A MECHANICAL SEED METER

COMPTEUR MECANIQUE DE GRAINES DE SEMENCE

English Abstract

A mechanical seed meter having a stationary housing and a rotatable bowl.
The stationary housing is provided with a first axial wall, an outer radial wall and a
flexible inner radial wall. The bowl is provided with seed receiving cells that form a
second axial wall for trapping singled seeds in the seed trapping area. A flexible
and resilient flap maintains the seed in the seed receiving cells. An axially extending
brush removes excess seeds from the seed receiving cells as they pass through the
seed puddle before entering the seed trapping area. The seed slides along the
radial outer wall by centrifugal force until it enters the outlet area from which the
outer radial wall becomes part of the outlet and the metered seed is deposited
through the outlet to a seed tube. Jammed seed, that is seed trapped in the seedreceiving cells, are provided with a downward force by a bump located in the outlet
and an upward force by a rotatable wheel located downstream from the outlet.

French Abstract

La présente invention vise un compteur mécanique de graines de semence, comportant un tambour fixe et un bol rotatif. Le tambour comporte une première paroi axiale, une paroi externe radiale et une paroi interne radiale flexible. Le bol comporte des cellules destinées à recevoir les graines de semence et formant la deuxième paroi axiale servant à retenir les graines individuelles dans la zone de rétention. Un rabat flexible et résilient maintient les graines de semence à l'intérieur des cellules de rétention. Une brosse à montage axial retire les graines de semence retenues en excédent dans les cellules avant leur arrivée dans la zone de rétention. Les graines de semence glissent le long de la paroi radiale externe sous l'effet de la force centrifuge jusqu'à ce qu'elles atteignent le point de sortie de la paroi externe où, après comptage, elle sont introduites dans un tube. Les semences coincées à l'intérieur des cellules sont délogées par l'interaction d'un bossage et d'une roue rotative située en aval du point de sortie.

Claims

The embodiments of the invention in which an exclusive property or privilege
is claimed are defined as follows:
1. A seed meter for an agricultural machine, the seed meter comprising:
a housing having an inlet for receiving seed and an outlet through which
metered seed is dispensed, the housing being provided with an axial inner wall
and
an outer radial wall, a radially extending flexible member mounted to the
housing
defines an inner radial wall, the axial inner wall, the radial outer wall and
the radial
inner wall defining a seed trapping zone;
a bowl being rotatively mounted to the housing, the bowl having a series of
individual seed receiving cells arranged about its axial periphery, the seed
receiving
cells rotatively move through the seed trapping zone, the seed receiving cells
defining an axial outer wall for trapping the seeds in the seed trapping zone;
seed entering the housing through the inlet form a seed puddle between the
housing and the bowl, individual seeds located in this puddle are taken up by
the
seed receiving cells in the bowl as it is rotated through the puddle and are
trapped
therein in the seed trapping zone, seed trapped in the seed receiving cells is
released by the outer radial wall of the housing as the seed is rotated
towards the
outlet, wherein the housing is further provided with a flexible and resilient
flap for
maintaining seed in the seed receiving cells before entering the seed trapping
zone.
2. The seed meter as defined by claim 1 wherein the outer radial wall of the
housing releases the seed from the seed trapping zone by terminating at the
outlet
and beginning again after the outlet.
3. The seed meter as defined by claim 2 wherein the bowl is provided with a
series of grooves corresponding to the individual seed receiving cells and
extending
inwardly therefrom.
4. The seed meter as defined by claim 3 wherein the axial inner wall is
provided with an axially extending flexible member for driving excess seeds
outwardly from the seed receiving cells before the seed receiving cells enter
the
seed trapping zone the flexible and resilient flap being located upstream from
the
axially extending flexible member.
5. The seed meter as defined by claim 4 wherein the radially extending
flexible member and the axially extending flexible members are brushes.

6. The seed meter as defined by claim 5 wherein the radially extending
flexible member is provided with a radially extending bump for imparting a
downward
force for pushing jammed seeds downwardly from the seed receiving cells.
7. The seed meter as defined by claim 6 wherein housing is provided with an
upwardly biassed rotatable wheel located downstream from the outlet for
pushing
jammed seeds upwardly from the seed receiving cells
8. The seed meter as defined by claim 7 the axial inner wall, the radially
extending flexible member, the axially extending flexible member and the
flexible
and resilient flap are mounted to a ring that can be separated from the
housing.
9. A seed meter for an agricultural machine, the seed meter comprising:
a housing having an inlet for receiving seed and an outlet through which
metered seed is dispensed, the housing being provided with an axial inner wall
and
an outer radial wall, a radially extending flexible member mounted to the
housing
defines an inner radial wall, the axial inner wall, the radial outer wall and
the radial
inner wall defining a seed trapping zone;
a bowl being rotatively mounted to the housing, the bowl having a series of
individual seed receiving cells arranged about its axial periphery, the seed
receiving
cells rotatively move through the seed trapping zone, the seed receiving cells
defining an axial outer wall for trapping the seeds in the seed trapping zone;
seed entering the housing through the inlet form a seed puddle between the
housing and the bowl, individual seeds located in this puddle are taken up by
the seed
receiving cells in the bowl as it is rotated through the puddle and are
trapped therein in
the seed trapping zone, seed trapped in the seed receiving cells is released
by the outer radial wall of the housing as the seed is rotated towards the
outlet, an
upwardly biassed rotatable wheel is located immediately downstream from the
outlet
for imparting an upward force on jammed seed in the seed receiving cells.
10. The seed meter as defined by claim 9 wherein the rotatable wheel is
rotatably mounted to a pivot link mounted to a boss on the housing.
11. The seed meter as defined by claim 10 wherein a biassing spring is located
between the pivot link and the housing for biassing the rotatable wheel
upwardly.

Description

CA 02215547 2000-03-28
A MECHANICAL SEED METER
This application is a Continuation-in-Part of US Patent No. 5,720,233.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The invention is directed to improvements in a mechanical seed meter which
can be used on planters, grain drills and air seeders.
2. Description of the Prior Art:
to In the United States the vast majority of crops are planted with row crop
planters, grain drills or air seeders. Row crop planters are designed to place
seeds
in rows far enough apart to permit the control of weeds by cultivation and to
improve
harvesting efficiency. Grain drills and air seeders are used in solid
planting, when
row spacing is too close to permit cultivating or other cultural practices.
All three seeding machines, meter seed so it can be planted uniformly in a
field. The row crop planters usually have the more sophisticated metering
equipment for singling seeds, whereas the drills and air seeders use
volumetric
meters which apply a fixed volume of seed per linear foot.
Singling mechanical seed meters used on planters include seed plate meters,
2 o finger pickup meters and "brush meters". A seed plate seed meter is a
mechanical
seed meter having a rotating plate located at the bottom of the seed hopper.
The
plate is provided with seed cells in which the seed is trapped. If the cells
are the
correct size, only one seed will be trapped in each cell. The plate is then
rotated
over the discharge area and the seed released. U.S. Patents 3,486,659,
4,282,985,
2s and 4,609,131 disclose various configurations for seed plate type seed
meters.
Another mechanical seed meter is the finger pickup seed meter. This meter
is used for corn and comprises a series of fingers that pass through the seed
reservoir. The fingers are initially open in the seed reservoir and then close
trapping
seed between the fingers and a stationary plate. Additional seed trapped by
the
3 o fingers is removed by passing the fingers over indentations in the
stationary plate as
the seed is transported to the discharge area where the finger is opened
releasing
the seed. One example of a finger pickup meter is disclosed in U.S. Patent
3,552,601

CA 02215547 1998-10-27
'S
Recently "brush meters" have been used for metering soybeans, sorghum,
cotton, etc. A vertical rotating seed plate having a plurality of seed cells
around its
periphery passes through the seed reservoir. Seed is trapped in the seed cells
by
brushes. Examples of "brush meters" are disclosed in U.S. Patents 4,924,786,
5,027,725 and 5,058,766.
SUMMARY
It is an object of the present invention to provide a simple mechanical seed
meter for singling seeds. The subject seed meter can be used on row crop
planters,
grain drills and air seeders.
The seed meter of the present invention comprises a stationary housing
having an inlet for receiving seeds from a seed hopper and an outlet through
which
the metered seeds are dispensed into a seed tube. The stationary housing is
provided with a seed trapping zone formed by a first axial wall, an outer
radial wall
and a radially extending brush defining a inner radial wall. The radially
extending
brush extends circumferentially from the seed puddle past the meter outlet.
The
seed trapping zone extending circumferentially about a portion of the inner
periphery
of the housing. A bowl having a plurality of seed receiving cells about its
periphery
is rotatively mounted to the housing by a hub. The seed receiving cells
cooperating
with the seed trapping zone to trap single seeds therein.
The seed receiving cells of the bowl pass through a seed puddle formed
between the bowl and the stationary housing picking up seeds. Seed caught in
the
seed receiving cells of the rotating bowl pass beneath a flexible and
resilient flap
which lightly presses and maintains the seeds received in the seed cells while
loosening any double seeded cells. An axially extending brush located a short
distance downstream from the flexible and resilient flap drives excess seeds
away
from the seed receiving cell. As the trapped seed passes the axially extending
brush it enters the seed trapping zone and is held therein by the seed
receiving cells
until released to the outlet. The seed is released by removing the outer
radial wall
so that the seeds fall into the outlet. The radially extending brush prevents
seed
from entering the outlet directly from the seed puddle. A radially extending
bump is
formed in the brush in the outlet to release any seeds that might become
wedged in
2

CA 02215547 1998-10-27
the seed receiving cells.
An upward biassed wheel is located immediately downstream from the outlet
and contacts the outer rim of the bowl. Seeds stuck in the seed receiving
cells are
pushed upwardly by the wheel loosening the seeds so they can release from the
seed receiving cell on the next pass.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an exploded view of the subject seed meter.
Figure 2 is a side view of the housing and hub of the seed meter.
Figure 3 is a side view of the bowl of the seed meter.
Figure 4 is a front view of the bowl of the seed meter.
Figure 5 is a cross sectional view taken along line 5--5 showing the seed
trapping zone of the seed meter.
Figure 6 is a perspective view of the hub.
DETAILED DESCRIPTION
Figure 1 is an exploded view of the subject seed meter. The subject seed
meter may be used on row crop planters, grain drills and air seeders. It is
particularly useful in row crop planters and more specifically for use with
soybeans
and other crops. The meter comprises a stationary housing 10 having two
elements. The first element is a solid metallic unit 12 which is provided with
a seed
inlet 14 (see Fig. 3) and a seed outlet 16. Unit 12 is provided with a axially
extending spindle 18 to which the rotatable elements of the seed meter are
attached. A wear strip 19 is mounted to the inner wall of unit 12 by tangs,
not
shown, that engage mounting holes in the unit. The wear strip is formed of
resilient
metal having a greater radius than the unit so that it stays in place when
mounted to
the unit.
The second housing element comprises a plastic ring 20 which is secured to
the first housing element 12 by plastic tangs 21, see Fig. 5. Tangs 21 are
received
in receiving apertures 23 formed in unit 12. The plastic ring defines a first
axial wall
22 and a radially extending flexible member 24 comprising a brush. The first
axial
wall 22 and the radially extending brush 24 together with the outer radial
wall 26,
form a seed trapping zone 28 for trapping single seeds S, best shown in Fig. 5
3

CA 02215547 1998-10-27
A hub 30 is rotatably mounted on spindle 18 and is provided with three
screws 32. A bowl 34 is mounted to hub 30 by passing the screws 32 through
curved slots 35 formed in the bowl and securing the bowl thereto by wing nuts
36.
The bowl is best illustrated in Figs. 3 and 4, it comprises a series of seed
receiving
cells 38 which are located around the axial periphery of the bowl. Each cell
is
provided with an inwardly extending groove 40 which helps to introduce seeds
into
the seed receiving cell 38. The width and depth of the grooves becomes smaller
as
the groove approaches the seed receiving cell. As seen in Fig. 5, the seed
receiving cells 38 form a second axial wall in the seed trapping zone to trap
singled
seeds. In addition, rotation of the seeds by the bowl 34 imparts a centrifugal
force
on the seeds forcing them radially outward against the outer radial wall 26.
The ring adjacent to the seed puddle is provided with a flexible and resilient
flap 48. The flap is provided with a base 49 that is mounted to the ring. The
flap
imparts a light downward force on the seed to maintain single seeds in the
seed
receiving cells. The ring is also provided with an axially extending flexible
member
42 comprising a brush having a triangular configuration. This brush is located
between the flap 48 and the seed trapping zone. This brush is held in place by
a
mounting plate 44. The mounting plate 44 is also provided with a screw 46
which is
screwed into ring 20 for securing the mounting plate to the ring.
In operation, seeds from a seed reservoir are deposited in the seed meter
through inlet 14. The seeds collect in a puddle formed between the seed bowl
34
and the housing 10. As the bowl is rotated in a counterclockwise direction,
seeds in
the seed puddle are directed into the seed receiving cells 38 by the grooves
40.
After they enter the cell they are then nudged by the flexible and resilient
insert 48
which loosens any double seeds in the seed cells. After this nudging, the
axially
extending brush 42 drives the excess seeds away from the seed cells so that
only
one seed remains in each seed cell before it enters the seed trapping zone. As
the
seed enters the seed trapping zone it is forced radially outward by
centrifugal force
against the outer radial wall 26 which is formed in the unit 12. It is kept
axially in
place by the first axial wall 22 and the second axial wall formed by seed
receiving
cell 38. The radially extending brush 24 forms the inner radial wall of the
seed
4

CA 02215547 1998-10-27
trapping zone. Brush 24 holds the seed in the seed receiving cells when the
meter
is stopped and when gravity exceeds the centrifugal force of the rotating bowl
acting
on the seed. The brush 24 also provides a flexible area to compensate for
overfilled seed receiving cells without breaking various components. As the
seed
enters the outlet area, the outer radial wall 26 falls away and forms part of
the outlet
16. In this way the seed is dropped into the outlet. The outlet in turn is
coupled to a
seed tube which directs seed into the planting furrow. To prevent seeds in the
seed
puddle from short circuiting the seed meter, the brush 24 extends past the
meter
outlet. A radially protruding bump 49 formed in ring 20 imparts a downward
force on
any seed that maybe wedged in a seed receiving cell, so that the seed
receiving cell
is open to be refilled during its next rotation through the seed puddle. In
addition a
rotatable plastic wheel 80 located immediately downstream from the outlet
provides
an upward force to dislodge jammed seed. The rotatable plastic wheel is
rotatably
mounted to a pivot link 82 that is biassed upwardly by spring 84. The spring
encircles a mounting bolt 86 on which the pivot arm is mounted. The mounting
bolt
in turn is mounted to a boss 88 extending from unit 12.
The hub 30, best illustrated in Figs. 1 and 6 is a plastic disk member 50
having an annular bore 52. The annular bore is mounted to spindle 18 and held
in
place by pin 53 and retaining ring 55. The periphery of the disk member 50 is
provided with a series of steps 54 which correspond to steps 56 formed in the
bowl
34. These steps comprise a means for adjusting the axial position of the bowl
relative to the stationary housing 10. By adjusting the rotative position of
the bowl
34 relative to the hub 30, the axial distance of the bowl 34 relative to the
stationary
housing 10 can be controlled. An indicator means comprising a pointer 60 on
bowl
34 and indicator marks 62 on hub 30 are used to inform the farmer of the
position of
the bowl relative to the hub. By checking a chart the farmer can then
determine the
size of the individual seed trapping areas and change the relationship for
different
seed sizes. The spindle 18 is provided with a coupling member, not shown, for
coupling the spindle to a source of rotative power for rotating the hub and
bowl.
Another feature that should be identified are finger catches 70 which extend
axially outwardly from the bowl and are used to assist the farmer in rotating
the bowl

CA 02215547 1998-10-27
relative to the hub when adjusting the axial position of the bowl relative to
the hub.
In addition the finger catches 70 are used to space the bowls when stacked to
protect the seed receiving cells.
To calibrate the meter, the spindle 18 and the hub bore 52 are provided with
threads. During calibration the deepest step 54 is set so that the bowl is
screwed
onto the spindle until the teeth of the seed receiving cells contact the first
axial wall
22. Calibration is then locked using a split pin inserted through the shaft
and hub.
This calibrating position has no indicating label.
The present invention should not be limited by the above described
embodiments, but should be limited solely by the claims that follow.
6

Representative Drawing