Patent Publication Number: US-8534476-B2

Title: Child-resistant closure shell, closure, and package

Description:
The present disclosure relates to closure shells for two-piece push-and-turn child-resistant closures, to closures that include such shells, and to packages that include such closures and shells. 
     BACKGROUND AND SUMMARY OF THE DISCLOSURE 
     U.S. Pat. No. 4,997,096 discloses a child-resistant closure having inner and outer plastic shells. The outer plastic shell has a base wall, a peripheral skirt and a circumferential array of lugs on an undersurface of the base wall. The inner plastic shell has a base wall, a peripheral skirt, at least one internal thread segment on the skirt, and a circumferential array of lugs on an outer surface of the base wall for opposed engagement by the internal lugs on the base wall of the outer shell. To remove the closure when it is threaded onto a container neck finish, the outer shell must be pushed axially against the inner shell and simultaneously rotated so that the lugs on the outer shell engage the lugs on the inner shell and rotate the inner shell with respect to the container neck finish. When the outer shell is rotated without applying an axial force to the outer shell, the lugs on the outer shell simply cam over the lugs on the inner shell and do not rotate the inner shell with respect to the container neck finish. Child-resistant closures of this type have been marketed for many years by applicants&#39; assignee under the trademark ARGUS-LOC. See also GB 1529999. A general object of the present disclosure is to provide improvements in child-resistant closures of this type, and to provide packages that include such improved closures. 
     The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other. 
     A plastic shell for a two-piece push-and-turn child-resistant closure in accordance with one aspect of the present disclosure includes a peripheral skirt, and a base wall from which the peripheral skirt depends. The base wall has a peripheral portion having a first thickness, a plurality of lugs disposed at least in part on the peripheral portion adjacent to the peripheral skirt, and a central portion having a second thickness less than the first thickness. The central portion includes a plurality of ribs having a third thickness greater than the second thickness and substantially equal to the first thickness and extending from the first peripheral portion toward a center of the base wall. 
     A child-resistant closure in accordance with another aspect of the present disclosure includes a plastic outer shell having an outer base wall with an outer peripheral portion and an outer central portion disposed within the outer peripheral portion. The outer shell also has an outer peripheral skirt extending from the outer peripheral portion, and a plurality of internal lugs disposed at least in part on the outer peripheral portion. A plastic inner shell of the closure has an inner base wall with an inner peripheral portion and an inner central portion disposed within the inner peripheral portion. The inner shell also has an inner peripheral skirt extending from the inner peripheral portion, at least one internal thread segment on the inner peripheral skirt, and a plurality of external lugs disposed at least in part on the inner peripheral portion of the inner base wall adjacent to the inner peripheral skirt for engaging the internal lugs of the outer shell. At least one of the central portions of the base walls has an array of ribs substantially equal in thickness to its corresponding peripheral portion. 
     A child-resistant closure in accordance with a further aspect of the disclosure includes a plastic outer shell including an outer peripheral skirt, and an outer base wall from which the outer peripheral skirt depends and having a plurality of internal lugs adjacent to the outer peripheral skirt. A plastic inner shell of the closure is disposed within the outer shell and includes an inner peripheral skirt with at least one internal thread segment, and an inner base wall from which the inner peripheral skirt depends and having a plurality of external lugs adjacent to the inner peripheral skirt. The outer base wall of the outer shell has an outer peripheral portion of a first thickness on which the internal lugs are disposed, an outer central portion having a second thickness less than the first thickness and including an outer plurality of ribs having a third thickness greater than the second thickness and substantially equal to the first thickness and extending in a direction from the outer peripheral portion toward an outer center of the outer base wall. The inner base wall of the inner shell has an inner peripheral portion of a fourth thickness on which the external lugs are disposed, an inner central portion having a fifth thickness less than the fourth thickness and including an inner plurality of ribs having a sixth thickness greater than the fifth thickness and substantially equal to the fourth thickness and extending in a direction from the inner peripheral portion toward an inner center of the inner base wall. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure, together with additional objects, features, advantages and aspects thereof, will be best understood from the following description, the appended claims and the accompanying drawings, in which: 
         FIG. 1  is a fragmentary sectional view of a child-resistant package in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 2  is a bottom view of a plastic outer shell of a closure of the package of  FIG. 1 ; 
         FIG. 3  is a sectional view taken substantially along line  3 - 3  in  FIG. 2 ; 
         FIG. 4  is a fragmentary sectional view on an enlarged scale of a portion of  FIG. 2  within circle  4 ; 
         FIG. 5  is a fragmentary sectional view taken substantially along line  5 - 5  in  FIG. 4 ; 
         FIG. 6  is a fragmentary sectional view on an enlarged scale taken substantially along line  6 - 6  in  FIG. 2 ; 
         FIG. 7  is a fragmentary sectional view on an enlarged scale taken substantially along line  7 - 7  in  FIG. 2 ; 
         FIG. 8  is a top view of a plastic inner shell of the closure of the package of  FIG. 1 ; 
         FIG. 9  is a sectional view taken substantially along line  9 - 9  in  FIG. 8 ; 
         FIG. 10  is a fragmentary sectional view on an enlarged scale of a portion of  FIG. 8  within oval  10 ; 
         FIG. 11  is a fragmentary sectional view on an enlarged scale taken substantially along line  11 - 11  in  FIG. 10 ; 
         FIG. 12  is a fragmentary sectional view on an enlarged scale taken substantially along line  12 - 12  in  FIG. 10 ; and 
         FIG. 13  is a fragmentary sectional view on an enlarged scale taken substantially along line  13 - 13  in  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  illustrates a child-resistant package  30  in accordance with an exemplary embodiment of the present disclosure as including a two-piece push-and-turn child-resistant closure  32  applied to a neck finish  34  of a container  36 . Container  36  can be of glass or plastic construction. Neck finish  34  is cylindrical and includes at least one external thread segment  38  to which closure  32  is applied. (The term “thread segment” is employed in its usual broad sense in this disclosure as including both single and multiple threads, and both continuous and discontinuous threads.) A foil seal  40  can be applied to the end surface of neck finish  34  to seal the package  30  during shipment and handling and/or to provide indication that the package  30  has not been opened. The child-resistant closure  32  includes a plastic inner shell  42  captured within a plastic outer shell  44 . 
     Referring to  FIGS. 2 and 3 , the outer shell  44  includes a base wall  46  and a cylindrical peripheral skirt  48  depending from the base wall  46 . As used herein, the term “peripheral” relates to a generally circumferential periphery. Referring to  FIGS. 6 and 7 , the base wall  46  preferably includes a peripheral portion  50  of a first thickness t 1  and a central portion  52  having a second thickness t 2  less than the first thickness of peripheral portion  50 . As used herein, the term “thickness” relates to cross-sectional thickness in a direction parallel to a longitudinal closure axis A ( FIG. 1 ). As shown in  FIGS. 1-3 , the central portion  52  of the outer shell  44  is disposed radially within the peripheral portion  50 , and preferably is imperforate although at least part of the central portion  52  could be open in accordance with some aspects of the present disclosure. Indicia can be provided on an outer surface of the base wall  46  to instruct a user how to open the package. 
     Referring to  FIGS. 2 and 3 , a circumferential array of a plurality of angularly spaced internal lugs  54  are disposed around the periphery of base wall  46  adjacent to skirt  48 . Also, although twenty-four lugs  54  are shown in  FIG. 2 , any suitable quantity of lugs  54  may be used. Each lug  54  preferably is L-shaped, having a first portion or leg  56  that extends radially inwardly along an undersurface of base wall  46 . Referring to  FIG. 3 , each lug  54  also has a second portion or leg  58  that extends axially downwardly along a radially inside surface of skirt  48 . As best seen in  FIG. 5 , undersurfaces  60  of legs  56  may be rounded and filleted. Also, as best seen in  FIG. 4 , radially inwardly facing surfaces  62  of legs  58  may be rounded. As shown in  FIG. 1 , there preferably is an internal bead  64  adjacent to the edge of skirt  48  remote from base wall  46  for capturing inner shell  42  within outer shell  44 . 
     Referring to  FIGS. 6 and 7 , the central portion  52  of the outer shell  44  also has a third thickness t 3  that may be substantially equal to the first thickness t 1  of the peripheral portion  50 . As used herein, the terminology “substantially equal” includes allowance for manufacturing tolerances, for example, +/−0.007″ or +/−30% for wall thicknesses. 
     As shown in  FIG. 2 , the central portion  52  includes a rib array  66 , which includes a plurality of ribs  68  disposed on an undersurface of the base wall  46 , and may also include a hub  70  disposed on the undersurface. The hub  70  may correspond to an injection molding gate. The central portion  52  also includes a plurality of web portions  71  that extend between the ribs  68 . The ribs  68  generally extend in a lateral direction from the peripheral portion  50  toward the central portion  52 , wherein radially outer edges of one or more of the ribs  68  are contiguous with the peripheral portion  50 . More specifically, the ribs  68  may be arranged in a spoke-like pattern and, thus, may extend in a radial direction from the peripheral portion  50  toward a center of the outer shell  44 , or to the hub  70 . However, the rib array  66  may be of any suitable shape and need not be symmetrical. Although twelve ribs  68  are shown, any suitable quantity of ribs may be used. In a preferred embodiment, however, and as shown in  FIG. 3 , there may be twice as many lugs  54  as ribs  68 , and the ribs  68  may be generally radially aligned with corresponding lugs  54  and interspersed among every other one of the lugs  54 . 
     Referring to  FIGS. 6 and 7 , the ribs  68  establish the third thickness t 3 , and the plurality of web portions  71  extend between the ribs  68  and establish the second thickness t 2 . As just one of many possible examples, the first and third thicknesses t 1 , t 3  may be about 0.045 inches, and the second thickness t 2  may be about 0.030 inches, for a shell of approximately 1.720 inches in diameter and approximately 0.638 inches in height. 
     Referring to  FIGS. 8 and 9 , the inner shell  42  includes a base wall  74  and a cylindrical peripheral skirt  76  depending from the base wall  74 . Peripheral skirt  76  has one or more internal thread segments  78  for securing the closure to external thread segments  38  on container neck finish  34  ( FIG. 1 ). Base wall  74  preferably has a peripheral portion  80  having a first (or fourth, when considering the outer shell thicknesses) thickness t 1(4) , and a central portion  82  having a second (or fifth) thickness t 2(5) , less than the first thickness t 1(4)  of peripheral portion  80 . The central portion  82  is disposed radially within the peripheral portion  80 , and preferably is imperforate although at least part of the central portion  82  could be open in accordance with some aspects of the present disclosure. A circumferential array of angularly spaced external lugs  84  is disposed around the periphery of base wall  74  adjacent to skirt  76 . Each lug  84  has a clockwise-facing cam face  86  and a counterclockwise-facing abutment face  88 . The upper or axially oriented faces  90  of lugs  84  preferably are rounded, as best seen in  FIG. 11 . 
     Referring to  FIGS. 12 and 13 , the central portion  82  of the inner shell  42  also has a third (or sixth) thickness t 3(6)  that may be substantially equal to the first thickness t 1(4)  of the peripheral portion  80 . Also, V-seals  92  can be provided on the undersurface of the peripheral portion  80  for sealing engagement with an end surface of the container neck finish  34  after removal of foil seal  40  ( FIG. 1 ). 
     As shown in  FIG. 8 , the central portion  82  includes a rib array  94 , which includes a plurality of ribs  96  disposed on a top surface of the base wall  74 , and may also include a hub  98  disposed on the top surface. As used herein, directional words such as top, bottom, upper, lower, radial, circumferential, lateral, longitudinal, transverse, vertical, horizontal, and the like are employed by way of description and not limitation. The hub  98  may correspond to an injection molding gate. The central portion  82  also includes a plurality of web portions  99  that extend between the ribs  96 . The ribs  96  generally extend in a lateral direction from the peripheral portion  80  toward the central portion  82 , wherein radially outer edges of one or more of the ribs  96  are contiguous with the peripheral portion  80 . More specifically, the ribs  96  may be arranged in a spoke-like pattern and, thus, may extend in a radial direction from the peripheral portion  80  to the center of the inner shell  42  or to the hub  98 . In a preferred embodiment, however, and as shown in  FIG. 8 , there may be the same quantity of lugs  84  as there are ribs  96 , and the ribs  96  may be generally radially aligned with the lugs  84 . 
     Referring to  FIGS. 12 and 13 , the ribs  96  establish the third thickness t 3(6) , and the plurality of web portions  99  establish the second thickness t 2(5) . As just one of many possible examples, the first and third thicknesses t 1(4) , t 3(6)  may be about 0.045 inches, and the second thickness t 2(5)  may be about 0.030 inches, for a shell of approximately 1.580 inches in diameter and approximately 0.482 inches in height. 
     The ribs  68 ,  96  reduce sinking and/or doming of the central portions  52 ,  82  of the base walls  46 ,  74  as the relatively thicker peripheral portions  50 ,  80  tend to shrink more than the relatively thinner webs  71 ,  99  during cooling after molding. The ribs  68 ,  96  also strengthen the base walls  46 ,  74  under load during use and improve material flow during molding. 
     The operation of the child-resistant closure  32  may be the same as or similar to that which is described in U.S. Patent Application Publication 2009/0032486, and which is assigned to the assignee hereof and is hereby incorporated by reference herein with the exception of paragraph 0031 thereof. 
     There thus has been disclosed a closure and a package that fully satisfy all of the objects and aims previously set forth. The disclosure has been presented in conjunction with an exemplary embodiment, and a number of 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. The disclosure is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.