Note: Descriptions are shown in the official language in which they were submitted.
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MIXING DEVICE FOR FODDER
The invention pertains to a mixing device, in particular for
fodder, such as grass, maize and/or feed concentrate.
From EP 1 175 828 a mixing device which can be driven by a
tractor is known which has two augers in a mixing chamber, with
a distributor cone being provided against the wall in the space
between the augers on either side of the mixing chamber. When
the mixing chamber is supplied with the fodder to be mixed, the
augers are operated. Rotating the spiral mixing blade causes the
fodder to be moved upwards, and a horizontal flow of the fodder
is also created. This flow is important for a homogeneous mixing
of the fodder, which is poured into the mixing chamber from
above in random quantities. This flow also has to lead as much
as possible to an equal dosing of the fodder. What has to be
prevented is that a large quantity of fodder is still present in
one section of the mixing chamber, while the section part is
already empty. When the dosing takes up a great deal of time and
proceeds in an irregular fashion, then the speed of the tractor
has to be adjusted to compensate. This effect is further
reinforced by the augers rotating more slowly when the tractor
is driven at a lower speed. Because of the flowing pressure and
the fodder being moved upwards, the fodder is conveyed over the
distributor cone and falls into the space of the other auger on
the other side of the distributor cone. It was found that this
periodic lifting of the fodder requires a lot of power. In
addition, it is important that the section between the augers
also will be completely emptied when dosing. If any fodder
should be left behind, fermentation or mould might occur,
especially when the mixing device has been parked for some time.
The object of the invention is to provide a mixing device where
the horizontal passage between the spaces of the different
augers is hampered as little as possible. Preferably, the design
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of the device has to be such that as little power as possible is
required.
The object of the invention is attained with a mixing device
comprising at least two rotatably driven vertical augers with a
spiral mixing blade. The augers are arranged in a mixing chamber
with a bottom and a wall extending around the augers. In a space
between the augers on either side of the mixing chamber against
the wall a distributor cone with a bevelled edge is provided,
which extends upwards from a lower tip on the bottom to an upper
tip on or near the wall. On either side of the bevelled edge a
guiding surface inclines obliquely towards the bottom. On the
undersides of the bevelled edge of the distributor cones a shoe
is mounted with a guiding surface on either side of a free
folding edge. Both of the guiding surfaces have a side which
connects to the bottom and a side which connects to the
distributor cone. The incline of the folding edge is less steep
than the incline of the bevelled edge of the distributor cone.
This measure makes it possible for the distributor cones to have
a steeper design, while the space between the shoes mounted
opposite one another can be kept small, thus preventing that
fodder will be left behind on the bottom of the mixing chamber,
outside the reach of the augers. Because the distributor cones
can have a steeper design, the passage above the shoes can stay
as wide as possible, so that the horizontal flow-through of the
fodder will be hampered as little as possible.
The shoe can be an integral part of the distributor cone or it
can be designed as a separately mounted part.
The free folding edge of the guiding surface of the shoe is for
instance at an angle of 30 degrees or more to the bottom.
The upper tip of the bevelled edge of the distributor cone can
for instance have shifted vis-à-vis the lower tip of the
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bevelled edge in the direction of the auger, which rotates
towards the said distributor cone. In plane projection, the
bevelled edge of the distributor cone as a result assumes a
sharp angle with the line between the points of rotation of the
two augers. This improves the guiding of the fodder still
further.
The two guiding surfaces on either side of the bevelled edge can
be flat or they can for instance be curved such that the line of
intersection with the bottom has a radius of curvature which,
with play, corresponds to the largest radius of the auger.
Around the bottom reach of at least one of the augers a wear
ridge or wear strip can be provided which is interrupted in the
space between the shoes mounted opposite one another. The wear
ridge can for instance be made of a wear-resistant metal.
At the free bevelled edge the distributor cone can be provided
with a clearance face which inclines obliquely laterally in the
direction of an auger rotating towards the clearance face.
Laterally, the clearance face is at an angle to the line between
the points of rotation of the augers. This angle may be 2 - 10
degrees, for instance 4 - 8 degrees, for instance about 6
degrees. It was found that as a result of this, considerably
less power is required to transfer the fodder from one side of
the distributor cone to the other. The flow-through takes place
in more efficient fashion.
Longitudinally, the clearance face can for instance be at an
angle of 36 degrees or less vis-à-vis the vertical. As a result
of this, the distributor cone has a steeper inclination than for
instance the distributor cones in EP 1 175 828. The passage
between the two distributor cones becomes wider as a result,
allowing the fodder to pass by the distributor cones more easily
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and greatly reducing the risk of fodder, particularly when it is
made up of stalks, such as hay or grass, becoming wedged.
The clearance face can for instance be designed such that it
tapers and narrows from the bottom to the top.
The top of the clearance face and/or of the free bevelled edge
of the distributor cone can have shifted vis-a-vis the underside
of the clearance face in the direction of an auger rotating
towards the distributor cone. Alternatively, however, the top of
the clearance face and/or of the free bevelled edge lies shifted
vis-a-vis the underside of the clearance face in the direction
of an auger rotating away from the distributor cone. In a
further possible embodiment, the top of the clearance face
and/or of the free bevelled edge can be at the same horizontal
distance from the augers as from the underside of the clearance
face and of the free bevelled edge, respectively.
The folding edge of the shoe, in horizontal projection, can for
instance be transverse to the line between the two augers.
Alternatively, however, the folding edge of the shoe can be
designed such that, in horizontal projection, it inclines
obliquely in the direction of an auger rotating towards the shoe
or, on the contrary, in the direction of an auger rotating away
from the shoe.
The side edges of the shoe which connect to the bottom will as a
rule be more or less immediately adjacent to the area where the
auger lobes are moved across the bottom. The location of the
side edges thus is essentially fixed and will remain essentially
unchanged, irrespective of the path followed by the free folding
edge of the shoe.
Very good mixing at low power can for instance be achieved using
an embodiment where the upper tip of the bevelled edge of the
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distributor cone has shifted vis-à-vis the lower tip in the
direction of the auger rotating towards the distributor cone,
while in the case of the shoe the upper tip of the folding edge
has shifted vis-à-vis the lower tip in the direction of the
5 auger rotating away from the shoe.
The free bevelled edge of the distributor cone can for instance
be a linear edge or a convexly or concavely curved edge. In the
same way the folding edge of the shoe can for instance be a
linear edge or a convexly or concavely curved edge.
If so desired, the mixing chamber wall may be provided with a
flanged edge near the distributor cone, with the top of the
clearance face being positioned at the free edge of the flanged
edge.
The mixing device can for instance be a mobile device. In that
case the device can for instance be pulled by means of a
tractor. In that case the augers can also be driven by the
tractor.
The augers can for instance be driven with the same senses of
rotation, but if so desired, they may also be driven with
opposite senses of rotation.
The mixing blade of the augers can for instance be equipped with
one or more knives.
The mixing blade of the auger, which is spiral-shaped, can be of
uniform width. In another embodiment, the width of the mixing
blade can decrease evenly from the bottom to the top.
The invention will be further elucidated with reference to the
drawing, wherein:
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Figure 1A: shows, in top view, a mixing device according to
the invention;
Figure 1B: shows the mixing device in longitudinal section
along the line C-C in Figure 1A;
Figure 1C: shows the mixing device in cross-section along the
line D-D in Figure 1A;
Figure 1D: shows the mixing device in cross-section along the
line E-E in Figure 1A;
Figure 2A: shows, in top view, a second possible embodiment
of the mixing device according to the invention;
Figure 2B: shows the mixing device of Figure 2A in
longitudinal section along the line C-C;
Figure 3A: shows, in longitudinal section, a third possible
embodiment of the mixing device according to the
invention;
Figure 3B: shows the mixing device of Figure 3A in cross-
section along the line B-B;
Figure 4A: shows, in top view, a fourth possible embodiment
of the mixing device according to the invention;
Figure 4B: shows the mixing device of Figure 4A in
longitudinal section along the line H-H;
Figure 5A: shows, in top view, a fifth possible embosiment of
the mixing device according to the invention;
Figure 5B: shows the mixing device of Figure 5A in
longitudinal section along the line C-C;
Figure 6: shows, in top view, a sixth possible embodiment of
the mixing device according to the invention;
Figure 7: shows, in top view, a seventh possible embodiment
of the mixing device according to the invention.
Figure 1A shows, in top view, a mixing device 1 according to the
invention, which is shown in longitudinal section along the line
C-C in Figure 1B. In Figure 1C it is shown in cross-section
along the line D-D, while Figure 113 shows a cross-section along
the line E-E in Figure 1A.
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The mixing device 1 comprises two rotatably driven vertical
augers 2, 3, provided with a spiral mixing blade 4. The augers
2, 3 are arranged in a mixing chamber 5 with a bottom 6 and an
oval closed wall 7 extending around the augers. The mixing
device 1 is provided with a chassis 8 with two wheels 9 and a
coupling device 10 for coupling to a tractor (not shown). When
the mixing device 1 is coupled to a tractor, the tractor can
also rotatingly drive the two augers 2, 3 via an unshown drive
coupling. The two augers 2, 3 in that case rotate with the same
sense of rotation, depicted in the drawing by means of arrows A.
The augers 2, 3 further comprise two lobes 11 rotating across
the bottom 6. The mixing blade or worm blade 4 is spiral-shaped
and gradually decreases in width from the bottom to the top. The
mixing blade 4 is equipped with a number of knives 12.
In the area 13 between the augers 2, 3 on either side of the
mixing chamber 5 against the wall 7 a distributor cone 14 is
provided, with a bevelled edge or folding edge 15 inclining
upwards from the bottom 6 to a top 16 on the wall 7. On either
side of the bevelled edge 15 of the distributor cone 14, a
guiding surface 18, 19 inclines obliquely towards the bottom 6
with a radius of curvature which, with play, corresponds to the
largest radius of the auger 2, 3. The distributor cone 14 on its
bevelled edge 15 is provided with a clearance face 20, which
inclines obliquely in the lateral direction X in the direction
of the auger 2 rotating towards the clearance face 20. The
lateral direction X of the clearance face 20 is at an angle a of
about 10 degrees to the line C-C between the points of rotation
of the augers 2,3.
The longitudinal axis of the clearance face 20 is at an angle of
about 1 degree or more vis-à-vis the vertical, depending on the
width of the mixing chamber, which in practice tends to vary
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from about 1.6 - about 2.4 metres. Because of this the folding
edge or top edge 15 of the distributor cone 14 is steep and the
passage between the two distributor cones 14 is wide, so that
fodder can easily flow through between the two auger spaces.
The top 16 of the clearance face 20 lies shifted vis-a-vis the
underside of the clearance face 20 in the direction of an auger
2 rotating towards the distributor cone 14.
On the underside of the clearance face 20 a shoe 25 is mounted.
The shoe 25 is provided with a triangular or polygonal guiding
surface 26 with a side 27 connecting to the bottom 6 by means of
wear strips 33, 34, a side 28 connecting to the distributor cone
14, and a folding edge 29. The folding edge 29 of the shoe 25,
in horizontal projection, inclines obliquely from top to bottom
in the direction of an auger 2 rotating towards the shoe 25. On
the other side of the folding edge 29 the shoe 25 comprises a
second guiding surface 30 with a side 31 connecting to the
bottom 6 by means of wear strips 33, 34 and a side connectingh
to the distributor cone 14.
Around the lowest outer circumference of the augers 2, 3, wear
strips 33, 34 are provided with some play, extending around the
augers 2, 3 as fully as possible.
In horizontal projection, as shown in Figure 1A, the folding
edge of the shoe 25 and the clearance face 20 are in the same
straight line.
Figures 2A and 2B show another possible embodiment 40, wherein
the distributor cones 14 are not provided with a clearance face.
In horizontal projection, as shown in Figure 2A, the folding
edge 29 of the shoe 25 and the bevelled edge 15 of the
distributor cone 14 are in the same straight line. Wear strips
33, 34 extend around the lowest reach of the augers 2, 3, with
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an interruption in the space between the shoes 25. The
undersides of the shoes 25 and the distributor cones 14 rest on
the wear strips 33, 34.
Figures 3A and 3B show an embodiment 50, which corresponds to
the embodiment 40 from Figures 2A and 2B, except that it does
not have the wear strips 33, 34. The distributor cones 14 and
the shoes 25 rest directly on the bottom 6.
Figures 4A and 4B show an embodiment 60, wherein the distributor
cone 14 is provided with a clearance face 20. The clearance
faces 20 of the two distributor cones 14 are both at right
angles to the line H-H through the points of rotation of the
augers 2, 3. The two clearance faces 20 lie slightly shifted
vis-a-vis the diameter F-F of the mixing chamber 5 in the
direction of the augers 2 and 3, respectively, rotating towards
the shoe 25. The folding edges 29 of the shoes 25 extend from a
point on the clearance face 20 to a lower tip 61 on the bottom 6
on the diameter E-E. In horizontal projection, as shown in
Figure 4A, the folding edge 29 of the shoe 25 thus is at a
slight angle to the longitudinal axis of the clearance face 20.
The shown embodiment 60 is shown without wear strips, but it can
also be realised including wear strips.
Figures 5A and 5B show an embodiment 70, wherein the upper tip
16 of the bevelled edge 15 of the distributor cone 14 has
shifted vis-a-vis the lower tip in the direction of the auger 2,
3 rotating towards the distributor cone 14. In the case of the
shoe 25, on the other hand, the upper tip of the folding edge 29
lies shifted vis-a-vis the lower tip in the direction of the
auger 2, 3 rotating away from the shoe 25 in question. The
bevelled edge 15 of the distributor cone 14 thus makes a kink
with the folding edge 29 of the shoe 25 both in the horizontal
projection of Figure 5A and in the vertical projection of Figure
5B. The guiding surface of the shoe 25, which faces the auger 2
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rotating towards the shoe 25, has a side 28 connecting to the
distributor cone 14. This side 28 is longer than the side 32 of
the other guiding surface 30 of the shoe 25 facing the other
auger 2, 3, which is also adjacent to the distributor cone 14.
5 In addition, the angle a of the side 28 to the bottom 6 in
vertical projection as shown in Figure SB is greater than the
angle p between the side 32 and the bottom 6.
The shown embodiment 70 is shown with wear strips 33, 34, but it
10 can also be realised without wear strips.
Figure 6 shows an embodiment 80, wherein the upper tip 16 of the
bevelled edge 15 of the distributor cone 14 has shifted vis-à-
vis the lower tip in the direction of the auger 2, 3 rotating
twoards the distributor cone 14. In the case of the shoe 25, on
the other hand, both the upper tip and the lower tip of the
folding edge 29 are on the diameter E-E extending in transverse
direction. This embodiment also can be designed with or without
wear strips.
Figure 7 shows an embodiment 90, which corresponds substantially
to the embodiment according to Figures 4A and 4B, except that it
does not have the clearance face 20. In horizontal projection,
as shown in the drawing, the upper tip 16 and the lower tip of
the bevelled edge 15 thus are on a line which runs parallel to
the diameter E-E extending in transverse direction. The free
edge 15 in that case lies slightly shifted vis-a-vis the
diameter E-E in the direction of the auger 2, 3 rotating towards
the distributor cone 14. In the case of the shoe 25, the upper
tip of the folding edge 29 connects to the bevelled edge 15 of
the distributor cone 14, while the lower tip is on the diameter
E-E.
This embodiment 90 also can be designed with or without wear
strips.
