Metering valve with improved metering chamber

Abstract

The present invention provides a metering valve for dispensing a fluid product, comprising a valve body (10) containing a metering chamber (20), the metering chamber (20) being defined by a chamber insert (40) and two O-rings, namely a valve seal (21) and a chamber seal (22), the chamber insert (40) comprising a cylindrical wall (49), an upper edge (41) cooperating with the valve seal (21) and a lower edge (43) cooperating with the chamber seal (22), a valve (30) being arranged in the valve body (10) between a rest position and a dispensing position. The invention relates to a method of manufacturing a chamber insert (40) for selectively dispensing the contents of the metering chamber (20) by axially sliding between the chamber insert (40) and the valve (30), the valve (30) being urged towards its rest position by a spring (8) which cooperates with the valve body (10) on the one hand and with the valve (30) on the other hand, the upper edge (41) of the chamber insert (40) comprising an annular cutout (45) formed on the radial inner side of the upper edge (41) so that the width of the upper edge (41) in contact with the valve seal (21) is always the same regardless of the width of the cylindrical wall (49).

Description

Technical Field

[0001] The invention relates to a metering valve for a device for dispensing a fluid product. Background Art

[0002] So-called metering valves that dispense a specific dose of fluid each time the valve is actuated are well known in the art and are generally assembled on a reservoir containing the fluid and a propellant expelled to carry out the dose.

[0003] Two main types of metering valves are known. A holding valve comprises a valve which partially closes a metering chamber in the rest position. More precisely, the exterior of the valve cooperates in a sealing manner with a chamber seal of the metering chamber in such a way that, in this rest position, the metering chamber is connected to the reservoir only via an internal passage of the valve. A so-called non-priming valve comprises a metering chamber which, at rest, opens into the reservoir and which fills up upon actuation when the user returns the device to the inverted use position.

[0004] Depending on the product to be dispensed and / or the patient, the dose dispensed at each actuation may vary, for example, from 25 μl to 75 μl. One solution is to use an insert of approximately the same width in the metering chamber, depending on the desired volume. This solution has the disadvantage of changing the behavior of the valve seal resting on the insert, especially from the point of view of seal deformation and expansion.

[0005] Furthermore, about fifteen years ago, for ecological reasons, the previously used, generally CFC-based propellants were replaced by other propellants, namely the propellants HFA-134a and / or HFA-227. It turned out that such a change of propellant would impose different constraints on the seals, regardless of the level of sealing performance of the seals, in particular their swelling or removability when in contact with these new propellants. Therefore, the sealing materials that are usually used in conjunction with CFCs in aerosol valves cannot be simply applied to the new propellants HFA-134a and / or HFA-227. Therefore, this transition needs to take several years, especially with the development of new sealing materials.

[0006] Today, it has been shown that the gases HFA-134a and / or HFA-227 are also harmful to the environment and it is necessary to replace them with less environmentally harmful gases such as HFA-152a or HFO1234ze.

[0007] However, this substitution again changes the behavior of the sealing materials used today in metering valves and in particular increases the expansion of the seals. This can cause problems for reliable actuation of the valve, with possible clogging of the valve and involving greater actuation forces. The solution would be to develop new sealing materials specifically adapted to this new propellant, but past experience with substitution of CFC gases shows that this may take several years. The present invention, on the contrary, seeks to retain the same sealing materials and therefore proposes structural changes to the valve that are able to compensate for the expansion of the seals, while limiting as much as possible the changes to the production and assembly lines of the valve.

[0008] Documents WO2014096657, FR3042785 and FR2860502 describe prior art devices. Summary of the invention

[0009] The object of the present invention is to provide a metering valve which does not have the above-mentioned disadvantages.

[0010] It is therefore an object of the present invention to provide a metering valve which does not change the behavior of the valve seal regardless of the volume of the metering chamber.

[0011] Another object of the present invention is to provide a metering valve that ensures reliable operation with less hazardous gases, such as HFA-152a or HFO1234ze, without changing the sealing material.

[0012] A particular object of the invention is to provide a metering valve which is simple and inexpensive to manufacture and assemble and which is reliable in operation.

[0013] The object of the present invention is therefore a metering valve for dispensing a fluid product, the metering valve comprising a valve body containing a metering chamber, the metering chamber being defined by a chamber insert and two annular seals, namely a valve seal and a chamber seal, the chamber insert comprising a cylindrical wall, an upper edge cooperating with the valve seal and a lower edge cooperating with the chamber seal, the valve sliding axially in the valve body between a rest position and a dispensing position to selectively dispense the contents of the metering chamber, the valve being urged towards its rest position by a spring cooperating with the valve body on the one hand and with the valve on the other hand, the upper edge of the chamber insert comprising an annular cutout formed on the radially inner side of the upper edge in such a way that the width of the upper edge in contact with the valve seal is always the same, regardless of the width of the cylindrical wall.

[0014] Advantageously, the cross section of the annular cutout has a rectangular shape.

[0015] Advantageously, the lower edge of the chamber insert is extended radially inwardly by a flange which increases the contact surface with the chamber seal, the contact surface being always the same regardless of the width of the cylindrical wall.

[0016] Advantageously, the metering chamber has a variable volume defined by the radial width of the cylindrical wall, in particular between 25 μl and 75 μl.

[0017] Advantageously, the metering chamber has a volume of 50 μl.

[0018] Advantageously, the metering chamber has a volume of 28 μl.

[0019] Advantageously, the axial dimension of the annular cutout is less than 15%, advantageously less than 10%, of the axial dimension of the cylindrical wall.

[0020] Advantageously, the annular cutout has an axial dimension smaller than that of a radial shoulder of the valve which bears underneath the valve seal in the rest position of the valve.

[0021] Another object of the invention is a device for dispensing a fluid product, comprising a metering valve such as defined above, mounted on a reservoir containing the fluid product and a propellant.

[0022] Advantageously, the propellant comprises HFA-152a and / or HFO1234ze. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and other features and advantages of the invention will appear more clearly from the following detailed description given by way of non-limiting example and with reference to the accompanying drawings, in which:

[0024] Figure 1 is a schematic transverse cross-sectional view of the dispensing valve according to the first embodiment in the rest position of the valve, which is in the upright storage position of the valve;

[0025] Figure 2 According to the second embodiment Figure 1 A similar view showing the valve in its actuated position;

[0026] Figure 3 and Figure 4 yes Figure 1 and Figure 2 A vertical cross-sectional detailed view of the metering chamber of ; and

[0027] Figure 4 See also Figure 3 ;

[0028] Figure 5 and Figure 6 yes Figure 3 and Figure 4 A cutaway perspective detailed view of a metering chamber;

[0029] Figure 6 See also Figure 5 DETAILED DESCRIPTION

[0030] In the following description, the terms "top", "bottom", "lower", "upper" and "vertical" refer to Figure 1 The upright position indicated in the figure, and the terms "axial" and "radial" refer to the longitudinal center axis of the valve.

[0031] Figure 1 Represents the valve in an upright storage position, ie a position in which the valve is arranged above the reservoir. Figure 2 Indicates the valve in the actuated position. It must be noted that the normal position of use of this valve is the inverted position, in which the valve is arranged below the reservoir, but in this Figure 2 The valve is shown in the upright position to simplify the Figure 1 Comparison of the static positions.

[0032] Figure 1 The metering valve represented in comprises a valve body 10 extending along a longitudinal central axis and containing a metering chamber 20. This metering chamber 20 is defined in a well-known manner between two annular seals, namely a valve seal 21 and a chamber seal 22. This metering chamber 20 is filled with a dose of fluid product from a reservoir before or after each actuation.

[0033] Inside the valve body 10, the valve 30 is in a stationary position with Figure 2 slides between the dispensing positions shown, the resting position is Figure 1 In the position shown, the valve 30 has been pushed into the valve body 10 in this dispensing position.

[0034] This valve is intended to be assembled on a reservoir containing the fluid and the propellant, preferably with the aid of a fixing element 5, which may be a crimpable, screwable or snap-fastened capsule, and advantageously with the insertion of a neck seal 6. Possibly, a ring 4 may be assembled around the valve body 10, in particular in order to reduce the dead volume in the inverted position and in order to limit the contact between the fluid and the neck seal 6. This ring 4 may be of any shape and Figure 1 The examples in are not limiting. Typically, the reservoir contains a fluid product and a propellant, in particular a formulation consisting of one or more active ingredients suspended and / or dissolved in a liquefied propellant and possible excipients. The propellant preferably comprises HFA-152a. In a variant, other harmless gases such as HFO1234ze may be used.

[0035] The valve body 10 comprises a cylindrical portion 15 in which the spring 8 is arranged and in which the collar 320 slides between its rest position and its dispensing position. Figure 1 , this cylindrical portion 15 is the lower portion of the valve body. This cylindrical portion 15 comprises one or more longitudinal openings 11, such as slots, extending laterally in said cylindrical portion 15 of the valve body over a portion of its axial height in the direction of the longitudinal centre axis. These openings 11 make it possible to fill the metering chamber 20 after each actuation when the valve 30 is returned from its dispensing position to its rest position, in the inverted use position in which the valve is arranged below the reservoir.

[0036] The valve 30 is urged towards its rest position by a spring 8 arranged in the valve body 10 and which cooperates on the one hand with this valve body 10 and on the other hand with the valve 30, preferably with a radial collar 320 of the valve 30. A metering chamber 20 is defined inside the valve body 10, said valve 30 sliding inside said metering chamber 20 so as to enable its content to be dispensed when the valve is actuated.

[0037] In a known manner, the valve 30 may consist of two parts, namely an upper part 31 (also called valve top) and a lower part 32 (also called valve bottom).

[0038] The upper part 31 comprises a central axial passage 35 provided with an axial outlet hole 301 and a radial inlet passage 302 arranged in the metering chamber 20 when the valve 30 is in its dispensing position. The upper part 31 also comprises a radial shoulder at Figure 1 In the rest position shown in FIG. 2 , this radial shoulder bears under the valve seal 21 in a known manner.

[0039] In this embodiment, the lower part 32 is assembled inside the upper part 31 .

[0040] An internal channel 33 is provided in the valve 30, in particular in the bottom portion 32, which makes it possible to connect the metering chamber 20 to the reservoir so as to fill said metering chamber 20 after each actuation of the valve, when the valve 30 returns to its rest position under the action of the spring 8. The filling is performed while the device is still in its inverted use position, with the valve arranged below the reservoir.

[0041] exist Figure 1 In the example of , when the valve 30 is in the rest position, the metering chamber 20 outside the valve 30 is substantially isolated from the reservoir 1 by the cooperation between the bottom part 32 of the valve 30 and the chamber seal 22. In this rest position, the metering chamber 20 therefore remains connected to the reservoir 1 only via the internal passage 33. Therefore, Figure 1 and Figure 2 The valve shown in Figure 1 is a holding valve. However, the present invention is also applicable to other types of valves, in particular non-starting types.

[0042] Advantageously, the pump body 10 comprises, at its lower axial edge, an axial profile 16 which projects upwards to define the actuation position of the valve by cooperating with the lower edge of the valve 30. This implementation ensures a precise and consistent definition of this actuation position for each actuation, independently of the compression of the spring 8. In addition, it makes it possible to relax the spring 8, which makes it possible to increase its service life.

[0043] This axial profile 16 can advantageously be made in the form of a sleeve offset radially inwards from the cylindrical portion 15, as in Figure 1 This particular implementation makes it possible to form a receiving space for the spring 8 between the sleeve 16 and the cylindrical portion 15, thus making it possible to guide the spring 8 and keep it in a repeatable position, thus limiting the risk of tilting the valve 30. It must be noted that Figure 1 This protruding contour 16 shown in FIG. 1 is not essential for the operation of the valve and it can be realized independently of the structure of the metering chamber.

[0044] The volume of the metering chamber 20 is defined by means of a substantially cylindrical chamber insert 40, wherein the cylindrical wall 49 has a roughly equal radial thickness, depending on the desired volume. Thus, it is primarily this cylindrical wall 49 that defines the volume of the metering chamber 20. This volume can advantageously vary between 25 μl and 75 μl. Thus, in the illustrated metering chamber 20 having a volume of 50 μl, the volume of the metering chamber 20 is 50 μl. Figure 3 and Figure 5 In the example of FIG. 1 , the radial width of the cylindrical wall 49 is greater than that of the metering chamber 20 having a volume of 28 μl. Figure 4 and Figure 6 is smaller in the example.

[0045] The valve seal 21 rests on an upper edge 41 of the chamber insert 40, and the chamber seal 22 is in contact with a lower edge 43 of the chamber insert 40. The upper edge 41 advantageously comprises a protruding profile 42 penetrating the valve seal 21, and the lower edge 43 advantageously comprises a protruding profile 44 penetrating the chamber seal 22. Advantageously, the lower edge 43 is extended radially inwardly by a flange 46 which increases the contact surface with the chamber seal 22.

[0046] According to the invention, the upper edge 41 of the chamber insert 40 comprises an annular cutout 45 formed on the radially inner side of said upper edge 41, the cross section of which is preferably rectangular. Thus, the upper edge 41 in contact with the valve seal 21 always has the same width, regardless of the width of the cylindrical wall 49. Thus, the positioning of the valve seal 21 on the chamber insert 40 is always the same, regardless of the width of the cylindrical wall 49 and thus the volume of the metering chamber 20. The cutout 45 will have a width that is more or less large, depending on the width of the cylindrical wall 49. Thus, the behavior of the valve seal 21 will always be the same, regardless of the volume of the metering chamber 20.

[0047] As can be seen in the figure, the axial dimension of this annular cutout 45 is relatively small. Therefore, the annular cutout 45 is formed only at the upper edge 41 and does not extend significantly axially in the metering chamber. Therefore, this annular cutout 45 has almost no effect on the volume of the metering chamber 20 defined by the radial dimension of the cylindrical wall 49. In particular, the axial dimension of the annular cutout 45 is less than 15%, advantageously less than 10%, of the axial dimension of the cylindrical wall 49. Likewise, the axial dimension of the annular cutout 45 is less than the axial dimension of the radial shoulder of the top portion 31 of the valve 30, as can be seen in FIG. Figure 1 , Figure 3 and Figure 4 It can be seen in.

[0048] The presence of the cutout 45 further makes it possible to absorb and compensate for deformations of the valve seal 21 , in particular the expansion of its upper part when in contact with the gas HFA-152a or HFO1234ze relative to the conventional gases HFA-134a and / or HFA-227.

[0049] Advantageously, in the variant with the flange 46, the lower edge 43 and said flange 46 together form a contact surface with the chamber seal 22 which is always the same, regardless of the width of the cylindrical wall 49. Therefore, the positioning of the chamber seal 22 on the chamber insert 40 is always the same, regardless of the width of the cylindrical wall 49 and thus the volume of the metering chamber 20. Therefore, the behavior of the chamber seal 22 will always be the same, regardless of the volume of the metering chamber 20.

[0050] Although the invention has been described with reference to two specific embodiments thereof, it should be understood that the invention is not limited to the examples shown. On the contrary, any useful modifications may be made thereto by a person skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

1. A metering valve for dispensing a fluid product, the metering valve comprising a valve body (10) containing a metering chamber (20), the metering chamber (20) being defined by a chamber insert (40) and two annular seals, a valve seal (21) and a chamber seal (22), the chamber insert (40) comprising a cylindrical wall (49), an upper edge (41) cooperating with the valve seal (21) and a lower edge (43) cooperating with the chamber seal (22), a valve (30) in the valve body (10) sliding axially between a rest position and a dispensing position for selectively dispensing the contents of the metering chamber (20), the valve (30) being urged towards its rest position by a spring (8) cooperating with the valve body (10) on the one hand and with the valve (30) on the other hand, characterized in that The metering chamber (20) has a variable volume defined by the radial width of the cylindrical wall (49), the upper edge (41) of the chamber insert (40) includes an annular cutout (45) formed on the radial inner side of the upper edge (41), so that regardless of the width of the cylindrical wall (49), the width of the upper edge (41) in contact with the valve seal (21) is always the same, wherein the valve body includes an axial profile at its lower axial edge, the axial profile protruding upward to define the actuated position of the valve by cooperating with the lower edge of the valve.

2. The metering valve according to claim 1, wherein the cross section of the annular cutout (45) is rectangular.

3. A metering valve according to claim 1 or claim 2, wherein the lower edge (43) of the chamber insert (40) is extended radially inwardly by a flange (46), which increases the contact surface with the chamber seal (22), which contact surface is always the same regardless of the width of the cylindrical wall (49).

4. The metering valve according to claim 1, wherein the metering chamber (20) has a variable volume between 25 μl and 75 μl.

5. The metering valve according to claim 4, wherein the metering chamber has a volume of 50 μl.

6. The metering valve according to claim 4, wherein the metering chamber has a volume of 28 μl.

7. A metering valve according to claim 1 or claim 2, wherein the axial dimension of the annular cutout (45) is less than 15% of the axial dimension of the cylindrical wall (49).

8. The metering valve according to claim 7, wherein the axial dimension of the annular cutout (45) is less than 10% of the axial dimension of the cylindrical wall (49).

9. A metering valve according to claim 1 or claim 2, wherein the axial dimension of the annular cutout (45) is smaller than the axial dimension of a radial shoulder of the valve (30) which bears beneath the valve seal (21) in the rest position of the valve (30).

10. A device for dispensing a fluid product, characterized in that: The device comprises a metering valve according to any one of the preceding claims, mounted on a reservoir containing the fluid product and the propellant.

11. The device of claim 10, wherein the propellant comprises HFA-152a and / or HFO1234ze.

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