ES2977337T3 - Capping device for the neck of a container - Google Patents

Abstract

The invention relates to a capping device intended to be fixed to a neck (2) of a container comprising a locking collar (4), the capping device comprising: - a cap (1) having a helical thread (7) intended to cooperate with a helical thread (6) formed in the neck (2); - a lower ring (9) axially fixed to the neck (2); - an articulation device (10) joining the cap (1) to a second sector (17) of the lower ring (9), the articulation device extending over a first angular interval which is cut into two equal parts by a bisector plane Pb; the helical thread (7) developing around the axis X in a first direction and having a lower end and an upper end, the lower end of the helical thread (7) being arranged in a second angular interval which is defined between the bisector plane Pb and a radial plane placed at 160° from the bisector plane Pb in a second direction opposite to the first direction.

Description

DESCRIPTION

Capping device for the neck of a container

Technical field

The invention relates to an assembly comprising a container and a capping device which is equipped with a cap and allows said cap to be kept fixed to the neck of a container, thereby preventing the cap from being completely lost.

Technological background

Document ES1232089U discloses a capping device that includes a lower ring intended to be axially fixed on the neck of a container, a cap that includes a thread intended to engage a complementary thread formed in the neck of the container and a joint that joins the cap with the lower ring. The lower ring includes hooking means intended to retain the lower ring with the neck of the container. The section of the diameter of the lower ring in which there are hooking means extends between 25 and 75% of the diameter of the lower ring. The section of the lower ring that is connected to the cap by the joint device lacks hooking means, which allows said section to rotate between a lowered position and a raised position, in particular, to allow the cap to be unscrewed. Furthermore, the cap includes ratchet means intended to cooperate with the complementary ratchet means formed in the lower ring and, therefore, allows the cap to be kept in an open, tilted position.

This capping device is not entirely satisfactory. Indeed, despite the absence of any means of engagement in the lower ring section connected to the cap by the hinge, manipulating the cap to allow the lower ring section connected to the cap to rotate into a raised position when the cap must be moved from the open tilted position to the closed position is not easy.

Summary

An underlying idea of the invention is to propose a capping device that allows a cap to be kept attached to the neck of the container and is reliable, easy to make and use.

According to one embodiment, the invention provides a capping device intended to be fixed to the neck of a container including a hole and a locking collar, the capping device including:

- a plug including a top wall and an outer peripheral skirt, the outer peripheral skirt having a helical thread intended to cooperate with a helical thread formed in the neck to allow:

• unscrewing the cap from the neck about an X axis to move the cap from a closed position in which the upper wall closes the neck opening and the peripheral skirt surrounds the neck towards a released position in which the cap is no longer engaged with the neck; and

• a screwing of the cap onto the neck to move the cap from the released position to the closed position;

- a lower ring axially fixed to the neck and rotatably movable on the neck about said axis X, said lower ring including a first sector including engagement elements projecting radially towards the inside of the lower ring and intended to be arranged beneath the engagement collar to axially retain the lower ring on the neck of the container, the first sector and the second sector of the lower ring being articulated with each other so that the second sector rotates relative to the first sector between a lowered position in which the second sector is intended to be arranged beneath the engagement collar and a raised position in which the second sector is intended to be arranged at least partially above the engagement collar;

- an articulation device that connects the plug to the second sector of the lower ring and is configured to allow the plug to rotate between the released position and an open tilted position in which the plug is disengaged from the hole in the neck, the articulation device extends over a first angular interval that is cut into two equal parts by a bisector plane Pb;

- the lower ring is configured so that the second sector rotates relative to the first sector from the lowered position towards the raised position to allow the cap to move from the closed position towards the released position;

- the lower ring can move radially from front to rear to facilitate the passage of a part of the second sector on each side of the engagement collar during the movement of the second sector between the lowered position and the released position, the helical thread developing around the axis X according to a first direction and having a lower end and defined between the bisector plane Pb and a radial plane positioned at 160° from the bisector plane Pb according to a second direction opposite to the first direction, so that a lower front part of the outer peripheral skirt lacks a helical thread

This facilitates the engagement of the cap into the neck when the cap is moved from the open tilted position to the closed position.

In other advantageous embodiments, such a capping device may have one or more of the following characteristics.

In one embodiment, the lower end of the helical thread is arranged in an angular interval defined between two radial planes, respectively, positioned at 90° and 160° from the bisector plane Pb according to the second direction of rotation. In one embodiment, the first sector of the lower ring includes a front zone that is diametrically opposite to the second sector and two engagement zones that are each arranged between the front zone of the first sector and the second sector, the engagement elements being arranged only in the two engagement zones to allow radial movement of the lower ring. In this way, the tensile forces that will be exerted on the lower ring to allow the second sector to move between the lowered position and the raised position are lower, which facilitates the use of the capping device.

According to one embodiment, the front area of the second sector extends over an angular range between 90 and 150°.

In one embodiment, each of the two engagement zones extends over an angular range of between 30 and 90°.

According to one embodiment, the two engagement zones extend over angular sectors which are symmetrical to each other with respect to the bisector plane Pb.

In one embodiment, the engaging elements are protuberances projecting radially inwards.

According to one embodiment, the second sector extends over an angular range between 90 and 150°.

In one embodiment, the engaging elements are protuberances projecting radially inwards.

According to one embodiment, the second sector has no hooking elements.

In one embodiment, the capping device further includes a locking device configured to lock the cap in the tilted open position, said locking device including a stop projecting radially outwardly from the cap and configured to bear against the engagement collar of the neck during movement of the cap from the tilted open position to the released position to exert on the second sector a tensile force having a component directed radially outward and a component directed axially upward to assist movement of the second sector between the lowered position and the raised position. This makes it possible to further facilitate the use of the capping device, in particular when the cap must be moved from the tilted open position to the closed position.

In one embodiment, the stop is configured so that, during movement of the cap from the released position to the open tilted position, the stop abuts against an upper end of the second sector of the lower ring to move it from the raised position to the lowered position. This also makes it easier to use the capping device.

In one embodiment, the locking device further includes a heel that is formed on the outer peripheral skirt of the cap and extends axially, the heel being configured to bear against a helical rib of the helical thread formed on the neck of the container during movement of the cap from the tilted open position to the released position to exert on the second sector a tensile force having a radially outwardly directed component and an axially upwardly directed component to assist movement of the second sector from the lowered position to the raised position.

In one embodiment, the stop projects radially outwards from the heel.

In one embodiment, the articulation device includes two blades and the heel is formed between the two blades.

According to one embodiment, the articulation device includes two blades and the capping device also includes a device for locking the cap in the tilted open position, said locking device including a stop that is formed on the outer peripheral skirt, between the two blades of the articulation device, and that is configured to rest against the neck of the container when the cap is in the tilted open position, the heel having an inner face on which at least one rib of the helical thread is formed. This allows to improve the pressure resistance of the capping device.

According to one embodiment, the invention also relates to an assembly comprising a container equipped with a neck including a hole, a locking collar and a helical thread and a capping device mentioned above, the lower ring being axially fixed to the neck and being rotatably movable on the neck around said axis X.

Brief description of the figures

The invention will be better understood and other purposes, details, features and advantages thereof will become more apparent from the following description of various particular embodiments of the invention, given by way of illustration only and not of limitation, with reference to the accompanying drawings.

Figure 1 is a three-quarter perspective view of a capping device.

Figure 2 is a sectional view of a container neck intended to receive the capping device of Figure 1.

Figure 3 is a side view of the capping device mounted on the neck of the container and showing the cap of the capping device in a released position where it is no longer engaged with the neck of the container.

Figure 4 is a perspective view of the capping device mounted on the neck of the container and showing the cap of the capping device in a tilted open position in which the cap is disengaged from the neck hole.

Figure 5 is a side perspective view of the capping device.

Figure 6 is another side perspective view of the capping device.

Figure 7 is a rear perspective view of the capping device.

Figure 8 is a front perspective view of the capping device.

Figure 9 is a sectional view of the capping device mounted on the neck of the container and showing the cap of the capping device in a tilted open position in which the cap is disengaged from the neck hole.

Figure 10 is a sectional view of the capping device mounted on the neck of the container and showing the cap of the capping device in an intermediate position between the released position and the tilted open position.

Figure 11 is a perspective view of the capping device mounted on the neck of the container and showing the cap of the capping device in the tilted open position.

Detailed description of the implementation modes

In the description and figures, the X axis corresponds to the axis of rotation of the cap 1 of the capping device when it is screwed onto the neck 2 of the container. By convention, the "radial" orientation is directed orthogonally to the X axis and the axial orientation is directed parallel to the X axis. The terms "external" and "internal" are used to define the relative position of one element with respect to another, by reference to the X axis, an element close to the X axis being thus described as internal as opposed to an external element located radially on the periphery.

The terms "upper" and "lower" are used to define the relative position of one element with respect to another by reference to a position in which the hole 3 of the neck 2 is oriented upwards and the stopper 1 is in the closing position on the neck 2 of the container, an element intended to be positioned lower down being called lower and an element intended to be positioned higher up being called upper. The terms "in front" and "behind" are used to define the relative position of one element with respect to another along a diameter perpendicular to the axis X. With reference to Figures 1 to 10, an assembly is described below comprising a stoppering device, shown in particular in Figure 1, and a container equipped with a neck 2, shown in particular in Figure 2.

As shown in Figure 2, the neck 2 of the container has an upper end in which an orifice 3 is formed for pouring the contents of the container. The neck 2 of the container includes a support collar 4 projecting radially outward and a latching collar 5 also projecting radially outward and axially arranged between the support collar 4 and the orifice 3. A cylindrical portion is formed axially between the support collar 4 and the orifice 3. Furthermore, the neck 2 includes, axially placed between the latching collar 5 and the orifice 3, a helical thread 6 formed by a series of helical ribs, projecting radially outward from an external surface of the neck 2. The helical thread 6 is intended to cooperate with a complementary helical thread 7 formed from a series of helical ribs formed in the stopper 1 of the stopper device.

In one embodiment, the helical thread 6 formed on the neck 2, as well as the helical thread 7 formed on the plug 1 are interrupted. In other words, the adjacent helical ribs are separated by a space forming a vent and allowing, in particular, the evacuation of the gas present inside the container while the plug 1 is still engaged on the neck 2.

The stoppering device includes a lower ring 9 which is retained in the neck 2 of the container, a plug 1 which is intended to cover the hole 3 of the container in order to seal it, a hinge device 10 joining the plug 1 to the lower ring 9 and a locking device positioned to lock the plug 1 in an open tilted position, shown in Figures 4, 9 and 11. In the open tilted position, the plug 1 is disengaged from the hole 3 of the container and does not hinder the pouring of the contents of the container.

As illustrated in Figures 7 and 8, the articulation device 10 extends over an angular interval S1 which is cut into two equal parts by a vertical bisector plane Pb.

Returning to Figure 1, it can be seen that the cap 1 includes an upper wall 13 intended to be arranged substantially orthogonally to the axis X, facing the hole 3 of the neck 2 when said cap 1 is in the closed position. The cap 1 also includes an external peripheral skirt 14 intended to surround the neck 2 of the container when the cap 1 is in the closed position. The external peripheral skirt 14 extends downwards perpendicular to the upper wall 13, from the external periphery of said upper wall 13.

The outer peripheral skirt 14 has, on its inner face, a helical thread 7, visible in Figures 2 and 5 to 7, formed by a series of helical ribs extending around the axis X according to a first direction of rotation. The helical thread 7 is intended to cooperate with the helical thread 6 formed on the outer surface of the neck 2. In this way, the cap 1 is suitable for being screwed onto the neck 2 in order to close the container and for being unscrewed from the neck 2 in order to open the container. The cap 1 can thus be moved between a closed position and a released position, shown in Figure 3. In said released position, the cap 1 is no longer coupled with the neck 2. It is therefore suitable for tilting into the open tilted position, shown in Figures 4, 9 and 11, in which the cap 1 is disengaged from the hole 3 of the neck 2 so that it does not hinder the pouring of the contents of the container.

9, the cap 1 also includes an internal skirt 8, which extends perpendicularly downwards from the upper wall 13 of the cap 1 and is sized to be inserted inside the hole 3 of the neck 2. The cap 1 also includes an annular lip 15 extending, from the upper wall 13, radially between the internal skirt 8 and the external peripheral skirt 14. The internal skirt 8 and the annular lip 15 are sized so that, when the cap 1 is in the closed position, on the neck 2 of the container, the internal skirt 8 is in contact against the internal face of the neck 2 while the annular lip 15 is in contact against the external face of the neck 2. Thus, the internal skirt 8 and the annular lip 15 make it possible to ensure the tightness of the closure.

Advantageously, the lower ring 9 is, before the first opening of the container, connected to the cap 1 by frangible bridges, not visible in the figures, intended to break during the opening of the cap 1. These frangible bridges thus constitute inviolability seals.

The lower ring 9 is held axially on the neck 2 of the container while being rotatable relative to it around the axis X. As shown in Figure 3, the lower ring 9 includes two parts which are hinged to each other, i.e. a first sector 16 and a second sector 17 by which the lower ring 9 is connected to the cap 1 by means of the hinge device 10.

In one embodiment, the lower ring 9 includes two narrowed zones, i.e. the radial thickness of which is less than the radial thickness of the lower ring 9 outside said narrowed zones. The two narrowed zones delimit the first sector 16 and the second sector 17. The narrowed zones thus form pivots which allow the articulation of the second sector 17 with respect to the first sector 16.

According to another embodiment, the lower ring 9 does not have narrowed areas delimiting the first and second sectors 16, 17.

The second sector 17 is capable of pivoting upwardly relative to the first sector 16, between a lowered position in which the second sector 17 is intended to be arranged below the engagement collar 5 and a raised position, in which the second sector 17 is arranged at least partly above the engagement collar 5. This allows the cap 1 to move upwardly relative to the neck 2 of the container, until the helical thread 7 of the cap 1 disengages from the helical thread 6 formed in the neck 2 of the container. In other words, when the cap 1 is unscrewed, the lower ring 9 is driven in rotation about the axis X while the second sector 17 of the lower ring 9 rotates relative to the first sector 16 to the raised position to allow an axial, upward movement of the cap 1 from the closed position to the released position, represented in figure 3. When the cap 1 rotates from the released position to the tilted open position, the second sector 17 of the lower ring 9 rotates in the opposite direction relative to the first sector 16 and then returns to the lowered position. Moreover, as described in more detail below, the second sector 17 also rotates relative to the first sector 16 from the lowered position to the raised position when the cap 1 rotates from the tilted open position to the released position.

The lower ring 9 is held axially on the neck 2 of the container by means of the engaging collar 5, in particular visible in FIGS. 5 to 7. The engaging collar 5 has a frustoconical outer surface which tapers upwards, i.e. in the direction of the opening 3 of the container. The engaging collar 5 delimits, downwards, i.e. in a direction opposite the opening 3, a projection. The first sector 16 of the lower ring 9 includes engaging elements 18 which cooperate with the engaging collar 5 formed on the container in order to axially retain the lower ring 9 to the neck 2 of the container. The latching elements 18 are protuberances, shown in detail in particular in FIGS. 5 and 6, which project radially inwards from the first sector 16 of the lower ring 9. The retaining elements 18 have a radial dimension which increases from bottom to top, i.e. in the direction of the upper edge of the lower ring 9. During assembly of the stoppering device on the neck 2 of the container, the latching elements 18 slide against the frustoconical surface of the latching collar 5 and are then locked by an elastic return behind the latching collar 5.

As shown in Figures 5 and 6, the first sector 16 of the lower ring 9 includes a front area 19 which is diametrically opposite to the second sector 17 of the lower ring 9 and two engagement areas 20, 21 which are arranged on either side of the front area 19 and are each arranged between the front area 19 and the second sector 17 of the lower ring 9. The engagement elements 18 are only arranged in the two engagement areas 20, 21. Thus, due to the absence of engagement elements 18 in the front area of the first sector 16, there is a radial space between the lower ring 9 and the neck 2 which allows the lower ring 9 to move from front to back and vice versa. The radial clearance between the lower ring 9 and the neck 2 according to the front/back direction is, for example, between 0.5 and 1 mm. This facilitates the passage of a portion of the second sector 17 on either side of the engagement collar 5 during the movement of the second sector 17 between the lowered position and the raised position. In other words, the tensile forces that will be exerted on the lower ring 9 to allow the second sector 17 to pass on either side of the engagement collar 5 are lower.

Advantageously, the second sector 17 extends over an angular range between 90 and 150°, and for example, of the order of 120°, the front zone of the second sector 16 extends over an angular range between 90 and 150°, for example, of the order of 120°, while each of the two engagement zones 20, 21 extends over an angular range between 30 and 90°, for example, of the order of 60°.

On the other hand, the bisector plane Pb cuts the second sector 17 into two equal parts, as well as the front part of the second sector 17. The angular intervals corresponding to the two engagement zones 20, 21 are therefore symmetrical to each other with respect to the bisector plane Pb.

The articulation device 10 is configured to allow the cap 1 to rotate between the released position, shown in Figure 3, in which the external peripheral skirt 14 extends downwardly from the upper wall 13 of the cap 1, and the open tilted position, shown in Figures 4, 9 and 11, in which the external peripheral skirt 14 extends upwardly from the upper wall 13 of the cap 1. In the embodiment shown, the articulation device 10 includes two blades 11, 12, in particular visible in Figure 4, which join the cap 1 and, more particularly, the external peripheral skirt 14 of the cap 1 to the lower ring 9, and more particularly, to the second sector 17 of the lower ring 9. The two blades 11, 12 are symmetrical with respect to the bisector plane Pb.

The locking device includes a bead 22, in particular visible in Figure 1, which is formed on the outer peripheral skirt 14 of the plug 1. The bead 22 is arranged between the two sheets 11, 12. The lower end of the bead 22 is advantageously located at the same height as the lower end of the outer peripheral skirt 14. The bead 22 includes a stop 23 extending circumferentially around the axis X and projecting radially outwards from the bead 22.

During the movement of the plug 1 from the released position towards the open tilted position, the stop 23 bears against the upper end of the second sector 17 of the lower ring 9 which tends to return said second sector 17 towards the lowered position.

On the other hand, during the movement of the cap 1 from the open, tilted position towards the released position, at first, the stop 23 bears against the engagement collar 5, as shown in Figure 10, to exert on the second sector 17 of the lower ring 9 a tensile force having a component directed radially outwards and a component directed axially upwards. This makes it possible to move the lower ring 9 from front to rear so as to press the front area 19 of the first sector 16 of the lower ring 9 against the neck 2 of the container in order to facilitate the movement of the second sector 17 towards the raised position. This also makes it possible to assist the movement of the second sector 17 between the lowered position and the raised position.

Then, as shown in Figure 10, during the movement of the cap 1 from the open tilted position towards the released position, the outer surface of the heel 22 comes at a second moment to rest against the upper surface of a helical rib of the helical thread 6 formed on the neck 2 of the container, which also makes it possible to exert on the second sector 17 a tensile force having a component directed radially outwards and a component directed upwards to move the second sector 17 towards the raised position.

On the other hand, as shown in Figure 11, the lower end 24 of the helical thread 7 formed on the inner face of the outer peripheral skirt 14, i.e. the beginning of the helical thread 7, is arranged in an angular interval S2 defined between the bisector plane Pb and a radial plane Pr located at 160° from the bisector plane Pb according to a second direction opposite to the first direction of rotation, i.e. in the direction of rotation of the helical thread 7 about the axis X. Thus, a lower front portion 25 of the outer peripheral skirt 14 is devoid of a helical thread 7, which makes it easier to engage the cap 1 on the neck 2 of the container. This arrangement is particularly advantageous when the cap 1 is likely to be presented in a slightly rearwardly displaced position when it comes into contact with the neck 2 of the container. This is particularly the case when the hooking elements 18 are absent from the front area 19 of the first sector 16 and, consequently, the lower ring 9 can move radially from front to back with respect to the neck 2 of the container.

Advantageously, the lower end of the helical thread 7 is arranged in an angular interval defined between two radial planes respectively positioned at 90° and 160° from the bisector plane Pb according to a second direction of rotation opposite to the direction of the helical thread 7 of the plug 1.

Furthermore, as schematically represented in Figures 8, 9 and 10, at least one of the ribs of the series of ribs of the helical thread 7 is formed on the inner face of the shoulder 22. In other words, at least one of the ribs of the helical thread 7 is formed between the two sheets 11, 12 of the articulation device 10. The presence of said rib formed on the shoulder 22 makes it possible to increase the pressure resistance of the helical thread 7 and therefore prevents the cap 1 from opening unintentionally due to excessive pressure in the container, in particular when it is intended to receive carbonated beverages.

The kinematics of the cap 1 are as follows. During the first unscrewing, the cap 1 leaves the closed position and moves away from the lower ring 9 into the released position, illustrated in figure 3. The frangible bridges are broken in the course of this movement. Furthermore, during this unscrewing movement of the cap 1, the lower ring 9 is dragged in rotation about the axis X and the second sector 17 of the lower ring 9 rotates towards the raised position as the cap 1 moves away from the engagement collar 5.

The plug 1 can then be rotated backwards in the direction of the open, tilted position in which the outer peripheral skirt 14 extends upwards from the upper wall 13. During the movement of the plug 1 backwards in the direction of its open, tilted position, the stop 23 abuts against the upper end of the second sector 17 of the lower ring 9, so that the second sector 17 of the lower ring 9 rotates from the raised position to the lowered position.

As shown in Figure 9, when the second sector 17 of the lower ring 9 is in the lowered position and the plug 1 is in its open, tilted position, the stop 23 is abutted against the locking collar 5. In this way, the plug 1 remains in its open, tilted position since, due to this abutment of the stop 23 against the locking collar 5, the plug 1 cannot rotate towards the released position in which the plug 1 faces the dispensing orifice 3 while the second sector 17 of the lower ring 9 remains in the lowered position. This makes it possible to increase the minimum opening angle of the cap 1. Thus, advantageously, when the cap 1 is in its open tilted position and the second sector 17 of the lower ring 9 is in the lowered position, the opening angle of the cap 1 is greater than 120° and, advantageously, greater than or equal to 145° and, for example, of the order of 180°. The opening angle corresponds to the protruding angular sector formed at the intersection between a plane parallel to the upper wall 13 of the cap 1 and a horizontal plane.

In order to re-close the cap 1, the user tilts the cap 1 forwards into the released position. During this tilting, the stop 23 bears against the engagement collar 5 to exert on the second sector 17 of the lower ring 9 a tensile force having a radially outwardly directed component which makes it possible to move the lower ring 9 from front to back and an axially upwardly directed component which makes it possible to assist the movement of the second sector 17 of the lower ring 9 into the raised position. The outer surface of the bead 22 also bears against a helical rib of the helical thread 6 which also facilitates the movement of the second sector 17 of the lower ring 9 into the raised position.

When the second sector 17 is in the raised position and the cap 1 is in the released position, the cap 1 can then be screwed back onto the neck 2 of the container. During screwing, the lower ring 9 is driven into rotation about the axis X and the second sector 17 of the lower ring 9 rotates towards the lowered position as the cap 1 is brought closer to the engagement collar 5.

Advantageously, the entire capping device is moulded in one piece from a synthetic material such as polyethylene, and advantageously high-density polyethylene. Advantageously, the capping device is moulded in the configuration of Figure 1, i.e. in a closed position, in which position it can be mounted directly on the neck 2 of the container.

Although the invention has been described in relation to several particular embodiments, it is more than evident that it is in no way limited by them and that it includes all the technical equivalents of the described means, as well as their combinations if these fall within the scope of the invention as defined by the claims.

The use of the verb "consist of", "comprising" or "including" and their conjugated forms do not exclude the presence of other elements or stages other than those established in a claim.

In the claims, any reference signs in parentheses are not to be construed as a limitation of the claim.

Claims (11)

1. A capping device intended to be fixed to the neck (2) of a container including a hole (3) and a locking collar (4), the capping device including: - a plug (1) comprising an upper wall (13) and an outer peripheral skirt (14), the outer peripheral skirt (14) having a helical thread (7) intended to cooperate with a helical thread (6) formed in the neck (2) to allow: • unscrewing the cap (1) from the neck (2) about an X axis to move the cap (1) from a closed position in which the upper wall (13) closes the hole (3) of the neck (2) and the peripheral skirt surrounds said neck (2) towards a released position in which the cap (1) is no longer coupled with the neck (2); and • screwing the cap (1) onto the neck (2) to move the cap (1) from the released position to the closed position; - a lower ring (9) axially fixed to the neck (2) and rotatably movable on the neck (2) about said axis X, said lower ring (9) including a first sector (16) including engagement elements (18) projecting radially inwards from the lower ring (9) and intended to be arranged beneath the engagement collar (5) to axially retain the lower ring (9) on the neck (2) of the container, the first sector (16) and the second sector (17) of the lower ring (9) being articulated with each other so that the second sector (17) rotates relative to the first sector (16) between a lowered position in which the second sector (17) is intended to be arranged beneath the engagement collar (5) and a raised position in which the second sector (17) is intended to be arranged at least partially above the engagement collar (5); - an articulation device that joins the plug (1) to the second sector (17) of the lower ring (9) and is configured to allow the plug (1) to rotate between the released position and an open tilted position in which the plug (1) is disengaged from the hole (3) of the neck (2), the articulation device extends over a first angular interval that is cut into two equal parts by a bisector plane Pb; - the lower ring (9) being configured so that the second sector (17) rotates relative to the first sector (16) from the lowered position towards the raised position to allow the cap (1) to move from the closed position towards the released position; the helical thread (7) developing around the X axis in a first direction and having a lower end and an upper end; - the lower ring (9) being able to move radially to facilitate the passage of a part of the second sector (17) on each side of the coupling collar (5) during the movement of the second sector (17) between the lowered position and the released position, the plugging device being characterized in that - the lower end of the helical thread (7) is arranged in a second angular interval defined between the bisector plane Pb and a radial plane placed at 160° from the bisector plane Pb according to a second direction opposite to the first direction, so that a lower front part (25) of the external peripheral skirt (14) lacks a helical thread (7). 2. Capping device according to claim 1, wherein the lower end of the helical thread (7) is arranged in an angular interval defined between two radial planes, respectively, positioned at 90° and 160° from the bisector plane Pb according to the second direction of rotation. 3. Capping device according to claim 1 or 2, wherein the first sector (16) of the lower ring (9) includes a front zone (19) which is diametrically opposite to the second sector (17) and two engagement zones (20, 21) which are each arranged between the front zone (19) of the first sector (16) and the second sector (17), the engagement elements (18) being arranged only in the two engagement zones (20, 21) to allow radial movement of the lower ring (9). 4. Capping device according to claim 3, wherein the front area (19) of the first sector (16) extends over an angular range between 90 and 150°. 5. Capping device according to claim 3 or 4, wherein each of the two engagement zones (20, 21) extends over an angular range between 30 and 90°. 6. Capping device according to any one of claims 3 to 5, wherein the two engagement zones (20, 21) extend over angular sectors that are symmetrical to each other with respect to the bisector plane Pb. 7. Capping device according to any one of claims 1 to 6, wherein the hooking elements (18) are protuberances projecting radially inwards. 8. Capping device according to any one of claims 1 to 7, wherein the second sector (17) extends over an angular range between 90 and 150°. 9. Capping device according to any one of claims 1 to 8, wherein the capping device further includes a locking device configured to lock the cap (1) in the tilted open position, said locking device including a stop (23) projecting radially outwardly from the cap (1) and configured to bear against the engagement collar (5) of the neck (2) during movement of the cap (1) from the tilted open position to the released position to exert on the second sector (17) a tensile force having a radially outwardly directed component and an axially upwardly directed component to assist movement of the second sector (17) between the lowered position to the raised position. 10. Capping device according to claim 9, wherein the stop (23) is configured so that, during the movement of the cap (1) from the released position towards the open tilted position, the stop (23) rests against an upper end of the second sector (17) of the lower ring (9) to move it from the raised position to the lowered position. 11. A capping device according to claim 9 or 10, wherein the locking device further includes a heel (22) which is formed on the outer peripheral skirt (14) of the cap (1) and extends axially, the heel (22) being configured to bear against a helical rib of the helical thread (6) formed in the neck (2) of the container during movement of the cap (1) from the open, tilted position to the released position to exert on the second sector (17) a tensile force having a radially outwardly directed component and an axially upwardly directed component to assist movement of the second sector (17) from the lowered position to the raised position. <12. Assembly comprising a container equipped with a neck (2) including a distribution hole (3), a coupling collar (5) and a helical thread (6) and a capping device according to any one of claims 1 to 11, the lower ring (9) being axially fixed to the neck (2) and rotatably movable on the neck (2) around said axis X.