Abstract:
A deboning method and a deboning apparatus is provided whereby a meat block at the humerus part having a part of the scapula remaining therein, which corresponds to the shoulder part of a back split block of an animal meat (for example, beef, pork, horse meat, goat meat or poultry meat), can be completely automatically deboned after a simple pretreatment by human hand.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a continuation of International Application PCT/JP2005/001300 (published as WO2006/080085 A1) having an international filing date of 25 Jan. 2005, the contents of which is incorporated by reference herein. 
     
    
     BACKGROUND  
       [0002]     The present invention relates to a deboning method and a deboning apparatus in which a meat block (hereinafter referred to as the “work”) including a humerus part and a part of a scapula at a shoulder part  70  of a halved block of back split meat such as beef, pork, horse meat, sheep meat, goat meat or poultry meat can be completely automatically deboned after a simple pretreatment by human hand as seen from a diagram of cuts of the pork in  FIG. 18 . The present invention more particularly relates to a deboning method and a deboning apparatus in which, after removing a remaining part of a forearm bone left at a time when a joint portion between the forearm bone and a humerus is cut and exposing the joint portion of the humerus as a pretreatment by human, such a work conveyed with a loader is deboned and in which middle steps of cutting muscle of meat, measuring a length of the humerus and peeling off a meat part can mechanically be performed, whereby a deboning treatment is completely automated to reduce a treatment time and improve a treatment efficiency.  
         [0003]     Heretofore, to debone back split meat blocks, in a meat treatment place for these back split meat blocks, beef or pork is largely divided into five parts including shoulder, loin, belly, thigh and fillet.  
         [0004]     Among these parts, an apparatus which debones a shoulder part is disclosed in, for example, WO2004/068953 A1 (Prior Art 1).  
         [0005]     This deboning apparatus has a purpose of realizing a meat deboning apparatus for medium and small treatment plants in which a space is saved and a cost is reduced. This apparatus is a deboning apparatus for an arm/shoulder loin part  70  shown in  FIG. 18  of a cut block of meat such as pork, beef, horse meat, sheep meat, goat meat or the like subjected to a pretreatment by hand including back splitting and largely dividing of the meat. The apparatus is more particularly a small-sized meat deboning apparatus in which as the pretreatment, the meat is divided to remove a shoulder loin part and a spare rib, a forearm bone is removed, and muscle around a humerus and a scapula is then cut. The cut meat subjected to the maximum pretreatment is subjected to a minimum necessary deboning treatment. The scapula is peeled off (the scapula is removed) and the humerus is automatically removed to separate the meat.  
         [0006]     In this deboning apparatus, as shown in  FIG. 19 , on a downstream side of an introducing station  010 , a scapula deboning station  011  in which a scapula is peeled off is disposed with a predetermined space S from the introducing station  010 , and a humerus deboning station  012  in which a humerus is removed is similarly disposed with a space S equal to the above predetermined space. On a downstream side of the humerus deboning station  012 , a bone part discharge station  013  in which a bone part of the humerus remaining after meat separation at the above station is discharged is disposed. The stations are disposed in order and constitute a deboning line having ends.  
         [0007]     In the introducing station  010 , at a gap of a fixed conveyance path  014   a  including two extending rails which form a conveyance path and between which the space S is disposed, a constricted part of the humerus of a work  050  is inserted and hung. The work includes an arm part of back split meat which has been roughly divided into five parts and from which a shoulder loin part and a forearm bone have been removed. In consequence, an introduction step  022  is performed.  
         [0008]     Subsequently, in the next first conveyance step  023 , a pushing section  019  is operated to introduce the work  050  subjected to the introduction step into a movable conveyance path  015   a  of the adjacent scapula deboning station  011  via tact conveyance (a mechanism in which a pressurizing cylinder is operated to pressurize and advance the work as much as a unit station corresponding to one stroke of the pressurizing cylinder), and the work is held at the station  011 . When the work is held, the pushing section  019  leaves the work  050  at an original position of the movable conveyance path  015   a , and returns to an original position of the introducing station  010 .  
         [0009]     Subsequently, in the next scapula deboning step  024 , the movable conveyance path  015   a  of the station  011  where the work  050  introduced in the previous step is held is detached from the original position to move up to a deboning treatment position, where a scapula  052  is peeled off and removed, thereby ending the deboning treatment. The movable conveyance path  015   a  holds a work  051  and returns to the original position.  
         [0010]     Subsequently, in the next second conveyance step  025 , the work  051  subjected to the above deboning step is introduced into a movable conveyance path  017   a  of the adjacent humerus deboning station  012  via a pushing section  020  of the tact conveyance, and held at the station  012 . When the work  051  is held, the pushing section  020  leaves the work  051  at an original position of the movable conveyance path  017   a , and returns to an original position of the scapula deboning station  011 .  
         [0011]     Subsequently, in the next humerus deboning step  026 , the movable conveyance path  017   a  of the humerus deboning station  012  where the work  051  introduced in the previous step is held is detached from the original position to move up to the deboning treatment position where the humerus is removed and meat  053  is peeled off, thereby ending the deboning treatment. The movable conveyance path  017   a  holds a humerus  054  and returns to the original position.  
         [0012]     Subsequently, in the next conveyed bone part discharge step  027 , a humerus  054  subjected to the above deboning step is conveyed and discharged to the adjacent bone part discharge station  013  via a pushing section  021  of the tact conveyance. When the humerus is discharged, the pushing section  021  returns to the original position of the humerus deboning station.  
         [0013]     Through the above-mentioned introduction→first conveyance→scapula deboning→second conveyance→conveyed bone part discharge steps, the deboning treatment of the work ends.  
         [0014]     It is to be noted that the introduction is performed immediately after the pushing sections  019 ,  020  and  021  linearly and integrally connected via a coupling pestle simultaneously return to their original positions as old positions by a returning operation of an actuator described later immediately after the subsequent-stage first conveyance, second conveyance and conveyed bone part discharge steps. The stations are replenished with the following works, and the deboning can continuously be performed.  
         [0015]     Moreover, in Japanese Patent Application Laid-Open No. 2004-236577 (Prior Art 2), with respect to a work to be subjected to deboning in a state in which a half block of back split meat is hung, as a deboning apparatus which can cope with either a left block or a right block at random, a meat deboning method and a meat deboning apparatus are disclosed in which it is judged that the block is the left block or the right block. According to the judgment result, a portion to be switched at a left or right switching station is switched to the left or the right to form a left or right random deboning treatment line, and the left and right lines can selectively be used to effectively perform the deboning treatment. Moreover, the work can be introduced with an automatic loading device, the bone part can securely be held during the deboning, and a bone joint can be prevented from being dislocated.  
         [0016]     As shown in  FIG. 20 , this apparatus includes a pretreatment section  030  which cuts muscle of a work including a back split meat block to be deboned in a hung state; a work introducing section  031  which introduces the pretreated work into a deboning treatment line formed by the meat deboning apparatus of the invention via the automatic loading device; a left or right judgment section  032  which judges whether the introduced work suspended from a clamper corresponds to the left block or the right block; a left or right switch operating section  033  which outputs a left or right switch signal to the corresponding station on a downstream side according to the judgment result of the judgment section; a left or right switch station  034  which receives the left or right switch signal to switch a portion required to be switched; a tact feed section  035  which performs the switching to form a left or right random deboning line; and a deboning discharge section  036 .  
         [0017]     Moreover, the following operation is performed according to the judgment result of the left or right judgment section  032 .  
         [0018]     The left or right judgment section  032  judges that the introduced meat block corresponds to the left block or the right block. In response to a judgment signal, the left or right switch operating section  033  allows the corresponding left or right switch station  034  to switch a treatment position to the left or the right and to select a left treatment jig or a right treatment jig. In cooperation with the tact conveyance of the tact feed section  035 , the left or right random deboning line is formed.  
         [0019]     The meat blocks including an inner shoulder part and a leg part are sorted as the right and left blocks at the subsequent-stage deboning line, and branched to right and left deboning lines for exclusive use, and the deboning is substantially automatically performed at the deboning lines for exclusive use, respectively.  
         [0020]     According to the above-mentioned constitution, it is judged that the meat block is either the left or right block, and the left or right random deboning line is used in accordance with the judgment. In consequence, unlike the conventional right and left deboning lines for exclusive use, equipment costs can be reduced, an operation ratio can be improved, and the operation can efficiently be performed. Since an idling time of an equipment is reduced owing to the improvement of the operation ratio, a facility can securely hygienically be controlled, and deboning and scrapping can be performed under a more preferable hygienic environment.  
         [0021]     However, the shoulder part of the work to which each prior art described above is applied is a shoulder part including a forearm bone, a humerus and a scapula as shown in  FIGS. 5 and 6  of Prior Art 2, or a shoulder part including at least the humerus and the scapula as shown in  FIG. 19  which is an accompanying drawing of Prior Art 1. On the other hand, as shown in  FIG. 21 , an upper part of a shoulder part is cut along a portion (a cutting line x) which is easily cut along lumbar vertebras. In consequence, a part of the scapula is left. A lower part of the shoulder part is cut along a joint part (a cutting line y) between a forearm bone and a humerus.  
         [0022]      FIG. 21  shows a framework of a slaughtered pig. In  FIG. 21 , reference numerals  040  are lumbar vertebras (seven vertebras),  041  are thorn projections,  042  is a thighbone,  043  are ribs,  044  is a scapula,  045  is a forearm bone and  046  is a humerus.  
         [0023]     Especially, in the North America, as described above, the pork is cut along the cutting lines x and y, and the part of the remaining forearm bone  045  is sold as bone meat including the bone attached as it is.  
         [0024]     The shoulder part cut at such a cutting position has a problem that the part cannot be subjected to the deboning treatment with the deboning apparatus described in the above prior art.  
         [0025]     Moreover, in the device of Prior Art 1, as shown in  FIG. 19 , the work is temporarily stopped in the deboning step of the scapula and the deboning step of the humerus. Subsequently, the work is temporarily removed from a conveyance path, and moved up to the deboning treatment position where the scapula or the humerus is removed and the meat is peeled off. After ending such a deboning treatment, a step of returning the work to the conveyance path is performed. Therefore, there is a problem that it takes much time to perform the deboning treatment.  
       SUMMARY OF THE INVENTION  
       [0026]     The present invention has been developed in view of such a conventional technical problem, and an object thereof is to realize a deboning method and a deboning apparatus for carrying out the deboning method in which a deboning treatment can be applied to a shoulder part including a part of a scapula left at a time when an upper part is cut along a portion easily cuttable along lumbar vertebras and including a lower part cut at a joint portion between a forearm bone and a humerus.  
         [0027]     Moreover, a second object of the present invention is to realize a deboning method and a deboning apparatus in which, to debone the shoulder part, the shoulder part hung with a clamping device is conveyed and subjected to a deboning treatment without discontinuing the conveyance, whereby a treatment time can be reduced and a treatment efficiency can be improved.  
         [0028]     The present invention achieves such objects. A first aspect of the invention relates to a method of deboning a meat block which is cut along a joint part between a forearm bone and a humerus and at an upper part of a scapula, including the humerus and a part of the scapula while hanging and conveying the meat block with a loader, the method comprising: a first step of perpendicularly cutting the meat block to expose bone parts; a second step of peeling off the meat from an upper part of the humerus to a part of the humerus below the center thereof with a meat separator and horizontally cutting muscle of the center of the humerus; a third step of further peeling off the meat down to a joint part between the humerus and the scapula with a meat separator and measuring a length from a reference position positioned at the upper part of the humerus to the joint part between the humerus and the scapula to determine a lowering position of the meat separator in the subsequent step based on a value of the length thus measured; a fourth step of peeling off, in a stepwise manner, the meat around the joint part with a meat separator while cutting the muscle around the joint part between the humerus and the scapula; and a fifth step of cutting muscle around the scapula and peeling off the meat around the scapula with a meat separator.  
         [0029]     In the first invention, as described above, the meat block cut along the joint part between the forearm bone and the humerus and at the upper part of the scapula and including the humerus and a part of the scapula is regarded as a target of the deboning (such a work of a part constituting the deboning target of the present invention will hereinafter be referred to as the “target work”). Preferably, in a pretreatment, a remaining part of the forearm bone is removed to expose a bone of the joint part of the humerus, and the work hung and conveyed with the loader is subjected to the deboning treatment.  
         [0030]     In the first step, the target work is perpendicularly cut to expose the bone part. As means for performing this step, for example, a round blade cutter or the like perpendicularly arranged so as to come close to or away from the target work along a conveyance path may be used.  
         [0031]     Subsequently, as the second step, the meat is peeled off from the upper part of the humerus to the part of the humerus below the center thereof by use of the meat separator. Moreover, the muscle of the center of the humerus is horizontally cut, for example, with the horizontally arranged round blade cutter or the like. When this muscle is cut, the meat which covers the humerus can further be peeled off close to the joint part between the humerus and the scapula.  
         [0032]     Subsequently, as the third step, while the meat is further peeled off down to the joint part between the humerus and the scapula with the meat separator, the length from the reference position positioned at the upper part of the humerus to the joint part between the humerus and the scapula is measured to determine a lowering stroke of the meat separator in the subsequent step, that is, during the peeling of the meat around the joint part between the humerus and the scapula and around the scapula, based on the value of the length thus measured. In this case, preferably, when a clamping position where the target work is clamped with the loader is regarded as the reference position, the reference position is clarified, and the measurement to the joint part between the humerus and the scapula is facilitated. When the clamping position is a constricted part of the joint part between the forearm bone and the humerus, the work is easily clamped. More preferably, when a length from the reference position to an upper surface of a projection of the joint part between the humerus and the scapula is measured, a measurement point is clarified.  
         [0033]     Subsequently, the muscle around the joint part is peeled off in the stepwise manner with the meat separator while cutting the meat around the joint part between the humerus and the scapula (the fourth step). Furthermore, the muscle around the scapula is cut, and the meat around the scapula is peeled off with the meat separator (the fifth step).  
         [0034]     According to the first invention, the slight pretreatment by hand is involved, but the substantially completely automated deboning treatment of the target work can be realized. In consequence, reduction of a treatment time and improvement of a treatment efficiency can be achieved.  
         [0035]     Moreover, the treatment step is finely divided into the first to fifth steps. In a stage of each treatment step, while cutting the muscle bonded to the bone, the meat is finely peeled off in the stepwise manner. In consequence, the humerus of the target work does not have to be separated from the scapula, and the bones can completely be separated without leaving any extra meat at the bone.  
         [0036]     A second aspect of the present invention is related to the apparatus to carry out the deboning method according to the first invention, in which a meat block cut along a joint part between a forearm bone and a humerus and at an upper part of a scapula and including the humerus and a part of the scapula is subjected to a deboning treatment while hung and conveyed with a loader, wherein the loader is configured to pass through a plurality of stations and perform the deboning treatment while the loader hangs the meat block to convey the meat block in a horizontal direction, at least a part of the stations includes a round blade cutter to cut muscle arranged along a conveyance path of the meat block, a meat separator which separates meat of the meat block from a bone, and a measurement device which measures a length from a reference position positioned at an upper part of the humerus to a joint part between the humerus and the scapula, and a lowering stroke from an original height (a height before lowering) of the meat separator arranged at each of the stations is determined based on the measured value.  
         [0037]     In the second invention, the loader is constituted so as to pass through the plurality of stations to perform the deboning treatment while the loader conveys the hung meat block in the horizontal direction. Along this conveyance path, the meat separator and the round blade cutter for cutting the muscle are disposed for each step, the muscle which covers the bone is cut, and the meat is peeled off. The length from the reference position positioned at the upper part of the humerus to the joint part between the humerus and the scapula after the meat is peeled off is measured with the measurement device, and the lowering stroke from the original height of the meat separator is determined based on this measured value.  
         [0038]     According to the second invention, a slight pretreatment by hand is involved, but a substantially completely automated deboning treatment of a target work can be realized. In consequence, reduction of a treatment time and improvement of a treatment efficiency can be achieved.  
         [0039]     Moreover, in each stage of a treatment step, while muscle bonded to the bone is cut by the round blade cutter for cutting the muscle, the meat is peeled off in a stepwise manner by the meat separator. In consequence, the humerus of the target work does not have to be separated from the scapula, and the meat can finely be separated. The meat can completely be separated without leaving any extra meat at the bone.  
         [0040]     Furthermore, halfway in the treatment step, the reference position is set to the upper part of the humerus, the length from this reference position to the joint part between the humerus and the scapula is measured, and a lowering stroke of the meat separator is set based on the measured value at each station. Therefore, even if an arm part of a treatment target has different length and size, a cutting position of the round blade cutter, a reference height and the lowering stroke of the meat separator can be changed so as to cope with the difference according to circumstances.  
         [0041]     In this second invention, preferably the meat separator has two separation surfaces which face each other along the conveyance path of the meat block, and includes a driving device which vertically moves the separation surfaces. In consequence, a meat content of the target work can be peeled off in a state in which the target work is nipped between the separation surfaces, and the meat separator having a simple structure and a satisfactory separation performance can be constituted. In addition, when a conveyance speed of the target work and a lowering speed of the separation surfaces are regulated, a speed at which the meat content is peeled off can freely be regulated.  
         [0042]     More preferably, the plurality of stations are substantially installed at an equal height level, and the loader hangs and conveys the meat block at a substantially constant height over all deboning steps. According to this constitution, a speed of the treatment can further be increased, the reduction of the treatment time and the improvement of the treatment efficiency can further be achieved, and an apparatus constitution can be simplified.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0043]     The invention will be described in detail with reference with reference to the following figures, wherein:  
         [0044]      FIG. 1  is the whole constitution diagram of a first embodiment of a deboning apparatus according to the present invention, (a) is a plan view, (b) is an elevational view, (c) is a sectional view cut along the C-C line of (b), and (d) is a right side view;  
         [0045]      FIG. 2  shows a target work (an arm part) regarded as a deboning target of the present invention, (a) is a plan view showing a state before a pretreatment by hand, (b) is an elevational view of the state, (c) is a plan view showing a state after the pretreatment by hand, and (d) is an elevational view of the state;  
         [0046]      FIG. 3  is a step diagram showing each deboning step according to the first embodiment;  
         [0047]      FIG. 4  is a perspective view of a device for use in a second station of the first embodiment;  
         [0048]      FIG. 5  is a perspective view of a meat separator  20  for use in the first embodiment as obliquely viewed from above;  
         [0049]      FIG. 6  is a perspective view of the meat separator  20  obliquely viewed from below;  
         [0050]      FIG. 7  is a perspective view of a device for use at a third station of the first embodiment as viewed from an upstream side in a conveyance direction of a target work;  
         [0051]      FIG. 8  is a perspective view of the device of  FIG. 7  as viewed from a downstream side in the conveyance direction of the target work;  
         [0052]      FIG. 9  is an elevational view of the device of  FIG. 7  as viewed from the upstream side in the conveyance direction of the target work;  
         [0053]      FIG. 10  is a back view of the device of  FIG. 7  as viewed from the downstream side in the conveyance direction of the target work;  
         [0054]      FIG. 11  is a perspective view of a device for use in a fourth station of the first embodiment as viewed from above on the left side;  
         [0055]      FIG. 12  is a perspective view of the device of  FIG. 11  as viewed from above on the right side;  
         [0056]      FIG. 13  is a perspective view of a device for use in a fifth station of the first embodiment as viewed from above on the left side;  
         [0057]      FIG. 14  is a perspective view of the device of  FIG. 13  as viewed from above on the right side;  
         [0058]      FIG. 15  is a perspective view of a device for use in a sixth station of the first embodiment;  
         [0059]      FIG. 16  is a perspective view of a device for use in a seventh station of the first embodiment;  
         [0060]      FIG. 17  is a perspective view of the device of  FIG. 16  as viewed from below;  
         [0061]      FIG. 18  is a diagram of cuts of pork;  
         [0062]      FIG. 19  is a step diagram showing one example (Prior Art 1) of a conventional apparatus which debones a shoulder part;  
         [0063]      FIG. 20  is a step diagram showing one example (Prior Art 2) of a conventional method of deboning a meat block; and  
         [0064]      FIG. 21  is a diagram showing a framework of a slaughtered pig.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0065]     The present invention will hereinafter be described in accordance with an embodiment in detail with reference to the drawings. Dimensions, materials, shapes, relative arrangements and the like of constituting components described in this embodiment do not limit the scope of this invention, and are merely illustrated examples, unless specifically described.  
         [0066]     In the whole constitution diagram of  FIG. 1  according to a first embodiment of the present invention, an apparatus of the present embodiment has two lines of left and right, A is a region where a pretreatment is performed by hand, and B is a deboning treatment region by the apparatus of the present embodiment. Reference numeral  1  is a conveyer on which a target work is mounted and carried, and  2  is a cutting board on which operators h 1  to h 3  perform the pretreatment. In the present apparatus, after the operators perform the pretreatment in the region A, the workers h 3  hang the target work from a clamping unit of a loader to convey the work to a mechanical treatment region.  
         [0067]      FIG. 2  shows a shape of a target work (an arm part) w for use in the present embodiment. In the drawing, s and t are cut surfaces cut by a cutting device, j is a humerus, r is a remaining part of a forearm bone, k is an upper part of a scapula, p is a joint part between the forearm bone and the humerus, q is a joint part between the humerus j and the scapula k, and m is a meat part attached to these bone parts. In  FIG. 2 , (a) and (b) show a state before the pretreatment by hand, and (c) and (d) show a state in which the remaining part r of the forearm bone is removed by hand to expose the joint part p between the humerus j and the forearm bone.  
         [0068]      FIG. 3  shows treatment steps of the present embodiment. In this drawing, (a) shows a state after the pretreatment of the target work w by hand, that is, the same state as that shown in FIGS.  2 ( c ) and ( d ), and (b) shows a step of hanging the target work w from a clamping unit  3  of a loader (not shown) of the apparatus according to the present embodiment. It is to be noted that a unit having a conventionally known structure is used in the clamping unit  3 . In the present embodiment, a constricted part close to the joint part p between the humerus j and the forearm bone is clamped. Moreover, (c) shows a treatment at a first station of the apparatus according to the present embodiment. The meat part m of the target work w is provided with a cut c in a vertical direction by a round blade cutter  4  attached to a cutting device (not shown) in the vertical direction to expose the bone part. Subsequently, the clamping unit  3  is rotated by 90 degrees to direct the target work w in a conveyance direction a, and the work is conveyed to a second station.  
         [0069]     In the second station (d), the meat is peeled off from the upper part of the humerus down to a part of the humerus below the center thereof by a meat separator. Moreover, muscle of the center of the humerus is horizontally cut.  FIG. 4  is a perspective view of a device  10  for use in the second station. In  FIG. 4 , reference numeral  20  is a meat separator having two separation plates  21  facing each other via a conveyance path of a meat block and including a driving device which vertically moves the separation plates  21 , and  11  is a round blade cutter disposed at an upper portion of a housing  22  of the meat separator  20  in a horizontal direction. A rotary shaft  12  of the cutter is rotated by a driving motor  13 . The driving motor  13  is connected to a piston of an air cylinder  14  disposed on an upper surface of the housing  22  via a bracket  19 . The bracket  19  constitutes a parallelogram link mechanism together with rotary support points  15 ,  16  and links  17 ,  18 . According to this constitution, the round blade cutter  11  can linearly reciprocate so as to come close to or away from the conveyance path of the target work w formed at a gap u between the separation plates  21  of the meat separator  20 .  
         [0070]     Moreover, the round blade cutter  11  is attached to the housing  22  to which the separation plates  21  are attached via the support points  15 ,  16  and the air cylinder  14 , and vertically moves integrally with the housing  22  together with the separation plates  21 .  
         [0071]     Next, the driving device which vertically reciprocates the separation plates  21  of the meat separator  20  will be described with reference to  FIGS. 5 and 6 . In  FIGS. 5 and 6 , the housing  22  to which a pair of separation plates  21  are integrally attached via the gap u forming the conveyance path of the target work w is supported so as to be vertically and linearly movable in the reciprocating manner by support points  23 ,  24  and links  25 ,  26  forming a parallelogram link mechanism at one side surface of the housing and support points  27 ,  28  and links  29 ,  30  similarly forming a parallelogram link mechanism at the other side surface.  
         [0072]     Reference numeral  31  is an air cylinder which vertically drives the housing  22 . As shown in  FIG. 6 , a piston  31   a  of the air cylinder  31  is extended down from a substrate  32  through a hole  32   a  disposed at the substrate  32  of the meat separator  20 , and connected to one end of an arm  33  having a support point  34  fixed to a lower surface of the substrate  32 . A rod  35  having the other end attached to a lower surface of the housing  22  is attached to the other end of the arm  33 , and the arm  33  rotates in response to a vertical movement of the piston  31   a  to vertically move the housing  22 .  
         [0073]     At a connecting portion between the arm  33  and the support shaft  34 , an engagement piece  36  extends from the arm  33 , and the engagement piece  36  selectively abuts on any of upper surfaces of stoppers  37 ,  38  and  39  having different heights. Reference numerals  40  and  41  are air cylinders. When the air cylinders  40  and  41  are simultaneously or individually operated, any of the stoppers  37  to  39  can abut on the engagement piece  36  to adjust a stroke in three stages. At a forward end of the piston  31   a  of the cylinder  31 , an original height before lowering the meat separator  20  is set. When the cylinder moves backwards, any of the stoppers  37  to  39  abuts on the engagement piece  26 , so that the meat of the target works w can be peeled off at the different heights. Every time the work moves from the stopper  37  to  39 , a lowering stroke increases. The piston is connected to the stoppers  37  to  39 , and any of the stoppers  37  to  39  can selectively be arranged at a position on which the engagement piece  36  abuts. It is to be noted that reference numeral  42  is a support block which is attached to a back surface of the substrate  32  and which supports the support shaft  34  as the rotation center of the arm  33 .  
         [0074]     According to such a constitution, in a case where the air cylinder  31  is driven to vertically and linearly move the housing  22  so that the separation plates  21  forming the conveyance path of the target work w are lowered as much as a set length to peel off the meat part of the target work was much as the set length, any of the stoppers  37  to  39  is arranged at the position on which the engagement piece  36  abuts. In consequence, the housing  22  is lowered to a desired position from an original position set at a forward end position of the piston  31   a  of the cylinder  31 .  
         [0075]     Returning back to the second station of the first embodiment, at the second station, as shown in  FIG. 3 ( d ), when the device  10  of  FIG. 4  is used, the target work w is inserted into the gap u between the separation plates  21 , the meat separator  20  simultaneously lowers from an origin height o to a lowered position d, and the meat part of the target work w is peeled off to a part of the humerus below the center thereof from the upper part of the humerus j, while the target work w is moving through the gap u. Moreover, the round blade cutter  11  is allowed to come close to the target work w, and horizontally cuts the muscle of the center of the humerus.  
         [0076]     Next, a third station will be described. At the third station, as shown in  FIG. 3 ( e ), while the meat is further peeled off to the vicinity of the joint part q between the humerus j and the scapula k by the meat separator, a length from a reference position positioned at the upper part of the humerus j (a clamping position with the clamping unit  3  in the present embodiment) to an upper part of a projection of the joint part q between the humerus j and the scapula k is measured. The lowering stroke of the meat separator in the subsequent step is determined based on this measured value. A device  50  for use in the third station will be described with reference to FIGS.  7  to  10 . In FIGS.  7  to  10 , reference numeral  51  is a measurement plate. The measurement plate  51  is attached to a plate  52  so as to be rotatable centering on a rotary shaft  51   a  of the measurement plate. Similarly, a tip end art of the target work w positioned on the conveyance path is constantly urged downwards by a coil spring  53  having one end attached to the plate  52 . The other end of each of links  56 ,  57  each having one end attached to rotation support points  54 ,  55  is attached to the plate  52  to form a parallelogram link mechanism. Moreover, the plate  52  is attached to a piston of an air cylinder  58 . According to this constitution, the measurement plate  51  can linearly reciprocate so as to come close to or away from the target work w at the conveyance path which is the gap u formed between a pair of separation plates  21  facing each other.  
         [0077]     On the other hand, reference numeral  61  is a peeling plate having a cutter  62  at a tip end thereof. The peeling plate  61  is attached to a bracket  64  so as to be rotatable centering on a rotation support shaft  61   a , and an arm piece  63  which protrudes from the peeling plate  61  is connected to a piston of an air cylinder  65  attached to the bracket  64 . In consequence, the tip end blade  62  of the peeling plate  61  can vertically be moved by the air cylinder  65  above the gap u constituting the conveyance path of the target work w.  
         [0078]     Moreover, the bracket  64  is connected to a piston of an air cylinder  66  installed at the housing  22 . Moreover, the other end of each of links  69  and  70  each having one end connected to rotation support points  67 ,  68  is connected to the bracket  64  to form a parallelogram link mechanism. Therefore, according to this constitution, the peeling plate  61  can linearly reciprocate so as to come close to or away from the conveyance path of the target work w.  
         [0079]     It is to be noted that, since both of the measurement plate  51  and the peeling plate  61  are installed on the housing  22  constituting the meat separator  20 , the plates vertically move together with the vertical movement of the meat separator  20 .  
         [0080]     In a device  50  constituted in this manner, when the target work w enters the conveyance path formed at the gap u between the separation plates  21  from a conveyance direction a, the meat separator  20  starts lowering, and the separation plates  21  lower. Therefore, the meat attached to the humerus j is peeled off from the original height o to the lowered position d in the vicinity of the joint part q between the humerus j and the scapula k.  
         [0081]     Next, the measurement plate  51  comes close to the conveyance path of the target work w to ride on the joint part q between the humerus j and the scapula k from behind the humerus j. The measurement plate  51  simultaneously lowers together with the peeled meat, touches the upper surface of the joint part q between the humerus j and the scapula k, and stops there.  
         [0082]     Subsequently, when the peeling plate  61  comes close to the conveyance path of the target work w and the peeling plate  61  comes in contact with a rear part of the humerus j of the target work w to peel off the meat of the upper surface of the joint part q between the humerus j and the scapula k behind the humerus by a lowering movement of the cutter  62 .  
         [0083]     Subsequently, the meat separator  20  starts lowering, and the separation plates  21  lower. Therefore, the meat attached to the humerus j is peeled off from the original height o to the lowered position d in the vicinity of the joint part q between the humerus j and the scapula k by the cutter  62  of the peeling plate  61 . The measurement plate  51  simultaneously lowers together with the peeled meat, touches the upper surface of the joint part q between the humerus j and the scapula k, and stops there.  
         [0084]     It is to be noted that, since angle sensors  59  for detecting a tilt angle of the measurement plate  51  are attached to the plate  52 , the lowered position of a contact plate  51   b  attached to the tip end of the measurement plate  51  can be measured by these sensors  59 . In consequence, since the length from the reference position (the clamping position with the clamping unit  3 ) of the target work w to the joint part q between the humerus j and the scapula is detected, the lowering stroke (the present embodiment has three alternatives of large, medium and small strokes) of the meat separator in the subsequent step is selected based on this measured value.  
         [0085]     Subsequently, the target work w is moved to a fourth station. At the fourth station, as shown in  FIG. 3 ( f ), the muscle around the joint part q between the humerus j and the scapula k is cut by a round blade cutter and the meat is further peeled off by a meat separator.  
         [0086]      FIGS. 11 and 12  are both perspective views of a device for use in the fourth station. In  FIGS. 11 and 12 , reference numeral  71  is a round blade cutter which cuts the muscle attached to a part behind the joint part q of the target work w. The cutter is arranged in a vertical direction crossing the conveyance direction of the target work w at right angles. Reference numeral  72  is a motor which drives the rotary shaft of the round blade cutter  71 , and the motor is attached to a bracket plate  73 . The bracket plate  73  is connected to a piston of an air cylinder  74  installed at the housing  22  of the meat separator  20 . Moreover, the other end of each of links  77 ,  78  each having one end attached to rotation support points  75 ,  76  is attached to the bracket plate  73  to form a parallelogram link mechanism. According to this constitution, the round blade cutter  71  can linearly reciprocate so as to come close to or away from the conveyance path of the target work w. It is to be noted that reference numeral  79  is a safety plate which covers the round blade cutter  71 , and the plate is attached to the bracket plate  73 .  
         [0087]     Reference numeral  81  is a round blade cutter for cutting muscle. The cutter is arranged in parallel with the conveyance path of the target work w, and an upper portion of the cutter is obliquely arranged in such a direction as to come away from the conveyance path. The cutter is rotated by a driving motor  82  attached to a bracket plate  83 . The bracket plate  83  is connected to a piston of an air cylinder  84  installed at the housing  22 . Moreover, the other end of each of links  87  and  88  each having one end attached to rotation support points  85 ,  86  is attached to the bracket plate  83  to constitute a parallelogram link mechanism. According to this constitution, the round blade cutter  81  can linearly reciprocate so as to come close to or away from the conveyance path of the target work w. It is to be noted that reference numeral  89  is a safety plate which covers the round blade cutter  71 , and the plate is attached to the bracket plate  83 .  
         [0088]     It is to be noted that, since the round blade cutters  71  and  81  are both installed on the housing  22  constituting the meat separator  20 , the cutters vertically move together with the vertical movement of the meat separator  20 .  
         [0089]     In the fourth station, as shown in  FIG. 3 ( f ), when the target work w enters the conveyance path formed at the gap u between the separation plates  21 , the housing  22  on which the round blade cutters  71  and  81  are fixed lowers from the original height o of the housing as much as a stroke (to the position d) determined based on the measured value obtained in the third station. Therefore, the meat around the joint part q is peeled off as much as the lowering stroke. The round blade cutters  71  and  81  are simultaneously pushed out to the conveyance path, the round blade cutter  71  cuts the muscle attached to a periphery of a rear part of the joint part q, and the round blade cutter  81  cuts the muscle attached to a side surface of the joint part q.  
         [0090]     Subsequently, the target work w is conveyed to a fifth station. In the fifth station, as shown in  FIG. 3 ( g ), the muscle around a lower part of the joint part q between the humerus j and the scapula k is further cut with three round blade cutters, and the meat is further peeled off by the meat separator.  
         [0091]      FIGS. 13 and 14  are perspective views of a device for use in the fifth station as obliquely viewed from above on the left and right sides. In  FIGS. 13 and 14 , reference numeral  91  is a round blade cutter which cuts the muscle attached to a lower part behind the joint part q of the target work w. The cutter is arranged in a vertical direction crossing the conveyance direction of the target work w at right angles. Reference numeral  92  is a motor which drives and rotates the round blade cutter  91 , and the motor is attached to a bracket plate  93 . The bracket plate  93  is connected to a piston of an air cylinder  94  installed at the housing  22  of the meat separator  20 . Moreover, the other end of each of links  97 ,  98  each having one end attached to rotation support points  95 ,  96  is attached to the bracket plate  93  to form a parallelogram link mechanism. According to this constitution, the round blade cutter  91  can linearly reciprocate so as to come close to or away from the conveyance path of the target work w. It is to be noted that reference numeral  99  is a safety plate which covers the round blade cutter  91 , and the plate is attached to the bracket plate  93 .  
         [0092]     Reference numeral  101  is a round blade cutter for cutting muscle. The cutter is arranged in parallel with the conveyance path of the target work w, and an upper portion of the cutter is obliquely arranged in such a direction as to come away from the conveyance path. The cutter is rotated by a driving motor  102  attached to a bracket plate  103 . The bracket plate  103  is connected to a piston of an air cylinder  104  installed at the housing  22 . Moreover, the other end of each of links  107  and  108  each having one end attached to rotation support points  105 ,  106  is attached to the bracket plate  103  to constitute a parallelogram link mechanism. According to this constitution, the round blade cutter  101  can linearly reciprocate so as to come close to or away from the conveyance path of the target work w. It is to be noted that reference numeral  109  is a safety plate which covers the round blade cutter  101 , and the plate is attached to the bracket plate  103 .  
         [0093]     Reference numeral  111  is a round blade cutter disposed on such a side as to face the conveyance path of the target work w with respect to the round blade cutter  101 . The cutter is fixed and rotated by a bracket  113   b  which fixes a driving motor  112  via a swing shaft  113   a  attached to a bracket  113  mounted on and fixed to the upper surface of the housing  22 . Reference numeral  114  is a coil spring attached to an arm  115  having one end fixed to the bracket  113 , and the other end of the spring is attached to the bracket  113   b . When the swing shaft  113   a  swings, the round blade cutter  111  is urged with such a force as to press the joint part q from below.  
         [0094]     According to a device  90  constituted in this manner, in the fifth station, when the target work w enters the conveyance path formed at the gap u between the separation plates  21 , as shown in  FIG. 3 ( g ), the housing  22  on which the round blade cutters  91 ,  101  and  111  are mounted and fixed lowers from the original height o to the lowered position d set based on the length of the humerus j measured in the third station. In consequence, the meat around the joint part q is peeled off. Furthermore, the round blade cutters  91  and  101  are pushed out to the conveyance path, the round blade cutter  91  cuts the muscle attached to a part around a lower rear part of the joint part q, and the round blade cutter  101  cuts the muscle attached to a lower side surface of the joint part q. Moreover, the round blade cutter  111  cuts the lower side surface of the joint part q on such a side as to face the round blade cutter  101 . In the fifth station, the peeling of the meat attached to the joint part q is completed.  
         [0095]     Subsequently, the target work w is conveyed to a sixth station. In the sixth station, as shown in  FIG. 3 ( h ), the muscle attached to a periphery of the scapula k is cut by two round blade cutters, and the meat attached to the scapula k is peeled off by a meat separator.  
         [0096]      FIG. 15  is a perspective view of a device for use in the sixth station as obliquely viewed from above. In  FIG. 15 , reference numeral  121  is a round blade cutter for cutting the muscle attached to the surface of the scapula k. The cutter is arranged in a horizontal direction, and a rotation driving motor  122  of the cutter is rotatably connected to a support shaft  123  via a bracket  124 . Reference numeral  125  is an air cylinder supported by an arm  126  attached to the upper surface of the housing  22 . When a piston of the air cylinder is connected to the bracket  124 , the round blade cutter  121  can reciprocate in such a direction as to come close to or away from the conveyance path of the target work w formed at the gap u between the separation plates  21 .  
         [0097]     Reference numeral  131  is a round blade cutter arranged in a horizontal direction at such a position as to face the round blade cutter  121  via the conveyance path. A rotation driving motor  132  of the cutter is rotatably attached to a support shaft  133  via a bracket  134 . Reference numeral  135  is an air cylinder supported by an arm  136  attached to the upper surface of the housing  22 . When a piston of the air cylinder is connected to the bracket  134 , the round blade cutter  131  can reciprocate in such a direction as to come close to or away from the conveyance path of the target work w formed at the gap u between the separation plates  21 .  
         [0098]     According to a device  120  constituted in this manner, in the sixth station, when the target work w enters the conveyance path formed at the gap u between the separation plates  21 , as shown in  FIG. 3 ( h ), the housing  22  on which the round blade cutters  121  and  131  are mounted and fixed lowers from the original height o to the lowered position d set based on the length of the humerus j measured in the third station. Therefore, the meat around the scapula k is peeled off. Moreover, the round blade cutters  121  and  131  are simultaneously pushed out to the conveyance path to cut the muscle attached to opposite sides of the surface of the scapula k of the target work w.  
         [0099]     Subsequently, the target work w moves to a seventh station. In the seventh station, the peeling of the meat attached to the scapula k is completed by the meat separator.  
         [0100]      FIG. 16  is a perspective view of a device for use in the seventh station. In  FIG. 16 , reference numeral  141  is a round blade cutter arranged in a horizontal direction. The round blade cutter is preliminarily installed at a limit position so as to cut the scapula k at the limit position, in a case where the scapula is longer than a set limit length. A rotation driving motor  142  of the round blade cutter  141  is rotatably connected to a support shaft  143  attached to the upper surface of the housing  22  via a bracket  144 . Reference numeral  145  is an air cylinder supported by an arm  146  attached to the upper surface of the housing  22 . Since a piston of the air cylinder is connected to the bracket  144 , the round blade cutter  141  can reciprocate in such a direction as to come close to or away from the conveyance path of the target work w formed at the gap u between the separation plates  21 .  
         [0101]     According to a device  140  constituted in this manner, in the seventh station, unlike the other stations, the separation plates  21  are inserted at a height d shown in  FIG. 3 ( h ). Since the meat part m needs to be peeled from the height, the original height o needs to be varied. A mechanism which vertically moves the housing  22  of the device of  FIG. 16  in order to vary the height is shown in  FIG. 17 .  
         [0102]     In  FIG. 17 , reference numeral  151  is an air cylinder which vertically drives the housing  22 , and a piston  151   a  of the air cylinder  151  is extended below a substrate  152  through a hole  152   a  disposed at the substrate  152  of the meat separator  20 , and connected to one end of an arm  153  having a support shaft  154  fixed to a lower surface of the substrate  152 . A rod  155  having the other end attached to the lower surface of the housing  22  is attached to the other end of the arm  153 . The arm  153  rotates in response to a vertical movement of the piston  151   a  to vertically move the housing  22 .  
         [0103]     At a connecting portion between the arm  153  and the support shaft  154 , an engagement piece  156  extends from the arm  153 , and the engagement piece  156  selectively abuts on any of upper surfaces of stoppers  157 ,  158 ,  159  and  160  having different heights.  
         [0104]     Reference numeral  161  is an air cylinder. A piston of the air cylinder is connected to stoppers  157  to  160 , and any of the stoppers  157  to  160  can selectively be arranged at a position on which the engagement piece  156  abuts. It is to be noted that  162  is a support block which is attached to a back surface of the substrate  152  and which supports the support shaft  154  as a rotation center of the arm  153 . It is to be noted that a height of the housing can be changed in four stages of the stoppers  157  to  160  by the air cylinder  161 , but three stages of the stoppers  158  to  160  are actually used. Every time the height is changed from the stoppers  157  to  160 , the original height o lowers. A backward end of the meat separator  20  is fixed at a stroke end.  
         [0105]     According to such a constitution, when the target work w enters the conveyance path formed at the gap u between the separation plates  21  and the scapula k is cut to an allowable length as shown in  FIG. 3 ( i ), the round blade cutter  141  does not operate, the only meat separator  20  operates to peel off the meat attached to the scapula k, and the meet is completely separated from the bone part to drop down. If the scapula k is longer than an allowable length, the round blade cutter  141  is pushed out to the conveyance path of the target work w, and an extra part over the allowable length is cut.  
         [0106]     In the seventh station, as shown in  FIG. 3 ( i ), the original height o of the meat separator is set to a lower position, and the meat separator once moves up from the original height o to a raised position d set based on the length of the humerus j measured in the third station. When the meat separator lowers from the raised position, the meat attached to a periphery of the scapula k is completely peeled off and allowed to drop down.  
         [0107]     Subsequently, after the only remaining bone part is conveyed with the loader, the clamping unit  3  is rotated by 90 degrees and directed to a discharge side, and the bone part is removed.  
         [0108]     According to such a first embodiment, slight pretreatment by hand is involved, but the substantially completely automated deboning treatment of the target work can be realized. In consequence, reduction of a treatment time and improvement of a treatment efficiency can be achieved.  
         [0109]     Moreover, while the target work w hung from the loader is conveyed at a substantially constant height, the work can be subjected to all the steps of the first to seventh stations without discontinuing the conveyance halfway. Therefore, large reduction of the treatment time and rapid improvement of the treatment efficiency can be achieved.  
         [0110]     Furthermore, since the treatment step is finely divided into the first to seventh stations and the cutting of the muscle bonded to the bone and the peeling of the meat are finely performed in the stations, unlike Prior Art 1, the humerus j of the target work w does not have to be separated from the scapula k, and the meat can completely be separated without leaving any extra meat at the bone.  
         [0111]     In addition, halfway in the treatment steps, the reference position is set to the constricted part of the humerus j clamped with the loader, the length from this reference position to the upper part of the joint part between the humerus and the scapula is measured, and a lowering length of the meat separator in each station is set based on the measured value. Therefore, even if the arm part of the treatment target has different length and size, a cutting position of the round blade cutter and a reference height and the lowering length of the meat separator can be changed so as to cope with the difference according to circumstances.  
         [0112]     According to the present invention, in a bone removing treatment of a meat block of a humerus part including a remaining part of a scapula of a shoulder part in the half block of back split meat, a slight pretreatment by hand is required, but a substantially completely automated deboning treatment can be realized. Therefore, reduction of a treatment time and improvement of a treatment efficiency can be achieved. Moreover, the treatment is divided into first to fifth steps. In each stage of the treatment step, while muscle bonded to a bone is cut, the meat is finely peeled off in a stepwise manner. Therefore, the humerus of a target work does not have to be separated from the scapula, and the meat can clearly be separated without leaving any extra meat at the bone.  
         [0113]     Moreover, halfway in the treatment steps, a reference position is set to an upper part of the humerus, a length from this reference position to a joint part between the humerus and the scapula is measured, and a lowering stroke of a meat separator in each station is set based on the measured value. Therefore, even if an arm part of a treatment target has different length and size, a cutting position of a round blade cutter and a reference height and the lowering stroke of the meat separator can be changed so as to cope with the difference according to circumstances.  
         [0114]     Further preferably, the meat block hung from a loader is conveyed at a substantially constant height, and a target work can be subjected to all the steps without discontinuing the conveyance halfway and without deviation the target work from a conveyance path of the work. Therefore, large reduction of the treatment time and rapid improvement of the treatment efficiency can usefully be achieved.