EP0939039B1 - Dispensing head for the dispensing of a material and assembly for dispensing under pressure equipped with such a head - Google Patents

Description

The present invention relates to a head for dispensing a product according to the preamble of claim 1. The invention also relates to a packaging assembly according to the preamble of claim 11.

The products likely to be thus distributed from a set of the aforementioned type are in particular cosmetic products, hygiene products and cleaning products. In the field of body and hair care, there may be mentioned, for example, the packaging in pressurized cans of foaming shaving creams, self-foaming shaving gels, hair dyes, cold hair reducers, shampoos, depilatory foams, anti-sun foams and make-up removal foams, in particular in self-foaming form.

In the aforementioned distribution assemblies, the ejected product travels through an ejection channel to an outlet orifice. However, once the user has released the pressure exerted on the push button, practically in all cases of dispensing of products having the above consistency, the ejection channel does not have time to empty, so that there remains of the product in an amount all the greater as the outlet orifice is formed in an elongated application nozzle.

However, the aforementioned products are of such a nature that once the distribution is finished, they tend to continue to exit slowly from the election channel (by expansion in the case of a foam or by flow in the case of liquid or viscous products) , which causes soiling on the push-button, or in general, on the dispensing head, or even on the user's hand.

It has already been proposed to remedy this drawback by ensuring that the outlet orifice is closed when the container is in the rest position, this orifice being released only when the push-button is operated.

Thus, document FR-A-2 617 809, in the name of the applicant, proposes a dispensing assembly for products having a viscous or pasty consistency, or else distributed in the form of foams from a container provided with a mobile push button provided with an ejection channel. According to this document, the ejection channel leads into a chamber delimited by a fixed part attached to the container and constituting, with said movable push-button, a dispensing head, the chamber opening to the outside through a orifice outlet, the movable push button comprising means capable of closing said outlet orifice in the rest position of the push button and of releasing it when the latter is actuated.

Tests carried out by the applicant have shown that the tightness of the assembly according to FR-A-2 617 809 leaves something to be desired. In particular, residual product has been found in the space formed between the top of the container and the dispensing head. In addition, the mounting of the movable push button and of the fixed part must be carried out in two distinct stages, and requires special tools.

The present invention relates to a dispensing head, the construction of which is simplified and the mounting of which on a tank is facilitated relative to the assembly according to FR-A-2 617 809.

Document EP-A-0 031 123 describes a dispensing head having an outlet channel, the end of which forms an outlet orifice, closed in the rest position by a central shutter. The central obturator and the outlet channel are made of a rigid material, a zone of thin channel being provided, at a location remote from the outlet orifice, allowing the retraction of the channel, and thus the release of the outlet. This device has the disadvantage that the seal between the shutter and the outlet orifice leaves something to be desired, in particular when the outgoing product is an expanding foam. Indeed, because the outlet and the shutter are made by molding in a rigid material, the precision of these parts is insufficient to ensure a reliable seal.

We also know from document FR-A-2 684 080, a dispensing head of the aforementioned type, having an outlet channel whose free end forms inside a rigid peripheral valve seat. This peripheral seat cooperates, in the rest position with a central shutter of rigid material, connected to a movable actuating member, capable of causing the retraction of the shutter and thus releasing the outlet orifice. This dispensing head has, like the embodiment according to the previous document, leaks. In addition, the adjustment of the shutter is difficult to do, its molding is complicated and the assembly of the assembly is difficult to achieve industrially.

Also, the invention relates to a head for dispensing a pressurized product, in particular a liquid, comprising the features of claim 1.

According to an advantageous embodiment, the rigid or semi-rigid actuating means are axially movable over a stroke greater by an axial distance than the stroke of the dispensing means, the return of the actuating means to the rest position being on the one hand by the restoring force exerted by elastic means of the pump or the valve, and on the other hand by the elastic restoring force exerted by the shutter means. Such elastic means generally comprising a spring on which the pump or valve stem is mounted. By the term "rigid or semi-rigid actuating means" is meant means whose structure or material used is non-deformable under normal conditions of use.

The subject of the invention is also a pressure conditioning assembly comprising a reservoir for the product to be dispensed, provided with a valve or a pump and provided with a dispensing head as defined above. According to a preferred embodiment of the invention, this assembly is provided with a valve with an emerging stem, in communication with the distribution means, the product contained in the reservoir being pressurized by means of a propellant chosen from liquefied hydrocarbons or chlorofluoroalkanes, nitrogen, compressed air, carbon dioxide, dimethyl ether or their mixtures.

For example, the product packaged in the reservoir is advantageously a self-foaming gel containing a foaming agent such as isopentane, a foam such as a shaving foam, a liquid foundation, a depilatory foam or a hair coloring product.

According to an interesting aspect of the invention, the actuation means and the distribution means are arranged so that an actuation pressure initially causes the passage of the shutter means from the first to the second position, then, in a second step, putting the outlet channel into communication with said reservoir, said distribution means returning from the distribution position to the closed position, under the effect of a restoring force generated by elastic means of the pump or the valve.

By this arrangement, any flow of residual product located between the valve or the dispensing pump and the dispensing orifice can be instantly and reliably avoided, to ensure the cleanliness of the assembly after each use. The seal in the rest position occurs at the dispensing orifice. This seal is guaranteed, even if the product contains foaming agents such as isopentane which, at atmospheric pressure tends to cause the product to expand for a period of up to ten minutes.

Furthermore, advantageously, the closure means ensure, in the aforementioned second position, a seal between the distribution means and the actuation means. By this arrangement, it is possible to avoid fouling of the mechanism which would then risk hampering the mobility of the actuating means relative to the distribution means. According to an interesting aspect of the invention, the sealing means are formed of an elastomeric material, that is to say of an elastically compressible material in its three dimensions, such as natural or synthetic rubbers.

To this end, advantageously, the actuating means have an annular portion surrounding the dispensing means and one free end of which is situated substantially in the vicinity of the dispensing orifice (s), these shutter means being formed by 'An annular member mounted inside said annular portion of the actuating means, said actuating means being mounted to slide relative to the distribution means. Advantageously, this annular member defines a skirt of which a free edge ensures, in the second position, the seal between the actuating means and the dispensing means.

In an advantageous embodiment, the actuating means as well as the sealing means are produced by bi-injection of a first and a second physico-chemically compatible thermoplastic material. Also, the first material consists, for example of a polyethylene, or of a polypropylene, which are relatively rigid materials. In this case, the second material consists of an elastomer chosen from the group of propylene / ethylene copolymers; polyether blockamides; polyvinyls; terpolymers of ethylene, propylene and a diene (EPDM); block styrene-butadiene polymers (SBS); block styrene-ethylene-butadiene polymers (SEBS-SIS); thermoplastic polyurethanes; mixtures of polypropylene with one of the following elastomers: block styrene-ethylene-butadiene polymers (SEBS-SIS); terpolymers of ethylene, propylene and a diene (EPDM); styrene-butadiene block polymers (SBS).

According to an interesting embodiment, the outlet opening (s) open perpendicular to the outlet channel, straight on the internal face of the annular member. Thus, during the distribution of product, the annular member acts as a jet breaker, avoiding accidental projections and splashes of product, which is advantageous for the distribution of very liquid products or products subjected to strong pressurization.

Advantageously, the dispensing head comprises a part intended for its attachment to the reservoir, for example an annular hoop, this part being secured to the actuation means via an articulation zone, for example a film hinge.

• la figure 1 représente une vue en perspective d'un ensemble de conditionnement sous pression muni d'une tête de distribution, conforme à un mode de réalisation de l'invention ;
• la figure 2 représente une vue partielle en perspective de l'ensemble de la figure 1, représenté en cours d'utilisation ;
• la figure 3 montre une vue partielle agrandie en coupe longitudinale de l'ensemble de la figure 1, représenté en position de repos ;
• la figure 4 montre une vue agrandie en coupe longitudinale des moyens d'obturation en position de repos ;
• la figure 5 représente une vue en coupe longitudinale des moyens d'obturation en position de distribution.

The invention consists, apart from the arrangements set out above, of a certain number of other arrangements which will be explained below, in connection with a nonlimiting exemplary embodiment, described with reference to the appended figures, among which :

• FIG. 1 represents a perspective view of a pressure conditioning assembly provided with a dispensing head, in accordance with an embodiment of the invention;
• Figure 2 shows a partial perspective view of the assembly of Figure 1, shown in use;
• Figure 3 shows an enlarged partial view in longitudinal section of the assembly of Figure 1, shown in the rest position;
• Figure 4 shows an enlarged view in longitudinal section of the shutter means in the rest position;
• FIG. 5 represents a view in longitudinal section of the closure means in the dispensing position.

In Figures 1 and 2, there is seen in perspective a distribution assembly according to the invention, generally designated by the reference 1. This assembly, of axis X consists of a reservoir 2 containing a liquid product, in particular foaming and d 'a dispensing head 4, mounted on the reservoir using a cylindrical hoop 6. The hoop 6 carries a circular plate 8 in which a cutout 10 is made. This cutout 10 delimits a space in which a button is arranged -pusher 12, articulated pivoting with the plate 8 by means of a film hinge 14. The push-button 12 has an actuating surface 13, disposed eccentrically relative to the axis X and on which the user presses to dispense a dose of product. The push button is provided with a dispensing nozzle 16, produced in the form of cylindrical tubing, and secured to the actuating surface 13. In the rest position of the assembly, as mounted in FIG. 1, the axis of the tip 16 is coincident with the axis X. The tip 16 has a free end 15, inside which is disposed an annular closure means 18. This closure means 18 is advantageously made of a elastomeric material, such as a terpolymer of polypropylene ethylene and a diene (EPDM). Such a material is marketed by the MONSANTO Company under the trade name of Santoprene®. Inside the annular closure means is disposed a distribution member 20. In the rest position, the distribution member 20 does not protrude outwards relative to the annular closure means 18.

When the user presses on the actuating surface 13 of the push button 12, by pivoting around the film hinge 14, the latter is inserted slightly into the space delimited by the cutout 10. During this action, the 'end piece 16 and the closure means 18 recede relative to the dispensing member 20, thereby freeing the free end 22 of a dispensing channel.

In Figure 3, we see the dispensing head 4 of Figures 1 and 2, shown in axial section. This head is mounted on the top of an aerosol container 2. This container 2, made for example of aluminum, has a turtleneck 24, on which is fixed, by crimping, a valve holder cup 26. The cup 26 has a dome 28 in which a dispensing valve 30 with an emerging stem 32 is mounted. The free end of the stem 32 is engaged in a corresponding bore made in the lower end of the dispensing member 20. The dispensing member is provided with a central distribution channel 34 which ends in front of a solid portion 20a situated at the free end of the distribution member 20. Just in. below the portion 20a, the central channel 34 opens onto two radial channels 22 arranged, in the rest position, facing the internal wall of the annular closure means 18. The valve 30 is connected to a dip tube 36 which ends , generally near the bottom of the tank 2.

As can be seen in FIG. 3, the dispensing member is made up of four portions 20b, 20c, 20d and 20e, of increasing diameter. The portion 20b has a diameter slightly smaller than the diameter of the solid portion 20a. Between the smaller diameter portion 20b and the portion 20c, a junction area 20f has the shape of a truncated cone 20f. The portion 20c is separated from the portion 20d by a step 20g. Likewise, between portion 20d and portion 20e an offset is produced at 8 p.m. One or more annular beads 20i can be provided for centering the dispensing member 20 in the nozzle 16 (see FIG. 4).

In the rest position of the assembly 1, the step 20g is disposed at a small axial distance δ _c of a corresponding shoulder 16a produced inside the end piece 16, while, when the push button is actuated 12, this step 20g is capable of coming into abutment against the projection 16a. Typically, this distance δ _c is from 0.8 mm to 1.0 mm. This axial distance δ _c allows, as will be seen in detail below, a slight axial movement of the endpiece 16 relative to the dispensing member 20.

With reference, in particular to FIGS. 4 and 5, it can be seen that the annular closure means 18 has two cylindrical skirts 18a and 18b, arranged concentrically and oriented in the direction of the reservoir. The first skirt 18a, of diameter greater than the diameter of the second skirt 18b, is embedded in a housing 16b of a shape complementary to the shape of the skirt 18a, produced in the wall of the endpiece 16, near its free end 15 The free end 15 has a rim 15a, in contact with a smaller diameter area 18c formed by the upper end of the shutter means 18. This arrangement makes it possible to axially block the shutter means 18 inside. tip 16.

The second skirt 18b has a free end 19 which comes to bear resiliently on the inclined surface of the truncated cone 20f. It should be noted that between the external surface of the skirt 18b and the internal wall of the endpiece 16, a space 23 is provided to allow a radial clearance of the free end 19 of the second skirt. This movement allows the stressing of the skirt 18b.

The annular closure means 18 also has a central cylindrical passage 18d in which is arranged the portion of smaller diameter 20b of the distribution member 20. The central passage 18d has an end 18th of diameter slightly greater than the diameter of the rest of the passage 18d. In this 18th end is housed, in the rest position, the solid portion 20a of the stud distribution member 20. With reference to FIG. 4, by the arrangement described, the shutter means ensures the closing of the distribution channel 34 , via the radial channels 22. The second skirt 18b ensures, on the one hand a good seal between the dispensing member 20 and the internal wall of the end piece 16, and on the other hand, exerts, in response to a force exerted on the actuating surface 13, an elastic support on the dispensing member 20 in the direction of the reservoir 2. In addition, it allows a return by elastic return of the shutter means 18 opposite the channels 22.

It should be noted that, advantageously, the sealing means 18 is put in place during the manufacture of the dispensing head 1 by a technique of biinjection of an elastomeric thermoplastic material (forming the sealing means) and a rigid thermoplastic material (forming in one piece the push button and the hoop).

The operation of the dispensing assembly of the invention is as follows: to dispense product, the user presses on the actuating surface 13 in the direction of the arrow F (see FIG. 3). As shown in FIG. 5, the end 19 of the skirt 18b is deformed, the end piece 16 descends relative to the distribution member 20 over an axial distance δ _c and the ends 22 of the distribution channel are released. When the user continues to press, the shoulder 16a abuts against the edge formed by the step 20g. By this operation, the dispensing member 20 is brought into a lower axial position, sufficient to actuate the dispensing valve. Product P is then dispensed, as indicated by the arrows P in FIG. 5.

When the pressing action on the actuating surface 13 ceases, the dispensing member 20 returns to the closed position under the effect of a restoring force exerted by the elastic means on which the valve stem is mounted. .

The end piece 16 rises with the dispensing member 20. When the dispensing member 20 reaches the upper end of the travel, the end piece 16 continues its race over a height δ _c , under the effect of the elastic restoring force. exerted by the skirt 18b, thus causing the return of the shutter means 18 opposite the channels 22. Thus, the distribution is stopped clear, and any late flow of product is prevented. In particular in the case of a product with strong expansion like a foam or a self-foaming gel, the whole always remains clean.

In the foregoing detailed description, reference has been made to a particular embodiment of the invention. It is obvious that variants can be made without departing from the invention as claimed below.

Claims (13)

1. Head (4) for dispensing a product (P) under pressure, comprising:

   a) dispensing means (20) intended to be mounted on a pump or a valve (30) surmounting a reservoir (2) containing the product, and defining an outlet duct (34) for the product, opening to at least one dispensing orifice (22);

   b) rigid or semi-rigid actuating means (16) comprising an actuating surface (13) capable of being pushed by a user such that the actuating means are capable of coming into engagement with the dispensing means in order to move the latter from a closed position into a dispensing position in which the outlet duct (34) is in communication with the said reservoir (2);

   c) shut-off means (18) integral with the actuating means (16) and capable, in response to a pressure exerted on the actuating means (16), of moving from a first position in which they seal off the said orifice(s) (22) into a second position in which the said orifice(s) is (or are) uncovered so as to allow the product to exit under pressure, characterized in that the said shut-off means (18) are formed of a material that is elastically deformable so that it can return to the said first position by elastic return when the actuating pressure ceases and in that the actuating means can move with respect to the dispensing means.
2. Dispensing head according to Claim 1, characterized in that the actuating means (16) can move axially over a travel that exceeds the travel of the dispensing means (20) by an axial distance (&), the actuating means (16) returning to the position of rest partly as a result of the return force exerted by elastic means of the pump or of the valve, and partly under the elastic-return action generated by the shut-off means (18).
3. Dispensing head according to Claim 2, characterized in that the actuating means (16) and the dispensing means (20) are arranged in such a way that an actuating pressure first of all causes the shut-off means (18) to move from the first into the second position and then, secondly, causes the outlet duct (34) to be brought into communication with the said reservoir (2), the said dispensing means returning from the dispensing position into the closed position under the effect of a return force generated by the elastic means of the pump or of the valve.
4. Dispensing head according to any one of Claims 1 to 3, characterized in that the shut-off means (18) also, in the said second position, provide sealing between the dispensing means (20) and the actuating means (16).
5. Dispensing head according to any one of the preceding claims, characterized in that the actuating means (16) have an annular portion surrounding the dispensing means and a free end of which lies more or less in the vicinity of the dispensing orifice(s), the said shut-off means being formed of an annular member mounted inside the said annular portion of the actuating means, the said actuating means (16) being mounted so that they can slide with respect to the dispensing means (20).
6. Dispensing head according to Claim 5, characterized in that the said actuating means (16) and the said shut-off means (18) are produced by two-shot injection moulding of a first and of a second thermoplastic material which are physico-chemically compatible.
7. Dispensing head according to the preceding claim, characterized in that the said first material consists of a polyethylene or of a polypropylene and in that the second material consists of an elastomer chosen from the group of ethylene/propylene copolymers; poly(ether-block-amide)s; polyvinyls; ethylene-propylene-diene terpolymers (EPDM); styrene-butadiene block copolymers (SBS); styrene-ethylene-butadiene block copolymers (SEBS-SIS); thermoplastic polyurethanes; blends of polypropylene with one of the following elastomers: styrene-ethylene-butadiene block copolymers (SEBS-SIS); ethylene-propylene-diene terpolymers (EPDM); and styrene-butadiene block copolymers (SBS).
8. Dispensing head according to any one of Claims 5 to 7, characterized in that the said annular member defines a skirt (18b), a free edge (19) of which, in the said second position, provides sealing between the actuating means (16) and the dispensing means (20).
9. Dispensing head according to any one of the preceding claims, characterized in that the outlet orifice(s) (22) open at right angles to the outlet duct (34).
10. Dispensing head according to any one of the preceding claims, characterized in that it comprises a part (6) intended for fixing it onto the reservoir, the said part being integral with the actuating means (16) via an articulation region (14).
11. Unit for packaging under pressure, comprising a reservoir (2) for a liquid product (P) to be dispensed and fitted with a valve (30) or a pump, characterized in that it is fitted with a dispensing head (4) in accordance with any one of the preceding claims.
12. Packaging unit according to Claim 11, characterized in that it is fitted with a valve (30) with an emerging stem (32) in communication with the dispensing means (20), the reservoir being able to contain the said product under pressure particularly by means of a propellant gas.
13. Use of a packaging unit (1) according to Claim 11 or 12 for dispensing a self-foaming gel, a foam or mousse, or a hair-colouring product.