This invention is concerned with containers and in particular containers with closure systems of the kind which are commonly called "tamper evident" or "pilfer proof". Tamper evident or pilfer proof closures for containers are known in which a strip or band is provided around a closure member of the container, and has to be removed before the closure member can be removed to give access to the contents of the container. Thus the presence of the undisturbed band is evidence that the container has not previously been opened. Examples of such closures are to be found in EP 0148168 and EP 0280488.

According to a first aspect of the present invention there is provided a container having a tamper evident closure, wherein the tamper evident means comprises a removable band which circumferentially embraces an area of cooperation between the container closure member and the container which must be radially expanded in order to remove the closure member from the container.

The said band prevents the radial expansion of the said area, which cannot therefore take place until the band is removed. Preferably, the container, the closure member, and the removable band are all moulded from plastics material. However, it would be possible for either the container or the closure member to be formed of a more rigid material such as glass or metal, so long as one or other of them is so formed as to permit the said radial expansion.

In a preferred arrangement, at the said area of cooperation between the closure member and the container, the closure member and the container

are formed with respective annular shoulders which interengage to prevent axial separating movement of such parts in the absence of said radial expansion. The closure member may comprise a cap which engages over the mouth of the container, with the band embracing the cap. Alternatively the closure ^• member may comprise a plug which fits in the mouth of the container, with the band embracing the container mouth. In a preferred embodiment the band is held against axial displacement between two external annular shoulders on the container, and the closure member respectively. In such an arrangement, the band may be such that its outer circumferential surface is flush with the outer circumference surfaces of the said shoulders.

The scope of the invention also extends to a closure member alone, for use in the assembly already described. Thus viewed from a second aspect the invention provides e closure member for use in an assembly according to the first aspect of the invention, which closure member is a cap for engagement over a mouth of the container of the assembly, the said cap being moulded from plastics material with a ring of the plastics material for providing the said band extending around and axially away from the edge of the cap and joined thereto by at least one frangible portion, a part of the cap adjacent the said ring having an external circumferenti surface arranged to receive the said ring teleεcopically thereon and the said part of the cap being formed internally with means for cooperating with the container mouth in such manner that the said part of the cap must be radially expanded in order to remove it from the container.

The scope of the invention further extends to a container alone, for use in the assembly already described. Thus viewed from a third aspect the

invention provides a container for use in an assembly according to the first aspect of the invention, which container has a mouth for receiving a closure member of the assembly in the form of a plug, the container being moulded from plastics material with a ring of the plastics material for providing the said band extending around and axially away from the edge of the container mouth and joined thereto by at least one frangible portion, a part of the container mouth adjacent the said ring having an external circumferential surface arranged to receive the said ring telescopically thereon and the said part of the container mouth being formed internally with means for cooperating with a said closure plug in such manner that the said mouth must be radially expanded in order to remove the closure plug from the container.

The frangible portion(s) attaching the plastics ring to the closure member or container may be of substantially less thickness than the ring. The present invention also provides improved methods of making a closure member and a container. Thus viewed from another aspect the invention provides a method of making a closure member for an assembly according to the first aspect of the invention, which closure member is a cap for engagement over a mouth of the container of the assembly, comprising moulding the said cap from plastics material with a ring of the plastics material for providing the said band extending around and axially away from the edge of the cap and joined thereto by at least one frangible portion, a part of the cap adjacent the said ring having an external circumfer¬ ential surface arranged to receive the said ring telescopically thereon and the said part of the cap being formed internally with means for cooperating with the container mouth in such manner that the said part of the cap must be radially expanded

in order to remove it from the container, detaching the said ring of plastics material from the cap by way of the said frangible portion(s) so as to form the said band and, simultaneously with said detachment, engaging the said band telescopically over the said external circumferential surface of the cap.

Viewed from yet another aspect the invention provides a method of making a container for an assembly according to the first -aspect of the invention, which container has a mouth which is adapted to receive therein a plug constituting the said closure member of the assembly, comprising moulding the said container from plastics material with a ring of the plastics material for providing the said band extending around and axially away from the edge of the mouth of the container and joined thereto by at least one frangible portion, a part of the container mouth adjacent the said ring having an external circumferential surface arranged to receive the said ring telescopically thereon and the said part of the mouth being formed internally with means for cooperating with the closure plug in such manner that the said part of the mouth must be radially expanded in order to remove the closure plug therefrom, detaching the said ring of plastics material from the container mouth by way of the said frangible portion(s) so as to form the said band and, simultaneously with said detachment, engaging the said band telescopically over the said external circumferential surface of the container mouth.

The said ring may be broken from the closure member or the container at the end of the moulding operation, before removal from the mould. Alternatively, the ring may be left joined to the closure member or container on removal from the mould and then broken therefrom and moved to engage the said external

circumferential surface during the operation of assembling the closure member and the container, or at some intermediate time between the moulding and such assembly. The following is a description, by way of example only, of an embodiment of a closure member and container in accordance with the invention, reference being made to the accompanying drawings, in which: Figure 1 is a cross-sectional view of part of the closure member as moulde , and

Figure 2 is a cross-sectional view of part of the closure member fastened to a container body. The closure member and the container are moulded from flexible plastics material such as is conventionally used in the container-manufacturing industry.

The closure member comprises a cap having a cylindrical side wall 10 and a recessed top 11. The wall 10 has an outwardly-extending annular flange 12 and an internal annular protrusion 13 with an upper face 14 forming an annular shoulder which extends inwardly at a more acute angle than its lower face 15 extends in an outwards direction. As shown in Figure 1, moulded integrally with the closure member and depending from the wall 10 ^hereof is an annular strip or band 16, which has an internal diameter slightly greater than the external diameter of the wall 10, so as to be capable of being telescopically engaged thereon. The strip 16 is, as moulded, attached to the wall 10 by a thin, frangible, portion 17.

Figure 2 shows the position of the closure cap and the band 16 when the closure is fastened to a container. The container mouth has a side wall 18 with an upwardly-extending rim 19, the upper part 20 of which is accommodated in an annular recess 21 in the cap. The rim 19 has an external

configuration which corresponds partly to the internal configuration of the wall 10 of the cap. In particular, the rim 19 has an external recess 22 with an upper face 23 forming an annular shoulder which is inclined at a similar angle to the shoulder 14 of the protrusion 13 on the cap. The rim 19 has an outer face 24 which tapers inwardly above the face 23. It also has an external peripheral flange 25 beneath the recess 22. As a result of the configurations of the inside of the cap and the outside of the container mouth, the cap can be pressed on to the mouth of the container and retained thereon by the interengagement of the shoulders 14 and 23. The band 16, now detached from the cap and engaged telescopically on the external circumferential surface of the wall 10 of the cap, is located between flanges 12 and 25 and positively prevents removal of the cap from the container, by preventing the radial expansion of the wall 10 of the cap which is necessary to achieve such removal until the band itself is removed. Specifically, as can be seen in Figure 2, the band 16 prevents the shoulder 14 from moving past the shoulder 23 until the band is removed.

Although not shown in the drawings, it is possible to provide an annular lip extending upwardly from the circumference of flange 25 to overlie the lower part of the band 16. This provides a further degree of tamper prevention, in that it helps to prevent the insertion of an object, such as a knife, between the band 16 and the flange 25 with a view to forcibly prising off the cap. Thus the band 16 provides tamper evident means whose presence in an undisturbed condition provides evidence that the container has not previously been opened. The band 16 is provided with release means for breaking it, which may be of any suitable kind, so that the band can be peeled off the cap to enable the cap to be removed from the container. The

release means may for example comprise an easily breakable portion of the band, or separable connecting means.

The band 16 may be moved into its position surrounding the cap wall when the cap is being removed from the mould, or it may be moved into such position when the cap is being pressed into position on the container mouth, or at some intermediate time between moulding and pressing on to the container. Once the band is removed, then the cap may be easily removed from the container. As the cap is pulled upwardly, the protrusion 13 is expanded by the interaction of the shoulders 14 and 23 until the shoulders disengage from one another, at which point the cap may be simply lifted off.

It will be appreciated that while the above embodiment describes the band 16 being formed on the closure member, it could equally well be provided on the container mouth, with the closure member than being in the form of a plug fitting in the container mouth.

It is to be clearly understood that there are no particular features of the foregoing specification, or of any claims appended hereto, which are at present regarded as being essential to the performance of the present invention, and that any one or more of such features or combinations thereof may therefore be included in, added to, omitted from or deleted from any of such claims if and when amended during the prosecution of this application or in the filing or prosecution of any divisional application based thereon. Furthermore the manner in which any of such features of the specification or claims are described or defined may be amended, broadened or otherwise modified in any manner which falls within the knowledge of a person skilled in the relevant at, for example so as to encompass, either implicitly or explicitly, equivalents or generalisations thereof.