WO 2008/155552 PCT/GB2008/002103 CLOSURE SYSTEM AND ITS METHOD OF FORMING The present invention relates to a closure system comprising a neck and a cap engageable with the neck. The 5 closure system includes tamper evident means comprising a locking member attached to the neck such that, having applied the cap to the neck, the cap is prevented from being removed from the neck prior to breaking of the tamper evident means. 10 Paperboard cartons have long been known to benefit from the addition of a plastics pouring device or spout commonly referred to as a "fitment". Such devices commonly comprise a neck and many are initially closed by an integrally moulded disc within the neck structure. The disc is joined 15 to the neck by means of a frangible tear-line and is provided with a grip mechanism in the form of a pull-ring or pull-tab. A user, on initial opening of the paperboard carton, grasps the grip mechanism and tears the moulded disc away from the neck structure along the frangible tear-line. 20 These devices are generally additionally provided with a cap which surrounds the outside features of the neck and provides the facility to reclose the carton once it has been opened. Such devices thus provide reasonable tamper evidence as 25 well as sealing properties appropriate to aseptic or extended life applications. The disadvantage that such devices have is their well known potential for splashing the packaged product as a result of the sudden release of the disc on opening. 30 In another variation of the fitment system no disc is provided within the neck structure and, instead, the interaction between the cap and neck is designed to provide WO 2008/155552 PCT/GB2008/002103 -2 both a primary seal and the tamper evident capability. Whilst this variation overcomes the problem associated with the frequent splashing of the packaged product on opening, it has provided poor compatibility with standard long life 5 (aseptic) cleaning systems. This is because, in order to provide a satisfactory primary seal, it has been thought necessary for the surfaces of the cap to engage closely with the surfaces of the neck with the result that it has then been difficult to flush the surfaces of the assembled 10 fitment with an aseptic cleaning solution. If a fitment cannot be processed in this way, then it cannot be used to contain products intended to have an extended shelf life and the usefulness of the fitment is therefore limited. Furthermore, depending on the nature of the tamper 15 evidence, if the tamper evident feature is intended to be retained on either the cap or the neck (as opposed to simply being discarded), there is a risk that the tamper evident feature may become detached during normal use. This is regarded as a major issue since if the tamper evident 20 feature were to fall into the receptacle into which the packaged contents were being dispensed and this went unnoticed by the user there then exists the possibility of the tamper evident feature contaminating the dispensed product or, worse still, the user swallowing the tamper 25 evident feature if, as is often the case, the product is intended for human consumption. Because of this risk the tamper evident features of fitments of this type have become increasingly complex and costly to manufacture. In contrast to this trend the present invention 30 provides a closure system of reduced complexity and which is cheaper to manufacture in which a locking member is attached to the neck, the locking member being orientated in a first -3 position with respect to the neck to facilitate moulding of the neck and orientated in a second position with respect to the neck to prevent removal of at least a portion of the cap from the neck. Furthermore, the locking member is moved 5 from the first position to the second position upon application of the cap to the neck. Whilst it is recognised that the use, on a cap, of a radially inwardly projecting locking bead to engage below a radially outwardly projecting abutment surface provided on a .0 neck is well known to prevent the lifting up of the cap, such an arrangement requires the creation of an undercut on the neck in order to produce the abutment surface. This is both complex and expensive to produce. In particular, such a neck, it if is to be moulded, requires a mould tool having .5 parts that open in at least two transverse directions. Similarly, although it is known to provide tamper evident means which include folded features, these are typically provided on the cap and form an inverting band which folds upwardly and inwardly from a lower edge of the .0 cap skirt. By contrast, in the closure system of the present invention the locking member is attached to the neck at a point part way up the neck wall and, in use, is inverted downwards, away from the dispensing orifice. This arrangement also serves to limit the potential for levering 25 up the underside of the cap in order to defeat the tamper evident feature.
4 Object of the Invention It is the object of the present invention to substantially overcome or ameliorate one or more of the disadvantages of the prior art. 5 Summary of the Invention The present invention provides a closure system comprising: a neck, a cap engageable with the neck, and a locking member attached to the neck, the locking member being orientated in a 1o first position with respect to the neck to facilitate moulding of the neck and locking member and orientated in a second position with respect to the neck to prevent removal of at least a portion of the cap from the neck, the locking member being moved from said first position to said second position upon application of the cap to the neck. is Preferably, the neck and locking member are moulded as one piece. Preferably, the locking member hinges about a point of attachment to the neck in moving from said first position to said second position. 20 Preferably, the locking member is joined to the neck by a flexible connection. Preferably, the neck defines a longitudinal axis and, when in said first position, the locking member is inclined with respect to said axis, and, when in said second position, the locking member is orientated substantially parallel to said axis. 25 Preferably, the neck defines a longitudinal axis and the locking member comprises a locking surface remote from the location at which the locking member is attached to the neck, the locking surface lying in a plane substantially at right angles to said longitudinal axis when the locking member is in said second position. 30 Preferably, the neck comprises a wall to which the locking member is attached, the locking member extending transversely to the wall when in said first position and extending substantially parallel to the wall when in said second position.
5 Preferably, the cap comprises an inwardly directed projection adapted to engage with the locking member when the locking member is in said second position. Preferably, the neck is cylindrical and the inwardly directed projection comprises 5 an annular or part annular locking bead. Preferably, the cap comprises a skirt section and a tamper evident band frangibly connected to the skirt section, the inwardly directed projection being provided on the tamper evident band. 10 Preferably, in said second position, the locking member retains the tamper evident band with respect to the neck such that an attempt to remove the cap from the neck results in a breaking of the frangible connection between the skirt section and the tamper evident band. 15 Preferably, the neck is provided with engagement means for repeated and releaseable engagement with complimentary engagement means provided on the cap. Preferably, the locking member comprises a plurality of mutually spaced locking 20 elements disposed about a perimeter of the neck, each locking element being attached to the neck and moveable between a respective first position in which the locking element is orientated with respect to the neck to facilitate moulding of the neck and the locking element and a respective second position in which the locking element is orientated with respect to the neck to prevent removal of at least a portion of the cap from the neck. 25 Preferably, the plurality of locking elements are joined by a web of material. Preferably, the web of material is of reduced thickness compared to the locking elements. 30 Preferably, the web of material comprises one or more pleats. Preferably, the neck comprises a cylindrical wall and defines a circular bore spaced radially inwardly of the cylindrical wall, the circular bore being sealingly engaged 35 by an annular plug provided on the cap upon application of the cap to the neck.
6 Preferably, the closure system comprises a fitment for attachment to a carton or other container. Preferably, the closure system is integrally moulded with a container, the neck 5 forming a neck of the container. The present invention further provides a method of forming the neck of a closure system described above, comprising the steps of: providing a plurality of mould parts capable of cooperating to define a mould 10 cavity suitable for the formation of the neck; closing the mould parts to form said mould cavity by moving said mould parts along, or parallel to, a single axis; introducing plastics material into said mould cavity; separating said mould parts by moving said mould parts along, or parallel to, said is same single axis; and ejecting the moulded neck.
7 Brief Description of the Drawings Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: 5 Figure I is a perspective view of a closure system embodying the present invention; Figure 2 is an elevational view of the closure system of Figure 1; Figure 3 is a cross sectional view of a neck portion of the closure system; [The next page is page 11] WO 2008/155552 PCT/GB2008/002103 - 11 Figure 4 is a detailed cross sectional view of the neck portion of the present invention showing a flexible locking member; Figure 5 is an elevational view of the neck portion of 5 the closure system; Figure 6 is a cross sectional view of a cap portion of the closure system; Figures 7(a), (b) and (c) are cross-sectional views of the closure system showing the movement and resultant 10 position of the flexible locking member when the cap portion is applied to the neck portion; Figure 8 is a cross sectional view of the closure system once the cap portion has been fully applied; Figure 9 is a cross sectional view of the closure 15 system after the cap portion has been removed and with a tamper evident band retained on the neck portion. As shown in Figures 1 and 2, a closure system embodying the present invention may take the form of a fitment 10. The fitment 10 comprises a neck portion 12 and a cap portion 20 14. The neck portion 12 is shown in more detail in Figures 3 to 5 and comprises an apertured flange 16 having substantially smooth and planar upper and lower surfaces 18 and 20, respectively. 25 Surrounding the aperture, a cylindrical wall 22 projects upwardly from the upper flange surface 18 to form a smooth lower neck portion. At an end remote from the apertured flange 16, the cylindrical wall 22 merges with an upwardly and radially inwardly projecting wall 24. This 30 upwardly and radially inwardly projecting wall 24 in turn merges with a second cylindrical wall 26 which has both a reduced internal diameter and a reduced external diameter WO 2008/155552 PCT/GB2008/002103 - 12 compared to the first cylindrical wall 22. However, the first cylindrical wall 22 is of reduced wall thickness compared to both the upwardly and radially inwardly projecting wall 24 and the second cylindrical wall 26 as 5 well as the apertured flange 16. At an end remote from the upwardly and radially inwardly projecting wall 24, the second cylindrical wall 26 merges with a downwardly and radially inwardly directed annular rim 28 which terminates at a cylindrical surface 30 10 defining a dispensing aperture or bore 32. The second cylindrical wall 26, which defines an upper neck portion, is provided on an external surface with engagement means 34 with which to engage complimentary engagement means provided on the cap portion 14. In the 15 example shown, the engagement means 34 take the form of a male, equi-spaced, multi-lead helical thread configuration which includes three threads or leads 36. It will be apparent however, that the engagement means 34 may take a number of different forms and, in particular, need not be 20 limited to three threads or leads but may comprise one or two threads as appropriate. The engagement means 34 may also comprise four, five or more threads if so desired. In the illustrated embodiment, each thread 36 extends about 1200 around the circumference of the second 25 cylindrical wall 26. Once again however, it will be understood that threads of a lesser or greater extent may also be employed. For example, each thread 36 may extend within a range from 900 to more than 3600. Preferably the helical thread configuration has a fine thread density to 30 limit the vertical float of the cap portion 14 with respect to the neck portion 12. Thus, the thread density preferably lies within a range of between 6 and 12 threads WO 2008/155552 PCT/GB2008/002103 - 13 per linear inch. Most preferably of all, the helical thread configuration has a thread density of approximately 8 threads per linear inch. By contrast, on an external surface of the first 5 cylindrical wall 22, at or near where it merges with the upwardly and radially inwardly projecting wall 24, the neck portion 12 is provided with a plurality of upwardly and radially outwardly directed locking members 40. The locking members 40 are mutually spaced and arranged 10 circumferentially around the neck portion 12. Each locking member 40 is joined to the first cylindrical wall 22 and/or the upwardly and radially inwardly projecting wall 24 by a thin web 42 which, with the locking member 40, defines, in cross-section, an upwardly and radially outwardly directed 15 lower surface 44 which terminates in an end surface 46. The end surface 46, remote from the first cylindrical wall 22 and the upwardly and radially inwardly projecting wall 24, extends substantially at right angles to the lower surface 44 before joining, again at right angles, with a 20 downwardly and radially inwardly directed upper surface 48. This upper surface 48 in turn merges with a substantially downwardly directed necking surface 50 before merging with an upper surface 52 of the web 42. As can be seen more clearly in Figure 5, the locking 25 members 40 are curved such that the lower surface 44 has substantially the same radius of curvature and centre of curvature as the first cylindrical wall 22. Being of substantially constant wall thickness, other than in the region of the web 42 and necking surface 50, the upper 30 surface 48 is similarly curved. Although the locking members 40 are shown as being mutually spaced and arranged circumferentially around the WO 2008/155552 PCT/GB2008/002103 - 14 neck portion 12, it will be understood that one or more (or, indeed, all) of the locking members 40 may be joined by pleats or folds extending between their respective side surfaces. These pleats or folds may be of reduced wall 5 thickness compared to the locking members 40 to enhance their flexibility or else may be of substantially the same wall thickness and scored or necked along intended fold lines. On an internal surface, adjacent the transition between 10 the apertured flange 16 and the first cylindrical wall 22, the neck portion 12 is provided with a radially inwardly projecting bead 38, the purpose of which will be described in more detail below. Turning to the cap portion 14 shown in Figure 6, the 15 cap portion comprises a circular top 60 having an undersurface 62. The circular top 60 merges at a radially outer edge with a downwardly and radially outwardly inclined surface 64 which, in turn, merges with a depending annular side wall 66 to form a downwardly extending skirt portion. 20 The depending annular side wall 66 is provided, on an inner surface 68, with complimentary engagement means 70 for repeated and releaseable engagement with the engagement means 34 provided on the neck portion 12. As before, this engagement means 70 may take many forms but, in the example 25 shown, comprise a male, equi-spaced, multi-lead helical thread configuration having three threads or leads 72 and a thread density of approximately 8 threads per linear inch. Once again, however, it will be appreciated that the complimentary engagement means 70 need not be limited to 30 three threads or leads but may comprise one or two threads as appropriate. The complimentary engagement means 70 may also comprise four or five or more threads if so desired.
WO 2008/155552 PCT/GB2008/002103 - 15 In the embodiment shown, each thread 72 extends approximately 1200 around the inner surface 68 of the depending annular side wall 66. However, it is to be understood that this thread length may be increased or 5 decreased if desired. For example, each thread 72 may extend in a range from 900 to more than 3600. Likewise, the thread density is not intended to be limited to being about 8 threads per linear inch but, nevertheless, preferably lies within the range from about 6 to about 12 threads per linear 10 inch. As will be apparent to those skilled in the art, if one of the engagement means 34 or 70 comprises a male helical thread configuration, then the other of the two engagement means may comprise a helical groove configuration. In the 15 case of two male helical thread configurations, it will be apparent that one or both of the thread configurations may be interrupted at intervals along its length. The two thread configurations may be shaped so as to slip past one another when a direct, axial downward force is 20 applied to the cap portion 14 to urge the cap portion into engagement with the neck portion 12.. In other words, when the cap portion 14 is pushed onto the neck portion 12, the threads 72 on the cap'portion 14 snap over the threads 36 on the neck portion 12 before interengaging with them. This 25 may be made possible by appropriate shaping of the threads 36 and 72, for example, by forming the threads with an asymmetric cross-section or by making them less pronounced. Alternatively, if it is desired to rotate the cap portion 14 onto the neck portion 12, the threads 36 and 72 may be of 30 symmetrical, as opposed to asymmetrical, cross-section and may be more pronounced.
WO 2008/155552 PCT/GB2008/002103 - 16 In addition to the complimentary engagement means 70, the interior of the cap portion 14 is provided with an annular plug 74 which depends from the undersurface 62 of the circular top 60 and is spaced radially inwardly of the 5 depending annular side wall 66. The annular plug 74 is defined by a respective radially inner and outer walls 76 and 78. The radially outer plug wall 78 merges at an end remote from the circular top 60 with a generally downward and radially inwardly directed surface 80. This generally 10 downward and radially inwardly directed surface 80 intersects the radially inner plug wall 76 and, together, serves to provide the annular plug 74 with a bevelled radially outer surface and a tapering cross-section. The tapering cross-section is further accentuated by the fact 15 that, whereas the radially outer plug wall 78 extends in a direction substantially perpendicular to the plane of the undersurface 62, the radially inner plug wall 76 extends from the undersurface 62 in a direction which is both downward and radially outward. 20 By contrast, on an exterior of the cap portion 14, the depending annular side wall 66 is provided on its outer surface with a plurality of circumferentially spaced, vertically extending ribs 82 which serve as knurls to facilitate the gripping of the cap portion 14 by a user. 25 The vertically extending ribs 82 also facilitate the assembly of the cap portion 14 to the neck portion 12 during the mechanical process for the assembly of the fitment 10. As is common with a number of caps, a small downwardly directed dimple 84 is formed in the centre of the circular 30 top 60 so that any flash left after the cap portion 14 has been moulded does not project above a plane defined by the upper surface of the circular top 60.
WO 2008/155552 PCT/GB2008/002103 - 17 In addition to the foregoing features, the inner surface 68 of the depending annular side wall 66 is provided with a radially inwardly projecting bead 86 at an end remote from the circular top 60. The radially inwardly projecting 5 bead 86 is, in turn, defined by a radially inwardly and downwardly directed surface 88 which merges with the inner surface 68 and, with it, forms an internal shoulder 90. At an end remote from the inner surface 68, the radially inwardly and downwardly directed surface 88 merges with a 10 downwardly and radially outwardly directed surface 92 before this last surface, in turn, merges with an end surface 94 of the depending annular side wall 66, the end surface 94 extending generally at right angles to the inner surface 68. Between the radially inwardly projecting bead 86 and 15 the engagement means 70, the depending annular side wall 66 is provided with a plurality of circumferential slits or spaces 96. These slits or spaces 96 are mutually spaced by frangible bridging elements 98 and together serve to define a circumferential line of weakness which divides the 20 downwardly extending skirt portion defined by the depending annular side wall 66.into an upper skirt section and a lower skirt section in which the-lower skirt section is capable of functioning as a retained tamper evident band 100. As will be apparent to those skilled in the art, the circumferential 25 slits or spaces 96 may be formed as a secondary slitting operation and may be created mechanically after the cap portion 14 has been moulded. Alternatively, the slitting operation may be performed after the cap portion 14 has been assembled onto the neck portion 12. In another arrangement 30 the circumferential slits or spaces 96 may be formed during the process of moulding the cap portion 14. Although moulding the circumferential slits or spaces 96 provides the WO 2008/155552 PCT/GB2008/002103 - 18 advantage that no secondary operations are then required to the cap portion 14 other than assembly to the neck portion 12, one disadvantage is that the strength of the bridging elements 98 can not be easily adjusted without major re 5 tooling. Another disadvantage is that without correct maintenance there is a risk that flashing may occur within the circumferential slits or spaces 96 which may, in turn, adversely affect the tamper evident properties of the fitment 10. Both these disadvantages are addressed by a 10 secondary slitting operation. In addition the cap portion 14 can then be moulded using a single axis mould tool. Such mould tools, in which the mould components open and close along only a single axis, are generally less complex, less costly and may run faster and more efficiently than their 15 multi-axis counterparts. Furthermore, the strength or dimensions of the bridging elements 98 can be easily adjusted by replacing a single blade in the slitting machine. The disadvantage, of course, is that a second machine is required to do the slitting and these can be 20 costly when required to run at high volumes. In order to assemble the fitment 10, the cap portion 14 is offered up to the neck portion 12 in the orientation illustrated schematically in Figures 7(a), (b) and (c). The cap portion 14 may be applied to the neck portion 12 by 25 means of a push-on application, whereby the threads 72 on the cap portion 14 snap over those provided on the neck portion 12, or else by means of a rotary application in which the cap portion 14 is threaded onto the neck portion 12 and the two thread configurations interengage in the 30 conventional manner. In any event, prior to the interengagement of the threads 36 and 72, the radially inwardly projecting bead 86 provided on the inner surface 68 WO 2008/155552 PCT/GB2008/002103 - 19 of the depending annular side wall 66 passes over the engagement means 34 provided on the neck portion 12. This is, in part, facilitated by the riding of the engagement means 34 up the downwardly and radially outwardly directed 5 surface 92 of the radially inwardly projecting bead 86 as the cap portion 14 is applied to the neck portion 12. Having reached the position shown in Figure 7(a) continued movement of the cap portion 14 in the direction of the neck portion 12 causes the end surface 94 of the 10 depending annular side wall 66 to come into engagement with the locking members 40. As shown in Figure 7(b), this engagement occurs at a location radially outwardly of the web 42 and causes the locking members 40 to fold or rotate downwardly about the connection between the web 42 and the 15 first cylindrical side wall 22. This movement continues until such time as the lower surface 44 of the locking member 40 is pressed against the smooth first cylindrical wall 22. It will be remembered that these two surfaces share a substantially common radius and centre of curvature 20 to enable the locking members 40 to hug the first cylindrical wall 22 in a close confronting relationship notwithstanding the fact that the wall is cylindrical in nature. As the locking members 40 hinge downwardly, the 25 radially inwardly projecting bead 86 slides down the upper surface 48 until such time as the components reach the position shown in Figure 7(c). In this position the radially inwardly projecting bead 86 has passed beyond the end surface 46 of the locking member 40 and occupies a 30 position between the locking member 40 and the apertured flange 16. Furthermore, the locking member 40 is received within the shoulder 90 defined by the radially inwardly and WO 2008/155552 PCT/GB2008/002103 - 20 downwardly directed surface 88 of the radially inwardly projecting bead 86 and the inner surface 68 of the depending annular side wall 66. At the same time, the natural resilience of the material used to form the locking members 5 40 tends to urge the locking members 40 to rotate in such a way as to return to their as-moulded, starting position shown in Figure 7(a). Although this movement is prevented by the presence of the cap portion 14, nonetheless this bias causes the upper surface 48 of the locking members 40 in the 10 region close to the end surface 46 to engage even more pressingly with the inner surface 68 of the depending annular side wall 66. This, of course, in turn means that the end surface 46 of the locking members 40 is brought evermore reliably into confronting relationship with the 15 radially inwardly projecting bead 86. As the cap portion 14 is applied to the neck portion 12, the annular plug 74 is also received within the bore 32 defined by the cylindrical surface 30 at the radially inner end of the downwardly and radially inwardly directed annular 20 rim. 28. In so doing, the generally downward and radially inwardly directed surface 80 slides along the cylindrical surface 30 causing the annular plug 74 to flex slightly radially inwardly. This same movement also causes the downwardly and radially inwardly directed annular rim 28 to 25 flex slightly downwardly. Once fully received within the bore 32, the restoring force inherent in the resilient nature of the design and materials making up the annular rim 28 and the annular plug 74 causes the radially outer plug wall 78 to be urged into sealing engagement with the 30 cylindrical surface 30. Thus, in the assembled condition, the interaction between the annular plug 74 and the cylindrical surface 30 constitutes a primary seal.
WO 2008/155552 PCT/GB2008/002103 - 21 With the closure system in the assembled condition, the fitment 10 may be applied to a paperboard or other carton in the conventional manner. In this regard it will be noted that the opening to the neck portion 12 defined by the 5 radially inwardly projecting bead 38 facilitates the insertion of a spud of a manipulation tool. Since the apertured flange 16 has substantially smooth and planer upper and lower surfaces 18 and 20, the fitment 10 may be bonded either to the outside or to the inside of a carton 10 panel as desired. However, in another arrangement, the neck portion 12 may be provided with one or more additional projections which co-operate with the apertured flange 16 to retain the fitment 10 in a specific orientation with respect to the carton panel to which the fitment is to be attached. 15 Once the fitment 10 has been applied to a carton, the fitment provides that carton with a closure that can be repeatedly opened and closed as desired and which offers excellent sealing and re-sealing characteristics. In addition, the fitment 10 also provides a tamper evident 20 capability to alert a consumer should the contents of the carton have been compromised prior to initial opening. This tamper evident capability is provided in the form of a retained tamper evident band 100 which must first be separated from the cap portion 14 before the cap portion can 25 be removed from the neck portion 12. If a consumer finds that the tamper evident band 100 has been separated from the cap portion 14 before the fitment 10 has first been opened by them then it is possible that the contents of the carton may have been tampered with or may have become adversely 30 affected in some other way. The tamper evident capability of the fitment 10 functions as follows.
WO 2008/155552 PCT/GB2008/002103 - 22 In the assembled condition the cap portion 14 is prevented from being removed from the neck portion 12 in an axial direction by the interengagement of the engagement means 34 and 70 and by the engagement of the end surfaces 46 5 of the locking members 40 with the radially inwardly projecting bead 86. Furthermore, the close proximity of the end surface 94 of the depending annular side wall 66 with the upper flange surface 18 precludes the insertion of a tool between the two surfaces to prise the cap portion 14 10 off the neck portion 12. In order to remove the cap portion therefore, a user is required to rotate the cap portion 14 with respect to the neck portion 12. This causes the threads 72 of the engagement means 70 to rise up the threads 36 of the engagement means 34 and bring the radially 15 inwardly and downwardly directed surface 88 of the radially inwardly projecting bead 86 more firmly into engagement with the end surfaces 46 of the locking members 40. Continued upward movement of the cap portion 14 with respect to the neck portion 12 is resisted by the locking members 40 with 20 the result that the upward force exerted by a user in unscrewing the cap portion is applied to the circumferentially spaced bridging elements 98 which serve to connect the upper skirt section of the depending annular side wall 66 to the retained tamper evident band 100. The 25 relative size of the webs 42 compared to the bridging elements 98 ensures that the bridging elements 98 will fracture as a user continues to unscrew the cap portion 14 long before any damage is sustained by the locking members 40. 30 As shown in Figure 9, once the bridging elements 98 have been broken, the cap portion 14 may be removed and the contents dispensed from the carton. The cap portion 14 WO 2008/155552 PCT/GB2008/002103 - 23 may be reapplied and subsequently removed from the neck portion 12 as often as it is desired. Even though the bridging elements 98 have been fractured, it will be noted that the fact that the locking members 40 remain folded and 5 trapped between the first cylindrical wall 22 and the inner surface 68 ensures that the tamper evident band 100 is retained on the neck portion 12 and cannot be removed without causing.physical damage to the fitment 10 and/or the associated packaging. 10 In the example shown, the tamper evident band 100 remains in essentially the same position with respect to the neck portion 12 both before and after initial opening. However, it will be appreciated that in order to provide the tamper evident band 100 with a drop down capability which 15 may more easily alert a consumer to potential tampering, all that is required is to elongate the portion of the cylindrical wall 22 between the apertured flange 16 and the end surfaces 46 of the locking members 40 when in their downwardly folded configuration. 20 The design of the neck portion 12 illustrated in Figures 3 to 5 provides considerable manufacturing advantages and cost savings. Although it would be possible to mould a plastics fitment in which the neck portion had the same configuration as that illustrated in Figure 7(c) 25 but in which the locking members were formed as radial protrusions from the first cylindrical wall (rather than as hinged elements that fold down into this position), such a fitment would be considerably more expensive to produce. In particular, in such an arrangement the end surfaces of the 30 locking members would represent an undercut which could only sensibly be formed using a mould tool having components that opened and closed along two transverse axes. By contrast, WO 2008/155552 PCT/GB2008/002103 - 24 the neck portion 12 illustrated in Figures 3 to 5 can be formed using a mould tool having components that open and close along only a single axis. This represents a significant saving in tooling costs and a simplification of 5 the manufacturing process. Although the necking surface 50 is shown in Figure 4 as being substantially downwardly directed, in fact the surface may extend from the upper surface 48 to the upper surface of the web 42 at an angle of between 0.50 and 10 to a 10 longitudinal axis of the neck portion indicated by reference numeral 54 while still enabling the mould tool responsible for producing the neck portion 12 to open and close in a direction parallel to the longitudinal axis 54 and without requiring mould tool components to open and close in a 15 direction transverse to that axis. Another advantage of using locking members 40 which, in their initial position, are directed upwardly and radially outwardly from the cylindrical wall 22 but which may be folded or hinged so as to engage or otherwise hug the 20 cylindrical wall is that it allows the first cylindrical wall 22 to be formed with a reduced wall thickness compared to other parts of the neck portion 12. This has a direct saving on the amount of plastics material necessary to mould the fitment 10 and translates into an important reduction in 25 the cost of manufacture. Although it might be thought that reducing the wall thickness of the first cylindrical wall 22 might compromise the operation of the fitment 10, the fact that, in the assembled condition, the locking members 40 are pressed up against the first cylindrical wall 22 means that, 30 in use, the effective thickness of the lower neck portion at the point where it engages with the radially inwardly projecting bead 86 is comparable to other regions of the WO 2008/155552 PCT/GB2008/002103 - 25 neck portion 12 and more than capable of fulfilling its function. Another advantage of using locking members 40 that can flex from an initial, as-moulded, position to an operable, 5 in-use, position is that they may serve to eliminate any vertical float of the cap portion 14 with respect to the neck portion 12. This is because the cap portion 14 may be fully retained by the interengagement between the end surfaces 46 of the locking members 40 and the radially 10 inwardly projecting bead 86. The natural resilience of the locking members 40 which tends to urge them to return to their as-moulded position and so causes the upper surface 48 adjacent the end surface 46 to be urged into evermore pressing engagement with the inner surface 68 of the 15 depending annular sidewall 66 also helps to prevent the cap portion 14 from becoming loose during transit between the point of manufacture and the point of final application of the fitment 10 to a carton. Another advantage of the described closure assembly is 20 that the primary seal between the annular plug 74 and the cylindrical surface 30 is located a small but non-zero distance 102 from the inner surface of the second cylindrical wall 26. Typically, this distance 102 may be between 0.1mm and 5mm. In a preferred embodiment this 25 distance 102 is between 1.8mm and 2.1mm. This spacing between the position of the primary seal and the inner surface of the second cylindrical wall 26 has the advantage of allowing the ingress of cleaning solutions of the type used during rinsing processes. This configuration also has 30 the advantage of allowing light to penetrate to all surfaces of the neck portion 12 for the purpose of hygiene treatment WO 2008/155552 PCT/GB2008/002103 - 26 and so allows the fitment 10 to be used in aseptic packaging applications. In addition, the natural hoop strength of the downwardly and radially inwardly directed annular rim 28 5 serves to strengthen the neck structure and prevents the second cylindrical wall 26 from collapsing radially inwards. This added strength may be utilised to permit further decreases in wall thickness thereby enabling further savings in manufacturing costs in terms of the quantity of plastics 10 material needed to mould the closure system. The fact that the annular rim 28 is directed downwardly and radially inwardly provides the advantage that any product left on the rim after dispensing will tend to drain back through the dispensing orifice defined by the bore 32 15 rather than draining down the outside of the neck portion 12 and onto the treads 36. Although the present invention has been described in relation to a fitment for attachment to a carton, it will be appreciated by those skilled in the art that the invention 20 is not so limited and that the closure assembly may be formed integrally with a container if so desired.