Patent Publication Number: US-6983678-B2

Title: Apparatus and method for portioning and automatically off-loading portioned workpieces

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 09/619,423, filed Jul. 19, 2000 now U.S. Pat. No. 6,826,989. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to an apparatus for portioning and/or trimming workpieces, and more particularly to an apparatus for portioning or trimming workpieces by shape, weight, or other physical parameter and then automatically off-loading the portioned workpieces. 
     BACKGROUND OF THE INVENTION 
     Workpieces, including food products, are cut or otherwise portioned into smaller portions by processors in accordance with customer needs. Also, excess fat, bone, and other foreign or undesired materials are routinely trimmed from food products. It is usually highly desirable to portion and/or trim the workpieces into uniform sizes, for example, for steaks to be served at restaurants or chicken fillets used in frozen dinners or in chicken burgers. Much of the portioning/trimming of workpieces, in particular food products, is now carried out with the use of high-speed portioning machines. These machines use various scanning techniques to ascertain the size and shape of the food product as it is being advanced on a moving conveyor. This information is analyzed with the aid of a computer to determine how to most efficiently portion the food product into optimum sizes. For example, a customer may desire chicken breast portions in two different weight sizes, but with no fat or with a limited amount of acceptable fat. The chicken breast is scanned as it moves on a conveyor belt and a determination is made through the use of a computer as to how best to portion the chicken breast to the weights desired by the customer, so as to use the chicken breast most effectively. 
     Portioning and/or trimming of the workpiece can be carried out by various cutting devices, including high-speed water jet cutters or rotary or reciprocating blades, as the food product continues to travel on the conveyor. Once the portioning/trimming has occurred, the resulting portions are off-loaded from the conveyor by hand to be placed on a second take-away conveyor for further processing or, perhaps, to be placed in a storage bin. The manual off-loading of portioned pieces is often unsatisfactory because it is difficult for the worker to visually distinguish between portions that might vary by only a few ounces. As a result, the portioned piece may be placed onto the wrong conveyor or into the wrong storage bin. Also, the portioning of food products, especially fish, poultry or meat, typically occurs at relatively low temperatures, in the range of 40 degrees. Performing the same repetitive off-loading tasks in this cold environment can lead to physical ailments as well as creating an undesirable work environment. As such, relatively high worker turnover is not uncommon. 
     The present invention is directed at automatically portioning workpieces, including food products, and then automatically off-loading the portioned workpieces for further processing, for storage, etc. In addition, the present invention is capable of recognizing which particular portioned piece is being off-loaded so that portioned pieces of like weight, shape, or other physical parameter are routed to the proper off-loading conveyor, storage bin, etc. 
     SUMMARY OF THE INVENTION 
     The present invention includes a system for automatically portioning and/or trimming workpieces to desired reduced sizes and then automatically removing the portioned workpieces for routing to other locations based on the size, weight, or other physical parameter of the portioned workpiece. The system includes a first conveyor having a moving support service adapted to support and advance a workpiece to be portioned. The workpiece is cut/trimmed into one or more desired reduced size portions at a cutting station. Thereafter, a pickup device picks up the workpiece from the first conveyor to carry the portioned workpiece to locations removed from the first conveyor. A control subsystem tracks the locations on the moving support surface of the workpiece portions before and after portioning and directs the pickup device to pick up a desired workpiece portion and carry such desired workpiece portion to a specific remote location based on a physical parameter or other attribute of the portioned workpiece. In this manner, like portioned workpieces are removed to the same location remote from the first conveyor. 
     In a further aspect of the present invention, the pickup device includes an attachment end portion that is attachable to the portioned workpiece. In addition, the pickup devices are supported for movement relative to the first conveyor to carry the portioned workpieces away from the first conveyor to a location remote from the first conveyor. 
     In a further aspect of the present invention, the attachment end portion of the pickup device adheres to the portioned workpiece by suction. 
     In another aspect of the present invention, the attachment end portion of the pickup device includes a suction tip or head, and a suction source is connected to the suction tip to cause the suction tip to adhere to the workpiece. 
     In an additional aspect of the present invention, the suction source is produced by a venturi in air flow communication with the suction tip. Pressurized air is supplied to the venturi, causing the venturi to generate a reduced pressure air source. 
     In a further aspect of the present invention, the suction tip is downwardly extendible for attachment to a workpiece and then upwardly retractable to lift the workpiece off of the conveyor and carry the workpiece to a location remote from the conveyor. 
     In another aspect of the present invention, the pickup device is mounted on the carriage for supporting and guiding the pickup device for movement relative to the conveyor. 
     In a further aspect, the present invention includes an impingement or restraining device which is located relative to the pickup device for restraining the upward movement of sections of the workpiece that do not comprise the portioned workpiece to be picked up by the pickup device. 
     In another aspect of the present invention, the weight, size, or other desired physical parameter(s) of the portioned workpiece is ascertained or measured downstream of the pickup device, and based on such information, the portioning subsystem may be recalibrated so as to produce portions of the desired size or other physical parameter. 
     In accordance with an additional aspect of the present invention, the portioning/trimming of the workpieces is carried out utilizing high speed water jets as cutters. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a side elevational view of a portioning machine utilized in the present invention; 
         FIG. 2A  is a schematic plan view of the manner in which portioned workpieces are off loaded from the portioning machine based on physical characteristics of the portioned workpiece; 
         FIG. 2B  is a block diagram of the overall process of the present invention; 
         FIG. 3A  is a perspective view of the off loader station of the present invention; 
         FIG. 3B  is an elevational view of  FIG. 3A ; 
         FIG. 3C  is an end elevational view of  FIG. 3A ; 
         FIG. 3D  is an enlarged, fragmentary end view similar to  FIG. 3C , specifically illustrating the support structure and drive system for carriages used to move pickup devices of the present invention; 
         FIG. 3E  is an isometric view of  FIG. 3D ; 
         FIG. 3F  is an enlarged, fragmentary view of a portion of  FIG. 3D , specifically illustrating the carriage support structure; 
         FIG. 3G  is a plan view of  FIG. 3F ; 
         FIG. 4A  is an isometric view of a pickup device of the present invention; 
         FIG. 4B  is a side elevational view of  FIG. 4A  taken along lines  4 B— 4 B; 
         FIG. 4C  is a front elevational view of  FIG. 4A  taken along lines  4 C— 4 C of  FIG. 4B ; 
         FIG. 4D  is an enlarged isometric view of a skirt utilized in conjunction with the pickup device of  FIGS. 4A–4C ; 
         FIG. 4E  is an enlarged elevational view of the hold down device shown in  FIGS. 3B and 3C  to hold the workpiece in place while a portion thereof is being removed using the pickup device of the present invention; 
         FIG. 4F  is a fragmentary isometric view showing the pickup device, the skirt and hold-down devices; 
         FIG. 5  is an elevational view of an alternative pickup device; 
         FIG. 6A  is an elevational view of a further preferred hold down device of the present invention; 
         FIG. 6B  is a cross-sectional view of a portion of  6 A taken along lines  6 B— 6 B thereof; 
         FIGS. 6C and 6D  are alternative cross-sectional views corresponding to  FIG. 6B ; 
         FIG. 6E  is another preferred embodiment of a pickup device according to the present invention; 
         FIG. 7  is a further preferred embodiment of a pickup device in accordance with the present invention; and 
         FIG. 8  is a schematic view of a high speed water jet nozzle and a carriage therefor used in the portioning station shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to  FIGS. 1 ,  2 A, and  2 B in general terms, the present invention includes a portioning apparatus  20  having a moving conveyor  22  for supporting workpieces WP to be portioned at a portioning station  24  and to carry the portioned pieces PP to an unloading station  26 . A plurality of pickup devices  28  pick up the portioned pieces PP off the conveyor  22  at the unloading station  26  and place the portioned pieces onto removal or take-away conveyors  30  moving outwardly alongside the conveyor  22 . The removal conveyors  30  deposit the portioned pieces PP onto sorting conveyors  32  from which the portioned pieces are placed into specific receiving bins or hoppers  34 A,  34 B,  34 C,  34 D,  34 E,  34 F,  34 G, and  34 H at a sorting station  36 . A weighing station  38  may be incorporated into sorting conveyor  32  to verify the weight of the portioned piece PP. This information can be utilized by the sorting station  36  so that the correct portion piece is removed to the correct sorting/receiving bin  34 . This information may also be utilized by the portioning apparatus  20  to make adjustments so that the portioned pieces are of the desired size. 
     Also in accordance with the present invention, the portioning apparatus retains or keeps track of the location of each workpiece WP on the conveyor  22 , and the subsequent locations of the portioned pieces PP on the conveyor  22  downstream of the portioning station  24  as well as the locations of the portioned pieces on the removal conveyors  30 . With this information, the proper portioned pieces can be automatically placed in the desired receiving bins  34  at the sorting station  36 , without human intervention. 
     Next, describing the present invention in more detail, portioning machines similar to apparatus  20  are known in the art, with the exception of the unloading station  26 , which is novel to the present invention. Such portioning machines, or portions thereof, are disclosed in prior patents, for example, U.S. Pat. Nos. 4,962,568 and 5,868,056, which are incorporated by reference herein. As is typical, the portioning machine includes a conveyor  22  spanning the entire length of the apparatus  20 , with the conveyor having a moving belt  60  that slides over a support structure  62  constructed in a standard manner. The conveyor belt  60  is driven at a selected speed by a drive motor (not shown) in a standard manner. The drive motor can be composed of a variable speed motor to thus adjust the speed of the belt  60 . The workpieces WP are carried on the conveyor belt  60  to be operated on by the portioning apparatus  20  and then transported to the sorting station  36 . 
     The workpieces WP are first carried by the conveyor  22  to a scanning station  40  whereat the workpieces are scanned to ascertain selected physical parameters, for example, their size and shape, and then determine their weight, typically by utilizing an assumed density for the workpieces. In addition, it is possible to locate discontinuities (including voids), foreign material, and undesirable material in the workpiece, for example, bones or fat in a meat portion. 
     The scanning can be carried out utilizing a variety of techniques, including a video camera to view a workpiece illuminated by one or more light sources. Light from the light source is extended across the moving conveyor belt  60  to define a sharp shadow or light stripe line, with the area forwardly of the transverse beam being dark. When no workpiece is being carried by the conveyor, the shadow line/light stripe forms a straight line across the conveyor belt. However, when a workpiece passes across the shadow line/light stripe, the upper, irregular surface of the workpiece produces an irregular shadow line/light stripe as viewed by a video camera directed downwardly on the workpiece and the shadow line/light stripe. The video camera detects the displacement of the shadow line/light stripe from the position it would occupy if no workpiece were present on the conveyor belt. This displacement represents the thickness of the workpiece along the shadow line/light stripe. The length of the workpiece is determined by the length of time that shadow lines are created by the workpiece. In this regard, an encoder is integrated into the conveyor  22 , with the encoder generating pulses at fixed time intervals corresponding to the forward movement of the conveyor. 
     In lieu of a video camera, the scanning station  40  may instead utilize an x-ray apparatus for determining the physical characteristics of the workpiece, including its shape, mass and weight. X-rays may be passed through the object in the direction of an x-ray detector. Such x-rays are attenuated by the workpiece in proportion to the mass thereof. The x-ray detector is capable of measuring the intensity the x-rays received thereby after passing through the workpiece. This information is utilized to determine the overall shape and size of the workpiece, as well as the mass thereof. An example of such an x-ray scanning device is disclosed by U.S. Pat. No. 5,585,603, incorporated by reference herein. 
     The data information measured/gathered by the scanning devices is transmitted to a computer  42 , preferably on board the portioning apparatus  20 , which records the location of the workpiece on the conveyor as well as the shape and other parameters of the workpiece. With this information, the computer determines how to optimally cut or portion the workpiece at the portioning station  24 , the portioning may be carried out by various types of cutting/portioning devices including high-pressure water jets as disclosed in U.S. Pat. Nos. 4,875,254; 5,365,186 and 5,868,056. Other types of cutting devices may be utilized, including band saws, reciprocating saws, circular saws, guillotine knives, and lasers. Workpieces can be portioned in accordance with desired portion sizes, maximum fat content or thickness and other parameters. 
       FIG. 8  illustrates one particular portioning apparatus  66  located at station  24  that may be utilized in conjunction with the present invention. The portion apparatus  66  in basic form includes a support structure  68  extending across the conveyor  22  for supporting and guiding a carriage  70  for movement transversely to the direction of movement of the conveyor. The carriage  70  is powered by a drive system  72  including in part, a motive system  74  and a drive train  76 . A second, longitudinal support structure  78  is cantilevered outwardly from carriage  70  in a direction generally aligned with a direction of movement of the conveyor  22 . A second longitudinal carriage  80  is adapted to move along longitudinal support structure  78  by the drive system  72 . In this regard, a second motive system  82  powers the longitudinal carriage  80  through the drive train  76 . A high-speed water jet nozzle  84  is mounted on the longitudinal carriage  80  to move therewith as the nozzle operates on (cuts) the underlying workpiece WP being carried by the conveyor  22 . 
     As shown in  FIG. 8 , the transverse support structure  68  includes a beam structure  86  that extends transversely across the conveyor  22  at an elevation spaced above belt  60 . The ends of the beam structure  86  are supported by brackets  88  and  90  extending upwardly from the conveyor&#39;s support structure  62 . The support structure  62  also includes a track for guiding the carriage  70  along beam structure  86 , composed of an upper rail  92  and a lower rail  94  attached to face of beam structure  86  facing the carriage. The carriage  70  includes a generally rectangularly shaped bed portion  96  with rollers  98  attached to the corners of the bed portion. 
     The carriage  70  is powered to move back and forth along beam structure  86  by motive system  74 . In this regard, a timing belt  100  extends around a drive pulley  102  located at the upper end of motive system  74 , and also around an idler pulley  104  of an idler assembly  106  mounted on the upper end of bracket  88 . The belt  100  makes a loop around beam structure  86 , extending closely along the side walls of the beam, with the ends of the belt connected to the back side of carriage bed  96 . 
     The motive system  74  includes the servo motor  108  controllable by computer  42  to move the carriage  70  back and forth along beam structure  86  as desired. A drive shaft  110  extends up from the servo motor  108  to power the drive pulley  102 . As further shown in  FIG. 8 , the longitudinal support structure  78  cantilevers transversely from carriage  70  to be carried by the carriage. The support structure  78  includes a beam member  112  that tapers in the direction of its distal end. An elongate track  114  extends along the side of the beam member  112  for guiding the longitudinal carriage  80 . The carriage  80  includes a substantially planar, rectangularly shaped bed portion  116  and rollers  118  at each of its corners adapted to ride along the upper and lower edges of track  114 . 
     Carriage  80  is moved back and forth along track  114  by drive system  72 . In this regard, the drive system includes a second motive system  82 , constructed similarly to motive system  74 , to power a timing belt  120  which is trained around a drive pulley  122  mounted on the upper end of motive system  82  and also trained around an idler pulley  124 , which is located below idler pulley  104 . The belt  120  also trains around idler pulleys  126  and  128  mounted on carriage  70 . A further idler pulley  130  is mounted on the distal end of beam  112 . The ends of the belt  120  are attached to the bed  116  of carriage  80  so that rotation of the drive pulley  122  results in movement of the belt  120  which in turn causes transverse carriage  80  to move along track  114 . As with motive system  74 , ideally, motive system  82  includes a servo motor  132 , which is drivingly engaged with drive pulley  122  by a drive shaft  133 . 
     A cutting tool in the form of a high-pressure liquid nozzle assembly  84  is mounted on the longitudinal carriage  80  to move therewith. The nozzle assembly includes a body portion  134  that is secured to the carriage bed  116 . The nozzle assembly  84  also includes a lower outlet tip  136  directed downwardly towards conveyor belt  60 . An entrance elbow  138  is attached to the upper end of the nozzle body  134 . High-pressure liquid nozzles of the type of nozzle assembly  84  are articles of commerce. High-pressure water is supplied to nozzle assembly  84  by supply lines, not shown, in a manner well-known in the art. 
     In operation, as workpieces WP are carried along conveyor  22 , the nozzle assembly  84  is moved along selected paths of travel by carriages  70  and  80  powered by drive system  72 . Carriage  70  moves the nozzle  84  transversely, and carriage  80  moves the nozzle longitudinally relative to the direction of travel of the conveyor  22 . This enables the nozzle to travel quickly along complicated routes which are programmed into the operation of the servo motors of the motive systems  74  and  82  by computer  42 . 
     As most clearly illustrated in  FIGS. 3A ,  3 B,  3 C,  3 D, and  3 E, off load station  26  includes a plurality of pickup devices  28  for removing selective portioned workpieces PP from conveyor  22  and depositing such portioned workpieces onto take-away conveyors  30 . The off load station  26  includes an overhead framed structure  150  that spans between the adjacent end of the portioning station cabinet  152  and a frame end structure  154 , which also supports the adjacent end of the conveyor  22 . The overhead frame includes a plurality of side-by-side cabinets  156 , each housing a drive system  158  for associated pickup devices  28  positioned below the cabinets. Preferably, each of the cabinets is generally rectangular in shape and has a front access door  160 . Three side-by-side cabinets  156  are illustrated, with the cabinets attached to each other to create a rigid, unitary beam structure. The drive system  158  includes, among other components, a servo motor  162  schematically shown in  FIG. 3D  as positioned above a servo motor cooling fan  164 , which in turn is positioned on a mounting platform  166  spaced above cabinet floor  168  by a plurality of support legs  170 . A coupling  172  is attached to the output shaft (not shown) of the servo motor and also attached to the upper end of a drive shaft  174  that extends through an opening formed in cabinet floor  168 . As most clearly shown in  FIGS. 3C and 3D , a drive pulley  176  is coupled to the lower end of the drive shaft  174 . 
     The pickup devices  28  are carried by carriages  180  that ride along frame assemblies  182  that in turn are attached to the underside of cabinets  156  by a mounting bar  186  attached to and extending along the underside of the cabinet floor  168  in a direction generally transversely to the direction of travel of conveyor  22 . The mounting bar  186  projects from a generally rectangularly shaped mounting flange  188 , also attached to the underside of the cabinet floor  168 . A drive shaft hub  190  projects downwardly from a clearance hole formed in the mounting flange  188  for receiving the drive shaft  174  therethrough. Preferably, roller or other types of bearings are positioned within the upper and lower end portions of the hub  190  for positioning and supporting the drive shaft  174 . 
     The carriage frame assemblies  182  each include a longitudinal beam  192  attached to the underside of an edge flange  194  projecting upwardly from the beam along a portion thereof that is positioned below a corresponding cabinet  156 . Longitudinal slots  196  are formed in the edge flange  194  through which extend hardware members, for instance, bolts that engage within threaded cross-holes extending through mounting bar  186 . In this manner, the frame assembly  182  may be longitudinally adjusted relative to the mounting bar  186 , as will be discussed more fully below. Spaced-apart upper and lower rod tracks  200  and  202  are mounted to beam  192  at the ends of the rod tracks by end flange plates  204  and  206 , which are attached to the ends of the beam  192 . A pair of rod tracks  200  and  202  are located on each side of the beam  192 . An idler pulley  208  is spaced outwardly from flange plate  206  on an upright support shaft  210 , which in turn is attached to upper and lower mounting ears  212  projecting from the upper and lower portions of flange plate  206 . An endless cog or gear belt  214  ( FIG. 3G ) spans between the drive pulley  176  and the idler pulley  208 . 
     The tension on belt  214  may be adjusted by shifting the position of beam  192  and, thus idler pulley  208 , relative to the drive pulley  176  so that moving the idler pulley away from the drive pulley will increase a tension on the belt  214 , while shifting the idler pulley toward the drive pulley will reduce the tension on the belt. The movement of the beam  192  is accomplished through the use of a threaded stud  216  that projects outwardly from the end of mounting bar  186  through a clearance opening formed in a take-up tab  218  projecting upwardly from the upper surface of beam  192  at a position spaced a short distance from the end of the mounting bar. Hardware members in the form of nuts  220  are threadably engaged over stud  216  to bear against the opposite sides of the tab  218  thereby to position the tab relative to the end of the mounting bar  186 . Once the desired tension of the belt  214  is achieved, the nuts  220  capture the tab  218  therebetween. 
     Next, referring specifically to  FIGS. 3D ,  3 E,  3 F,  3 G,  4 A,  4 B,  4 C, and  4 F, the pickup devices  28  include carriages  180  carried by frame assemblies  182 . The carriages  180  each include a slider block  230  secured to the four corner portions of a planar, substantially rectangular carriage plate  232 . The slider blocks include clearance holes for receiving rod tracks  200 ,  202 . Ideally, a bushing  233 , or other anti-friction device, is pressed or otherwise securely positioned within the clearance hole of the slider block to help the carriage anti-frictionally slide along the frame assemblies  182 . 
     The carriage  180  is secured to the backside of carriage plate  232  by a clamping plate  233 A, which presses the belt  214  against a clamping block  233 B, secured to the back surface of the carriage plate  232  as best shown in  FIG. 4B . The surface of the clamping plate  233 A facing the belt may be grooved to match the contour of the belt teeth so as to securely retain the belt between the plate  233 A and the block  233 B. Hardware members extend through clearance holes formed in the plate  233 A above and below the belt, to extend within aligned threaded holes formed in the block  233 B. In this manner, the belt  214  is securely attached to the pickup carriage  180  without having to drill holes or otherwise alter the belt  214 . 
     Each of the pickup devices  28  includes a linear actuator in the form of a pneumatic cylinder assembly  234 , which is secured to and carried by carriage  180 . The cylinder portion  236  of each cylinder assembly is held in place on carriage  180  by a lower attachment block  238  which is mounted on the carriage plate  232  by hardware members  240 . A close-fitting clearance hole is vertically formed in attachment block  238  to slidably receive cylinder portion  236  therein. The lower end of the cylinder portion  236  abuts the upper surface of an end block  244 , which has a narrow slot formed therein to provide clearance for the cylinder rod  246  which projects downwardly from the cylinder portion  236 . The upper end of the cylinder portion  236  is securely held in place by a quick release clamp assembly  248  composed of a stationary half  250  and a pivotal half  252  hinged to the stationary half by a pin  254 . The stationary half  250  and pivot half  252  of the clamp assembly  248  are shaped to define a circular receiving seat  256  for securely clamping against the upper end portion of the cylinder  236 . The pivot half  252  is held in closed position by a spring-loaded pivot pin  258  that extends outwardly through clearance slots provided in the adjacent portions of clamp stationary half  250  and clamp pivot half  252  to extend through a clearance hole formed in a transverse pin  259 . A compression spring  259 A is engaged over the free end portion of pin  258  to press against transverse pin  259  so as to help retain the transverse pin engaged within a semicircular seat  257  formed in the pivot half  252 . 
     Referring specifically to  FIGS. 4A–4C  and  4 F, a suction tip or head  260  is attached to the lower end of rod  246  for adherence to the portioned workpiece PP being removed from conveyor  22 . A compressible bellows cup assembly  261  is attached over an extension neck  261 A projecting downwardly from the main body portion of tip  260 . The bottom  261 B of the bellows assembly is cup-shaped so as to achieve a secure attachment with the portioned workpieces PP to be picked up. A center bore or passage  261 C extends through the tip  260  and extension neck  261 A to present an opening  261  D at the bottom of the extension neck. 
     In certain situations, it may be important to keep the suction tip  260  from rotating thereby to maintain the orientation of the portioned workpiece. This is accomplished by use of a guide rod  262  having its lower end fixed to a tab  264  projecting outwardly from the generally cylindrically-shaped suction tip  260 . The upper end portion of the rod  262  slides within a vertical clearance hole formed in the attachment block  238 . In this manner, guide rod  262  is disposed in a space parallel relationship with cylinder rod  246 . Other systems can be utilized to prevent the suction tip  260  from rotating. 
     Suction is applied to the suction tip  260  by use of a venturi assembly  270  mounted on the carriage  180 . Pressurized air is supplied to the venturi assembly  270  by supply line  272 . The venturi creates a source of reduced air pressure which is transmitted to suction tip  260  by line  274  that is connected to a side port  276  formed in the body of suction tip  260 . This side port is in fluid flow communication with the central air passageway  261 C extending longitudinally upwardly from the bottom of the suction tip to the elevation of the side port. Ideally, an air valve (not shown) is used to supply pressurized air to the venturi  270  to generate a reduced pressure air source when desiring to pick up a portioned workpiece, while also supplying pressurized air to a second side port  278  of the suction tip  260  when desiring to break the suction connection between the cup assembly  261  and the workpiece, thereby to disengage the suction tip from the portioned workpiece. The side port  278  is also connected in fluid flow communication with the tip air passageway  261  C. The positive pressure air source can also be used to “backblow” the suction tip  260  to clean out the suction tip or remove matter that may have become lodged therein. During this backblow operation, the air valve discontinues air flow to the venturi assembly  270  so as to not induce the matter to enter suction line  274 . 
     The pickup device  28  is described above as utilizing suction action to grasp the portioned workpieces PP. However, other types of methods may be employed to pick up the portioned workpieces. For example, if the workpiece is composed of magnetically conductive material, the pickup device may utilize a magnet. In addition, the pickup device may consist of a clamp or jaw structure capable of physically grasping the workpiece for lifting off the conveyor  22  and then releasing the workpiece at a desired remote location from the conveyor. Alternatively, the pickup device may include forks or tines in place of the suction tip/head  260  to spear the portioned workpiece PP. As a further alternative, the pickup device may consist of very cold (below freezing temperature) tabs that “stick” to the workpiece thereby to pick up the workpiece from the conveyor  22 . 
     Referring specifically to  FIGS. 4D and 4F , the pickup devices  28  include a retaining skirt or housing  280  designed to substantially surround the cylinder rod  246  and suction tip  260 , and thereby also surround the portioned workpiece PP lifted off of the conveyor  22  by the pickup device, as described more fully below. The skirt is mounted on the carriage plate  232  by a tab  282  projecting upwardly from the skirt as shown in  FIG. 4D . Hardware members, not shown, extend through clearance holes formed in the tab and aligned clearance holes formed in the plate  232  to engage nuts (not shown). The skirt is generally in the shape of an octagon, with one panel missing to define a longitudinal gap  283  in the skirt to reduce the weight of the skirt and also provide access to the cylinder assembly  234 . One or more of the panels may include slot  284  formed therein so as to reduce the weight of the skirt. At the bottom of the skirt, the panels flare outwardly so as to define an enlarged entrance opening  286  for the portioned workpiece as the portioned workpiece is lifted upwardly into the skirt by retraction of the rod  246  of the cylinder assembly  234 . 
     It will be appreciated that the skirt/housing  280  may be of configurations other than that illustrated in  FIGS. 4D and 4F . In this regard, a cage structure (not shown) composed of wire elements or other structural members may be utilized in place of the skirt  280 . Such cage structure would provide lateral restraint to the workpiece portion PP being carried by the pickup device. As in the skirt/housing  280 , the cage can be constructed with a bottom opening through which the workpiece portion PP passes upwardly when being removed from the conveyor  22  and exits downwardly when being deposited at a location remote from the conveyor. 
     A plurality of hold-down assemblies  290  are utilized to retain the portioned workpiece downwardly against the conveyor belt  60  while the pickup device  28  lifts a desired portion upwardly off of the belt. This may be especially useful if the individual portions of the workpiece are not completely severed from each other at the portioning station  24 . This is not uncommon if a high speed water jet is used to portion or trim a meat product, such as a chicken breast. The water jet may not always completely sever cartilage or the tough pieces of meat product. 
     In one preferred embodiment of the present invention, the hold down assembly  290  includes a post  292  extending downwardly from the underside of a cabinet  156 . The post is illustrated in  FIGS. 4E and 4F  as generally rectangular in cross-sectional shape. A slider coupler assembly  294  is used to attach a hold down blade assembly  296  to the lower end portion of the post  292 . The coupler assembly  294  includes a slide channel  298  having a web portion overlying one surface of the post  292  and rather narrow flange portions overlying the edges of the post so as to be slideable along the height of the post, while retaining the slide channel against movement in other directions relative to the post. A longitudinal slot is formed in the web section of the side channel  298  through which extends the stud portion of an adjustment knob  300  to engage within a threaded hole formed in post  292  thereby to securely clamp the coupler assembly  294  to the post at a desired elevation along the height of the post thereby to position the bottom of the blade assembly  296  at a desired elevation relative to conveyor belt  60 . 
     The coupler assembly  294  includes generally U-shaped intermediate section  302  that projects downwardly from slide channel  298  to transversely interconnect with a horizontal, generally rectangular-shaped slide plate  303 . The slide plate has a slot formed therein in the direction generally parallel to the direction of travel of the belt  60 . The downward extended stud portion of a knob  304  extends through the slot  305  of the slide plate  303  to engage with a threaded through hole formed in the bar portion  306  of the blade assembly  296  thereby to securely clamp the slide plate  303  to the blade assembly while allowing the blade assembly to be adjusted transversely to its length, i.e., in the direction parallel to the movement of the conveyor belt  60 . The slide plate  303  is held captive between guide ridges  307  extending transversely across the bar  306  and spaced apart to closely receive the slide plate  303  therebetween. It can be appreciated that the guide ridges  307  restrict any substantial transverse movement of the blade assembly  296  relative to coupler assembly  294  (lengthwise along bar  306 ) or rotational movement about a vertical axis corresponding to the center of knob  304 . 
     With respect to the construction of the blade assembly  296 , end tabs  308  extend downwardly from the ends of bar  306  to pivotally couple to the upper edge portion of longitudinal pivot bar  310 . The end tabs  308  are generally triangular in shape, with the apex of the triangle located in the downward direction for supporting a pin  311  extending therethrough to extend into the adjacent edge portion of the pivot bar  310 . A relatively thin blade  312  is attached to the lower edge portion of the pivot bar to project downwardly from the bottom edge of the bar towards the upper surface of the belt  60 . As shown in  FIG. 4F , in one embodiment of the present invention, the lower edge of the blade  312  is serrated. Such lower edge portion can be formed in other shapes, for example, in the form of v-shaped teeth or prongs. A stop tab  314  overlies one face of the pivot bar  310  at one end thereof and in alignment with an end tab  308 . An adjustment screw  316  extends through a threaded opening formed in the stop tab  314  to bear against the adjacent edge of end tab  308 . The engagement of the adjustment screw  316  with a stop tab  314  may be varied thereby to alter the nominal orientation of the pivot bar  310  and thus the blade  312 . 
     In use, the pivot blade  312  is able to pivot about pin  311  thereby to raise the blade  312  upwardly away from the belt  60  when a workpiece WP carried by the belt passes beneath the hold down assembly  290 . However, if a workpiece portion PP is being lifted upwardly by the pickup device  28 , the adjacent portion of the workpiece may be retained downwardly against the conveyor belt  60  by the impingement of the blade  312  against the workpiece. When an upward force is placed on the blade  312  by the workpiece, the pivot bar  310  tends to pivot about pin  311 , but is prevented from doing so by stop tab  314 . 
     As shown in  FIGS. 3A ,  3 B,  3 C, and  4 F, a plurality of hold down assemblies  290  may be utilized with each frame assembly  182 . Ideally, a hold down assembly  290  is positioned in front of and behind each pickup device  28  (relative to the direction of movement of the conveyor belt) and positioned laterally with respect to the belt to coincide with the general location of the lanes along which the workpieces WP travel along the belt. 
     Referring specifically to  FIG. 2A , portioned workpieces PP are removed from conveyor  22  by the pickup device  28  and deposited on the take-away conveyors  30  which carry the portioned workpieces to sorting conveyors  32 . It will be appreciated that in conjunction with the present invention, the computer  42  is capable of retaining or keeping track of which particular portioned workpiece PP is placed on the take-away conveyors  30  as well as a location of the portioned workpieces on the conveyor  30 . The computer  42  is also capable of keeping track of or retaining the locations of the portioned workpieces PP on the sorting conveyors  32 . This information is used at the sorting station  35  to place the proper portioned workpiece in the proper receiving bin  34 . For example, the workpiece WP may be portioned into different sizes at portioning station  24 . As noted above, the sizes and locations on the conveyor  22  of the portioned workpieces PP is known, with that information the workpieces are removed from the conveyor by the pickup devices  28  and deposited onto the take-away conveyor  30  at a position on the conveyor known to the computer  42 . To this end an encoder can be incorporated into the take-away conveyor in a manner that is known in the art. In turn, the conveyor  30  deposits the portioned workpiece PP on the sorting conveyor  32  at locations known to the computer  42 . The sorting conveyors likewise can utilize encoders. This information is employed by the swing arms  320  that swing across the sorting conveyors  32  to place the portioned workpieces PP into selected bins  34  according to a desired parameter, such as the weight of the portioned piece. 
     A series of four bins  34 E, F, G, and H are positioned longitudinally of the sorting conveyors  32  so that portioned workpieces PP of four different sizes or other selected physical parameter(s) may be placed within the bins. As will be appreciated, in accordance with the present invention, a fewer number or a greater number of bins  34  may be positioned lengthwise of the sorting conveyors  32 . The bins being filled are illustrated in  FIG. 2A  as positioned between the two side-by-side sorting conveyors  32 . Once full, the bins can be shifted or moved out from between the two sorting conveyors (down the page in  FIG. 2A ) and empty bins  34  placed in registry between the two sorting conveyors  32 . The fact that a bin is full can be automatically determined in several ways, such as by incorporating a scale into the station at which the bin is located as they are being filled. Also, the number of portioned workpieces PP placed into the bin by the swing arm  320  can be counted. 
     The swing arms  320  can be powered by a convenient source such as electricity or pressurized fluid. Swing arms similar to swing arms  320  are articles of commerce. 
     Optionally, in the present invention, a weighing station  38  may be positioned along the sorting conveyors  30  or integrated into the construction of the sorting conveyor. The purpose of the weighing station  38  is to weigh the portioned pieces PP as they move along the sorting conveyors. This information can be utilized to operate and control the swing arms  320  rather than relying on the computer  42  to keep track of the positions of the portioned pieces PP on the sorting conveyors. Also, the information from the weighing stations  38  can be used to confirm the weight of the portioned pieces portioned at the portioning station  24 . If the weight of the portioned workpieces is beyond an acceptable range, this information can be fed back to the portioning station  24  to adjust the manner in which the workpieces are being portioned by the portioning apparatus  66 . In this manner, the calibration of the portioning apparatus  66  may be continually monitored and updated as needed. Of course, for calibration purposes, rather than utilizing weighing station  38 , the portioned workpieces PP may be removed manually from the take-away conveyor  30  or sorting conveyor  32  and weighed by a machine operator. If such weighing determines that the portioned pieces are not within the desired range, the portioning apparatus  66  may then be adjusted as required. 
     In the use of the apparatus  20  of the present invention, workpieces WP are placed on the belt  60  of the conveyor  22  for movement along the apparatus, first passing through the scanning station  40  and through a portioning station  24  and then to an unloading station  26 . The workpieces ideally are placed in multiple lanes on the conveyor so as to increase the rate at which the workpieces can be portioned and/or trimmed.  FIG. 2A  illustrates two separate lanes being used along the conveyor  22 . At the scanning station, the workpieces are scanned to ascertain selected physical parameters, for example the overall size and shape of the workpiece. This information can be used to determine the weight of the workpiece by utilizing an assumed density for the workpiece. The scanning can be carried out by a variety of existing techniques, including video cameras that view the workpiece as illuminated by one or more light sources. As an alternative, x-rays can be used to scan the workpiece. Information from the scanning of the workpiece is used to determine how to optimally cut or trim the workpiece through the use of a computer  42 . The computer can be programmed with software to analyze how to best cut the workpiece of a particular size and/or shape to produce portioned pieces of desired sizes, shapes or other physical parameters. 
     Information from the scanning of the workpiece is used to control cutting/portioning devices, for example high speed water jet nozzles  84  carried on a carriage  80  adapted to move back and forth along a longitudinal support structure  78  extending parallel to the direction of movement of the conveyor. The support structure is cantilevered from a second carriage  80  which is powered to move back and forth along a beam structure  86  that spans across the conveyor  22  at an elevation above the conveyor belt. In this manner, the high speed water jet nozzle  84  can quickly travel along complicated routes under the control of the computer  42  to not only portion the workpiece, but also to trim the workpiece as needed. The locations of the workpieces on the conveyor are tracked and such locations retained by the computer as the workpiece moves through the scanning station and through the portioning station and to the offload station  26 . 
     At the offload station, pickup devices  28  remove selective portioned workpieces PP from the conveyor and deposit such portioned workpieces onto a take-away conveyor  30 . The pickup devices in construction include a linear actuator in the form of a pneumatic cylinder assembly  234  having a rod  246  extendable downwardly towards the conveyor belt  60 . A suction tip or head  260  is carried by the free end of the rod to securely attach to a portioned workpiece. A venturi  270  generates a suction supplied to the tip or head  260 . The pickup device is carried by a carriage  180  adapted to travel along a transverse frame assembly  182  by an endless belt  214  which is powered by a servo motor  162 . Once the pickup device has attached to a workpiece portion PP, the pickup device is retracted upwardly to lift the workpiece portion off the conveyor and away from the remainder of the workpiece. The carriage is activated to travel transversely relative to the conveyor to overlie a take-away conveyor  30  on which the workpiece portion is deposited. 
     A hold-down assembly  290  is optionally employed to hold the workpiece surrounding the portioned workpiece PP downwardly against the conveyor  22  as the pickup device is lifting the portioned workpiece upwardly. When lifted upwardly, the suction tip  260 , and the portioned workpiece PP being carried thereby, enter a skirt or shroud  280  that substantially encircles the pickup device and the workpiece portion. The skirt surrounds and restrains the workpiece as the carriage  180  travels laterally from the conveyor  22  to the take-away conveyor  30 . This travel occurs very quickly generating a high acceleration when beginning its lateral movement and a high deceleration rate when coming to a stop over the take-away conveyor  30 . Without the skirt  280 , the workpiece, especially if a food product, may tend to swing back and forth during the high acceleration and deceleration of the carriage  180 . 
     From the take-away conveyor  30  the workpiece is routed to a sorting conveyor  32  passing through a sorting station  36 . Swing arms  320  are located along the sorting conveyor to slide the portioned pieces into receiving bins  34 . A weighing station  38  may be incorporated into the structure of the sorting conveyor  32  or may be separately constructed. The purpose of the weighing station is to weigh the portioned workpieces PP as they pass by thereby to make sure that the workpieces are within the desired weight range. If this is not the case, the information from the weighing station may be utilized to adjust the operation of the portioning station  24 . Thus, a feedback loop is created so that the cutters used at the portioning station  24 , e.g., high speed water jet nozzles  84 , are adjusted as necessary to help ensure that the workpieces are uniformly portioned to the desired sizes. Moreover, this information can be used to recognize if the pickup devices  28  are not operating properly, for instance if they become plugged so that they are not capable of lifting the portioned workpieces off of the conveyor  22 , in which case no workpieces would be passing over the weighing station  38 . 
     It will be appreciated that through the present invention it is possible to continuously and quickly portion workpieces, such as meat products, into desired sizes and also to trim the workpieces, for instance, to remove fat, bone or other undesirable content from a meat product. Through the present invention, the portioned workpieces PP are sorted into sizes or by other parameters and placed in bins  34  or other receptacles. The computer  42  is capable of keeping track of the sizes and other physical parameters of the portioned workpiece as well as the location of such portioned workpiece on the main conveyor  22 , the take-away conveyors  30 , and the sorting conveyors  32 . Thus, it is not necessary for personnel to physically remove the portioned pieces from the conveyor  22  and place the portioned pieces onto a take-away conveyor, such as conveyor  30  or to place the portioned workpieces into receptacles such as bins  34 . It is often difficult for a worker to differentiate among portioned pieces that may differ in size by only an ounce or two. However, the present invention is capable of quickly, accurately, and repeatedly making this distinction among workpieces, or other distinctions by which workpieces are graded and/or sorted. Moreover, meat products are portioned in environments wherein the room temperature is typically at about 40 degrees, which quite cold, and very difficult for personnel to withstand on a daily basis. Whereas the portioning apparatus  20  of the present invention is substantially immune to such cold temperatures. 
       FIGS. 5 ,  6 A– 6 E, and  7  illustrate alternative embodiments of pickup devices in accordance with the present invention. The pickup device  360 , shown in  FIG. 5 , includes a linear actuator  362 , which is illustrated in the form of a fluid cylinder, but can be other configurations, such as in the form of an electrical actuator. The cylinder assembly  362  includes a cylinder portion  364  having its upper end secured to an angled mount  366 , which in turn may be secured to cabinets  156  of the overhead frame structure  150 . The rod portion  368  of the cylinder assembly  362  is secured to an intermediate flange  370  projecting laterally from longitudinal follower bracket  372 . The upper end of the follower bracket includes a collar portion  374  that closely encircles the cylinder  364 . As the rod  368  extends and retracts, the follower bracket  372  is lowered and raised causing the collar portion  374  to slide along the length of the cylinder portion. A camming groove  376  is formed in the exterior of the cylinder  364 , with the groove twisting approximately 90 degrees from its upper end to its lower end. A follower pin  378  projects inwardly from the bracket  372  at an elevation corresponding to collar portion  374  to extend into the groove  376 . It will be appreciated that as rod  368  is extended the follower bracket  372  is moved downwardly and simultaneously rotated about the longitudinal axis of the cylinder assembly  362 . Correspondingly, when the rod  368  is retracted, the follower bracket  372  is raised upwardly and simultaneously rotated in the reverse direction due to the follower pin  378  riding within groove  376 . 
     The follower bracket  372  includes a lower flange portion  380  having a center bore formed therein for receiving the upper portion of slide rod  382 . Ideally, a bushing is disposed between the slide rod  382  and the center bore of the flange  380 . A suction tip or head  384  is secured to the lower end of the slide rod  382 , which tip/head is in fluid flow communication with a venturi  386  attached to and interconnected in fluid flow communication with the suction tip  384  by a nipple  388 . The venturi  386  is similar to venturi  270 , discussed above and is capable of generating a reduced pressure supply for the suction tip  384 . A bellows-type pickup cup  390  is secured to the lower end suction tip  384  for physically interfacing with portioned workpieces PP. 
     A compression spring  392  encircles the slide rod between the suction tip  384  and the bottom side of the flange  380  thereby to nominally retain the slide rod extended transversely relative to the follower bracket  372  while allowing the slide rod to retract upwardly relative to the follower bracket  372 , for instance, when the follower bracket is being lowered and the pickup cup  390  makes contact against the upper side of the portioned workpiece. A retaining nut  394  is positioned on the upper end of the slide rod  382  to prevent the slide rod from downwardly disengaging from the flange  380 . A vertical groove  396  is formed lengthwise in the exterior of the slide rod  382  and is sized to closely receive the end portion of a transverse pin  398  spanning across the inside diameter of flange  380  so as to keep the slide rod from rotating relative to the follower bracket  372 . 
     Next, referring to  FIG. 6A , a pickup device  400  includes linear actuator similar to that shown in  FIG. 5  having a threaded extension  401  projecting from the end of rod  402 . The extension  401  is bolted to an attachment bracket  404  with nuts  406 . Bracket  404  includes a reduced thickness flange portion  408  having the clearance hole formed therein for receiving a hub  409  therein. A hollow slide rod  410  is sized to be closely slidably receivable within the hub  409 . In a manner similar to a slide rod  382 , the slide rod  410  is adapted to retract upwardly relative to flange  408  when pushed upwardly from the bottom, but is urged in nominal downward position by an extension spring  412  that encircles the slide rod and bears against a washer  414  positioned beneath hub  409 . A T-connector  422  is attached to the lower end of the hollow slide rod  410 , which T-connector includes an inlet nipple  424  connected to a source of pressurized air through line  426 . A bellows-type pickup cup  428  is attached to the lower end of the T-connector  422  by a nipple  430 . A threaded nipple fitting  432  is attached to the upper end of the slide rod  410  through the use of a collar  434 . A line  436  supplies a partial vacuum to the hollow slide rod  410  and suction cup  428  from a vacuum source (not shown), for instance a venturi similar to venturi  386  in  FIG. 5 . 
     As also illustrated in  FIG. 6A , a horizontal hold down foot  440  is attached to the lower end of a slide rod  442 . The upper portion of the slide rod slidably engages through a close fitting clearance hole formed in bracket  404 . A cap  444  is secured to the upper end of the slide rod to prevent the slide rod from sliding downwardly out of engagement with the bracket  404 . In a manner similar to compression spring  412 , a compression spring  446  nominally draws the slide rod  442  to a downward position, shown in  FIG. 6A . The upper end of the compression spring bears against a washer  448  positioned beneath the bracket  404 , while the lower end of the spring bears against the upper surface of a stop collar  450 . A set screw  452  engages through a threaded hole extending through collar  450  to lock against the outer surface of the slide rod  442 . 
     In operation when the rod  402  is lowered far enough, the hold down foot  440  bears against the workpiece. The slide rod is capable of retracting upwardly relative to bracket  404 , as the rod  402  is further lowered so as to impart a maximum load in the workpiece even as the rod  402  is further lowered. As the rod is lowered further, the pickup cup  428  engages the workpiece portion to be lifted up through the vacuum action applied to the suction cup through hose  436  attached to the upper end of the hollow slide rod  410 . Thereafter, as the rod  402  is retracted upwardly to lift the workpiece portion attached to cup  428 , the hold down foot  440  retains pressure against the upper side of the workpiece surrounding the workpiece portion PP to be carried away. In this manner, the hold down foot assists in making sure that the portioned workpiece being lifted away is cleanly detached from the remainder of the workpiece. 
     In top view, the foot may be C-shaped, D-shaped, loop-shaped, circular or of other shape to suit the shape of the workpiece being cut. In addition, as shown in  FIGS. 6C and 6D , the foot may have a sharpened downwardly extending edge to also cut the workpiece surrounding the portion to be lifted away. In plan view, the cutter type feet may be shaped to correspond with the circumference of the workpiece to be carried away. In this manner, the cutter foot helps to further cut the workpiece to be carried away from the remainder of the workpiece, if a clean cut has not occurred previously. 
       FIG. 6E  illustrates a pickup device  460  which is similar in construction to pickup device  400 , but utilizing a different hold down system  462 . The components in  FIG. 6E  that correspond to the components of  FIG. 6A  are identified with the same part number, but with the addition of a prime symbol. For expediency the construction and function of these components will not be repeated here. 
     The hold down assembly  462  includes an elongated roller  464  axled to the lower end of a trailing pivot rod  466 . The upper end portion of the pivot rod is pinned to the lower end of a bracket  468  to pivot about axis  469 . The bracket  468  depends downwardly from the underside of a flat mounting plate  470  attachable to the underside of a cabinet  156  (not shown). A torsion spring  472  is positioned relative to axis  469  to impart a downward force on the lower end of the pivot rod  466 . A stop screw  474  engages through a threaded crosshole formed in the upper end portion of the pivot rod to bear against the under surface of mounting plate  470  to nominally position the roller  464  relative to conveyor belt  60 . 
     It will be appreciated that the roller  464  imparts a downward retaining force on the workpiece adjacent to the workpiece portion PP that is being lifted away by the pickup device  460 . To this end, the roller  464  may have a serrated outer perimeter to provide better traction against the workpiece. The roller  464  ideally is of sufficient length to span across the width of the workpiece as shown in  FIG. 6E . 
     The pickup device  480  shown in  FIG. 7  also includes a linear actuator having a downwardly extendable rod  482  attached to the upper end of a hollow tube  484  which has an outside diameter to closely and slidably engage through a slide hub  486 . A stop washer  487  is attached to the lower end of tube  484  and has an outer diameter that underlies a bottom edge of the slide hub  486  to prevent the slide tube from slidably disengaging in the downward direction from the hub  486 . A compression spring  488  bears against a stop cap  490  fixed to the upper end of the tube  484 . The cap  490  has a central clearance hole for receiving the lower threaded tip portion  492  of the rod  482  therein, thereby to attach the rod to the tube  484 . The lower end of the compression spring  488  bears against the upper end of the slide hub  486  to nominally push the slide hub downwardly against the stop washer  487 . The upper end portion of a generally U-shaped yoke  494  is attached to the exterior of the slide hub  486  at diametrically opposed locations on the slide hub, and a hold-down foot  496  is attached to the lower end of the yoke  494 . The hold down foot  496  functions in a manner similar to the hold down foot  440  shown in  FIG. 6A . 
     A slide tube  498  engages closely within a hollow slide hammer  500  fixedly attached to a cross member  502  fixed within tube  484 . The slide hammer  500  carries and positions the slide tube  498  while allowing the slide tube to slide within the slide hammer. An end cap  504  closes off the upper end of the slide tube  498  and also is sized to prevent the tube  498  from downwardly detaching from the slide hammer  500 . A compression spring  506  nominally positions the slide tube  498  downwardly relative to the slide hammer  500 . The upper end of the compression spring bears against the underside of the slide hammer  500 , while the lower end of the spring  506  bears against a tube cross fitting  508  attached to the lower end of the slide tube  498 . One or more vacuum generators or venturis  510  and  512  are connected in fluid flow communication with the fitting  508 . A bellows cup  514  is attached in fluid flow communication beneath the fitting  508  by a nipple  516  in a manner similar to the pickup devices described above. 
     The pickup device  480  shown in  FIG. 7  operates in a manner similar to the pickup devices described above, with the hold down foot  496  bearing against the workpiece around the perimeter of the portion workpiece PP to be lifted upwardly. In this regard, when the actuator rod  482  is extended downwardly, the hold down foot  496  bears against the workpiece with the applied load determined by the size or other parameters of compression spring  488 . As the rod  482  continues to extend downwardly to engage the bellows cup  514  with the workpiece PP portion to be lifted up, the slide hub  486  slides relative to the tube  484 . Thereafter, when the rod  482  is being retracted upwardly to lift the workpiece portion off of the conveyor, the hold down foot  496  retains pressure against the upper side of the surrounding workpiece thereby to assist in detaching the workpiece portion from the surrounding workpiece if needed, for example if the workpiece portion is not cleanly cut from the remainder of the workpiece. 
     While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.