METERING VALVE

Metering valve having a valve body (10) containing a metering chamber (20) defined by a chamber insert (40) and a top and a bottom seal. The chamber insert (40) has a cylindrical wall (49) with an upper edge (41) cooperating with the top seal and a lower edge (43) with the bottom seal. A valve shut-off element (30) slides between rest position and dispensing positions. The valve shut-off element is urged towards its rest position by a spring (8) cooperating with the valve body (10) and the valve shut-off element. The lower edge of the chamber insert forms a flange and has a downward axial projection (48). The bottom seal has an axial opening (225) accepting an axial projection (45) and passing through the axial opening. The rest position of the valve shut-off element is defined by contact between the axial projection and a part of the valve shut-off element.

The present invention relates to a metering valve for a device for dispensing a fluid product.

So-called metering valves, in which upon each actuation of the valve, a specific dose of fluid product is dispensed, are well-known in the state of the art, and are generally assembled on a reservoir containing the fluid product and a propellant used to perform the expulsion of the dose.

Two types of metering valves are mainly known. So-called retention valves comprise a valve shut-off element which, in the rest position, partially closes the metering chamber. More precisely, the outside of the valve shut-off element co-operates in leaktight manner with the chamber seal of the metering chamber such that, in the rest position, the metering chamber is connected to the reservoir only via the internal channel of the valve shut-off element. So-called non-priming valves comprise a metering chamber which, at rest, is open on the reservoir and which is filled at the time of actuation, when the user returns the device into the inverted position of use. In these types of valves, the rest and actuating positions of the valve shut off element are generally defined by elements that are more or less deformable, i.e. the compressed spring in the dispensing position, and the top seal in the rest position. Consequently, these positions are not always very exactly reproducible, in particular the rest position, which depends on the state of the top seal.

Documents FR3043392 and U.S. Pat. No. 3,547,317 describe devices of the state of the art.

An object of the present invention is to provide a metering valve that does not have the above-mentioned drawbacks.

An object of the present invention is thus to provide a metering valve in which the rest position of the valve shut-off element is independent of the seals of the valve.

A particular object of the present invention is to provide a metering valve that is simple and inexpensive to manufacture and to assemble, and that is reliable in operation.

An object of the he present invention is thus a metering valve for dispensing a fluid product, comprising a valve body containing a metering chamber, said metering chamber being defined by a chamber insert and two annular seals, a top seal and a bottom seal, said chamber insert comprising a cylindrical wall, of which an upper edge cooperates with the top seal and a lower edge cooperates with the bottom seal, wherein a valve shut-off element slides axially in the valve body between a rest position and a dispensing position, in order selectively to dispense the contents of said metering chamber, wherein the valve shut-off element is urged towards its rest position by a spring cooperating on the one hand with the valve body and on the other hand with the valve shut-off element, wherein the lower edge of the chamber insert forms a flange which extends radially inwards from the cylindrical wall, wherein the lower edge comprises at least one axial projection projecting axially downwards, and wherein the bottom seal comprises at least one axial opening, each axial opening accepting a respective axial projection and each axial projection passing completely through the respective axial opening so that the rest position of the valve shut-off element is defined by contact between the at least one axial projection of the chamber insert and a part of the valve shut-off element.

Advantageously, said lower edge comprises three axial projections distributed around its periphery.

Advantageously, said valve shut-off element comprises a radial collar which comprises a radial wall part, against which said spring bears, which is extended at its outer radial edge by an axial wall part extending axially upwards from said radial wall part, the upper axial edge of said axial wall part cooperating with the lower axial edge of said at least one axial projection to define the rest position of said valve shut-off element.

Advantageously, said collar includes at least one cutout in its periphery, aligned with a radial outlet channel and a radial inlet channel of said valve shut-off element.

Advantageously, said bottom seal includes, on its internal radial edge, a radial sealing lip that extends radially inwards and axially downwards.

Advantageously, in the rest position of said valve shut-off element, said radial sealing lip is positioned in a recess formed between the outer surface of said valve shut-off element and said axial wall portion of said collar of said valve shut-off element.

Advantageously, said bottom seal is fixed, in particular by assembly or overmolding, to said lower edge of said chamber insert.

Advantageously, said top seal comprises, on its internal radial edge, a radial sealing profile comprising a central recess defined between two radial projections that cooperate with said valve shut-off element to achieve sealing.

Advantageously, said top seal and/or said bottom seal include at least one axially projecting profile on at least one of its(their) upper and/or lower surfaces.

Advantageously, said metering chamber has a variable volume, in particular of between 25 and 75 μl, defined by the radial width of said cylindrical wall.

Another object of the present invention is a device for dispensing a fluid product comprising a metering valve such as described above, said valve being mounted on a reservoir containing the fluid product and a propellant.

In the description below, the terms “top”, “bottom”, “lower”, “upper” and “vertical” refer to the upright position represented inFIGS.1and2, and the terms “axial” and “radial” refer to the longitudinal central axis X of the valve.

FIG.1represents the valve in the upright storage position, i.e. the position in which the valve is arranged above the reservoir (not shown).FIG.2represents the valve in the dispensing position. It must be noted that the normal position of use of such a valve is an inverted position, with the valve arranged under the reservoir, but in thisFIG.2, the position of use of the valve has been represented in the upright position, to simplify the comparison with the rest position ofFIG.1.

The metering valve represented inFIG.1comprises a valve body10extending along a longitudinal central axis X. Inside said valve body10, a valve shut-off element30slides between a rest position, which is the position shown inFIG.1, and a dispensing position as shown inFIG.2, in which the valve shut-off element30has been pushed into the valve body10.

This valve is intended to be assembled on a reservoir (not shown) containing the fluid product and a propellant, preferably by means of a fixing element5, which can be a crimpable, screw-fastenable, or snap-fastenable capsule, and advantageously with interposition of a neck seal6. Possibly, a ring4can be assembled around the valve body10, in particular to decrease the dead volume in the inverted position and so as to limit contact between the fluid product and the neck seal6. This ring4can be of any shape, and the example ofFIG.1is not limiting. In general, the reservoir contains the fluid product and the propellant, in particular a formulation made up of one or more active principle(s) in suspension and/or in solution in a liquefied propellant, as well as possible excipients. The propellant advantageously comprises an HFA gas, e.g. HFA 134a and/or HFA 227. Preferably, the propellant comprises HFA-152a. In a variant, other non-harmful gases can be used, such as HFO1234ze.

The valve shut-off element30is urged towards its rest position by a spring8that is arranged in the valve body10and that cooperates on the one hand with the valve body10and on the other hand with the valve shut-off element30, preferably with a radial collar320of the valve shut-off element30. A metering chamber20is defined inside the valve body10, said valve shut-off element30sliding inside said metering chamber20so as to enable its contents to be dispensed when the valve is actuated.

Advantageously, the valve shut-off element30may be made of one single piece, namely a top portion31(also known as a valve shut-off element top) and a bottom portion32(also known as a valve shut-off element bottom). The top portion31comprises a central axial channel35provided with an axial outlet orifice301and a radial inlet channel302which is arranged in the metering chamber20when the valve shut-off element30is in its dispensing position. The bottom portion32includes said central internal channel34provided with an axial inlet orifice341, and a radial outlet channel342. The bottom portion32also includes the collar320on its outer surface.

The radial collar320comprises a radial wall part, against which the spring8bears, which is extended at its outer radial edge by an axial wall part321extending axially upwards from said radial wall part. Thus, a recess is defined between the outer surface of the valve shut-off element30and said axial wall portion321.

The collar320may include at least one cutout329in its periphery, aligned with said radial outlet channel342and said radial inlet channel302, as can be seen inFIG.6.

The internal axial channel34makes it possible to connect the metering chamber20to the reservoir, so as to fill said metering chamber20. Filling is performed when the device is in its upsidedown working position, with the valve arranged below the reservoir.

In the example inFIG.1, when the valve shut-off element30is in its rest position, the metering chamber20is connected to reservoir1by the internal axial channel34of the valve shut-off element30. In that rest position, the metering chamber20thus remains connected to the reservoir1and can be emptied by gravity in the upright position inFIG.1. The valve represented inFIGS.1and2is thus a valve of the non-priming type. However, the invention is also applicable to other types of valve, in particular valves of the retention type.

The valve body10includes a cylindrical portion15in which the spring8is arranged, and in which the collar320slides between its rest and dispensing positions. In the position ofFIG.1, this cylindrical portion15is the lower portion of the valve body. This cylindrical portion15comprises one or more longitudinal openings11, such as slots, extending laterally in said cylindrical portion15of the valve body, over a portion of the axial height of the valve body in the direction of the longitudinal central axis. These openings11make it possible to fill the metering chamber20before each actuation, when in the inverted position of use (with the valve arranged below the reservoir), the valve shut-off element30is in its rest position.

Advantageously, the pump body10comprises, at its lower axial edge, an axial profile16projecting upwards, to define the dispensing position of the valve shut-off element by cooperating with the lower edge325of the valve shut-off element30. This implementation guarantees a precise and identical definition to each actuation of this dispensing position, independent from the compression of the spring8. Also, it makes it possible to ease the spring8, which makes it possible to increase its service life.

This axial profile16can advantageously be made in the shape of a sleeve radially offset inwards from said cylindrical portion15, as represented inFIG.1. This particular implementation makes it possible to form a receiving space for the spring8between said sleeve16and said cylindrical portion15, making it possible to hold the spring8it in a repeatable position. It must be noted that this projecting profile16represented inFIG.1is not essential for the operation of the valve, and it could be implemented independently from the structure of the metering chamber.

The metering chamber20is defined between two annular seals, a top seal or valve shut-off element seal21and a bottom seal or chamber seal22, in a well-known manner. This metering chamber20is filled before each actuation with a dose of fluid product from the reservoir, when the user returns the device into the inverted position.

The volume of the metering chamber20is defined by means of a chamber insert40, of substantially cylindrical shape, with a cylindrical wall49having a more or less large radial thickness according to the desired volume. This volume can advantageously vary between 25 and 75 μl.

The top seal21rests on the upper edge41of the chamber insert40, and the bottom seal22is in contact with a lower edge43of the chamber insert40.

Advantageously, the top seal21includes at least one first axially projecting profile210on its top surface and at least one second axially projecting profile211on its bottom surface. In the embodiment shown inFIG.5, the first projecting profile210includes two concentric peripheral beads made in the vicinity of the outer radial edge of the top seal21. Likewise, the second projecting profile211also comprises two concentric peripheral beads made in the vicinity of the outer radial edge of the top seal21. It should be observed that the two axially projecting profiles210,211are not necessarily identical. These axially projecting profiles210,211improve the sealing between the chamber insert40and the fixing element5.

On its internal radial edge, the top seal21advantageously comprises a radial sealing profile215to improve the dynamic sealing with the valve shut-off element30during its movement during the actuation of the valve. In the embodiment shown, the radial sealing profile215includes a central recess216defined between two radial projections217,218that cooperate with the valve shut-off element30to achieve sealing. This implementation makes it possible to guarantee perfect sealing when the valve shut-off element30moves in one direction and then in the other direction during actuation.

Advantageously, the bottom seal22has an axially projecting profile221on its bottom surface. In the example shown inFIG.4, the axially projecting profile221includes a peripheral bead that is made in the vicinity of the outer radial edge of the bottom seal22. This axially projecting profile221improves sealing between the chamber insert40and the pump body10.

On its internal radial edge, the bottom seal22advantageously comprises a radial sealing lip220to improve the dynamic sealing with the valve shut-off element30during its movement during the actuation of the valve. The deformable lip220extends radially inwards and axially downwards. This implementation makes it possible to guarantee perfect sealing when the valve shut-off element30moves in one direction and then in the other direction during actuation. Moreover, this radial sealing lip allows easy filling of the reservoir through the valve without risk of damaging the bottom seal22.

The lower edge43of the chamber insert40forms a flange which extends radially inwards from the cylindrical wall49.

According to the invention, said lower edge43includes at least one axial projection45projecting axially downwards. In the example ofFIG.3, there are four axial projections45distributed around the periphery. Correspondingly, the bottom seal22includes at least one axial opening225, each receiving an axial projection45of the chamber insert40. Each axial projection45passes completely through its respective axial opening225. Thus, in the rest position of the valve shut-off element30, the upper axial edge of the axial wall portion321of the collar320of the valve shut-off element30is in contact with the lower axial edge of each axial projection45of the chamber insert40. Thus, the rest position of the valve shut-off element30is defined by contact between two rigid parts of the valve, and is therefore independent of the seals, and in particular of the top seal21.

In this rest position, the radial sealing lip220of the bottom seal22is positioned in the recess formed between the outer surface of the valve shut-off element30and the axial wall portion321of the collar320of the valve shut-off element30. This makes it possible to avoid any axial contact between said lip220and the valve shut off element, and thus to preserve the integrity of said sealing lip. Furthermore, this embodiment makes it possible to limit the dead volume in the valve.

The bottom seal22can be assembled mechanically on the lower edge43of the chamber insert40. Advantageously, the lower seal22is overmolded onto the lower edge43of the chamber insert40.

Although the present invention is described above with reference to a particular embodiment thereof, naturally it is not limited by the examples shown. On the contrary, any useful modification could be applied thereto by a person skilled in the art, without going beyond the ambit of the present invention, as defined by the accompanying claims.