Patent Publication Number: US-8540476-B2

Title: Pipette tip loader and transporter

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pipette tip transport and loading system. 
     2. Description of the Related Art 
     Pipette tips are widely used in chemistry, biomedical and bioengineering testing for transporting and dispensing discrete amounts of a liquid sample. A typical pipette tip is made of plastic and formed with a substantially conical head and a frustoconical body. In most applications, pipette tips are used in large quantities, making individual handling of the pipette tips highly inconvenient. Consequently, pipette tips are typically loaded into pipette tip platforms so that the user need not handle the pipette tips individually. By utilizing platform loading, liquid samples can be efficiently stored and transported in large quantities. 
     Platforms of pipette tips are often stacked and packaged one atop the other. For example, refill packs are sold including a tower of stacked platforms, packaged within a housing. Typically, some sort of device is used to transfer platforms from the stack and to deposit a platform into a pipette tip rack, one platform per rack. Standard pipette tip racks and platforms typically have a rectangular upper surface which defines an array of apertures. In a rack, liquid samples may be transferred to and/or from pipette tips in the rack from an array of pipettors. 
     A number of devices have been developed that facilitate unloading pipette tip platforms from a stack of pipette tip platforms. U.S. Pat. Nos. 5,392,914, 5,441,702, 5,612,000 and 6,007,779 to Lemieux et al., and U.S. Pat. No. 5,779,984 to Kelly et al. each describe refill packs for pipette tip racks. The refill packs described in those patents enclose stacks of pipette tip platforms in a box-like packaging having an open lower end from which the pipette tips in the lowest platform in the stack extend. The packaging is grasped by the user and the pipette tips in the lowermost platform are manually fitted into a pipette tip rack. The pipette tip platforms are held within the rack by a flange extending around the perimeter of the open end of the refill pack. When the packaging is pressed downwardly, the flange is deformed outwardly by the downward force exerted by the lowermost pipette tip platform, and the platform is forced through the flange and remains on the rack. Once the platform has passed through the flange, the flange elastically returns to its original position, retaining the rest of the pipette tip platforms within the packaging. 
     There exists a continuing need for alternative, reusable loading devices which can dispense units of platform-loaded goods in a single dispensing action, and can be simply and reliably operated. 
     SUMMARY 
     Embodiments of the invention relate to a system for storing and/or transporting platforms of pipette tips. The system includes packaging in which a stacked tower of platforms may be transported. The packaging and platforms may for example be a refill pack of disposable pipette tips. The packaging may include first and second sides each of which forms a partial enclosure. The sides may be folded upward to overlap each other, thereby forming a complete enclosure around the tower of pipette tip platforms. From a sealed position, the respective sides may fold down until the sides are flat, leaving the tower of platforms accessible at every level. 
     Embodiments of the present invention further include a loader for transferring platforms from the packaging to a rack for holding pipette tip platforms. The loader in general may be formed of a clear, semi-rigid, thermoplastic polymer resin having a degree of elasticity. The loader includes a top surface and four downwardly extending sides. A lower portion of the sides may flare outward. The loader further includes indentations formed within a pair of opposed sides of the loader. The indentations define shelves on an interior of the loader. The loader and the respective shelves within the loader are sized so that, when the loader is in an unbiased position, a platform is able to fit within the interior of the loader with edge portions of the platform supported on each of the shelves. When in this position, the loader is able to transport a platform of pipette tips away from the packaging. 
     Once a platform of pipette tips is loaded into the loader, the loader may transport the platform to a pipette tip rack of known construction. As the loader moves down over the rack, the flared edges in the sides of the loader will form a line of engaging contact with peripheral edges of the rack. Upon continued downward movement of the loader, the peripheral edges of the rack will elastically force the flared portions and sides outward away from each other. This spreading apart of the sides pulls the shelves out from under the platform to release the platform to the rack. 
     This type of offload of platforms presents advantages over other types of transport loaders in that a platform is extricated from the loader using a downward force and motion while the platform is securely positioned within the rack. This minimizes the possibility that pipette tips will get jostled and/or dislodged from the platform. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a stack of pipette tip platforms including stacked pipette tips seated within a transport packaging and including a loader, all according to embodiments of the present invention. 
         FIG. 2  is an alternative perspective view of a stack of pipette tip platforms including stacked pipette tips seated within a transport packaging and including a loader, all according to embodiments of the present invention. 
         FIG. 3  is a perspective view of a loader according to embodiments of the present invention. 
         FIG. 4  is a perspective view of a loader according to an alternative embodiment of the present invention, in position over a pipette tip rack. 
         FIG. 5  is a side view of a rack and loader according to embodiments of the present invention. 
         FIG. 6  is a cross-sectional view through the loader and rack of  FIG. 5 . 
         FIG. 6A  is an enlarged sectional view of a portion of the loader shown in  FIG. 6 . 
         FIG. 7  is a cross-sectional view through the alternative loader of  FIG. 4 . 
         FIG. 8  is a side view of the alternative loader and rack of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention will now be described with reference to  FIGS. 1 through 8 , which in general relate to a rack for pipette tips. It is understood that the present invention may be embodied in many different forms and should not be construed to being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey embodiments of the invention to those skilled in the art. Indeed, the invention is intended to cover alternatives, modifications and equivalents of these embodiments, which are included within the scope and spirit of the invention as defined by the appended claims. Furthermore, in the following detailed description of embodiments of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be clear to those with ordinary skill in the art that the present invention may be practiced without such specific details. 
       FIGS. 1 and 2  are different perspective views of a system  100  for transporting pipette tips according to embodiments of the present invention. System  100  includes packaging  102  for transporting a tower of stacked pipette tip platforms  104 , each of which includes an array of pipette tips  106 . The system  100  further includes a pipette tip loader  108  for transferring pipette tip platforms  104  from packaging  102  as described hereinafter. The bottom-most platform  104  in packaging  102  may include pipette tips  106  seated within a shipping base  110  of known construction which includes an array of apertures for receiving the array of pipette tips  106  in the lowermost platform  104 . The shipping base may be biodegradable, sustainable and/or recyclable. 
     In embodiments, the packaging  102  and its contents may be a refill pack of disposable pipette tips, but it is understood that the packaging  102  need not be a refill pack in alternative embodiments. Moreover, packaging  102  need not house a loader  108  in embodiments, but rather operate with a loader  108  that is not transported within the packaging  102 . As seen in  FIGS. 1 and 2 , packaging  102  includes first and second sides  102   a  and  102   b , shown in the open position in  FIGS. 1 and 2 . Each of sides  102   a  and  102   b  forms a partial enclosure, and may be folded upward to overlap each other, thereby forming a complete enclosure around the tower of pipette tip platforms  104 , loader  108  and shipping base  110 . From a sealed position, the respective sides  102   a  and  102   b  may fold down 90° until the sides are flat, leaving the tower of platforms  104  accessible at every level. The sides  102   a  and  102   b  may be returned to a closed position by manually pushing the sides back to their upright positions. 
     The sides  102   a  and  102   b  may be sealed in engagement with each other around platforms  104  and loader  108  by a clasp  112  fitting within a slot  114  to thereby seal the pipette tip platforms  104  and loader  108  within packaging  102 . In the sealed position, packaging  102  may be shipped or otherwise transported with its contents maintained therein. While the clasp  112  and slot  114  form a simple but effective closure for the respective sides of packaging  102 , it is understood that other types of closures may be used to seal packaging  102  for transport. Moreover, it is understood that additional locking mechanisms may be provided along the length of the sides  102   a  and  102   b  to further maintain the enclosure around the contents of packaging  102 . 
     In embodiments, packaging  102  may be formed of an 84% post consumer recycled fiber called CCNB (clay coated news back) that is 0.020″ thick. It is understood that the packaging may be formed to other thicknesses and of other fibers and other materials such as cardboard and/or plastic. All graphics on the packaging may be done in a soy based ink to eliminate heavy metals, though other printing materials are possible. 
     Each of the pipette tip platforms  104  may be of known construction, formed of a plastic support plate including an array of holes for storing an array of pipette tips. In embodiments, each pipette tip platform  104  may be an 8 by 12 array of 96 apertures for receiving 96 pipette tips  106 . However, it is understood that the loader  108  of the present invention may be sized to work with different sized platforms and pipette tips. For example, the loader may be configured to work with platforms supporting pipette tips having volumes of 20 ul and lower, volumes of 250 ul-1 ul, and volumes of 1250 ul to 1000 ul. It is understood that the loader may be configured to work with platforms supporting pipette tips having other volumes in further embodiments. 
     Packaging  102  may be shipped with, for example, a tower of 13 stacked platforms  104 , but it is understood that the number of stacked platforms may vary in alternative embodiments. The height of the tower within packaging  102  may vary, depending on the number of platforms  104  used, the length and diameter of the pipette tips  106  used, and whether or not the packaging is shipped with a loader  108 . It is understood that the height of the contents within packaging  102  may be smaller than the height of the packaging, for example where packaging is shipped with less than the maximum number of platforms  104  than packaging  102  can hold. Once packaging  102  has reached its destination, packaging  102  may be opened into the position shown in  FIGS. 1 and 2 , and loader  108  may thereafter be used to remove platforms  104  from packaging  102  as explained below. It is understood that the loader  108  explained hereinafter may be used to transfer platforms from packaging  102  or locations other than packaging  102  described above. 
     Referring now to  FIG. 3 , loader  108  in general may be formed of a clear, semi-rigid, thermoplastic polymer resin having a degree of elasticity. The loader  108  may be opaque in alternative embodiments, and the degree of elasticity may vary in alternative embodiments with the provision that the loader be capable of flexing to allow the loader to grip and release a platform  104  as explained hereinafter. Loader  108  may be formed by injection molding or other known fabrication processes, and includes a top surface  120  and four downwardly extending sides  122   a  through  122   d  (also collectively referred to as sides  122 ). The four respective sides  122   a - d  may include lower portions  124   a - d , distal from top portion  120 , which flare outward, the function of which is explained hereinafter. It is understood that portions of each side  122 , apart from portions  124 , may also flare outward, or may extend substantially perpendicularly down from top surface  120 . 
     The top surface  120  of loader  108  may include an array of frustoconical posts  128  extending down from a top surface of loader  108  into an interior of loader  108  defined by the downwardly extending sides  122 . Posts  128  are seen from their rear surfaces in  FIG. 3 , and are shown from their front surfaces in the cross-sectional view of  FIG. 7  (showing a loader  108  of an alternative configuration as explained hereinafter). The posts  128  are arrayed within loader  108  to fit within the open upper ends of pipette tips  106  within the platform  104  being transported by loader  108  as explained hereinafter. The posts  128  help secure a platform  104  and pipette tips  106  within the loader  108  and minimize wobbling of the pipette tips  106  within the loader  108  so that the tips can be inserted into a pipette tip rack easily with a minimum of alignment difficulty. The frustoconical shape of the posts allows the loader  108  to be used with different diameter pipette tips  106 . 
     Loader  108  further includes indentations  134  formed within opposed sides  122  of the loader  108 . In embodiments, each of two opposed sides  122  may include a pair of indentations, but it is understood that each of two opposed sides  122  may include a single indentation  134  or more than two indentations  134  in further embodiments of the present invention. As best seen in  FIG. 6 , the enlarged view of  FIG. 6A  and in the loader according to the alternative embodiment shown in  FIGS. 7 and 8 , each of the indentations  134  define a shelf  138  within the interior of loader  108 . Whether sides  122  extend perpendicularly straight down from top surface  120 , or flare outward from top surface  120 , embodiments of the loader  108  and the respective shelves  138  within the loader  108  are sized so that, when the loader is in an unbiased position, a platform  104  is able to fit within the interior of the loader with edge portions of the platform  104  supported on each of the shelves  138  as shown in  FIG. 6 . When in this position, the loader  108  is able to transport a platform  104  of pipette tips  106  away from the packaging  102 . 
     The loading of a platform  104  into loader  108  according to a first embodiment of the present invention will now be described with reference to  FIGS. 1 through 3  and  5  through  6 A. In operation, a force may be applied to top surface  120  of loader  108  to force the loader down over the edges of the top platform  104  in packaging  102 , as shown in  FIGS. 1 and 2 . The loader  108  will self-align itself to the platform  104  as pressure is applied. During the downward movement of loader  108  over the edges of the platform  104 , the edges of the platform engage the indentations  134 , and the indentations may deform to allow the loader to continue to move down over the platform. Once the indentations are clear of the edge of the platform  104 , the indentations may elastically return to their unbiased form, so that the platform  104  is then supported on each of the shelves  138 . In this position, the platform  104  is secured within loader  108  and loader  108  may lift the platform off of the stack of platforms in packaging  102 . 
     In the embodiments shown in the drawing figures, the indentations  134  and shelves  138  are provided in sides  122   a  and  122   c  to grip the platforms  104  across a width dimension of the platforms. In alternative embodiments, the indentations  134  and shelves  138  may be provided in sides  122   b  and  122   d  to grip the platforms  104  across a length dimension of the platforms. 
     Once secured within the loader  108 , the platform may be lifted upward until the tips  106  are clear of the pipette tips in the next lower platform  106  (or shipping base  110  in the event of the lowermost platform). The loader  108  and platform  104  of tips  106  may then be transported to a tip rack  126  of known construction as shown in  FIGS. 5 and 6 . The rack  126  may include upper peripheral edges  140  around the periphery of the rack. The loader  108  is then pushed down over the rack  126 , so that the pipette tips  106  seat within the respective apertures of rack  126 . As the loader  108  moves down over the rack  126 , the flared edges  124  will form a line of engaging contact with peripheral edges  140 , at least along the sides  122  of loader  108  including the shelves  138 . 
     Upon continued downward movement of the loader  108 , the peripheral edges  140  of rack  126  will elastically force the flared portions  124  and sides  122  outward away from each other (again, at least along the sides  122  of loader  108  including the shelves  138 ). This spreading apart of sides  122  will also pull the shelves  138  out from under the platform  104 . The sizes of the loader  108  and shelves  138  are provided so that the platform  104  is either seated on or near to being seated on the rack  126  when the peripheral edge has spread the sides  122  so that the shelves release the platform. 
     This type of offload of platforms presents advantages over other types of transport loaders in that a platform is extricated from the loader using a downward force and motion while the platform is securely positioned within the rack. This minimizes the possibility that pipette tips will get jostled and/or dislodged from the platform  104 . In loaders which move upward while extricating the platform from the loader, it is possible that a platform will remain in the loader longer than intended. In this event, when the platform does eventually dislodge from the loader, the loader may have already separated from the rack and the platform will then fall from a distance into the rack or miss the rack completely. 
     Once the shelves  138  are clear of the platform  104 , the platform  104  is released from loader  108  and is seated within the rack  126 . The loader may then be lifted off of the rack  126  and the sides  122  return to their unbiased positions. The loader may then return to the stack of platforms in packaging  102 , and the next platform may be removed and placed in a rack  126  as described above. This process may be repeated until all of the platforms are removed from packaging  102 . The shipping base  110  preferably does not spread apart the sides of the loader  108 , or does so minimally. Thus, the loader is able to move down over the last platform on the shipping base  110  and position the last platform on the shelves  138  without the edges of the shipping base spreading the shelves  138  wider than the width or length of the platform. The last platform may then be carried away as described above. 
     It is understood that loader  108  may have different configurations to load and release a platform  104  by other methods than that described above with respect to  FIGS. 3 ,  5  and  6 . For example, one alternative embodiment is shown in  FIGS. 4 ,  7  and  8 . In this embodiment, the sides  122   a - d  need not include flaring portions (though they may), and a rack  126  need not include peripheral edges that spread apart the sides of the loader  108 . In the embodiment of  FIGS. 4 ,  7  and  8 , a platform  104  may be loaded into loader  108  off of the top of the stack within packaging  102  as described above in the prior embodiment. In this embodiment, the shelves may be provided in either opposed sides  122   a  and  122   c  defining the width of the loader, or in sides  122   b  and  122   d  defining the length of the loader. Once the platform is secured in the loader  108 , the loader may then transport the platform  104  over to a rack  126 . 
     In this embodiment, once a platform  104  is seated within the rack  126 , the pair of sides  122  in the loader not including the indentations  134  and shelves  138  may be pinched inward toward each other. Pinching the pair of sides not including the shelves  138  will bias the pair of sides including the shelves  138  outward. Thus, by pinching the sides not including the shelves  138 , the sides including the shelves  138  move outward so that the shelves  138  move clear of the platform. At this point, the platform is released to the rack  126 . Once the platform  104  is released, the sides which were pinched inward may be released and the sides  122  may return to their unbiased positions. 
     In a further alternative embodiment, the loader  108  and shelves  138  may be sized so that, in an unbiased position, the shelves  138  on opposed sides of the loader  108  are spread apart too wide to support a platform  104  thereon. In this embodiment, the loader may be positioned over a platform  104  at the top of the stack within packaging  102 . Once the loader is positioned sufficiently down over the platform so that the shelves  138  are positioned at an elevation beneath the platform  104 , the opposed sides  122  of the loader including the shelves may be pinched inward to bring the shelves  138  under the platform. In this embodiment, the shelves may be provided in the opposed sides defining the length of the loader or the width of the loader. 
     Once the shelves  138  are biased inward to support the platform  104  thereon, the platform may be lifted and carried away from the packaging  102  to a rack  126 . During transport, the sides of the loader  108  including the shelves  138  remain biased inward to maintain the platform  104  within the loader  108 . Once at a rack  126 , the loader may be lowered to seat the platform within the rack  126 . 
     In this embodiment, once a platform  104  is seated within the rack  126 , the pair of sides  122  in the loader including the shelves that have been biased inward may be released. The sides including the shelves then return to their unbiased positions free of the platform  104 . The loader  108  may then be removed from the rack  126 , leaving the platform seated within the rack. 
     In the embodiments described above, opposed sides of the loader included only a single tier of indentations and shelves at a given elevation of the loader. That is, when the loader is held horizontally, all of the shelves  138  in the above embodiments are substantially coplanar with each other with respect to a substantially horizontal plane through the loader. In a further embodiment of the invention, each of two opposed sides  122  of the loader may include two or more tiers of indentations and shelves at different elevations of the loader. That is, in an embodiment including two such tiers, a first set of the shelves  138  reside in a first reference plane through the loader, and a second set of the shelves  138  reside in a second reference plane through the loader substantially parallel to the first reference plane. 
     This alternative embodiment may serve at least two functions. First, a platform held between first and second tiers of indentations/shelves may be constrained against moving up or down within the loader during transport. Second, it is conceivable that more than one platform may be loaded into a loader at the same time, with each platform being supported on the shelves of a different tier. The multi-tiered loader embodiment may be loaded and unloaded as indicted in one or more of the above-described loader embodiments. 
     A loader according to any of the above-described embodiments may be used to manually load a platform and transport that platform from packaging  102  to a rack  126 . It is alternatively conceivable that a robotic assembly may be provided which would grip and bias the loader as described in the above embodiments to load a platform and transport that platform from packaging  102  to a rack  126 . 
     While the loader described above has been described as off-loading a single platform to a given rack  126 , it is understood that the loader may be used to off-load a plurality of platforms to a single rack in a stacked configuration. Thus, for example, a loader according to embodiments of the present invention may load a plurality of platforms into a shipping base  110  within packaging  102 . Once the loader has loaded a number of stacked packages, the packaging may be sealed as described above and transported. 
     The foregoing detailed description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.