EP0313906A1 - Screw for a container - Google Patents

Abstract

The screwcap (1) for the closure of a container has a tamper-proof safeguard, situated in the region of the lower cap shell (2), with intended break points (4) and it is coated in the region of the tamper-proof safeguard with at least one layer (9) of plastic. This allows the screwcap to be unscrewed easily, easily recognisably and without any risk of injury for the purpose of opening the container and to be screwed up again for closure. <IMAGE>

Description

The invention relates to a screw cap for the closure of a container, with a tamper-evident device with predetermined breaking points located in the area of the lower edge of the cap jacket.

Screw caps made of metal are known, so-called "pilferproof closures", which have a ring at the lower edge of the cap jacket as tamper-evident protection, which ring is connected to the cap jacket by tearing predetermined breaking webs. When the cap is unscrewed, the ring separates from the cap jacket due to the tear-off predetermined breaking webs and remains at the mouth of the container. In the process, needle-point break-off points form on the predetermined breaking bars, both on the cap and on the ring, which frequently lead to injuries. The ring remaining on a container must be removed in order to reuse the container, which is usually only possible by overcoming the corresponding difficulties.

Furthermore, so-called lamellar closures are known, in which the lower edge of the cap jacket is provided with embossing notches oriented perpendicular to the edge, which act as lines of weakness and define predetermined breaking points, which are evenly distributed around its circumference in the lower region of the cap jacket, two of each other Areas of adjacent embossing notches form a lamella or a segment. When unscrewing such closures, the embossing notches should tear and the individual lamellae or segments bend outwards in order to signal an open container.

However, if the metal of such a lamella fastener is not embossed far enough, which is inevitable given the usual thickness tolerances of the sheets and the machining tolerances with the embossing tools, such a fastener can be opened only with great difficulty or not at all. In addition, there is considerable risk of injury due to the bending of the individual slats. This increases considerably with large-volume containers and bottles by frequently opening and reclosing the lamella screw caps.

The invention has for its object to improve a screw cap with tamper-evident for the closure of bottles, wide-mouth bottles and other containers so that it can be opened easily, clearly and without any risk of injury.

The screw cap created to solve this problem is characterized in that it is coated with at least one plastic layer in the area of tamper-evident securing.

The screw cap according to the invention has the advantage that the adhesive plastic layer covers sharp cutting edges and breaking points after opening the screw cap, so that the risk of injury is reduced to a minimum. The plastic layer can also break or tear in the area of the predetermined breaking points, so that after loosening the screw cap, e.g. from a bottle, the first time it is opened is visually visible.

The plastic layer can e.g. by spraying, dipping or shrinking a strapping plastic ring.

Both screw caps with a lower locking ring and so-called lamella closures can be coated with at least one plastic layer in the manner according to the invention, with the advantage that predetermined breaking points are defined by full incisions can be renated, since the plastic layer holds the parts separated from each other by full cuts. Screw caps equipped with plastic layers according to the invention can thus be easily unscrewed by hand, with adhering parts of the plastic layer covering the sharp cut edges and breaking points in order to avoid injuries.

Of course, it is also possible, in particular in the case of a slat closure, to connect the individual securing slats to one another in a previously known manner by means of embossing notches. A remaining wall thickness of the screw caps remains uncut. A cap designed in this way can be provided with a preferably transparent plastic layer in the area of tamper-evident securing. When opening a container, the predetermined breaking points in the metal of the screw cap tear. The transparent plastic can stretch because it is somewhat tougher and less break-active than the metal of the actual screw cap, so that the plastic layer does not tear. As a result, the transparent plastic can be used to visually clearly identify the tamper-proof securing, the undamaged but transparent plastic preventing the risk of injury occurring with conventional lamella closures.

The plastic layer is preferably arranged in such a way that it covers at least one surface of the tamper-evident device and an adjacent surface area of the cap jacket. This measure has the advantage that the plastic layer is involved in the connection between tamper-evident device and screw cap. The plastic layer can thus also perform load-bearing functions, so that predetermined breaking points can be made correspondingly weaker, which makes opening of the containers easier by manually unscrewing the screw caps.

The plastic layer can be designed as an outer strapping or casing. However, it is also possible to use the plastic to be placed inside. Furthermore, an arrangement on both sides, both inside and outside, is possible on the screw cap.

Especially with fruit or sugar-containing contents of a container which is respectively closed with the screw cap according to the invention, with an additional inner coating, by arranging an inner plastic layer, favorable twisting values for the screw cap result. At the same time, the inside of the plastic layer also protects the container mouths. In particular in the known so-called lamella closures, the broken and unprotected lamellas can scrape over the container mouth each time the container is opened and closed again. Scratching increases the roughness on the one hand and thus the corresponding turning values for the screw cap during the next closing process; on the other hand, the scratches lead to irreparable damage to the container mouth over time. Damage to the container mouths can in turn easily lead to injuries, especially when drinking directly from the containers. In contrast, when using the screw cap designed according to the invention, damage to the mouths of the containers can be avoided, which also has a positive effect with regard to a reduction in rejects or a longer preservation of the value of the containers.

The manufacture of the screw caps, which are provided in the manner according to the invention with plastic layers in the area of tamper-evident protection, is particularly easy due to the simplified design of the predetermined breaking points in the form of full-cut joints, between which thin, tear-off webs remain, and in particular compared to predetermined breaking points formed by embossing notches Tolerances in sheet thicknesses and processing tools largely independent.

Of course, it is possible to screw, for example strapped, the plastic layers according to the invention caps not only made of metal, but also made of plastic. Even with plastic screw caps, the outer and / or inner plastic layers in the area of tamper-evident protection offer the same advantages of reducing the risk of injury at torn predetermined breaking points as well as simplifying the production of the predetermined breaking points themselves and thus the actual tamper-evident protection.

The e.g. strapping plastic layer can be applied in the manner of a coating, which can be easily integrated into existing production plants for screw caps known per se. The closure of containers with screw caps, which are provided with the plastic layers in the manner according to the invention, is also possible in a manner known per se without corresponding machine conversions.

Preferably the material for the plastic layers is a sprayable compound, e.g. Polyvinyl chloride. However, other plastics can also be used which are suitable for the respective application.

So that the plastic layer to be attached to the screw cap adheres perfectly, an adhesive varnish coating can also be applied under the plastic layer.

Each plastic layer, outside and / or inside, can also be at least partially drawn around the lower edge of the tamper-evident device. This arrangement reduces the risk of injury, since edges at the lower edge of the cap shell are practically protected by a covering by means of the plastic layer.

• Fig. 1 eine Halbschnittansicht einer Schraubkappe mit unver­ sehrter Originalitätssicherung und umreifender Kunst­stofflage,
• Fig. 2 die Schraubkappe gemäß Fig. 1 im Halbschnitt mit nach Abschrauben von einem Behälter beschädigter Originali­tätssicherung,
• Fig. 3 die durch Einkreisung in Fig. 2 gekennzeichnete Ein­zelheit Z in vergrößerndem Maßstab,
• Fig. 4 die Halbschnittansicht einer Pilferproof-Schraubkap­pe, von der die Originalitätssicherung vollständig abgerissen ist,
• Fig. 5 eine Halbschnittansicht einer Schraubkappe, bei der die Originalitätssicherung sowohl innen als auch au­ßen mit einer Kunststofflage beschichtet ist und
• Fig. 6 eine Pilferproof-Schraubkappe mit bei vollständig ab­gerissener Originalitätssicherung, sowohl innen als auch außen mit einer Kunststofflage beschichtet.

Embodiments of the invention, from which further inventive features result, are shown in the drawing. Show it:

• Fig. 1 is a half-sectional view of a screw cap with un originality assurance and strapping plastic layer,
• 2 the screw cap according to FIG. 1 in half section with tamper-evident device damaged after unscrewing from a container,
• 3 shows the detail Z marked by encirclement in FIG. 2 on an enlarged scale,
• 4 shows the half-sectional view of a pilferproof screw cap, from which the tamper-evident device has been completely torn off,
• Fig. 5 is a half-sectional view of a screw cap, in which the tamper-evident device is coated both inside and outside with a plastic layer and
• Fig. 6 is a pilferproof screw cap with a completely torn off tamper-evident, both inside and outside coated with a plastic layer.

Fig. 1 shows a screw cap 1 in a half-sectional view. The screw cap 1 is made in a known manner from aluminum sheet and is used as a so-called guarantee closure for closing containers, for which purpose a tamper-evident device with predetermined breaking points is arranged in the region of the lower edge of the cap shell. In the exemplary embodiment shown in FIG. 1, tamper-evident protection consists of slit-shaped full cuts 3 running around a circular line, between which tear-off webs 4 remain as predetermined breaking points. Furthermore, from the lower edge 5, vertical incisions 6 are provided, which are arranged distributed uniformly on the circumference of the screw cap. It is common for the full cuts 6 to have five segments or lamellae 7 distributed around the circumference of the screw cap or its tamper-evident device. Between the full cuts 6 and the horizontal full cuts 3, webs 8 remain as predetermined breaking points.

In Fig. 1 the screw cap is shown with undamaged tamper evident. When unscrewing, e.g. from a screw neck of a bottle, the individual segments or lamellae 7 are spread outwards, the full cuts 6 bending up, the webs 8 being able to tear and thus damage to the lower region occurring and being visible.

It is possible, particularly in the case of so-called pilfer proof closures, to form the segments or lamellae as a continuous ring. The full cuts 6 are then missing, so that the entire ring is separated by horizontal cuts 3 from the lower edge of the cap shell 2 of the screw cap 1 and remains connected to it only by the standing webs 4. When the screw cap 1 is unscrewed, the webs 4 tear off and the entire ring remains on the bottle neck.

The tamper-evident securing essentially consisting of the segments or slats 7 is, as can be seen in FIG. 1, coated on the outside with a plastic layer 9 which is at least partially drawn around the lower edge 5 in order to defuse this edge and to avoid the risk of injury. The covering plastic layer 9 also protects the sharp edges of the tearing off webs 4 and 8 or the cut edges of the full interfaces 6 and 3 in the case of tamper-evident protection damaged by unscrewing a screw cap from a container.

FIG. 2 shows the screw cap according to FIG. 1 after unscrewing, in which the segments or lamellae 7 and the full kerf 6 and 3 have deformed. Fig. 2 also shows that the plastic layer 9 is also torn open by the tearing full-cut joints 6, which is particularly visible on the left half of the screw cap shown uncut. Fig. 2 also shows that the full cut 6 is torn further, so that the web 8 still present between the already deformed horizontal cut 3 and the full cut 6 in FIG. 1 is torn off.

Fig. 3 shows that marked by encirclement in Fig. 2 Detail "Z" on an enlarged scale. The same components are labeled with the same reference numbers. 3 shows in particular how the plastic layer 9 strapping a screw cap in the area of the tamper-evident securing can also extend into the full-cut joints 3 and 6, in order to later protect sharp edges in the event of tearing predetermined breaking points and deforming tamper-evident tampering and to avoid the risk of injury. It can also be seen how the plastic layer 9 surrounds the lower sharp edge 5 of the tamper-evident device and thereby reduces the risk of injury.

Fig. 4 shows a screw cap in half section with damaged tamper-evident protection, which is designed in the form of a ring, already described, connected by horizontal kerfs 3 and intermediate tear-off webs 4 to the cap jacket in the manner of a pilferproof closure. The ring has remained on the neck of the container due to the unscrewing of the screw cap 1a from a container (not shown). All that is visible is the sharp-edged tear-off points 11 that still remain on the lower free edge 10 of the cap casing 2a, which indicate areas in which the strapping plastic layer is torn, from which only the upper part 9a connected to the cap casing 2a is visible. Another part is torn off and remains on the fallen circlip, which is not visible here.

FIG. 5 shows a screw cap 1b in a half-sectional view, in which the tamper-evident device which has already been damaged (see also FIG. 2) is both provided with an outer plastic layer 9 and also has a further plastic layer 12 on the inside. The inner plastic layer provides a favorable torque when opening or a user-friendly soft turning of the caps. In addition, the inner plastic layer prevents the container mouths from being scratched.

Fig. 6 shows a screw cap in an embodiment corresponding to FIG. 4 with a torn retaining ring, the Screw cap in turn had an outer plastic layer and an inner plastic layer corresponding to the arrangement shown in FIG. 5, which was divided into parts 9a and 12a remaining on the screw cap by separating the one-piece locking ring. The parts 9a and 12a in turn protect the sharp lower edge and in particular the needle-point tear-off points at which the locking ring has separated from the screw cap.

Claims (11)

1. metal screw cap for the closure of a container, with a tamper-evident device in the area of the lower cap shell with predetermined breaking points,
characterized,
that it is coated with at least one plastic layer (9, 12) in the area of tamper-evident securing. 2. Screw cap according to claim 1, characterized in that the plastic layer (9, 12) covers at least one surface of the tamper-evident device and an adjacent surface area of the cap member (2). 3. Screw cap according to claim 1 and / or 2, characterized in that the plastic layer (9) is designed as a strapping arranged on the outside of the cap. 4. Screw cap according to claim 1 and / or 2, characterized in that the plastic layer (12) is arranged on the inside of the cap. 5. Screw cap according to claim 1 and / or 2, characterized in that a plastic layer (9, 12) is arranged on the inside and outside of the cap. 6. Screw cap according to one of the preceding claims, characterized in that standing webs (4, 8) are provided as predetermined breaking points between full kerfs (3, 6). 7. Screw cap according to one of the preceding claims, characterized in that each plastic layer (9, 12) is attached in the manner of a coating. 8. Screw cap according to one of the preceding claims, characterized in that the material for each plastic layer (9, 12) is a transparent tough plastic. 9. Screw cap according to claim 8, characterized in that the Material for the plastic layer (9, 12) is polyvinyl chloride. 10. Screw cap according to one of the preceding claims, characterized in that an adhesive coating is applied between each plastic layer and the surface of the screw cap. 11. Screw cap according to one of the preceding claims, characterized in that at least one of the plastic layers (9, 12) is at least partially pulled around the lower edge (5) of the tamper-evident device.

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