DIFFUSER FOR PRESSURE VESSEL

Description

[0001] The invention relates to a valve for a container according to the preamble of claim 1.

[0002] Valves generally consist of a body and a cup. The valve body is attached to the cup, forming an internal chamber containing a spring, a seal, and at least part of the valve itself. The spring pushes the valve against the seal, thus closing the valve. An access opening is essential for inserting the seal, spring, and valve before final assembly. Traditionally, the cup is crimped onto the top of the valve body, which has a ring-shaped protrusion at its apex for this purpose. This method works well when the cup is made of metal. However, the current trend is to eliminate metal parts and replace them with plastic whenever possible to facilitate the recycling of aerosol generators. Therefore, some valves exist in which the cup is also made of plastic.

[0003] In this case, it is possible to have a single-piece assembly consisting of the valve body and the cup, with the internal space then closed by a washer welded from above. Such a valve is shown, for example, in document WO 2016 / 202754 A1. The drawback of this solution is that if the weld between the washer and the cup were defective, the washer could detach and be forcefully ejected, potentially injuring the user.

[0004] In other variations, the valve body is attached to the cup by snap-fitting. For example, see document FR 2 508 136 A1. This requires more complex molds to produce both the snap-fit ​​tabs on the cup or valve body and the corresponding recesses on the other part. Furthermore, the parts must be oversized to accommodate the height of the attachment.

[0005] Document EP 0 108 550 A2 describes a valve in which the valve body is welded to the cup, with the valve seal positioned in a recess in the cup. Sealing is achieved only at the interface between the valve and the valve seal.

[0006] US document 3,741,446 A describes another example of an anterior art valve.

[0007] The objective of the invention is to remedy these drawbacks.

[0008] This objective is achieved with a valve according to claim 1.

[0009] To facilitate welding the valve body to the cup, it is preferable that the inner face of the cup and the valve body be made of plastic, preferably polypropylene (PP) or another polyolefin. For the assembly to function correctly, the materials used for one part must be compatible with those of the other.

[0010] In order to give the cup greater rigidity, it consists of at least one outer metallic layer, preferably aluminum or tinplate, and an inner layer of plastic material, preferably polypropylene (PP) or another polyolefin.

[0011] According to the invention, the valve body comprises a tubular body equipped at one end of an annular tapered edge, which tapered edge is in tight contact against the valve seal by surrounding the central opening, as well as a fixing ring by which the valve body is welded to the cup.

[0012] According to the invention, the central opening of the cup is formed in the bottom wall of a cylindrical well, with the valve seal positioned against the bottom wall of the cylindrical well. The advantage of a well is that it allows the central opening to be raised relative to the peripheral edge used to secure the valve to the housing. It also allows for the placement of reinforcing ribs on the outer face of the cup, in contact with the outer face of the cylindrical well.

[0013] The end of the valve body with the tapered edge penetrates the cylindrical well. The weld is made between the fixing ring inserted into the well and the bottom wall of the well.

[0014] The invention also relates to a method for manufacturing a valve according to the invention. This method comprises the following steps: The spring is placed in the bottom of the valve body; the valve seal is mounted on the valve stem; the valve / seal assembly is inserted into the valve body so that the lower end of the valve rests against the spring; the cup is then put in place, passing the free end of the valve stem through the central opening of the cup when the valve is of the stem type for a male valve, then the cup is brought close to the valve body until the valve body is in contact with the inner face of the cup; the cup and the valve body are welded, preferably by ultrasonic welding or by rotational welding.

[0015] The invention is described in more detail below with the aid of the figures which show: Fig. 1 : an exploded cross-sectional view of a valve according to an embodiment not covered by the text of the claims; Fig. 2 : a cross-sectional view of the valve of the figure 1 ; Fig. 3 : a cross-sectional and perspective view (a) of the valve body of the valve figure 1 , and (b) of the stem; Fig. 4 : a cross-sectional and perspective view of the valve cup of the figure 1 .

[0016] The invention relates to a valve (1) for a pressure vessel. The valve (1) is mainly composed of: of a cup (50) and a valve body (10) in which are placed: a spring (20), a valve having here the shape of a stem (30) and a valve seal (40).

[0017] The valve (1) of the invention can be used in all positions. In the figures illustrating this application, the valve is shown with the stem pointing upwards. The references "up" / "down" or "upper" / "lower" have only a relative value with respect to the representations in the accompanying figures. It is understood that the valve can be used in all positions and that what is at the top in the position shown here will not necessarily be so in use. Furthermore, the valve extends longitudinally with respect to a principal axis (A), which is vertical in the representations in the accompanying figures. The terms "radial," "axial," and "transverse" refer to this principal axis (A).

[0018] As with any cup-type valve, the cup (50) forms a partition between the side of the valve intended to be placed inside the housing and the other side intended to be outside the housing. The terms "inside" and "outside" refer to the elements located on the inside or outside of the cup. The terms "internal" and "external" refer to a particular component (in particular the valve body) and define what is inside or outside that component, regardless of whether it is located on the inside or outside face of the cup.

[0019] The example presented here is a male-type valve having a stem (30) as its valve, a portion of whose stem protrudes from the valve. The invention can also be applied to a female-type valve having a seat as its valve, located in the valve body and actuated by an external stem (generally that of a diffuser) penetrating the valve.

[0020] The valve body (10) consists primarily of a tubular body (11) partially closed at one end, called the lower end, by a bottom wall (12) having an inlet opening (121). The tubular body (11) and the bottom wall (12) together define an internal chamber (13). Vertical ribs (131) may be provided in the bottom of the internal chamber, near the bottom wall. These ribs project radially from the tubular body towards the center of the internal chamber, forming a receiving space in which one end of the spring (20) can be received and retained radially. A retaining lug (14) may be provided on the outer face of the bottom wall (12) for attaching, for example, a dip tube or anti-sag means. This lug (14) is tubular in shape and surrounds the inlet opening (121).

[0021] At least one opening (112) may be provided in the tubular body (11), which opening forms a passage connecting the outer and inner faces of the tubular body. This opening, which is not mandatory, serves as an additional gas intake to improve the quality of the spraying.

[0022] The second end of the tubular body (11) terminates in a tapered edge (111). It is surrounded by a retaining ring (15) which consists of a tubular wall connected to the second end of the tubular body by a transverse wall (151). This transverse wall is, for example, parallel to a plane perpendicular to the main axis (A). It can be solid, as in the present example, or serrated if it is not necessary to ensure a seal between the two faces of this transverse wall. The annular edge (upper face) (152) of the retaining ring (15) is preferably provided with at least one excess material extending completely around the ring and serving as an energy director during the ultrasonic welding of the valve body to the cup. In the example shown here, there are two rings of excess material (152a, 152b).

[0023] The cup (50) consists of a plate equipped of a peripheral edge (51) intended for fixing the cup to a housing not shown, and of a central opening (52) through which passes a product outlet rod.

[0024] The stem can be carried by a valve to be inserted at least partially into the valve body (i.e. by a stem) if it is a male type valve, or by a diffuser intended to actuate the valve if it is a female type valve.

[0025] The cup can be made entirely of plastic. As in the present example, it consists of an outer metallic layer (53) and an inner plastic layer (54). The edge (521) of the central opening (52) can be straightened, particularly on the outer face.

[0026] The stem (30) is of a common shape. It consists of a cylindrical wall (31) open at its upper end (311) and closed at its lower end, forming a product outlet channel. One or more orifices (312) located at the bottom of the outlet channel pass radially through the cylindrical wall to bring the inner and outer faces of said cylindrical wall (31) into contact. The cylindrical wall (31) constitutes the product outlet stem. This cylindrical wall continues as a ring (32) of larger diameter, having vertical channels or ribs on its outer face to allow the product to flow around the ring. The outer shell of this ring has a diameter slightly smaller than the inner diameter of the tubular body (11) of the valve body so that it can enter the valve while being guided.On its upper annular face, the crown (32) is provided with a sealing rib (321) to ensure a seal with the valve seal (40). The crown (32) continues downwards with a guide tenon (33) intended to cooperate with the second end of the spring (20).

[0027] The valve seal (40) is also a conventional component. It is an annular seal whose internal diameter is chosen to tightly enclose the cylindrical wall (31) of the stem. The external diameter is chosen so that the entire tapered edge (111) of the tubular body of the valve body can bear tightly against the valve seal (40). In this example, the valve seal is positioned within the space defined on one side by the inner face of the retaining ring and on the other by the transverse wall (151).

[0028] The spring is wedged between the bottom wall (12) of the valve body and the guide pin (33) of the stem.

[0029] The valve of the invention is assembled as follows. The spring (20) is placed in the bottom of the internal chamber (13) with its first end located between the vertical ribs (131). The valve seal (40) is mounted on the stem (30) so that it closes the orifices (312) of the stem and also makes a tight seal against the sealing rib (321). The stem / seal assembly is inserted into the valve body by means of the guide pin (33) so that the latter (33) penetrates the second end of the spring (20). The cup is then put in place by passing the free end of the stem through the central opening (52). The cup is brought close to the valve body until the annular edge (152) is in contact with the inner face (54) of the cup. In this position, the valve seal (40) is in a tight contact against the tapered edge (111).All that remains is to weld the cup and the valve body at the annular edge (152). This welding can be carried out by any suitable means, and in particular by ultrasonic welding or by rotational welding.

[0030] In the example not covered by the text of the claims presented here, the cup is substantially flat at and around the valve body. The height of the inner face of the retaining ring is substantially the same as the thickness of the valve seal (40). The tapered edge (111) helps to press the seal tightly against the inner face of the cup. The seal between the cup (50) and the valve body (10) is thus ensured by the valve seal being pressed against the inner face (54) of the cup by the tapered edge (111), forming an annular seal all around the central opening (52). The weld at the interface between the retaining ring and the cup therefore does not need to be leak-proof. It only needs to hold the valve body against the cup against the effect of the spring (20) and ensure that the valve seal (40) is properly pressed against the inner face (54) of the cup.It is therefore possible that the weld is not continuous.

[0031] According to the invention, the central opening (52) is located on a bottom wall of a well into which at least part of the crown (32) of the stem penetrates.

[0032] The upper portion of the valve body, with its tapered edge (111) and retaining ring (15), also extends into the well. The weld between the valve body (10) and the cup is made at the bottom wall of the well. The retaining ring (15) remains at the top of the tubular body, as in this example, and is sized to extend into the well. Alternatively, the cylindrical side walls of the valve body and the well could be welded together.

[0033] In a second embodiment not covered by the text of the claims, the weld is made at a peripheral section of the cup surrounding the well. In this case, only the upper part of the tubular body (11) with the tapered edge (111) penetrates the well, while the retaining ring, which is wider than the well, is positioned lower than the tapered edge.

[0034] In a third embodiment not covered by the claims, the valve seal (40) is fixed to the bottom wall of the well, for example by overmolding. In this case, it is no longer necessary for a tapered edge of the valve body to hold it against the inner face of the cup. The valve body does not penetrate the well. The well acts as the upper part of the valve body, and the valve body itself can be shorter. The retaining ring, wider than the well, remains at the top of the valve body. As in the second embodiment, the weld is made at a peripheral section of the cup surrounding the well. The weld of the valve body can then be made leak-proof. If the weld is not leak-proof, it is also possible to retain a tapered edge as in the example shown here and to interpose a second seal between the peripheral section and the tapered edge.

[0035] The cup can be reinforced to better withstand the pressure inside the aerosol generator. In this example, since the outer layer (53) is metallic, it is sufficient to give the outer face (53) of the cup a concave shape and the inner face (54) a convex shape. Such a measure may prove insufficient, particularly when the cup is made entirely of plastic. In this case, vertical and radial reinforcing ribs can be provided on at least one face of the cup, specifically on the outer face (53). When the cup has a well, it is possible to place reinforcing ribs that are much taller and more effective than when the cup is simply domed.

[0036] The valve body and the cup must be compatible to allow the valve body to be welded to the cup. Polypropylene, or other polyolefins, are suitable materials for both the valve body and the plastic layer of the cup. The valve body and the cup do not necessarily have to be made of the same plastic.

[0037] The advantage of the valve according to the invention lies in the fact that no part can be ejected from the valve. Indeed, all the parts are located on the inner face of the cup, and none are designed to pass through the central opening. The weld between the valve body and the cup is not subjected to any tensile stress. It therefore does not need to be particularly strong. List of References

[0038] 1 Valve according to the invention 10 Valve body 11 Tubular body 111 Tapered edge 112 Passage opening 12 Bottom wall 121 Inlet opening 13 Internal chamber 131 Vertical ribs 14 Tenon 15 Fixing ring 151 Transverse wall 152 Annular slice of the fixing ring 152a Weld overhang 152b Weld overhang 20 Spring 30 Stem 31 Cylindrical wall 311 Lower end 312 Orifices 32 Ring 321 Sealing rib 33 Spring guide tenon 40 Valve seal 50 Cup 51 Peripheral edge 52 Central opening 521 Reinforcing edge 53 Metallic outer layer 54 Plastic inner layer AA Main shaft

Claims

1. Valve (1) for pressurized container, comprising: - a valve body (10) in which are placed: • a spring (20), • a valve member (30), and • a valve seal (40), as well as - a valve cup (50) having an outer face (53) and an inner face (54) and being provided with a central opening (52) through which an outlet rod (31) for the product can pass, the valve body (10) being fixed to the inner face (54) of the valve cup (50) by welding, the valve seal (40) being pressed against the valve cup while surrounding the central opening (52), the valve body comprising a tubular body (11) provided with a fixing crown (15) by which the valve body is welded to the valve cup, the central opening (52) of the valve cup being made in a bottom wall of a cylindrical well having a lateral wall, wherein the valve seal being placed against the bottom wall of the cylindrical well, the weld being made between the fixing crown (15) introduced into the well and the bottom wall of the well, the tubular body (11) of the valve body being provided at one end with an annular tapered edge (111) which bears sealingly against the valve seal (40) while surrounding the central opening (52), the valve cup being provided with a peripheral edge (51) intended for fixing the valve cup to a can, the lateral wall or the cylindrical well having an outer face that is part of the outer surface of the valve cup characterized in that the valve cup is constituted by at least one metallic outer layer (53) and by an inner layer (54) in plastic material, and the outer face of the valve cup is concave, and the inner face of the valve cup is convex to withstand the pressure in effect within the aerosol generator.

2. Valve (1) according to claim 1, characterized in that the annular upper face (152) of the fixing crown (15) is provided with at least one extra thickness of material that extends all around the crown and serves as energy director during ultrasonic welding of the valve body on the valve cup.

3. Valve (1) according to one of claims 1 or 2, characterized in that the inner face (54) of the valve cup is made of polypropylene or another polyolefin, and / or in that the valve body is made of plastic material, preferably polypropylene or another polyolefin, and / or the metallic outer layer (53) is made of aluminum or tinplate.

4. Valve (1) according to claim 1 or to claim 3 associated with claim 1, characterized in that the weld is not continuous, so it is not leak-proof.

5. Valve (1) according to one of the preceding claims, characterized in that reinforcing ribs are provided on at least one face of the valve cup.

6. Valve (1) according to claim 5, characterized in that the reinforcing ribs are provided on the outer face of the valve cup and are in contact with the outer face of the cylindrical well.

7. Method for manufacturing a valve according to one of the preceding claims, characterized by the following steps: - the spring (20) is placed in the bottom of the valve body (10); - the valve seal (40) is mounted on the rod of the valve member (30), or the valve seal is placed against the bottom wall of the cylindrical well while surrounding the central opening of the valve cup; - the valve member or the valve member / seal assembly is inserted into the valve body so that the lower end (33) of the valve member bears against the spring (20); - the valve cup is then put in place, following which the valve cup is brought closer to the valve body until the valve body (10) is in contact with the inner face (54) of the valve cup and the annular tapered edge (111) of the valve body bears sealingly against the valve seal (40) placed against the bottom wall of the cylindrical well while surrounding the central opening (52) of the valve cup; - the valve cup and the fixing crown of the valve body are welded, preferably by ultrasonic welding or by spin welding, wherein the weld is made between the fixing crown (15) inserted into the well and the bottom wall of the well.

8. Method according to claim 7, characterized in that during positioning of the valve cup on a male type valve, the free end of the rod of the valve member is passed through the central opening of the valve cup (50) before bringing the valve cup closer to the valve body.