NZ528117A - A container and closure - Google Patents

Abstract

A closure (2) for a container having a threaded neck around an opening into the container and one or more teeth (9) around the container below the threaded neck for threadingly engaging a closure on the container to close the container typically after filling the container. The closure comprises a complementary threaded interior and a ring (3) integral with the closure intended after opening of the container by removal of the closure to remain engaged on the neck below means projecting laterally below the threaded neck of the container over which the ring passes during first fitting of the closure to the container. The ring has one or more formations (10) on an interior surface of the ring which are shaped to engage the one or more formations about the neck of the container to prevent the ring from counter-rotating when the closure is unscrewed from the container. The closure includes at least one face (12) arranged to contact the ring and tend to face the ring away from the closure during initial unscrewing of the closure, to assist in causing the ring to drop on the neck of the container relative to its initial position to provide an indication that the container has been opened.

Description

28 1 17 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION No: Date: A CONTAINER AND CLOSURE We, OPTOPLAST (NZ) LIMITED, a New Zealand company, of 7 Tauhinu Road, Miramar, Wellington, New Zealand, do hereby declare this invention to be described in the following statement: INTELLECTUAL PROPERTY OFFICE OF M.Z - 9 SEP 2003 RECEIVED 82942 l.DOC FIELD OF THE INVENTION The invention relates to an improved container and closure, such as a lightweight plastic bottle and cap for example.

BACKGROUND OF THE INVENTION In a conventional pilfer-proof ring closure for a lightweight relatively non-rigid bottle such as a polyethylene bottle for example, in which the closure comprises cap and a rign from the which the cap separates when the cap is first removed, the ring is prevented from turning with the cap when the cap is undone by ratchet teeth around the neck of the bottle which engage the ring and prevent the ring from counter-rotating with the cap 10 as the cap is unscrewed. Typically however the ring has a larger diameter and is not effectively captured on the neck of the bottle. Thus, after the cap has been removed and when the bottle is tipped up to pour contents such as milk for example from the bottle, the ring can fall off the neck of the bottle. This is undesirable as the ring may drop onto food or into a glass onto or into which milk is being poured.

It is standard for PET bottle closures to capture the ring below a large diameter stiff annular lip or flange around and below the treaded neck of the bottle. When the cap is unscrewed, upward movement of the cap breaks plastic linkages between the cap and the ring which remains securely caught beneath the flange around the bottle neck. However when the cap incorporating the ring is initially fitted to the neck of the bottle, 20 the neck of the bottle and bottle itself must have sufficient rigidity to withstand the downward force applied to the bottle in order to force the relatively tightly fitting ring carried by the cap, over the annular flange around the bottle neck. In general, designs for the neck and closures of PET bottles or containers are not suitable for lightweight polyethylene bottles typically formed by blow molding, which do not have sufficient 25 inherent rigidity to withstand this force. For this same reason, where an annular flange is formed in a lightweight polyethylene bottle below the threaded portion of the neck of the bottle, the flange has a much smaller interference with the cap ring than would be the case in a PET bottle. 82942_1.DOC An important purpose of providing a ring integrally molded with the cap of the bottle is to make the closure tamper-evident. That is, the first time that the cap is unscrewed from the bottle the cap and ring separate, and even if the cap is subsequently replaced it should be apparent that the bottle has been opened. For example, after initial opening of 5 the bottle when the ring separates from the cap the design of the bottle neck and cap may be such that the ring drops further downwardly on the neck of the bottle so that even when the cap is subsequently replaced and screwed tight, there is a greater gap between the ring and cap than before making it evident that the bottle has been opened. This is not achieved if as is the case with some designs the ring remains in the same 10 place on the bottle - when the cap is replaced the cap and ring assume the same position so that to casual observation the bottle may appear unopened when that is not the case.

Another known form of closure for a polyethylene bottle has a ring which is the same diameter as the cap, but a disadvantage with this is that the cap cannot easily be dropped onto the neck of the bottle on a filling line, before twisting of the cap to close the bottle. 15 Also the ring does not drop on the neck of the bottle when the cap and ring are separated on initial opening of the closure, to provide an indication even after the cap has been replaced that the bottle has been opened.

SUMMARY OF THE INVENTION It is an object of the invention to provide an improved or at least alternative container 20 such as plastic bottle and closure or cap for the container.

In broad terms in one aspect the invention comprises a container having a threaded neck around an opening into the container and a closure for threadedly engaging on the container neck to close the container typically after filling the container, and a ring which until fitting of the closure to the container and then opening of the container by 25 removal of the closure is integral with the closure, the ring being intended after opening of the container by removal of the closure to remain captured about the neck of the container, in which the container has one or more formations around the container below the threaded neck and the ring has one or more formations on an interior surface of the ring which formations on the container neck and interior of the ring interengage 82942 l.DOC intellectual property office of n.z. 16 DEC 2003 RECEIVED at least when the closure is unscrewed from the container to assist in retaining the ring about the neck of the container by preventing the ring from counter-rotating during unscrewing of the closure, means projecting laterally below the threaded neck of the container over which the ring passes during first fitting of the closure to the container 5 and below which the ring engages, and at least one face on the closure which contacts the ring and tends to force the ring away from the closure during initial unscrewing of the closure, to assist in causing the ring to drop on the neck of the container relative to it's initial position to provide an indication that the container has been opened.

In a preferred form the container is a bottle, typically molded from a light-weight plastics material such as polyethylene by blow molding, and the closure is a cap for the bottle. Alternatively however the container may instead be for example a plastic pot or a tube, and the closure a lid for the pot or cap for the tube. The term "neck" is to be understood in the case of, for example, a pot container as referring to the portion of the container around and immediately below the open top of the container, to which the lid of the container is screwed on to fit the lid to the container, and in such a case does not necessarily require that the part of the container immediately below the opening is of narrower diameter than the balance of the container (in the case of a pot the opening and "neck" immediately below the opening may be the widest part across the container, which tapers with a reducing diameter to the base of the pot as is common).

Typically the means projecting laterally from the neck of the container below the threaded neck will comprise a circular ring integrally molded in the exterior of the neck of the container below the threaded portion of the neck of the container. It may not be essential however that such a threaded ring or flange be continuous about the neck of the container, and instead it may be acceptable for the ring to be captured on the neck of the container below a series of projections laterally from the neck of the container, spaced radially around the neck of the container for example.

Preferably the internal diameter of the closure ring is greater than the external diameter of the threaded neck of the container, so that the closure will self-locate if dropped onto the neck of the container, before rotation of the closure or cap to screw the closure or 30 cap fully home onto the neck of the container. Typically on a production line where intellectual property office of n.z. 1 6 DEC 2003 DFr.Fivcn 82942 l.DOC bottle to close the bottle. Where in accordance with the invention the ring has a slightly larger diameter than the external diameter of the neck of the container, the cap will drop onto and be retained on the neck of the container until at the next step it is rotated to screw the cap home onto the container, and it is not necessary to precision place the cap 5 onto the neck of the container.

In broad terms in another aspect the invention comprises a closure for a container having a threaded neck around an opening into the container and one or more teeth around the container below the threaded neck for threadedly engaging a closure on the container to close the container typically after filling the container, the closure 10 comprising complementary threaded interior and a ring integral with the closure intended after opening of the container by removal of the closure to remain engaged on the neck below means projecting laterally below the threaded neck of the container over which the ring passes during first fitting of the closure to the container , and the ring having one or more formations on an interior surface of the ring which are shaped to 15 engage the one or more formations about the neck of the container to prevent the ring from counter-rotating when the closure is unscrewed from the container, and the closure including at least one face arranged to contact the ring and tend to face the ring away from the closure during initial unscrewing of the closure, to assist in causing the ring to drop on the neck of the container relative to it's initial position to provide an indication 20 that the container has been opened.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show a bottle and cap according to a preferred form of the invention, by way of example and without intending to be limiting, in which: Figure 1 is a side view of the bottle and cap; Figure 2 is a view of the preferred form neck of the bottle (without cap in place); Figure 3 is a view of the preferred form neck of Figure 2 from above; Figure 4 is a view of the preferred form cap before fitting to the container; 82942 l.DOC intellectual property office of n.z. 16 DEC 2003 DErCIUBh Figure 5 is a cross-section view of the preferred form cap along line A-A of Figure 6; and Figure 6 is a view of the preferred form cap from below.

DETAILED DESCRIPTION OF PREFERRED FORM The invention is further described with reference to the bottle and cap shown in the drawings in which the neck of the bottle and cap are according to a preferred form of the invention, but it is to be understood that the invention is not limited to all details of the preferred form neck and cap construction, and also that the preferred form while described as applied to a bottle and cap, and may have application to other containers 10 and closures such as referred to previously. Also, where the invention is applied to a bottle and cap, the bottle in particular and also cap may be of any desired shape or size.

Referring to Figure 1, a bottle 1 is closed by a plastic cap 2 which when initially fitted to the bottle has integral therewith a ring 3. The bottle may be formed by blow molding for example, from a lightweight plastics material such as polyethylene, so that the bottle 15 is relatively thin walled and non-rigid. Such bottles are commonly used for retail sale of milk in one or two litre sizes or other sizes, and also the retail sale of bottled water or fruit drink for example, in various sizes. The cap 2 and ring 3 are typically formed together as an integral component by injection molding. Integral plastic linked portions 4 connect the ring 3 to the cap 2 as particularly shown in Figures 4 and 5.

The bottle comprises a neck portion generally indicated at 6 in Figure 2, incorporating a molded thread 7 as is shown. The interior of the cap comprises a molded thread 8 by which the cap may be screwed on to the neck 6 of the container to close the container. One or more teeth 9 are molded in the container immediately below the threaded portion 7 as shown in Figure 2, and complementary teeth 10 are provided in the interior 25 of the ring 3 as shown in Figures 5 and 6. The shape and orientation of the teeth 9 and 10 is such that when the cap is initially screwed home onto the neck of the bottle, the teeth 10 on the interior of the ring 3 will ride over the teeth 9 about the neck of the bottle below the threaded portion 7 without preventing rotation of the ring in the tightening direction of the cap, but when the cap is counter-rotated the teeth 10 on the 82942 l.DOC intellectual property office of n.z. 1 6 DEC 2003 cap will catch against the teeth 9 on the bottle neck to prevent counter-rotation of the ring with the cap as the cap is being unscrewed. The term "teeth" should be understood broadly as being intended to encompass any molded formation(s) or shape(s) on the bottle beneath the thread 7 which will be engaged with a ratchet-like action by a shape 5 or shapes on the interior of the ring 3, to enable the ring to rotate in the tightening direction of the cap onto the bottle but which prevents counter rotation of the ring. Thus when the cap is unscrewed from the bottle, the ring 3 remains stationary (allowing perhaps for a small degree of initial counter-rotation of the ring with the cap), which causes breakage of the plastic linkages 4 formed between the cap and ring as the cap 10 continues to be unscrewed from the bottle.

A circular flange 11 is also formed about the neck of the bottle below the thread 7 as shown in Figures 2 and 3. The flange 11 retains the ring 3 on the bottle after the cap has been unscrewed. During installation of the closure when the cap is initially screwed home onto the bottle, the ring rides over the flange 11. The ring is then positioned 15 beneath the flange 11. As the cap is subsequently unscrewed, upward movement of the cap on the neck of the bottle relative to the ring which is below the lateral flange 11 may also assist in breaking the plastic linkages 4 formed between the cap and ring. The cap comprises two projections 12 from the lower edge of the cap as shown, which engage into two complementary shaped recesses 13 in the ring 3, as best seen in Figures 4 and 20 5. The projections 12 in recesses 13 have complementary angled faces 14 and 15 respectively. When the cap is unscrewed and during initial movement of the cap when the cap rotates but the ring which is captured by interaction of the teeth 9 on the bottle and teeth 10 on the interior of the cap does not, the angled faces 14 on the projections 12 from the bottom edge of the cap will engage and ride up against and over the faces 25 14 of the ring. This applies a downward force on the ring during initial movement of the cap, relative to the rotating ring, which further assists in ensuring that the ring remains captured on the neck of the bottle, below the flange 11.

In the preferred form shown two such projections 12 engage with two complementary recesses 13 in the ring, but in an alternative form only a single projection may be 30 provided on the underside of the cap, or alternatively again a multiple number of 82942 l.DOC projections may be provided spaced around the lower edge of the cap which engage the ring, for example. The projections 12 need not be positioned and shaped exactly as shown, so long as they provide one or more "camming" surfaces which engage the ring to apply a relative downward force to the ring relative to the cap during the initial 5 unscrewing movement of the cap. For example, the projections 12 or equivalent could be provided in a more concealed location partly within the lower interior of the cap.

In the preferred form the teeth 10 on the interior of the ring 3 are shaped so that as well as engaging the teeth 9 around the lower part of the neck of the bottle to prevent counter-rotation of the ring, they will also engage the underside of the flange 11 to also 10 assist in preventing the ring from rising back up over the flange 11, as the cap is unscrewed. However, in an alternative form, any desired shape or shapes formed on the interior of the ring may be provided to engage the laterally extending flange 11 on the bottle neck. Further, the flange 11 need not be a continuous circular flange around the neck of the bottle below the thread 7, but may be formed as spaced segments around the 15 neck of the bottle which project laterally from the neck of the bottle, or other radial projection from the neck of the bottle for example.

In summary, on closing the bottle with the cap the cap is placed and screwed home onto the threaded neck of the bottle. As the cap is screwed home the ring rides over the laterally extending flange 11 around the lower neck of the bottle and the teeth 10 on the 20 interior of the ring ride over the ratchet teeth 9 around the bottle neck. During the initial subsequent unscrewing movement of the cap, the ring 3 is captive both so that it cannot counter-rotate on the neck of the bottle, and the interaction of the projections 12 from the lower edge of the cap against the ring pushes the ring downwardly to ensure that the ring remains captive on the bottle neck below the flange 11, as the cap is removed. 25 Preferably the ring is a sufficiently loose fit on the neck of the bottle and/or the interaction of the projections 12 on the lower edge of the cap against the ring when the cap is initially unscrewed, result in the ring dropping down the neck of the bottle slightly when the cap and ring are separated on initial opening, to provide an indication even after the cap has been replaced that the bottle has been opened, by a space which is 30 apparent between the bottom of the cap and the top of the ring. 82942 l.DOC In the preferred form the internal diameter of the ring is slightly greater than the internal diameter of the threaded portion of the cap, and thus also the external diameter of the threaded neck of the bottle. Thus on a production line, when the cap is dropped onto the neck of the bottle it will self-locate and sit relatively securely on the top of the neck of 5 the bottle until it is screwed home in the next production step . It is therefore not necessary to precisely position the cap relative to the bottle, which is advantageous when the bottles are moving on a production line and caps are dropped from a chute or otherwise approximately placed on the necks of the bottles, before being screwed home, in a situation where it may be more difficult to precisely bring the cap and bottle together. Where the ring has a slightly greater internal diameter than the external diameter of the threaded neck of the bottle so that the ring is a lose fit around the neck of the bottle when separated from the cap, this further assists in ensuring that the ring will drop down on the neck of the bottle when the ring a cap are separated during initial opening of the bottle, to provide an indication that the bottle has been opened.

The foregoing describes the invention in a preferred form thereof. Alterations and modifications as will be obvious to those skilled in the art are intended to be incorporated in the scope hereof. 82942J.DOC

Claims (7)

CLAIMS:

1. A container having a threaded neck around an opening into the container and a closure for threadedly engaging on the container neck to close the container typically after filling the container, and a ring which until fitting of the closure to the container 5 and then opening of the container by removal of the closure is integral with the closure, the ring being intended after opening of the container by removal of the closure to remain captured about the neck of the container, in which the container has one or more formations around the container below the threaded neck and the ring has one or more formations on an interior surface of the ring which formations on the container neck and 10 interior of the ring interengage at least when the closure is unscrewed from the container to assist in retaining the ring about the neck of the container by preventing the ring from counter-rotating during unscrewing of the closure, means projecting laterally below the threaded neck of the container over which the ring passes during first fitting of the closure to the container and below which the ring engages, and at least one face 15 on the closure which contacts the ring and tends to force the ring away from the closure during initial unscrewing of the closure, to assist in causing the ring to drop on the neck of the container relative to it's initial position to provide an indication that the container has been opened.

2. A closure and container according to claim 1 wherein the container is a bottle, 20 molded from a light-weight plastics material

3. A closure and container according to claim 1 or claim 2 wherein the means projecting laterally from the neck of the container below the threaded neck comprises an annular flange integrally molded in the exterior of the neck of the container below the threaded portion of the neck of the container. 25 4. A closure and container according to any one of claims 1 to 3 wherein the internal diameter of the ring is greater than the external diameter of the threaded neck of the container, so that the closure will self-locate if dropped onto the neck of the container, before rotation of the closure or cap to screw the closure or cap fully home onto the neck of the container. - 10- 82942 l.DOC intellectual property office of n.z. '6 DEC 2003

RECEIVE!)

5. A closure and container according to any one of claims 1 to 4 wherein the ring has a substantially continuous dimension about the neck of the container without a reduced dimension section of the ring intended to facilitate breakage and removal of the ring after opening of the closure. 5

6. A closure for a container having a threaded neck around an opening into the container and one or more teeth around the container below the threaded neck for threadedly engaging a closure on the container to close the container typically after filling the container, the closure comprising complementary threaded interior and a ring integral with the closure intended after opening of the container by removal of the 10 closure to remain engaged on the neck below means projecting laterally below the threaded neck of the container over which the ring passes during first fitting of the closure to the container , and the ring having one or more formations on an interior surface of the ring which are shaped to engage the one or more formations about the neck of the container to prevent the ring from counter-rotating when the closure is 15 unscrewed from the container, and the closure including at least one face arranged to contact the ring and tend to face the ring away from the closure during initial unscrewing of the closure, to assist in causing the ring to drop on the neck of the container relative to it's initial position to provide an indication that the container has been opened. 20

7. A closure according to claim 6 wherein the ring has a substantially continuous dimension about the neck of the container without a reduced dimension section of the ring intended to facilitate breakage and removal of the ring after opening of the closure. 11 - 82942 l.DOC fINTELLJpUAL property office of n.z. 16 DEC 2003 RECEIVED