The invention relates to a method for mechanically separating a block of mutually adhering objects, in particular fruits like currants or raisins, by inserting a plurality of profiled agitating members into the block from at least one side, and moving the agitating members in the block, wherein the agitating members are inserted into the block in substantially the same direction and perform a rotating movement around an axis running substantially parallel to the direction of insertion. A method including these steps, albeit for mechanically mixing animal fodder or forage, is known from
When fruits, and particularly somewhat sticky fruits such as for instance currants or raisins, are compressed for a long time, there is a chance that they adhere or stick to each other such that they form a more or less solid block. This occurs for instance when the fruits are packaged in a box or bag which is almost completely full.
Currants and raisins are thus often transported in bulk packaging from the countries where they are produced to processing locations close to the market. At these processing locations the currants or raisins are then removed from the bulk packaging and either re-packed in small packages suitable for retail sale or processed into products such as ready-to-eat meals or dough for currant and raisin pastry. After unpacking of the bulk packaging, the currants or raisins, which often come out of the bulk package as a block, must then be separated again. It is of great importance here that care is taken to prevent damage. On the other hand, the separating must of course take up as little time and manpower as possible.
The prior art document
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There is therefore a need for a method for mechanically separating a block of mutually adhering fruits, in particular currants or raisins, which can be performed rapidly and with relatively little effort, and wherein the fruit is damaged as little as possible. According to the invention this is now achieved in that the agitating members are disposed in mutually adjacent rows, and the agitating members in a first row rotate in the one direction and the agitating members in an adjacent row in the other direction. By making use of agitating members, which can be inserted into the block and then moved carefully, the block is broken into smaller pieces and eventually into individual fruits in relatively rapid and simple manner, wherein the risk of damage is low. The block can be kept in motion very efficiently by the rotating movement of the profiled agitating members. When the agitating member has for instance a helical profile, the block can be moved up and downward on the agitating member by periodically reversing the direction of rotation, whereby the block is shaken apart effectively. Rotating the agitating members in different directions allows an efficient separation to be achieved.
For an optimal effectiveness each agitating member is preferably of at least partly tapering form in the direction of insertion. It can thus be readily inserted into the block, wherein the force on the block increases gradually.
In order to enable the method to be performed with simple means, it is advantageous when the agitating members are disposed fixedly and the block is brought into contact therewith. The agitating members are herein preferably in upright position and the block descends thereon under the influence of the force of gravity. A complicated feed mechanism can thus be dispensed with.
An efficient separation of the objects with minimal damage thereto is in this case achieved when the block is urged upward by the agitating members. The block.thus as it were "dances" on the agitating members under the influence of the opposing influences of the force of gravity and the agitating members, whereby the objects are shaken loose therefrom.
In order to separate the objects in efficient manner the objects separated from the block by the at least one agitating member are preferably discharged through at least one sorting opening, the size of which roughly corresponds to that of the individual objects.
The invention also relates to an apparatus according to claim 7 for separating a block of mutually adhering objects with which the above described method can be carried out. According to the invention such an apparatus comprises a plurality of substantially parallel profiled agitating members adapted to be inserted from a side into the block; and means for moving the agitating members, the moving means being adapted to rotate each agitating member around an axis running substantially parallel to the direction of insertion; wherein the agitating members are disposed in mutually adjacent rows; and the moving means are adapted to rotate the agitating members in a first row in the one direction and the agitating members in an adjacent row in the other direction.
Preferred embodiments of the separating apparatus according to the invention associated with the above described preferred variants of the method form the subject-matter of the dependent claims 9 to 12.
In order to enable proper processing of the block, the agitating members can be disposed in a container accommodating the block to be separated, and the at least one sorting opening can be formed in or close to a bottom of the receiving container, so that the separated objects can leave the container under the influence of the force of gravity.
In order to simplify placing of the block in the separating apparatus, and to prevent separated objects remaining behind in the apparatus, it is recommended that the container is at least partly funnel-shaped and the at least one sorting opening is defined between the agitating members and the funnel-shaped part of the container.
The container can comprise a funnel-shaped part for each agitating member.
So as to prevent reduced blocks of not yet completely separated fruits from leaving the apparatus in such an embodiment via a space between the rows left clear by a number of adjacent agitating members, at least one at least partly tapering, stationary separating member is then preferably disposed therein which partly defines the sorting opening(s).
The invention is now elucidated on the basis of an embodiment, wherein reference is made to the accompanying drawing, in which:
An apparatus 1 for separating a block B of mutually adhering fruits, in particular currants or raisins R, comprises a number of agitating members 2 for inserting from a side into block B. Separating apparatus 1 further comprises means 3 for moving the agitating members 2. In the shown embodiment the agitating members 2, which are tapered or conical in the direction of insertion, are each bearing mounted in a transmission unit 26 fixed in a frame 4. Frame 4 is disposed such that agitating members 2 are oriented practically vertically. Mounted on frame 4 is a container 5 in which block B is received, whereafter it sinks gradually further over agitating member 2 under the influence of the force of gravity. In the shown embodiment the direction of insertion is therefore substantially vertical.
Agitating members 2, six in number in the shown embodiment, are disposed in container 5 in two rows of three. Container 5 is at least partly funnel-shaped, with a relatively wide top side 6 and a narrower underside 7. In the shown embodiment container 5 is of rectangular cross-section, with two long side surfaces 9 and two short side surfaces 10, wherein side surfaces 9, 10 each incline so that a rectangular funnel is formed. In order to further accentuate the funnel shape at the position of each agitating member 2, ribs 11 flaring in a V-shape are formed on the inner side of the inclining side surfaces 9, 10. These ribs 11 also function as friction-loosening members whereby raisins R are scraped or rubbed off the outer sides of block B. On the underside, at the position of the bearing-mounting of agitating members 2, container 5 ends in a peripheral wall 12 which is defined by six cylinders and inside which are incorporated moving means 3.
On the underside 7 of container 5 circular sorting openings 13 are defined between the agitating members and V-shaped ribs 11 on side walls 9, 10. In the centre of container 5, where spaces are left clear in each case between the rows of agitating members 2, these sorting openings 13 are partly bounded by tapering or pyramid-shaped stationary separating members 14, which protrude here slightly less far into container 5 than agitating members 2. The width of sorting openings 13 roughly corresponds with the thickness of the objects R for separating.
On top side 6 the container 5 is provided with covering means 15, here in the form of a transparent lid with a fixed part 16 and a part 17 slidable therealong in rails 18.
Under the influence of moving means 3 the agitating members 2 are each rotatable around an axis A running roughly parallel to the direction of insertion. In the shown embodiment the agitating members 2 are profiled in the sense that a helical rib 19 is welded onto the conical form. Moving means 3 can be adapted to rotate agitating members 2 in a fixed direction such that block B is forced upward by helical ribs 19 counter to the influence of the force of gravity. Block B hereby as it were comes to "dance" on agitating members 2, wherein it strikes each time against ribbed side walls 9, 10 so that raisins R are shaken loose from the sides of block B. Moving means 3 can optionally rotate agitating members 2 reciprocally so that block B is moved alternately up and downward by helical ribs 19, whereby it is shaken even more intensively. Moving means 3 are further adapted to rotate the agitating members 2 in the one row in a first direction R1 and the agitating members 2 in the other row in the opposite direction R2.
For this purpose the moving means 3 comprise a motor 20 which is mounted on a side of container 5 and which via a right-angled transmission 21 drives two parallel screw spindles or worms 22 having screw thread in opposing directions. These worms 22 are in engagement with toothed wheels (not shown here) in transmission units 26 of Agitating members 2, which are thus rotated in opposing directions. It is of course also possible to envisage other transmission methods, for instance by means of toothed belts or chains. For safety reasons motor 20 is otherwise connected controllably to a switch (not shown here) which indicates a closed position of covering means 15.
In the shown embodiment there is further arranged in frame 4 a discharge conveyor 23 which runs under sorting openings 13 and which is driven by a motor 24. Motor 24 can be synchronized with motor 20 of moving means 3 such that discharge conveyor 23 also runs when separating apparatus 1 is in operation. This is important because sorting openings 13 cannot be closed. In the shown embodiment this conveyor 23 discharges the separated objects R to an elevator conveyor 25 which connects thereto and which carries objects R to a subsequent processing station.
The separation of a block B of mutually adhering fruits using apparatus 1 as described above now proceeds as follows. After the slidable part 17 of the lid has been slid open, block B is placed in container 5, wherein it come to rest on the tips of the conical agitating members 2. The lid is then closed again, whereafter motors 20 and 24 are started. Agitating members 2 then start to rotate and, using their ribs 19, release individual fruits R from block B. An increasing amount of space is herein created around agitating members 2, whereby block B drops down increasingly further over the agitating members 2, which thus penetrate still more deeply into block B. Block B is moreover forced upward by the rotation of the profiled agitating members 2 and thus kept in continuous movement. The sides of block B herein come into contact with the ribbed side walls 9, 10 of container 5, whereby fruits R are here also loosened. The fruits R detached out of or from block B fall through sorting openings 13 in the bottom of container 5 onto discharge conveyor 23. Fruits R are discharged by conveyor 23, in this embodiment to elevator conveyor 25, which must therefore be started simultaneously with separating apparatus 1. Block B is thus broken up into individual fruits R with minimal effort and at relatively high speed, wherein the risk of damage to the fruits is minimal.
Although the invention is elucidated above on the basis of one embodiment, it will be apparent that it the invention not limited thereto. The agitating members could for instance have a shape and dimensions other than shown here, and could also be moved in a different way. The number of agitating members and their disposition could also be varied. At least some of the agitating members could for instance be oriented horizontally. In addition, the container could take a different form. The form and position of the sorting openings could also be chosen differently. Finally, a collecting container could for instance also be placed at the bottom of the frame instead of a discharge conveyor, or the frame could be arranged directly above a further processing device, for instance a mixing machine. The scope of the invention is therefore defined solely by the following claims.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.