EP0596836B1 - Tamper-band - Google Patents

Abstract

A tamper-proof closure (1) made of plastic has a closure cap (2) and a tamper-proof band (3) which can be engaged in a positive-locking manner with the neck (6) of a container. The tamper-proof band (3) is connected by connection webs (4) to the closure cap (2). In this case, primary connection webs (4a) and secondary connection webs (4b) are provided. The secondary connection webs (4b) are dimensioned such that they tear and are destroyed under tensile loading far more easily than the primary connection webs (4a). <IMAGE>

Description

The invention relates to a guarantee closure and to a method and a device for producing a guarantee closure. Warranty closures for closing containers are known and used in large numbers. As a rule, such a closure is provided with a guarantee band which is connected to the closure in a separable manner by a number of connecting webs. The guarantee band is brought into engagement with the container neck by means of a retaining element, usually a protruding bead, an undercut, individual cams. Additional fixation can e.g. can also be achieved by heat shrinking. It is also known to provide combinations of differently shaped retaining elements. The guarantee tape can be e.g. be designed in the case of disposable beverage bottles so that it is completely separated from the cap and remains on the bottle neck. On the other hand, it is also e.g. from US-PS-5,074,425 to provide the guarantee tape with fixed connecting webs by which it is held on the guarantee closure after the tear-off connecting webs have been severed. Such guarantee tapes are therefore usually provided with one or more vertical tear lines.

When opening for the first time, the guarantee band is at least temporarily held back on the bottle neck, so that when the closure is opened, the connecting webs tear and indicate that it has been opened.

Such closures can be produced in one piece in a plastic injection molding process together with the guarantee tape. However, it is also known to subsequently add a weakening line between the closure cap on blank blanks and attach the guarantee tape. Such devices and methods are known from US Pat. No. 3,673,761 (Leitz / CIBA-Geigy AG), DE-OS-14 82 603 (Teillac / ALCA SA) or US Pat. No. 4,895,265 (LUC et al./The West Co.), or the US-PS-3,673,761 known.

With these closures, the line of weakness is applied to a container by means of a cutting tool before or after the blank blank is placed on it. A knife, a heated cutting edge or a rotating circular saw-type cutting tool can serve as the cutting tool. The weakening of the material can be applied to a heated blank blank or to the cold material. The type of cutting tool and process parameters, in particular also the cutting temperature, obviously depend on the type of plastic used, the size and type of the line of weakness, the speed of the process, etc. Laser cutting tools can also be used in such processes.

On the other hand, guarantee closures made of metal are also known, in which a guarantee element is subsequently attached. The guarantee element is usually ring-shaped with a first holding section, with which it can be positively connected to the closure cap. The holding section - and thus the closure cap - is connected to the guarantee band by means of connecting webs.

There are also other methods of making guarantee closures, such as Compression molding, two-component injection molding and the like are known.

One difficulty with closures of this type is that the connecting webs have to be so stable on the one hand that they cannot be removed from a tool, stored, manipulated or put on of the closure on a container can be destroyed or damaged. On the other hand, they should reliably tear or break with every slight manipulation, at least when opening for the first time or trying to open them. From US-PS-4,322,009 (Mumford / Owens-Illinois Inc.), for example, a guarantee closure is therefore known, the connecting webs of the same thickness and dimension are produced in such a way that the guarantee band and the guarantee closure are separated from one another only by a narrow gap and when screwed together with one another Can come in contact.

A guarantee closure is known from US Pat. No. 5,074,425 (Wüstman et al./Crown Cork AG), in which the connecting webs are weakened on a side facing the tear-open position.

The object of the invention is to improve guarantee closures, in particular the various types of guarantee closures described above, in such a way that connecting webs are created which, on the one hand, are sensitive and easily damaged during an attempted manipulation, and on the other hand are stable during storage and removal from the mold.

According to the invention, this object is achieved according to the characteristics of the claims.

The arrangement of primary and secondary connecting webs with different load capacities ensures that the connection between the guarantee band and the sealing cap is sufficiently firm for manufacture, storage and manipulation. However, when the container is opened and the connecting webs are subjected to tension, the weaker connecting webs are destroyed almost immediately. Especially if the secondary connecting webs have a thinner cross-section or in any case thinner minimum cross-section than the primary connecting webs, leave only a slight material stretch before they break. The secondary connecting webs are more easily destroyed when the tamper is manipulated than the primary connecting webs. However, as soon as the secondary connecting webs are destroyed, the primary connecting webs have to absorb the entire tensile stress when the container is opened, so that they also tear as a result. The invention provides that at least two secondary connecting webs are arranged in the space between two primary connecting webs, which share the load with the primary connecting webs when subjected to tensile stress and, after tearing, shift the total load onto the primary connecting webs.

The different resilience of secondary connecting webs and primary connecting webs can be realized primarily by different material thickness and / or by weakening zones in the connecting webs. For example, the secondary connecting webs are weakened by incisions or material tapering, and the primary connecting webs are formed without weakening while the material thickness is otherwise the same. On the other hand, it is also conceivable to provide both the secondary connecting webs and the primary connecting webs with material weaknesses, the secondary connecting webs being weakened more than the primary connecting webs.

In terms of the method, the invention can be implemented particularly simply if weakening zones are attached to a blank blank with a cylindrical wall section and a cap base at predeterminable circumferential areas, different weakening zones forming primary connecting webs and secondary connecting webs that have different material strength. For example, connecting webs can be produced by material cuts in the cylindrical wall section, the material thickness of the remaining connecting webs being variable by the depth of cut.

Such material weakenings can be applied particularly advantageously by a separating device with a cutting edge, in which differently shaped recesses are provided for forming the primary and the secondary connecting webs. The cutting edge can be heated in a known manner.

Of course, the weakening of the material can also be done in other ways, e.g. using milling, heated tongs or laser cutters. It would also be e.g. It is conceivable to manufacture guarantee closures with identical connecting webs in the injection molding process or in the compression molding process and subsequently to weaken, in particular cut, individual of the connecting webs in order to produce secondary connecting webs. Alternatively, it would also be conceivable to manufacture the sealing cap and the guarantee band separately and to subsequently connect the guarantee band in the region of the connecting webs to the sealing cap, e.g. to engage in a positive fit, to glue or to weld the connecting webs.

Figur 1

eine Verschlusskappe mit den Merkmalen der Erfindung im Querschnitt,

Figur 2

die Verschlusskappe gemäss Figur 1 in Ansicht beim Öffnen,

Figur 3a

die Darstellung eines Teilschnitts längs der Linie A-A in Figur 1 in vergrössertem Massstab,

Figur 3b

eine Seitenansicht der Darstellung gemäss Figur 3a,

Figuren 4 und 5

abgewandelte Ausführungsvarianten der Erfindung in einer Schnitt-Ebene analog Figur 3a,

Figur 6a

einen Teilschnitt analog Figur 3a durch ein weiter abgewandeltes Ausführungsbeispiel der Erfindung,

Figur 6b

eine Seitenansicht der Darstellung gemäss Figur 6a,

Figuren 7a bis 7c

Darstellungen einer weiteren abgewandelten Variante von Verbindungsstegen,

Figuren 8 und 9

die schematische Darstellung von Steganordnungen,

Figur 10

eine schematische Darstellung einer Einrichtung zum Herstellen eines Garantieverschlusses, und

Figur 11

die Darstellung des Schneiden-Verlaufs der Vorrichtung gemäss Figur 10 in vergrössertem Mass-stab.

The invention is explained below in exemplary embodiments with reference to the drawings. Show it:

Figure 1

a closure cap with the features of the invention in cross section,

Figure 2

1 in view when opening,

Figure 3a

1 is an enlarged scale representation of a partial section along the line AA in FIG. 1,

Figure 3b

3 shows a side view of the illustration according to FIG. 3a,

Figures 4 and 5

modified embodiment variants of the invention in a sectional plane analogous to FIG. 3a,

Figure 6a

3 a partial section analogous to FIG. 3a through a further modified embodiment of the invention,

Figure 6b

6 shows a side view of the illustration according to FIG. 6a,

Figures 7a to 7c

Representations of a further modified variant of connecting webs,

Figures 8 and 9

the schematic representation of web arrangements,

Figure 10

a schematic representation of a device for producing a guarantee closure, and

Figure 11

the representation of the cutting course of the device according to Figure 10 on an enlarged scale.

According to FIGS. 1 and 2, a guarantee closure 1 produced by injection molding consists of a closure cap 2 and a guarantee band 3. The guarantee band 3 is connected to the closure cap 2 by connecting webs 4. The screw cap 2 is screwed onto a container neck 6, with a bead 7 of the guarantee band 3 being form-fitting as a counter-bead retaining element 8 snaps onto the container neck 6. The connecting webs 4 are designed as primary connecting webs 4a and secondary connecting webs 4b. As can be seen from FIGS. 2 and 3, the primary connecting webs 4a have a substantially larger diameter and thus a larger cross section than the secondary connecting webs 4b. As a result, when the bottle is opened, the relatively thin secondary connecting webs 4b, which can hardly be elastically stretched due to the small cross section, initially tear, whereby the force exerted on the primary connecting webs 4a increases suddenly and the primary connecting webs 4a also begin to tear. In the manner shown primarily in FIG. 2 and FIG. 3b, the guarantee band first begins to tear at one point. With the progressive tearing of the secondary connecting webs 4b, all the primary connecting webs 4a also tear, so that the guarantee closure 1 can be separated from the container neck 6.

FIG. 4 shows a modified exemplary embodiment in which primary connecting webs 4a and a first number of secondary connecting webs 4b ₁ and a second number of secondary connecting webs 4b _{2 are} provided. Analogous to FIGS. 1 to 3a and 3b, the secondary connecting webs 4b ₁ are much thinner and therefore easier to destroy by tensile stress than the primary connecting webs 4a. The secondary connecting webs 4b ₂ are made even thinner than the first secondary connecting webs 4b ₁ . A gradual tearing of the connecting webs can thus be achieved, starting with the connecting webs 4b ₂ , then following the connecting webs 4b ₁ and finally the primary connecting webs 4a.

In the exemplary embodiment according to FIG. 4, a much stronger fastening web 9 is also provided in a known manner, which does not tear when the guarantee closure is opened. In addition, there is a predetermined breaking point on guarantee strip 3 9a is provided, on which the guarantee band 3 can tear open vertically.

FIG. 5 shows a modified exemplary embodiment in which the secondary connecting webs 4b both have a smaller cross section than the primary connecting webs 4a and are also weakened on one side by beveling. In this way, tearing of the secondary connecting webs can be controlled from their weakened flanks.

FIGS. 6a and 6b show an exemplary embodiment in which a primary connecting web 4a has essentially the same cross section as a secondary connecting web 4b. Both connecting webs 4a and 4b are weakened on tapering flanks 15, so that lateral tearing is promoted from there. However, as can be seen from the side view according to FIG. 6b, the secondary connecting web 4b is additionally weakened laterally by a notch 10, so that it tears in front of the primary connecting web 4a.

FIGS. 7a to 7c show a similar exemplary embodiment, in which primary connecting webs 4a and secondary connecting webs 4b have approximately the same cross section in the upper region. However, while the primary connecting web 4a runs without weakening, a weakening zone designed as a notch 10 is provided on the outside of the secondary connecting web 4b. FIG. 7c shows schematically the section along the line A-A, in FIG. 7a on an enlarged scale, from which the course of the notch 10 can be seen.

FIG. 8 shows an arrangement of primary connecting webs 4a and 4b, four secondary connecting webs 4b being provided alternately in the spaces between the primary connecting webs 4a. The primary connecting webs 4a are approximately the same thickness as the wall of the guarantee tape 3, whereby good manufacturing properties result both in manufacture with injection molding tools and in subsequent cutting of the closures. The 4 secondary connecting webs 4b as a whole bring about a significant improvement in the connection between the closure cap 2 and the guarantee band 3. However, their small cross-section ensures that when the closure is opened, the secondary connecting webs tear relatively quickly and thus the total load on the Pass primary connecting webs 4a.

FIG. 9 shows an exemplary embodiment in which three secondary connecting webs 4b are arranged in each intermediate space between two primary connecting webs 4a in order to stabilize the entire length of the guarantee band.

Figures 10 and 11 show schematically how e.g. 9 can be made from a blank blank 12 according to FIG. A cutting knife 13 engages the blank blank 12 in order to produce the connecting webs in the configuration according to FIG. 9. The blank 12 is unrolled by a device (not shown) on the heated cutting knife 13 such that the cutting knife 13 cuts through the wall of the blank 12. Only in the area of the cutouts 14 does the cutting knife 13 not completely penetrate the wall of the blank 12, so that webs 4a and 4b are left out.

FIG. 11 shows the front edge of the cutting knife 13 in a greatly enlarged illustration. It can be seen from this that larger cutouts 14a are provided on the cutting knife 13 for producing the primary connecting webs and smaller cutouts 14b for producing the secondary connecting webs.

Of course, by shaping the cutouts 14, 14a, 14b in a suitable manner, practically any web shape can be used and form graded cross-sectional shapes. For example, more than two differently weaker secondary connecting webs or different cross-sectional shapes of individual connecting webs can also be generated.

Claims (6)

1. A guarantee closure, preferably of plastics material, for closing a container opening, preferably with a screwthread, comprising a closure cap (2) which can be fitted onto a neck (6) of the container in positively locking relationship, a guarantee strip (3) which can be brought into engagement with at least one retaining element (7) with the neck (6) of the container opening, and a plurality of desired-rupture legs (4a, 4b, 4b₁, 4b₂) which connect the closure cap (2) to the guarantee strip (3), characterised in that the desired-rupture legs (4a, 4b, 4b₁, 4b₂) have first desired-rupture legs (4a) and second desired-rupture legs (4b; 4b₁, 4b₂) which are weaker in comparison with the first desired-rupture legs, wherein the first desired-rupture legs (4a) have a higher level of tensile and shear strength than the second desired-rupture legs (4b; 4b₁, 4b₂) and wherein at least two second desired-rupture legs (4a; 4b₁, 4b₂) are arranged in the intermediate space between each two first desired-rupture legs (4a).
2. A guarantee closure according to claim 1 characterised in that three second desired-rupture legs (4b; 4b₁ 4b₂) are arranged in the intermediate space between each two first desired-rupture legs (4a).
3. A guarantee closure according to one of the preceding claims characterised in that the second desired-rupture legs (4b; 4b₁, 4b₂) are of smaller diameter or material cross-section than the first desired-rupture legs (4a).
4. A guarantee closure according to one of claims 1 and 2 characterised in that the second desired-rupture legs (4b; 4b₁, 4b₂) each have at least one weakening zone (10, 15).
5. A guarantee closure according to one of claims 1 to 4 characterised in that the first desired-rupture legs (4a) have at least one weakening zone (10, 15).
6. A guarantee closure according to one of claims 1 to 3 characterised in that the first desired-rupture legs (4a) and the second desired-rupture legs (4b; 4b₁ 4b₂) each have at least one weakening zone (15, 10) and that the first desired-rupture legs are weakened less than the second desired-rupture legs.

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