Abstract:
A child-resistant closure and container package includes a container having a finish with an external thread and pockets in the thread. A closure has a base wall, a peripheral skirt with an internal thread and lugs on the internal thread for receipt in the pockets, and a spring element on the base wall for engagement with the container finish to bias the closure away from the container finish and resiliently urge the lugs into the pockets. A liner is urged by the spring element into engagement with the container finish. The liner may include a base with metal and plastic layers for induction-welded sealing engagement with the finish such that, upon removal of the closure, the metal and plastic layers remain secured to the finish and the liner base is removed with the closure. The metal and plastic layers may be removed by a user for access to the contents of the container, and the liner base continues to serve as a package seal during use of the package.

Description:
[0001]     This application is a division of application Ser. No. 09/982,249 filed Oct. 16, 2001. 
     
    
       [0002]     The present invention is directed to child-resistant closure and container packages, to closures and containers for such packages, and to methods of making such packages, closures and containers.  
       BACKGROUND AND SUMMARY OF THE INVENTION  
       [0003]     Child-resistant closure and container packages are conventionally employed for prescription vials, vitamin bottles and a number of other applications. The present invention deals particularly with those types of child-resistant packages that involve application of axial pressure to the closure and simultaneous turning of the closure with respect to the container in order to remove the closure from the container. The present invention involves a number of features or aspects in a child-resistant closure, container or package, which may be implemented separately from or more preferably in combination with each other.  
         [0004]     The present invention embodies a number of features or aspects that may be used separately from or, more preferably, in combination with each other. In accordance with a first aspect of the present invention, a child-resistant closure and container package includes a container having a finish with at least one external thread and pockets in the thread. A closure has a base wall, a peripheral skirt with at least one internal thread and lugs on the internal thread for receipt in the pockets, and a spring element on the base wall for engagement with the container finish to bias the closure away from the container finish and resiliently urge the lugs into the pockets. A liner preferably is urged by the spring element into engagement with the container finish. The liner may include abase with metal and plastic layers for induction-welded sealing engagement with the finish such that, upon removal of the closure, the metal and plastic layers remain secured to the finish and the liner base is removed with the closure. The metal and plastic layers may be removed by a user for access to the contents of the container, and the liner base continues to serve as a package seal during use of the package. The package may alternatively be supplied with a mono-layer liner, or without a liner.  
         [0005]     In accordance with another aspect of the present invention, the pockets in the at least one external thread on the container finish are formed on an undersurface of the external thread and do not extend axially through the thread, such that the upper surface of the external thread is continuous throughout the external thread. This feature helps prevent cross threading during application of the closure to the container finish. In accordance with a further feature of the invention, the at least one external thread on the container finish and the at least one internal thread on the closure skirt may be of elongated dimension as compared with industry standards, and thread abutment stops are formed on the ends of the threads to prevent over-tightening of the closure and potential damage to the spring element. The elongated external thread on the container finish, particularly in combination with the pockets that do not extend axially through the external thread, permits the container to be used with a conventional non-child-resistant closure if desired, for example, by elderly persons. In dual lead packages, each thread on the closure may extend over an arc of 190° for example, and each thread on the finish may extend over an arc of 180°. In a single lead package with the thread stop at the bottom of the thread on the container finish, the closure thread may extend over an arc of 450° and the finish thread may extend over an arc of 455°. In single lead packages with the thread stop at the top of the closure thread, the closure thread may extend over an arc of 370° and the finish thread may extend over an arc of 360°.  
         [0006]     A closure in accordance with a further aspect of the present invention is of integrally molded plastic construction. The closure has a base wall, a peripheral skirt with at least one internal thread and lugs on an upper surface of the thread, and a spring element on the base wall for engagement with a container finish to bias the lugs into opposing thread pockets on the container finish. The lugs have an angulated surface sloping toward an end of the thread remote from the base wall and a circumferentially facing radially extending abutment surface on an end of the lugs facing the opposing end of the thread. The spring element preferably comprises a circumferentially continuous conical lip that extends radially and axially inwardly from the base wall adjacent to the skirt. The lip tapers in thickness from the base wall to the free end of the lip to promote differential flexing of the lip upon engagement with a container finish or with a liner in opposed engagement with the container finish. The free end of the lip is rounded to permit sliding of the lip along the surface of a liner without binding or tearing. A container in accordance with yet another aspect of the invention includes an integrally molded plastic body having a finish with at least one external thread and pockets on an undersurface of the thread that do not extend axially through the thread, such that the upper surface of the thread is continuous throughout the thread. The pockets in the external thread have a circumferentially extending axially angulated cam surface and a radially extending abutment surface opposed to the cam surface.  
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0007]     The invention, together with additional objects, features and advantages thereof, will be best understood from the following description, the appended claims and the accompanying drawing in which:  
         [0008]      FIG. 1  is a perspective view of a closure and container package in accordance with one presently preferred embodiment of the invention;  
         [0009]      FIG. 2  is a fragmentary sectional view of the closure and container finish in the package of  FIG. 1 ;  
         [0010]      FIG. 3  is an enlarged sectional view of the portion of  FIG. 2  within the area  3 ;  
         [0011]      FIG. 4  is a sectioned elevational view of the closure in the package of  FIGS. 1-3 ;  
         [0012]      FIG. 5  is a bottom plan view of the closure illustrated in  FIG. 4 ;  
         [0013]      FIG. 6  is a sectional view taken substantially along the line  6 - 6  in  FIG. 4 ;  
         [0014]      FIG. 7  is a fragmentary sectional view taken substantially along the line  7 - 7  in  FIG. 6 ;  
         [0015]      FIG. 8  is a fragmentary sectional view on an enlarged scale of the portion of  FIG. 4  within the area  8 ;  
         [0016]      FIG. 9  is a fragmentary sectional view of the portion of  FIG. 8  within the circle  9 ;  
         [0017]      FIG. 10  is a fragmentary elevational view of the finish of the container in the package of  FIGS. 1-3 ;  
         [0018]      FIG. 11  is a fragmentary side elevational view of the container finish illustrated in  FIG. 10 ;  
         [0019]      FIGS. 12 and 13  are fragmentary sectional views taken substantially along the lines  12 - 12  and  13 - 13  in  FIG. 11 ;  
         [0020]      FIG. 14  is a top plan view of a closure in accordance with a modified embodiment of the invention;  
         [0021]      FIG. 15  is a fragmentary sectional view similar to that of  FIG. 2  but illustrating the closure of  FIG. 14 ;  
         [0022]      FIG. 16  is an enlarged sectional view of the portion of  FIG. 15  within the area  16 .  
         [0023]      FIG. 17  is a partially sectioned exploded elevational view of a container finish, liner and closure in accordance with another embodiment of the invention;  
         [0024]      FIG. 18  is a partially sectioned elevational view taken from the direction  18  in  FIG. 17 ;  
         [0025]      FIG. 19  is a sectioned elevational view taken in a plane extending through the closure and container finish in  FIG. 17  perpendicular to the axis of the finish;  
         [0026]      FIGS. 20-23  are sectional views taken along the respective lines  20 - 20 ,  21 - 21 ,  22 - 22  and  23 - 23  in  FIG. 19 ; and  
         [0027]      FIG. 24  is a fragmentary sectional view similar to that of  FIG. 3 , but illustrating another embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0028]      FIG. 1  illustrates a child-resistant closure and container package  20  in accordance with one presently preferred embodiment of the invention as comprising a closure  22  threadably secured to the finish of a container  24 . Closure  22  ( FIGS. 1-9 ) is preferably of integrally molded plastic construction having a circular base wall  26  and a depending peripheral skirt  28 . An internal helical thread  30  extends around the inside surface of peripheral skirt  28  between an upper end  32  and a lower end  34  adjacent to the free edge of peripheral skirt  28 . (Directional adjectives such as “upper” and “lower” are employed by way of description and not limitation with reference to the vertical and upstanding orientations of the closure and container illustrated in the drawings. Thus, upper end  32  of thread  30  is adjacent to closure base wall  26 , while lower thread end  34  is adjacent to the free edge of skirt  28 .) Upper end  32  of thread  30  contains the usual tapered thread lead-in, while lower end  34  is flat, faces circumferentially and is disposed in the plane of the diameter of the closure. A plurality of circumferentially spaced lugs  36  are formed on the upper surface of thread  30 . The illustrated embodiment includes a single internal thread  30  having four lugs  36  at 90° spacing from each other, with the first lug being spaced 90° from thread end  32 . Each lug  36  has a flat circumferentially oriented abutment surface  38  disposed in a plane that includes the closure axis, and a sloping cam surface  40  facing in the opposite direction from abutment surface  38 . In the illustrated embodiment of the invention, the profile of lug  36  follows the thread helix angle for about 5°, and then tangentially tapers into the thread over an angle of 25°.  
         [0029]     A spring element  42  in the illustrated embodiment takes the form of a conical lip that extends axially and radially inwardly from base wall  26  adjacent to the junction of base wall  26  and peripheral skirt  28 . Alternatively, spring lip  42  may extend axially and radially inwardly from the upper end of skirt  28  adjacent to the juncture with base wall  26 . Spring lip  42  is circumferentially continuous, as best seen in  FIG. 5 , and tapers in thickness from base wall  26  to the free edge  44  of the lip. As best seen in  FIGS. 8 and 9 , free edge  44  of lip  42  is rounded—i.e., has a rounded convex contour facing axially downwardly with respect to base wall  26 . The tapering contour of spring lip  42  promotes differential flexing of the spring lip, as will be described. Closure  22  illustrated in the drawings is of integral injection molded plastic construction, such as HDPE or PP. However, other plastic materials are also envisioned.  
         [0030]     Container  24  ( FIGS. 1-3  and  10 - 13 ) includes a hollow body  50  from which a finish  52  axially extends to form the container mouth. Finish  52  is cylindrical and has a central axis that is coincident with the central axis of closure skirt  28  in assembly. A helical external thread  54  extends around finish  52  from an upper end  56  to a lower end  58 . A thread abutment stop  60  projects radially outwardly from finish  52  and extends axially (i.e., parallel to the central axis of the finish) from lower thread end  58  to a bead  61  that externally surrounds finish  52 . Abutment stop  60  has a flat circumferentially facing face  62  disposed in the plane of the finish diameter. A series of pockets  64  are spaced around the underside or undersurface of thread  54 . In the illustrated embodiment of the invention, there is a single external thread  54  having four pockets  64  at 90° spacing from each other, with the first pocket being disposed at a spacing of 90° from thread start  56 . Each pocket  64  has a circumferentially oriented abutment face  66  and an angulated cam face  68 . Each abutment face  66  is flat and disposed in a plane that includes the axis of the finish. In a preferred embodiment of the invention illustrated in the drawings, each pocket  64  follows the thread helix angle for about 10°, and then tangentially tapers into the thread over an angle of about 25°. It will be particularly noted in  FIG. 12  that each pocket  64  does not extend axially entirely through thread  54 , leaving a portion  68  contiguous with the upper surface of the thread, so that the upper surface of thread  54  is continuous throughout the length of the thread. This feature helps prevent jamming of the closure on the thread as the closure is applied to the container. Container  24  is preferably of integrally molded construction, such as HDPE, PP or PET.  
         [0031]     A liner  70  is preferably disposed between closure spring lip  42  and the upper edge of container finish  52 , at least when the package is initially assembled. Liner  70  in the embodiment of  FIGS. 1-13  comprises a disk having sequential layers of cellulose  72 , wax  74 , metal  76  and plastic  78 . (These layers are not illustrated to scale in the drawings.) Liner disks of this type are conventional in and of themselves. Liner  70  is in axial abutment with the upper edge or sealing surface of container finish  52 , being held against the container by resilient compression of spring lip  42 . As previously noted, the tapering contour of spring lip  42  helps promote differential flexing of the spring lip. That is, upon initial engagement of liner disk  70 , the thinner free edge of the spring lip will initially deflect, and the base portion of the spring lip will not deflect until substantial additional force is applied. The rounded contour of spring lip free edge  44  helps promote sliding of the spring lip along the upper surface of the liner without gouging or tearing.  
         [0032]     Liner  70  may be initially assembled to closure  22 , and preferably is of a diameter to be loosely retained within the closure by the upper reach of closure internal thread  30 . Alternatively, liner  70  may have a greater diameter than closure skirt  28  and be held by friction within the closure skirt. When container  24  is filled with product, and the closure and liner subassembly is assembled to the container, conventional induction equipment is employed to heat metal layer  76 , vaporize wax layer  74  and melt plastic layer  78  so as to secure the metal and plastic layers to the upper edge of container finish  52 . When closure  22  is thereafter removed from the container by a user, cellulose layer  72  is removed with the closure, while metal layer  76  and plastic layer  78  remain with the container for removal by the user. This not only seals the contents of the container until ready for use, but provides an indication to the user of potential tampering. Cellulose layer  72  remains in the closure loosely or frictionally captured between the closure base wall and the upper reach of the thread. Layer  72  provides a sealing function during continued use of the package.  
         [0033]     When the closure is applied to the container, both at the time of filling and during use, lugs  36  on closure thread  30  enter and ride under pockets  64  in container external thread  54 . Cam surfaces  40  on lugs  36  cooperate with cam surfaces  68  in pockets  64  to facilitate threading of the closure onto the container. As previously noted, the fact that pockets  64  do not extend fully through the finish external thread also helps prevent crossing of the threads. When the closure is fully applied to the container, spring lip  42  urges closure  22  axially upwardly with respect to the container finish so that lugs  36  nest within pockets  64 . When it is thereafter attempted to remove the closure from the container finish, lug abutment faces  38  will cooperate with pocket abutment faces  60  to prevent unscrewing of the closure in the absence of sufficient axial force on the closure to compress spring lip  42  and permit the lugs to clear the pockets. This structure provides the child-resistant feature of the invention.  
         [0034]     In the embodiment of the invention illustrated in  FIGS. 1-13 , the circumferential dimensions of closure internal thread  30  and finish external thread  54  are greater than the one-turn thread dimensions recommended by the Closure Manufacturers Association and the Society of the Plastics Industry. The spiral threads preferably both extend at least 450° around the closure and the container finish. In one presently preferred single-thread embodiment with thread stop  60  disposed at the lower end of finish thread  54 , the closure thread extends over an arc of 450° and the finish thread extends over an arc of 455°. Thread abutment stop  60  on container finish  52  ( FIGS. 10-11  and  13 ) cooperates with stop face  34  ( FIGS. 4-6 ) on closure internal thread  30  to prevent over-tightening of the closure on the container finish, and possible damage to spring lip  42  due to over compression. The elongated dimension of container external thread  54  permits the container to be used with a non-child-resistant closure, for example, by the elderly who may have difficulty opening the child-resistant closure. The continuous internal thread on the non-child-resistant closure will readily bridge pockets  64  on the container finish. The extended finish thread length will ensure that the closure thread (typically about 360° in total length) does not engage and potentially jam on container finish thread stop  60 .  
         [0035]      FIGS. 14-16  illustrate a closure and container package  80  in accordance with a modified embodiment of the invention. Package  80  includes a closure  82  secured to finish  52  of container  24 . The primary difference between package  80  in  FIGS. 14-16  and package  20  in  FIGS. 1-13  lies in the fact that a tear band  84  is integrally molded onto the lower edge of closure peripheral skirt  86 , being secured thereto by frangible bridges or a thin frangible membrane. Tear band  84  extends from the lower edge of skirt  86  to a position adjacent to bead  61  on container finish  52 . Thus, closure  82  cannot be axially compressed with respect to container finish  52  in order to remove the closure without first removing tear band  84  from the lower edge of the closure. Tear band  84  thus provides a tamper-indicating capability to the package  80  illustrated in  FIGS. 14-16 . The tear band also removes top load forces from spring lip  42  to prevent damage to the spring lip under long term top load conditions. The remainder of package  80  is the same as package  20 , and identical reference numerals are employed in the drawings to indicate identical parts.  
         [0036]      FIGS. 17-23  illustrate a container and closure package  90  in accordance with another embodiment of the invention as comprising a container  92 , a closure  94  and a liner  96 . Container  92  has a cylindrical finish  98  with dual external threads  100 ,  102 . Each thread  100 ,  102  has two circumferentially spaced pockets  68  with abutment faces  66  as previously described. The pockets in each thread are at 90° spacing from each other, and the pockets in thread  100  are substantially diametrically opposed to the pockets in thread  102 . Each thread  100 ,  102  preferably extends over an arc of at least 180°, plus a 10° lead-in. The upper end of each thread  100 ,  102  terminates in a circumferentially facing flat abutment face  104 . Abutment faces  104  preferably lie in a common plane that intersects the central axis of the container finish.  
         [0037]     Closure  94  in this embodiment has a base wall  26 , a peripheral skirt  28  and a spring lip  42  as in the previous embodiments. Closure  94  is a dual-thread closure, containing a pair of internal threads  106 ,  108 . Each internal thread preferably extends over an arc of 190°, plus a 10° lead-in. Each thread  106 ,  108  includes a circumferentially spaced pair of lugs  36  with circumferentially oriented abutment surfaces  38  and sloping cam surfaces  40  as previously described. Lugs  36  are at 90° spacing. The upper end of each thread—i.e., the end adjacent to closure base wall  26 —terminates in an axially upwardly extending thread abutment stop  110 . Each abutment stop projects radially inwardly from skirt  28  and has a circumferentially facing abutment stop face  112  opposed to the stop face  38  of the adjacent lug  36  on that thread. When the closure is threaded onto the container, abutment face  112  of stop  110  cooperates with abutment face  104  at the upper end of each external thread  100 ,  102  to prevent over-tightening of the closure onto the container and potential damage to spring element  42 .  
         [0038]     Liner  96  in the embodiment of  FIGS. 17-23  is either a single-layer or multiple-layer liner that is not welded or otherwise secured to the container finish. Liner  96  may comprise a single layer of cellulose, for example. In assembly, liner  96  is captured within closure  94  by internal threads  106 ,  108  adjacent to base wall  26  of the closure. When the closure is applied to the container, liner  96  seals against the axial edge of closure finish  98 . When the closure is removed from the container finish, the liner stays with the closure.  FIG. 21  illustrates the amount  116  of radial overlap between lugs  36  on the closure internal thread and pockets  64  on the container finish external thread.  FIG. 21  also illustrates the distance  118  that closure  94  must be depressed against the force of spring lip  42  in order for lugs  36  to clear pockets  64 . The embodiment of  FIGS. 17-23  has the advantage that formation of the opposing thread stops adjacent to the upper end of the closure thread helps to reduce over-torquing the closure caused by bypassing the thread stops due to ovalization.  
         [0039]      FIG. 24  illustrates a package  120  that is similar to those previously discussed, but in which the liner has been eliminated. Closure  122  of package  120  has a spring lip  124  that is compressed against finish  52  of container  24 . Spring lip  124  is similar to lip  42  discussed above, but is designed to achieve the desired compression of the spring lip without the liner being present. Spring lip  42  also obtains a measure of sealing against the container finish.  
         [0040]     There have thus been disclosed a child-resistant closure and container package, a closure, a container, and a method of making a child-resistant closure and container package, which fully satisfy all of the objects and aims previously set forth. Three embodiments of the invention have been disclosed, and a number of modifications and variations have been discussed. Other modification and variations will readily suggest themselves to persons of ordinary skill in the art. The invention is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.