Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Technical Field
.
This inve~tion relates to seed deposition apparatus
such as, for example, a seed drill.
It has been appreciated that the crop yield per unit
area can be increased by sowing the seeds more evenly
over the area, and that if cereal seed is sown randomly
in rows then a row spacing of approximately 2~ inches
closely approaches the ideal seed spacing. However,
such close row spacing presents technical pro~lems with
conventional coulters because of the restricted space
in which they have to operate. This is true of
conventional double disc coulters in which seed and
fertilizer is generally fed to the space between the
two discs so as to fall into the slit formed by them in
the ground.
It has also been appreciated that fertilizer is best
placed away from seeds to avoid scorching and that the
fertilizer is used to the best advantage to give
increased yields if it is placed below but within 2
inches of the seeds. ~lso, it is known to provide a
single disc coulter with seed and fertilizer feed rneans
that supplies seed and fcrtilizer alongside onc another
in the slit formed by the disc wlth the fertilizer
below the seed.
Disclosure of the Invention
-
~n object of the present invention is to provide a
coulter that is suitable for sowing rows of seed at a
close spacing of approximately 2~ inches with fertilizer
below but within 2 inches of the seed.
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This object is achieved according to the invention by
providing a coulter comprising a double disc opener
with first feed means that feeds material to the space
between the discs so as to pass into the slit opened in
the ground by the discs characterised in that second
feed means is provided adjacent to the outer face of one
or each disc so as to feed material to the soil along-
side said slit.
If the second feed means feeds material to both sides of
the discs, then they can sow two rows at the required
spacing of 2~ inches, the minimum limit on the spacing
being determined by the width of the two discs.
Placement of fertilizer below the level of the seeds can
be achieved by feeding fertilizer between the discs to
the deepest part of the slit opened by them.
Preferably, a soil engaging member is located adjacent
to the outer face of one or each disc so as to engage
the soil and form a furrow in the adjacent shoulder of
said slit of a shallower depth than said slit, said
second feed means serving to Eeed material into said
furrow.
Each soil engaging member may take the form of a plate-
like member located alongside the disc to deflect soil
away from it and so form the furrow. Possibly said
second feed means carries said plate-like member at its
lower end.
Alternatively, the soil engaging member may incorporate
the second feed means, for example, said soil engaging
member may comprise a tubular feed member with a lower
end that engages the sround to form the furrow.
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Description of the Drawings
The invention will now be described by way of example
with reference to the accompanying drawings in which:-
Figure 1 is a side view of a coulter according to oneembodiment of the invention,
Figure 2 is a plan view of the coulter of Figure 1,
Figure 3 i5 a rear view of the coulter of Figure 1,
Figure 4 is a schematic drawing showing the form of the
openings made in the soil by a coulter or coulters
according to Figure 1,
Figure S is a schematic drawing showing the form of the
openings made in the soil by a modified form of the
coulter of Figure 1,
Flgure 6 is a side view of a modified form of the
coulter of Figure 1,
Figure 7 is a side view of a coulter according to an
alternative embodiment of the invention,
is a rear view of the coulter of Figure 7,
Figure 9 is a side view o the coulter of Fi~ure 1
fitted with depth control means, and
~ure 10 is a side view of the coulter of Figure 1
fitted with seed covering means.
Description of the Best Mode of Carrying out the
Invention
Figures 1 to 3 illustrate a coulter according to the
invention comprising a double disc opener, the two
discs 1 being rotatably supported on either side of an
axle support block 2 that is connected to a drag bar 3.
The axes of the two discs 1 are inclined such that the
discs converge downwards and forwards in the convent-
ional manner for a double disc coulter. The support
block 2 projects above the edges of the discs along
their upper forward portions and is formed with an
aperture 4 that passes downwards from the upper surface
of the block 2 and opens above the ground between the
discs. The upper end of the aperture 4 is adapted to
receive the delivery end of a fertilizer supply pipe 5
so that fertilizer can be fed into the centre of the
slit formed between the discs (See Figure 4).
A soll engaging device 7 is provided adjacent to the
outer face of each disc 1 so as to form a furrow 8 in
the shoulder of said slit 6 and to feed seed into said
furrow (See Figure 4). Each device 7 comprises a
tubular conductor 9 that is connected to the top of the
support block 2 via a support flange 10 and extends
downwards and rearwards above the disc hub 11 terminating
just beyond the trailing peripheral edge of the disc. An
apexture 12 in the flange 10 communicates with the upper
end of the conductor 9 and is adapted to receive the end
of a seed supply pipe 13. The conductor 9 is substantially
triangular in section and has an inner face 14 alongside
the disc 1 and an outer face 15 that diverges rearwards
away from the disc 1 so that it readily deflects soil
outwards to ~orm said furrow 8. The inclination OL the
leading edge of the conductor 9 further aids said soil
deflection. The open lower end 16 of the conductor 9
terminates in a plane that is inclined rearwards and
upwards from the disc at an acute angle with the ground
surface so as to direct seed more effectively into the
ground (See Figure 1).
The form of the opening made in the soil by the coulter
of Figures 1 to 3 is shown schematically in Figure 4,
the seeds being placed in the furrows 8 formed by the
lower ends of the conduc~ors 9 at a spacing of x = 2~
inches, and the fertilizer being placed in the deeper
central slit 6 between the two furrows 8 formed in the
shoulders of the slit. The drawing shows a cross-
section through three coulter passes spaced 2 x = 5
inches apart so that the adjacent rows of seed of
adjacent passes are also spaced 2~ inches apart.
The coulter of Figures 1 to 3 can also be used to sow a
single row of seeds by feeding seeds to just one of the
conductors 9. This would be desirable in sowing crops
such as peas and beans or sowing seeds in conditions
that will not support narrow rows but where placement of
fertili~er away from the seeds is essential. Further,
the coulter could be especially adapted to sow single
rows by providing just one conductor 9 alongside one of
the discs. The form of the opening in the ground made
by such a modified coulter is illustrated schematically
in Figure 5, three adjacent coulter passes at 5 inch row
spacing being shown.
In order to ensure that the seed is placed accurately in
the furrows 8 and does not fall into the central slit 6,
the conductors 9 may be a~apted at their lower ends so
s~
as to direct the seed outwards.
The conductors 9 of the coulter illustrated in Figures
1 to 3 terminate just beyond the rear peripheral edges
of the discs 1 but it will be appreciated that they may
terminate short of the edges of the discs 1. Such an
embodiment is illustrated in Figure 6. In this embodi-
ment, because the lower end of the conductor 9 is
directly alongside the disc 1, the shoulder of the
central slit 6 is supported by the disc 1 as the furrow
8 is formed in it. The chance of the shoulder of the
slit collapsing as the furrow is formed is therefore
reduced.
The embodlment of Figure 6 also illustrates another
change in arranging the conductors 9 so that they are
~ore upright and are located rearwards of the hub 11.
Another alternative embodiment of the invention is
illustrated in Figures 7 and 8 in which the soil engaging
device 7 comprises a plate-like soil deflector 17 having
a leading edge 18 that is spaced close to the outer ~ace
of the adjacent disc 1 and diverges rearwards away from
said face. The leading edge 18 is also inclined rear-
wards irom top to bottom and the deflector plate as a
whole converges downwards towards the disc. The rear
edge of the deflector plate is spaced away from the disc
to allow the escape of seed.
Seed is fed to the space between the deflector plate 17
and disc 1 by a tubular conductor 19. The deflector
plate 17 is carried on the lower end of the conductor 19
and is connected to it by two rivets 20. The conductor
19 is connected at its upper end through a flange 10 to
the disc support block 2 in a similar manner to that in
the embodiment of Figures 1 to 3. A seed supply pipe
feeds seed to the conductor through an aperture 12 in
the flange 10.
In an alternative embodiment the deflector plate 17 may
be supportea independently of the conductor 19.
Separate metering units may be provided to feed seed to
each outer conductor 9, 19 and to feed fertilizer to the
aperture 4 hetween the discs. Elowever, in an alternative
embodlment a single seed metering unit may be provided
and the flow split between the two outer conductors 9,
19. In yet other embodiments, the seed may be fed to
the aperture 4 between the discs and the fertilizer fed
to the two outer conductors 9, 19. The actual feed of
seed and fertilizer may be by gravitational or pneumatic
action.
Although the double disc opener is inherently suitable
for maintaining a constant sowing depth, separate depth
control means may be provided. This may take the ~orm
of a press-wheel bchind the discs, an annular flange on
the outer face of one or both discs, or a skid trailing
from the drag bar.
depth control device is illustrated in Figure 9
comprising a pair of skids 21 that are connected to the
drag bar 3 by a pivot pin 22 and trail either side of
the discs 1, each skid passing round the adjacent
conductor 9 to the rear of the discs. The skid is
formed from a strip of sheet or plate metal and is
twisted through 90 in front of the conductor 9 from a
horizontally orientated portion 23 to an upright
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orientated portion 24. The portion 23 acts as the
depth control device, the depth being controlled by
adjustment of a screw 25 that couples the two skids to
the drag bar 3 rearwards of the pivot pin 22.
The twisted portion of the skid between portions 23 and
24 and the leading end of the upright portion 24 serve
as a soil deflector. The trailing ends 25 of the skids
are turned inwards towards one another and serve as seed
covering means.
A coulter according to the invention may be provided
with seed covering means 26 that is connected to the
seed conductors 9 on either side of the discs and trails
behind them as shown in Figure 10. Depth control means
such as a press- wheel may similarly be connected to the
seed conductors so as to trail behind the discs.
