Patent Publication Number: US-7210593-B2

Title: Tamper-evident quick twist closure

Description:
This application claims priority from U.S. Provisional Application 60/391,349 filed Jun. 25, 2002, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to closures in general, and more particularly to a one-piece injection molded cap having a tamper-evident breakaway bottom ring. After initial removal of the cap and separation of the breakaway ring, the cap can be snapped back onto the container for resealing contents contained therein. 
     BACKGROUND OF THE INVENTION 
     A twist closure for a container, such as a cap for a soft drink bottle having a threaded neck portion, is typically provided with a top portion and an elongated skirt portion downwardly depending therefrom that circumscribes the outer periphery of a threaded container neck. Removing the closure from the container is conventionally accomplished by rotating the closure along the threaded neck in the counterclockwise direction, while securing the closure onto the container is conventionally accomplished by rotating the closure along the threaded neck in the clockwise direction. The threading on the container neck usually restricts the rotating direction of the closure to one direction for removal and one direction for attachment. This unidirectional movement is somewhat limiting and can be inconvenient at times. In addition, the conventional, elongated skirt portion tends to prolong the process of attaching and removing closures from containers. 
     Recognizing some of the limitations of prior art twist closures, the present inventors have designed a closure that is economical to manufacture, requires less material, is simple and easy to manipulate and is further provided with a tamper-evident feature that depends from an abbreviated skirt portion. The inventive closure interacts with a container neck that enables attachment of such closure by a downward pressing of such closure onto the container neck, yet enables removal from the container neck by a shortened rotation of such closure in either the clockwise or counterclockwise direction. 
     SUMMARY OF THE INVENTION 
     A one-piece injection molded closure comprises a cap with a tamper-evident ring that is designed to snap engage a specialized container neck. The container is provided with an upper bead around the container lip and a lower bead located further down on the side of the neck. Inside the cap is a continuous ring of teeth that engage teeth located inside the container neck wall. When the cap is snapped onto the container neck, both sets of corresponding teeth are automatically engaged and a plug seal provided on the closure engages the container upper bead. By turning the cap clockwise or counter-clockwise, the side angles of the teeth force the cap to disengage upwards, causing it to ride up over the upper bead and unsnap from the container neck. 
     The cap and tamper-evident ring are initially joined by a plurality of tapered posts extending along the side skirt, which creates open skirt areas that save material and reduce the overall production part cost. The cap is initially seated on the upper bead of the container neck, while the tamper-evident ring is initially seated on the lower bead. When the closure is opened for the first time, the tapered posts break away along a top surface of the ring, causing the ring to separate from the cap and slide down the container neck below the lower bead, which bead keeps the ring from coming off the container neck. The bottom ring being broken indicates the cap had been opened. 
     The upper bead of the container, which assumes an annular ring configuration, is engaged by a complementary annular ring under the skirt of the cap. The closure further contains a plug seal to retain it firmly against the container neck. The turning of the cap relative to the container neck insures that the annular ring under the skirt of the cap unsnaps from the upper bead or lip of the container before the teeth are totally disengaged. 
     The one-piece closure of the present invention was developed to reduce material, production time and basic assembly cost, making it more desirable to manufacture when compared to other caps. An efficient thin cap design makes the inventive closure extremely attractive to produce. Because such design eliminates typical threads found on most containers and interior cap side walls, the cap can be pushed directly down onto the container, which eliminates the time and assembly equipment associated with threaded caps. The angles provided on both sides of the engaging and disengaging teeth that are located around the top inside skirt of the cap enable the cap to be automatically self centering left or right when the cap is assembled to the top of the container. 
     This design also provides a consumer with a fast, efficient and easy way to remove the cap without unthreading, squeezing or pulling. When the consumer twist&#39;s the cap left or right, the teeth become small cams and eject the cap from the container, causing the upper bead to unsnap and the cap to open. The cap is simple and easy to open but still requires a deliberate left or right turning action, which virtually eliminates the possibility of an accidental opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cross-sectional and partial perspective view of one embodiment a closure cap secured to a container of the present invention and shown without a tamper-evident ring for purposes of illustration. 
         FIG. 2  is a bottom perspective view of the closure cap of  FIG. 1 . 
         FIG. 3  is a top perspective view of the closure cap of  FIG. 1 . 
         FIG. 4  is a plan view of the closure cap of  FIG. 1 . 
         FIG. 5  is an exploded, front elevational view of the closure cap and container of  FIG. 1  during assembly of the cap onto the container. 
         FIG. 6  is a front perspective view of a container neck having ejector teeth along an inner wall. 
         FIG. 7  is a plan view of the container neck of  FIG. 6 . 
         FIG. 8A  is a schematic view of the interaction between the teeth of the closure cap and container during the opening/removal process. 
         FIG. 8B  is a schematic view of an alternative interaction between teeth of the closure cap and container during the opening/removal process. 
         FIG. 9  is a perspective view of the closure cap of the present invention with a tamper-evident ring attached thereto. 
         FIG. 10  is a side elevational view of the cap and ring of  FIG. 9 . 
         FIG. 11  is a cross-sectional view taken through a diameter of the cap, tamper-evident ring and container of  FIG. 9 . 
         FIG. 12  is a cross-sectional view taken through a diameter of just the cap and tamper-evident ring of  FIG. 9 . 
         FIG. 13  is a perspective view of one embodiment of the container of  FIG. 9 . 
         FIG. 14  is a partial side elevational view of a separated tamper-evident ring positioned on the container of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is of the best mode or modes of the invention presently contemplated. Such description is not intended to be understood in a limiting sense, but to be an example of the invention presented solely for illustration thereof, and by reference to which in connection with the following description and the accompanying drawings one skilled in the art may be advised of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts. 
       FIGS. 1–8B  illustrate one embodiment of the closure of the present invention with the tamper-evident ring  300  separated from the cap  100  to illustrate aspects of the cap  100  that enable engagement and disengagement of the cap  100  with a container  200 , while  FIGS. 9–14  illustrate a container  200  and a cap  100  with the tamper-evident ring  300  attached thereto. 
     Cap  100 , which is preferably injection molded as a single piece, has an outer pressing surface  110 , an inner sealing area  115  ( FIG. 2 ) and a side skirt  120  depending downwardly from said outer pressing surface  110 . Skirt  120  may be provided with a tactile gripping surface with raised ridges  130  to help a consumer facilitate the twisting of the cap  100  in either the clockwise or counterclockwise direction as explained herein. Such raised edges  130  may extend along the entirety of the side skirt  120  and onto the top  110  of the cap  100  as shown in  FIG. 3 . The central portion  140  of the top  110  of the cap  100  may be textured or scuffed so that graphics or twist direction indication ( FIG. 4 ) or any other message or design may be easily imprinted thereon by means known in the art. 
     Cap  100  is further initially provided with a tamper-evident ring  300  that is designed to snap engage a container neck provided with an upper bead or lip  220  and a lower bead  225  spaced from said upper bead or lip  220  ( FIG. 13 ). The cap  100  and tamper-evident ring  300  are initially joined by a plurality of tapered posts  310  extending along the side skirt  120 , which create open skirt areas  320  that save material and reduce the overall production part cost. The cap  100  is initially seated on the upper bead  220  of the container neck, while the tamper-evident ring  300  is initially seated on the lower bead  225  as shown in  FIGS. 10–12 . The lower bead  225  is made slightly larger than the cap diameter intentionally for the assembly process, such that during the assembly, direct down pressure is applied to the circumference of the tamper-evident ring  300  and to the top section  110  of the cap  100 , which insures that the tamper-evident ring  300  does not separate from the cap  100  during assembly. 
     Securing of the cap  100  to the container  200  is further facilitated by an annular ring  170  located on the inside of the side skirt of the outer ring  120  surrounding and locking into position the upper bead or lip  220  of the container  200 . When the cap  100  is removed from the container  200  for the first time by rotating the cap  100  relative to the tamper-evident ring  300  and lower bead  225 , the tapered posts  310  break away along a top surface  330  ( FIGS. 9 ,  10 ) of the ring  300 , causing the ring  300  to separate from the cap  100  and slide down the container neck below the lower bead  225  ( FIG. 14 ), which bead  225  keeps the ring  300  from coming off the container  200 . Alternatively, the tapered posts  310  may break away along the intersection of the posts  310  and the side skirt  120 , causing the ring  300  and posts  310  (see dotted posts in  FIG. 14 ) to slide down the container neck below the lower bead  225 . The tamper-evident ring  300  being separated from the cap  100  indicates the cap  100  had been opened. It will be appreciated that the cap  100  of the present invention, once it has been initially separated from the tamper-evident ring  300 , may be attached to a container  200  having an upper bead  220  and a lower bead  225  as shown in  FIGS. 9–14 , or only an upper bead  220  as shown for ease of illustration in  FIGS. 1–8 , it being understood that cap engagement with the lower bead  225  is no longer necessary once the tamper-evident ring  300  has been separated from the cap  100 . 
     Returning now to  FIGS. 1–8B , the inner sealing area  115  or bottom side of the cap  100  generally comprises a plug seal  150  having a tapered bottom edge  155  ( FIG. 2 ) that is configured to sealingly fit into the container  200  as shown for example in  FIG. 1  as an outer wall  160  of the plug seal abuts an inner wall  210  of the container  200 . Circumferentially located around the inner sealing area  115  is a plurality of downwardly-extending engaging members or teeth  180 , which are generally formed as oppositely-sloped edges  182 ,  184  joined at a point of inflection  183 , which point of inflection may be sharp  183  ( FIG. 8A ) or rounded  183   a  (as defined between edges  182   a  and  184   a  of teeth  180   a  of cap  100   a  of  FIG. 8B ). Container  200 , which is typically injection blown, has at least one, and preferably a plurality (such as four as shown in  FIG. 6 ) of upwardly projecting engaging members or teeth  230  ( FIG. 8A , or teeth  230   a  in the embodiment in  FIG. 8B ), which mate with teeth  180  (or teeth  180   a  in the embodiment of  FIG. 8B ) on the underside  115  of the cap  100 , as described further herein. Container teeth  230  may be provided as single teeth as shown in  FIG. 6 , or in pairs as shown in  FIG. 13 , or as a continuous row of teeth (not shown) complementary to the continuous row of teeth  180  provided on the cap  100 . 
     To secure the cap  100  back onto the container  200  once the tamper-evident ring  300  has been separated from the side skirt  120 , the plug seal  150  is brought downwardly into the container  200  so that the outer wall  160  of the plug seal  150  abuts the inner wall  210  of the container  200  and is further secured by additional sufficient downward pressure on the outer pressing surface  110  of the cap  100  so that the underside annular opening  170  of the outer ring  120  of the cap  100  surrounds and locks into place the upper bead or lip  220  of the container  200 . This downward pressure also aligns the registration of the upwardly-extending teeth  230  on the container  200  into the corresponding teeth  180  on the cap  100 , such that the mating teeth  180  and  230  become self-aligning with respect to each other. Thus, the cap  100  is held secure by both the teeth registration and by the locking of the annular ring  170  with the lip or upper bead  220  of the container  200 . Of course, this assembly process applies equally for the initial assembly of the cap  100  having the tamper-evident ring  300  attached thereto, although  FIGS. 1–8  illustrate the cap  100  without the ring  300  attached thereto and with a container  200  that does not have the lower bead  225  as shown in  FIGS. 9–14 , for purposes of illustrating the attachment of the cap  100  to the container  200  after the tamper-evident ring  300  has been separated from the cap  100 . 
     To remove the closure  100  from the container  200 , the top  110  may be twisted by the consumer in either the clockwise or counterclockwise direction. The twisting of the cap  100  causes the teeth  180  (or  180   a  in the embodiment of  FIG. 8B ) to function as cam surfaces relative to the teeth  230  (or  230   a  in the embodiment of  FIG. 8B ), such that the teeth  180 ,  180   a  are forced upwardly over the lower teeth  230 ,  230   a . In other words, in the embodiment of  FIG. 8A , surface  184  is forced upwards in response to a counterclockwise rotation of the cap  100  as shown, while in the embodiment of  FIG. 8B , surface  184   a  is forced upwardly over lower tooth  230   a  in response to a counterclockwise rotation of the cap  100   a .  FIGS. 8A and 8B  illustrate identical functional processes, the only difference being the structural configuration of the teeth. Of course, the movement arrows illustrated in  FIG. 8A  are not meant to be viewed in a limiting sense, but can be reversed if the cap  100  is rotated in the opposite direction relative to the container  200 . Movement of the cap  100  upwardly relative to the container  200  causes the outer bead or lip  220  of the container  200  to push downwardly on the underside  170  of the outer ring  120 , causing it to spread or move outwardly until the cap  100  is released from the container  200 . 
     If the tamper-evident ring  300  is attached to the side skirt  120  during the initial removal of the cap  100  from the container  200 , then the removal operation described above also results in the separation of the ring  300  from the side skirt  120  and the resultant positioning of the ring  300  on the container neck as shown in  FIG. 14 . If the tamper-evident ring  300  has already been separated from the side skirt  120 , and the re-attached cap  100  is being removed from the container  200  from a second or subsequent time, then the removal operation described above merely results in the complete removal of the cap  100  from the container  200 . 
     The closure of the present invention provides a lower manufacturing because of a simplified and faster assembly process. The initial assembly requires a straight downward force on the cap  100  and side skirt  120  to engage the teeth  180 ,  230  and snap the cap  100  and ring  300  assembly over the container&#39;s upper and lower beads  220 ,  225 . The angles provided on both sides of the engaging and disengaging teeth  180 ,  230  that are located around the top inside skirt of the cap  100  enable the cap  100  to be automatically self centering left or right when the cap  100  is assembled to the top of the container  200 . The closure does not require threading or turning to secure it onto the container and has thus simplified the assembly machinery and process along with reducing assembly time. 
     Furthermore, because the cap design eliminates typical threads found on most containers and interior cap side walls, the cap can be pushed directly down onto the container, which eliminates the time and assembly equipment associated with threaded caps. In addition, this design provides a consumer with a fast, efficient and easy way to remove the cap  100  without unthreading, squeezing or pulling. When the consumer twist&#39;s the cap  100  left or right, the teeth  180 ,  230  become small cams and eject the cap  100  from the container  200 , causing the upper bead  220  to unsnap and the cap  100  to open. The cap  100  is simple and easy to open but still requires a deliberate left or right turning action, which virtually eliminates the possibility of an accidental opening. 
     While the present invention has been described at some length and with some particularity with respect to the several described embodiments, it is not intended that it should be limited to any such particulars or embodiments or any particular embodiment, but it is to be construed with references to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the invention. Furthermore, the foregoing describes the invention in terms of embodiments foreseen by the inventor for which an enabling description was available, notwithstanding that insubstantial modifications of the invention, not presently foreseen, may nonetheless represent equivalents thereto.