GB2184102A

GB2184102A - Tamper-indicating closure

Info

Publication number: GB2184102A
Application number: GB08626295A
Authority: GB
Inventors: Geoffrey Alan Ryder
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1986-11-04
Filing date: 1986-11-04
Publication date: 1987-06-17
Also published as: GB8626295D0; DE8708658U1; FR2597074A3; DE3720588A1; FR2597074B3; FR2605984A1

Description

1 GB2184102A 1

SPECIFICATION

Sealed container-closure combination This invention relates particularly to a sealed screw-top container and more generally to a sealed combination comprising a container and a closure in which after the seal has been broken, the closure can be disengaged from or re-engaged with the container by movements of the closure relative to the container.

Containers of this type have many uses. For example, do-it-yourself shops sell small screwtop containers containing sample quantities of paint. Such containers usually have a small brush integral with the screw- top so that customers can easily sample the paint. However it has been found that some customers feel free to sample the paint in the shop by sur- reptitiously opening the container and painting the shop fittings. One object of this invention is to reduce this problem by providing a sealed combination of a container and a closure in which the sealing means is both simple and easily broken by a customer but which nevertheless requires a deliberate and positive act to break the seal and which is conspicuous when broken.

Accordingly, this invention provides a sealed combination comprising a container and a closure in which after the seal has been broken, the closure can be disengaged from or reengaged with the container by movement of the closure relative to the container wherein the closure comprises an obstructing means (for example, means comprising an inwardly projecting lug) which extends only a part way round the outer perimeter of the closure which obstructs a portion of the container (for example, an outwardly projecting lug) so as to prevent a relative movement of the container and closure which would lead to disengagement of the closure from the container and wherein the obstructing means is joined to the remainder of the closure by at least two breakable joins disposed one either side of the obstructing means and which can be broken by hand (possibly with the aid of a readily available tool such as a coin or a car key) whereby manually breaking the join allows movement of the obstructing means to clear the obstruction of the obstructed bortion of the container and so permit disengagement of the closure from the container. The need to break a part of the closure discourages most customers from surreptitiously opening the combination or performing other types of pilfering. This is especially so because the obstructing means extends only part way round the outer perimeter of the closure which means that the break creates an assymetry which is more conspicuous than the symmetrical break which would be created by an obstructing means which extends all the way around the perimeter. Preferably the obstruct- ing means extends for 3 to 30% of the way round the outer perimeter. A further advantage of a sealed container-closure combination of this invention is that because the obstructing means extends only part way round the outer perimeter of the closure, it is possible to have a closure in which the shape of the outer perimeter does not need to follow the shape of inner perimeter which engages the con- tainer.

Preferably the breakable joins comprise optionally perforated strips of thin (that is to say thinner than the adjacent portion of the closure) web which is thin enough to be easily broken by tearing or cracking. Typically the thickness of the web may be from 0.0 1 % to 50% of the thickness of the adjacent portion of the closure. Usually two strips, one either side of the obstructing means, will be used and these strips may be connected by a third strip above the obstructing means whereby the obstructing means is bounded on three sides by the strips. When the movement of the closure relative to the container involves a screw action, at least two of the strips should extend transversely of the screw-threads. Usually both at least a portion of the obstructing means and the obstructed means extend either inwardly or outwardly of the container and preferably the obstructing means and the obstructed portion of the container comprise inwardly and outwardly extending projections. Preferably the obstructed portion of the container may be shaped (for example curved or chamfered) to enable the closure complete with its obstruction means to be engaged on the container with a snap-action to produce the sealed combination. To achieve a good snap-action, the closure should be made from resilient material and for this reason when a closure employs a snap- action, it is preferred to make it (preferably by injection moulding) from a thermoplastics material such as a polyolefin (for example polypropylene or a high or low density polyethylene or a copolymer of ethylene and vinyl accetate or polystyrene), an acrylonitrite butadiene styrene copolymer, an ethylene- propylene rubber, a polyvinyl chloride, a nylon or a polyacetal. When the closure does not need to operate with a snap-action, it may be made from the above resilient materials or alternatively from more rigid materials, for example thermosetting resins such as urea-formaldehyde resins or thermoplastics containing fillers such as chalk, talc or wood flour. Filled thermoplastics are often brittle and so form easily breakable joins. The container is conveniently though not necessarily made from the same material as the closure.

By way of further illustration, a preferred embodiment of the invention will now be de scribed with reference to the drawings of which:

Figure 1 is a perspective view of a hollow closure complete with its obstructing means, 2 GB2184102A 2 Figure 2 is an alternative perspective view showing the inside of the hollow closure shown in Figure 1 Figure 3 is a perspective view of a container and Figure 4 is a plan view of the container shown in Figure 3 when closed by the closure of Figure 1 and which is shown in horizontal section taken on the line AA shown in Figure 1. The screw-thread on the container has 75 been omitted for clarity.

Figure 5 is an exploded perspective view of a combination of a container and a compound closure, Figure 6 is a horizontal section taken on the 80 line BB shown in Figure 5 except that all screw-threads have been omitted for clarity.

Figure 7 is a horizontal section taken on the line CC shown in Figure 5.

Figure 8 is a vertical section through the 85 cap on line DD shown in Figure 5.

Figure 1 shows a hollow closure 1 complete with a panel 2 which carries an inwardly ex tending obstructing lug 3 (shown in Figure 3) and which is joined to the remainder of closure 1 by manually, breakable strips of thin web 4 which extend either side of and above panel 2. A screw-thread 7a is provided inside closure 1 (see Figure 2) and screw- thread 7a 30 can co-operate with screw-thread 7b (see Fig- 95 ure 3) sci that closure 1 can be screwed onto container 5. Two of the strips of thin web (4) extend transversely of screw-threads 7a and 7b and are spaced apart such that panel 2 extends about 0. 07% of the way around the 100 horizontal outer perimeter of the lower portion of closure 1 as shown in Figure 4. It will be noted that this outer perimeter is square and so its shape does not follow the circular shape of the inner perimeter which engages 105 neck 6 of container 5.

Figure 3 shows a container 5 with a neck 6 provided with screw-thread 7b which is en gageable with the corresponding thread 7a provided inside closure 1. Neck 6 is also pro- 110 vided with an outwardly extending obstructa ble lug 8 provided with a curved chamfer 9.

Figure 4 shows a sealed combination in which closure 1 has been screwed clockwise onto neck 6 of container 5 so that obstructing 115 lug 3 travelled over chamfer 9 on lug 8 out wardly deforming the lower portion of closure 1 until lug 3 passed over lug 8 to return in wards with a snap-action to assume the posi tion shown in Figure 4. Lug 3 then prevents 120 anticlockwise unscrewing of closure 1 by ob structing lug 8. To clear the obstruction, a customer must insert a thumb nail, coin or sharp ended tool under panel 2 and then exert an outwards force to break web 4 so allowing 125 panel 2 and its obstructing lug 3 to move clear of obstructed lug 8. Closure 1 can then be disengaged from neck 6 of container 1 by clockwise unscrewing.

As an alternative to thin web 4, there may 130 be used a breakable join which comprises a line of perforations or a layer of easily breakable adhesive. Figures 1 to 4 illustrate a screw-top combination but the invention may also be applied to combinations in which the closure makes a push-fit onto the container. A tab may be provided on panel 2 to facilitate breaking of web 4 without using a tool.

Figures 5 to 8 illustrate an alternative embodiment of the invention which employs a compound closure comprising a handle portion 11 push- fitted onto a knurled cap 20. Compound closures avoid the need to mould an undercutting screw-thread inside a hollow handle portion and also enables the portion which engages the container to be made from a material (e.g. polyethylene) chosen for example for its solvent resistance whilst the handle portion is made from a material (e.g. polypropylene) chosen for example for its aesthetic appeal.

Figure 5 shows a container 15 having a neck 16 provided with a screwthread 17b and an outwardly extending obstructable lug 18. Figure 5 also shows circumferentially knurled cap 20 provided with internal screwthreads 17a as shown in Figure 8 which enable cap 20 to be screwed onto neck 16. Figure 5 further shows hollow handle portion 11 complete with panel 12 which carries an inwardly extending obstructing lug 13 and which is joined to the remainder of handle portion 11 by breakable strips of thin web 14. Handle portion 11 also has four diagonally inwardly extending ribs 10 so dimensioned as to make an interference push-fit with cap 20 as shown in Figure 7 when handle portion 11 is pushed onto cap 20.

To assemble a sealed combination, cap 20 is first screwed clockwise onto neck 16 and then handle portion 11 is push-fitted onto cap 20 in the orientation shown in Figure 7. This causes obstructing lug 13 to obstruct lug 18 and prevent the compound closure 11 and 20 from being removed from container 15 by anticlockwise unscrewing. The obstruction can be cleared by breaking ribs 14 and removing panel 12.

Knurls 21 on knurled cap 20 assist in locating ribs 10 against cap 20. In particular, knurls 21 resist the tendency for ribs 10 to be defledted to the left or right during pushfitting and so they promote the achievement of a firm interference push-fit which prbvents handle portion 11 and cap 20 from being separable by hand.

If it is felt that an interference push-fit is insufficient to prevent separation of handle portion 11 from cap 20, then handle portion 11 can be provided with positive means for preventing separation, for example an integral protrussion which snap-fits either under cap 20 or into a recess in cap 20.

This invention also provides a closure suitable for use in the combinations hereinbefore 51 o 1 1 v t 3 GB2184102A 3 described and in particular it provides such a closure provided with an integral paint applicator (usually a paint brush) so that customers can conveniently sample paint from the con5 tainer.

Claims

1. A sealed combination comprising a container (5) and a closure (1) in which after the seal has been broken, the closure (1) can be disengaged from or re- engaged with the container (5) by movement of the closure (1) relative to the container (5) wherein the closure (1) comprises an obstructing means (2) which extends only part way round the outer perimeter of closure (1) and which obstructs a portion (8) of the container (5) so as to prevent a relative movement of the container (5) and closure (1) which would lead to disen- gagement of the closure (1) from the container (5) and wherein the obstructing means (2) is joined to the remainder of the closure (1) by at least two breakable joins (4) disposed one either side of the obstruction means and which can be broken by hand whereby manually breaking the joins (4) allows movement of the obstructing means (2) to clear the obstruction of the portion (8) of the container (5) and so permit disengagement of the closure (1) from the container (5).

2. A combination as claimed in Claim 1 wherein the breakable join (4) comprise breakable strips of web which is thinner than the adjacent portion of the closure.

3. A combination as claimed in either Claim 1 or Claim 2 wherein the breakable strips (4) comprise one or more lines of perforations.

4. A combination as claimed in any one of Claims 1 to 3 wherein the relative movement of the container and closure involves a screw action guided by co- operating screw-threads on the container and on the closure and wherein the breakable joins extend transversely of the screw-threads.

5. A combination as claimed in any one of the preceding Claims wherein the shape of the outer perimeter of the closure (1 or 11) does not follow the shape of the inner perimeter which engages the container (5 or 15).

6. A combination as claimed in any one of the preceding claims wherein the closure (1) is made from a resilient material and the portion (8) of the container (1) which is obstructed is shaped so as to enable the closure (1) com- plete with is obstructing means (2) to be engaged onto the container (5) with a snap-action to produce the sealed combination.

7. A combination according to any one of Claims 1 to 6 wherein the closure is a com- pound closure (11 and 20) comprising a handle portion 11 on which is provided the obstructing means (12) and a cap (20) made from a material different to that from which the handle portion (11) is made.

8. A combination according to any one of Claims 1 to 6 wherein the closure is a compound closure (11 and 20) comprising a handle portion 11 on which is provided the obstructing means (12) and a cap (20) and wherein the handle portion (11) makes a push- fit onto the cap (20).

9. A combination according to Claim 8 wherein the cap (20) is circumferentially knu rled.

10. A closure (1 or 11 and 20) suitable for use in a combination comprising the closure and a container (5 or 15) as claimed in any one of the preceding claims wherein the clo sure comprises an obstructing means (2 or 12) for obstructing a portion (8 or 18) of the container and the obstructing means is joined to the remainder of the closure by a join (4 or 14) which can be broken by hand and which closure is as defined in any one of Claims 1 to 9.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd, Dd 899 1685, 1987. Published at The Patent Office, 25 Southampton Buildings, London, WC2A 'I AY, from which copies may be obtained.

1