EP1216930B1 - Cap for containers for liquid products - Google Patents

Description

The present invention relates to a threaded cap for a container of liquid products.

Corks used in product packaging liquids such as beverages and, in particular, beverages carbonates include in particular a side skirt provided with a internal thread connecting the threaded neck of the container and connected to a top plate internally carrying means sealing means for cooperating with the upper edge of said neck.

In most cases, the skirt extends down through a zone of weakness by a separable band of inviolability coming into taken with an annular projection formed on the neck, below the thread.

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

In addition, so that there is a sufficient contact area between the neck and the side wall of the crown, it is appropriate to give the latter an important height.

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

These risks are, moreover, accentuated by employment, of a single constitutive material such as polyethylene, less creep resistant than polypropylene used for plugs traditional equipped with an attached seal.

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

However, to obtain a satisfactory seal, it is necessary here also to exert a couple of screwing important because the lip must be folded at least 90 ° upwards on itself and / or against the board.

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

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 perfect the mold and the control of the manufacturing process and in particular the phase of cooling, which leads to a slowing down 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 optimum sealing because it is not possible to control the constraints of deformation of the lip on such a great length, without have setting means on the inner wall of the plug.

EP 0 644 125 basis for the preamble of claim 1 provides yet another mode of embodiment in which the lip is connected to a shoulder formed in the connection zone between the skirt and the plate; said shoulder consisting of a lower face and a radially face vertical interior intended to come opposite the neck, in the position of closing the cap.

However, this shoulder is nothing more than an extra thickness of the wall of the skirt which ensures no wedging and exerts no strain of deformation of the lip. However, this gap is prejudicial to the tightness of the packaging, in particular in the area above the joint plane of the container neck.

The present invention aims to solve these problems techniques satisfactorily.

This object is achieved, according to the invention, by means of a threaded cap of the above type, characterized in that said lip is connected to the underside of the shoulder on the side of its zone of junction with the inner side wall of the skirt delimiting a radial projection on said shoulder so that in the position of closure of the stopper, said lip marries, under constraints, to least part of the outer curvilinear circumference of the upper edge of the collar.

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

According to a variant, said inner lip is constituted or carried by an independent annular element disposed in the plug.

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

According to an advantageous characteristic, said inner lip is intended to be interposed under constraints, in the closed position of the cap, between on the one hand an inner shoulder secured to the face bottom of the tray and on the other hand the neck of the container.

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

According to yet another feature, said tray is provided in the center of a set of radial stiffening ribs. The case where appropriate, these ribs are leaned against the inner shoulder.

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

According to another advantageous characteristic, the face radially outer of said ring is provided, in the lower part, of 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 projecting from the inside of the neck in the closed position of the cap is greater than the dead stroke of unscrewing 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 feature, said lip device has a first rectilinear section connected by a end to said outer shoulder, and extended to its other end via a bend by a second rectilinear section.

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

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

According to yet another feature, 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 above the joint planes of said neck, this which guarantees a good seal.

According to a specific variant, the lower face of the tray is provided with a ring extending towards the inner lip.

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

The cooperation of flexible lips (peripheral and / or interior), with the corresponding shoulders, makes it possible to optimize 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 following description with reference to the accompanying drawings, in which:

• Figures 1A, 2A, 3A and 4A show sectional views of four embodiments of the plug 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 semi-closed position on the neck, and in the sealed position of the container;
• Figures 1D and 1E show partial sectional views of two embodiments.
• Figures 2B and 2C show partial sectional views of the embodiment of Figure 2A, respectively in the position of semi-closure on the neck and sealing;
• Figures 3B and 3C show partial sectional views of the embodiment of Figure 3A, respectively in semi-closed position on the neck, and sealing.
• FIGS. 4B and 4C show partial cross-sectional views of the embodiment of FIG. 4A, in semi-closed and sealed position, respectively

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

In general, this cap comprises 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. The skirt 1 is extended towards the bottom by a tamper band 11 via a weakening zone 12 likely to be broken by unscrewing the cap.

The top plate 2 of the plug internally carries sealing means for cooperating with the upper part of the neck C and in particular its upper edge B.

The section of the upper edge B is bounded laterally by a side by an outer curvilinear circumference b (referred to as "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 elements comprise a radially outer shoulder 4, formed in the connection zone between the skirt 1 and the plate 2, presenting a radial projection 41 and carrying a peripheral lip 3, elastically deformable which extends, at rest, as shown in Figure 1A, to down towards the X axis of the cap.

Lip 3 is thus placed across the race upward of the upper edge B of the neck C when screwing the cap on the recipient.

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

The continuation of the screwing causes the progressive deformation of the lip 3 by the edge B until the lip 3 marries, under constraints, at least a portion of the outer curvilinear periphery b of the edge B being interposed and crushed in the space between the shoulder 4 and said collar as shown in Figure 1C being backed against the projection 41.

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

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

In the embodiment of FIG. 1D, the lip 3 comprises a first rectilinear section 31, connected at one end to the face lower shoulder 4, and extended at its other end, via a elbow 30, to a second rectilinear section 32.

The bend 30 defines an angle α between the two sections 31, 32 whose value is positive or negative and between 0 and 60 °, of a on 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 ° with respect to the axis X of the plug.

This geometry makes it possible to ensure the conformation of the lip device 3 on the upper edge B of the collar in the closed position, as shown 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 of the projection 41, are determined so that the lip 3 marries at least a portion of the periphery b of the edge B in a sealed manner, above the joint planes of the cervix (not shown) by covering, the case where appropriate, the adjacent lower part of the curvilinear circumference b.

These joint planes consist of thin vertical ribs resulting from container manufacturing operations. Indeed, the molding of the container and / or its preform, and in particular of the neck C, may be carried out by means of a mold formed of two separable shells delimiting, between their edges in contact, a very narrow gap where the Plastic material can flow and form parasitic veins. These ribs remain on the neck of the container after finishing.

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

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

In the embodiment of FIGS. 2A to 2C, the means are provided with an inner annular lip 6, elastically deformable.

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

Thus, its 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 plug, so as to ensure a seal complementary to that provided with the outer circumference b of edge B by the peripheral lip 3.

In this position shown in FIG. 2C, the lip 6 is interposed and crushed, under stress, between a protrusion radial 51 carried by an inner shoulder 52 integral with the face bottom of the tray 2 and the upper edge B of the collar, just like the lip device 3 between the outer shoulder 4 and the edge B.

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

The face of the shoulder 52 turned next to 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 ring 5 is extended downwards and is intended to extend coaxially to the cervix C, next to the lip 3.

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

The lower face of the tray is provided with a ring 21 extending in the groove 20 towards the lip 3. The ring 21 ensures the location and concentration of the C-neck support efforts, transmitted by the lip 3, on a circular line of the plate 2.

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

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

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

The travel of the crown 5 and the contact of the boss 53 against the inner wall of the neck C allow to offer a second zone additional sealing of that located on the outer circumference 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, in closing position of the cap, is greater than the dead stroke of unscrewing prior to the separation of the tamper-evident band 11 by rupture of the zone of weakness 12.

In these conditions, the upper edge B of the collar C meets the end of the crown 5 first, when moving ascending, and leaves this crown last, during its descent.

This arrangement thus makes it possible to maintain the watertightness and avoid any accidental degassing and / or any venting detrimental to the quality of the liquid product, even in case of unscrewing accidental or fraudulent partial failure not leading to the break-up of zone of weakness 12.

The inner wall of the neck is always preserved from aggressions which may occur during manufacture, transfer and bulk storage of containers and / or preforms, unlike the outer wall, particularly in the case of returnable containers.

As a result, the condition of the internal surfaces of the collar, coming into contact with the inner lip 6 and / or the boss 53, participates according to the invention, thanks to the favorable synergy of the various means sealing, to obtain a very high level of hermeticity, whatever the conditions of use.

Claims (16)

1. Cap for a liquid-product container, of the type comprising a lateral skirt (1) provided, on the one hand, with an internal thread (10) and with a lower tamper-proof strip (11) and connected, on the other hand, to an upper top (2) carrying internally sealing means intended for cooperating with the upper edge (B) of the neck (C) of the container, and comprising an outer shoulder (4) formed in the connection zone between the skirt (1) and the top (2), the said shoulder consisting of a radially inner face intended to come opposite the neck (C) and a lower face carrying an elastically deformable peripheral lip (3) extending, at rest, downwards in the direction of the axis (X) of the cap and intended, in the closing position of the cap, to be interposed between the said shoulder (4) and the said neck (C), characterized in that the said lip is connected to the lower face of the shoulder towards the junction zone of the latter with the inner side wall of the skirt (1), at the same time delimiting a radial projection (41) on the said shoulder (4), in such a way that, in the closing position of the cap, the said lip mates under stress with at least part of the outer curved perimeter (b) of the upper edge (B) of the neck.
2. Cap according to Claim 1, characterized in that the said sealing means comprise, furthermore, an elastically deformable inner annular lip (6) positioned in such a way that its free end mates under stress with at least the inner perimeter (b') of the upper edge (B) of the neck in the closing position of the cap.
3. Cap according to Claim 2, characterized in that the said inner lip (6) consists of or is carried by an independent annular element arranged in the cap.
4. Cap according to Claim 2, characterized in that the said inner lip (6) has a connecting diameter to the top (2) between the outside and inside diameters of the said neck (C) and is inclined at an angle (γ) of between 0 and 45° with respect to the axis of the cap.
5. Cap according to one of Claims 2, 3 or 4, characterized in that the said inner lip (6) is intended, in the closing position of the cap, to be interposed under stress between, on the one hand, an inner shoulder (52) integral with the lower face of the top (2) and, on the other hand, the neck (C) of the container.
6. Cap according to Claim 1 or 5, characterized in that that face of the outer shoulder (4) and/or of the inner shoulder (52) which is located opposite the neck (C) in the closing position of the cap has an undercut (40, 50).
7. Cap according to one of the preceding claims, characterized in that the said top (2) is provided at its centre with a set of radial rigidifying ribs (7).
8. Cap according to one of the preceding claims, characterized in that the said sealing means comprise, in addition, a centring and/or locking ring (5) integral with the top (2) and extending coaxially opposite the said peripheral lip (3), at the same time delimiting, with the said outer shoulder (4) and/or the lip (3), a groove (20) in which the neck (C) is seated in the closing position of the cap.
9. Cap according to Claim 8, characterized in that the radial outer face of the said ring (5) is provided, in the lower part, with a boss (53) intended to come to bear against the inner side wall of the neck (C).
10. Cap according to Claim 8 or 9, characterized in that the height of that portion of the ring (5) which projects on the inside of the neck in the closing position of the cap is greater than the idle travel of the unscrewing operation prior to separation of the tamper-proof strip (11).
11. Cap according to one of the preceding claims, characterized in that the said peripheral lip (3) is connected to the lower face of the outer shoulder (4).
12. Cap according to one of the preceding claims, characterized in that the said peripheral lip (3) comprises a first rectilinear segment (31) connected at one end to the said outer shoulder (4) and prolonged at its other end, via a bend (30), by a second rectilinear segment (32).
13. Cap according to Claim 12, characterized in that the bend (30) defines an angle (α) between the two segments (31, 32), the value of which is between 0 and 60°.
14. Cap according to one of the preceding claims, characterized in that the said peripheral lip (3) or its first segment (31) is inclined at an angle (β) of between 20° and 60° with respect to the axis (X) of the cap.
15. Cap according to any one of the preceding claims, characterized in that the thickness of the said peripheral lip (3) and the geometry of the outer shoulder (4) are determined in such a way that the bearing contact between the said lip (3) and the upper edge (B) of the neck takes place above the parting planes of the said neck.
16. Cap according to one of the preceding claims, characterized in that the lower face of the top (2) is provided with a retainer (21) extending in the direction of the inner lip (3).

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