GB2232569A

GB2232569A - Dibber drills

Info

Publication number: GB2232569A
Application number: GB9011530A
Authority: GB
Inventors: William Peter Billington; John Butler
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1989-05-24
Filing date: 1990-05-23
Publication date: 1990-12-19
Also published as: GB8911928D0; GB9011530D0

Abstract

A metering and dibbing assembly in which a stationary seed-control ring 26 operates in conjunction with a seed-ejector blade 28 to allow each open-topped slot 22 of a rotating cell ring 20 to carry away a single seed from an associated seed chamber to which it is exposed. This seed is subsequently transferred from the slot 22 to the dibber wheel 30 and extension of the appropriate dibber element 38 then presses the seed into the ground. <IMAGE>

Description

DIBBER DRILLS The present invention relates to dibber drills, that is to say to machines using one or more dibber elements to press a hole in the ground with the seed to be planted in or on the consolidated soil at the bottom of the hole.

UK Patent Application 88 28736 discloses a metering and dibbing assembly for use in a dibber drill, the assembly comprising a rotary feed section, inlet means for introducing seed at successive seed-accepting slots formed in the radially inner periphery of the rotary feed sectlon, a rotary dibber section having a plurality of dibber elements at least in part housed in radially disposed bores in the dibber section, and cam means operative to withdraw successive dibber elements to allow the transfer of seed from the feed section into the associated bores for these elements and thereafter to move the dibber elements in a radially outward movement so as to press the seed into the ground. This assembly is hereinafter referred to as a metering and dibbing assembly of the type hereinbefore defined.

According to the present invention, a metering and dibbing assembly of the type hereinbefore defined includes a seed-control element having a first section which exposes at least part of the slots to the inlet means for the intake of seeds into the slots, a second section which partially covers the open sides of the slots to maintain the captured seed within the slots whilst allowing removal of any surplus seed or seeds not within the slots, and a third region which seals off the open sides of the slots to enable the captured seeds to be retained within the slots until they can be transferred to the rotary dibber section for planting.

The invention also includes a dibber drill incorporating the metering and dubbing assembly of the present invention.

An embodiment of the invention will now be described,by way of example only, with reference to the accompanying somewhat diagrammatic drawings in which: Figures 1 and la are respectively a part-sectional side view and a scrap side view of a rotary metering and dibbing assembly according to the present invention; Figure 2 shows, on a larger scale, an end view of the same assembly partly sectioned along the line II-II of Figure 1; Figure 3 shows, on a still larger scale, an exploded scrap view of the assembly In the region of section 111-11 in Figure 1; Figure 4 is a view similar to that of Figure 3 but showing a design modification; and Figure 5 is a scrap view of part of the assemblies shown in Figures 3 and 4.

Thus referring now to the drawings, a rotary metering and dibbing assembly 10 in accordance with the present invention is provided with a seed hopper 12 connected via a tube 14 with an arcuate seed chamber 16 in a circular cover plate 18 of the assembly.

Reference numeral 20 indicates a rotatable cell ring having in its inner circumference1 a plurality of radially-extendfng slots 22 each just large enough to accept a seed from the seed chamber 16 (Figure 3). Each of these slots is preceded (on rotation of the cell ring) by a lead-in chamfer 24 to assist in seed capture.

Details of the slot arrangement are shown in Figure 5 from which it will be seen that the all-1mportant lead-in chamber 25 intersects the cell at a line on the cell diameter (pitch circle) and is therefore half the depth of the cell. The reasons for this are to assist in seed capture and to ensure easy lateral movement by the ejector blade 28 of any unwanted seed without damaging seeds or displacing the seed already in the cell.

The transfer of seeds from chamber 16 and their subsequent retention in the cell ring slots 22 is controlled by a stationary, lnternally-stepped, seed-control ring 26.

As can be seen from Figure 3, the seed-control ring 26 comprises a first section 26A which exposes the open sides of the slots 22 for the intake of seeds from chamber 16. To allow gravity to assist this transfer, the floor of the seed chamber preferably slopes down e.g. at 45 , to finish flush with the upper surface of section 26A The second section 26B of the seed control ring covers the lower halves of the slots 22 to maintain within the slots seed captured at section 26A. At the same time, any surplus seed can be returned to the seed chamber 16 by a seed-ejector blade 28 which is spr7ng-loaded to bear against the inner circumference of the cell ring 20 and against the inner wall of a low-friction phosphor-bronze backing plate 29.

The third section 26C of control ring 26 seals off the open sides of the slots to enable the seeds to be retained there until they are transferred to the dibber wheel (30) for planting.

This transfer is effected by a pulse of air from an air supply tube 32 through the single aperture 34 in the backing plate 29 which closes the far sides of slots 22. Withdrawal of the appropriate one of dibber elements 38 for this purpose is effected by the action of the cam track 40 in the cam wheel 42 which additionally closets the top ends of slots 22.

The dibber guide rollers (44) running within the cam-track 40 are each mounted on one end of a stud 46. The other end of the stud carries a second roller 48 running between guide wedges 50 on the dibber wheel 30 to give the dibber elements operational rigidity.

The dibber wheel 30 and the cell ring 20 secured to it, are rotated about a central support axle 52 by an externally powered derive shaft 54 acting through appropriate internal gearing (not shown).

In an alternative version (not shown), power comes from the land wheels and the drive to the seeder is direct through belts with no internal gearing.

At its lowermost point, the cam track has a "beak" portion 56 to produce the rapid in-and-out action of the dibber elements 38 required to push the seed into the ground. Once embedded in the soil, adhesion forces prevent the seeds from being withdrawn with the dibber elements.

Shoe piece 58 (pivotally mounted at its upper end) prevents premature escape of the -transferred seeds.

In an alternative design, shown in Figure 4, the seed chamber 116 is circumferential and formed by the constant cross-sectional profile of the inner face of the cover plate so that the seed is not restricted in the same way as with the arcuate seed chamber of the previous embodiment.

The arrangement is such that the lower (outer) half of each slot (122) is always covered so that once a seed ts in a slot it cannot be displaced laterally until it reaches its predetermined discharge point. Entry of the seed into the slot on capture is not therefore truly from the side as in the original embodiment, but more radially and assisted by the lead-in chamber 124.

In this new arrangement, the ejector blade 28 of the earlier embodiment has been replaced by an integral ejector part 200 of a ring 202. This ring is stationary and flush against the face of phosphor bronze backing plate 129. Its width ts the same as that of the cell ring 120 and its outer circumference is a running fit against the inner circumference of the cell ring.

An arcuate cut-out 204 in ring 202 allows the seed into radial contact with the slots in ring 120. It ts the forward end of this cut-out that forms the ejector part 200 referred to above.

In an alternative version (not shown), the ring 202 is an integral part of cam plate 142, thus reducing the number of components and simplifying manufacture.

The open sides of the slots in the cell ring 120 are effectively "sealed by the adjacent face of the cover plate which is a close running fit to the outer face of the cell ring.

As the diameter of the cover plate face in the region of the cell ring slots is equal to the pitch circle diameter of these slots, and the slots are closed by the outer circumference of the ring 202, the seed is captive in its slot once it has passed under the ejector part 200.

Additional information about the operational regime and general constructional features of assemblies and drills of this type may be had from UK Patent Application 88 28736 referred to above

Claims

CLAIMS 1. A metering and dibbing assembly of the type hereinbefore defined including a seed-control element having a first section which exposes at least part of the slots to the inlet means for the intake of seeds into the slots, a second section which partially covers the open sides of the slots to maintain the captured seed within the slots whilst allowing removal of any surplus seed or seeds not within the slots, and a third region which seals off the open sides of the slots to enable the captured seeds to be retained within the slots until they can be transferred to the rotary dibber section for planting.
2. A dibber drill incorporating a metering and dibbing assembly as claimed in Claim 1.
3. A metering and dibbing assembly or dibber drill substantially as hereinbefore described with reference to, and/or as illustrated in, Figures 1 to 3 and 5 of the accompanying drawings.
4. A meterlng and dibbing assembly or dibber drill substantially as hereinbefore descrlbed with reference to, and/or as illustrated in, Figures l,la,2,4 and 5 of the accompanying drawings.