De-Boning Machine

This invention relates to a method and apparatus for de-boning meat. In particular, this invention relates to a method and apparatus suitable for use in removing meat from pork or beef shoulders or ribs and legs of poultry and the like.

Considerable difficulty has been experienced for many years in attempting to de-bone meat and despite the fact that numerous attempts have been made to provide de-boner machines, the majority of the de-boning operations which are carried on today are manual.

In one mechanized de-boning process which is presently in use, the meat is removed from the bone under pressure and the bone is crushed under the meat removing pressure. The principal problem with this process is that difficulty is experienced in attempting to effectively separate the bone particles from the required meat.

In most jurisdictions, de-boned meat is subject to government inspection and if bone particles are detected in the meat, a complete batch of de-boned meat may be rejected as being unsuitable for subsequent processing with the result that it is necessary to check each individual de-boned product for bone particles and this can be a labour intensive, time consuming operation. Because of these difficulties, the industry continues to rely upon highly skilled individuals who perform a manual deboning operation. This is a costly and time consuming operation.

The method and apparatus of the present invention permits mechanical de-boning at high speed without requiring highly skilled operators and without damaging the bone during the removal of the meat.

Our de-boning machine preferably consists of a pair of complimentary dies having oppositely disposed de-boning faces arranged to bear against the meat surrounding a bone located therebetween as the dies are moved toward one another to expell the meat from the bone while preserving the integrity of the bone and having cutter means arranged to extend about the perimeter of the bone supporting portions of the de-boning faces to cut the meat which has been laterally displaced away from the film and sinew which normally surrounds a bone, so as to separate the desired meat from the bone.

In order to reduce the likelihood of breaking or transferring the bone in use, the bone locating recess or recesses are preferably lined with the resiliently flexible liner in at least the areas of the recess arranged to underlie at least a portion of the selected bone most likely to be crushed or broken during closing.

In many applications, a resilient liner may be sufficient to prevent crushing of a bone during de-boning, however, in order to further ensure that the bone is not broken during de-boning, we prefer to provide a yieldable support in at least one of the de-boning recesses arranged to underlie at least the portions of the selected bone most likely to be crushed. The yieldable support is adapted to yield when the loads applied to close the dies approach a load likely to cause the bone to disintegrate. By providing a yieldable support, the de-boning machine is made more able to operate with selected bones of a wide range of thickness.

The sinew surrounding a bone are extremely difficult to cut. We are able to cut the sinew closely adjacent the perimeter of the bone locating recess by providing a raised cutter edge on a de-boning face of said dies and ensuring that the cutter edge is made from material which is sufficiently hard to enable it to be embedded in the de-boning face of the other die, in order to form a recess which cooperates with the ridge to apply shearing forces to the sinew which are to be cut in use.

Preferably, the distance between the edge of the bone locating recess and the side edges of the dies, is relatively small so that the meat which is forced off the bone is discharged into an unrestricted space as soon as possible after it is removed from the bone so as to minimize the damage to the structure or texture of the meat caused by expelling the meat from the dies with only a very minor portion of the meat being compressed to destruction during final closing of the dies at the point of cutting.

When it is necessary to de-bone a piece of meat such as a hog shoulder, in which the hock, picnic shoulder and bladebone are intrically connected, we provide a mechanism for gripping the flat bladebone and removing it while the remainder of the shoulder is retained by the de-boning dies.

We also provide a mechanism which facilitates the location of the meat bearing bones in the de-boning dies. This mechanism is preferably adapted to facilitate the removal of the bladebone.

To permit meat bearing bones of opposite hand to be processed by the de-boning machine of the present invention, the machine is adapted to receive the bones from opposite sides, thereof.

In use, during the closing of the moulds, the deformable liner will gradually nestle around the bone while pressing the surrounding meat portions laterally outwardly from the mould. The resiliently deformable material thus prevents crushing or comminution of the bone. Preferably, the resiliently deformable material is in the form of one or more layers of elastic material such as rubber. A suitable elastic material is that identified by the trade mark TERMULEEN, which is manufactured by DuPont DeNemours. By providing the deformable material in layers, lateral displacement of one layer relative to the other is possible, thereby facilitating the displacement of the liner in order to accommodate irregular bone configurations.

In some applications, it may be desirable to include cutter blades embedded within the resiliently deformable material to cut or nick the surface of the meat as the dies close to facilitate the separation of the meat to allow it to discharge from opposite sides of the mould along a clearly defined shear line. In other applications, however, these knives may not be necessary and in some applications should be avoided in order to ensure that the knives do not damage the bone.

According to one aspect of the present invention, a de-boning machine comprises: a device for de-boning pieces of meat, comprising by a frame, a first die arranged in the frame and having a continuous cutting edge substantially matching the shape of the bone in the piece of meat, a second die arranged in said frame opposite the first die element and driving means for moving the first die element and the second die away from and towards one another.

According to a further aspect of the invention the deboning device may be provided with centering means for having the bone in the uncut piece of meat in the correct position before the cutting- and counterelements are pressed upon each other. In this way even bones having an irregular shape can be punched out without damaging the bone.

The invention will be more clearly understood after reference to the following detailed specification read in conjunction with the drawings wherein:

FIG. 1 is a partially sectioned pictorial view of a de-boning machine constructed in accordance with the embodiment of the present invention.

FIG. 2 is a plan view of a meat bearing bone of a type which can be de-boned by the de-boning machine illustrated in FIG. 1.

FIG. 3 is a cross-sectional view of the meat bearing bone of FIG. 1 taken on the line 3--3 of FIG. 2.

FIG. 4 is a plan view of the de-boning die of FIG. 5 taken on line 5--5 of FIG. 5.

FIG. 5 is a cross-sectional view of a pair of de-boning dies arranged in a closed position taken on line 5--5 of FIG. 4.

FIG. 6 is a sectional view similar to FIG. 5 illustrating the meat being removed from the bone.

FIG. 7 is an enlarged sectional view of a portion of the closed dies of FIG. 5 illustrating the cutting edge in more detail.

FIG. 8 is a longitudinal cross-sectional view of a de-boning mechanism constructed in accordance with an embodiment of the present invention.

FIG. 9 is a plan view of the lower die of FIG. 8.

FIG. 10 is a longitudinal cross-sectional view of a de-boning machine constructed in accordance with a further embodiment of the present invention.

FIG. 11 is a plan view of the lower die of FIG. 10 showing the position of a bone after removal of the meat.

FIG. 12 is a plan view of a lower mould constructed in accordance with a further embodiment of the present invention.

FIG. 13 is a cross-sectional view of a die constructed in accordance with a further embodiment of the invention.

FIG. 14 is a pictorial view taken from above of a cutter element for use in the die of FIG. 13.

FIG. 15 is a side-view of the cutter element of FIG. 14.

FIG. 16 is an enlarged detailed view of a portion of the gripper elements of the support mechanism illustrated in FIG. 1.

FIG. 17 is a perspective plan view of a further embodiment of the invention including centering means.

FIG. 18 and 19 both are elevational side views of the embodiment according to FIG. 17, each showing the centering means in a retracted and protruding position of said centering means respectively.

With reference to the drawings, the reference numeral 100 refers generally to a de-boning mechanism which comprises a de-boning machine generally identified by the reference numeral 102 and a pair of meat loading devices generally identified by the reference numeral 104. The de-boning machine 102 is in the form of press and consists of a frame 1. Preferably, the press is designed to apply high pressure loads of the order of 200 tons, such loads being frequently required in order to ensure that meat sinews can be severed upon closing of the dies.

De-boning is achieved between dies 2 and 3. The upper die 3 is rigidly mounted on the press and the lower die 2 is mounted on a ram 56 which is adapted to move the lower die 2 up and down in the direction of the arrow P1. The lower die 2 has a de-boning face 106 in which a bone locating recess 5 is formed. A raised cutting edge 4 extends about the perimeter of the de-boning face 106 laterally outwardly from the recess 5. The upper die 3 also has a de-boning face 106 in which a bone locating recess 5 is located. The recesses 5 of the dies 2 and 3 are shaped to generally conform the shape of a selected bone.

FIGS. 2 and 3 of the drawings illustrate a typical pork shoulder which is generally identified by the reference numeral 108 and which is a typical selected meat product which requires de-boning. The shoulder 10 includes fore shank bones 14 which extend within the hock portion, an armbone 15 which extends within the picknick portion and a bladebone 16 which extends within the butt portion. As shown in FIG. 3 of the drawings, the bladebone 16 is generally flat and has a ridge portion 18. During the de-boning operation, the selected meat portion is preferably arranged with the ridge portion 18 extending downwardly as will be described hereafter.

The recess 5 which is formed in the dies 2 and 3 is shaped to generally correspond to the configuration of the fore shank bones 14 and armbones 15 although it will be understood that this recess may be arranged to correspond to the shape of any other bone which is to be removed by the de-boning apparatus of the present invention. The recess 5 has an edge 19 extending about the periphery thereof and a narrow land portion 110 extending laterally outwardly from the edge of the recess 5. The faces 112 and 114 of the dies 2 and 3 which extend away from the edge of the land 110 diverge rapidly with respect to one another so as to provide a space into which meat may be deflected or extruded during closing of the dies.

As previously indicated, considerable difficulty has been experienced in attempting to sever meat sinew and the film which normally surrounds a bone. We have found that an effective cutting device is provided by forming a raised cutting edge 4 extending about the perimeter of the recess 5 in the lower die and a complimentary recess 21 extending about a face plate 20 which is mounted on the upper die 3 as shown in FIG. 7. The raised cutting edge 4 may have a truncated U-shaped configuration as illustrated in FIG. 7 or it may be a sharp V-shaped edge. A deformable face plate 20 of a material which is significantly more ductile than that of the cutting edge 4 is located on the upper die 3 and in use the lower die 2 is pressed against the upper die 3 to form a recess 21 in the plate 20. The recess 21 will then cooperate with the cutting edge 4 to shear sinews extending thereacross, thereby severing the sinews in use.

In using the de-boning dies of the type described in FIGS. 1 and 4 to 7, the meat bearing bone is positioned with the bone located within the recess 5 of the lower die and the press is closed. As the press closes, meat is forced out of the cavity formed between the recesses 5 and because the recesses 5 are proportioned to form a cavity which is only slightly smaller than the bone, the major portion of the meat is expelled laterally out of the cavity. The cavity is, as previously indicated, shaped to ensure that the die will close before the bone is broken or crushed.

While we have been able to de-bone meat using dies constructed in accordance with the embodiment of the invention illustrated in FIGS. 1 and 4 to 7, we have found that the likelihood of damaging the bone can be greatly reduced by introducing a resiliently deformable liner into each mould cavity. The resiliently deformable liner is preferably in the form of a pad of elastic material such as a food grade rubber. As shown in FIG. 8 of the drawings, the recess 40 which is formed in the lower die 52 and the recess 42 formed in the upper die 51, are merely rectangular shaped troughs and it will be understood that the troughs extend over substantially the full length of the upper and lower dies 52 so that the end walls which are not shown are of substantially the same thickness as the side walls. In the embodiment illustrated in FIG. 8, a plurality of layers of deformable material are located in each recess 40 and 42. The layers which are located in the recess 40 include a first layer 44, a second layer 57 and a third layer 46, all of which are continuous and made from a resilient elastic material. Two additional layers 48 are provided, each of which is formed with the plurality of passages 58 which open vertically therethrough in the direction of movement of the dies. The passages 58 are located at a plurality of spaced intervals throughout the width as shown in FIG. 8 and throughout the length of each perforated layer 48. These passages 58 serve to facilitate relative movement between adjacent layers so that the layers of resilient material can deform readily to the contour of the bone 53. The resiliently deformable insert which is located within the upper die 51 also consists of a plurality of layers including a perforated layer which again serve to conform to the configuration of the bone 53. Preferably, although not essentially, small shallow recesses are formed in the outer faces of the upper and lower most layers of the inserts of the lower and upper dies respectively, so as to center the bone.

It will be noted that the perforations 58 which are formed in the resilient layers, do not extend to the side edges of the perforated layers with the result that a column is formed about the side edges of each recesses which has a compression resistance which is greater than that of the remainder of the perforated area. That is to say, the side edges of the flexible inserts are preferably more rigid than the main body of the flexible inserts with the result that the meat which is being extruded when the dies approach the closed position, is driven out of the die cavity rather than being retained within the die cavity because of the compression of the resilient inserts.

In the embodiment illustrated in FIG. 8, a cutter blade 59 is mounted on the upper die 51 and is slidable in the direction of the arrows P5, so as to move downwardly to sever the meat which is extruded beyond the die in order to remove the meat as required in use. The cutter blade 59 extends about the entire periphery of the upper die.

In use, the lower die 52 is raised and lowered by activating the ram 56 by means of a power source through a valve mechanism which is diagramatically illustrated to ensure that the ram 56 is a double acting ram which may be raised and lowered as required. Initially, the lower die 52 is lowered and the meat piece within which the bone is located is positioned on the upper surface of the upper most layer of resilient material. The ram 56 is then activated to raise the lower die toward the upper die. As the two dies come together, the resilient inserts will initially compress the meat toward the bone and deflect the meat outwardly away from the bone. This reaction will continue until the dies have closed to the position shown in FIG. 8 wherein substantially all of the meat is removed from the bone. Thereafter, the cutter blades 59 are activated to sever the meat 58 which is spaced outwardly from the dies from the remaining material which is connected to the bone which is generally the sinew and film which surrounds the bone which is undesirable as a content in the meat for subsequent processing. Thus it will be seen that the bone can be substantially stripped of meat without damaging the bone. Because the bone does not break and its integrity is not destroyed, no bone particles are discharged into the meat 54.

The embodiment of the de-boning machine illustrated in FIG. 10 of the drawings differs from that of FIG. 8 merely in that the upper die 51 is mounted on the ram 56' and is the moveable die element. In addition, a plurality of piston assemblies generally identified by the reference numerals 60 are mounted in the base of the lower die 52. Preferably, a piston assembly 60 is provided to underlie each enlarged bone portion. The piston assembly 60 comprise a piston head 61 mounted on a shaft 62 which has a threaded end 63 mounted in a support plate 64. The support plate 64 rests on a diaphragm 65 which is clamped to extend across a pressure chamber 66. A fluid inlet 67 communicates with the chamber 65. A contoured liner 82 is mounted on the upper face of each piston and a sleeve 84 surrounds the wall of each piston to facilitate movement of the piston. A step or ledge 69 extends from the edge of each sleeve 84 to the side of the cavity of the lower mould. This ledge serves to ensure that the side edges of the flexible inserts will not yield to the same extent as the perforated portions of the liners and to the same extent as the portions of the liners which are supported by the pistons 61. This rigidity at the edge of the insert is important for the reason previously discussed in that it ensures that while the main body portion of the inserts is sufficiently resilient to deform about the thicker portions of the bone, the side edges will not readily deform to trap meat inwardly thereof before the dies are closed.

In the embodiment of the device illustrated in FIG. 10, the dies 51 and 52 will close as previously described to expell the meat from the dies. During lowering of the upper die 51, the resilient inserts will initially be deformed by contact with the thicker portions of the meat surrounding the thicker portions of the bone and continued closing will cause the resilient inserts to nestle around the bone. Because of the wide range of thicknesses which the bones may have which are to be de-boned, and because of the difference in thickness at different positions along the length of the bone, the extent to which it would be necessary to compress the resilient material may vary considerably, with the result that the forces applied to the bone may be substantially greater at the thicker portions thereof than they are at the thinner portions. In order to ensure that excessive forces are not applied at the thicker portions of the bone, the pistons 61 are positioned to underlie these thicker portions and the pistons 61 will yield to prevent excessive forces being applied so that the maximum force which can be applied by the resilient inserts can be determined by controlling the pressure in the pressure chamber 66. This mechanism permits extremely high pressures to be applied to the mould halves on closing to ensure that the sinews are severed in the manner previously described with reference to FIGS. 4 to 7 of the drawings. In this respect, it will be understood that the cutting edge 21 may be provided on the upper edge 52 with a complimentary recess being provided in the lower edge of the die 51.

FIGS. 11 and 12 illustrate further embodiments of the present invention. In FIG. 11, three circular pistons 61 are illustrated and a pair of complimentary support pads 60' are shown extending between the pistons 61. It will be understood that the support pads 60' may be supported by the diaphragm 65 so as to yield as required.

FIG. 12 illustrates a further embodiment wherein a plurality of circular passages 80 are formed in the base of the die 52 and a pin 82 is slidably mounted in each passage 80. Again the pins 82 will rest on a diaphragm 65 so as to yield when subjected to excessive pressures resulting from closing of the die.

A further embodiment of the invention is illustrated in FIGS. 13, 14 and 15 of the drawings wherein a cutter member 71 is mounted in a chamber 79 formed in the resilient layer 57 and enclosed by resilient layers 58. The cutter 74 has a blade portion 73 which has a sharpened edge 72. A suitable cutter member is illustrated in FIGS. 14 and 15 of the drawings. The cutting edge 72 is arranged to project through the outward most layer 58 so as to bear against the meat as the dies close to form an incision in the meat which facilitates the removal of the meat from the bone. The shape of the cutter blade is selected so as to provide the most effective form of incision, depending upon the type of meat which is being processed.

One or more such cutter members may be located within the upper or lower dies as required in use. The cutter blades should be strategically located and proportioned to ensure that the cutting edge is not driven against the bone during de-boning to an extent sufficient to damage the bone. As previously indicated, it is important to ensure that the bone is not broken or crushed during de-boning.

Referring again to FIG. 1 of the drawings, it will be seen that the loading mechanism 104 comprises clamps 7 which are mounted on arms 8. The arms 8 are pivotally mounted by means of pivot pins 10 on shoulders 120 which project outwardly from a turret 9. The turret 9 is mounted for rotation about a vertical axis on a support post 122. Each arm 8 is connected to one end of a ram 11, the other end of which is connected to a bracket 12 which is mounted on the turret 9. The ram 11 is connected to a high-pressure fluid (source) and is operable to project radially from its associated shoulder 120 when the ram 11 is in the contracted position. Extension of the ram 11 causes its associated arm 8 to pivot upwardly about its pivotal connection 10. The operating mechanism for the jaws 7 which is housed within the compartment 124, is connected to a high-pressure fluid by means of conduits 13.

To permit de-boning of meat pieces of opposite hand, two loading mechanisms 104 are provided and are arranged one on either side of the de-boning machine so that meat pieces can be positioned by operation of either one of the loading mechanisms.

In use, when de-boning a pork shoulder of the type illustrated in FIGS. 2 and 3 of the drawings, an incision 126 is initially made for the purposes of exposing the flat upper face of the bladebone 16. The meat is then gripped by the clamps 7 such that the portions 17 of reduced thickness of the bladebone is located in the knotch 77 (FIG. 16) which is located at the distal end of each of the arms 75 of the clamps 7. It will be noted that the arms 75 have pointed ends 76 which facilitate puncturing of the meat during closing of the clamps 7. It will also be noted that the recesses 77 are proportioned to ensure that while the clamps 7 secure the neck portion 17 of the bladebone 16, the bone is not broken by the clamping mechanism. It will be understood that the recesses 77 are arranged and proportioned to permit the bladebone 16 to be self-aligning during initial loading and during subsequent removal of the bladebone.

In use, after a portion of meat is clamped by the clamp 7, the turret 9 is rotated in the direction of the arrow P2 to position the meat with the portion which is to be de-boned resting in the recess of the lower die member as shown in FIG. 5. The ram 56 is then actuated to move the dies to the closed position. When the dies have been sufficiently closed to secure the fore shank and arm bones, the ram 11 is extended and this action causes the gripper member 7 to pull the bladebone away from its connection to the arm bone and rips the blade bone from its surrounding meat. Thus, the bladebone is removed from its surrounding meat without damage to the bladebone. Consequently, the meat previously surrounding the bladebone does not contain any bone chips or splinters and its texture is not destroyed. Thereafter, the movement of the ram 56 causes the dies 2 and 3 to close to remove meat from the bone which is located therebetween in the manner previously described.

From the foregoing, it will be apparent that various modifications of this structure are possible. For example, it will be understood that while the loading turrets may be used to advantage in a number of applications, there are also applications in which manually loading of the dies may be advantageous than mechanical loading. It will also be apparent that various shoots or slides may be provided adjacent the dies to facilitate the discharge of the meat and the separated bones into appropriate reciprocals.

In a further modification of the apparatus described above, the dies may be adapted to remove the meat from a pork shoulder including the meat surrounding the bladebone. That is to say the entire meat portion illustrated in FIG. 2 of the drawings, may be positioned between the dies and the meat removed by compression between the resilient members of the dies rather than having the bladebone ripped from its surrounding meat as previously described. A die having a recess such as that illustrated in FIG. 4 of the drawings may be suitable for this purpose.

In the embodiment according to FIG. 17, 18 and 19 the cutting device is provided with centering means 80, which serves to locate the bone in the meat piece exactly in the center line of the mould, for instance, according to the position of the bone as shown in FIG. 11.

The centering means 80 is in the form of a plurality of arms 81, which are arranged in parallel groups which have one end fastened to a rod 82 which is pivotably mounted on a pair of levers 83 which are secured to a driving shaft 84. The driving shaft is journalled in the frame members 85 which are secured to the upper mould 51 of the de-boning device.

The rod 82 has a bracket 86 mounted thereon which has a free end which is provided with a roller 87. The roller is guided in a cam-track 88 which is carried by the frame 85.

At the opposite side of the mould 51 a similar structure is provided in order to create a pair of opposite arms 81, the free ends of which are pointed to the lower mould 52.

The centering arms 81 are movable simultaneously into the space in between the upper and lower mould and are spaced therefrom. The simultaneous movement is acieved by a linkage 89 pivotably journalled on crank arms 90 of both driving shafts 84 of the opposite centering arms 81.

One of the shafts 84 is provided with a crank arm 91 to which any suitable driving means can be connected.

The working of the centering means as described hereabove is as follows:

Assuming that the centering arms 81 are being in the first position as shown in FIG. 17 and 19, said arms are protruding into the space between the lower and upper mould 52 and 51 respectively. Assuming further that a piece of meat is placed upon the lower mould 52, the centering arms 81 will penetrate the piece of meat, so that the end faces of the arms 81 will urge the bone 53 to the correct position with respect to the cavity in the mould. The centering action of the arms 81 will be ameliorated by the particular position of the end faces of the arms 81 including a certain angle with respect to each other.

When raising the lower mould 52 further the pressing action of the arms 81 upon the bone will be increased. The centering action will continue up to the moment when a bracket 92 fastened to the mould 52 will reach a stop member 93 of a driving rod 94, which is fastened to the crank 91 of the driving shaft 84. At that moment any further raising of the lower mould 52 will push the rod 94 upwards and so turn the shaft 84 accordingly, the levers 83, in clockwise direction. As a result the arms 81 will be retracted and the retracting movement will be guided by the movement of roller 87 along the cam-track 88.

The opposite arms 81 at the left side in FIG. 19 are also retracted as the driving shaft 84 is turned clockwise by means of the linkage 89.

The arms 81 will be brought in the retracted second position, according to FIG. 18, so the lower mould 52 can reach the upper mould undisturbed by the arms 81. For cutting the piece of meat the moulds are in the position of for instance FIG. 8.

After removing the piece of meat and the bone which has been removed therefrom, another piece of meat may be inserted as soon as the lower mould 52 is again in the position of FIG. 18. Thereupon, the rod 94 can be lowered by a suitable driving means, for instance a hydraulic cylinder 95, so bringing the arms 81 into the first position of FIG. 19.

Within the scope of the invention, it will be clear that the protruding arms may have any suitable form, wherein it is just necessary that the end faces thereof are positioned so that the urging action is directed to the lower mould 52 in order to have the bone centered accurately.

From the foregoing, it will be apparent that the present invention provides a simple and efficient mechanism which facilitates the removal of meat from bones while preventing undesirable breaking of the bones.