WO2005004579A1

WO2005004579A1 - A device at a distrubutor head

Info

Publication number: WO2005004579A1
Application number: PCT/SE2004/001037
Authority: WO
Inventors: Bodo Pöhls; Denny Mischke; Klaus Müller
Original assignee: Väderstad-Verken Ab
Priority date: 2003-07-11
Filing date: 2004-06-28
Publication date: 2005-01-20
Also published as: SE0302060D0; SE525180C2; DE112004001272B4; DE112004001272T5; SE0302060L

Abstract

A device at a distributor head (8) for a seed drill with at least one blocking member (24) that blocks at least one outlet (22). The blocking member (24) is provided with holes (26) of a size that allows air flow through the outlet (22) but prevents seed being conducted through.

Description

A device at a distributor head

The present invention relates to a device at a distributor head for a seed drill according to the ingress of Claim 1.

BACKGROUND OF THE INVENTION

In today's farming, pneumatic seed drills are often used. At these, the seed is conducted from a seed container to a distributor head through a tube with the help of an air flow. In the distributor head, the seed is distributed to a number of different outlet tubes each of which leads to a seed coulter or a seed nozzle.

For certain types of crops, for example wheat, the seed has a small grain size and can be sown in relatively close rows and with small spaces between the seeds in the respective row. For other types, for example maize, with a larger grain size a greater spacing is usually needed between the rows and also between the grains. It is therefore usual to use different seed drills for these different types of crops.

It is however possible to use for example for maize the same seed drills as are used traditionally for example for wheat seed. This can be achieved by blocking a number of outlets from the distributor head whereby the seed is only distributed to certain seed coulters or nozzles situated at the required distance from each other.

In such cases the majority of the outlets are blocked. This can however cause problems in the form of too high flow velocity through the open outlets for the required precision. This can in turn be counteracted by decreasing the air stream, which instead can lead to the air stream not having the ability to 'lift' the seed from the low placed outlet from the seed container to the high placed inlet to the distributor head. ALMS OF THE INVENTION

The aim of the invention is to achieve a solution that allows a seed drill normally used for small-seeded crops to be used for large-seeded crops with a greater row spacing and with satisfactory precision. The solution should in addition be cost effective, reliable in operation and include fast and easy conversion of the seed drill between different types of seed.

SUMMARY OF THE INVENTION

With a device according to the characterisation part of Claim 1, certain outlets for seed are blocked. By however allowing air flow through all outlets, a sufficiently large air flow for good precision and function can be used without the seed flow though the outlets open to seed being too great.

Devices according to Claims 2-5 define the preferred embodiments with several blocking members that are suitably similarly distributed in the distributor head which gives optimal function, where the proportion of blocked outlets is optimised for maize drilling for seed drills that are normally used for small-seeded crops.

Furthermore, Claims 6-8 define the preferred embodiments where a traditional distributor head with radially directly outlets can be quickly converted for different seeds by an exchange of a wall part at which the blocking members are arranged for another wall part with another or no blocking arrangement.

The further characteristics and advantages of the invention are described more fully below with the help of an embodiment and diagrams relating thereto. DRAWING SUMMARY

Figure 1 shows a seed drill drawn by a tractor.

Figure 2 shows a distributor head according to the invention.

DETAILED DESCRIPTION OF AN EMBODIMENT

Figure 1 shows a seed drill 2 drawn by a tractor. The seed drill 2 comprises a seed container 6 for seed and in certain cases for fertiliser too. From the seed container 6 the seed is conducted via conduits (not shown in Figure 1), usually pipes, to one or several distributor heads 8 with a plurality of outlets from where the seed is conducted in hoses 10 out to seed coulters or seed nozzles (not shown in Figure 1). A fan 12 is adapted to generate an air flow that transports the seed from the seed container 6 via the distributor heads 8 to the seed coulters (or equivalent).

Figure 2 shows a distributor head 8 in detail. For reasons of space and clarity, only some of the reference representations of one or more of several identical or corresponding components are shown in the diagram.

The distributor head 8 comprises an essentially cylindrical distributor chamber 18 with an inlet 16 from a connecting conduit 14 in the form of a pipe from the seed container. At the radial periphery 18 of the distributor chamber are an number of essentially similarly shaped outlets 20, 22 arranged symmetrically around the entire circumference. Furthermore, the distributor chamber is lined with an annular wall part 30, which in the figure is formed from transparent material. Each outlet 20, 22 is connected with seed coulters (or equivalent) via a respective tube 10.

The construction in principle described thus far is known. The distributor head 8 shows in addition to this a number of blocking members 24 according to the invention, here four that are similarly shaped. The blocking members 24 are bow-shaped with a convex surface in towards the centre of the distributor chamber 18 and are symmetrically arranged in the distributor chamber 18. The blocking members 24 comprise a number of small holes 26 of a size that allows air flow from the pipe 14 through the blocked outlets 22 out to the hoses 10 but prevents seed being conducted through the outlets 22.

Each blocking member 24 blocks five outlets 22. For the distributor head shown there are thus twenty blocked outlets 22 and four open outlets 20. A solution is achieved hereby where approx. 83% of the outlets are blocked. When drilling maize with a seed drill that is normally used for small-seeded crops it has been shown that 75-85% of the outlets should be blocked for best results. It is thereby advantageous to allow one blocking member to block 3-6 outlets in relation to each open outlet.

The blocking member 24 is detachably via screw connections 28 fixed to the annular wall part 30 which is in turn detachably connected to the distributor head with a plurality of wing nut connections 34.

The invention can be varied within the framework of the patent claims. Accordingly, both the shape and placement of the blocking members and the distributor head can be varied. The embodiment described is however preferred since it allows an even and precise flow of seed where the bow-shaped convex surface of the blocking member in towards the distributor chamber reduces the risk of seed becoming stuck in the holes or other flow-disrupting phenomena.

Claims

1. A device at a distributor head (8) for a seed drill (2) adapted to be connected to at least one seed container (6) via a connecting conduit (14), which distributor head (8) comprises a plurality of outlets (20, 22) connected with seed nozzles, which distributor head (8) is adapted to conduct seed from the seed container (6) to the seed nozzles with the help of an air flow, with at least one blocking member (24) arranged in the distributor head (8) blocking at least one outlet (22), characterised in that the blocking member (24) is provided with holes (26) of a size that allows air flow from the connecting pipe (14) to the outlet (22) but prevents seed being conducted through the outlets (22).

2. A device according to Claim 1, characterised in that the blocking organ (24) blocks several, preferably 3-6, outlets (22).

3. A device according to either one of the preceding claims, characterised in that the distributor head (8) comprises a plurality of blocking members (24).

4. A device according to any one of the preceding claims, characterised in that the blocking members (24) together block 75-85% of the number of outlets

(20, 22).

5. A device according to any one of the preceding claims, characterised in that a plurality of essentially similarly shaped blocking members (24) are symmetrically arranged in the distributor head (8).

6. A device according to any one of the preceding claims, characterised in that the blocking member (24) is arranged, preferably detachably, via a detachable wall part (30) in the distributor head (8).

7. A device according to Claim 6 where the distributor head (8) comprises an essentially cylindrical distributor chamber (18) with outlets (20, 22) essentially symmetrically arranged around the radial periphery of the distributor chamber (18), characterised in that the detachable wall part (30) is essentially annular in shape.

8. A device according to Claim 7, characterised in that the blocking member (24) is bow-shaped with a convex surface towards the centre of the distributor chamber (18).