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EP 0 943 408 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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13.06.2001 Bulletin 2001/24 |
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Date of filing: 16.03.1998 |
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A mixing device, in particular for preparing concrete or the like
Mischvorrichtung für Beton, im besonderen
Dispositif de mélange, particulièrement pour béton
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Designated Contracting States: |
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AT BE CH DE ES FR GB GR IT LI NL PT |
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Date of publication of application: |
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22.09.1999 Bulletin 1999/38 |
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Proprietor: MERLO S.P.A. INDUSTRIA METALMECCANICA |
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I-12020 S. Defendente di Cervasca (IT) |
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Inventors: |
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- Merlo, Amilcare
12020 Fr. S. Defendente di Cervasca (IT)
- Galfrè, Renato
12020 Fr. S. Defendente di Cervasca (IT)
- Brondetto, Adriano
12020 Fr. S. Defendente di Cervasca (IT)
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Representative: Marchitelli, Mauro et al |
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Buzzi, Notaro & Antonielli d'Oulx Srl,
Corso Fiume 6 10133 Torino 10133 Torino (IT) |
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References cited: :
DE-C- 510 548 GB-A- 248 658 GB-A- 638 766
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FR-A- 1 143 532 GB-A- 333 492
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| Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The present invention relates to a mixing device, in particular for preparing concrete
or the like.
[0002] Mixing devices can be classified in mixers with fixed or movable casing. The present
invention relates specifically to a mixing device with movable casing.
[0003] Mixing devices with movable casing of the more common type present a rotatable motorized
container having an open mouth for charging the products to be mixed, sometimes used
also for discharging the mixed product by inclinating the container. Within the rotatable
container there are generally provided formations for entraining the product to be
mixed, which are fixed to the container.
[0004] DE-C-510 548 discloses a mixing device according to the preamble of claim 1, including
a disk fixed on a shaft about which the container is rotatably mounted. In the mixing
device disclosed in DE-C-510 548 the rotation of the container raises the product
to be mixed above the disk. Then, the product falls on the upper surface of the disk,
slides thereon and then falls back in the container.
[0005] The problem on which the present invention is based is to provide a mixing device
of the type defined in the preamble of claim 1, which has an improved mixing efficiency
with respect to the known solutions.
[0006] According to the present invention, this object is achieved by a mixing device having
the features forming the subject of claim 1.
[0007] The device according to the invention will now be described in detail with reference
to the annexed drawings, given purely by way of non-limiting example, wherein:
- figure 1 is a schematic perspective view of a mixing device according to the present invention,
- figure 2 is a side elevation view of the device of figure 1, wherein the container has been
sectioned,
- figure 3 is a view according to arrow III of figure 2, and
- figure 4 is a perspective view from a different angle of the device of figure 1.
[0008] With reference to the figures, a mixing device intended in particular for the preparation
of concrete or the like is indicated at 10.
[0009] The device 10 comprises a container 12 rotatable about its axis 14. The container
12 has a bottom wall 16 and a lateral wall 18 which in the example shown in the figures
has a cylindrical shape, whose axis is coincident with the axis of rotation 14. The
end of the cylindrical wall 18 opposite to the bottom wall 16 is open, so as to form
a charging mouth 20.
[0010] As shown in figure 2, on the external side of the bottom wall 16 of the container
12 is located a support 22 fixed to the output shaft of a geared motor assembly 24
which is carried by a stationary base 26. The geared motor assembly drives in rotation
the container 12 about the axis 14. The axis of rotation 14 is preferably arranged
with an inclination α with respect to a vertical direction (figure 2) which is comprised
approximately between 20° and 36°.
[0011] An idle mixing disk is placed within the container 12 and is free to rotate about
its axis of symmetry 30. The disk 28 is carried by a support arm 32 placed outside
the container 12 and connected to the stationary base 26, for example by means of
a pair of parallel flanges 34. The support arm 32 has preferably a bracket configuration
and carries at its free end a hub 36 on which the disk 28 is mounted.
[0012] The disk 28 is contained in a plane which is inclined with respect to a horizontal
plane of an angle comprised between 0° and 20°. The support arm 32 could be provided
with an adjustment mechanism of any known type, adapted to permit a regulation of
the angle of inclination of the disk 28. In alternative, the disk 28 could be in an
invariable position and means could be provided for adjusting the position of the
container 12. The container 12 could also be overturned to permit a rapid discharge
of the mixed product. Adjustment of the relative angular position between the disk
and the axis of rotation of the container could be advantageous for adapting the device
to the characteristics of the product which is intended to be mixed. However, this
adjustment is not indispensable and in the simplest embodiment of the device according
to the present invention the disk 28 and the container 12 are in an invariable relative
position.
[0013] In order to define the relative position of the disk 28 with respect to the container
12 it is convenient to imaginary devide the container 18 with a plane passing for
the axis of rotation 14 and orthogonal to the plane of a representation of figure
2. In this way, the container 12 presents an upper section and a lower section. The
disk 28 is placed substantially tangent to the internal wall of the upper section
of the container 12. The inclined disposition of the disk 28 is such that the diagonal
38 formed by the interception of the plane of the disk with the plane of figure 2
is inclined upwardly in the direction which goes from the wall toward the centre of
the container 12. Furthermore, the zone of the disk 28 placed towards the centre of
the container 12, indicated at H, is at a level with respect to the ground which is
higher with respect to the lower point of the mouth 20, indicated at K. In this way,
a part of the disk 28 will always the above the level of the material to be mixed,
since this level could never exceed the level of point K. In figure 2 it is indicated
at L a generic level of the material to be mixed contained in the container 12. The
disposition of the disk 28 is such that in operation the part of the disk 28 adjacent
to the wall of the container 12 is immerged in the material to be mixed while the
part of the disk 28 placed towards the centre of the container 12 is above the level
L.
[0014] In operation, the rotation of the container 12 about the axis 14 imparts to the material
to be mixed a rotation about the same axis. Since a part of the disk 28 is immerged
in the material in movement, the disk 28 is brought into rotation about its axis 30
by the friction contact with the moving material. In order to increase the entrainment
action of the disk 28 by the material, the disk 28 could by provided with an entrainment
blade 40 fixed to the disk 28 and projecting from the lower surface of the latter.
The entrainment blade 40 is preferably inclined with respect to the axis of rotation
30 of the disk 28 and is placed so that it does not interfere with the walls of the
container 12.
[0015] As stated above, the material to be mixed is maintained in movement by the rotation
of the container 12 and entrain in rotation the disk 28 about the axis 30. The upper
surface of the disk 28 collects therefore a certain quantity of material in the zone
wherein the disk is immerged in the material to be mixed.
[0016] The rotation of the disk transports the material collected on the upper surface of
the disk above the level L. The material placed on the upper surface of the disk 28
is intended to fall beyond the edge of the disk in the zones wherein the disk is raised
with respect to the level L of the material to be mixed. This continuos action of
raising and falling from above of the material produces a mixing action much more
efficient than the one which is obtained only with the rotation of the container 12.
[0017] At the end of the mixing treatment, the material can be discharged from the device
10 by placing a channel-shaped chute 42 below the disk 28. The channel-shaped chute
42 extends above the lowest point K of the container 12 and is carried by a support
structure which is not shown in the figures. The channel-shaped chute 42 is removed
during mixing and is inserted below the disk 28 only when the mixing is over and it
is necessary to evacuate the mixed material. A part of the material which is raised
above the level L by virtue of the rotation of the disk 28 falls on the chute 42 and
flows downwardly outside the container 12 where it is collected for the subsequent
use.
[0018] The device according to the present invention could be modified in various way with
respect to the embodiment disclosed and illustrated. For example, the container 12
could have a different shape since the cylindrical profile of the lateral wall is
not essential for carrying out the invention.
1. A mixing device, in particular for preparing concrete or the like, comprising
- a motorized container (12) having a charging mouth (20), rotatably mounted about
a first axis (14) and
- a mixing disk (28) arranged within the container (12),
characterized in that the mixing disk (28) is free to rotate about a second axis (30) and is arranged so
that in use it extends partly above and partly below the level (L) of the material
to be mixed.
2. A mixing device according to claim 1, characterized in that the disk (28) is contained in a plane inclined with respect to a horizontal plane
of an angle comprised between 0° and 20°
3. A mixing device according to claim 1, characterized in that the axis of rotation (14) of the container (12) is inclined with respect to a vertical
direction of an angle approximately comprised between 20° and 36°.
4. A mixing device according to claim 3, characterized in that the container (12) has a bottom wall (16) fixed to a support (22) connected to the
output shaft of a geared motor assembly (24) carried by a stationary support base
(26).
5. A mixing device according to claim 4, characterized in that said disk (28) is mounted in a freely rotatable way at the end of an arm (22) carried
by said stationary support base (26).
6. A mixing device according to claim 1, characterized in that it comprises an entrainment blade (40) fixed to the disk (28) and projecting from
the surface thereof facing in the container (12).
7. A mixing device according to claim 1, characterized in that it comprises a chute (42) for evacuating the mixed product, arranged in an inclined
position below a zone (H) of the disk (28) and above a zone (K) of the mouth (20).
1. Mischvorrichtung, insbesondere zur Herstellung von Beton oder dergleichen, umfassend:
- einen motorisierten Behälter (12) mit einer Beschickungsöffnung (20), der um eine
erste Achse (14) drehbar gelagert ist; und
- eine Misch-Scheibe (28), die in dem Behälter (12) angeordnet ist,
dadurch gekennzeichnet, daß
die Misch-Scheibe (28) frei um eine zweite Achse (30) drehbar und so angeordnet ist,
daß sie im Betrieb teilweise über und teilweise unter der Höhe (L) des zu mischenden
Gutes läuft.
2. Mischvorrichtung gemäß Anspruch 1, dadurch gekennzeichnet, daß die Scheibe (28) in
einer Ebene enthalten ist, die in einem Winkel zwischen 0° und 20° zur Horizontalebene
geneigt ist.
3. Mischvorrichtung gemäß Anspruch 1, dadurch gekennzeichnet, daß die Rotationsachse
(14) des Behälters (12) bezüglich einer vertikalen Richtung in einem Winkel von ungefähr
20° bis 36° geneigt ist.
4. Mischvorrichtung gemäß Anspruch 3, dadurch gekennzeichnet, daß der Behälter (12) eine
Bodenwand (16) aufweist, die an einer Halterung (22) befestigt ist, die an die Kraftabgabewelle
einer von einem stationären Unterbau (26) getragenen untersetzten Motoranordnung (24)
angeschlossen ist.
5. Mischvorrichtung gemäß Anspruch 4, dadurch gekennzeichnet, daß die Scheibe (28) frei
drehbar am Ende eines von dem stationären Unterbau (26) getragenen Armes (32) gelagert
ist.
6. Mischvorrichtung gemäß Anspruch 1, dadurch gekennzeichnet, daß sie ein Mitnahmeblatt
(40) umfaßt, das an der Scheibe (28) befestigt ist und von deren dem Behälter (12)
zugewandten Oberfläche absteht.
7. Mischvorrichtung gemäß Anspruch 1, dadurch gekennzeichnet, daß sie eine Schüttrinne
(42) zum Abtransport des Mischproduktes umfaßt, die in einer geneigten Stellung unter
einer Zone (H) der Scheibe (28) und über einer Zone (K) der Öffnung (20) angeordnet
ist.
1. Appareil de mélange, destiné en particulier à la préparation de béton ou analogue,
comprenant :
un réceptacle (12) entraîné par un moteur, ayant une embouchure (20) de chargement
et monté afin qu'il tourne autour d'un premier axe (14), et
un disque de mélange (28) disposé dans le réceptacle (12),
caractérisé en ce que le disque de mélange (28) est libre de tourner autour d'un
second axe (30) et il est disposé afin que, pendant l'utilisation, il s'étende partiellement
au-dessus et partiellement au-dessous du niveau (L) du matériau à mélanger.
2. Appareil de mélange selon la revendication 1, caractérisé en ce que le disque (28)
est contenu dans un plan incliné par rapport à un plan horizontal d'un angle compris
entre 0 et 20°.
3. Appareil de mélange selon la revendication 1, caractérisé en ce que l'axe de rotation
(14) du réceptacle (12) est incliné par rapport à une direction verticale d'un angle
approximativement compris entre 20 et 36°.
4. Appareil de mélange selon la revendication 3, caractérisé en ce que le réceptacle
(12) a une paroi de fond (16) fixée à un support (22) raccordé à l'arbre de sortie
d'un ensemble motoréducteur (24) porté par une base fixe de support (26).
5. Appareil de mélange selon la revendication 4, caractérisé en ce que le disque (28)
est monté afin qu'il puisse tourner librement à l'extrémité d'un bras (22) porté par
la base fixe de support (26).
6. Appareil de mélange selon la revendication 1, caractérisé en ce qu'il comprend une
palette d'entraînement (40) fixée au disque (28) et dépassant de la surface de celui-ci
tournée vers le réceptacle (12).
7. Appareil de mélange selon la revendication 1, caractérisé en ce qu'il comprend une
goulotte (42) d'évacuation du produit mélangé, disposée en position inclinée au-dessous
d'une zone (H) du disque (28) et au-dessus d'une zone (K) de l'embouchure (20).