AU674098B2 - A seed metering apparatus - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicants: Actual Inventors: WAYNE DOUGLAS SEABROOK and GARRY VICTOR SEABROOK WAYNE DOUGLAS SEABROOK and GARRY VICTOR SEABROOK 0 0* 000 P 00 Address for Service: Invention Title: CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

A SEED METERING APPARATUS Details of Associated Provisional Applications: No. PM2016 Filed 27 October, 1993 The following statement is a full description of this invention, including the best method of performing it known to us:- THIS INVENTION is concerned with a seed metering apparatus. In particular, the invention is concerned with a seed metering apparatus which may be employed in a seed planter for row crops.

Currently, a seed metering apparatus of the following type is employed in a seed planter. These metering apparatus include one or more plates which rotate about an inclined axis adjacent a wall of a hopper for containing seeds. The hopper includes an adjustable gate assembly or baffle adjacent the rotating plate which regulates the amount of seeds supplied to a lower portion of the plate. The plate has apertures or recesses of a size commensurate with the size of the seeds involved and these apertures or recesses are located at equal spacings 15 around the periphery of the plate and as the plate rotates through seeds in the hopper, each aperture or recess picks up a single seed. The plate may be caused to rotate either in a clockwise or anti-clockwise direction and where two such plates are arranged in a 20 side by side relationship within the hopper, they are eo often caused to rotate in opposite directions. Once a seed is picked up by an aperture or recess in the plate, the seed is elevated out of the supply of seeds in the hopper and is conveyed to a dispensing window located at approximately 12 o'clock, that is, adjacent the uppermost portion of the inclined wall of the hopper relative to which the plate is mounted. A dispensing tube or shute extends from the window and the seeds fall from the plate through the window and into the tube. Since the window is located at approximately the 12 o'clock position and because dispensing of the seeds from the plate imparts a tangential force to each of the seeds, this causes a component of horizontal motion to be imparted to the seeds as they pass through the window and into the tube.

With apparatus of the type described above, there is a difficulty in dispensing seeds and having them drop accurately from the plate and in directing them into the ground. As the apertures or recesses in the plate are designed to pick up one seed at a time, those apertures or recesses must be of a size commensurate with the size and type of seed being dispensed. Because of this, the seeds do not always fall smoothly from the apertures or recesses in the plate and some seeds are carried further along the window than others before they drop from the plate into the dispensing window. Some seeds are dispensed immediately from the apertures or recesses in the plate once the window is reached and as the plate rotates while other seeds may become stuck and fail to fall at all. Where two pick-up plates are employed they must be timed to rotate such that seeds are dispensed alternately from each of the plates. If a seed fails to be dispensed from one of the apertures or 15 recesses and into the dispensing window from one of the plates immediately it reaches the dispensing window, the seeds may not be planted into the ground at the desired spacing.

Some apparatus of the type mentioned employed a brush or other device to assist in the removal of the seeds from the apertures or recess to ensure that they are dispensed from the plate through the dispensing window. Such brushes or devices can interfere with the timed dispensing of seeds through the dispensing window.

The seeds in such an apparatus often contact side walls of the dispensing tube because the seeds are caused to travel horizontally across the dispensing window and this hinders timed dispensing.

For an inclined plate seed dispensing apparatus to deposit seeds at substantially equal spacings relative to the soil, the seeds must all fall at equal timed instances and this does not occur with the prior apparatus described above.

According to one aspect, the present invention provides a seed metering apparatus locatable at an inclined angle in a seed hopper, the apparatus including: a support with a dispensing window, a drive associated with the support, a dispensing plate on the support and having a plurality of dispensing apertures at predetermined spaced locations therein and mounted on the support for rotation by the drive, a transfer plate overlying the dispensing plate and fixed relative to the support and having a transfer zone located upstream of the window, a pick-up plate with a plurality of pick-up apertures at predetermined locations therein, respective said pick-up apertures being coincident with respective said dispensing apertures in the dispensing plate, the pick-up plate being mounted on the support separated from the dispensing plate by the transfer plate and for rotation by the drive to maintain the apertures in the 15 pick-up plate in coincidence with the apertures in the Sdispensing plate, whereby the dispensing window is located such that tangential force imparted to the seeds as a consequence of rotation of the dispensing plate directs the seeds downwardly and transfer of seeds from S 20 the pick-up plate to the dispensing plate occurs as the pick-up apertures in the pick-up plate move from an upstream end of the transfer zone towards a downstream end of the transfer zone and upstream of the dispensing window.

The dispensing plate and the pick-up plate may be rotated either in a clockwise or anti-clockwise direction. Where the plates rotate in a clockwise direction when viewed from the interior of the seed hopper, the dispensing window is located at or adjacent a position of about 3 o'clock relative to a path described by pick-up apertures in the pick-up plate as that plate rotates. Alternatively, where the plates rotate in an anti-clockwise direction, the dispensing window is located at or adjacent a position of about 9 o'clock relative to a path described by pick-up apertures in the pick-up plate as that plate rotates.

The seed hopper may include a single apparatus according to the invention and in which case the planting machine may have a plurality of such hoppers at transverse locations across the machine. Alternatively, a single hopper may be present and a plurality of apparatus according to the invention may be associated with that hopper.

The pick-up plate may have a single row of circumferentially spaced seed pick-up apertures.

Alternatively, a plurality of such rows of seed pick-up apertures may be present. Where there are a plurality of rows of apertures, the apertures in one row are staggered relative to the apertures in an adjacent row.

The dispensing plate need only have a single row of apertures where the pick-up plate has a single row of apertures. If the pick-up plate has more than one row 15 then the dispensing plate has at least a corresponding *number of rows of apertures.

The transfer zone may comprise a slot in the transfer plate. Preferably, the slot is arcuate.

The transfer slot in the transfer plate S 20 preferably extends through approximately 1200 although it may extend through a greater or lesser arc than this.

Preferably the upstream end of the slot extends generally radially of the path described by the apertures in the dispensing and pick-up plates as the plates rotate while the downstream end extends at an angle skewed to the radial direction.

Preferably the downstream end of the slot is located just past the dispensing window. The dispensing plate preferably has a plurality of rows of dispensing apertures with the apertures in one row being staggered relative to the apertures in an adjacent row.

A preferred embodiment of the invention will now be described with reference to the drawings in which: Figure 1 is a diagrammatic side elevational view of a seed hopper to which a seed metering apparatus according to an embodiment of the invention has been fitted; Figure 2 is a rear perspective view of the seed metering apparatus according to an embodiment of the invention; Figure 3 is a front elevational view of the metering apparatus of Figure 2 with some parts partially broken away; and Figure 4 is an exploded perspective view of the metering apparatus according to an embodiment of the invention.

Figure 1 shows a seed hopper 10 having a cover 11, a baffle 12 and a front wall relative to which the seed metering apparatus 13 of the invention is fitted.

Seeds 14 within the hopper are presented to the apparatus 13 by baffle 12 which extends from an upper part of sloping front wall 15 of the hopper 10 and terminates 15 above rear sloping wall 16. The baffle enables the seeds to be presented to the apparatus 13 such that they extend only part way over a lower portion of the apparatus.

A planting machine (not shown) adapted to plant seeds in a plurality of rows spaced transversely of the direction of travel of the machine would have a like plurality of hoppers each having an apparatus 13 as illustrated in Figure 1. The dispensing window of each apparatus 13 described in greater detail below has associated with it a tube for directing the seeds to a soil opening device which forms part of the machine.

These tubes and soil opening devices are known and do not form part of the invention.

The hopper 10 to which the metering apparatus 13 of the invention is fitted is intended to be mounted to the planting machine such that it travels in the direction indicated by the arrow shown in Figure 1.

Figure 2 of the drawings shows the rear of the metering apparatus 13. The rear faces towards the direction of travel indicated by the arrow in Figure 1.

A drive shaft 20 is journalled for rotation in bearings 21, 22 and carries a bevel gear 23 at a location between the bearings 21, 22. Bevel gear 23 engages crown gear 24 which is mounted at one end of a locating shaft 25 (see Figure The apparatus 13 has a support 26 provided with a dispensing window 27. In use the apparatus 13 is located at an inclined angle of about 550 and the window is located at a position of about 3 o'clock when the apparatus is mounted as shown in Figure 1 and the dispensing and pick-up plates are adapted for rotation in a clockwise direction when viewed from inside the hopper.

The front of the apparatus 13 is shown in Figure 3. The support receives a circular dispensing plate 30 located immediately adjacent an inner face of the support 26. Transfer plate 31 is immediately adjacent the dispensing plate 30 and overlying that plate. Pick-up plate 32 extends over the transfer plate 31 and the various plates are held together relative to 15 the support 26 by a fixing plate 33 and a fastener 34.

Figure 4 shows an exploded perspective view of the apparatus 13 of the invention. The support 26 has a circular recessed area 40 within which the dispensing plate 30 is received. Locating shaft 25 extends through S 20 aperture 41 in area 40. Shaft 25 has a drive arm 42 secured to it for rotation with the shaft 25. A drive pin 43 is secured to arm 42.

Dispensing plate 30 is circular in shape and has a central aperture 44 through which the shaft extends and a spaced aperture 45 for receiving drive pin 43. Preferably the apertures in the dispensing plate are either equal in size or larger in size than the apertures in the pick-up plate. Plate 30 has a plurality of seed dispensing apertures 46 arranged in radially spaced rows.

The apertures 46 in each row are circumferentially spaced from one another and the apertures in one row are staggered with respect to the apertures in an adjacent row. Each aperture consists of an opening in an upper surface of the plate 30, an opening in the under surface of the plate and a through passage between the openings.

It is preferred that the openings in the under surface are larger than the openings in the upper surface, such a configuration assists with seed dispensing. When the I -LI dispensing apertures are caused to move over the window 27, seeds in the apertures are dispensed from the apertures 46 into the window 27 in a progressive manner from an aperture in an outermost row, from an aperture in an adjacent row and so on until the plate has rotated sufficiently to once again expose the next aperture in the outermost row. In this way seeds are progressively and at substantially equal intervals dispensed through the window 27. Since the window 27 is located at the 3 o'clock position relative to the rotation of the plate tangential force imparted to the seed as it is dispensed from plate 30 causes the seed to pass through window 27 and downwardly through the tube (not shown) 0 O. associated with the window. In this way contact of the 9 seed with walls of the tube is minimised and hence the seeds have a relatively unimpeded passage from the window. Of course, if the dispensing and pick-up plates rotate in an anticlockwise direction the dispensing window would be located at the 9 o'clock position.

20 Transfer plate 31 is secured to the support 26 by fasteners 51, 52. The plate 31 has a central aperture 53 of a size greater than the length of arm 42. Arcuate slot 54 extends through about 1200 and terminates at or just past a lower edge of the window 27. Plate 31 overlies plate 30 and some of the apertures 46 are visible through slot 54 in plate 31.

A seed pick-up plate 32 is positioned over plate 31. Plate 32 has an aperture 57 for receiving shaft 25 and a spaced aperture 58 for receiving drive pin 43. That part of the plate 32 shown in full outline has a single row of relatively large seed pick-up apertures and is representative of a pick-up plate for large seeds.

The portion of plate 32 shown in broken outline is intended to be representative of a plate having four rows of pick-up apertures of smaller size for seeds of a commensurate size.

The apertures 59 or 60 depending upon which type of pick-up plate is present in the apparatus 13 are I M coincident with associated apertures in dispensing plate Operation of the apparatus 13 is as follows.

The apparatus is arranged in a hopper like that shown in Figure i. A plurality of like hoppers extend across a vehicle which travels over the ground at a particular speed and the rotation of the plates 30 and 32 is related to the ground speed of the vehicle.

Plate 32 picks up seeds in apertures 59 or (depending upon which plate is employed). These seeds are prevented from immediately passing throug', to dispensing plate 30 by transfer plate 31. However, once 'pertures 59, 60 progress to slot 54 such transfer is then possible since the seeds in plate 32 have the time 15 it takes for the apertures 59, 60 with seed to progress from the upstream end of slot 54 until the window 27 is reached within which to transfer to the plate immediate transfer is not necessary.

Once transfer has occurred and the seeds in apertures 46 in dispensing plate 30 are exposed to the *window 27 dispensing in orderly and timed manner is then possible. To further ensure such orderly and timed dispensing the dispensing apertures may be either the same as or larger than the pick-up apertures. To assist in the transfer of seeds from plate 32 through slot 54 i'"'"and into the apertures in plate 30 a brush or assembly which knocks the plates may be used to dislodge any seeds which become stuck in plate 32. The time for the seeds to move along the slot 54 is sufficient for such an operation to take place.

Claims (12)

1. A seed metering apparatus locatable at an inclined angle in a seed hopper, the apparatus including: a support with a dispensing window, a drive associated with the support, a dispensing plate on the support and having a plurality of dispensing apertures at predetermined spaced locations therein and mounted on the support for rotation by the drive, a transfer plate overlying the dispensing plate and fixed relative to the support and having a transfer zone located upstream of the window, a pick-up plate with a plurality of pick-up apertures at predetermined locations therein, respective said pick-up apertures being coincident with respective said dispensing apertures in the dispensing plate, the pick-up plate being mounted on the support separated from the dispensing plate by the transfer plate and for rotation by the drive to maintain the apertures in the pick-up plate in coincidence with the apertures in the dispensing plate, whereby the dispensing window is located such that tangential force imparted to the seeds as a consequence of rotation of the dispensing plate directs the seeds downwardly and transfer of seeds fr, the pick-up plate to the dispensing plate occurs as pick-up apertures in the pick-up plate move from an upstream end of the transfer zone towards a downstream end of the transfer zone and upstream of the dispensing window.

2. The apparatus of Claim 1 wherein the drive includes a drive pEn extending through the support and the dispensing plate and the pick-up plate include respective drive apertures for receiving the drive pin.

3. The apparatus of Claim 2 wherein the drive includes a locating shaft and the dispensing plate and the pick-up plate include respective central apertures for receiving the locating shaft about which they rotate, said drive pin being connected to said locating shaft by a drive arm.

4. The apparatus of any one of Claims 1 to 3 wherein the transfer zone is a slot.

The apparatus of Claim 4 wherein the slot is arcuate.

6. The apparatus of Claim 4 or 5 wherein the transfer slot extends through about 120*.

7. The apparatus of any one of Claims 4 to 6 wherein the transfer slot has the upstream end extending radially of a path defined by the pick-up apertures in the pick-up plate.

8. The apparatus of any one of Claims 1 to 7 wherein the dispensing plate has a plurality of circumferentially extending spaced rows of dispensing apertures with the dispensing apertures in one row being staggered relative to the dispensing apertures in an adjacent said row.

9. The apparatus of Claim 8 wherein the dispensing apertures are larger in size than the pick-up apertures. 20

10. The apparatus of Claim B wherein the dispensing plate has four said rows of apertures.

11. The apparatus of any one of Claims 1 to wherein the dispensing apertures consist of an opening in Sean upper face of the plate adjacent the transfer plate, an opening in an under face of the plate adjacent the support and a through passage between the openings whereby the openings in the under face are larger than the openings in the upper face.

12. The apparatus of any one of Claims 1 to 11 30 wherein the pick-up plate has a plurality of circumferentially extending spaced rows of pick-up apertures with the pick-up apertures in one said row being staggered relative to the pick-up apertures in an adjacent said row. /Y K~ -ktLi A seed metering apparatus substantially as herein described with reference to the drawings. DATED this 17 day of October, 1994. WAYNE DOUGLAS SEABROOK and GARRY VICTOR SEABROOK By their Patent Attorneys CULLEN CO. S IS S 55 oooo I 0 S C ABSTRACT A seed metering apparatus is described for mounting at an inclined angle relative to a seed hopper. The apparatus has a pick-up plate rotatably mounted with seed pick-up apertures extending circumferentially spaced around the plate. A transfer plate with an arcuate transfer slot is located between the pick-up plate and a rotatably mounted dispensing plate. The dispensing plate has a plurality of circumferentially spaced dispensing apertures each coincident with a respective said pick-up aperture. Seeds may be transferred from the pick-up plate to apertures in the dispensing plate as those apertures move from one to another end of the transfer slot. The plates are received on a support with a dispensing window adjacent a downstream end of the transfer s2ot. Seeds are dispensed from the dispensing plate through the dispensing window. o *eeoc e*