Patent Publication Number: US-2022234789-A1

Title: Closure

Description:
FIELD OF THE INVENTION 
     The present invention relates to a closure, especially a closure for containers for liquids. In particular, the invention relates to a closure for neck finishes of blow molded containers. 
     BACKGROUND OF THE INVENTION 
     Containers for large volumes of liquids such as e.g. containers for washing agents or milk bottle are often blow molded plastic containers. A disadvantage of these blow molded containers are geometric inaccuracies and seams at the opening of the container which complicate the positioning of the closure on the neck finish and hence the reliable sealing of the individual container opening. 
     It is an object of the invention to provide a closure with an improved sealing which compensates geometric inaccuracies of the neck finish of the liquid container. 
     SUMMARY OF THE INVENTION 
     The invention relates to a closure for sealing a neck finish of a liquid container. The closure comprises a top deck and an outer skirt extending from the top deck in an axial direction away from the top deck comprising at least one locking means (respectively locking structure) for engaging the closure to the neck finish of the liquid container. The locking means can be a thread arranged on the outer skirt or a snap lock to snap the closure on the neck finish. Other locking means are also possible. Depending on the application, the closure may further comprise a hinge. 
     A deformable primary sealing lip is arranged on an inner surface of the top deck and extends, respectively protrudes, in a circumferential manner along the inner surface of the top deck. The primary sealing lip is preferably deformable with respect to the top deck. With respect to its cross-section the primary sealing lip comprises a dorsal end connected to the inner surface of the top deck and a free distal end arranged opposite to the dorsal end. Preferably, the primary sealing lip has in the cross-section an elongated shape extending from the dorsal end towards the distal end featuring a first and a second side (opposite of the first side) in between the dorsal end and distal end. Furthermore, the primary sealing lip is arranged with respect to its cross section in an inclined manner facing inwardly (in the radial direction towards a center axis of the closure; the center axis extending in the axial direction, perpendicular to the radial direction). Hereby, the second side of the primary sealing lip is facing the inner surface of the top deck. 
     Preferably, the primary sealing lip features in an undeformed position (before initially applying the closure on the neck finish) a larger inclination angle than in a deformed position (after initially applying the closure on the neck finish). The inclination angle is thereby defined between the primary sealing lip and the inner surface of the top deck facing radially inwards (towards the center axis). Depending on the application, the first and/or the second side of the primary sealing lip may be essentially straight in the undeformed position, e.g. the primary sealing lip may have a rectangular cross-section in the undeformed position. Hence, the inclination angle is essentially uniform over the primary sealing lip. However, also curved embodiments of the first and/or second sides are possible in the undeformed position. For injection molded plastic closures a curved design is possible, as long as it is demoldable. In the case of a curved sealing lip, the inclination angle can be understood as an average angle. The primary sealing lip may be at least partially plastically deformable, such that a deformed position of the primary sealing lip is maintained after initially applying the closure to the neck finish. An inclination angle of the primary sealing lip in the undeformed position can be i.g. in the range of α=30-60 deg (degree). The (average) inclination angle of the primary sealing lip in the deformed position and in the applied position of the closure on the neck finish may be in the range of α=10-50 deg, however other angles are also possible. To facilitate the deformation of the primary sealing lip, the primary sealing lip may further comprise a thinning at the dorsal end with respect to the cross-section of the primary sealing lip, close to the inner surface of the top deck. 
     Preferably, at least one supporting element protrudes from the inner surface of the top deck, configured to support the primary sealing lip with respect to the neck finish in an applied position of the closure. The supporting element is arranged coaxially to the primary sealing lip to provide a uniform sealing over the circumference. Furthermore, the supporting element may be arranged on the inner surface of the top deck at least partially inside of the primary sealing lip. Preferably, the supporting element is in a radial direction arranged closer to the center axis of the closure than the primary sealing lip. Depending on the application, the supporting element may also be deformable. In an applied position of the closure, the at least one supporting element, is advantageously at least partially arranged within a projection area of the deformed primary sealing lip in the axial direction and on the inner surface. In that way, the supporting element is connected to the inner surface of the top deck in the radial direction between the distal end and the dorsal end of the deformed primary sealing lip in an applied position of the closure. 
     When the closure is applied for the first time, the primary sealing lip preferably engages first with the distal end with a rim of the neck finish. If the closure is applied further (e.g. the closure may be screwed further down on the neck finish) the primary sealing lip begins to deform and establishes a surface contact along the first side of the primary sealing lip. As the application pressure of the closure increases the primary sealing lip further bends radially inwards and engages with the supporting element on its second side. When the closure is fully applied, the primary sealing lip has preferably a surface contact at least partially along the first side of the primary sealing lip and is in contact with the inner edge of the rim of the neck finish. On the second side, the primary sealing lip is in contact with the at least one supporting element. The supporting element thereby supports the contact of the primary sealing lip against the rim by increasing the pressure on the inner edge of the rim. The overall sealing of the closure against the neck finish is thus enhanced. In the applied position of the closure a chamber may be formed between the primary sealing lip and the at least one supporting element. Enclosed air in the chamber thereby increases the sealing quality since it contributes to the deformability of the primary sealing lip around the rim of the neck finish. 
     Depending on the application, the at least one supporting element may be a secondary sealing lip, which is also inclined radially inwards, facing away from the outer skirt, as described for the primary sealing lip. Respectively, the secondary sealing lip may also be deformable. For good sealing qualities the outer rim of the neck finish in the axial direction can be arranged in the radial position between the dorsal end of the primary sealing lip and a distal end of the secondary sealing lip with respect to a cross section of the (primary and secondary) sealing lips in the undeformed position before initially applying the closure. 
     In another variation of the closure according to the invention, the at least one supporting element may be a circumferential first bump. Furthermore, the closure may comprise a circumferential second bump as a second supporting element arranged radially inwards of the circumferential first bump which extends along the primary sealing lip. For a uniform sealing along the circumference of the neck finish, the circumferential first bump is preferably arranged coaxially to the circumferential second bump. Good results can be achieved, if the circumferential second bump has a larger height in axial direction and in respect to the inner surface of the top deck than the circumferential first bump. Preferably, the circumferential first and second bump are arranged at least partially within the projection area of the inclined and deformed primary sealing lip on the inner surface in an applied position of the closure. In that case, the circumferential first and the second bump each connected via a base to the inner surface of the top deck, are arranged with their bases at least partially between the distal end and the dorsal end of the deformed primary sealing lip in an applied position of the closure. 
     The primary sealing lip and the at least one supporting element may be formed as an integral part of the closure or can be interconnected to the top deck as a separate element. Preferably, the closure is made by a (first) plastic material, in particular an injection molded plastic material. Thereby, the primary sealing lip and/or the supporting element may be made at least partially of a second plastic material, which is softer than the (first) plastic material of the other closure parts. The first and the second plastic material may injection molded in a two material injection molding process. 
     It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The herein described invention will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the invention described in the appended claims. The drawings are showing: 
         FIG. 1  A closure according to a first variation of the invention in a perspective partly sectionized view; 
         FIG. 2  The closure according to  FIG. 1  in a front view; 
         FIG. 3  A detail of  FIG. 2  of a primary and secondary sealing lip; 
         FIG. 4  The process of applying the closure according to  FIG. 1  to a neck finish; 
         FIG. 5  The schematic drawing of the primary and secondary sealing lip in a deformed and applied position; 
         FIG. 6  The schematic drawing of a second variation of the closure with the primary sealing lip in a deformed position. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts. 
       FIG. 1  and  FIG. 2  show a closure according to a first variation of the invention in a partly sectionized view.  FIG. 1  is a perspective view;  FIG. 2  is a front view. The closure  1  comprises a top deck  3  and an outer skirt  4  extending from the top deck  3  in an axial direction z away from the top deck  3 . The closure  1  as depicted, is a screw cap, with a thread as a locking means  5 . Alternatively, the closure could also feature other locking means to interconnect and engage the closure  1  to a neck finish of a liquid container (not shown). A with respect to the top deck  3  a deformable primary sealing lip  6  is arranged on an inner surface  7  of the top deck  3  and protrudes in a circumferential manner along the inner surface  7  of the top deck  3 . In a cross section, as it can be seen in  FIG. 2  and  FIG. 3 , the primary sealing lip  6  comprises a dorsal end  8  connected to the inner surface  7  of the top deck  3  and a free distal end  9  arranged opposite to the dorsal end  8 . The primary sealing lip  6  is arranged with respect to its cross section in an inclined manner facing radially inwards towards a center axis  17  and away from the outer skirt  4 . Next to the primary sealing lip  6 , a supporting element  10 , in form of a secondary sealing lip  13 , is protruding from the inner surface  7  of the top deck. In the shown variation, the secondary sealing lip  13  has essentially the same shape and geometry as the primary sealing lip  6 . However, other embodiments are possible. The secondary sealing lip  13  is arranged coaxially to and at least partially inside of the primary sealing lip  6 . The secondary sealing lip  13  is configured to support the primary sealing lip  6  with respect to the neck finish  2  in an applied position of the closure  1 . 
     If the closure  1  is applied for the first time on a neck finish  2  of the liquid container, the primary and the secondary sealing lip  6 ,  13  are deformed. Preferably, the primary and the secondary sealing lip  6 ,  13  are at least partially plastically deformed, such that a deformed position at least of the primary sealing lip  6  is maintained after initially applying the closure  1  to the neck finish  2 .  FIG. 4   a )-g) show the process of applying the closure  1  according to the first variation of the invention to a neck finish  2 .  FIG. 4 a   ) illustrates the neck finish  2  not yet applied and the primary and secondary sealing lip  6 ,  13  in an undeformed position. In  FIG. 4 b   ) a rim  16  of the neck finish  2  comes in contact with the distal end  9  of the primary sealing lip  6 . If the closure  1  is applied further, as illustrated in  FIG. 4 c   ) the primary sealing lip  6  starts to bend and to deform under the pressure of the neck finish  2 . At this stage of applying the closure to the neck the primary sealing lip  6  has on a first side  18  a surface contact with the rim  16  of the neck finish  2 . Furthermore, due to the bending of the primary sealing lip  6  a chamber  11  is formed between the primary and the secondary sealing lip  6 ,  13 . Furthermore, the secondary sealing lip  13  may also come briefly into contact with the rim  16  during the application. In  FIG. 4 d - g   ) it can be seen that the primary sealing lip  6  is pushed inwards over the inner edge  20  of the rim  16  of the neck finish  2  in the radial direction. The secondary sealing lip  13 , now in contact with a second side  19  of the primary sealing lip  6 , is further bent and supports the primary sealing lip  6  to enhance the sealing quality. Due to the deformation of the primary and/or the secondary sealing lip  6 ,  13  the chamber  11  may change its geometry in the process and building up a pressure inside the chamber  11  when being reduced in volume. The enclosed air in the chamber  11  thus further supports the sealing.  FIG. 5  illustrates the detail of closure  1  according to  FIG. 3  in a fully applied position of the closure  1  on the neck finish  2 . In the applied position of the closure the secondary sealing lip  13 , is at least partially arranged within a projection area  12  of the inclined primary sealing lip  6  in the axial direction and on the inner surface  1  (projection is indicated by dashed line). 
       FIG. 6  shows a schematic drawing of a second variation of the closure  1  in a deformed position of the primary sealing lip  6 . The closure (even though not shown in full) may be designed according to the closure  1  of the first variation with a top deck  3  and an outer skirt  4  having a thread as a locking means  5 , however, the second variation of the sealing means, respectively the primary sealing lip  6  and the at least one supporting element  10 , may also be used on other closure geometries, such as hinged closures and/or closures with a snap lock as a locking means. 
     In the illustrated second variation, the primary sealing lip  6  is combined with two supporting elements  10 : A circumferential first and second bump  14 , 15 . The circumferential first and second bump  14 , 15  are arranged on the inner surface  7  of the top deck  3 , extending from said top deck  3 . Furthermore, the primary sealing lip  6  and the circumferential first and second bump  14 , 15  are arranged coaxially with respect to each other. In particular, the circumferential first and second bump  14 ,  15  are preferably arranged at least partially within the projection area  12  of the inclined primary sealing lip  6  on the inner surface  7  in an applied position of the closure  1  (projection is indicated by dashed line). As it can be seen, the first and the circumferential second bump  14 , 15  may have different heights (in the axial direction) in respect to the inner surface  7  of the top deck  3 . Good sealing results may be achieved, if the circumferential second bump  15  arranged radially inwards of the circumferential first bump  14  extends in axial direction further away from the inner surface  7  than the circumferential first bump  14 . 
     The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. 
     
       
         
           
               
             
               
                   
               
               
                 LIST OF DESIGNATIONS 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1 
                 Closure 
               
               
                 2 
                 Neck finish 
               
               
                 3 
                 Top deck 
               
               
                 4 
                 Outer skirt 
               
               
                 5 
                 Locking means 
               
               
                 6 
                 Primary sealing lip 
               
               
                 7 
                 Inner surface 
               
               
                 8 
                 Dorsal end 
               
               
                 9 
                 Distal end 
               
               
                 10 
                 Supporting element 
               
               
                 11 
                 Chamber 
               
               
                   
                 (Supporting element) 
               
               
                 12 
                 Projection area 
               
               
                 13 
                 Secondary sealing lip 
               
               
                 14 
                 (First) Bump 
               
               
                 15 
                 (Second) Bump 
               
               
                 16 
                 Rim 
               
               
                 17 
                 Center axis 
               
               
                 18 
                 First side 
               
               
                 19 
                 Second side 
               
               
                 20 
                 Inner edge (rim)