BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is broadly concerned with apparatus and methods for inversion of bodies, and particularly pork bellies during processing thereof. More particularly, the invention is concerned with such apparatus and methods wherein a body to be inverted is directed towards a rotatable drum, the body is clamped to the drum, and through further rotation of the drum the body is inverted and deposited onto exit structure permitting downstream processing of the body. 
         [0003]    2. Description of the Prior Art 
         [0004]    In conventional processing of pork bellies, the skinned bellies are placed on a first moving belt. Trimmers working astride the belt trim and detail the moving bellies. Next, the bellies are manually inverted and placed on a second belt so as to expose the undersides of the bellies on the second belt. The second belt runs slower than the first belt, creating an inversion/transfer point which is dangerous and can lead to hand injuries. Additional workers downstream of the inversion/transfer point can then trim the now-exposed undersides of the bellies. After this trimming operation, the bellies are commonly brined for production of bacon. The manual inversion process is highly labor-intensive, owing to the fact that the bellies typically weigh 16-24 lbs. Hence, the personnel inverting the bellies are prone to over-exertion and repetitive motion injuries. 
         [0005]    There is accordingly a real and unsatisfied need for apparatus to carry out pork belly inversions without the need for significant manual labor. However, providing such equipment is not a straightforward matter. This stems from the fact that the bellies are of varying weights and dimensions, and moreover may be in different conditions, e.g., partially frozen or completely fresh. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention overcomes the problems outlined above and provides apparatus for inverting bodies of meat, such as pork bellies, without the need for manual lifting and turning thereof. The apparatus of the invention broadly comprises a rotatable drum including a clamping assembly operable to clamp the body of meat to the drum, and to release the body of meat after inversion thereof. Entry structure, such as a conveyor, is used to deliver incoming bodies of meat to the inversion drum; similarly, exit structure is provided to convey the released body of meat away from the drum. 
         [0007]    In preferred forms, the drum is made up of an inner drum subassembly and an outer drum subassembly. Coupling mechanism is provided to selectively interconnect the outer drum subassembly to the inner drum subassembly during rotation of the latter. Such coupling structure may be in the form of one or more lock pin cylinders operably attached to one of the drum subassemblies and including a shiftable rod, with a series of apertures provided on the other of the drum subassemblies. The lock pin cylinder is operable to extend the rod into one of the apertures in order to interconnect the drum subassemblies. 
         [0008]    The drum clamping assembly preferably comprises an elongated, transversely extending clamping rod and structure supporting the clamping rod for selective movement thereof toward and away from the drum. The support structure may comprise a pair of shiftable mounting struts secured to the opposed ends of the clamping rod, with a piston and cylinder assembly operably coupled with at least one of the mounting struts and operable to selectively move the clamping rod toward and away from the drum. 
         [0009]    In the method of the invention, a body of meat is directed towards a rotatable drum and is clamped to the drum. The drum is caused to rotate in order to invert the body of meat, whereupon it is released from the drum and conveyed in an inverted position away from the drum. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of an inversion device in accordance with the invention, depicting the exit end thereof and illustrating the main drive assembly; 
           [0011]      FIG. 2  is a perspective view similar to that of  FIG. 1 , but showing the outer drum subassembly position sensing arrangement; 
           [0012]      FIG. 3  is a perspective view of the inversion device, viewing the input end thereof; 
           [0013]      FIG. 4  is a plan view of the inversion device; 
           [0014]      FIG. 5  is a vertical sectional view taken along the line  5 - 5  of  FIG. 4 , and illustrating the internal components thereof; 
           [0015]      FIG. 6  is a vertical sectional view taken along the line  6 - 6  of  FIG. 4 , and illustrating further details of the device; 
           [0016]      FIG. 7  is a vertical sectional view taken along the line  7 - 7  of  FIG. 4 , and illustrating details of the drum and exit conveyor; 
           [0017]      FIG. 8  is a perspective view of the drum of the inversion device, with one of the conveyor lift cams removed to better illustrate the construction of the drum; 
           [0018]      FIG. 9  is a perspective view of the inner drum subassembly; 
           [0019]      FIG. 10  is a perspective view of the outer drum subassembly; 
           [0020]      FIG. 11  is a partial vertical sectional view illustrating one of the rotary unions used for supplying positive pressure air to the operating cylinders of the device; 
           [0021]      FIG. 12  is a fragmentary perspective view in partial vertical section illustrating the operation of a lock pin cylinder operable to interconnect the inner and outer drum subassemblies; 
           [0022]      FIG. 13  is a fragmentary view in partial vertical section further illustrating the operation of a lock pin cylinder; 
           [0023]      FIG. 14  is a partially schematic side view of the device illustrating the approach of a pork belly to be inverted; 
           [0024]      FIG. 15  is a view similar to that of  FIG. 14 , but illustrating the pork belly advanced onto the inversion drum of the device; 
           [0025]      FIG. 16  is a view similar to that of  FIG. 15 , but illustrating the pork belly clamped to the inversion drum; 
           [0026]      FIG. 17  is a view similar to that of  FIG. 16 , but illustrating the pork belly rotated towards the exit conveyor while still being clamped to the inversion drum; 
           [0027]      FIG. 18  is a view similar to that of  FIG. 17 , depicting the pork belly fully inverted and partially on the exit conveyor, but still clamped to the inversion drum 
           [0028]      FIG. 19  is a view similar to that of  FIG. 18 , but illustrating the pork belly as it is being unclamped from the inversion drum; 
           [0029]      FIG. 20A  is the first portion of a schematic flow diagram setting forth the preferred normal sequence of operation of the inversion device; 
           [0030]      FIG. 20B  is a continuation of the flow diagram of  FIG. 20A , under a first operational condition respecting the sensed positions of succeeding meat bodies entering the device; and 
           [0031]      FIG. 20C  is a continuation of the flow diagram of  FIGS. 20A and 20B , under a second operational condition respecting the sensed positions of succeeding meat bodies entering the device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]    Turning now to the drawings, an inversion device  30  is illustrated in  FIGS. 1-4  and broadly includes an inversion drum  32 , an entry conveyor  34 , and exit conveyor  36 . These components are supported by a floor-mounted frame assembly  38  and are situated within a housing  40 . Although not shown, it will be appreciated that the operating components of device  30  are covered by appropriate guards and the like. 
         [0033]    The inversion drum  32  comprises an inner subassembly  42  ( FIG. 9 ) and a surrounding outer subassembly  44  ( FIG. 10 ). The inner subassembly  42  includes a pair of circular end plate assemblies  46  and  48  as well as a surrounding cylindrical slotted wall  50 . As illustrated in  FIGS. 1-4 , the entire subassembly  42  is supported on a central, transversely extending shaft  52 . The outer ends of shaft  52  are supported on bearings  54  secured to housing  40 , as shown. Each end plate assembly  46 ,  48  includes a circular, spoked member  58  and an outer annular plate  60  having a plurality of apertures  61  therethrough. A drive sprocket  56  is secured to the extreme lefthand end of shaft  52 , as viewed in  FIG. 9 . The end plate assemblies  46  and  48  are keyed to shaft  52  by means of couplers  62  so that the end plates and wall  50  rotate with the shaft  52 . 
         [0034]    A primary drive motor  66  is located within housing  40  and has a variable frequency drive within the motor control cabinet thereof. The motor is coupled with a gear reducer assembly  68  having an output shaft  70 , and a sprocket  72  keyed to the latter. A drive chain  74  is trained around the sprockets  72  and  56  for powered rotation of the inner subassembly  42 . 
         [0035]    The outer subassembly  44  ( FIG. 8 ) is disposed about the inner subassembly  42  and includes a pair of end plates  76  and  78 , respectively adjacent the end plates  46  and  48  of inner subassembly  42 . Each of the end plates  76 ,  78  has a tubular, outwardly projecting extension sleeve  80  which receives shaft  52 ; a bushing  82  is provided between the shaft  52  and extension sleeve  80  ( FIG. 11 ). A series of elongated, transversely extending, circumferentially spaced, stationary support elements  84  are connected to and between the plates  76 ,  78 . 
         [0036]    The plates  76 ,  78  both have a pair of opposed pneumatic lock pin cylinders  86 , each including a shiftable rod  88  sized to fit within a selected aperture  61  of an adjacent plate  60  (see  FIGS. 12 and 13 ). Additionally, each plate  76 ,  78  carries a pair of opposed, transversely extending, radially shiftable clamping rods  90 . Each of these rods is supported by a pair of end-mounted struts  94  shiftable within guides  95 . The struts  94  are in turn operatively connected to a respective pivot link  96 . Pneumatic clamping piston and cylinder assemblies  98  are also supported on each plate  76 ,  78 , with the pistons thereof coupled to a corresponding link  96 , in order to effect selective radial movement of the clamping rods  90 . A pair of opposed clamping rod-receiving notches  100  are provided in each of the plates  76 ,  78  ( FIG. 10 ) to accommodate full inward shifting of the clamping rods. The plates  76 ,  78  also carry a pair of opposed, stationary cams  102  at a position adjacent the clamping rods  90 . Finally, the right extension  80 , as viewed in  FIGS. 10 and 11 , includes a circular sensing plate  104  which carries a pair of opposed, projecting dowels  106  and  107  which extend in opposite directions from the plate  104  ( FIG. 7 ). 
         [0037]    In order to supply positive pressure air to the lock pin cylinders  86  and the clamping rod piston and cylinder assemblies  98  on demand, a rotary union  108  is keyed to each of the extension sleeves  80 . A source of pressurized air (not shown) is directed to each union  108 , and appropriate pneumatic lines  110  extend from each union  108  to the associated cylinder  86  or assembly  98 . 
         [0038]    The entry conveyor  34  ( FIG. 6 ) includes a first wire mesh conveyor belt  112  mounted on a frame  114  and trained about end sprockets  116 . A pair of optical sensors  118  are supported on frame  114  and are positioned in opposition above belt  112 . The conveyor  34  is powered by means of a drive chain  120  ( FIG. 5 ), which is coupled with a sprocket  122 , the latter rotated via drive shaft  70 . The chain  120  is also trained about an upper sprocket  126  keyed to transverse shaft  128  ( FIG. 6 ). The shaft  128  also supports the end sprocket  116  nearest inversion drum  32 , as well as a second pivoting frame  130 , such that shaft  128  defines the pivot axis for the frame  130  and frame  114 . The outermost end of the shaft  128  is further equipped with a small sprocket  144  ( FIG. 4 ). The inclination of belt  112  can be altered by means of connectors (not shown) which mate with selected apertures  134  ( FIG. 5 ) provided in housing extensions  136  on opposite sides of the belt  112 . 
         [0039]    The overall entry conveyor  34  ( FIG. 6 ) includes a second wire mesh conveyor belt  138  supported by the pivoting frame  130 , which also support the end sprockets  140  on respective shafts  142 . The end of shaft  142  ( FIG. 4 ) closest to belt  112  has a sprocket  132  keyed thereon ( FIG. 4 ). A short drive chain  146  is trained about sprockets  132  and  144 , so as to drive the belt  138 . 
         [0040]    It will be observed that the shaft  128  forms a pivot for both of the conveyor belts  112  and  138 . The belt  112  can be adjusted in terms of its inclination, as previously described. Moreover, owing to this construction of the entry conveyor  34 , the entirety of belt  138  is also pivotal about shaft  128  through the medium of the pivoting frame  130 . The importance of this feature will be made clear hereinafter. 
         [0041]    The exit conveyor  36  is disposed below the drum  32  and includes a frame assembly  148  ( FIG. 6 ) supporting two sets of end sprockets  150 . A belt  152  is trained about the sprockets  150  and serves to convey inverted product away from the drum assembly  32 . The belt  152  is powered by means of a motor  154  also including a variable frequency drive, and a gear reducer assembly  156 , the latter being operatively coupled with upper sprockets  150 . 
         [0042]    Operation of the device  30  is controlled by means of a conventional, programmable digital controller (not shown) and the variable frequency drives for each motor  66  and  154 . The optical sensors  118  are operatively coupled with the controller, along with a pair of proximity sensors  158  and  160 . As best seen in  FIGS. 2 and 7 , the sensors  158 ,  160  are supported on opposite sides of the sensing plate  104 , such that the sensor  158  senses the proximity of dowel  106 , whereas sensor  160  senses dowel  107 . The variable frequency drives (not shown) and motors  66  and  154  are also operatively connected with the controller. 
         [0043]    In order to selectively operate the cylinders  86  and  98  ( FIG. 5 ), conventional solenoid valves (not shown) are coupled between the digital controller and the unions  108 . Thus, when these cylinders are to be operated, the digital controller signals the appropriate solenoid valve to effect the desired cylinder operation. These electrical and pneumatic control elements are themselves conventional, and thus need not be described in detail. 
       Operation 
       [0044]    The operational sequence of device  30  is illustrated in pictorial  FIGS. 14-19  and in the flow diagram of  FIG. 20 . In general, the operational sequence involves first conveying a body  162  to be inverted using entry conveyor  34  ( FIG. 14 ) until the body  162  passes under one of the clamping rods  90  of the rotating outer drum subassembly  44  ( FIG. 15 , referred to as clamping rod  90 A). Then rod  90 A is moved radially inwardly by operation of the associated cylinders  98 A to clamp the body  162  against the outer subassembly  44  ( FIG. 16 ). Simultaneously, the outer subassembly  44  is engaged with the inner subassembly  42  through actuation of the lock pin cylinders  86 A, so that the two subassemblies rotate in unison. Next, the drum  32  rotates so as to invert the body  162  above conveyor belt  152 , and also causes the cams  102 B to pivot belt  138  upwardly, allowing the other opposed clamping rod  90 B to pass beneath the belt in its outwardly extended condition while a second body  164  is being delivered via entry conveyor  34  ( FIG. 17 ). The drum  32  continues to rotate until the majority of the body  162  is placed on moving belt  152  and the second body  164  passes under clamping rod  90 B ( FIG. 18 ). In the next steps, the cylinders  98 A operate to shift clamping rod  90 A radially outwardly to thereby release the now-inverted first body  162  onto conveyor belt  152 , and cylinders  98 B retract rod  90 B to clamp body  164  to drum  32 . This sequence of steps then continues as successive bodies are delivered to the device  30 , inverted, and moved downstream on exit conveyor  152 . 
         [0045]    Referring to the block diagram of  FIGS. 20A-20C , a more detailed description of the normal operation of device  30  is provided, using two different operational conditions respecting the relative sensed positions of succeeding meat bodies  162 .  164 , at the entrance conveyor  112 . Where appropriate, the reference numerals used in the preceding Figures have been employed. “Solenoid Valve A” and “Solenoid Valve B” refer to the conventional solenoid valves operatively connected to the cylinders  86 A,  86 B,  98 A, and  98 B described previously. The other references are to conventional control hardware and steps well known to those skilled in the art, including the lockout valve, E-stops, and the timers. 
         [0046]    It will thus be appreciated that device  30  is able to efficiently invert meat bodies such as pork bellies on a continuous basis while completely eliminating manual labor. The device has a number of unique features which render it particularly useful in this connection. For example, the provision of the cams  102  together with pivotal mounting of the conveyor belt  138  makes it possible to maintain the adjacent clamping rod  90  in an extended condition as it clears the belt  138 , so as to facilitate entry of an incoming pork belly into the space between the clamping rod and drum  32 . Additionally, belt  138  fills the gap between belt  112  and drum  32  to convey “limp” or fresh bellies successfully to the drum  32  without the bellies falling between the belt  112  and drum  32 . Additionally, both of the entry conveyor belts  112 ,  138  are powered using a single drive shaft and the belt  38  continues its movement even during upward pivoting thereof. In this same regard, the inclination of the conveyor belt  112  can be adjusted without the need for disconnecting the drive. The use of the lock pin cylinders  86  also allows quick, reliable interconnection of the inner and outer drum subassemblies  42 ,  44  in properly timed relationship.
A device ( 30) is provided for the inversion of bodies of meat (e.g., pork bellies 162, 164) during processing thereof in order to eliminate the manual labor involved in conventional packing house operations. The device ( 30) includes a rotatable inversion drum ( 32) made up of inner and outer drum subassemblies ( 42, 44), which are selectively interconnected by means of lock pin cylinders ( 86). An entry conveyor ( 34) serves to direct incoming meat bodies to the drum ( 32) and an exit conveyor ( 36) is provided to convey inverted meat bodies away from the drum ( 32). In preferred forms, the drum ( 32) has a pair of circumferentially spaced apart, elongated, transversely extending clamping rods ( 90), which are selectively shiftable towards and away from the drum ( 32) in order to sequentially clamp an incoming meat body to the drum ( 32) during rotation thereof, and to release the meat body after inversion thereof onto exit conveyor ( 36). The operation of device ( 30) is controlled by appropriate sensors ( 118, 158, 160) operably coupled with a digital controller.