Device for packaging and applying a cosmetic product

A device for packaging and applying a cosmetic product comprises a mechanism for receiving a stick of cosmetic product, a base cover forming a first housing for receiving a first portion of the mechanism, a first seal between an element of the base cover and an element of the mechanism, and a cap fixed on the base cover in order to define a second housing receiving a second portion of the mechanism. A second seal is provided between the cap and said element of the base cover and/or said element of the mechanism. The first and second housings are connected in a sealed manner by the element of the base cover and/or the element of the mechanism.

CROSS-REFERENCE TO RELATED APPLICATION

This Application is a 35 USC § 371 US National Stage filing of International Application No. PCT/FR2019/051774 filed on Jul. 16, 2019 and claims priority under the Paris Convention to French Patent Application No. 18 57046 filed on Jul. 27, 2018.

FIELD OF THE DISCLOSURE

The present invention relates to a device for packaging and applying a cosmetic product, notably a solid cosmetic product in stick form. The invention relates also to a mechanism for a device for packaging and applying a cosmetic product in stick form.

PRIOR ART

In the field of cosmetic products in stick form, such as lipsticks, for example, a device for packaging and applying the cosmetic product essentially comprises a base cover, a cap and a mechanism intended to receive a stick of cosmetic product. The mechanism is received in the base cover. The mechanism has a base, a tube and a cup. The mechanism is designed to move the cup and, thus, the stick of cosmetic product, in the tube with respect to the base, between a retracted position, of closure of the packaging device, and an extended position, of application of the cosmetic product. In this type of device, the stick of cosmetic product is generally moved between its two positions, by pivoting the tube with respect to the base of the mechanism, the base having a helical groove for guiding at least one protuberance rigidly secured to the cup rotated with respect to the base via the tube.

Application FR-A-2 662 921 describes an example of such a device for packing and applying a cosmetic product.

However, a cosmetic product in stick form generally comprises one or more volatile components, such as solvents for example. These volatile components are likely to evaporate in the packaging and application device, which is detrimental to the life span of the cosmetic product.

To limit this evaporation of the volatile components of the cosmetic product, EP-A-1 197 162 describes a packaging and application device in which the cap is provided with an internal sleeve, which is elastically deformable, having a relief complementing a relief formed by an insert in the base of the packaging and application device. This insert is received between the cover of the base of the packaging and application device and the base of the mechanism. A complementarity of the shape of the reliefs is implemented between the tube of the mechanism and the cover of the cap of the packaging and application device to ensure the seal-tightness. However, in this case, a trade-off is required as to the material used to form this internal sleeve. Indeed, while the aim of the relief complementing the relief formed by the insert is to obtain a seal-tightness, which requires a certain flexibility, the aim of the internal sleeve is also to increase the mechanical strength of the cap. Moreover, when the cap is removed, the relief of the insert and the insert itself are visible along the tube of the mechanism. This is detrimental to the esthetics of the packaging and application device.

There is therefore a need for a packaging and application device that does not present at least some of the drawbacks of the prior art. In particular, there is a need for a packaging and application device that makes it possible to conserve the cosmetic product for a long time. Advantageously, the packaging and application device is nevertheless easy to recap. Also, the esthetic of the packaging and application device is preferably maintained.

BACKGROUND OF THE DISCLOSURE

To this end, the invention proposes a packaging and application device for a cosmetic product comprising:a mechanism intended to receive a stick of cosmetic product, the mechanism having a base, a tube and a cup for receiving the stick of cosmetic product, the mechanism being designed to move the cup with respect to the tube, between a retracted position, of closure of the packaging and application device, and an extended position, of application of the cosmetic product,a base cover, forming a first housing for receiving a first portion of the mechanism,a first seal inserted between an element of the base cover and an element of the mechanism, anda cap, adapted to be fixed onto the base cover to define a second housing receiving a second portion of the mechanism, a second seal being inserted between the cap and at least one out of said element of the base cover and said element of the mechanism, the first and second housings being linked in a seal-tight manner by said element of the base cover and/or said element of the mechanism.

Thus, advantageously, the device according to the invention proposes a dual seal that makes it possible to limit, and even prevent, the evaporation of the solvents and other volatile products of the cosmetic product out of the housings.

Moreover, the first and second housings being linked in a seal-tight manner, a volume is formed inside the packaging and application device which, in the closed state of the device, is seal-tight, thus preventing the evaporation of components of the cosmetic product.

Also, the positions of the first and second seals can advantageously be chosen so that these seals are not visible to a user, regardless of whether the packaging and application device is closed or open.

According to preferred embodiments, the packaging and application device according to the invention comprises one or more of the following features, taken alone or in combination:the base cover comprises a base cladding shell and a ferrule fixed onto the base cladding shell, the element of the base cover being preferably the ferrule;the base cover further comprises a base insert, the base insert being preferably received in the base cladding shell, inserted between the ferrule and the base of the mechanism, if necessary;one out of the first seal and the base insert is overmolded, notably overmolded by injection-molding, on the other out of the first seal and the base insert;the first seal is clamped against the ferrule and/or the element of the mechanism and/or the base insert, if necessary;the cap comprises a cover and a cap insert fixed in the cover, the cap insert at least partly defining the second housing;one out of the cap insert and the second seal is overmolded, in particular overmolded by injection-molding, on the other out of the cap insert and the second seal;the second seal comprises a portion inserted, preferably clamped, between the cap insert and the element of the mechanism;the cap further comprises a cap embellisher, fixed in the cover, preferably close to an outlet of the cap, the cap insert being preferably between the cover and the cap embellisher;a portion of the second seal is inserted, preferably clamped, between the cap embellisher and the element of the mechanism;the second seal further comprises a portion inserted, preferably clamped, between the cap embellisher and the cap insert;the first seal and/or the second seal is/are made of one out of Hytrel® and Arnitel®;the first seal and/or the second seal is/are domed toward the mechanism;the packaging and application device has, in the closed state in which the cap is fixed to the base cover, an air passage through the mechanism between a first orifice emerging in the first housing and a second orifice emerging in the second housing;the cup has a cylindrical shape that is open at both of its ends, a first end of the cup emerging in the first housing and a second end of the cup emerging in the second housing;the element of the mechanism is the base of the mechanism; andthe base of the mechanism comprises a bush forming a helical path for guiding the cup and a ring fixed on the base, said element of the mechanism being preferably the bush or the ring.

According to another aspect, a mechanism is described that is intended to receive a stick of cosmetic product, in particular for a packaging and application device as described above in all its combinations, the mechanism having a base, a tube and a cup, the cup being intended to receive the stick of cosmetic product, the cup having at least one relief of a section complementing the section of a helical groove in the base, the relief of the cup being received in the helical groove so that pivoting the tube with respect to the base of the mechanism causes a movement of the cup with respect to the tube between a retracted position and an extended position, of application of the cosmetic product, in which mechanism an air passage fluidically connects a first orifice in the mechanism with a second orifice in the mechanism.

The base can comprise a bush in which the helical groove is formed and a ring fixed to an end of the bush, the second orifice being in the ring or between the tube and the ring.

The first orifice can be in the bush or between the bush and the ring.

The bush can have longitudinal ribs on its outer surface, the air passage passing preferably at least partly between two longitudinal ribs.

The cup can have a cylindrical shape with radially inward protuberances for holding the stick of cosmetic product in position and at least one outward-protruding relief for guiding the cup in the helical groove in the base, the cup being open at both of its ends.

The tube can surround the cup, the tube being fixed in longitudinal translation with respect to the bush.

The tube can be secured in rotation to the cup, the tube preferably having two longitudinal slits passed through by the at least one relief of the cup, protruding outward to guide the cup in the helical groove in the base.

Also described is a packaging and application device as described above in all its combinations, in which the mechanism is as described above in all its combinations, the air passage fluidically connecting the first housing and the second housing.

DETAILED DESCRIPTION OF THE DISCLOSURE

Hereinafter in the description, the elements that are identical or have an identical function bear the same reference symbol in the various figures. For brevity in the present description, these elements are not described in detail with respect co each figure.

FIGS.1to3show an example of a device10for packaging and applying a cosmetic product.

Here, the cosmetic product takes the form of a stick. The cosmetic product can notably be a lipstick, a color product, a skin- or lip-care product, in particular a lip balm, a sun protection product for the lips or the skin.

This packaging and application device10comprises, as is visible inFIG.1, a base cover12, a mechanism14and a cap18. To close the packaging and application device10, the cap18can be fixed onto the base cover12, for example by elastic fitting (or snap fitting). In the example illustrated, the base cover12comprises a ferrule16which forms the interface with the cap18. However, other means for fixing the cap18onto the base cover12are accessible to the person skilled in the art. Notably, the cap18can be screwed or tightly fitted onto the base cover12, notably onto the ferrule16. Also, when the base cover12comprises an element made of magnetic material, the cap18can be magnetized on this element of the base cover12. This element of the base cover12can notably be the ferrule16.

As is known per se, the mechanism14receives a stick of cosmetic product (not represented in the figures). The mechanism here comprises a base20, a cup19and a tube22. The mechanism14is designed to move the cup19, to which the stick of cosmetic product is fixed, with respect to the tube22, between a retracted position, allowing the closure of the packaging and application device10, and an extended position, for application of the cosmetic product, in which the stick of cosmetic product protrudes from the tube22. The retracted position allows the closure of the packaging and application device10by fixing the cap18onto the base cover12, notably onto the ferrule16.

In the example illustrated, the cup19has an essentially cylindrical shape that is open at both of its ends. The cup19does however have radially-inward protuberances191to hold the stick of cosmetic product in position in the cup19. In the absence of a stick of cosmetic product, the two ends of the cylindrical part of the cup19are fluidically connected. In other words, the protuberances19, preferably do not block the section of the cylindrical part of the cup19. Furthermore, the cylindrical part of the cup19advantageously has no opening on its cylindrical surface, so that the two ends of the cylindrical part of the cup19are fluidically connected in a seal-tight manner.

The mechanism14of the packaging and application device10is described hereinbelow, with respect toFIGS.3to6in particular.

The base20of the mechanism14here comprises a bush21and a ring23, fixed onto the bush21. The ring23is for example made of metal. The ring23is for example obtained by stamping a metal sheet. The ring23also has no opening on its cylindrical lateral wall. Thus, the openings at the two longitudinal ends of the ring23are fluidically connected in a seal-tight manner inside the ring23.

The bush21comprises, on its outer surface, ribs25. Here, these ribs25are longitudinal. The ribs25are, here, rectilinear. The bush21also comprises, according to the example illustrated, a first circumferential groove27and a second circumferential groove29. The second circumferential groove29receives a fold31of the ring23in order to axially fix the ring23onto the bush21.

Moreover, the bush21has, on its inner surface, at least one helical groove39. The cup19has at least one relief33, preferably at least two reliefs complementing the section of the at least one helical groove39, received in this at least one helical groove39. Thus, the at least one helical groove39allows the cup19to be guided in a helical movement by pivoting the cup19with respect to the bush21. In this particular case, the relief or reliefs33of the cup19extend through longitudinal slits made in the tube22. Thus, the cup19is mounted securely in rotation with the tube22. The tube22is fixed in longitudinal translation in the direction X, with respect to the bush21.

Notably, as is particularly visible inFIGS.5and6, an air passage F1(or leakage path) fluidically connects a first orifice35in the mechanism14, here between the bush21and the ring23, at a first end of the ring23, with a second orifice37in the mechanism14, at a second end of the ring23, opposite the first end. Here, the second orifice37is situated between the ring23and the tube22. Thus, air can flow freely between the first orifice35and the second orifice37, through the mechanism14. Notably, the air flows here between the bush21and the ring23, first of all, then between the tube22and the ring23. The ribs25on the outer surface of the bush21, which also extend on the outer surface of the bush21, covered by the ring23, facilitate this circulation of air. Also, a notch can be made in the bush21, at the first orifice35to facilitate the flow of air. The position of the air passage F1with respect to the bush21is more clearly visible inFIG.6.

The base20of the mechanism14is secured, notably secured in rotation, to the base cover12. In particular, the bush21is secured in rotation to the base cover12, whereas the cup19and the tube22can pivot together with respect to the base cover12. Thus, in the example illustrated, the stick of cosmetic product can be brought out by pivoting the tube22with respect to the base cover12.

Moreover, the base cover12of the packaging and application device10forms a housing L1for receiving a portion of the base20of the mechanism14. The base cover12is, here, fixed to the base20of the mechanism14so that the base cover12and the base20of the mechanism are secured in rotation about a longitudinal axis X of the packaging and application device10.

In the example illustrated, the base cover12is essentially formed by a base cladding shell24, the ferrule16and a base insert26, received and fixed in the base cladding shell24. Here, the housing L1for receiving a portion of the base20is mostly defined by the base insert26. The base insert26is held fixed in the cladding shell24for example by snap-fitting, fitting or gluing. Here, the base20of the mechanism14is received tightly in the base insert26. Furthermore, the circumferential groove27on the outer surface of the bush21can receive one or more reliefs protruding on the radially inner surface of the base insert26, so as to ensure that the base20of the mechanism14and the base insert26are held in relative longitudinal position.

As is more particularly visible inFIG.3, a first seal28is inserted between the ferrule16of the base cover12, and the ring23of the base20of the mechanism14. In particular, the first seal28is clamped against the ring23of the base20of the mechanism14. Evaporation of the volatile components involved in the composition of the cosmetic product, along the base of the mechanism20, between the insert26and the base20of the mechanism14, to the outside of the device10, is thus limited, even avoided.

The base insert26is described hereinbelow in more detail, notably with respect toFIGS.8to11. As is visible in these figures, the base insert26has an essentially cylindrical bush form, open on a single longitudinal side, where the base insert26is in contact with the first seal28. Contact between the base insert26and the first seal28is, for example, obtained by chemical adhesion between the materials forming the base insert26and the first seal28. The base insert26has ribs30on its inner cylindrical face26i. These ribs30are, here, longitudinal. Here, the ribs30are substantially rectilinear. The ribs30allow the base20of the mechanism14and the base insert26in which the base20of the mechanism14is received to be secured in rotation. Notably, the ribs30prevent a relative rotation of the bush21of the mechanism14with respect to the base insert26, about the longitudinal axis X of the packaging and application device10. As can be seen notably inFIGS.8and11, in the example described, the base insert26has twelve ribs30. Advantageously, the ribs30are evenly distributed angularly on the inner cylindrical face26iof the base insert26.

On its bottom face26inf, the base insert26has studs32. The base insert26has, for example, six studs on its bottom face26inf. The studs32are advantageously evenly distributed angularly. The studs32are advantageously situated close to the edge of the bottom face26infof the base insert26. The studs32facilitate the reception of the base insert26, flat on the bottom of the base cladding shell24. The studs32here have a substantially rectangular parallelepipedal shape. However, the studs32can take other shapes.

It will be noted that the bottom surface26infis the base surface of the bush formed by the base insert26, that is to say its longitudinal end surface, opposite its opening.

Moreover, the base insert26has, on its outer cylindrical surface26e, substantially at the opening, protruding reliefs34, of substantially triangular shape. Here, three such reliefs34are produced. These reliefs34are angularly separated by an angle of substantially 90°. These reliefs34are intended to wedge the base insert26in the base cover12for example via the ferrule16, which has a housing for receiving the base insert26of substantially complementary section. Complementary section is understood here to mean a section allowing a fixing by complementarity of shapes. These reliefs thus make it possible to prevent a relative rotation of the base insert26with respect to the base cover12about the longitudinal axis X of the packaging and application device10. Thus, the rotation of the base cover12is transmitted to the bush21of the mechanism14via the base insert26.

Moreover, as is visible notably inFIGS.8,9and11, the first seal28is, here, secured to the base insert26. Advantageously, in fact, the first seal28is overmolded, for example by injection-molding, on the base insert26, or the base insert26is overmolded, for example by injection-molding, on the first seal28.

This first of all makes it possible to rigidly fix the first seal28to the base insert26. Thus, when assembling the packaging and application device10, there is only one piece to be handled, corresponding to the assembly consisting of the base insert26and of the first seal28. This overmolding also makes it possible to ensure the seal-tightness between the first seal28and the base insert26. The overmolding also allows different materials to be used for the base insert26and the first seal28, the base insert26being, for example, made of a more rigid material than the material from which the first seal is made.

Alternatively, the first seal28and the base insert are made as a single piece, of one and the same material. In this case, the first seal28and the base insert26, as a single piece, can be made of thermoplastic material or metal, for example aluminum or ZAMAC alloy.

Also alternatively, the first seal28can be borne independently on the base insert26, the first seal28and the base insert26then being two distinct pieces. The first seal28and the base insert26can then be assembled together, possibly reversibly.

It should be noted here that the base insert26extends only on one longitudinal side of the first seal28. However, as a variant, the base insert26can extend on either side of the first seal28, in the longitudinal direction X of the packaging and application device10. In this case, the first seal28forms a ring held captive in the base insert26. Such a configuration can notably be obtained by overmolding, for example by injection-molding, the base insert26on the first seal28.

The first seal28here has a main portion28pof tubular, preferably cylindrical, shape. At the free end of the main portion28b, the seal28forms a bead28b. Here, the bead28bis oriented radially inward.

In the example illustrated inFIGS.1and3, notably, the ferrule16covers the first seal28. Thus, the first seal28is concealed from a user by virtue of the presence of the ferrule16. The esthetic appearance of the packaging and application device10is thereby preserved.

Moreover, as is visible inFIG.1, notably, the cap18here comprises a cap cover36, a weight38, a cap insert40and a cap embellisher44. A second seal42is mounted in the cap18.

Advantageously, the second seal42is overmolded, for example by injection-molding, on the cap insert40, or the cap insert40is overmolded, for example by injection-molding, on the second seal42. It is thus possible to easily fix the second seal42to the cap insert40, which makes it possible to handle only one piece when assembling the packaging and application device10. Furthermore, the seal-tightness of the contact between the second seal42and the cap insert40is thus assured.

According to a variant that is not illustrated, in the case where the cap insert40is overmolded on the second seal42, the cap insert40can extend longitudinally on either side of the second seal42.

According to another variant that is not illustrated, the cap insert40and the second seal42are a single piece and made of one and the same material. In this case, the second seal42and the cap insert40, as a single piece, can be made of thermoplastic material or a metal, for example aluminum or ZAMAC alloy.

Also alternatively, the second seal42can be borne independently on the cap insert40, the second seal42and the cap insert40then forming two distinct pieces. The second seal42and the cap insert40can then be assembled together, possibly reversibly.

As illustrated, the cap cover36has a bush form, closed at one end. The cap cover36has an essentially esthetic function. The cross section of the cap cover36is, here, substantially square. However, the cross section of the cap cover36can also be round or take any other shape, notably a polygonal shape.

The weight38is fixed inside the cap cover36. To do this, for example, the cap cover36is overmolded on the weight38or, conversely, the weight38is molded in the cap cover36. Also alternatively, the weight38can be fixed for example by gluing in the cap cover36. The weight38advantageously has an annular shape. Here, the outer section of the weight38is of substantially square shape, matched to the section of the cover36, whereas the internal section of the weight38is of substantially circular shape, suitable for receiving the cap insert40, as is particularly visible inFIG.7.

The cap embellisher44is used to close the housing inside the cover36so as to hold the weight38, the cap insert40and the second seal42in position with respect to the cap cover36and to the cap embellisher44. The cap embellisher44here has elastically deformable arms44bto allow the cap embellisher44to be fixed onto the cap insert40, by elastic fitting (or snap-fitting). The cap embellisher44also covers the second seal42, so as to conceal the second seal42from a user. The esthetic appearance of the packaging and application device10is thereby enhanced.

The cap insert40and the second seal42are more clearly represented inFIGS.12to15.

As illustrated notably inFIG.14, the cap insert40has, on its outer lateral surface40e, notches46. Here, these notches46are substantially longitudinal. The notches46emerge also on the bottom surface40fof the cap insert40. According to the example illustrated, the cap insert10has eight notches46. The notches46are evenly distributed angularly. The notches46can cooperate with complementary protruding reliefs, formed on the bottom of the cover36, to secure the cap insert40and the cover36in rotation on the longitudinal axis X. Also, or alternatively, the notches46facilitate the fixing of the weight38by clamping on the cap insert40.

The cap insert40also has two longitudinal ribs48on its outer lateral face40e. Here, the two longitudinal ribs48are opposite, produced at 180° from one another. These ribs48can notably allow the cap insert40to be guided in the cap cover36and/or in the weight38during its introduction, for example by cooperation with complementary grooves produced on the inner face of the cap cover36and/or in the weight38. The two longitudinal ribs48also allow, by complementarity of shapes, the cover36, the weight38and the cap insert40to be secured in rotation. Furthermore, in the example illustrated, a movement of the weight38toward the opening of the cap36is prevented by the presence of protruding reliefs50on the radially outer surface of the cap insert40.

Set back from its outlet, the cap insert40forms protruding reliefs54, extending radially outward to give the cap insert40a section substantially complementing the internal section of the cover36. It is thus possible to fix the cap insert40in the cover36by complementarity of shapes.

Moreover, in the example illustrated, the second seal42comprises a substantially tubular, preferably cylindrical, main part42p. In particular, the main part42pis substantially cylindrical with symmetry of revolution. The main part42pof the second seal42is for example disposed around the end portion of the cap insert40. The main part42pcan notably be disposed around the end portion of the cap insert40, so as to be in contact with the reliefs54. A portion of the main part42pcan be clamped against the cap insert40and/or against the cap embellisher44.

At its end opposite the cap insert40, the main part42pof the second seal42forms a radially-inward bead42b. The corresponding portion of the main portion42p, where the bead42bis produced, is inserted between the base20of the mechanism14and the cap embellisher44, and is in particular clamped against the ring23of the base20of the mechanism14.

Evaporation of the volatile products involved in the composition of the cosmetic product, along the tube22of the mechanism14, inside the cap insert40, then, possibly, along the base20of the mechanism14toward the outside of the device10, is thus limited, even avoided.

The first seal28and/or the second seal42can notably be made of one out of Hytrel® and Arnitel®. The base and cap inserts can notably be made of PCTA (polycyclo-hexylene dimethylene terephthalate acid).

In the example which has just been described, advantageously, the purpose of the first seal28is to ensure the seal-tightness of a first housing L1, defined in the base insert26, preventing evaporation of the components of the cosmetic product through the cup19, between the bush21and the base insert26, then along the bush21and/or the ring23, to the outside of the device10. For this, here, the first seal28is, on the one hand, clamped on the ring23of the base20of the mechanism14, and, on the other hand, overmolded on the base insert26.

Similarly, the purpose of the second seal42is to ensure the seal-tightness of a second housing L2, defined in the cap insert40, thus preventing evaporation of components of the cosmetic product from the cup19, then between the tube22and the cap insert40, to the outside of the device10. Here, for this, the first seal42is, on the one hand, clamped on the ring23of the base20of the mechanism14, and, on the other hand, overmolded on the cap insert40.

The ring23links the first and second housings L1, L2in a seal-tight manner. In the closed state of the packaging and application device, a volume receiving the stick of cosmetic product is thus defined, this volume being seal-tight.

In other words, here, the volume defined by the base insert26, the first seal28, the ring23, the second seal42and the cap insert40constitutes a volume that is seal-tight with respect to the outside and that contains notably the stick of product.

However, having achieved seal-tightness of the housings L1, L2, a “piston effect” can occur when the packaging and application device10is closed. This “piston effect” can cause movement of the stick of product in the cup by creation of a pressure difference at the two ends of the stick of cosmetic product.

This piston effect is avoided in the example described above by virtue of the presence of the air passage F1in the mechanism14which fluidically connects the first and second housings L1, L2. Thus, air can circulate between these two housings L1, L2, ensuring a substantially identical pressure in the two housings L1, L2. Here, the air passage F1extends more specifically between the ring23and the bush21. Thus, despite this air passage F1, the housings L1, L2and the ring23do indeed define a volume, inside the packaging and application device, which is seal-tight with respect to the outside.

In the present case, the two ends of the cup19emerge in a respective housing L1, L2. Thus, advantageously, a substantially identical pressure is ensured between the two opposite surfaces of the stick of cosmetic product, received in the cup19.

Furthermore, the air is not trapped in one or other of the two housings L1, L2, but can, on the contrary, flow from one of the housings to the other. The stresses on the stick of product are therefore distributed on each side of the stick.

In the example illustrated, it is the assembly formed by the first and second housings L1, L2and the air passage F1which constitutes a seal-tight volume, in the closed state of the packaging and application device10, with respect to the outside of the packaging and application device10, by virtue of the presence and the position of the first and second seals28,42.

The invention is not limited to just the embodiments described hereinabove with respect to the figures, but does, on the contrary, lend itself to numerous variants accessible to the person skilled in the art.

First of all, the second seal42can comprise an annular portion, extending radially inward from the main part. This annular portion can advantageously be clamped against the lip, around the outlet of the cap insert, and/or against the base of the mechanism.

Moreover, in the example described, the first and second seals form beads. Alternatively or in addition, the first seal and/or the second seal is/are domed toward the mechanism. This enhances the effect of these seals.

Also, the positions of the first and second seals can be different, as long as the seals are clamped against one and the same element of the mechanism and/or one and the same element of the base cover, this element of the mechanism and/or this element of the base cover linking, in a seal-tight manner, the first and second housings. The element of the base cover can notably be the ferrule, as in the example described above, or the base cladding shell. The element of the mechanism can notably be the bush, the ring or the tube of the mechanism.