Patent Publication Number: US-2023159238-A1

Title: Pressure retention closure

Description:
TECHNICAL FIELD 
     This patent application discloses innovations to closures for containers and, more particularly, to a pressure retention closure for a container having a threadless finish. 
     BACKGROUND 
     Trends in beverage consumption lean toward the drinking “experience” rather than just traditional consumption. Consumer insights reveal a desire to consume beverages from a drinking glass rather than a traditional bottle. Of particular interest as it relates to containers having more of a drinking glass-type design is the finish portion of the container, and in particular, the need for the finish to have a larger diameter than conventional beverage containers. The finish needs to be functional, in that it must be engageable with a closure, but also not displeasing to the consumer when consuming the beverage packaged in the container. 
     In traditional beverage packages, the container typically includes a threaded finish and the closure has a complementary threaded portion that is configured to be mated with the finish threads to couple the closure to the container. While the threaded arrangement is certainly well-suited for meeting the functional purpose of engaging the container finish with a closure, the look and feel of a threaded container finish is not particularly pleasing to consumers, especially those seeking a drinking glass-type experience. That is, for a consumer wanting to consume a beverage from a container having a drinking glass-type design, a threaded container finish neither looks like the top portion of a drinking glass, nor feels like a drinking glass when the finish contacts the consumers lips due to the threads on the outer surface of the finish. Accordingly, there is a desire for drinking glass-type containers having a large diameter mouth and a finish that is not threaded, but rather includes other threadless closure-engaging features. 
     However, in order to provide containers having a threadless finish, a threadless container closure must also be provided. In addition to being suitable for closing and sealing the container, the threadless container closure must also be configured to withstand and retain relatively high internal pressure generated within the container as a result of, for example, one or a combination of carbon dioxide in the beverage (i.e., carbonation), heat to the which the beverage is exposed after the container is closed and sealed by the closure, and agitation to which the beverage is exposed after the container is closed and sealed by the closure. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other. 
     A threadless pressure retention closure for a container in accordance with one aspect of the disclosure comprises a pressure closure assembly and an outer release shell configured to be coupled to the pressure closure assembly. The pressure closure assembly comprises a pressure relief valve and an inner shell having an inner shell base wall configured to retain the pressure relief valve, a pressure relief slot for exposing a portion of the pressure relief valve, and an outer skirt extending away from the inner shell base wall and including a first circumferential portion and a second circumferential portion. The outer release shell includes a first portion having a first portion base wall configured to overlap a first corresponding portion of the inner shell base wall when assembled, and a pressure relief tab corresponding to the pressure relief slot of the inner shell. The first portion further includes an outer skirt extending away from the first portion base wall and configured to wrap around the first circumferential portion of the outer skirt of the inner shell of the pressure closure assembly when assembled. The outer release shell further includes a second portion having a second portion base wall configured to overlap a second corresponding portion of the inner shell base wall when assembled, and an outer skirt extending away from the second portion base wall. 
     In accordance with another aspect of the disclosure, a threadless pressure retention closure for a container comprises a pressure closure assembly and an outer release shell configured to be coupled to the pressure closure assembly. The pressure closure assembly comprises a pressure relief valve and an inner shell having an inner shell base wall configured to retain the pressure relief valve, a pressure relief slot for exposing a portion of the pressure relief valve, and an outer skirt extending away from the inner shell base wall and including a circumferentially interrupted portion and a circumferentially continuous portion. The outer release shell includes a first portion having a first portion base wall configured to rest on top of a corresponding portion of the inner shell base wall when assembled, and a pressure relief tab projecting therefrom corresponding to the pressure relief slot of the inner shell. The first portion further includes an outer skirt extending away from the first portion base wall and configured to wrap around the circumferentially interrupted portion of the outer skirt of the inner shell when assembled. The outer release shell further includes a second portion having a second portion base wall configured to overlap a second corresponding portion of the inner shell base wall when assembled, and an outer skirt extending away from the second portion base wall and being diametrically larger than the outer skirt of the first portion. 
     In accordance with yet another aspect of the disclosure, a threadless pressure retention closure for a container comprises a pressure closure assembly and an outer release shell configured to be coupled to the pressure closure assembly. The pressure closure assembly includes a pressure relief valve having a central hub and a radially outer disc, and an inner shell having an inner shell base wall with a central valve retention aperture for retaining the central hub of the pressure relief valve of the pressure closure assembly, a semi-circular pressure relief slot extending partially circumferentially around the central valve retention aperture for exposing the radially outer disc of the pressure relief valve, a pressure relief pad at one end of the valve release aperture, and an outer skirt extending away from the inner shell base wall and including a circumferentially interrupted portion and a circumferentially continuous portion. The outer release shell includes a semi-circular major portion having a major base wall configured to rest on top of a corresponding portion of the inner shell base wall when assembled, and a pressure relief tab projecting therefrom corresponding to the semi-circular pressure relief slot of the inner shell and configured to rest on the pressure relief pad when assembled. The major portion further includes an outer skirt extending away from the major base wall and configured to wrap around the circumferentially interrupted portion of the outer skirt of the inner shell when assembled. The outer shell further includes a semi-circular minor portion having a minor base wall stepped axially away from the major base wall and configured to be spaced above a corresponding portion of the inner shell base wall when assembled, and an outer skirt extending away from the minor base wall and diametrically larger than the outer skirt of the major portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side elevation view of a pressurized package comprising a container and a container closure in accordance with an illustrative embodiment of the present disclosure; 
         FIGS.  2  and  3    are perspective views of an illustrative embodiment of a pressure closure assembly of the container closure illustrated in  FIG.  1   ; 
         FIGS.  4  and  5    are perspective views of an illustrative embodiment of an outer release shell of the container closure illustrated in  FIG.  1   ; 
         FIGS.  6  and  7    are perspective views of an illustrative embodiment of the container closure illustrated in  FIG.  1    comprising the pressure closure assembly illustrated in  FIGS.  2  and  3    and the outer release shell illustrated in  FIGS.  4  and  5   ; 
         FIG.  8    is a cross-sectional view of a portion the pressurized package illustrated in  FIG.  1    taken along the line  8 - 8  in  FIG.  6   , wherein the container closure is in a closed position or state; 
         FIG.  9    is another cross-sectional view of a portion of the pressurized package illustrated in  FIG.  1   , wherein the container closure is between the closed position or state and an open position or state; 
         FIG.  10    is a perspective view of a portion of the pressurized package illustrated in  FIG.  1   , wherein the container closure is in a closed position or state; 
         FIG.  11    is a perspective view of a portion of the pressurized package illustrated in  FIG.  1   , wherein the container closure is between the closed position or state and an open position or state; 
         FIG.  12    is a perspective view of a portion of the pressurized package illustrated in  FIG.  1   , wherein the container closure is in the open position or state; 
         FIG.  13    is a cross-sectional view of a portion of another illustrative embodiment of a pressurized package wherein the container closure is in a closed position or state; 
         FIG.  14    is a perspective view of an illustrative embodiment of an inner shell of the pressure closure assembly illustrated in, for example,  FIGS.  2  and  3   ; and 
         FIG.  15    is a perspective view of another illustrative embodiment of an outer release shell of the container closure illustrated in  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION 
     The pressure retention closure described herein is configured to be coupled with a threadless neck finish of a container and to also withstand and retain a relatively high internal pressure generated within the container as a result of, for example, one or a combination of carbon dioxide in the beverage (i.e., carbonation), heat applied to the beverage after the container is closed and sealed by the closure, and agitation of the beverage after the container is closed and sealed by the closure. In an embodiment, the pressure retention closure is a threadless, multi-shell, clamp-on closure that is configured to seal the container to which it is coupled when in a closed position or state, and to vent gas in the container to atmosphere as the closure is rotated from the closed position or state toward an open position or state, while keeping the closure securely attached to the container. 
     With specific reference to the drawing figures,  FIG.  1    shows an illustrative embodiment of a pressurized package  10  that includes, at least in part, a container  12  and a closure  14  configured to be assembled with or coupled to the container  12  to close and seal the container  12 . In  FIG.  1   , the container  12  and closure  14  are shown in a partially assembled state with the downward arrows representing the direction in which the closure is pressed when assembling closure  14  with the container  12 . 
     The container  12  may be used for packaging any number of goods or products. For instance, the container  12  may be used to package various types of beverages, for example and without limitation, carbonated beverages. The container  12  may also be used to package products other than beverages, for example, various types of food products, liquids, gels, powders, and the like. Accordingly, the present disclosure is not intended to be limited to the container  12  being used to package any particular type(s) of goods. 
     The container  12  may be composed of glass, plastic, or any other material suitable for both packaging the products or goods identified above, as well as withstanding internal pressure generated in the container  12  when the container  12  is filled and sealed by the closure  14 . As shown in  FIG.  1   , the container  12  may include a base  16  and a body  18  extending from the base  16 , and further includes or defines a longitudinal axis A. The container  12  may further include a shoulder  20  extending from the body  18 , a neck  22  extending from the shoulder  20  or directly from the body  18 , and a finish  24  extending from the neck  22  (i.e., a neck finish) or from the body  18 . The container  12  may further include an open mouth  26  surrounded by an outer sealing lip or sealing surface  28 . The sealing surface  28  is an axially-facing surface that faces away from the container body  18  and that, in an at least one embodiment, is flat such that it extends perpendicular to the axis A of the container  12 . In an embodiment, the finish  24  of the container  12  is a threadless finish having a closure attachment feature in the nature of an excavate outer bead  30  that may have a smooth outer surface. The finish  24  may also include an inner sealing surface  32  extending along the longitudinal axis A that, in an embodiment, comprises a cylindrical inner sealing surface. As will be described below, when the container  12  and closure  14  are assembled together, in at least some embodiments, the inner sealing surface  32  is engaged with a seal carried by the closure  14 . 
     As briefly described above, the closure  14  is configured to be assembled with the container  12 , and the finish  24  thereof, in particular, to close and seal the container  12 . In an embodiment, the closure  14  comprises a pressure retention closure configured to retain and withstand pressure generated within the container  12  when the closure  14  is assembled with the container  12 , and that, in at least some embodiments, comprises a threadless, multi-shell, clamp-on closure. In an embodiment, the closure  14  comprises a pressure closure assembly  34  (best shown in  FIGS.  2  and  3   ) and an outer release shell  36  (best shown in  FIGS.  4  and  5   ) configured to be coupled to the pressure closure assembly  34  to form the closure  14 . 
       FIGS.  2  and  3    show an illustrative embodiment of the pressure closure assembly  34  of the closure  14 . In an embodiment, the pressure closure assembly  34  includes a pressure relief valve  38  and an inner shell  40 . In the illustrated embodiment, the pressure relief valve  38  comprises a central hub  42  (best shown in  FIG.  2   ) and a radially outer disc  44  (best shown in  FIG.  3   ). As will be described below, the inner shell  40  is configured to retain the pressure relief valve  38 , and, in an embodiment, the central hub  42  thereof, in particular, and the pressure relief valve  38  is configured to cover and seal a pressure relief slot  46  of the inner shell  40  (best shown in  FIG.  2   ). 
     With continued reference to  FIGS.  2  and  3   , the inner shell  40  comprises an inner shell base wall  48  having a first or top surface  50  facing in a first direction, a second or bottom surface  52  facing in a second direction opposite the first direction, and a longitudinal axis B extending between and through the top and bottom surfaces  50 ,  52 . In an embodiment, the base wall  48  includes a valve retention aperture  54  extending between and through the top and bottom surfaces  50 ,  52  of the inner shell base wall  48  that is configured to receive and retain therein a portion of the pressure relief valve  38 , for example, the central hub  42 . In the illustrated embodiment shown in  FIG.  2   , the valve retention aperture  54  is located at the center of the base wall  48  (i.e., is coaxial with the axis B), while in other embodiments, the aperture  54  may be located at a different location on the base wall  48 . In other embodiments, the relief valve  38  may be coupled with the inner shell  40 , and the base wall  48  thereof, in particular (i.e., the bottom surface  52  of the base wall  48 ), using other known techniques, for example, using an adhesive, a heat staking process, or one or more fasteners, to cite a few examples. 
     In at least some embodiments such as that shown in  FIG.  3   , the inner shell base wall  48  further includes an annular channel  56  and an axially thinned portion  58  at a radially outer periphery of the base wall  48 . As will be described in greater detail below, when the inner shell  40  is assembled with the container  12 , the annular channel  56  and axially thinned portion  58  of the inner shell base wall  48  rests on and engages the sealing surface  28  of the container  12 . Additionally, in some embodiments of the inner shell, such as, for example, that illustrated in  FIG.  14    (inner shell  140 ), the inner shell base wall (base wall  148 ) may further include one or more features  59  in or on the first or top surface (top surface  150 ) thereof that help facilitate the venting of gas in the container to atmosphere, as will be described in greater detail below. The features  59  may comprise, for example, one or more grooves recessed into the top surface  150  of the base wall  148 , one or more projections extending axially outward from the top surface  150 , or a combination of both one or more grooves and one or more projections. 
     The inner shell  40  further comprises the pressure relief slot  46  briefly described above. The pressure relief slot  46  extends between and through the top and bottom surfaces  50 ,  52  of the inner shell base wall  48 . In an embodiment, the pressure relief slot  46  comprises a semi-circular slot extending partially circumferentially along the base wall  48  and, in an embodiment, at least partially circumferentially around the valve retention aperture  54  in the base wall  48 . The pressure relief slot  46  exposes a portion of the relief valve  38 , which, as will be described in greater detail below, allows for the manipulation of the valve  38  to vent gas in the container  12  to atmosphere. More specifically, and as shown in  FIG.  3   , when the relief valve  38  is assembled with the inner shell  40 , the disc portion  44  of the valve  38  engages the bottom surface  52  of the base wall  48  and overlies or covers and seals the relief slot  46 . The portion of the valve  38  overlying the slot  46  is accessible from the top surface  50  of the inner shell base wall  48 . 
     As shown in  FIG.  2   , the inner shell  40  may further include a pressure relief pad  60  located adjacent to the pressure relief slot  46  on the top surface  50  of the inner shell base wall  48 . The pad  60  is configured to engage a pressure relief tab  62  of the outer release shell  36  when the inner shell  40  and outer release shell  36  are assembled together and oriented in a particular way (i.e., in an orientation corresponding to a closed position or state of the closure  14 ). In other words, when the inner shell  40  and outer release shell  36  are assembled together and oriented in a particular way, the tab  62  of the outer release shell  36  rests on the pad  60  of the inner shell  40 . In an embodiment such as that illustrated in  FIG.  2   , the pad  60 , which may be recessed into the top surface  50  of the inner shell base wall  48 , is located at one end of the pressure relief slot  46 . 
     As illustrated in  FIGS.  2  and  3   , the inner shell  40  further includes an outer skirt  64  extending away from the inner shell base wall  48  in an axially inwardly direction (i.e., in a direction away from the top surface  50  of the base wall  48 ). In an illustrative embodiment, the outer skirt  64  includes a first circumferential portion  66  extending circumferentially about a first portion of the inner shell base wall  48 , and a second circumferential portion  68  extending circumferentially about a second, different portion of the inner shell base wall  48 . In at least some embodiments, such as, for example, that shown in  FIG.  2   , the first circumferential portion  66  of the outer skirt  64  may comprise a circumferentially interrupted portion of the outer skirt  64 . As illustrated in  FIGS.  2  and  3   , the interrupted portion  66  of the outer skirt  64  may include a plurality of petals  70  with spaces  72  therebetween. However, in other embodiments, rather than being circumferentially interrupted, the first portion  66  may instead be circumferentially continuous. 
     Unlike the first portion  66  of the outer skirt  64  which may be circumferentially interrupted, in the embodiment illustrated in  FIGS.  2  and  3    the second portion  68  of the outer skirt  64  may comprise a circumferentially continuous portion of the outer skirt  64 . However, in other embodiments, for example, when the first portion  66  of the outer skirt  64  is circumferentially continuous, rather than being circumferentially continuous, the second portion  68  may instead be circumferentially interrupted as described above with respect to first portion  66 . 
     Regardless of whether first or second circumferential portions  66 ,  68  of the outer skirt  64  are circumferentially continuous or interrupted, the outer skirt  64  is configured to clamp or snap onto the finish  24  of the container  12 . More specifically, in an embodiment, the inner diameter of the outer skirt  64  of the inner shell  40  is equal to or less than the outer diameter of the finish  24 , and the outer bead  30  thereof, in particular, such that as the inner shell  40  is pressed onto the finish  24  of the container  12 , the outer skirt  64  of the inner shell  40  deflects radially outwardly and then snaps back radially inwardly after the outer skirt  64  clears the bead  30 . As a result, the first and/or second circumferential portions  66 ,  68  of the outer skirt  64  wrap around and grip the outer bead  30  to secure the inner shell  40 , and thus, the closure  14 , to the container finish  24 . 
     In addition to the features described above, in an illustrative embodiment such as that illustrated in  FIG.  3   , the inner shell  40  includes an inner skirt  74  extending from the inner shell base wall  48  in an axially inwardly direction (i.e., in a direction away from the top surface  50  of the inner shell base wall  48 ). In an embodiment, the inner skirt  74  is circumferentially continuous and circumscribes the disc portion  44  of the relief valve  38 . As shown in  FIG.  3   , the inner skirt  74  has a radially inwardly-facing inner surface  76  and a radially outwardly-facing outer surface  78 . In an embodiment, the inner skirt  74  includes an annular seal channel  80  extending radially inwardly into the outer surface  78  of the inner skirt  74  that is configured to carry an annular seal  82 , as is shown in, for example,  FIG.  8   . In other embodiments, however, the inner skirt  74  may not include the annular seal channel  80  but rather the annular seal  82  may be molded onto, coupled with, or integrated into the skirt  74  using known techniques such that the seal  82  is carried by the skirt  74 . In any event, when the inner shell  40  is assembled with the container  12 , the annular seal  82  seals against the inner sealing surface  32  of the container finish  24 . Accordingly, when the inner shell  40  and the container  12  are assembled together, the finish  24  of the container  12  is located between the inner skirt  74  and the outer skirt  64  of the inner shell  40 . 
     Turning now to  FIGS.  4  and  5   , an illustrative embodiment of the outer release shell  36  of the closure  14  is shown. As described above, the outer release shell  36  is configured to be coupled to the pressure closure assembly  34 . More specifically, the outer release shell  36  is configured to be clamped or snapped onto the inner shell  40  of the pressure closure assembly  34 . 
     In an embodiment, the outer release shell  36  comprises a first portion  84 , a second portion  86 , and an axis C. In the embodiment illustrated in  FIGS.  4  and  5   , the first and second portions  84 ,  86  each comprise a semi-circular portion of the outer release shell, though it will be appreciated that the first and second portions  84 ,  86  may certainly have other suitable shapes or configurations. Depending on the implementation, one of the first or second portions  84 ,  86  may be larger than the other, and in such an instance, the larger portion may be considered to be the “major” portion and the smaller portion may be considered to be the “minor” portion. For example, in the embodiment illustrated in  FIGS.  4  and  5   , the first portion  84  is larger than the second portion  86 , and as such, the first portion  84  may be considered to be the major portion of the outer release shell  36 , and the second portion  86  may be considered to be the minor portion of the outer release shell  36 . 
     In any event, the first portion  84  includes a first portion base wall  88  configured to overlap, and in some embodiments, rest on, a first corresponding portion of the inner shell base wall  48  when the outer release shell  36  and the inner shell  40  are assembled together. As with the inner shell base wall  48  described above, the first portion base wall  88  includes a first or top surface  90  (best shown in  FIG.  4   ) facing in a first direction and a second or bottom surface  92  (best shown in  FIG.  5   ) facing in a second direction opposite the first direction. In an embodiment wherein the first portion base wall  88  rests on a corresponding portion of the inner shell base wall  48  when the inner shell  40  and outer release shell  36  are assembled together, the bottom surface  92  of the first portion base wall  88  rests on the top surface  50  of the inner shell base wall  48 . 
     While the description above is with respect to an embodiment wherein the first portion base wall  88  rests on a corresponding portion of the inner shell base wall  48  when the outer release shell  36  and inner shell  40  are assembled together, in other embodiments, the first portion base wall  88  does not rest on the inner shell base wall  48  but rather is spaced above the inner shell base wall  48  such that there is a gap or channel therebetween. Accordingly, the present disclosure is not intended to be limited to any particular arrangement(s) of the first portion base wall  88  and inner shell base wall  48 . 
     As briefly described above and illustrated in  FIG.  5   , the first portion  84  of the outer release shell  36  further includes a pressure relief tab  62 . The tab  62  corresponds to the pressure relief slot  46  of the inner shell  40  and, in at least some embodiments, is configured to rest on the pressure relief pad  60  of the inner shell  40  when the outer release shell  36  and inner shell  40  are assembled together. The pressure relief tab  62  projects and extends from the bottom surface  92  of the first portion base wall  88  in an axially inwardly direction (i.e., in a direction away from the top surface  90  of the first portion base wall  88 ). 
     As will be described in greater detail below, when the inner shell  40  and outer release shell  36  are assembled together, the outer release shell  36  is rotatable or configured for rotation relative to the inner shell  40 . When the outer release shell  36  is rotated from a first or closed position or state towards a second or open position or state, the tab  62  moves off of the pressure relief pad  60  on which it rests when the outer release shell  36  is in the first or closed position (in an embodiment wherein the inner shell  40  includes the relief pad  60 ), and drops into the pressure relief slot  46  of the inner shell  40 . Upon dropping into the slot  46 , the tab  62  engages a portion of the relief valve  38  (e.g., the disc portion  44 ) and displaces or pushes it away from the bottom surface  52  of the inner shell base wall  48 . The displacement of the valve  38  creates a gap between the relief valve  38  and the inner shell base wall  48  through which gas in the container  12  may escape to atmosphere. More specifically, gas may escape from between the pressure relief valve  38  and the inner shell  48  and, as will be described below, between the inner shell  40  and the outer release shell  36 . 
     While in the embodiment described above the pressure relief tab  62  extends from the base wall  88  of the release shell first portion  84 , in other embodiments, the pressure relief tab  62  may instead extend from the second portion  86  of the outer release shell  36 , but may otherwise be configured and operative as described above. Accordingly, the present disclosure is not intended to be limited to any particular arrangement or orientation of the pressure relief tab  62 . 
     In addition to the features described above, the first portion  84  of the outer release shell  36  further includes an outer skirt  94 . The outer skirt  94  extends from the first portion base wall  88  in an axially inwardly direction (i.e., in a direction away from the top surface  90  of the first portion base wall  88 ). As shown in  FIGS.  6  and  7   , the outer skirt  94  is configured to engage with and wrap around at least a portion of the outer skirt  64  of the inner shell  40 , for example, the first circumferential (e.g., circumferentially interrupted) portion  66  of the inner shell outer skirt  64 . More specifically, the outer skirt  94  of the first portion  66  of the outer release shell  40  is configured to clamp or snap onto the outer skirt  64  of the inner shell  40  to couple the outer release shell  36  and inner shell  40  together. While the outer release shell  36  and inner shell  40  are coupled together, the outer release  36  is nevertheless configured for rotation relative to the inner shell  40 . 
     The second portion  86  of the outer release shell  36  includes a second portion base wall  96  that is configured to overlap a second corresponding portion of the inner shell base wall  48  when the outer release shell  36  and the inner shell  40  are assembled together. The second portion base wall  96  includes a first or top surface  98  facing in a first direction and a second or bottom surface  100  facing in a second direction opposite the first direction. 
     In an embodiment such as that shown in  FIGS.  5  and  8   , the second portion base wall  96  is configured to be spaced above a corresponding portion of the inner shell base wall  48  when the inner shell  40  and outer release shell  36  are assembled together. In such an embodiment, the top and bottom surfaces  98 ,  100  of the second portion base wall  96  are stepped axially away from the top and bottom surfaces  90 ,  92  of the first portion base wall  88 , respectively. Further, as best shown in  FIG.  8   , when the outer release shell  36  and inner shell  40  are assembled together, because the second portion base wall  96  is spaced about the inner shell base wall  48 , a channel or pathway  102  is formed between the bottom surface  100  of the second portion base wall  96  and the top surface  50  of the inner shell base wall  48  through which gases may flow when the outer release shell  36  is rotated relative to the inner shell  40 . 
     While the description above is with respect to an embodiment wherein the second portion base wall  96  is spaced above a corresponding portion of the inner shell base wall  48  when the outer release shell  36  and inner shell  40  are assembled together, in other embodiments, the second portion base wall  96  is not spaced above the inner shell base wall  48 , but rather rests on the inner shell base wall  48 . For example, in the embodiment of the outer shell illustrated in  FIG.  13    (outer shell  136 ), the top and bottom surfaces (surfaces  198 ,  1100 ) of the second portion base wall (base wall  196 ) are coplanar with the top and bottom surfaces (surfaces  190 ,  192 ) of the first portion base wall (base wall  188 ), respectively. Accordingly, when the inner shell  40  and outer release shell  136  are assembled together, the bottom surface  1100  of the second portion base wall  196  rests on the top surface  50  of the inner shell base wall  48 . Accordingly, the present disclosure is not intended to be limited to any particular arrangement(s) of the second portion base wall  96  and inner shell base wall  48 . 
     In addition to the base wall  96 , the second portion  86  of the outer release shell  36  may further include an outer skirt  104 . The outer skirt  104  extends from the second portion base wall  96  in an axially inwardly direction (i.e., in a direction away from the top surface  98  of the second portion base wall  96 ). As shown in  FIGS.  6  and  7   , the outer skirt  104  is configured to overlap and wrap around at least a portion of the outer skirt  64  of the inner shell  40 , for example, the second circumferential (e.g., circumferentially continuous) portion  68  of the inner shell outer skirt  64 . More specifically, the outer skirt  104  of the second portion  86  of the outer release shell  36  is configured to clamp or snap onto the outer skirt  64  of the inner shell  40  to couple the outer release shell  36  and inner shell  40  together. While the outer release shell  36  and inner shell  40  are coupled together, the outer release  36  is nevertheless configured for rotation relative to the inner shell  40 . 
     In addition to the above, in at least some embodiments, one or more of the bottom surface of the base wall of the first portion of the outer release shell and the bottom surface of the base wall of the second portion of the outer release shell may include one or more features therein that help facilitate the venting of gas in the container to atmosphere. For example, in the embodiment of the outer release shell illustrated in  FIG.  15    (outer release shell  136 ), the base wall (base wall  188 ) of the first portion ( 184 ) may further include one or more features  95  in the second or bottom surface (surface  192 ) thereof that help facilitate the venting of gas in the container to atmosphere. The features  95  may comprise, for example, one or more grooves recessed into the bottom surface  192  of the base wall  188 , one or more projections extending axially outward from the bottom surface  192 , or a combination of both one or more grooves and one or more projections. While  FIG.  15    shows and the description above is with respect to the first portion  184  of the outer release shell  136  having one or more features  95  in the base wall bottom surface  192 , it will be appreciated that in other embodiments, in addition to or instead of the base wall bottom surface  192  having one or more features  95  therein, the bottom surface (bottom surface  1100 ) of the base wall ( 196 ) of the second portion (second portion  186 ) may include one or more features therein (not shown) to facilitate the venting of gas to atmosphere. 
     As shown in  FIG.  4   , the outer release shell  36  may further include one or more throughgoing slots  106  at a radially outer periphery of the second portion base wall  96 . In an embodiment, the slot  106  comprises a semi-circular slot that extends circumferentially along a part or the entirety of the second portion  86  of the outer release shell  36 . One purpose of the slot  106  is to allow for the molding of a lift ledge  108  of the outer release shell  36 , which will be described below. Additionally, however, the slot  106  may provide a pathway through which gas in the container is vented to atmosphere when at least a portion of the relief valve  38  of the pressure closure assembly  34  is displaced. While in the embodiment described above and shown in  FIG.  4    only the second portion  86  of the outer release shell  36  includes the slot  106 , in other embodiments, the first portion  84  of the outer release shell  36  may additionally or alternatively include such a slot, or the outer release shell  36  may include a circumferentially continuous slot that extends about the entire circumference of the outer release shell  36 . Accordingly, the present disclosure is not intended to be limited to any particular arrangement or orientation of a throughgoing slot in the outer release shell  36 . 
     As described above, both the first and second portions  84 ,  86  of the outer release shell  36  have outer skirts—first portion  84  includes the outer skirt  94 , and the second portion  86  includes the outer skirt  104 . In at least one embodiment, the outer skirts  94 ,  104  have different inner and/or outer diameters. For example, in the embodiment illustrated in  FIGS.  4  and  5   , the inner and outer diameters of the of the skirt  104  are larger than the inner and outer diameters of the outer skirt  94 . In another embodiment, however, the inner and outer diameters of the outer skirt  94  may be larger than the inner and outer diameters of the outer skirt  104 . 
     In an embodiment wherein the outer skirt of one of the first and second portions  84 ,  86  of the outer release shell  36  has at least an inner diameter that is larger than that of the other of the first and second portions  84 ,  86 , the portion of the outer release shell  36  having a larger diameter may also include a radially inwardly extending lift ledge  108  (best shown in  FIG.  8   ) at the end of the outer skirt opposite the base wall of the outer release shell  36 . For example, in the embodiment illustrated in  FIG.  8    wherein the second portion  86  of the outer release shell  36  is diametrically larger than the first portion  84 , the second portion  86  includes the lift ledge  108  at the end of the outer skirt  104  opposite the base wall  96  of the second portion  86 . As will described in greater detail below, in an embodiment wherein the first portion  66  of the inner shell  40  is circumferentially interrupted as shown in  FIGS.  2  and  3   , the combination of the larger diameter of the outer skirt  104  and the lift ledge  108  at the end of the outer skirt  104  allows for the release of the petals or segments  70  of the interrupted portion  66  of the inner shell  40  from the container finish  24 , thereby allowing for the closure  14  to be removed from the container  12 . 
     With reference to  FIGS.  6 - 12   , the assembly of the the pressure closure assembly  34  with the outer release shell  36 , the coupling of the closure  14  to the container  12 , and the operation of closure  14  after it has been coupled with the container  12  will now be described. 
     As shown in one or more of  FIGS.  6 - 9   , the inner shell  40  of the pressure closure assembly  34  is configured to be clamped or snapped onto the finish  24  of the container  12 , and the outer release shell  36  is configured to be clamped or snapped onto the inner shell  40 . As best shown in  FIGS.  8  and  9   , when the inner shell  40  is assembled with the container  12 , the annular seal  82  of the inner skirt  74  of the inner shell  40  seals against the inner sealing surface  32  of the container finish  24 , and the outer skirt  64  of the inner shell  40  wraps around the outer bead  30  of the container finish  24 . 
     As described elsewhere above, when the outer release shell  36  and the inner shell  40  are coupled or assembled together (i.e., the outer release shell  36  is snapped onto the inner shell  40 ), the outer release shell  36  is rotatable relative to the inner shell  40 . More specifically, the outer release shell  36  is rotatable from a first or closed position or state in which the closure  14  seals the container, and thus, retains the pressure in the container  12 , to a second or open position or state in which the closure  14  vents gas in the container  12  to atmosphere. As shown in  FIG.  10   , when the closure  14 , and the outer release shell  36  thereof, in particular, is in the closed state or position, the outer release shell  36  is circumferentially oriented with respect to the inner shell  40  so that the outer skirt  94  of the first portion  84  (e.g., major portion) of the outer release shell  36  grips the corresponding circumferential first portion  66  (e.g., interrupted portion) of the outer skirt  64  of the inner shell  40 . When oriented in this way, and in an embodiment wherein the inner shell  40  includes the relief pad  60 , the pressure relief tab  62  (not shown in  FIG.  10   ) of the first portion  84  of the outer release shell  36  rests on the pressure relief pad  60  (not shown in  FIG.  10   ). 
     As the outer release shell  36  is rotated relative to the inner shell in, for example, a counterclockwise direction as shown in  FIG.  11   , toward the second or open position, the tab  62  is moved off of the pressure relief pad  60  (if applicable) and drops into the pressure relief slot  46  in the base wall  48  of the inner shell  40 . Upon dropping into the slot  46 , the tab  62  engages a portion of the relief valve  38  (e.g., the disc portion  44 ) and, as shown in  FIG.  9   , displaces or pushes the relief valve  38  away from the bottom surface  52  of the inner shell base wall  48 . As a result, a gap is formed between the relief valve  38  and the inner shell base wall  48  through which gas in the container may escape to atmosphere (i.e., gas may escape from between the pressure relief valve  38  and the inner shell  40 , and from between the inner shell  40  and the outer release shell  36 ). More specifically, gas in the container  12  passes between the relief valve and the inner surface base wall  48 , through the relief slot  46  and out to atmosphere through spaces or gaps between the inner shell  40  and outer release shell  36 . In an embodiment, wherein the channel or pathway  102  is formed between the bottom surface  100  of the second portion base wall  96  of the outer release shell  36  and the top surface  50  of the inner shell base wall  48 , the gas may pass out to atmosphere through the slot  106 . 
     As the outer release shell  36  continues to rotate towards the open position or state, the tab  62  travels within the relief slot  46  and continues to displace the relief valve  38  as it moves to allow for continued venting of the container  12 . When the tab  62  reaches the end of the relief slot  46  such that the outer release shell  36  cannot rotate any further, the inner shell  40  and outer release shell  36  are oriented as shown in  FIG.  12    such that the outer skirt  104  of the second portion  86  (i.e., minor portion) of the outer release shell  36  substantially circumferentially overlaps the first circumferential portion  66  (e.g., the interrupted portion) of the outer skirt  64  of the inner shell  40 . It will be appreciated that for purposes of this disclosure, the term “substantially” is intended to mean that the outer skirt  104  of the second portion  86  of the outer release shell  36  overlaps the entirety of the first circumferential portion  66  of the inner shell outer skirt  64 , or overlaps at least a majority of the first circumferential portion  66  of the inner shell outer skirt  64 . 
     In any event, when the outer skirt  104  of second portion  86  of the outer release shell  36  is oriented in this manner and the second portion  86  of the outer release shell  36  includes the lift ledge  108  at the end of the outer skirt  104 , the lift ledge  108  is liftable to engage and lift up on an edge of the outer skirt  64  of the inner shell  40  to remove the closure  14  from the container  12 . In an embodiment wherein the second portion  86  of the outer release shell  36  includes a larger diameter than the first portion, the larger diameter results in a gap between the outer release shell  36  and the skirt  64  and allows the edge of the outer skirt  64  of the inner shell  40  being lifted to be pulled further away from the outer bead  30  of the container  12  than if it had a smaller diameter, thereby facilitating the removal of the closure  14  from the container  12  and making the removal easier. 
     The disclosure has been presented in conjunction with several illustrative embodiments, and additional modifications and variations have been discussed. Other modifications and variations readily will suggest themselves to persons of ordinary skill in the art in view of the foregoing discussion. For example, the subject matter of each of the embodiments is hereby incorporated by reference into each of the other embodiments, for expedience. The disclosure is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.