EP1216930A1 - Cap for containers for liquid products - Google Patents

Abstract

The cap, consisting of a lateral skirt (1) with an internal thread, a lower security strip and a top plate (2), has a seal in the form of an inner shoulder (4) in the zone where the skirt adjoins the top plate, equipped with an elastic peripheral lip (3) which points downwards when at rest and fits between a radial projection (41) on the shoulder and the rounded outer edge (b) of the container neck (C) when the cap is closed. A variant of the design has a second annular seal lip interacting with the inner edge of the container neck, and the lip can be carried by a separate component fitted inside the cap.

Description

The present invention relates to a threaded plug for liquid product container.

The caps used in the packaging of products liquids such as beverages and, more particularly, beverages carbonates include in particular a side skirt provided with a internal thread ensuring connection with the threaded neck of the container and connected to an upper plate internally carrying means sealing intended to cooperate with the upper edge of said neck.

In most cases, the skirt extends downwards via a embrittlement zone by a separable tamper-evident band taken with an annular projection provided on the neck, below the thread.

There are already plugs of the type described in the EP 76778 where the sealing means are freed from the presence with an attached gasket and are made in one piece with the plug. In this document, the sealing means comprise a crown rigid intended to be force fitted into the neck of the container. However, this fitting creates constraints even in the upper plate, which, under the action of time, heat and internal pressure, produces cracks and / or deformation detrimental both to the seal and to the aesthetics.

In addition, for there to be sufficient contact area between the neck and the side wall of the crown, give the latter an important height.

The main consequences of this configuration are, on the one hand, to impose a high tightening torque and, on the other hand, to increase the risks of violent escape which are generally caused by late degassing.

These risks are further accentuated by employment, of a single constituent material such as polyethylene, minus creep resistant than polypropylene used for closures traditional fitted with an attached gasket.

Another embodiment is described in EP 481 981 where the sealing means consist of a flexible lip intended to be folded back on itself and crushed by the upper edge of the collar cap closing position.

However, to obtain a satisfactory seal, it is here also necessary to exert a significant tightening torque because the lip must be folded up at least 90 ° on itself and / or against the plate.

In addition, the deformation of the lip is difficult to control especially in the absence of means for centering the cervix.

A variant described in WO 00/56615 consists in thinning and to lengthen the flexible lip.

However, the length and fineness of this lip are then excessive to the point of making it difficult to adjust the mold as well as the control of the manufacturing process and in particular the phase of cooling, which results in a slower rate of production.

In addition, this variant aims to fill the entire upper edge of the container neck with a single lip.

However, this single lip does not provide a level tightness because it is not possible to control the deformation stresses of the lip over such a long length, without have wedging means on the inner wall of the plug.

The object of the present invention is to solve these problems techniques satisfactorily.

This object is achieved, in accordance with the invention, by means of a threaded plug of the previous type, characterized in that said means sealing include an outer shoulder provided in the area connecting the skirt and the plate, having a radial projection and bearing an elastically deformable peripheral lip extending, at rest, down towards the axis of the plug and intended, in closed position of the cap, to be inserted between the projection of said shoulder and neck by marrying, under constraints, at least part the curvilinear outer periphery of the upper edge of the neck.

According to a first embodiment, said means sealants further include an inner annular lip elastically deformable positioned so that its end free wife under constraints, at least the inner periphery of the edge upper neck in the closed position of the cap.

According to a variant, said inner lip consists or carried by an independent annular element disposed in the cap.

According to another variant, said inner lip has a diameter connection to the plate between the outside diameters and inside of said neck and is inclined relative to the axis of the cap of a angle between 0 and 45 °.

According to an advantageous characteristic, said inner lip is intended to be inserted under constraints, in the closed position of the plug, between on the one hand an internal shoulder integral with the face bottom of the tray and secondly the container neck.

According to another characteristic, the face of the shoulder outer and / or inner shoulder, located opposite the collar cap closing position, has an undercut.

According to yet another characteristic, said tray is provided in its center a set of radial stiffening ribs. The case where appropriate, these ribs are backed by the inner shoulder.

According to a second alternative embodiment, said means sealing include, in addition, a centering ring and integral blocking of the plate extending coaxially opposite said peripheral lip delimiting, with said outer shoulder and / or the peripheral lip, a groove, in which the neck is housed, in the closed position of the cap.

According to another advantageous characteristic, the face radially outer of said crown is provided, in the lower part, a boss intended to bear against the internal lateral wall of the collar.

According to yet another characteristic, the height of the portion of the crown protruding inside the collar in the closed position of the cap is greater than the unscrewing dead travel prior to the separation of the tamper-evident band.

According to an advantageous characteristic, said lip device is connected to the underside of the outer shoulder.

According to yet another characteristic, said lip peripheral comprises a first rectilinear section, connected by a end at said outer shoulder, and extended at its other end via a bend by a second straight section.

Preferably, the elbow defines an angle between the two lip sections whose value is between 0 and 60 °.

In addition, said peripheral lip or its first section is inclined at an angle between 20 ° and 60 ° relative to the axis of the plug.

According to yet another characteristic, the thickness of said peripheral lip as well as the geometry of the outer shoulder are determined, so that the bearing contact between said lip and the upper edge of the neck is made above the joint planes of said neck, this which guarantees a good seal.

According to a specific variant, the underside of the plate is provided with a rod extending in the direction of the inner lip.

The invention makes it possible to ensure reinforced tightness of the container by means of a one-piece, single-material stopper capable of to be produced in a single molding operation (injection or compression), and offering screwing and unscrewing torques relatively weak and regular.

The cooperation of flexible lips (peripheral and / or interior), with the corresponding shoulders, optimizes their deformation and their positioning relative to the edges of the neck.

• les figures 1A, 2A, 3A et 4A représentent des vues en coupe de quatre modes de réalisation du bouchon de l'invention, à l'état libre avant fermeture du récipient ;
• les figures 1B et 1C représentent des vues partielles en coupe du mode de réalisation de la figure 1A respectivement en position de semi-fermeture sur le col, et en position de fermeture étanche du récipient ;
• les figures 1D et 1E représentent des vues partielles en coupe de deux variantes de réalisation.
• les figures 2B et 2C représentent des vues partielles en coupe du mode de réalisation de la figure 2A, respectivement en position de semi-fermeture sur le col et de fermeture étanche ;
• les figures 3B et 3C représentent des vues partielles en coupe du mode de réalisation de la figure 3A, respectivement en position de semi-fermeture sur le col, et de fermeture étanche.
• les figures 4B et 4C représentent des vues partielles en coupe du mode de réalisation de la figure 4A, respectivement en position de semi-fermeture et de fermeture étanche

The invention will be better understood on reading the description which follows with reference to the appended drawings, in which:

• Figures 1A, 2A, 3A and 4A show sectional views of four embodiments of the cap of the invention, in the free state before closing the container;
• Figures 1B and 1C show partial sectional views of the embodiment of Figure 1A respectively in the semi-closed position on the neck, and in the sealed closure position of the container;
• Figures 1D and 1E show partial sectional views of two alternative embodiments.
• Figures 2B and 2C show partial sectional views of the embodiment of Figure 2A, respectively in the semi-closed position on the neck and sealed;
• Figures 3B and 3C show partial sectional views of the embodiment of Figure 3A, respectively in the semi-closed position on the neck, and sealed.
• FIGS. 4B and 4C represent partial sectional views of the embodiment of FIG. 4A, respectively in the semi-closed and sealed-closed position

The cap shown in the figures is intended for capping containers for liquid products, such as drinks (mineral water, fruit juice, sodas ...). These containers can be made of glass or plastic material, by blowing air into preforms.

Generally, this plug includes a side skirt 1 provided with an internal thread 10 and connected to an upper plate 2.

The geometry and, in particular, the pitch of the thread 10, are adapted to the threads F of the neck C of the container. Skirt 1 is extended towards the bottom by a tamper-evident band 11 via a weakening zone 12 likely to be broken by unscrewing the cap.

The upper plate 2 of the cap internally carries sealing means intended to cooperate with the upper part of the neck C and in particular its upper edge B.

The section of the upper edge B is delimited laterally by a side by an outer curvilinear periphery b (called "drinking") and the other side by an inner circumference b 'generally curvilinear.

In the context of the invention, the sealing means are made in one piece with the skirt 1 and the plate 2, and using the same plastic material, which is preferably polyethylene.

In the embodiment of FIGS. 1A to 1C, these means sealing comprise a radially outer shoulder 4, formed in the connection zone between the skirt 1 and the plate 2, having a radial projection 41 and carrying a peripheral lip 3, elastically deformable which extends, at rest, as shown in Figure 1A, towards the bottom towards the X axis of the plug.

The lip 3 is thus placed across the race ascending from the upper edge B of the neck C when the cap is screwed on the recipient.

In the semi-closed position of FIG. 1B, the edge B of the neck C comes into contact with the lip 3.

The continued screwing leads to the progressive deformation of lip 3 by edge B until lip 3 marries, under constraints, at least part of the curvilinear outer periphery b of edge B being inserted and crushed in the space between the shoulder 4 and the said neck as shown in FIG. 1C, leaning against the projection 41.

The face of the shoulder 4 facing the neck C presents, from preferably, above the projection 41, an undercut 40 allowing compensate for possible centering defects, dimensional deviations dilation, realization of the neck and / or the stopper.

However, in order to distribute the deformation stresses of regularly along the lip 3, the face 40 of the shoulder 4 and / or the tray 2 located opposite the neck C may have, according to a variant shown in FIGS. 3A to 3C, a profile complementary to that of edge B.

In the embodiment of FIG. 1D, the lip 3 has a first straight section 31, connected at one end to the underside of shoulder 4, and extended at its other end, via a bend 30, to a second rectilinear section 32.

The elbow 30 defines an angle α between the two sections 31, 32 whose value is positive or negative and between 0 and 60 °, from a either side of the axis of the first section 31.

The lip 3 (and here the first section 31) is inclined with a angle β between 20 ° and 60 ° relative to the axis X of the plug.

This geometry ensures the conforming of the lip device 3 on the upper edge B of the neck in the closed position, as illustrated in Figure 1C.

More generally, the profile and the thickness (between 0.2 and 0.6 mm) of the lip 3 as well as the geometry of the shoulder 4 and in particular from the projection 41, are determined so that the lip 3 hugs at least part of the periphery b of the edge B, above the neck joint planes (not shown) covering, if applicable where appropriate, the adjacent lower part of the curved periphery b.

These joint surfaces are made up of fine vertical ribs resulting from the container manufacturing operations. Indeed, molding of the container and / or of its preform, and in particular of the neck C, can be made using a mold made up of two separable shells delimiting, between their edges in contact, a very narrow gap where the plastic material can creep and form parasitic ribs. These ribs remain on the container neck after finishing.

A good seal can therefore only be ensured when the lip 3 is in abutment against a smooth surface of the neck C, that is to say devoid of any roughness, which is only above the plans of seal.

In the variant of FIG. 1E, the peripheral lip 3 is associated with a centering and / or blocking crown 5 carried by the bottom wall of the tray 2. The lowest point of the crown 5 is located above the level of the free end of the lip 3 at rest, in its position before closing as shown in FIG. 1A. Of preferably, the plate 2 is provided, in its center, with a set of ribs stiffening radials 7 attached here to the crown 5.

In the embodiment of FIGS. 2A to 2C, the means sealing have an inner annular lip 6, elastically deformable.

This annular lip 6 is here integral with the plate 2 and is inclined towards the X axis of the plug, at an angle γ between 0 and 45 ° with a diameter of connection to the plate 2 between the outside and inside diameters of neck C.

So her free end is likely to come to marry, under constraints, the curvilinear inner periphery b 'of the upper edge B of the neck C, in the closed position of the cap, so as to ensure waterproofing complementary to that provided with the outer periphery b from edge B by the peripheral lip 3.

In this position shown in FIG. 2C, the lip interior 6 is interposed and crushed, under constraints, between a projection radial 51 carried by an internal shoulder 52 secured to the face bottom of tray 2 and upper edge B of the neck, just like the lip peripheral 3 between the outer shoulder 4 and the edge B.

According to a variant not shown, the lip 6 is worn or consisting of an independent element, in the form of a ring or disc which is arranged in the bottom of the cap.

The face of the shoulder 52 turned opposite the neck C present here above the projection 51, an undercut 50 whose function is similar to that of the undercut 40 of the shoulder 4.

In the embodiment of FIGS. 3A to 3C, the crown 5 is extended downward and is intended to extend coaxially to the neck C, opposite lip 3.

The crown 5 delimits, with the outer shoulder 4 and the lip 3, a groove 20, in which the upper edge B of the collar C in the closed position so as to ensure centering and additional seal inside the collar C.

The underside of the plate is provided with a ring 21 extending in the groove 20 in the direction of the lip 3. The ring 21 provides the location and the concentration of the support efforts of the C pass, transmitted by the lip 3, on a circular line of the plate 2.

Although shown only in Figures 3B and 3C, the rod 21 can be used in combination with the embodiments of the other figures.

The radially outer face of the crown 5 is provided, in its lower part, a boss 53.

The boss 53 bears against the internal lateral wall of the collar C in semi-closed position (figure 3B) and closed position (figure 3C), which causes the lower part of the crown 5 to pivot towards inside the collar.

The movement of the crown 5 and the contact of the boss 53 against the inner wall of the neck C provide a second zone sealing complementary to that located on the outer periphery b of the edge B.

In the embodiment of FIGS. 4A to 4C, the height of the portion of the crown 5 projecting inside the neck C, cap closing position, is greater than the dead travel of unscrewing prior to the separation of the tamper-evident band 11 by rupture of the embrittlement zone 12.

Under these conditions, the upper edge B of the neck C meets the end of the crown 5 first, when it moves ascending, and leaves this crown last, during its descent.

This arrangement thus keeps the seal and avoid any untimely degassing and / or any venting detrimental to the quality of the liquid product, even if unscrewed partial accidental or fraudulent that does not lead to the termination of the embrittlement zone 12.

The internal wall of the cervix is always protected from attack exterior likely to occur, during manufacture, transfer and bulk storage of containers and / or preforms, unlike the outer wall, especially in the case of returnable containers.

As a result, the state of the internal surfaces of the neck, coming in contact with the inner lip 6 and / or the boss 53, participates according to the invention, thanks to the favorable synergy of the different means tightness, obtaining a very high level of airtightness, whatever the conditions of use.

Claims (16)

Cap for container of liquid products of the type comprising a side skirt (1) provided on the one hand, with an internal thread (10) and a lower tamper-evident band (11) and connected on the other hand, to a upper plate (2) internally carrying sealing means intended to cooperate with the upper edge (B) of the neck (C) of the container, characterized in that said sealing means comprise an external shoulder (4) formed in the zone connecting the skirt (1) and the plate (2), having a radial projection (41), and carrying an elastically deformable peripheral lip (3) extending, at rest, downwards in the direction of the axis ( X) of the stopper and intended, in the closed position of the stopper, to be inserted between the projection (41) of said shoulder (4) and said neck C by marrying, under stress, at least part of the outer curvilinear periphery (b) from the upper edge (B) of the neck. Plug according to claim 1, characterized in that said sealing means further comprise an elastically deformable inner annular lip (6) positioned so that its free end conforms, at least to the inner circumference (b ' ) from the upper edge (B) of the neck in the closed position of the cap. Plug according to claim 2, characterized in that said inner lip (6) is formed or carried by an independent annular element disposed in the plug. Cap according to claim 2, characterized in that said inner lip (6) has a diameter for connection to the plate (2) between the outside and inside diameters of said neck (C) and is inclined relative to the axis of the cap d 'an angle (γ) between 0 and 45 °. Cap according to one of claims 2, 3 or 4, characterized in that said inner lip (6) is intended to be interposed, under stress, in the closed position of the cap, between, on the one hand, an inner shoulder (52) secured to the underside of the plate (2) and, on the other hand, the neck (C) of the container. Cap according to claim 1 or 5, characterized in that the face of the outer shoulder (4) and / or of the inner shoulder (52), located opposite the neck (C) in the closed position of the cap, has an undercut (40, 50) Cap according to one of the preceding claims, characterized in that said plate (2) is provided at its center with a set of radial ribs (7) for stiffening. Cap according to one of the preceding claims, characterized in that said sealing means comprise, in addition, a centering and / or locking ring (5) integral with the plate (2) and extending coaxially opposite of said peripheral lip (3) by delimiting with said outer shoulder (4) and / or the lip (3) a groove (20) in which the neck (C) is housed, in the closed position of the plug. Cap according to claim 8, characterized in that the radially outer face of said crown (5) is provided in the lower part, with a boss (53) intended to bear against the internal lateral wall of the neck (C). Cap according to claim 8 or 9, characterized in that the height of the portion of the crown (5) projecting inside the neck in the closed position of the cap is greater than the dead travel of the unscrewing prior to the separation of the tamper-evident band (11). Cap according to one of the preceding claims, characterized in that the said peripheral lip (3) is connected to the underside of the outer shoulder (4). Cap according to one of the preceding claims, characterized in that said peripheral lip (3) has a first rectilinear section (31) connected by one end to said external shoulder (4) and extended at its other end via an elbow (30) by a second straight section (32). Cap according to claim 12, characterized in that the elbow (30) defines an angle (α) between the two sections (31, 32) whose value is between 0 and 60 °. Cap according to one of the preceding claims, characterized in that said peripheral lip (3) or its first section (31) is inclined with an angle (β) between 20 ° and 60 ° relative to the axis (X) of the plug. Stopper according to any one of the preceding claims, characterized in that the thickness of said peripheral lip (3) as well as the geometry of the external shoulder (4) are determined, so that the bearing contact between said lip (3) and the upper edge (B) of the neck is made above the joint planes of said neck. Cap according to one of the preceding claims, characterized in that the lower face of the plate (2) is provided with a rod (21) extending in the direction of the inner lip (3).

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