Patent Document

This application claims the benefit of U.S. provisional patent application Ser. No. 61/108,789 filed on Oct. 27, 2008. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a system for handling food products from an apparatus that slices or forms the food products. Particularly, the invention relates to food product positioning system for positing food products on a conveyor. 
     BACKGROUND OF THE INVENTION 
     Food product machines, particularly high speed slicers, produce groups of food products. Those groups may be stacked vertically or may be shingled. Food patty forming machines product food product including formed meat patties. The food products may be conveyed away from the food product machine by a main conveyor. The groups of food products may then be supplied to packaging equipment, such as a fill and package apparatus, in a food product stream to be packaged for shipment. The food products as received from the food product machine may not be in a preferred predefined position or orientation on the conveyor to facilitate optimum or efficient downstream processing, such as packaging. 
     Sliced food products may be formed from a slicer such as disclosed in U.S. Pat. Nos. 5,628,237, 5,974,925, herein incorporated by reference, and commercially available as a FX180® slicer machine. The slicer may also be such as disclosed in U.S. Patent Application No. 60/999,961, herein incorporated by reference, and commercially available as a PowerMax4000™ slicer available from Formax Inc. of Mokena, Ill., USA. Formed food products may be made by a patty forming machine such as disclosed in, for example, U.S. Pat. Nos. 3,952,478; 4,054,967; 4,182,003; and 4,329,828, and PCT published applications WO 99/62344, and WO 2005/02766782 A2, herein incorporated by reference, or those commercialized by Formax, Inc. of Mokena, Ill., including the F-26™, ULTRA26™, Maxum700®, F-19™, F-400™, or F-6™ patty forming machines. 
     In one type of fill and package apparatus for sliced food products, a slicer delivers groups of slices or “drafts” onto a conveyor. The drafts are conveyed spaced-apart in a stream to a staging conveyor where the stream is converted to lateral rows of drafts. Such a staging conveyor is described in U.S. Pat. No. 5,810,149, herein incorporated by reference, and commercially available as the A*180 Autoloader from Formax, Inc. of Mokena, Ill., U.S.A. Alternatively, the drafts may be placed on the conveyor by the slicing machine in lateral rows of drafts alleviating the need of a staging conveyor. Fill and package apparatus for sliced or formed food products are disclosed in U.S. Pat. No. 7,065,936 or 7,328,542, which are herein incorporated by reference. 
     In one type of fill and package apparatus for formed food products, the patty forming machine delivers a formed food product or a stack of food products onto an output conveyor. When formed food products are provided as a stack of food products, a food product forming machine may eject a number of food products on top of one another before the food products are advanced by the output conveyor. Also, a paper interleaving device such as disclosed in U.S. Patent Application No. 60/730,304, which is hereby incorporated by reference, and commercially available from Formax Inc., may be placed at the output of the food product forming machine to interleave paper between each food product in a food product stack. Whether the food products lay individually or in stacks on the output conveyor, the food products may be arranged in transverse rows. 
     The food product groups must be maintained within close tolerances, particularly as to weight; under-weight groups constitutes a potential fraud on the ultimate users and overweight groups may represent an appreciable loss of revenue to the plant operator. Even with the most sophisticated and technologically advanced controls, the slicing machines and like food product machines that produce the groups of food products may not always maintain those groups within the preset tolerance limits. This is particularly true when the food product machine first starts in operation and again whenever there is any change in operation, such as a change from one food loaf to another in the operation of a food loaf slicer or a change of bacon slabs in a bacon slicer. Moreover, even those food products that are within the preset tolerance, known as “accept” groups, must be transported to a packaging station or other utilization location. 
     To minimize waste, it is desirable to correct any out-of-tolerance or “reject” food product groups. A check weight conveyor, such as disclosed in U.S. Pat. Nos. 6,997,089 and 5,499,719, and U.S. Patent Application Ser. Nos. 60/729,957, and 11/454,143, may be used to divert rejected food products to an off-weight stream or food product correction stream or location. When rejected food products are taken out of the main food product stream a food product vacancy is created in the food product stream. 
     The present inventors recognize it is advantageous to re-orientate or reposition food products received from a food product machine on a conveyor. The present inventors recognize it would be desirable to provide a device capable of precisely orientating or positioning one or more food products on a moving conveyor. The present inventors recognize that it would be desirable to provide a device capable of precisely orientating or positioning food products on a moving conveyor to facilitate efficient and optimum or efficient downstream processing, such as packaging. 
     SUMMARY OF THE INVENTION 
     The invention includes a food handling system having a positioning system. The positioning system includes a main conveying surface, an electronic sensor, a controller and a robot. The main conveying surface is configured to move food products. The electronic sensor is configured to capture position data about one or more food products on the main conveying surface within a sensor range of the sensor. The controller is signal-connected to the electronic sensor and the robot. The controller is configured to receive data captured by the sensor and is configured to instruct the robot to move a food product to a destination position. The robot is configured to reposition one or more food products on the conveying surface according to instructions sent by the controller. 
     In one embodiment, the robot has a longitudinal working range for positioning a one or more food products to a destination position either upstream or downstream from an original position of the food product with respect to a conveying direction of the conveying surface. 
     In one embodiment, the robot has a lateral working range for positioning one or more food products to a destination position transverse from an original position of the food product in relation to a conveying direction of the conveying surface. 
     In one embodiment, the sensor captures an orientation of one or more food products on the conveying surface within the sensor range. 
     In one embodiment, the controller has instruction for determining whether a food product is in a mis-orientated position on the conveying surface by comparing a measured orientation with a predefined orientation or a predefined orientation range. The controller has instructions for directing the robot to move a particular food product from the misorientated position to a corrected orientation. The robot has a rotatable ripper for rotating an orientation of one or more food products about at least one axis of rotation. 
     In one embodiment, the controller has instruction for determining whether a food product is in a misaligned position on the conveying surface. The controller has instructions for directing the robot to move a particular food product from the misaligned position to an aligned position. 
     In one embodiment, each food product has a transverse position and a longitudinal position on the conveying surface. The sensor is capable of generating a signal representing a captured position including the transverse and the longitudinal position of one or more food products on the conveying surface within the sensor range. The controller has position determining instructions configured to compare the captured position with a predefined position to determine whether the product is mis-positioned; and the controller is configured to send corrected food product movement instructions to the robot to move a mis-positioned food product to a corrected food product position. 
     In one embodiment, the controller has a datastore having at least one predefined transverse centerline value representing a transverse position on which selected food products are to be aligned to form a transverse row on the conveying surface. The controller has a misaligned food product calculating instruction for determine whether a measured food product position value received from the sensor is outside of the transverse centerline value. The controller is configured to instruct the robot to move one or more misaligned food products into an alignment position on the transverse centerline. 
     In one embodiment, the controller has a datastore having at least one predefined longitudinal centerline value representing a longitudinal position on which the food products are to be aligned to form a transverse row on the conveying surface. The controller has a misaligned food product calculating instruction for determine whether a measured food product position value received from the sensor is outside of the longitudinal centerline value. The controller is configured to instruct the robot to move misaligned food products into an alignment position on the longitudinal centerline. 
     In one embodiment, the robot is configured to re-positioning food products on the conveying surface while the conveying surface is moving. The robot may also be configured to re-orientate food products while the conveying surface is moving. 
     In one embodiment, the robot has a gripper for holding the food product. The gripper has at least two gripping arms. The gripper has an open position for releasing a food product, and a closed position for holding and transporting a food product. The gripping arms may have lower supports for supporting the bottom of a food product when the grippers are in a closed position. 
     In one embodiment, the system includes a rotatable slicing blade, a conveying assembly, and a support for holding a loaf in a cutting path of the rotatable slicing blade, the slicing blade arranged to rotate in the cutting path to slice drafts from the loaf, the drafts being plural slices formed in a pile on the conveying assembly and the piles are transported onto the main conveyor. 
     In one embodiment, the system includes a patty-forming machine, the patty-forming machine having a machine frame, a mold plate having at least one cavity and mounted to reciprocate in a longitudinal direction with respect to the frame to position the cavity between a fill position and patty knock out position, a food product delivery channel for delivering food product into the cavity, the food product delivery channel mounted stationary with respect to the frame and having a fill opening into the cavity when the mold plate is in the fill position, one or more knockout plungers for expelling the formed food product from the mold plate onto an output conveyor when the mold plate is in the knockout position. 
     Numerous other advantages and features of the invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims, and from the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic side view of a food product slicing and packaging line that incorporates the invention; 
         FIG. 1A  is an enlarged side view, taken from  FIG. 1 , of an output conveyor including a weigh conveyor and a classifying conveyor; 
         FIG. 1B  is an end view of an optical grading system and the classifying conveyor; 
         FIG. 1C  is a simplified schematic side view of the food product slicing and packaging line of  FIG. 1  using a slicing apparatus; 
         FIG. 1D  is a simplified schematic side view the line of  FIG. 1C  with a food product forming apparatus replacing the slicing apparatus; 
         FIG. 2  is a top view taken from  FIG. 1 ; 
         FIG. 3  is a side view of a packing station; 
         FIG. 4  is a side view of the packing station with the shuttle robot not completely shown; 
         FIG. 5A  is a side view of a gripper; 
         FIG. 5B  is a second side view of the gripper and a main conveyor; 
         FIG. 5C  is a top view of the gripper; 
         FIG. 6  is an enlarged top view taken from  FIG. 2  of a main conveyor, a working area of an alignment robot, an off-weight conveyor, a correction station, a parking station, and a fill station; 
         FIG. 7  is an enlarged top view taken from  FIG. 2  of the main conveyor, the working area of the alignment robot, the off-weight conveyor, the correction station, the parking station, and the fill station showing food products shaped different from those shown in  FIG. 6 ; and 
         FIG. 8  is a side view of the alignment robot and the main conveyor. 
     
    
    
     DETAILED DESCRIPTION 
     While this invention is susceptible of embodiment in many different forms, there are shown in the drawing and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. This application claims the benefit of U.S. provisional patent application Ser. No. 61/108,789 filed on Oct. 27, 2008, which is hereby incorporated by reference. 
     System Overview 
     As shown in  FIGS. 1 and 2 , a system according to the invention includes a slicing machine  20  which cuts slices from one or more loaves and deposits the slices on an output conveyor assembly  30 , forming shingled or stacked drafts, or food products. The drafts can be piles, bunches or groups of thin sliced product. The slicing machine  20  can be of a type as described in U.S. Pat. Nos. 5,649,463; 5,704,265; and 5,974,925; as well as patent publications EP0713753 and WO99/08844, herein incorporated by reference. The slicing machine  20  can also be a FORMAX FX180 machine, commercially available from Formax, Inc. of Mokena, Ill., U.S.A. In  FIG. 1C  the slicing machine  20  is shown in simplified form. The slicing machine is for cutting off a series of slices from a food loaf “L.” The slicing machine is located upstream from the sensor range and produces food products received by the conveying surface. The slicing machine has a rotatable slicing blade “B”, a conveying assembly  30 , and a support “S” for holding a loaf in a cutting path of the rotatable slicing blade. The slicing blade is arranged to rotate in the cutting path to slice drafts from the loaf, the drafts, such as shingled or stacked slices  150  (described below) on the conveying assembly and the drafts are transported onto the main conveyor  120 . 
     In one embodiment shown in  FIG. 1A , the output conveyor assembly  30  includes a check weight conveyor  32 , such as disclosed in U.S. Pat. Nos. 6,997,089 and 5,499,719, and U.S. Patent Application Ser. Nos. 60/729,957, and 11/454,143, wherein unacceptable drafts can be rejected and diverted. In another embodiment as shown in  FIG. 1B , the conveyor assembly  30  includes an optical grading system  70 , such as disclosed in U.S. Pat. No. 6,997,089, which is herein incorporated by reference. In another embodiment, the conveyor assembly  30  comprises a classifying conveyor  42  as shown in  FIG. 1A . The weighing conveyor  32 , and the optical grading system  70 , and the classifying conveyor  42  are located upstream of a main conveyor  120  and an alignment robot  200 . 
     An off-weight conveyor  220  is at least partially adjacent to the main conveyor  120  as shown in  FIG. 2 . The off-weight conveyor  220  connects to a weight correction station  228 . The weight correction station  228  connects to a parking station  230 . 
     The system comprises an alignment and orientation camera or sensor  210  that has a sensor range area  212  focused on an area upstream and/or within a working diameter or area  209  of an alignment robot  200 . The alignment robot is located above the main conveyor  120 . A shuttle robot  100  is located above or adjacent to a downstream end portion of the main conveyor  120  and a fill station  110  and has a shuttle working diameter or area  410 . A shuttle camera or sensor  420  having at least one sensor range  430  focused on a downstream end of the main conveyor. A packaging machine  60 , such as a Multivac R530, available from Multivac, Inc. of Kansas City, Mo., U.S.A., is located below the main conveyor  120 . 
     In one embodiment, the system comprises a staging conveyor located between the machine  20  and the robot  200 . Drafts are conveyed spaced-apart in a stream to a staging conveyor where the stream is converted to lateral rows of drafts. Such a staging conveyor is described in U.S. Pat. No. 5,810,149 and is commercially available as the A*180 Autoloader from Formax, Inc. of Mokena, Ill., U.S.A. Alternatively, the drafts may be placed on the conveyor by the slicing machine in lateral rows of drafts alleviating the need of a staging conveyor. 
     At the fill station  110  of the packing machine  60 , the shuttle robot  100  delivers food products from an upstream main conveyor  120  into containers  131 . The containers  131  may be formed in a group of rows of pockets  131  formed in a lower web  133  of film by the packaging machine  60 . Downstream of the fill station  110 , in the direction D, is a sealing station  170 . The containers or pockets  131  that are filled with food product, are sealed by an upper web of film in the sealing station  170 . 
     The machine  20  may also be replaced by a food product forming machine  20 ′ such as disclosed in, for example, U.S. Pat. Nos. 3,952,478; 4,054, 967; 4,182,003; and 4,329,828, and PCT published applications WO 99/62344, and WO 2005/02766782 A2. The food product forming machine delivers a formed food product or a stack of food products onto an output conveyor  30 . Therefore the shingled or stacked drafts  150  may also be formed food products  150 , both of which may be referred to as food products  150 . The formed food product  150  may be such as those shown in  FIG. 6  or may be of another formed shape. Whether the food products  150  lay individually or in stacks on the conveyor  30 , the food products may be arranged in rows transverse to the conveying direction.  FIG. 1D  shows in schematic form the food product forming machine  20 ′. The forming machine is located upstream from the sensor range, The patty-forming machine has a machine frame “F”, a mold plate “M” having at least one cavity “C” and mounted to reciprocate in a longitudinal direction with respect to the frame to position the cavity between a fill position and patty knock out position. A food product delivery channel “H” is for delivering food product into the cavity “C.” The food product delivery channel is mounted stationary with respect to the frame and has a fill opening into the cavity when the mold plate is in the fill position. One or more knockout plungers “P” are provided for expelling the formed food product from the mold plate onto the output conveyor  30  when the mold plate is in the knockout position. The output conveyor delivers formed food products onto the main conveyor  120 . 
     A controller  180 , such as an electronic circuit, a programmable logic controller (PLC), a microprocessor, a CPU, computer, or other control device, is signal-connected to the shuttle robot  100 , the alignment robot, the packing machine  60 , the machine  20 , a sensor or camera  210 , the sealing station  170 , and at least one of a vacancy detector  214   a  and vacancy detector  214   b.    
     The controller may comprise a datastore being a electronic or computer hardware or software memory or harddrive containing predefined values, such as food product orientation values, food product longitudinal position values, food product lateral position values, transverse centerline value representing a transverse position on which selected food products are to be aligned, longitudinal centerline values representing a longitudinal position on which the food products are to be aligned, food product position values. These values may be user defined or predefined for various types of food products. The controller an instruction storage area for storing preprogrammed, user defined, or other instructions that the controller uses to process and/analyze the data according to machine operation programming. 
     Off-Weight Conveyor 
       FIGS. 2 ,  6 , and  7  shows the off-weight conveyor  220  comprises an adjacent longitudinal portion  222 , a downstream end portion  224 , and an upstream end portion  226 . The off weight conveyor  200  is connected to a correction station  228 , which may be a weight correction station. The weight correction station  229  is connected to a food product parking station  230 . 
     In one embodiment, the longitudinal portion  222  is adjacent and parallel to the main conveyor  120 . The weight correction station  228  and the parking station  230  are adjacent and parallel to the main conveyor  120  on a side of the conveyor  120  opposite the longitudinal portion  222 . The parking station is downstream  230  from the weight correction station  228 . The correction station  228  is connected to the longitudinal portion  222  by the upstream end portion  226 . The upstream end portion  226  curves from its connection point with the longitudinal portion to be positioned perpendicularly to the conveying direction. The upstream end portion extends under the main conveyor  120  and curves to connect with the correction station  228 . Thus, the upstream end portion  226  forms a U shape as it extends under the main conveyor. In another embodiment, portions of the off-weight conveyor  220  may not curve to connect to one another, but rather may connect at an angle including a right angle. In another embodiment, the upstream end portion  226  may cross the main conveyor  120  non-perpendicularly. Moreover, the upstream end portion may cross above the main conveyor  120 . 
     The downstream end portion  240  is located between a pickup location  140  at a downstream end of the main conveyor  120  and the fill station  110  ( FIG. 1 ). The downstream end portion connects to the longitudinal portion  222  and curves from its connection point with the longitudinal portion to be positioned perpendicularly with the conveying direction. The downstream end portion  224  is vertically positioned below a conveying surface of the main conveyor  120  and above the filling station  110 , as best shown in  FIG. 4 . In another embodiment, the downstream end portion  224  is vertically positioned co-planer with the conveying surface. In another embodiment, the downstream end portion  224  may be positioned non-perpendicularly with respect to the conveying direction. 
     Alignment Robot 
       FIG. 1  shows an alignment robot  200  downstream from the food product machine  20  and the output conveyor  30 . In one embodiment, the camera or sensor  210  is upstream of the alignment robot  200 . The sensor range area  212  of the sensor or camera  210  is focused on an area upstream and or within the working diameter or area  209  of an alignment robot  200 . The camera  210  and the alignment robot are signal-connected to a controller  180 . In one embodiment, the alignment robot  200  may be a picker robot or a delta robot, such as disclosed in U.S. Pat. Nos. 7,188,544, 6,577,093, and U.S. Patent Application No. 2006/0182602, each patent and patent application being herein incorporated by reference. A device of the basic delta robot concept is disclosed in U.S. Pat. No. 4,976,582 and is incorporated by reference. In another embodiment, the alignment robot  200  may be a four arm picker/delta robot such as the Quattro™ 650 robot manufactured by Adept Technologies Inc. having its corporate headquarters located in Livermore, Calif. in 2008. 
     As shown in  FIG. 8 , the alignment robot  200  is located above the main conveyor  120  and the off weight conveyor  220 . In one embodiment the robot has a base  205 . Four motors are mounted in the base  205  and move four first arms  201 ,  202 ,  203 ,  204 . A pair of pull rods are pivotably attached to each first arm. Pull rods  202   a  and  202   b  connect to first arm  202 ; pull rods  204   a  and  204   b  connect to first arm  204 ; pull rods  201   a  and  201   b  (not shown) connect to first arm  201 ; pull rods  203   a  (not shown) and  203   b  connect to first arm  203 . Each pair of pull rods pivotably connect to a movable plate  206 . The first arms, the connector arms and the movable plate comprise an arm system  208  of the robot. A gripper  160 , such the one shown in  FIG. 5 , may be attached to the movable plate  206  for gripping and moving a food product. 
     The robot can be placed in a frame construction (not shown) above the conveyor  120 . In one embodiment, the arm system  208  is able to rotate with at least three degrees of freedom in Cartesian X, Y and Z directions. 
     In one embodiment, the robot  200  has the working area or diameter  209  ( FIGS. 2 ,  6 ,  7 ) of 1300 mm along the Cartesian x and y axes. The robot  200  has a working height, in the vertical direction or the Cartesian z axis, in the range of 250 mm to 500 mm. The robot has the ability to rotate the movable plate  206  one hundred and eighty degrees in one direction and one hundred and eighty degrees in the opposite direction. The robot has a maximum linear movement speed of 10 meters per second and a rate of acceleration of 150 meters per second squared. 
     Alignment and Orientation Sensor 
     In one embodiment, as shown in  FIGS. 1 , and  8 , the alignment and orientation sensor or camera  210  is located upstream of the alignment robot  200  and downstream of the output conveyor assembly  30 . Regardless of where the camera  210  is located, the sensor range area  212  of the camera  210  is focused on an area upstream and/or within the working diameter or area  209  of an alignment robot  200 . The camera  210  is signal-connected to the controller  180 . The camera  210  is mounted on a support structure (not shown) above or adjacent to the conveyor  120 . 
     The camera  210  and controller  180  comprises a vision system. In one embodiment, the camera  210  is that described in U.S. Pat. No. 6,997,089, which is herein incorporated by reference. The vision system is controlled by the controller  180 . The controller  180  may be an electronic circuit, a programmable logic controller (PLC), a microprocessor, a CPU or other control device. In one embodiment, the camera  210  and the controller  180  may comprise a single unit. 
     In one embodiment, the camera  210  is an ELECTRIM EDC-1000N black and white 640×480 pixel digital camera  34  with a 4.8 mm lens. The controller  180  includes a digital frame grabber PC-104 printed circuit board, and a PC-104 CPU main processor board. In this embodiment, the vision system may also include a light source to provide illumination of the food product  150 . 
     Alignment Robot Operation 
     In operation, the camera  210  scans each food product  150  or each row of food products  151  as they pass under the camera  210  on the conveyor  120  and within the sensor range area  212 . The camera sends data to controller  180  concerning various characteristics of the food product  150 , including food product position, orientation, and alignment on the conveyor  120 . The controller  180  has instructions for analyzing the data. 
     When the controller executes instructions to determine a particular food product or stack of food products is not in a predefined preferred orientation, the controller  180  will send re-orientation instructions to the robot  200 . When misorientated food product  150  is within the working diameter  209 , the robot will move the food product to the preferred position and orientation according to the re-orientation instructions from the controller  180 . 
     As shown in  FIG. 6 , food product  150   a  is misorientated within food product row  151   a . The controller  180  receives position, orientation, and alignment data or information about food product  150   a  from the camera  210 . While or before the food product reaches the working diameter  209 , the controller executes analyzing instructions comparing location and orientation values received from the camera to predefined location and orientation values. If a particular food product is determined by the controller to be mis-positioned or mis-orientated, the controller sends instructions to the robot to move food product  150   a  into a predefined proper or preferred orientation and/or orientation. When food product  150   a  reaches the working diameter  209  of the robot  200 , the robot carries out the instruction and moves and re-orientates the food product so that is it in proper orientation and alignment as shown by food products  150   b  and  150   c . Food products  150   b  and  150   c  represent food product  150   a  after it is reorientated by the robot and conveyed downstream at various points downstream. 
     Referring to  FIG. 7 , the food products of row  151   c  are misaligned longitudinally and transversely with the conveying direction and they are also misorientated. The camera  210  will have obtained position data about each food product at or upstream of the working diameter  209  of the robot  200 . Assuming food product  150   e  fits the predefined proper position and orientation, the controller will instruct the robot  200  to move food product  150   d  along the y axis toward the edge of the conveyor  180 , rotating it slightly to be square with a plane defined by the conveyor edge. The controller will instruct the robot  200  to move food product  150   f  downstream in the X direction relative to the row  151   c . The controller will instruct the robot  200  to re-orientate food product  150   g  to be square with the plane defined by the conveyor  120  edge. The robot will carry out these instructions making the appropriate movement of the food products while the food products are within the working diameter  209  so food product row  151   c  is aligned and orientated as shown by food product row  151   h  after the robot carries out the instructions from the controller  180 . The controller is able to instruct the robot  200 , and the robot is able to carry out any repositioning instructions while the conveyor  120  is in continuous motion. To determine what food products are to be within a particular row, the controller will analyze data from the sensor comprising a row width for food products positioned therein and defining the scope of food products to be considered as within a given row. The row width is a predefined area within which food products are to be aligned on a predefined row alignment within a predefined row. 
     The controller  180  may be programmed to provide orientation or alignment instructions for food products or food product rows according to any user defined or pre-defined orientation or alignment on the conveyor  120 . 
     In one embodiment, the camera  210  will detect when a stack of food products  150  is not properly stacked or aligned in the vertical direction along the Cartesian Z axis ( FIG. 1 ). The controller  180  will instruct the robot to correct the vertical mis-alignment, for example, by straightening the stack with the arms  161  ( FIG. 5A ) of the gripper  160 , when the robot has the gripper  160 , such as shown in  FIG. 5A , attached to the movable plate  206 . The robot may also align by moving individual food product of a food product stack to bring the food product stack into the preferred vertical alignment. 
     Off-Weight Conveyor Operation—Robot Uncorrectable Food Products 
     In one embodiment, the camera  210  will detect and the controller will determine when a food product/food product stack is not correctable by the alignment robot  200 . An uncorrectable food product is when a food product  150  or a stack of food products is misaligned or misorientated to the extent that the robot  200  cannot bring the food product or the stack of food products into the predefined preferred alignment or predefined preferred orientation. When a food product is uncorrectable, the controller will not instruct the robot  200  to correct the food product. In one embodiment, the uncorrectable food product will travel to a downstream end  122  ( FIGS. 6 ,  7 ) of the main conveyor  120 . The controller will not instruct the shuttle robot  100  to pick up the uncorrectable food product or stack or will affirmatively instruct the robot not to pick up the uncorrectable food product. The uncorrectable food product or stack will fall onto the downstream end  224  of the off-weight conveyor  220 . Alternatively, in another embodiment, the controller may instruct the shuttle robot  100  to pick up the uncorrectable food product and place it on the downstream end  224  of the off-weight conveyor  220 . 
     The off-weight conveyor  220  will convey the robot-uncorrectable food product to the off-weight station  228  where it will be corrected by a human  229  or another robot, or it will be discarded or recycled. At the off-weight station  228 , the food product may be added or subtracted to bring the food product or food product stack to a predefined weight or a predefined weight range. The food product may also be restacked, aligned or orientated at the off-weight station  228 . The corrected food product is moved to the parking station  230 . 
     Off-Weight Conveyor—Weighing and Classifying Conveyors 
     As shown in detail in  FIG. 1A , in one embodiment, the output conveyor  30  includes a classifier conveyor system  40 , such as described in U.S. Pat. No. 5,499,719, which is herein incorporated by reference. A classifier conveyor  42  is selectively pivoted by an actuator  44 , by signal from the controller  180 , to deliver food products alternately to the off-weight conveyor  220  or the main conveyor  120 . The actuator  44  can be a pneumatic cylinder with an extendable/retractable rod  46  connected to the classifier conveyor  42 . 
     The weighing conveyor  32  is located upstream of the classifying conveyor  42 . The weighing conveyor  32  signals to the controller  180  the weight of each food product or food product stack that passes over the weighing conveyor  32 . When the controller  180  determines that a particular food product or food product stack is not within a pre-defined weight range or a specific pre-defined weight, the controller  180  signals to the classifying conveyor  42  to lower the classifying conveyor to a reject position  42   b . In the reject position  42   b , the classifying conveyor connects to the upstream end portion  226  of the off-weight conveyor  220 . The off-weight food product is then carried by the off-weight conveyor  200  to the weight correction station  228 . When the classifying conveyor  42  is in a raised accept position  42   a , it connects with the main conveyor  120 . 
     The off-weight conveyor  220  will convey the off-weight food product to the off-weight station  228  where it will be corrected by a human  229  or another robot; it will be discarded or recycled. At the off-weight station  228 , food product slices may be added or subtracted to bring the food product or food product stack to a predefined weight or a predefined weight range. The food product may also be restacked, aligned or orientated at the off-weight station  228 . The corrected food product is then moved to the parking station  230 . 
     Optical Grading System and Classifying Conveyor 
     In one embodiment, the output conveyor  30  comprises an optical grading system  70 , such as disclosed in U.S. Pat. No. 6,997,089, which is incorporated by reference.  FIG. 1B  illustrates the optical grading system  70  which captures the image of the slice passing on the weighing conveyor  32 . When the weighing conveyor  32  senses the slice to be viewed on the scale, the controller  180  triggers the system  70  to capture the slice image. The system  70  will capture an image of the top of the slice on top of the stack  150  or, in the case of a single slice, the top of the slice. The optical grading camera  34  captures the slice image within an image field of vision  49  pixel-by-pixel. The shutter speed of the camera is fast enough to capture the image while the slice or stack is in motion. The image is then retrieved from the digital frame grabber printed circuit board into the memory of the system  70  or of the controller  180 . 
     Software can then perform various analyses on the digital image data. The software may be contained in the system  70 , or in the CPU  12 , or in the controller  180 . The slice perimeter or boundary dimensions are determined due to the brightness or color contrast between the slice and the weigh scale belting on which the slice is transferred. A grayscale analysis, pixel-by-pixel, can be undertaken by the software, wherein black is 0 and white is 255. An experimentally determined grayscale cutoff point between fat pixels (light) and lean pixels (dark) can be used to characterize each pixel as being fat or lean. The ratio of light pixels (fat) to dark pixels (lean) within the slice boundary is then calculated, as representative of a fat-to-lean ratio. Additionally, local areas constituting “flaws” in the slice can be quantified in size, by calculating and summing adjacent non-lean pixels, and then compared to a flaw tolerance or limit. A flaw can be a fat deposit, a gland, muscle or bone piece, a void, or other undesirable bit. 
     Alternatively, the calculations and routines utilized to capture and evaluate slice image data can be as described in U.S. Pat. Nos. 4,136,504; 4,226,540 and/or 4,413,279, all herein incorporated by reference. The mathematical analysis of pixel data can be as described in U.S. Pat. No. 5,267,168, herein incorporated by reference. 
     The data is calculated and compared to predetermined standards or customer programmable standards regarding overall fat content and flaw size and/or quantity limits. 
     A calculation is made to determine whether the slice is to be classified as a “pass”, that is, being below stringent fat content or flaw limits, or “reject”, that is being above acceptable fat content or flaw limits, or “grade-off”, that is being below acceptable fat content or flaw limits but above stringent fat content or flaw limits. 
     Based on the calculated parameters and the comparison to the pre-selected tolerances, the slice is determined to be a grade reject if the fat-to-lean ratio is greater than the allowable tolerance, or if the slice includes a flaw, or a pre-selected number of flaws, greater in size, individually and/or in the aggregate, than an allowable tolerance. These tolerances can be adjustable and determined by the user, typically as a plant standard. 
     Advantageously, in the production of straight stacks or shingled stacks of sliced product, each slice need not the scanned, rather, the top of each stack can be scanned to determine a fat-to-lean ratio, and the presence of flaws, after the stack has been cut and stacked from the loaf. The condition of the top slice, being cut from the loaf in the close vicinity of the remaining slices in the stack, is an accurate representation of the condition of all the slices in the stack. 
     When grading stacks of slices, the top slice of one stack is almost an exact representation of the bottom slice of the following stack. It may be advantageous to remember this image of the top slice of a stack and “flag” it as also representing the bottom of the next stack to pass below the camera. Combined with the next following image, the actual top of the stack, it can be accurately estimated, by evaluating the bottom and top slices of the stack, whether the entire stack meets the quality criteria. According to this procedure, it is not necessary to image each and every slice in the stack or draft to accurately characterize the quality of the stack. 
     Thus, the stack can then be characterized as a grade reject, grade off or acceptable stack based on the characteristics of one slice of the stack or based on the characteristics of the top and bottom slices of the stack. 
     If the slice or stack of slices is determined to be a grade reject, the classifier conveyor  42  will be pivoted by the actuator  44 , by signal from the controller  180  to put the classifier conveyor in a reject position  42   b . The reject position will direct the slice or stack of slices onto the off-weight conveyor  220 . All out-of-weight tolerance slices or groups of slices, regardless of their visual acceptance, can be placed on the off-weight conveyor  220 . Products placed on the off-weight conveyor are moved to the correction station  228 , where they may be corrected by weight, orientation, or position, or they may be removed from the station  228  for disposal or recycling. If the operator  229  or other machine of the correction station  228  corrects the food product then is it optionally moved to the parking station  230 . 
     Vacancy Filling 
     In one embodiment, the system has a vacancy reduction device or system that includes the alignment robot  200  also serving as a vacancy filling robot. When the classifier conveyor  42  diverts a food product to the off-weight conveyor  230  a vacancy is created in the food product stream on the conveyor  120 . An example vacancy is shown in food product row  151   c  in  FIGS. 6 and 7 . The camera or vacancy detector  210  will signal to the controller  180  that a vacancy exists in a particular location on the conveyor. Such a vacancy is shown by the absence of at least one food product as shown in food product row  151   c  in  FIG. 6  and food product row  151   d  in  FIG. 7 . A parking station sensor or food product detector  214   a  will signal to the controller when a food product is parked at the parking station  230 . The vacancy detector  214   a , as shown in  FIG. 7 , may be located adjacent to the parking station  230  or underneath (not shown) the parking station surface. Alternatively, the vacancy detector may be a sensor or camera  214   b  ( FIG. 1 ), such as the type of camera  210  described above, mounted to focus the sensor range area  214   c  on the parking station. In one embodiment, the parking station sensor sends a signal to the controller  180  indicating the number of food products or food product stacks parked at the parking station  230 . 
     The controller will instruct the robot to take a food product from a position on the parking station to fill a vacancy, if there is a food product available at the parking station when the vacancy is in the working diameter  209  of the robot. If the product was removed from the parking station the parking station will advance another available food product to fill the vacancy created by removal of the food product that filled the vacancy on the main conveyor  120 . In one aspect of the embodiment, if the food product was parked in the first position  231  then a conveying surface of the parking station will advance the next food product to the first position in the parking station. If there are no products in the parking station, the parking station conveying surface may stop advancing while the entire parking station is empty. 
     The controller is able to fill any vacancy in the food product stream, regardless of how it was created as long as it was created before the vacancy area advances out of the sensor area range  212  of the conveyor  120 . 
     Shuttle Sensor 
     In one embodiment, as shown in  FIGS. 1 , and  8 , the shuttle sensor or camera  420  is at the end of the main conveyor. Regardless of where the camera  420  is located, the shuttle sensor  420  has at least one sensor range  430 , as shown in  FIG. 7 . The sensor range  430  comprises an end portion of the main conveyor. The sensor range  430  may include the width of the main conveyor  120 . In another embodiment, the sensor  420  has a second sensor range  434  that comprises at least a portion  432  of the packing station  110 . The second sensor range  434  may encompass the shuttle working area  410 . The sensor  420  detects food products, such as those shown in food product row  151   h  in  FIG. 7 . The camera  420  is mounted on a support structure (not shown) above or adjacent to the downstream end  224  of the main conveyor  120 . 
     The camera  410  and controller  180  comprises a second vision system. The vision system of the camera  210  and the controller  180  may comprise the second vision system. In one embodiment, the camera  410  is that described in U.S. Pat. No. 6,997,089, which is herein incorporated by reference. The vision system is controlled by the controller  180 . The controller  180  may be an electronic circuit, a programmable logic controller (PLC), a microprocessor, a CPU or other control device. In one embodiment, the camera  420  and the controller  180  may comprise a single unit. 
     In one embodiment, the camera  420  is an ELECTRIM EDC-1000N black and white 640×480 pixel digital camera  34  with a 4.8 mm lens. The controller  180  includes a digital frame grabber PC-104 printed circuit board, and a PC-104 CPU main processor board. In this embodiment, the vision system may also include a light source to provide illumination of the food product  150 . 
     Shuttle Robot 
       FIGS. 3 and 4  illustrate the shuttle robot  100  of the system. The main or upstream conveyor  120  delivers food products  150  to the packing station  110 . The conveyor  120  may operate in a state of continuous motion. The food products  150  may be delivered in rows  151  where the number of food products  150  in the rows  151  correspond to the number of pockets or containers  131  in a row of containers  132 . 
     The shuttle robot  100  may be suspended above or located adjacent to the filling station  110  by a structure (not shown), so that the robot gripper  160  operates at least over the filling station and a downstream portion of the main conveyor  120 . The filling station  110  is adjacent to the main conveyor  120 . The shuttle robot has a range of motion covering Cartesian X, Y and Z directions such that the robot may move transversely and longitudinally with respect to the conveying direction and also vertically. In one embodiment, the shuttle robot operates in the shuttle working area  410 . The shuttle robot comprises a gripper  160  at a bottom of the shuttle robot  100 . 
     In one embodiment, the shuttle robot  100  is a six-axis robot having six degrees of freedom, such as disclosed in U.S. Pat. No. 5,901,613, which is incorporated by reference. A device of the basic six-axis robot concept is disclosed in U.S. Pat. No. 4,773,813, which is incorporated by reference. In another embodiment, the shuttle robot  100  may be a six-axis robot such as one of the Viper™ s650, s850, s1300, or s1700 robots manufactured by Adept Technologies Inc. having its corporate headquarters located in Livermore, Calif. in 2008. In another embodiment, the shuttle robot may be another type of robot having a working range in the Cartesian X, Y and Z directions. 
     In one embodiment, the robot  100  has a maximum payload in the range of 5 kg to 20 kg, a reach in the range of 653 mm to 1717 mm, and a repeatability rating in the range of plus or minus 0.020 mm to plus or minus 0.070 mm. In one embodiment, the robot has a joint range of motion for each joint as follows: joint 1 ±180°, joint 2 −200°, +65°, joint 3 +35°, +190°, joint 4 ±200°, joint 5 ±140°, joint 6 ±360°. 
     As shown in detail in  FIGS. 5A ,  5 B, and  5 C, the gripper  160  has a plurality of first arms  161   a - f , and a corresponding plurality of oppositely facing second arms  162   a - f . The first arms are connected together along or formed into a horizontal arm connection shaft  301 . Similarly the second arms  162   a - f  are connected together along or formed into a horizontal arm connection shaft (not shown). The arms move between an open position  165   b  and a closed or holding position  165   a . Each arm may have a lower support  169   a - f ,  167   a - f  for supporting a bottom of a food product. Each arm is connected at a pivot point  168  to a horizontal arm  168   a . The pivot point may lie on the horizontal arm connection shaft. Each horizontal arm is connected to a position plate  166 . The position plate  166  moves vertically by a pin  163  between a raised position  166   a  and a lowered position  166   b  by a solenoid  160   a  operatively connected to the pin  163 . The vertical movement of the position plate  166  causes each arm  161  to pivot about the pivot point  168 . The arms  161  are in the closed position  165   a  when the position plate  166  is in the raised position  166   a , and the arms  161  are in an open position  166   b  when the position plate is in a lowered position  166   b.    
     In one embodiment, the gripper  160  is connected to a cross plate  340  by a plurality of bolts  344  (not shown in  FIG. 5A ). The cross plate  340  is capable of supporting more than one gripper, such as gripper  310 . Gripper  310  is constructed and operates in the same manner as gripper  160 . The cross plate connects to the shuttle robot  100  at a connection location  342  with a plurality of bolts  344 ,  346 . 
     When the containers are pockets  131  formed from a web  133 , the packaging machine  60  has a dwell period. At the dwell period, the packaging machine  60  stops the motion of the lower web  133 . During the dwell period, the packaging machine  60  forms another group of empty pockets  131  upstream from the packing station  110  at a container-forming station  190 . The container forming station  190  is shown schematically in  FIG. 4 . After the dwell time period is over, the lower web of film  133  is advanced and new food products are deposited into new containers  131  as or after the lower web  133  advances to a new dwell position. 
     The shuttle robot  100  has at least one pickup location  140  at an end of the main conveyor  120  and at least one deposit position located  144  above a container  131  in the filling station  100 . The shuttle robot  100  may have a plurality of deposit positions located above a plurality of containers  131   a  in the filling station  100 . The filling station  100  may hold any number of containers for filling.  FIG. 4  shows a filling station having four containers  131  or four rows of containers. 
     During the dwell period, the robot  100  moves between the pickup position(s) and the deposit positions to move food products from the main conveyor  120  to the containers  131 ,  131   a.    
     The shuttle sensor  420  detects food products on a downstream end of the main conveyor within the sensor range  430  or second sensor range  434 . The shuttle sensor sends information to the controller regarding the location of food products within the sensor range. The controller determines whether and at what point the food products within the sensor range should be picked up and moved to the packaging station or the off weight conveyor by the shuttle robot. The controller instructs the robot to pickup one or more food products from the main conveyor at a location based on the location information received from the shuttle sensor. In one embodiment, the sensor detects which containers  131  in the packaging station are filled with food product and which are not filled with food product and sends that packaging fill information to the controller. The controller may instruct the robot to move food products from the main conveyor to the empty or incompletely filled containers in the packaging station based on the packaging fill information from the sensor. 
     As shown in  FIG. 4 , during each pass between a particular pickup location and a drop or deposit location, the gripper  160  of the shuttle robot  100  grips a food product or stack of food products at the pickup location  140  on the main conveyor  120 . The shuttle robot may approach the pickup location  140  in an open position as shown at  141 . The shuttle robot  100  surrounds the food product  150   a  with the gripper  160  at the pickup location and moves the arms  161  of the gripper to a closed position. The conveyor  120  may be in continuous movement during this time such that the pickup location  140  and the shuttle robot  100  are in continuous motion tracking the location of the food product  150   a.    
     The shuttle robot then moves the food product continuously or intermittently through a plurality of intermediate locations  143  to a particular deposit location  144  located above a container  131 . The container  131  may be empty or may be incomplete. When the shuttle robot is in deposit location  144  with a gripped food product, the gripper  160  will move to an open position releasing the food product to fall into the container  131 . 
     In one embodiment, as shown in  FIG. 5B , the main conveyor  120  is a strip or o-ring belt conveyor. Such a strip conveyor has a conveying surface having multiple belts or strips  330 ,  332 ,  334 ,  336  with gaps  331 ,  333 ,  335  provided between the belts. The belts are driven to rotate by a drive shaft  321  and operate around an idler shaft (not shown) opposite the drive shaft. The gaps between the belts of the strip conveyor are such that the food products  151 ,  151   a  being conveyed do not fall between the gaps. In one embodiment, the strip conveyor is in continuous movement as the gripper approaches one or more target food products on the strip conveyor. The gripper is in or is moved to an open position. The gripper tracks the movement of the food product(s) on the conveyor as the gripper lowers around the food product(s). The shuttle robot lowers the lower supports  169   a - f ,  167   a - f  of the arms  161   a - f ,  162   a - f  of the gripper  160  into the gaps of the strip conveyer below the conveying surface. The arms of the gripper are then closed bringing the lower supports  169   a - f ,  167   a - f  under the food products  151 ,  151   a . The shuttle robot  100  then lifts the food product off the strip conveyor by bringing the lower supports  169   a - f ,  167   a - f  above the conveying surface and moves the food product towards destination packaging. 
     In one embodiment, the shuttle robot may move food product to a container  101  while the container is moving into the packing station  110 . The shuttle robot may move and track the position of a container  131  and release a food product into the container while the container is moving into the packing station and before it is stationary during the dwell period. Loading food products into the containers  131  during the advance time period is a time efficient way to load the pockets. 
     After the containers  131  in the packing station have been loaded with food product, the group of containers in the packing station is advanced downstream to a sealing station  170 . Containers  131  in the sealing location are sealed closed by the application of an upper web of film. The controller  180  synchronizes movement of the shuttle robot with the movement of the containers  131  and the conveyor  120  when needed. 
     The shuttle robot may fill the containers in any order, including filling the container closest to the main conveyor  120  first and filling containers progressively toward the container located within the fill station and furthest from the main conveyor. Alternatively, the shuttle robot may fill the containers in reverse, wherein the first filled row of containers is the row furthest upstream in the direction D ( FIG. 1 ), and the shuttle robot advances to fill the second row, then advances again to fill the third row, etc. After the group of rows is filled during the dwell period, the containers  131  advance and an empty new group of containers  131  is moved into the fill station  110 . 
     In one embodiment, the gripper is configured to grip one food product or one stack of food products. In another embodiment, the shuttle robot has a gripper that is a row gripper capable of gripping more than one food product or an entire transverse row of food products and moving those food products to fill a transverse row of containers  131  in the fill station. In another embodiment, the row gripper has multiple corresponding pairs of gripping arms for gripping each food product of a row individually. This allows individual food products to be selectively gripped. The row gripper is capable of moving less than an entire transverse row of food products by selectively gripping the food products. This may be desirable if one or more of the food products of a food product row is uncorrectable or otherwise unsatisfactory for packing in one or more aspects, such as weight, form, or visual presentation. 
     In another embodiment, the row gripper is capable of gripping a longitudinal row or column of two or more food products to move and fill a longitudinal row of containers in the fill station. In another embodiment the row gripper has multiple corresponding pairs of gripping arms for gripping each food product of a longitudinal row individually. This allows individual food products to be selectively gripped. The row gripper is capable of moving less than a longitudinal row of food products by selectively gripping the food products. In another embodiment, the shuttle robot may comprise multiple shuttle robots for gripping and moving food products between the main conveyor and the packing station. 
     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is intended to cover by the appended claims all such modifications as fall within the scope of the claims.

Technology Category: 7