as can be seen from Figure 4.

In operation of this last embodiment, the cutter sections 16 are driven so as to rotate with the direction of travel of the machine and the soil thrown backwards and sidewardsto either side of the angled cutter sections 16 hits and slides down the dividing plates 26 to form the crests of the corrugations 24. As before, reference numerals 13 and 14 indicate a suitable broadcasting mechanism and levelling roller.

it will be appreciated that in operation of all the embodiments described above, the vast majority of the seed broadcast over the soil will fall into the troughs formed by the corrugated-forming means and only a very small proportion will fail to reach the troughs.

Claims (22)

1. A seed placement and covering device comprising means for forming stubble-bearing soil and other uncultivated soil into corrugations so that the majority of the seed broadcast over the soil will fall into the troughs so formed, and means for levelling the intervening soil ridges over the seed contained in the troughs thereby to give a substantially even seed coverage.

2. A device as claimed in Claim 1 in which the corrugation-forming means comprises a Cambridge roll modified by the inclusion of powered cutting sections to cultivate and clear the furrow bottoms.

3. A device as claimed in Claim 2 in which the cutting sections are separated by unpowered rolling sections adapted to form the ridge crests.

4. A device as claimed in Claim 2 or Claim 3 in which the powered and unpowered sections of the modified roll are contra-rotating.

5. A device as claimed in Claim 2 or Claim 3 in which the powered sections of the modified roll are arranged to rotate in the same direction ae the unpowered sections but at a different speed.

6. A device as claimed in any of Claims 2 to 5 in which the cutting sections have peripheral blades co-operating with one another two form soil ridges between adjacent cutting sections.

7. A device as claimed in Claim 6 in which successive ones of the cutting sections have alternately right and left-handed throw blades only.

8. A device as claimed in Claim 1 in which the corrugation forming means comprises a rotary member having cutting sections with adjacent cutting sections separated by vertically-extending partition means.

9. A device as claimed in Claim 6 or Claim 8 in which successive blades on each of the cutting sections are of right or left-handed throw.

10. A device as claimed in any of Claims 6 to 9 in which the blades subtend an angle of about 45 to the plane containing the tip of that blade and the rotation axis of the roll or other rotary member.

11. A device as claimed in any preceding claim in which the shaft on which the segments are mounted is segmented or articulated for wide sowings.

12. A device as claimed in any preceding claim including means for broadcasting the seed.

13. A device as claimed in any preceding claim in which the means for levelling the intervening soil ridges over the seed contained in the troughs comprises a single start helical coil roller.

14. A device as claimed in Claim 13 in which the helical coil roller is arranged with its shaft at a slight angle to the width direction of the device thereby to increase the angle of each roller pitch to the contacting soil and give a greater movement of soil than would otherwise be achieved.

15. A device as claimed in Claim 14 in which said angle lies between 10 and 20'.

16. A device as claimed in Claim 15 in which said angle is about 180.

17. A device as claimed in any of Claims 13 to 16 in which the helical coil roller comprises two separate roller sections of opposite hand arranged on opposite sides of the centre-line of the device.

18. A device as claimed in Claim 17 in which the two roller sections are interchangeable so as in operation each to move soil towards or away from said centre-line, as the case may be.

19. A device as claimed in any of Claims 13 to 18 including means for powering the helical coil roller thereby to increase sideways soil movement produced by the roller.

20. A device substantially as hereinbefore described with reference to, and/or as illustrated in, Figures 1 and 2 of the accompanying drawings.

21. A device substantailly as hereinbefore described with reference to, and/or, as illustrated in, Figures 1 and 3 of the accompanying drawings.

22. A device substantially as hereinbefore described with reference to, and/or, illustrated in, Figures 4 and 5 of the accompanying drawings.