EP0236233A1 - Disposable destructible cap and container provided with such a cap - Google Patents

Abstract

A disposable destructible cap made from a thermoplastic material and a container provided with such a cap. The cap (2) comprises a front closure wall (3), a lateral wall (4) whose lower part (42) penetrates into the neck (5) to form a seal between the cap and the neck, an annular flange (23) and a covering wall (24) comprising means for anchoring over the outer periphery of the neck. The container comprises, at its upper part, an annular shoulder (52) on which bears a rib carried by the annular flange of the cap and under which engages an anchoring lip of the cap. <IMAGE>

Description

The present invention relates to a single-use destructible stopper and a container such as a flask or a bottle, provided with a neck closed by such a stopper.

Numerous devices are known whose purpose is to ensure the tight closure of a bottle. Most of these devices relate to plugs which must seal, but also the inviolability of the closure until the time of use of the content, while allowing the filling by use of the plug. These devices generally include a plug, part of which is destructible and another part which is reusable.

The problem is quite different when it comes to avoiding and even preventing the reuse of the bottle or container. There are in this case containers whose closure is achieved by welding after filling the bottle, which therefore requires opening the container by cutting or tearing one end and in general to make it later unusable. This process has several drawbacks; in particular, the nature of the container and its contents must easily and safely lend itself to the welding operation, which restricts the field of use of the process. Another disadvantage is that the opening requires a certain effort, or at least manipulations of the container and tools which can present a certain danger, especially if the content is a toxic product, which may partially escape during the opening.

To provide more security in these opening operations, and to overcome the drawbacks of closing by welding, while retaining total tightness of the bottle before opening, and the almost impossibility of reuse, there are destructible caps for single use.

A plug of this type is known, for example, from French patent 2,518,501, the owner of which is the applicant for this patent.

The device for opening this destructible cap has a removable annular strip without significant effort thanks to a gripping tab.

Other particular characteristics of this plug, described in the document cited above, make opening all the more easy and safe.

The closure of a container by a stopper of this type is obtained by welding an annular part of the stopper to another annular part of the neck. This system involves precise positioning of the stopper on the neck of the neck and above all a precise annular weld since, in addition to maintaining the stopper, the weld seals the closure.

This precise weld can only be obtained with very precise thicknesses of the walls in contact. Tolerances of the order of 3/100 mm are necessary to ensure a perfect and reliable weld. In addition, due to the small dimensions of such plugs, the welding operation is difficult especially when it is carried out on flanges of very small width.

The present invention proposes to eliminate the aforementioned drawbacks, while ensuring perfect sealing of the closure and the impossibility of reusing a bottle.

According to the invention, a container provided with a neck is closed by a destructible single-use stopper made of thermoplastic material fixed permanently and sealingly on the free edge of the neck. The plug comprises a front closure wall and a side wall, the upper end of which is connected to the said front wall, and the lower part of which enters the neck and is in contact with the internal lateral face of the neck. This lower part extends substantially in the extension of the upper part which is destructible.

The stopper also includes an annular transverse flange connected to the side wall at the level of the median part comprised between the lower part penetrating into the neck, and the destructible upper part.

According to the invention, the plug further comprises a covering wall extending downwards, substantially vertically, connected to the external edge of the flange, and comprising anchoring means on the external periphery of the neck.

More particularly, the lower part of the side wall of the stopper ends downwards by a portion whose external face has a taper gradually reducing the external perimeter of the side wall, up to its end.

This conicity facilitates the penetration of the lower part of the stopper into the neck, and makes it possible to seal the closure by the fact that the external perimeter of the side wall is at least equal, and even slightly higher, over a certain height, at the perimeter of the internal lateral face of the neck with which the lower part of the lateral wall of the stopper is in contact.

It can therefore be seen that the invention provides an undeniable advantage in the production and sealing of container-stopper assemblies, with a destructible stopper and for single use.

Indeed, while the sealing previously required, to be reliable, a specific weld between precise parts, and therefore a significant cost, this sealing is now achieved, according to the invention, by a conical fitting of the stopper in the neck of the container. . The lower part of the wall of the plug of thermoplastic material is in fact compressed during its insertion into the neck due to the perimeter of said lower part, equal to or slightly greater than the internal perimeter of the neck.

As a result, sealing is guaranteed at a lower cost since the manufacturing tolerances of the neck and of the plug can be considerably enlarged, without compromising the reliability of the sealing means. It is thus possible to adopt a tolerance of ± 1/10 mm on the dimensions of the parts of the neck and of the stopper which are in contact, ie a tolerance approximately three times wider than previously.

In addition, simply placing the cap on the container and then inserting it into the neck until it stops on the one hand ensure the seal and on the other hand the maintenance of the plug by anchoring, without it being possible to remove it easily and without deterioration. A complicated and expensive welding or gluing device is therefore no longer necessary.

It is however possible to perfect the inviolability of the closure and therefore the non-reuse of the container or of the stopper, by a few lateral welding points between the covering wall of the stopper and the upper end of the neck. It should be noted that these few welding points do not require any particular precision either in their production or in the manufacture of the parts in contact, since the welding does not participate in the sealing, and that access by the periphery to the container neck is much easier for welding devices, than simultaneous access axially from below and from above.

The invention also relates to a container, the neck of which has an annular shoulder in its upper part, and a stopper, the underside of which of said annular transverse flange comprises an annular rib projecting downward and arranged coaxially with the stopper. Said rib comes into contact with the upper face of the annular shoulder, by its lower edge, to ensure a complementary seal between the stopper and the neck of the container.

The invention also relates to a container whose outer periphery of the neck is formed at its upper end, by a vertical wall connected to the outer edge of said annular shoulder of the neck. The means for anchoring the stopper to the neck consist of an annular lip extending transversely, towards the axis of the stopper, from the internal face of the covering wall of said stopper. When the plug is placed on the neck and pressed in abutment, said lip engages under the underside of the annular shoulder of the neck.

The invention also relates to a container whose upper vertical wall of the neck is connected by its lower edge to the outer edge of the annular shoulder. The inner face of said vertical wall has a generally frusto-conical shape and is connected by its edge of smaller diameter to the upper face of said shoulder, so that it is substantially parallel to the outer periphery of the annular rib of the plug, and forms with said rib a baffle.

It can be seen from the description which has just been given that the cap and the associated container, in accordance with the invention, have very advantageous features. The annular rib of the cap acts as an additional sealing element by its contact with the annular shoulder of the neck, and moreover, in combination with the inner face of the upper wall of the neck, and by the small distance which separates them, it creates a baffle further strengthening the sealing of the device.

The invention also relates to a container, the neck of which comprises, below the upper vertical wall, an annular groove in which the annular lip of the stopper engages. The upper side of the groove is formed by the lower face of the neck shoulder, and the lower side of the groove is connected to the wall of the neck, just below the lower edge of the cover wall of the cap, so that said lower edge is practically against the lower side of the groove, when the plug is in place, and that said edge is completely inscribed in the envelope surface of said neck wall.

The particularity presented by the annular groove made in the neck contributes to the ease of use of the container-stopper assembly, and to the safety of use. Indeed, the lower edge of the cover wall of the plug being embedded in said groove, it is practically impossible to grasp this edge to lift and remove the plug, even without the presence of the weld points. A perfectly safe device is thus obtained for closing a container provided with a neck, with a reinforced seal, and very simple to use and without expensive tools for the installation and the maintenance of the stopper on said container.

• - la figure 1 est une vue avec 1/2 coupe axiale du goulot d'un récipient et du bouchon selon l'invention ;
• - la figure 2 est une vue en coupe axiale agrandie de la zone de liaison et d'étanchéité entre le goulot et le bouchon ;
• - la figure 3 est une vue similaire à celle de la figure 2, où l'on voit la forme particulière d'un goulot avec une rainure dans laquelle s'encastre le dispositif d'ancrage du bouchon ;
• - la figure 4 est une vue de dessous d'un bouchon montrant des encoches réalisées à sa périphérie dans la paroi de recouvrement du bouchon ;
• - la figure 5 est une vue latérale du même bouchon pourvu d'encoches.
• - la figure 6 est une demi-vue en coupe selon VI-VI du goulot et du bouchon montrant les stries de blocage en rotation du bouchon; et
• - la figure 7 est une demi-vue latérale du goulot avec une paroi supérieure striée.

Other features and advantages of the invention will appear in the description of an embodiment particular of the invention, which will be made in relation to the accompanying drawings in which:

• - Figure 1 is a view with 1/2 axial section of the neck of a container and the cap according to the invention;
• - Figure 2 is an enlarged axial sectional view of the connection and sealing area between the neck and the plug;
• - Figure 3 is a view similar to that of Figure 2, where we see the particular shape of a neck with a groove in which is embedded the anchoring device of the plug;
• - Figure 4 is a bottom view of a plug showing notches made at its periphery in the cover wall of the plug;
• - Figure 5 is a side view of the same plug provided with notches.
• - Figure 6 is a half-sectional view along VI-VI of the neck and the plug showing the streaks of rotation blocking of the plug; and
• - Figure 7 is a side half-view of the neck with a striated upper wall.

Referring to Figures 1 and 2, we first describe a container and destructible cap disposable assembly according to the invention.

Throughout the description, we will consider the container placed so that the axis of the neck and the stopper is vertical.

On the other hand, it should be noted that the cross section of the neck and of the plug is not necessarily circular, and may have other shapes. For example, the invention can be applied to a container whose neck and cap have a generally polygonal or ellipsoid section.

The container 1 has a neck 5, the side wall of which has an inner face 51 which is vertical or substantially vertical. The upper part of the neck has an annular shoulder 52 extending radially outward from the side wall of the neck 5 in a plane perpendicular to the axis of the container 1.

An upper wall 53, substantially vertical, is connected by its lower edge to the outer edge of the shoulder 52, and extends upwards forming the upper end of the neck.

The destructible plug 2 consists of a front closing wall 3 and a side wall 4. This side wall 4 comprises an upper part 41 which constitutes the destructible part of the plug and includes means of destruction. These destruction means may consist of a removable side strip, a sectionable part, or any other means rendering the plug unusable after opening. The side wall 4 also includes a lower part 42, intended to penetrate into the neck 5.

Generally, the lower part 42 is disposed vertically substantially in the extension of the upper part 41 of the plug. The lower part 42 ends downwards by a portion whose external face 43 has the shape of a truncated cone whose smallest perimeter is connected to the lower end 44 of the side wall 4. The largest perimeter of the frustoconical external face 43 is connected to the substantially lateral external lateral face 45 of the lower part 42.

Said external lateral face 45 has a cross section slightly greater than that of the internal face 51 of the neck so that it deforms slightly by compression when it is introduced into the neck and ensures a very good seal between plug and neck.

The penetration of the plug into the neck is however limited by the stop of a flange 23 of the plug on the upper end of the neck. Said annular flange 23 extends transversely outward from the middle part of the side wall 4 of the plug so as to cover the upper end of the upper vertical wall 53 of the neck. A cover wall 24 is connected by its upper edge to the outer edge of the flange 23 and extends vertically downward, covering the upper vertical wall 53 of the neck. The face lower 25 of said flange 23 extends in a plane perpendicular to the axis and comprises an annular rib 26 of substantially triangular section projecting downward, and whose lower edge comes into contact, or even crashes a little , against the upper face 56 of the shoulder 52, when the plug is pressed in abutment. Therefore, the annular rib 26 behaves like a compressed joint between two planar surfaces.

In addition, the groove 26 has its external face of conical shape complementary to that of the internal face 55 of the vertical upper wall 53 of the neck. This arrangement facilitates on the one hand the establishment of the plug by providing additional guidance between the internal face 55 of the upper wall 53, and the external face of the rib. On the other hand, these faces being close to each other create a baffle which continues between the covering wall 24 and the vertical upper wall 53. The sealing is thereby considerably reinforced. Thus, even if the main sealing surfaces were accidentally damaged before or during the fitting of the stopper, the arrival of the liquid contained in the container would create a liquid film at the level of the lower edge of the rib 26, said film participating itself -even by its surface tension forces when sealing the device. Towards the bottom of the covering wall 24 and from its internal face 28, an annular lip 27 extends transversely towards the axis of the plug, and engages under the lower face 54 of the annular shoulder 52 of the neck , constituting the anchoring of the cap on the neck.

Preferably, the cross section of this lip 27 is approximately triangular; the upper face of the lip being perpendicular to the axis of the stopper, and the lower face being inclined, forming a chamfer in a truncated cone. The chamfer allows easy fitting of the plug, the shape of the chamfer forcing the covering wall 24 to expand elastically to pass around the upper side wall of the neck 53. Then when the plug comes into abutment, the lip 27 passes under the annular flange 52, and tightens by gripping under said flange. The the upper face of the lip being flat, the reverse operation of removing the plug is made much more difficult.

In order to facilitate the fitting of the plug, it is possible, in accordance with FIGS. 4 and 5, to produce in the covering wall 24 and the annular lip 27, vertical notches 28, extending vertically from the lower edge 29 and over a part of the height of said covering wall 24. These notches 28 are distributed over the periphery and thus form segments of covering wall, which can deform more easily when the plug is put in place.

Although the annular lip 27 ensures good retention of the plug and an awkward tearing of the latter, it is preferable to produce a few weld points between the covering wall 24 of the plug and the upper vertical wall 53 of the neck. These weld points can be easily produced, radially, for example by ultrasonic welding, a known method for assembling parts of thermoplastic material.

To be able to completely avoid these welding constraints, a particular arrangement of the neck is made, in accordance with FIG. 3. According to this embodiment, the plug 2 is identical to the plug of the previous embodiments, and it will not be described again here. The essential characteristic of this realization resides in the particular shape of the neck.

An annular groove 57 is produced in the neck below the upper vertical wall 53. The groove has a rectangular cross section, and its upper side constitutes the underside of the shoulder 52. The height of the groove is very slightly greater than the height of the annular lip 27 of the stopper, taken between the upper face of said lip and the lower end 29 of the covering wall 24.

The lower side 58 of the groove is substantially parallel to its upper side, and extends below the lower end 29 of the covering wall 24, and is connected to the wall 59 of the neck. This wall 59 of the neck has a larger external section than the external section of the wall of recovery. Thus the lower edge 29 is fully engaged in the groove 57, and it then becomes practically impossible to grasp it.

Obviously, the groove 57 may have a cross section of different shape.

This particular arrangement has the great advantage of not requiring soldering, while preventing the plug from being removed and the risks of re-use.

According to the embodiment which has just been described, the stopper is firmly held on the neck except in rotation about a vertical axis, in the case of a neck and a stopper of generally cylindrical shape. Despite the friction between the external lateral face 45 of the wall 4 of the stopper and the internal face 51 of the neck, and the jamming of the upper wall 53 of the neck between the lower face 25 of the flange 23 and the annular lip 27 of the stopper, the latter risks turning on itself if a sufficient rotational force is applied to it.

In order to avoid this possibility, it has been envisaged to block the plug with ultrasonic welding points, but this removes the advantage of the previous device which makes it possible to avoid the welding operation.

Another solution to prevent rotation of the plug consists in making vertical ridges 60, 61 around the entire circumference of the external face of the upper vertical wall 53 of the neck and of the internal face of the covering wall 24 of the plug. These two walls also have diameters determined respectively so that said vertical ridges 61 of the stopper engage with the ridges 60 of the neck when the stopper is in place to prevent rotation of said stopper with respect to the neck.

Said ridges preferably have a cross section of triangular shape and height of the order of a few tenths of mm.

This arrangement is particularly advantageous in the case where the destruction of the stopper when the container is opened requires an effort tending to rotate it, for example when the destruction means comprise a tear-off annular tongue.

Of course, various modifications can be made by those skilled in the art to the particular embodiments described above, by way of non-limiting example, without departing from the scope of the invention.

Claims (10)

1. Destructible stopper (2) for single use made of thermoplastic material intended to be fixed permanently and sealingly on the free edge of the neck of the neck (5) of a container (1), said stopper comprising a front wall (3 ) shutter and a side wall (4) whose upper end is connected to said front wall (3), and whose lower part (42), penetrating into the neck (5) and in contact with the inner side face (51) of said neck, extends substantially in the extension of the destructible upper part (41), also comprising an annular transverse flange (23) connected to the side wall (4) at the level of the middle part lying between the lower part (42) and the destructible upper part (41), characterized in that said plug (2) further comprises a covering wall (24) extending downward, substantially vertically, connected to the outer edge of the flange (23 ), and comprising anchoring means on the outer periphery neck, and in that the lower part (42) of the side wall (4) of the plug ends downwards by a portion whose external face (43) has a taper gradually reducing the outer perimeter of the side wall (4), to the lower end (44) of said side wall, and the outer perimeter of the lower part (42) of the side wall (4) being at least equal, over a certain height, to the perimeter of the inner side face (51) of the neck with which the side wall (4) of the cap is in contact so as to seal between the cap and the neck. 2. Cap according to claim 1, characterized in that the lower face (25) of the annular transverse flange (23) of the cap comprises an annular rib (26) projecting downwards and arranged coaxially with respect to the cap, and that the lower edge of said rib (26) is in contact with the upper face (56) of the annular shoulder (52) produced in the upper part of the neck, when the plug is in place on said neck. 3. Stopper according to claim 2, characterized in that the annular rib (26) of the annular flange (23) of the plug has a triangular section. 4. Cap according to one of claims 2 and 3, characterized in that the means for anchoring the cap (2) on the neck consist of an annular lip (27) extending transversely, towards the axis of the plug, from the internal face (28) of the covering wall (24) of said plug, said lip (27) engaging under the underside (54) of the annular shoulder (52) of the neck when the plug is pressed into abutment on said neck. 5. Cap according to claim 4, characterized in that the covering wall (24) of the cap and the annular lip (27) are at least partially segmented by vertical notches (28) produced in said covering wall (24) at from its lower edge (29) and distributed around its periphery. 6. Cap according to one of claims 1 to 5, characterized in that vertical grooves (61) are formed on the internal face of the covering wall (24) of the cap, so as to engage with vertical grooves (60 ) produced on the external face of the upper vertical wall (53) of the neck when the plug is in place on the neck. 7. Container provided with a neck (5) which comprises at its upper part an annular shoulder (52) characterized in that it is provided with a plug according to one of claims 1 to 6. 8. Container according to claim 7, characterized in that the neck has an upper vertical wall (53) connected by its lower edge to the outer edge of the annular shoulder (52) and that the inner face (55) of said upper wall (53) of the neck is of generally frusto-conical shape and is connected by its edge of smaller diameter to the upper face (56) of the shoulder (52), so that said inner face (55) of the upper wall (53 ) of the neck is substantially parallel to the outer periphery of the annular rib (26) of the cap and forms with said rib a baffle when the cap is in place on the neck. 9. Container according to one of claims 7 and 8, characterized in that the neck comprises below the upper vertical wall (53) an annular groove (57) in which engages the annular lip (27) of the cap and the upper side of which is constituted by the lower face (54) of the shoulder (52), the lower side (58) of said groove being connected to the wall (59) of the neck, below the lower edge (29) of the cover wall (24) of the plug, so that said lower edge (29) is practically against said lower side (58) of the groove, and is completely inscribed in the envelope surface of said wall (59) of neck. 10. Container according to one of claims 7 to 9, characterized in that the stopper is fixed, after positioning on the neck, by welding at several points of the covering wall (24) of the stopper, on the vertical wall upper (53) of the neck.

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