EP0564999B1 - Bottle cap with warranty ring - Google Patents

Abstract

In a plastic cap (1) which can be fitted, in particular screwed, onto a bottle neck, having a tamper-proof warranty ring (3) which is connected via an intended tearing point to the outer cap surface and, in the fitted-on position of the cap, engages behind a bead or the like constructed on the bottle neck, projections (6, 8) are provided, which are arranged in sections on the warranty ring, project radially inwards in the direction of the bottle neck and have at least two different constructions in their cross-sectional geometry (6, 8). <IMAGE>

Description

The invention relates to a cap that can be placed on a bottle neck with a locking ring according to the preamble of patent claim 1.

Beverage bottles are usually closed either by crown caps or by reusable screw caps. While the crown cap's originality is ensured by the fact that it is deformed when the bottle is opened and therefore cannot be reused, screw caps can be opened and then closed again without the consumer having to buy one such bottle can easily determine this. To ensure the originality of screw caps, they are provided with so-called tamper-evident rings. Circlips of this type are connected to the closure cap via a predetermined breaking point, so that the predetermined breaking point is damaged when the beverage bottle is opened and the opening of the bottle for the first time can thus be reliably recognized from the outside. To ensure this security function it is necessary that the retaining ring is held on the bottle neck until it breaks when the cap is removed. For this purpose, locking rings of this type are usually designed in such a way that they engage behind a projecting, circumferential bead radially inwards in the region of the bottle collar. When the cap is pulled off, the cap is moved upward in accordance with the thread pitch of the screw cap, while the retaining ring is held on the bottle collar in the region of the bead. This leads to increasing tensile stresses, which ultimately lead to the securing ring being torn off the cap along a predetermined predetermined breaking line.

The German patent DE 3206245 describes in this connection a guarantee ring made of plastic for metallic screw cap containers, the guarantee ring being received in a U-shaped, radially inwardly open bead at the lower end of the jacket of the screw cap. When the metal cap is unscrewed, the plastic ring is separated from the metal cap and remains on the beverage bottle.

From document DE-3038453 a screw closure for containers is known which comprises a safety ring which has a plurality of locking projections which are directed inwards on its inside and engage positively under or behind the radial projection of a beverage bottle. According to this solution, the safety ring is connected to the cap by means of a thin film-like web, so that when the cap is pulled off, the safety ring tears off along this web and remains on the bottle.

Another publication describes a screw cap for beverage bottles with a safety ring, which likewise has a latching approach, which is similar by means of an inwardly directed barb-like engagement which engages under the radial projection in the opening region of the container, this latching approach However, it is not circumferential but is only formed in sections. This has the advantage that the cap, which is formed in one piece together with the safety ring, is screwed onto the beverage bottle, the catch of the safety ring snapping behind the radial projection in the opening region of the container and thus a renewed opening of the cap is only possible by removing the locking ring from the cap tears off. With this solution, the locking ring remains on the bottle neck.

However, screw caps for beverage containers with a safety ring have to meet further requirements today. For cost reasons, it has now become indispensable to manufacture the cap together with the safety ring in one piece. Mounting the safety ring on a cap made of metal, for example, is no longer economical. Screw caps formed in one piece, which comprise the cap on the safety ring, are usually produced in such a way that the cap and the safety ring are initially produced as separate parts, the safety ring being welded to the cap in a second operation. Only in this way has it been possible to produce a cap of this type with a safety ring designed to engage behind.

Furthermore, it is no longer desirable for environmental reasons that the safety ring, which is preferably made of plastic, remains on the bottle neck, since the bottles are melted again during the recycling process, the plastic of the safety ring burning and thus polluting the atmosphere. From a recycling point of view, it is desirable today to make it easier to separate the different materials. For this reason, it is necessary to develop a screw closure with a safety ring in such a way that the safety ring is visibly damaged when the cap is removed and remains on the cap at the same time.

The object of the invention is to provide a cap with a safety ring for beverage bottles, which is simple and inexpensive to manufacture and eliminates the disadvantages shown.

This object is achieved by the characterizing features of claim 1, expedient developments of the invention being characterized by the features set out in the subclaims.

In accordance with the invention, the locking ring formed on the closure cap has protrusions arranged in sections, which protrude radially inwards in the direction of the bottle neck and engage behind the bead on the bottle neck. The projections formed on the locking ring have at least two different designs in their cross-sectional geometry. According to an advantageous embodiment, the cross-sectional geometry of a first projection is bead-like, with a rounded front end, and that of a second projection is edge-like, with a sharp, pointed edge, the projections tapering in a wedge shape in their lower region.

Due to the different cross-sectional geometry of the said projections, they perform different functions. The rounded bead-like projections serve primarily to horizontally expand the locking ring when the cap is pulled off, in that it is pulled upwards onto the circumferential projection on the bottle neck. The second projection, which is formed on the retaining ring and has a sharp, angular cross-sectional geometry, serves, on the other hand, to hold the retaining ring in the vertical direction on the bottle neck. Said horizontal expansion through the first projections in connection with the vertical retention of the second projection causes the securing ring to be torn open quickly and reliably.

For this purpose, a tear-off point extending essentially parallel to the cap axis is provided in the securing system, the tear-off point being formed in accordance with an advantageous embodiment by two preferably V-shaped recesses in the securing ring. A first V-shaped recess extends from the cap-side upper edge of the securing ring to the lower edge, while a second recess forms an incision in the axis of the first recess of the securing ring from the outer surface thereof. In order to facilitate the expansion and the tearing of the locking ring, recesses provided in the lower edge of the locking ring are advantageously provided. These recesses are advantageously located next to the bead-like projections and in alignment with the tear-off point below them. In order to enable a non-destructive placement of the cap on the bottle, the tear-off point is reinforced around the lower area by a web which bridges a film hinge or the tear-off point.

According to further advantageous refinements, in order to save material, the securing ring can have a plurality of rectangular recesses and the thread of the cap can only be formed in sections.

Fig. 1

eine schematische Querschnittsansicht des Schraubverschlusses;

Fig. 2

einen Horizontalschnitt durch den Sicherungsring;

Fig. 3

einen Horizontalschnitt durch die Verschlußkappe;

Fig. 4

einen Seitenansicht des Sicherungsringes im Bereich der Abreißstelle;

Fig. 5

die Querschnittsgeometrie des wulstartigen Vorsprunges, und

Fig. 6

die Querschnittsgeometrie des kantenartigen Vorsprunges.

An exemplary embodiment of the invention is explained in more detail below with the aid of various drawings. In it show:

Fig. 1

a schematic cross-sectional view of the screw cap;

Fig. 2

a horizontal section through the locking ring;

Fig. 3

a horizontal section through the cap;

Fig. 4

a side view of the locking ring in the region of the tear-off point;

Fig. 5

the cross-sectional geometry of the bead-like projection, and

Fig. 6

the cross-sectional geometry of the edge-like projection.

The closure element shown schematically in Fig. 1 in side section is generally designated 1. As can be seen from the illustration, the closure element 1 consists of the closure cap 2 and the locking ring 3. In the region of the cap shell, the molded thread 4, which is only partially formed here, can be seen. The locking ring 3 is connected to the cap via narrow tear-off webs 5. The differently shaped, radially inward projections at the lower end of the locking ring are clearly recognizable. The bead-like projection 6 with a rounded front end 7 is shown on the left and the edge-like projection 8, which has a sharp, pointed edge 9, is shown on the right. Furthermore, the configuration of a downwardly open recess 10 is shown at the lower edge of the locking ring 3. The recess 10 is preferably (not shown here) immediately next to the bead-like projections 6 and below a tear-off point (see FIG. 4). In addition, the locking ring 3 has window-like recesses, which are arranged here above the edge-like projection 8.

Fig. 2 shows a horizontal section through the closure cap at the level of the tear-off webs 5 of the locking ring 3. In addition to the semicircular tear-off webs 5, the projections 6 and 8 projecting radially inwards towards the bottle neck can be seen here, which, as shown here, have curves in the Open the wall of the circlip. Furthermore, the tear-off point 12 with the axially extending, V-shaped recess 13 can be seen. In particular, it is clear from this illustration that the edge-like projection 8 is arranged in the vicinity of the tear-off point 12.

FIG. 3 shows a further horizontal section through the closure cap in the region of the closure cap itself. The thread turns 4, which are formed in sections and are integrally formed on the cap jacket 2, can be seen clearly from this illustration. The threads 4 open into the wall of the cap shell 2 via curves.

Fig. 4 shows an embodiment of the tear-off point 12. This is essentially formed by two V-shaped recesses, the V-shaped recess 13 already described in FIG. 2 extending inwards from the outer surface of the retaining ring, so that the axis the recess is oriented parallel to the axial direction of the closure cap. A wider V-shaped recess 14 is arranged perpendicular to the V-shaped recess 13 and extends from the cap-side upper edge of the retaining ring to the lower edge, tapering to a point, the tip of the recess 14 coinciding with the axis of the recess 13. Furthermore, the recess 10 provided at the lower edge of the securing ring 3 can be seen, which is arranged in alignment with the tear-off point. To the right of the tear-off point, the edge-like projection 8 is arranged together with a window-shaped recess 11.

5 shows the more detailed details of the cross-sectional geometries of the bead-like projection 6. In particular, the representation shows the rounded profile 7 of the projection, to which the wedge-shaped region 15 adjoins at the bottom.

6 shows the cross-sectional geometry of the edge-like projection 8 with the sharp, pointed edge 9. The cross-sectional geometry of the edge-like projection 8 is characterized in particular by the projecting surface 16, which is at an angle α, which is preferably less than 90 °, with respect to the wall the locking ring is arranged.

The wedge-shaped tapering region 15 of the projection 8 extends below the sharp edge 9.

Claims (15)

1. Plastic cap which can be attached on a bottle neck and can, in particular, be screwed on, having an originality-warranty ring which is connected to the cap body via a predetermined breaking point and, in the attached position of the cap, engages behind a bead or the like formed on the bottle neck, the warranty ring (3) engaging behind the bead on the bottle neck by means of spaced-apart protrusions (6, 8) which are arranged in certain areas over the circumference of the warranty ring, characterized in that the protrusions (6, 8) project radially inwards in the direction of the bottle neck and are of at least two different designs as regards their vertical cross-section geometry, protrusions of a first cross-section geometry (6, 7) serving predominantly for horizontal widening of the warranty ring when the cap is pulled off, and protrusions of a second cross-section geometry (8, 9) retaining the warranty ring on the bottle neck in the vertical direction.
2. Cap according to Claim 1, characterized in that a first protrusion (6) is of a bead-like cross-section geometry with a rounded front end (7), and a second protrusion (8) is of an angular cross-section geometry with a sharp, pointed edge (9).
3. Cap according to one of the preceding claims, characterized in that the protrusions taper in the form of a wedge in their lower region (15).
4. Cap according to one of the preceding claims, characterized in that the angular and/or bead-like protrusions (6, 8) merge into the wall of the warranty ring (3) via rounded portions (17).
5. Cap according to Claim 2, characterized in that the angular protrusions (8) exhibit a projecting surface (16) which is set back, preferably by an angle α of 70° - 90° with respect to the inner circumferential surface of the warranty ring (3).
6. Cap according to one of the preceding claims, characterized in that the outer edges of the warranty ring (3) are rounded.
7. Cap according to one of the preceding claims, having a tear-off point, extending essentially parallel to the cap axis, in the warranty ring, characterized in that the tear-off point (12) is formed by two preferably V-shaped cutouts of the warranty ring (3), the first cutout (14) extending in a tapering manner from the cap-side upper edge of the warranty ring to the lower edge, and the second cutout (13) forming an incision in the axis of the first cutout of the warranty ring, from the outer surface thereof.
8. Cap according to Claim 1, characterized in that at least one bead-like protrusion (6) and one angular protrusion (8) are provided over the circumference.
9. Cap according to Claim 8, characterized in that three bead-like protrusions (6) are distributed uniformly over the circumference, and provision is made for at least one angular protrusion (8) between two bead-like protrusions in the vicinity of the tear-off point (12).
10. Cap according to one of the preceding claims, characterized in that groove-like, downwardly open cutouts (10) are arranged on the lower border of the warranty ring.
11. Cap according to Claim 10, characterized in that the groove-like cutouts (10) are arranged next to the bead-like protrusions (6).
12. Cap according to Claim 10, characterized in that a cutout (10) provided in the lower border of the warranty ring (3) is arranged in alignment with the tear-off point (12).
13. Cap according to one of the preceding claims, characterized in that the predetermined breaking point is formed between the warranty ring (3) and the cap (2) by narrow tear-off webs (5) which are formed at intervals over the circumference.
14. Cap according to one of the preceding claims, characterized in that window-like cutouts (11) are provided in the region of the warranty ring.
15. Cap according to one of the preceding claims, characterized in that the thread turns (4) integrally formed on the cap body (2) are produced in certain areas.

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