WO1997011309A1

WO1997011309A1 - Container for storing gas under pressure and handling cap for such a container

Info

Publication number: WO1997011309A1
Application number: PCT/EP1996/004094
Authority: WO
Inventors: Alain Bihorel
Original assignee: Shell Internationale Research Maatschappij B.V.
Priority date: 1995-09-19
Filing date: 1996-09-18
Publication date: 1997-03-27
Also published as: TNSN96119A1; FR2738897A1; MA23974A1; FR2738897B1

Abstract

Assembly of a container (1) for storing liquefied, compressed or dissolved gas under pressure, including a flange (3), particularly for the mounting of a valve, and of a handling cap (2) fitted with means (F) for fixing to the flange of the container. The flange (3) on its external perimeter includes at least one housing (5) directed radially inwards, and the means (F) for fixing the handling cap comprise, on the one hand, at least one locking element (7) which can move radially relative to the flange (3) and, on the other hand, a means (C) for controlling the position of the locking element(s) (7) to make it possible quickly either to fix the handling cap (2) on the container (1) or to release the handling cap (2).

Description

CONTAINER FOR STORING GAS UNDER PRESSURE AND HANDLING CAP FOR SUCH A CONTAINER

The invention relates to an assembly of a container for storing liquefied, compressed or dissolved gas, under pressure, which assembly includes a flange, particularly for the mounting a valve and a handling cap fitted with means for fixing to the flange of the container.

The invention relates more particularly, but not exclusively, to containers consisting of portable bottles for storing liquefied petroleum gas. The words "container" and "bottle" will be used indifferently. Such an assembly demands a certain number of operations on the part of the users for bringing the containers into service and replacing them. This is especially the case where bottles for liquefied petroleum gas, butane or propane are used domestically in combination with a cooking apparatus. Fixing the handling cap on the bottle is conventionally achieved by screwing the handling cap onto the flange of the bottle, which flange is thereto threaded. The conventional arrangement has a certain number of drawbacks: the engaging of the handling cap on the flange is not very convenient and is difficult to automate; there is a risk of seizure at the end of screwing-in and, in the other direction, a difficulty in unscrewing the handling cap which creates a need for lubrication to make rotation easier, and a contact which soils the hands of the user; progressive wearing of the screw thread leads to an increasing amount of play which may, in time, compromise the secureness of the fixing.

Furthermore, in order to fill the container or to connect it to a pressure-reducing valve with a view to using it, one should remove the handling cap.

Moreover, the carrying function permitted by the handling cap needs to be improved.

It is an object of the invention, above all, to provide an assembly of the sort previously defined, in which engaging and removing the handling cap are easier. It is desirable that filling the container and connecting it to a- pressure-reducing valve can be undertaken without having to remove the handling cap. Finally, it is desirable that the carrying function is improved.

The assembly of a container for storing liquefied, compressed or dissolved gas, under pressure, including a flange, particularly for the mounting a valve and a handling cap fitted with means for fixing to the flange of the container according to the present invention is characterized in that the flange on its external perimeter includes at least one slot directed radially inwards, and in that the means for fixing the handling cap comprise, on the one hand, at least one locking element which can move radially in order to interact with the slot in the flange and, on the other hand, a means for controlling the radial position of this (these) locking element (s) to make it possible quickly either to fix the handling cap on the container or to release the handling cap therefrom.

Advantageously, the slot in the flange consists of an annular groove running right around the flange so that the fixing of the handling cap to the container is achieved with the possibility of rotating the handling cap about the central longitudinal axis of the flange.

The locking element or elements advantageously consist (s) of (a) ball(s) . Suitably, four balls uniformly spaced around the circumference are provided. The handling cap includes a cylindrical base capable of surrounding the flange of the container and this cylindrical base includes holes passing radially through it to take the locking elements with the possibility of a radial displacement of these elements . The diameter of the holes, at the interior surface of the cylindrical base, is preferably smaller than the diameter of the balls, particularly via a restriction made at the exit orifice of the hole, to ensure that the ball is retained in the hole, while allowing this ball to project inwards over a distance sufficient to interact with the groove and provide fixing.

The groove of the flange may have a square cross section, open radially towards the outside.

The means for controlling the radial position of the locking elements is advantageously mounted so that it can rotate about the cylindrical base of the handling cap.

Suitably, the control means comprises a ring with a central opening in which the cylindrical base of the handling cap is engaged, the internal wall of this central opening including notches which can be placed in line with the holes of the cylindrical base to allow the locking elements to retract and to come out of the groove with release of the handling cap, while the regions of the internal wall of this ring other than the notches are capable of retaining the locking elements and keeping them projecting into the groove.

The ring is held in translation in the axial direction of the cylindrical base of the handling cap, particularly by snap-fastening. Reciprocal stops are provided on the ring and on the handling cap in order to define a first angular position corresponding to engagement of the locking elements in the housing of the flange, and a second angular position corresponding to the release of the bonnet and the notches of the ring coming in line with the holes in the base of the handling cap. In the case where four balls are provided as locking elements, the ring includes four corresponding notches, substantially in the form of obtuse-angled recesses. Advantageously, an elastic means, particularly a torsion spring, is provided for returning the ring to the first angular position against the handling cap, corresponding to the fixing of the handling cap on the container. By a manual action, the operator may bring the ring into the second limit stop position, for releasing the handling cap, the ring returning to its first position as soon as the user lets go of it.

The handling cap preferably comprises two substantially diametrically opposed uprights stretching upwards from the cylindrical base, these uprights being joined at the top by a type of frame with a substantially rectangular closed contour, off-centred with respect to the central longitudinal axis of the cylindrical base of the handling cap; the short side of this contour furthest from the central longitudinal axis of the handling cap forms the main handle, while the opposite short side forms an auxiliary handle; there are apertures between these handles and the cylindrical base of the handling cap, the aperture available between the auxiliary handle and the base of the handling cap being sufficient to allow access to the valve of the container for filling this container or fitting a pressure-reducing valve without it being necessary to remove the handling cap from the container. The control ring preferably comprises a radial extension to make it easier to rotate it; advantageously, this radial extension is situated on the same side as the main handle with respect to the cylindrical base of the handling cap. The invention also relates to a container for storing compressed or dissolved liquefied gas, under pressure, particularly a portable bottle of liquefied petroleum gas, including a flange for the mounting of a valve, this container being characterized in that the flange on its external perimeter includes at least one slot directed radially inwards. Suitably, the slot of the flange consists of an annular groove stretching around the entire perimeter of the flange.

The invention also relates to a handling cap for handling a container for storing liquefied, compressed or dissolved gas, under pressure, this handling cap being fitted with means for fixing on the flange of the container and being characterized in that these fixing means comprise, on the one hand, at least one locking element which can move radially relative to the base of the handling cap and, on the other hand, a means for controlling the radial position of this (these) locking element (s) to allow quick fixing the handling cap onto the container or releasing it from the container. As a preference, the locking elements consist of balls. The handling cap in general includes a cylindrical base capable of surrounding the flange of the container, and this cylindrical base includes holes passing through it, oriented radially, to take the locking elements with the possibility of radial displacement.

Apart from the arrangements set out hereinabove, the invention consists in a certain number of other arrangements which will be dealt with more explicitly hereinbelow with regard to a specific embodiment which is described with reference to the drawings appended hereto, but which is not in any way limiting.

Figure 1 of these drawings is a view in vertical section of the assembly of a bottle for liquefied petroleum gas, only the upper part of which has been represented, and a handling cap being arranged on the bottle, the handling cap being sectioned on two angularly offset planes.

Figure 2 is a horizontal section on the line II-II of Figure 1. Figure 3 is a vertical section through the cap body on the line III-III of Figure 1, the ring and the balls not being represented in this figure.

Figure 4 is a perspective view, on a smaller scale, of the ring of the handling cap. Figure 5 is a section, on a larger scale, of the ring on the line V-V of Figure 6.

Figure 6 is a view from above of the control ring. Figure 7 is a view from below, with parts cut away, of the handling cap equipped with the balls and with the ring, in the locked position.

Figure 8, in a similar way to Figure 7, with parts cut away, shows the handling cap with the ring in the unlocked position.

Finally, Figure 9 is a diagram illustrating the carrying of a bottle equipped with a handling cap according to the invention.

Referring to Figure 1 of the drawings, it is possible to see the assembly of a container for storing liquefied gas, consisting of a portable bottle 1 of liquefied petroleum gas and a handling cap 2 for handling this bottle 1.

The upper part of the bottle 1, the only part represented, has the conventional shape of a convex dome and at its top includes a flange 3 fitted with a tapped hole 4 for the mounting a valve, not shown. The bottle 1, as shown in Figure 1, is assumed to be empty. It should simply be noted that the valve mounted in the tapped hole 4 has a maximum diameter which is smaller than the outside diameter of the flange 3 so that a handling cap arranged over the flange 3 can also be arranged over the valve mounted in the tapped hole 4. The flange 3 is welded to the wall of the bottle 1.

The handling cap 2 can be mounted on that part of the flange 3 which projects outwards, relative to the wall of the bottle 1. To this end that part of the flange 3 includes a slot directed radially inwards in the form of an annular groove 5 stretching around the entire periphery of the flange 3. This groove 5 preferably has a square transverse section, open radially towards the outside. That part of the flange 3 which is situated above the groove 5 ends in a frustoconical chamfer 6. The handling cap 2 comprises a cap body 2a fitted with fixing means F for fixing it to the flange 3. These fixing means F comprise, on the one hand, at least one and preferably several locking elements consisting of balls 7 which can move radially relative to the cylindrical base 8 of the handling cap 2 and, on the other hand, a means C for controlling the radial position of the locking elements 7 to allow either the rapid fixing or the rapid release of the handling cap 2.

The cylindrical base 8 of the handling cap 2 is so designed as to surround the flange 3 of the container 1. This base 8 includes holes 9 (see Figure 3) passing through it, oriented radially, to take the balls 7 with the possibility of radial displacement. As better seen in Figure 8, four holes 9 uniformly spaced by 90° are provided in the base 8 and four balls 7 are housed in these holes 9. The diameter of the holes 9 is equal, to within an operating clearance, to that of the balls 7. However, the orifice 10 constituting the radially internal end of the holes 9, following a restriction, has a diameter slightly smaller than that of the ball 7 which is thus prevented from coming completely out of the hole 9 towards the inside. When the ball 7 is resting against the restriction formed by the orifice 10, it is projecting inwards, as shown in Figure 7, in the form of a spherical cup which is sufficiently large to interact with the walls of the groove 5.

It is immediately obvious that when the balls 7 are engaged in the groove 5, a translational link along the axis of the bottle 1 is produced between the handling cap 2 and the flange 3, while leaving the handling cap 2 free to rotate about the central longitudinal axis A of the base 8. During normal operation the central longitudinal axis A of the base 8 coincides with that of the flange 3 and that of the bottle 2.

The cap body 2a (Figure 3) comprises two substantially diametrically opposed uprights 11, 12 stretching upwards from the cylindrical base 8. These uprights 11, 12 have substantially the shape of rectangular plates at the bottom part and their transverse dimension increases at the top. As visible in Figure 1, the edges of the upright 12, at the top, diverge until they connect with a frame 13 with substantially rectangular contour, the mid-plane of which is substantially orthogonal to the central longitudinal axis A. As visible in Figures 7 and 8, the contour of the frame 13 is off-centred with respect to the central longitudinal axis A and the short side of the frame 13 furthest from the central longitudinal axis A is arranged in the form of a main handle 14, while the opposite short side forms an auxiliary handle 15. The transverse section of the main handle 14 (Figure 1) has a profile which is convex towards the inside making it easier to grasp hold of the handling cap and to handle the bottle. As visible in Figure 9, taking hold of the handling cap by the handle 14 causes an inclining of the carried bottle 1, the centre of gravity of which aligns itself vertically below the handle 14; this backwards inclination makes carrying easier. If need be, the auxiliary handle 15 may be used to help with the carrying of the bottle, either using two hands, or by two people.

The space inside the frame 13 is open. Furthermore, there are apertures 16, 17 between the handles 14, 15 and the cylindrical base 8. The aperture 17 provided between the auxiliary handle 15 closest to the central longitudinal axis A and the base 8 gives sufficient access to the valve (not represented, intended to be mounted in the tapped hole 4) to carry out the operations of filling the bottle 1 or of connecting a pressure- reducing valve, without it being necessary to remove the handling cap 2 from the bottle 1.

The means C for controlling the radial position of the balls 7 comprises a ring 18 mounted so that it can rotate about the cylindrical base 8 of the handling cap 2.

The ring 18 includes a central opening 19 (see Figures 4 to 6) bounded by a wall 20 snap-fastened into a groove 21 (Figure 3) provided at the periphery of the cylindrical base 8. The ring 18 is thus held in terms of translation relative to the cap body 2a.

More specifically, as visible in Figures 1 and 3, the exterior surface of the cylindrical base 8 of the cap body, at its lower end, has a chamfer 22 on its internal perimeter to make engagement on the flange 3 easier and, on its external perimeter, has a step 23 with a frustoconical surface, the diameter of which increases from the bottom upwards. This step 23 towards the bottom bounds the groove 21 via a retaining wall situated in a plane orthogonal to the central longitudinal axis A and having a relatively small radial dimension to allow the snap-fastening of the ring 18. Another wall 24, situated in a plane orthogonal to the central longitudinal axis A and of a larger dimension in the radial direction bounds the groove 21 at the top. A cutout 25 at right angles follows on from the wall 24 towards the top, as visible in Figure 3.

The dimension of the groove 21 in the direction of the axis A is equal to h (Figure 3) while the dimension of the cutout 25 in this same direction is equal to m, m generally being smaller than h.

The wall 20 of the ring 18, bordering the opening 19, has a thickness e -(see Figure 5) which is equal, to within an operating clearance, to the dimension h of the groove 21. The wall 20 is bounded on its external perimeter by a flange 26 with a reduced radial thickness, projecting in a direction parallel to the axis of the ring 18 over a distance p. This distance p is equal to the distance m to within the operating clearance. When the ring 18 is fitted to the base 8, the flange 26 determines, with the cutout 25, an annular housing 27 (Figure 1) with a rectangular section stretching around the entire circumference.

At the bottom and projecting radially inwards the wall 20 has a snap-fastening lip 28, the inside diameter of which is equal to the diameter of the groove 21. The upper face 29 of this lip 28 is frustoconical flaring out upwards. When the ring 18 is put in place, the interaction of this surface 29 with the step 23 of the cap body makes it easier for the ring 18 to be deformed and the step 23 to be overcome, the lip 28 then returns to its normal diameter which provides the snap-fastening, the transverse wall 24 of the bonnet body stopping the ring 18 towards the top. The wall 20 of the ring 18 includes notches 30 which are intended to be placed in line with the balls 7 to allow their radial displacement outwards and to allow them to come out of the groove 5, releasing the bonnet 2 relative to the flange 3. In the example under consideration, four notches 30, uniformly distributed around the circumference and therefore offset by 90° are provided. Each notch 30 has a transverse section in the form of an obtuse angle, the vertex of which faces outwards. The notches 30 are provided over the entire height of the wall 20 and intersect the lip 28, making it easier for the ring 18 to be deformed in order to overcome the step 23 during snap-fastening.

The notches are arranged to allow the balls 7 to come completely out of the groove 5 towards the outside, as shown in Figure 8, when they are placed in line with these balls.

By contrast, when the angular position of the ring 18 relative to the base 8 is such that the internal surface of the wall 20 bounding the opening 19 is in contact with the balls 7 as illustrated in Figure 7, the balls are pushed radially back inwards and project into the groove 5. The handling cap 2 is thus translationally linked to the flange 3 and to the bottle 1 in the direction of the central longitudinal axis A, but remains free to turn about the central longitudinal axis A.

The ring 18, as visible in Figures 4 to 6, includes an outward radial extension 31 with a substantially dovetail-shaped contour allowing the ring to be manoeuvred to make it turn about the central longitudinal axis A. This extension 31 has a dimension in the direction of the axis of the ring greater than that of the wall 20 and of the flange 26 and protrudes upwards above the upper edge of the flange 26 by a distance d (see Figure 5) . The extension 31 is integral with the ring 18 via a portion of cylindrical surface 32 including two extreme edges 33, 34 which are parallel to the axis of the ring 18 and arranged to act as limit stops in the positioning of this ring 18.

The cap body 2a includes mating stops 33a, 34a provided respectively on the substantially vertical edge of the uprights 11, 12 situated on the same side as the handle 14. When the ring 18 is snap-fastened, it is arranged such that its extension 31 is on the same side as this handle 14, as illustrated in Figure 1. The stops 33, 33a (see Figure 7) by their interaction determine a first angular position of the ring 18 for which the balls 7 are in contact with the internal surface of the wall 20, substantially half the angular distance between two notches 30; the balls 7 are thus kept projecting radially inwards into the groove 5. The stops 34 and 34a, by their interaction illustrated in Figure 8, determine a second angular position of the ring 18, relative to the cap body 2a and to the base 8. In this second angular position, the notches 30 are in line with the balls 7 which can thus be completely retracted from the groove 5. An elastic means R is provided for returning the ring 18, relative to the base, to the first position illustrated in Figure 7 corresponding to the fixing of the handling cap 2 on the flange 3. The elastic means R advantageously consists of a torsion spring 35 surrounding the base 8 of the handling cap and housed in the space 27 (see Figure 1) . The mid-plane of the spring 35 is orthogonal to the central longitudinal axis A of the base 8. One end of this spring 35 is bent upwards at right angles to be anchored in a hole 36 (Figure 7) provided in the horizontal face of the cutout 25 of the cap body 2a. The other end of the spring 35 is bent downwards at right angles to be engaged in a through-hole 37 provided in the ring 18. The spring 35 is preloaded and permanently acts upon the ring 18 so as to keep the limit stops 33 and 33a resting against each other, this corresponding to the fixing position of the ring 18 of Figure 7.

In order to obtain unlocking, the user has to act on the extension 31 to make the ring 18 turn and bring the stops 34, 34a to bear against each other, as illustrated in Figure 8.

This being so, the assembly of the components of the handling cap 2 and the fixing of this handling cap to the flange 3 or its dismantling, result from the foregoing explanations.

In order to put the handling cap 2 together, first of all the balls are put in place in the holes 9 of the bonnet body, preferably placed head down. The spring 35 is fitted, engaging one of its bent-over ends in the hole 36 of the cap body 2a.

The ring 18 is then snap-fastened into the groove 21, at the same time ensuring a preloading of the spring 35 and ensuring the engagement of the other end of this spring in the hole 37.

The handling cap 2 is thus put together and the ring 18 can rotate between the two limit stop positions illustrated in Figures 7 and 8.

To fix the handling cap 2 on the flange 3, the extension 31 is acted upon to bring the ring 18 into the angular position of Figure 8 and allow the balls 30 to be retracted and the base 8 to be engaged around the flange 3. When this fitting is finished, the extension 31 is let go, and the ring 18 returns to the locked position illustrated in Figure 7. The operation of fitting the handling cap 2 is therefore very quick; the same is true for separating it.

Because the handling cap 2 is free to rotate relative to the flange 3, the aperture 17 can be placed in the position most favourable to access to the valve (not shown) mounted on the tapped hole 4, which allows the bottle 1 to be filled, or the fitting of a pressure- reducing valve, without having to remove the handling cap 2. It should be noted that the extension 31 is provided on the opposite side to the aperture 17, to leave the space of this aperture completely free. In addition, the radial extension 31 could be dimensioned so that it protrudes upwards by a distance d sufficient to prevent the pressure-reducing valve from being introduced via the aperture 16 and force it to be introduced via the aperture 17, for example when the configuration of the pressure-reducing valve would present a problem of space after being introduced by the aperture 16. This dimensioning of the radial extension 31 thus gives a biasing effect.

The bottle 1 is made easier to carry, as already explained with regard to Figure 9.

Claims

I M S

1. Assembly of a container (1) for storing liquefied, compressed or dissolved gas, under pressure, including a flange (3) , particularly for the mounting a valve and a handling cap (2) fitted with means (F) for fixing to the flange of the container, characterized in that the flange (3) on its external perimeter includes at least one slot (5) directed radially inwards, and that the means (F) for fixing the handling cap comprise, on the one hand, at least one locking element (7) which can move radially relative to the flange (3) and, on the other hand, a means (C) for controlling the position of the locking elemen (s) (7) to make it possible quickly either to fix the handling cap (2) on the container (1) or to release the handling cap (2) therefrom.

2. Assembly according to claim 1, characterized in that the slot (5) in the flange (3) consists of an annular groove (5) stretching around the entire periphery of the flange (3) so that the handling cap (2) is fixed to the container (1) with the possibility of rotating about the central longitudinal axis (A) of the flange (3) .

3. Assembly according to claim 1 or 2, characterized in that the locking elements consist of balls (7) .

4. Assembly according to one of the preceding claims in which the handling cap (2) includes a cylindrical base (8) capable of surrounding the flange (3) of the container (1) , characterized in that this cylindrical base (8) includes holes (9) passing radially through it to take the locking elements (7) with the possibility of a radial displacement of these locking elements (7) .

5. Assembly according to one of the preceding claims, characterized in that the means (C) for controlling the radial position of the locking elements (7) is mounted so that it can rotate about the cylindrical base (8) of the handling cap (2) .

6. Assembly according to claim 5, characterized in that the control means (6) comprises a ring (18) with an opening (19) the wall (20) of which includes notches (30) which are intended to be placed in line with the locking elements (7) to allow them to come out of the groove (5) and release the handling cap (2) , while the rest of the surface of the wall (20) bounding the opening (19) is capable of keeping the locking elements (7) projecting into the groove (5) .

7. Assembly according to claim 6, characterized in that the ring (18) is held in translation relative to the cap body (2a) , particularly by snap-fastening.

8. Assembly according to claim 6 or 7, characterized in that the ring (18) comprises a radial extension (31) for taking hold of it, and that this extension is situated on the side of the handling cap (2) intended to be placed opposite a coupling to the valve of the container (1) .

9. Assembly according to any one of claims 6 to 8, characterized in that it comprises an elastic means (R) , particularly a torsion spring (35) , for returning the ring (18) to the position for fixing the handling cap (2) on the container (1) .

10. Assembly according to claim 9, characterized in that it comprises four locking elements, particularly four balls (7) distributed uniformly around the circumference, and that the ring includes four corresponding notches (30) , the elastic means (R) for returning the ring (18) ensuring that two stops (33, 33a) provided respectively on the ring and on the cap body (2a) corresponding to the fixing position come to bear against each other, while two other stops (34, 34a) are provided respectively on the ring (18) and the cap body (2a) to determine the position for releasing the handling cap (2) .

11. Assembly according to one of the preceding claims, characterized in that the handling cap (2) comprises two substantially diametrically opposed uprights (11, 12) stretching upwards from a cylindrical base (8) and joined at the top by a frame (13) with a substantially rectangular contour, off-centred with respect to the central longitudinal axis (A) of the base (8) of the handling cap (2) , the short side of the frame (13) furthest from the central longitudinal axis (A) of the cylindrical base (8) forming a main handle (14) , while the opposite short side, closer to the central longitudinal axis (A) , forms an auxiliary handle (15) , the mid-plane of the frame (13) being substantially orthogonal to the central longitudinal axis (A) of the base (8), there being apertures (16, 17) between the said handles (14, 15) and the base (8) , the aperture (17) between the auxiliary handle (15) and the base (8) giving sufficient access to a valve mounted on the bottle (1) for filling this bottle or connecting it to a pressure- reducing valve without it being necessary to remove the handling cap (2) , mounted so that it can rotate on the bottle (1) .

12. Container, particularly a bottle, for storing liquefied, compressed or dissolved gas under pressure, including a flange (3), particularly for the mounting of a valve, for an assembly according to one of claims 1 to 11, characterized in that the flange (3) on its external perimeter includes at least one slot (5) directed radially inwards.

13. Container according to claim 12, characterized in that the slot in the flange (3) consists of a groove (5) stretching around the entire periphery of the flange (3) .

14. Handling cap for a container for storing^' liquefied, compressed or dissolved gas according to claim 12 or 13, fitted with means (F) for fixing on the flange (3) of the container, characterized in that the means (F) of fixing the handling cap (2) comprise, on the one hand, at least one locking element (7) which can move radially relative to the handling cap (2) and, on the other hand, a means (C) for controlling the radial position of the locking element (s) (7) to make it possible quickly either to fix the handling cap (2) or to release it.

15. Handling cap according to claim 14, characterized in that the locking elements consist of balls (7) , particularly four of them, distributed uniformly around the circumference.

16. Handling cap according to claim 14 or 15, characterized in that it includes a cylindrical base (8) capable of surrounding the flange (3) of the container and that this cylindrical base (8) includes holes (9) passing radially through it to take the locking elements (7) with the possibility of radial displacement, while the means (C) for controlling the position of the locking elements (7) comprises a ring (18) mounted so that it can rotate about the cylindrical base (8) of the handling cap (2) , this ring (18) including a central opening (19) the wall (20) of which includes notches (30) intended to be placed in line with the locking elements (7) to allow them to come out of the groove and release the handling cap (2) , while the region of the wall (20) of the groove other than the region of the notches is capable of keeping the locking elements (7) projecting towards the inside of the cylindrical base (8) of the handling cap (2) .