Abstract:
Described is a pitting machine, system and process that singularizes or individualizes fruit pieces, such as cherries, olives, dates and plums and that attempts to remove pits and pit material from each fruit piece. A conveyor comprises depressions, wells or receptacles for accepting fruit pieces for processing. The conveyor accepts fruit pieces into wells, passes the fruit pieces into a pitting area wherein the pitting machine removes pit material from the fruit pieces by a matrix of punching needles or pitting needles. The matrix moves in an oscillatory fashion in synchronization with generally continuous movement of the fruit pieces engaged in the conveyor. The singularization enables easier and better processing, sorting, and quality checking of fruit pieces. Quality checking may be done before and after pitting of fruit pieces. Quality checking may include desired color and size of each fruit piece. Quality checking virtually ensures successful or sufficient removal of pits and pit material. Any fruit piece that fails quality checking can be ejected or rejected from the conveyor.

Description:
FIELD OF INVENTION 
     The present invention relates to a machine for sorting, or pitting, or sorting and pitting fruit pieces such as cherries, olives, dates and plums. 
     BACKGROUND 
     Historically, pitting machines have yielded a small percentage of fruit whose pit or portion of a pit remained in the fruit piece. A typical mechanism for removing a fruit pit or pit material has been the use of a punching needle that passes through the fruit, engages the pit or pit material, and ejects the pit or pit material from the individual fruit piece. One cause of missed pits or missed pit material has been that the pit is not centered beneath the punching needle such that the pit or pit material is too far to one side of the fruit piece. Other times, the missed pit or missed pit material breaks, leaving a portion of the pit or pit material in the fruit piece. Another source of a missed pit or missed pit material is the difficulty of adequately detecting the presence of a missed pit or missed pit material in fruit pieces that have passed through a pitting machine. 
     Producers, buyers, sellers and consumers of pitted fruits are highly discouraged by the presence of any remaining pits or pit material in pitted fruits. Increasingly, producers, buyers and sellers of pitted fruits are hesitant to market the fruit due to an increased number of lawsuits by consumers who have tragically bit into one of these left over pits and reaped a broken tooth or other malady. Producers, buyers and sellers have tried to minimize the occurrence of tragic missed pit or pit material events by having manual laborers check the fruit pieces after the fruit pieces have been processed through pitting machines. This process is labor intensive, expensive and unreliable. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter. The Summary is not intended to be used to limit the scope of the claimed subject matter. 
     One aspect of the present invention provides an improved method, system and machine for the removal of pits and pit material from fruit pieces. One implementation of a pitting system according to the present invention comprises a process to singularize fruit pieces by allowing only one fruit piece in each of a plurality of depressions or wells in a conveyor. In one particular implementation, in order to singularize fruit pieces, fruit pieces are introduced onto a conveyor. As fruit pieces move up an inclined portion of the conveyor, excess fruit pieces that are not accepted into an available depression in the conveyor continue to fall or roll back toward a lower part of the conveyor until the particular fruit piece is accepted into an available depression in the conveyor. 
     In the same or different implementation, fruit pieces resting in each depression can be screened by a detector such as an optical reader. Each fruit piece is measured and compared against one or more predetermined threshold values of pre-made measurements. For example, fruit can be measured for color and compared against an acceptable threshold value for color. If the measured value from a particular fruit piece does not meet a corresponding acceptable threshold value, the fruit piece is ejected from the depression and off of the conveyor. Rejected fruit pieces can be further processed or discarded. 
     Another aspect of the invention is removal of pits and pit material from fruit pieces. In the same or different implementation as previously described, the pitting system comprises a punching head which in turn is comprised of a matrix of punching needles, each punching needle being a predetermined size and shape for driving pits and pit material from a respective fruit piece and through an opening in the corresponding depression or well in which the fruit piece is resident. After the punching needle pushes the pit or pit material from the fruit piece, and through an opening in the bottom of the respective depression, the pit or pit material from each fruit piece is collected and discarded. Each punching needle is cleaned for a subsequent punching cycle and freed from any attached pit, pit material and fruit material, when the punching needle protrudes from the opening of the depression. Each punching needle is effectively wiped clean by brushes, water jets or other means. 
     In another aspect of the invention, a matrix of punching needles punches according to an oscillatory movement that is in synchronization with the conveyor. This allows the conveyor to be continuously moving throughout the pitting process. In a preferred implementation, the conveyor moves at a constant speed. 
     In another aspect of the invention, after each fruit piece has been punched, the conveyor moves the fruit pieces from a punching or pitting region to a screening area to screen the fruit pieces for any residual pit or pit material that could be left in a particular fruit piece or in a depression or well in the conveyor. If a pit or pit material is detected in a particular fruit piece, that particular, singularized fruit piece can be ejected from the depression and off the conveyor. Rejected fruit pieces are collected for subsequent processing. Subsequently, pitted fruit pieces that pass individual screening fall from or are removed from each depression or well. 
     These and other aspects of the invention are described further in the Detailed Description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the subject matter are set forth in the appended claims. The subject matter itself, however, as well as a preferred mode of use, are best understood by reference to the following Detailed Description of illustrative implementations when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a pitting machine according to an exemplary implementation; 
         FIG. 2  is a side view of the pitting machine shown in  FIG. 1  according to an exemplary implementation; 
         FIG. 2A  is a side view of an exemplary motion of a matrix of pitting needles as the pitting machine shown in  FIG. 1  operates; 
         FIG. 3A  is a side view of three contiguous links of a conveyor according to an exemplary implementation of the pitting machine; 
         FIG. 3B  is a side view of an alternative embodiment of three contiguous links of a conveyor according to an exemplary implementation of the pitting machine; 
         FIG. 4A  is an overhead view of a link of a conveyor shown in  FIG. 3A  according to an exemplary implementation of the pitting machine; 
         FIG. 4B  is an overhead view of links and conveyor rods shown in  FIG. 3B  according to a second exemplary implementation of the pitting machine; 
         FIG. 5  is an overhead view of a link of a conveyor according to another exemplary implementation of the pitting machine; 
         FIG. 6  is a side view of a link of the conveyor shown in  FIG. 3A  and a side view of a matrix of pitting needles according to an exemplary implementation of the pitting machine; 
         FIG. 7  is a perspective close up view of a portion of an individual pitting needle according to an exemplary implementation of the pitting machine; and 
         FIG. 8  is a selective overhead view of the pitting machine shown in  FIG. 1  showing cleaning brushes under belt links of the conveyor for maintaining punching or pitting needles relatively free of debris during operation. 
     
    
    
     DETAILED DESCRIPTION 
     While the invention is described below with respect to a preferred implementation, other implementations are possible. The concepts disclosed herein apply equally to other devices, systems and methods for separating pits or pit material from fruit pieces. Furthermore, the concepts applied herein apply more generally to the processing of food and other materials. The invention is described below with reference to the accompanying figures. 
       FIG. 1  shows a perspective view of one exemplary implementation of a pitting machine  100  according to the subject matter described herein. With reference to  FIG. 1 , fruit pieces  102  are conveyed from right to left in  FIG. 1 . Fruit pieces  102  are placed onto the conveyor  104  as the conveyor  104  moves in a counter-clockwise motion. The movement can be continuous or may stop and start, or may be continuous but may operate at varying speeds over time. In a preferred implementation, the movement is continuous and operates at a relatively fixed speed over time. 
     After fruit pieces  102  are loaded onto the conveyor  104 , the conveyor  104  brings the fruit pieces  102  up an incline. As the conveyor  104  operates, the fruit pieces  102  are shuffled backward or down the incline along the conveyor  104  and fall into depressions or wells  106  in the links of the conveyor  104 , one fruit piece  102  per well  106 . Accordingly, the fruit pieces  102  are individualized or singularized such that each well  106  holds exactly one fruit piece  102 . In this way, fruit pieces  102  are prepared for further processing. The wells  106  are addressed in more detail below. 
     In one implementation, a bar  150  and brushes  152  facilitate singularization. The bar  150  and brushes  152  also assist in preventing “doubles” (not shown) and undesirable material from remaining on the conveyor  102 . Doubles are two or more fruit pieces that have grown together or are otherwise stuck together. As the conveyor  102  operates, doubles and/or other undesirable material falls into a trough or sluice  154  where such doubles and/or other undesirable material is swept away to juices or other area. Water jets (not shown) facilitate movement of doubles and/or other undesirable material from the trough or sluice  154 . Fruit piece singularization, in conjunction with other aspects of the subject matter described herein, provides many benefits not previously possible. For example, such benefits include, but are not limited to, fewer pits per unit amount of pitted fruit pieces, faster processing of fruit pieces, and reduction in the amount of manual labor needed to process fruit pieces. 
     After being singularized, the fruit pieces  102  are carried through a screener or detector  108 . The screener or detector  108  can perform a variety of functions such as, for example, detecting color from each fruit or detecting the presence of more than one fruit piece in a particular well  106 . In an exemplary implementation, a color measurement is taken of the fruit piece  102  in each well  106  in a row of wells or depressions. The color measurements are compared against a predetermined threshold value for the color measurement. If the measured value from a particular fruit piece does not meet a corresponding acceptable threshold value, the fruit piece is ejected from the corresponding depression and is removed from the conveyor  104  before being pitted (an ejector for each well is not shown in  FIG. 1 ). Rejected fruit pieces at this stage can be collected and further processed or discarded. Other types of measurements at the screener or detector  108  are possible such as, but not limited to, temperature, chemical composition, size, and weight. Screening is optional and may be performed prior to or after pitting. The size of the screener or detector  108  may not be shown to scale in  FIG. 1  and may take up less or more space than shown in proportion to the other features of the subject matter shown in  FIG. 1 . Further, the screener or detector  108  may comprise one or multiple parts or sections along the conveyor  104 . 
     Next, singularized fruit pieces  102  are carried into a pitting section  110  or region where pits or pit material is removed from the fruit pieces  102 . The pitting section  110  comprises a punching head which in turn comprises a matrix bed  112  to which is attached a matrix or collection of pitting needles  114  and a wiping plate (partially shown in  FIG. 8 ). In one implementation, the pitting needles  114  are aligned in a plurality of rows corresponding to respective links of the conveyor  104 . The pitting needles  114  are preferably mounted in a fixed manner to the matrix bed  112 . Alternatively, a tension spring or other flex mechanism is attached to each pitting needle  114  to avoid damage or wear to a pitting needle  114  that encounters foreign matter (anything other than a fruit piece  102 ) which happens to get into a well  106 . 
     With reference to  FIG. 1 , each row of pitting needles  114  includes one or more alignment pins  116  which fit into a corresponding recess, passage or hole (not shown in  FIG. 1 ) in a corresponding link of the conveyor  104 . In a preferred implementation, an alignment pin  116  is similar in shape to a pitting needle  114 , but does not have any features on the tip of the alignment pin  116  for engaging pits or pit material. An alignment pin  116  may be smaller than, the same, or larger in size than a pitting needle  114 . One or more alignment pins  116  may be provided for each link of the conveyor  104 . In a preferred implementation, two alignment pins  116  are provided for each link of the conveyor  104 , one on each end of each link. 
     At an appropriate time during operating of the pitting machine  100 , a vertical actuator  118  plunges or moves the matrix bed  112  toward a section of the conveyor  104  thereby causing alignment pins  116  to engage corresponding links of the conveyor  104  and then causing pitting needles  114  to engage and pass into or through the wells  106  in the corresponding links of the conveyor  104 . 
     In an exemplary implementation of control of movement or operation of the pitting machine  100 , the pitting section  110  comprises a matrix bed cam  120  attached to a spindle  122 . In this implementation, the matrix bed cam  120  and spindle  122  rotate continuously causing the matrix bed  112  to move in a generally horizontal and reciprocating motion. The reciprocating motion allows the matrix bed  112  to move in coordination with the moving conveyor  104  such that the matrix bed  112  effectively tracks the motion of a portion of the conveyor  104  while this portion of the conveyor  104  is within the pitting section  110 . The shape of the matrix bed cam  120  is carefully crafted to effectuate the tracking motion of the matrix bed  112 . A motor  140  causes the conveyor  104 , the spindle  122  and any related or attached cams to rotate or advance. Thus, the various components of the pitting machine  100  operate in synchronization with each other. For example, the motor  140  causes the conveyor  104  to advance in synchronization with the operation of the spindle  122  and the punching of the matrix bed  112 . In this implementation, as the spindle  122  rotates, an alignment trigger cam (not shown) rotates and triggers the matrix bed  112  to partially drop toward the conveyor  104  which causes alignment pins  116  to engage respective conveyor links. The matrix bed  112  and pitting needles  114  then become more precisely aligned with the respective conveyor links. At this point in the pitting operation, as the spindle  122  continues to rotate, a matrix trigger cam  126  trips a pitting trigger  128 . The pitting trigger  128 , in turn, activates the vertical actuator  118  that forcefully plunges the matrix bed  112  toward the section of the conveyor  104  directly under the matrix bed  112 . Pits and pit material are forcefully pushed out of the fruit pieces  102  and out of the respective wells  106 . The vertical actuator  118  then withdraws the matrix bed  112  and pitting needles  114  from the wells  106  and free from the conveyor  104  as the matrix bed  112  moves horizontally in synchronization with the moving conveyor  104 . The parts of the pitting machine  100  are then free to repeat the pitting cycle or pitting process. 
     Alternatively, alignment of the matrix bed  112  and engagement of the alignment pins  116  happens simultaneously with the operation of a single matrix trigger cam  126 . In such a scenario, the alignment pins  116  are longer than the pitting needles  114  and thus the alignment pins  116  engage each link of the conveyor  104  before the pitting needles  114  engage the fruit pieces  102  in the wells  106 . In this alternative implementation, the alignment and pitting are part of the same vertical actuation and motion (controlled by a single cam). 
     Other mechanisms may be synchronized with the operation of the conveyor  104 . For example, an ejection cam  124  may trigger a row of pneumatic ejectors (not shown) near the end of the conveyor  104  to assist a pitted fruit piece  102  in leaving the conveyor. 
     Other implementations for coordinating the operation of the matrix bed  112  and the conveyor  104  are possible. In fact, any mechanism or combination of mechanisms for causing the same or similar motion or actuation is envisioned as part of the subject matter disclosed herein.  FIG. 1  shows a rotating spindle  122  and cams to coordinate the operation of the pitting machine  100  in synchronization with operation of a variable speed motor  140 . However, a programmable logic controller (PLC) could be used to control and coordinate some or all of the moving portions of the pitting machine  100  including, for example, operation of the conveyor  104  and horizontal and vertical movement of the matrix bed  112 . 
     After the fruit pieces  102  are pitted, with reference to  FIG. 1 , in the fruit pitting region  110 , the pitting needles  114  cause the pits or pit material to exit the fruit pieces  102  through the bottom of each corresponding well  106 . The pits or pit material, and any residual fruit material leaving the fruit pieces  102 , is collected in a sluice or collection region  138  under the fruit pitting region  110 . The pits or pit material (not shown) can then be transported, aggregated and further processed or discarded. Fruit pieces  102  which have passed through the fruit pitting region  110  remain in their respective wells  106  of the conveyor  104 . 
     Although not shown in  FIG. 1 , the fruit pitting region  110  also comprises a set of brushes and one or more wiping plates, one exemplary implementation of a wiping system for the pitting needles  114 . It is noted that  FIG. 1  also does not show compressed air hoses that, in an exemplary implementation, provide a means for the motion of the vertical actuator  118  and other components of the pitting system or pitting machine. Elements or features not shown in  FIG. 1  are omitted for clarity purposes only. The set of brushes is shown in  FIG. 2  and  FIG. 8  and the wiping system is explained more fully below in reference to  FIG. 8 . In short, a set of brushes is fixedly mounted below the conveyor  104  in the fruit pitting region  110 , and one or more wiping plates are mounted to the punching head above the conveyor  104  in the fruit pitting region  110 . The set of brushes removes pits or pit material as the pitting needles  114  retract from punching through the fruit pieces  102 . The wiping plate helps ensure that no fruit piece  102  persists on a pitting needle  114  when the matrix of pitting needles  114  retracts from the fruit pieces  102  and wells  106 . 
     In one implementation, the pitting machine  100  was found to process up to about 1,800 pounds (816 kg) of tart cherries per hour with each link comprising 20 wells  106  and the matrix bed  112  comprising 4 to 6 rows of pitting needles  114 . About one pound (0.45 kg) of cherries was pitted on each stroke of the pitting machine  100 . In this implementation, the pitting machine  100  was able to pit both tart and sweet cherries and was able to pit cherries faster than conventional means available—on the order of two to three times faster than by other known machines. 
     With reference to FIG.  1 ., the fruit pieces  102  then pass from a fruit pitting region and through a pit detection region  130 . Each well  106  that passes through the pit detection region  130  is evaluated to determine whether any pit or pit material remains in a fruit piece  102  or well  106 . The detection may be synchronized with or by the operation of the spindle  122 . Other means to synchronize the detection with the operation of the conveyor  104  are possible. The evaluation can be performed by a variety of methods and a variety of equipment. In one implementation, an x-ray detection machine (not shown in  FIG. 1 ) performs the evaluation. For example, an in-line, multi-line x-ray detection machine is commercially available from Smiths Detection (Alcoa, Tenn.). Other detection methods include ultrasound and infrared technologies. In a preferred implementation, infrared detection is used. The size of the pit detection region  130  and corresponding elements of detection may not be shown to scale in  FIG. 1  and may take up less or more space than shown in proportion to the other features of the subject matter shown in  FIG. 1 . 
     If a pit, portion of a pit, or any pit material is detected, the corresponding well  106  can be cleared by a puff of air or other ejection means and a catch system (not shown in  FIG. 1 , but shown in  FIG. 2 ). Any fruit piece  102  that is cleared can be collected and either discarded or further processed. In one implementation, any rejected fruit pieces  102  are collected and added to the pits and pit material obtained in the pitting region  110 . In an exemplary implementation, the collected pits and pit material are taken to juices, meaning an area for further processing to collect and prepare juice from a subset of harvested fruit pieces (e.g. cherries). 
       FIG. 2  is a side view of the pitting machine  100  shown in  FIG. 1 . With reference to  FIG. 2 , the conveyor  104  operates in a counterclockwise manner. Fruit pieces  102  travel on the top of the conveyor  104  and travel from right to left in  FIG. 2 . In one implementation, fruit pieces  102  are loaded onto the conveyor  104  in a receiving region  202 . The receiving region  202  may be of any size and orientation. In a preferred implementation, the conveyor  104  comprises an inclined region  204  wherein fruit pieces  102  become individualized or singularized in depressions or wells (not shown in  FIG. 2 ) in the conveyor  104 . As the conveyor  104  operates or advances, excess fruit pieces  102  which do not engage or lodge in depressions or wells in the conveyor  104  fall or slide back toward the receiving region  202 . Means other than an inclined region  204  may be used to individualize or singularize fruit pieces  102  on a conveyor  104 . For example, fruit pieces  102  may be loaded one at a time into a respective well as a conveyor  104  operates by passing fruit pieces  102  into channels or gates corresponding to the columns of wells in the conveyor  104 . Alternatively, instead of an inclined region  204 , fruit pieces  102  may be required to pass under a bar that is mounted at a fixed vertical distance above a horizontal conveyor  104 . In such an implementation, fruit pieces  102  which do not drop into wells in the conveyor  104  are forced to remain in a receiving region  202  without advancing with the conveyor  104  to a pitting region  110 . 
     With reference to  FIG. 2 , in one implementation, as the fruit pieces  102  are pitted in the pitting region  110 , the tips of the pitting needles  114  pass through the respective depressions or wells and protrude through a series of brushes  206  mounted in a fixed position below the conveyor  104 . As the matrix bed  112  moves from right to left in  FIG. 2 , the tips of the pitting needles  114  are brushed clean by brush filaments of the series of brushes  206 . As fruit pitting machine  100  continuously operates, the series of brushes  206  keep the pitting needles  114  relatively free of pits, pit material and residual fruit material. The series of brushes  206  are one of the features of the pitting machine  100  that allow the pitting machine  100  to operate continuously for a relatively long period of time without a need to stop its operation for cleaning, maintenance, retooling or other reason. Continuous operation is desirable for fruit crops that require pitting or other kind of processing within a relatively narrow timeframe (e.g. a few weeks). In other implementations, instead of a fixed series of brushes  206 , a set of rotating or moving brushes (not shown) may be used to keep protruding ends of pitting needles  114  free from debris. Alternatively, water jets strategically placed under the conveyor  104  in the pitting section  110  could perform the same function. 
     In a preferred implementation, the drive mechanism of the pitting machine  100  comprises a means or mechanism to prevent damage to the pitting needles  114  and/or other components if the drive mechanism experiences an unusual occurrence, abnormal resistance or malfunction. For example, a sheer pin  132  prevents the motor  140  from continuing operation of the pitting machine by preventing the spindle  122  from making further motion in the event of an unusual occurrence, abnormal resistance or malfunction in the mechanics of operation of the pitting machine. Any number or kind of damage preventing mechanisms may be combined with the pitting machine including mechanisms to prevent harm to human operators. 
     As shown in  FIG. 2 , the pitting machine  100  also comprises a sluice, trough or pit collector  138  for discharged pits, pit material, juice and any other material incident to pitting of fruit pieces  102 . One or more water hoses  134  bring water to spray nozzles  136 . The spray nozzles  136  flush water continuously or intermittently into or through the sluice, trough or pit collector  138 . The material collected is sent to juices or to some other area for processing. 
     Once fruit pieces  102  exit the pitting region, pitted fruit pieces are checked for the presence of pits and pit material in a pit detection region  130 . Detection may be done in one of various possible ways. In a preferred implementation, each well of a particular row of wells is checked. The result of a scan of each well may be used to cause an ejector  142  to eject from an identified well a rejected fruit piece. In one embodiment, the ejector  142  uses a burst or puff of air to eject a rejected fruit piece. Alternatively, a burst of water or solid pin may be used to eject or remove a rejected fruit piece from the conveyor  104 . The ejector  142  sends a rejected fruit piece against a curved collecting plate  144  mounted over the conveyor  104 . A second sluice, trough or pit collector  146  accepts rejected fruit pieces. In one implementation, collected rejected fruit pieces are sent to juices. 
       FIG. 2A  shows an exemplary tracking motion  216  of the matrix bed  112  and allied components shown in  FIG. 2  during operation of one implementation of a pitting machine  100 . In  FIG. 2A , the tracking motion  216  is of any component of the moving head such as the pitting needles  114  as the head moves to track the conveyor  104  and to pit fruit pieces. The tracking motion  216  operates in a clockwise direction in  FIG. 2A . The tracking motion  216  includes a first drop  218  and a second drop  220 . The first drop  218  and second drop  220  have been accentuated for illustrative purposes and may be more or less gradual and larger or smaller in distance or size than shown in  FIG. 2A . The first drop  218  corresponds to engagement of alignment pins attached to the matrix bed  112  with corresponding links of the conveyor  104 . The second drop  220  corresponds to a downward pitting action when pitting needles  114  are forced through fruit pieces  102 . The matrix bed  112  and allied components operate over both a vertical pitting distance  222  and a horizontal travel distance  224 . The horizontal travel distance  224  corresponds to a y direction (direction of travel of the conveyor  104 ), and the vertical travel distance corresponds to a z direct as shown. The matrix bed and allied components travel horizontally so that the pitting needles  114  track the motion of the conveyor  104  prior to, during pitting of the fruit pieces  102 , and removal of the pitting needles  114  from the wells and fruit pieces traveling on the conveyor. In a preferred implementation, both the vertical pitting distance  222  and the horizontal travel distance  224  are minimized so as to increase the frequency at which the pitting needles  114  can pit fruit pieces  102 . In this fashion, an increased throughput of fruit pieces per time unit is obtained. 
     With reference to  FIG. 1 ,  FIG. 2  and  FIG. 2A , in an exemplary implementation, the spindle  122  is responsible for the horizontal motion of the matrix bed  112  along the horizontal travel distance  224 . The spindle  122  turns at a relatively constant angular velocity. However, the horizontal velocity of the matrix bed  112  is not constant at all times and locations due to the uneven radius and particular shape of the matrix bed cam  120 . Consequently, the velocity is not constant at every place in the tracking motion  216  of  FIG. 2A . The shape of the matrix bed cam  120  is specially shaped so that the motion of the matrix bed  112  tracks the motion of the conveyor  104  prior to and during pitting of the fruit pieces  102 . The vertical motion of the matrix bed  112  is caused by a separate mechanism, the vertical actuator  118 . The spindle  122  via the motor  140  work together in conjunction with the vertical actuator  118  to effect the tracking motion  216  shown in  FIG. 2A . 
       FIG. 3A  is a side view of three contiguous links  300  of a conveyor according to an exemplary implementation of the pitting machine. With reference to  FIG. 3A , the width of each link  300  is not shown, but can be of any dimension. The width of one link  300  may be different from another link  300  as long as the distance between corresponding pitting needles in the matrix bed (not shown) corresponds to the distance between successive wells in contiguous links  300  of the conveyor. 
     A side surface  302  rides along the track of the pitting machine  100 . A cut away portion  304  allows other parts to engage and align the conveyor  104  and conveyor links  300 . A cylindrical void  306  accepts a track pin (not shown) or other mechanical part. In a preferred implementation, the links  300  are hooked together or connected by a chain link (not shown in  FIG. 3A ). Track pins (not shown) inserted in the cylindrical voids  306  may be attached to a wheel or other mechanism or part that allows each link  300  of the conveyor  104  to smoothly move within the pitting machine  100  and to be connected to or otherwise follow contiguous links  300 . 
     Each link  300  also comprises a convex surface  308  and a concave surface  310 . The convex surface  308  of one link  300  abuts with a corresponding concave surface  310  of another link  300 . The combination of a convex surface  308  on one end of a link  300  and a concave surface  310  on the other end of the same link  300  serves a plurality of purposes including the successful operation of the conveyor  104  around curves in either orientation (up or down relative to  FIG. 2 ). For example, the conveyor  104  is able to effectively bend in a concave-upward orientation and create an inclined section  204  as shown in  FIG. 2  and to wrap around the end section  208  as shown in  FIG. 2 . Each conveyor link  300  is thus able to pivot in either direction around an axis centered in its cylindrical void  306 . The cylindrical void  306  may be shallow or may extend through the entire link  300 . A conveyor is comprised of a series of conveyor links  300  and may operate in either direction, either moving toward the convex side of the conveyor links  300  or away from the convex side of the conveyor links  300 . 
     Each conveyor link  300  also comprises a plurality of wells  106 . While one well  106  is shown in  FIG. 3 , it is understood that, in the implementation shown in  FIG. 3 , multiple wells  106  are present. Preferably, the length of a link  300  (perpendicular to the view shown in  FIG. 3A ) is sufficient to accommodate a plurality of wells  106  with a preferred number of depressions or wells being between 10 and 40. 
     At the bottom of each well  106  is found a pitting needle passage  312  that is slightly larger in diameter than the diameter of a pitting needle  114  (not shown) and smaller than a fruit piece (not shown in  FIG. 3A ). The open nature of a pitting needle passage  312  may make it possible for a detector (not shown in  FIG. 3A ) to more accurately sense and detect the presence of pits or pit material and to detect or measure one or more qualities of fruit pieces in the wells  106 . In fact, in an exemplary implementation, detection is performed for each well  106  from the bottom of a link  300  through the pitting needle passages  312 . 
     Further, in one exemplary implementation, an exit channel  314  is formed along some or all of the length in the underside of the link  300  along some of the width of the link  300 . In other implementations, there is no exit channel  314  in each link  300 . An exit channel  314  is designed to be filled with one or more removable exit channel blocks (not shown in  FIG. 3A ). Exit channel blocks substantially fill the exit channel  314 . In a preferred implementation, a removable exit channel block is made from the same material as the link  300  and is replaced when one or more of the exit channels  314  shows signs of excessive wear. Wear occurs as the pitting machine  100  is operated and as pitting needles pass through the pitting needle passages  312  and through corresponding channels or openings in the removable exit channel block (not shown) which accommodate the passage of the pitting needles. 
     In an alternative implementation, a removable exit channel block is made from a different material than that used to make a link  300 , a material that exhibits different wear characteristics than those of the link material. The properties of the removable exit channel material can be carefully tailored to the fruit that is being pitted and to the shape and material of the pitting needles used in the pitting operation. The properties of the material used to make the removable exit channel block also can be carefully matched to pitting operating conditions such as to conveyor speed and punching frequency. 
     In a preferred implementation, each link  300  is made from an ultra high molecular weight (UHMW) polyethylene. Components made of UHMW polyethylene exhibit a preferred combination of properties for pitting fruit pieces. UHMW polyethylene has high abrasion resistance, low coefficient of friction, self-lubrication, a non-adherent surface, good chemical fatigue and impact resistance, and good noise dampening properties. UHMW polyethylene is very resistant to wear and abrasion. UHMW polyethylene is also a material that satisfies relevant requirements of the U.S. Federal Food and Drug Administration (FDA) and U.S. Department of Agriculture (USDA). Alternatively, each link  300  is made from a high density polyethylene (HDPE), polyurethane or nylon material. 
       FIG. 3B  is a side view of three contiguous links  350  and three conveyor rods  352  of a conveyor  104  according to a second exemplary implementation of a pitting machine. With reference to  FIG. 3B , the width of each link  350  is not shown, but can be of any dimension so long as it is sufficient to accommodate a well  106  and exit passage  312 . The width of one link  350  may be different from another link  350  as long as the distance between corresponding pitting needles in the matrix bed (not shown) corresponds to the distance between successive wells in contiguous links  350  of the conveyor. The length of a link  350  (perpendicular to the view shown in  FIG. 3B ) may be of any dimension. 
     In a preferred implementation, each link  350  is made from an UHMW polyethylene. When mounted in the conveyor  104 , each link  350  floats or is sandwiched between successive conveyor rods  352 . Each link  350  is thus somewhat isolated from the mechanical assembly of the conveyor  104  and is somewhat isolated from the tracking or motion of the conveyor  104 . Thus, each link has some freedom to move and to tightly align with the matrix head  112  and with a row of pitting needles  114  when a link  350  moves into the pitting region  110  of the pitting machine. 
     Each side of a link  350  comprises a concave surface  310  to interface with a corresponding conveyor rod  352 . With reference to  FIG. 3B , each link  350  may thus rotate in either direction (up or down) relative to an axis defined by an adjacent conveyor rod  352  when a second adjacent conveyor rod  352  moves up or down vertically during operation of the conveyor  104 . Each link  350  optionally comprises a cut away portion  304  which allows other parts of a pitting machine (not shown) to avoid, engage, align with or manipulate the conveyor links  350 . For example, teeth of a sprocket comprising part of the conveyor  104  may engage in the cut away portions  304  as links  350  pass over the sprocket. Each end of a conveyor rod  352  comprises a shoulder  354  and a narrowed end  356 . The narrowed end  356  is preferably threaded to accept a nut or other part. 
       FIG. 4A  is an overhead view of a conveyor link  300  of a conveyor  104  according to an exemplary implementation of the invention and as shown in  FIG. 3A . Other implementations of a link  300  are possible. With reference to  FIG. 4A , a plurality of wells  106  are aligned in a row along the length of the conveyor link  300 . In the bottom of each of the wells  106  is a pitting needle passage  312  which is slightly larger than the diameter of a corresponding pitting needle (not shown) and smaller than a fruit piece (not shown). A conveyor link  300  optionally comprises an alignment channel  402  formed near each end of the conveyor link  300 . As a pitting machine operates, an alignment pin (not shown in  FIG. 4A ) passes into its corresponding alignment channel  402  causing the matrix (not shown in  FIG. 4A ) and pitting needles (not shown in  FIG. 4A ) to directly and precisely align with one or more links  300  under the matrix. As the matrix moves downward toward the one or more conveyor links  300 , alignment pins engage corresponding alignment channels  402  prior to the pitting needles engaging the wells  106  and passing into the pitting needle passages  312 . In this way, the pitting needles are more precisely aligned with the one or more conveyor links  300  than merely synchronizing the passage of pitting needles into pitting needle passages  312  through the use of cams or other means. Thus, wear along the sides of the pitting needle passages  312  is avoided. 
     In operation, pitting needles puncture fruit pieces, engage pits of fruit pieces, and push through the fruit pieces and into corresponding pitting needle passages  312 . A pitting needle passage  312  must accommodate a pit, pit material and residual connected fruit material in addition to a pitting needle. Thus, a pitting needle passage  312  is preferably not as closely matched in diameter, as is the alignment pin to its corresponding alignment channel  402 . Accordingly, pitting needles ordinarily do not strongly contact the sides of pitting needle passages  312 . The use of alignment pins and alignment channels  402  reduces wear in the belt links  300  associated with pitting needles passing into or through pitting needle passages  312 . 
       FIG. 4B  is an overhead view of links  350  and conveyor rods  352  shown in  FIG. 3B  according to a second and preferred exemplary implementation of the pitting machine  100 . With reference to  FIG. 4B , each link  350  comprises one or more alignment channels  402 , such as, for example, on each end of each link  350 . Alignment channels  402  may be located in any place and in any orientation in each link  350 . The links  350  are conveyed or moved through the pitting machine  100  by advancing the conveyor rods  352 . The conveyor rods  352  are held in place relative to one another with rod links  404  and with nuts  406  placed on the ends of each conveyor rod  352 . While rod links  404  are shown connected to contiguous links  350 , other arrangements are possible such as by connecting three contiguous links  350  together. While a single link  350  is shown stretching from left to right, a conveyor  104  may support multiple links  350  across a single row between successive conveyor rods  352 . Alignment pins could then align each link  350  as one or more rows of links  350  pass into a pitting section  110  of a pitting machine  100 . 
       FIG. 5  is an overhead view of another exemplary implementation of a conveyor link  500  comprising a series of wells  106  which are offset from one another in a y-direction along the length of the conveyor link  500 . When wells  106  are offset from one another, for a given link  500 , a greater number of wells  106  can be formed in a given link  500 . Fewer links  500  for a conveyor  104  could be used in such an implementation. Spacer conveyor links (not shown in  FIG. 5 ) that do not have any wells can then be used between a series of conveyor links  500  shown in  FIG. 5 . 
     Any arrangement of wells  106  is possible. Each conveyor link  500  may need to be larger in the x-dimension or y-dimension in order to accommodate other configurations of wells  106 . Of course a corresponding matrix of pitting needles  114  would need to be modified to match a corresponding configuration of wells  106  such as those shown in  FIG. 5 . 
     A conveyor link  500  also comprises a cutaway portion  304  and cylindrical voids  306  which accept a pin (not shown) or other part for connecting conveyor links  500  together to form a conveyor or for causing the conveyor link  500  to move during operation of the pitting machine  100 . Each of the wells  106  comprises or is contiguous with a pitting needle passage  312 . 
       FIG. 6  is a side view along a length of the exemplary conveyor link  300  shown in  FIG. 3A  and  FIG. 4A . The view shown in  FIG. 6  is toward the concave side of the conveyor link  300 . With reference to  FIG. 6 , a cut away portion  304  is visible on each end of the conveyor link  300 . The cut away portion  304  allows other parts (not shown) to avoid, engage, align with or manipulate the conveyor links  300 . Cylindrical voids  306  in each end are shown by dotted lines. Alignment channels  402 , vertically situated, are similarly shown by dotted lines, one near each end of the conveyor link  300 . An alignment pin  116  is shown engaged into each of the corresponding alignment channels  402 . A single row of pitting needles  114  is shown attached to the matrix bed  112  with the understanding that the matrix bed  112 , in a preferred implementation, comprises multiple rows of pitting needles  114 . In  FIG. 6 , the working end of each pitting needle  114  is shown directly above its corresponding well  106  and corresponding pitting needle passage  312 . Each pitting needle passage  312  opens downward onto a corresponding and contiguous exit channel  314 , each exit channel  314  being block shaped in  FIG. 6 . 
     From a side view, the plurality of wells  106 , the pitting needle passages  312  and exit channels  314  are not visible and are shown by dotted lines. A fruit piece  102  is shown in one of the wells  106 . When the pitting machine operates, the matrix bed  112  moves up and down by way of a vertical actuator  118 . Other mechanisms to move the matrix bed  112  up and down are possible. 
     As shown in  FIG. 6 , the alignment pins  116  have engaged the alignment channels  402  thereby precisely aligning the corresponding conveyor link  300  in both an x-direction (left-right) and y-direction (forward and backward—perpendicular to the plane of  FIG. 6 ) relative to corresponding wells  106  and pitting needle passages  312 . As shown in  FIG. 6 , the pitting needles  114  have not engaged the fruit piece  102  and have not engaged the wells  106 . 
     The shape of each well  106  may be the same or varied as compared with the shape of other wells  106 . The shape of the wells  106  shown in  FIG. 6  is semicircular, but could be any other shape. The shape of wells  106  may depend on any number of factors and may be selected or formed depending on characteristics of fruit pieces to be pitted. For example, the shape may be parabolic, elliptical, conical or frustoconical in nature. The contour of each well  106  is shown as a smooth surface. However, the semicircular surface may be formed with ridges, divots, bumps, or some form of texture in order to yield desirable results when pitting a particular fruit. For cherries, it is preferable to use a relatively smooth surface in the wells  106 . 
     The size or diameter  602  of each well  106  shown in  FIG. 6  is uniform from well  106  to well  106 . However, the size or diameter  602  may vary from well  106  to well  106  and may vary according to position in any given conveyor link  300 . For example, the size or diameter  602  of the wells  106  may be larger in the center  616  of the conveyor link  300  and the size or diameter  602  of the wells  106  may be smaller toward the ends  618  of the conveyor link  300  as compared to an average size or diameter of the depressions in the particular conveyor link  300 . In another implementation, the size of the wells may vary from one conveyor link  300  to another conveyor link  300 . In this way, various sizes of fruit piece may be accommodated more easily or more rapidly such that the average residence time for a fruit piece of a given size being lower in the loading or inclined region or area  204  of the pitting machine  100  when there is varying sizes of wells  106  in the conveyor. Fruit pieces of different sizes may be directed to wells of a corresponding size for improved pitting. 
     The separation distance  604  between any two wells  106  is shown as uniform in  FIG. 6 , but can be varied between consecutive wells  106 . The variation in separation distance  604  may vary in any direction such as in an x-direction or y-direction or a combination of x-direction and y-direction. The arrangement of wells  106  may be done on any basis such as to maximize throughput of fruit pieces (relatively high packing fraction in two dimensions (e.g. x and y dimensions)) or for cleaning of pitting needles  114  or for some other reason. In a preferred implementation, wells  106 , and correspondingly pitting needles  114 , are arranged one directly in front of the other in a y-direction (perpendicular to the plane of  FIG. 6 ) so as to facilitate cleaning of the tips of the pitting needles  114  by brushes (as described further below). 
     In a preferred implementation, and as shown in  FIG. 6 , a depression depth  606  is a uniform size or depth across the conveyor link  300 . However, the depression depth  606  may vary from well  106  to well  106 , across a conveyor link  300  and from conveyor link to conveyor link in the conveyor. Variation in depression depth  606  would allow a uniform matrix of pitting needles  114  to contact each fruit piece  102  at a slightly different time during operation and is desirable in certain circumstances. Thus, during operation, the load on the components and vertical actuator  118  which pit the fruit pieces  102  would not spike when the pitting needles  114  impact the pits of the fruit pieces  102 . However, when the depression depth  606  is uniform across a single conveyor link  300  and from conveyor link to conveyor link, resistance across the matrix  112  is uniform and loading of fruit pieces  102  onto the conveyor  104  is more predictable and uniform. A uniform depression depth  606  is also desirable in manufacturing of conveyor links  300 . An actual depression depth  606  that is optimal for a particular type of fruit piece or particular crop of fruit (size of fruit piece) is obtained by trial and error. 
     In one implementation, the depression depth  606  is found by measuring when a majority of the pit of a particular type of fruit piece  102  is within the well  106  which leaves an amount of fruit exposed above the top plane of the conveyor link  300 . The distance of the fruit piece  102  above the top plane is referred to as an exposed distance  608 . When the fruit pieces  102  pass under the matrix  112  of pitting needles  114  to be pitted, the tips of the pitting needles  114  must be at a distance greater than the exposed distance  608 . In addition, a wiping plate (not shown in  FIG. 6 ) also must be located at a distance greater than the exposed distance so that the wiping plate does not impact the fruit pieces  102  as the fruit pieces  102  pass under the wiping plate. 
     After the fruit pieces  102  are pitted, the fruit pieces  102  are generally slightly compressed into the wells  106  and generally do not protrude to the same exposed distance  608  as when first entering the pitting area  110 . In one implementation, the front edge of wiping plate can show signs of wear where fruit pieces that exhibit an abnormally large exposed distance  608  impact the wiping plate as they pass into the pitting section  110  of the pitting machine  100 . 
       FIG. 7  is a perspective close up view of an individual pitting needle  114  according to an exemplary implementation of a pitting needle  114  designed for pitting a singularized fruit piece  102 . In a preferred implementation, pitting needles  114  are made from a stainless steel. However, each pitting needle  114  or portions of pitting needles may be made from other materials such as UHMW polyethylene and coated carbon fiber. 
     With reference to  FIG. 7 , according to one implementation, the tip of a pitting needle  700  is formed by creating multiple grooves  702  in a cylinder or rod.  FIG. 7  shows six symmetrical grooves  702  formed in the shaft of the pitting needle  700 . The grooves  702  form blades  704  that extend downward toward the tip  706  of the pitting needle  700 . Other numbers of grooves  702  and blades  704  are possible. The tip  706  of the pitting needle  700  is generally concave which allows the tip  706  to engage a pit or pit material and drive the pit or pit material toward the center of the pitting needle  700  instead of toward the outside diameter of the pitting needle  700 . A pit or pitting material that is pushed even slightly toward the outer diameter or surface of the shaft of the pitting needle  700  (and thus protrudes outside of a profile of the pitting needle  700 ) can cause the pit or pit material to rub against the needle passage  312  of a conveyor link  300  of the pitting machine and thus can either cause unnecessary wear of the needle passage  312 , the pitting needle  700 , or may allow the pit or pit material to escape the pitting process and remain in the fruit piece  102  or in a well  106 . None of such outcomes is desirable. Improved pitting is obtained by using pitting needles according to the design shown in  FIG. 7 . 
       FIG. 8  is a partial overhead view of the pitting machine shown in  FIG. 1  showing a partial set of cleaning brushes  206  under links  300  of the conveyor  104  for maintaining pitting needles  114  relatively free of debris during operation of the pitting machine  100 . For simplicity of illustration, only a partial set of cleaning brushes  206  is shown with an understanding that each column of wells  106  would travel over a set of corresponding cleaning brushes. Also for simplicity of illustration, only four links  300  of a conveyor  104  are shown. Solid or dark circles represent pitting needle tips  802  which have passed through fruit pieces (not shown) and wells  106 . Only four pitting needle tips  802  are shown for simplicity. 
     In operation, the pitting needle tips  802  and links  300  travel in synchronization in the direction shown (toward the y direction shown in  FIG. 8 ) while the cleaning brushes  206  are mounted to the machine  100 . In one implementation, cleaning brushes  206  are fixed above or near open channels in a plate (not shown) just under the conveyor  104 . The cleaning brushes  206  remain stationary as the pitting machine  100  is operated. As the pitting needle tips  802  move during operation of the pitting machine, the pitting needle tips  802  impact bristles of the cleaning brushes  206  thereby removing pits, pit material and associated pulp, skin and other material that is carried on the pitting needle tips  802 . Further, in one implementation, pitting needle tips  802  pass through the cleaning brushes  206  and are further wiped off as the pitting needle tips  802  travel vertically down and back up through the cleaning brushes  206 . 
     In  FIG. 8 , as the pitting machine operates and as the matrix head  112  moves, the pitting needle tips  802  travel vertically through the bristles of the cleaning brushes  206 . The debris on each pitting needle tip  802  comes from the fruit pieces as the pitting needle tips  802  pass through the fruit pieces, through the wells  106 , through the pitting needle passages  312  and protrude from the bottom of the links  300 . The bristles of the cleaning brushes  206  are sufficiently stiff to adequately remove most or all of the debris from the channels and concave recess of each of the pitting needle tips  802  on each pass of the pitting needle tips  802 . A cleaning mechanism other than fixedly mounted bristled cleaning brushes  206  could be employed. For example, spraying jets of water or rotating brushes could be used. Pits, pit material and other matter cleaned from the pitting needle tips  802  drop into a sluice, trough or collection region  138  below the cleaning brushes  206 . 
       FIG. 8  also shows a partial portion of a wiping plate  804  covering two columns of wells  106 . Needle shaft openings  806  allow the passage of needle tips  802  through the wiping plate  804 . The wiping plate  804  is situated or mounted above the conveyor  104  in the pitting section  110  of the pitting machine  100 . In the implementation of  FIG. 8 , the wiping plate  804  is attached to, and travels with, the movable punching head. In alternative embodiments, the wiping plate  804  may be fixedly attached to the pitting machine  100  and the needle shaft openings would be slots through which the needle tips  802  would pass as the pitting machine  100  operated. In either implementation, the wiping plate  804  serves to dislodge, as necessary, any fruit piece  102  from needle tips  802  as the needle tips  802  withdraw from the wells  106 . The cleaning brushes  206  and wiping plate  804  enable continuous cyclical operation of pitting needles removing pits and pit material from fruit pieces  102 . 
     The foregoing discussion has been presented for purposes of illustration and description. The description is not intended to limit the invention to the form or forms disclosed herein. Consequently, variation and modification commensurate with the above teachings, within the skill and knowledge of the relevant art, are within the scope of the present invention. The implementations described herein and above are further intended to explain the best mode presently known of practicing the invention and to enable others skilled in the art to utilize the invention as such, or in other implementations, and with the various modifications required by their particular application or uses of the invention. It is intended that the appended claims be construed to include alternate implementations to the extent permitted.