Abstract:
This disclosure relates to an apparatus for transporting a vessel and to a sorting apparatus. The apparatus has at least one support device adapted to support the vessel in a reclined orientation, and a pushing mechanism adapted to transport the vessel along the support device. Advantageously, the apparatus is relatively simple and does not require vessels to contact an endless conveyor. Thus, vessels can be more readily rotated, weighed, etc. This disclosure also relates to a method of sorting vessels. One application of the apparatus and method is in the sorting of test tubes containing blood samples for testing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority, under 35 U.S.C. §§119, 120, 363, and 371 of Australian Patent Application No. 2007904368, filed Aug. 15, 2007, and International Application No. PCT/AU2008/001078, filed Jul. 28, 2008, which designated the United States, and was published in English, the entire disclosures of which are all hereby incorporated herein by reference in their entireties. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    n/a 
       FIELD OF THE INVENTION 
       [0003]    The present invention relates to apparatus and methods for transporting and/or sorting vessels, and more particularly to apparatus and methods for sorting test tubes containing blood samples for testing. However, it should be appreciated that the invention is not limited to this particular field of use. For example, the test tubes may contain samples of other biological substances, solids, jellies, or other liquids. 
       BACKGROUND OF THE INVENTION 
       [0004]    The diagnostic pathology departments of modern hospitals and diagnostic laboratories can receive thousands of test tubes containing patient&#39;s blood samples every day. The process of sorting these samples to direct them to the various tests and operations that each sample requires can be a time consuming and labor intensive task. 
         [0005]    Typically, each test tube is labeled with a bar code that identifies the patient. The patient&#39;s records are normally stored in a database that is updated to include the tests and operations to be performed on each blood sample. In addition to testing, operations that may be required to be performed on each sample include aliquoting, centrifuging, addition of solutions or archiving. 
         [0006]    Various apparatus for sorting test tubes are known. One such apparatus is the “RSD 800A” made by PVT Probenverteiltechnik GmbH. This apparatus requires an operator to initially load the test tubes into racks. An automated arm loads the test tubes one by one onto a conveyor which receives the test tubes in a vertical orientation. The test tubes travel along a conveyor, and each test tube can be selectively submitted for various processes, such as bar code labeling, aliquoting, decapping and recapping. Another automated arm removes each test tube from the conveyor and places it in an allocated test tube rack. This apparatus is noted for a number of inefficiencies. Firstly, the system requires initial manual loading and sorting. Secondly, the loading of test tubes in a vertical orientation can be slow. Thirdly, the speed of the conveyor is affected by the speed of the various processes. The PVT apparatus has a maximum throughput of 800 test tubes per hour. In practice, a significant number of test tubes do not need to undergo any aliquoting or decapping process. Hence, for such test tubes these processes are effectively redundant. 
         [0007]    The “HCTS2000 MK2” made by m.u.t GmbH is an apparatus for sorting test tubes. The test tubes to be sorted are bulk loaded into a hopper and fed onto a conventional conveyor belt. The apparatus then transfers the test tubes to various output locations as required. The apparatus includes a bar code reader. Optionally, the apparatus can detect the test tube type and cap color. The disadvantage of this apparatus is that it uses conventional robotic arms, conveyor belts and carrousels to transport test tubes through the apparatus, which is expensive and complicated. 
         [0008]    U.S. Pat. No. 7,141,213 B1 (Pang et al), U.S. Pat. No. 5,814,276 (Riggs), and Japanese Patent Abstract 04104058A (Aloka Co Ltd) also disclose various apparatus for processing test tubes. The sorting apparatus disclosed in these documents generally use complicated automation methods and require the test tubes to be loaded in an orderly manner, rather than loaded in bulk. U.S. Pat. No. 6,325,129 B1 (Wright et al) discloses an apparatus for sequentially transferring test tubes from a bulk loaded hopper. 
         [0009]    The present invention seeks to provide a vessel transporting and/or sorting apparatus and method which will overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative. 
         [0010]    It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms a part of the common general knowledge in the art, in Australia or any other country. 
       SUMMARY OF THE INVENTION 
       [0011]    According to a first aspect of the present invention an apparatus for transporting a vessel is provided, comprising: 
         [0012]    at least one support device adapted to support the vessel in a reclined orientation, and 
         [0013]    a pushing mechanism adapted to transport the vessel along the support device. 
         [0014]    Advantageously, the overall construction of the apparatus is relatively simple, making the apparatus economical to construct compared with other apparatus that use conventional robotics. Another advantage of this apparatus is that the vessels are not in contact with an endless conveyor and so can be more readily rotated, weighed etc. Thus, the vessels can be weighed without needing to be lifted. 
         [0015]    Preferably, the apparatus further comprises at least two stations each station comprising a support device, wherein the pushing mechanism is adapted to transport the vessel from one station to another station. 
         [0016]    Preferably, at least one of the stations is adapted to acquire information relating to the vessel and at least another of the stations is a transfer station adapted to transfer the vessel to one of two or more output locations depending on the information acquired, thereby sorting the vessel. It should be understood that acquiring information relating to the vessel may involve acquiring information about the vessel itself, the contents of the vessel, or both. 
         [0017]    Advantageously, the throughput in vessels per hour of the apparatus is relatively high because each station is dedicated to only a single function, and the stations all operate simultaneously. The design of the transfer station in particular operates rapidly compared to most conventional robotic arms. 
         [0018]    Preferably, at least one support device is rotatable to change the orientation of the vessel. 
         [0019]    Preferably, the vessel is elongate and at least one support device is adapted to support the vessel in lengthwise alignment and the pushing mechanism is adapted to push the vessel lengthwise along the support device. 
         [0020]    Preferably, the or each support device is adapted to support the vessel in lengthwise alignment. 
         [0021]    Preferably, the apparatus further comprises a transducer adapted to determine the orientation of the vessel. 
         [0022]    Preferably, the transducer comprises an arm that contacts the vessel as it is transported past the transducer. 
         [0023]    Preferably, the orientation of the vessel is determined by measuring the position of the arm and the longitudinal position of the vessel as it is transported past the transducer. 
         [0024]    Preferably, the arm of the transducer is mounted on a pivot. 
         [0025]    Preferably, the transducer is adapted to measure the length of the vessel. 
         [0026]    Preferably, the vessel has a round cross-section and the transducer is further adapted to measure the diameter of the vessel. 
         [0027]    Preferably, the pushing mechanism comprises a plurality of protrusions, each protrusion being adapted to move between at least two stations and to contact the end of a vessel supported at one station and transport it to another station. 
         [0028]    Preferably, the protrusions are attached to an endless conveyor in spaced apart relation. 
         [0029]    Preferably, each support device has a recess extending along its length through which the protrusions pass in use. 
         [0030]    Preferably, the recess in each support device is below a vessel supported by the support device in use. 
         [0031]    Preferably, the support device of the transfer station is movable in a direction that is transverse to the main direction of travel of vessels through the station. 
         [0032]    Preferably, the transfer station comprises a second pushing mechanism adapted to push a vessel out of the transfer station. 
         [0033]    Preferably, at least one of the output locations is a vessel rack. 
         [0034]    Preferably, at least one of the stations comprises a bar code reader adapted to read a bar code on a vessel. 
         [0035]    Preferably, the vessel is elongate and the support device of the station comprising the bar code reader comprises a pair of rollers adapted to rotate a vessel on its longitudinal axis. 
         [0036]    Preferably, the apparatus further comprises a database adapted to match the bar code of a vessel to a patient. 
         [0037]    Preferably, the apparatus further comprises a feeder for feeding vessels to the at least one support device. 
         [0038]    Preferably, the feeder comprises a hopper for receiving the vessels and a depositor for receiving the vessels from an outlet of the hopper and sequentially depositing them on at least one support device. 
         [0039]    Advantageously, vessels can be poured directly into the hopper in any orientation, which saves considerable time and effort over prior art sorting apparatus that require the vessels to be loaded in an orderly manner, such as in racks. 
         [0040]    Preferably, at least one of the stations is adapted to weigh a vessel. Advantageously, because the weight of the respective support device is known and the support device forms part of the scales, the vessel does not need to be lifted in order for its weight to be measured. 
         [0041]    Preferably, at least one of the stations comprises an image capture device. 
         [0042]    Preferably, the image capture device is adapted to detect the color of a cap of a vessel. 
         [0043]    Preferably, the vessel is a test tube. 
         [0044]    Preferably, the test tube is adapted to store a blood sample. 
         [0045]    According to a second aspect of the present invention a method of sorting vessels is provided, comprising the following steps:
   i. Depositing a vessel in a feeder,   ii. Feeding the vessel to a support device of a station where it is supported on its side in a reclined orientation, and   iii. Transporting the vessel, while in the reclined orientation, to another station.   
 
         [0049]    Preferably, the vessel is a test tube. 
         [0050]    According to a third aspect of the present invention, a sorting apparatus is provided for sorting a vessel, comprising: 
         [0051]    at least one support device adapted to support the vessel in a reclined orientation, and 
         [0052]    a pushing mechanism adapted to transport the vessel along the support device. 
         [0053]    Preferably, the sorting apparatus further comprises at least two stations each station comprising a support device, wherein the pushing mechanism is adapted to transport the vessel from one station to another station. 
         [0054]    Preferably, at least one of the stations is adapted to acquire information relating to the vessel and at least another of the stations is a transfer station adapted to transfer the vessel to one of two or more output locations depending on the information acquired, thereby sorting the vessel. 
         [0055]    Preferably, the vessel is a test tube. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0056]    Notwithstanding any other forms which may fall within the scope of the present invention, a preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
           [0057]      FIG. 1  shows a typical blood sample test tube. 
           [0058]      FIG. 2  is a plan view of a test tube sorting apparatus in accordance with a preferred embodiment of the present invention. 
           [0059]      FIG. 3  is a side view of the test tube sorting apparatus of  FIG. 2 . 
           [0060]      FIG. 4  is a plan view of a feeder mechanism and bar code reader station of the test tube sorting apparatus of  FIG. 2 . 
           [0061]      FIG. 5  is a partial sectional side view along V-V of the feeder mechanism and the bar code reader station of  FIG. 4 . 
           [0062]      FIG. 6  is a sectional end view along VI-VI of the feeder mechanism of  FIG. 5 . 
           [0063]      FIG. 7  is a plan view of the orientation, weighing and imaging stations of the test tube sorting device of  FIG. 2 . 
           [0064]      FIG. 8  is a side view of the orientation, weighing and imaging stations of  FIG. 7 . 
           [0065]      FIG. 9  is a partial sectional side view along IX-IX of the bar code reader station of  FIG. 4 . 
           [0066]      FIG. 10  is an end view along X-X of the orientation station of  FIG. 8 . 
           [0067]      FIG. 11  is a plan view of the transfer station of the test tube sorting apparatus of  FIG. 2 . 
           [0068]      FIG. 12  is a side view of the transfer station of  FIG. 11 . 
           [0069]      FIG. 13  is a sectional view along XIII-XIII of the transfer station of  FIG. 11 . 
           [0070]      FIG. 14  shows the transfer station of  FIG. 11  in a position to deposit a test tube into a container. 
           [0071]      FIG. 15  shows the transfer station of  FIG. 11  in a position to deposit a test tube into a two dimensional test tube rack. 
           [0072]      FIG. 16  is sectional view along XVI-XVI of the transfer station in the position of  FIG. 15 . 
           [0073]      FIG. 17  is a side view of an orientation station having an alternative support device for a test tube sorting apparatus in accordance with a preferred embodiment of the present invention. 
           [0074]      FIG. 18  is an end view of the orientation station of  FIG. 17 . 
           [0075]      FIGS. 19 and 20  are sectional side views through a device to transfer test tubes to a two dimensional test tube rack for a test tube sorting apparatus in accordance with a preferred embodiment of the present invention. 
           [0076]      FIG. 21  is an end view of an orientation station having a support device for a test tube sorting apparatus in accordance with a preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0077]    The present invention may be embodied in a number of different forms and may be used for a number of different purposes. In a basic form, the invention is used for transporting vessels (e.g., test tubes) whilst in other forms (e.g., as depicted in the figures) it may be used for both transporting and sorting vessels (e.g., test tubes) and/or archiving vessels (e.g., archiving test tubes in fridges). 
         [0078]      FIG. 1  shows a typical test tube  1  containing a blood sample. The test tube  1  has a cap  2  and a hollow body  4 . A bar code  3  is affixed to the hollow body  4  and identifies the patient from whom the blood sample was taken. 
         [0079]    The color of the cap  2  and the length and diameter of individual test tubes  1  may vary depending on the type of test tube. These parameters can be used to determine the tests or operations that are required to be performed. 
         [0080]      FIGS. 2 to 16  show a test tube transporting and sorting apparatus  10  (henceforth “sorting apparatus  10 ”) in accordance with a preferred embodiment of the present invention. For clarity, some components of the apparatus  10  are not shown (e.g. various actuators, bearings, sensors, support structures, etc that are commonly used in machine design). 
         [0081]    Referring to  FIGS. 2 and 3 , test tube sorting apparatus  10  comprises a hopper  22 , a feeder mechanism  11 , a bar code reader station  12 , an orientation station  13 , a weighing station  14 , an imaging station  15  and a transfer station  16 . The bar code reader station  12 , weighing station  14  and imaging station  15  all involve acquiring information about the test tube  1 . It should be understood that acquiring information relating to the test tube  1  may involve acquiring information about the test tube  1  itself, the contents of the test tube  1 , or both. A pushing mechanism  20  sequentially transports test tubes  1  through each of the stations  12 ,  13 ,  14 ,  15  and  16  in a direction of travel indicated by arrow  8 . The apparatus  10  is arranged such that test tubes  1  at the stations  12  to  16  are substantially aligned lengthwise. The hopper  22  receives bulk loaded test tubes  1  to be sorted. Test tubes  1  can be poured directly into the hopper  22  in any orientation, which saves considerable time and effort over prior art sorting apparatus that require the test tubes to be loaded in an orderly manner, such as in racks. 
         [0082]    Referring to  FIGS. 4 ,  5  and  6 , the feeder mechanism  11  picks up test tubes  1  from the hopper  22  and sequentially deposits them at the bar code reader station  12 , which in this embodiment is the first station of the sorting apparatus  10 . As can be best seen in  FIG. 5 , the feeder mechanism  11  comprises a slide  23  that is raised and lowered inside the hopper  22  as required to transfer one or more test tubes  1  at a time to a secondary hopper  24 . The slide  23  has a top  30  and is shown in its raised position. When the slide  23  is lowered, as indicated by dashed outline  23 ′, the top  30  of the slide  23  is at the bottom of the hopper  22 , as indicated by dashed line  30 ′. This allows test tubes  1  in the hopper  22  to roll into the space vacated by the lowered slide  23 . Then, as the slide  23  is raised, it lifts the test tubes  1  above it. The top  30  of the slide  23  is inclined such that test tubes  1  lifted by it roll off the top  30  of the slide  23  into the secondary hopper  24  when the slide  23  is raised to the position shown in which the top  30  of the slide  23  is just above an opening into the secondary hopper  24 . 
         [0083]    Referring to  FIG. 6 , an endless belt  25 , with a plurality of spaced apart pegs  26  attached to it, carries test tubes  1  out of the secondary hopper  24  to a chute  27 . A test tube  1  can travel up the belt  25  with either its cap  2  or body  4  facing forwards. The secondary hopper  24  provides only a few test tubes  1  at a time and so prevents the feeding mechanism  11  from jamming, which might otherwise occur if the endless belt  25  received test tubes directly from the main hopper  22 . 
         [0084]    When a test tube  1  is required to be deposited at the bar code reader station  12 , a stepper motor  28  drives the belt  25  until a single test tube  1  is carried to the chute  27 . This test tube  1  then rolls down the chute  27  onto two rollers  32  that form a support device for the bar code reader station  12 . A sensor  29  detects the presence of a test tube  1  on the belt  25  and provides a signal to the stepper motor  28  to stop once the test tube  1  is delivered onto the chute  27 . Test tubes  1  are deposited at the bar code reader station  12  in a random orientation, which means that either the cap  2  end or the tube end of the test tube  1  can face forwards in the direction of travel  8 . 
         [0085]    The bar code reader station  12  comprises the two rollers  32  and a bar code reader  33 . The rollers  32  support the test tube  1  in a reclined orientation on its side, and are spaced apart such that there is an opening between them. The rollers  32  are rotated by a motor  36  through a belt  35 . Rotating the rollers  32  rotates the supported test tube  1  so that the bar code reader  33  can read the test tube&#39;s bar code  3 , irrespective of the rotational position of the test tube  1  when it arrives at the station  12 . A computer system (not shown) matches the bar code  3  to a patient&#39;s records stored in a database. 
         [0086]    After the bar code  3  is read, the test tube  1  is transported to the orientation station  13  by a pushing mechanism  20 . The pushing mechanism  20  comprises an endless belt  39  supported by a pulley  40  at each end of the sorting apparatus  10 . A plurality of protrusions  41  are attached to the outside of the belt  39 , and are equally spaced apart along the belt  39 . The belt  39  is driven intermittently by a stepper motor  42  (refer to  FIG. 2 ) rotating one of the pulleys  40  in a direction such that the protrusions  41  on the top side of the belt  39  move in the direction of travel  8 . 
         [0087]    Referring to  FIG. 5 , as the belt  39  is driven, a protrusion  41  extends into the opening between the rollers  32  to contact an end of the supported test tube  1 , and as the protrusion  41  passes through the opening it pushes the contacted test tube  1  to the adjacent orientation station  13 . As the test tube  1  is pushed from the bar code reader station  12  to the orientation station  13  it passes a transducer  45 . Referring to  FIG. 9 , the transducer comprises an arm  46  attached to a shaft  47 . The arm  46  pivots about the axis of the shaft  47  as indicated by the dashed outline  46 ′. The shaft  47  is attached to an angular encoder  48  (refer to  FIG. 5 ) such that the inclination of the arm  46  can be measured. As the test tube  1  passes the transducer  45  it contacts the arm  46  thus pivoting it. 
         [0088]    The position of the belt  39 , and thus the position of the protrusions  41  attached to it, can be determined at any instant from the rotational position of the stepper motor  42 . As the test tube  1  passes the transducer  45 , the instantaneous inclination of the arm  46  is captured by the encoder  48  at a number of positions of the belt  39 . This data is used to determine the orientation and other properties of the passing test tube  1 . The cap  2  of the test tube  1  has a larger diameter than the body  4  of the test tube  1 , and thus the arm  46  pivots further upwards as the cap  2  passes it than when the body  4  of the test tube  1  passes it. Therefore, the orientation can readily be determined by determining if the cap  2  passes the transducer  45  before or after the body  4  of the test tube  1 . Similarly, the captured data can be used to determine the diameter and length of the test tube  1  passing the transducer  45 . The length of the test tube  1  can be determined by determining the position of the belt  39  when the test tube  1  first contacts the arm  46 , and the diameter can be determined from the arm  46  position as it passes the body  4  of the test tube  1 . The length and diameter of each test tube  1  is stored by a computer for later reference. 
         [0089]    Referring to  FIGS. 7 ,  8  and  10 , the orientation station  13  comprises a support device  51 . The support device  51  is made up of two side members  52  separated by a block  53 . The lower portion of each side member  52  is bent inwards as shown in  FIG. 10 . The construction of the support device  51  is such that it can carry a test tube  1  on its side whilst providing a recess taking the form of an opening  54  that extends the length of the support device  51 . The protrusions  41  of the pushing mechanism  20  extend into and pass through the opening  54  to push a test tube  1  from the orientation station  13  to the adjacent weighing station  14 . Preferably, the side members  52  are made from transparent plastic sheet (e.g., polycarbonate). 
         [0090]    The orientation station  13  further comprises a rotary actuator  57 , such as a stepper motor, that rotates a shaft  58  through angular increments of 180°. The support device  51  is attached to the end of the shaft  58 . If a test tube  1  is transported to the orientation station  13  in the wrong orientation with its cap  2  facing the direction of travel  8 , as determined by the transducer  45 , then the actuator  57  rotates the support device  51  through 180°, as indicated by the dashed outline  51 ′ in  FIG. 7 . In this manner, test tubes  1  always leave the orientation station  13  with their body  4  facing the direction of travel  8 . 
         [0091]    The pushing mechanism  20  transports each test tube  1  from the orientation station  13  to the support device  51   a  of the weighing station  14 . The support device  51   a  is similar to the support device  51  of the orientation station  13 , and is attached to a load cell  60 . The load cell  60  measures the weight of the supported test tube  1 . The weight may be used to determine the amount of blood in the test tube  1 , and is stored by a computer for later reference. 
         [0092]    In one embodiment, the amount of blood can be determined by taking the total weight of the test tube  1 , subtracting the known tare weight of the test tube  1 , and calculating the amount of blood from the weight of the blood. If the tare weight of the test tube  1  is not known, it can in one embodiment be accessed from a look-up table provided by a computer database once the type of test tube has been identified by the transducer  45 . 
         [0093]    Each test tube  1  is then transported from the weighing station  14  to the support device  51   b  of the adjacent imaging station  15  by the pushing mechanism  20 . The imaging station  15  comprises an image capture device  62 , such as a digital camera. The support device  51   b  is similar to the support device  51  of the orientation station  13  except that it is fully open at the top to provide the image capture device  62  with an unobstructed view of the supported test tube  1 . The captured image is analyzed to determine the color of the test tube cap  2 , and may also be used to determine other properties of a test tube  1  or blood therein. This information is stored by a computer for later reference. 
         [0094]    Each test tube  1  is then transported from the imaging station  15  to the support device  51   c  of the adjacent transfer station  16  by the pushing mechanism  20 . The transfer station  16  transfers each test tube  1  to one of the output locations  17 ,  18  or  19  (refer to  FIG. 2 ). The output location for an individual test tube  1  is selected based on its bar code  3  as read by the bar code reader station  12 . The output location may also be selected based on the dimensions of the test tube  1  as determined by the transducer  45 , its weight as measured by weighing station  14 , the color of its cap  2  as determined by the imaging station  15  or by the volume of blood in the test tube as calculated above. 
         [0095]    The transfer station  16  comprises a linear actuator  64 . Referring to  FIG. 12 , the linear actuator  64  has a carriage  65 , and the support device  51   c  of the transfer station  16  is attached to the carriage  65 . The support device  51   c  is similar to the support device  51  of the orientation station  13 . The carriage  65  is driven by a stepper motor  66  (refer to  FIG. 2 ) through a ball screw or belt drive mechanism (not shown) such that the carriage  65  and the attached support device  51   c  are movable to any position along an axis  67  that is transverse to the direction of travel  8 . 
         [0096]      FIGS. 11 and 12  show the transverse position of the support device  51   c  when a test tube  1  is transported into it. Output location  17  comprises a funnel like guide  69  and a series of one dimensional test tube racks  68 . Empty racks  68  are progressively fed along a conveyor  70  and under the guide  69  such that each empty position of each rack  68  aligns in turn with the guide  69 . If a test tube  1  at the transfer station  16  is required to be transferred to the racks  68  then the support device  51   c  remains in the position shown in  FIGS. 11 and 12 , and as a protrusion  41  of the pushing mechanism  20  passes by it pushes the test tube  1  through the support device  51   c  and into the guide  69 . The test tube  1  then falls through the guide  69  into an empty position of a rack  68 . The filled racks  68  can then be manually or automatically transferred to another apparatus to perform the required operations on the test tubes  1 . 
         [0097]      FIG. 14  shows the transverse position of the support device  51   c  when a test tube  1  is required to be transferred to the output location  18 , which is an open container  71 . After the test tube  1  is pushed into the support device  51   c  in the position shown in  FIG. 11 , the stepper motor  66  transversely moves the support device  51   c  to the position shown in  FIG. 14 . Referring to  FIG. 13 , the transfer station  16  comprises a second pushing mechanism  72  built into the support device  51   c.  This second pushing mechanism  72  is similar in operation to the main pushing mechanism  20 . It comprises a belt  73  supported by two pulleys  75  with two equally spaced apart protrusions  74  attached to the outside of the belt  73 . A stepper motor  76  (refer to  FIG. 14 ) can rotate in either direction to move the protrusions  74  forwards or backwards as required. When the stepper motor  76  rotates, the protrusions  74  contact the end of a supported test tube  1 , which pushes it out of the support device  51   c . After the support device  51   c  moves to the position shown in  FIG. 14 , the stepper motor  76  drives the second pushing mechanism  72  such that it pushes the supported test tube  1  backwards out of the support device  51   c  and into the container  71 . Similarly to the racks  68 , the container  71  can be manually or automatically transferred if required to perform other operations on the test tubes  1  contained in it. 
         [0098]      FIGS. 15 and 16  show the transverse position of the support device  51   c  when a test tube  1  is required to be transferred to the output location  19 . Output location  19  comprises a guide block  79  and a series of two dimensional test tube racks  80 . In this embodiment, each rack  80  can hold forty test tubes  1  arranged as eight rows of five test tubes  1  per row. The guide block  79  has five holes  82 . Each hole  82  is adapted to guide a test tube  1  from the support device  51   c  to a position in a rack  80 . The five holes  82  are arranged such that their exits  83  simultaneously align with five positions on a single row of the rack  80 . Empty racks  80  are progressively fed by a conveyor  81  such that each row of each rack  80  aligns in turn with the exits  83  of the guide block  79 . 
         [0099]    The stepper motor  66  can transversely move the support device  51   c  to align with any one of the five holes  82 . When a test tube  1  is required to be transferred to a rack  80 , the support device  51   c  is positioned to align with one of the holes  82  as shown in  FIG. 15 , and the second pushing device  72  pushes the supported test tube  1  into the hole  82  as shown in  FIG. 16 . The test tube  1  then falls through the exit  83  of the hole  82  into a free position in the rack  80 . The filled racks  80  can then be manually or automatically transferred to another apparatus to perform the required operations on the test tubes  1 . 
         [0100]      FIGS. 19 and 20  show an alternative guide block  79   a  for transferring test tubes  1  to a two dimensional test tube rack  80 . The guide block has five holes  82   a  that are spaced apart transversely to align with a row of positions in a rack  80 , in a similar manner to the holes  82  in guide block  79 . The guide block  79   a  pivots about a shaft  85 . Test tubes  1  are transferred to the guide block  79   a  with the guide block  79   a  pivoted upwards such that the holes  82   a  are horizontal, as shown in  FIG. 19 . Once a test tube  1  is transferred to each of the holes  82   a , the guide block  79   a  is pivoted downwards and the test tubes  1  fall through the holes  82   a  into an empty row in a rack  80 . A curved barrier  86  prevents the test tubes  1  from falling through the holes  82   a  until the guide block  79   a  is pivoted fully downwards. 
         [0101]    The sorting apparatus  10  operates by repeatedly driving the pushing mechanism  20  then stopping it whilst the stations  12  to  16  perform their respective functions simultaneously. In this embodiment, each time the pushing mechanism  20  is driven, the protrusions  41  move a distance equal to their spacing, and each time the pushing mechanism  20  stops it remains stationary for enough time to allow the slowest of the stations  12  to  16  to perform its respective function. The throughput in test tubes per hour of the sorting apparatus  10  is relatively high because each station  12  to  16  is dedicated to only a single function, and the stations all operate simultaneously. The design of the transfer station  16  in particular operates rapidly compared to most conventional robotic arms. The overall construction of the apparatus  10  is relatively simple, making the apparatus  10  economical to construct compared with other apparatus that use conventional robotics. 
         [0102]    Many different arrangements of support devices and pushing mechanisms are possible within the scope of the invention. As an example,  FIGS. 17 and 18  show an alternative embodiment of an orientation station  13   a  having an alternative support device  51   d . Support device  51   d  has an open channel like construction. It supports a test tube  1  on its side like support device  51 , but it has a recess in the form of opening  54   d  extending its length above the supported test tube  1 . In this embodiment, an alternative pushing mechanism  20   a  comprises a belt  39   a  running above and to the side of the orientation station  13   a  with protrusions  41   a  extending down into the opening  54   d  to push the test tube  1 . 
         [0103]      FIG. 21  shows a further alternative embodiment of an orientation station  13   b  having a further alternative support device  51   e  for a test tube sorting apparatus in accordance with the present invention. The support device  51   e  is constructed from a tube having a recess along its length in the form of an opening  54   e.    
         [0104]    The embodiments described above have pushing mechanisms comprising a single endless belt  39 . However, in other embodiments two or more belts may be used in sequence, each with protrusions  41  attached. Furthermore, the pushing protrusions  41  may be attached to and driven by means other than an endless belt. 
         [0105]    In other embodiments the transducer  45  may comprise an arm  46  that moves linearly, rather than pivoting, or in still other embodiments the transducer  45  may comprises a non-contact sensor such as a laser beam. 
         [0106]    The scope of the present invention is not limited to the arrangement of the sorting apparatus  10  described above. Alternative embodiments of the invention may have more or less stations, and more or less output locations than the sorting apparatus  10 . For example, a sorting apparatus may not have a weighing or imaging station. Or, an embodiment of the present invention may for example only have a single output location. Also, it is possible for two functions to be combined at a single station. For example, an image capture device may be added to the bar code reader station or the image capture device may be used to read the barcode as well, or a load cell may be built into the orientation station. 
         [0107]    While the invention has been described with reference to a number of preferred embodiments it should be appreciated that the invention can be embodied in many other forms. For example, each support device could include a cradle, the recess being provided by an open top of the cradle and extending along the length of the cradle. The protrusions would pass through the open top of the cradle in use to push the test tubes. In this case, the endless conveyor would be located above the support devices. The structural form of the cradle can take many different forms, for example, it could take the form of a solid body or a structural framework. 
         [0108]    In yet another embodiment, each support device could include a C-type section oriented to provide a side recess extending along the length of the C-type section. The protrusions would pass through the side recess of the C-type section in use to push the test tubes. In this case, the endless conveyor would be located to one side of the support device. The structural form of the C-type section can take many different forms, for example, it could take the form of a solid body or a structural framework. 
         [0109]    It should be understood that although the detailed description of the invention refers to transporting and sorting test tubes, this is but one example of a type of vessel that can be transported and/or sorted by embodiments of the invention. For example, other embodiments of the invention are adapted for transporting and/or sorting elongated vessels, bowls, bottles, containers and/or beakers. The vessel may be empty or may contain a substance (e.g., blood). 
         [0110]    In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “forward”, “rearward”, “radially”, “peripherally”, “upwardly”, “downwardly”, and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms. 
         [0111]    In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e., to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.