Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to a seed-drill with
single-disc shares, arranged alternately, and spaced laterally
from each other, in at least two -transverse rows lying one
behind the other, upon an equal number of transverse carriers
located with similar spacing one behind the other, the said
shares being adapted to pivot in a vertical plane with the
aid of holders, and being set at an acute angle to the
direction of travel.
A seed-drill of this kind is described in U.S.
Patent 3,705,560. In this machine, the holders of ~he single-
disc shares have at least two hinged arms arranged one above
the other and at least approximately parallel with each other.
The advantages of this machine is that, even in
weed-ridden fields, the seed can be sown in relatively closely~
spaced rows, since the distances between individual single-disc
shares on one transverse carrier are so great that it is
impossible for jamming to occur, even with large amounts of
vegetation. Moreover, the same holders are used for all of
the shares. The parallelogram design of the holders also
promotes satisfactory sowin~, since the angle of incidence
of the shares is independent of the depth of penetration.
One of the disadvantages of this machine is that ~-
the bearings upon which the shares rotate upon the holders are
narrow, wear rapidly, and need frequent replacement during the
life of the machine. The replacement is labour and time-
consuming, since the bearings are retained at both ends by
parts of the holders. Furthermore, if bearing defec-ts develop
while the machine is in use, undesirable interruption of the
sowing operation arises.
This disadvantage is particularly serious if the
machine is being used for direct-seeding, i.e. in fields which
have not been prepared for seeding, since the previous harvest,
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in the conventional manner, by means of soil-cultivating
equipment. The ground in such fields is hard and considerable
lateral ~orces ~herefore act upon the shares, set at an angle
to the direction of travel, and therefore upon the bearings
thereof. Even with a small amount of wear in the bearings,
the shares can no longer produce furrows of the necessary width
for seeding. Instead, they form narrow channels into which the
seeds do not fall and are therefore left lying on the ground
uncovered. This is aggravated by the fact that this fault is
apt to go unobserved for some time, resulting in a considerable
reduction in yield.
The narrow bearings carrying the holders on the trans-
verse carriers have the same disadvantages. Moreover, the
effect of wear in these bearings is such that guidance of the
shares in the ground is affected by varying lateral pressures
acting upon them, and the seed-furrows can no longer be kept
straight.
Now it is the purpose of the present invention to
improve the arrangement of the single-disc shares and their
holders upon the transverse carriers, in such a manner that the
seed-drill will sow satisfactorily over long periods, even
when used for direct seeding.
According to the invention, this purpose is achieved
in that wide bearings are provided for mounting the single-disc
shares upon the holders, and for mounting the said holders
upon the transverse carriers, the said shares being mounted,
easily detachably, upon one side of the said holders, and the
said holders being secured to brackets arranged upon the
transverse carxiers. This reduces wear in the bearings carry-
ing the shares on the holders and in the bearings carrying theholders on the transverse carriers, thus ensuring that the said
bearings will have a long life. Furthermore, the arrangement
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provides for simple installation and removal o~ the shares and
holders if any defects arise, since the said components may be
removed laterally and new components may be similarly replaced
laterally upon the corresponding parts.
A particularly durable and wear resistant bearing for
the shares may be obtained by using for each share two anti-
friction bearings spaced laterally from each other.
In the case of a seed drill according to the invention
in which the holders for the single disc shares comprise at
least two hinged arms located one above the other and at least
approximately parallel with each other, provision is also made
for the bearings, at least in the lower arms, on the transverse
carriers, to be almost as wide as the lateral distance between
the shares arranged on one transverse carrier. This produces
a particularly rugged and stable mounting for the holders,
advantageously designed in the form of parallelograms. A
simple and durable design is achieved, without in any way im-
pairing stability, by providing the bearings, at least for the
lower arms of the holders, with bearing elements made of a
synthetic material,
If the lower arms of the holders are designed to
resist torque, the transverse forces, applied by soil resistance
to the shares, will be absorbed, in a favourable manner, just
above the shares. The resulting torque will therefore be kept
within limits and this, in turn, will have a favourable effect
upon the bearings carrying the arrns on the transverse carriers.
Moreover it is also possible, as a result of this arrangement,
to make the upper arms of the holders significantly lighter, ~;
since all they have to carry is the compressive and tensile
loads acting in the direction of travel.
According to a preferred example of embodiment of
the invention, the arms for the holders are hinged to vertical
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carriers equipped at their lower ends with holder parts running
in the direction of travel, the bearings for the single disc
shares being located on the front holder parts, and a lateral
distance being provided between each of the said bearings and
the lower arms.
Finally, in the design according to the invention,
pressure rollers, in alignment with the single disc shares
located on the front holder parts, are mounted to rotate freely
on the rear holder parts, upon vertical carriers, the said
pressure rollers being set at an angle of incidence running in
a direction opposite to that of the angle of incidence of the
said s~gle disc shares. In this way, the lateral forces pro-
duced by soil resistance, and acting upon the single disc shares,
are very largely compensated for by the lateral forces acting
upon the pressure rollers, with the result that the bearings
provided for the holders are subjected to substantially less
stress.
The invention is explained hereinafter in greater
detail, in conjunction with the drawings attached hereto, and
which illustrate the invention by way of example, wherein:
Figure 1 is a side elevation of a seed drill accord-
ing to the invention, and
Figure 2 is a diagrammatic representation, in plan
view, of the arrangement of the single disc shares.
The seed drill according to the invention comprises
a frame 1 upon which is arranged alternately a plurality of
single disc shares, at equal distances S from each other,
adapted to pivot in a vertical plane, with the aid of holders
4 on two transverse carriers 5, the distance Z between trans
verse carriers 5, as seen in the direction of travel indicated
by arrow 6, being equal to the distance between the two trans-
verse rows 3.
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Each holder 4 has two arms 7,8 located one above the
other, the rear ends of which are hinged to a vertical carrier
9, whereas the front end of upper arrn 7 is hinged to an adjust-
ing mechanism 10 and the front end of lower arm 8 is hinged
to frame 1 in such a manner that it pivots in a vertical plane.
The lower ends of carriers 9 are equipped with holder parts 11
extending forwardly, as seen in the direction of travel 6,
upon which single disc shares 2, forming an acute angle of
incidence ~ in relation to the said direction of travel, are
mounted to rotate freely upon wide bearings 12 arranged on one
side of the said holder parts. Mounted rotatably upon holder
parts 13 extending rearwardly from carriers 9, and behind
shares 2, are pressure rollers 14 forming an angle of incidence
~, in relation to the direction of travel, the said angle
running in a direction opposite to that of angle ~.
In this design, single dîsc bearings 12 each have two
anti-friction roller bearings spaced widely apart by a distance
L. The same bearings are used, in a one sided arrangement,
for the pressure rollers 1~ mounted on rear holder parts 13.
In contrast to this, bearings 16 of torque resistant
lower arms 8 are equipped with bearing elements 17 made of a
synthetic material and are of a width B which is less than
lateral distance ~, between the shares arranged upon a transverse
carrier 5, only by the width of bearing brackets 18.
Vertical carriers 9 are arranged pivotably upon one
side of arms 7,8 by means of wide bearings 19 which are also
provided with bearing elements 17 made of a synthetic material.
This arrangement is such that a lateral distance D exists between
each single disc share bearing 12 and lower arm 8.
Adjusting mechanism 10 comprises, for each transverse
row 3 of shares, levers 22 united by transverse tubes 20,21,
the levers in the rear transverse row being connected to those
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in the front transverse row by means of struts 23. Adjusting
spindle 24 allows levers 22 to be pivoted back and forth in
the direction of travel 6. This alters the inclination of
vertical carriers 9 and produces, in conjunction with pressure
rollers 14, variations in the depth of penetration T of the
shares into the soil.
While the machine is in operation, seed in storage
tank 25 is fed, through metering unit 26, and seed lines 27, to
single disc shares 2, when it falls into seed furrows 28 pro-
duced by the said shares.
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