RU2395438C2 - Can sealer - Google Patents

Abstract

FIELD: transport, package. ^ SUBSTANCE: invention relates to sealing device for can made from sheet metal. Proposed device comprises: tubular case (10) made from sheet metal with circular top wall (12) with inner edge (12a) that makes can top opening (A). Said top edge (12) forms convex-arc seat (S). Proposed sealer comprises also cover (20) incorporating base section (21), peripheral section (22) with circular support section (23) with its cross section representing concave arc. Circular section (24) extends radially outside of peripheral section (22) to allow seating on circular top wall (12) in closing cover (20). Circular gasket (30) is clamped by special part on closing cover (20) to form appropriate circular sealing space between cover (20) and tubular case (10). Said tubular case (10) comprises sidewall (11) furnished with top edge (11a). Circular top wall (12) is formed by circular radial rib (16) formed by recess on sidewall (11) extending inside tubular case (10), below sidewall top edge (11a). ^ EFFECT: better seal for long-term storage, ease of can opening. ^ 13 cl, 11 dwg

Description

The present invention relates to a closure device for cans made of sheet metal and which are cans of this type that comprise a tubular body closed at the bottom and bearing an annular upper wall having an inner edge that forms an upper opening for the can and which is configured to to form a seat for the closure device, made in the form of a convex arc, on which, with the possibility of removal, the lid is mounted and held axially in the form of one part from eraser or sheet metal.

Certain foods, such as certain foods, require packaging that can remain airtight for extended periods of storage, avoiding the ingress of air, as well as contamination and oxidation of stored foods.

Not to mention the above requirements, certain products, for example some food products, are subject to their gradual consumption and necessitate the use of a lid of a can, which is a lid of a resealable type, so that during the gradual expenditure of a stored product it can be re-closed as many times as required , with a guarantee of tightness of the can and protection of the contents remaining in it.

In addition, in some cases, in addition to the tightness required for long periods of storage and the characteristics of gradual expenditure, it is desirable that the lid of the can be easily opened without the need for auxiliary devices or tools, such as keys, knife handles, etc., and so that its initial opening is carried out by violating the sealing means, which should indicate an autopsy.

Known lids, which are mounted by pressing into a ring connected by a double seal with the upper edge of the side wall of the tubular body of the can, do not by themselves guarantee the required tightness for long periods of storage, and it is necessary to repeatedly provide sealing means, which should indicate that the tightness not broken until a first opening occurs, the sealing means being usually formed by aluminum foil or other suitable material, to which is connected by double seaming to the upper edge of the side wall of the can together with the annular upper wall.

This well-known solution requires the use of tools to open the lid, as well as to cut the sealing means, which should indicate the opening performed at the initial opening of the can.

Lids made of sheet metal or plastic are also known from previous technical solutions, which are peripherally made with a circumferential groove having a cross section generally in the form of a concave arc, turned outward, which is mounted and held axially in the seat for the closure device provided in the peripheral inner edge of the annular upper wall of the tubular body of the can. Landing the circumferential groove of the lid on the seat in the form of a concave arc provides the possibility of obtaining a sealing region, which also acts as an area for axially holding the lid relative to the tubular body of the can.

Although the solution mentioned above, which is described in the Brazilian patent application PI 0203950-8 in the name of the applicant of this patent application, guarantees reliable axial retention of the lid relative to the tubular body of the can with a high degree of tightness in this sealing region, such a sealing region does not guarantee the degree of tightness, sufficient to comply with the requirements for the storage of certain products for long periods, with regard to food products intended for export and having hygroscopic nical characteristics, as well as readily oxidizable on contact with ambient oxygen.

Due to the limitations of the known technical solutions, the object of the invention is to provide a can closure device that guarantees a high degree of tightness over long periods of storage, as well as the ease of opening the lid without the use of special devices and the possibility of its re-closing manually, with a guarantee of the same degree tightness to initial opening.

Another objective of the invention is to provide a closure device mentioned above, which indicates the initial opening of the cans.

The proposed closure device can be used with cans containing a tubular body of sheet metal, which is closed from below and carries, by double seaming or deformation, or some other fixing means, an annular upper wall having an inner edge that forms an upper hole for cans, and which are bent so as to create a seat made in the form of a convex arc.

The closure device according to the invention further comprises a lid generally formed as a single part and comprising a base portion which is dimensioned to cover said upper hole, a peripheral portion provided with a circumferential support portion, the cross section of which is made in the form of a concave arc and which are dimensioned for mounting and holding axially against the seat when the lid is mounted on the top opening of the can, as well as an annular portion protruding radially outward eriferiynogo portion and adapted to seat on the annular upper wall upon closure of the cover.

According to the invention, at least one of: the annular upper wall of the tubular body and the annular portion of the lid carries an annular gasket to be pressed by the other part when closing the lid, so as to form a corresponding annular sealing region between the lid and the tubular body.

The creation of a second annular sealing region between the lid and the tubular body generally located radially outward from the seat provides the ability to achieve a higher degree of tightness when closing the lid on the tubular body of the can.

Below the invention will be described with reference to the accompanying drawings, given as an example of possible embodiments of the invention, in which:

Figure 1 is a perspective view of a possible design of a plastic cover intended for use in a closure device according to the invention and comprising a sealing portion;

Figure 1a is an exploded perspective view of the lid of Figure 1 after it is first opened;

Figure 2 is a partial diametrical cross-sectional view along II-II in Figure 1 of a lid mounted on the upper end of the can, while it illustrates a first embodiment of a closure device according to the invention;

Figure 3 is a view similar to the view of Figure 2, but illustrating a second embodiment of a closure device;

Figure 4 is a view similar to the views of Figures 2 and 3, but illustrating a third embodiment of a closure device according to the invention;

5 is a view similar to the views of FIGS. 2, 3 and 4, but illustrating a fourth embodiment of the closure device according to the invention, in which the ring gasket carries a lid;

6 is a view similar to the view of Figure 5, but illustrating a fifth embodiment of the proposed closure device;

FIG. 7 is a diametrical cross-sectional view of yet another sheet-can design of sheet metal when using the closure device in the embodiment of FIG. 2;

7a is a view similar to that of FIG. 7, but illustrating a metal cover with its annular portion including a circumferential rib;

Fig. 7b is a sectional view showing enlarged details of a can-lid closure device of Fig. 7a;

Fig. 8 is a diametrical cross-sectional view of a structure consisting of a metal can and a plastic cap that contains a sealing portion and in which the closure device of Fig. 2 is used;

Fig. 8a is a view similar to that of Fig. 8, but illustrating the use of a plastic cap with a seal and with its annular portion including a circumferential rib;

Fig. 8b is a cross-sectional view with enlarged details of a can-lid closure device of Fig. 8a;

Fig. 9 is a view similar to that of Fig. 8a, but showing a design variant for the upper edge of the side wall of the can.

Figure 1-6 shows the design of the cans with a tubular body 10 of sheet metal, closed on top by a lid 20 in the form of a single part made of plastic, while the can is provided with a closing device, which is an object of the present invention.

As shown in cross section in FIGS. 2-6, a generally cylindrical tubular body 10 comprises a side wall 11 having an upper edge 11a, wherein the tubular body 10 is closed from below by a bottom wall (not shown) that is integral with it, or connected by a double roll-up, or attached to the side wall 11 otherwise.

2-6, the tubular can body 10 further comprises an annular upper wall 12 peripherally attached to the upper edge 11a of the side wall 11 by double rolling 13, wherein the annular upper wall 12 has an inner edge 12a defining an upper opening A in the can, moreover, it is generally bent upward and radially outward, forming a tubular rib 14 defining a seat S for the lid having a cross section in the form of a convex arc.

From the description of the embodiments of FIGS. 7 and 8, it will be better understood that the inner edge 12a of the annular upper wall 12 need not be bent to form a tubular rib 14, since it is sufficient that this bend forms a cross-sectional seat S in the form of a convex arc.

The can shown in FIGS. 2-6 in partial cross section also includes a lid 20 in the form of a single plastic part, for example polypropylene, comprising a base portion 21 that carries a peripheral portion 22 representing a generally cylindrical outer surface 22a provided with a peripheral a supporting portion 23, the cross section of which is in the form of a concave arc, turned radially outward, and which is dimensioned so that the cover is mounted and held axially against the seat S, when the cover 20 is mounted on top hole A cans. The cover 20 further comprises an annular portion 24 protruding radially outward from the peripheral portion 22 and mounted on the annular upper wall 12 when closing the tubular body 10 with the cover 20.

In the present constructions, the cylindrical outer surface 22a of the peripheral portion 22 of the lid 20 comprises a circumferential protrusion 23a that together with the cylindrical outer surface 22a and above it forms a circumferential supporting portion 23 having a cross section in the form of a concave arc. However, it should be borne in mind that the circumferential support portion 23 may have various configurations, for example, in the form of a circumferential outer groove made generally in the cylindrical outer surface 22a of the peripheral portion 22 of the cover 20 and having a cross section in the form of a concave groove rotated radially outward.

Figures 1-6 show a cap 20 made of plastic, and its annular portion 24 by means of brittle jumpers 26 contains a peripheral sealing portion 25, which comprises a skirt 25a that is generally tightly mounted around the tubular body 10 for a double roll-up 13, so as to remain axially holding under the last or under any deformation formed in the region of the upper edge 11a of the side wall 11 of the tubular body 10, while the sealing portion 25 further comprises an upper ring 25b located on top of the most remote a portion of the annular upper wall 12 of the tubular body 10 of the can and containing internal brittle jumpers 26, continuing axially. The brittle jumpers 26 are arranged so as to combine, at angularly spaced points, the inner edge 25g of the upper ring 25b and the peripheral outer edge of the annular portion 24 of the cover 20.

The brittle interrupt jumpers 26 break when they are exposed to a certain pulling force when separating the sealing portion 25 from the annular portion 24 when the cover 20 is first opened.

In the example of the construction of the plastic cover, the sealing portion 25 has an interruption 25c in its circumferential extension that extends along at least a portion of the height of the skirt 25a, while the interruption 25c forms a defined circumferential gap between the respective opposing edges of the skirt 25a on both sides interruption 25s. The annular portion 24 comprises a gripping tongue 27 protruding axially radially outward and also axially downward through the interruption 25c of the sealing portion 25, for example, remaining substantially flush with the skirt 25a, while the gripping tongue 27 can only be activated by hand when part of the sealing portion 25 will be destroyed.

In the presented construction, the skirt 25 contains the ends of the sealing bridge 25d extending in the circumferential direction over both interruptions 25c of the sealing section 25 and the catch tongue 27. The sealing bridge 25d has a first end 25e that is inserted into the skirt 25a by means of the connecting means 25f that is destructible, when the first end 25e is forcefully moved away from the skirt 25a, for example, by a pulling action radially outward to release access to the gripping tongue 27.

Providing a gripping tongue 27 makes it easy to remove a portion of the base 21 from the seating position at the seat S, as well as controlling and gradually opening the can at first in an area near the gripping tongue 27, and then in the rest of the seating, preventing product from spilling from the can.

According to the invention, the grip tab 27 may be either solid or at least partially hollow to form a handle, as in the present construction.

It should be borne in mind that the grip tab 27 can be continuous and can be formed from the corresponding part of the skirt 25a, remaining essentially at the same level with the last and maintaining a gap 29 with it.

As shown, the skirt 25a may include an inner, circumferential protrusion 25h protruding axially from the peripheral edge of the annular portion 24 and dimensioned to be axially mounted and locked under the double roll 13 at the upper end of the tubular body 10 and around the latter.

In the closure device according to the invention, one or both of the parts formed by the annular upper wall 12 of the tubular body 10 and the annular portion 24 of the cover 20, carry an annular gasket 30, which is positioned and dimensioned to press it against the other of the mentioned parts when closing the cover , with the formation of the corresponding sealing annular region between the cover 20 and the tubular body 10.

In the design of FIGS. 2, 3 and 4, the annular gasket 30 is attached to the annular upper wall 12 of the tubular body 10 so that it remains in a radial outward position relative to the seat S. FIG. 2 shows the annular gasket 30 attached directly to the upper side of the annular upper wall 12. In an embodiment, the annular gasket 30 may be made of a suitable polymer resin, for example plastisol, which is melted and molded directly on the annular outer wall of the tubular to rpusa 10.

It should be borne in mind that the annular gasket 30 can be formed from different materials compatible with the products being packaged and have a certain compressibility to guarantee the formation of a second sealing region in addition to the region that is formed by fitting the peripheral section 22 of the cover 20 to the seat S.

Thus, when closing the lid 20, its peripheral portion 22 has a circumferential support portion 23 mounted on the lid seat S located on the tubular body 10, while ensuring the formation of the first sealing region, which also acts as an axial holding region for the lid 20 seated on the annular upper wall 12 of the tubular body 10. In this closed state of the lid 20, the annular gasket 30 will be axially pressed to ensure the formation of a corresponding or second sealing ring an area that is sufficiently impervious to guarantee the tightness of the inside of the can for the long storage periods that are necessary for certain foods, in particular when they are intended for export.

FIG. 3 shows an embodiment in which the annular portion 24 of the lid 20 comprises two circumferential ribs 28 that are configured and dimensioned to press the annular gasket 30 attached to the annular upper wall 12 of the tubular body 10 when closing the lid 20, guaranteeing more severe deformation of the annular gasket 30 and a more reliable seal. It should be borne in mind that the annular portion 24 of the cover 20 may include only one circumferential rib 28 or more than two ribs 28, or, in addition, there may not be any circumferential ribs 28, as shown in FIGS. 2, 4, 5, 7 and 8.

FIG. 4 shows a structure in which an annular gasket 30 is formed or otherwise attached in a circumferential recess 19 provided on an annular upper wall 12 of the tubular body 10, wherein the annular gasket 30 is generally dimensioned so that it protrudes slightly axially outward the circumferential recess 19 for pressing the annular portion 24 of the cover 20. The circumferential recess 19 is preferably dimensioned to better limit, together with its radially inner and outer walls, the expansion of the annular gasket 30 when it is applied in the molten state directly to the annular outer wall 12 of the tubular body 10.

FIGS. 5-6 show structures in which the annular gasket 30 is attached under the annular portion 24 of the cover 20 to press against the annular upper wall 12 of the tubular body 10 in an inverted position with respect to the position shown in FIGS. 2, 3 and 4.

5, the annular gasket 30 is secured in a circumferential recess 29 provided in the annular portion 24 of the cover 20, while the annular gasket 30 protrudes axially outward from the circumferential recess 29 to press the annular outer wall 12 of the tubular body 10 when closing the cap 20. The circumferential recess 29, the dimensions must be dimensioned so that it contains a radial extension of the annular gasket 30 when it is molded onto the annular portion 24 of the cover 20 in an inverted position.

FIG. 6 shows a structure in which the annular gasket 30 is attached to the annular portion 24 of the cover 20 by being pressed by a circumferential rib 18 formed by deforming the annular upper wall 12 of the tubular body 10. As discussed above with respect to the circumferential rib 28 of the cap 20, the annular upper the wall 12 of the tubular body 10 may include more than one circumferential rib 18.

Figures 7, 7a and 8a show an embodiment in which the annular upper wall 12 of the tubular body 10 is formed by a circumferential radial rib 16 formed by a recess formed by deformation of the side wall 11 of the tubular body 10, with the circumferential radial rib 16 protruding to the inner parts of the tubular body 10 under the upper edge 11a of the side wall 11.

7 shows an embodiment in which the annular gasket 30 is attached to the annular upper wall 12 of the tubular body 10 or, more precisely, to the circumferential radial rib 16, which defines the annular upper wall 12, while the cover 20 is made of plastic or sheet metal and it has the same base portion 21, the peripheral portion 22 and the annular portion 24 already described in connection with the plastic cover embodiments shown in FIGS. 1-6. In this design, when closing the latter, the annular portion 24 of the lid 20 presses the annular gasket 30, thereby forming a corresponding sealing region at a distance from that which is formed by fitting the circumferential support portion 23 of the lid 20 to the seat S, which has already been described above in relation to options for execution according to Fig.1-6.

As you can see, the circumferential radial rib 16 has an inner edge 12a, which is configured to form the upper opening "A" of the can and the seat S in the form of a preferably convex arc, on which the circumferential support section 23 is installed and held on, having a cross section in in the form of a concave arc and provided in the peripheral portion 22 of the cover 20, as described in connection with the design options in FIGS. 1-6. The circumferential radial rib 16 may have a cross section of any shape corresponding to the formation of the seat S. In Figs. 7 and 7a, the circumferential radial rib 16 has a cross section in the form of a horizontal "V", while in Figs. 8 and 8a, the cross section takes horizontal "U" shape. FIG. 7a shows a closure device similar to that of FIG. 7, but having an annular portion 24 of a sheet metal cover 20 deformable to insert at least one circumferential rib 28 turned downwardly dimensioned to compress the annular gasket 30 as described with reference to the device of FIG. 3.

In the design of FIG. 7a, it can be seen that the inner edge 12a of the annular upper wall 12 defined by the circumferential radial rib 16 is configured to form not only a convex arc shaped seat S, but also a circumferential upper protrusion 12b protruding upward from the annular upper wall 12 of the tubular body 10 to form a barrier preventing excessive radial expansion inwardly of the material of the annular gasket 30 when the latter is molded directly onto the annular upper wall 12 to prevent allow the flow of the still molten material of the annular gasket 30 to the inside of the tubular body 10 through the seat S. It should be borne in mind that the circumferential upper protrusion 12b need not be formed near the inner edge 12a of the circumferential radial rib 16. It can be formed in other areas of the upper walls 12 radially outermost, as is the case in the device shown in FIG. 4, in which a circumferential upper protrusion 12b can be formed by the radially inner wall of the circumferential recess 19. O However, it should be borne in mind that in addition to the circumferential recess 19, the annular upper wall 12 can be provided with a circumferential upper protrusion 12b located radially so that it is spaced from the circumferential recess 19 to act as an additional barrier preventing the radial expansion into the material of the annular gasket 30, when the latter is molded directly on the annular inner wall 12 of the tubular body 10.

As shown in FIG. 8, the lid 20, made generally of plastic, may have its own annular portion 24 comprising, at the periphery by brittle jumpers 26, a sealing portion 25 with a structure similar to that described for the lid of FIGS. 1-6, but taking into account that the skirt 25a is configured to create a step 25x that is installed under the edge 11a of the side wall 11 of the tubular body 10, while the edge 11a can take the form of an outer supporting portion acting as an element of the tubular body 10, as well as an upward an axial stop for the skirt 25a of the sealing portion 25.

On figa presents a closure device similar to the closing device according to Fig, but having an upper wall 12, from the bottom containing at least one circumferential rib 18, which is dimensioned to press the annular gasket 30 when closing the cover 20, as described in relation to to Fig.6.

As shown in the device according to FIG. 7a, the device according to FIG. 8a has an inner edge 12a of a circumferential radial rib 16, which is designed to form, in addition to a convex-arc shaped seat S, an upper, circumferential protrusion 12b protruding upward from the annular the upper wall 12 of the tubular body 10 to form a barrier to prevent unwanted radial expansion of the seat S, the material of the annular gasket 30, when the latter is applied to the annular upper wall 12 of the tubular body 10.

It should be borne in mind that the circumferential rib 28 of the annular portion 24 of the cover 20, as shown in FIGS. 7a and 9, can be replaced by one or more circumferential ribs included on top of the annular upper wall 12 of the tubular body 10, as shown in FIG. 6 the attached figures to press the annular gasket 30 attached under the annular portion 24 of the cover 20.

Fig. 9 shows a capping device of the type shown in Figs. 8 and 8a, in which the upper edge 11a of the side wall 11 of the tubular body 10 is bent outward, downward and inward to form a tubular rib 17, which is connected externally to the upper edge 11a of the side wall 11 and extending downward beyond the circumferential radial rib 16, covering the recess that forms the latter. In Fig. 9, the annular portion 24 of the lid 20 at the bottom contains at least one circumferential rib 28, which is dimensioned to press the annular gasket 30 when closing the lid.

As shown in the drawing, the tubular rib 17 has a free lower end portion 17a bent inward and outward and located adjacent to the side wall 11 of the tubular body 10 under the circumferential radial rib 16. The tubular rib 17 is generally elongated in the direction of the axis of the can, having a median extension 17b, essentially parallel to the side wall 11 of the tubular body 10 in the region into which the circumferential radial rib 16 is inserted.

In the structure of FIGS. 7, 7a, 8, and 8a, the peripheral portion 22 of the cover 20 carries on the outside a circumferential support portion 23 with a cross section in the form of a concave arc for mounting and holding axially against the seat S, as already described in connection with FIG. 2-6.

Since only some variants of the invention are described herein, it is understood that modifications to the form and arrangement of elements are possible without departing from the scope of the invention defined in the attached claims.

Claims (13)

1. A can closure device comprising: a tubular body (10) of sheet metal and which is closed from below and carries an annular upper wall (12) having an inner edge (12a) forming an upper opening (A) for the can, which is bent so which forms a seat (S) in the form of a convex arc; and a cover (20) containing in one part a section (21) of the base, a peripheral section (22) provided with a circumferential support section (23), the cross section of which is made in the form of a concave arc, and which are dimensioned for mounting and holding axially against the landing places (S) when the lid (20) fits into the upper opening (A) of the can; an annular portion (24) protruding radially outward from the peripheral portion (22) and used to fit on the annular upper wall (12) when closing the lid (20), and the annular gasket (30), which carries at least one part of the annular upper wall (12) of the tubular body (10) and the annular portion (24) of the cover (20), and the annular gasket (30) is pressed by another part when closing the cover (20) with the formation of the corresponding annular sealing region between the cover (20) and the tubular housing (10), and the tubular housing (10) contains a side a tenk (11) provided with an upper edge (11a), and an annular upper wall (12) is formed by a circumferential radial rib (16) formed by a recess on the side wall (11) radially protruding into the tubular body (10) under the upper edge (11a) side wall (11), characterized in that the circumferential radial rib (16) has such a cross section to form in the seat (S) the first sealing region when the circumferential radial rib (16) is planted on the circumferential support section (23). 2. The device according to claim 1, characterized in that the annular gasket (30) is pressed by at least one circumferential rib (18, 28) included in another part of: the annular upper wall (12) of the tubular body (10) and annular portion (24) of the cover (20), when closing the cover. 3. The device according to claim 2, characterized in that the annular gasket (30) is attached to the annular portion (24) of the cover (20), and the circumferential rib (18) is formed by deformation of the annular upper wall (12) of the tubular body (10). 4. The device according to claim 1, characterized in that the cover (20) is molded in one piece of plastic with an annular section (24), including a circumferential rib (28) from below to press this rib to the annular gasket (30) attached to annular upper wall (12) of the tubular body (10). 5. The device according to claim 1, characterized in that the peripheral portion (22) of the cover (20) has a generally cylindrical outer surface (22a) containing a circumferential protrusion (23a), which forms a circumferential surface on top and together with the outer surface (22a) supporting section (23), the cross section of which has the shape of a concave arc. 6. The device according to claim 1, characterized in that the side wall (11) of the tubular body (10) is made with an upper edge (11a), to which an annular upper wall (12) is connected peripherally by double rolling. 7. The device according to claim 1, characterized in that the circumferential radial rib (16) has an inner edge (12a) made to form a seat (S) in the form of a convex arc. 8. The device according to claim 1, characterized in that the inner edge (12a) of the circumferential radial rib (16) is formed to form a circumferential upper protrusion (12b) protruding upward from the annular upper wall (12) of the tubular body (10), so that to form a barrier for radial expansion of the material of the annular gasket (30) to the seat (S) when forming the annular gasket (30) directly on the annular upper wall (12). 9. The device according to claim 1, characterized in that the upper edge (11a) of the side wall (11) of the tubular body (10) is bent outward, downward and inward, so as to form a tubular rib (17) included externally in the upper edge (11a) ) of the side wall (11) and continuing downward for the circumferential radial rib (16), covering the recess that forms this rib. 10. The device according to claim 9, characterized in that the tubular rib (17) has a free lower end portion (17a), bent inward and upward and located adjacent to the peripheral side wall (11) of the tubular body (10) under the circumferential rib (16) . 11. The device according to any one of claims 1 to 6, characterized in that the cover (20) is made in the form of a single plastic part, while the annular section (24) by means of brittle jumpers (26) contains a sealing section (25) around the periphery, comprising a skirt (25a) for seating around the tubular body (10) and holding axially under the upper edge (11a) of the side wall (11). 12. The device according to claim 11, characterized in that the sealing section (25) has an interruption (25c), continuing at least at a part of the height of the skirt (25a), while the annular section (24) of the cover (20) contains a radial a gripping tongue (27) extending over said interruption (25c), wherein the skirt (25a) contains the ends of the sealing bridge (25d) peripherally extending over the interruption (25c) of the sealing portion (25) and over the gripping tongue (27), and one from the ends of the sealing bridge (25d) is included in the skirt (25a) by connecting means (25f), times yvaemym when this end is withdrawn from the skirt (25a). 13. The device according to claim 1, characterized in that the annular gasket (30) is formed of plastic, such as plastisol, and is directly molded on one of: from the annular upper wall (12) and the annular portion (24) of the cover (20).

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