WO2005117564A1

WO2005117564A1 - A seed dispersal unit

Info

Publication number: WO2005117564A1
Application number: PCT/AU2005/000792
Authority: WO
Inventors: Dave Scott
Original assignee: D Scott Nominees Pty Ltd
Priority date: 2004-06-04
Filing date: 2005-06-02
Publication date: 2005-12-15

Abstract

A seed dispersal unit (10) includes a body (12) defining an inlet opening (14) through which a mixture of air and seeds is received in the body (12). The body (12) further defines an outlet opening (16) through which seeds are ejected from the body (12) and at least one discharge opening (18) through which a portion of the air in the mixture is able to be discharged from the body (12). The seed dispersal unit (10) also includes a variable tuning mechanism (20) in communication with the inlet opening 14 for controlling the portion of the air discharged through the at least one discharge opening (18).

Description

"A seed dispersal unit"

Cross-Reference to Related Applications The present application claims priority from Provisional Patent Application No 2004903021 filed on 4 June 2004, the content of which is incorporated herein by reference.

Technical Field The invention relates to the planting of seeds. More particularly, the invention relates to a seed dispersal unit.

Background to the Invention Changes in farming practices has seen the development of planting technology that is capable of planting seeds with increased precision. In particular, producers desire to utilise planting techniques which minimise the disturbance of soil during the planting operation. Whilst a variety of ground engaging mechanisms exist, the common method for reducing the disturbance of soil is by reducing the width and depth of the planting trench formed in the ground in which seeds are to be placed. When coupled with a pneumatic seeding device (air-seeder), seeding performance is determined by the amount of air mixed with seed as it is delivered into a narrow planting trench. The volume and velocity of the air exiting a planting boot outlet may cause the seeds to bounce partly or completely out of their targeted position within the seed trench. The degree of poor performance caused by this seed bounce phenomenon is influenced by factors such as the density and size of seeds, volume and velocity of air at the outlet and the rate of seed application.

Summary of the Invention According to a first aspect of the invention, there is provided a seed dispersal unit which includes: a body defining at least one inlet opening through which a mixture of air and seeds is received in the body, the body further defining an outlet opening through which seeds are ejected from the body and at least one discharge opening through which a portion of the air in the mixture is able to be discharged from the body; and a variable tuning mechanism in communication with the inlet opening for controlling the portion of the air discharged through the at least one discharge opening. The tuning mechanism may comprise a lid releasably attached to the body, the lid defining the at least one discharge opening. A size of the at least one discharge opening may be variable for varying the open area. The lid may include a vortex finder arranged about the at least one discharge opening. The vortex finder may be defined by a hollow tube extending into the body from the at least one discharge opening. At least one of a length and a bore of the tube may be variable for additional variability of the tuning mechanism. The variability of the tube may be provided by means of a plurality of interchangeable lids, each lid having a tube having one of a length and a bore differing from any of the other lids. The vortex finder may be eccentrically arranged relative to a central axis of its associated lid. Instead, the variability of the tuning mechanism may be provided by a plurality of interchangeable lids, each lid defining at least one discharge opening having an open area differing from any of the other lids. Each lid of the plurality of interchangeable lids may include a vortex finder arranged about the at least one discharge opening. Each vortex finder may be defined by a hollow tube extending into the body from the at least one discharge opening. At least one of a length and a bore of the vortex finder may be variable for additional variability of the tuning mechanism. Each lid of the plurality of interchangeable lids may have a vortex finder of one of a different length and bore. Each vortex finder may be eccentrically arranged relative to a central axis of its associated lid. The body may include a first body portion and a second body portion attached to the first body portion. Instead, the first body portion and the second body portion may be releasably attached to each other. The inlet opening may be defined by at least one opening in the first body portion. The outlet opening may be defined by the second body portion. The second body portion may include a helix formed on an inner wall of the second body portion, the helix defining a path the seeds follow as they move towards the outlet opening. According to a second aspect of the invention, there is provided a seed dispersal unit which includes: at least one first body portion defining at least one inlet opening for receiving a mixture of air and seeds and at least one discharge opening through which a portion of the air in the mixture is able to be discharged from the first body portion; and a second body portion defining an outlet opening through which seeds are ejected, the second body portion being releasably attached to the first body portion. The seed dispersal unit may include a set of first body portions. Each first body portion may define the at least one discharge opening. The at least one discharge opening of each first body portion may have a different open area than the at least one discharge opening of any of the other first body portions. A height dimension of each first body portion in the set of first body portions may differ from the height dimension of any other first body portion of the set of first body portions.

Brief Description of Drawings Embodiments of the invention are now described, by way of examples, with reference to the accompanying diagrammatic drawings in which: Figure 1 shows a three dimensional view, from a first side, of a seed dispersal unit, in accordance with an embodiment of the invention; Figure 2 shows a three dimensional view, from a second side, of the seed dispersal unit of Figure 1 ; Figure 3 shows a top view of the seed dispersal unit of Figure 1; Figure 4 shows a side view of the seed dispersal unit of Figure 1; Figure 5 shows a sectional side view of the seed dispersal unit of Figure 1 taken along line A- A in Figure 4; Figure 6 shows a sectional side view of the seed dispersal unit of Figure 1 taken along line B-B in Figure 4; Figure 7 shows a schematic representation of a planting system including a plurality of seed dispersal units; Figure 8 shows a three-dimensional view, from a first side, of a seed dispersal unit, in accordance with another embodiment of the invention; Figure 9 shows a side view of the seed dispersal unit of Figure 8; Figure 10 shows a sectional side view of the seed dispersal unit of Figure 8 taken along line C-C in Figure 9; Figure 11 shows a sectional side view of the seed dispersal unit of Figure 8 taken along line D-D in Figure 9; Figure 12 shows a top view of a lid of the seed dispersal unit of Figure 8, with a vortex finder in a first position; and Figure 13 shows another top view of the lid of the seed dispersal unit of Figure

8, with the vortex finder in a second position. Detailed Description of the Exemplary Embodiments In Figures 1 to 7 of the drawings, reference numeral 10 generally designates a first exemplary embodiment of a seed dispersal unit. The seed dispersal unit 10 includes a body 12 defining an inlet opening 14 through which a mixture of air and seeds is received in the body 12. The body 12 further defines an outlet opening 16 through which seeds are ejected from the body 12 and at least one discharge opening 18 through which a portion of the air in the mixture is able to be discharged from the body 12. The seed dispersal unit 10 also includes a variable tuning mechanism 20 in communication with the inlet opening 14 for controlling the portion of the air discharged through the at least one discharge opening 18. The body 12 includes a first body portion 22 and a second body portion 24 attached to the first body portion 22. The first body portion 22 is in the form of a hollow cylinder and has a height 'h' as shown in Figure 5 of the drawings. The first body portion 22 includes an inlet tube 26 which defines the inlet opening 14. The inlet tube 26 of the first body portion 22 is arranged such that a side 28 of the inlet tube 26 is tangential to a wall 30 of the first body portion 22 as shown most clearly in Figure 3 of the drawings. The second body portion 24 is frusto-conical in shape and includes a helix 32 (Figures 5 and 6) formed on an inner wall 34 of the second body portion 24. The helix 32 defines a path the seeds follow as they move towards the outlet opening 16. The first body portion 22 and the second body portion 24 are manufactured as separate units and are joined together in a concentric arrangement by complementary connection formations 36. The connection formations 36 are an internal thread on the first body portion 22 and an external thread on the second body portion 24. The connection formations 36 provide for efficient and rapid disengagement of the first body portion 22 from the second body portion 24. Thus, the first body portion 22 can be rapidly replaced by a different first body portion 22 of a different height 'h' as requirements demand to facilitate partial tuning of the unit 10 to control the amount of air discharged through the, or each, discharge opening 18. The tuning mechanism 20 comprises a lid 38 releasably attached to the first body portion 22. The lid 38 defines a plurality of apertures to form the discharge opening 18. The variability of the tuning mechanism 20 is further facilitated by a plurality of interchangeable lids 38, each lid 38 defining at least one discharge opening 18 having an open area differing from any of the other lids 38. Each lid 38 is releasably attachable to the first body portion 22. The lid 38 includes tabs 40 to facilitate attachment of the lid 38 to the first body portion 22. The tabs 40 extend below a bottom edge of the lid 38 and have a recessed region 42 defining a catch 44. An end of the first body portion 22 includes a radially outwardly projecting lip 46 protruding outwardly from the first body portion 22 and shaped to allow clipping engagement of the catch 44 to retain the lid 38. In use, an operator can choose a lid 38 having an open area to adjust the desired performance, more particularly, to adjust the portion of the air discharged through the discharge opening 18. Referring now to Figures 8 to 13, in which, with reference to Figures 1 to 6 of the drawings, like reference numerals refer to like parts unless otherwise specified, a second exemplary embodiment of the invention is now described. In this embodiment, the lid 38 defines the discharge opening 18 in the form of a single aperture. The discharge opening 18 is bounded by a vortex finder 48. The vortex finder 48 includes a hollow tube 50 extending a length TX from the discharge opening 18, as shown in Figure 10 of the drawings, to a free end 52. In this embodiment, an operator can choose from a plurality of interchangeable lids 38 each with vortex finders 48 having length 'L' and/or bore differing from any of the other lids 38. In addition, the vortex finder 48 could be arranged concentrically or eccentrically with its associated lid 38 as shown in Figures 12 and 13, respectively. The vortex finder 48 in Figures 12 and 13 is arranged such that rotation of the vortex finder 48 positions the vortex finder 48 concentrically or eccentrically relative to the first body portion 22. Increasing the eccentricity reduces the portion of air discharged through the discharge opening 18 and increases the amount of air exiting through the outlet opening 16 with the seeds. Thus, in use, the seed dispersal unit 10 can be tuned to effect a required planting velocity of seeds being ejected through the outlet opening 16. The resultant effect of tuning the lid dynamics may therefore be to vary the percentage of the inlet air diffused to the atmosphere through the discharge opening 18 from the main body 12 as compared to air exiting through the outlet opening 16 with the seed. The tuning range may be adjustable from 0% of available air exiting via the outlet opening 16, up to 80% of the available air exiting through the outlet opening 16. The need to tune the air stream may arise as a result of very heavy application rates or the seeding of very light weight seeds. In use, the seed dispersal unit 10 forms part of a planting system 54 (Figure 7). The planting system 54 is connected to a power take off of a tractor (not shown) and includes a hopper 56 containing a batch of seeds and a plurality of seed dispersal units 10 arranged to plant a plurality of rows during a single pass across a field. Each seed dispersal unit 10 is responsible for the sowing of seeds for a single row. The hopper 56 is connected via a feed line 58 to the inlet opening 14 of each seed dispersal unit 10. Each seed dispersal unit 10 is mounted to a frame (not shown) of the planting system 54 by a mount 60. The mount 60 includes a U-bolt 62 threaded at both ends and nuts 64 to be received on the ends of the TJ-bolt 62. The seeds are fed from the hopper 56 to the inlet opening 14 of each seed dispersal unit 10. The seeds are gravity fed from the hopper 56 through the feed line 58 in the direction indicated by arrow 66 to the inlet opening 14 of each seed dispersal unit

10. Instead, a blower (not shown) is used to blow the seeds at a desired feed velocity through the feed line 58 to the inlet opening 14. The arrangement of the inlet tube 26, as described above, in combination with the length of the first body portion 22 and the velocity at which the seeds are fed to the inlet opening 14, allows the seeds to follow the wall 30 of the first body portion 22 in a circular pattern. As the seeds move around the wall 30 of the first body portion 22 they also drop down towards the second body portion 24. When the seeds reach the second body portion 24 and, by virtue of the path on which the seeds are travelling, the seeds come into contact with the helix 32. From this point of contact with the helix 32 the seeds follow a path defined by the helix 32. The shape of the second body portion 24 and of the helix 32 increases the velocity of the seeds travelling through the second body portion 24. Once the seeds reach the end of the helix 32, the seeds are discharged through the outlet opening 16. The velocity at which the seeds are discharged is determined by the portion of the air discharged through the discharge opening 18. In use, soil or debris often results in blockages of a seed boot (not shown) in communication with the outlet opening 16 of an associated seed dispersal unit 10 of the planting system 54. Such blockages result in uneven field coverage of a crop as the blockages prevent certain of the seeds from passing through the outlet opening 16. However, when such blockages occur when the seed dispersal units 10 are in use, the seed dispersal unit 10 directs the mixture to be discharged through the discharge opening 18 such that the seeds are sprayed to a height above the lid 38 to provide a visual indication of the blockage to an operator. It is, accordingly, an advantage of the invention that a seed dispersal unit 10 is provided with a tuning mechanism 20 which can be varied to control the velocity at which seeds are discharged through the outlet opening 16. In addition, the seed dispersal unit 10 comprises interchangeable components to facilitate the adjustment of the tuning mechanism 20. Thus, it is an advantage of the invention, that the seed dispersal unit 10 reduces the degree of inaccuracy caused by seed bounce in a planting trench for a wide variety of seed types, application rates, and air volumes and velocities. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A seed dispersal unit which includes: a body defining at least one inlet opening through which a mixture of air and seeds is received in the body, the body further defining an outlet opening through which seeds are ejected from the body and at least one discharge opening through which a portion of the air in the mixture is able to be discharged from the body; and a variable tuning mechanism in communication with the inlet opening for controlling the portion of the air discharged through the at least one discharge opening.

2. A seed dispersal unit as claimed in claim 1 in which the tuning mechanism comprises a lid releasably attached to the body, the lid defining the at least one discharge opening.

3. A seed dispersal unit as claimed in claim 2 in which a size of the at least one discharge opening is variable for varying the open area.

4. A seed dispersal unit as claimed in claim 2 or claim 3 in which the lid includes a vortex finder arranged about the at least one discharge opening.

5. A seed dispersal unit as claimed in claim 4 in which the vortex finder is defined by a hollow tube extending into the body from the at least one discharge opening.

6. A seed dispersal unit as claimed in claim 5 in which at least one of a length and a bore of the tube is variable for additional variability of the tuning mechanism.

7. A seed dispersal unit as claimed in claim 6 in which the variability of the tube is provided by means of a plurality of interchangeable lids, each lid having a tube having one of a length and bore differing from any of the other lids.

8. A seed dispersal unit as claimed in any one of claims 4 to 7 in which the vortex finder is eccentrically arranged relative to a central axis of its associated lid.

9. A seed dispersal unit as claimed in claim 1 in which the variability of the tuning mechanism is provided by a plurality of interchangeable lids, each lid defining at least one discharge opening having an open area differing from any of the other lids.

10. A seed dispersal unit as claimed in claim 9 in which each lid includes a vortex finder arranged about the at least one discharge opening.

11. A seed dispersal unit as claimed in claim 10 in which the vortex finder is defined by a hollow tube extending into the body from the at least one discharge opening.

12. A seed dispersal unit as claimed in claim 11 in which at least one of a length and a bore of the vortex finder is variable for additional variability of the tuning mechanism.

13. A seed dispersal unit as claimed in claim 12 in which each lid of the plurality of interchangeable lids has a vortex finder of one of a different length and bore.

14. A seed dispersal unit as claimed in any one of claims 9 to 13 in which the vortex finder is eccentrically arranged, relative to a central axis of its associated lid.

15. A seed dispersal unit as claimed in any one of the preceding claims in which the body includes a first body portion and a second body portion attached to the first body portion.

16. A seed dispersal unit as claimed in claim 15 in which the first body portion and the second body portion are releasably attached to each other.

17. A seed dispersal unit as claimed in claim 15 or claim 16 in which the inlet opening is defined by at least one opening in the first body portion.

18. A seed dispersal unit as claimed in any one of claims 15 to 17 in which the outlet opening is defined by the second body portion.

19. A seed dispersal unit as claimed in any one of claims 15 to 18 in which the second body portion includes a helix formed on an inner wall of the second body portion, the helix defining a path the seeds follow as they move towards the outlet opening.

20. A seed dispersal unit which includes: at least one first body portion defining at least one inlet opening for receiving a mixture of air and seeds and at least one discharge opening through which a portion of the air in the mixture is able to be discharged from the first body portion; and a second body portion defining an outlet opening through which seeds are ejected, the second body portion being releasably attached to the first body portion.

21. A seed dispersal unit as claimed in claim 20 which includes a set of first body portions.

22. A seed dispersal unit as claimed in claim 21 in which each first body portion defines the at least one discharge opening, the at least one discharge opening of each first body portion having a different open area than the at least one discharge opening of any of the other first body portions.

23. A seed dispersal unit as claimed in claim 21 or claim 22 in which a height dimension of each first body portion in the set of first body portions differs from the height dimension of any other first body portion of the set of first body portions.

24. A seed dispersal unit as claimed in any one of claims 20 to 23 in which the second body portion includes a helix formed on an inner wall of the second body portion, the helix defining a path the seeds follow as they move towards the outlet opening.