EP3060490A1

EP3060490A1 - Self-opening closure with optimized force transmission

Info

Publication number: EP3060490A1
Application number: EP14771563.5A
Authority: EP
Inventors: Fritz Dill; David Koller; Markus J. SCHELLENBERG
Original assignee: Terxo AG
Current assignee: Terxo AG
Priority date: 2013-10-25
Filing date: 2014-09-19
Publication date: 2016-08-31
Anticipated expiration: 2034-09-19
Also published as: US20160229582A1; TR201908056T4; CA2924665A1; CH708742A1; CN105683051A; WO2015058912A1; IL244536A0; PL3060490T3; EP3279103B1; EA201690772A1; EP3060490B1; EP3279103A1; US9708096B2; ES2730210T3; ZA201602836B; ES2655516T3; PL3279103T3

Abstract

The invention relates to a self-opening closure with a pouring spout (12), a self-opening sleeve (20) which is guided in the connector in a helical manner, and a cover (30) which covers the pouring spout (12). A driver cam (24) is formed on the self-opening sleeve, said driver cam defining a guide surface (241). The cover has a driver (34) which defines a front edge (341). The front edge interacts with the guide surface of the driver cam. The front edge and the guide surface are inclined by the same angle of inclination relative to the longitudinal axis in order to allow an optimal force transmission between the cover and the self-opening sleeve. Additionally, the guide surface can be designed in a concave manner, and the front edge of the driver can be rounded in a corresponding manner in order to prevent a radial deflection of the driver towards the inside.

Description

TITLE Self-opening closure with optimized power transmission

TECHNICAL AREA

The present invention relates to a so-called self-opener closure, which is suitable for opening and reclosing a composite packaging.

STATE OF THE ART

Flowable foods such as drinks are often packaged in composite packaging. In such packaging usually a cardboard carrier on both sides with plastic, usually polyethylene (PE), laminated. To provide an oxygen barrier, a barrier layer of aluminum or an oxygen-impermeable plastic such as EVOH and auxiliary layers for laminating the barrier layer are often additionally present. It is known to weaken the package wall in the openable area to facilitate opening, e.g. By punching a line of weakness in the cardboard carrier or by punching a complete hole from the cardboard carrier before laminating the films.

In order to open such packages, various self-opening closures have become known from the prior art, in which a self-opening sleeve, which usually has a plurality of teeth, is guided via a threaded connection in a Ausgiessstutzen. A screw cap acts on the first unscrewing so with the Selbstöffnerhülse together that it moves downwards helically and thereby pierces or cuts with her teeth underneath the packaging wall underneath. To take the self-opening sleeve, one or more drivers are formed on the screw cap, which cooperate with corresponding driving cam on the inner peripheral wall of Selbstöffherhülse. In general, the drivers have a running parallel to the longitudinal axis of the Ausgiessstutzens, in the circumferential direction pointing leading edge, which cooperates with a likewise pointing in the circumferential direction surface of the corresponding driving cam. This is the case, for example, in EP 1 088 764 A1, in WO 03/002419 A1 or in WO 2008/092289 A2. Self-opening closures often require a relatively large force application to produce the torque required for initial opening on the lid. The necessary forces are difficult to apply, especially for elderly or sick people. It is therefore desirable to minimize the torque required for initial opening as much as possible.

WO 2004/000667 Al and WO 2006/050624 AI disclose self-opener closures in which the self-opening sleeve does not perform a helical motion, but is initially pushed axially without rotation down the first time the shutter and then performs a pure rotation. In order to force this form of movement, corresponding vertically and horizontally extending ribs are provided on the inside of the Ausgiessstutzens and the outside of the self-opening. The lid has drivers in the form of cylinder wall segments, whose respective front edge initially at an acute angle obliquely to the lid surface and then perpendicular to the lid surface, ie axially, runs. The obliquely extending to the lid surface area of the leading edge of the driver cooperates with driving cams on the self-opening sleeve to push this when unscrewing the lid first vertically down, while the axially extending portion of the leading edge serves to subsequently take the driving cams in the circumferential direction and the self-opening sleeve to put it in a pure rotation. Since in such closures the path traveled by the self-opening sleeve in its initial axial movement against the resistance of the packaging wall is very short, in such closures often even greater opening forces than with closures with threaded self-opening sleeves are overcome. PRESENTATION OF THE INVENTION

It is an object of the present invention to provide a self-opener closure which makes it possible to open a package with reduced effort. simultaneously It should be possible to produce such a closure easily and with little cost of materials.

This object is achieved by a self-opener closure according to claim 1. Advantageous developments are specified in the dependent claims.

A self-opener closure is proposed which comprises:

a tubular Ausgiessstutzen which defines a longitudinal axis and is provided on its inner side with an internal thread;

a cover which covers the pouring spout at the top and which serves the purpose of

Opening the closure relative to the Ausgiessstutzen rotatable in an opening direction and in order to reclosure of the closure in a direction opposite to the opening direction closing direction is rotatable, wherein the lid has at least one driver defining a leading edge; and

a Selbstöffnerhülse, which is provided with an external thread, which in the

Engages inside thread of the Ausgiessstutzens, and having on its inner side at least one driving cam, wherein the driving cam defines a guide surface which cooperates when opening the closure with the leading edge of the driver to helically move the Selbstöffnerhülse from its initial position in the Ausgiessstutzen,

wherein the leading edge is inclined downwardly at a first inclination angle relative to the longitudinal axis, and wherein the guide surface is inclined relative to the longitudinal axis by the same inclination angle as the leading edge. This design is based on the recognition that in self-opener closures of the prior art, in which the leading edge of the driver is parallel to the axis of rotation, the power transmission between the lid and the self-opening is not optimally solved when the self-opening sleeve ausfuhrt a helical movement. In a running parallel to the axis of rotation Mitnehmerkante the user applied to the cover opening torque is transmitted exactly in the circumferential direction, ie, the opening torque is converted into a pure torque on the self-opening sleeve. In fact, the self-opening sleeve moves in a helical movement not only in the circumferential direction, but also has a Movement component in the axial direction down. Therefore, it is better for the opening torque to be converted into both a torque applied to the self-opening sleeve and an axial force acting downwardly on the self-opening sleeve. The present invention ensures optimum power transmission by the front edge of the driver (which is located at the front in the opening direction) being inclined downwards and cooperating with a correspondingly inclined guide surface on the driving cam. As a result, the opening torque is partially converted into a torque applied to the self-opening sleeve and partially into an axial force. At the same time, the forces acting on the opening between the driver and the driving cam are distributed particularly uniformly over the guide surface of the driving cam in this manner. As a result, the frictional forces acting between the driver and driving cam are minimized. Overall, the torque required to open the closure for the first time is reduced. The angle of inclination of the front edge of the driver is preferably greater than or equal to the pitch angle of the internal thread, but is at least 50% of the pitch angle of the internal thread in Ausgiessstutzen to produce a sufficiently large force component down. In practice, an inclination angle of the leading edge of about 10 ° -30 ° has proven.

The lid usually has a top wall and a circumferential side wall. On the inside of the side wall usually one or more guide structures are formed, which cause a guide of the lid on Ausgiessstutzen. Preferably, these guide structures are a single or multi-start internal thread, but it can also be provided, for example, a bayonet guide, in which the lid first performs a pure rotation when opening and then is axially removable. At Ausgiessstutzen usually also one or more guide structures are formed, which are complementary to the guide structures on the lid. If, for example, an internal thread is provided on the cover, the guide structure on the pouring spout is a complementary external thread. The driver is preferably mounted on the top wall of the lid and preferably extends downwardly from the top wall. It preferably has the basic shape of a cylinder wall segment, wherein the front edge of the cylinder wall segment the mentioned leading edge of the driver forms and is accordingly inclined relative to the longitudinal axis. Preferably, exactly one driver is present.

In order to prevent the driver from evading the opening forces radially inwardly the first time the closure is opened, the guide surface is preferably not flat with respect to the radial direction, but rather concave, so that it at least partially surrounds the front edge of the carrier when the closure is opened. Accordingly, the leading edge of the driver is preferably correspondingly convexly curved.

Preferably, the guide surface has no sharp kinks. In this way it can be avoided that the driver and the driving cam hooked together so that the opening process is hindered. Preferably, the leading edge of the driver has a shape that is at least partially complementary to the shape of the guide surface of the driving cam. As a result, at least one area of the guide surface lies flat on the opening of the closure and not only pointwise on the leading edge of the driver. The guide surface is preferably along its entire length at the front edge of the driver, which is referred to here as the "length" parallel to the front edge of the driver.Thus, the forces acting on opening over a larger area are transmitted, ie the pressure (force Preferably, the length of the guide surface is at least 2 mm Preferably, the closure is designed such that the self-opening sleeve after initial opening of the closure remains in its lower end position, Thus, when re-closing of the driver is not taken back in the direction of its initial position upwards.To enable this, the driving cam is preferably formed in a ramp with respect to the opening direction in front of the guide surface area ramped obliquely to the opening direction inwardly directed sliding surface which merges continuously (without steps) in an inner cylindrical surface of the self-opening sleeve. The driver then slides when reclosing the closure with its trailing edge on the ramp-like sliding surface of the Driving cam, so that the driver dodges when reclosing through the driving cam radially inward and slides past the driving cam.

In order to facilitate the sliding of the driver on the sliding surface, the trailing edge of the driver is preferably inclined by a second inclination angle relative to the longitudinal axis, wherein the second inclination angle is greater in magnitude than the first inclination angle. In particular, it is preferred that the second inclination angle is at least 50% larger, more preferably at least twice as large as the first inclination angle. In practice, a slope angle of the trailing edge in the range of about 30 ° - 45 ° has proven. If the trailing edge should be continuously curved with respect to the longitudinal axis, this information refers to the inclination angle in the middle of the trailing edge.

The resulting driver has in its upper region, near the top wall of the lid, its greatest extent along the circumferential direction, while this extension continues to decrease towards the bottom (towards its free end). As a result, the driver is most stable there, where the largest forces act on initial opening, namely in the upper region, which is effective at the beginning of the opening movement, when the self-opening sleeve begins to separate the packaging wall. In addition, by this design, the force acting on the driver during opening and closing reaction forces transferred particularly well to the top wall of the lid and thus to the entire lid structure, and it is avoided that there are places where excessive stresses occur in the material to Deformation or even lead to a termination of the driver. Due to this optimized power transmission, the driver can be made very thin in the radial direction. This not only has advantages for the production (lower material consumption), but also minimizes the forces when re-closing, as a thinner driver can be easily deflected inwards. In order to prevent the self-opening sleeve falling down out of the Ausgiessstutzen, a radially inwardly extending retaining cam may be formed at the lower end of the Ausgiessstutzens. In addition, measures are conceivable to prevent the self-opening sleeve again in the direction of the starting position moved back, for example, that the axial distance between two thread segments of the internal thread tapers at the lower end of the Ausgiessstutzens to produce a clamping action on a cooperating thread of the external thread of the self-opening sleeve.

The self-opening sleeve preferably has a support ring on which the external thread is formed, and a first tooth, which extends from the support ring projecting downwards and defines a front cutting edge. The front cutting edge is preferably inclined at a third angle of inclination relative to the longitudinal axis. This angle preferably corresponds at least to the pitch angle of the internal thread of the pour spout, preferably at least twice this pitch angle. As a result, the cutting edge acts on the packaging wall during cutting, partly along the direction of movement of the self-opening sleeve and partly downwards. The self-opening sleeve may have a second tooth, which follows the first tooth with respect to the opening direction. If exactly two teeth are present, if the self-opening sleeve otherwise has no further teeth, it is preferred if the second tooth at an angular distance of about 90 ° - 180 °, preferably from about 110 ° - 150 °, more preferably from about 130 °, with respect to the circumferential direction or opening direction, measured from tip to tip, follows the first tooth. But it is also conceivable that the self-opening sleeve has three or more teeth, in which case the distance between the teeth should be chosen correspondingly lower.

A self-opening sleeve with exactly two teeth at said distance has been proven especially in composite packaging in which a hole was punched in the cardboard before the lamination of the plastic and, if necessary, metal layers. In such prepunched packaging, this hole is covered by a film composite which may be quite tough and may be quite ductile, thereby resisting tearing. By exactly two teeth acting on the film composite, the film composite is clamped when opening, so to speak between two tooth tips. As a result, the film composite is easier to travel. It has also been confirmed in tests that for pre-cut packaging two teeth are optimal. However, closures with only one tooth or with exactly three teeth can also be used. Preferably, the second tooth extends with respect to the longitudinal axis substantially equal to the first tooth down. As a result, two regions of the film composite are simultaneously reached by the tooth tips, so that the clamping effect occurs early and a high tear effect is achieved.

Preferably, the second tooth has a front cutting edge that extends at substantially the same inclination angle relative to the longitudinal axis as the front cutting edge of the first tooth. As a result, both teeth have the same cutting action. This has a positive effect on the further opening process after the film composite has been touched once.

A ring segment (a cylinder wall segment-shaped material region) may extend continuously between the first tooth and the second tooth, extending downwardly from the support ring, this ring segment after the first opening of the closure together with the first and second teeth down out of the Ausgiessstutzen sticking out, in particular by at least 1 mm. On the one hand, this material area reinforces the self-opening sleeve and thus contributes to its stability. On the other hand, such a material area can also serve to keep the cut-out packaging segment ("flap") away from the pouring opening after cutting.

In order nevertheless to ensure a good emptying, the self-opening sleeve preferably has a segment along its circumference, which remains substantially completely within the pouring spout after the first opening of the closure. In other words, there is a peripheral region in which the self-opening after the first opening of the closure does not project downwards out of the pouring spout or at most by the thickness of the packaging wall, concretely at most about 1 mm, preferably at most 0.5 mm, from the Outlet protrudes. In this area (hereinafter also referred to as "residual emptying gap"), the contents of the container can pass unhindered into the pour spout, without any part of the self-opening sleeve would be in the way. In order to prevent the self-opening sleeve from moving inadvertently after the closure has been mounted, eg due to vibrations during application or during later transport, the self-opening sleeve may have a locating cam on its inside at a certain distance from the driving cam. The catch is located after the assembly of the closure and before the first opening of the closure between the driving cam and the fixing cam. As a result, the mobility of the self-opening sleeve relative to the driver (and thus against the screw cap) is limited. Ideally, such a movement (play) of the self-opening sleeve is completely prevented. But at least the game is limited to a small angle range, eg of max. 20 °, limited.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be described below with reference to the drawings, which are given by way of illustration only and are not to be interpreted as limiting. In the drawings show:

Fig. 1 is a perspective view of a closure according to a first

Embodiment in its open position;

Fig. 2 is another perspective view of the closure of Fig. 1;

Fig. 3 is a central longitudinal section through the closure of Fig. 1 in his

Starting position;

Fig. 4 is a perspective view of the base of the closure of Fig. 1;

5 is a perspective view of the self-opening sleeve of the closure of FIG.

Fig. 6 is a perspective view of the lid of the closure of Fig. 1;

Fig. 7 is a perspective view of the closure of Fig. 1 in its

Starting position; and

8 shows a perspective view of a self-opening sleeve of a closure according to a second embodiment, with only one tooth; and

Fig. 9 is a perspective view of a self-opening sleeve of a closure according to a third embodiment, with three teeth. DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 to 7 illustrate different views of a first embodiment of a closure according to the invention. This variant of the closure is particularly suitable for composite packaging, which have a cardboard layer with pre-punched opening, which is laminated with plastic films and optionally a metal foil. The closure consists of a base 10, which is shown alone in FIG. 4, of a self-opening sleeve 20, which is shown alone in FIG. 5, and of a cover 30, which is shown alone in FIG.

The base 10 has a base plate 11 for connecting the closure to a packaging wall, not shown. The base plate 11 has a circular opening which is surrounded by a tubular, cylindrical Ausgiessstutzen 12. The pour spout 12 extends from the base plate 11 up to a circumferential, circular upper edge 13 upwards. The spout 12 defines due to its cylindrical basic shape a central longitudinal axis L (see Fig. 3) and an opening direction U along its circumference (see Fig. 4). Accordingly, a radial direction is a direction extending outward from the central longitudinal axis L toward the peripheral wall of the pouring spout 12.

On the inside of Ausgiessstutzens 12, an internal thread 14 is formed, which has a pitch angle α relative to a plane which is perpendicular to the longitudinal axis 11 has. In the present example, it is a two-start thread with a pitch angle α of about 6.5 ° and about 1.5 turns. At the lower end of the thread 14, a retaining cam 19 is formed. On the outside of Ausgiessstutzens 12 an external thread 15 is formed, which has a significantly smaller pitch angle than the pitch angle α of the internal thread. Below the external thread 10 a plurality of retaining webs 16 are arranged on the base, which cooperate with a guarantee strip, which will be described in more detail below. Ramps 17 on the base plate 11 support the transport of the closure in an application device. Reinforcing ribs 18 reinforce the base plate 11 on its underside. The self-opening sleeve 20 has a support ring 21 on which two teeth 22, 23 are formed. The support ring 21 is provided on its outer side with an external thread 25 which is complementary to the internal thread 14 of the Ausgiessstutzens 12. In the present example, the (also zweigängige) external thread 25 is slightly more than half a turn.

On the inside of the support ring 21, a hook-like driving cam 24 is formed. This defines a guide surface 241 which is inclined to the longitudinal axis L and not flat with respect to the radial direction, but concavely curved. In this case, the guide surface 241 no sharp kinks. The guide surface is approx. 4 mm long. As seen in the opening direction in front of the guide surface 241 of the driving cam 14 is wedge-shaped or ramp-shaped and forms an opening direction inwardly inclined ramp-like sliding surface 242. This sliding surface 242 has no steps or kinks and is continuous in the cylindrical inner peripheral surface of the support ring 21 on.

At some distance from the driving cam, located in the opening direction behind the driving cam, there is a fixing cam 243, which can be seen in FIG. Each of the two teeth 22, 23 has a front cutting edge 221 or 231 and a blunt rear edge 222, 232. The front cutting edge 221 or 231 is inclined at an angle δ relative to the longitudinal axis downwards. In the present example, the inclination angle is about 18 °. The rear edge 232 or 232 extends at an angle to the longitudinal axis L, which is considerably larger than the angle δ. In the present example, this angle is about 65 °. The two teeth are at a distance of about 120 ° along the circumferential direction. Between the first and the second tooth, a ring segment 26 (ie, a cylinder wall segment-shaped material region) is formed, which extends from the support ring 21 downwards. As seen in the opening direction in front of the first tooth 22 and behind the second tooth 23 further ring segments 27 are formed, which extend but only a relatively small area from the support ring 21 down. Between these two ring segments 27 there is a gap which defines a residual emptying area 28 and whose function will be explained in more detail below. The teeth 22, 23 and shell wall portions 26, 27 are opposite the support ring 21st slightly offset radially inwards. In between, a circumferential edge 29 is formed on the inside of the self-opening sleeve 20, which simultaneously forms the lower edge of the self-opening sleeve 20 in the case of the residual emptying area 28. The cover 30 has a cover wall 31 and a circumferential, substantially cylindrical side wall 32. On the inside of the side wall 32, an internal thread 33 is formed, which cooperates with the external thread 15 on the spout 12. From the top wall 31 of a single driver 34 extends axially downwards. The driver 34 forms a leading edge 341 and a trailing edge 342. The leading edge 341 is inclined relative to the longitudinal axis L by an angle ß. The angle ß in the present example is about 20 °. It is thus significantly larger than the pitch angle α of the internal thread 14 in the spout 12. The trailing edge 342 is inclined relative to the longitudinal axis L by an angle γ. In the present case, the angle γ is approximately twice as large as the angle β in the present case and has the opposite sign for this purpose. The driver has the basic shape of a cylinder wall segment, wherein the helical leading edge of the cylinder wall segment forms the aforementioned leading edge 341 of the driver and the helical trailing edge of the cylinder wall segment forms the mentioned trailing edge 342 of the driver. The lower edge of the driver runs perpendicular to the longitudinal axis. The front edge 341 of the driver 34 is formed in a region which extends over the entire length of the front edge 341, complementary to the guide surface 241 of the driving cam 24. As a result, this region of the front edge 341 lies flat against the guide surface 241. At the lower end of the side wall 32 of the lid 30, a guarantee strip 35 is formed with inwardly directed retaining cams 36. A cut is made ("slitting") between the side wall 32 and the guarantee strip 35 so that the guarantee strip is connected to the rest of the cover only over thin areas of material This prevents the guarantee strip 35 from being separated from the remaining lid when it is opened for the first time, falls down onto the base plate 11, thus indicating the first opening known to the art.

The closure is preferably made in two pieces, the base 10 and the self-opening sleeve 20 being made in one piece in a single injection mold, e.g. made of HDPE. For this purpose, the self-opening sleeve 20 is initially connected at its upper edge via thin material bridges 201 (FIG. 5) to the underside of the base 10 after production. these bridges of material are broken during the assembly of the closure. The lid 30 is made in a separate injection mold and may be made of the same material as the base 10 and the self-opening sleeve 20. Such a two-piece production of the closure is basically known from the prior art.

The closure is assembled by pressing the self-opening sleeve 20 axially into the pour spout 12 and pressing the lid 30 axially onto the spout 12. The closure is then in its initial position, which is illustrated in Figures 3 and 7. The self-opening sleeve 20 is located completely within the pour spout 12. As can be seen in FIG. 7, in this position the catch 34 is arranged between the drive cam 24 and the fixing cam 243. This prevents inadvertent rotation of the self-opening sleeve 20 in the assembled closure. In this form, the closure is positioned over an overlaminated opening of the package wall and attached to the package wall (e.g., welded or glued).

To open the package for the first time, the user turns the lid 30 counterclockwise (ie, in the opening direction U). In this case, the cover 30 takes over the driver 34 and the driving cam 24 with the self-opening sleeve 20 and also puts them in rotation. In this case, the front edge 341 of the driver 34 over the entire length of the driving cam 24 on the guide surface 241 of the driving cam 24 and slides on this. Due to the threaded connection between the self-opening sleeve 20 and the Ausgiessstutzen 12, the self-opening sleeve 20 moves downwardly helically. The teeth 22, 23 pierce the laminated films and, if necessary, the metal layer on the opening of the packaging wall and then cut them further on. The lid 30 takes the self-opening sleeve 20 until it has reached its lower open position, as illustrated in FIG. At this point listen the external thread 15 on Ausgiessstutzen 12 and the internal thread 33 on the lid 30 to interlock, and the lid 30 can be deducted from Ausgiessstutzen 12. The self-opening sleeve is prevented by the retaining cam 19 from further downward rotation, so that they can not fall down from the spout 12 down. The teeth 22, 23 and the ring segments 26, 27 now project downwards out of the pour spout 12. In the residual emptying region 28, however, the self-opening sleeve 20 does not protrude downwards out of the pouring spout 12, or at least does not protrude down beyond the packaging wall. This facilitates the emptying of the container.

When first opening the shutter, the driver 34 exerts a force on the driving cam 24, which is directed obliquely downwards. By this power transmission between driver 34 and driving cam 24, the downward movement of the self-opening sleeve 20 is supported. The thereby acting reaction forces are transmitted over the entire length of the base of the driver 34 on the top surface 31 of the lid 30, without causing excessive tensions occur. Overall, such a nearly optimal power transmission is guaranteed. By the hook-like configuration of the driving cam 24 while a radial deflection of the driver 34 is prevented inwardly.

To reclosure, the user puts the lid 30 back on the spout 12 and screwed the lid 30 back on the spout 12. In this case, the driver 34 slides with its trailing edge 342 on the sliding surface 242 of the driving cam 24 and is thereby deflected radially inwardly, so that the self-opening sleeve 20 remains in its lower open position.

FIG. 8 illustrates by way of example a self-opening sleeve (cutting ring) according to a second exemplary embodiment of the present invention. Corresponding parts are provided with the same reference numerals as in the embodiment of Figures 1 to 7. This embodiment is particularly suitable for packaging that does not have a pre-punched and overlaminated opening. This can also be packaging from a single-layer plastic wall. In this case it is advantageous to provide only a single tooth 22. In this way, the Opening forces optimally concentrated on a single point. Apart from this, the closure of FIG. 8 is designed essentially the same as that of FIGS. 1 to 6. A self-opening sleeve (cutting ring) according to a third exemplary embodiment is shown by way of example in FIG. Here are three teeth 22, 23, 23 'present, the tips are spaced by about 70 °. Otherwise, corresponding parts are in turn provided with the same reference numerals as in the embodiment of Figures 1 to 7.

Of course, a variety of modifications are possible without departing from the scope of the invention. It is particularly conceivable not to connect the lid via a threaded connection with the Ausgiessstutzen, but for example to provide a bayonet-type connection, in which the lid first performs a pure rotation when opening and is then withdrawn axially. It is obvious that such a variant has only a small influence on the interaction of the driver with the driving cam. Of course, the shape of the tooth or teeth can also be chosen differently than in the present example. In addition, a (blunt) tooth-shaped hold-down may be provided to bend the cut-out segment of the packaging wall ("flap") back inside the package so that this cutout does not hinder the pouring out of the contents of the package In principle, the pouring spout can, instead of being formed on a separate base element, also be embodied integrally with the packaging wall or form the upper end of a bottleneck.

LIST OF REFERENCE NUMBERS

Base 243 locating cams

Base plate 25 external thread

Outlet nozzle 26 Ring segment upper edge 27 Ring segment

Internal thread 28 gap

External thread 29 edge

Retention bars 30 Lid

Ramp 31 top wall

Reinforcement Rib 32 Sidewall

Holding cam 33 internal thread

Self-opening sleeve 34 driver

Material bridges 341 leading edge

Carrier ring 342 Trailing edge of first tooth 35 Guarantee tape front cutting edge 36 Projections rear edge L Longitudinal axis of second tooth U Opening direction of front cutting edge α Incline angle of trailing edge ß Inclination angle

Driving cams Ί inclination angle

Guide surface δ inclination angle

sliding surface

Claims

PATENT CLAIMS

Self-opening closure, comprising:

a tubular pouring spout (12), which defines a longitudinal axis (L) and is provided on its inside with an internal thread (14) with a pitch angle (a);

a lid (30) covering the pouring spout (12) upwards, which can be rotated in an opening direction (U) for the purpose of opening the closure and in a closing direction opposite to the opening direction (U) in order to re-close the closure, the lid (30) has at least one driver (34) defining a front edge (341); and

a self-opening sleeve (20), which is provided with an external thread (23) which engages in the internal thread (14) of the pouring spout (12), and which has at least one driving cam (24) on its inside, the driving cam (24) being a Guide surface (241) is defined, which cooperates with the front edge (341) of the driver (34) when the closure is opened for the first time in order to move the self-opening sleeve (20) in the pouring spout (12) downwards in a screw-like manner from a starting position into an open position,

characterized in that the front edge (341) is inclined downwards relative to the longitudinal axis (L) by a first angle of inclination (ß), and that the guide surface (241) is inclined relative to the longitudinal axis (L) by the same angle of inclination as the front edge (341) slopes.

Self-opening closure according to claim 1, wherein the first inclination angle (ß) is at least 50% of the inclination angle (a) of the internal thread (14) of the pouring spout (12).

Self-opening closure according to claim 1 or 2, wherein the guide surface (241) is designed to be continuously concavely curved with respect to a radial direction, so that it surrounds the front edge (341) of the driver (34) when the closure is opened for the first time.

4. Self-opening closure according to claim 3, wherein the front edge (341) of the driver (34) is convexly curved.

5. Self-opening closure according to claim 3 or 4, wherein the front edge (341) of the driver (34) has at least partially a shape that is complementary to the shape of the guide surface (241) of the driver cam (24).

6. Self-opening closure according to one of claims 3-5, wherein the guide surface (241) rests along its entire length on the front edge (341) of the driver (34) when the closure is opened for the first time.

7. Self-opening closure according to one of the preceding claims,

wherein the driving cam (24) is designed in a ramp shape in front of the guide surface (241) with respect to the opening direction (U), with a sliding surface (242) directed inwards at an angle to the opening direction (U), which continuously extends into an inner cylindrical lateral surface of the self-opening sleeve (20). passes, and

wherein the driver (34) slides over the sliding surface (242) of the driver cam (24) when the closure is reclosed.

8. Self-opening closure according to claim 7, wherein the driver (34) defines a rear edge (342) which is inclined relative to the longitudinal direction by a second angle of inclination (γ), the second angle of inclination (γ) being larger in magnitude than the first angle of inclination (ß ).

9. Self-opening closure according to one of the preceding claims, wherein the

Self-opening sleeve (20) has a support ring (21) on which the external thread (23) is formed, and at least one first tooth (22) which extends downwards protruding from the support ring (21) and defines a front cutting edge (221).

10. Self-opening closure according to claim 9, wherein the self-opening sleeve (20) has a second tooth (23) which is at an angular distance from the first tooth (22). of approximately 90° - 180° with respect to the opening direction, measured from tip to tip, and otherwise has no further teeth.

11. Self-opening closure according to claim 10, wherein the second tooth (23) extends downwards with respect to the longitudinal axis (L) substantially the same distance as the first tooth (22).

12. Self-opening closure according to claim 10 or 11, wherein the second tooth (23) has a front cutting edge (231) which extends at substantially the same angle of inclination relative to the longitudinal axis as the front cutting edge (221) of the first tooth (22).

13. Self-opening closure according to one of claims 10-12, wherein a ring segment (26) is formed continuously between the first tooth (22) and the second tooth (23), which extends downwards from the support ring (21), this ring segment (26) protrudes downwards out of the pouring spout (12) together with the first and second teeth (22, 23) after the closure has been opened for the first time.

14. Self-opening closure according to one of the preceding claims, wherein the self-opening sleeve (20) has a circumferential region (28) in which the self-opening sleeve (20) does not protrude downwards from the pouring spout (10) after opening the closure for the first time or at most by approx . 1 mm protrudes downwards from the pouring spout (10).

15. Self-opening closure according to one of the preceding claims, wherein the self-opening sleeve (20) has a fixing cam (243) on its inside, and wherein the driver (34) is positioned between the driving cam (24) and the fixing cam (243) before the closure is opened for the first time ) is arranged so that the self-opening sleeve is immovable relative to the screw cap (30) or is movable by a maximum of 20 ° relative to the screw cap (30).