A TAMPER EVIDENT CLOSURE FOR A THREADED CONTAINER

Description

FIELD OF THE INVENTION

The present invention provides a tamper evident closure for a container having external threads and a locking shoulder and more particularly a tamper evident closure having a tuck ring with segments that bend radially outward along hinge bridges upon removal of the entire closure from the container.

BACKGROUND

Closures for containers having an externally threaded neck and a locking shoulder are commonly referred to as capsules. Capsules are applied to the externally threaded neck by a rolling process. A capsule blank is drawn from a sheet of thin ductile metal such as an aluminum-based alloy. As formed, the capsule has a top panel and a depending cylindrical skirt. The depending skirt is formed of an upper main body portion and a lower locking band portion. These two portions are divided by a peripheral interrupted slit line, with intervening bridges, so that the locking band is connected to the main portion of the skirt by the spaced bridges.

The capsule is applied to the neck of the container by application of a pressure block to the top portion of the capsule and at the same time a thread roller deforms the upper portion of the capsule into conformity with the threads of the container neck. The lower edge portion of the locking band is turned under the locking shoulder using a roller, preferably acting simultaneously with the thread rolling operation. This band when so applied acts to seal the container.

In certain prior art capsules of this type, turning of the capsule to disengage the threads results in fracturing of the bridges connecting the locking band to the main body of the capsule, leaving the band still engaged with the shoulder of the bottle to visually indicate that the container has been opened.

Closures of this type have enjoyed commercial success in the art but provide an impediment to the recycling of the container as the bands must be first removed from the containers before they are recycled. The time and effort required to remove the bands, in some instances, renders recycling of such containers economically infeasible and the containers are sent to land fill.

FIGS. 1-2 show a capsule manufactured and sold by the applicant of the present application. The prior art tamper evident capsule 10 has a top wall 12, a cylindrical skirt 14 depending therefrom having an upper portion 16 and a lower portion 18. A peripheral slit 20 separates the lower portion 18 from a tuck ring 22. The slit 20 is interrupted by a plurality of bridges 24. A plurality of vertical slits 26 divide the tuck ring 22 into segments 28 and each segment is connected to the lower portion 18 by two bridges spaced from one another to form a pair of bridges. Each pair of bridges is separated by a gap 30 and a vertical slit 26 is centrally disposed with the gap. The capsule 10 has 12 bridges and six tuck ring segments 22. Upon removal of the capsule from a threaded container, the tuck ring breaks along the vertical slits and the tuck ring segments flare radially outward and each tuck ring segment remains connected to the capsule by a pair of bridges. The capsule shown in FIGS. 1 and 2 is in a used condition. The capsule makes a subtle sound of crackling when it is removed to indicate a first opening of the container. The capsule can be reconnected to the container but upon further openings, no crackling sounds will be heard.

SUMMARY OF THE INVENTION

Disclosed herein is a tamper evident closure for containers having a threaded neck and a locking shoulder. The capsule has a shell of a ductile metal having a top and an annular skirt defining a cavity. The skirt has an upper portion having threads projecting into the cavity for engaging the threaded neck, a lower portion having a tuck ring, and a peripheral slit between the upper portion and the lower portion. The slit is interrupted by a plurality of hinge bridges, a plurality of pairs of sacrificial bridges spaced from one another by a gap, and a plurality of vertical splits. One of each split is in registration with a respective gap. The tuck ring is adapted to be turned under the shoulder for locking therewith. The sacrificial bridges and the tuck ring break upon removal of the closure to divide the tuck ring into segments between the vertical splits. The segments bend radially outward along the hinge bridges by a camming action on the locking shoulder on removal of the entire closure from the container.

Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings and attachments in which:

FIG. 1 is a side elevational perspective view of a prior art capsule.

FIG. 2 is a bottom perspective view of a prior art capsule.

FIG. 3 is a bottom perspective view of a capsule of the present invention.

FIG. 4 is a perspective view of the capsule of FIG. 3 connected to a bottle in a scaled condition.

FIG. 5 is a perspective view of the capsule of FIG. 3 connected to a bottle in a used condition and showing a hinge bridge connecting a tuck ring segment to a skirt of the capsule.

FIG. 6 is a perspective view of the capsule of FIG. 3 connected to a bottle in a used condition and showing a broken vertical split.

FIG. 7 is a bottom perspective view of a capsule in a used condition.

FIGS. 8A-8C show steps in a bending test of a used capsule.

FIG. 9 shows a perspective view of a capsule of FIG. 3 showing a hinged bridge.

FIG. 10 shows a side-elevation perspective view of a capsule of FIG. 3 showing a pair of sacrificial bridges.

FIG. 11 shows a side-elevation perspective view of an alternate embodiment of a capsule showing a hinged bridge.

FIG. 12 shows a side-elevation perspective view of an alternate embodiment of a capsule showing a pair of sacrificial bridges.

DETAILED DESCRIPTION

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.

FIGS. 3-10 show a tamper evident capsule 100 of the present invention. FIGS. 10-12 show an alternate embodiment of a capsule of the present invention. The capsules 100 shown in FIGS. 3-4 have not yet been attached to a bottle and are in an unused condition. The capsules shown in FIGS. 5-10 have been attached and removed from a bottle and are in a used condition. Capsule 100 has a top wall 102 and a cylindrical skirt 104 depending therefrom and defining a cavity 105. The skirt has an upper portion 106 and a lower portion 108. The upper portion supports a set of threads 110 on an inner surface and extending into the cavity 105. The threads 110 are for mating with threads of a threaded container. A peripheral slit 112 separates the lower portion 108 from a tuck ring 114. The slit 112 is interrupted by a plurality of hinge bridges 116 circumferentially spaced from one another and connecting the tuck ring 114 to the lower portion 108 of the skirt 104.

Additionally, the slit 112 is interrupted by a plurality of sacrificial bridges 118. The sacrificial bridges 118 appear in pairs separated by a first gap 120. Each pair of sacrificial bridges 118 is positioned between a pair of hinge bridges 116 by a second gap 122. The second gap 122 is larger than the first gap 120.

A plurality of vertical splits 124 divide the tuck ring 114 into segments 126. The vertical splits 124 are in registration with a central portion of the first gap 120. Upon twisting of the capsule about a vertical axis 127 during removal of the capsule 100 from a threaded container (FIGS. 4-6), the plurality of sacrificial bridges 118 and the plurality of vertical splits 124 break dividing the tuck ring 114 into segments 132. (FIGS. 5 and 6) FIG. 7 shows a used capsule entirely removed from the container. The tuck ring segments 132 flare radially outwardly and each tuck ring segment 132 remains connected to the capsule 100 by a single hinge bridge 116 of the plurality of hinge bridges. In an alternate embodiment shown in FIGS. 11 and 12, two hinge bridges 116a,b connect each tuck ring segment to the capsule 100. This is a tamper evident feature of the capsule.

The fracturing of the sacrificial bridges 118 and the vertical splits 124 cause an audible sound to indicate a first opening of the container. This is another tamper evident feature. The used capsule 100 can be reconnected to the container but upon further openings, no audible sound will be emitted. In a preferred form, the audible sound will have a volume of 50 db to 70 db and most preferably about 60 db when measured by a sound level meter positioned 10 cm from the capsule.

The upper portion 106 of the capsule preferably has a knurling pattern 134 on an external surface to enhance the grip of a user. The knurling pattern can be applied using techniques well known to those of ordinary skill in the art. The capsule 100 preferably is removed by a user with a force of from 3 lbf·in (3.44 kgf·cm) to 13 lbf·in (14.95 kgf·cm). The capsule can be formed from a blank cut from a sheet of a thin ductile metal, preferably of a thickness of 0.18 mm to 0.23 mm according to DIN 546. Suitable aluminum alloys are sold, for example, under reference Nos. EN AW-8011/A or EN AW-3105.

The capsule 100 of FIGS. 1-10 has six sacrificial bridges 118, three hinged bridges 116, and three vertical splits 124.

However, in an alternate embodiment shown in FIG. 11-12, the hinged bridges 116 are divided into two segments 116a,b by a third gap 140. Thus, in the embodiment there are six sacrificial bridges 118, six hinged bridges 116, and three vertical splits. The diameter of the capsule preferably is from 15 mm to 40 mm and more preferably from 18 mm to 36 mm. The height of the capsule preferably is from 10 mm to 40 mm and more preferably from 18 mm to 36 mm.

A suitable threaded container with a locking shoulder includes numerous bottles, including wine bottles having a BVS type glass finishes according to EN 16293 (2020) “Glass Packaging—Deep BVS finishes for “still wines” with redraw on application. Spirit bottles having a BVP EN 15543 (2008) Screw Thread Finishes for Bottles are also suitable.

The capsule 100 will preferably include a liner disc inserted into the chamber and in contact with an inner surface of the top wall. The liner can be retained within the capsule using a bead feature, for example. The liner participates in the control of oxygen permeability. The liners typically are of a multilayer polymeric structure and their construction and use are well known to those having ordinary skill in the art.

Example

A number of capsules 100 were formed as shown in FIG. 5 for testing. Capsule blanks were cut from a 0.21 mm thick aluminum-based alloy EN AW-8011A and formed into capsules by drawing. The capsules had a diameter of 25 mm and a skirt height of 18 mm. Fifteen capsules were attached to a threaded container with a locking shoulder using a rolling technique described in a Cetic Bottling Guide no 6 (March 2020) Revision 2 “Metallic Screw Capping for Still Wines on BVS Type Glass Finishes—with Redraw.” During the application of a cap, a pressure block applies pressure to the top of the closure, ensuring the compression of the seal and a redraw of the closure edge. Thread rollers press the metal of the closure into the free spaces of the finish thread and tuck rollers crimp the metal under the finish locking bead. The capsules were removed from the container using a torque measuring device such as a spring torque meter or an electronic torque meter. A suitable electronic torque meter includes the one sold by ACRN Electronic Torquemeter NBA 6 Nm device. The opening torque was measured to be on average of 7.31 lbf·in (8.41 kgf·cm).

Additionally, the sound level was measured in a number of samples and on average the sound level was 60 db.

A number of samples of the used capsules were subjected to a sharp edge test, and a tuck ring folding test. The sharp edge test was carried out in accordance with Underwriters Laboratories UL 1439 (2004) Tests for Sharpness of Edges of Equipment using a sharp-edge tester. The sharp-edge tester has a handle with a pivoted arm. A constant-tensioning spring secured to the handle applies a constant force to the arm. The arm has a head and is wrapped with three layers of tape. The two outer layers serve as sensing tapes, and the inner layer acts as an indicating tape. The head of the tester was applied to samples of a used capsule and there were no instances where the indicating tape was damaged. Thus, the test samples passed the sharp-edge test.

The tuck ring folding test as shown in FIGS. 8A, B, C was applied to five samples of used capsules. A tuck ring segment was folded back and forth by hand across the hinged bridge until the tuck ring segment separated from the capsule. On average, eight folds were required to remove the tuck ring from the capsule. Five samples of prior art capsules shown in FIGS. 1-2 were subjected to the same test and required, on average, 5.2 folds to remove the tuck ring segment from the capsule. This is a 54% increase over the current design.

Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood within the scope of the appended claims the invention may be protected otherwise than as specifically described.