Abstract:
Knives ( 10, 20 ) for carving out meat slabs ( 1 ), whose cutting edges ( 14, 24 ) are ground in such a way that they do not cut into the rib bones ( 2 ), or back bones), and at the same time assure cutting as closely as possible to the rib or back bones.

Description:
DESCRIPTION  
         [0001]    The invention relates to a knife for the mechanical separation of a meat slab from the rib bones of a portion of a slaughtered animal, containing the meat slab, the associated rib bones and the associated back bones. The invention furthermore relates to a knife for the mechanical separation of a meat slab from the back bone of a portion of a slaughtered animal, containing the meat slab, the associated back bones and the associated rib bones.  
           [0002]    Such knives are disclosed in the older German patent application 100 37 300.3 (see FIG. 2, reference numerals  9 ,  10 ) and are represented in FIG. 1 of the present application. This arrangement with a portion of a slaughtered animal consisting of the meat slab  1 , the rib bones  2  and the back bones  3  is represented in FIG. 1. It has a knife  10  for separating the meat slab  1  from the rib bones  2 , and a knife  20  for separating the meat slab from the back bone  3 . The knife  10  is connected to the drive mechanism  4 , which can be linearly displaced vertically in respect to the drawing plane, the knife  20  is connected to a drive mechanism  5 , which is also displaceable.  
           [0003]    The object of the present invention is based on improving the efficiency of these two knives, which are employed together for carving meat slabs. This means that, on the one hand, the cutting edges of the knives should not cut into the bone, but, on the other hand, should cut as closely as possible to the bone, i.e. so that all the meat is carved out with the meat slab.  
           [0004]    The attainment of this object is achieved by means of the special design of the knives in accordance with the features recited in the characterizing portions of claims 1 or 5. Advantageous further developments of the invention are defined in the dependent claims. 
       
    
    
       [0005]    Exemplary embodiments of the invention will be described in greater detail in what follows, making reference to the drawings.  
         [0006]    [0006]FIG. 1 shows a perspective view of an arrangement in accordance with the prior art for separating a meat slab from the bones of a slaughtered animal,  
         [0007]    [0007]FIG. 2 a  is a view from above on an exemplary embodiment of a knife  10  for separating the meat slab  1  from rib bones  2 ,  
         [0008]    [0008]FIG. 2 b  is a plan view of the knife  10  in FIG. 2 a  in the direction of the arrows IIb-IIb,  
         [0009]    [0009]FIG. 2 c  is a section along the arrows IIc-IIc in FIG. 2 b,    
         [0010]    [0010]FIG. 2 d  is a section along the arrows IId-IId in FIG. 2 b,    
         [0011]    [0011]FIG. 2 e  is a section along the arrows IIe-IIe in FIG. 2 b,    
         [0012]    [0012]FIG. 3 a  is a view from above on an exemplary embodiment of a knife  20  for separating the meat slab  1  from the back bones  3 ,  
         [0013]    [0013]FIG. 3 b  is a plan view of the knife  20  in FIG. 3 a  in the direction of the arrows IIIb-IIIb,  
         [0014]    [0014]FIG. 3 c  is a view from above corresponding to FIG. 3 a  on a further exemplary embodiment on a knife  20 . 
     
    
       [0015]    The knife  10  is used for separating the meat slab  1  from the rib bones  2 . The knife  10  consists of a fastening plate  11  and a plane, bulging area  13 . The fastening plate  11  has bores  12 . These are used for fastening the knife  10  to a drive mechanism  4 . Since other options for fastening are also possible, reference is made in the claims to the fastening plate and the bores as “fastening means”. The shaping of the area  13  is used for adaptation to the curvature of the rib bones  2 .  
         [0016]    In FIG. 1, the cutting direction S extends vertically in relation to the drawing plane, in FIG. 2 a  in the direction of the inserted arrow S. The knife  10  has a cutting edge  14  in the cutting direction S, which is formed by grinding the parallel lateral faces  15 ,  16  of the knife  10 , and which maintains a defined distance from the lateral face  15  of the knife  10  which rests against the rib bone  2 . In the opposite cutting direction S′ it has a corresponding cutting edge  14 ′. As can be seen in FIG. 2 a,  the area  13  tapers between the two symmetrically arranged cutting edges  14 ,  14 ′ from the fastening plate  11  in the direction toward the free end area  17 . This results in that the cutting edge  14  is set obliquely in the cutting direction S starting at its area located near the fastening plate  11  in the direction of its free end area  17  in such a way that the area close to the fastening plate  11  in front of the free end area  17  comes into cutting connection with the meat slab  1 . The obliqueness of the cutting edge  14  in respect to the cutting direction S has an angle α of 80° to 50°, preferably 70°. The following is achieved by this: if the meat slab  1  is viewed along a line extending vertically in relation to the cutting direction, the cutting edge  14  first cuts the meat in the area near the fastening plate  11  because of the course of the cutting edge  14  provided by the oblique placement, and only thereafter cuts with the portion of the cutting edge which is set back in the movement direction and is assigned to the indentation  18  and the end area  17 . Thus, while the cutting edge  14  cuts with the free end area  17  and in the area of the indentation  18 , the portion of the meat slab  1  located above it and vertically in respect to the cutting direction S, which had already been cut, is held by the bulging plane area  13  of the knife. Thus, this oblique portion of the cutting edge  14 , which is provided with the indentation  18 , is for one used for an exact guidance of the cut, and furthermore for a force reduction, and by this assures a cut close to the bone with a maximum yield of meat and high cutting quality. A corresponding indentation  18 ′ is provided on the cutting edge  14 ′, which operates in the cutting direction S′.  
         [0017]    Viewed in the cutting direction, the cutting edge  14  extends along a special course (FIG. 2 b ). It runs from the fastening plate  11  as far as the indentation  18  at a distance from the lateral face  15  resting against the rib bones  2 , which amounts to a quarter to one-half of the thickness of the knife  10  (see FIG. 2 c ). Adjoining this, in the area of the indentation  18  the cutting edge  14  substantially runs in a linear continuation of the lateral face  15  of the knife  10  resting against the rib  2  (FIG. 2 d ), and in the free end section  17  of the knife  10  has a distance from the lateral face  15  of one fifth to one-half of the thickness of the knife  10  (FIG. 2 e ). The thickness of the knife  10  between the otherwise parallel lateral faces  15  and  16  is 3 to 5 mm, preferably 4 mm. As a whole, the cutting edge  14  describes a curve maintaining a defined distance from the lateral face  15 . It is assured in this way that in the center cutting area the cutting edge is always guided through the lateral face  15  in the area  13  distanced by a defined minimum amount from the rib bone. By means of this the knife  10  is prevented from cutting into the rib bones.  
         [0018]    In the exemplary embodiment the knife  10  is symmetrically embodied as a result of the arrangement of two cutting edges  14 ,  14 ′ for the opposite cutting directions S, S′.  
         [0019]    [0019]FIG. 3 a  shows a front plan view of the knife  20  for separating the meat slab  1  from the back bones  3 . The knife  20  is arranged substantially horizontally (FIG. 1) and has a fastening plate  21  and a flat area  23  which, at the free end of the knife  20 , makes a transition into a step-shaped shoulder  28 . The fastening plate  21  has bores  22  which are used for fastening the knife  20  on the drive mechanism  5 . Since other options for fastening are also possible, reference to this is made in the claims as “fastening means”.  
         [0020]    The step-shaped shoulder  28  is used for adaptation to the shape of the connection of the back bones  3  with the rib bones  2  (FIG. 3 b ).  
         [0021]    In FIG. 3 a,  the cutting direction is also identified by an arrow S. The knife  20  has a cutting edge  24  in the cutting direction S, which is formed by grinding the otherwise parallel lateral faces  25 ,  26  and which maintains a defined distance from the lateral face  25  of the knife  20  resting against the back bone  3 . As can be seen in FIG. 3 a,  the cutting edge  24  is placed obliquely from its area located near the fastening plate  21  up to its free end area  27 —the same as the cutting edge  14  of the knife  10 —in such a way that the area of the blade  23  close to the fastening plate  21  comes into cutting engagement with the meat slab  1  before the free end area  27 . The curved area of the cutting edge  24 , which is placed obliquely in respect to the cutting direction S, between the fastening plate  21  and the shoulder  28  can be approximately described by the straight line G shown in dash-dotted lines. The angle β between S and G is 20 to 70°, preferably approximately 45°. The effect of this design is analogous to the one already described in connection with the knife  10 : the portion of the meat slab  1 , which was just cut by the cutting edge  24  near the shoulder  28 , is held by the flat area  23  during cutting, wherein in this area the cutting edge  24  precedes the shoulder  28 . One the one hand, this assures a high yield of meat and, on the other hand, prevents cutting into the back bone  3 .  
         [0022]    The course of the cutting edge  24  viewed from the cutting direction, can be seen in FIG. 3 b.  It runs from the fastening plate  21  as far as the vicinity of the shoulder  28  at a distance from the lateral face  25  resting against the back bone  3 , which is a quarter to one-half of the thickness of the knife  20 , which itself is 3 to 5 mm, preferably approximately 4 mm. Adjoining this, in the area of the transition into the step-shaped shoulder  28 , the cutting edge  24  comes closer to the lateral face  25  by one-tenth to one-third. It can also completely lie in a linear continuation of the lateral face  25 . The cutting edge  24  has an S-shape in the area of the shoulder  28 . Toward the end of the higher located area of the shoulder  28 , the cutting edge  24  has a distance of one-half to three-quarters of the thickness of the knife  20  from the lateral face  25 . As a whole, the course of the cutting edge  24  describes a curve, which has a z-shape and runs out slowly between the lateral faces  25  and  26  and maintains a defined distance from the lateral face  25 .  
         [0023]    In the exemplary embodiment in FIG. 3 c , the cutting edge  24  has a protrusion prior to the transition of the area  23  into the shoulder  28 , which takes up approximately one-third of the distance L between the border of the area  23  and the fastening plate  21  and the shoulder  28 . In this way an indentation, namely an indentation  31 , is also created in the knife  20 . This shape has also been shown to be advantageous.