Patent Publication Number: US-6662957-B2

Title: Container having closure with elastomeric diaphragm and barrier cup

Description:
This is a continuation of application Ser. No. 09/607,905, filed Jun. 30, 2000, now U.S. Pat. No. 6,375,022. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hermetically sealed barrier closure for a container that can provide a liquid-tight reseal after the hermetic seal is broken. 
     2. Description of Related Art 
     Tubes and containers 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 may not provide an adequate liquid-tight seal, and 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 to the container after the initial opening. Thus, an entirely separate closure is required to reclose the container after the initial use. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a resealable barrier closure for a container. The container includes a closed bottom, an open top and a continuous side wall extending therebetween. An annular snap ring or other engagement structure may project outwardly from the side wall at a location spaced slightly from the open top of the container. 
     The resealable barrier closure includes a shell with a top wall that generally conforms to the shape of the open top of the container. The top wall of the shell may include an aperture extending therethrough for accommodating a needle cannula that may be used to deposit material into the container or to withdraw material from the container. 
     The shell of the resealable barrier closure further includes an outer skirt that is dimensioned to telescope over the open top of the container. Inner circumferential portions of the outer skirt may include a snap ring or other engagement structure for resealable engagement with the snap ring or other such engagement structure on the container. 
     The shell further includes an inner skirt projecting from the top wall and spaced circumferentially inwardly from the outer skirt. The inner skirt preferably defines an outside diameter approximately equal to the inside diameter of the opening to the container. Thus, the shell can be tightly fitted onto the open top of the container, with the inner skirt engaged against the inner surface of the container adjacent the open top and with the outer skirt engaged with the outer surface of the container adjacent the open top. 
     The resealable barrier closure further includes an elastomeric diaphragm that is resiliently engaged within the inner skirt of the shell. Thus, the elastomeric diaphragm biases the inner skirt outwardly and helps to achieve a liquid tight seal between the inner skirt and the inner surface of the container adjacent the open top. 
     The resealable barrier closure further includes a barrier for sealing the container. The barrier may be formed substantially into the shape of a cup, and thus may have a bottom wall and a side wall extending upwardly from the bottom wall. The bottom wall extends continuously across the bottom end of the inner skirt and across the bottom surface of the elastomeric diaphragm. The side wall of the barrier surrounds the inner skirt of the shell. The barrier may further include a top flange that extends outwardly from the side wall. The top flange lies adjacent the bottom surface of the top wall of the shell and extends substantially continuously between the inner and outer skirts. 
     The resealable barrier closure is mounted to the open top of the container such that the outer skirt telescopes around the open top and such that the inner skirt and portions of the barrier surrounding the inner skirt telescope into the open top. The closure is urged downwardly onto the container until the snap ring on the outer skirt engages the snap ring on the container. This complete seating of the closure with the container achieves intimate contact between the outer surface of the side wall of the barrier and the inner surface of the side wall of the container. Additionally, the top flange of the barrier achieves intimate contact with both the top edge of the container and the bottom surface of the top wall of the shell. This assembly may be heated so that the barrier is bonded to adjacent regions of the shell and the container to provide a hermetic seal. 
     The container may be opened by urging the closure upwardly relative to the top of the container. Forces on the closure cause the snap rings to disengage and cause the barrier to separate from the container. The container may be resealed by urging the closure downwardly until the snap ring of the shell engages the snap ring on the container. This snapped engagement ensures that the inner skirt is fully telescoped within the open top of the container. Resilient forces exerted by the elastomeric diaphragm urge the inner skirt and adjacent portions of the barrier seal into fluid-tight engagement with the container. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of the container and resealable barrier closure of the present invention. 
     FIG. 2 is a longitudinal cross-sectional view of the plastic shell of the closure shown in FIG.  1 . 
     FIG. 3 is a top plan view of the elastomeric diaphragm of the closure. 
     FIG. 4 is a side elevational view of the elastomeric diaphragm. 
     FIG. 5 is a top plan view of the barrier cup of the closure shown in FIG.  1 . 
     FIG. 6 is a side elevational view of the barrier cup. 
     FIG. 7 is a longitudinal cross-sectional view of the closure in the first mounted condition on the container. 
     FIG. 8 is a cross-sectional view similar to FIG. 7, but showing the closure fully mounted on and sealed to the container. 
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings in which the like reference characters refer to like parts throughout the several views thereof, FIGS. 1,  6  and  7  illustrate a closure assembly  10  that is used for hermetically sealing and subsequently resealing a container  12 . Container  12  includes a closed bottom, an open top  16  and a cylindrical side wall  18  extending therebetween. Side wall  18  of container  12  defines an inside diameter “a” and an outside diameter “b” as shown in FIG.  1 . The outer surface of side wall  18  in proximity to open top end  16  is characterized by an outwardly extending annular snap ring  20  which defines an outside diameter “c”. Snap ring  20  includes an upwardly and outwardly facing ramp surface and a downwardly facing lock surface aligned in a radial plane of container  12  that is spaced from top  16  of container  12  by a distance “d”. 
     Closure assembly  10  includes a shell  22  as shown in FIG.  2 . Shell  22  is generally of a stepped cylindrical configuration and includes a top end  24  and a bottom end  26 . Top end  24  is characterized by an annular top wall  28  having a substantially circular aperture  30  extending centrally therethrough. Top wall  28  further includes an annular downwardly facing barrier support surface  32  and an annular downwardly facing diaphragm support surface  34  which is spaced inwardly from barrier support face  32 . 
     Shell  22  further includes a generally cylindrical outer skirt  36  extending downwardly from top wall  28  to bottom end  26  of shell  22 . Outer skirt  26  defines an inside diameter “d” which is approximately equal to outside diameter “e” of snap ring  20  on container  12 . The inner circumferential surface of outer skirt  36  is characterized by an annular inwardly extending snap ring  38  spaced downwardly from barrier support wall  32  by a distance “f” approximately equal to or slightly greater than distance “d” between top end  16  of container  12  and the bottom face of snap ring  20 . Inwardly extending snap ring  38  of shell  22  defines an inside diameter “g” which is approximately equal to outside diameter “b” of portions of container  12  spaced from snap ring  20 . 
     Outer skirt  36  further includes an outwardly extending holder interference rib  40  substantially adjacent bottom end  26  of shell  22 . Holder interference rib  40  defines an outside diameter approximately equal to or slightly greater than the inside diameter of a container holder with which container  12  and closure  10  may be employed. These dimensions enable an interference fit with the holder for preventing push back of container  12  in response to forces generated by blood flowing into container  12 . 
     Shell  22  further includes substantially cylindrical inner skirt  42  which is concentric with outer skirt  36  and spaced inwardly therefrom. Inner skirt  42  extends a short axial distance from a location on top wall  28  between barrier support surface  32  and diaphragm support surface  34 . Outer circumferential portions of inner skirt  42  furthest from top wall  28  include an annular bead  44  which defines an outside diameter approximately equal to or slightly greater than inside diameter “a” of container  12 . Inner circumferential portions of skirt  42  define a uniform inside diameter “h”. 
     Closure assembly  10  further includes a short cylindrical elastomeric diaphragm  46  as shown most clearly in FIGS. 3 and 4. Diaphragm  46  is unitarily molded from a thermoplastic elastomer or thermoset resin and defines an axial length approximately equal to the axial length of inner skirt  42 . Additionally, diaphragm  46  further defines a diameter “j” which is approximately equal to or slightly greater than inside diameter “h” of inner skirt  42  of shell  22 . With these relative dimensions, diaphragm  46  can be slidably inserted within inner skirt  42  such that outer circumferential regions of one circular face of diaphragm  46  are seated against diaphragm support seat  34  of shell  22 . The opposed circular face of diaphragm  46  will be substantially coplanar with the lower end of inner skirt  42 . With these relative dimensions, diaphragm  46  provides a fluid tight seal against diaphragm support surface  34  and against inner skirt  42 . Additionally, diaphragm  46  exerts an outward biasing force against inner skirt  42  that will generate a minor outward deflection of inner skirt  42 . 
     Closure assembly  10  further includes a barrier cup  48  that is unitarily formed from a liquid and gas impermeable material that will provide a vapor barrier. For example, barrier cup  48  may be formed from a metallic foil, or from a metallic foil laminated on one or both sides with a plastic material. Alternatively, barrier cup  48  may be formed from a metalized polyester, a ceramic coated polyester, polyester-polyoefilin, PVDC or other material that provides a vapor barrier. The barrier cup also may be coated on one or both sides with an adhesive to provide structural integrity with other parts of closure  10  and to achieve a hermetic seal with container  12 , as explained herein. Barrier cup  48 , as shown in FIGS. 5 and 6, is formed to define a substantially circular bottom wall  50  having an outside diameter approximately equal to inside diameter “a” of container  12 . Barrier cup  48  further includes a short cylindrical side wall  52  extending upwardly from bottom wall  50  a distance approximately equal to the axial length of inner skirt  42  of shell  22 . Side wall  52  defines an inside diameter approximately equal to the outside diameter of inner skirt  42  at locations between bead  44  and barrier support surface  32 . Barrier cup  48  further includes a flange  54  extending outwardly from locations on side wall  52  furthest from bottom wall  50 . Flange  54  defines a radial dimension approximately equal to the radial dimension of barrier support surface  32  on shell  22 . 
     Closure  10  is assembled by urging elastomeric diaphragm  46  into inner skirt  42 , such that outer circumferential regions of one circular face of diaphragm  46  seat against diaphragm support surface  34  of shell  22 . Additionally, the outer cylindrical surface of diaphragm  46  will be biased against the inner cylindrical surface of inner skirt  42 . In this mounted condition, the lower circular face of diaphragm  46  will substantially align with the lower end of inner skirt  42 . Assembly of closure  10  proceeds by urging barrier cup  48  over inner skirt  42  such that the lower end of inner skirt  42  abuts bottom wall  50  of barrier cup  48 , and such that flange  54  of barrier cup  48  seats against barrier support surface  32  of shell  22 . 
     Outer skirt  36  of shell  22  then is telescoped over portions of side wall  18  of container  12  adjacent open top  16 . Snap ring  38  of outer skirt  36  will engage snap ring  20  of container  12  as shown in FIG.  7 . However, snap ring  20  of container  12  includes an upwardly and outwardly facing ramp surface that facilitates outward deflection of outer skirt  42  sufficient for snap ring  38  to pass below snap ring  20  of container  12 . Outer skirt  42  then will resiliently return to an undeformed condition, with snap ring  38  thereof engaged below snap ring  20  on container  12  as shown in FIG.  8 . In this condition, flange  54  of barrier cup  48  will be urged tightly between top end  16  of container  12  and barrier support surface  32  of shell  22 . Additionally, in this fully mounted condition, side wall  52  of barrier cup  48  will be squeezed between annular bead  44  of inner skirt  42  and the inner circumferential surface of side wall  18  on container  12 . The assembly of closure  10  and container  12  then may be subjected to heat for adhering or bonding barrier cup  48  to both container  12  and shell  22  for providing a hermetic seal of the inside of container  12 . 
     The assembly of closure  10  and container  12  may be used in a conventional manner by urging a needle cannula through aperture  30  in shell  20  and piercing the needle cannula through both elastomeric diaphragm  46  and bottom wall  50  of barrier cup  48 . The needle cannula may be used to deposit material, such as blood, into container  12  or to withdraw material from container  12 . Upon withdrawal of the needle cannula from closure assembly  10  and container  12 , elastomeric diaphragm  46  will reseal the puncture site to continue to provide a liquid tight seal of container  12 . However, the puncture of barrier cup  48  will have broken the hermetic seal. 
     In situations where closure assembly  10  and container  12  are used for depositing a sample of material, such as blood, container  12  with the blood or other material therein my be sent to a laboratory for analysis. Closure  10  may be removed from container  12  merely by exerting an upward force on shell  22  relative to container  12 . The upward force will cause annular lock bead  38  of outer skirt  36  to ride over annular lock bead  20  on container  12 , while simultaneously breaking the seal between barrier cup  48  and container  12 . Upon complete removal of closure  10  from container  12 , a probe or other laboratory instrument may be employed to access material in container  12  and to remove a portion of that material. Any remaining materials in container  12  can be resealed merely by urging closure  10  back over top  16  of container  12 . More particularly, the above-described dimensions of annular bead  44  on inner skirt  42  and the biasing forces exerted by elastomeric diaphragm  46  on inner skirt  42  will achieve a fluid tight seal of container  12 . Additionally, snap ring  38  of shell  22  can be urged below snap ring  20  of container  12  for releasably locking closure  10  in its sealed engagement with container  12 .