Abstract:
A laboratory tube cap presenter for a tube, such as a test tube, a medical vial or other vessel that may be capped by an automated capper in a robotic tube handling apparatus, the tube cap presenter having a magazine of pre-oriented tube caps that cooperates with a selector mechanism and a shuttle mechanism to transport a selected tube cap to a presentation station where the tube cap is oriented for pick up by the pickup mechanism of a robotic tube handling apparatus.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present invention is based on U.S. Provisional Patent Application Ser. No. 61/742,400, filed Aug. 10, 2012 entitled, “Laboratory Tube Cap Presenter for Capping Laboratory Tubes,” filed in the names of Alexander V. Drynkin and David B. Miller. The priority of this provisional application is hereby claimed and the application is hereby incorporated herein by reference thereto. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a laboratory tube cap presenter in the form of a machine that automates the task of orienting and positioning the cap of a laboratory tube, typically a test or sample tube that is processed by an automated or robotic tube handler. A tube handler moves one or more laboratory tubes from station to station for any of a variety of laboratory procedures. Frequently, the laboratory tube is capped at some step in the procedure necessitating the cap to be positioned at a pickup location before capping. 
     There exist tube cap feeders that position and orient tube caps for pickup by an automatic tube handler. However, the task of feeding tube caps from a supply to a robotic tube handling apparatus becomes substantially more difficult when the height of the tube cap is less than its diameter. For such a condition, the feed process is challenging because the tube cap can easily become disoriented when in a stacked column. The disoriented tube cap can then jam the feed mechanism, halting the automated tube handling process. 
     The laboratory tube cap presenter of this invention is designed to feed tube caps, including the difficult to handle cap that has a height that is less than the diameter of the cap, to a location and in an orientation to be transferred to a capping station. The tube cap is then typically transported to a capping station by automated tube handling apparatus where the tube cap is installed on a laboratory tube by a capping mechanism. 
     SUMMARY OF THE INVENTION 
     The laboratory tube cap presenter of this invention is designed to individually feed tube caps from a bulk supply of laboratory tube caps to a location and in an orientation that can be transferred to a capping station. The laboratory tube cap presenter is particularly designed to co-operate with a robotic tube handling apparatus having a picker mechanism that engages the presented cap and transports the cap to a capping station. The laboratory tube cap presenter in its preferred embodiment is constructed to engage a magazine or cartridge of pre-oriented tube caps and shuttle selected caps to the presentation station where the cap can automatically or manually be retrieved for further processing. Typically the automated tube cap presenter is an auxiliary component in an automated tube capping operation and cooperates with a robotic tube handler. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the laboratory tube cap presenter of this invention with an outer casing removed to reveal the operational components. 
         FIG. 2  is a front elevational view of the tube cap presenter of  FIG. 1  with a tube cap carrier in an alternate position. 
         FIG. 3  is an enlarged partial perspective view of a portion of the tube cap presenter of  FIG. 2  with the tube cap carrier in the alternate position. 
         FIG. 4  is an enlarged partial cross-sectional view of the apparatus of  FIG. 3 . 
         FIG. 5  is an end view of the tube cap presenter of  FIG. 1  with the tube cap carrier located at an orientation station. 
         FIG. 6  is an end view of the tube cap presenter of  FIG. 1  with the tube cap carrier located at the orientation station and a tube cap presentation pin raised to a presentation position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The laboratory tube cap presenter of this invention, shown in  FIGS. 1 and 2 , is designated generally by the reference numeral  10 . The construction of the tube cap presenter  10  is designed as a desk top component that typically co-operates with a robotic tube handling apparatus having a picker mechanism that can retrieve a tube cap presented for pickup by the subject tube cap presenter. It is to be understood that the presented tube cap can be manually retrieved or retrieved by any of a variety of different mechanical mechanisms. As such, modifications to the component construction to accommodate different systems for which the tube cap presenter  10  is an accessory are to be expected and do not affect the core invention disclosed herein as a preferred embodiment and are therefore not shown herein. 
     As shown in  FIGS. 1 to 3 , the tube cap presenter  10  has an external housing  12  that is in part removed to reveal the internal sheet-metal frame  14  with an intermediate deck  15  for containing and supporting the electro-mechanical assemblies for extracting a tube cap  16  from a storage magazine  18 . The storage magazine  18  holds hundreds of tube caps  16  in vertical guide channels  20  formed by dividers  22 . In the storage magazine  18  the tube caps  16 , typically flat tube caps, are oriented side-to-side with the axis of the circular caps being horizontal rather that the traditional stacking of tube caps on a vertical axis in a cylindrical column. In stacking the tube caps  16  in a channel, the flat tube caps, which typically have a height less that the cap diameter, do not become disoriented and jammed in the magazine  18  during depletion. The storage magazine  18  is preferably detachable for quick replacement with a filled magazine or substitution with a magazine of different caps in size, color or configuration. 
     The storage magazine  18  abuts a sorting shunt  24  that has a gateway panel  26  with similar guide channels  28  that are aligned with the guide channels  20  of the magazine  18  as shown in the enlarged partial perspective view of  FIG. 3 . It is contemplated that the storage magazine  18  is replaceable in the manner of a pre-loaded cartridge and therefore each magazine includes a barrier blade  30  with a blade stop  33  that locates at the bottom of the magazine to prevent the caps from escaping during installation or replacement. The two protruding thumbscrews  32  allow easy removal of the barrier blade  30  before operation. The storage magazine  18  and the gateway panel  26  of the sorting shunt  24  have open slots  34  and  36  along the major portion of the guide channels  20  and  28  to allow visual inspection of the content of the magazine  18  and gateway panel  26 . These slots  34  and  36  may permit limited corrective action in the rare event of a feed problem because of a disoriented cap. 
     The sorting shunt  24  includes a displaceable actuator assembly  40  that includes a block and release mechanism  38  and a cap carrier  42  for transport of a released cap  16  to an orientation station  44 . The displaceable block and release mechanism  38  has a spool  46  that slides on a square spindle  48  connected at one distal end  50  to the shaft (not shown) of a drive motor  52  by a collet  54  and at the other end to a bearing  56  mounted to the internal frame  14 . Incremental rotation of the spindle  48  on electrical command, rotates the spool  46 . The spool  46  is rotated about twenty degrees in opposite directions from a home position by the drive motor  52  for generating the reversible linear motion in the block and release mechanism  38 . 
     The spool  46  of the block and release mechanism  38  has a structural cage  58  shown also in  FIG. 4  with upper and lower slotted channel members  60  and  62  that bracket the spool  46  and connect to a pivotal back plate  64 . The construction as shown in  FIGS. 3 and 4  allows reverse linear reciprocal motion of two hooked fingers  66  and  67  extending from the channel members  60  and  62 , respectively. The hooked fingers  66  and  67  engage the flange  68  of selected blocking pins  69 . 
     This restricted movement in the block and release mechanism  38  is accomplished by bearing pins  70  and  72  projecting from each end of the spool  46  that engage open slots  74  and  76  in the side elements  78  of the channel members  60  and  62 . The open slots  74  and  76  accommodate the slight vertical displacement of the bearing pins  70  and  72  on partial rotation of the spool  46 . Horizontal displacement of the slotted channel members  60  and  62  without corresponding vertical displacement is accomplished by guide rollers  80  that ride on the spool surface  82  and have extending shafts  84  that extend into elongated slots  86  in the side elements  78  of the channel members  60  and  62 . The shafts  84  are positioned and retained by clips  87 . The pivotal interconnection of the channel members  60  and  62  with the back plate  64  by pin  88  and guide shaft  90  maintain the spool cage  58  around the spool  46  as the actuator assembly  40  is transported horizontally across the inner side  92  of the gateway panel  26 . 
     The inner side  92  of the gateway panel  26  has upper and lower pin racks  94  and  96  that are formed by U-channels  98  that accommodate the series of blocking pins  69  that project in pairs into each guide channel  28 . The upper blocking pins  100  block the passage from the storage magazine  18  through the gateway panel  26  until the pin is retracted allowing a cap  16  to drop to the simultaneously extended lower blocking pin  102 . When the lower blocking pin  102  is retracted, the tube cap  16  resting on the lower blocking pin  102  is released to a cap receptacle  104  on the cap carrier  42  positioned below the opened channel of the gateway panel  26 . 
     Simultaneously, the upper pin  100  is extended preventing caps from the magazine  18  from passing through the gateway. For clarity, the upper pin  100  and the lower pin  102  are shown displaced from the actuator assembly  40 , but each of the pins  69  in the series of upper and lower pins  100  and  102  is biased by a compression spring  105  to maintain controlled positioning during operation. 
     The cap carrier  42  is part of the overall displaceable actuator assembly  40 . Together with the block and release mechanism  38 , the cap carrier  42  is transported in a housing carriage  106  toward the orientation station  44 . The housing carriage  106  has an attached guide block  107  that is slideably engaged with a rail  108  mounted along the inside back of the frame  14 . The cap carrier  42  is slideably connected to the housing carriage  106  on guide rods  109  to extend the travel of the cap carrier  42  to the orientation station  44  outside the main frame  14  as shown in  FIG. 1 . Displacement of the housing carriage  106  and cap carrier  42  is accomplished by a drive belt  110  that loops around a drive capstan  111  and an idler wheel  112  on the intermediate deck  15 . 
     The drive belt  110  has a point of attachment to a tab  113  that depends from the cap carrier  42  as shown in the enlarged, partial perspective view of  FIG. 7  with the drive belt removed for clarity. Rotation of a stepping motor  114  drives the drive capstan  111  and looped drive belt  112  and displaces the cap carrier  42  and connected housing carriage  106  alongside the gateway panel  26 . When the cap carrier  42  has received a cap  16  and is programmed to travel the extended distance to the orientation station  44 , the housing carriage  106  is halted in its travel by a stop (not visible) and the cap carrier  42  with its pivotally connected actuator assembly  40  advances to project a portion of the cap carrier  42  and the actuator assembly  40  outside of the internal frame  14  to the orientation station  44 . 
     During operation the housing carriage  106  and the carried cap carrier  42  are transported to a selected position under one of the guide channels  28  of the gateway panel  26  where a tube cap  16  trapped in the guide channel  28  is released by the block and release mechanism to the receptacle  104  at the end of the cap carrier  42 . 
     The cap carrier  42  of the actuator assembly  40  has a retractable presentation pin  116  in a pivotal housing  118 . The presentation pin  116 , which has been retracted by action of the block and release mechanism  38  is urged against the inside of the tube cap  16  that has been released to the receptacle  104  of cap carrier  42 . In the event the presentation pin  116  is urged against the top of an incorrectly loaded cap or an empty receptacle  115 , the anomaly is sensed by sensors  117 , and the cap is ultimately rejected at the orientation station  44  or the sequence is aborted. A cap  16  that is correctly positioned is retained by the presentation pin  116  which is biased by a spring  123 . The presentation pin  116  is a mounting post for positioning the tube cap  16  at a specified location for pickup. 
     As shown in  FIG. 4 , the block and release mechanism  38  has a depending tab  120  that engages a flange  122  on the internal end of the presentation pin  116 . On rotation of the spool  46  of the block and release mechanism the presentation pin  116  is retracted while the tube cap  16  simultaneously seats in the receptacle  104  of the cap carrier  42 . On reverse rotation of the spool  46 , the pins  88  reverse allowing the next tube cap to drop into the ready position. The presentation pin  116  when released extends a contact end  119  (shown in dotted line) that contacts the inside of a tube cap  16  trapped in the receptacle  104 . 
     The captured tube cap  16  retained by the extended presentation pin  116  is then shuttled to the orientation station  44  at one end of the internal frame  14 . As the housing carriage  106  with the block and release mechanism  38  reaches the limit of its travel, a pivotal, depending latching roller  130 , shown in  FIG. 7 , contacts a projecting ramp  131 , to unlatch the cap carrier  42  and pin actuator housing  118  from the main housing carriage  106 . The released cap carrier  42  continues independent travel on the guide rods  109  to the orientation station  44 . 
     A second stationary stabilizer pin  121  in the pivotal housing  118  of the actuator assembly  40  cooperates to hold a cap  16  on the contact end  119  of the presentation pin  116  as it travels to the orientation station  44 , as shown in  FIGS. 5 and 6 . It is to be understood that certain of the cooperation actuating elements are shown displaced from one another for clarity, but are typically biased by springs that typically urge one element against the other as is well known in the art. 
     The pivotal housing  118  for the presentation pin  116  of the cap carrier  42  extends through an opening  132  in the internal frame  14 , as shown in  FIGS. 1, 5 and 6 . The pivotal housing  118 , as shown in  FIG. 4 , has a pivot axel  134  and a depending cam plate  136  that is engageable by a pivot actuator  138  on the outside of the frame  14  at the orientation station  44 . The cam plate  136  of the pivotal housing  118  has a stop pin  142 , and a cooperating cam slot  144  that is engageable with an actuator roller  146  on the end of a crank arm  148  of the pivot actuator  138 . The crank arm  148  pivots on drive shaft  150  connected to a drive motor  152 . The crank arm  148  has a diametric extension plate  154  that cooperates with a sensor unit  158  to sense rotational travel of the crank arm  148 . 
     As shown in  FIG. 5 , the extended presentation pin  116  engages the inner side of the tube cap  16  positioned in the receptacle  104  of the cap carrier  42  located at the orientation station  44 . While engaging the tube cap  16  the drive motor  152  is activated and the crank arm  148  swings the actuator roller  146  into engagement with the cam slot  144  of the cam plate  136 . As the actuator roller  146  travels in the cam slot  144 , the pivotal housing  118  with the presentation pin  116  swings a quarter turn with an upward lift until cam plate  136  is restricted by the stop pin  142  to a holding location, as shown in  FIG. 6 . In the position shown in  FIG. 6 , the presented cap  16  can be conveniently removed manually, or more typically, by an accessory robotic pickup mechanism of a capping machine. 
     Referring again to  FIG. 1 , the tube cap presenter  10  has an electronics compartment  162  below the intermediate deck  15  having one or more electronic circuit boards  164  that provide the electronics for controlling the operation. The circuit boards  164  include a controller with an internal processor  166  for the electromechanical operation of the system. The tube cap presenter  10  also includes an electronic interface to an external processor such as a general purpose computer or the control system of an auxiliary system such as an automated capper. 
     The sequence of operations can be controlled with a user application with a variety of options suitable to a particular task. For example, each of the vertical guide channels can be filled with caps of different color or barcode class marking and can be selectively accessed according to the requirement of the user. Or, for expediency, caps in the vertical guide channels closest to the presentation station can be first exhausted before moving to the next closest channel. These and other variations in operation are expected and do not depart from the scope of the claims.