Abstract:
A compressible and expandable sample tube holder includes a housing with a plurality of adjacent section members, movable toward and away from each other. Biasing members normally maintain the section members in an expanded condition. In the compressed condition the spacing between section members is reduced. A sample tube breakage detector for the sample tube holder includes slidable plungers having a protracted position that corresponds to a broken sample tube and a retracted position that corresponds to an unbroken sample tube in the sample tube holder. A detector compares the plunger positions before and after a centrifuge spin operation to detect any broken sample tubes in the sample tube holder. A gripper device for gripping the sample tube holder includes a lifting probe with an actuatable eccentric portion to hold the sample tube holder and a stabilizer to stabilize the sample tube holder during lifting. The gripper device and breakage detector are raised and lowered by a raising and lowering device having first and second telescoping members.

Description:
[0001]    This invention relates to a lab cell centrifuging module in an automated body fluid analysis system, and more particularly to an expandible centrifuge bucket for sample tubes, a bucket gripper device with a sample tube breakage detector, and an input-output device for raising and lowering the expandible bucket relative to the centrifuge.  
         OPERATION SUMMARY  
         [0002]    The lab cell centrifuging module (also referred to as the “module”) is a system that receives capped sample tubes, from an incoming section of a main conveyor, for centrifuging and decapping. Sample tubes are robotically positioned in expandible buckets within the system that hold, for example, fifteen sample tubes. A system robot sequentially transfers four loaded buckets into a centrifuge for spinning. The spun sample tubes are then robotically removed from the centrifuge and robotically transferred to a decapper device for decapping. The decapped sample tubes are robotically delivered to an outgoing section of the main conveyor for transport to another processing station.  
           [0003]    During startup there are four empty buckets  19  (FIG. 37) on each of three queues  13 ,  14  and  15  (FIGS.  2 - 4 ) for a total of twelve buckets. Four buckets are located on the unloading queue  13  (FIG. 4) and four buckets are located on each loading queue  14  and  15 . The buckets  19  (FIG. 37), which are in a normally expanded condition, are positioned toward the same corresponding end of each of the queues  13 ,  14 ,  15 , that is the forward left end, as shown in FIG. 3, also known as the home position  37  (FIGS. 32 and 35) of the queues  13 ,  14 ,  15 .  
           [0004]    A first of the continuing robotic operations of the module is to load one of the loading queues, such as the loading queue  14 , with capped sample tubes. The capped sample tubes are transported to the module on an incoming section of the main conveyor  1 . The sample tube delivery robot  8  (FIG. 3) transfers capped sample tubes from the conveyor  1  to buckets  19  in the loading queue  14 .  
           [0005]    When up to all four buckets  19  in the loading queue  14  have been loaded with capped sample tubes, the buckets are shifted to the opposite end of the loading queue  14  by a slide carriage  24  (FIG. 35) that is a component of the loading queue  14 .  
           [0006]    The loading queue  14  is sized such that when buckets are shifted from the home end  37  (FIGS. 32 and 35) to the opposite end thereof, the bucket  19  which was at the home end is now aligned with bucket deflectors  26 ,  27 . The bucket deflectors  26 ,  27  compress the normally expanded bucket  19  to enable the bucket gripper robot  7  to transfer the deflected or compressed buckets to the centrifuge  4  (FIG. 2) through an opening  28  in the unloading queue  13  (FIG. 3).  
           [0007]    While the bucket transfer operation from the loading queue  14  to the centrifuge  4  is taking place, the sample tube delivery robot  8  (FIG. 3) begins to transfer capped sample tubes from the incoming section of the conveyor  1  to the next loading queue  15 . Thus the bucket transfer operation from the loading queue  14  to the centrifuge  4  takes place simultaneously with the sample tube transfer operation from the conveyor  1  to the loading queue  15 .  
           [0008]    In addition, as soon as a loaded bucket is transferred from the loading queue  14  to the centrifuge  4  by the bucket gripper robot  7 , the bucket gripper robot  7  transfers an empty bucket from the unloading queue  13  back to the loading queue  14  to replace the loaded bucket that was just removed for transfer to the centrifuge. This exchange operation between loaded buckets from the loading queue  14  and unloaded buckets from the unloading queue  13  continues until all loaded buckets from the loading queue  14  are in the centrifuge and are replaced by empty buckets from the unloading queue  13 .  
           [0009]    Once again the exchange of buckets between the unloading queue  13  and the loading queue  14  takes place simultaneously while capped sample tubes are also simultaneously transferred, one by one, from the incoming section of the conveyor  1  to the loading queue  15 . Thus, there is alternate loading of empty buckets on the loading queues  14  and  15 .  
           [0010]    When all loaded buckets  19  from the loading queue  14  are transferred into the centrifuge  4  a spin operation begins and the unloading queue  13  is empty of all buckets.  
           [0011]    During the spin operation the sample tube delivery robot  8  continues to transfer sample tubes from the incoming section of the conveyor  1  to the loading queue  15 . When the spin cycle is completed the bucket gripper robot  7  sequentially removes a bucket  19  of spun sample tubes from the centrifuge  4 , places the bucket of spun sample tubes on the unloading queue  13 , and removes a bucket  19  of sample tubes from the loading queue  15  for placement in the centrifuge  4 , in the centrifuge space vacated by removal of the bucket of spun sample tubes. This sequential operation continues until all four buckets  19  of spun sample tubes from the centrifuge  4  are removed and replaced by loaded buckets  19  from the loading queue  15 . Thus there is alternate transfer of loaded buckets  19  from the loading queues  14  and  15  to the centrifuge  4 .  
           [0012]    The sample tube gripper robot  6  also simultaneously removes individual spun sample tubes from the buckets  19  that are removed from the centrifuge  4  and placed on the unload queue  13 . The removed individual spun sample tubes are transported by the sample tube gripper robot  6  to either one of the decappers  16 ,  17  (FIG. 3).  
           [0013]    While the bucket exchange is taking place between buckets in the loading queue  15  and the spun buckets from the centrifuge the sample tube delivery robot  8  once again transfers capped sample tubes from the incoming section of the main conveyor  1  to the empty buckets in the loading queue  14 . This cycle of operations by the sample tube gripper robot  6 , the bucket gripper robot  7  and the sample tube delivery robot  8  take place simultaneously and repetitively.  
           [0014]    Decapped sample tubes are transferred by the sample tube gripper robot  6  from the decappers  16 ,  17  to a rectangular path conveyor  18  (FIGS. 3 and 4). The sample tube delivery robot  8  transfers a spun and decapped sample tube from the rectangular path conveyor  18  to the conveyor  1  for transport to another processing station.  
         SUMMARY OF THE INVENTION  
         [0015]    The invention includes a compressible and expandable sample tube holder having a housing with a predetermined number of sample tube openings for receiving sample tubes. The housing includes a plurality of adjacent section members, including a pair of end section members, and at least one middle section member, assembled together in side by side arrangement. Each of the section members are movable toward and away from an adjacent section member. Biasing means are provided between the end section members and the middle section member to maintain the end section members and the middle section member in a side by side spaced relationship that defines an expanded condition of the housing. The housing has a compressed condition when opposing forces applied to the end section members overcome the biasing means and reduce the spaced relationship between each of the section members a predetermined amount. Connecting means are provided on each of the section members to secure each of the section members together in the movable adjacent side-by-side arrangement.  
           [0016]    The invention also includes a sample tube breakage detector having a housing with a plurality of slidable plungers. The plungers have an orientation corresponding to the orientation of sample tube positions in a sample tube holder. The plungers are separately retractable and separately protractible with respect to the housing, and each of the plungers have an end portion with a sample tube engagement surface that extends outwardly of the housing. Biasing means are associated with each of said plungers to separately urge the plungers into a first protracted position wherein the sample tube engagement surface of each plunger is a first predetermined distance from said housing. The protracted position of the plunger is correlatable with a broken sample tube in the corresponding sample tube position of the sample tube holder or a tubeless position in the corresponding sample tube position of the sample tube holder. The plungers are also separately movable against the force of the respective biasing means to a retracted position wherein the tube engagement surface is moved a predetermined amount toward the housing. The retracted position of each plunger is correlatable with an unbroken sample tube in the corresponding sample tube position of the sample tube holder.  
           [0017]    The sample tube breakage detector also includes detection means in the housing cooperable with each of the plungers to detect the protracted or retracted position of the respective plungers before and after a centrifuge spin operation of the sample tube holder with sample tube. Thus a comparison of the protracted or retracted plunger positions detected by the detection means before and after the centrifuge spin operation of sample tubes in the sample tube holder permits determination of whether a sample tube, previously detected in an unbroken condition in the sample tube holder before the centrifuge spin operation, has suffered breakage after the centrifuge spin operation.  
           [0018]    The invention further includes a gripper device for gripping the sample tube holder, which gripper device cooperates with the sample tube breakage detector. The gripper device can be incorporated with the sample tube breakage detector structure as an integral part of the sample tube breakage detector, and includes an elongated lifting probe depending from the housing of the sample tube breakage detector proximate one side of the housing. The lifting probe includes a fixed post having a first axis, and a gripper portion at a lower end of the post, away from the housing. The gripper portion has a second axis, and is movable with respect to the post from an axially aligned position with the post, wherein the second axis of the gripper portion and the first axis of the post are axially aligned, to an axially eccentric engagement position, wherein the second axis of the gripper portion is offset from the first axis of the post to permit engagement of the gripper portion against a portion of a sample tube holder such that the sample tube holder is held by the lifting probe. Stabilizing means are also provided on the housing for stabilizing the sample tube holder during lifting engagement of the sample tube holder by the lifting probe.  
           [0019]    The invention additionally includes a device for raising and lowering an object such as the sample tube breakage detector and the sample tube holder that is gripped by the sample tube breakage detector. The raising and lowering device includes a base and first and second telescoping members movable with respect to the base. The second telescoping member is movable to extended and retracted positions with respect to the first telescoping member. First drive means are mounted to the base and joined to the first telescoping member to move the first telescoping member in opposite directions with respect to the base. Second drive means are mounted on the first telescoping member and are joined to the second telescoping member to move the second telescoping member in opposite directions with respect to the first telescoping member and the base.  
           [0020]    The invention accordingly comprises the constructions and methods hereinafter described, the scope of the invention being indicated in the claims.  
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0021]    In the drawings,  
         [0022]    [0022]FIG. 1 is a simplified perspective view of the lab cell centrifuging module cabinetry, and a main conveyor schematically shown alongside the module for bringing sample tubes to the module and taking sample tubes away from the module;  
         [0023]    [0023]FIG. 2 is a simplified perspective view of the module of FIG. 1 with the cabinet doors removed to show the general components of the module, including a centrifuge on the lower left and electronic power and control devices on the lower right;  
         [0024]    [0024]FIG. 3 is a simplified top perspective view of tabletop components of the module including two load queues, an unload queue, two decappers positioned within the confines of a rectangular path conveyor, a sample tube gripper robot and a bucket gripper robot on one cross beam, and a sample tube delivery robot on another cross beam, and an external conveyor alongside the module;  
         [0025]    [0025]FIG. 4 is a simplified plan view of the tabletop components shown in FIG. 3, and the external conveyor;  
         [0026]    [0026]FIG. 5 is a simplified schematic elevation view of the bucket gripper robot, the sample tube gripper robot, tabletop components as shown in FIG. 3 and the external conveyor;  
         [0027]    [0027]FIG. 6 is a simplified schematic elevation of the bucket gripper robot engaging a bucket in the unloading queue;  
         [0028]    [0028]FIG. 7 is a fragmentary perspective view, partially exploded, of the back side of the cross beam that supports the sample tube gripper robot and the bucket gripper robot;  
         [0029]    [0029]FIG. 8 is a fragmentary perspective view, partially exploded of the tabletop structure of FIG. 3, with two disposal chutes normally underneath the decappers for receiving caps expelled from the decappers;  
         [0030]    [0030]FIG. 9 is a fragmentary perspective view, partially exploded, of the rectangular path conveyor framework surrounding the decappers;  
         [0031]    [0031]FIG. 10 is a non-exploded view of the structure shown in FIG. 9;  
         [0032]    [0032]FIG. 11 is an exploded perspective view of the support beam shown in FIG. 3 for the sample tube gripper robot and the bucket gripper robot;  
         [0033]    [0033]FIG. 12 is a perspective view of the sample tube gripper robot fingers and the robot finger support structure;  
         [0034]    [0034]FIG. 13 is an exploded view of the structure shown in FIG. 12;  
         [0035]    [0035]FIG. 14 is an enlarged perspective view of the sample tube gripper robot shown in FIG. 7;  
         [0036]    [0036]FIG. 15 is a perspective view of an input-output device of the bucket gripper robot, in a slightly extended position for raising and lowering the bucket gripper head (dotted) relative to the robot support beam;  
         [0037]    [0037]FIG. 16 is a view similar to FIG. 15 showing the input-output device fully retracted and including a flexible harness;  
         [0038]    [0038]FIG. 17 is a simplified sectional view taken on the line  17 - 17  of FIG. 15;  
         [0039]    FIGS.  18 - 20  show three views of the input-output device of FIG. 17 in progressively extended positions;  
         [0040]    [0040]FIG. 21 is a partially exploded perspective view of the input-output device as shown in FIG. 15, with some parts omitted for purposes of clarity;  
         [0041]    [0041]FIG. 22 is an exploded perspective view of the outer telescoping member of the input-output device shown in FIG. 21;  
         [0042]    [0042]FIG. 23 is an unexploded perspective view of the outer telescoping member shown in FIG. 22;  
         [0043]    [0043]FIGS. 24, 25,  26 ,  27 ,  28 ,  29 ,  30  and  31  show the exploded and assembled components of the bucket gripper head for the bucket gripper robot;  
         [0044]    [0044]FIG. 32 is a perspective view of the unloading queue, from the table top components of FIGS.  2 - 5  and  8 ;  
         [0045]    [0045]FIG. 33 is a partially exploded perspective view of the unloading queue as shown in FIG. 32;  
         [0046]    [0046]FIG. 34 is a partially exploded perspective view of the middle structure of the unloading queue shown in FIG. 33;  
         [0047]    [0047]FIG. 35 is a perspective view of one of two similar loading queues from the tabletop components of FIGS.  2 - 5  and  8 , with one sample tube bucket on the loading queue in a home position, and one sample tube bucket in an elevated unloaded position prior to being compressed from a normally expanded condition;  
         [0048]    [0048]FIG. 36 is a partially exploded perspective view of the loading queue shown in FIG. 35;  
         [0049]    [0049]FIG. 37 is a perspective view of the sample tube bucket in its normally expanded condition;  
         [0050]    [0050]FIG. 38 is a top plan view thereof in engagement with a hold down device  60  from one of the queues;  
         [0051]    [0051]FIG. 39 is a simplified schematic bottom plan view of the bucket in a compressed condition for release from the hold down device;  
         [0052]    [0052]FIG. 40 is an exploded perspective view of the sample tube bucket elements;  
         [0053]    [0053]FIG. 41 is a perspective view of one of three similar middle sections of the sample tube bucket shown in FIGS.  37 - 40 ;  
         [0054]    [0054]FIG. 42 is a front elevational view of the sample tube bucket;  
         [0055]    [0055]FIG. 43 is a top plan view of the sample tube bucket with leaf springs in one of the sample tube openings;  
         [0056]    [0056]FIG. 44 is a side elevational view of the sample tube bucket middle section shown in FIG. 41;  
         [0057]    [0057]FIG. 45 is a fragmentary perspective view of a leaf spring slot in one of the sample tube receiving openings-of the sample tube bucket;  
         [0058]    [0058]FIG. 46 is a sectional view taken on the lines  46 - 46  of FIG. 45;  
         [0059]    [0059]FIG. 47 is a sectional view taken on the line  47 - 47  of FIG. 43;  
         [0060]    [0060]FIGS. 48 and 49 are sectional views taken on the lines  48 - 48  and  49 - 49  of FIG. 42;  
         [0061]    [0061]FIG. 50 is a perspective view of one of the two similar end sections of the sample tube bucket;  
         [0062]    [0062]FIG. 51 is a front elevational view of the opposite side of the sample tube bucket end section shown in FIG. 50;  
         [0063]    [0063]FIG. 52 is a top plan view of the bucket end section;  
         [0064]    [0064]FIG. 53 is a perspective view of one of the two bucket leaf springs for each sample tube receiving opening in the sample tube bucket;  
         [0065]    [0065]FIG. 54 is a front elevation view of the sample tube bucket end section as shown in FIG. 50;  
         [0066]    [0066]FIG. 55 is a side elevational view of one of the opposite sides of the sample tube bucket end section shown in FIG. 54;  
         [0067]    FIGS.  56 - 58  are sectional views taken on the lines  56 - 56 ,  57 - 57 , and  58 - 58  of FIG. 54; and  
         [0068]    [0068]FIGS. 59 and 60 are fragmentary end elevation views of the input-output device and bucket gripper device for the bucket gripper robot before and after engagement with a sample tube bucket. 
     
    
       [0069]    Corresponding reference numbers indicate corresponding parts throughout the several views of the drawings.  
       DETAILED DESCRIPTION  
       [0070]    Referring to the drawings, FIG. 1 shows a main conveyor  1  of the type disclosed in U.S. Pat. No. 6,374,989 for  A Conveyor System For A Clinical Test Apparatus,  which is incorporated by reference herein. FIG. 1 also shows a six door housing  2   a  for the lab cell centrifuging module  2  (FIG. 2). The conveyor  1  is not part of the lab cell centrifuging module  2 .  
         [0071]    [0071]FIG. 2 shows a centrifuge  4  which is preferably a standard off-the-shelf centrifuge device, a tabletop assembly  5  operated by three robots which include a sample tube gripper robot  6 , a bucket gripper robot  7  and a sample tube delivery robot  8 . The robots  6  and  8 , which pick individual sample tubes, each have the same type of pneumatic fingers  6   a  and  8   a  (FIG. 3) that open and close in parallel relationship. A waste collection bin  9  (FIG. 2) receives caps from decapped sample tubes. A robot control cabinet  10  (FIG. 2) includes the computers, electronics and power supplies for the lab cell centrifuging module  2 .  
         [0072]    The robots  6 ,  7  and  8  (FIG. 2) are mounted on cross beams  11  and  12 , across the tabletop assembly  5 . Further details of the robots  6 ,  7  and  8  and the robot mounting structure for mounting the robots  6 ,  7  and  8  on the beams  11  and  12  are disclosed in U.S. Pat. No. 6,293,750 for  Robotics For Transporting Containers And Objects Within An Automated Analytical Instrument and Service Tool For Servicing Robotics,  which is incorporated by reference herein.  
         [0073]    The sample tube gripper robot  6  and bucket gripper robot  7  (FIG. 3) are commonly mounted on the beam  11 , which defines a front side of the module  2 . The sample tube delivery robot  8  is mounted on the beam  12  (FIG. 3).  
         [0074]    Three component boxes shown schematically and labeled  150 ,  151 ,  152  in FIG. 7 are known electronic motion controllers that control the drives  153 ,  154  and  131  corresponding to movement of the sample tube gripper robot  6  in the “x” direction, movement of the bucket gripper robot  7  in the “x” direction and movement of the bucket gripper robot  7  in the “z” direction (FIG. 3). “Z” and “y” movement of the sample tube gripper robot  6  are pneumatically actuated.  
         [0075]    [0075]FIG. 11 shows the beam  11  for the sample tube gripper robot  6  and the bucket gripper robot  7 , with “x” drives  153 ,  154  for the robots  6  and  7 , and respective robot drive belts  165 ,  165 . Each of the robot drive belts  165  has its own “x” drive  153 ,  154 .  
         [0076]    The tabletop assembly  5  (FIGS. 2, 3,  4  and  8 ) contains three queues, which include an unloading queue  13  and two loading queues  14  and  15 . The two loading queues  14  and  15  are the same. In addition there are two similar decappers  16  and  17  (FIGS.  2 - 4 ) and a relatively small rectangular path conveyor  18  (FIGS.  3 - 4 ) where sample tubes move around the decapper  16 ,  17  within the lab cell centrifuging module  2 . Thus the conveyor  18  which is part of the lab cell centrifuging module  2  is distinct and separate from the main conveyor  1  which is not part of the module  2 .  
         [0077]    Since the lab cell centrifuging module  2  has the moving robots  6 ,  7  and  8  the upper doors of the housing  2   a  (FIG. 1) for user access to the module are normally locked as a safety measure. As a further safety measure when any of the upper doors are opened the power to the unit is shut off via safety relays  155  (FIG. 7). Robot movement is thus shut down for operator safety.  
         [0078]    [0078]FIG. 2 also shows a centrifuge access path  18   a  in dotted outline. The access path  18   a  defines the “z” path of the bucket gripper robot  7  as it moves into and out of the centrifuge  4 . FIG. 3 includes a top perspective view of the tabletop assembly  5 , the robots  6 ,  7  and  8  and the main conveyor  1 .  
         [0079]    The tube gripper robot  6  moves in three axes—“x” and “z”, and also pivots a small amount about the “z” axis, as shown in FIG. 3, to accomplish a “y” shift. The bucket gripper robot  7  (FIG. 3) moves only in the “z” and “x” axes. The sample tube delivery robot  8  (FIG. 3) moves in all three directions “x” and “z” and pivots about the “z” axis to accomplish a “y” shift.  
         [0080]    The tabletop assembly  5  (FIG. 3) includes the unloading queue  13 , the two loading queues  14 ,  15 , the internal conveyor  18  and the two decappers  16  and  17 . All three robots  6 ,  7  and  8  and all three robot movements are programmed so as not to interfere with one another.  
         [0081]    An interface gate  75 , shown schematically in FIG. 3, is of the type shown in the previously referred to U.S. Pat. No. 6,374,989 and is employed on the conveyor  1 . The interface gate  75  is a wheel (not shown) with four positions. When a sample tube on the conveyor  1  arrives at the gate  75  the wheel turns 90 degrees and brings the sample tube (not shown) into a known position accessible by the sample tube delivery robot  8 . The sample tube delivery robot  8  is programmed to stop at a sample tube access position also referred to as the pick position  74 .  
         [0082]    A puck  54  (FIG. 4) of the type shown in U.S. Pat. No. 5,897,090 for  Puck For Sample tube,  which is incorporated herein by reference, is a small container that holds sample tubes that are transported on the conveyors  18  and  1 . Incoming sample tubes on the conveyor  1  (FIGS. 3 and 4) are stopped at the interface gate  75 . The interface gate turns 90 degrees to place individual sample tubes in the pick position  74  (FIG. 3). The sample tube delivery robot  8  can access the pick position  74  (FIG. 3) and is notified by system software that there is a sample tube in the pick position  74 .  
         [0083]    The sample tube delivery robot  8  thus moves to the pick position  74 , picks the sample tube and moves the sample tube to one of the available loading queues  14  or  15  (FIG. 3) which hold sample tube carriers or buckets  19  for the centrifuge  4 . The sample tube bucket  19  is also referred to as a centrifuge bucket (FIG. 37) and is essentially a container or holder with sample tube receiving openings that can hold up to 15 sample tubes in a 3×5 matrix.  
         [0084]    The sample tube delivery robot  8  thus picks a sample tube in the interface gate  75  on the conveyor  1  (FIGS. 3 and 4), moves that sample tube into one of the loading queues, either  14  or  15 , and then into one of the tube positions in the sample tube bucket  19 . Each of the loading queues  14 ,  15  is configured with four sample tube buckets  19 . The loading queues  14  and  15  thus provide a space for 4 buckets×15 sample tubes or sixty sample tubes per four bucket batch (FIG. 4).  
         [0085]    The system software determines when a loading queue  14  and  15  is interpreted as full—so it is not necessary to have all sixty sample tubes loaded into the four sample tube buckets  19  in the loading queues  14  and  15  to trigger a removal of the bucket  19  from the loading queue  14  and  15  to the centrifuge  4 . Thus the centrifuge process is based on a time limit rather than a quantity of sample tubes in a sample tube bucket  19 .  
         [0086]    A desired throughput for the lab cell centrifuging module  2  is to spin three hundred sample tubes per hour. If there are sixty sample tubes maximum per four bucket batch and five four bucket batches are spun per hour, the result is 5 spin cycles×60 sample tubes per 4 bucket spin cycle=300 spun sample tubes. Thus each four bucket batch has a programmed cycle time of approximately twelve minutes (sixty minutes divided by five batches results in twelve minutes per batch). These twelve minutes include the pure spin time and the time to load the buckets with sample tubes and unload the spun sample tubes from the sample tube buckets for decapping. The twelve minute cycle time is user configurable, not fixed. But once the cycle time is established the default is after twelve minutes and the loading queue is interpreted as ready to go to the centrifuge  4  whether or not all sample tube buckets  19  in the loading queue  14  and  15  are filled with sample tubes.  
         [0087]    For discussion purposes it can be assumed at startup that the centrifuge  4  is currently empty and that all sample tube buckets  19  in the three queues  13 ,  14  and  15  are in the position shown in FIG. 4. The loading queues  14  and  15  (FIG. 4) each contain four empty sample tube buckets  19  and the unloading queue  13  contains four empty sample tube buckets  19 . The four bucket positions on a slide carriage  24  in the loading queues  14 ,  15  are marked  20 ,  21 ,  22  and  23  (FIGS. 35 and 36).  
         [0088]    The sample tube delivery robot  8  (FIG. 3) moves individual capped sample tubes from a pick position  74  on the interface gate  75  of the conveyor section  1  to the sample tube buckets  19  on the load queue  14 , for example. Ideally all four sample tube buckets  19  on the load queue  14  will be filled with capped sample tubes by the sample tube delivery robot  8 . However, sample tube buckets  19  that are in the position on the load queue  14  as shown in FIG. 4 are not accessible by the bucket gripper robot  7  or the sample tube gripper robot  6 . Therefore the slide carriage  24  on the load queue  14  must move the sample tube buckets  19  from the home position  37  (FIG. 35) of the slide carriage  24  in a direction toward the opposite end of the load queue  14 .  
         [0089]    The sample tube bucket position  23  is thus aligned with the bucket deflectors  26  and  27  (FIG. 35) that compress the normally expanded sample tube bucket  19  (FIG. 37). The space on the load queue  14  between the bucket deflectors  26  and  27  also define a bucket pick position  25  (FIG. 35) which is accessible by the bucket gripper robot  7 , which moves along an access path  65  in the “x” direction. Thus the bucket gripper robot  7  moves over the compressed sample tube bucket  19 , moves down to engage the bucket  19 , picks the bucket  19  and moves over along the access path  65  on top of the centrifuge  4 . There is an open lid for the centrifuge  4 , and the bucket gripper  7  with a bucket  19  moves down into the centrifuge  4  below the tabletop  5  through an opening  28  (FIG. 3) in the unloading queue  13 .  
         [0090]    Inside the centrifuge  4  are four bucket receiving positions in a cross pattern (not shown). Thus when the first sample tube bucket  19  is deposited into the centrifuge  4  the system software triggers that event and the centrifuge bucket receiving cross pattern rotates 90 degrees. The bucket gripper  7  moves back to the loading queue  14  to the deflector position of the deflectors  26 ,  27 . Meanwhile the loading queue slide carriage  24  has moved to place the next bucket position, such as the position  22 , into the bucket pick position  25  (FIG. 35) between the two deflectors  26  and  27  so that the bucket gripper  7  can access it.  
         [0091]    The bucket gripper  7  (FIG. 3) picks the bucket from the position  22  (FIG. 35) moves it into the centrifuge opening  28  (FIG. 3) moves it down into the centrifuge  4  and comes back up. The bucket receiving cross pattern in the centrifuge  4  rotates 90 degrees. That happens four times until all four buckets  19  from all four positions  20 ,  21 ,  22  and  23  of the loading queue  14  (FIG. 4) are inside the centrifuge  4 .  
         [0092]    The centrifuge is filled to capacity when it contains four of the sample tube buckets  19  in a cross pattern.  
         [0093]    It should be noted that the centrifuge  4  has a top cover with a lid (not shown). The centrifuge software triggers that lid to close when the centrifuge is loaded with four sample tube buckets  19  before the spinning operation begins. The centrifuge lid must be closed during spinning because there is a refrigerating capability inside the centrifuge, and also for safety purposes because of the high speed rotating devices.  
         [0094]    During the described bucket transfer process from one of the loading queues  14  to the centrifuge  4  by the bucket gripper robot  7 , the sample tube delivery robot  8  will continue to load sample tubes into the other loading queue  15 . Therefore, one of the two loading queues  14 ,  15  is always available for the sample tube delivery robot  8 . As a result when one batch of four sample tube buckets  19  is spinning in the centrifuge  4 , one of the loading queues  14 ,  15  is being loaded by the sample tube delivery robot  8 , which transfers capped sample tubes from the conveyor  1  to a selected loading queue.  
         [0095]    The sample tube delivery robot  8 , independently of the robots  6  and  7 , loads capped sample tubes from the interface gate  75  on the conveyor  1  (FIG. 3) by picking sample tubes from the pick position  74  of the interface gate  75  (FIG. 3) and moving them into sample tube buckets  19  in the available loading queue  14  or  15 . Meanwhile the centrifuge  4  spins. Thus there is simultaneous activity.  
         [0096]    Centrifuge spin time is a selectable parameter of the system software that depends on the type of sample being spun. Spin time varies from urine to blood to whole blood to whatever body fluid is being spun. The lab cell centrifuging module  2  can be used not only for blood but for other types of body fluid and the spin time is a matter of choice, such as eight minutes or twelve minutes, for example. A predetermined spin time is specified to calculate the throughput of the system.  
         [0097]    After the centrifuge spin cycle is completed the centrifuge lid opens again, the bucket gripper robot  7  moves down into the centrifuge  4  along the path  18   a  (FIG. 2), picks a sample tube bucket  19  from the centrifuge  4  and moves it up through the opening  28  in the unloading queue  13  (FIGS. 3 and 32).  
         [0098]    The unloading queue  13  (FIG. 32) also has four bucket positions  31 ,  32 ,  33  and  34  on a slide carriage  36 , similar to the slide carriage  24  of the loading queues  14 ,  15 . The unloading queue  13  (FIG. 32) also has a bucket compressing device or mobile deflector  35 .  
         [0099]    After the bucket gripper  7  picks a sample tube bucket  19  from inside the centrifuge  4  and moves the bucket up through the opening  28  in the unloading queue  13  the slide carriage  36  (FIGS. 3, 4 and  32 ) moves over the opening  28 . The mobile deflector  35  also moves simultaneously to a position just over the opening  28  that is now covered by the slide carriage  36 . The bucket gripper robot  7  will then move down to place the sample tube bucket  19  at the position  31  on the slide carriage  36  (FIG. 32).  
         [0100]    Position  31  is now Just over the opening  28  that is covered by the slide carriage  36  and in between the two mobile deflectors  35 .  
         [0101]    The bucket gripper robot  7  releases the sample tube bucket  19  into the bucket position  31  and moves back up. Then the slide carriage  36  and the mobile deflector  35  move back to the home position  37  as shown in FIG. 32. When the slide carriage  36  and the mobile deflectors  35  are in the home position  37  the opening  28  to the centrifuge is once again uncovered.  
         [0102]    Meanwhile the centrifuge bucket receiving cross (not shown) rotates 90 degrees and moves the next bucket  19  of spun sample tubes into the bucket pick position inside the centrifuge  4 . The bucket gripper robot  7  moves down through the centrifuge opening  28  in the unloading queue  13  into the centrifuge  4 , picks the next spun sample tube bucket  19 , moves up and the same cycle is repeated. The slide carriage  36  of the unloading queue  13  (FIG. 32) moves over the centrifuge opening  28 , the mobile deflector  35  moves together with the slide carriage  36  over the centrifuge opening  28 , the bucket gripper  7  (FIG. 3) moves down puts the sample tube bucket  19  in the second bucket position  32  (FIG. 32) on the slide carriage  36 , which is now just over the opening  28 , releases the bucket  19  and moves up. And the bucket removal process from the centrifuge  4  continues until all four spun sample tube buckets  19  are removed and positioned on the unloading queue  13  (FIG. 4).  
         [0103]    Once all four of the spun sample tube buckets  19  are unloaded from the centrifuge  4  into the unloading queue  13  each sample tube bucket  19  will have up to fifteen sample tubes. The next function is to decap these spun sample tubes by decappers  16 ,  17  (FIG. 3), which are of the type shown in U.S. Pat. No. 6,257,091 for  Automatic Decapper,  which is incorporated by reference herein. During decapping the cap is removed from a spun sample tube by the decappers  16 ,  17  (FIGS. 4 and 5) and the uncapped sample tube is ultimately transported back to the conveyor  1  to the interface gate  75  in a place position  73  (FIG. 3) to permit the conveyor  1  to transport the spun and decapped sample tube to another processing station.  
         [0104]    The lab cell centrifuging -module  2  includes two decappers  16 ,  17  to maintain a desired throughput since one decapper is not fast enough to decap the sample tubes at a desired rate, and because the sample tube gripper robot  6  can be operated to move sample tubes faster to the decapper than one decapper can decap them. The decappers  16  and  17  have doors  40  and  41  (FIG. 3) that sequentially open to permit sequential insertion of a capped sample tube in each decapper.  
         [0105]    During operation of the two decappers  16  and  17  (FIG. 3) the respective upper doors  40  and  41  are opened. The sample tube gripper robot  6  puts a capped sample tube into one decapper, releases the sample tube, moves out, and the upper door of the decapper closes. A turning device (not shown) inside the decapper lowers the capped sample tube to a specific position while a clamp (not shown) holds the cap to thereby separate the sample tube and the cap. The respective decapper doors  40 ,  41  open and release a respective cap, which falls down a chute  161 ,  162  (FIG. 8) into a waste bin  9  (FIG. 2).  
         [0106]    The tube gripper robot  6  (FIG. 3) moves back and forth over the unloading queue  13  to the first available bucket in the unloading queue  13  where the spun sample tubes are located and picks a capped sample tube from the bucket  19 . The sample tube gripper robot  6  (FIG. 3) moves in the “x” direction and can access sample tubes at only one specific “y” position on the unloading queue  13 . Thus sample tube rows in the unloading queue  13  must be aligned with the pick position of the sample tube gripper robot  6 . When one row of five sample tubes are unloaded from the unloading queue  13  the sample tube bucket  19  must be moved by the slide carriage  36 , an amount equal to the distance between sample tube rows, to position the next row of five sample tubes in alignment with the pick position of the sample tube gripper robot  6 .  
         [0107]    The sample tube gripper robot  6  then moves in the “x” direction and in alignment with a row of unpicked sample tubes in the unloading queue  13 . The unloading queue  13  must then realign a new row of capped sample tubes for the sample tube gripper robot  6  each time the sample tube gripper robot  6  completes removal of a previous row of capped and spun sample tubes from a sample tube bucket  19 .  
         [0108]    Referring to FIG. 4 which is a top view of the tabletop assembly  5 , a reference line  50  indicates the “x” direction path of movement of the sample tube gripper robot  6 . The path line  50  is used for purposes of explanation and is not a scaled representation of the actual movement path of the sample tube gripper robot  6 . The sample tube gripper path  50  is also at the predetermined “y” position on the unloading queue  13  where the sample tube gripper robot  6  can pick sample tubes. Thus the sample tube gripper path  50  and the bucket gripper access path  65  are actually coincident.  
         [0109]    There are five pick positions on the tube gripper path  50  such as indicated by the reference circles  51 ,  52 ,  56 ,  57  and  58  (FIG. 4) along the tube gripper path line  50 . The reference circles  51 ,  52 ,  56 ,  57  and  58  correspond to the five sample tube positions in the sample tube bucket  19  on the sample tube gripper path  50  in the unloading queue  13 .  
         [0110]    Therefore, the sample tube gripper robot  6  moves to position  52  on the path line  50  (FIG. 4) picks the first sample tube, brings that sample tube to one of the decappers such as  16 , the decapper  16  closes its door  41 , decaps the sample tube and the sample tube gripper robot  6  moves back along the path line  50  and picks the next sample tube at the pick position  51  (FIG. 4), and moves it to the other decapper  17 .  
         [0111]    After the sample tube from the pick position  52  is decapped in the decapper  16  the decapper door  41  opens. The sample tube gripper robot  6 , after delivering the capped sample tube from the next pick position  51  into the decapper  17  picks the uncapped sample tube from the decapper  16  and moves it to a puck position  53  on the rectangular path conveyor  18  (FIG. 4) where an empty puck  54  should be available. The puck position  53  aligns with the sample tube gripper path  50 . Other empty pucks on the rectangular path conveyor  18  are designated by the circles  54 .  
         [0112]    Thus the sample tube gripper robot  6  moves to the decapper  16 , where the sample tube has been decapped and the decapper door  41  is open. The sample tube gripper robot  6  removes the decapped sample tube from the decapper  16  moves the decapped sample tube to the rectangular path conveyor  18 , to the puck position  53  (FIG. 4) releases the sample tube into a puck  54  and moves to the next sample tube in the bucket row on the sample tube gripper path  50 . The sample tube gripper robot  6  repeats this process five times whereby the row of sample tubes on the gripper path  50  in the sample tube bucket  19  is emptied of spun sample tubes for decapping.  
         [0113]    Next the unloading queue  13  slide carriage  36  (FIG. 32) moves the sample tube buckets  19  a small “y” distance to align the next row of available spun and capped sample tubes in the bucket  19  in alignment with the sample tube gripper path  50  (FIG. 4). The reference line  55  (FIG. 4) indicates the next available row of capped sample tubes that will move into alignment with the sample tube gripper path  50  to enable the sample tube gripper robot  6  to pick the next row of five capped and spun sample tubes from the sample tube bucket  19 .  
         [0114]    It should be noted that the slide carriage  36 , when supporting the buckets  19  on the unloading queue  13 , prevents the sample tube buckets  19  from dropping back into the centrifuge opening  28  (FIGS. 3, 4 and  32 ).  
         [0115]    As previously noted each sample tube bucket  19  (FIG. 37) has three rows of five sample tube positions or fifteen sample tubes per bucket. Four sample tube buckets  19  occupy the unloading queue  13  for total of sixty sample tubes (FIG. 4). If all sixty sample tube positions in the four buckets  19  are filled with sample tubes, the slide carriage  36  of the unloading queue  13  must make twelve moves to align each five row line of sample tube positions with the sample tube gripper path  50  (FIG. 4).  
         [0116]    When all capped and spun sample tubes in a sample tube bucket  19  (FIG. 4) are unloaded by the sample tube gripper robot  6  from the unloading queue  13  the bucket gripper robot  7  moves to the pick position above the centrifuge opening  28 . The unloading queue slide carriage  36  (FIG. 32) moves that empty sample tube bucket  19  to the pick position over the centrifuge opening  28  (FIG. 4), and the mobile deflectors  35  (FIG. 32) move to the pick position opening over the centrifuge opening  28  to compress the normally expanded sample tube bucket  19  (FIG. 4). The bucket gripper robot  7  then picks up the just emptied sample tube bucket  19  from the unloading queue  13  and moves the empty sample tube bucket  19  back to an empty loading queue such as  14  or  15  (FIG. 3).  
         [0117]    Once the first empty sample tube bucket  19  is transferred from the unloading queue  13  onto the loading queue  14 , the slide carriage  36  (FIG. 32) of the unloading queue  13  aligns the next available bucket row with the sample tube gripper path  50  (FIG. 4). The sample tube gripper robot  6  sequentially removes these sample tubes (up to five sample tubes) into the decappers  16  and  17 . Sample tube row alignment with the sample tube gripper path  50  occurs three times for each sample tube bucket  19  because there are three rows of five sample tube positions in each sample tube bucket  19  (FIG. 4).  
         [0118]    As previously noted, when a sample tube bucket  19  on the unloading queue  13  is empty it will be made accessible to the bucket gripper robot  7  by movement of the slide carriage  36  and the mobile deflector  35  of the unloading queue  13  (FIG. 4) above the centrifuge opening  28 . The bucket gripper robot  7  moving along the access path  65  (FIG. 32) picks the empty sample tube bucket  19  and moves the empty bucket  19  into the loading queue  14  or  15 . Thus the unloading queue  13  moves the empty sample tube bucket  19  into the position where it can be picked by the bucket gripper robot  7 , and the slide carriage  24  of the loading queue  14  or  15  provides an open bucket receiving space for the bucket gripper robot  7  to unload the empty sample tube bucket  19 . The loading queue  14 ,  15  (FIG. 35) has four sample tube bucket positions  20 ,  21 ,  22  and  23  that can now be filled with the empty buckets  19  transported by the bucket gripper robot  7 . Bucket exchanges continue for each loading queue  14 ,  15  until all of the sixty sample tubes from the four sample tube buckets  19  on the unloading queue  13  are decapped.  
         [0119]    The bucket gripper robot  7  always transfers empty sample tube buckets  19  from the unload queue  13  to the same “y” position in the loading queues  14  or  15 . Thus the positioning of the empty sample tube buckets  19  into the loading queues  14 ,  15  is determined by the slide carriage  24  of the loading queues  14 ,  15 . If a loading queue  14  or  15  is empty all sample tube bucket positions  20 ,  21 ,  22  and  23  (FIGS. 35 and 36) are empty.  
         [0120]    When the unloading queue  13  has a sample tube bucket  19  that has been emptied of sample tubes the empty bucket  19  becomes accessible to the bucket gripper robot  7  which moves along a predetermined “x” path or access path  65  (FIG. 32) in a predetermined “y” position over the unloading queue  13 . The bucket gripper robot  7  moves down and picks the empty bucket  19  from a bucket position  31  (FIG. 32) on the slide carriage  36  of the unloading queue  13 , moves up (same “y” position) and makes an “x” movement on the access path  65  above one of the loading queues  14  or  15 . The loading queue  14 ,  15  moves the empty bucket position  23  on the slide mechanism  24  to the same “y” position as the bucket gripper robot  7 . Thus the loading queue  14 ,  15  (FIG. 35) positions the empty bucket position  23  in the slide mechanism  24  to align with the access path  65  (FIG. 35) beneath the bucket gripper robot  7  (FIG. 4).  
         [0121]    The access path  65  for the bucket gripper robot  7  is noted on FIGS. 32 and 35. The bucket gripper  7  is only able to move back and forth in the “x” direction and up and down in the “z” direction but does not move in the “y” direction. Thus the access path line  65  determines the “y” position of the bucket gripper robot  7 . Therefore the slide carriage  36  of the unloading queue  13  and the same slide carriage  24  of the loading queues  14 ,  15  must move an appropriate amount in the “y” direction to permit removal of a sample tube bucket  19  from the unloading queue  13  and disposition of the same bucket onto a loading queue  14 ,  15 .  
         [0122]    There is a predetermined pickup position for the bucket gripper robot  7  along the access path  65  for removing an empty sample tube bucket  19  from the unloading queue  13  (FIG. 32). There are also predetermined drop-off positions along the path  65  for drop off of the empty sample tube bucket  19  in the loading queues  14 ,  15 .  
         [0123]    The slide carriage  36  of the unloading queue  13  (FIG. 32) moves the first empty sample tube bucket into alignment with the access path  65 . The bucket gripper robot  7  can now access the empty sample tube bucket  19  and picks that bucket, moves it in an “x” direction along the path  65  above the loading queue  14  or  15 . The loading queue slide carriage  24  moves the first bucket position  23  (FIG. 35) to where the bucket gripper robot  7  is holding the empty bucket. Then the bucket gripper robot  7  moves down, puts the empty bucket  19  onto the position  23 , releases the bucket, moves up, and moves in the “x” direction along the path  65  back to the unloading queue  13 .  
         [0124]    The unloading queue slide carriage  36  (FIG. 32) then moves to place the empty sample tube bucket  19  at bucket position  32  in alignment with the bucket gripper access path  65  so that the bucket gripper robot  7  (FIG. 4) can pick the next empty sample tube bucket  19 . The bucket gripper robot  7  picks the empty sample tube bucket  19  from the bucket position  32  (FIG. 32) and moves it back to the available loading queue  14 ,  15  (FIG. 4). The loading queue slide carriage  24  (FIG. 35) moves in the “y” direction to present the next empty bucket receiving position  22  in alignment with the bucket gripper access path  65 . The bucket gripper robot  7  (FIG. 4) moves down, releases the bucket  19  into the bucket receiving position  22  on the loading queue slide carriage  24  (FIG. 35) and moves back to the unload queue  13  where the empty sample tube bucket  19  at the position  33  (FIG. 35) is moved to access path  65  and so on.  
         [0125]    The rectangular conveyor  18  (FIGS. 3 and 4) receives decapped sample tubes that the sample tube gripper robot  6  removes from the decappers  16 ,  17  and places the decapped sample tubes in pucks  54  on the conveyer  18 . The conveyor  18  (FIGS. 3 and 4) includes four belts moving the pucks  54  along a rectangular path in one direction. FIGS. 9 and 10 show framework for the internal conveyor  18  and the belt drives  166 ,  167 ,  168  and  169  for each of the four conveyor belts of the conveyor  18 . The decapped sample tubes are removed from the decappers  16  or  17  and placed in an empty puck  54  at position  53  on the conveyor  18  (FIG. 4). A puck release mechanism  70  (FIGS. 4 and 8) on the conveyor  18  releases the puck  54  and the conveyor  18  moves the puck  54  to the internal pick position  72  (FIG. 4) at the conveyor  18 . A mechanism  71  (FIGS. 4, 8  9  and  10 ) holds the puck  54  at the pick position  72 . The puck holding mechanism  71  (FIG. 4) includes a retractable pin device or puck stopper  170  (FIGS. 9 and 10) for stopping movement of the pucks on the conveyor  18 . A sensor  171  indicates that there is a sample tube in the puck  54 .  
         [0126]    Thus the conveyor  18  (FIG. 4) defines a rectangular path of moving pucks  54  with decapped sample tubes. The sample tube gripper robot  6  will always move an uncapped sample tube from one of the decappers  16  or  17  to an empty puck  54  at the position  53  on the conveyor  18  (FIG. 4). The puck release mechanism  70  at position  53  (FIG. 4) releases a puck  54  with an uncapped sample tube for movement to the pick position  72  on the conveyor  18 .  
         [0127]    The sample tube gripper robot  6  picks the next decapped sample tube from the decapper  16 , for example, and brings the decapped sample tube to the next empty puck  54  at the puck position  53  (FIG. 4). The puck release mechanism  70  (FIG. 4) releases the puck  54  when it receives a decapped sample tube to provide a chain of pucks  54  with decapped sample tubes directed to the puck holding mechanism  71 . The pucks  54  with decapped sample tubes line up on the conveyor  18  at the puck holding mechanism  71  at the pick position  72  on the conveyor  18  (FIG. 4).  
         [0128]    The pick position  72  (FIG. 4) is also accessible by the sample tube delivery robot  8 . Thus if there is a puck  54  with a decapped sample tube, the sample tube delivery robot  8  will pick the decapped sample tube from the conveyor  18  at the pick position  72  and will move that decapped sample tube to the interface gate  75  on the main conveyor  1  at a place position  73  (FIGS. 3 and 4). The decapped sample tube is inserted in a puck  54  at the place position  73  on the conveyor  1  (FIG. 4) for movement by the conveyor  1  to other processing stations (not shown).  
         [0129]    The sample tube delivery robot  8  will then pick a capped sample tube in the interface gate pick position  74  on the conveyor  1  (FIG. 4) and move the capped sample tube to one of the open spots in a sample tube bucket  19  in the loading queues  14 ,  15 . Thus the sample tube delivery robot  8  is not only continuously loading capped sample tubes from the conveyor  1  into sample tube buckets  19  on the loading queues  14  and  15 , but on the way back is also transporting decapped sample tubes from the stop position  72  on the conveyor  18  to the interface gate place position  73  (FIGS. 3 and 4).  
         [0130]    Referring again to FIGS. 3 and 4 the sample tube delivery robot  8  moves to pick position  74  on the conveyor  1 , picks a capped sample tube from the conveyor  1 , moves the capped sample tube into one of the load queues  14  or  15  (FIG. 4), moves back to the puck stop position  72  on conveyor  18  and, if there is an available uncapped sample tube there, picks that uncapped sample tube and moves it into the place position  73  on the main conveyor  1 . Then the sample tube delivery robot  8  (FIG. 3) moves to the pick position  74  (FIG. 4) on the main conveyor  1 , picks an incoming capped sample tube from the main conveyor  1 , brings the capped sample tube to one of the buckets  19  on load queue  14  or  15 , and on the way back again stops at the puck stop position  72  (FIG. 4) on conveyor  18 , picks an uncapped sample tube, brings it to place position  73  on the main conveyor  1  to complete the pick-up and delivery cycle for the sample tube delivery robot  8 .  
         [0131]    In the bucket movement cycle the bucket gripper robot  7  picks sample tube buckets  19  filled with sample tubes out of the loading queues  14  and  15  and moves the buckets  19  into and out of the centrifuge  4  through the opening  28  (FIG. 3). The bucket gripper robot  7  also moves sample tube buckets  19  after a spin cycle, that have been removed from the centrifuge  4 , placed on the unloading queue  13 , unloaded while on the unloading queue  13 , and transfers such unloaded buckets  19  from the unloading queue  13  onto the loading queues  14  or  15  for reloading. The sample tube gripper robot  6  continuously transfers spun sample tubes from the sample tube buckets  19  in the unloading queue  13  into the decappers  16  and  17  (FIGS. 3 and 4). The sample tube gripper robot  6  (FIG. 3) also moves uncapped sample tubes from the decappers  16  or  17  to the position  53  (FIG. 4) on the conveyor  18 .  
         [0132]    As previously indicated the centrifuge  4  has four bucket receiving receptacles or spaces of predetermined size in a cross-pattern that accommodate standard sample tube buckets or centrifuge buckets (not shown) available from the manufacturer of the centrifuge  4 . The bucket receiving receptacle in the centrifuge defines the bucket size. Standard centrifuge buckets are not used in the centrifuge  4  because standard centrifuge buckets have only a 4×3 position matrix for sample tubes with a bucket capacity of twelve instead of fifteen sample tube positions. A four bucket batch of standard centrifuge buckets accommodates only forty-eight sample tubes rather than sixty sample tubes per four bucket batch of the present sample tube buckets  19 , thus affecting throughput.  
         [0133]    Another consideration dictating against the use of standard centrifuge buckets is that sample tubes are moved in and out of the centrifuge buckets by a robot. The sample tube positions in a standard centrifuge bucket make it difficult for the sample tube gripper robot  6  to pick individual sample tubes out of a standard bucket without interference with other sample tubes in the standard centrifuge bucket. A further problem is that the standard centrifuge buckets must be manually held down to avoid bucket lift during sample tube withdrawal since the standard centrifuge buckets have no built in hold down features.  
         [0134]    For example, referring to FIG. 38 the centers of two sample tube positions are indicated by the reference numbers  80  and  81 . The corresponding distance between the sample tube centers  80  and  81  in a standard centrifuge bucket (not shown) would make it difficult for the sample tube gripper robot  6  and the sample tube delivery robot  8  to remove and replace individual sample tubes in the standard centrifuge buckets without interfering with nearby sample tubes in the standard centrifuge bucket.  
         [0135]    To solve this interference problem the expandable centrifuge bucket or sample tube bucket  19  (FIG. 37) was developed. The sample tube bucket  19  has 3×5=15 positions to provide a capacity of sixty sample tubes per four bucket batch. Thus the sample tube bucket  19  can be in an expanded condition (FIGS. 4 and 37) when sample tubes are individually removed, and in a compressed condition (FIG. 39) when the bucket  19  is disposed in the centrifuge  4 .  
         [0136]    The mobile deflectors  35  (FIG. 32) on the unloading queue  13 , which compress the sample tube bucket  19  from a normally expanded condition to a compressed condition, are mobile because they must move to the position  65  shown in FIG. 32 to align with the bucket gripper robot  7 , to enable the bucket gripper robot  7  (FIG. 3) to engage the sample tube bucket  19 . The mobile deflectors  35  (FIG. 32) must then move away from the centrifuge opening  28  on the unloading queue  13  (FIG. 4) to enable the bucket gripper robot  7  to deposit the compressed sample tube bucket  19  through the opening  28  into the centrifuge  4  (FIG. 2). The mobile deflector assembly with pneumatic driven mobile deflectors  35  are shown in FIG. 33. The belt drive  180  moves the slide carriage  36  (FIG. 33). The slide carriage  36  (FIG. 32) for the unloading queue  13  is substantially the same as the slide carriage  24  (FIG. 35) for the loading queues  14 ,  15 . Member  183  (FIG. 34) connects the slide carriage  36  to a drive belt  181 .  
         [0137]    The loading queue deflectors  26 ,  27  have a fixed position because the sample tube delivery robot  8  brings sample tubes to the sample tube buckets  19  in the loading queues  14 ,  15  when the sample tube buckets  19  are positioned beyond the deflectors  26 ,  27 . The sample tube buckets  19  are thus positioned to receive sample tubes in the loading queues  14 ,  15  in an expanded condition. FIG. 35 shows a sample tube bucket  19 , above one of the loading queues  14 ,  15 , with arrows  189  indicating the compression force provided by the deflectors  26  and  27 . Home sensors  185  (FIG. 33) and  184  (FIG. 36) indicate a home position of the slide carriages  36  and  24 .  
         [0138]    The sample tube bucket  19  (FIG. 37) is constructed of five sample tube holding sections, including similar end sections  82 ,  83  (FIGS.  40 ,  50 - 52  and  54 - 58 ) and similar middle sections  84 ,  85  and  86  (FIGS.  40 - 49 ). Projecting clasp portions  87  (FIG. 40) are formed on each of the bucket sections  82 ,  83 ,  84 ,  85  and  86 . Thus the bucket end sections  82  and  83  each include two clasp portions  87  and the bucket middle sections  84 ,  85 ,  86  have four clasp portions  87 .  
         [0139]    The clasps  87  of one bucket section engage in notches  87   a  on adjacent bucket sections. The notches  87   a  define a bucket section expansion displacement distance identified by the reference number  88 , (FIG. 40) to provide an expandable and compressible accordion-like assembly of the bucket sections  82 ,  83 ,  84 ,  85  and  86 . Coil springs  89  (FIG. 40) between adjacent bucket sections bias the bucket sections to a normally expanded condition (FIG. 37).  
         [0140]    Leaf springs  91  (FIGS. 40, 43,  47  and  53 ), preferably two for each sample tube receiving opening  92  in the bucket  19 , as shown in FIG. 43 are provided to bias a sample tube  78  against a rounded side  93  of the sample tube receiving opening  92 . The leaf spring  91  (FIG. 43) is used because various different sample tube diameters may be used in the sample tube bucket  19 . The leaf springs  91  press the sample tube  78  to the rounded side  93  of the sample tube receiving opening  92  on FIGS. 37 and 40. The leaf springs  91  thus urge the sample tubes  78  in the sample tube receiving opening  92  into a specific pick position that is accessible by the sample tube delivery robot  8 .  
         [0141]    A small offset  102  (FIG. 53) is provided on the leaf spring  91  to lock the leaf spring in a spring receiving recess  103  (FIGS. 43, 45 and  46 ) at the sample tube receiving opening  92 . There are two spring receiving recesses  103  (FIG. 43) for each sample tube receiving opening  92  to accommodate the two leaf springs  91  that are provided in each sample tube receiving opening  92 .  
         [0142]    Rubber pads or sample tube cushions  90  (FIG. 40) are provided on the bottom of each sample tube receiving opening  92 . Since the centrifuge  4  spins up to 4500 rpm a small blemish or burr on the bottom of the sample tube receiving opening  92  in the bucket  19  or on the bottom of the sample tube  78  can cause the sample tube to split. The rubber pad  90  is a buffer or cushion, between the sample tube  78  and the sample tube bucket  19  at the bottom of the sample tube receiving opening  92 .  
         [0143]    A lower end portion of the bucket end sections  82  and  83  (FIG. 50) includes two small rectangular openings  95  used together with slide carriage teeth  60  (FIGS. 32 and 35) to hold the sample tube bucket  19  on the slide carriages  24  and  36  when the sample tubes are withdrawn by the sample tube gripper robot  6 .  
         [0144]    Generally, there is a frictional force between the sample tubes  78  and the sample tube receiving openings  92  in the sample tube bucket  19 . There is also a possibility that sample tubes  78  will become stuck in the sample tube bucket  19  for one or more different reasons such as bar code labels (not shown) on the sample tube  78  that partially peel away and adhere within the sample tube receiving opening  92  in the sample tube bucket  19 . Thus it is necessary to hold the sample tube bucket  19  down while the sample tube gripper robot  6  or the sample tube delivery robot  8  picks the sample tube  78  from the sample tube bucket  19 .  
         [0145]    In order to accomplish hold down of the sample tube bucket  19  during robotic removal of sample tubes from the bucket  19  slide carriage teeth  60  (FIGS. 32 and 35) are provided on opposite sides of the slide carriages  24  and  36  of the unloading queue  13  and the loading queues  14 ,  15 . The slide carriage teeth  60  engage a small rectangular opening  95  (FIG. 50) at the lower end portion of the bucket end sections  82 ,  83  to hold the buckets  19  down. The slide carriage teeth  60  are provided in all four bucket positions  20 - 23  and  31 - 34  of the respective slide carriages  24  and  36  (FIGS. 32 and 35).  
         [0146]    The sample tube buckets  19  also include an angle portion  101  (FIGS.  54 - 57 ) at the bottom of the bucket, at the end sections  82  and  83 , to enable the bucket to self guide when being moved downwardly into the centrifuge receptacle. Recesses  104  (FIG. 50) are provided in the bucket end sections  82  and  83  based on weight and stability considerations.  
         [0147]    The bucket gripper robot  7  (FIG. 3) includes a bucket gripper head  110  (FIGS.  3 ,  29 - 31  and  59 - 60 ) having two similar depending thick posts  111  and  112  and two similar depending thin posts  113  and  114 . A lower end portion  121  of the thick posts  111  and  112  can rotate to an eccentric position (FIGS. 29 and 30) which creates a small projecting edge  121   a  (FIGS. 30 and 60) on the lower end portion  121 . A turning device inside the post  111  turns 180 degrees and moves the lower end  121  to an eccentric position, thus creating the edge  121   a.    
         [0148]    The lower end portion or eccentric portion  121  of the thick posts  111  and  112  is actuated by a drive  125  (FIGS.  28 - 31 ), which is housed by a cover  124  (FIG. 28), for a belt  145  (FIG. 26) inside the gripper head  110  that turns the eccentric posts  147 ,  147  (FIGS.  24 - 26 ) that extend from the end portions  121  inside the thick posts  111  and  112 .  
         [0149]    The bucket end sections  82 ,  83  include a shelf-like top portion  119  (FIGS. 40 and 50) having a post receiving opening  118  above a recess  105  and a similar post receiving opening  120  above a recess  106  that is deeper than the recess  105 . The two thick posts  111 ,  112  are thus used for picking up a sample tube bucket  19  by entering the post receiving openings  120  in the bucket end sections  82 ,  83  (FIGS.  50 - 52 ) in a non-eccentric condition. The posts  111  and  112  are then placed in the eccentric position such that the eccentric created edge  121   a  fits in the recess  106  (FIGS. 50, 59 and  60 ) in the end sections  82  and  83  below the shelf portion  119 .  
         [0150]    The eccentric edge  121   a  of the posts  111 ,  112  engage the lower surface of the bucket shelf  119 , which prevents removal of the eccentric portion  121  from the opening  120 . Thus interference of the eccentric edge  121   a  with the shelf surface  119  enables the bucket gripper robot  7  to lift the sample tube bucket  19  using the thick posts  111  and  112  to engage the post receiving openings  118 ,  120  in opposite end sections  82  and  83  of the sample tube bucket  19 .  
         [0151]    During engagement of the bucket gripper robot  7  with a sample tube bucket  19 , the bucket  19  is in a compressed condition (FIG. 39). The bucket  19  is also held in the compressed condition by the bucket gripper robot  7  when the bucket  19  is lifted and transported. The sample tube bucket  19  is also maintained in a compressed condition in the cross-pattern bucket receiving receptacles (not shown) of the centrifuge  4 . The two thin posts  113  and  114  (FIGS. 29, 30,  31  and  59 - 60 ) pass into the respective post receiving openings  118  of the shelf  119  at the bucket end sections  82 ,  83  (FIG. 31) to engage a surface  122  at the bottom of the recess  105 .  
         [0152]    One of the thin posts  113 ,  114  (FIG. 31) is used purely for guidance and to prevent bucket tilt during bucket lifting and is shorter than the other thin post. The longer of the thin posts  113 ,  114 , in addition to serving a guidance and tilt prevent function, is used to determine that a sample tube bucket  19  is present when the bucket gripper robot  7  descends to a bucket pick-up position. Thus the longer of the thin posts  113 ,  114  will compress in height when it engages the bucket surface  122  (FIG. 31) and such compression causes a signal to be generated. FIGS. 59 and 60 show an eccentric portion  121  of the thick post  111  in a gripping position in a sample tube bucket  19 . FIGS. 59 and 60 also show at  192  the thin sensor post  113  compressed to indicate the presence of a sample tube bucket. FIG. 59 shows the normal protraction of the thin sensor post  113  when there is no sensing engagement with the sample tube bucket  19 .  
         [0153]    Thus when the thin sensor post  113 , for example, engages the bucket surface  122 , the post  113  will retract into the bucket gripper head  110  (FIGS. 59 and 60) and enable a sensor to detect the retractive movement via an optical flag, for example, and thereby provide an optical signal indicating the presence of a sample tube bucket  19 . The bucket sensing optical signal also directs the eccentric portion  121  of the thick posts  111 ,  112  (FIGS. 59 and 60) to move into the eccentric position. The eccentric is driven by the motor  125  (FIG. 28) which moves the belt  145  (FIG. 26) to rotate the eccentric shafts  147  that are joined to the eccentric portions  121 . Once the eccentric shafts  147  rotate the eccentric portions  121  to an eccentric position (FIG. 60) the bucket gripper robot  7  can move up with the sample tube bucket  19 . It will be noted that a base surface  122   a  (FIGS. 50, 59 and  60 ) of the recess  106  in the sample tube bucket  19  clears the bottom of the eccentric portion  121  of the thick posts  111  and  112 .  
         [0154]    The bucket gripper head  110  (FIGS. 29 and 30) of the bucket gripper robot  7  also includes fifteen depending spring loaded retractable posts or plungers  123  that correspond to and align with the fifteen sample tube positions in a compressed sample tube bucket  19 . An enlarged washer  123   a  is fixed to the lower end of each retractable plunger post  123  and a coil spring  129  (FIGS. 29 and 30) on the plunger  123 , which bears against the washer  123   a,  urges the plunger  123  into a protracted position. The plunger post  123  is thus spring biased in a downwardly protracted position but has the capability to retract up into the bucket gripper head  110  of the bucket gripper robot  7 .  
         [0155]    Retractive movement of the plungers  123  is individually detected inside the bucket gripper head  110  by fifteen sensors that correspond to each of the fifteen plungers  123 . The fifteen sensors detect the presence or absence of a sample tube for a particular sample tube position in the bucket. The plungers  123  can thus operate as detectors of broken sample tubes.  
         [0156]    A guide  126  (FIG. 28) for the plungers  123  (FIGS. 29 and 30) guides retractive movement of the plunger  123  in the bucket gripper head  110 . A mechanical flag  127  (FIGS. 26 and 28) on an upper end of the plunger post  123  moves parallel to the guide  126  and activates an optical sensor below the flag  127  when the plunger post  123  is retracted to indicate whether a sample tube is present.  
         [0157]    When the four sample tube buckets  19  filled with up to sixty sample tubes are disposed in the centrifuge  4  there is a likelihood, especially with glass sample tubes, that one or more of the sample tubes will break during spinning because of high forces generated during the spinning operation. Before the bucket gripper head  110  releases a sample tube bucket  19  filled with sample tubes into the centrifuge  4  the operating software saves a record of the presence and location of sample tubes in the fifteen sample tube positions in the sample tube bucket  19 . Such record is based on an identification of sample tube presence in the sample tube bucket  19  as determined by the optical sensors corresponding to the fifteen retractable plungers  123  of the bucket gripper head  110 .  
         [0158]    If there is a sample tube present in the sample tube bucket  19  the plunger  123  corresponding to the occupied sample tube position in the bucket  19  is moved up in a retracted position based on engagement of the plunger washer  123   a  with the capped end of the sample tube. If there is no sample tube present in one or more sample tube positions of the sample tube bucket  19 , the plungers  123  corresponding to the sample tube positions in the bucket  19  remain protracted (a default position).  
         [0159]    Therefore, the plunger sensors in the bucket gripper head  110  provide information before a centrifuge operation of whether or not there is a sample tube present in the sample tube bucket  19  for each sample tube position in the bucket  19 . FIGS. 59 and 60 show plungers  123  in a retracted and non-retracted position relative to the bucket gripper head  110 , indicating whether or not some or all sample tubes are present in the sample tube bucket  19 . A record of sample tube occupancy in the sample tube bucket  19  is also obtained from the bucket gripper head  110  after the centrifuge operation is complete to determine whether or not there is a sample tube present in each sample tube position of the spun sample tube bucket  19 .  
         [0160]    Unit software will compare the sample tube position information after the centrifuge operation with the sample tube position information before the centrifuge operation and determine if there is a broken sample tube. Thus the unit software saves an information record of 4×15 sample tube positions for each sample tube bucket  19  before spinning and compares that information with position information obtained when the bucket gripper robot  7  removes the sample tube buckets  19  from the centrifuge  4  after the spin operation is completed.  
         [0161]    When the sample tube buckets  19  are unloaded from the centrifuge  4  by the bucket gripper robot  7  and one of the plungers  123  is in the protracted default position, such protraction may indicate that a sample tube is broken. If that plunger  123  was in a retracted position before the spinning operation, indicating the presence of a sample tube, then it can be determined from a comparison of the tube occupancy record information of the sample tube bucket before and after centrifuge spinning that a particular sample tube in a particular position in the sample tube bucket  19  is broken. Thus the bucket gripper robot  7  has a broken sample tube detector feature in the bucket gripper head  110 .  
         [0162]    When a broken sample tube is discovered after a centrifuge spin operation the bucket gripper head  110  will release the sample tube bucket  19  so that the bucket  19  remains in the centrifuge  4 . The bucket gripper robot  7  will then move up and out of the centrifuge  4  without the bucket  19 . The centrifuge lid will close and further robot operation will cease. A signal will be sent to a monitoring station that a broken sample tube is detected. The centrifuge lid must then be opened and any debris inside must be removed.  
         [0163]    Thus there are sixteen optical sensors inside the bucket gripper head  110 . Fifteen sensors are used for detecting broken sample tubes and the sixteenth sensor is for detecting the presence of a sample tube bucket  19 . An electronic intelligence unit communicates with the robot control cabinet  10  based on information detected by the bucket gripper robot  7 .  
         [0164]    It is necessary to move the sample tube buckets  19  a certain height up from the tabletop  5  and down into the centrifuge  4  and keep the movement mechanism within the height of the unit cabinet  2  (FIG. 1). Vertical movement of the bucket gripper robot  7  in the “z” direction cannot be accomplished with one single post because the length of a single post would be longer than the distance between the tabletop  4  and the top of the cabinet  2 . Therefore a single post would extend above the unit  2 , which is not acceptable. To solve this problem an input-output extender device  130  for raising and lowering the sample tube buckets  19  (FIGS. 3, 15,  16 ,  17  and  8 - 20 ) was developed.  
         [0165]    A mounting collar  128  (FIGS. 29 and 30) for the extender device  130  is provided on the bucket gripper head  110 . A mounting hub  143  (FIGS. 16 and 21) at the end of an inner post  135  (FIG. 15) is mounted to the mounting collar  128  (FIGS.  28 - 30 ). FIGS.  17 - 20  show the bucket gripper extender device  130  in different extended positions. A flexible wiring harness  144  (FIG. 16) is joined at one end to a connector  149  (FIGS. 29 and 30) on the bucket gripper head  110  and secured to a bracket  145  (FIGS. 16 and 21) that moves with the inner post  134 . An opposite end of the wiring harness  144  is joined to the support plate  142  (FIG. 16) at  146  for connection to a connector  157  (FIG. 7). The connector end  149  (FIGS. 29 and 30) of the harness  144  (FIG. 16) can thus move with the inner post  135  and the bucket gripper head  110  (FIG. 15) while maintaining an electrical connection with the bucket gripper head  110  at the connector  149  (FIGS. 29 and 30).  
         [0166]    The extender device  130  includes two telescoping posts  134 ,  135  (FIGS.  15 - 21 ) that are movable on the support plate  142 . A drive motor  131  (FIGS.  15 - 21 ) at the support plate  142 , drives a toothed endless belt  132  (FIGS. 15 and 17- 21 ) that moves the outer post  134 .  
         [0167]    Referring to FIGS. 13, 14,  15  and  21  the toothed belt  132  (FIG. 21) is secured by a bracket  138  (FIG. 21) to the outer post  134  to move the outer post  134  up and down. Vertical movement of the outer post  134  causes a spindle  136 , mounted to an upper end of the outer post  134  (FIGS. 15 and 21), to rotate relative to a fixed toothed belt  137  (FIGS. 15 and 16). The fixed belt  137  has one end fixed at  139  to an upper end portion of the support plate  142  (FIGS. 15 and 16) and an opposite end fixed at  140  to a lower end portion of the support plate  142 . Rotation of the spindle  136  causes movement of a toothed endless belt  133  mounted on the outer post  134  (FIGS. 15, 16 and  21 ) and attached to the inner post  135  by fasteners  141  (FIG. 17).  
         [0168]    Movement of the endless belt  133  thus raises or lowers the inner post  135  relative to the outer post  134  (FIGS.  18 - 20 ). It should be noted that the inner and outer posts  134  and  135  extend and retract simultaneously. Thus the inner and outer posts  134  and  135  move at the same rate, in the same direction, at the same time.  
         [0169]    A various changes can be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.