Boning device and method
The invention relates to a device for boning meat such as shoulder or rib of beef, legs of fowl or the like, said device mainly comprising a frame, a cutting element arranged in said frame and having a cutting edge being continuous and similar to the shape of bone in the piece of meat, a counter-element arranged in the frame and driving means for moving the cutting element and the counter-element towards and away from one another. 
     The device of the kind set forth in the preamble enables punching or cutting a bone from a piece of meat in the manner described in the copending U.S. patent application No. 462,395 Jan. 31, 1983 now U.S. Pat. No. 4,577,369. 
     The invention has for its object to improve the above-mentioned device so that in finally cutting the meat tissue membranes and/or sinews are not cut, but left on the bone. 
     The device according to the invention is distinguished in that the cutting and/or counter element is (are) provided within the space bounded by the cutting edge with one or more arresting members projecting towards the other element. 
     Thanks to the projecting arresting members the space between the two elements is closed at the critical places where sinews and/or members are present on the bone before the cutting operation proper takes place. 
     The arresting members may have any shape, for example, of a plate or a stamp. 
     In order to facilitate a separation between the meat to be cut off and the bone with sinews and/or membranes to be retained the edge of the arresting member may be bevelled. 
     If the device is equipped with a cutting and/or counter-element having each a cavity within the space enclosed by the cutting edge, which cavity is filled with a flexible mass, the invention furthermore proposes to arrange the or each arresting member between said mass and the boundary of the cavity so that the arresting member can slide along the wall of the opposite cavity. In this way co-operation is created between the projecting edge of the arresting member and the opposite, flexible mass of the other element. With such a construction fastening of the arresting member is facilitated, whereas nevertheless a satisfactory arresting effect is ensured. 
     Further the invention relates to a device for boning pieces of meat such as shoulder or rib pieces, legs of fowl and the like, said device comprising a frame, a cutting element arranged in said frame and having a continuous cutting edge substantially matching the shape of the bone in the piece of meat, a counter-element arranged in said frame and driving means for moving the cutting and counter-elements towards and away from one another, in which the bottom of the cavity of the cutting and/or counter-elements is provided with one or more supporting members displaceable in the direction of movement of said elements against an elastic force. 
     The cavity inside the cutting edge is preferably filled with elastic elements and materials which smoothly engage the piece of bone in order to move a maximum amount of meat outside the cutting edge. The problem involved is that due to the high pressure the piece of bone may break down so that bone splinters might get into the severed meat. 
     The invention has for its object to obviate said problem and provides a device which is distinguished in that an undeformable bridge piece fitting in the cavity is provided on each of two yielding supporting members. 
     The bridge piece follows the movement of two members moving differently. The bridge piece transfers these different yielding movements more uniformly to the deposited piece of bone, which prevents rupture. 
     In order to prevent sinews or membranes from getting beyond the cutting edge, the bridge piece is provided with extensions directed towards opposite elements and being able to operate as a retaining partition. 
     In a further development of the device embodying the invention the cavity of the element inside the cutting edge may furthermore be provided with firmly supported or locally rigidly supported, releasable fillers, which urge the piece of bone into the correct position during the pressing operation. Moreover, these fillers ensure a correct guide of the meat to the cutting edge. 
    
    
     The invention will be described more fully with reference to an embodiment. 
     The drawing shows in: 
     FIG. 1 a plan view of a cutting element embodying the invention provided with arresting members, 
     FIG. 2 a sectional view taken on the line II--II in FIG. 1, 
     FIG. 3 a sectional view taken on the line III--III in FIG. 1, 
     FIG. 4 a vertical sectional view of part of the device with respect to the cutting and counter elements, the sectional view of the cutting element being taken on the line V--V in FIG. 5 and VI--VI in FIG. 6, 
     FIG. 5 a plan view of the cutting element, 
     FIG. 6 a bottom view of the counter element, 
     FIG. 7 a sectional view taken on the line VII--VII in FIG. 5. 
    
    
     Referring to the figures reference numeral 1 designates the upper counter element having a wall part 3 standing on a carrying plate 2. The shape of the wall part 3 matches the contour line around the bone B to be cut out (see FIGS. 1 and 2). 
     Below the counter element 1 is arranged a cutting element fastened in a similar manner to a supporting plate (not shown) and also constructed in the form of a wall part 4 corresponding with the wall part 3. The wall parts 3 and 4 constitute the cutting or punching matrices proper. The top side of the wall part 4 is bevelled and terminates in a cutting edge 5, which co-operates with the flat underside of the wall part 3 (see FIG. 2). 
     A cavity formed by the wall parts 3 and 4 is filled with a flexible mass 6, which may be formed by various layers of a material having relatively different elasticities. Furthermore the cutting matrix is constructed with a stamp 7 carried by a plunger 8 in order to cause the flexible layers 6 to yield during punching. The plunger 8 forms part of the hydraulic driving circuit by which also the matrices 3 and 4 are moved towards and away from one another. 
     According to the present invention inside the standing walls 3 and 4 of the matrices are arranged arresting elements 9 extending as far as beyond the cutting edge 5 and the underside of the matrix 3 respectively in the direction towards the opposite matrix element. The arresting elements 9 have a relatively small size and bring about an arresting effect at those places where sinews and/or membranes of the bone B might be urged laterally beyond the cutting edge 5 during the cutting operation. The arresting members may have any shape. The arresting members 9&#39; have the shape of plates curved in accordance with the contour line of the wall part 3. On the contrary, the arresting element 9&#39; has a lense-shaped cross-section and has a flat side 10 facing the bone. The arresting element 9&#39;&#34; has a trapezoidal cross-section, the top being directed towards the bone. 
     Finally the arresting element 9&#34;&#34; has the shape of a stamp having a vaulted top face rising in outward direction. On the side facing the bone the stamp has crescent-shaped recesses 11 in which fits the projecting part of one part of the bone B. 
     It should be noted that the matrix with the arresting members arranged therein is specularly symmetrical with respect to the sectional line III--III (see FIG. 1) in order to permit of working the left-hand and right-hand shoulder pieces with the same matrix. 
     Each arresting member 9 is supported on the bottom of the cavity in the matrix of the counter element 3 or in a recess in the wall part 4 of the cutting element (see FIG. 3). In this way a firm support is ensured for the arresting members. 
     Moreover, each arresting member is releasably fastened by means of a screw nipple 12 in the cavity so that the matrix can be simply adapted to differently shaped bone pieces by arranging matching arresting members therein. 
     From the figures it is apparent that the arresting members 9 are disposed so that they exactly slide along the inner wall of the opposite matrix wall when the cutting and counter elements are driven. In this way an accurate seal is ensured because the arresting member presses by its end edge against the flexible mass. 
     The invention is not limited to the above-described embodiment. Within the scope of the invention an embodiment can be conceived in which the arresting elements are movably arranged in the matrix, when the flexible filling of the matrices is dispensed with. 
     Referring now to the FIGS. 4-7, reference numeral 31 designates the cutting element having an upwardly directed cutting edge 32. The cutting edge co-operates with the counter-element 33, the elements being pressed to one another as shown in FIG. 4 by means of a hydraulic ram (not shown). 
     The elements are supported by carriers 34 and 35 respectively, the carriers 34, for example, being fastened to a slide 36 reciprocated by the ram in the direction of the arrow P1, whereas the carrier 35 is rigidly secured in the frame 37 of the device. 
     The cavity 38 of the cutting element 31 accomodates a plurality of supporting members 39 movable in the direction of the arrow P1 and having the shape of a stamp. Each stamp 39 is carried by a pin 40 connected with a bender 41, which is operative in a cylindrical space 42 in the carrier 34. 
     The size and the shape of the stamps 39 depend on the place accompanied thereby in the cavity 38 of the cutting element. 
     At least two stamps are provided each with a bridge piece 43, the bridge piece being covered by a layer of elastic material 44. The layer 44 may have cavities 45 for receiving thick parts of the piece of bone, for example, joints between the bones. 
     The counter element is also provided with recesses 46. The recesses 45, 46 of the cutting and counter elements respectively need not be directly located one above the other, they may be relatively off-set in the horizontal plane. This depends on the shape of the thickeneed piece of bone and it contributes to an improved positioning or clamping of the piece of bone during pressing. 
     The bridge piece 43 may be locally provided along the circumference with raised parts projecting towards the counter element and extending above the elastic layer 44, said parts 47 being indicated in the drawing at the ends of the bridge pieces. 
     There may furthermore be provided filling pieces 48, which may have any shape and which are preferably removable from the cavity 38 so that they can be replaced by other pieces in accordance with other kinds of meat to be treated. 
     The filling piece 48 may, as a whole, be firmly supported in the element. As shown in FIG. 7 the filling piece 48 may lie on the one hand on a projecting face of the element and on the other hand on the top face of the bridge piece 43. As a further alternative the support may be provided by the yielding members 39, 40. 
     The cavity in the counter element may also be provided with filling pieces 49 having a bone and meat guiding function respectively. 
     The device described above operates as follows: 
     After the cutting elements 31 on the slide 36 has been lowered, a space is formed between the two elements so that the piece of meat to be processed can be deposited on the cutting element 31. The user has to arrange the piece of bone above the cavity 8 of the cutting element, after which he actuates the device so that the cutting element 31 is moved upwards in the direction of the arrow P1. The piece of the bone itself finds the cavities 45 and 46 respectively and if the piece of bone comprises two pivoting bones, it assumes the positions indicated by the lines V--V and VI--VI respectively. 
     During the further upward movement, before the cutting edge reaches the counter element, the rams 42 are energized by supplying a fluid so that the stamps 39 are moved upwards and press the piece of bone by high pressure between the elastic layers 44. The residual meat is moved beyond the cutting edge 32, after which the meat is severed. Sinew and connective tissue are retained inside the cutting edge 32 by the extensions 47 of the bridge piece 43 and the filling pieces 48, 49 respectively. 
     Bone fracture is now avoided since the nonuniform, vertical movements of the stamps 39 are averaged because the piece of bone is lying on a bridge piece 43. It will be obvious that the bridge pieces 43 can freely tilt in the cavity 38 so that the supporting face on the top face of the bridge pieces 43 may be sharply bent. 
     The filling piece 48 will also perform a tilting movement in clockwise direction (FIG. 7), which movement ensures correct centering of the bone. During pressing after the establishment of the contact of the cutting element with the counter element meat residues will assembly in the pressing cavity and be conducted away through passages 50. 
     The invention is not limited to the embodiments described above.