Patent Publication Number: US-2023141518-A1

Title: High speed nut cracking apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of PCT Application No. PCT/US2021/037872 filed on Jun. 17, 2021, which claims the benefit of U.S. Provisional Application No. 63/040,349 filed on Jun. 17, 2020, both applications of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     Nut cracking apparatus for cracking nuts generally include an endless conveyor that delivers nuts to a rotating turret. Nuts are cracked by providing a motive force for a shuttle to impact a crack die in which a nut is held. The current disclosure is directed to a high speed compact nut cracking apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a rear end view of the nut cracking apparatus. 
         FIG.  2    is a perspective view showing the front and right sides of the nut cracking apparatus. 
         FIG.  3    is a view from line  3 - 3  of  FIG.  1   . 
         FIG.  4    is a view from line  4 - 4  of  FIG.  1   . 
         FIG.  5    is a view showing the turret and motor with the door and an outer panel removed. 
         FIG.  6    is a partially exploded view of the rotatable turret of the nut cracking apparatus. 
         FIGS.  7 - 10    show an exploded view of the rotated turret. 
         FIG.  11    is a view of the rotatable turret mounted in the frame of the nut cracking apparatus. 
         FIGS.  12 - 17    show the direction of the section views for  FIGS.  18 - 23   . 
         FIG.  18    is a section view from line  18 - 18  of  FIG.  12   . 
         FIG.  19    is a section view from line  19 - 19  of  FIG.  13   . 
         FIG.  20    is a section from line  20 - 20  of  FIG.  14   . 
         FIG.  21    is a line from section  21 - 21  of  FIG.  15   . 
         FIG.  22    is a section from line  22 - 22  of  FIG.  16   . 
         FIG.  23    is a section from line  23 - 23  of  FIG.  17   . 
         FIG.  24    is a view of the exit end of a shuttle cylinder housing. 
         FIG.  25    is a view of the entry end of the shuttle cylinder housing. 
         FIG.  26    is a perspective view of a shuttle cylinder housing. 
         FIG.  27    is a view of the exit end of the center hub. 
         FIG.  28    is a view of the entry end of the center hub. 
         FIG.  29    is a view of the exit end of a cylinder seal plate. 
         FIG.  30    is a view of the entry end of the cylinder seal plate. 
         FIG.  31    is a view of the exit end of a cylinder head plate. 
         FIG.  32    is a view of the entry end of the cylinder head plate. 
         FIG.  33    is perspective view showing the exit end of a cylinder front plate. 
         FIG.  34    is a view showing the entry end of the cylinder front plate. 
         FIG.  35    is a view of the exit end of a piston cylinder body. 
         FIG.  36    is a view of the entry end of the piston cylinder body. 
         FIG.  37    is a perspective view of a cylinder end plate segment. 
         FIG.  38    is a view looking at the side of a cylinder end plate segment. 
         FIG.  39    is a side view of a cylinder end plate segment. 
         FIG.  40    is a view of the exit end of the exit face of a valve. 
         FIG.  41    is a view of the entry end of the valve. 
         FIG.  42    is a perspective view of the valve. 
         FIG.  43    is a view of the interior of a valve cover plate. 
         FIG.  44    is a view of the exit end of a valve adapter plate. 
         FIG.  45    is a view of the entry end of the valve adapter plate. 
         FIG.  47    is a perspective view of the valve adapter plate. 
         FIG.  46    is a side view of the valve adapter plate. 
         FIG.  48    is a view of the entry end of the valve plate with the valve positioned adjacent thereto. 
         FIG.  49    is a cross section of an alternate embodiment of a piston. 
     
    
    
     DESCRIPTION OF AN EMBODIMENT 
     A high speed nut cracking apparatus  5  has a rear end  10 , a forward end  15 , a left or first side  20  and a second or right side  25 . A door  30  is pivotally connected by a hinge or otherwise to the frame and is movable between open and closed positions. Thee nut cracking apparatus is an internally ported nut cracker  5 , in that there are no external hoses or other external means used to provide air to the moving parts of the apparatus. As is explained in more detail below, the nut cracking apparatus  5  has a movable piston and a shuttle that interact to crack nuts. The air that moves the piston and the shuttle is provided directly through passageways defined through a rotating turret. The passageways that deliver air to the cylinders in which the pistons and the shuttles are positioned are completely contained within the rotating turret. The nut cracking apparatus  5  can crack nuts at a high speed which may vary, depending on the size of the particular nut being cracked. The nut cracking apparatus  5  may exceed a rate of at least 750 nuts/minute, and in some cases much higher, for example 950 nuts/minute. Nut cracking apparatus  5  may for example have an overall size of, for example about 27.2 inches wide, 21.7 inches high and 40.2 inches long, when the apparatus  5  is in position over a conveyor without legs attached. Known nut crackers capable of cracking nuts at such speeds are much larger. The apparatus  5  of the current disclosure eliminates parts, for example air hoses, and a piston rod extension, which allows a sizable reduction in the width and length of high speed nut cracking apparatus. The elimination of the air hoses is possible as a result of providing the air passageways through the turret to move the pistons and shuttles within the turret. 
     In addition to having a much smaller footprint than known crackers, the nut cracking apparatus  5  provides for the removal and replacement of internal parts with little disassembly, and with the ability to make certain that replacement of parts is accurate and easy. Nut cracking apparatus  5  includes a frame  31  with a left side  32 , right side  34 , rear  36  and forward side  38 . Frame  31  in the embodiment shown is positioned on legs  33 . The height of apparatus  5  with legs  33  attached is about 50.7 inches. Nut cracking apparatus  5  includes a top  39  and a bottom  40 . Top  39  has an open portion through which nuts to be cracked are delivered. Cracked nuts may pass through the bottom of the frame  31  to a conveyor or other apparatus, and may be delivered to the conveyor or other apparatus with a chute  41  that receives the cracked nuts. 
     A turret  43  is rotatably mounted in frame  31 . Rotatable turret  43  includes a plurality of nut cracking units  42 . Nut cracking units  42  are utilized to hold and crack nuts as turret  43  rotates. Nut cracking units  42  have longitudinal central axis  44 . A motor  46  which may be a variable speed drive motor is mounted to frame  31  with brackets  48  or other means known in the art. 
     A drive sprocket  50  is rotated by motor  46 . A drive chain  52  engages drive sprocket  50 . Nut cracking apparatus  5  includes a first follower sprocket  54  and a second follower sprocket  56 . First and second follower sprockets  54  and  56  rotate about bearings mounted to brackets attached to frame  31  in a manner known in the art. A turret sprocket  58  is connected to turret  43  and will rotate turret  43  about a shaft  97 . An endless conveyor drive sprocket  60  is connected to a shaft  70  and will rotate therewith. Endless conveyer  62  is driven by conveyor drive sprocket  60 . 
     A center divider  64  is mounted to the frame and separates the frame into a hopper portion  66  which has an open top  67  into which nuts are provided and a drive portion  68  which includes the majority of the working and moving parts. 
     Shaft  70  is rotatably mounted in first bearing  72  that is connected to frame  31  on the right side thereof. Shaft  70  extends through drive portion  68  and is rotatably mounted in a second bearing  74  that is mounted to center divider  64 . Shaft  70  extends therethrough into the hopper portion  66 . Endless conveyor  62  is supported by and slides over a slide  63  connected in frame  31 . Endless conveyor  62  is mounted on a forward chain sprocket  76  and a rear chain sprocket  78 . Forward chain sprocket  76  is fixed to shaft  70  and rotates therewith. The rotation of forward sprocket  76  moves the chain from the rear to the forward end of the nut cracking apparatus  5 . Endless conveyor  62  comprises a nut chain  80  fixed to a roller chain  82 . Roller chain  82  engages forward chain sprocket  76 . Nut chain  80  defines a plurality of nut pockets  84 . Nuts delivered into hopper  66  will be received in nut chain pocket  84  and delivered to a pick up point  86  at which the nut cracking units  42  will engage a nut carried in one of the nut pockets  84 . In one embodiment pickup point  86  is just before a nut cracking unit  42  reaches bottom dead center, for example between 1 and 10 degrees, and in one embodiment between 2 and 5 degrees and in one embodiment about 3 degrees prior to bottom dead center. The foregoing values are exemplary only and not limiting. Nuts delivered into hopper  66  will fall downward on chute  41 . Nuts will gather on a floor  90  which may be a vibrating floor  90 . The vibration of floor  90  will encourage nuts to pass into nut pockets  84 . Slide  63  may have a curved upper surface. The curved upper surface of slide  63  will create a curvature in the endless conveyor  62  and may aid in allowing nuts to properly seat in nut pockets  84 . A vibrator  92  of a type known in the art may be utilized to vibrate floor  90 . A plurality of deflectors  94  are attached to center divider  64  to remove nuts that may be carried improperly and to ensure only one nut is carried in a nut pocket. Nuts are delivered into open upper end  67  into hopper  66 .  FIGS.  43  and  46    show a vibrator mount plate  91  to which vibrator  92  is mounted. Pan to vibrator mounts  93  translate the vibration of the vibrator  92  to the floor  90 . The view shows a slot  95  which allows the mount plate  91  to reciprocate in the rear to forward direction. 
     Rotatable turret  43  is mounted on shaft  97  that is fixed at both ends to frame  31 . Turret  43  will rotate about shaft  97  on bearings  98  and  99 . Spacers  101  and  103  may be positioned on shaft  97  as needed. Rotatable turret  43  includes a valve plate  100  which is a rotatable valve plate  100 . Rotatable valve plate  100  is positioned in a valve plate housing  102 . A valve seal  104  is positioned in valve plate housing  102  between an end plate  106  of valve plate housing  102  and valve plate  100 . A valve gasket  108  is positioned between valve plate  100  and a shuttle cylinder housing  110 . Valve plate  100  is mounted to shuttle cylinder housing  110  with a plurality of fasteners  112  extending through openings  114  in valve plate  100  and threaded into corresponding openings in shuttle cylinder  110 . Shuttle cylinder housing  110  has a plurality of shuttle cylinders  116  extending therethrough. Shuttle cylinder housing  110  has an air entry end  115  and an air exit end  117 . A plurality of shuttles  118  are received in shuttle cylinder housing  110 , and more specifically a single shuttle  118  is received in each of shuttle cylinders  116 . Shuttles  118  may comprise generally cylindrical shuttles. A shuttle return seal  120  is positioned at a first, or rear end  122  of each shuttle cylinder  116  and will be positioned between valve plate  100  and shuttle  118 . Shuttle cylinders  116  have forward end  124 , and when air is applied at rear end  122 , shuttle  118  will move toward a crack die  130  to impact crack die  130  and crack a nut that is engaged therewith. Air is applied through entry end  115  directly to the rear end of shuttle cylinder  116  to move the shuttle  118  toward the forward end  124  and into crack die  130 . Shuttle cylinder  116  has an air passageway from the entry end  115  to the exit end  117 . Air is provided therethrough to move the shuttle  118  from the forward end  124  to the rear end  122  of shuttle cylinder  116  to reset the shuttle to move once again toward the crack die  130 . 
     A plurality of crack dies  130  are positioned in a crack die holder  132 . Crack dies  130  have impact face  129  and a nut holding face  131 . Nut holding face  131  may comprise a generally V-shaped nut holding face for engaging and holding a nut to be cracked. Crack dies  130  can be removed and replaced so that different sizes of nuts can be easily accommodated and cracked with nut cracking apparatus  5 . Crack dies  130  may be held in place in a crack die holder  132  with crack die seals  134 . Crack die holder  132  is mounted to an end of shuttle cylinder housing  110  with a plurality of fasteners  136  extending through openings  138  and threaded into openings in shuttle cylinder housing  110 . Thus, the only disassembly required to replace crack dies  130  is the removal of fasteners  136 , which are accessible without removal of any other parts, and replacing the crack dies  130  with those having the desired nut holding face  131  for the size of nut to be cracked. 
     A plurality of fasteners  140  may extend through a central opening  142  in crack die holder  132  and used to connect other parts of turret  43  as explained below. Fasteners  140  extend through openings  144  in shuttle cylinder housing  110  and are threaded into corresponding holes in center hub  150 . 
     Center hub  150  comprises a radially outwardly extending plate  146  in a central portion thereof. Center hub plate  146  has bushing openings  148  therethrough to receive a plurality of guide bushings  147 . Fasteners  145  may be used to hold guide bushings  147  in place. A gasket  152  may be positioned between center hub  150  and shuttle cylinder housing  110 . Center hub  150  has an air entry end  149  and an air exit end  151 . 
     Starting now at the right side of nut cracking apparatus  5  turret sprocket  58  is mounted to a cylinder end plate  154 . Cylinder end plate  154  is a sectioned end plate, and may comprise first and second portions  155  and  156 . Because cylinder end plate  154  is a sectioned end plate, the removal and replacement of selected parts without major disassembly is possible. Cylinder end plate  154  is mounted to a piston cylinder body  160  and may have a gasket  161  therebetween. Piston cylinder body  160  has an exit end  162  for exiting air, and an entry end  163  for entering air. Fasteners  166  connect turret sprocket  58  to cylinder end plate  154 . Fasteners  168  connect cylinder end plate  154  to cylinder body  160 . A cylinder body gasket  170  is positioned between cylinder body  160  and a cylinder front plate  172 . A cylinder head gasket  174  is positioned between cylinder front plate  172  and a cylinder head plate  176 . A second cylinder head gasket  180  is positioned between cylinder head plate  176  and cylinder seal plate  182 . 
     A plurality of fasteners  184  extend through cylinder seal plate  182 , cylinder head gasket  180  and cylinder head plate  176  and are threaded into cylinder body  160 . A plurality of fasteners  192  extend through a central opening  153  of cylinder end plate  154 , through openings in cylinder body  160 , cylinder body gasket  170 , cylinder front plate  172 , first cylinder head gasket  174 , cylinder head plate  176 , second cylinder head gasket  180 , cylinder seal plate  182  and threaded into openings in center hub  150 . Cylinder head plate  176  has air entry end  186  and air exit end  188 . 
     A plurality of pistons  200  extend through piston cylinders  202  defined in piston cylinder body  160 . Piston  200  comprises a piston head  204 . Piston cylinders  202  have a rear end  201  and a forward end  203 . Piston head  204  may have grooves in which cup seals  206  are placed and may have a wear strip  208  in a groove therebetween. A piston rod  210  extends from piston head  204 . Piston rod  210  has an opening  211  extending for a portion of the length thereof, and is thus hollow for a portion thereof. Nut clamping end  212  may be a V-shaped end  214  which is configured to secure a nut for cracking as will be described in detail herein. Pistons  200  reciprocate between a retracted position  215  and an extended position  216  in which the piston rod extends through guide bushing  147  to secure a nut with crack die  130 . Wiper seals  217  and wear bushings  218  may be used to slidingly and sealingly secure piston rod  210  in cylinder head plate  176 . In order to remove and replace pistons  200 , the only disassembly required is to loosen chain  52 , remove sprocket  58  and one, or both of sections  155  and  156  of cylinder end plate  154 . No removal of hoses or other parts is needed which makes removal and replacement of pistons  200  a simple operation allowing for replacement of worn pistons, or a change to a piston  200  for cracking different sized nuts. 
     In an additional embodiment the piston may comprise a piston  500  with a piston head  502  and a piston rod  504  extending therefrom having a nut clamping end  506 . Piston rod  504  does not have a hollow portion as described with respect to piston rod  210 , and it is understood that the piston rod in either case may be solid, or have a hollow portion, so that the weight of the piston rods can be modified as desired. Nut clamping end  506  may be shaped like nut clamping end  212  of piston  200 . Pistons  500  will move within piston cylinders  202  as previously described with respect to pistons  200 . Piston head  502  has a generally cylindrical center portion  508  with a wear strip  509  which may be for example a DELRIN® ring. Piston head  502  has a rear portion  510  that slopes radially inwardly in a rear direction from center portion  508  and has a forward portion  512  that slopes radially inwardly in the forward direction. Thus, in cross section as shown in  FIG.  49   , the piston head  502  generally has the shape of seven sides of an octagon. 
     In the additional embodiment described, piston cylinders  202  have bumper seals  514  comprising a rear bumper seal  516  and a forward bumper seal  518  which are engaged by piston head  502  in the retracted and extended positions of the piston  500 . Rear bumper seal  516  has an engagement profile  517  which is a generally frustoconical engagement profile  517 . Likewise, forward seal  518  has a frustoconical engagement profile  519 . Rear portion  510  of piston head  502  has mating profile  511  to engage the frustoconical profile on rear seal  516 . Forward portion  512  likewise has an engagement profile  513  that mates with the frustoconical engagement profile  519  on forward seal  518 . The operation of the cracker described herein is identical whether using pistons  200  or pistons  500 . 
     Returning now to the left side rotating valve plate  100  is received in valve housing  102 . A valve  220  is mounted to a valve adapter plate  222  which is in turn connected to a valve cover plate  224 . Valve adapter plate  222  has an air entry side  223  and an air exit side  225 . Valve cover plate  224  has fittings on a side thereof to receive air hoses to provide feed, release, reset and crack air. The openings are identified as a feed opening  226 , a release opening  228 , a reset opening  230  and a crack opening  232 . Air is provided to each opening such that nut cracking units  42  will engage and hold a nut. As the turret  43  rotates, feed air will urge a piston  200  into the extended position  216  to hold a nut against a crack die  130 . Crack air will urge the shuttle  118  in the shuttle cylinder to impact crack die  130  and crack the nut held between a piston  200  and a crack die  130 . Release air is applied to move the piston  200  to the retracted position  215 . Reset air is applied to move the shuttle to the rear end  122  of the shuttle cylinder  116 . Crack air is applied a second time to cause a second impact to crack die  130  to remove any fragments from crack die  130 . Reset air is then reapplied to move the shuttle  118  to the rear end  122  of shuttle cylinder  116 , and the nut cracking unit  42  is ready to repeat the process. Although a particular sequence of the cracking process is described herein, it is understood that other sequences are possible and that described herein is not limiting. The passageways from the valve  220  to the piston  200  that move the piston between the retracted and extended positions  215  and  216  are through the turret  43 . No hoses are needed to provide air to any piston cylinders as is the manner of use in prior art crackers. Thus, each of the components from the valve  220  to the cylinder body  160  and ultimately to the cylinder end plate  154  have ports and passages that communicate air all the way through the turret  43  to move the piston rod  200  between the feed, or extended position  216  and the release, or retracted position  215 . 
     Valve cover plate  224  is internally ported so that the feed, release, reset and crack openings  226 ,  228 ,  230  and  232  respectively are communicated to feed, release, reset and crack openings in valve adapter plate  222 . Openings in valve cover plate  224  include first and second reset openings  240  and  242  a feed opening or feed slot  244 , a release opening or a release slot  246  and a crack opening  248  which is a curved cracked slot opening  248 . An exhaust opening  243  is defined in valve cover plate  224 . Valve adapter plate  222  is connected to valve housing plate  224  with fasteners through opening  226 . Air will pass into and through valve adapter plate  222  from valve housing plate  224 . Valve adapter plate  222  has a plurality of cylindrical extensions extending therefrom. Cylindrical extensions  250 , which may be referred to as bushings  250 , include a feed air extension  252 , a release air extension  254 , a first crack extension  256 , a second crack extension  258 , a first reset extension  260  and a second reset extension  262 . Extension  252  defines a feed opening  264 . Release, first crack, second crack, first reset, and second reset cylindrical extensions  256 ,  258 ,  260  and  262  define release opening  266 , first crack opening  268 , second crack opening  270 , first reset opening  272  and second reset opening  274  respectively. A relief port  275  is defined in valve adapter plate  222 . 
     Air entry face  223  of the valve adapter plate  222  has a crack slot  280  that aligns with crack slot  248  in valve housing plate  224 . Crack slot  280  has first and second crack openings  268  and  270  at opposed ends thereof. A feed slot  282  aligns with feed slot  244  in valve housing plate  224  and has feed opening  264  at an end thereof. A release slot  284  aligns with release slot  246  in valve housing plate  224  and has opening  266  at an end thereof. Appropriate shaped seals  286  may be utilized to seal valve adapter plate  222 , to valve housing plate  224  when connected. 
     Valve  220  has plurality of openings  288  to receive the cylindrical extensions  250 . Valve  220  is placed onto cylindrical extensions  250  which are inserted into openings  288 . Valve  220  has an air exit face  290  positioned adjacent valve plate  100 . Feed and release openings  292  and  294  are defined in valve  220 . Likewise, first and second crack openings  296  and  298  are defined in valve in  220 . Finally, reset openings which comprise first and second reset openings  300  and  302  are defined in valve  220 .  FIG.  47    is a view of the turret with the valve  220  adjacent the rotating valve plate  100  and the valve cover plate  224  and valve plate housing  102  disconnected. Valve  220  extends through a valve opening  303  in valve plate housing  102 . Valve  220  may be allowed to slightly float against valve plate  100  in its installed position. 
     As described herein a nut cracking unit  42  comprises a piston  200  and associated shuttle  118  and crack die  130 . As shown in a number of the figures, each nut cracking unit  42  has a plurality of openings in the turret  43  associated therewith. For example, each nut cracking unit  42  has a feed port  304 , release port  306  a crack port  308  and a reset port  310  associated therewith in valve plate  100 , as shown in  FIG.  45   . As the turret  43  rotates, when the nut cracking unit  42  is ready for receiving a nut shuttle  118  will be at the rear  122  of a shuttle cylinder  116  and the piston  200  will be in a retracted position  215 . Turret  43  rotates clockwise from the vantage point  FIG.  45   . As turret  43  rotates, feed air will pass from feed air opening  264  in valve adapter plate  222  to opening  292  in valve  220  which will align with feed port  304  in valve plate  100 . Feed air will pass through turret  43  and move piston  200  to the extended position  216  where it will hold a nut against crack die  130 . 
     As the turret  43  continues to rotate, crack air will pass through opening  268  in valve adapter plate  222  and into crack opening  296  in valve  220  which will provide air through the crack opening or crack port  308 . Crack air will move shuttle  118  forward to impact crack die  130  and crack a nut. This is the first crack position. Release air is then provided through release air port  266  in valve adapter plate  222  through release air opening  294  in valve  220  and release port  306  in valve plate  100 . Release air will pass through turret  43  and will move piston  200  to the retracted position  215 . Continued turret rotation will cause reset air to pass into the forward end of shuttle cylinder  116  to move the shuttle  118  to the rear  122  of the shuttle cylinder  118 . Reset air passes from reset port  274  in valve adapter plate  222  through reset air port  302  in valve  220  and reset air port  310  in valve plate  100 . This is the second reset position. After the release, a second crack occurs with air provided through second crack port  270  in valve adapter plate  222  and crack opening  308  in valve plate  100 , and then another reset occurs through reset port  272  in valve adapter plate  222  and  300  in valve  220 . This is referred to as the first reset. 
       FIGS.  18 - 23    show the various positions of the nut cracking apparatus  5  and specifically the various positions of the nut cracking units  42 . In the cross sections shown therein, certain features, for example the gaskets  108 ,  170 ,  174  and  161  are not seen simply as a result of the lack of thickness to those features.  FIG.  19    shows the retracted position  215  of piston  200  of a nut cracking unit  42  prior to feed air being received. It also shows release air passage  313  through the turret. As shown therein, air is directed from the valve  220  through the turret  43  in passageway  313  that requires no external hoses or other fittings. Passage  313  is thus completely contained in turret  43 . The retracted position  215  is likewise the release position as this is a position in which each nut cracking unit  42  is ready to be rotated to collect, or pick up a nut and proceed through the cracking process. 
     The extended, or feed position  216  showing a feed air passage  315  is shown in  FIG.  18   . Feed air passage  315  likewise requires no external hose or tubing and air is directed through the turret  43  so that it acts on the rear end  201  of piston cylinder  202  to urge piston  200  to the extended position. In the feed position the piston  200  will hold a pecan or other nut in place and will urge the nut against the crack die  130 . 
       FIG.  20    shows the first crack position  316 . In the first crack position  316  of the nut cracking unit  42  air is fed through valve  220  to the rear end  122  of shuttle cylinder  116  to urge the crack shuttle  118  in a direction toward the crack die  130 . As a result, the nut being held between the piston  200  and the crack die  130  will be cracked. Air is provided directly from valve  220  through valve plated into the rear end  122  of shuttle cylinder  116 . As noted before,  FIG.  19    shows the release position into which piston  200  is moved after the first crack. The second reset position is shown in  FIG.  21    which shows a reset passage  319 . This is referred to as the second reset since it occurs after the initial crack. Air is communicated directly into reset passage  319  from valve  220  through rotating valve plate  100 . Reset passage  319  is defined in shuttle cylinder housing  110  and provides air to the forward end of shuttle cylinder  116  to move shuttle  118  to the reset position. 
       FIG.  22    shows the second crack referred to as the second crack position. The second crack is utilized to remove any shell fragments or other residue that might be lodged in the crack die so that as the nut cracking unit  42  picks up another nut it will maintain a straight efficient cracking position. The crack air for the second crack is provided directly to the rear end  122  of shuttle cylinder  116  through the valve plate  100  after the air exits valve  220 . A first reset position is shown in  FIG.  23   . This is the first reset position in that it is the operation that must occur prior to the rotation of the turret  43  so that the nut cracking unit  42  can engage a nut to proceed with the cracking process. The first and second resets occur through the same passage  319  after the air exits valve  220 . 
       FIGS.  24 - 26    show details of shuttle cylinder  110 . As noted, shuttle cylinder housing  110  has a plurality of shuttle cylinders  116 . Shuttles  118  are positioned in shuttle cylinders  116  for movement therein as described. Each shuttle  118  comprises a part of a nut cracking unit  42 . Shuttle cylinder housing  110  has a reset passage  319  defined therethrough from an entry end  331  to an exit end  332 . A connecting slot  334  is defined in exit end  332  of shuttle cylinder  116  so that reset air will pass through reset passage  319  and be communicated from slot  334  to the forward end  124  of shuttle cylinder  116  to urge shuttle  118  to the rear end  122  of the shuttle cylinder  116 . The reset air for the first reset passes from the valve plate  100  into reset passage  319 . Crack air is provided directly to the rear end of the shuttle cylinder  116 . 
     Shuttle cylinder housing  110  has feed air passages  336  extending therethrough from an entrance end or air entry end  115  to the exit end or air exit end  117  of shuttle cylinder housing  110 . Feed passages  336  will receive feed air from feed port  304  in valve plate  100 . 
     Shuttle cylinder housing  110  has a release port  342  extending from air entry end  115  to the air exit end  117 . Release air will be provided through release port  306  in valve plate  100  and will be received in a slot  344  defined in the entry end  115  of shuttle cylinder  110 . Release air is communicated from slot  344  into a release air port  342 . 
     Center hub  150  has a plurality of feed air passages  350  extending from the air entry end  149  to the air exit end  151  thereof. Center hub  150  also defines a release passage  356  therethrough from entry end  149  to exit end  151 . Center hub  150  has a first hub portion  352  and a second hub portion  354 . First hub portion  352  is at the entry side, and second portion  354  is at the exit side. It is apparent from the drawings that first hub portion  352  will fit through opening  142  defined in crack die holder  132 . A connecting slot  358  extends radially outwardly from release air passage  356  at the exit end thereof. Air passes from slot  344  in shuttle cylinder  110  into release port  342  and into release air passage  356  in center hub  150 . Feed air passes directly from feed air passages  336  into feed air passages  350  in center hub  150 . 
     Cylinder seal plate  182  is positioned adjacent second hub portion  354 . A gasket  183  may be positioned between cylinder seal plate  182  and second hub portion  354 . Cylinder seal plate  182  has a plurality of feed ports  360  therethrough and a plurality of release ports  362  therethrough. Feed ports  360  and release ports  362  extend from an air entry end  364  to an air exit end  366  thereof. Feed air will be received from feed passages  350  in central hub  150  and will pass through cylinder seal plate  182 . Release air will pass radially outwardly from release passages  356  in center hub  150  in connecting slots  358  and will pass into release ports  362  in cylinder seal plate  182  at the entry end  364  thereof. Cylinder seal plate  182  has openings  368  which allow the reciprocation of pistons  200  therethrough. Cylinder head gasket  180  has openings  369  and  371  to provide for the passage of feed air from feed port  360  and release air from release port  362  therethrough. 
     Cylinder head plate  176  has a plurality of feed air passages  372  extending from the air entry end  186  to the air exit end  188  thereof. The exit end of cylinder head plate  176  has an eyebrow-shaped communicating slot  378  which as explained below will communicate feed air to the rear end  201  of each piston cylinder  202  which is the feed end of each piston cylinder  202 . A release air slot  380  receives release air at a bottom end  381  thereof from ports  362  in cylinder seal plate  182 . Slot  380  extends only partially through cylinder head plate  176  and once air is received from port  362  it will pass through slot  380  into a release air port  382 . Release air port  382  will communicate air through a release air delivery slot  384  into the release or forward end  203  of the piston cylinder  202  in cylinder body  160 . Release air will pass through the piston rod openings  386  in cylinder front plate  172  and in mating openings in the cylinder body gasket  170 . Air received therein will urge piston rod  210  toward the rear end of the piston cylinder  202 . Feed air will pass through feed air passage  372  and will be communicated by arcuate slot  378  into a feed air port  390  in cylinder front plate  172 . 
     Cylinder body  160  has a feed air port  392  that extends from the air entry end  163  to the air exit end  162  thereof. Air passes from feed air port  392  into a feed air port  400  defined in cylinder end plate  154 . Feed air passes into feed air port  400  and through a connecting passage  402  defined in cylinder end plate  154 . Feed air is then passed through an exit feed air port  404  where it acts on piston rod  210  to urge piston rod  200  to the feed position shown in  FIG.  18   . Because cylinder end plate  154  is sectioned, it provides for easy removal and the easy extraction of selected pistons  200 . One of the advantages of the design of the current disclosure is that pistons  200  may be easily removed and replaced since the turret  43  is internally ported as opposed to having external air tubing for driving pistons. 
     In operation, the motor is operated at a desired speed and an air supply provides air to a manifold  408 . The manifold will supply air to regulators associated with feed, release, reset and crack control knobs  410 ,  412 ,  414  and  416 . Air will be fed from the manifold  408  to the feed, release, reset and crack openings  226 ,  228 ,  230  and  232  in valve cover plate  224 . The feed and crack air may be passed through a lubricator to help seal moving parts associated with the shuttles  118  and pistons  200 . Cracker apparatus  5  will crack at high speeds, as much as  750  nuts per minute. Air used to move pistons  200  between the extended and retracted positions  215  and  216  passes through turret assembly  43  directly from valve  220  with no external tubing or hoses. Feed passage  315  comprises passage  336  in shuttle cylinder  110 , passage  350  in turret center hub  150 , port  360  in cylinder seal plate  182 , passage  372  in cylinder head plate  176 , port  390  in cylinder front plate  172  and port  392  in cylinder body  160  where it is delivered through cylinder end plate  154  to piston cylinder  202 . Release passageway  313  likewise passes from valve  220  all the way to the front end of the cylinder body  160  and is comprised of port  342  in shuttle cylinder housing  110 , passage  356  in center hub  150 , port  362  in cylinder seal plate  182  and port  382  in cylinder head plate  176 . First and second portions  155  and  156  of cylinder end plate  154  are easily removed, which provides easy access for the removal of selected pistons  200 . Pistons  200  may be easily removed and replaced, and there is no danger of connecting hoses to an incorrect air port, since there are no external air ports or hoses providing air to the pistons  200 . 
     As conveyor  62  moves, nuts are picked up in nut pockets  84 . The nut pockets  84  deliver nuts to the pickup point  86 . Feed air is delivered through feed passage  315  and piston  200  moves to the feed position to hold a nut against the crack die  130 . Crack air is applied, and the shuttle  118  moves into crack die  130  to crack the nut. Crack die  130  will move slightly when impacted by shuttle  118 . The distance that crack die  130  moves can be adjusted by adding a shim of a desired width between crack die holder  132  and shuttle cylinder housing  110 , or by adjusting the length of the crack die  130 . Exhaust opening  243  allows air to be exhausted from the system as the pistons  200  and shuttles  118  move during the cracking process. 
     A singulator  418 , best seen in  FIG.  3   , is pivotally mounted to a bracket that is connected to center divider  64 . Singulator  418  will extend through a slot in the center divider and into a slot in the nut chain  80 . The singulator is adjustable, and the width of the nut chain  80  is such that the singulator  418  will ensure that only one nut will fit in any single nut pocket. In other words, two nuts will not fit end to end in a single nut pocket. The singulator  418  may have a curvature if necessary to match the travel path of the endless conveyor  62 . 
     Embodiments include. 
     Embodiment 1. A nut cracking apparatus comprising a frame; a rotatable turret mounted to the frame, the rotatable turret including a rotatable valve plate at an end thereof; a plurality of nut cracking units in the rotatable turret. Each nut cracking unit comprises a piston movable from a retracted position to an extended position; and a crack die aligned with the piston against which the piston secures a nut in its extended position. An air supply is communicated with the rotatable valve plate, the rotatable turret defining a feed air passage associated with each nut cracking unit therethrough from the rotatable valve plate to a rear end of a piston cylinder in which the piston is housed through which air passes to urge the piston from a retracted to an extended position. 
     Embodiment 2. The nut cracking apparatus of embodiment 1 further comprising a stationary valve positioned adjacent the rotatable valve plate, the stationary valve defining a feed air opening therethrough communicated with the air supply, the rotatable valve plate having a feed air opening associated with each nut cracking unit, feed air being sequentially supplied from the feed air opening in the stationary valve to the feed air openings in the rotatable valve plate into the feed air passages as the rotatable turret rotates. 
     Embodiment 3. The nut cracking apparatus of either of embodiments 1 or 2, the nut cracking apparatus of claim  2 , each nut cracking unit further comprising a shuttle cylinder having a shuttle disposed therein movable in the cylinder from a rear end toward a forward end to impact the crack die. 
     Embodiment 4. The nut cracking apparatus of either of embodiments 2 or 3, the stationary valve having first and second crack air openings communicated with the air supply, the rotating valve plate having a single crack air opening associated with each nut cracking unit through which crack air is provided twice from the stationary valve to a rear end of a shuttle cylinder to urge the shuttle into the crack die of the nut cracking unit during a single rotation of the rotatable turret. 
     Embodiment 5. The nut cracking apparatus of any of embodiments 1-4 the rotatable turret defining a release air passage therethrough associated with each nut cracking unit from the rotatable valve plate to a forward end of the piston cylinder through which release air is communicated to urge the piston from an extended to a retracted position. 
     Embodiment 6. The nut cracking apparatus of any of embodiments 3-5, the shuttle movable into the crack die a first time during a rotation of the turret to crack a nut when the piston is in an extended position upon the application of air to the rear end of the shuttle cylinder and movable into the crack die a second time during the same rotation of the turret. 
     Embodiment 7. The nut cracking apparatus of any of embodiment 1 the rotatable turret comprising a piston cylinder body defining a plurality of piston cylinders; a shuttle cylinder housing defining a plurality of shuttle cylinders; and a shuttle in each shuttle cylinder movable from a rear end of the shuttle cylinder to a forward end to impact the crack die of the nut cracking unit, the piston cylinder body and shuttle cylinder body defining air passages therethrough that form at least a portion of the feed air passages associated with each nut cracking unit. 
     Embodiment 8. A nut cracking apparatus comprising: a frame; a piston cylinder body rotatably mounted in the frame, the piston cylinder body defining a plurality of piston cylinders with a piston movably disposed therein from a retracted position to an extended nut holding position; a shuttle cylinder housing rotatable with the piston cylinder body, the shuttle cylinder housing defining a plurality of shuttle cylinders each with a shuttle movably disposed therein; a crack die positioned at a forward end of each shuttle cylinder, the shuttle movable from a rear end to a forward end of the shuttle cylinder to impact the crack die; and an air supply communicated with a rear end of the shuttle cylinder body, the air supply providing air to the rear end of the shuttle cylinder to move the shuttle in the shuttle cylinder twice to generate first and second impacts on the crack die during a single rotation of the shuttle cylinder body. 
     Embodiment 9. The nut cracking apparatus of embodiment 8, one of the first and second impacts occurring to crack a nut held between the piston and crack die when the piston is in the extended position, the other of the first and second impacts occurring after a nut has been cracked. 
     Embodiment 10. The nut cracking apparatus of either of embodiments 8 or 9, the shuttle cylinder housing and piston cylinder body each defining a plurality of feed air passages therethrough, each feed air passage in the shuttle cylinder housing communicated with a feed air passage in the piston cylinder body, each feed air passage in the piston cylinder body communicated with a rear end of a piston cylinder to communicate feed air thereto. 
     Embodiment 11. The nut cracking apparatus of embodiment 10, further comprising a center hub positioned between the shuttle cylinder housing and the piston cylinder body, the center hub having a plurality of feed air passages therethrough communicating the feed air passages in the shuttle cylinder body with the feed air passages in the piston cylinder body. 
     Embodiment 12. The nut cracking apparatus of embodiments 10 or 11, further comprising a valve plate connected to and rotatable with the shuttle cylinder body and a stationary valve positioned adjacent the valve plate, the feed air provided to the feed air passages in the shuttle cylinder body through the stationary valve and the valve plate. 
     Embodiment 13. The nut cracking apparatus of any of embodiments 10-12, further comprising a cylinder end plate connected to the piston cylinder housing and defining a plurality of ports therethrough communicating the feed air passages in the piston cylinder body with a rear end of the piston cylinders. 
     Embodiment 14. The nut cracking apparatus of any of embodiment 13, the cylinder end plate comprising first and second end plate sections removably connected to the piston cylinder housing. 
     Embodiment 15. A nut cracking apparatus comprising a frame; a rotatable turret mounted to the frame; a turret sprocket connected to the rotatable turret; a drive sprocket connected to and rotated by a motor; a chain engaging the drive sprocket and turret sprocket, the turret sprocket rotated by the motor, the rotating turret comprising: a plurality of pistons movable in piston cylinders from a retracted position to an extended nut holding position; a plurality of shuttles movable in shuttle cylinders from a rear end to a forward end thereof; and a plurality of crack dies positioned at the forward end of the shuttle cylinders; a rotatable valve plate positioned adjacent the rear end of the shuttle cylinders; The nut cracking apparatus further comprising an air supply communicated with a stationary valve positioned adjacent the rotatable valve plate; and the turret defining air passages for providing air communicated through the rotatable valve plate to the piston cylinders and shuttle cylinders to move the pistons and shuttles in their respective cylinders, the air passages being completely contained within the rotating turret. 
     Embodiment 16. The nut cracking apparatus of embodiment 15 comprising a plurality of nut cracking units, each nut cracking unit comprising one of the plurality of pistons, one of the plurality of crack dies and one of the plurality of shuttles, the valve plate defining a plurality of air ports communicable with each nut cracking unit to move the pistons and shuttles in the piston cylinders and shuttle cylinders. 
     Embodiment 17. The nut cracking apparatus of either of embodiments 15 or 16, the stationary valve defining first and second crack air openings, crack air being supplied to a rear end of each shuttle cylinder from the first and second crack openings through the rotatable valve plate during a single rotation of the valve plate to impact the crack die with the shuttle first and second times during the single rotation. 
     Embodiment 18. The nut cracking apparatus of any of embodiments 15-17 the rotatable turret comprising a piston cylinder body defining the piston cylinders, the piston cylinder body defining a feed air passage for communicating feed air to a rear end of each piston cylinder; and a shuttle cylinder housing defining the shuttle cylinders, the shuttle cylinder housing defining a feed air passage for communicating air to the feed air passage in the piston cylinder body. 
     Embodiment 19. The nut cracking apparatus of embodiment 18 further comprising a center hub positioned between the piston cylinder body and the shuttle cylinder housing, the center hub having feed air passages communicating the feed air passages in the shuttle cylinder housing with the feed air passages in the piston cylinder body. 
     Embodiment 20. The nut cracking apparatus of any of embodiments 15-19 being less than 28″ wide, 22″ high and 41″ long and capable of cracking nuts at a rate in excess of 750 nuts/minute. 
     Embodiment 21. A nut cracking apparatus comprising: a frame; a rotatable turret mounted to the frame; a plurality of nut cracking units in the rotatable turret. Each nut cracking unit comprises a piston having a piston head and a piston rod extending therefrom movable in a piston cylinder from a retracted position to an extended position and a crack die aligned with the piston against which the piston secures a nut in its extended position. A forward seal defining a frustoconical engagement surface is positioned at a forward end of each of the piston cylinders and a rear seal defining a frustoconical engagement surface is positioned at a rear end of each of the piston cylinders. The piston head comprises a generally cylindrical center portion sealingly engaged with the piston cylinder and a rear portion sloping radially inwardly in a rear direction from the center portion and defining a rear engagement surface for mating with the frustotoconical engagement surface on the rear seal. 
     Thus, it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention.