Abstract:
The invention relates to method and apparatus for removing bones from meat, such as pin-bones from fish filet e.g. whitefish such as cod comprising a conveyor ( 2 ) for transporting the meat and a bone removing unit ( 5 ) for removing the bones as the meat is transported along the conveyor. The bone removing unit ( 5 ) is movably hinged to the frame ( 1 ) of the apparatus and moveable in an approximated up- and downward direction toward the conveyor ( 2 ). The conveyor comprises an upwardly extending edge ( 52 ) allowing the bone removal unit to be brought into contact with a particular area to remove the bones that are primarily located therein. In this manner it is possible to adjust the apparatus according to the configuration figure of each individual fish filet.

Description:
TECHNICAL FIELD OF THE INVENTION  
         [0001]    The invention relates to method and apparatus for removing bones from meat, such as pin-bones from fish filets, in particular whitefish such as cod, comprising a conveyor for advancing the filets along and a bone removing unit for picking unwanted bones from a particular area of the meat as it is transported along the conveyor.  
         BACKGROUND OF THE INVENTION  
         [0002]    Unwanted bones in fish filets such as whitefish in particular cod are one of the main concerns of fish processors. Unwanted bones, especially small bones on the dish of the customer or even worse if swallowed can have devastating effect for fish producers. Just one such instance can easily in an increasingly demanding market, result in a negative publicity and price and sales reduction which can seriously damaged a producer. Therefore it should not surprise anyone that fish producers all over the world spent much effort in finding bones and removing them. This is and has been very labour consuming operation. Some of the bones are difficult to find or their removal can be complicated without cutting away some portion of the fish meat. Larger part of fish processing is however being mechanised, e.g. de-heading, filleting and skin removing. Numerous apparatus and method have been introduced to either find bones in the meat or to remove the bones.  
           [0003]    The closest related state of the art concerning the present invention is U.S. Pat. No. 5,525,101 issued Jun. 11, 1996 to Jan Söderlind of Sweden. The invention relates to a device for removing fish bones from fish meat or quills from killed poultry. The device comprises a cylinder provided with gripping means shaped as holes, a counter pressure element for achieving a squeezing function between the counter pressure element and the cylinder. The cylinder is mounted axially on the driving shaft for driving the cylinder. The cylinder is uncovered i.e., it is not contained in any apparatus housing. The counter pressure element is designed with a lip, bearing against the rotatably driven element, at least by means of an edge. The invention further relates to a cylinder for a device which is provided with a plurality of recesses running across its envelope surface in the longitudinal direction. The recesses have at least one sharp edge formed along the joining line between the envelope surface and the inner surface of the recess.  
           [0004]    Although the above described prior art must be considered as huge step forward within the technology it has been proved that the device suffer from numerous disadvantage and has not worked as expected.  
           [0005]    First of all the device is hand held, which result in that the accuracy and efficiency largely depends on the skills of the worker operating the device. As the device is hand held the possibilities to automate the process further is limited. It is demanding job to hold the device in the hand with its electrical power supply etc. Another disadvantage is that the rotational velocity of the cylinder and the advancing speed of the fish file has proven to be very important for the operation. It is not possible to control this ratio with the above described device.  
           [0006]    Further from Danish Utility Model DK 1999 00226 U4 concern apparatus where the bone removal unit is movably hinged to a frame above a conveyor conveying fish filets to be processed. The bone removal unit is then elevated semi- or fully automatically toward the upwardly facing surface of the filets and driven over the entire surface of the filet. This has shown to be an effective method in for example processing salmon filets. However there are still number of disadvantages associated with this method. The main disadvantage is that the entire surface of the filet is brought into contact with the bone removing unit which can easily lead to damaging of the surface are. Further some bones are not necessarily located in the portion of the meat reachable by the removing unit (where the filet is thickest). This is for instance the case for cod-fish where the pin bones are located in a area of the filet somewhat different from salmon e.g. where the filet is less thick.  
         GENERAL DESCRIPTION OF THE INVENTION  
         [0007]    It is the aim of the invention, to present apparatus and method for removal of bones from meat portions, such as fish filet, in an simple and effective manner. The removal of bones is effected with automatic adjustment of the apparatus according to the individual shape/requirement of each meat portion. This is achieved in a manner enabling the removal of bones from the fish filet without requiring a skilled person.  
         DETAILED DESCRIPTION OF THE INVENTION  
         [0008]    The aim of the invention is achieved by the apparatus being unique in that the apparatus comprising a frame, a conveyor arranged on said frame for advancing said fish filet in a conveying direction, as well as supporting said filet during the bone removal process, a bone removing unit arranged on said frame, said bone removing unit being moveably hinged to the frame in the area above the conveyor for the purpose of bone removal as the filet is advanced along said conveyor, wherein the conveyor comprises: upwardly extending edge for elevating a particular area of the filet, above the conveyor surface, preferably the area corresponding to the spine, in such a manner the bone removal unit is allowed to be brought into contact to that particular area to remove the bones that are primarily located there in.  
           [0009]    The invention is further unique as described in the characteristic part of the patent claims 2-11. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    In the following the invention is described in more details with reference to the drawings;—in which  
         [0011]    [0011]FIG. 1 shows a side view of the apparatus,  
         [0012]    [0012]FIG. 2 shows in more close-up details the arrangement of the bone removing unit,  
         [0013]    [0013]FIG. 3 shows the removal of a pin-bone from the fish filet,  
         [0014]    [0014]FIG. 4 shows side view of the apparatus, in particular one preferred embodiment of the elevation of the conveyor,  
         [0015]    [0015]FIG. 5 shows a perspective view of apparatus including one preferred embodiment of the elevation of the conveyor,  
         [0016]    [0016]FIG. 6 shows the apparatus seen from the in-feed section,  
         [0017]    [0017]FIG. 7 shows a specific long bone direction means and/or bone removal unit, and  
         [0018]    [0018]FIG. 8 shows one example of in-feed device for use in connection with the apparatus. 
     
    
     MORE DETAILED DESCRIPTION OF THE DRAWINGS AND ONE PARTICULAR PREFERRED EMBODIMENT OF THE INVENTION  
       [0019]    [0019]FIG. 1 shows a overall view of the set-up of the apparatus, showing a side view of the bone removing unit and the conveyor for transporting the meat the bones are to be removed from. A conveyor ( 2 ) having an in-feed end ( 3 ) and out-feed end ( 4 ) resting on a supporting frame structure ( 1 ). On the frame ( 1 ) and above the conveyor ( 2 ) a bone removing unit ( 5 ) is moveably hinged. The bone removing unit ( 5 ) is hinged to the frame ( 1 ) via two individually movable arms ( 16 ). A motor ( 17 ) for rotating the axle ( 6 ) of the bone removing unit ( 5 ) is connected to the bone remover via belt transmission ( 18 ). The up- and downward movement of the unit ( 5 ) is done via moveable arms ( 16 ) regulated via a spring or a lifting/lowering device numbered  19  on the drawing. The number  19  on FIGS. 1 and 2 can also represent a servo motor arranged to raise and lower the bone removing unit ( 5 ) towards and from the fish on the conveyor. By the use of a servo motor ( 19 ) the movement of the bone removing unit can be controlled much easier. It is even possible to have the bone removing unit to follow a specific curve path when it is in contact with the fish. The pressure (depth) can be increased in the ”bone located are” and then released immediately after. The arms ( 16 ) are arranged parallel to each other and therefor allow parallel up- and downward movement of the unit ( 5 ). Thereby the placement of the unit ( 5 ) is independent with respect to the conveyor ( 2 ) plane and/or the thickness of the fish or meat portion. The bone removing unit ( 5 ) comprise two main parts, a rotatably driven axle ( 6 ) and a counter pressure element ( 8 ). Further, an optional feature is a first pressure element ( 12 ) located immediately before the axle ( 5 ) and counter pressure element ( 8 ). The pressure element ( 12 ) function as a height adjuster in cases when the up and downward movement of the bone removing unit ( 5 ) is not controlled by for example a servo motor ( 19 ). The element ( 12 ) follows the contour of the fish and adjust thereby how close the axle ( 5 ) with the engagement elements ( 7 ) and the counter pressure element ( 8 ) comes to contact with the surface of the meat. The conveyor surface is elevated at least in the area where the bone removing unit is brought into to the filets. The elevation means ( 51 ) is shown in more details on FIGS.  2  to  6 , but in principle as shown extend longitudinally along the conveyor and thereby forms an edge ( 52 ) which elevates a particular portion of the filet. The figure further illustrate the conveyance of fish filets ( 21 ) from the in-feed end ( 3 ) under the bone removing unit ( 5 ) and towards the out-feed end ( 4 ). Fish filets ( 21 ) are arranged on an elevation means ( 51 ) on the conveyor ( 2 ), thereby bringing the particular portion where the bones are located in closer to the bone removing unit ( 5 ).  
         [0020]    [0020]FIG. 2 shows in more close-up details the arrangement of the bone removing unit ( 5 ), how it is hinged to the frame ( 1 ) and how the up- and downward movement of the unit ( 5 ) is performed. The contact between the bone removing unit ( 5 ) and the elevated portion of the filet is further illustrated in greater details. A fish filet ( 21 ) is arranged on the elevation means ( 51 ) so that portion the bones are to be removed from is sitting on edge ( 52 ) of the elevation means ( 51 ).  
         [0021]    [0021]FIG. 3 shows the removal of a pin-bone ( 22 ) from the fish filet ( 21 ). The pin-bones ( 22 ) are primarily located in a area corresponding to a line of the spine of the fish. By the way of elevating this non-skin side of the filet above other portion of the filet the bones can be much easier removed and only a small portion of the meat contacted. When the filet is again placed in normal flat position the area that was in contact with the bone removing unit is almost non-visible. The counter pressure element ( 8 ) interact with the engagement elements ( 7 ) of the rotatably driven axle ( 6 ) of the bone removing unit. The bone ( 22 ) is intercepted between the counter pressure element and the engagement element and thereby pulled out of the fish filet. The engagement element ( 7 ) or teeth can be of varying size and form as exemplified additional recess ( 91 ) depth.  
         [0022]    [0022]FIG. 4 shows side view of the apparatus. An elevation means ( 51 ) is arranged on the conveyor ( 2 ). As illustrated in the detailed part of the figure one example of the elevation is shown where it is made of a number of triangular formed units ( 53 ) arranged on the conveyor and form a rim or rail along the entire conveyor ( 2 ). By arranging the filets on the edge of this rim or rail ( 52 ) it is possible to bring the bone removing unit closer into contact with the area in the filet where the bones are primarily located in. A in-feed channels ( 81 ) are further shown for placing the fish filets prior to entering into the conveyor.  
         [0023]    [0023]FIG. 5 shows a perspective view of apparatus with one preferred embodiment of the elevation means ( 51 ) on the conveyor ( 2 ). There are shown three elevation means ( 51 ). On the outside there are pressure means or devices ( 55 ) keeping a side pressure on the fillets arranged on the elevation means ( 51 ). By pressing on the sides the portions of the filets being placed in-between and enveloped thereby are held in their position while the bone removal is taken place.  
         [0024]    [0024]FIG. 6 shows the apparatus seen from the end section. Three elevation units rail ( 53 ) is are arranged side by side on the conveyor ( 2 ). Outside there are pressure means ( 55 ) pressing the rails together and thereby the filet portion placed therein. A cross sectional cut of the upwardly extending edge, a triangular formed ( 53 ) link, having one side ( 56 ) approximately vertical. The angle of the top rim ( 52 ) can vary from considerably or from 15° up to almost 160° in specific instances depending of the type of product to be processes and the importance of bone removal rate in respect to the yield, e.g. how much meat is removed during the bone removal.  
         [0025]    [0025]FIG. 7 illustrates one example of a specific long bone direction means and/or bone removal unit ( 77 ). This unit comprises a pair of belt or chain drive ( 71 ,  72 ) running over a set of three wheels ( 73 ,  74 ,  75 ), where of both belt run over two of the same wheels ( 73 ,  74 ) but the third wheels ( 75 ) being a different. This resulting in the belts forming two triangular whereof one falls within the other and belt together forms a v-shaped channel ( 76 ) narrowing in the conveyor direction and end where the belts falls together over the front wheel ( 73 ).  
         [0026]    It thus will be appreciated that the objects of the present invention have been fully and effectively accomplished. It will be realised, however, that the foregoing preferred specific embodiment has been shown and described for the purpose of this invention and are subject to change without departure from its basic principles. Therefore, this invention includes all modifications and equivalents encompassed within the spirit and scope of the following claims.