Patent Publication Number: US-11046490-B2

Title: Container cap comprising tamper evidence means

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a National Stage of International Application No. PCT/EP2017/063417, filed on Jun. 2, 2017, which claims priority to European Patent Application No. 16173061.9, filed on Jun. 6, 2016, the entire contents of which are being incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention concerns a cap for a container comprising tamper evidence means. 
     The invention also relates to a package comprising such cap. 
     BACKGROUND OF THE INVENTION 
     In the packaging arts, it is generally known to provide resealable closures on containers whose contents are not necessarily consumed all at once. They are used for packaging a wide variety of products, and are notably favoured for beverages and other comestibles. 
     A number of different kinds of resealable closures are known, for instance swinging lever closures, caps, and sliding push-pull closures. Among such closures, caps are regarded as particularly advantageous in that the consumer may open, re-seal, and re-open the container without the need of tools. Of these, the two types which command the overwhelming majority of market share are the press-on snap cap and the screw-on cap. 
     Screw-on caps are generally fabricated from a hard plastic or metal, and comprise internal threads which engage complementary threads disposed about the neck of the container. When screwed tightly to the container they provide a tight, leakage-resistant seal, and cannot be dislodged during normal use by external shocks and impacts as snap-caps can. 
     However, screw-on caps are less than ideal, in that they require a large amount of force to open and close. This poses difficulties to children, the elderly, and others who do not have sufficient strength or manual dexterity to properly tighten and loosen such a closure. Moreover, the provision of threads in the cap and on the neck of the container requires an increased level of precision in the manufacture of both relative to other types of closures, increasing the cost of the container. 
     Snap-caps, in contrast, are generally flat and fabricated from a flexible plastic, and typically comprise an annular groove disposed on a lower surface of the cap; this annular groove clasps a bead disposed about a mouth of the container; when attaching the cap the bead is pressed into the groove, causing the groove to open enough to permit the bead to seat therein. 
     At this point, the elasticity of the cap causes the groove to close around the seated bead, retaining the cap on the container. To open the container, the cap is merely grasped at one edge and bent upwards; the groove deforms to permit the bead to be extracted from the cap as it is removed from the container. 
     Such snap-caps are inexpensive to fabricate and require relatively little force to open and close. However, this also means that the strength of the joint between cap and container is weak. As a result, the cap may be easily dislodged when the cap or container are subjected to external shocks, small pressures and impacts (particularly from the lateral direction) that may be encountered during transport and use of the container, leading to leakage and spills. In addition, such snap-caps are usually provided with tamper evidence means generally made of a film or rigid material covering the cap and the neck of the container and which is not easily removable. 
     There is thus a need for a cap for a container which may be easily opened and closed, which is resilient to shock and impact, which is inexpensive to fabricate and implement and which comprises efficient and easy removable tamper evidence means. It is therefore an object of the invention to provide a closure which presents at least some of these attributes. 
     SUMMARY OF THE INVENTION 
     According, therefore, to a first aspect, there is provided a cap for a container, according to claim  1 . Said cap comprises a disc-shaped top section extending generally in a horizontal plane, an annular side section projecting substantially perpendicularly from the perimeter of said disc-shaped top section along a vertical axis to an extremity defining a rim portion, a locking flange disposed at an extremity of said annular side section opposite said disc-shaped top section and comprising an immobile portion and a mobile portion, and a locking flap extending from at least a portion of the rim portion of said annular side section and being mobile between,
         a locked first position wherein the mobile portion of said locking flange contiguous with said locking flap extends inwardly from an interior face of said annular side section, and   an unlocked second position in which said mobile portion of said locking flange is at least partially recessed relative to said interior face of said annular side section.       

     According to the invention, the cap further comprises first tamper evident means comprising a tamper evidence member attached to the annular side section and to the locking flap, said locking flap being thereby immobilized in the locked first position when the tamper evidence is in place defining thereby its functional position, in which the tamper evident member is partially frangible when the cap is first opened leading the locking flap to reach the unlocked second position so that the tamper evidence member remains attached to one of annular side section or locking flap after the cap is first opened. 
     This is advantageous in that the cap may be securely attached to a container simply by putting the locking flap in the first position. Since disposing the locking flap places the locking flange in a position where it projects inwardly from the annular side section of the cap, when the cap is disposed on a container it will engage and lock to an undercut near the mouth of the container, in the form of a suitably-dimensioned a rim or channel in the neck of the container. In this way, a seal is created between the cap and the container. 
     Conversely, when the locking flap is moved into the second unlocked position, the locking flange is disposed exterior to the imaginary surface formed by the extension of the interior face of the annular side. In other words, when the locking flap is disposed in the unlocked second position, the locking flange is displaced into a position where it will not engage the container and prevent the cap from being removed therefrom. 
     This is also advantageous in that since the locking flap extends from the extremity of the annular side section of the cap where the locking flange is also disposed, the locking flap forms a lever whose deflection moves the locking flange between the locked first position and the unlocked second position. The locking flap will thus multiply the force applied to it by the user, permitting a greater sealing and retaining force to be realized between the cap and the container than would be possible by a simple snap-on operation. The cap is thereby rendered resistant to being inadvertently removed. 
     Conversely, for a given sealing force the amount of force that must be applied by the user to open and close the container is greatly reduced, facilitating the use of the container by those who would otherwise have difficulty manipulating the closure means known in the art. 
     In addition, the proposed tamper evidence member integrated to the proposed snap-cap adds new functionalities to the cap. Indeed, it is necessary to displace the tamper evidence member from either one of annular side section or locking flap of the cap to displace the locking flap from the locked first position into the unlocked second position. Damage to the partially frangible tamper evidence member will indicate to the consumer that the container has been tampered with. With the proposed solution, the consumer can easily see if the cap has already been opened or not. 
     Furthermore, since the partially frangible tab immobilizes the locking flap, the tab will serve to prevent the locking flap from moving and the cap from being dislodged when the locking flap is inadvertently subjected to impact or abrasion prior to use, such as during transport or storage. 
     Moreover, as the partially frangible tab is an integral part of the cap, there is no need to provide any separate tamper-evident devices with the container, nor implement any particular machine or apparatus in the production line for its implementation. 
     In addition, as the tamper evidence member is only partially frangible, it will remain attached to the cap to either one of annular side section or locking flap and spreading it into the nature will be avoided. 
     In a preferred embodiment, the tamper evident member is a partially frangible tab. 
     This is advantageous in that the partially frangible tab can be easily manipulated by the user. As a result, both the tab and the cap can be removed with one hand. Thus while the consumer is holding the container with one hand, with the other hand he can easily remove both the tab and the cap without any large amount of force or specific dexterity. 
     Preferably, the partially frangible tab comprises a first part attached to one of annular side section or locking flap that is frangible and a second part respectively attached to one of locking flap or annular side section that is not frangible. 
     This is advantageous in that tab is unavoidable as clearly visible by the consumer who can easily identified if the cap has already been manipulated. 
     In addition, the second part remains attached to one of locking flap or annular side section when the cap is first opened leading the locking flap to reach the unlocked second position. 
     In the proposed embodiments, the tab is located on the main parting line of the injection mould so that the injection is easy reliable and accurate for making frangible parts like bridges on different locations of the tab. 
     In a preferred embodiment, the tab forming the first tamper evidence means is integral with the annular side section. The whole cap can then be produced in one time integrating said first tamper evidence means. 
     In another preferred embodiment, the first part of the tab that is frangible comprises at least one frangible bridge attached to the locking flap. 
     The use of frangible bridges is particularly advantageous in that they can be broken without any large amount of force using only one finger while still allowing a secure connection avoid inadvertent rupture. 
     In a particularly interesting embodiment, the second part of the tab that is not frangible is connected to the annular side section by a hinge. 
     This allows the tab to remain connected to annular side section of the cap and not to be completely detached from the cap. The loss of the tab into the nature is then avoided which is a great advantage especially when the container is given to kids. 
     Thanks to this specific feature, the tab fades and lies against the annular side section. As the tab is faded, it does not anymore constitute a hitching point on which the consumer can hurt when he grips the container to open it again by manipulating the cap. 
     According to a second embodiment of the invention, the hinge of the tab forming the tamper evidence member is inclined with respect to the vertical axis defined as the direction of the annular side section projecting substantially perpendicularly from the perimeter of the disc-shaped top section. 
     The inclined hinge advantageously, avoid any interaction between the upper surface of tab and the locking flap when the locking flap is manipulated from the locked position to the unlocked position for the opening of the container. 
     Preferably, the hinge is inclined from 20 to 60° with respect to the vertical axis. This feature allows to have a trajectory of the lower part of the tab not interfering with the locking flap when it has to be moved from first locked position to second unlocked position. 
     The proposed cap is provided with notches located at the lateral intersection of the locking flap and the annular side section and according to the invention, the cap further comprises second tamper evidence means located between two opposite internal edges of the notches. 
     This specific location of the second tamper evidence means, at the mechanical frontier between the mobile portion of the locking flange and the non-mobile portion of the cap is particularly advantageous in that any change in the conformation of the notches will have an effect on these second tamper evidence means. 
     As a preferred solution, the second tamper evidence means comprises a connection conformed as a plastic bridge connection between two opposite internal edges of the notches. Said connections is conceived so as to break when the locking flap is moved from the first locked position to the second unlocked position. 
     As for the first tamper evidence means, the second tamper evidence means is integral with the cap. 
     Hence, these second tamper evidence means works independently from the first tamper evidence means so that it ensures for the end consumer a double security for checking if the container has already been opened. 
     The invention is also related to a package comprising a cap and a container, said container comprising a mouth provided with a neck having a shoulder, in which said cap is disposed upon the mouth of said container such that the locking flange of said cap engages the shoulder of the neck of the container. 
     Such a package is very comfortable for the consumer as he can drink directly through the neck of the container with no plastic part remaining attached to said neck. It configuration also allows to increase the hygiene of the neck. 
     According to additional features of the cap, the locking flap is bistably mobile between the locked first and unlocked second positions. 
     This is advantageous in that the locking flap is biased to move to and hold itself in either of the two positions. As a result, the locking flap is rendered more resistant to inadvertent deflection, while retaining a high ease of operation. 
     Preferably, the locking flap is bistably mobile about a centre position defined by a plane parallel with the disc-shaped top section and intersecting the extremity of the annular side section, such that it forms an oblique angle with the annular side section when said locking flap is disposed in the locked first position, and forms an acute angle with the annular side section when said locking flap is disposed in the unlocked second position. 
     This is advantageous in that the position of the flap relative to the rest of the cap gives an intuitive visual indicator of whether the cap is locked to the container. Specifically, when the flap is pointing “down,” i.e. towards the container, the cap is locked to it; when the flap is pointing “up,” i.e. away from the container, it is unlocked and may be removed from the container. 
     Furthermore, configuring the bistable motion of the flap in such a way is advantageous in that it naturally facilitates the manipulation of the locking flap between the locked first and the unlocked second positions. For instance, when moving the locking flap from the locked first into the unlocked second position when the container is normally oriented (i.e. with the neck pointing upwards), the user will pull on the locking flap in such a way as to also pull on the cap, thereby facilitating its separation from the container. Conversely, when moving the locking flap into the locked first from the unlocked second position, the user will press on the locking flap in such a way that the cap is pressed into the container, facilitating the motion of the locking flap and ameliorating the sealing that results. The use of the cap is thereby made more intuitive. 
     In one possible embodiment, the locking flap extends from the extremity of the annular side section along the entire perimeter of said extremity. 
     Such a cap will realize the greatest possible sealing force, in that the cap engages the container upon which it is used over its entire circumference. 
     In another possible embodiment, the locking flap extends from the extremity of the annular side section along a portion of the perimeter thereof, the locking flange being thereby divided into an immobile first portion and a mobile second portion contiguous with said locking flap. 
     This is advantageous in that, by restricting the locking flap to a portion of the annular side section, the force that is needed to displace the locking flap between the first and second positions is reduced. When working in combination with the immobile first portion of the locking flange, the mobile second portion will realize a closure force sufficient for many applications, while minimizing the force necessary to open and close the container. 
     Optionally, the immobile first portion of the locking flange extends from a segment of the annular side section comprising between 20° and 80°, inclusive, of the annular side section. 
     Optionally, the mobile second portion of the locking flange extends from a segment of the annular side section comprising between 20° and 80°, inclusive, of the circumference of said annular side section. 
     This is advantageous in that the reduced length of the immobile first and mobile second portions of the locking flange will reduce the cost of fabricating the cap and the effort required to attach and remove it, while maintaining a sealing force sufficient for many applications. 
     Preferably, the immobile first portion and the mobile second portion of the locking flange are disposed substantially symmetrically about the annular side section. 
     Most preferably, the immobile first portion is disposed directly opposite the mobile second portion. 
     This is advantageous in that the sealing force that is applied to the container by the locking flanges will be symmetrical about the axis of the container. The cap will therefore avoid any deformation of the container when the locking flap is placed in the locked second position, reducing in turn the possibility of leaks past the cap. The reliability of the cap is thereby improved. 
     Advantageously, the locking flap is a segment of a hollow conic frustum. 
     A locking flap in such a configuration is particularly desirable in that, for a cap with an overall cylindrical aspect, it minimizes the amount of material required to fabricate the cap, rendering it lighter and less expensive to produce. A conic section has the further advantage of being readily adaptable to the contours of curved containers, naturally sitting pressed against the exterior of the container when the locking flap is disposed in the locked first position. This obviates the need for plastic overwraps or other such additional packaging means to retain the locking flap in place. 
     Optionally, the cap further comprises a sealing ring projecting from the disc-shaped top section and disposed coaxially within the annular side section. 
     This is advantageous in that the sealing ring will come in contact with an interior surface of the container. As the neck of the container enters into an interference fit with the sealing ring and the annular side section, the sealing effectiveness of the cap is further improved. 
     Preferably, the sealing ring projects from the disc-shaped top section following an oval or elliptical curve. 
     This is advantageous in that the non-circular form of the sealing ring will serve to centre the cap upon the mouth of the container when the former is placed upon the latter with an angled or off-cantered orientation. The usability and reliability of the cap is thereby further improved. 
     In connection with the use of the specific claimed cap, there is provided a preform for the fabrication of a container, comprising a neck opening into a mouth at one extremity. 
     For complete correspondence between the claimed cap and the neck of the container that is fabricated, the preform leading to the container further comprises a shoulder disposed about said neck proximate to said mouth, said shoulder being configured to be engaged by a locking flange of a cap according to the preceding description. 
     This is advantageous in that a preform so configured, and a container fabricated from such a preform, will be ideally suited to accommodate a cap as described above and realize a tight, secure seal therewith. 
     The claimed cap is hence mounted on a container and used in a package comprising a container fabricated from a preform as described above, and a cap as described above, said cap being disposed upon the mouth of said container such that the locking flange of said cap engages the shoulder of the neck of said container. 
     Such a package is advantage in that it realizes the advantages of the cap described above in the form of a package that may be used for the distribution of products to end consumers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional features and advantages of the present invention are described in, and will be apparent from, the description of the present embodiments which are set out below with reference to the drawings in which: 
         FIGS. 1A, 1B &amp; 1C  are respectively bottom perspective; top perspective and front views, of a cap according to a first embodiment of the invention in the first locked position; 
         FIGS. 2A &amp; 2B  are partial cross-sectional views of the cap of  FIGS. 1A, 1B &amp; 1C , in a locked and unlocked position, respectively, without the tamper evidence means; 
         FIG. 3  is a cross-sectional view of the cap of  FIGS. 1A &amp; 1B ; 
         FIGS. 4A, 4B &amp; 4C  are respectively front and top perspective views of the cap of  FIGS. 1A, 1B &amp; 1C  after the tamper evidence member has been manipulated in the first locked and second unlocked position; 
         FIGS. 5A, 5B &amp; 5C  are respectively front, side and top perspective views, of a cap according to a second embodiment of the invention in the locked position; 
         FIGS. 6A &amp; 6B  are views of the cap of  FIGS. 5A, 5B &amp; 5C  in the locked first and unlocked second position, after the tamper evidence member has been manipulated; and 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     For a complete understanding of the present invention and the advantages thereof, reference is made to the following detailed description of the invention. 
     It should be appreciated that various embodiments of the present invention can be combined with other embodiments of the invention and are merely illustrative of specific ways to make and use the invention and do not limit the scope of the invention when taken into consideration with the claims and the following detailed description. 
     As used in this specification, the words “comprises,” “comprising,” and similar words, are not to be interpreted in an inclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to.” 
     Furthermore, in the following description, it should be understood that terms used to express geometric or other such relations (e.g. “parallel”) between components are considered as being substantive terms rather than exact ones, and that as a result the qualifier “substantially” is to be read into any such term unless stated otherwise. 
     The invention is further described with reference to the following examples. It will be appreciated that the invention as claimed is not intended to be limited in any way by these examples. 
       FIGS. 1A, 1B &amp; 1C  are respectively bottom perspective; top perspective and front views, of a cap according to a first embodiment of the invention. Of course, it will be understood that the cap depicted in  FIGS. 1A to 1C  is intended to be attached to a container, and as such for the purposes of this document orientative terms such as “top” and “bottom”, “horizontal” and “vertical” shall be assumed to be as for a cap which is attached to an upright container. 
     In  FIG. 1A , the cap  100  comprises globally a disc-shaped top section  102  and an annular side section  104 . The annular side section  104  extends from the perimeter  106  of the disc-shaped top section  102  in a substantially perpendicular direction, with the result that the cap  100  is of a generally cylindrical form, with one open end  108  opposite the disc-shaped top section  102  which accommodates a neck of a container (not shown) to which the cap  100  is attached. The open end  108  is delimited by the rim  110  of the cap  100 , said rim  110  constituting an extremity of the annular side section  104  opposite the disc-shaped top section  102 . 
     As can be seen, the annular side section  104  presents progressive varying thickness (see the different circular lines on the annular side section  104 ). A specific annular portion  105  of the annular side section  104  is provided as gripping means in the process of capping the container with the cap  100 . Thanks to the annular portion  105 , the capping head of the bottling line is able to grip the cap and bring it above the container for the capping of said container. 
     The cap  100  is further provided with a locking flange  111 , which is in this embodiment separated into the immobile portion  112  of the locking flange and a mobile portion  114  of the locking flange. The portions  112 ,  114  of the locking flange  111  engage a ridge or channel provided in a neck of a container to which they are attached, thereby retaining the cap thereupon and sealing the container. 
     The immobile portion  112  of the locking flange  111  is disposed upon a circumference of the annular side section  104  such that it is opposite the mobile portion  114  of the locking flange  111 . 
     It should be noted that in certain embodiments such as this one, the several portions  112 ,  114  of the locking flange  111  may collectively extend over only a portion of the circumference of the annular side section  104 ; this may be done to economise on material and reduce the amount of force needed to attach the cap to the container. In such cases, the locking flange  111  is ideally configured such that the parts thereof are disposed along the circumference of the annular side section  104  in a symmetrical fashion, as is the case here with the immobile portion  112  and the mobile portion  114  of the locking flange  111 . 
     Furthermore, in such embodiments it may be particularly advantageous to configure the locking flange such that each part thereof extends over a portion of the circumference of the annular side section comprising between 20° and 80° thereof; in the present embodiment, the immobile portion  112  and the mobile portion  114  of the locking flange  111  each extend over approximately 45° of the circumference of the annular side section  104 . 
     It will be readily recognized, however, that in other embodiments the portions of the locking flange may extend over different, not necessarily identical or symmetrical, portions of the circumference of the annular side section, according to the particularities of the application in which that embodiment is to be employed. 
     The cap  100  is further provided with a locking flap  116 , extending from a portion of the rim  110  of the cap  100 . The locking flap  116  is substantially coincident with the mobile portion  114  of the locking flange in this embodiment, and mobile between a locked first position as depicted here, and an unlocked second position wherein the locking flap  116  is rotated towards the disc-shaped top section  102  about the portion of the rim  110  contiguous with said locking flap  116 , thereby forming an acute angle with the annular side section  104  of the cap  100 . 
     Where the cap  100  is fabricated from a flexible, elastic material (e.g. HDPE plastic, LDPE plastic or PP plastic), this will cause the mobile portion  114  of the locking flange to rotate towards the disc-shaped top section  102  as well. The cap  100  is provided with notches  118 . By bringing flexibility for the removal of the cap, the notches  118  reduce stress concentrations at the intersection of the locking flap  116  and the annular side section  104 , reducing the likelihood of cracking and tearing. The notches  118  play the role of mechanical frontier between the mobile portion of the locking flange and the non-mobile portion of the cap (the immobile portion  112 , rim  110 ). 
     Thanks to the notches  118 , there is a functional separation of the mobile parts—mobile portion  114 , locking flap  116  . . . —and the non-mobile parts—the immobile portion  112 , rim  110  . . . —of the cap  100 . 
     In the present case, the notches have the shape of a horse&#39;s saddle which still allows to bring flexibility to the non-mobile parts when the cap  100  is removed from the container. 
     Caps such as the cap  100  depicted here are thus ideal for fabrication by injection moulding or other such processes which can produce relatively complex shapes quickly and inexpensively. 
       FIG. 1B  shows the cap  100  from above. The cap  100  is provided with a partially frangible tab  120 , which is moulded integrally with the cap  100  and connected therewith by frangible sprues or bridges  122  to the locking flap  116  and by a thin wall forming a hinge  124  to the annular side wall  104 . In the present embodiment the frangible bridges  122  and the thin wall  124  are made of plastic (same material as the cap) and are made integral with the cap. The frangible bridges  122  and the thin wall  124  are disposed substantially parallel respectively with the locking flap  116  and the annular side wall  104 . This causes the tab  120  to block the motion of the locking flap  116 , holding it in the locked first position as shown here in  FIG. 1B . 
     To open the container, the user must snap off the tab  120  by grasping it and deflecting it so as to snap the frangible bridges  122  and rotate the hinge  124  to have the tab  120  fading out and lying against the annular side wall  104  (the final position will be presented and described in connection with  FIGS. 4A &amp; 4B ). To facilitate this manipulation, the tab  120  is here provided with ridges  126 , which improve the user&#39;s grip upon the tab  120 . 
     Other way of snapping off the tab can be envisaged, for example, a vertical upwards movement on the locking flap  116  has the effect of breaking the bridges  122  and the hinge  124  can then rotate to allow taking off the cap  100  from the container neck. 
     The tab  120  is, as here, preferably configured such that the cap  100  cannot be removed from the container to which it is attached without the tab  120  being removed first. In this way, the tab  120  serves as a tamper-evident device, in that any tampering with the container will be immediately noticeable to the consumer in the form of a damaged or missing tab  120 . 
     Thus, the configuration of the tab  120 , the frangible bridges  122  and hinge  124 , in particular the force required to break and/or shear said frangible bridges  122  and rotate hinge  124 , may be adapted to the product contained within the container, and/or the profile of the consumer for which the product is destined. 
     Of course, it should be understood that in other embodiments there may be provided multiple tabs, or tabs in a different configuration than that which is depicted in  FIG. 1B . It may be particularly advantageous to mould words or images into the tab, or provide the tab in some other configuration which is adapted to the particular application in which it is employed. 
     The proposed solution allows advantageously the tab  120  to remain attached to the annual side section  104  thanks to the hinge  124 . As the tab  120  remains attached, it cannot be detached and “lost” in the environment. This is very important from a sustainability and recycling point of view. 
     As mentioned the complete cap  100  comprising among other top section  102 , annular side section  104 , locking flap  116 , tab  120  and hinge  124  is made in one piece from one material. Said material may be a thermoplastic polymer such as HDPE plastic, LDPE plastic or PP plastic. 
     Along with the description of  FIGS. 1A &amp; 1B ,  FIG. 1C  shows the cap  100  having top section  102  and annular side section  104 . Annular side section  104  comprises annular portion  105  as gripping means in the process of capping the container with the cap  100 . As clearly conceivable by the skilled person, the design, shape and proportions of annular portion  105  can modified as long as it keeps the specific disclosed function. The cap  100  is further provided with a locking flap  116  mobile between a locked first position and an unlocked second position wherein the locking flap  116  is rotated towards the disc-shaped top section  102  in order to move from the locked first position to the unlocked second position. As already presented the cap  100  is provided with a partially frangible tab  120 , which is moulded integrally with the cap  100 . The tab  120  allows blocking the motion of the locking flap  116 , holding it in the locked first position and act therefore as tamper evidence means for the consumer. As clearly shown in  FIG. 1C , tab  120  is attached perpendicularly to the annular side section  104  and locking flap  116 . In the present case, the main axis of tab  120  is positioned vertically with respect to the positioning presented in  FIG. 1C  and along the longitudinal axis of an upright container to which the cap is attached. The angle between the hinge  124  of the tab  120  (not visible in  FIG. 1C ) and the vertical axis is null. 
       FIGS. 2A &amp; 2B  depict the cap  100  with the locking flap  116  in a locked first position and an unlocked second position, respectively. For ease of understanding of the way the cap  100  is working, the tamper evidence means comprising the tab  120  with bridges  122  and hinge  124  are not represented. In  FIG. 2A , the cap  100  is depicted as disposed upon a container  200  (depicted here in schematic form) at a neck  202  thereof. The container  200  is fabricated from a preform (not shown), which is furnished with a shoulder  204  against which the mobile portion  114  of the locking flange is brought into abutment. The shoulder  204  extends about the entire circumference of the neck  202  of the container, so that the cap  100  need not be placed in any particular orientation when being attached to the container  200 . 
     The cap  100  is retained upon the neck  202  of the container  200  by the interaction of the locking flange  111  with the shoulder  204 , in particular where the mobile portion  114  of the locking flange  111  projects beyond an interior face  206  of the annular side section  104  and prevents the cap  100  from being removed from the container  200 . 
     It should be noted that, while the shoulder  204  is here in the form of a bead of square cross-section which encircles the neck  202  of the container  200 , other configurations may be more appropriate for other embodiments of the invention. For instance, the shoulder may comprise the uppermost face of a channel which is cut or moulded into the neck of the container, or it may comprise the underside of a ring or bead which encircles the neck. The actual form of the shoulder, as with the form of the cap and its constituent components, should thus be considered to be at least partially a function of the application in which the cap and corresponding container is to be employed. 
     It is also evident in  FIG. 2A  that the locking flap  116  is fabricated integrally with the cap  100 , in that the locking flap  116  is joined to the annular side section  104  at a hinge  208 . The hinge  208  is, in this embodiment, merely a localized reduction in the thickness of the plastic used to fabricate the cap  100 , and as such makes the locking flap  116  mobile with respect to the annular side section  104  while simplifying the fabrication of the cap  100 . 
     Furthermore, in this embodiment the locking flap  116  is provided in the form of a segment of a hollow conic frustum. Thus, given that the hinge  208  is located at the root of the locking flap  116  where it extends from the annular side section  104  along a constant, circular-segment curve, the locking flap  116  will be bistable about a plane  210 , which extends through the hinge  208  parallel with the disc-shaped top section  102  of the cap  100 . 
     In other words, the locking flap  116  will naturally put itself into either the locked first position shown in  FIGS. 1A, 1B, and 2A , or the unlocked second position shown in  FIG. 2B  (discussed below). 
     It should also be noted that, owing to the positioning of the hinge  208 , the locking flap  116  will serve to act as a lever when it is operated. This multiplies the force that is brought to bear by the mobile portion  114  of the locking flange against the shoulder  204 , thereby increasing the strength with which the cap  100  is attached to the container  200  and the resistance of the seal between the two. 
       FIG. 2B  depicts the cap  100  and the container  200  when the locking flap  116  is disposed in the unlocked second position. The locking flap  116  has been rotated upwards along a path  212 , resulting in the mobile portion  114  of the locking flange rotating outwards away from the shoulder  204 . 
     In the present embodiment depicted here in  FIGS. 2A &amp; 2B , the locked first and the unlocked second position are substantially symmetric about the plane  210 , which thus comprises the centre point of the bistable motion of the locking flap  116 . However, other configurations of the motion of the locking flap, in particular the configuration of the locked first and unlocked second positions relative to the rest of the cap, may vary as a function of the application. 
     Returning to the present embodiment, as a result of the displacement of the locking flap  116  into the second unlocked position, the mobile portion  114  of the locking flange is in a position which is recessed relative to the interior surface  206  of the annular side section  104 . This is illustrated here in  FIG. 2B  by an imaginary surface  214 , which is an extension of the interior surface  206  of the annular side section  104 ; the mobile portion  114  of the locking flange is positioned so as not to intersect the imaginary surface  214 . 
     With the mobile portion  114  of the locking flange so positioned, the cap  100  can now be easily withdrawn from the neck  202  of the container  200 , as the mobile portion  104  of the locking flange can no longer come into contact with the shoulder  204 . 
       FIG. 3  depicts the cap  100 , which is provided with a sealing ring  300  which extends from the disc-shaped top section  102  towards the rim  110 , extending coaxially within the annular side section  104 . The sealing ring  300 , in cooperation with the interior surface  206  of the cap  100 , forms an annular notch  301  which is configured to accommodate the mouth  302  of a container  200  therein. 
     Thus, in the present embodiment as depicted here in  FIG. 3 , when the cap  100  is attached to the container  200 , the neck  202  lodges in the annular notch  301 , creating an interference fit therewith. This further augments the quality of the seal between the cap  100  and the container  200 , and prevents the accidental dislodgement of the cap  100  when the locking flap  116  is disposed in the unlocked second position as discussed above. 
     In  FIG. 3  it is illustrated how the cap  100  engages the container  200  to lock itself thereto. The part of the immobile portion  112  of the locking flange nearest the disc-shaped top portion  102  of the cap  100  is the locking face  303 A, which is disposed substantially perpendicularly with the interior surface  206  of the cap  100 . When the cap  100  is disposed upon the container  200 , the locking face  303 A will abut the shoulder  204 , preventing the cap  100  from being withdrawn from the container  200 . 
     Likewise, the mobile portion  114  of the locking flange comprises a locking face  303 B. As the mobile portion  114  of the locking flange rotates with the locking flap  116 , the angle that the locking face  303 B forms with respect to the interior surface  206  of the cap  100  will vary. 
     Thus, when the locking flap  116  is disposed in the locked first position, as illustrated in  FIG. 3 , the locking surface  303 B will project substantially perpendicularly from the interior surface  206 , such that it will come into abutment with the shoulder  204  and prevent the cap  100  from being removed from the container  200 . Conversely, when the locking flap  116  is rotated into the unlocked second position, the locking surface  303 B will be disposed so that it no longer engages the shoulder  204 . In such a disposition, the mobile portion  114  of the locking flange is recessed relative to the interior surface  206 , with the locking surface  303 B being at least substantially parallel and continuous with the interior surface  206 , if not extending outwardly from it. 
     Moreover, in the case where the cap  100  is not fully pressed down onto the container  200  prior to moving the flap  116  into the locked first position, the motion of the locking surface  303 B of the mobile portion  114  of the locking flange will serve to lever the cap  100  into the proper position. 
     Specifically, the locking surface  303 B will bear against an edge  304  of the shoulder  204 , such that as the locking flap  116  is rotated into the locked first position, it will exert a force on the container  200  that will cause the cap  100  to be further tightened against the container  200 , and then retaining the cap  100  in place once the locking flap  116  is fully disposed in the locked first position. The locking flap  116  will thus multiply the efforts of the user, fixing the cap  100  to the container  200  with a maximum of force and, consequently, a high-integrity seal. 
     Both the sealing ring  300  and the interior surface  206  of the annular side section  104  are further provided, respectively, with sealing beads  305 ,  306 , which extend over the entire circumference of the sealing ring  300  and the interior surface  206 . The sealing beads  305 ,  306  serve to concentrate the force of the interference fit exerted upon the neck  202 , further improving the strength of the seal between the cap  100  and the container  200 . 
     It may be particularly desirable for the neck  202  to comprise a local increase of the thickness of the neck  202  of the container  200  near the mouth  302 , as depicted here. This serves as a reinforcement of the mouth  302 , offering improved strength to the container  200 . Also, the amount of material used to fabricate the container  200  may be reduced, while maintaining a tight seal between the mouth  302  and the sealing beads  305 ,  306 . 
     It should also be noted that the forms (i.e. cross-sectional profiles) of the sealing beads  305 ,  306  that are depicted here are merely exemplary. It will be readily understood that, in any particular embodiment, the sealing beads will be configured according to the application in which the cap is to be employed and according to the desired effect they are intended to have. 
     In this embodiment, the sealing ring  300  is substantially circular in form. However, in other embodiments it may be preferable to provide a sealing ring in a non-circular form, for instance projecting from the disc-shaped top portion  102  along an oval or elliptical curve. Such a form will, in certain applications, help to bring the cap  100  into alignment with the neck  202  of the container when the two are not aligned with each other. In any case, the sealing beads  305 ,  306  will be substantially circular, in that they will comprise local variations in size to compensate for local deviations in the radius of the sealing ring  300  and achieve correct sealing with the container  200 . 
     Furthermore, in this embodiment the cap is fabricated such that it is of a substantially constant thickness, resulting in a U-shaped profile for the sealing ring  300 . This is advantageous in that it facilitates the moulding of the cap  100 ; however, in other embodiments it may be preferable to provide the sealing ring  300  as a simple projection from the disc-shaped top section of the cap rather than as a folded curve as seen in this embodiment. The exact configuration may be chosen with respect to the application in which the cap is to be employed. 
     The design of the sealing ring  300  of the cap  100  may be optimized to allow a good contact force with the neck  202  of the container  200  while still keeping the ability to be folded during opening. 
     In addition, the locking flap  116  is provided with a tab  120  forming tamper evidence means. The tab  120  is connected to the locking flap  116  via frangible bridges  122  and a hinge  124 . When the locking flap  116  is first manipulated, the frangible bridges  122  breaks and the force applied to the locking flap  116  push on the tab  120  leading hinge  124  to rotate so that the tab  120  fades out and lies against the annular side wall  104 . The final position of the tab  120  clearly indicates to the consumer that the cap has first been opened. As presented in this embodiment, the main axis of tab  120  is positioned vertically with respect to the presented figure along the longitudinal axis of an upright container to which the cap is attached. 
     Finally, it should be noted that the container  200  is provided with a support ring  308 . The support ring  308  permits the manipulation of the container  200 , particularly during a blow-moulding process in which a preform is expanded into the container  200 , but also generally during the filling and sealing of the container  200 . In this embodiment the support ring  308  is provided separately from the shoulder  204 ; however, it may be advantageous in other embodiments that the locking flange engages the support ring directly. 
     Moreover, when the locking flap  116  is disposed in the locked first position, it will extend over the support ring  308  so as to at least partially cover it, giving the container  200  a generally streamlined form and preventing the support ring  308  from being caught on anything when the container  200  is manipulated or transported. 
       FIGS. 4A, 4B &amp; 4C  are respectively front and top perspective views of the cap of  FIGS. 1A, 1B &amp; 1C  after the tab forming tamper evidence means has been manipulated in the first locked position and second unlocked position. 
       FIGS. 4A &amp; 4B  are front and perspective views of cap  100  after tab  120  has been moved by grasping tab  120  and deflecting it so as to snap the frangible bridges  122  and rotate the hinge  124  to have the tab  120  fading out and lying against the annular side wall  104 . In more details, during this movement, tab  120  begins to deform, slides on the left (or right) side until complete rupture of the bridges  122  and then the hinge  124  pivots vertically and is twisted on the left (or right) side according to the direction that tab  120  will take. 
     Due to the fact that the rotation axis of hinge  124  is vertical (perpendicular to annular side section  104  and locking flap  116 ), hinge can rotate towards the right direction or towards the left direction. 
     The fact that once manipulated, the axis of the tab  120  appears shifted from the vertical axis of hinge  124  is due to the fact that before hinge  124  rotates, the consumer snaps the frangible bridges and tab deforms thereby twisting the hinge on one of the sides. 
     Thanks to hinge  124  being non frangible contrary to bridges  122 , the tab remains connected to the annular side section  104  of cap  100 . 
     In the current position, the locking flap  116  is in the first locked position and the cap  100  cannot be removed from the container&#39;s neck. 
       FIG. 4C  shows perspective view of cap  100  in the second unlocked position in which the cap can be removed from the container&#39;s neck. One can see on  FIG. 4C  the final position of the tab  120  after it has been manipulated and after the locking flap  116  has been moved from the first locked position to the second unlocked position. 
     The proposed tamper evidence means is particularly advantageous in that once manipulated, it does not interfere with the locking flap  116  allowing for opening the cap  100 . Indeed, the locking flap  116  can be moved from the first locked position to the second unlocked position without any difficulties as the tab  120  accommodates itself within the free space between the annular side section  104  and the locking flap  116  in the second unlocked position. 
       FIGS. 5A, 5B &amp; 5C  respectively represent front, side and top perspective views, of a cap according to a second embodiment of the invention in the locked position. 
     The referenced number already used in connection with  FIGS. 1A to 1  C will be used for the same referring elements. 
     In this second embodiment of the invention, the tab  120  has a different positioning than the tab of the first embodiment. As can be seen from  FIGS. 5A to 5C , the hinge  124  of tab  120  is not positioned vertically but inclined with respect to the vertical axis defined as the direction of the annular side section  104  projecting substantially perpendicularly from the perimeter of the disc-shaped top section  102 . 
     As can been seen from  FIGS. 5A and 5C , the hinge  124  is inclined with respect to the vertical axis. Preferably, the hinge  124  is inclined from an angle α of about 20 to 60° with respect to the represented vertical axis. In the presented embodiment, the hinge  124  is inclined from about 45° with respect to the vertical axis. The proposed hinge inclination of 45° is optimal as the consumer can handle break the tab  120  and remove the cap with one hand. 
     In addition to the proposed tamper evidence means using a partially frangible tab  120 , it is presented in this second embodiment additional tamper evidence means as second tamper evidence means for the consumer to be able to identify if the container/bottle has already been opened and the cap removed or manipulated. 
     The proposed second tamper evidence means can be used on the different embodiments of the present invention alone or in combination with the proposed first tamper evidence means already described using partially frangible tap  120 . 
     As already disclosed in  FIGS. 1A to 1C , the notches  118  located between the mobile portion of the locking flange  111  and the non-mobile portion of the cap  100  (the immobile portion  112 , rim  110 ) play the role of mechanical frontier between these two portions of the cap  100 . 
     This specific location is used to implement second tamper evidence means as any movement of the locking flap  116  will cause a change in the conformation of this notches  118 . 
     Second tamper evidence means  128  represented on  FIGS. 5B and 5C  are located between the internal edges  132  of the notches  118  creating a connection  132  between the two internal edges  132  of the notches  118 . 
     This connection  132  is conformed as a plastic bridge connection between the two opposite internal edges  132  of the notches  118 . It is made from the same material as the cap  100  and is integral with the cap. 
     The connection  132  is a plastic bridge of about XX width between the edges  132  of the notches  118 . 
     These second tamper evidence means  128  are positioned on both sides of the cap at each location of the notches  118 . 
     Thus, when the locking flap  116  of cap  100  is first moved from the first locked position to the second locked position, in addition to the breakage of the bridges  122  of the tab  120 , the connection  130  between the two internal edges  132  of the notches  118  is broken indicating that the cap has been manipulated for opening. 
     During breakage of connection  130 , sole the plastic bridge connection breaks and the remaining plastic portions remains attached to the internal edges  132  of the notches  118 . No plastic element is removed or scattered over nature. 
     These second tamper evidence means  128  also allows reinforcing the positioning of the cap on the neck of the container during phases of the supply chain (transportation, storage . . . ). 
     As can be seen from these figures in comparison with  FIGS. 1A to 1C , is that the length of the locking flap  116  may vary. In the present case, the length of the locking flap  116  of  FIGS. 1A to 1C  is longer than the one of  FIGS. 5A to 5C . This has no effect on the way the proposed tamper evidence means globally work but the length of the locking flap  116  may vary during the conception of the cap according to the type of movement and/or force to be applied on the locking flap. 
       FIGS. 6A &amp; 6B  represent views of the cap of  FIGS. 5A, 5B &amp; 5C  in the locked first and unlocked second position, after the tamper evidence member  120  has been manipulated. 
     In this second embodiment, when the tab  120  is pressed, it begins to deform and slides until the bridges  122  are broken, the hinge  124  rotates around this specific angle. Due to the specific hinge angle, there is no twisting of the hinge during this movement and the tab  120  fades out and lies against the annular side wall  104 . Thus, there is not interaction between tab  120  and the locking flap  116  when the locking flap  116  is further moved from the first locked position to the second unlocked position. 
     As can be seen on  FIG. 6A , the second tamper evidence means  128  are still in functional (with their tamper evidence function) when the tab  120  has been manipulated and the locking flap  116  in the first locked position. 
     From  FIG. 6B , it can been seen that the second tamper evidence means  128  break when the locking flap  116  is first handled from the first locked position to the second unlocked position. The plastic bridge connection of connection  130  is broken leaving the notches  118  fully functional. 
     It will be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the appended claims.