Abstract:
Method for obtaining an inner fillet and device for mechanically detaching the undesired tendon part from an inner fillet. The poultry carcass is mounted on a fixing member and positioned so that the tendons are exposed. A processing device, comprising rotating cutters, either partially or completely detaches the tendon from the inner fillets. The cutters make a uniform incision at the moment when the inner fillet and the associated tendon are still essentially in their natural position. The fillets may then be removed manually or mechanically from the carcass.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Netherlands Application No. 1012683 filed on Jul. 23, 1999. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a method for obtaining an inner fillet from a poultry carcass part and to a device for processing a carcass part, for the purpose of obtaining the inner fillet from the carcass part. 
     DISCUSSION OF THE PRIOR ART 
     The inner fillets, also called tenders, of poultry, such as chickens or turkeys, are positioned on the breastbone (sternum) on both sides of the crest (crista sterni) thereof and are some of the most valuable meat parts of the poultry. 
     Removing the inner fillets from a carcass according to the prior art, as described in EP-A-0,695,506, is done by removing the wings from the carcass part, making a separation in the opening bounded by the wishbone and the breastbone, and then scraping away the inner fillets from the carcass part. According to U.S. Pat. No. 5,314,374, another method of removing inner fillets is partially cutting and scraping away inner fillets from a carcass part without wings, and then pulling away the inner fillets from the carcass part by means of gripping members. According to EP-A-0,695,506 still another way of removing inner fillets involves separating the membrane connections between the inner fillets and the breastbone, cutting open the canalis triosseus, and pulling away the inner fillets by means of the wings connected thereto through tendons. 
     A common drawback of the above-mentioned methods is that at least part of the tendon, which connects the inner fillet with the associated wing, remains connected to the removed inner fillet. To process the inner fillets into high value consumer products, such as “nuggets” in which tendon parts are undesirable, the tendons must subsequently be removed. The removal of tendons from the inner fillets usually must be done manually. This method requires a considerable use of expensive human labor, may be imprecise and consequently result in only moderate quality meat, and compromises the hygiene of the meat. 
     U.S. Pat. No. 5,395,283 discloses a device for automatically cutting off a part from the tendon connected to each inner fillet from inner fillets conveyed in trays. The inner fillets are placed and positioned in the trays manually. No solution is provided for removing the complete undesired tendon part from an inner fillet. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to provide a method and a device for mechanically detaching (either partially or completely) the undesired tendon part from an inner fillet. The poultry carcass is mounted on a fixing member and positioned so that the tendons are exposed. A processing device, comprising rotating cutters, either partially or completely detaches the tendon from the inner fillets. The cutters make a uniform incision at the moment when the inner fillet and the associated tendon are still essentially in their natural positions. The fillets may then be removed manually or mechanically from the carcass. The automated method and device according to the invention results in substantial savings in labor costs, as well as improving the quality and accuracy of the processing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a part of a filleting line with a processing device according to the invention. 
     FIG. 1 a  is a side elevation view of an inner fillet with a part of the tendon attached. 
     FIG. 2 is a side elevation view demonstrating the operation of a guide of the processing device according to the invention. 
     FIG. 3 is a perspective view of the processing device according to FIG. 1 without the protective hood. 
     FIG. 4 is a side elevation view demonstrating the operation of the processing device according to FIG.  1 . 
     FIG. 5 is a perspective view of another embodiment of a processing device according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1,  2 ,  3 , and  4  show a filleting line  2  in which carriers  6  are moved in the direction of arrow  8  along a rail  4 . Each carrier  6  comprises a basic body  6   a  with a tray  6   b  on which obtained fillet parts can be placed if desired. At the side of the basic body  6   a  a poultry part fixing member  6   c  is provided, which is rotatable in a controlled manner around an axis which is directed centrally through the poultry part fixing member  6   c  and transverse to the side of basic body  6   a . A so-called breast cap  10  (a breast part without skin, without clavicula, without wings, with ribs, and with or without a part of the back) of poultry is fixed on the poultry part fixing member  6   c  in such a way that the longitudinal axis of the breastbone  12  thereof is directed essentially vertically. 
     In FIG. 1, the outer fillets  14  of the breast cap  10  are partially pulled away, exposing at least a part of inner fillets  16  facing the shoulder joint, with attached tendons running to the shoulder joint. In FIGS. 2-4 the outer fillets  14  are absent. The inner fillets  16  essentially are in their natural position and are attached to the breastbone  12  with membranes. The tendon part to be removed from each inner fillet  16  extends essentially to inside the canalis triosseus. The longitudinal direction of the inner fillets  16  is essentially at right angles to the conveyance direction  8 . 
     In the filleting line, a processing device  18  secured to a frame  20  is placed fixed relative to the rail  4 . The processing device  18  comprises a guide  22  and two rotating cutters  24 ,  26  (FIG. 3) driven in opposite directions according to respective arrows  28  and  30  by means of respective motors  32  and  34 . As shown in FIGS. 1,  3  and  4 , the axis of rotation of the motors  32 ,  34  is oblique relative to a vertical line. In FIG. 1 a protective hood  40  is placed around the rotating cutters  24 ,  26  to protect operators. 
     FIG. 1 a  shows the inner fillet  16 , a tendon  16   a  attached thereto, and a tendon attachment  16   b . Arrows  17   a ,  17   b ,  17   c ,  17   d  and  17   e  indicate different positions where an incision in the area of the tendon attachment  16   b  can be made according to the invention. The incision  17   a  is in the inner fillet  16  outside the tendon attachment  16   b . The incision  17   b  is in the inner fillet  16  at the edge of the tendon attachment  16   b . The incision  17   c  is in the inner fillet  16  in the tendon attachment  16   b . The incision  17   d  is at the end of the inner fillet  16  on the transition of the tendon attachment  16   b  to the tendon  16   a . The incision  17   e  is in the tendon  16   a . 
     As shown in FIGS. 2 and 4, the breast cap  10  is tilted away by the guide  22  in the area of the collar bones (os coracoidus) at the back side of the breast cap  10  in the direction of arrow  36 , and thus is positioned at an angle relative to the rotating cutters  24 ,  26 . In this way, the rotating cutters  24 ,  26  are prevented from cutting into bone parts, releasing undesired bone residues. The rotating cutters  24 ,  26  are positioned to either partially or completely detach the tendon from the inner fillet. The rotating cutters  24 ,  26  are situated one behind the other in the path of the breast cap  10  for a certain incision  17   a ,  17   b ,  17   c ,  17   d  or  17   e  essentially at right angles to the longitudinal direction of both inner fillets  16 . It is also possible to use only one rotating cutter or to use one or more stationary or resiliently positioned cutters. It is also possible to reverse the directions of rotation  28  and  30 . The cutters do not merely have a cutting function, but also a positioning function by the cutting forces exerted on the breast cap  10  relative to the guide  22 . The position or height of incision is adjustable by varying the placement of the motors  32 ,  34  on the frame  20 , taking into account the dimensions of the breast caps  10  or inner fillets. 
     After the incision of the breast cap  10 , the inner fillets  16  are removed manually or mechanically, the undesired tendon parts remaining on the carcass. 
     It is to be observed here that the envisaged incision, which in practice will be a cutting-through or a near-cutting-through, can be obtained not only by one or more cutters, but also with other cutting means, such as a water jet. 
     Further it is to be observed that the cutting means may not only be situated stationary along the conveyance path of the conveyor, but can also be made movable for bringing them synchronously with the conveyance of the carriers into the path of the carcass parts for providing the envisaged incision. The carcass part may be conveyed intermittently, and may stand still at the time of incision. 
     Also it is to be observed that it is not essential to the invention that the wings be removed from the carcass part to be processed in the processing device  18 . If the carcass part comprises wings, these wings can be simply kept outside the working range of the rotating cutters  24 ,  26  or other cutting means by means of suitable guides, such that in spite of the presence of wings the intended incision is obtained. 
     Further it is to be observed that the tendon incision can also be obtained by conveying the breast cap  10  with the breastbone  12  parallel to the arrow  8  and having cutters or other cutting means engage the inner fillet or tendon parts to be incised from the sides of the breast cap  10 . This is explained in more detail with reference to an example embodiment shown in FIG.  5 . 
     FIG. 5 shows carriers  40  on which front halves  42  of poultry with inner fillets  44  are conveyed in the direction of arrow  46 . A cutting device  48  is situated stationary along the conveyance path of the front halves  42 . The cutting device  48  comprises two disks  50   a ,  50   b  which are driven through respective axes  52   a ,  52   b  (indicated with dashed lines) in the direction of respective arrows  54   a ,  54   b  by means of drive devices not shown in detail. The axes  52   a ,  52   b  rotate inside stationary jackets  56   a  and  56   b , respectively, on which under the respective disks  50   a ,  50   b  respective gear rings  58   a ,  58   b  are provided. On each disk  50   a ,  50   b , a rotating cutter  64   a ,  64   b , respectively, is mounted rotatable around a respective axis  60   a ,  60   b , and provided with a respective gear wheel  62   a ,  62   b  (not visible) engaging the respective gear ring  58   a ,  58   b . The edges of the disks  50   a ,  50   b  are not cutting. The cutters  64   a ,  64   b  rotate in opposite directions  66   a ,  66   b , respectively, by the rotation of the disks  50   a ,  50   b  in the respective directions  54   a ,  54   b , the angular velocity of the cutters  64   a ,  64   b  being greater than the angular velocity of the disks  50   a ,  50   b , and the circumferential speed of the disks  50   a ,  50   b  preferably being greater than the conveyance speed of the front halves  42 . The rotation of the disks  50   a ,  50   b  is synchronized with the carriers  40  such that the cutters  64   a ,  64   b  engage subsequent front halves  42  always at the same place. The cutters  64   a ,  64   b  cut into or through the tendons  16   a  of the inner fillets  44 , in particular above the tendon attachment  16   b  of the tendons  16   a  to the inner fillets  44 . The longitudinal direction of the inner fillets  44  is essentially parallel to, or at a small angle to, the conveyance direction  46 . The disks  50   a ,  50   b  may be provided with supplemental cutting means  68   a ,  68   b  for breaking membrane connections between the breastbone of the front half  42  and the inner fillets  44 . 
     The functions performed by the disks  50   a ,  50   b  and cutters  64   a ,  64   b ,  68   a  and  68   b , may also be performed with suitably placed stationary or moving guides and cooperating stationary or moving cutting means which engage carcass parts provided on carriers which are moved continuously or intermittently. 
     It is also possible not to place the carcass parts on top of the carriers, but to place them below carriers, the breastbone being directed downwards from the carrier. This situation is, for example, obtained by rotating the carriers 40 through 180 degrees around a horizontal longitudinal or transverse axis. 
     While the invention has been described and illustrated in its preferred embodiments, it should be understood that departures may be made therefrom within the scope of the invention, which is not limited to the details disclosed herein.