GB2136782A

GB2136782A - Pilferproof closure

Info

Publication number: GB2136782A
Application number: GB08407186A
Authority: GB
Inventors: James Frederick Herbert; Fred Brooke-Smith
Original assignee: Metal Closures Ltd
Current assignee: Arconic Closure Systems International UK Ltd
Priority date: 1983-03-22
Filing date: 1984-03-20
Publication date: 1984-09-26
Also published as: GB2136782B; GB8407186D0

Abstract

A pilferproof closure made from malleable metal having a top and a depending skirt has a circumferentially extending slit 13 interrupted by frangible bridges 14 to form a retaining band 15 below the slit. The retaining band has cut on its inner surface a circumferentially extending score line 16 and/or a set of axial score lines 17 extending from the free edge of band towards the slit for making it more difficult to tamper with the closure without leaving visible sign of the tampering. <IMAGE>

Description

SPECIFICATION Improvements relating to pilfer-proof closures This invention relates to closures and more particularly to closures of the pilfer-proof type which are made from a malleable metal such as aluminium or aluminium alloy and which incorporate a slit extending circu mferentially of the skirt of the closure, the slit being interrrupted by frangible bridges at angularly spaced intervals about the lengthwise axis of the closure. The part of the skirt below the skit is known as the security band. On application of the closure to the screwlthreaded neck of a container such as a bottle, a part of the skirt above the level of the circumferential slit is rolled into conformity with the screw-thread on the bottle and the security band is substantially fixed against axial movement towards the top of the bottle.Such fixing is commonly achieved by deforming the free edge portion of the band under the bottom edge of a peripheral shoulder moulded on the external suface of the neck or by deforming an axially intermediate part of the band into contact with at least the upper edge portion of a peripheral groove moulded in the external surface of the neck. When the closure is unscrewed the bridges are fractured and the security band is left on the bottle, whence it may subsequently be removed.

However such closures have been found to have been tampered with by using a spatula or a similar bladed tool to prise the said parts of the security band away from the surface of the bottle suficiently far to enable the closure to be unscrewed without fracturing the bridges, the closure subsequently being carefully re-applied so that there is no obvious sign that the closure has been tampered with.

According to the invention in one aspect there is provided a closure for application to the screwthreaded neck of a container, comprising a top and a peripheral skirt depending from the top, a slit extending circumferentially of the skirt and interrupted at angularly spaced intervals by frangible bridges, and a circumferentially extending score line cut on the radially-inner surface of the skirt at a location axially intermediate the slit and the free edge of the skirt.

According to the invention in another aspect there is provided a closure for application to the screwthreaded neck of a container, comprising a top and a peripheral skirt depending from the top, a slit extending circumferentially of the skirt and interrupted at angualrly spaced intervals by frangible bridges, a plurality of axially-extending score lines cut on the radially inner surface of the skirt and extending from the free edge of the skirt towards said slit and a circumferentially extending score line cut on the radially-inner surface of the skirt at a location axially intermediate the slit and the free edge of the skirt In still another aspect the invention provides a closure for application to the screw-threaded neck of a container, comprising a top and a peripheral skirt depending from the top, a slit circumferentially of the skirt and interrupted at angularly spaced intervals by frangible bridges, and a plurality of axiallyextending score lines cut on the radially inner surface of the skirt and extending from the free edge of the skirt towards said slit.

Where the axial score lines are provided, it is preferred that there should be at least six such lines equiangularly spaced about the lengthwise axis of the closure.

Where the axial and circumferential score lines are provided in combination, the axial score lines may either intersect or stop short of the circumferential score lines.

Where, as is usual, a closure is designed to fit a particular container neck form, the circumferential score line will prefereably be positioned so as, when applied to the container, to be located at a point of stress concentration where the scurity band is deformed inward under the upper wall portion of a peripheral groove or the lower edge of a peripheral shoulder on the container.

Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is an underneath perspective view of a first closure according to the invention prior to application to a container.

Figure 2 is a local sectional elevation on the line 2-2 of Figure 4, Figure 3 is a local sectional elevation on the line 3-3 of Figure 4.

Figure 4 is a fragmentary plan view on the line 4-4 of Figure 2, Figure 5 is a local sectional view elevation showing the closure of Figures 1 to 5 applied to the neck of a bottle, Figure 6 isa perspective view from underneath of an applied second closure according to the invention, Figure 7 is a local sectional elevation of the closure of Figure 6, Figures 8 and 9 are respectively fragmentary sectional plan views on the lines 8-8 and 9-9 respectively of Figure 7, and Figure 70 is a local sectional view showing the closure of Figure 6 applied to the neck of a bottle.

Referring to first to Figures 1 to 5, the closure shown is made from a malleable metal alloy and comprises a tap 10 and a depending skirt 11. A wadding gasket 12 is located against the underside of the top. Spaced above the free bottom edge of the skirt is a circumferential slit 13 interrupted by say ten or twelve frangible bridges 14 so thatthe bottom portion of the skirt forms a security band 15 in the well-known manner. A circumferentially extending score line 16 is cut on the radially-onner surface of the band at a location spcaed above the bottom edge of the band, and six or more axial score lines 17 are cut to extend along the radially inner surface of the band from the free edge of the band to the score line 16.

The score line 16 is so positioned that when the closure is hown applied to the bottle as shown in Figures, a screw-thread 18 having been formed on the upper portions of the skirt in the well-known manner the score line 16 is disposed at the location of a sharp inward bend formed on the bottle where the bottom edge portion 19 of the security band is deformed inwardly under a peripheral shoulder 20 in the neck of the Bottle. The score line 16 is thus disposed at a location of high stress concentration resulting from the said deformation.

Any attempt to prise the portion 19 away from the shoulder is likely to result in tearing along one or more of the score lines 17, but if the attempt is successful the straightening and the necessary subsequent reforming of the band at the location of the score line 16 results in the occurrence of a fracture at the line 16 which thus reveals the tampering.

Figures 6 to 10 show an application of the invention to another form of pilfer-proof closure which is made from malleable metal alloy and in which the security band is much deeper than in the construction of Figures 1 to 5 and is secured against axial movement towards the mouth of the bottle by being bent inward at the location of the sharp upper edge of a peripheral groove 21 in the external surface of the neck, so that the security band portion is deformed into engagement with at least the upper wall portion 22 of groove 21. Again the security band has a circumferential score line 16 and six or more evenly spaced axial extending score lines 17 cut in its radially inner surface and may extend halfway through the thickness of the metal. In this instance, the score lines 17 stop short of the score line 16 but extend from the bottom edge of the band into the groove in the neck.

The ideal number of score lines 17 on a 31 mm closure is thought to be six, but the number will vary with the size of the closure. Thus it is thought that the score lines should be in the range 10 to 25mm apart and preferably in the range 15 to 20mm apart.

The prising of the security band outward away from the neck strains the metal adjoining the side edges of the tool and if a score line is adjacent either or both side edges of the tool the chances of tearing the metal at the location of one or other of the score lines are increased because there is then only a narrow band of unweakened metal between a score line 17 and the side edge of the tool to share in absorbing the strain. However, if the axial score lines are too close together, tampering with the security band may result in the score lines bending open, enabling the closure to be re-applied without leaving evidence of tampering.

Even if the attempt to circumvent the proper operation of the score lines 17 is successful, the person tampering with the closure still has to contend with the score line 16, which operates in the same way as described in Figure 5 to show evidence of the attempted tampering.

In alternative constructions, a circumferential score line 16 alone is provided, positioned as to be at a point of stress concentration as described above.

In other alternative constructions the circumferential score line 16 is omitted and only the axial score lines 17 are provided.

It will be understood that the invention is applicable to all forms of metal closures where a pilferproof band is provided, and that the shape and form of the closure above the band is immaterial.

Claims

1. A closure for application to the screwthreaded neck of a container, comprising a top and a peripheral skirt depending from the top, a slit extending circumferentially of the skirt and interrupted at angularly spaced intervals by frangible bridges and a circumferentially extending score line cut on the radialy-inner surface of the skirt at a location axially intermediate the slit and the free edge of the skirt.

2. A closure for application to the screwthreaded neck of a container, comprising a top and peripheral skirt depending from the top, a slit extending circumferentially of the skirt and interrupted at angularly spaced intervals by frangible bridges, and a plurality of axially-extending score lines cut on the radially inner surface of the skirt and extending from the free edge skirt of towards said slit.

3. A closure for application to the screwthreaded neck of a container, comprising a top and a peripheral skirt depending from the top, a slit extending circumferentially of the skirt and interrupted at angularly spaced intervals by frangible bridges, a plurality of axially-extending score lines cut on the radially inner surface of the skirt and extending from the free edge of the skirt towards said slit and a circumferentially extending score line cut on the radially-inner surface of the skirt at a location axially intermediate the slit and the free edge of the skirt.

4. A closure as claimed in claim 2 or claim 3, wherein the said axially extending score lines number at least six and are equiangularly spaced about the lengthwise axis of the closure.

5. A closure as claimed in claim 3 or claim 4 when appendantto claim 3, wherein the axial score lines stop short of the circumferential score line.

6. A closure as claimed in any one of claims 2 to 5, wherein the axial score lines are 15mm to 20mm apart.

7. In combination, a container having a screwthread on its neck and, below the thread a surface facing generally in the opposite direction to the mouth of the container and extending about the neck, and a closure made from malleable metal engaged on said thread, said closure having a top and a peripheral skirt depending from the top, a slit extending circumferentially of the skirt at a level below the screw-thread, which slit is interrupted at angularly spaced intervals by frangible bridges, and a circumferentially extending score line cut on the radially inner surface of the skirt at a location between the slit and the free edge of the skirt at or adjacent which location a sharp inward bend is formed in the skirt to cause the skirt to lie against said surface of the container.

8. The combination claimed in claim 7 wherein the skirt has formed on its inner surface a plurality of axial score lines extending from the free edge of the skirt towards said circumferentially-extending score line.

9. In combination, a container having a screwthread on its neck and, below the thread a surface facing generally in the opposite direction to the mouth of the container and extending about the neck, and a closure made from malleable metal engaged on said thread, said closure having a top and a peripheral skirt depending from the top, a slit extending circumferentially of the skirt at a level below the screw-thread, which slit is interrupted at angularly spaced intervals by frangible bridges, a portion of the skirt below the slit being formed inward to lie against said surface, and the skirt having on its inner surface a plurality of axial score lines extending from the free edge of the skirt towards said circumferentially-extending score line

10. A closure for application to the screwthreaded neck of a container, which closure is substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 or in Figures 6 to 9 of the accompanying drawings.

11. The combination, with a container having a screw-threaded neck, of a closure substantially as hereinbefore described with reference to and as illustrated in Figure 5 or in Figure 10 of the accompanying drawings.