NZ208039A - Tamper proof closure cap designed to facilitate easy removal from its forming mould - Google Patents

Description

2 08039 Priority Date(s): ... .V.... A ... .....

Complete Specification Filed: .c^.'.4 7^/f. CI=S=: . li'iWl987 Publication Date: P.O. Journal, No: .

Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION "TAMPER PROOF CLOSURE CAP" ^"7WE SUN COAST PLASTICS, INC. a corporation organised under the laws of Florida, U.S.A. of 2202 Industrial Boulevard, Sarasota, Florida 33580, U.S.A. hereby declare the invention, for which -I-/we pray that a patent may be granted to -ae^us, and the method by which it is to be performed, to be particularly described in and by the following statement (followed by page TA.) *039 la A TAMPER PROOF CLOSURE CAP AND A MOULD FOR MAKING SAME This invention relates to a tamper proof closure cap and a mould for making same. Such caps are sometimes referred to as tamper-evident type caps. More, particularly, embodiments of the invention relate to a 5 closure cap moulded from plastics material, which cap includes an integral skirt, this skirt being designed to serve a tamper proof function. Embodiments also provide a moulding tool which is designed to facilitate formation of a cap with an integral tamper proof skirt. This 10 moulding tool includes a mechanism for removing the cap from the mould simply, quickly and effectively without damage to the tamper proof skirt. 508039 * Tamper proof closure caps for containers are known in the art, and are increasingly in demand for a wide variety of applications.

A recurring problem in the production of tamper proof closure caps is the difficulty in making such a device 10 sufficiently strong that it can be removed from a mould intact, and remain intact during handling, shipment, and application to a container, yet sufficiently weakened where the tamper proof skirt portion is attached to the cap itself that the skirt will tear away from the cap 15 whenever the cap is removed from its container. This difficulty has led to a wide variety of cap.designs, has led to a variety of techniques for applying the caps to the container so as to compensate for design flaws dictated by manufacturing considerations, and has led to 20 the design of complex mould configurations. These difficulties have adversely affected the cost of manufacturing such caps, particularly when they are made of plastic or other synthetic materials. Thus, the prior art discloses caps which must be cut 2nd heated after 25 the moulding step. The cutting is necessary to produce a weakened area between the cap and a depending security ring, and the heating is necessary to deform the security. ring onto the container being capped. Other pater v. / 2 08039 3. disclose closure caps wherein the lower security ring is connected to the upper cap portion in such a way that the inside diameter of the security ring is equal to the outside diameter of the cap. This is done to facilitate the removal of the device from the mould, 5 but serves to increase the size of the mould and further requires a deforming step after the cap is placed on a container to insure that the security ring engages the container. Other patents disclose a closure cap which is designed with an annular v-shaped groove which provides 10 a weakened area for allowing the security ring to break away from the cap. However, the moulding of such a cap requires a tool having complex cams and angle pins which increase the complexity and thus the cost of the mould. All of these factors adversely affect the cost 15 of manufacturing and applying closure caps with tamper proof rings, or skirts.

Because manufacturing techniques impose restrictions on the shape of a cap, it would be desirable to provide a 20 tamper proof closure cap design which is more cost effective from a manufacturing standpoint. This would involve a cap design which would be easy to apply to a container and would be effective to provide evidence of cap removal while at the same time would permit a tool 25 design which would be relatively simple and inexpensive, yet would permit reliable manufacture of the cap. It would further be desirable to provide a closure cap 2083 A designed for easy application to a container so as to avoid the heat shrinking methods which have been used in the prior art. Preferably, such a cap would merely be pressed onto the container or threaded on and the tamper proof skirt portion would "snap over" a corresponding bead on the container finish without damaging the cap. This has not been possible with prior cap designs, since the expansion of the skirt portion necessary to allow it to fit over a finish bead would either fracture the skirt or cause it to stretch and thus require heating to return it to its initial size, it would, therefore, be desirable to have a tamper proof closure cap having the capability of fitting over a finish bead to provide the desired security but not the need for additional steps and without the danger of fracture.

As a result of Patent Office searches, the present Specification applicants have become aware of British Patent/No. 2022063 A (PLASTIVIT S.A.) The Plastivit reference discloses a closure cap for containers, comprising an outer closure shell having a transverse top wall and an annular side wall depending from the perimeter of said transverse top wall and integrally formed therewith and defining a top open end thereof, an inner sealing member on the transverse top wall of the outer closure shell and a skirt portion connected to the open end of the outer closure shell forming thereby an extension of said annular side wall, said skirt portion defining a first annular abutment surface, said outer closure shell defining serve as mould-engaging surfaces during removal of the / annular abutment surface, said first and second abutment surfaces being 208039 closure cap from its forming mould, said skirt portion having a plurality of ribs and a security ring portion, said ribs connecting said security ring portion to said outer closure shell.

Whist Plastivit recognises the advantages of designing a closure cap which can be formed in a mould without requiring the mould to have transversely movable elements, the resultant closure cap exhibits a configuration which is open to improvement in at least 10 three respects. Firstly improvements can be made in terms of release from the mould; secondly in terms of flexure of an internal bead when the cap is placed over a bead or retaining flange on a container? and thirdly the users of closure caps prefer a configuration which 15 lends itself to a substantially uniform outer conf igurat ion.

The Plastivit reference also discloses amould for forming a closure cap having a closure shell and an integrally formed tamper proof security ring secured 20 thereto by frangible ribs, comprising upper and lower mould portions co-operating in a closed position to define a closure cap cavity, a movable core ring mounted on said lower mould portion and adapted to engage the inner surface of a closure cap formed in said 25 cavity, and an annular stripper ring including an inner part adapted to engage the outer surface of a closure cap formed in said cavity, said inner part having a first substantially transverse 30 surface portion defining a first stripper ring shoulder, and said inner part also having a second s'ubstantially transverse surface portion, defining a second shipper ring shoulder, said first and second st.riRE^r ring shoulders being adapted to engage correspjonc| ®f6bVr:. 35 and second annular abutment surfaces on sajjld ^security \ ;v. - 5 208039 ring and closure shell, of a closure cap formed in said closure cavity, said stripper ring being operable to remove simultaneously said closure shell and said security ring from the movable core ring.

This mould can be enhanced in order to obtain the improvements in the moulded closure cap above-mentioned. According to one aspect of the present invention a closure cap as defined above is characterised in that said skirt portion defines first and second inwardly tapered surfaces intersecting said first and second annular abutment surfaces, said first and second annular abutment surfaces extending transversely outwardly from said first and second inwardly tapered surfaces, and said skirt portion further includes an inwardly curved exterior surface which extends between and intersects said first annular abutment surface and said second inwardly tapered surface.

In terms of the closure cap configuration, this closure cap exhibits the characteristic of enhanced release from the mould during the stripping operation without fracture of the ribs linking the security ring portion to the closure shell. The particular configuration of the first a.nd second inwardly tapered exterior surfaces and the inwardly curved exterior surface result in a configuration which assists the operation of the stripping ring and which subsequently assists the release of the closure cap from the stripping ring. In contrast Plastivit has substantially axially directed surfaces intersecting the abutment surfaces.

In an embodiment the closure cap is a unitary article moulded from plastics material, the outer closure member being substantially rigid and the sealing member--being formed integrally therewith.

In another embodiment the sealing member is & fr separately in a "two-shot" process and attached 20803y otherwise integral cap, i.e. the outer closure member and skirt being unitary and formed in the same moulding operat ion.

The skirt portion is frangible at the ribs which define 5 a weakened region. Once the closure cap is applied to a container it cannot be removed without fracture of the ribs and leaving behind the security portion as evidence of opening.

In preferred embodiments of the closure cap said ribs 10 define the second inward tapered surface. As abovementioned this tapered surface enhances release of the cap. It also contributes to the flexure of the security ring portion when the closure cap is placed on a container.

In preferred embodiments said security ring portion has an outer, annular peripheral surface itself having a diameter substantially equal to a major portion of an outer, peripheral surface of said outer closure shell, said peripheral surface being of substantially uniform 20 diameter. This feature of the closure cap resu Jts in a closure cap more attractive to users. For maketing purposes, it is desirable that the closure cap exhibits a substantially uniform external diameter over both the closure shell and the security ring portion. This 25 enables the user readily to apply a decorating finish, for example by applying a foil outer. This configuration also enhances the undercut configuration of the first and second abutment surfaces, which are inwardly directed relative to the outer envelope of the 30 closure shell. In contrast, the Plastivit security ring lies well within such an envelope.

In an embodiment an upper edge of said security ring is spaced below a lowermost radial surface of the outer closure shell.

This feature enhances the capability the s^purity TV if 2080S9 ring portion to flex when the closure cap is placed on a container, especially a container having a retaining flange or bead.

In the preferred embodiments the skirt portion further 5 includes an inwardly facing annular bead in which at least one expansion groove is formed, said bead being located below said first abutment surface.

This feature enables the closure cap to be secured on a container without damage to the annular bead or the 10 ribs, whilst maintaining the integrity of the security ring.

In the preferred embodiments an interface betveen inner surfaces of said ribs and the outer closure shell intersects an interface between the lowermost surface 15 and an inner, annular surface of said closure shell, and wherein the inner surfaces of said ribs are inwardly tapered surfaces, and said security ring portion has an inner, annular surface of greater diameter than the diameter of the inner, annular surface of said outer 20 closure shell, whereby said security ring portion is spaced outwardly of said inner, annular surface of said outer closure shell, this configuration assisting the flexing of the annular bead over a retaining shoulder on a container when the closure is applied to the container 25 without resulting fracture of said ribs.

This feature contrasts sharply with the Plastivit closure which exhibits a security ring having a major portion of its outer configuration axially aligned with the inner periphery of the closure cap. The closure cap 30 herein enhances the capacity of the security skirt, and in particular the bead thereon, to flex when placed upon a closure having a retaining flange or bead.

According to a second aspect of the present invention there is provided a mould for forming a closure cap 35 characterised in that said first and ^^oond^^trippW h Ik T ring shoulders are both directed outwardly with respect to the axis of said stripper ring, and wherein said inner part further defines a first inwardly directed surface portion which surface portion intersects said shoulder, and wherein said inner part further defines a second inwardly directed surface portion which surface portion intersects said first inwardly directed surface portion and said first stripper ring at their respective outermost edges, and wherein said inner part further defines an additional inwardly directed surface portion which surface portion intersects said second .tripper ring shoulder at its innermost edge, and wherein in said mould cavity said first inwardly directed surface portion of said mould part forms an inwardly curved exterior surface of said closure cap, said second inwardly directed surface portion of said mould part forms an inwardly tapered surface of the ribs of said closure cap, said first and second shoulders form first and second annular abutment surfaces of said closure cap, and said additional surface portion forms an inwardly tapered exterior surface of said closure cap, the configuration of said first and second inwardly directed portions and said first and second shoulders and said additional surface portion enhancing the release of a moulded closure from said mould cavity. The advantages which accrue from the use of this mould relate both to the stripping operation and to the parting of the closure cap from the stripper ring as explained above in relation to the closure cap. In a preferred embodiment the mould is configured such that in a moulding operation in said mould cavity said second inwardly directed surface of ' * ' part forms outer surfaces of said 208039 cap such that said rib outer surfaces define said second inwardly tapered surface of said closure cap.

This mould feature enhances the release of the closure cap.

In a preferred embodiment of the mould, said mould cavity and said movable core ring are configured such that a closure moulded therein is provided with a security ring portion having an outer, annular peripheral surface itself having a diameter 10 substantially equal to a major portion of an outer, peripheral surface of an outer closure member of said closure shell, and said mould cavity is configured such that said peripheral surfaces are of substantially uniform diameter.

This mould feature relates both to an improved interrelationship between the mould and closure cap in terms of stripping and release, and also to an advantageous closure cap configuration which exhibits a substantially uniform outer envelope.

In a preferred embodiment of the mould, said core ring and inner part of said stripper ring are so configured that a closure formed in said mould cavity has an upper edge of .said security ring spaced below a lower most radial surface of the outer closure shell. As stated in 25 relation to the closure cap, this feature enhances the ability of the security ring portion to flex during application of the closure cap to a container. In a preferred embodiment of the mould, wherein said core ring is configured to form said skirt 30 portion of said closure cap with an inwardly extending annular bead having at least one expansion groove and with said bead located below said first abutment surface.

This feature likewise enhances the of .tie resulting moulded closure cap to j'Jg.e secures on f a • f£ollowed My page 10a) / " r ° ^ 208039 ** - io. - container without damage to the annular bead or the ribs whilst maintaining the integrity of the security ring. In a preferred embodiment of the mould, said core ring is configured to form a closure cap in said cavity which closure cap has an interface between inner surfaces of said ribs and the outer closure shell which intersects an interface between the lower most surface and an inner, annular surface of said closure shell, and wherein said core ring is so configured to form said closure cap such that inner surfaces of said ribs are inwardly tapered surfaces, and said security ring portion has an inner, annular surface of greater diameter that the diameter of the inner, annular surface of said outer closure shell, whereby said security ring portion is spaced outwardly of said inner, annular surface of said outer closure shell.

This feature of the mould results in a mould closure cap having a configuration which assists the flexing of the annular bead over a retaining shoulder on a container when the closure is applied to the container.

Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a partial view in cross-section of a closure cap which incorporates the tamper proof feature according to the present invention; Figures 2-6 schematically illustrate in cross-section the mould and the closure cap, as well as the sequence steps for ejecting the closure cap from the mould; I^\ ici^ife 7 is a partial, enlarged, cross-sectional view of TOstripper ring illustrated in Figures 2-6. (followed by page 10b) • I 208039 »* 10b Description of a Preferred Embodiment Turning now to a more detailed consideration of the present invention, there is illustrated in Figure 1 a closure cap 10 having a longitudinal axis A-A. The cap includes an outer closure shell 12 comprising an annular side wall 14 and a transverse top 16. The annular side wall 14 may include serrations 18 on its exterior surface an a conventional thread 20 on its interior surface. 11.

An annular sealing member 22 is formed as part of the closure member and preferably is similar to that shown in U.S. Patent No. 4,143,785. Alternatively, the sealing member 22 can be constructed in accordance with the 5 two-shot design shown in U.S. Patent No. 4,308,965. Connected to and formed as a continuation of the side wall 14 is a tamper proof skirt 24 which is formed unitarily with the cap, but which is separable therefrom. The tamper proof skirt 24 comprises an annular security 10 ring portion 26 having a weakened region generally indicated at 27, the weakened region being provided by, and thus defined by a series of spaced connection ribs 28, each of which extends between the ring portion 26 and the annular wall 14. The ribs 28 each taper 15 upwardly and inwardly toward the inner peripheral edge of a lower surface 30 forming the bottom of sidewall 14. The surface 30 is generally perpendicular to the axis A-A of the cap and defines a first transverse shoulder for the cap. Each rib is tapered to define a 20 narrowed region 32 at its connection, or interface, with the surface 30, which region on each of the ribs is designed to fracture when the cap is removed from a container on which it has been placed, thereby leaving the ring 26 on the container as evidence of tampering.

The ring portion 26 includes a bead 34 formed on its lower edge and extending inwardly. This bead is adapted to engage the lower edge of a corresponding bead formed 208<3&9 12. on the exterior finish of the container to which the cap is to be applied. The bead 34 inhibits removal of the ring portion 26 from the container, thereby causing the fracturing of the ribs 28.

The outer surface of the ring portion 26 is shaped to facilitate removal of the ring from the shaping tool, or mould, which is used in the manufacture of the cap. Accordingly, the ring 26 is defined by a lower surface 35 which is essentially concentric with the axis A-A and which extends from the bottom of skirt 24 to a location above the bead 34 and identified by the plane C illustrated in Figure 1. From this location, the exterior surface indicated at 36 tapers inwardly and upwardly, preferably at an angle of approximately 10° from the vertical. It should be noted that the exterior surfaces of the ribs 28, which were previously said to be tapered inwardly, also are tapered at approximately 10° from the vertical as indicated at 38.

The inwardly sloping surface 36 terminates at a transversely extending annular shoulder 40 which lies about midway between the plane C and the top edge of the skirt portion 24. Extending upwardly from the outer periphery of the shoulder 40 is the surface portion " which is arcuate and which extends upwardly and inw^flly to intersect the inner vertical surface 44 of the (frtng -v z - —.« «/ np 16DEC1986 13. jt Pe^ ^ portion 26. Surfaces 42 and 44 intersect top edge 45 of the security ring portion 26 at which location the ribs 28 join the ring 26. The lower edge 45, the spaced ribs 28, and the bottom surface 30 define a plurality of apertures 46 which extend around the circumference of the cap and which define the weakened region. Preferably, the arcuate surface 42 has a radius of about 0.125" for a typical cap structure, but this may vary with different sizes of caps.

The significance of these exterior surfaces of the ring portion will become more apparent from the following discussion of the moulding tool used to form the cap.

A tool or mould for making the cap 10 is illustrated in Figures 2-6 as including top and bottom halves 47 and 47' which co-operate to define a mould cavity in which the cap is formed. The top half of the mould 47 includes an upper cavity mould portion 48 which defines the exterior 20 configuration of a cap cavity 49. The interior portion of the cavity 49 is defined by the lower half ^7' of the mould which includes a lower support core 50, an annular movable core ring 52 coaxial with and mounted for limited motion along support core 50, and an axial centre pin 54 25 movable within support core 50. An exterior annular stripper ring 56 is mounted for axial motion outside and with respect to the support core 50, with the interior surface of the stripper ring 56 including a mould 20S039 portion 57 which co-operates with the top half 47 of i the mould to define a portion of the exterior surface of the cap 10. More particularly, the mould portion 57 of the stripper ring 56 defines the transverse shoulder portions 30 and 40 as well as the tapered surfaces 36 and 42, the ribs 28, and the apertures 46 during the moulding operation. Thus, the moulding region 57 of the stripper ring 56 shapes and defines the weakened region of the tamper proof ring.

The core 50 includes an upper surface 60 which defines and forms the inner surface of the top of cap 10, and further includes a lower annular support shoulder 62 (Fig. 2) which receives the bottom edge of the core ring 52 to position that ring during the moulding operation so that its top is flush with the top of core 50.

Accordingly, the top of the core ring 52 defines a part of the interior surface of the top of cap 10, including grooves 64 which define the sealing portion 22. The core ring 52 also defines on its outer peripheral surface the shape of the interior surface of wall 14, and includes grooves 66 for forming the thread 20, and also includes a groove 68 for forming the bead 34.

The unique co-operation between the stripper ring 56 and the remainder of the mould for releasing the cap 10 without damaging the tamper proof skirt 24 is illustrated in Figures 3-6. Figure 2 shows the mould portions 47 and m . 47' in the closed position, subsequent to the formation of the closure cap 10 by conventional injection of a suitable plastics material from an injection device (not shown) through an injection cavity 70 formed in the 5 upper portion 47 of the mould, and through a port 72 into cavity 49. After the cap is formed, the mould is opened by separating the upper and lower portions 47 and 47', as by moving the elements 50, 52, 54 and 56, together with cap 10, downwardly in the direction of 10 arrow A (Fig. 3) and away from the upper mould portion 47. This withdraws the closure cap 10 from the cavity 49, the cap being held secure on the downwardly moving element, as shown in Fig. 3- The downward movement continues until a sufficient clearance is achieved 15 relative to the upper cavity mould 48 to permit removal .

I of the closure cap 10 from the lower mould elements in j i I the manner to be described.

Once a sufficient clearance is achieved, the cap is i stripped from the lower mould portion 47' by moving the j stripper ring 56 and the centre pin 54 upwardly with respect to the support core 50 in the direction . indicated by the arrows B in Fig. 4. This motion carries the cap and the annular core ring 52 upwardly 25 on the support core 50. As illustrated in Fig. 4, the support core 50 includes a central support post which surrounds and guides the centre pin 54 and which includes and enlarged head portion 74 which defines a lower | ! ! j i transversely extending shoulder 76. The movable core ring 52 slideably engages the enlarged portion 74 and includes at its lower end an inwardly extending shoulder portion 78 which extends inwardly below the enlarged 5 portion of the support core 50 so that the opposed shoulders 76 and 78 act as a motion-limiting stop for the core ring 52. Thus, the upward motion of the stripper ring 56 and the centre pin 54 carries the core ring 52 upwardly until the shoulder 78 engages the opposed 10 shoulder 76 to stop the upward motion of the core ring.

At this time, the security ring portion 26 of the skirt 24 has moved upwardly with respect to the core 50 sufficiently far to be free of the core.

After the core ring 52 stops, the centre pin 54 and the stripper ring 56 continue to move upwardly with respect to the centre core 50 and with respect to the now-stopped core ring 52. This continued motion of the stripper ring 56 and the centre pin 54 removes the finished cap 10 20 from the movable core ring. The engagement of the j 1 stripper ring 56 with the shoulders 30 and 40 formed on j L the exterior of the cap enables the stripper ring to j i force the cap upwardly to disengage the threads 20 from j ! the corresponding grooves 56 and to disengage the bead 25 34 from its corresponding groove 68 in the core ring 52.

Ordinarily, such a removal operation would be expected to cause serious damage to the security ring, for the % I. 17 £08039 narrow ribs 32 in the weakened region between the cap side wall and the security ring' will often fracture during such a removal operation, resulting in an unacceptable level of rejects. However, the stripper 5 ring 56 engages not only the bottom of the cap by means of shoulder 30, but also engages the security ring by means of shoulder *10, so that the upward motion of the stripper ring not only forces the cap up and off of the core ring 52, but also applies an upward force to the 10 security ring portion 26, thereby preventing longitudinal stress in the ribs 28, Furthermore, the engagement of the stripper ring 56 with the exterior surfaces of the skirt 24 above the region of the bead 34 permits the bead to flex outwardly (in a direction indicated by the arrow 15 D in Fig. *0 sufficiently to clear the core ring 52 while at the same time preventing the weakened portion of the skirt 24 above the surface area 36 from flexing outwardly and being stressed. The moulding region 57 of the stripper ring 56 engages the surfaces 36 and 42 20 as well as the shoulder 40, the ribs 28 and the shoulder 30 to prevent these areas, which are reduced in thickness and therefore comprise the weakened region of the skirt, from flexing outwardly during the cap stripping. Thus, the pivot point for the lower bead portion of the 25 security ring is effectively shifted down from the area of the ribs 28 to the area of the plane C (Fig. 1).

MM 18. 30803$ Movement of the bead 3^ out of its corresponding groove 68 during the stripping operation is facilitated by the provision of a plurality of vertically extending slots 80. These slots allow the bead to expand in a radial 5 direction and thus to more easily pass over the core ring 52. These slots serve, in addition, to facilitate the application of the closure to a container, enabling the security ring to expand radially during application of the container as the bead 3^ passes over a corres-10 ponding bead on the container finish.

Once the cap 10 has been moved upwardly by the stripper ring 56 and by the centre pin 5^ in the manner described above, the stripper ring 56 is stopped and the cap 10 is 15 separated therefrom by further upward movement of the centre pin 5^ in the direction indicated by the arrow E in Fig. 6. Only a slight flexing of the skirt 2H inwardly, in the direction of the arrows F in Fig. 5, is needed for this purpose, and this movement is facil-20 itated by the taper of the surfaces 36 and 38 and the curvature of the surface 42.

The unique stripper ring 56 and the corresponding mating surfaces on the cap 10 co-operate to consistently produce 25 a cap with its tamper proof skirt portion intact, thereby eliminating the loss of cap production due to damage caused during removal from the forming mould. As 19' Si 0803$ illustrated in Fig, 7, the stripper ring 56 includes a top surface 82 which is adapted to engage and to form the surface 30 of the cap side wall 14. In addition, the stripper ring includes an interior surface 84 which 5 is shaped to form and thus to engage the surfaces 36, 40, 42 and 38 of the skirt 24. Thus the stripper ring includes mating surfaces 85, 86, 88 and 90, respectively. In addition, the inner surface of the stripper ring carries a plurality of blocks 92 which extend inwardly 10 to engage the exterior surface of the movable core ring 52 when the mould is in its closed position so as to form the apertures 46 between the ribs 28, illustrated in Fig. 1.

Thus there has been described a new and unique closure cap for containers as well as a novel mould arrangement and method for stripping the cap therefrom.

Claims (14)

208039 20 - WHAT KK CLAIM IS:

1. A closure cap for containers, comprising an outer closure shell having a transverse top wall and an annular side wall depending from the perimeter of said transverse top wall and integrally formed therewith and defining a top open end thereof, an inner sealing member on the transverse top wall of the outer closure shell and a skirt portion connected to the open end of the outer closure shell forming thereby an extension of said annular side wall, said skirt portion defining a first annular abutment surface , said outer closure shell defining a second annular abutment surface, said first and second abutment surfaces being adapted to serve as mould-engaging surfaces during removal of the closure cap from its forming mould, said skirt portion having a plurality of ribs and a security ring portion , said ribs connecting said security ring portion to said outer closure shell, characterized in that said skirt portion defines first and second inwardly tapered surfaces intersecting said first and second annular abutment surfaces , said first and second annular abutment surfaces extending transversely outwardly from said first and second inwardly tapered surfaces, and said skirt portion further includes an inwardly curved exterior surface which extends between and intersects said first annular abutment surface and said second inwardly tapered surface,

2. A closure cao as claimed in Claim 1, where"-iii{ fe^fd,; //% ribs define said second inwardly taperec^ surface, =0SO5"=).

3. A closure cap as claimed in either Claim 1 or Claim 2, wherein said security ring portion has an outer, annular peripheral surface itself having a diameter 5 substantially equal to a major portion of an outer, peripheral surface of said outer closure shell, said peripheral surfaces being of substantially uniform diameter.

4. A closure cap as claimed in any one of Claims 1 to 3, wherein an upper edge of said security ring is spaced below a lowermost radial surface of the outer closure shell.

5. A closure cap as claimed in any one of Claims 1 to 4, wherein said skirt portion further includes an inwardly facing annular bead in which at least one expansion groove is formed, said bead being 5 located below said first abutment surface.

6. A closure cap as claimed in Claim 5, wherein an interface between inner surfaces of said ribs and the outer closure shell intersects an interface between the lowermost surface and an inner, annular 5 surface of said closure shell, and wherein the inner surfaces of said ribs are inwardly tapered surfaces, and said security ring portion has an inner, annular surface of greater diameter than the diameter of the inner, annular surface of said outer 10 closure shell , whereby said security ring portion is spaced outwardly of said inner, annular surface of said outer closure shell , this configuration assisting the flexing of the annular bead over a retaining shoulder on a container when the closure is 15 applied to the container without resulting fracture of said ribs

7. A mould for forming a closure cap having a closure shell and an integrally'. fdtfeeSk tamper «? ■•y 208039 22 proof security ring secured thereto by frangible ribs , comprising upper and lower mould portions 5 co-operating in a closed position to define a closure cap cavity , a movable core ring mounted on said lower mould portion and adapted to engage the inner surface of a closure cap formed in said cavity. 10 and an annular stripper ring including an inner part adapted to engage the outer surface of a closure cap formed in said cavity, said inner part having a first substantially transverse surface portion defining a first 15 stripper ring shoulder, and said inner part also having a second substantially transverse surface portion defining a second stripper ring shoulder, said first and second stripper ring shoulders being adapted to engage corresponding first and second annular 20 abutment surfaces on said security ring and closure shell , of a closure cap formed in said closure cavity ,said stripper ring being operable to remove simultaneously said closure shell and said security ring from the movable core 25 ring , characterised in that said first and second stripper ring shoulders are both directed outwardly with respect to the axis of said stripper ring, and wherein said inner part further defines a first inwardly directed surface portion which surface 30 portion intersects said shoulder , and wherein said inner part further defines a second inwardly directed surface portion which surface portion intersects said first inwardly directed surface portion and said first stripper ring shoulder at their 35 respective outermost edges, and whe.rein said inner part further defines an additional' inwardly directed surface portion which// ^itface portion vy .. . .. V- ■■■■■■.:-, , 208039 40 - 23 - intersects said second stripper ring shoulder at its innermost edge, 40 and wherein in said mould cavity said first inwardly directed surface portion of said mould part forms an inwardly curved exterior surface of said closure caps, said second inwardly directed surface portion of 45 said mould part forms an inwardly tapered surface of said closure cap, said first and second shoulders form first and second annular abutment surfaces of said closure cap, 50 and said additional surface portion forms an inwardly tapered exterior surface of said closure cap, the configuration of said first and second inwardly directed portions and said first and second 55 shoulders and said additional surface portion enhancing the release of a moulded closure cap from said mould cavity.

8. A mould as claimed in Claim 7, wherein in a moulding operation in said mould cavity said second inwardly directed surface of said stripper ring part forms outer surfaces of said ribs of said 5 closure cap such that said rib outer surfaces define said second inwardly tapered surface of said closure cap.

9. A mould as claimed in either Claim 7 or Claim 8, wherein said mould cavity and said movable core ring , are configured such that a closure cap moulded therein is provided with a security ring portion 5 having an outer, annular peripheral surface itself having a diameter substantially equal to a major portion of an outer, peripheral surface , of closure member of said closure shell, </and saia-* 06DECI986 Vs 808039 '•l*-'\ - 24 - mould cavity is configured such that said 10 peripheral surfaces are of substantially uniform diameter.

10. A mould as claimed in any one of Claims 7 to 9, wherein said core ring and inner part of said stripper ring are so configured that a closure cap formed in said mould cavity has an upper edge 5 of said security ring spaced below a lower most radial surface of the outer closure shell.

11. A mould as claimed in any one of claims 7 to 10, wherein said core ring is configured to form said skirt portion of said closure with an inwardly extending annular bead having at least one 5 expansion groove and with said bead located below said first abutment surface.

12. A mould as claimed in any one of Claims 7 to 11, wherein said core ring is configured to form a closure cap in said cavity which closure cap has an interface between inner surfaces of said 5 ribs and the outer closure shell which intersects an interface between the lower most surface and an inner, annular surface of said closure shell, and wherein said core ring is so configured to form 10 said closure cap such that inner surfaces of said ribs are inwardly tapered surfaces, and said security ring portion has an inner, annular surface of greater diameter that the diameter of the inner, v annular surface of said outer closure shell 3 3 NOV sa*d security ring portion is spaced outwardly of said inner, annular surface of said outer -IT' 1 "osure shell. - 25 - 808039

13. A closure cap for containers arranged, constructed and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.

14. A mould for forming a closure cap arranged, constructed and adapted to operate substantially as hereinbefore described with reference to any one of the drawings.