Abstract:
A method and apparatus for deshelling shellfish, particularly lobsters. An automated processing line conveys shell-fish through a plurality of stations that sanitize, butcher, cut, and extract the meat, and then packages and prepares the package for sale. Vision systems with multi-axis robots guide and manipulate the shellfish through the processing line. Customized breaking blocks are used to sever parts of the shellfish, for example, the tail, knuckles and claws of a lobster, and a customized gripping device is provided for securing the severed parts in position on a conveyor. A water knife is then used to precisely cut the shell of the severed part.

Description:
BACKGROUND INFORMATION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a process for deshelling shellfish, particularly lobsters. 
         [0003]    2. Discussion of Prior Art 
         [0004]    The act of processing lobster meat is an inherently tedious process. The bulk of the editable meat that is found within a lobster is in the claws, knuckles, and tail, constituting a total of seven different pieces, each of which presents its own challenges for picking. Due to the inherent challenges, deshelling lobsters and picking the meat for food preparation has always been a process that requires a significant amount of manual labor, which increases the costs of production and the time that it takes to generate large quantities of prepared meat. 
         [0005]    What is needed, therefore, is an automated process of removing lobster meat from the lobsters shell. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The invention is an automated process for deshelling and removing meat from shellfish, and in particular, lobster, and the apparatus therefor. The process starts by sanitizing the lobster. The lobster is then butchered to sever the tail, the knuckles, and claws from the lobster body. The severed body parts are then cut along the shell, and the meat is then extracted and packaged. The apparatus includes a steam station, butchering station, cutting station, extraction station, batching station, and retort station. 
         [0007]    The steam station uses high temperature short time pasteurization to sanitize the shells and meat, and also causes the meat to separate from the shell. A conveyor belt brings the sanitized lobster to the butchering station, which uses a vision system to capture the location and dimensions of the lobster on the belt. One or more vision-guided robots then pick up the lobster by the body and then uses a number of butchering blocks to sever the tail, claws, and knuckles. Those parts are then sent to the cutting station, where a specially designed gripping conveyor secures the parts while a water knife cuts the shell. Those cut shells are then conveyed through the extraction station, where another vision system captures the location and dimension of the cut part, and additional vision-guided robots extract the meat and discard the shells. The extracted meat is then sent on to the packaging station, where it is packaged, and then to a retort station, which prepares the package for transport and sale by cooking the meat in the sealed package and then chilling the package to preserve the final product. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The drawings are not drawn to scale. 
           [0009]      FIG. 1  is a perspective view of the lobster deshelling processing line according to the invention. 
           [0010]      FIG. 2  is a plan view of the processing line. 
           [0011]      FIG. 3  is a perspective view of the processing line. 
           [0012]      FIG. 4  is a top view of the equipment shown in  FIG. 3 . 
           [0013]      FIG. 5  is a view of the vision system capturing the dimensions of a lobster. 
           [0014]      FIG. 6  is a perspective view of a breaking block. 
           [0015]      FIG. 7  is a perspective view of a breaking block. 
           [0016]      FIG. 8  is a perspective view of the cutting chamber. 
           [0017]      FIG. 9  is a side view of the cutting chamber. 
           [0018]      FIG. 10  is a perspective view of the gripper conveyor. 
           [0019]      FIG. 11  is a top view of the gripper conveyor. 
           [0020]      FIG. 12  is a top view of a single gripper. 
           [0021]      FIG. 13  is a top view of a double gripper. 
           [0022]      FIG. 14  is a perspective view of a meat extraction station. 
           [0023]      FIG. 15  is a perspective view of the meat extraction station, showing the head of the robot and the blower. 
           [0024]      FIG. 16  is a perspective view of the meat extraction station showing the head of the robot and the blower. 
           [0025]      FIG. 17  is a perspective view of a portion of the grip track. 
           [0026]      FIG. 18  is a perspective view of the cam slide. 
           [0027]      FIG. 19  is a perspective view of the nose spring. 
           [0028]      FIG. 20  is a perspective view of the nose slide. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art. 
         [0030]      FIGS. 1 and 2  illustrate an automated processing line  100  for deshelling shellfish, and in particular, for deshelling lobster. The processing line  100  comprises a steam station  10 , a butchering station  20 , a cutting station  40 , an extraction station  60 , a batching station  80 , and a retort station  90 . The general process is as follows: lobsters are sent through the steam station  10  where they are sanitized. Preferably, the lobsters are already dead. The lobsters then pass through the butchering station  20  where the tails, claws, and knuckles are separated from the lobster&#39;s body. The separated parts are then sent through a cutting station  40  where they are tightly gripped and where the shells are cut. The cut lobster parts exit the cutting station  40  and pass through the extraction station  60 , where the shells are removed and the meat extracted. The meat is then sent to a batching station  80 , where is it packaged, and then on to a retort station  90  where the packaged product is cooked, then chilled, and made ready for transport and sale. 
         [0031]    The steam station  10 , illustrated in  FIGS. 1 and 2 , is constructed in this embodiment as a tunnel in which high temperature short time pasteurization takes place, which is a well-known method of heat pasteurization. As the lobster passes through the steam station  10 , the pasteurization process sterilizes the outside of the shell and the surface of the meat inside the shell, and causes the meat to detach from the shell. This process does not cook the meat and primarily serves to sanitize the lobster prior to the shell being cracked and the meat removed. 
         [0032]      FIGS. 1-7  illustrate the butchering station  20 , which includes a first conveyor belt  21 , a first vision system  22 , one or more butchering robots  24 , and one or more breaking blocks  25 . The sterilized lobster exits the steam station  10  and enters the butchering station  20  via the conveyor belt  21  and passes under the first vision system  22 , which captures the lobster&#39;s dimensions. Many conventional vision systems may be suitable for this task, such as, for example, the IN-SIGHT vision system sold by Cognex Corporation. Once the vision system  22  has captured the location and dimensions of the lobster, the information is relayed to one or more of the butchering robots  24 . The butchering robots  24  are vision-guided robotic systems, such as, for example, six-axis vision-guided robots. Each individual robot  24  is capable of butchering a single lobster, and multiple robots  24  may be used to process a larger quantity of lobster. 
         [0033]    Using the information from the vision system  22 , the butchering robot  24  grips the lobster at the center of its body. It then puts the lobster into a suitable one of the breaking blocks  25 , which are secured to a work station  26 , and twists the body to sever the body part. The embodiment of the processing line  100  that is adapted to deshell lobster, for example, includes three different breaking blocks, a tail breaking block  25 A shown in  FIG. 6 , a knuckle breaking block  25 B shown in  FIG. 7 , and a claw breaking block (not shown). Each breaking block  25  includes an insertion opening  32  and a grip wedge  34 . The butchering robot  24  recognizes which body part, tail, knuckle, or claw, is to be cracked and moves the appropriate body part into the insertion opening  32  of the appropriate breaking block  25 , wedges the part into grip wedge  34 , and then rotates the body to sever the body part. The severed part is then placed back on the conveyor  21  and sent to the cutting station  40 . An exit conveyor  28  may also be provided to provide for separate sorting of certain body parts, such as the tail, which may have value as an in-shell product. It is understood, that, depending on the particular type of shell fish that is to be shelled with the processing line  100  according to the invention, other types of breaking blocks may be used and that the scope of this invention is not limited to the types of breaking blocks shown in the figures. 
         [0034]      FIGS. 8 and 9  illustrate the cutting station  40 , which includes a second vision system  42 , a plurality of water knives  44 , and a second conveyor  46 , referred to hereinafter as a gripping conveyor  46 . The body part is moved onto the gripping conveyor  46  from the conveyor belt  21 , where it is securely gripped and brought into the cutting station  40 , which, in this embodiment, is constructed as a tunnel. As the body part approaches the entrance to the cutting station  40 , the second vision system  42  creates an image of the body part, identifies the part, captures its precise dimensions and position on the gripping conveyor  46 , and then calculates a desired cut pattern to remove the shell. For example, the shell on the claw is cut around the outer edge, whereas the shell on the knuckle is cut on both ends. Once the cut pattern is determined, the water knife  44  cuts the shell accordingly. 
         [0035]      FIGS. 10-12 and 17-20  illustrate the gripping conveyor  46 , which has been specially constructed for processing lobster meat. The gripping conveyor  46  includes a conveyor belt  47 , cam tracks  48 , and a plurality of grip bars  49  that extend across the width of the gripping conveyor  46 . Affixed to the conveyor belt  47  are a plurality of grip tracks  51 , which extend out from the belt  47  toward the cam tracks  48 . The grip tracks  51  are formed as a shallow channel, having a bottom and two short sides that extend upward to form the channel and inner ends of the grip bars  49  are captured in the channels. The grip bar  49  is a spring loaded bar comprising a nose slide  52 , a nose spring  54 , and a cam slide  56 , and that is coupled to a wheel  57  placed in the cam track  48 . The nose slide  52  has a first end  53  that extends through the nose spring  54  and is coupled to the cam slide  56  and a second end  55  that is in contact with the severed lobster part. The first end  53  of the nose slide has a knob or protrusion that is slidably captured in a groove  56 A on one end of the cam slide  56 ; the wheel  57  is attached to the other end of the cam slide  56 . As the conveyor belt  47  moves, the grip tracks  51  move the grip bars  49  along the cam tracks  48 . 
         [0036]    The cam tracks  48  are wider at the entry and exit ends of the cutting station  40  to allow the severed lobster part to enter and exit the gripping conveyor  46  without interference from the grip bars  49 . Inside the cutting station, the distance between the cam tracks  48  narrows which causes the grip bars  49  to slide toward the center of the conveyor belt  47  in the grip tracks  51  and to close in on the severed lobster part. The nose springs  54  cause the grip bars  49  to apply compression to the lobster part, holding it in place on the conveyor  47 . The number and spacing of the grip bars is such, that multiple grip bars  49  are in contact with each severed lobster part. 
         [0037]      FIG. 13  illustrates a second embodiment of the gripping conveyor  46  that includes two conveyor belts  47 A,  47 B, which are separated by a link  59 . Nose slides  52 A are affixed in the link  59  and support one side of the severed lobster part. Grip bars  49  as described in the first embodiment secure the severed part in place by applying pressure to the side of the body part opposite the nose slides  52 A. 
         [0038]      FIGS. 14-16  illustrate the meat extraction station  60 , which includes a third conveyor belt  62 , a third vision system  64 , shown in  FIGS. 3 and 4 , one or more extraction robots  66 , and a blower  68 . As the body part with its cut shell enters the meat extraction station  60 , the third vision system  64  identifies the type of body part that is on the conveyor  62 . The extraction robot  66  is a programmable vision guided robot, such as a six-axis or delta robot, and uses the information from the vision  64  to extract the meat. Different methods of extraction may be used, depending on the particular part. For example, the claw has been cut around its outer edge and the robot may simply remove the upper half and dump the meat onto the conveyor. The knuckle has been cut on each end, and the robot may pick up the knuckle and position it in front of the blower  68 , which will use a burst of air or liquid, such as water, to force the meat out of the shell. The embodiment shown includes a first conveyor  62 A and second conveyor  62 B, where the meat-filled body part enters the station  60  on second conveyor  62 B, and the delta extraction robot  66  places the shelled meat on the first conveyor  62 A, and the empty shell is placed, or remains, on the second conveyor  62 B. 
         [0039]    Once the meat has been extracted from the shell, it continues along the conveyor  62  to the batching station  80 , where the meat is packaged. The packages are sent on to the retort station  90  for final conditioning in preparation for sale. For example, the packages are first exposed to heat, to cook the meat, and then are chilled. Automated processes for packaging and preparing the package for sale are known and are not discussed in any detail herein. 
         [0040]    It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the process may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.