DE20211828U1 - tamper-evident closure - Google Patents

Description

Patent attorney Dr. My\. ^# .:. *.·"..· *..*,:.. 07/31/2002/93931

MÜHLHOFF, Hartmut, Dipl.-Ing.

Tamper-evident closure

The invention relates to a tamper-evident closure for containers with a screw cap and a tamper-evident ring which is directly or indirectly connected to the screw cap via axial webs which tear open when the screw cap is opened for the first time, thus enabling the screw cap to be removed from the container.

Tamper-evident closures for containers are known, in which a closure cap placed on the container opening is attached to a tamper-evident ring in such a way that only after the webs connecting the closure cap to the tamper-evident ring are torn open can the closure cap be separated from the tamper-evident ring and the closure cap can be completely removed from the container opening.

What known tamper-evident closures have in common is that when the closure cap is rotated, the tamper-evident ring is prevented from rotating or from moving axially by projections arranged on the container. This triggers tensile and shear forces acting on the webs, which ultimately lead to the webs tearing off.

For example, US-A-4 907 708 discloses a tamper-evident closure in which the closure cap is firmly connected to the tamper-evident ring via webs and projection means on the container neck and on the tamper-evident ring are designed in such a way that the tamper-evident ring is forced to move in both axial directions relative to

EN 2ü:>11828Ui

Patent attorney Dr. My ·..· .:. ·..'·..* ·..'.:.. July 31, 2002/93931

the container neck and is thereby prevented from axial displacement relative to the closure cap. The disadvantage of this known tamper-evident closure is the required precise adherence to the local position of the projection means on the closure cap and on the container, which is associated with a correspondingly high manufacturing effort and means a high rejection rate.

EP-A-0 589 254 discloses a tamper-evident closure in which the tamper-evident ring is firmly connected to the closure cap via webs in the same way. The tamper-evident ring has a first projection center! which can be brought into an engaging relationship with a radial ring collar on the container neck when the closure is first attached to the container neck. A second projection means arranged at a distance from the first projection means on the tamper-evident ring means that the tamper-evident ring is freely movable axially between the two projection means. The disadvantage here is also the need to place the projection means of the container precisely between the two projection means of the tamper-evident ring and also that when the closure is first closed, the first projection means of the tamper-evident ring, for example an annular projection or bead, has to be guided over the projection means of the container and stretched radially in the process, which can already lead to damage at this point.

Based on this known state of the art, it is the object of the invention to develop a tamper-evident closure which, with the simplest possible design and manufacture, enables easy assembly during initial closure and secure locking of the closure cap and which can be used on conventional containers without major modifications.

The task is solved according to the invention with the characteristic features

ui

Patent attorney Dr. My *..* .:. ·..*·..* *..'.:.. 07/31/2002/93931

The object of the invention is achieved in that the tamper-evident ring consists of an outer ring with several elastic tabs angled radially towards the container opening and an inner ring which is connected to the outer ring by means of thin axial webs and to the screw cap via a clamping connection. Advantageous embodiments of the invention are specified in the subclaims.

According to the invention, the tamper-evident ring is a separately manufactured component which, with its tabs evenly distributed around the circumference of the outer ring and with the inner ring, is inserted into the closure cap from below to such an extent that the outer ring extends the closure cap downwards. An outwardly projecting annular bead formed on the inner ring, which is fitted into a correspondingly formed recess in the closure cap, represents a force-fit connection in the axial direction between the inner ring and thus between the tamper-evident ring and the closure cap. The tamper-evident ring with its inner ring remains rotatable within the closure cap.

The functionality of the tamper-evident closure with the tamper-evident ring according to the invention is as follows:

During the initial closure, the closure cap with the inserted tamper-evident ring is screwed onto the container opening from above. The tamper-evident ring with its radial tabs arranged diagonally inwards is pushed axially downwards over the external thread of the container. The tabs of the tamper-evident ring have just enough space to fit between the outer ring and the external thread. After overcoming the external thread, the elastic tabs below the thread spring back against the container wall, whereby they are inclined according to their angled orientation.

Patent attorney Dr. Mey *..* .&iacgr;. *·»"··* *..%:.. 07/31/2002/93931

point upwards towards the container opening.

If the closure cap is screwed on further until the screwing end is reached, the tamper-evident ring, which can rotate in the closure cap, remains in this position because the tabs are now pressed tangentially against the cams arranged on the container wall below the external thread and thus it is also not possible to rotate the tamper-evident ring.

When the screw cap is opened for the first time by turning the cap, these cams prevent the tamper-evident ring from rotating together with the cap. In addition, the axial upward displacement of the cap initially pulls the outer ring upwards with its tabs and presses it against the last thread of the external thread. As the cap is unscrewed further and axially displaced upwards, which the tamper-evident ring can no longer follow, tensile and shear stresses are created between the tamper-evident ring and the cap, which ultimately lead to the thin webs tearing open.

The original frictional connection between the tamper-evident ring and the closure cap via the inner ring is thus eliminated and the closure cap can be completely removed without hindrance, while the separated outer ring remains on the container below the external thread.

Further details, advantages and features of the invention are explained in more detail below using an embodiment shown in schematic drawing figures.

Patent attorney Dr. Mey '··* ·&idigr;· *.·*'··" \·"«!.. 07/31/2002/93931

Show it:

Fig. 1 is a horizontal section through a tamper-evident ring according to the invention,

Fig. 2 is a vertical section through the tamper-evident ring of Fig. 1,

Fig. 3 is an enlarged partial view of Fig. 2 (detail A of Fig. 1 and

of Fig. 2),

Fig. 4 is a vertical section through a tamper-evident closure according to the invention,

Fig. 5a-d a container neck with tamper-evident ring in different screw-on positions.

In Figures 1 and 2, a tamper-evident ring 15 according to the invention is shown in a horizontal section (Fig. 1) and a vertical section (Fig. 2). The tamper-evident ring 15 consists of an outer ring 16 with several, in the example shown sixteen, tabs 19 evenly distributed around the circumference and an inner ring with an annular bead 20. The connection between the outer ring 16 and the inner ring 18 is provided by sixteen webs 17, which are also designed as predetermined breaking points and extend into web extensions 17' on the inner ring 18. In the example shown, the tabs 19 and the webs 17, 17' are arranged offset from one another. The tabs 19 are angled radially upwards and the webs 17 and the web extensions 17' are arranged vertically upwards.

DE 202*41 &ogr; ·::=:> Ul

Patent attorney Dr. Mey '··* ·&iacgr;· *..·*.." *..*ei«. July 31, 2002/93931

For a better overview, the right end of Fig. 2 is shown enlarged as detail A in Fig. 3 in a partial section. This makes it particularly clear that the outer ring 16 forming the lower end of the tamper-evident ring 15 is only connected to the inner ring 18 via the thin webs 17. The inner ring 18 has an outwardly projecting annular bead 20 which, as a projection means, produces the rotatable, but in the axial direction positive and non-positive connection with the screw cap 12 (see Fig. 4).

Figure 4 shows a tamper-evident closure 10 with a tamper-evident ring 15 according to the invention in the initial closure position. A screw cap 12 is screwed onto the external thread 13 of the container neck 11 until the cap base 23 with the HF sealing disc rests on the upper edge of the opening of the container 11, with the HF sealing disc sealing the container opening 14 in the usual way, which can be unsealed for initial use using a knife 24.

The inner ring 18 of the tamper-evident ring 15 is inserted from below into the recess 21 of the screw cap 12 to such an extent that the annular bead 20, in cooperation with an annular projection 25 arranged at the lower end of the recess 21, produces an axial force-fitting connection.

By screwing on the screw cap 12, the tamper-evident ring 15 attached to the screw cap 12 was pushed over the external thread 13 so far that the tabs 19 are located below the external thread 13 and, due to their oblique alignment, now rest with their ends on the container wall. At least one cam 22 arranged below the external thread 13 on the container wall prevents

DE 202*41 828 U1

Patent attorney Dr. Mey *··* ·&idigr;· *..**..* *..*ei.. 07/31/2002/93931

When the screw cap 12 is turned when it is opened, the tamper-evident ring 15 does not rotate as the tabs 19 are prevented from doing so by the cam(s) 22.

In Figures 5a to 5d, the position of the tamper-evident ring 15 is shown schematically for different screw positions of the screw cap 12. The screw cap 12 itself is not shown here, but only the container neck 11 with external thread 13 and the tamper-evident ring 15, characterized by the schematic individual parts 16, 17, 18, i.e. outer ring 16, axial webs 17 and inner ring 18.

Fig. 5a shows the beginning of the screwing process. The tamper-evident ring 15, consisting of outer ring 16 with tabs 19 and inner ring 18, is located at the level of the first thread, with the tabs 19 resting on the thread.

In Fig. 5b, the screwing-on process has progressed further, the tamper-evident ring 15 has been moved downwards and is now at the level of the second thread. Due to the downward movement, the tabs 19 have slipped over the first thread and are now resting on the second thread.

In Fig. 5c, when the screw cap 12 was further screwed on, the tamper-evident ring 15 was pushed further down over the external thread 13, so that the tabs 19 were pushed down over the last thread and are now located below it. The tamper-evident ring 15 remains in this position when the screw cap 12 is further screwed on, since the cams 22 arranged laterally on the container neck 11 prevent the tamper-evident ring 15 from rotating.

EN 20:>il828 Ui

Patent attorney Dr. Mey *··* »!· "..**.·* *···»&Sgr;*· 07/31/2002/93931

Fig. 5d shows the beginning of the first unscrewing of the screw cap 12. During the unscrewing process, during which the tamper-evident ring 15 could not follow the upward movement of the screw cap 12, the inner ring 18 was separated from the outer ring 16 by tearing off the webs 17 (see Fig. 3). The inner ring 18 remaining in the screw cap 12 is now located between the first and second thread, while the outer ring 16 with its tabs 19 remains below the external thread 13 on the container neck.

The invention is not limited to the application example shown, but can be used with a variety of known and different screw closures whose screw caps allow the use of a tamper-evident ring.

"&igr; f ^:

··

Patent attorney Dr. My ·..· .:. ·..*·..· %.*,:.. 07/31/2002/93931

List of reference symbols Tamper-evident closure 10 container 11 Screw cap 12 External thread container 13 Container opening 14 Originality ring 15 Outer ring 16 axial webs 17 Bridge approach 17' Inner ring 18 Tabs 19 Ring bead on the inner ring 20 Recess 21 axial cam on the container 22 Cap bottom 23 Knife 24 annular projection 25

Claims (7)

1. Tamper-evident closure ( 10 ) for containers with a screw cap and a tamper-evident ring ( 15 ) which is connected directly or indirectly to the screw cap ( 12 ) via axial webs ( 17 ) which tear open when the screw cap is opened for the first time and thus enable the screw cap ( 12 ) to be removed from the container, characterized in that the tamper-evident ring ( 15 ) consists of an outer ring ( 16 ) with several elastic tabs ( 19 ) angled radially at an angle to the container opening ( 14 ) and an inner ring ( 18 ) which is connected to the outer ring ( 16 ) by means of thin axial webs ( 17 ) and to the screw cap ( 12 ) via a clamping connection. 2. Tamper-evident closure ( 10 ) according to claim 1, characterized in that tabs ( 19 ) and webs ( 17 ) are arranged evenly distributed over the circumference of the outer ring ( 16 ). 3. Tamper-evident closure ( 10 ) according to claim 1 or 2, characterized in that the tamper-evident ring ( 15 ) with its inner ring ( 18 ) is inserted from below into the lower part of the screw cap ( 12 ) such that the outer ring ( 16 ) extends the screw cap ( 12 ) downwards. 4. Tamper-evident closure ( 10 ) according to claim 3, characterized in that, in order to produce the clamping connection, the inner ring ( 18 ) has an outwardly projecting annular bead ( 20 ) which is fitted into a correspondingly designed recess ( 21 ) in the lower part of the screw cap ( 12 ), whereby a force-fitting connection is produced in the axial direction between the screw cap ( 12 ) and the inner ring ( 18 ) and thus between the tamper-evident ring ( 15 ). 5. Tamper-evident closure ( 10 ) according to claim 3 or 4, characterized in that the tamper-evident ring ( 15 ) with its inner ring ( 18 ) is rotatable within the screw cap ( 12 ). 6. Tamper-evident closure ( 10 ) according to one or more of claims 1 to 5, characterized in that the tabs ( 19 ) of the tamper-evident ring ( 15 ) are dimensioned such that they fit between the outer ring ( 16 ) and the external thread ( 13 ) of the container. 7. Tamper-evident closure ( 10 ) according to one or more of claims 1 to 6, characterized in that at least one axially projecting cam ( 22 ) is arranged on the container below its external thread ( 13 ), against which the tabs ( 19 ) of the tamper-evident ring ( 15 ) are pressed when the screw cap ( 12 ) is in a correspondingly low position when it is rotated and which thus prevents further rotation of the tamper-evident ring ( 15 ).