surrounding meat from elongate first and second animal bones articulated by an intermediate joint

The invention relates to an automated method for harvesting surrounding meat from elongate first and second animal bones, in particular poultry bones, articulated by an intermediate joint that pivotally connects confronting longitudinal ends of the first and second bones. The invention further relates to an apparatus for automatically performing the method.

It is know to automatically harvest meat from whole poultry legs including an upper leg and a lower leg articulated by a knee joint. Such methods are described in patent documents US 5277649, US 5810653, and US 5813908. A common feature of these prior art methods is that the bones opposite the knee joint are held in alignment during the entire meat removing process. Having the bones aligned certainly makes it easier to strip and move the meat as a sleeve from the bones with linearly movable mechanical means, such as grippers or diaphragms. However cutting of tissue at the knee joint to separate the meat therefrom needs more effort, and is not always successful in that it tends to compromise the yield of meat harvested from the bones. Also the means required to perform the tissue cutting at the knee joint with the bones in an aligned position with part of the meat still surrounding the knee joint are complicated, which impairs reliably of such mechanisms. Accordingly there still exists a desire to improve the known whole leg deboning methods to allow the automatic processing steps to be performed more reliably, and with higher yield of the meat products harvested from slaughtered poultry.

Accordingly it is an object of the present invention to propose an improved method for harvesting meat from articulated animal bones. In a more general sense it is thus an object of the invention to overcome or reduce at least one of the disadvantages of the prior art. It is also an object of the present invention to provide alternative solutions which are less cumbersome in assembly and operation and which moreover can be made relatively inexpensively. Alternatively it is an object of the invention to at least provide a useful alternative.

To this end the invention provides for an automated method and an apparatus for performing the method as defined in one or more of the appended claims.

More in particular the automated method for harvesting surrounding meat from articulated animal bones includes at least the steps of collecting meat surrounding the first bone as a sleeve, and meat surrounding the second bone as a sleeve, at an intermediate joint that pivotally connects confronting longitudinal ends of the first and second bones to form a collar around the intermediate joint, of bringing the first and second bones in a folded relationship about the intermediate joint with the collected meat still only attached in vicinity to the intermediate joint, of holding the first and second bones in the folded relationship, while mechanically gripping the meat collected adjacent to the intermediate joint in a location where the collected meat is free from the folded first and second bones, of relatively moving the gripped collected meat and the intermediate joint away from one another over a predefined distance to tension tissue between the collected meat and the intermediate joint, at least one step of cutting tensioned tissue to separate the collected meat from the intermediate joint, and a step of allowing the collected meat to be freed from the first and second bones while kept in the folded relationship. In this way an entire poultry leg can be suspended from two adjacent hooks and be folded about the knee joint. The step of collecting meat surrounding the first bone, and meat surrounding the second bone, at the intermediate joint can include scraping of meat parts towards the knee joint. The step of gripping the meat adjacent to the intermediate joint in a location where the collected meat is free from the folded first and second bones, may also be replaced by meat applying a gripper/scraper for scraping the meat over the knee joint. Relatively moving the gripped meat and the intermediate joint away from one another over a predefined distance may then also move the meat over the knee joint or over the intermediate joint. In the at least one step of cutting tissue to separate the meat from the intermediate joint cuts can be made from opposite sides of a plane through the folded bones to sever muscular tissue. In the method of the invention the step of relatively movement to tension tissue can include a first partial step of relatively moving the gripped collected meat and the intermediate joint partially away from one another at an intermediate distance less than the predefined distance, a second partial step of cutting tensioned tissue, and a third partial step of relatively moving away the meat and the intermediate joint from the intermediate distance to the predefined distance. After moving the gripper to a predetermined full distance, further cuts can be made from opposite sides of a plane through the folded bones. With the complex nature of bones and muscular tissue it is not always possible or feasible to cut all the connecting tissue between bones and edible meat in one step. Some tissue can only be exposed for cutting after surrounding tissue has been cut away first. Moreover tensioning the tissue to be cut makes it easier to avoid accidentally cutting bone chips that would contaminate the edible product that is harvested.

Alternatively or additionally the method of the invention can further have its step of relatively moving to the predefined distance followed by releasing the mechanical gripping of the meat and then gripping the collected meat in closer proximity to the intermediate joint, and again relatively moving the meat and the intermediate joint apart at the predefined distance to tension and expose further tissue for cutting. The gripper/scraper upon releasing its gripping action is returned to

substantially its first position, where it reengages the meat. Thereupon the gripper is returned to substantially the predetermined position and the knee joint can be engaged by guiding/retaining means, while another cutting step is performed on opposite sides of the plane through the folded bones. Such a procedure further assists in exposing difficult to reach tissue for cutting, and in accurately cutting such tissue.

The method of the invention can further have the step of allowing the collected meat to be freed from the first and second bones preceded by a step of aligning tissue with a rotating cutting blade that passes between the intermediate joint and the meat to completely separate the collected meat from the intermediate joint. The rotating cutting blade is then

advantageously positioned transverse to a plane common to the folded first and second bones. With this rotary cutter the meat can be completely separated from the knee joint. Such a final cutting operation can be performed from a single one of the sides opposite of the plane through the folded bones, provided that the rotary cutting blade is positioned transverse to the common plane.

According to one practical embodiment the folded first and second bones during tissue tensioning and cutting are advanced through a path of movement that extends in a plane common to the folded first and second bones.

In another embodiment relative movement of the collected meat away from the intermediate joint can be effected by moving the collected meat away from the intermediate joint.

In yet another embodiment holding of the folded first and second bones can be in a suspended position with the intermediate joint depending downwardly.

Upon the step of collecting the meat surrounding the first bone and the second bone at the intermediate joint, the meat collected as a collar at the intermediate joint can in another variation be cut longitudinally of the first and second bones. Such a further preparatory step may assist the meat in moving beyond the joint. Also prior to the at least one step of cutting tissue of the meat collected at the intermediate joint, tensioned tissue extending between the collected meat and the intermediate joint can brought into alignment with at least one cutting element. This bringing into alignment with at least one cutting element, may include in particular bringing of the tissue in alignment with a first cutting blade on one side of a plane common to the folded first and second bones, and with a second cutting blade on an opposite side of the common plane.

The invention further includes an apparatus for automatically performing the method of any one of the above variants.

Further advantageous aspects of the invention will become clear from the appended description and in reference to the accompanying drawings, in which:

Figure 1 is an isometric view of a meat harvesting unit suitable for contributing to the invention;

Figure 2 is a fragmentary isometric view of an overhead conveyor suitable to cooperate with the harvesting unit of Figure 1 in performing the method of the invention;

Figure 3 is a longitudinal cross section of the unit of Figure 1; Figure 3A is a enlarged fragmentary portion of Figure 3;

Figure 4 is an isometric view of a gripper useful in the unit of Figure 1 viewed from an upstream position in the direction of movement, and shown in an opened release position; and

Figure 5 is an isometric view of the gripper of Figure 4 viewed from a downstream position in the direction of movement, and shown in a closed gripping position.

The isometric view Figure 1 shows a meat harvesting unit 1 suitable for carrying out the method steps of the invention. The unit 1 includes a through-shaped frame 3, which can be supported on legs 5, as shown, or be attached to a frame of a meat processing plant (not shown), but well known in the art). Mounted inside of the through-shaped frame 3, is an endless conveyor 7, of which an upper stretch moves in the direction of arrow 9. Mounted an, and moved by the endless conveyor 7 is a plurality of grippers 11. During movement in the direction of arrow 9, the grippers 11 are successively moved past a first pair of tissue cutting blades 13, a second pair of tissue cutting blades 15, a pair of opposite knife guides 17, and final cutting blade 19. The first and second parts of tissue cutting blades 13, 15 are each in the form of opposite circular cutting blades, which are spring biased towards one another. The opposite circular cutting blades are non- rotatably fixed, but may be loosened and adjusted for a fresh cutting edge on another portion of the circumference. The pair of opposite knife guides 17 are opposite of a central path of movement indicated by dash-dotted line 21, and guide the knee joint of the first and second bones 39, 41 with respect to the level of the final cutting blade 19. The knife guides may extend up to and beyond the centre of rotation of the final cutting blade 19, and will slightly lift the bones 39, 41 in respect of the hooks 37. The final cutting blade 19 is a single rotary cutting blade that is positioned in interference with the central path of movement 21. The final cutting blade 19 is positively driven for continuous rotation by a motor unit 23.

As shown in Figure 2 poultry legs 25 are moved through the path of movement 21 in the direction of arrow 9 by means of an overhead conveyor 27. The overhead conveyor 27 extends along a centre line 29 and includes a plurality of carriage 31 mounted for movement along a truck 33 and interlinked in this example bya common chain 35. Other types of conveyors are also conceivable, but the example shon here is merely for explanatory purposes. Each carriage 31 carries a depending assymetric double hook 37. One of the asymmetric double hooks 37 in Figure 2 by way of example carries a poultry leg 25, which is suspended by first and second bones 39, 41. The first and second bones 39, 41 are in a folded relationship about an intermediate joint which is surrounded by collected meat 43 that is still attached in the vicinity of the intermediate joint.

In Figure 3, which is a longitudinal cross section of the unit 1 of Figure 1, it is illustrated by dash-do6tted centre line 29 where the overhead conveyor 27 of Figure 2 extends. The poultry legs 25 suspended as shown in Figure 2 will enter the meat harvesting unit 1 from the right hand side of Figure 3, and then are conveyed in the direction of arrow 9. The path of movement of the suspended poultry legs 25 is schematically indicated by dash-dotted line 21.

The grippers 11 as seen in Figure 3, each have a guide roller 45 engaged in a guide track 47. As best seen in a detail view of Figure 3A, the guide track 47 has a first section 47A extending at an uppermost level of elevation. A second section 47B extends at a loer intermediate level of elevation. A third section 47C extends at a lowermost level of elevation, and a short fourth section 47D extends at an upper intermediate level. After the first four sections 47A-47D the guide track 47 in a fifth section 47E returns to the lowermost level of elevation, and only at the downstream end of the upper stretch of the conveyor 7, as shown in this example, returns to an uppermost level sixth section 47F. However this sixth section 47F is optional, and the guide track may also continue at its lowermost level, until the gripper 11 is in a position where it cannot interfere with the first and second bones 39, 41.

As seen in Figures 3 and 3A the endless conveyor 7 extends around first and second return rollers 49, 51. The grippers 11 are formed into an endless conveyor chain by intermediate spacer links 53 pivotally connected by laterally extending hinge pins 55. The laterally extending hinge pins 55 are engaged by circumferentially spaced notches 57 on the first and second return rollers 49, 51.

Figures 4 and 5 are isometric views of the gripper 11 as viewed from opposite directions. Figure 4 shows the gripper 11 from an upstream position in the direction of movement 9 with the gripper 11 open. Figure 5 shows the gripper 11 from a downstream position in the direction of movement 9, and with the gripper 11 closed. The gripper 11 has opposite support links 59, 61 interconnected by a bridge element 63. Each of the opposite support links 59, 61 carries laterally extending hinge pins 55 for pivotally connecting with spacer links 53 (as shown in Figure 3A). The bridge element 63 is provided with two vertically extending through bores for slidingly accommodating parallel pillars 65 extending upwardly from a bracket 67 carrying the guide roller 45. The arrangement is such that the parallel pillars 65 move up and down with the guide roller 45, while the bridge 63 remains in a stationary position. An upper saddle 69 is mounted on top of the parallel pillars 65 for up and down movement therewith. First and second gripper jaws 71, 73 are pivotally arranged on the upper saddle 69 for movement between an open release position (Figure 4) and a closed gripping position (Figure 5). It is further shown in Figure 4 that the gripper jaws pivots each have a gripper jaw bias spring 75 for biasing the first and second gripper jaws 71, 73 to the gripping position of Figure 5. As further seen in Figure 5, each of the first and second gripper jaws 71, 73 has a respective first and second jaw arm 77, 79. Lateral followers 81 act on tappets 83 to move the jaw arms 77, 79 to move the first and second gripping jaws 71, via the respoective arms 77, 79 into their open release position against the bias force of the bias springs 75. Not visible in the drawing Figures, but conventional,the frame 3 has guide means for guiding and supporting the support links 59, 61, as well as lateral cam track means for moving the followers 81 inwardly and outwardly. The gripping and releasing action of the gripper jaws 71, 73 is controlled in correspondence with the position of a gripper 11 in relation to the guide track 47. The bridge 63 of each gripper 11 can be provided with a tray 85 for temporarily supporting the meat 43 (Figure 2). The operation of the above-described meat harvesting unit 1 in performing the method steps will now be described below. An animal part with surrounding meat, such as the poultry leg 25 is held in a folded relationship about an intermediate joint with collected meat 43 still attached in vicinity of the intermediate joint. The folded poultry leg 25 is suspended by distal ends of its first and second bones 39, 41 from the asymmetric double hook 37. The hook 37 is preferably asymmetric to accommodate a common length difference between the first and second bones 39, 41.

An entire poultry leg 25 is thus suspended from the double hook 37, as shown in Figure 2, and is foled about the knee joint. Meat parts

surrounding each of the first and second bones 39, 41 have previously been scraped towards the knee joint. The folded poultry leg with the meat collected in vicinity of the knee joint, but still attached thereto, is entering the meat harvesting unit 1 as shown in Figures 1, 3 and 3A from a right hand side. The suspended poultry legs 25 are then further conveyed by the overhead conveyor 27 along the central path of movement 21. Starting at the right hand side of Figures 3 and 3A the poultry leg 25 is engaged between the opened gripper jaws 71, 73 of a relevant one of the plurality of grippers 11. In this position at the right hand start of the guide track 47 the upper saddle 69 of the relevant gripper 11 is at an uppermost position with respect to the bridge element 63. At this point the gripper jaws 71, 73 are aligned with a location where the meant 43 collected at the knee joint is just beyond the folded first and second bones 39, 41, and the knee joint. From this point on the gripper jaws 71, 73 are mechanically allowed to close by means of the bias springs 75.

Closing of the gripper jeans 71, 73 has been made possible by allowing the followers 81 to relax and the tappets 81 to move laterally outwardly. It will be clear to the skilled person that movement of the followers 81 can be controlled by conventional lateral cam tracks, which require no further disclosure. The double hook 37 and the gripper 11 are now conveyed in synchronisation with one anoter, and the guide roller 45 is moving from the uppermost level of the first guide track section 47A to the lower intermediate level of the second guide track section 47B. Movement of the guide roller 45 from its uppermost to a lower intermediate position lowers the upper saddle 69 in the same amount by the parallel pilars 65 sliding downwardly through the bridge element 63. This results in tensin being exerted on the collected meat 43 away from the knee or intermediate joint, and exposes tissue still attached the meat to the bones. While advancing along the second guide track section 47B the poulty leg 25 along the central path of movement is engaged by the first pair of tissue cutting blades 13. Opposite circular cutting blades of this first pair are spring based to one another, and mounted for idle rotation. The first pair of cutting blades 13 is positioned to cut tissue at the intermediate or knee joint. From the second guide track section 47B to the third guide track section 47C the guide roller 45 is moved further downwardly to a lowermost level. In this position the upper saddle 69 of the gripper 11 is also in its lowest position with respect to the bridge element 63. As a rsult the meat 43 gripped by the first and second gripper jaws 71, 73 is moved even further away from the joint, as permitted by the tissue already cut by the first pair of cutting blades 13. In this further tensioned state the poultry leg is advanced further along the third guide track section 47C to meet with the second pair of tissue cutting blades 15. The opposite spring biased circular cutting blades of the second pair 15 and further tissue that has been exposed by moving the gripper jaws 71, 73 with the gripped meat 43 from the lower

intermediate level to the lowermost level. After passing the second pair of cutting blades 15 the poultry leg 25 and gripper 11 advance towards the fourth section 47D of the guide track 47. This fourth seciton 47D is a relatively short section, which raises the guide roller 34 to an upper intermediate level. Prior to the upper saddle 69 being raised to the upper intermediate level, the first and second gripper jaws 71, 73 are opened by the followers 81 being moved laterally inwardly. As a result of the followers 81 moving inwardly the tappets 83 press against the first and second arm jaws 77, 79 to open the first and second gripper jaw s 71, 73. When the disengaged gripper jaws 71, 73 have reached the upper intermediate position directed by the short fourth section 47D and the guide roller 45, the gripper jaws are closed again to grip the remaining tissue and meat at a level gain closer to the intermediate knee joint. After regripping the upper saddle 69 and gripper jaws 71, 73 are lowerd again to their lowermost level when the guide roller 45 passes into the fifth guide track section 47 at the lowermost level. In this newly tensioned position of the tissue extending between the joint and the meat 43 the poultry leg 25 is passed over and partially between a pair of opposite knife guides 17 for cutting tissue on both lateral sides of the poultry leg. After exitting the opposite knife guides 17, the carriage 31, poultry leg 25, and gripper 11 advance together past the final rotary diven cutting blade 19, to completely separate the collected meat 43 from the first and second bones 39, 41. The collected meat 43 is then received on the tray 85 and continues through the path of movement 21 until the tray 85 is forced away from its horizontal position when the hinge pins 55 of the gripper have engaged the spaced notches 57 of the second return roller 51, as shown at the left hand side of Figure 3. At this point the gripper jaws 71, 73 are released and lifted back to the uppermost position.

Accordingly an automated method is described for harvesting surrounding meat from elongate first and second animal bones articulated by an intermediate joint that pivotally connects confronting longitudinal ends of the first and second animal bones. The method collects meat surrounding as a sleeve the first bone and meat surrounding as a sleeve the second bone at the intermediate joint to form a collar around the

intermediate joint. The method further brings the first and second bones in a folded relationship about the intermediate joint with the collected meat still only attached in vicinity to the intermediate joint, and holding the first and second bones in the folded relationship. The meat collected adjacent to the intermediate joint is mechanically gripped in a location where the collected meat is free from the folded first and second bones, and the meat and the intermediate joint are moved away from one another to tension tissue between the collected meat and the intermediate joint. The method is completed by cutting tensioned tissue to separate the collected meat from the intermediate joint, and by allowing the collected meat to be freed from the first and second bones while in the folded relationship.

It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description and drawings appended thereto. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described. It will be clear to the skilled person that the invention is not limited to any embodiment herein described and that modifications are possible which may be considered within the scope of the appended claims. Also kinematic inversions are considered inherently disclosed and can be within the scope of the invention. In the claims, any reference signs shall not be construed as limiting the claim. The terms 'comprising' and

including' when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Thus expression as 'including' or 'comprising' as used herein does not exclude the presence of other elements, additional structure or additional acts or steps in addition to those listed. Furthermore, the words 'a' and 'an' shall not be construed as limited to 'only one', but instead are used to mean 'at least one', and do not exclude a plurality. Features that are not specifically or explicitly described or claimed may additionally be included in the structure of the invention without departing from its scope.

Expressions such as: "means for ..." should be read as: "component configured for ..." or "member constructed to ..." and should be construed to include equivalents for the structures disclosed. The use of expressions like: "critical", "preferred", "especially preferred" etc. is not intended to limit the invention. To the extend that structure, material, or acts are considered to be essential they are inexpressively indicated as such. Additions, deletions, and modifications within the purview of the skilled person may generally be made without departing from the scope of the invention, as determined by the claims.