GB2185244A

GB2185244A - Pilfer-proof ring

Info

Publication number: GB2185244A
Application number: GB08600505A
Authority: GB
Inventors: Thomas Duncan Brownbill
Original assignee: ROBERT MOSS PLC
Current assignee: ROBERT MOSS PLC
Priority date: 1986-01-09
Filing date: 1986-01-09
Publication date: 1987-07-15
Also published as: GB8600505D0; GB2185244B

Abstract

A pilfer-proof ring for use with a threaded container closure comprises an upper portion 25 having means 29 for engagement with the closure skirt, a lower portion 40 connected to said upper portion by a plurality of frangible nibs 33, dog elements 30,46 for the transmission of rotational torque between said upper and lower portions, and engagement means 42 on the lower portion for engaging with a cooperating portion on the container. On application to a closure, the means 29 is engaged with the closure skirt. When the closure is applied to the container, the upper ring is urged axially towards the lower, while rotational movement brings the dogs on the upper portion into torque transmitting engagement with those on the lower portion, thus urging the lower portion into engagement with the cooperating means on the container without breaking the frangible nibs. <IMAGE>

Description

SPECIFICATION Improvements in and relating to pilfer-proof rings The present invention relates to pilfer-proof rings and has particular reference to a pilferproof ring for use with a closure for a container comprising a substantially disc like crown having a cylindrical depending skirt therefrom and provided with a screw thread on the internal surface of the skirt.Such closures are well known for application to screw threaded containers; containers adapted to receive such closures are usually provided with a neck portion having a cooperating screw thread on the external surface thereof and an annular band below the screw thread adapted to receive or engage with a retaining portion of the pilfer-proof ring so that on removal of the closure, the lower portion of the pilferproof ring is retained by the said band while the upper part is separated therefrom by the action of unscrewing the closure thus indicating sampling of the contents.

Existing pilfer-proof rings and their associated closures suffer from the disadvantage that they need to be a relatively loose fit over the threads and the band in order to preclude damage to the frangible portion during application to a container.

Hitherto this has provided a problem in the application of a closure plus ring to a container since the closure has to be applied to the container by axial pressure alone thus causing the screw threaded portion of the closure to ride over the screw threads on the container neck until the threads themselves "snap" into position thereby retaining the closure on the container. In some circumstances, unless the relative rotational position of the closure with respect to the container is accurate, adequate sealing between any wad juxtaposed the underside of the crown of the closure and the rim of the container may well not be effected.

There is a need, therefore, for a pilfer-proof ring which i) provides a clear indication of whether or not the contents of the container have been pilfered, ii) can be applied to the container by the normal screw action of applying the closure to the container thus ensuring a more adequate seal for the contents of the container, and iii) the separatable components will clearly separate to indicate that the container has been opened since the application of the closure during manufacture.

According to the present invention, there is provided a pilfer-proof ring for use with a container closure which ring comprises, an upper ring portion having means for engaging with the skirt of a closure with which it is to be employed, a lower ring portion connected to said upper ring portion by means of a plurality of frangible nibs, dog elements provided on each of the upper and lower ring portions whereby dog elements on the upper portion are adapted to engage dog elements on the lower portion for the transmission of rotational torque between said upper and said lower portion, engagement means provided on the lower portion for engaging with a cooperating portion on the container to which the pilfer-proof ring may be applied, the arrangement being such that on application to a closure, the means for engaging provided on the upper portion is engaged with the skirt thereof and such that when the closure is applied to a container by the application of axial pressure and rotation thereof to engage the thread of closure with that of the container, the upper ring is urged axially towards the lower, while the rotational movement thereof brings the dogs on the upper portion into torque transmitting engagement with those on the lower portion, thus urging the lower portion into engagement with the cooperating portion on the container without breaking the frangible nibs.

On removal, unscrewing of the closure will withdraw the upper ring portion, while the lower ring portion is retained by means of its interengagement with the cooperating portion on the container neck thus resulting in breaking of the frangible nibs, thus indicating that the contents of the container have been sampled.

The engaging means on the upper ring portion may be an annular barb adapted to engage with a cooperating annular recess in the inner surface of the closure skirt; said annular recess may be disposed between the screw thread and the lower extremity of the skirt.

The lower portion may have a peripheral projection adapted to engage the underside of the skirt of the closure during application of the closure to a container.

The frangible nibs are tapered towards one of said upper or lower ring portions to form a break line which ruptures on removal of the closure from the container. The nibs may be flexible to allow limited rotational movement between the upper ring portion and the lower ring portion without breakage of the nibs. The nibs may extend between the part annular surface of each dog element and the juxtaposed ring portion, and may be flexible to allow axial movement of one ring portion relative to another to bring the part annular surface of each dog element into abutment with the adjacent ring.

The dog elements on the upper ring portion may depend therefrom and align in the arc, containing said upper ring portion. The dog elements on the lower ring portion may upstand therefrom and lie in the arc of the dog elements of the upper ring portion, the arrangement being such that rotation of one of the ring portions will bring the edges of a dog element on an upper ring portion into abutment with the adjacent edge of a dog element on the lower ring portion, thus resulting in torque transmission, one with respect to the other.

The dog elements themselves serve to limit the relative rotation between the upper ring portion and the lower ring portion, they also serve to limit the relative compression or axial compression between the upper ring portion and the lower ring portion, thus preserving the integrity of the frangible nibs during application of the closure incorporating the pilfer-proofing assembly to a container to which it is to be employed.

The invention includes a closure incorporating a pilfer-proof ring in accordance with the invention, the invention further includes a container having an upstanding screw threaded neck, engaging means juxtaposed the screw threads on said neck adapted to engage said upper ring portion of the pilfer-proof ring. The invention further includes a container having a closure and pilfer-proof ring in accordance with the invention closing the dispensing opening thereof. A compressible wad may be provided in the underside of the crown of the closure to prevent the contents of the container contacting the material from which the closure is formed.

Typically, the closure may be formed of a polypropylene copolymer and the ring may be formed of a low density polyethylene.

Following is a description by way of example only and with reference to the accompanying informal drawings of a method of carrying the invention into effect.

In the drawings: Figure 1 is a part section through a closure incorporating a pilfer-proof ring in accordance with the present invention.

Figure 2 is a part section through the pilferproof ring shown in Figure 1.

Figure 3 is a side view on arrow A of Figure 2.

Turning first to Figure 1, the closure 10 has a circular crown portion 11 having a generally depending cylindrical skirt 12 extending downwardly from the periphery of crown 11. The junction of the upper surface of the crown 11 and the skirt 12 is provided with external chamfer portion 13. The external surface 14 of the skirt is provided with a plurality of axially disposed circumferentially spaced ribs 15 to define a knurlled surface to the outer portion of the skirt to aid gripping and manipulation during application and removal of the closure to a container.

The internal surface of the skirt is provided with an annular recess 16 juxtaposed crown 11 adapted to receive a sealing wad for the closure (not shown). The internal surface 17 of skirt 12 is provided with a screw thread 18 adapted to cooperate with a similar thread provided on a neck of a container to which the closure is intended to be applied. The internal surface of the skirt downwardly of the thread is cut away to provide a generally annular rebate 19, the upper portion of which is defined by an upwardly tapering frustoconical wall 20, and the lower portion of which defines a barb-like recess 21. The annular rebate 19 is defined by a lower extension 22 of the skirt and is substantially cylindrical on its internal surface 23.

The pilfer-proof ring comprises a circumferential upper ring 25 having a substantially cylindrical internal surface 26 and a frustoconical outer surface 27 adapted to engage with and abut the corresponding frustoconical wall 20 in the lower part of the skirt 12 of closure 10.

The underside 28 of the ring 25 has an annular surface which together with frustoconical surface 27 defines a barb portion 29 which is adapted to engage with barb-like recess 21 provided on the internal surface 17 of the skirt.

The underside 28 is provided with a plurality of depending dog elements 30, each of which lies within an arc containing the upper ring portion 25 the inner surface of each dog element being continuous with the internal surface. Each depending dog element has a pair of side surfaces 31 and an arcuate lower surface 32. Lower surface 32 carries a nib element 33, the side walls 34 of which taper to provide an area of cross-section of the nib at a minimum at the end thereof remote from the dog element 30 to which the nib 33 is attached. Each depending dog element 30 contains at least one depending nib 33 which is formed integral with it and with an annular lower ring portion 40.

Lower ring portion 40 is substantially concentric with upper ring 25 and has an internal surface 41 which is substantially co-cylindrical with internal surface 26 of upper ring 25. Internal surface 41 is provided towards its lower end with an inward annular projection 42 adapted to engage under a cooperating band on the neck of a container or alternatively, within a recess appropriately provided thereon.

The lower ring 40 has a radial extent such that the external surface thereof 43 is substantially co-cylindrical with external surface 44 of the lower extension 22 of skirt 12, the arrangement being such that with the pilferproof ring in position on the closure 10, the upper surface 45 is spaced from the undersurface 24 defining the lower extremity of skirt 12.

Upper surface 45 carries a plurality of arcuate upwardly extending dog elements 46 arcuately disposed about lower ring 40 such that the internal surface 47 of dog element 46 is substantially continuous with internal surface 41 of lower ring 40. Each dog element carries on its upper surface at least one nib 33 having side walls 44 tapering towards the adjacent upper ring 25, so that the junction between the narrow cross-section of nib 33 and the undersurface 28 of upper ring 25 constitutes the break or sacrilege point.

The spacing between the upper surface 48 of dog element 46 is substantially identical to the spacing between the under surface 32 of dog element 30 and the upper surface 45 of the lower ring.

In operation, the pilfer-proof ring is inserted into the closure with the upper ring portion entering over the internal surface 23 of lower skirt extension 22 so that the barb portion 29 of the upper ring engages with the barb-like recess 21 to retain the upper ring in position on the closure. On application of the closure to the container, the pilfer-proof ring carried by the skirt of the closure 10 is entered over the neck of the container and axial pressure is applied to the closure to urge the thread 18 on the internal surface 17 of skirt 12 of closure 10 to commence engagement with the cooperating thread on the containers.At the same time, the inward annular projection on the lower ring portion engages and binds against the thread/external surface of the container neck with a result that the upper ring portion 25 is urged axially towards lower ring portion 40 so that the spacing between the undersurface 24 of skirt 12 and the upper surface 45 of lower ring 40 are brought into abutment thus limiting the extent of the compression. At the same time the lower surface 32 of each of dogs 30 is brought into substantial abutment with upper surface 45 of lower ring 40 and similarly upper surface 48 of dog 46 carried by the lower ring 40 is brought into substantial abutment with the undersurface 28 of upper ring 25.To accommodate this compressive movement, the nibs 33 flex to allow this compressive movement, but do not break and the compressive movement is limited by the abutment of the remote surfaces of each dog against the adjacent ring surface on the one hand and by the abutment of the lower extremity 24 of skirt 12 against the upper surface 45 of lower ring 40 on the other.

To engage the screw thread between the closure and the neck of the container, a rotary motion is applied so that the screw thread draws the closure onto the neck of the container until the rim thereof engages and seals against the wad carried in the crown of the closure as described above. The internal diameter of the cylindrical surface of the upper ring 25 is selected to be an interference fit with the external surface of the container to which the closure is applied, thus serving to provide some resistance to screwing action on the one hand, but at the same time maintaining a positive interlock between the barb portion 29 of upper ring 25 and a barb-like recess 21 on the internal surface of the skirt.

Thus, rotation of the closure produces a rotary torque within the upper ring itself by virtue of the contact and interengagement between the frustoconical wall 20 on the internal surface of the skirt and a frustoconical outer surface 27 of the upper ring 25. This results in relative rotational movement of the upper ring and the dogs 30 carried thereby until a side wall 31 of the upper dogs 30 engage with an adjacent side wall of a lower dog 46 to provide torque transmitting engagement between the upper and lower rings.The nibs 33 which are still under compression as a result of the continued axial movement of the closure relative to the neck of the container and the relative resistance of the lower ring in sliding axially therealong, means that each of nibs 33 is flexed and is thus able to accommodate the limited rotational movement of the upper ring with respect to the lower without rupture or the nibs. The rotational movement is continued until the lower ring is urged to a position where the inward projection 42 engages under the retaining band on the neck of the container while at the same time the wad juxtaposed the crown enters into sealing engagement with the rim of the container neck.

In this applied configuration, the container is now closed in tamper-proof manner. Any attempt to remove the closure by unscrewing the closure will result in the upper ring portion 25 being withdrawn with the closure by virtue of the interengagement between the barb portion 29 and the barb-like recess 21 on the internal surface of the skirt while the lower ring is retained about the retention band on the neck of the container due to the interengagement of the projection 42 with the underside thereof. Continued unscrewing of the closure results in upward movement and rotational movement of upper dogs 30 with respect to lower dogs 46 while at the same time producing rupture of each nib 33 along its line of minimum cross-section at the junction with the adjacent ring.Continued withdrawal results in axial withdrawal of dog 30 from the gap between adjacent lower dogs 46 with a result that the closure can now be removed from the container. The lower ring is retained about the neck of the container and lies loosely thereabout so that on reapplication of the closure, it is quite clear that the nibs 33 have been broken and that access to the contents of the container has either been gained or at least attempted.

An additional feature of the pilfer-proof closure assembly in accordance with the present invention is that because of the interference fit of the internal surface 26 of upper ring 25 with the external surface of the container resistance to unscrewing is greater than in a normal closure with a result that the still cap tive upper ring portion retained by the closure acts as an anti-back off facility for the closure which precludes accidental unscrewing by vibration or other means.

The pilfer-proof rings and closure assemblies in accordance with the present invention and as specifically described above provide for a pilfer-proof ring which can be applied by the normal screw-on action of a closure and thus avoid the forced fitting of the threads of the closure over the threads on a bottle as heretofore provided. Furthermore, compressive movement of the upper ring to the lower does not result in rupture of the nibs as with prior art rings, since the spacing between the surfaces of the upper and lower dogs to their adjacent rings permits only limited compressive movement before the dogs abut the adjacent ring, thus precluding any further compression. Similarly, rotational movement is permitted since relative rotation between the upper and lower rings is again precluded by the interference between upper and lower dogs, thus precluding unrestricted rotational movement in a manner such that results in rupture of the nibs.

Claims

1. A pilfer-proof ring for use with a container closure which ring comprises, an upper ring portion having means for engagement with the skirt of a closure with which it is to be employed, a lower ring portion connected to said upper ring portion by means of a plurality of frangible nibs, dog elements provided on each of the upper and lower ring portions whereby dog elements on the upper portion are adapted to engage dog elements on the lower portion for the transmission of rotational torque between said upper and said lower portions, engagement means provided on the lower portion for engaging with a cooperating portion on the container to which the pilfer-proof ring may be applied, the arrangement being such that on application to a closure, the means for engaging provided on the upper portion is engaged with the skirt thereof and such that when the closure is applied to a container by the application of axial pressure and rotation thereof to engage the thread of closure with that of the container, the upper ring is urged axially towards the lower, while the rotational movement thereof brings the dogs on the upper portion into torque transmitting engagement with those on the lower portion, thus urging the lower portion into engagement with the cooperating means on the container without breaking the frangible nibs.

2. A ring as claimed in claim 1 wherein the engaging means on the upper ring portion is an annular barb adapted to engage with a cooperating annular recess in the inner surface of the closure skirt.

3. A ring as claimed in claim 2 wherein the annular recess is disposed between the screw thread and the lower extremity of the skirt.

4. A ring as claimed in any preceding claim wherein the lower ring portion has a peripheral projection adapted to engage the underside of the skirt of the closure during application of the closure to the container.

5. A ring as claimed in any preceding claim wherein the frangible nibs are tapered towards one of the said upper or lower ring portions to form a break line which ruptures on removal of the closure associated therewith from the container.

6. A ring as claimed in any preceding claim wherein the frangible nibs are flexible to allow limited rotational movement between the upper ring portion and the lower ring portion without breakage of the nibs.

7. A ring as claimed in any preceding claim wherein the frangible nibs extend between the part annular surface of each dog element and the juxtaposed ring portion, and are suffici ently flexible to allow axial and rotational movement of one ring portion relative to another to bring the annular surface of each dog element into abutment with the adjacent ring.

8. A ring as claimed in any preceding claim wherein the dog elements on the upper ring may depend therefrom and are aligned in an arc, containing said upper ring portion.

9. A ring as claimed in any preceding claim wherein the dog elements on the lower ring portion upstand therefrom and lie in the arc of the dog elements of the upper ring portion, the arrangement being such that rotation of one of the ring portions will bring an edge of a dog element on an upper ring portion into abutment with an adjacent edge of a dog element on the lower ring portion, thus resulting in torque transmission, one with respect to the other.

10. A ring as claimed in any preceding claim wherein the dog elements serve to limit the relative rotation between the upper ring portion and the lower ring portion, and serve to limit the axial compression between the upper ring portion and the lower ring portion, thereby preserving the integrity of the frangible nibs during application of the closure incorporating the pilfer-proofing assembly to a container to which it is to be employed.

11. A closure incorporating a pilfer-proof ring as claimed in any preceding claim and engaging means juxtaposed screw threads on the internal surface of the skirt thereof adapted to engage with the upper ring portion of said pilfer-proof ring.

12. A closure as claimed in claim 11 wherein a compressible wad is provided in the underside of the crown of the closure to prevent the contents of the container from contacting the material from which the closure is formed.

13. A closure as claimed in claim 11 or claim 12 having a substantially circular crown portion and a generally depending skirt extending downwardly from the periphery of the crown.

14. A closure as claimed in any one of claims 11 to 13 wherein the junction of the upper surface of the crown and the skirt is provided externally with a chamfered portion.

15. A closure as claimed in any one of claims 11 to 14 wherein the external surface of the skirt is provided with a plurality of axially disposed circumferentially spaced ribs to define a knurled surface to the outer portion of the skirt to aid gripping and manipulation during application and removal of the closure.

16. A closure as claimed in any one of claims 11 to 15 wherein the internal surface of the skirt is provided with an annular recess juxtaposed the crown thereof and adapted to receive a sealing wad for the closure.

17. A closure as claimed in any one of claims 11 to 16 wherein the internal surface of skirt is provided with a screw thread adapted to cooperate with a similar thread provided on a neck of a container to which the closure is intended to be applied.

18. A closure as claimed in any one of claims 11 to 17 wherein the internal surface of the skirt downwardly of the thread is cut away to provide a generally annular rebate, the upper portion of which is defined by an upwardly tapering frustoconical wall, and the lower portion of which defines a barb-like recess.

19. A closure as claimed in claim 18 wherein the annular rebate is defined by a lower extension of the skirt and is substantially cylindrical on its internal surface.

20. A closure as claimed in any one of claims 11 to 19 carrying a pilfer-proof ring which comprises a circumferential upper ring having a substantially cylindrical internal surface and a frustoconical outer surface adapted to engage with and abut the corresponding frustoconical wall in the lower part of the skirt thereof.

21. A closure as claimed in claim 20 wherein the underside of the ring has an annular surface which together with said frustoconical surface defines a barb like portion which is adapted to engage with barb-like recess provided on the internal surface of said skirt.

22. A closure as claimed in claim 20 or 21 wherein the underside of said ring is provided with a plurality of depending dog elements, each of which lies within an arc containing said upper ring portion, the inner surface of each dog element being continuous with the said internal surface.

23. A closure as claimed in claim 22 wherein each depending dog element has a pair of side surfaces and an arcuate lower surface.

24. A closure as claimed in claim 23 wherein said lower surface carries a nib element, the side walls of which taper to provide an area of cross-section of the nib at a minimum at the end thereof remote from the dog element to which the nib is attached.

25. A closure as claimed in claim 24 wherein each depending dog element contains at least one depending nib which is formed integral with it and with said annular lower ring portion.

26. A closure as claimed in any one of claims 11 to 25 wherein the lower ring portion is substantially concentric with said upper ring and has an internal surface which is substantially co-cylindrical with the internal surface of said upper ring.

27. A closure as claimed in claim 26 wherein said internal surface is provided towards its lower end with an inward annular projection adapted to engage under a cooperating band on the neck of a container.

28. A closure as claimed in claim 27 wherein the inward annular projection is adapted to engage within a recess provided on the neck of a container.

29. A closure claimed in any one of claims 11 to 28 wherein the lower ring has a radial extent such that the external surface thereof is substantially co-cylindrical with external surface of the lower extension of the skirt of the closure, the arrangement being such that with the pilfer-proof ring in position on the closure, the upper surface of the lower ring is spaced from the undersurface of the skirt of the closure.

30. A closure as claimed in any one of claims 11 to 29 wherein the upper surface of the lower ring carries a plurality of arcuate, upwardly-extending, dog elements circumferentially spaced about the lower ring such that the internal surface of each dog element is substantially continuous with internal surface of said lower ring.

31. A closure as claimed in claim 30 wherein each dog element carries on its upper surface at least one nib having side walls tapering towards the adjacent upper ring, so that the junction between the narrow crosssection of said nib and the undersurface of the upper ring constitutes a break or sacrilege point thereof.

32. A closure as claimed in claim 30 or claim 3 1 wherein the spacing between the upper surface of each dog element is substantially identical to the spacing between the under surface of dog element carried by the upper ring and the upper surface of the lower ring.

33. A closure as claimed in claim 11 and substantially as herein described with reference to and as illustrated in the accompanying drawings.

34. A pilfer-proof ring as claimed in claim 1 and substantially as herein described with ref erence to and as illustrated in the accompanying drawings.

35. A container having a neck configured to receive a closure and pilfer-proof ring assembly, in combination with the closure and/or pilfer-proof ring assembly claimed in any preceding claim.