Note: Descriptions are shown in the official language in which they were submitted.
The invention relates to a seed drill with disc
shares arranged alternately and, as seen in the direction of
travel, staggered in relation to each other, in two transverse
rows arranged one behind the other, and adapted to pivot in a
vertical plane with the aid of holders, the said seed drill
having individual share discs each forming an acute angle of
attack with the said direction of travel.
A seed drill of this kind is already known from
German OS 19366~35. In this machine the individual share discs
are arranged rotatably, in pairs, on holders and run at alter-
nate angles of attack of between ~ and 6 to the direction of
travel. They are also set at an angle of inclination of between
l and 3, running towards the angle of attack, in relation to
a plane running through their lower edges in the direction of
travel. Furthermore, a pressure roller is provided on each
holder behind the share discs. These pressure rollers are not
set at an angle to the direction of travel, nor to a vertical
plane running in that direction.
As may easily be gathered from the drawings attached ;
to the said OS, the said share discs are very thin and have an
outside diameter of about 300 mm, whereas the outside diameter
of the pressure rollers is about 2/3 larger. Finally, the
pressure rollers which are relatively narrow, run exactly cen-
trally of the slots or furrows produced in the ground by the -
share discs.
As regards use for direct sowing, in which the seed
is to be sown in ground untouched since the previous harvest,
this known seed drill has the disadvantage that a substantial
number of the seeds fed to the share discs cannot fall into the
narrow furrows produced thereby and are thus left uncovered on
the surface of the ground. The larger the amount of unrotted
vegetation remaining on the ground since the previous harvest,
and this includes chemically killed weeds and base vegetation,
the more apparent this disadvantage. If this vegetation is
pressed into the soil by -the share discs, not only is the width
of the furrows still further reduced, but the seeds reaching
the furrows fall upon this vegetation and are thus deprived
of the soil cover needed for their growth. In addition to
this, the angle of inclination of the share discs presses the
said vegetation against the walls of the furrow produced in
the soil, which prevents them from being properly closed by
the pressure rollers, all the more so because each pressure
roller has a central rib around its periphery arranged cen-
trally over the furrow.
In addition to this, and because of the small outside
diameter of the share discs, there is a danger of the vegeta-
tion accumulating in front of the discs, thus making it necessary
to interrupt the operation of the machine at frequent intervals
in order to remove these accumulations and allow the share
discs to operate properly. Another disadvantage is that the
share discs, because they are so thin, are subject to relatively
rapid wear, especially in the case of heavy soil containing
minerals, and this means frequent replacement of the discs.
However, in this known seed drill replacements are difficult
because the share discs, with their bearings, must be removed
from the axle bolts in the holders.
It is therefore an object of the present inven~ion to
improve this known seed drill, to ensure that the machine per-
forms satisfactorily, especially when used for direct sowing,
over long periods of use.
According to the invention, this purpose is achieved
in that the individual share discs have an outside diameter of
about 400 mm and a thickness of at least 4mm, and in that the
angle of attack of individual share discs is about 7 to 9.
Even with heavy soils with large amounts of vegetation, thls
arran~ement produces quite broad furrows into which the seeds
fed to the share discs can safely fall. Since, as these furrows
are formed, the soil is pushed aside without being simultaneously
compressed by the share discs, the vegetation lying upon the
ground which, because of its toughness, cannot be cut, is pulled
apart in such a manner as to allow the seeds to fall therethrough
onto the soil at the bottom of the furrows, and thus to be
provided with the soil cover necessary to their growth.
The dimensions of the share discs according to the
invention ensure satisfactory operation of the seed drill
since, on the one hand, the large diameter of the share discs
prevents the accumulation of vegetation in front of them and,
on the other hand, they are sufficiently thick to make replace-
ments for wear necessary only at long intervals, even when the
machine is used in heavy soil containing minerals, and such
replacements may thus be carried out when the machine is not
needed.
Replacement of the share discs is furthermore sub-
stantially facilitated by the fact that each share disc issecured detachably, on one side only, by means of countersunk
bolts, to a hub, the sald hub being mounted rotatably on the
holder and being also removable from one side. This makes it
possible to remove each share disc per se, i.e. i~ can be re-
moved easily from the holder without the hub or the bearing and
a new disc can then be fitted. Removal of the hub with or
without the disc is also simple and easy.
Replacement is further facilitated ln that the
countersunk bolts are in the form of socket head bolts. This
is particularly necessary if a poorly soluble metal adhesive
is used to screw the bolts into the hubs. On the other hand,
this type of attachment ensures particularly secure seating of
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the share discs on the hubs and -thus in the holders.
In one preferred example of embodiment of the seed
drill, in which a pressure roller is located on the holder
behind each share disc, according to the invention the pressure
rollers are also arranged alternately in two transverse rows
arranged one behind the other, and form an acute angle of attack
to the direction of travel, the said angle of attack running
in a direction opposite to that of the angle of attack of the
share discs. Moreover, the said pressure rollers are about
400 mm in diameter and about 100 mm in width. This also
provides large spaces between individual pressure rollers,
which do not become plugged even with large amount of vegeta-
tion. Furthermore, the lateral forces applied by the soil to
the disc shares are equalized for each holder. The closing
and compressing operations of the rollers is also substantially
improved, since earth pushed aside by the share discs, while the
furrows are made, is moved by the said rollers back into the
furrows, after the seeds have been deposited, and is pressed
down again. This ensures continuous covering of the seeds
with soil, with no gaps, thus providing the soil cover required
for rapid growth.
This covering and compressing work may be still
further improved by arranging for the pressure rollers to be
set, towards their angle of attack, at an acute angle of in-
clina-tion to a vertical plane running parallel with the direc-
tion of travel. It has been found advantageous for the angle
of attack and the angle of inclination to amount to about 10.
If the pressure rollers are mounted rotatably upon
the holders and can be removed from one side, this improves the
reliability of the machine over long periods of service, since
the replacement of a defective pressure roller is substantially
simplified and accelerated. To this end, it is desirable for
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the pressure rollers to be removable from the same side of the
holders as the share discs.
Furthermore, the present invention provides for each
pressure roller to roll upon the ridge of earth thrown up by
the share discs in front. This improves the ability of the
said rollers to return the earth to the furrows.
Finally, and according to the invention, the distance
between the transverse rows of share discs and of pressure
rollers, as seen in the direction of travel, is larger than
the distance from the front edge of the share disc and the
rear edge of the pressure roller on the same holder. In this
way, the free passage between the share discs and pressure
rollers in the front transverse row is at no time affected by
the share discs and pressure rollers in the rear transverse row.
This allows large quantities of vegetation to pass the said
discs and rollers without accumulating in front of or between
them. The arrangement also improves the accessibility to the
said discs and rollers, and substantially facilitates, the
replacement thereof.
In one aspect of the present invention, there is
provided a seed drill with disc shares arranged alternately
and, as seen in the direction of travel, in staggered relation-
ship with each other, in two transverse rows one behind the
other, and adapted to pivot in a vertical plane by means of
holders, the said seed drill having individual share discs
each forming an acute angle of attack with the said direction
of travel, characterized in that the individual share discs are
about 400 mm in outside diameter and at least 4 mm in thickness,
and in that the magnitude of the angle of attack for the indi-
vidual share discs is about 7 to 9.
The invention is explained hereinafter in greater
detail, in conjunction with the drawings attached hereto.
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The invention is illustrated by way of example in the accompany-
ing drawings wherein:-
Figure 1 is a plan view of a plurality of share discsand pressure rollers arranged on the seed drill according to
the invention in two transverse rows one behind the other,
Eigure 2 is a rear view, to an enlarged scale, show-
ing the position of a pressure roller in relation to the share
disc in front of it, and
Figure 3 is a plan view, also to an enlarged scale,
of a share disc and the pressure roller associated therewith.
The seed drill according to the invention comprises
a frame 1 equipped with two transverse elements 2,3 arranged
at a distance A one behind the other. Arranged alternately
upon the said transverse elements, with the aid of holders 4,
is a plurality of share discs each consisting of a disc share
5, in transverse rows 7,8 and staggered in relation to each
other, and adapted to pivot in a vertical plane. Since holders
4 are all of the same design, the distance between transverse
rows 7,8, as seen in the direction of travel 6, is the same as
that between transverse elements 2,3. Moreover, as regards
the alternating and staggered arrangement, the lateral distance
between adjacent share discs corresponds exactly to the width
R between the furrows in which the seeds are to be placed.
Each share disc 5 forms an acute angle of attack
of 8 to a straight line 9 running parallel with the direction
of travel 6, the angle of attack of the share discs in rear
transverse row 8 being exactly equal to anyle of attack ~ of
the discs in front of transverse row 7, but running in the opposite
direction. Mounted rotatably upon holders 4, behind share
discs 5, are pressure rollers 10, forming an angle of attack
of 10 to a straight line 9 running parallel with the direction
of travel, and arranged alternately on transverse rows 11,12.
....... .
As seen in the direction of -travel, these transverse rows are
at the same distance A from each other as transverse rows 7,8
of share discs 5. This distance A is substantially greater
than distance L between front edge 13 of a share disc 5 and
rear edge 14 of pressure roller 10 arranged upon the same holder
4.
As shown in Figure 2, pressure rollers 10 also form
an angle of inclination ~ of 10 with a vertical plane running
parallel with direction of travel 6, through a line 15, the
said angle of inclination running in the same direction as
angle of attack ~. Thus each pressure roller 10 runs over
the ridge of soil 17 thrown up by share discs 5, in front of
the said roller, while the furrow is being made, pressing the
said soil back into the said furrows 16.
As shown clearly in Figure 3, each share disc 5 has
an outside diameter D of 400 mm and a thickness d of 4 mm.
Furthermore, each share disc 5 is removable from one side,
being secured to hub 19 by means of four socket head counter-
sunk bolts lg. The said hub may also be removed from one side
of holder 4, upon which it rotates freely on a double roller
bearing 20, being secured against axial displacement by means
of a circlip 21. Share discs 5 are still further secured by
using a poorly soluble metal adhesive when the countersunk
bolts are screwed into hub 19.
Pressure rollers 10 have a width b of 100 mm and the
same outside diameter D of 400 mm. They are also mounted upon
holders 4 and are removable from the same side as the share
discs. Bearing bolt 22 is secured against axial displacement
by folding cotter pin 23.
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