ES2713421T3 - Fastening ring of a bag in a pressure dispenser and pressurization procedure of a pressure dispenser provided with such a bag - Google Patents

Abstract

Fixing ring (3a; 3b) for a pressure dispenser consisting of a container provided with a mouth (11), a valve mounted on a cup provided with a peripheral edge (231) and a fixing ring on which it is a bag is fixed, said fixing ring being provided with a central part (31) having an outer face designed for fixing a bag (4) and whose cross section is inferior to the mouth (11) of the container for which it is intended for the ring and a collar (32) for fixing the ring between the edge of the mouth (11) of the container and the peripheral edge (231) of the valve cup and / or to ensure the tightness between the ring and the cup and / or between the ring and the edge of the mouth (11) of the container, the diameter of the collar (32) being greater than the diameter of the mouth (11) of the container for which the ring is intended, characterized in that the ring is provided with a connecting part (33) sit between the central part (31) and the collar (32) and on whose outer face at least one passage (361) has been made, the step (361) not extending beyond said connecting part and being sized to that, when the ring is placed in the mouth (11) of a container with its or its steps located at the height of the edge of the mouth (11) of the container, the step (s) extend to one side and another of the edge of the mouth (11) and each form a path that contacts the part of the outer face of the ring located outside the container and the part of the outer face of the ring located inside the container.

Description

DESCRIPTION

Ring for fixing a bag in a pressure dispenser and pressurizing procedure for a pressure dispenser provided with such a bag

The invention relates to a fastening ring for a pressurized dispenser, as well as to a pressurization process for a pressurized dispenser provided with a ring according to the invention. The pressure dispensers for which the ring of the invention is intended are constituted by a container, by a valve mounted on a cup and by a fixing ring on which a bag is fixed. The fixing ring is provided with a central part having an outer face designed for fixing a bag and whose cross section is lower than the section of the mouth of the container for which the ring is intended and a collar for fixing of the ring between the rim of the mouth of the container and the peripheral edge of the cup of the valve and / or to ensure the sealing between the ring and the cup and / or between the ring and the rim of the mouth of the container, the collar diameter greater than the diameter of the mouth of the container for which the ring is intended.

There are several ways to pressurize a pressurized dispenser depending on whether the valve is a metering valve or a simple valve, whether the product to be conditioned is viscous or not and whether it is in a bag or directly in the container.

Initially, the propellant gas was introduced through an opening made in the bottom of the container that already contained the product to be conditioned. After pressurization, the opening was closed with a small plug called "plug". This technique is still used in certain cases, but other methods have been developed. In the case of a low-viscous product stored in a bag protected from the propellant gas, it is common to put the bag valve in the container first, lift the cup to introduce the propellant gas into the container through the slot located between the peripheral edge of the cup and the wound edge of the container neck. Then, the cup is fixed on the container by flapping or crimping. Finally, the bag is filled with the product to be conditioned making it penetrate through the valve. If the product to be conditioned is not placed in a bag, it is possible to introduce the product first, position the valve on the container, add the propellant gas through the slit created by raising the valve and then flare or crimp the valve. The propellant gas can also be added through the valve.

The filling solution through the valve is not always applicable. It is not convenient, for example, for the metering valves that have an intermediate tank that can not be opened both outside and inside the container. The solution described above is also not applicable if the product to be conditioned is not fluid enough to flow fast enough through the very narrow path through the valve or if the remains can not be easily cleaned.

If the product to be conditioned is too viscous or too thick, as is, for example, the case of silicone, of glue, of sticky materials, of food doughs such as masses of churros, it is not possible, with a Minirno cost, make it penetrate the container or the inner bag through the valve, not even through a large flow valve. In addition, the problem of cleaning the valve after refilling is considered, as there is usually a product on the wall. Therefore, it is necessary to pour the product into the container or bag before placing the valve. When the product is directly contained in the container, the pressurization is done by passing the gas between the valve cup and the neck of the container before fixing the cup on the container. If, on the other hand, the viscous product is contained in a bag, it is often fixed, not to the valve as for fluid products, but to the neck of the container. It can be clamped tightly between the valve cup and the neck of the container or welded to a fixing ring whose upper part is clamped between the neck of the container and the cup. Reference is made, for example, to the patent application published under WO 2013/131846 A1. In this case, the ring provided with the bag is placed on the neck of the container resting on its collar, the product is poured into the bag through the large diameter channel of the ring. After refilling, the valve is placed on the cusp of the ring and its cup is crimped or flared on the container neck by sealingly locking the collar of the ring between them. Next, the propellant gas is introduced into the container according to the traditional method, that is, by means of an opening made in the bottom of the container, which opening is then closed with the aid of a plug.

The object of the invention is to simplify the pressurization of a dispenser provided with a valve and a fixing ring on which a bag is fixed and thus prevent the bottom of the container from being punctured.

This object is achieved in accordance with the invention, due to the fact that the ring is provided with a connection part located between the central part and the collar and on whose outer face at least one passage is made, not extending the step (s) beyond said joint part and being dimensioned so that, when the ring is placed in the mouth of a container with its or its steps located at the height of the edge of the mouth of the container, the step (s) extend to one side and another of the edge of the mouth and each form a path that communicates the part of the outer face of the ring located on the outside of the container and the part of the outer face of the ring located inside the container. In this way it is possible to penetrate the gas into the container through the step or when the ring is placed on the neck of the box with its steps at the height of the mouth edge of the box. container, protruding above and below said edge.

To ensure tightness during pressurization, it is preferable to dimension the collar to ensure tightness between the ring and the peripheral edge of the cup when the ring is placed in the mouth of a container with its or its steps located at the height of the edge of the cup. the mouth of the container and gas is introduced into the container passing through the step (s).

In a particular variant, the ring is provided with a single annular passage that completely turns the ring.

The ring can also be provided with at least one of the following elements: (i) a pin for fixing a dip tube, (ii) a pin for fixing an anti-sinking means, (iii) an anti-sinking means , (iv) fins to facilitate the fixation of a bag. Preferably, it is provided with a flexible bag fixed on its central part. By means of anti-sinking means, means must be understood in particular that prevent the bag from collapsing, that is to say, that it collapses on itself creating pockets that are isolated from the valve and whose contents can not be extracted.

The ring can be supplied alone or with a bag fixed on its central part.

In a preferred embodiment of the invention, the ring is provided on its outer face at the level of the or of the passages of a projection parallel to the collar, the outer diameter of the projection being greater than the diameter of the mouth of the container and the height being of the projection such that the step (s) extend from one side to the other of said projection. In certain cases, it may be useful to provide the ring with a valve provided with means for fixing it on the fixing ring so that when the valve is mounted on the ring, it is immobilized with respect to the ring, at least in the axial direction. The means for fixing the valve on the ring can be constituted by a connector fixed on the lower end of the valve rod, the connector being provided with at least one hook dimensioned so that when the valve is mounted on the ring with the peripheral edge of its cup supported against the collar of the ring, the hook (s) are hooked behind the bearing surfaces made in the ring, preferably, behind the lower edge of the central part of the ring, so that when the valve it is mounted on the ring, which is immobilized with respect to the ring, at least in the axial direction. The method of the invention is characterized by the following steps

(a) introducing the ring into the container so that the bag is inside the container;

(b) filling the bag with the product to be conditioned;

(c) colocation of the valve in the ring so that the peripheral edge of the valve cup is supported against the collar of the ring and ensures a tight connection;

(d) displacement of the ring, if necessary, so that the gas passage (s) extend to one side and to the other of the edge of the mouth of the container;

(e) introducing the gas into the container through the passage (s);

(f) insertion of the assembly constituted by the ring and the valve until the peripheral edge of the cup and the collar are in contact with the container;

(g) sealing the cup on the container by clamping the collar of the ring between them.

In step (g) it is preferable to fix the cup on the container by flared, by setting or by any other assembly procedure. If the cup and the container are made of plastic, for example, they can be welded together. In step (e) the cup can be maintained on the ring so that a tight connection is formed.

In a first embodiment of the method of the invention, in step (a), the ring is introduced into the container until the step (s) is at the level of the edge of the mouth of the container extending from one side to the other. said edge so that it is not necessary to move the ring in step (d).

In a second embodiment of the method, in step (a), the ring is inserted into the container until its collar rests on the edge of the mouth of the container. In step (d), the ring is partially removed from the container until the step (s) is at the level of the edge of the mouth of the container extending from one side to the other of said edge.

In the second embodiment of the method, in step (c), the valve is fixed to the ring with the help of fixing means provided on the valve. Preferably, the valve is fixed to the ring in step (c) by press fit of the hooks behind the bearing surfaces made in the ring. To partially remove the ring from the container in step (d), a traction is exerted on the valve cup, for example, by aspiration.

The invention is described in more detail below, with the help of the figures showing:

Figure 1: a sectional view of a first embodiment of a fixing ring according to the invention; Figure 2: an enlarged view (a) of the ring of figure 1 and (b) of a second embodiment of a ring of fixing according to the invention;

Figure 3: an exploded view of a dispenser according to a first embodiment;

Figure 4: an exploded view of the valve of the dispenser of Figure 3;

Figure 5: an exploded view of a dispenser according to a second embodiment;

Figure 6: an exploded view in section of the valve of the dispenser of figure 5;

Figure 7: an exploded and perspective view of the valve of figure 5;

Figure 8: a sectional view of the valve of figure 7 mounted on the ring of figure 1;

Figure 9: the different stages of the filling procedure of the dispenser of the first embodiment; Figure 10: the different stages of the filling procedure of the dispenser of the second embodiment; Figure 11: perspective view of the ring of the invention provided with a bag;

Figure 12: partial section view of the dispenser of figure 3.

For reasons of clarity of the description, spatial references are used such as "lower" and "upper", "above" and "below" or "inside the container" and "outside the container". It should be noted that the ring, on the one hand, and the valve, on the other hand, are manufactured independently from each other and independently of the container. The protection refers specifically to the ring only. Accordingly, the spatial references have been made with respect to the ring and the valve as they are intended to be used, assembled in a pressure dispenser whose valve is placed above the container. This does not prevent the dispenser from being used in all positions, specifically, with the valve under the container. Likewise, the valve, the ring and the container all have a certain rotational symmetry about an axis (A) that passes through the rod, the ring and the container. This axis is visible in figure 3. The terms "axial" and "radial" are applied to this axis and signify parallel and perpendicular to this axis respectively.

The invention relates to a pressurization process of a dispenser provided with a valve and an internal bag. For this, a particular ring has been developed. In the embodiment examples presented in the figures, the retained valve is a high flow valve. The person skilled in the art will understand, however, that any type of valve can be used, in particular, dosing valves or even traditional valves with which a filling through the valve would be feasible. The dispensers provided with a bag are essentially constituted by a container, by a valve, by a fixing ring and by a bag fixed on the fixing ring.

A fixing ring is generally constituted by a tubular central part (31) on whose outer face the bag (4) is fixed. The cross section of this central part is lower than the section of the mouth (11) of the neck of the container, so that it can penetrate freely in this mouth. The central part (31) is crowned by a collar (32) that widens away from the axis (A) and whose outer edge has a diameter greater than the diameter of the mouth (11) of the neck of the container (1). This collar serves essentially to limit the penetration of the ring in the container. It also serves to ensure tightness, on the one hand, between the cup and the ring and, on the other hand, between the container and the ring. Between the central part (31) and the collar (32) there is a union part (33) whose transversal section is also lower than the section of the mouth (11) of the neck of the container, so that it can freely penetrate through the mouth. The cross section of this joining part is generally greater than the cross section of the central part (31) although this is not imperative.

In addition to these main elements, the ring can also be provided with a pin to fix, for example, a dip tube. It may also be provided with anti-sinking means (34), for example, in the form of one or more parallel helical elements (341) that extend over part or all of the depth of the bag. The anti-sinking means can form an integral part of the ring, as in the present example, or can be fixed to a pin, for example, by force fixing or by screwing. They can also be welded by ultrasound or by any other suitable method.

Traditionally, the filling of a dispenser provided with a large flow valve and an internal bag begins by placing the ring in the container so that the collar (32) thereof is resting on the edge (12) of the mouth ( 11) from the neck of the container. The product to be conditioned is introduced into the bag through the central channel (35) passing through at least the union part (33) and the central part (31) of the ring. Next, the valve is introduced into the central channel (35) until the peripheral edge (231) of the cup (23) comes in contact with the collar (32) of the ring and the wound edge (12) surrounding the mouth (11) from the neck of the container. In this phase, the cup is flaring or crimped on the neck to ensure tightness between the ring and the cup and between the ring and the rolled edge (12).

When the dispenser is full, the ring is therefore trapped between the neck of the container (1) and the cup (23). The product to be conditioned is in the bag (4) while the propellant gas is in the space between the bag and the wall of the container (1). In the dispensers for bagless viscous products, the pressurization is done before fixing the valve to the container. For this, the cup is held above the neck of the container forming an annular groove between the cup and the rolled edge of the container. The gas can then be introduced into the container through this annular groove. In the case of a dispenser with an internal bag, it is not enough to keep the cup above the neck of the container, since the slit thus obtained is located between the cup (23) and the collar (32) of the ring so that the gas would penetrate the bag and not in space located between the bag and the wall of the container. The collar (32) of the ring having a diameter less than the diameter of the cup, is not accessible when the cup is placed on top. Therefore, it is not possible to grip the ring to lift it and form a slit between the ring and the rolled edge (12) of the container. This is the reason why the pressurization of the dispensers with a large flow valve and an inner bag can only be done through an opening in the bottom of the container.

The method of the invention provides for passing the gas through passages located between the outer face of the ring and the neck of the container, before finally inserting the ring and the valve to close the dispenser, and then sealingly fix the cup to the container .

For this, the ring (3a, 3b) of the invention is provided on the outer face of its joining part (33) with one or more steps (361). These steps are limited to the union part, that is, they do not continue along the collar or beyond it, nor along the central part on which the bag is fixed. Also, the steps are dimensioned so that, when the ring is placed in the mouth (11) of a container with its passages (361) located at the height of the rolled edge (12) of the mouth (11) of the container, the or the steps extend on either side of the edge (12) of the mouth (11). This situation is very visible, specifically, in figures 9vi, 10vi and 10vii. Each of the steps thus forms a way that communicates the part of the outer face of the ring located on the outside of the container and the part of the outer face of the ring located inside the container. In the example presented in this document, the steps take the form of vertical grooves (361) made on the outer face of the ring wall. These grooves are made in a part of the wall of the joining part (33). Its height is such that when the ring is placed in the mouth of the container with its steps located at the height of the rolled edge (12), these steps protrude above and below the rolled edge. When the dispenser is ready for use, the union part and the steps are inside the container, on the outside of the bag. They do not play any paper, so that the presence of the passages (361) in this part has no effect on the final sealing of the dispenser. This base version of the ring according to the invention is shown in Figure 2b.

In a realization variant not represented, there is only one step that goes around the ring completely. For this, the cross section of the joining part must, at least for part of its height, be such that, when the ring is in the pressurization position, an annular free space is formed between the edge of the opening and the wall from the union part to the level of this step.

In a variant embodiment of the invention shown in figure 2a, the ring (3b) is also provided with a projection (36) located in the connection part (33). This projection (36) is parallel to the collar (32) and has a diameter slightly greater than the diameter of the mouth (11) of the container so that the ring can rest in an intermediate position, resting on this projection (36) on the edge rolled (12) of the container. The steps (361) pass through the ledge. The passages and the projection (36) are dimensioned so that when the ring is supported with its projection against the rolled edge of the opening, the gas can flow freely from the outside of the container to the interior passing through these passages. In a full state, the projection (36) does not play any paper, so that the presence of the steps (361) in this projection has no effect on the final sealing. The bag (4) is fixed, preferably by welding, on the outer face of the central part (31) of the ring. In order to facilitate this fixation and to guarantee it a great resistance, two vertical and pointed fins (312), placed one opposite the other, can be provided on the outer surface of the central part. These fins give the central part a radial section (that is, perpendicular to the axis (A)) in the shape of a tray. It should be understood that the radial section is substantially diamond-shaped whose angles at the ends of the minor diagonal are obtuse and rounded, while the angles at the ends of the greater diagonal are sharp and pointed. The tray-shaped cross section is smaller than the mouth section of the container and generally smaller than the cross section of the joint part, which in turn has a generally round section.

Two ways of proceeding to pressurize the dispensers provided with a ring according to the invention are possible. In a first embodiment, presented in FIG. 9, a fixing ring (3b) provided with a projection (36) is used, as shown in FIGS. 1 and 2a. The stages of filling are the following:

Step (a), the ring (3b) of the invention is placed in the container (1). This ring is provided with a bag (4) that can be wound around the axis (A) and maintained in that position by means of a self-adhesive tape that can be easily broken. This step has been represented schematically in Figure 9 (i). The ring is not fully inserted in the container, but only placed in an intermediate position with its projection (36) against the rolled edge (12) of the container. The bag is inside the container.

Stage (b). The filling head is then introduced into the central channel (35) and the product to be packaged is poured into the bag that is unwound as it is being filled. The filling head is designed so that it rests against the inner wall of the central channel (35) ensuring sealing against the outside. This stage is represented schematically in Figure 9 (ii). At the end of the filling, the filling head is moved away.

Stage (c). The valve (2a; 2b) is then placed in the upper part of the central channel (35) of the ring so that the peripheral edge (231) of the cup is supported on the collar (32) of the ring. This stage is visible in Figure 9 (iii).

Stage (d). In this first embodiment, the ring (3b) rests on the rolled edge of the neck of the container resting on its projection (36). Therefore, it is not necessary to move it. The pressurization can be carried out directly after step (c) in the course of step (e).

Stage (e). The pressurization can start. The cup remains supported by force on the collar so that a tight joint is formed between the two pieces. To do this, we must pay attention not to lean too hard on the ring to avoid the risk of inserting it in the container beyond its projection. To increase the tightness between the cup and collar (32) of the ring, a gasket can be placed on the bottom of the peripheral edge of the cup. However, in general, since the ring is made of a sufficiently flexible plastic material, it can assume this function. The gas penetrates into the interior of the container passing through the passages (361). Then it is in the space between the bag and the wall of the container. As a result of the pressure of the gas, the ring is pushed against the cup, thus increasing the tightness between the ring and the cup. When the seal between the collar (32) and the peripheral edge of the cup is secured by holding the cup on the collar, the gas can not penetrate the bag. This step is represented in FIG. 9 (iv), an enlargement of the gas passage being shown in FIG. 9 (vi).

Stage (f). Once the pressurization is finished, a pressure is exerted on the cupel to force the ring to completely penetrate the container despite the retention effect of its projection (36). When the projection (36) has passed into the container, the valve, and with it the ring pushed by the valve cup, continue down the container until the collar (32) of the ring and the peripheral edge (231) of the cup are supported against the rolled edge (12) of the container. The ring is then in the low position, as shown in Figure 9 (v).

Stage (g). In this phase of filling, it is possible to fix the cup permanently on the container. This fixation can be done in different ways depending on the materials used. If the cup is metal, it can be flared over the container. In this case, the wall of the peripheral edge of the cup is ejected outwards towards the lower edge of the rolled edge (12) so that the wall molds to the shape of the rolled edge trapping the collar between them in a staked manner ( 32). It is also possible to set it instead of flaring it. If the cup and the container are plastic, it is possible to weld them together. Due to the tightness after flaring or crimping both between the ring and the cup, and between the ring and the rolled edge (12), the inner channel (35) of the ring and the contents of the bag are insulated from the outside, only at the level of the valve, but also at the level of the joint formed by the contact between the collar and the peripheral edge (231) of the cup. Also, the space between the container and the bag is insulated from the outside by the joint formed by the collar (32) and the rolled edge (12) of the container.

A second way of proceeding is presented in figure 10. For this second way of proceeding, a ring with or without projection (36) can be used. Although Figure 10 shows the procedure taking as an example the ring (3b) with a projection, the person skilled in the art will understand that it does not perform any paper and that the process can therefore be carried out with a base ring (3a). This second method allows to use the filling machines in which the cup is lifted to pass the gas between the cup and the rolled edge. For this embodiment, it is necessary to use a particular valve. While for the first embodiment only a conventional valve is sufficient, for example, a traditional high-flow valve consisting of a rod (21), a gasket for the PU valve (22) and a cup (23), as shown in FIG. has shown in figure 4, for the second embodiment it is necessary to provide on the valve means for fixing the latter to the ring. In the example presented in figures 5 to 8, the fixing means are constituted by a connector (24) fixed to the lower end of the rod (21) of the valve. The connector is provided on its upper part with a connecting ring (241) and on its lower part with one or several hooks (242). As for the lower end of the rod (21) is provided with a pin (211) intended to penetrate the opening of the connecting ring (241) to center the two pieces before welding them together. It is assumed that other fixing means can be contemplated and that it is possible to renounce the centering pin (211). Also in this case, it is possible to use any type of valve, such as a metering valve or a classic valve with which a filling could be contemplated through the valve.

The procedure of the second embodiment is developed in the following manner.

Stage (a). The ring (3a; 3b) is placed in the container (1). This ring is provided with a bag (4) that can be wound around the axis (A) and maintained in that position by means of a self-adhesive tape that can be easily broken. The ring is fully inserted in the container (1) in the low position, that is, until the collar (32) is supported against the rolled edge (12) of the container and the bag is inside the container. The projection (36), when there is one, is therefore located inside the container. This stage is visible in Figure 10 (i).

Stage (b). The product to be conditioned is then poured into the bag through the central channel (35) of the ring. Also in this case, the filling head of the machine is inserted in the upper part of the central channel (35) ensuring a tight connection with the wall of the central channel. This stage is represented in figure 10 (ii).

Stage (c). After filling, the filling head moves away. The valve is then placed, as schematically shown in Figure 10 (iii). To do this, the rod (21) provided with the connector (24) penetrates in the central channel (35) of the ring until the peripheral edge (231) of the cup abuts against the collar (32) of the ring and the rolled edge (12) of the container. The hooks (242) of the connector are dimensioned so that in this position, they come to engage behind the support surfaces made in the ring. In the present case, these support surfaces are constituted by the lower edge (311) of the central part (31) of the ring (3a, 3b). This position is clearly visible in figures 8 and 10 (iii). Once the hooks are hooked on the ring, the valve and the ring go to form a single piece and can no longer move with respect to each other, at least in the axial direction of the ring.

Stage (d). It is then possible to lift the valve as in the traditional procedures. However, since the valve is fixed to the ring through the hooks (242), the displacement towards the top of the valve entails an identical displacement of the ring and of the filled bag. In general, the lifting of the valve is done by pulling on the cup (23). When the ring (3b) is provided with a projection (36), it is sufficient to lift the ring until this projection is near the rolled edge (12) of the mouth of the container. It is not necessary to remove the protrusion from the container. Therefore, it is not necessary to exercise a very strong traction. This situation is clearly visible on the right side of Figure 10 (vi). When the ring (3a) has no protrusion, the ring rises until the steps (361) are at the height of the rolled edge (12) of the container extending from one side to the other of this rolled edge. This situation is clearly visible on the right side of Figure 10 (vii).

Step (e) Once the ring (3a, 3b) is in the intermediate position, it is possible to penetrate the pressure gas passing through the passages (361) as shown in figures 10 (iv) and 10 (vi). ) for the ring (3b) with a projection, or in the 10 (vii) for the ring (3a) without projection. As a result of the pressure of the gas, the ring remains stuck against the cup and thus ensures the tightness between the ring and the cup. As the union between the collar (32) of the ring and the peripheral edge (231) of the cup is sealed, the gas can not enter the bag, nor the conditioned product leave it.

Stage (f). When the pressurization is finished, the valve with the ring and the bag are lowered again until the peripheral edge (231) of the cup and the collar (32) are in contact with the rolled edge of the container. The ring is thus again in a low position as shown in Figure 10 (v).

Stage (g). In this phase of the procedure, it is possible to fix the cup on the container. As in the first method, this fixation can be done, for example, by flapping the cup on the wound edge or crimping it. If the cup and the container are plastic, it is also possible to weld one over the other.

Although the figures show dispensers provided with a high flow valve, it is evident that it is possible to use other types of valves, such as, for example, metering valves, with which a filling of the bag through the valve is not feasible or even normal valves, with which filling by the valve would be feasible.

List of references:

1 Container

11 Mouth of the container

12 Rolled edge that surrounds the mouth

2a / b High flow valve

21 Rod

211 Connection plug

22 Coupling for PU valve

23 Copela

231 Peripheral edge of the cup

24 Valve / ring fixation connector

241 Connection ring

242 Hooks

3a / b Fixing ring

31 Central part

311 Bottom edge of the central part

312 Fins

32 Collarrn

33 Part of union

34 Anti-sinking means 341 Helical elements 35 Central channel

36 Outgoing

361 Steps to the gas bag

Claims (15)

1. Fixing ring (3a; 3b) for a pressure dispenser constituted by a container provided with a mouth (11), a valve mounted on a cup provided with a peripheral edge (231) and a fixing ring on the that a bag is fixed, said fixing ring being provided with a central part (31) having an outer face designed for fixing a bag (4) and whose cross section is lower than the mouth (11) of the container for the that the ring and of a collar (32) is intended for fixing the ring between the mouth edge (11) of the container and the peripheral edge (231) of the valve cup and / or to ensure tightness between the valve. ring and the cup and / or between the ring and the rim of the mouth (11) of the container, the diameter of the collar (32) being greater than the diameter of the mouth (11) of the container for which the ring is intended, characterized because the ring is provided with a union part (33) located between the part e central (31) and the collar (32) and on whose outer face at least one step (361) has been made, not extending the step (361) beyond said joining part and being dimensioned so that, when the ring is placed in the mouth (11) of a container with its or its steps located at the height of the rim of the mouth (11) of the container, the step (s) extend from one side of the mouth to the other ( 11) and each form a path that puts the part of the outer face of the ring located on the outside of the container and the part of the outer face of the ring located inside the container in contact. 2. Fixing ring (3a; 3b) according to the preceding claim, characterized in that the collar is dimensioned to ensure tightness between the ring and the peripheral edge of the cup when the ring is placed in the mouth (11) of a container with its or its steps located at the height of the mouth edge (11) of the container and by which gas is introduced into the container passing through the step (361). 3. Fixing ring (3a; 3b) according to one of the preceding claims, characterized in that it is provided with a single annular passage that completely turns the ring. 4. Fixing ring (3a; 3b) according to one of the preceding claims, characterized in that it is also provided with at least one of the following elements: (i) a pin for fixing a dip tube, (ii) a pin for fixing an anti-sinking means, (iii) anti-sinking means (34, 341), (iv) fins (312) to facilitate the fixation of a bag. 5. Fastening ring (3a; 3b) according to one of the preceding claims, characterized in that it is provided with a flexible bag (4) fixed at its central part (31). 6. Fastening ring (3b) according to one of the preceding claims, characterized in that it is provided on its outer face at the level of the step (361) of a projection (36) parallel to the collar (32), the diameter being exterior of the projection greater than the diameter of the mouth (11) of the container and the height of the container being such that the step (s) (361) extend on either side of the projection. 7. Fastening ring (3a; 3b) according to one of the preceding claims, characterized in that it is provided with a valve (2b) provided with means (24, 241, 242) to fix it on the fixing ring (3a; 3b) ) so that when the valve (2b) is mounted on the ring (3a; 3b), it is immobilized with respect to the ring, at least in the axial direction. 8. Fixing ring (3a; 3b) according to the preceding claim, characterized in that the means for fixing the valve (2b) on the ring (3a; 3b) are constituted by a connector (24) fixed on the lower end ( 211) of the valve stem (21), the nozzle being provided with at least one hook (242) dimensioned so that when the valve is mounted on the ring with the peripheral edge (231) of its cup (23) supported against the collar (32) of the ring, the hook (s) (242) are hooked behind the bearing surfaces made in the ring, preferably, behind the lower edge (311) of the central part (31) of the ring, so that when the valve (2b) is mounted on the ring (3a; 3b), it is immobilized with respect to the ring, at least in the axial direction. 9. Procedure for pressurizing a pressure dispenser constituted by a container, by a valve mounted on a cup and by a fixing ring according to one of the preceding claims and on which a bag is fixed, characterized by the following steps: (a) introducing the ring (3a; 3b) into the container (1) so that the bag is inside the container; (b) filling the bag (4) with the product to be conditioned; (c) positioning the valve (2a; 2b) in the ring (3a; 3b) so that the peripheral edge (231) of the valve cup is supported against the collar (32) of the ring; (d) displacement of the ring (3a; 3b) if necessary so that the passage (s) for the gas (361) extend to one side and to another of the mouth edge (11) of the container; (e) introducing the gas into the container (1) through the passage (s) (361); (f) insertion of the assembly constituted by the ring (3a; 3b) and the valve (2a; 2b) until the peripheral edge (231) of the cup and the collar (32) are in contact with the container; (g) sealing the cupel (23) on the container (1) by clamping the collar (32) of the ring between them. Method according to claim 9, characterized in that in order to fix the cup (23) on the container in step (g), the cup is flared, crimped or welded on the container (1). Method according to claims 9 or 10, characterized in that in step (a), the ring (3b) is inserted into the container until the step (361) is at the height of the mouth edge (11). ) of the container extending from one side to the other of said edge so that it is not necessary to displace the ring in step (d). Method according to claims 9 or 10, characterized in that in step (a), the ring (3a; 3b) is inserted in the container until its collar (32) rests on the edge of the mouth (11) of the container and that in step (d), the ring (3a; 3b) is partially removed from the container until the step (361) is at the height of the mouth edge (11) of the container extending to a side and another of said edge. 13. Method according to claim 12 applied in a pressure dispenser provided with a valve provided with fixing means, characterized in that in the step (c), the valve (2b) is fixed to the ring (3a; 3b) with the help of its fixing means (24). 14. Method according to claim 13, characterized in that the valve is fixed to the ring in step (c) by pressure adjustment of the hooks (242) behind the bearing surfaces (311) made in the ring. Method according to claims 13 or 14, characterized in that in order to partially remove the ring (3a; 3b) from the container in step (d), a traction is exerted on the cup (23) of the valve.