Patent Application
20220274770
The invention relates to a valve for pressurized container, comprising:
the valve body being fixed to the inner face of the cup.
Valves according to the preamble are commonly used for pressurized containers, in particular for aerosol dispensers. A valve body is fixed to a cup, forming an internal chamber in which are located a spring, a seal, and between the two, at least a portion of the valve member. The spring pushes the valve member against the seal so that the valve is closed. To insert the seal, the spring and the valve member, it is essential to have an opening for access before final assembly. Traditionally, the cup is crimped on the top of the valve body, which for this purpose is provided with an annular extra thickness at its top. This method works very well when the cup is metallic. However, the current trend is to eliminate metal parts and replace them with plastic whenever possible, in order to facilitate recycling of aerosol dispensers. Valves are therefore known in which the cup too is made of plastic.
In this case, it is possible to have a single-piece unit constituted by the valve body and the cup, the internal space then being closed by a washer welded from above. Such a valve is known from document WO 2016/202754 A1, for example. The drawback of this solution lies in the fact that, if the weld between the washer and the cup were defective, the washer could come off and be forcefully expelled, at the risk of injuring its user.
In other variants, the valve body is fixed to the cup by snap-fastening. As an example, document FR 2 508 136 A1 can be cited. This requires more complex molds to make, on the one hand, the snap-fastening tabs on the cup or the valve body, and on the other hand, the corresponding recesses on the other part. In addition, the parts must be oversized to take into account the height of the fixation.
The objective of the invention is to remedy these drawbacks.
This objective is achieved by the fact that the valve seal is pressed against the cup while surrounding the central opening, and by the fact that the valve body is fixed to the inner face of the cup by welding. This solution makes it possible to have parts that are easier to manufacture. In addition, no part can be expelled towards the user in the event of a faulty fixation of the valve body on the cup.
In order to facilitate welding of the valve body to the cup, it is preferable that the inner face of the cup and the valve body are made of plastic material, preferably polypropylene (PP) or another polyolefin. For the assembly to succeed, it is sufficient for the materials chosen for one of the parts to be compatible with that of the other part.
In order for the cup to have greater rigidity, it can be constituted by at least one metallic outer layer, preferably aluminum or tinplate, and by an inner layer in plastic material, preferably polypropylene (PP) or another polyolefin.
The valve body can comprise a tubular body provided with
The valve body can be welded to a flat portion of the cup which extends beyond the valve body. The cup can also have a domed shape so that its inner face or its outer face has a generally convex shape. In both cases, the edge of the central opening can be folded upright, in particular folded upright on the side of the outer face. Such a cup that is flat at least at the valve body, or slightly convex, can be chosen, for example, if the cup will contain at least one metallic layer. The upright-folded edge helps to reinforce the cup.
In another variant embodiment, the central opening of the cup is made in a bottom wall of a cylindrical well, the valve seal being placed against the bottom wall of the cylindrical well. The benefit of a well can be to raise the central opening relative to the peripheral edge that serves to fix the valve on the can. It can also make it possible to place reinforcing ribs on the outer face of the cup, in contact with the outer face of the cylindrical well. Reinforcing ribs can be provided on at least one face of the cup, even when the central opening of the cup is not made in a bottom wall.
When the valve body has a tapered edge and the central opening of the cup is located at the bottom of a well, it is preferable that the end of the valve body provided with the tapered edge penetrates in the cylindrical well. Depending on needs, the weld can be made either between the fixing crown introduced into the well and the bottom wall of the well, or between the fixing crown wider than the well and a peripheral section of the cup which surrounds the well. It is also possible to envision welding the side walls of the valve body and of the well to each other.
In another variant of a cup with the central opening placed at the bottom of a well, the valve body can comprise a tubular body provided with a fixing crown by which the valve body is welded to the cup, with the valve body being placed completely outside the well, the weld being made between the fixing crown wider than the well and a peripheral section of the cup which surrounds the well.
The invention also relates to a method of manufacturing a valve according to the invention. This process provides the following steps:
The invention is described in more detail below with the aid of the figures which show:
The invention relates to a valve (1) for a pressurized container. The valve (1) is constituted mainly by:
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 directed upwards. The references “top”/“bottom” or “upper”/“lower” have only a relative value in relation to the representations of the accompanying figures. It is self-evident that the valve can be used in all positions and that what is up in the position shown here will not necessarily be so during use. Further, the valve extends longitudinally with respect to a main axis (A), which is vertical in the representations of the accompanying figures. The terms “radial”, “axial” and “transverse” refer to this main axis (A).
As with any valve with cup, the cup (50) forms a separation between the side of the valve intended to be placed inside the can and the other side intended to be outside the can. The terms “inner” and “outer” refer to the elements located on the inner side or on the outer side of the cup. The terms “internal” and “external” refer to a specific component (in particular the valve body) and define what is inside or outside said component, regardless of whether it is a component located on the inner or outer face of the cup.
The example presented here is a male type valve having as valve member a stem (30), of which a portion of the rod protrudes out of the valve. The invention can also be applied to a female type valve having as valve member a valve seat located in the valve body and requiring actuation by an outer rod (generally, that of an actuator) penetrating into the valve.
The valve body (10) is formed mainly by a tubular body (11) partially closed at a first 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) can be provided in the bottom of the internal chamber, near the bottom wall. These ribs protrude radially from the tubular body towards the center of the internal chamber, forming a receiving space in which a first end of the spring (20) can be received and retained radially. A fixing tenon (14) can be provided on the external face of the bottom wall (12) for fixing, for example, a dip tube or anti-collapsing means. This tenon (14) has a tubular shape and surrounds the inlet opening (121).
At least one opening (112) can be provided in the tubular body (11), which opening forms a passage bringing the external face and the internal face of the tubular body in contact. This opening, which is not required, serves as an additional gas inlet to improve the quality of the spraying.
The second end of the tubular body (11) ends with a tapered edge (111). It is surrounded by a fixing crown (15) which is constituted by 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 crenellated if it is not necessary to ensure sealing between the two faces of this transverse wall. The annular edge surface (upper face) (152) of the fixing crown (15) is preferably 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 cup. In the example presented here, there are two rings of extra thickness of material (152a, 152b).
The cup (50) is constituted by a plate provided with
The rod can be carried by a valve member to be inserted at least partially into the valve body (thus, by a stem) if it is a valve of the male type, or by an actuator intended to actuate the valve if it is a female type valve.
The cup can be made entirely in plastic material. It is also possible that it is constituted, as in the present example, by a metallic outer layer (53) and an inner layer (54) in plastic material. The edge (521) of the central opening (52) can be folded upright, in particular on the side of the outer face.
The stem (30) has a usual shape. It is formed by a cylindrical wall (31) open at its upper end (311) and closed at its lower end, forming an outlet channel for the product. One or more orifices (312) placed at the bottom of the outlet channel pass radially through the cylindrical wall to bring the internal face and the external face of said cylindrical wall (31) in contact. The cylindrical wall (31) constitutes the product outlet rod. This cylindrical wall is continued by a crown (32) of larger diameter having on its external face vertical channels or vertical ribs allowing the product to bypass the crown. The outer envelope of this crown has a diameter slightly smaller than the internal diameter of the tubular body (11) of the valve body so that it can enter into the latter while being guided. On its upper annular face, the crown (32) is provided with a sealing rib (321) to ensure sealing with the valve seal (40). The crown (32) is continued downwards by a guiding tenon (33) intended to cooperate with the second end of the spring (20).
The valve seal (40) is also a classic part. It is an annular seal, the internal diameter of which is chosen to fit tightly and sealingly around 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 sealingly against the valve seal (40). In the present example, the valve seal takes place in the space delimited, on the one hand, by the internal face of the fixing crown, and on the other hand, by the transverse wall (151).
The spring is caught between the bottom wall (12) of the valve body and the guiding tenon (33) of the stem.
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, on the one hand, it obstructs the orifices (312) of the stem, and on the other hand, it bears sealingly against the sealing rib (321). The stem/seal assembly is inserted into the valve body by the guiding tenon (33) so that the latter (33) penetrates into 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 closer to the valve body until the annular edge surface (152) contacts the inner face (54) of the cup. In this position, the valve seal (40) bears sealingly against the tapered edge (111). All that remains is to weld the cup and the valve body to each other at the annular edge surface (152). This weld can be made by any suitable means, and in particular by ultrasonic welding or by spin welding.
In the example presented here, the cup is substantially planar at the location of the valve body and around the valve body. The height of the internal face of the fixing crown is substantially identical to the thickness of the valve seal (40). The tapered edge (111) helps to press the seal in a sealed manner against the inner face of the cup. Sealing between the cup (50) and the valve body (10) is therefore ensured by the valve seal being squeezed 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 fixing crown and the cup therefore does not need to be sealed. It must only 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 therefore would be possible for the weld not to be continuous.
It would also be possible for the cup not to be flat, and in particular, for the central opening (52) to be on a bottom wall of a well in which at least a portion of the crown (32) of the stem penetrates.
In a first variant embodiment, the upper portion of the valve body with the tapered edge (111) and the fixing crown (15) also penetrates in the well. Welding between the valve body (10) and the cup is performed at the bottom wall of the well. The fixing crown (15) remains at the top of the tubular body, as in the present example, and it is dimensioned to penetrate into the well. It could also be envisaged to weld the cylindrical side walls of the valve body and of the well.
In a second variant embodiment, the weld is made at a peripheral section of the cup which surrounds the well. In this case, only the upper portion of the tubular body (11) with the tapered edge (111) penetrates in the well, whereas the fixing crown, which is wider than the well, is placed lower than the tapered edge.
In a third variant embodiment, 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 keep it pressed against the inner face of the cup. The valve body does not penetrate in the well. The well plays the role of the upper portion of the valve body and the valve body itself can be shorter. The fixing crown, which is wider than the well, remains at the top of the valve body. As in the second variant, the weld is made at a peripheral section of the cup which surrounds the well. Welding of the valve body can then be carried out in a sealed manner. If the weld is not sealed, it is also possible to keep a tapered edge, as in the example presented here, and to interpose a second seal between the peripheral section and the tapered edge.
The cup can be reinforced so that it better withstands the pressure within the aerosol dispenser. In the present example, insofar the outer layer (53) is metallic, it can be sufficient to give a concave shape to the outer face (53) of the cup, and a convex shape to the inner face (54). Such a measure can prove to be insufficient, in particular when the cup is made exclusively of plastic material. In this case, vertical and radial reinforcing ribs can be provided on at least one of the faces of the cup, in particular on the outer face (53). When the cup includes a well, it is possible to place reinforcing ribs much higher and more effective than when the cup is simply domed as in the present example.
The valve body and the cup must be compatible to allow the valve body to be welded to the cup. For example, polypropylene, or other polyolefins, can be chosen for the valve body and for the cup or the plastic material layer of the cup. The valve body and the cup are not necessarily made in the same plastic material.
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 side of the inner face of the cup and none is dimensioned to pass through the central opening. The weld between the valve body and the cup is not subjected to any tensile force. It therefore does not need to be particularly resistant.
| Number | Date | Country | Kind |
|---|---|---|---|
| FR 1908421 | Jul 2019 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/069713 | 7/13/2020 | WO |
