U.S. patent application number 15/653496 was filed with the patent office on 2017-11-02 for seed meter.
The applicant listed for this patent is Precision Planting LLC. Invention is credited to Derek Sauder.
Application Number | 20170311535 15/653496 |
Document ID | / |
Family ID | 46880051 |
Filed Date | 2017-11-02 |
United States Patent
Application |
20170311535 |
Kind Code |
A1 |
Sauder; Derek |
November 2, 2017 |
SEED METER
Abstract
A seed meter for an agricultural planter in which the seed disc
is rotatably mounted within a seed meter housing. As the seed disc
rotates, the apertures in the disc rotate along a seed aperture
path through a horizontally adjacent seed pool area. The seed disc
includes cavities disposed along the seed aperture path to agitate
the seeds in the seed pool area. A singulator having multiple
co-planar singulator surfaces is biased against the seed side
surface of the seed disc.
Inventors: |
Sauder; Derek; (Tremont,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Precision Planting LLC |
Tremont |
IL |
US |
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|
Family ID: |
46880051 |
Appl. No.: |
15/653496 |
Filed: |
July 18, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14793360 |
Jul 7, 2015 |
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15653496 |
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14006569 |
Sep 20, 2013 |
9351440 |
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PCT/US2012/030192 |
Mar 22, 2012 |
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14793360 |
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61466047 |
Mar 22, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01C 7/084 20130101;
A01C 7/128 20130101; A01C 7/046 20130101; A01C 7/12 20130101; A01C
7/123 20130101; A01C 7/04 20130101; A01C 7/105 20130101; A01C 7/16
20130101; A01C 7/044 20130101 |
International
Class: |
A01C 7/04 20060101
A01C007/04; A01C 7/12 20060101 A01C007/12; A01C 7/12 20060101
A01C007/12; A01C 7/12 20060101 A01C007/12; A01C 7/10 20060101
A01C007/10; A01C 7/08 20060101 A01C007/08; A01C 7/04 20060101
A01C007/04; A01C 7/16 20060101 A01C007/16; A01C 7/04 20060101
A01C007/04 |
Claims
1. A seed distribution element for precision pneumatic seed drills,
comprising: a sowing disc which is rotated by a motor-driven
transmission drive shaft at controlled speed; a housing with a
fixed portion and a portion which is movable relative to the fixed
portion and can be closed against the fixed portion; a seed
collection chamber being defined in the fixed portion; a pneumatic
suction chamber being defined in the movable portion; the sowing
disc being interposed between the fixed and movable portions and
having opposed surfaces delimiting the chambers; the sowing disc
having at least one ring of selector holes extending between the
opposed surfaces; and a seal which is arranged on the movable
portion and is capable of sliding contact with the facing surface
of the disc when the fixed and movable portions are closed against
one another; wherein a pressure differential is provided between
the opposed surfaces in the region of a circumferential segment of
the ring of holes; wherein the seed distribution element further
comprises a thrust-bearing element of the sowing disc, which
thrust-bearing element is supported rotatably in the movable
portion in order to withstand at least some of the axial load
produced by the disc on the seal.
2. The seed distribution element according to claim 1, wherein the
thrust-bearing element is rotated with the disc when the fixed and
movable portions are closed against one another.
3. The seed distribution element according to claim 1, wherein the
thrust-bearing element comprises a thrust-bearing plate which can
bear on that surface of the sowing disc which faces the seal, in a
zone radially inside of the ring of holes.
4. The seed distribution element according to claim 3, wherein the
thrust-bearing element comprises a drive element which is fixed for
rotation with the plate and can be coupled with the drive shaft of
the disc when the fixed and movable portions are closed against one
another.
5. The seed distribution element according to claim 4, wherein the
drive element is self-centring relative to the drive shaft.
6. The seed distribution element according to claim 4, wherein the
drive element comprises a coupling member which rotates jointly
with the thrust-bearing plate but has radial and/or circumferential
clearance so as to be self-centred during rotational coupling with
the drive shaft of the disc.
7. The seed distribution element according to claim 1, wherein the
movable portion is hinged to the fixed portion.
8. A sowing element for precision seed drills comprising a frame on
which a seed distribution element according to claim 1 is
mounted.
9. A seed drill comprising a supporting structure on which a
plurality of sowing elements according to claim 8 are mounted.
10. A kit for the retrofitting of seed distribution elements of
precision pneumatic seed drills wherein the distribution elements
are of the type including: a sowing disc which is rotated by a
motor-driven transmission drive shaft at controlled speed; a
housing with a fixed portion and a portion which is movable
relative to the fixed portion and can be closed against the fixed
portion; a seed collection chamber being defined in the fixed
portion; a pneumatic suction chamber being defined in the movable
portion; the sowing disc being interposed between the fixed and
movable portions and having opposed surfaces delimiting the
chambers; the sowing disc having at least one ring of selector
holes extending between the opposed surfaces; and a seal which is
arranged on the movable portion and is capable of sliding contact
with the facing surface of the disc when the portions are closed
against one another; wherein a pressure differential is provided
between the opposed surfaces in the region of a circumferential
segment of the ring of holes; wherein the kit comprises the movable
portion pre-assembled with a thrust-bearing element of the sowing
disc, which thrust-bearing element is supported rotatably in the
movable portion in order to withstand at least some of the axial
load produced by the disc on the seal.
11. The kit according to claim 10 wherein the movable portion and
the thrust-bearing element comprise at least one feature according
to claim 2.
12. The kit according to claim 10 wherein the movable portion and
the thrust-bearing element comprise at least one feature according
to claim 3.
13. The kit according to claim 10 wherein the movable portion and
the thrust-bearing element comprise at least one feature according
to claim 4.
14. The kit according to claim 10 wherein the movable portion and
the thrust-bearing element comprise at least one feature according
to claim 5.
15. The kit according to claim 10 wherein the movable portion and
the thrust-bearing element comprise at least one feature according
to claim 6.
16. The kit according to claim 10 wherein the movable portion and
the thrust-bearing element comprise at least one feature according
to claim 7.
17. A seed meter for an agricultural planter, said seed meter
comprising: a seed disc which is rotated by a motor-driven shaft at
controlled speed; a meter housing with a fixed portion and a
portion which is movable relative to the fixed portion and can be
closed against the fixed portion; a seed pool area being defined in
the fixed portion; a vacuum area defined in the movable portion;
the seed disc being interposed between the fixed and movable
portions and having opposed surfaces delimiting the seed pool area
from the vacuum area; the seed disc having at least one ring of
seed apertures extending between the opposed surfaces; and a seal
which is arranged on the movable portion and is capable of sliding
contact with the facing surface of the disc when the fixed and
movable portions are closed against one another wherein a pressure
differential is provided between the opposed surfaces in the region
of a circumferential segment of the ring of seed apertures; wherein
the seed meter further comprises a thrust-bearing element of the
seed disc, which thrust-bearing element is supported rotatably in
the movable portion in order to withstand at least some of the
axial load produced by the disc on the seal.
18. The seed meter according to claim 17, wherein the
thrust-bearing element is rotated with the disc when the fixed and
movable portions are closed against one another.
19. The seed meter according to claim 17, wherein the
thrust-bearing element comprises a thrust-bearing plate which can
bear on that surface of the seed disc which faces the seal, in a
zone radially inside of the ring of seed apertures.
20. The seed meter according to claim 19, wherein the
thrust-bearing element comprises a drive element which is fixed for
rotation with the plate and can be coupled with the shaft of the
disc when the fixed and movable portions are closed against one
another.
21. The seed meter according to claim 20, wherein the drive element
is centered relative to the shaft.
22. The seed meter according to claim 20, wherein the drive element
comprises a coupling member which rotates jointly with the
thrust-bearing plate.
23. The seed meter according to claim 17, wherein the movable
portion is mechanically coupled to the fixed portion.
24. An agricultural planter comprising a frame on which a seed
meter according to claim 17 is mounted.
25. An agricultural planter including a supporting structure on
which a plurality of seed meters according to claim 24 are
mounted.
26. An assembly for a seed meter of an agricultural planter wherein
the seed meter is of the type including: a seed disc which is
rotated by a motor-driven shaft at controlled speed; a meter
housing with a fixed portion and a portion which is movable
relative to the fixed portion and can be closed against the fixed
portion; a seed pool area being defined in the fixed portion; a
vacuum area defined in the movable portion; the seed disc being
interposed between the fixed and movable portions and having
opposed surfaces delimiting the seed pool area from the vacuum
area; the seed disc having at least one ring of seed apertures
extending between the opposed surfaces; and a seal which is
arranged on the movable portion and is capable of sliding contact
with the facing surface of the disc when the fixed and movable
portions are closed against one another; wherein a pressure
differential is provided between the opposed surfaces in the region
of a circumferential segment of the ring of seed apertures; wherein
the assembly comprises, in said movable portion, a thrust-bearing
element of the seed disc, which thrust-bearing element is supported
rotatably in the movable portion in order to withstand at least
some of the axial load produced by the disc on the seal.
27. The assembly according to claim 26 wherein the thrust-bearing
element is rotated with the disc when the fixed and movable
portions are closed against one another.
28. The assembly according to claim 26 wherein the thrust-bearing
element comprises a thrust-bearing plate which can bear on that
surface of the seed disc which faces the seal, in a zone radially
inside of the ring of seed apertures.
29. The assembly according to claim 26 wherein the thrust-bearing
element comprises a drive element which is fixed for rotation with
the plate and can be coupled with the shaft of the disc when the
fixed and movable portions are closed against one another.
30. The assembly according to claim 29 wherein the drive element is
centered relative to the shaft.
31. The assembly according to claim 29 wherein the drive element
comprises a coupling member which rotates jointly with the
thrust-bearing plate.
32. The assembly according to claim 26 wherein the movable portion
is mechanically coupled to the fixed portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/793,360, filed Jul. 7, 2015, which is a continuation of U.S.
application Ser. No. 14/006,569 filed Sep. 20, 2013, which is the
National Stage of International Application No. PCT/US2012/030192
filed Mar. 22, 2012, which claims the benefit of U.S. Provisional
Application No. 61/466,047, filed Mar. 22, 2011.
BACKGROUND
[0002] In recent years, growers of corn and other crops have come
to recognize the importance of planting individual seeds at the
appropriate spacing due to increased seed and crop input prices,
but also because they have the ability to monitor the economic
impact of skips, doubles or misplaced seeds using modern planter
monitors. For these reasons modern seed meters have been developed
that include features which improve the singulation of seeds.
However, each added feature increases the amount of time that the
grower must spend replacing wear parts or making other adjustments
prior to or during planting operations. Due to weather and other
factors, the available time to plant corn and other crops is often
extremely limited, with each planter required to cover hundreds of
acres while limited in speed due to reduced seed meter performance
at higher planting speeds.
[0003] Thus, there is a need for a seed meter having improved
singulation and seed spacing capability at higher speeds and which
is also easily repairable and modifiable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 illustrates a side elevation view of a single row
unit of a conventional row crop planter.
[0005] FIG. 2 is a perspective view of an embodiment of a seed
meter.
[0006] FIG. 3 is a partial perspective view of an embodiment of a
seed meter.
[0007] FIG. 4 is another partial perspective view of an embodiment
of a seed meter.
[0008] FIG. 5 is a partial side elevation view of an embodiment of
a seed meter.
[0009] FIG. 6 is another partial perspective view of an embodiment
of a seed meter.
[0010] FIG. 7 is another partial perspective view of an embodiment
of a seed meter.
[0011] FIG. 8 is another side elevation view of an embodiment of a
seed meter.
[0012] FIG. 9 is another side elevation view of an embodiment of a
seed meter.
[0013] FIG. 10 is a partial side elevation view of an embodiment of
a seed meter.
[0014] FIG. 11 is a partial side elevation view of an embodiment of
a seed meter.
[0015] FIG. 12A is a perspective view of an embodiment of a seed
singulator and an embodiment of an axial spring.
[0016] FIG. 12B is another perspective view of an embodiment of a
seed singulator and an embodiment of an axial spring.
[0017] FIG. 12C is another perspective view of an embodiment of a
seed singulator and an embodiment of an axial spring.
[0018] FIG. 12D is another perspective view of an embodiment of a
seed singulator and an embodiment of an axial spring.
[0019] FIG. 13A is another perspective view of an embodiment of a
seed meter.
[0020] FIG. 13B is another partial perspective view of an
embodiment of a seed meter.
[0021] FIG. 13C is a partial perspective view of an embodiment of a
seed meter.
[0022] FIG. 14 is a perspective view of a seed disc, vacuum seal
and an embodiment of an ejector wheel assembly.
[0023] FIG. 15 is a perspective view of a vacuum cover, a vacuum
seal, and an embodiment of an ejector wheel assembly.
[0024] FIG. 16 is a perspective view of a vacuum cover and vacuum
seal.
[0025] FIG. 17A is a perspective view of an embodiment of an
ejector wheel assembly.
[0026] FIG. 17B is a side elevation view of an embodiment of an
ejector wheel assembly.
[0027] FIG. 18A is a side elevation view of another embodiment of a
seed disc and another embodiment of an ejector wheel assembly.
[0028] FIG. 18B is a side elevation view of an embodiment of a seed
disc and an embodiment of an ejector wheel assembly.
[0029] FIG. 18C is a side elevation view of an embodiment of an
ejector wheel.
[0030] FIG. 18D is a top view of an embodiment of an ejector
wheel.
[0031] FIG. 19A is a partial side elevation view of an embodiment
of seed disc.
[0032] FIG. 19B is a cross-sectional view of a seed disc along the
section X-X of FIG. 19A.
[0033] FIG. 19C is a partial perspective view of an embodiment of a
seed disc.
[0034] FIG. 20A is a partial side elevation view of another
embodiment of a seed disc.
[0035] FIG. 20B is a cross-sectional view of a seed disc along the
section Y-Y of FIG. 20A.
[0036] FIG. 20C is a cross-sectional view of a seed disc along the
section Z-Z of FIG. 20B.
[0037] FIG. 20D is a perspective view of an embodiment of a seed
disc.
DESCRIPTION
[0038] Referring now to the drawings, wherein like reference
numerals designate identical or corresponding parts throughout the
several views, FIG. 1 illustrates a single row unit 10 of a
conventional row crop planter. As is well known in the art, the row
units 10 are mounted in spaced relation along the length of a
transverse toolbar 12 by a parallel linkage 14 which permits each
row unit 10 to move vertically independently of the toolbar and the
other spaced row units in order to accommodate changes in terrain
or upon the row unit encountering a rock or other obstruction as
the planter is drawn through the field. Each row unit 10 includes a
frame 16 which operably supports a seed hopper 18, a furrow opening
assembly 20, a seed meter 100, a seed tube 46 and a furrow closing
assembly 50.
[0039] The furrow opening assembly 20 comprises a pair of furrow
opening discs 22 which are rotatably mounted on shafts 26 secured
to a shank 30 comprising a part of the row unit frame 16. The
furrow opening assembly 20 further comprises a pair of gauge wheels
32 rotatably supported by gauge wheel arms 35 also secured to the
frame 16. As the planter is drawn through the field, the rotating
furrow opening discs 22 cut a V-shaped furrow 40 through the soil
surface 36. The egress end of the seed tube 46 is disposed between
the rearwardly diverging furrow opening discs 22.
[0040] In operation, as the planter is drawn through the field
along the direction of travel as indicated by the arrow 38, the
seed hopper 18 communicates a constant supply of seeds 42 to the
seed meter 100. The seed meter 100 meters or dispenses individual
or "singulated" seeds 42 at regularly spaced intervals into the
seed tube 46. The seed tube 46 directs the seeds downwardly and
rearwardly between the diverging furrow opening discs 22 before
depositing the seeds into the V-shaped furrow 40. The seeds are
then covered with soil by the furrow closing assembly 50. A seed
sensor 60 detects the passage of seeds through the seed tube 46 as
is known in the art.
Novel Seed Meter Embodiments
[0041] Embodiments of a novel seed meter 100 are illustrated in
FIGS. 2-20. Referring to FIGS. 2 and 3, the seed meter 100 includes
a housing comprised of a vacuum cover 110 and a seed housing 105.
As described further herein, the seed meter 100 functions by
selecting one seed at a time from seeds communicated into the seed
housing 105 and dispensing each seed through the seed exit 180. A
vacuum inlet 115 is coupled to the vacuum cover 110. Vacuum hoses
or tubes (not shown) connect the vacuum inlet 115 to a vacuum
source (not shown) such as a vacuum impeller.
[0042] The seed housing 105 includes pivots 113 (FIG. 3) and tabs
103 (FIG. 2). When assembled, the tabs 103 extend through holes in
the vacuum cover 110 such that retaining springs 108 may be biased
against pivots 113 and tabs 103 to retain the seed housing 105 in
position against the vacuum cover 110.
[0043] Referring to FIG. 3, the seed meter 100 is shown with the
vacuum cover 110 and other components removed for clarity. A shaft
183 is rotatably coupled to bearings 184. Bearings 184 are held in
place by the vacuum cover 110. A drive plate 186 is coupled to and
rotates with the shaft 183. Drive plate 186 is releasably coupled
to a seed disc 120. Seed disc 120 includes apertures 122 and
preferably includes drive teeth 121. In operation, the seed disc
120 may be rotated by a driven gear (not shown) coupled to drive
teeth 121 (as described further herein) or by a driven shaft (not
shown) coupled to an adapter 185 (FIG. 2) mounted to the shaft
183.
[0044] Turning to FIG. 4, the interior of the seed housing 105 is
shown with the seed disc 120, drive shaft 183 and drive plate 186
removed. A brush 112 is mounted to seed housing 105 such that its
bristles contact the seed-side surface of the seed disc 120. A
singulator 130 is mounted to the seed housing 105 (as described
further herein) which cooperates with the seed disc 120 to
singulate the seeds before they are dispensed through the seed exit
180. The singulator preferably includes multiple singulator
surfaces in contact with a seed side surface 140 of the seed disc
120.
[0045] Referring to FIGS. 5, 6, and 13A-C, seeds are communicated
into the seed meter 100 beneath a baffle 160 mounted to the seed
housing 105. A seed pool area 150 (FIG. 5) is disposed horizontally
adjacent to the seed disc 120 near a bottom end of the seed housing
105 for collection of seeds communicated into the seed meter.
[0046] The height of baffle 160 may be adjusted along guides 164
and 166. The baffle 160 is mounted to the seed housing 105 by rivet
162, which extends outside the seed housing 105 (as best seen in
FIGS. 9 and 13C) and may be moved vertically by the operator along
a notched slot 117 without disassembling the housing. Each notch in
slot 117 is sized to hold the rivet 162 in place such that the
operator can select the height of baffle 160 by pushing the rivet
up and down. As illustrated, visual indicators (e.g., numbers 1
through 4) are preferably located adjacent to the notches for
positioning the rivet 162 at corresponding heights of the baffle
160 for ease of reference.
Removable Floating Singulator Embodiments
[0047] Referring to FIGS. 6-8, the singulator 130 is releasably
mounted to the seed housing 105 so as to bias the singulator
against the seed disc 120 while allowing the singulator to "float"
both axially and longitudinally with respect to the axis of
rotation of the seed disc. The singulator is releasably coupled to
an axial spring 137 by attachment ears 139. The axial spring 137 is
preferably made of a material (e.g., spring steel) which is
elastically deformable. The axial spring 137 is mounted to bosses
142. The bosses 142 are sized such that the singulator 130 is
biased against the face of the seed disc 120 when the seed disc is
in its normal position. Thus, when the seed disc 120 is deflected
axially away from the vacuum cover 110, the tension in axial spring
137 increases, allowing the singulator to remain in contact with
the seed disc without interfering with the rotation of the seed
disc. Likewise, when the seed disc is deflected axially toward the
vacuum cover 110, the tension in axial spring 137 decreases such
that the singulator remains in contact with the seed disc.
[0048] Radial spring 111 is mounted to the seed housing 105 such
that in operation, the radial spring biases the singulator radially
against the seed disc 120 when the seed disc is in its normal
position.
[0049] Referring to FIGS. 12A-D, the singulator 130 is illustrated
in detail attached to the axial spring 137. The singulator 130
includes base 133, arms 136, upper lobe plate 134 and lower lobe
plate 132. The upper lobe plate 134 includes three singulation
lobes, while the lower lobe plate 132 includes two singulation
lobes. In operation, attachment ears 139 grasp the base 133. When
the axial spring 137 is attached to the singulator 130, the
attachment ears 139 extend past and away from the base 133 and are
easily manipulated and deflected. It should be appreciated that
other configurations of the singulator 130 could be used to achieve
the objectives described herein.
[0050] It should be appreciated that the singulator 130 is easily
replaceable with another singulator with a different lobe
configuration for different seeds or if it is necessary to replace
the singular due to wear on the singulator lobes. The singulator
130 is removable by pulling it away from the axial spring 137 with
sufficient force that the attachment ears 139 deflect away from
each other sufficiently to release the base 133. The attachment
ears 139 may also be deflected away from each other with one hand
while pulling the singulator 130 away from the axial spring 137
with the other. Likewise, the singulator 130 may be replaced by
pressing the base 133 of the singulator between the attachment ears
139 with sufficient force to cause the attachment ears to deflect
away from each other to allow the base of the singulator to pass
between them. To replace the singulator, the base 133 may be pushed
between the ears causing them to deflect away from one another
before returning to the normal position in which the base of the
singulator is again secured between the ears. In this way the
singulator 130 may be easily removed and replaced by hand without
the use of tools and without removing or changing the location of
axial spring 137, which remains in the correct location to bias the
singulator 130 against the seed disc 120 while allowing the
singulator 130 to "float" with deflections or deformations of the
seed disc.
[0051] Referring to FIGS. 10 and 11, the seed meter 100 is
illustrated with the seed housing 105 and other components removed
so that the singulator 130 may be seen in its preferred location
biased against the seed-side surface 140 of the seed disc 120. The
seed-side surface 140 is preferably normal to the axis of rotation
of the seed disc 120. The seed-side surface 140 is also preferably
substantially flat with the exception of cavities 128, described in
more detail later. For clarity, only the upper and lower lobe
plates 132 and 134 are shown in FIG. 11. In operation, the seed
disc 120 rotates in the direction indicated by arrow 129 such that
the seed apertures 122 travel along a seed aperture path. A portion
of the seed aperture path is adjacent to the seed pool area 150. As
the seed apertures 122 turn past the seed pool area 150 at the
bottom of the seed housing 105, a vacuum side of each seed aperture
is placed in fluid communication with the vacuum source such that
one or more seeds 42 become entrained over apertures 122. As the
seed-bearing apertures rotate between the upper and lower lobe
plates 132,134, the lobes of the lobe plates bump, rotate and
position the seeds so that only one seed is firmly entrained over
the aperture while the other seeds drop back into the seed pool
150, thereby leaving one seed per aperture. After the apertures 122
rotate past the 3 o'clock position as viewed in FIG. 11, the
apertures 122 are no longer in communication with the vacuum source
resulting in the seeds being released from the apertures and
falling into the seed exit 180.
[0052] Referring to FIGS. 14-16, the vacuum cover 110 includes a
continuous mounting groove into which a vacuum seal 190 is press
fit. In operation, the vacuum seal 190 is pressed against the
vacuum-side of the seed disc 120 and the interior of the vacuum
seal is in communication with the vacuum inlet 115 (FIG. 1) such
that as the apertures 122 rotate past the perimeter of the vacuum
seal 190 toward its interior they are placed in fluid communication
with the vacuum source.
Removable Seed Ejector Assemblies
[0053] It has been found that seeds or partial seeds may become
lodged in the seed apertures 122 and remain there even after the
apertures 122 pass outside of the vacuum seal 190 where no vacuum
is imposed. This is undesirable because when the apertures re-enter
the seed reservoir an additional seed may not be entrained in an
aperture holding a seed or partial seed. Thus, referring again to
FIGS. 14-16, a seed ejector assembly 170 is preferably mounted to
the vacuum cover 110. The seed ejector assembly 170 includes a
shaft 174, a mounting clip 172, a lever arm 175 and an ejector
wheel 176 having plungers 177. The ejector wheel 176 is rotatably
coupled to the lever arm 175. The lever arm is rotatably coupled to
the shaft 174. The shaft is rotatably received within the mounting
clip 172. As best seen in FIG. 15, the mounting clip 172 is
attached to a mounting port 179, which is preferably formed
integrally with the vacuum cover 110. As best seen in FIG. 14, as
the seed disc 120 rotates, the ejector wheel 176 rotates and the
plungers 177 enter each seed aperture 122, knocking out any seeds,
partial seeds or debris in the seed apertures from the back side or
vacuum-side of the seed disc 120.
[0054] As best illustrated in FIGS. 14 and 15, a spring 171 is
preferably disposed between the lever arm 175 and the vacuum cover
110. The spring 171 has a first end held in place at a first end by
a knob 173 on the lever arm 175 and has a second end held in place
by cavity 192 in the vacuum cover 110. It should be appreciated
that the spring 171 biases the ejector wheel 176 against the disc
and allows the seed ejector assembly 170 to "float" with
deflections or deformations of the seed disc 120.
[0055] It should be appreciated that the user may wish to remove
the seed ejector assembly 170 or replace it due to wear on the
ejector wheel 176, to install a differently configured seed ejector
assembly, or for other reasons. As illustrated in FIGS. 16, 17A and
17B, the mounting clip 172 may be easily removed from and
reattached to the mounting port 179 without the use of tools. The
mounting port 179 includes apertures 196 and a tab 195. Mounting
clip 172 includes rigid hooks 197 and resilient hook 198. During
installation, the user first inserts rigid hooks 197 into apertures
196, then preferably presses mounting clip 172 against vacuum cover
110 such that resilient hook 198 deflects around tab 195 and
returns to a relaxed state secured around tab 195. It should be
appreciated that in addition to deflection of resilient hook 198
with respect to mounting clip 172, the mounting clip 172 also
preferably deflects to allow resilient hook 198 to deflect around
the tab 195. After attachment, the mounting clip 172 is secured
against mounting port 179 until the user removes the mounting clip
by bending the mounting clip to release the resilient hook 198 from
tab 195 and then moving the rigid hooks 197 free of the apertures
196.
Alternative Ejector Wheel and Disc Embodiments
[0056] Turning to FIGS. 18A-18D, a modified seed ejector assembly
270 is illustrated in cooperation with a modified seed disc 220.
The seed disc 220 includes an array 224 of apertures 222. The seed
disc 220 further includes an array 234 of guide cavities 232. The
guide cavity array 234 is preferably substantially concentric with
the seed aperture array 224.
[0057] The seed ejector assembly 270 includes a lever arm 275. The
lever arm 275 is preferably pivotally biased toward the seed disc
220 as described herein with respect to the lever arm 175. As best
illustrated in FIG. 18B, the seed ejector assembly 270 also
includes an ejector wheel 276 pivotally mounted to the lever arm
275 and a guide wheel 286 pivotally mounted to the lever arm 275.
Continuing to refer to FIG. 18B, the ejector wheel 276 and the
guide wheel 286 are preferably pivotally mounted to the lever arm
by a retaining pin 272 extending through central apertures in the
ejector wheel and guide wheel. The retaining pin 272 preferably
allows the ejector wheel 276 and the guide wheel to translate
slightly toward and away from the lever arm 275 such that the
ejector wheel and guide wheel are allowed to translate radially
toward and away from the center of the seed disc 220. As best
illustrated in FIGS. 18C and 18D, the ejector wheel 276 includes
radially arranged plungers 278 and the guide wheel 286 includes
radially arranged guide teeth 288. The seed ejector assembly
preferably includes more guide teeth 288 than plungers 278, and
preferably includes three guide teeth per plunger. The ejector
wheel 276 is preferably fixed to the guide wheel 286 such that the
ejector wheel is constrained to rotate synchronously with the guide
wheel. Each plunger 278 is preferably aligned with one of the guide
teeth 288. For example, as shown in FIG. 18D, the upper and lower
plungers 278 are aligned with upper and lower guide teeth along a
plane A1 and the left and right plungers 278 are aligned with left
and right guide teeth along a plane A2.
[0058] In some embodiments of the ejector wheel 276, the plungers
278 include tips 277. In some embodiments of the seed disc 220, the
apertures 222 are tapered to small openings 223 (FIG. 18A). The
tips 277 are preferably sized to fit within the small openings 223.
It should be appreciated that in such embodiments, more precise
alignment of the ejector wheel 276 with respect to the seed disc
220 is necessary in order to knock seeds or debris from the small
openings 223 without interference between the ejector wheel and
seed disc.
[0059] In operation, as the disc rotates, the guide teeth 288
sequentially engage the guide cavities 232. The plungers 278
sequentially engage the seed apertures 222. Referring to FIG. 18A,
the guide cavity array 234 is aligned with the seed aperture array
224 such that each seed aperture 222 is aligned with a guide cavity
232 along a plane (e.g., plane A3) intersecting the center of the
seed disc 220. It should be appreciated that guide teeth 288 engage
guide cavities 232 when the plungers 278 are not engaging the seed
apertures 222, thus moving the ejector wheel 286 to the proper
angular position to successfully engage each seed aperture.
Additionally, it should be appreciated that as the ejector wheel
translates with respect to the retaining pin 272, the guide teeth
232 likewise retain the ejector wheel 286 at the proper radial
distance from the center of the seed disc 220 such that the ejector
wheel can successfully engage each seed aperture 222.
Seed Disc Cavities
[0060] Referring to FIGS. 19A-19C, the seed disc 120 preferably
includes seed disc cavities 128 disposed near the radial edge of
the seed disc. The cavities 128 are preferably disposed to pass
adjacent to the seed pool area 150. Each cavity 128 is preferably
disposed forward of an adjacent seed aperture 122 along the
direction of travel of the seed aperture path. The cavities 128 are
preferably disposed between each pair of seed apertures 122. Seed
apertures 122 are preferably substantially normal to the surface
140 of the seed disc 120; i.e., a central axis of each seed
aperture 122 is preferably substantially normal to the surface 140
of the seed disc 120. Raised surfaces 123 with respect to the
bottom of the associated cavity 128 are preferably disposed between
each aperture 122 and the adjacent cavity 128. The upper surface of
the raised surfaces 123 are preferably co-planar with the surface
140 of the seed disc 120.
[0061] Each cavity 128 preferably comprises an agitation cavity
sized to agitate the seeds in the seed pool area 150. Thus the
cavities 128 are preferably sized to allow significant movement of
seeds 42 into and out of the cavities as each cavity moves adjacent
to the seed pool 150. The outer perimeter of the cavity 128 is
preferably larger than the outer perimeter of the adjacent seed
aperture 122. The area of an intersection between the surface 140
of the seed disc 120 and each cavity 128 is preferably greater than
the area of an intersection between the surface 140 and each seed
aperture 122. It should be appreciated that each seed aperture is
sized to allow limited movement of seeds 42 into the seed aperture.
Moreover, the cavities 128 are preferably wider than the average
size of seeds 42 to be planted using the seed disc 120. Moreover,
the depth D (FIG. 19B) of the cavities 128 is preferably greater
than 0.05 inches.
[0062] Referring to FIG. 10 in combination with FIG. 19, each
cavity 128 preferably has an inner sidewall 242 and an outer
sidewall 240 located at distances Ri, Ro respectively from the
center C (i.e., the central or rotational axis) of the disc. The
difference between the radii Ro and Ri is preferably greater than
the diameter of the seed apertures 122. The radius Ro is preferably
larger than the distance between the seed aperture and the center
of the seed disc 120. The radius Ro is preferably larger than the
radius Ra between a distal end of said seed aperture 122 and the
center of the disc 120.
[0063] In operation, as the seed disc 120 rotates through the seed
pool area 150 located to the side of the seed disc (as best
illustrated in FIG. 11), seeds move in and out of the cavities 128
such that the seed pool is stirred or agitated. This agitation
improves the successful loading of seeds on the seed apertures 122,
particularly at relatively high planting speeds which correspond to
faster seed disc rotation speeds.
[0064] Each cavity 128 preferably includes a sidewall 124 oriented
to face the seed pool area 150 as the cavity rotates into the seed
pool area. The sidewall 124 is preferably substantially vertical
(FIG. 19B), i.e., substantially normal to the surface 140 of the
seed disc 120. As viewed along the rotational axis of the seed disc
(FIG. 19A), the sidewall 124 is preferably curved, and preferably
is semicircular. In operation, the sidewalls 124 sequentially enter
the seed pool area 150 and push the seeds such that the seed pool
is stirred and agitated.
[0065] The cavities 128 preferably include a bevel 126 oriented to
face away from the seed pool as the disc 120 rotates into the seed
pool area 150. An angle A (FIG. 19B) between bevel 126 and the
surface 140 of the seed disc 120 is preferably between 15 and 35
degrees with respect to the surface of the disc. In operation, when
seeds are released from the disc (at approximately the 3 o'clock
position on the view of FIG. 11), seeds occasionally fall toward
the disc and into the cavity 128 located below the seed aperture
122. In such instances, the seed bounces or slides against the
bevel 126, smoothly transitioning the seed back out of the cavity
128 and increasing consistency between seed fall times.
[0066] Although a seed disc 120 is disclosed herein including
series of seed apertures 122 and cavities 128 having the same
radial distance from the center of the seed disc, other embodiments
include rows of seed cavities
[0067] Referring to FIGS. 20A-20D, an alternative seed disc 320 is
illustrated having cavities 328 disposed between seed apertures
322. Each cavity 328 preferably includes vertical sidewalls 324 and
bevels 326. Each cavity 328 preferably includes a beveled inner
sidewall 342 and a beveled outer sidewall 340. The beveled
sidewalls 342, 340 reduce the interior volume of the cavity 328 and
allow seeds to smoothly transition out of the cavity 328 while the
seeds are being agitated in the seed pool area 150. Thus each
beveled sidewall 342, 340 discourages entrapment of seeds in the
cavities 328, particularly smaller seed varieties.
[0068] Although the various improvements described herein are
illustrated with respect to a vacuum-type seed meter, they would be
equally applicable to other seed singulating meters, including
positive-air meters such as that disclosed in U.S. Pat. No.
4,450,979 to Deckler, incorporated herein in its entirety by
reference.
[0069] The foregoing description is presented to enable one of
ordinary skill in the art to make and use the invention and is
provided in the context of a patent application and its
requirements. Various modifications to the preferred embodiment of
the apparatus, and the general principles and features of the
system and methods described herein will be readily apparent to
those of skill in the art. Thus, the present invention is not to be
limited to the embodiments of the apparatus, system and methods
described above and illustrated in the drawing figures, but is to
be accorded the widest scope consistent with the spirit and scope
of the appended claims.
* * * * *