Abstract:
An animal part holder has first and second gripper plates between which an animal part can be slid. A mechanism coupled to the gripper plates for yieldably biasing the gripper plates toward one another so that the gripper plates engage and grip an animal part disposed between the gripper plates. In addition, the mechanism is configured to cause the gripper plates to tighten their grip on the animal part in response to a pulling force tending to pull the animal part out of the grip of the holder. A method of gripping the bone of an animal part includes disposing the bone between gripper plates and applying a biasing force to the gripper plates to cause the gripper plates to bear against the bone with a force. The method may further include applying a force to the gripper plates greater than the biasing force in response to a pulling force applied to the animal part to cause the gripper plates to grip the bone tighter.

Description:
REFERENCE TO RELATED APPLICATION 
       [0001]    Priority is hereby claimed to the filing date of U.S. provisional patent application 62/030,709 filed on Jul. 30, 2014, the entire contents of which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates generally to meat processing and more specifically to devices for holding the bones of suspended meat parts securely as the meat parts are conveyed along a processing path and processed at processing stations. 
       BACKGROUND 
       [0003]    Modern processing of meat and meat parts usually includes suspending animals and cut-away animal parts from overhead holding devices that convey the animals and animal parts along a processing path. This is particularly true for poultry and poultry parts, which today are processed largely by automated cut-up and processing machines disposed at stations along the processing path. The discussion that follows will disclose the present invention for purposes of clarity in terms and within the context of poultry processing and specifically the processing of chickens. It will be understood, however, that the processing of chickens is not a limitation of the invention and that the invention is applicable to any meat processing operation wherein meat parts are suspended from an overhead conveyor. 
         [0004]    Several devices are available for holding chickens and chicken parts in a suspended orientation as they move along a processing path. For example, shackles have long been used to suspend chickens and chicken carcasses by their legs as they are moved in sequence along a poultry processing path. Another example is hook-shaped holders having a space defined between two fixed upstanding prongs. Such, holders often are used to hold the bone of a chicken part securely as the meat is stripped away from the bone or as other cut-up and processing steps are performed. For instance, legs and drumsticks often are suspended from such holders by the ankle joint, which has a large diameter compared to the diameter of the attached leg bone. The leg bone slides easily into the space between the upstanding prongs and the larger ankle joint is disposed in the fork of the holder and is too large to slip through the space in most cases, but not all. In some cases, the ankle bone does slip out of the space and the chicken part may be ruined or require hand processing. Pronged holders and shackles have therefore not proven completely reliable for holding securely the chicken carcasses and chicken parts as they are pulled on and processed by modern processing machines. 
         [0005]    The problem stems in part from the fact that the joints at the ends of bones may vary in size relative to the diameter of the bone and, in fact, can vary significantly is size from chicken to chicken. They also can be rather slippery and contain more soft cartilage relative to the bones to which they are attached. As a consequence, a significant percentage of chicken parts tend to slip out of traditional holders as suspended carcasses and parts encounter meat stripping, cut-up, and other processing machines along the processing line. This can result in unwanted waste and can require that the slipped-out chicken parts be hand processed, which is inefficient and costly. 
         [0006]    A need exists for a holder that grips the bones of meat parts and particularly chicken parts in such a way that the bones are not pulled out of the holder as chickens and chicken parts are conveyed through meat strippers, cut-up stations, and other processing equipment. It is to the provision of a meat part holder that addresses this and other needs that the present invention is primarily directed. 
       SUMMARY 
       [0007]    Briefly described, a meat part holder is attachable to an overhead conveyer system that carries the holders in single file along a processing path. The holder has a pair of opposing gripper plates that are biased toward one another by a spring. When the bone of a chicken part is slipped between the opposing gripper plates just below a joint at the end of the bone, the gripper plates are forced apart against the bias of the spring to allow the bone to slide into a space between the plates. The spring then biases the gripper plates firmly against the bone just below the joint. The biasing force of the spring ensures that the gripper plates remain in firm contact with the bone just below the joint to prevent the joint of the bone from slipping through the gripper plates. Furthermore, pivot arms are arranged such that the gripper plates actually exert more force against the bone as the meat part is pulled downwardly away from the meat part holder. This occurs, for instance, as the part encounters a meat stripping machine disposed along the processing path, which pulls downwardly on the meat to separate the meat from the bone. As a result, a bone between the gripper plates is held even more firmly in response to downward force applied to a chicken part. The suspended bones of chicken parts such as, for example, poultry thighs no longer slip out of their holders during processing, thereby increasing efficiency and return rates. 
         [0008]    The invention will be understood better upon review of the detailed description set forth below taken in conjunction with the accompanying drawing figures, which are briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a view from the front showing a holder according to the invention holding a chicken thigh. 
           [0010]      FIG. 2  is a view from the back showing the holder of  FIG. 1  holding a chicken thigh. 
           [0011]      FIG. 3  is a view from the side showing the holder of  FIG. 1  holding a chicken thigh. 
           [0012]      FIG. 4  is perspective view of the holder of  FIG. 1  in its fully closed configuration. 
           [0013]      FIG. 5  is a perspective view of the holder of  FIG. 1  in its fully opened configuration. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    The specific example described below will be given for clarity within the context of suspending chicken thighs from the illustrated holder that exemplifies the invention. It will be understood, however, that the invention is not limited to use with chicken thighs and is applicable to suspending whole chickens, chicken carcasses, drumsticks, and other chicken parts as they are moved along a processing line. 
         [0015]    Referring now to the drawing figures, wherein like reference numerals indicate like parts throughout the several views,  FIG. 1  shows a meat part holder  11  that embodies principles of the present invention in one preferred form. The holder  11  in this instance is shown holding the leg bone of a chicken thigh  12  just below the knee joint  13  of the leg bone. The thigh is thus suspended from the holder as shown as the holder and the thigh are moved along the processing path. The holder includes a mounting head  14  by which the holder may be mounted through a remounting device (not shown) to an overhead conveyor system in a known manner. The mounting device may include turning blocks and the like to allow the holder  11  to be rotated to various orientations for processing as it moves along the processing path. 
         [0016]    An elongate plate  16  is secured to and depends from the mounting head  14  and has an upper end portion  17  and a lower end portion  18 . An elongated guide slot  19  is formed through the plate  16  as shown, which accommodates vertical movement of the head of a pivot bolt  47 , as described in more detail below. A first tension arm  21  has a proximal end  24  ( FIG. 2 ) and a distal end  26  and is pivotally mounted to the plate  16  at is proximal end by means of pivot bolt  22 . A second tension arm  23  likewise is pivotally mounted at its proximal end  27  ( FIG. 2 ) to the plate  16  by means of the same pivot bolt  22 . Both tension arms are secured sufficiently loosely to the pivot bolt so that they are held in place but free to pivot about the axis of the pivot bolt  22 . 
         [0017]    A first leg  31  has a crooked configuration rather resembling a hockey stick and defines an angled upper portion  30  and a generally vertically extending lower portion  35 . The first leg  31  has a proximal end  36  ( FIG. 2 ) and a distal end  33 . Similarly, a crooked second leg  32  has an upper portion  40 , a lower portion  45 , a proximal end  37  and a distal end  34 . The first and second legs  31  and  32  are pivotally connected together intermediate the ends of their upper portions in scissor-like fashion by means of pivot bolt  47 . The proximal end  36  ( FIG. 2 ) of the first leg  31  is pivotally connected to the distal end of tension arm  23  by means of pivot bolt  49 . Likewise, the proximal end  37  of the second leg  32  is pivotally connected to the distal end of tension arm  21  by means of pivot bolt  28 . The head of the pivot bolt  47  that pivotally attaches the two legs  31  and  32  is slidably captured within the guide slot  19 . 
         [0018]    A first gripper plate  38  is welded or otherwise attached to the distal end of leg  31  and a second gripper plate  39  is welded to the distal end of leg  32 . As perhaps best illustrated in  FIG. 3 , the first gripper plate  38  is formed with a narrowing upturned forward end  41 . Similarly, the second gripper plate  39  is formed with a narrowing upturned forward end  42 . The forward ends of the gripper plates together define a tapered slot through which a worker may insert the bone of a chicken thigh to load the chicken thigh into the holder, as illustrated by arrow  69  in  FIG. 3 . As shown in  FIG. 4 , the first gripper plate  38  extends rearwardly further than the second gripper plate  39  and is formed with stop portion  62 . The stop portion  62  extends to the left in  FIG. 4  and behind the rear edge  63  of second gripper plate  39 . The stop portion  62  thus functions as a stop when a chicken thigh is loaded into the holder. This ensures that the bone of the chicken thigh becomes properly positioned between the gripper plates and does not move too far through the slot. Finally, the second gripper plate  39  in this embodiment is formed with a protrusion  68  that extends toward the first gripper plate  38 . The protrusion  68  prevents the bone of a chicken thigh loaded into the holder from accidentally sliding forwardly out of the holder as it encounters various processing stations along the processing path. 
         [0019]    Referring to  FIG. 2 , the pivot bolts  28  and  29  extend rearwardly from the tension arms and each is provided with a grommet  64  and  65  respectively. In the illustrated embodiment, an extension spring  51  extends between the pivot bolts  28  and  29  and its ends are attached to the grommets  64  and  65  by means of spring hooks  52  and  53 . The extension spring pulls the pivot bolts  28  and  29  toward one another. This, in turn, yieldably biases the gripper plates  38  and  39  toward one another due to the scissor-like pivoting about pivot bolt  47  of the first and second legs  31  and  32 . Of course, other means of providing the biasing force can be substituted for the extension spring such as, for instance, compression springs, leaf springs, coil springs, or even magnets and all such alternatives are intended to be included within the scope of the invention exemplified in the figures. 
         [0020]    As shown in  FIG. 4 , the inward biasing force F provided by the extension spring  51  moves the gripper plates  38  and  39  toward one another until the head of the pivot bolt  47  engages the bottom of guide slot  19 . This defines the minimum distance between the gripper plates, which preferably is less than the smallest diameter thigh bones that are expected to be loaded into the holder. Conversely, as illustrated in  FIG. 5  the gripper plates  38  and  39  can be spread apart against the bias of the extension spring  51 . As the gripper plates spread, the head of the pivot bolt  47  moves upwardly within the guide slot  19  until it engages with the upper end of the guide slot. This defines the maximum distance between the gripper plates, which preferably is greater than the largest diameter bones that are expected to be loaded into the holder. 
         [0021]    In use, a plurality of holders is suspended in a spaced apart configuration from an overhead conveyer. The conveyor is designed to convey the holders in single file along a processing path pasta loading station. A worker or workers at the loading station loads chicken thighs into the holders by moving the end portions of the thigh bone of each chicken thigh  12  through the tapered slot defined by the narrowing upturned forward ends  41  and  42  of the gripper plates. As the bone of the poultry thigh  12  moves through the slot, the gripper plates are forced away from each other against the bias of the extension spring  51 . When the bone of the poultry part moves beyond the inward projection  68  of the gripper plate  39 , the gripper plates snap back toward one another under the influence of biasing force F provided by the extension spring. 
         [0022]    Since the bone of the chicken thigh is wider than the minimum distance between the gripper plates, the snapping, back of the gripper plates causes the facing edges of the gripper plates to engage and grip the bone firmly with a force determined by the spring constant of the extension spring. The joint of the bone is now just above the gripper plates as shown in  FIG. 1 . The biased engagement of the bone by the gripper plates just beneath the joint inhibits the bone from being pulled downwardly out of the holder during meat stripping and other operations. This is because the joints, although not as large in the case of thighs as the ankle joint of a drumstick, still are larger than the diameter of the thigh bone itself. It is difficult for the larger joint to slide through the inwardly biased gripper plates. 
         [0023]    Further, the inventor has discovered that downward force on a chicken thigh suspended from the gripper plates of the holder actually increases the force applied to the bone by the edges of the gripper plate. This is because any downward movement of the gripper plates, however slight, as a result of the downward force tends to pull down on the pivot bolt  47 . This, in turn, causes the gripper plates to move toward one another as a result of the scissor motion of the legs  31  and  32  about the pivot bolt  47 . Thus, the greater the force tending to pull a chicken thigh downwardly out of the holder, the more tightly the gripper plates grip the thigh bone of the thigh. 
         [0024]    The ultimate result is that chicken thighs that previously have been prone to slip or be pulled out of fixed prong holders during meat stripping and other operations are held firmly and reliably within the holder of the present invention. Of course, on rare occasions, the joint may break away from the end of the bone; however, instances of this are much less common than joints slipping out of holding devices of the prior art. Thus, the inefficiencies attendant dealing with slipped-out poultry parts are virtually eliminated. 
         [0025]    The invention has been illustrated and described in this disclosure in the form of one particular preferred embodiment that serves as an example of the much broader inventive concept. It will be apparent to the skilled artisan, however, that the invention is not limited to the illustrated exemplary embodiment but rather is far more expansive. For example, the particular configuration of the arms of the illustrated embodiment may be changed in many ways that perform the same function in the same way and obtain the same result. The extension spring may be otherwise configured and located For example, a compression spring between the top of the guide slot  19  and the head of the pivot bolt  47  would fall within the scope of the invention, as would leaf springs or coil springs. Alternatively, attracting and/or repulsing magnets may be substituted for the compression spring to provide the biasing force. The illustrated embodiment is a prototype and the final embodiment is expected to be different in appearance but nevertheless within the scope of the invention illustrated by the prototype. 
         [0026]    The holder of this invention has been found particularly useful for suspending chicken thighs from the overhead conveyor of a chicken cut-up line. However, virtually any meat part may be held by and suspended from the holder of the present invention with improved resistance to being pulled out of the holder. Therefore, traditional fixed prong holders that successfully, hold drumsticks suspended from their ankle joints may be replaced by holders of the present invention so that they may be used to suspend thighs and other hard-to-hold chicken parts as well. In fact, the inventor envisions that traditional shackles and other chicken part holders may well be replaced universally by the holder of the present invention. For example, pairs of holders according to the present invention may be substituted for the holding prongs of traditional shackles to suspend chickens and chicken carcasses securely by both legs from the conveyor system. The holders of this invention may be suspended from the conveyor, used to suspend parts as they move around a carousel, or both. These and other additions, deletions, and modifications, both subtle and gross, may be made to the illustrated embodiment of the invention described herein without departing from the spirit and scope of the invention itself, which is circumscribed only by the claims hereof.