EP2331418B1 - Cap with a cut weakening line and method for making said cap - Google Patents

Abstract

The invention relates to a cap (1) that comprises a circular skirt (12), said cap including an irremovable portion (12-2) fixedly attached about the neck of a vessel (2) and a removable portion (12-1) removably attached to the neck, the irremovable and removable portions being separated by a first weakening line (20). In order to maintain the removable portion of the skirt attached to the irremovable portion of the skirt after the first opening, the skirt is provided with a second peripheral weakening line (34). It is also provided that the first weakening line extends less than 360°, while the two ends (34A, 34B) of the second weakening line are located along the periphery of the skirt respectively between a first (28A) of the two ends of a linking portion of the skirt and the hasp (26-1) closest to said first end, and between the second end (28B) of the linking portion and the hasp (26-6) closest to said second end.

Description

The present invention relates to a cap for a container neck, and a method of manufacturing such a cap.

The invention relates, in general, to plugs comprising a skirt which surrounds the neck of a container and a lower part of which, when it is considered that this neck extends vertically with its upwardly directed mouth, is intended to to remain around the neck after the first opening of the cap and is in particular in the form of a tamper-evident band. The remainder of the skirt, that is to say its upper part, is provided removable relative to the neck, while being initially connected to the lower non-removable portion of the skirt by frangible bridges, distributed along the periphery of the skirt and able to be broken at the first opening of the cap. The weakening line formed by these bridges serves as a witness of this first opening, for the attention of users. In the context of the present invention, the nature of the removable connection between the upper skirt portion and the container neck is indifferent, so that the invention also aims, for example, the so-called "snap" caps, it that is to say the plugs able to be clipped around the neck, that the caps screwed.

The invention is more particularly concerned with plugs whose line of weakness is cut off, that is to say which comprises a succession of through-cuts, cut through the wall of the skirt and along its periphery, of to define, between two successive notches, one of the aforementioned frangible bridges. Achieving the line of weakening by cutting rather than molding is preferred because it is more economical and more practical since it does not require the use of complex molds, provided for example with drawers. However, a weakening line obtained by cutting is traditionally provided to extend over the entire periphery of the skirt and in a plane perpendicular to the longitudinal axis of the skirt, which limits the possibilities of arrangements of the caps, to the difference of the plugs whose line of weakening is obtained by molding, such molded lines can include including a portion of non-breakable material which connects the removable skirt portion to the non-removable skirt portion, even when the closure is open, as proposed in US-A-5,215,204 , this document disclosing a plug according to the preamble of claim 1.

The object of the present invention is to improve in a simple and economical manner the manufacture of cut-off line caps, to have a plug whose removable skirt portion remains connected to the non-removable skirt portion after the first opening of the cap.

For this purpose, the invention relates to a cap for a container neck, as defined in claim 1.

The idea underlying the invention is to seek to improve existing methods and means for cutting in a plug a traditional line of weakness to, firstly, achieve this line of weakness on a portion only of the skirt so as to leave a non-breakable connection portion between the removable and non-removable skirt portions and, on the other hand, cut a second weakening line which extends over less than half of the periphery of the skirt. the skirt and which is located, when it is considered that the axis of the skirt is vertical with its non-removable part directed downwards, vertically above and on either side of the aforementioned non-breakable connection portion. The notches of these first and second lines of weakness are distinguished from molded embodiments because they have, before the first opening of the stopper, contiguous edges which, in particular, thus prevent dust and dirt from reaching the inside. of the skirt via these weakening lines. The cutting of the second weakening line is quick and easy to achieve insofar as this weakening line extends into the removable skirt portion which, traditionally, has an axial dimension greater than the non-removable skirt portion , the latter being reduced most of the time to a thin strip of inviolability, for which the presence of the permanent restraint means around the neck limits the possibilities of development by cutting. When opening the cap according to the invention for the first time, the bridges of the first line of weakness break, while the connecting portion remains without being able to be driven upwards by the removable skirt portion. because of the retention of the non-removable skirt portion around the container neck. The upward movement of the removable skirt part, under the action of the user, causes deformation of the strand interposed between the first and second lines of weakening, more precisely the deformation of the lateral portions of this strand arranged on either side of the connecting portion, by relative spacing of the edges of the or notches of the second weakening line. This deformation of the strand is facilitated by the first weakening line in the sense that the aforementioned lateral portions of the strand are, throughout their entire length, devoid of jumpers along this first line of weakening, if it is not possible to the vertical plumb of the ends of the second weakening line.

Thus, the plug according to the invention is as efficient as the plugs with weakening lines molded in the sense that the removable skirt portion remains connected to the non-removable skirt portion after the first opening of the plug, via of the aforementioned connecting portion, with the significant advantages that the molds for manufacturing the plugs according to the invention are less complex and less fragile, while including more molding cavities, than molds for manufacturing molded plug caps. In addition, it is possible to quickly and easily switch from making existing plugs with a single cut-off line to making plugs according to the invention, by adding or removing the necessary arrangements for cutting the second line. of weakening, thus offering a great flexibility of production of different plugs.

Advantageous features of the plug according to the invention, taken individually or in any technically possible combination, are specified in the dependent claims 2 to 9.

The invention also relates to a method of manufacturing a cap for a container neck, as defined in claim 10. A method of manufacturing a cap according to the preamble of claim 10 is known from the document US 2007/089587 .

This process makes it possible to manufacture the stopper as defined above, with the production advantages mentioned above.

• la figure 1 est une vue schématique en perspective d'un bouchon conforme à l'invention, illustrant ce bouchon mis en place autour d'un col de récipient et dans une configuration ouverte ;
• la figure 2 est une coupe longitudinale du bouchon avant sa première ouverture, les moitiés gauche et droite de cette figure illustrant ce bouchon respectivement avant et après sa mise en place autour du col de récipient ;
• les figures 3 et 4 sont des coupes respectivement selon les plans III-III et IV-IV de la figure 2, illustrant le bouchon avant sa mise en place autour du col de récipient ;
• la figure 5 est une vue en élévation du bouchon mis en place autour du col de récipient et en train d'être ouvert pour la première fois, la direction d'observation de cette figure correspondant à la flèche V indiquée à la figure 3 ;
• les figures 6 et 7 sont des vues respectivement analogues aux figures 3 et 4, illustrant une première variante de réalisation du bouchon conforme à l'invention ; et
• les figures 8 et 9 sont des vues respectivement analogues aux figures 3 et 4, illustrant une seconde variante de réalisation du bouchon conforme à l'invention.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings in which:

• the figure 1 is a schematic perspective view of a plug according to the invention, illustrating the plug placed around a container neck and in an open configuration;
• the figure 2 is a longitudinal section of the plug before its first opening, the left and right halves of this figure illustrating this plug respectively before and after its introduction around the container neck;
• the Figures 3 and 4 are sections respectively according to plans III-III and IV-IV of the figure 2 illustrating the stopper before being placed around the container neck;
• the figure 5 is an elevational view of the stopper placed around the container neck and being opened for the first time, the observation direction of this figure corresponding to the arrow V indicated in FIG. figure 3 ;
• the Figures 6 and 7 are views respectively similar to Figures 3 and 4 illustrating a first embodiment of the plug according to the invention; and
• the Figures 8 and 9 are views respectively similar to Figures 3 and 4 , illustrating a second variant embodiment of the plug according to the invention.

On the Figures 1 to 5 is shown a plug 1 adapted to be removably attached to a neck 2 of a container. The plug 1 considered here by way of illustration is a plug fixed on the neck by screwing. In practice, the neck 2 is integral with the rest of the container, especially when the latter is a glass or plastic bottle as shown on the drawing. figure 1 , or adapted to be permanently attached to a wall of the container, at an opening through this wall.

The plug 1 and the neck 2 have respective generally tubular shapes, whose central longitudinal axes are substantially coincident, under the reference XX, when the cap is screwed onto the neck. For convenience, the following description is oriented by considering that the terms "upper" and "top" correspond to a direction generally parallel to the axis XX and from the body of the container to its neck 2, that is to say say a direction directed towards the party high of figures 1 , 2 and 5 , while the terms "lower" and "lower" correspond to an opposite direction.

The neck 2 comprises a generally cylindrical body 4 with a circular base of axis XX. At its upper end, this body 4 defines a rim 3 at which the liquid in the container is intended to be poured. As shown in the right part of the figure 4 , on the outer face of the body 4, the neck 2 comprises, successively from its rim 3, a thread 5 and a boss 6, which both extend radially outwardly from the body.

The plug 1, considered screwed on the neck 2, is open at its lower end and closed at its upper end by a bottom wall 10, at the outer periphery of which extends axially downwardly a tubular skirt 12 centered on the XX axis and circular base. The cap here advantageously comprises a lip 14 which extends axially downwards from the bottom wall 10, centrally on the axis XX, inside the outer skirt 12. When the cap is screwed onto the neck 2, the bottom wall 10 extends above and across this neck, while the skirt 12 externally surrounds the body 4 and the lip 14 is pressed sealingly against the inner face of the body.

The skirt 12 is provided with an internal thread 16 which extends radially inwardly of the main wall of the skirt, in a manner complementary to the thread 5 of the neck 2. The cooperation of the threads 5 and 16 makes it possible to screw and unscrew the skirt 12 around the collar. Advantageously, to facilitate the drive by the user of the skirt 12 around the X-X axis, the outer face of this skirt is provided with elongate ribs 18 which extend parallel to the X-X axis. These ribs 18 allow the user to grip the stopper 1 more easily.

During the first unscrewing of the plug 1, the skirt 12 is adapted to separate into two distinct parts, namely an upper portion 12 ₁ , integral with the bottom wall 10, and a lower portion 12 ₂ initially connected to the part upper 12 ₁ at a weakening peripheral line 20 located axially in the current portion of the skirt. As shown on the figure 1 , the skirt portion 12 ₁ is intended to be completely disengaged from the neck 2, so that this portion 12 ₁ internally carries the screw thread 16 and externally the ribs 18. The skirt portion 12 ₂ is, for its part, intended to remain around the neck 2. For this purpose, this portion 12 ₂ is provided internally with pallets 22 which extend radially inwardly projecting from the inner surface of the skirt 12 and which are located generally in the same plane perpendicular to the axis XX, being distributed over the entire periphery of the skirt. When the cap is assembled at the neck 2, these vanes extend axially below the boss 6 and are adapted, when the cap is raised for the first time, to abut axially against this boss.

As clearly visible on the figure 3 , the weakening line 20 is generally inscribed in a plane perpendicular to the axis XX and comprises peripheral notches, here seven in number and respectively referenced 24 ₁ to 24 ₇ , each of which passes radially right through the wall of the skirt 12. These notches 24 ₁ to 24 ₇ succeed each other along the line 20, in other words, along the periphery of the skirt. Each pair of two notches immediately successive delimits, between the two notches of the pair, a frangible bridge that connects, in the direction of the axis XX, the skirt portions 12 ₁ and 12 ₂ . The six bridges present here, successively referenced 26 ₁ to 26 ₆ , are distributed substantially uniformly over the total length of the weakening line 20.

As clearly visible on the figure 3 , the weakening line 20 does not extend over the entire periphery of the skirt 12 but, on the contrary, is interrupted by a portion 28 of the skirt permanently connecting the skirt portions 12 ₁ and 12 _2. This portion of skirt 28 is generally inscribed in the same plane perpendicular to the axis XX, in which is inscribed the weakening line 20, separating, along the periphery of the skirt, the two notches 24 ₁ and 24 ₇ respectively located at both ends 20A and 20B of the line of weakness 20. For practical reasons that will be understood later, the skirt portion 28 is located on the side of the plug 1 considered to be the rear side of this plug, as far as this side is intended in use to be directed away from the user.

The skirt portion 28 extends around the axis XX on an angle α ₂₈ which, in the embodiment considered on the Figures 1 to 5 is approximately 50 °, but which in practice has a value between 5 and 90 °, preferably between 40 and 70 °.

As clearly visible on the figure 3 , the skirt portion 28 comprises, at each of its two peripheral ends 28A and 28B, a non-breakable bridge 30 ₁ , 30 ₂ integral with the skirt portions 12 ₁ and 12 ₂ . Next to the periphery of the skirt, the bridges 30 ₁ and 30 ₂ are separated by a cut 32 passing radially right through the wall of the skirt 12.

The skirt 12 further comprises a second weakening peripheral line 34, distinct from the weakening line 20. As clearly visible on the figure 4 , this weakening line 34 is inscribed in a plane perpendicular to the axis XX, being delimited in the removable skirt portion 12 ₁ , so that, as shown in FIG. figure 2 a non-breakable strand 36, consisting of a peripheral fragment of the wall of the skirt 12 and belonging to the removable skirt portion 12 ₁ , is interposed in the direction of the axis XX between the weakening lines 20 and 34.

In the example of realization considered on the Figures 1 to 5 , the weakening line 34 is constituted, throughout its length, a single peripheral notch 38 which passes radially right through the wall of the skirt portion 12 ₁ .

The weakening line 34 extends around the axis XX at an angle β ₃₄ which, in the embodiment of FIGS. Figures 1 to 5 is about 135 ° but in practice has a value strictly less than 180 °, preferably between 60 ° and 175 °, preferably 90 ° and 170 °.

In addition, the angular positioning, around the axis XX, of the weakening line 34 is provided so that its two peripheral ends 34A and 34B are located, along the periphery of the skirt 12, on either side of the the skirt portion 28, without going beyond the frangible bridges respectively closest to the ends 28A and 28B of this portion 28 along the line of weakness 20, namely the bridges 26 ₁ and 26 ₆ . In other words, as clearly visible on the figure 5 which will be discussed in detail below, the ends 34A and 34B of the line of weakness 34 are respectively vertically plumb or a peripheral point of the notches 24 ₁ and 24 ₇ or the bridges 26 ₁ and 26 ₆ , as it is also the case for the embodiment considered here. That is to say that here, the angle, noted α ₂₆ on the figure 3 , between the radii at the axis XX which pass respectively by the bridges 26 ₁ and 26 ₆ has a value and an angular positioning around the axis XX identical to the value and the positioning of the angle β ₃₄ .

In this way, as noted on the figure 5 , the strand 36 includes a running portion 36 ₁ permanently connected, over its entire length, to the non-removable skirt portion 12 ₂ by the connecting portion 28, and two side portions 36 ₂ and 36 ₃ which are respectively disjointed, both of the non-removable skirt portion 12 ₂ due to the notches 24 ₁ and 24 ₇ , and the remainder of the removable skirt portion 12 ₁ due to the notch 38, except at the peripheral ends 36A and 36B strand 36, which are integral with the remainder of the skirt portion 12 ₁ and which, before the first opening of the plug 1, are connected, in the direction of the axis XX, to the skirt portion 12 ₂ respectively by the bridges 26 ₁ and 26 ₆ .

In addition, to ensure homogeneous behavior of the strand 36, in particular its lateral portions 36 ₂ and 36 ₃ , along the periphery of the skirt 12, the skirt portion 28 and the weakening line 34 are centered on one another. other in the sense that the bisector of angle α ₂₈ occupies the same angular position about axis XX as the bisector of angle β ₃₄ .

When the user first opens the cap 1 by rotating the skirt portion 12 ₁ about the axis XX to unscrew it from the neck 2, the skirt portion 12 ₂ is retained, in the direction of the XX axis, around this neck by the boss 6 while the skirt portion 12 ₁ is spaced from the skirt portion 12 ₂ upwards. To do this, the weakening lines 20 and 34 are solicited jointly. More specifically, the skirt portion 28 immobilizes, with respect to the skirt portion 12 ₂ , the central portion 36 ₁ of the strand 36, while the lateral portions 36 ₂ and 36 ₃ of this strand deform along their length, thanks to the free the relative spacing of the edges of the notch 38 and that of the edges of the notches 24 ₁ and 24 ₇ , without being hindered by the presence of bridges that induce a certain resistance. The portions 36 ₂ and 36 ₃ of the strand 36 thus extend over their entire length relative to the remainder of the skirt portion 12 ₁ and with respect to the skirt portion 12 _2. In a substantially concomitant manner, the various bridges 26 ₁ to 26 ₆ break simultaneously. The plug 1 is then in the configuration illustrated in FIG. figure 5 .

Continuing unscrewing of the skirt portion 12 ₁ , the strand portions 36 ₂ and 36 ₃ further deform, progressively passing from a substantially horizontal extended configuration to an extended inclined configuration with respect to the horizontal, up to complete disengagement of the threads 5 and 16. The user can then tilt the skirt portion 12 ₁ backward, using the skirt portion 28 as a tilting hinge about a geometric axis ZZ substantially orthoradial to the axis XX and passing through the bridges 30 ₁ and 30 ₂ , as represented on the figure 1 . The articulation of the skirt portion 28 in the manner of a hinge is facilitated by the presence of the notch 32 in the sense that the latter limits the stresses necessary to twist the bridges 30 ₁ and 30 ₂ around the axis ZZ.

In order to manufacture the stopper 1, the skirt 12 is at the same time closed by the bottom wall 10 and provided with the lip 14, the threading 16, the ribs 18 and the pallets 22. This skirt is obtained in particular by molding a plastic material.

Then, with the aid of a first cutting blade, not shown in the figures, both the weakening line 20 and the portion 28 are produced in the direction in which the first blade passes right through the wall. of the skirt 12 to cut the notches 24 ₁ to 24 ₇ , as well as the notch 32. With the aid of a second cutting blade, the weakening line 34 is produced, by passing through this blade the wall of the skirt portion 12 ₁ so as to cut the notch 38. Of course, the cutting action by the first blade and the cutting action by the second blade are indexed both along the axis XX and angularly around this axis so as to obtain the adequate relative positioning between, on the one hand, the weakening line 20 and the skirt portion 28 and, on the other hand, the weakening line 34.

In practice, the cutting actions by the aforementioned first and second blades are carried out either one after the other or, preferably, concomitantly, by driving the skirt 12 and these two relative to each other. cutting blades in rotation about the axis XX.

On the Figures 6 and 7 is shown an alternative embodiment of the plug 1, referenced 100. The plug 100 is distinguished from the plug 1 by its second weakening line, referenced 134. The other components of the plug 100 being identical to those of the plug 1, they carry the same alphanumeric references.

As clearly visible on the figure 7 , the weakening line 134 consists of two peripheral notches 138 ₁ and 138 ₂ , which follow one another following the periphery of the skirt portion 12 ₁ , with interposition of a frangible bridge 140 connecting, in the direction of the axis XX, the strand 36 and the remainder of the skirt portion 12 ₁ . This bridge 140 makes it possible to prevent, or at least to limit, the separation of the edges of the weakening line 134 during the demolding of the plug, as well as when the plug 100, after its manufacture, is assembled around the neck of container 2, in particular being force-fitted around the neck, until the pallets 22 are engaged under the boss 6.

At the first opening of the plug 100, the bridge 140 breaks to allow the relative spacing of the edges of the line of weakness 134. In practice, the breaking strength of the bridge 40 is low in that the bisector Δ ₁₃₄ of the angle β ₁₃₄ passes through this bridge 140: thus, the bridge 140 is located angularly, about the axis XX, in the zone of the weakening line 134 where apply the strongest axial stresses when the cap 100 is opened.

On the Figures 8 and 9 is shown another variant of the plug 1, referenced 200. The components of the plug 200 identical to those of the plug 1 have the same alphanumeric references.

The plug 200 is distinguished from the plug 1 by its second weakening line 234 which comprises three peripheral notches 238 ₁ , 238 ₂ and 238 ₃ , which follow one another along the periphery of the skirt portion 12 ₁ , with the interposition of a jumper frangible 240 ₁ between the notches 238 ₁ and 238 ₂ and another frangible bridge 240 ₂ between the notches 238 ₂ and 238 ₃ . In a similar manner to the bridge 140, the bridges 240 ₁ and 240 ₂ keep the notches 238 ₁ to 238 ₃ closed during the demolding of the plug and its assembly at the neck 2.

Moreover, as clearly visible by comparison of figures 4 and 9 the value of the angle β ₂₃₄ is greater than that of the angle β ₃₄ . In the example shown in figure 9 β ₂₃₄ is about 165 °.

The stopper 200 is also distinguished from the stopper 1 by the angular dimensions of its first weakening line 220 and its connecting portion 228, as can be clearly seen by comparing the figures 3 and 8 however, it is noted that the structure, as such, of the weakening line 220 and the skirt portion 228 is similar to that of the weakening line 20 and the skirt portion 28 of the cap 1. Thus, , line the weakening device 220 comprises seven notches 224 ₁ to 224 ₇ , respectively similar to the notches 24 ₁ to 24 ₇ , as well as six frangible bridges 226 ₁ to 226 ₆ , respectively similar to the bridges 26 ₁ to 26 ₆ . Similarly, the skirt portion 228 successively comprises an end bridge 230 ₁ , a peripheral notch 232 and an opposite end bridge 230 ₂ , respectively similar to the bridge 30 ₁ , the notch 32 and the bridge ₂ .

However, the angle α ₂₂₆ associated with the bridges 226 ₁ and 226 ₇ of the line 220 has a value greater than the angle α ₂₆ , so that this angle α ₂₂₆ has a value and an angular position around the axis XX, identical to the value and the angular positioning of the angle β ₂₃₄ .

In addition, the angle α ₂₂₈ associated with the skirt portion 228 has a value greater than that of the angle α ₂₈ : in the exemplary embodiment considered at the figure 8 the α ₂₂₈ angle is about 60 °.

In this way, the skirt portion 228 and the weakening line 234 are sized so that the bridge 230 ₁ and the bridge 240 ₁ are aligned in the direction of the axis XX while the bridge 230 ₂ and the bridge 240 ₂ are also aligned in this direction. In this way, when the cap 200 is opened for the first time, the bridges 240 ₁ and 240 ₂ break from the beginning of the upward drive of the skirt portion 12 ₁ due to its unscrewing because these bridges are angularly positioned around the axis XX, vertical plumb with the most rigid zones of the skirt portion 228, namely the bridges 230 ₁ and 230 ₂ .

• pour ce qui concerne la ligne d'affaiblissement 20 ou 220, le nombre de ses entailles, et donc de ses pontets, peut être différent de celui considéré sur les figures ;
• pour ce qui concerne la portion de jupe 28 ou 228, elle peut être dépourvue de l'entaille 32 ou 232, ce qui revient à dire qu'alors cette portion de jupe est constituée d'un unique pont non frangible, qui s'étend sur tout l'angle α₂₈ ou α₂₂₈ et qui, de ce fait, peut être qualifié de « pont large » ;
• pour ce qui concerne la ligne d'affaiblissement 34, 134 ou 234, elle peut comporter plus que deux pontets frangibles, tels que les pontets 240₁ et 240₂, en particulier si l'on cherche à renforcer la résistance de cette ligne d'affaiblissement lors du démoulage et de l'assemblage du bouchon autour du col de récipient ;
• on rappelle que la fixation amovible du bouchon 1, 100 ou 200 sur le col 2 peut être prévue autrement que par vissage, notamment par clipsage, la partie de jupe 12₁ étant alors pourvue intérieurement d'une bande de clipsage, éventuellement fragmentée en plusieurs clips distincts, à même d'être mise en prise avec un bord extérieur saillant, prévu à l'extrémité supérieure du col ; et/ou
• la retenue à demeure de la partie de jupe 12₂ autour du col 2 peut être obtenue par d'autres formes de réalisation que les palettes 22.

Various arrangements and variants of the plugs 1, 100 and 200, and the method for manufacturing them, as described above, are also possible. As examples:

• as regards the line of weakness 20 or 220, the number of its notches, and therefore its bridges, may be different from that considered in the figures;
• as regards the portion of skirt 28 or 228, it may be devoid of notch 32 or 232, which is to say that then this portion of skirt consists of a single non-breakable bridge, which extends over the whole angle α ₂₈ or α ₂₂₈ and which, therefore, can be described as a "wide bridge";
• as regards the weakening line 34, 134 or 234, it may comprise more than two frangible bridges, such as bridges 240 ₁ and 240 ₂ , in particular if one seeks to reinforce the resistance of this line of weakening during demolding and assembly of the stopper around the container neck;
• it is recalled that the removable attachment of the plug 1, 100 or 200 on the neck 2 may be provided otherwise than by screwing, in particular by clipping, the skirt portion 12 ₁ then being provided internally with a clipping band, possibly fragmented into several separate clips, capable of being engaged with a protruding outer edge, provided at the upper end of the neck; and or
• the indwelling restraint of the skirt portion 12 ₂ around the collar 2 can be obtained by other embodiments than the pallets 22.

Claims (10)

1. A stopper (1; 100; 200) for a container neck (2), which stopper includes a tubular skirt (12) suitable for surrounding the neck and provided with a first peripheral line of weakness (20; 220) that is made up both of cut through notches (24₁ to 24₇; 224₁ to 224₇) that succeed one another around the periphery of the skirt, and also, between said notches, of non-cut breakable bridges (26₁ to 26₆; 226₁ to 226₆) that are adapted to being broken when the stopper is opened for the first time and that, before the stopper is opened for the first time, interconnect, in the direction of the axis (X-X) of the skirt, a non-removable portion (12₂) of the skirt, which portion is provided with retainer means (22) for retaining it permanently around the neck, and a removable portion (12₁) of the skirt, which portion is provided with fastener means (16) for fastening it removably to the neck;
   said stopper being characterized in that the skirt (12) is provided with a second peripheral line of weakness (34; 134; 234) that extends through less than 180° about the axis (X-X) of the skirt, that is made up of at least one cut through notch (38; 138₁, 138₂; 238₁ to 238₃) and that is defined in the removable skirt portion (12₁) in a manner distinct from the first line of weakness (20; 220), with a non-breakable strip (36) being interposed in the direction of the axis of the skirt;
   and in that the first line of weakness (20; 220) extends through less than 360° about the axis (X-X) of the skirt (12) such that the two notches (24₁ and 24₇; 224₁ and 224₇) situated at respective ones of the peripheral ends (20A and 20B) of the first line of weakness are separated by a tether portion (28; 228) of the skirt that is not cut, at least in part, and that is adapted to interconnect the non-removable skirt portion (12₂) and the strip (36) non-breakably, while the two peripheral ends (34A and 34B) of the second line of weakness (34; 134; 234) are situated, around the periphery of the skirt, respectively between a first one (28A) of the two peripheral ends (28A and 28B) of the tether portion and the bridge (26₁) that is closest to said first end along the first line of weakness, and between the second peripheral end (28B) of the tether portion and the bridge (26₆) that is closest to said second end along the first line of weakness.
2. A stopper according to claim 1, characterized in that the tether portion (28; 228) is adapted to interconnect the non-removable skirt portion (12₂) and the strip (36) tiltably about an axis (Z-Z) that is substantially circumferential relative to the axis (X-X) of the skirt (12).
3. A stopper according to claim 1 or claim 2, characterized in that the two peripheral ends (34A and 34B) of the second line of weakness (34; 134; 234) are aligned, in the direction of the axis (X-X) of the skirt (12), respectively with the bridge (26₁) that is closest to the first end (28A) of the tether portion (28; 228) and the bridge (26₆) that is closest to the second end (28B) of the tether portion.
4. A stopper according to any preceding claim, characterized in that the tether portion (28; 228) extends through more than 5° and through less than 90° about the axis (X-X) of the skirt (12), and preferably through more than 40° and through less than 70° about said axis.
5. A stopper according to any preceding claim, characterized in that the tether portion is constituted by a non-breakable single bridge.
6. A stopper according to any one of claims 1 to 4, characterized in that, at each of its peripheral ends (28A, 28B), the tether portion (28; 228) is provided with a non-breakable bridge (30₁, 30₂; 230₁, 230₂) and, in its main portion, said tether portion is provided with at least one cut through notch (32; 232).
7. A stopper according to any preceding claim, characterized in that the second line of weakness (34; 134; 234) extends through more than 60° and through less than 175° about the axis (X-X) of the skirt (12) and preferably through more than 90° and through less than 170° about said axis.
8. A stopper according to any preceding claim, characterized in that the second line of weakness (134) is made up of two cut through notches (138₁ and 138₂) and of one breakable bridge (140) interposed between said two notches around the periphery of the skirt (12), said bridge preferably being positioned substantially in the middle of the second line of weakness.
9. A stopper according to any one of claims 1 to 7, characterized in that the second line of weakness (234) is made up of at least three cut through notches (238₁ to 238₃) and of breakable bridges (240₁, 240₂) interposed between successive ones of said notches around the periphery of the skirt (12), each of the breakable bridges of the second line of weakness preferably being aligned, in the direction of the axis (X-X) of the skirt, with the non-breakable bridge constituting the tether portion or else with one of the non-breakable bridges (30₁, 30₂; 230₁, 230₂) belonging to the tether portion (28; 228).
10. A method of fabricating a stopper (1; 100; 200) for a container neck (2),
    in which method there is provided a tubular skirt (12) suitable for surrounding the neck (2), and provided both with retainer means (22) for retaining it permanently around the neck, and also with fastener means (16) for fastening it removably to the neck;
    and in which method the skirt and a first blade are driven in rotation relative to each other about the longitudinal axis (X-X) of the skirt so that the first blade cuts a first peripheral line of weakness (20; 220) in the skirt, which line of weakness is made up both of cut through notches (24₁ to 24₇; 224₁ to 224₇) and also, between said notches around the periphery of the skirt, of non-cut breakable bridges (26₁ to 26₆; 226₁ to 226₆) that are adapted to being broken when the stopper is opened for the first time and that, before the stopper is opened for the first time, interconnect, in the direction of the axis of the skirt, a non-removable portion (12₂) of the skirt, which portion is provided with the retainer means (22), and a removable portion (12₁) of the skirt, which portion is provided with the fastener means (16);
    said method being characterized in that the skirt (12) and a second blade are driven relative to each other about the axis (X-X) of the skirt through less than 180° so that the second blade cuts a second peripheral line of weakness (34; 134; 234) in the removable skirt portion (12₁) with a non-breakable strip (36) being interposed in the direction of the axis of the skirt;
    and in that, the skirt and the first blade are driven in rotation relative to each other over an angular stroke that is strictly less than 360° about the axis of the skirt so that the two notches (24₁ and 24₇; 224₁ and 224₇) situated at respective ones of the peripheral ends (20A and 20B) of the first line of weakness (20; 220) are separated by a tether portion (28; 228) of the skirt that is not cut, at least in part, by the first blade and that is adapted to interconnect the non-removable skirt portion (12₂) and the strip (36) non-breakably, while the skirt and the second blade are driven in rotation relative to each other in such a manner that the two peripheral ends (34A an 34B) of the second line of weakness (34; 134; 234) are situated, around the periphery of the skirt, respectively between a first one (28A) of the two peripheral ends (28A and 28B) of the tether portion (28; 228) and the bridge (26₁) that is closest to said first end along the first line of weakness, and between the second peripheral end (28B) of the tether portion and the bridge (26₆) that is closest to said second end along the first line of weakness.

Images