Abstract:
An apparatus for handling portions of products, in particular food products, includes a product conveyor which conveys the portions sequentially along a conveying direction and at least one sensor which serves to determine the weight of the conveyed portions. The apparatus includes an automatic weight compensation unit which is arranged in the vicinity of the product conveyor and which serves additionally to place at least one single product on a portion in dependence on the determined weight of the portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application claims priority from German Patent Application No. DE 10 2010 012 727.2, filed Mar. 25, 2010, entitled “APPARATUS FOR HANDLING PORTIONS OF PRODUCTS,” which is fully incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to an apparatus for handling portions of products and, more particularly, to an apparatus for handling portions of food products. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention relates to an apparatus for handling portions of food products, the apparatus having a product conveyor which conveys the portions sequentially along a conveying direction and having at least one sensor which serves to determine the weight of the conveyed portions. 
         [0004]    Such an apparatus can be used, for example, in the food industry to supply product slices cut off by a cutting apparatus, such as a high-performance slicer, portion-wise to a downstream processing apparatus, for example to a packaging machine. The weight of each conveyed portion is determined by means of the sensor. To ensure that only those portions are further processed which satisfy a preset weight specification, portions of incorrect weight are either sorted out or are brought to a required desired weight by a manual correction before the further processing. Both ultimately impair the efficiency of the production plant. 
         [0005]    It is therefore an object of the invention to provide an apparatus which allows a more efficient handling of product portions. 
         [0006]    This object is satisfied by an apparatus having a product conveyor which conveys the portions sequentially along a conveying direction and having at least one sensor which serves to determine the weight of the conveyed portions. 
         [0007]    In accordance with the invention, the apparatus further includes an automatic weight compensation unit which is arranged in the vicinity of the product conveyor and which serves additionally to add at least one single product to a portion in dependence on the determined weight of the portion. A low-weight portion can be brought to a desired or predetermined weight by the addition of single products, for example single cut product slices, to an existing portion. A sorting out or a manual correction of portions of incorrect weight is thus superfluous. The throughput of conveyed portions and thus also the efficiency of the total plant is increased by the automatic weight compensation. 
         [0008]    The invention disclosed herein can be implemented in various ways, some examples of which are set forth in the description and shown in the accompanying drawing. 
         [0009]    In accordance with an embodiment, a product supply separate from the product conveyor is associated with the weight compensation unit and sequentially provides single products to the weight compensation unit. The weight compensation unit in this way always has a sufficient number of individual products for a weight compensation. The separate product supply can, for example, be fed from the same cutting apparatus as the product conveyor or a separate cutting apparatus can be provided for the product supply. 
         [0010]    The weight compensation unit can be configured to add at least one product to a portion if the determined weight of the portion is below a preset threshold value. As soon as a portion having too low a weight is therefore conveyed, the weight compensation unit ensures that the weight is adapted accordingly by addition of one or more single products. 
         [0011]    The weight compensation unit is preferably configured to add a plurality of single products sequentially to a portion until the weight of the portion has reached a preset desired value. In this way, relatively very low-weight portions can also be brought to the wanted desired weight. 
         [0012]    The product conveyor can be arranged downstream of a product processing apparatus preparing the portions, for example a cutting apparatus, with a control device ensuring that the prepared portions do not exceed a preset maximum weight. It is thus therefore achieved by means of the control device that only such portions are prepared and conveyed which are of the correct weight or of low weight within a tolerance range. It is ensured in this manner that a weight compensation can always be achieved by an addition of single products to a portion, while it is generally not necessary to remove single products from a portion. A particularly simple design of the weight compensation unit is hereby possible since no measures have to be taken to remove and, where necessary, to convey single products back. 
         [0013]    In accordance with a further embodiment, the weight compensation unit includes a robot, in particular a robot working in accordance with the delta principle. The addition of single products to a portion can take place in that the robot picks up a single product from a product supply and places it on an underweight portion by means of a suitable end effector such as a product gripper or a vacuum suction apparatus. 
         [0014]    The robot can additionally serve to pick up a conveyed portion and to place it in a placement area. The weight compensation unit can thus advantageously be realized by a robot which is anyway provided for transferring the conveyed portions. The robot in other words satisfies a dual function. Since the supplementing of underweight portions by additional single products is only necessary in individual cases with a suitable control of the product processing apparatus, such a dual-function use of the robot is possible without a problem. 
         [0015]    In accordance with a further embodiment, at least one further robot is provided to pick up conveyed portions from the product conveyor and to place them in a placement area, wherein the placement area is preferably associated with a packaging machine or with a further conveying apparatus. An arrangement of a plurality of robots can therefore be provided to transfer conveyed portions from the product conveyor to, for example, a product placement area of a packaging machine or to a further product conveyor. At least one of these robots can in this respect satisfy the already mentioned dual function in that it not only serves for the transfer of products, but also for the compensation of the product weight. This robot is expediently provided with its own product supply and can be controlled in a suitable manner by means of a control device. 
         [0016]    A product supply of the weight compensation unit can be configured as a product conveyor which conveys individual products sequentially along a supply direction, for example as a band conveyor. The supply of the single products can in this respect take place in a suitable direction transversely or parallel to the conveying direction of the conveyed product portions. 
         [0017]    In accordance with a further embodiment of the invention, the product supply is arranged downstream of a cutting apparatus for preparing single products. This cutting apparatus is advantageously that cutting apparatus which also serves for the production of the conveyed product portions since in this manner no separate cutting apparatus has to be provided for the preparation of the single products for the weight compensation. An embodiment is, however, naturally also imaginable in which a separate cutting apparatus is associated with the weight compensation unit. 
         [0018]    The invention also relates to a method for handling portions of products, in particular food products, in which the weight of a conveyed portion is determined by means of at least one sensor and at least one single product is additionally automatically added to the portion in dependence on the determined weight. 
         [0019]    The invention will be described in the following by way of example with reference to the drawing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  shows a schematic plan view of an apparatus in accordance with the invention for handling portions of products. 
       
    
    
     REFERENCE NUMERAL LIST 
       [0000]    
       
           10  slicer 
           12  band conveyor 
           14  product slice 
           16 ,  16 ′ portion 
           17  transfer apparatus 
           18  first robot 
           19  second robot 
           20  third robot 
           22  pick-up area 
           24  placement area 
           25  product placement area 
           26  sensor 
           30  weight compensation unit 
           32  product supply 
           40  end effector of the first robot 
           41  end effector of the second robot 
           42  end effector of the third robot 
         F conveying direction 
         Z supply direction 
       
     
       DETAILED DESCRIPTION 
       [0040]    An apparatus in accordance with the invention for handling portions  16  of food products such as slices of meat, sausage or cheese is shown in  FIG. 1 . A slicer  10  cuts off individual product slices  14  from a product loaf, not shown, at high speed and said individual product slices fall onto a band conveyor  12  and are conveyed by it along a conveying direction F. A control device, not shown, of the slicer  10  and/or of the band conveyor  12  provides that a plurality of cut-of product slices  14  in each case form a portion  16 . 
         [0041]    To transfer the portions  16  from the belt conveyor  2  to a product placement area  25  of a packaging machine not shown in detail, a transfer apparatus  17  is provided which includes a first robot  18  and a second robot  19 . In addition, a third robot  20 , whose function will be explained in more detail in the following, is disposed downstream of the first and second robots  18 ,  19  in the conveying direction F. In the example shown, the robots  18 ,  19 ,  20  are so-called “pick and place” robots with delta kinematics. The total number of the totality of robots provided is based on the respective required transfer performance. Three robots are shown here only by way of example. 
         [0042]    The portions  16  are transported by the band conveyor  12  into a reception zone  22 , are picked up by end effectors  40 ,  41  of the first two robots  18 ,  19  viewed in the conveying direction F and are transferred into a placement area  24  defined by the product placement area. In this respect, depending on the application, sorting procedures and/or the positioning of the portions  16  on the product placement area  25  to form a format set can be carried out as additional tasks. After their transfer, the portions  16  transferred into the placement area  24  are further transported in the conveying direction F. 
         [0043]    The weight of the conveyed portions  16  is determined at a position disposed between the slicer  10  and the pick-up area  22  by means of a sensor  26 . The sensor  26  can, for example, be electronic scales, an optical detection device or the like. 
         [0044]    To avoid the output of portions  16  of incorrect weight, an automatic weight compensation unit  30  is provided which includes the third robot  20 , i.e. that is the last robot viewed in the conveying direction F, as well as a product feed  32  separate from the band conveyor  12 . 
         [0045]    The product supply  32 , which can be configured as a band conveyor or as a belt conveyor, sequentially conveys single product slices  14  along a supply direction Z to provide them for picking up by the third robot  20 . The supply direction Z extends transversely to the conveying direction F in the embodiment shown. The product slices  14  for the product supply  32  can be placed on by hand, for example, or can be produced by a separate cutting system, not shown. 
         [0046]    The slicer  10  and the band conveyor  12  are operated such that the prepared portions  16  do not exceed a preset maximum weight. It is therefore ensured—for example via the setting and/or control of the slicer  10  or of the band conveyor  12 —that only portions  16  which are below weight and of correct weight within a tolerance range are produced, but in no way over-weight portions  16 . 
         [0047]    A control device, not shown, checks with reference to signals provided by the sensor  26  whether the respective determined weight of the portions  16  is below a preset threshold value. The control device therefore recognizes which of the portions  16  transferred by the first robot  18  and by the second robot  19  into the placement area  24  are underweight and which are not. Accordingly, the third robot  20 —controlled by the control device—picks up a product slice  14  from the product supply  32  by means of an end effector  42  and places it in the placement area  24  on a portion  16  recognized as underweight as soon as it is conveyed past it. If the weight of a single product slice  14 —known in advance—is not sufficient to bring the underweight portion  16  to the preset desired value, the third robot  20  sequentially places one or more further product slices  14  on the respective portion  16  until the weight of the portion  16  has reached the preset desired value. 
         [0048]    With a sufficiently exact knowledge of the product loaf to be sliced and with a corresponding control of the cutting apparatus or of the product conveyor, it is possible to keep the weight of the conveyed portions  16  so exactly that a weight compensation is required only relatively rarely. In this case, the third robot  20  can be utilized not only for the automatic weight compensation, but also—corresponding to the first and second robots  18   19 —additionally for the transfer of the portions  16  from the band conveyor  12  to the product placement area  25 . 
         [0049]    As a result therefore, due to the automatic weight compensation, only such portions  16  are output to the packaging machine whose weight corresponds to the wanted desired weight within a preset tolerance, wherein optionally single portions  16 ′ can have a larger number of product slices  14  than other portions  16 . 
         [0050]    The number and use of the robots  18 ,  19 ,  20  as well as the number and arrangement of any further product supplies  32  can be adapted to the respective application in a variety of ways. It is thus possible, for example, to use the first robot  18  viewed in the direction of conveying F or a plurality of or all robots present for the weight compensation as required instead of the third robot  20 . The weight compensation can equally be carried out on the band conveyor  12  or on the product placement area  25  depending on the application. 
         [0051]    If instead of the third robot  20 , the first robot  18  is, for example, used for the weight compensation, it is expedient to carry out the weight compensation on the band conveyor  12  instead of on the product placement area  25 , i.e. that is to place additional product slices  14  on underweight portions  16  while they are still on the band conveyor  12 . Only portions  16  of the correct weight are thus provided for transfer to the following robots  19 ,  20  in this constellation.