Abstract:
A closure assembly is provided for a specimen collection container. The closure assembly includes a bottom ring and top ring assembly. The bottom ring is removably attachable to the open end of the container. The top ring assembly, which is removably attached to the bottom ring, includes a mounting ring and a pierceable, resealable septum that closes the bottom ring and permits pierceable instrument access therethrough. The container interior can also be accessed by the removal of the bottom ring from the open end of the container or by the removal of the top assembly from the bottom ring.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a two piece closure assembly for containers that allows for sample purity while enabling direct access to a sample by diagnostic instrument probes. 
     2. Description of Relevant Art 
     Tubes, containers and other collection devices include an open top having a closure that can be removed or opened to access the interior of the container. 
     Some closures comprise an elastomeric stopper that can be urged into the open top of the container to provide a liquid-tight seal. The stopper can be removed to access the interior of the container and then can be replaced in the opening to reseal the container. The stopper provides a liquid tight seal both before the initial opening of the container and during any reclosure of the container. However, stoppers do not provide a hermetic seal which is necessary in some instances to ensure sterility. 
     Other closures include structure for threaded or snap fit engagement with the top of the container. These closures are convenient for periodically accessing the contents of the container, but also do not provide a hermetic seal. 
     Some containers have a barrier bonded or hermetically sealed over the open top of the container. The barrier is substantially impermeable to most gases and liquids, and hence, the contents of the container can be hermetically sealed prior to use. However, these barriers cannot reseal the open top of the container after the initial opening. Thus, an entirely separate closure is required to re-close the container after the initial use. 
     Additionally, there is a need in the art for closures which may be able to both maintain the purity of a sample and also easily enable direct access to a sample by diagnostic probes. 
     SUMMARY OF THE INVENTION 
     The invention provides a closure assembly for a specimen collection container having an open end and opposed closed end and a side wall therebetween, defining a container interior. The closure assembly includes a bottom ring removably attachable to the open end of the container and a top ring assembly removably attachable to the bottom ring for closing the open end of the container. The top ring assembly further includes a mounting ring removably attachable to the bottom ring, the mounting ring having an opening therein for communication with the container interior. A pierceable, resealable septum closing the opening and permitting pierceable instrument access therethrough is also included. Furthermore, the container interior is accessible through the open end by removing the bottom ring from the open end and by the removal of the mounting ring from the bottom ring. 
     More particularly, the closure assembly is screw attachable to the open end of the container so as to provide replaceable removal therefrom. The top ring assembly is attached to the bottom ring by a snap fit which allows access to the container through the bottom ring. 
     Thus, the container is accessible by unscrewing the cover assembly or by removal of the top ring assembly of the bottom ring. 
     Furthermore, the present invention provides a kit of parts adapted for closing a specimen collection container having an open end, a closed end, and a cylindrical side wall defining a container interior. The kit of parts includes a bottom ring removably attachable to the open end of the container and a top ring assembly. The top ring assembly is adapted for removable attachment of the bottom ring for closing the open end. The top ring assembly includes a mounting ring removably attachable to the bottom ring and a pierceable septum for permitting instrument access to the container interior therethrough. The kit also includes a replacement ring adapted for removable attachment to the bottom ring for closing the open end. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a longitudinal cross-sectional view of the closure assembly of the invention. 
         FIG. 2  is a longitudinal cross-sectional view of the top ring assembly of the closure assembly of  FIG. 1 . 
         FIG. 3  is a top plan view of the top ring assembly shown in  FIG. 2 . 
         FIG. 4  is a longitudinal cross-sectional view of the bottom ring of the closure assembly of  FIG. 1 . 
         FIG. 5  is an exploded perspective view of the closure assembly of the invention. 
         FIG. 6  is a longitudinal cross-sectional view of a replacement top ring. 
         FIG. 7  is a longitudinal cross-sectional view of the container and closure assembly with the replacement top ring of  FIG. 6 . 
         FIG. 8  is a longitudinal cross-sectional view of a container. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings in which the like reference characters refer to like parts throughout the several views thereof,  FIG. 1  illustrates closure assembly  70  that is used for hermetically sealing and subsequently resealing a container  12  ( FIG. 8 ). 
     Container  12  as shown in  FIGS. 7 and 8 , includes a closed bottom  17 , an open top at the opposite end  14  of the closed bottom  17 , and a cylindrical side wall  16  extending therebetween defining an interior  19 . Located on the outer surface of side wall  16  in proximity to open top  14  are external screw threads for engagement with closure assembly  70 . 
     Closure assembly  70  includes a top ring assembly  20  and bottom ring  50  as shown in  FIGS. 1 and 5 . As more fully shown in  FIGS. 2 and 3 , the top ring assembly  20  is fabricated from three parts: a molded plastic mounting ring  21 , a septum  31  and a barrier  41 . 
     The molded plastic mounting ring  21  is generally an annular member including an annular bottom wall  22  having opposed surfaces  23  and  24 . Ring  21  defines a central opening  25  therethrough. Depending downwardly from the periphery of bottom surface  24  is an outwardly directed annular snap rib  26 . Extending upwardly from the outer perimeter of the bottom wall  22  is an annular shoulder  27 . An inwardly directed notch  28  is formed between the snap rib  26  and a protrusion  29  along the annular shoulder  27 . A centrally located annular boss  30  extends upwardly from the bottom wall  24  and inwardly of the annular shoulder  27  to define an open cylindrical region  35 . 
     Top assembly  20  further includes a disc-like septum,  31 . Septum  31  is unitarily molded from a thermoplastic elastomer or thermoset resin and defines an outer diameter which is approximately equal to inner diameter of annular snap rib  26 . This allows the septum  31  to be force fitted into the mounting ring  21  adjacent surfaces  24  of wall  22  to close the opening  25 . Septum  31  includes a central raised portion  33  which extends into the cylindrical region  35 . The upper surface  36  of raised portion  33  is tapered inwardly toward a flat center  37 . Septum  31  is capable of being pierced by a needle cannula or other probe instrument (not shown) to access or deposit material into container  12 . The cannula is directed toward the flat center  37  by the inward taper of the septum  31 . Upon withdrawal of a needle cannula, septum  31  will reseal the puncture site. 
     Top assembly  20  further includes a barrier layer  41  having a top face  42  and a bottom face  43 . Barrier layer  41  is unitarily formed from a liquid and gas impermeable material that will provide a vapor barrier. For example, barrier layer  41  may be formed from a metallic foil, such as aluminum foil, or from a metallic foil laminated on one or both sides with a plastic material. Alternatively, barrier layer  41  may be formed from a metalized polyester, a ceramic coated polyester, polyester-olefin, PVDC or other material that provides a vapor barrier. The barrier layer  41  is coated on both faces  42  and  43  with an adhesive to provide structural integrity with the septum  31  and container  12 . 
     Closure assembly  70  also includes bottom ring  50  as seen in  FIGS. 1 ,  4 ,  5 ,  7  and  8 . The bottom ring  50  is generally an annular member having a top end  51  and a bottom end  52 . A cylindrical side wall,  53 , extends therebetween. The inner surface  54  of the side wall  53 , proximal to the top end  51  has an internal retaining groove  55  that is engageable with the outwardly extending snap rib  26  of mounting ring  21  of top assembly  20 . The cooperative structure of the retaining groove  55  of ring  50  and the snap rib  26  of mounting ring  21  allows for removable snap fit engagement between the top ring  21  and the bottom ring  50 . Below and proximal to the retaining groove  55  of the inner wall surface  54  are internal screw threads  56  that are engageable with external threads,  18 , on container  12  for removable screw attachment at ring  50 . 
     The top ring assembly  20  is snapped into the bottom ring  50  to complete the closure assembly  70 . The top end  51  of the side wall  54  of the bottom ring  50  engages with the annular shoulder  27  of the top ring assembly  20 . The snap rib  26  becomes seated within retaining groove  55  in a secure but removable fashion. On assembly, the closure assembly  70  is threadably engaged with the container  12 . This engagement may be accomplished on a device assembly line. After the closure assembly  70  is engaged to the container  12 , container  12  is passed through an induction field to heat and fuse the barrier  41  to container  12 , resulting in an effective seal against the entry of oxygen. 
     The closure assembly  70  can be removed by manually twisting the entire closure assembly  70 . Alternatively, laboratory uncapping machines may be used to automatically uncap the top ring assembly  20  of the closure assembly  70 . Removing only the top ring assembly  20  enables the interior  19  of the container  12  to direct access by laboratory instruments. 
     The container  12  is resealable. If the closure assembly  70  has been manually removed by unscrewing, it may be screwed back onto the container  12  Alternatively, if the top assembly  20  has been automatically removed by a laboratory uncapping machine, a replacement top ring  80  can be used to reseal the closure. 
     Replacement top ring  80  is shown in  FIGS. 6 and 7 . The replacement top ring  80  is fabricated from molded plastic and includes a bottom wall  81  with opposed surfaces  82  and  83 . Depending downwardly from the bottom wall  81  is a perimetrically extending annular snap rib  84 . Extending upwardly from the outer perimeter of the bottom wall  81  is an annular shoulder  85 . An inwardly directed notch  86  is formed between snap rib  84  and protrusion  88  of the annular shoulder  85 . Internal to the snap rib  84  is a plug seal ring  87  for annular engagement with container  12  at an internal location. A centrally located annular boss  89  extends upwardly from the bottom wall  81 , inwardly from the annular shoulder  85  and internal to the plug seal ring  87 . 
     Replacement top ring  80  is snapped into bottom ring  50  to complete replacement closure assembly  90  ( FIG. 7 ). The top end  51  of the side wall  54  of the bottom ring  50  engages with the annular shoulder  85  of the replacement top ring assembly  80 . The snap rib  84  becomes seated within retaining groove  55  in a secure but removable fashion. Plug seal ring  87  is disposed on the inner surface of side wall  16  of container  12  proximal to the open top  14 . On assembly, replacement closure assembly  90  is threadably engaged with the container  12 . 
     If it becomes necessary to access the contents of the container  12  again, the replacement top ring  80  can be removed by a laboratory uncapping machine or the replacement closure assembly  90  can be unscrewed from the container  12 . 
     Various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention.