DE69107443T2 - Process for vacuum packaging of products, in particular cosmetic or pharmaceutical products, in containers of variable sizes, closed by a distribution element without exhaust air. - Google Patents

Description

The invention relates to a process for vacuum packaging liquid to pasty products such as dairy products and creams used in cosmetics or pharmaceuticals. It enables them to be offered in dispensers consisting of a tank with a variable capacity closed by an "airless" dispenser pump, i.e., according to the expression established in the field, without re-intake of air. Means are provided, among other things, for varying the capacity of the tank so that, when the tank is full, its shell exerts a relative pressure on the enclosed product, thus ensuring good dispensing of the product when the pump is first activated. The same means, during the emptying of the dispensers, allow product to be pumped without the simultaneous intake of air. The resulting dispensers for liquid to pasty products are particularly convenient. They are also part of the invention as is a device used to apply the present method.

Until now, the only type of liquid to paste dispensers in which an air vacuum was created comprised a rigid tank (such as a bottle or a metal container) associated with a distribution device. The latter in this case takes the form of a valve. However, the corresponding packaging process includes a phase during which the air remaining in the filled tank is sucked in between the neck of this tank and the valve which is placed on it, but not yet fixed. This then has the effect of placing the interior of the tank under negative pressure, while the valve is hermetically sealed on the collar. A subsequent phase consisting of definitively fixing the valve to the neck (by crimping, rolling, etc.) can then be carried out at any time after the end of the suction operation. This method is mainly used for distributors that are kept under pressure by a propellant gas. The instantaneous creation of the vacuum in the tank makes it possible to offer the space necessary for this gas without ultimately obtaining a significant overpressure. The propellant gas is then introduced through the valve fixed to the tank.

In the case of variable capacity tanks associated with pumps without air re-intake or airless pumps, this method is no longer applicable in accordance with the state of the art. For example, in the case of a flexible shell, the suction would then have the effect of deforming the tank when part of the product was emptied. And while its contents would remain at atmospheric pressure, the distribution device would not be particularly tightly fitted to the neck. Thus, shortly after the end of the suction, air would flow back into the tank, which would then regain its shape.

However, if the attachment of the distributor takes place very quickly after the air has been removed, the state-of-the-art methods can of course be used. However, the initial content of the distributor thus created does not correspond to the maximum capacity of its tank. In practice, product is always removed along with the air, since the duration of the vacuum cannot be precisely adjusted. In other words, the tank is oversized, which leads to an increase in the cost price of the distributor. The economic loss thus generated is all the more significant as it is generally a matter of mass production.

The aim of the present invention is to propose a method for creating an air vacuum in a tank of variable capacity filled with a liquid or pasty product and for attaching a distribution element to it, without air re-entering the tank during the corresponding operation and by its maximum capacity is maintained.

This is achieved by means of a process for vacuum packaging a product of a consistency ranging from that of a liquid to that of a paste in a tank of variable capacity closed by a distribution member without re-absorption of air, this process comprising at least one phase of sealingly fixing the member on the tank filled with the product, characterized in that the sealing of the member is carried out while the tank is located in a space in which an air vacuum is maintained.

Variants of this method are described in more detail in claims 2 to 12.

The present invention further proposes a device that makes it possible to apply this method, wherein the tank has a neck onto which the distribution element can be tightly fixed and where, before the phase of tightly fixing the element, at least the following phases take place:

1/ Fixing the tank in a cup that has an open top so that the neck sits on the top, and

2/ Filling the tank with the product through the neck, after which the organ is placed on the neck,

characterized in that the device comprises a crown which can be placed tightly against the top of the cup at the bottom to form the space, means being provided for sucking the air out of the space, and in that the device is provided with means for fastening the pump, which are arranged in the middle of the crown.

Various embodiments of this device are described in claims 14 to 25.

The advantages of the present invention are not so much at the level of the process or the device that applies it, but rather relate to the obtained Distributors. First of all, the product contained in them remains protected from air. There is therefore no risk of oxidation, contamination or hardening due to drying out; all undesirable processes both from the point of view of the quality of the product distributed and from the point of view of the distribution itself.

For tanks that can be deformed before they are filled so as to increase their capacity, the distributors obtained according to the present process are particularly interesting. In fact, when the distributor is tightly fixed to the tank, the disappearance of the previous deformation causes the product contained in the tank to be pressurized, since its capacity has a tendency to decrease all at once. This pressurization is also reinforced by the internal vacuum created, which causes the atmospheric pressure to compress the walls of the tank even more. This greatly facilitates the start-up of the distributor. This is particularly valuable for pasty products since the air bubbles are practically all removed. It follows that the present process enables the development of distributors whose multiple performances could not otherwise be exploited.

The invention is explained in more detail below using the detailed description of a non-limiting embodiment of the invention with reference to the accompanying figures.

Figures 1 to 4 show a deformable tank, which is advantageously used to form a distributor according to the invention. It is shown from the front and from the side in Figures 1 and 2, respectively, which also show it partially cut away. In Figure 3 the same tank is shown in plan view and in Figure 4 in section according to the plane III-III of Figure 1.

Figure 5 shows in perspective a first distributor according to the invention, which, among other things, contains figures.

Figure 6 is an axial section through a priming pump without air re-intake, which is advantageously used together with the tank of Figures 1 to 4 to form a distributor according to the invention.

Figures 7 and 8 show a longitudinal section through a cup which is advantageously used in the method according to the invention to secure a tank such as that of Figures 1 to 4. The vice which this cup contains is shown with open jaws in Figure 7 and with closed jaws in Figure 8.

Figure 9 is a plan view of a carousel which is advantageously used in the method according to the invention.

Figure 10 shows a longitudinal section of the cup of Figures 7 and 8, with the tank it holds in the process of being filled.

Figure 11 shows a similar section to Figure 10, but with the tank full. Above the cup you can also see an axial section through a device according to the invention.

Figures 12 to 14 show the device of figure 11 at different times of fastening a distribution pump to a tank according to the invention. They show: the creation of a vacuum in a space surrounding the tank, the bringing into contact with the pump and finally the squeezing of the latter.

Figures 15 and 16 show details of the crimp connection unit of the pump which contains the device according to the invention of Figures 11 to 14. The clamps of this unit shown in axial section in Figure 16 are shown in Figure 15 from below.

Figure 17 shows a detail of another embodiment of the squeezing unit of a device according to the invention.

Figure 18 shows in axial section details of a rolling unit of a pump according to the invention.

Figure 19 is an axial section through a latchable pump which can form a distributor according to the invention.

Figure 20 is an axial section through a second distributor according to the invention.

Figure 21 is an axial section through a third distributor according to the invention.

Figures 22 and 23 are axial sections through the distributor of Figure 21, shown respectively at the beginning and during the filling of the tank.

Figure 24 shows in axial section a pump without air recirculation, which is advantageously used to form a fourth distributor according to the invention. This pump is shown in the rest position.

Figure 25 is a partial section through the pump of Figure 24, but this time shown in the lower insertion position for a propellant gas.

Whenever possible, the same reference symbols are used to designate elements with the same function in the different distributors.

Figures 1 to 4 show, from the front, from the side, from above and in cross-section, a tank with variable capacity, which is advantageously used in the context of the present process to package a liquid to pasty product. A tank of a similar type has already been published, among others, in European patent application No 0 324 289, filed on October 24, 1988 by the company STEP. Typically, it has a shell 10 of essentially flat shape in the rest position with an approximately elliptical constriction 11 which ends in a cylindrical neck 15. In this case, the shell and neck are made of one piece, for example from a flexible plastic material such as polyethylene or polypropylene. While the constriction 11 and the neck 15 then have a sufficient material thickness to be relatively rigid, the wall of the shell 10, on the other hand, has a small thickness overall. However, the lateral folds 12 and the bottom 13 of the shell 10 are reinforced in the manner of the constriction 11. This can be seen better in Figures 1 and 2, where the tank is shown partially sectioned (according to plane II-II of Figure 2 and plane II of Figure 1 respectively).

This structure then gives the tank particular deformation properties. Indeed, as soon as a force F is applied to bring the lateral folds 12 closer together (as shown diagrammatically in Figure 4, which shows the tank in section along the plane III-III of Figure 1), each of the thin sides of the shell bends and hollows outwards (see the deformed perimeter shown in dashed lines). This results in a considerable increase in the internal volume of the tank, in other words, its capacity.

The filling of this tank is advantageously carried out while it is kept deformed. In the same state, it is preferably hermetically sealed by a distribution pump P. When the external force is released, a distributor is obtained which looks like the unit shown in Figure 5. On the one hand, the constriction 11, due to its relative rigidity, retains a shape suitable for receiving, for example, a cap which would rest on the base 16. On the other hand, the casing 10 remains deformed because the product enclosed inside prevents it from regaining its flat resting shape. In turn, the casing 10 keeps the product under pressure.

The presence of this pressure is valuable for a good dispensing of the product by the distribution pump P. This dispensing is normally carried out by pushing the hollow rod 40 of the pump P back into the cap 30. The pressure prevailing inside the tank then serves less to dispense the product (that is the task of the pump) than to start the distribution device.

Although a pump without pre-pressure may be suitable, it is preferable to use a pump of the type shown in axial section in Figure 6. This latter is the subject of French patent FR 2 343 137, filed in 1976 by the company VALOIS. It usually consists of a pump body 50, one end of which (at the bottom of the figure) is located in the product tank and communicates with it via an opening 54. This body 50 does not have an air inlet opening, as is sometimes the case when it is intended to replace the dose of product dispensed in the tank with a quantity of air. In the trade, the corresponding type of pump without air re-intake is called "airless". In addition, it is not intended to use a dip tube to bring the product from the bottom of the tank to the opening 54 of the pump body 50, the small thickness of the tank prohibiting the presence of such a tube inside it. A seal 52, which is partially held by a crown 51 which is clamped to the bottom of the pump body 50, closes the opening 54 and thus takes over the function of an inlet valve flap within the pump chamber 55.

The other end 53 (top in the figure) of the pump body 50 is open. It houses a piston 60 which slides tightly inside the body 50 to isolate the pump chamber 55 from the outside. A return spring 75 is arranged between the crown 51 and the piston 60 and opposes the reduction in volume of the pump chamber 55. In order to form the outlet valve of the chamber 55, the pump of Figure 6 provides for cooperation between the actuating rod 40, the piston 60 and a ring 70 held against the piston 60 by means of the return spring 75. In this cooperation, another spring 64, less flexible than the previous one, also opposes the relative displacement of the hollow rod 40 and the piston 60.

When the pump chamber 55 is filled with product, pressing the rod 40 first causes the piston 60 and ring 70. As their volume decreases, the pressure in chamber 55 increases, keeping the intake valve closed. Very quickly, the pressure reaches a so-called "pre-pressure" value, from which pushing in the rod 40 no longer pulls the piston 60 and it is then rather the spring 64 that compresses. Then the lateral channel 42 of the rod 40 detaches from the piston 60 so that its internal channel 41 is put in communication with the pump chamber 55. The contents of the latter are then forcefully expelled outwards until the ring 70 hits the crown 51.

As soon as the hollow rod 40 is no longer actuated, the spring 64 relaxes. The outlet valve flap of the pump chamber 55 therefore closes, since the lateral channel 42 is again in front of the piston 60 and the ring 70 reinforces the tight fit of this ring on the rod 40. Then, the return spring 75 relaxes in turn. This results in the volume of the pump chamber 55 increasing. And the depression that this could entail with respect to the contents of the tank is then compensated by the inlet of product through the opening 54.

For operation according to the principle just described, a cap 30 is also provided to form the necessary stop. It also makes it possible to isolate the open end 53 of the pump body from the outside. For this purpose, a seal 34 is arranged between the cap 30 and the pump body 50, while the hollow rod 40 passes through it with a certain clearance. This allows the rod and the piston to be pressed in by air in the pump body 50, without this air being able to penetrate into the tank.

Finally, in the version of the pre-pressure pump of Figure 6, a crimp collar 20 is arranged to rest on a base 31 of the cap 30. This collar 20 is intended to sit on the neck 15 of a tank, the seal 23 then resting on the latter. It is described below, how this collar 20 can make it possible to fix on a tank the pre-pressure pump of Figure 6 or, more generally, a distribution pump P without re-intake of air, and this hermetically enough so that there is no appreciable exchange between ambient air and the interior of the tank during the life of the distributor thus made.

In practice, the variable capacity tanks just described are more likely to be manufactured by blowing. This results in dimensions that can vary from one tank to another. In addition, they are generally filled using a dosing cylinder, the content of which also varies from one dose dispensed to the next. All this makes it impossible to fill the tanks up to the top of their necks, and it is usually not possible to fill them completely.

If a pump as described above is then mounted on the tank without further precaution, air will inevitably surround the pump body. And the pressure exerted by the shell of the tank on its pasty contents is not sufficient to pump it sufficiently. It can only fill a small amount of it through the inlet valve flap into the interior of the pump chamber 55. This amount therefore only increases the amount of air originally in the chamber.

In this situation, where this chamber does not contain any product at all, experience shows that the pump's suction is practically impossible as soon as the product has a somewhat pasty consistency. In fact, when the rod 40 is first actuated, the air originally present in the chamber 55 is compressed, while the corresponding volume is reduced. However, due to the great compressibility of this gas, its pressure does not increase sufficiently to oppose the spring 64. The pump's outlet valve therefore remains closed. And while the pump chamber regains its maximum volume, no depression is created which could cause the inlet valve to open. In other words, the pump chamber remains empty of any product and the corresponding distributor cannot satisfy the user.

Therefore, the distributor described so far, which consists of a specific pre-pressure pump and a specific tank of variable capacity, can only be used if, during its manufacture, all the air remaining in the tank filled with product is removed. This is precisely the result that is made possible by the present vacuum packaging process, which will now be described in detail. It should be noted that this process applies to a variety of other distributors and tanks. However, first of all, only the preferred distributor of the previous pages will be presented in order to illustrate the present process.

The first phase of the method according to the invention consists in mechanically deforming the tank R. For this purpose, it is possible to use, for example, the small device shown in longitudinal section in Figures 7 and 8. This is actually a vice 1, here consisting of two parts joined together. The first of these parts is a cup 110 open at the top, made for example of an aluminium alloy. In particular, in Figure 7, one can see the two opposite vertical sides 111 and a base 112, the sides 111 being fixed to the base 112 by assembly dowels 114. Inside the cup 110, arranged against the two vertical sides 111, there are two clamping jaws. One of these clamping jaws (with the reference 120) is fixed to the cup 110, for example by means of an assembly dowel 121. The other (with reference 130) is mobile and can be moved in translation inside the cup 110 parallel to its bottom 112. For this purpose, the clamping jaw 130 carries on one of its sides pins 139 that can be inserted into holes made transversely in the side 111 of the cup against which the clamping jaw 130 is arranged.

A cylindrical rod 131 is connected in the same way to the jaw 130 and passes through the face 111. It projects outwards from the cup 110 and ends in a head 132 of larger diameter. This head encloses a roller 133 which is inserted so that it partially emerges from the end of the head 132. Finally, a spring 134 surrounds the rod 131. It rests on the one hand on the external surface of the face 111 and on the other hand on the shoulder formed by the head 132. The spring 134 therefore always tends to pull the rod 131 out of the cup 110, i.e. to press the movable jaw 130 against the face 111, as shown in Figure 7.

In order to effect the displacement of the jaw 130 from this position to the position shown in Figure 8 with the jaws brought together, the vice 1 can comprise a second part consisting of a block 140 fixed to the side 111 from which the rod 131 projects (by means of dowels 141 as shown in dashed lines). The block 140 has a cavity 142 which passes through it entirely. A first portion of the cavity 142 is designed to receive internally the part of the rod 131 which projects from the cup 110 and its head 132. A cylindrical protection 143 is then advantageously interposed to ensure good sliding of the rod 131. Beyond the head 132, the cavity 142 widens to accommodate a cylindrical cam 144 in the assembly. However, the cam 144 has a notch into which the part of the roller 133 which protrudes from the head 132 can fit. Depending on whether the roller 133 penetrates into the notch of the cam 144 (Figure 7) or is only in contact with the cylindrical surface of the cam 144 (Figure 8), the rod is more or less pressed into the cup 110. For the purpose of manual actuation of the cam 144, a lever 146 is advantageously secured thereto (for example by forcing) and protrudes from the block 140. It may include a handle 145.

However, the block 140, as well as the cam 144 and its lever 146, are mainly of interest in the case of a laboratory application of the vice 1. If industrial use is envisaged, it is advantageous to arrange various cups 110 radially on a carousel 100, as shown schematically in plan view in Figure 9. The cups then no longer have a block 140, so that the rod 131 with its spring 134 and its roller 133 are completely exposed outside the side 111 of the cup. It is then possible to provide a ramp 101 located at the level of the various rollers 133. It must also be arranged at such a distance from the axis of rotation of the carousel that the rollers 133, by resting on them, cause the rods 131 to be pressed into the cups and consequently the jaws of the corresponding vices 1 to be brought closer together.

In this case, the ramp 101 preferably occupies only a part of the circumference of the carousel. During its stretch outside the ramp 101, a cup 110 then maintains its jaws 120 and 130 at the maximum distance. This distance is in fact calculated so that a tank R such as the one described above can be inserted into the cup 110 through its open top. Its lateral folds 12 are then arranged between the jaws, which possibly have guide grooves 128 and 138 for this purpose. In addition, its bottom is advantageously located in a groove 113 to keep it in place (see Figure 7).

When the cup is in front of the ramp 101, the tank R is thus deformed, as stated at the beginning. In Figure 8, which shows the shape then assumed by the tank R from the side, it can be seen that only the central area of the folds 12 is stressed (by adapted reliefs of the clamping jaws within the grooves 128 and 138). The lower The area of these folds 12 is in fact bevelled to facilitate the introduction of the tank into the cup. The area 14 corresponding to the shell 10 is not intended to participate in any significant way in the deformation of the assembly.

After this first phase of deformation of the tank (which occurs, for example, when the associated cup arrives before the mark 1 of Figure 9), a second phase of the present process takes place. It is the phase of filling the tank with product. It is advantageously carried out by means of a filling head, of which only the injection pipe 2 is shown in Figure 10. This head could, for example, be arranged above the carousel of Figure 9, before the mark 2. In other words, the tank, which then presents itself below it, is deformed, with its cup passing in front of the ramp 101. Advantageously, the injection nozzle 2 is first lowered to the bottom of the tank by passing through its open neck 15. As product 80 flows out of it, the injection nozzle 2 is then raised again so that its end 210 always remains above the surface 81 of the product. If necessary, the cup 110 is lowered in relation to a fixed injector 2. In any case, the arrangement of the injector 2 outside the product 80 avoids the entrapment of air bubbles. Finally, a mass of the product 80 occupies practically the entire deformed tank, leaving only a small volume of air near the collar 11 in the space 82 shown in Figure 11.

A distribution device is then placed on the tank R. If it is a pump such as that in Figure 6, also shown in Figure 11, its pump body 50 is inserted inside the neck 15 of the tank, while its crimping collar 20 simply rests on this neck. The cup 110 is then brought, for example, in front of the mark 3 in Figure 9, to pass through the third and final phase of the present process. For this purpose, it is located in front of a final packaging device 3. An example of this device 3 is shown in axial section in Figures 11 to 14 in various positions. In the following lines it is explained according to which principle such a device according to the present invention operates. Without going into detail about all the components making up this device, its main groups of elements will be described in a more functional manner in the course of the description of the use of the present device. It will only be pointed out that the various elements of each group have as their main function to facilitate the assembly of the device, unless they are necessary for its proper operation. At the same time, the sequence of the third phase of the present process carried out by this device 3 is explained.

Once the cup 110 and its deformed tank R filled with product 80 and equipped with its pump not yet crimped have been placed under the device 3, as shown in Figure 11, the device 3 and the cup 110 are displaced relative to one another until the relative position shown in Figure 12 is reached. To this end, a first cylinder 310 enables, for example, the assembly of elements with reference numbers from 311 to 319 forming the head of the device 3 to be lowered. Such a cylinder is advantageously part of a machine commonly used for assembling distributors.

The head of the device 3 then drives the elements with references 300 to 308, which form a sort of lower crown. For this purpose, pressurized air is introduced through the pipe 314 (see arrow B). If necessary, part of this air is expelled through the pipe 314' (see arrow B'), which is arranged symmetrically with respect to the axis of the device 3. Overall, however, care is taken to keep the pressure at a sufficient level to keep the head of the device (elements 310 to 319) and its lower crown (elements 300 to 308) apart. being held.

Thus, the lower crown finally comes into contact with the top of the cup 110. Contact is preferably made at the level of a damping seal 306, while the cup 110 is advantageously provided with an annular part 115. Although it was present in the previous phases of the process according to the invention, this part 115, which has not yet been mentioned, allows the cup 110 to have a circular edge against which the sealing lip 307 arranged at the bottom of the device 3 can rest. The air pressure maintained between the head and the lower crown at the level of the lines 314 and 314' then ensures that the crown 300 rests on the cup 110 with a force greater than that developed by the cylinder 310.

A space located both inside the cup 110 and inside the device 3 is then isolated from the outside. A vacuum is immediately created in the corresponding space due to the application of suction through the pipes 308 (see arrow A near the base of the lower crown) and 318 (see arrow A' near the head of the device 3). The internal space thus reduced to negative pressure thus includes not only the periphery of the tank R, but also the space 82 inside this tank R, which communicates with its periphery around the pump P, which is not yet crimped (see Figure 11). Taking into account the structure of the pump preferably used, the connection is naturally made between the neck 15 and the crimping collar 20, since the mechanical and hydraulic conditions together initially exclude the opening of its outlet valve flap. However, the unwanted air is thus expelled from the room 82.

While the suction continues through the lines 308 and 318, the head of the device 3 is lowered somewhat lower onto the cup 110 due to the termination of the supply of pressurized air through the line 314 (see Figure 13, where arrow B is no longer shown). The air initially introduced between the head of the device and its lower crown to keep these two groups of elements at a distance is thus removed through the duct 314'. The system then functions as a leakage damper. In order to increase its damping effect, a flow control valve (not shown) can also be arranged at the outlet of the duct 314' to control the air outlet.

Thus, the central element 317 of the device 3 or centering member is placed on the pump P of the distributor with all the necessary precautions to prevent the latter from being jammed. When the leak-damping member reaches its final position, the pump P is thereby brought into abutment against the neck 15, the periphery of the centering member 317 pressing against the crimping collar 20. The pressing force is also chosen so that the seal 23 arranged between the collar and the neck (see Figure 6) is slightly compressed for optimum sealing.

From this moment, a third group of elements, called hereinafter the squeezing unit, enters into operation of the device according to the present invention. In Figure 14, these elements bear the reference numerals 320 to 329. They are located mainly near the axis of rotation of the device. If one compares their relative positions in Figure 14 with those in Figure 13, one can see:

- a central rod 329 inserted into the axis of the head of the device. It can slide therein so that it can be lowered with respect to the head. For this purpose, a second cylinder (not shown) integral with the conventional machine mentioned above can be used in a similar way to the first cylinder which operates the head;

- a cylindrical sleeve 325, also called a closure cone, with the same axis as the device and fixed connected to the rod 329, so that the sinking of this rod causes the sinking of the sleeve;

- Crimp terminals 320. These, which are described in more detail below with the help of Figures 15 and 16, are this time firmly connected to the head of the device.

In a well-known manner, these clamps 320 are in fact in the form of a thin metal cylinder, a good end portion of which has radial notches arranged at equal distances from one another around the cylinder. The notches thus separate tongues 321 which are thin enough to be radially flexible. For example, the clamps shown from below in Figure 15 comprise ten tongues separated by ten notches. The free end of the tongues is also more solid. Externally, they form together a widening truncated cone. Internally, each zone has a tooth-shaped cross-section.

At the end of the complete pressing in of the leak-damping member formed by the head of the device and its lower crown, the toothed end of the tongues 321 rests around the distribution pump P at the level of the edge of the crimping collar 20. This is shown in Figure 13. The second cylinder then causes the rod 329 and the sleeve 325 to descend. The latter then forces the various tongues 321 of the clamp 320 to approach each other. And as the notches separating them close, the outside diameter of the cylinder formed by the union of the tongues decreases. The small teeth finally rest on the edge of the collar. Provided that the height separating the lower circumference of the centering member 317, which serves as a support, and the tip of the teeth is suitably chosen, the collar is then folded over onto the curve of the neck of the tank, as shown in more detail in Figure 16. By squeezing it open, it now isolates the interior of the tank from the atmosphere, and the suction of air through the lines 308 and 318 can be stopped without running the risk of the space 82 becoming filled again with air. From this point on, the product contained in the tank is already under pressure from the ambient air, which compresses the deformable walls of the tank. This contributes to the reduction of the space 82.

From then on, it is necessary to lift the sleeve 325 and the rod 329 to free the distributor from the grip of the clamp 320. Then the assembly of the head of the device and its lower crown can be pulled upwards again. For example, the cup 110 continues its journey on the carousel to finally free itself from the ramp 101 so that its jaws 120 and 130 relax. Then the shell of the tank, no longer held deformed, increases the pressure of the product it encloses. From now on, the space 82 has completely disappeared and product is automatically admitted into the pumping chamber through its inlet valve flap. In other words, the problem of the suction of the pre-pressure pumps is solved, as shown in Figure 6.

However, there are cases in which this automatic pre-filling of the pump chamber is undesirable. This is particularly the case when a pusher is subsequently to be attached to the actuating rod 40 of the pump. The corresponding operation is in fact accompanied by a pressing of the rod 40. This is of course followed by the dispensing of the contents of the pump chamber. It is understood that an initial gaseous content is desirable in order to avoid contamination of the pusher with paste and to keep the packaging chains clean.

In these cases, another embodiment of the present device is preferred. This does not differ from the previous one with regard to the groups of elements 300 to 308 which form its lower crown and 310 to 318 which form its actual head. Only the crimping unit and, more precisely, the centering member 317 is modified. Figure 17 shows the difference in detail.

Thus, in this version of the present device the centering member 317 is made up of two coaxial cylindrical parts, the upper part 337 being tightly fitted around the lower part (which retains the actual function of the centering member 317). The centering member 317 is also hollow so as to house inside a piston 332 with a piston rod 331 having the same axis as the axis of the centering member 317 and with a diameter comparable to that of the actuating rods 40 of the pumps P. Finally, the hollow of the centering member 317 is provided so that the piston 332 can separate therein, in the usual way, an upper chamber 373 and a lower chamber 371, the isolation of the two chambers being ensured by a seal 335 arranged around the piston 332.

The latter then moves in the cavity of the centering member 317 under the combined action of first of all a pressure, in particular air pressure, introduced into the upper chamber 373 through the duct 334 of the piston rod 331, and then of a return spring 336 arranged around the rod 331 in the lower chamber 371. In Figure 17, this spring pushes the piston 332 completely upwards, which abuts against the upper part 337 at the level of a shoulder 330 of its rod 331 provided for this purpose. By pressurizing the upper chamber 373, the piston 332 can descend against the action of the spring 336, the air contained in the lower chamber being removed through the air outlet 372.

This is followed by the free end of the piston rod 331 being brought into contact with the actuating rod 40 of the pump P and then the pressing of the latter, driven by the rod 331. In particular for the type of pump P described above, this has the effect of putting the pump chamber 55 in communication with the outside of the distributor (see Figure 6). A gas can then be introduced into this chamber 55 through an internal channel 333 which passes through the entire assembly of the rod 331 and its piston 332. Seals 338 and 339, respectively around the piston rod 331 and the base of the centering member 317 arranged around prevent the gas injected through the channel 333 from escaping.

The use of the piston 332 in the manner described above actually takes place at the end of the third phase of the present packaging process and more precisely after the pump P has been fixed to the tank R, while the space formed by the tight fitting of the device 3 onto the cup 1 is still under vacuum. The gas thus injected into the pump chamber can be air at atmospheric pressure, nitrogen at a pressure higher than atmospheric pressure (for example 2 bars) or any other gas at a pressure corresponding to the objective pursued. This objective consists in creating a pressure in the pump chamber such that, after the vacuum around the distributor has been removed, the product it contains does not enter the pump chamber. In other words, the gas must be injected at a sufficient pressure so that, when the original volume of the pump chamber is restored, it is at a pressure higher than the pressure prevailing in the tank of the distributor after its packaging.

This addition to the third phase of the present process, which corresponds to practical accidents, is not, however, necessarily within the scope of the present invention. The reader will even note that it is completely useless in the case of pumps whose inlet into the pump chamber is not controlled by a non-return valve (ball or seal). Not only would it not eliminate the danger of product entering the pump chamber after the chamber has been opened, but it would result in the destruction of the result of the present vacuum packaging process, particularly in the case of air injection through the channel 333.

Apart from the distributor formed by the special deformable sleeve and the special pre-pressure pump described so far, it is clear that the present packaging process has a much wider field of application is applicable. First of all, the types of distribution elements can be very different. This applies not only to their type, but also to their method of attachment to the tank. The crimp connection mentioned above is of course a widely used method of attachment, but rolling is just as common. However, it is generally limited to the attachment of relatively large distribution members (diameter greater than 1"). In this case, use is made of crimping cups 20 such as those shown in section in Figure 18. For example, in the manner of the collar described above, the cup partially covers the pump and its outer edge must, as a result of the crimping, clamp the tank R, in this case a metal container 10e protecting a deformable inner shell 10i. Between these two support points, the cup has an annular groove. The teeth of the clamp 320 fit inside this groove to press the cup under the edge of the tank, while the centering member 317 exerts its abutment force on this edge. The fastening principle therefore remains the same, but the centering member 317 is arranged around the clamp 320. The person skilled in the art will understand that a device similar to that for the vacuum crimping connection according to the present invention can be designed to allow a crimping in this case. under vacuum (for example due to a cam which, by moving around the clamps, causes them to spread apart).

In the same way, the present method can be applied to the fastening of the distribution member by snap-fitting. As shown for example in Figure 19, the pump P then comprises, instead of a collar or a squeezing cup, a ring provided internally with a relief 22. This relief is adapted, for example, to snap-fit onto the curvature of the neck of a tank. The device 3 useful for carrying out the third phase of the method is in this case like that of Figures 11 to 14, except that the squeezing unit is not present. The Fastening is then easy, while the centering element gently comes into contact with the leak damping element on the ring 20.

As regards the tanks R, the same variety remains, provided they are provided with means for varying their capacity. Among the latter, one can first of all mention a tank having a double shell 10 as shown in section in Figure 20. The outer shell 10e is, for example, rigid, while the inner shell 10i or pocket is soft. They can be made in one piece by coextrusion, their only connection point being the perimeter of the collar 15. Then an air hole 17 allows the space between the two shells to be kept at the same pressure as the perimeter of the tank.

It is thus possible to remove the air from the filled inner shell 10i by applying the second and third phases of the present process. To do this, however, it is appropriate that during the first phase the double-shell tank has been placed in a cup similar to that of Figures 7 and 8, even if its jaws are only compressed to hold the tank firmly (and no longer to give it a pre-deformation). After packaging, the inner shell of this tank gradually deforms as more product is dispensed. However, its rigid outer shell still gives it a manageable shape.

Another tank R that can be used in the context of the present invention is shown in axial section in Figure 21. It has a rigid casing 10 of cylindrical shape. This has a constriction in the form of a neck 15 at one end. A collar 20 allows a pump P to be squeezed onto the neck 15, as shown for example in the figure. A seal 23 ensures the tightness of the fastening. In addition, the rod 40 of the pump P is inserted into a push-button 90 which has a distribution nozzle 91. A guide cylinder 92, which for example fits around the collar 15 of the tank also allows correct relative displacement of the push button 90 with respect to the pump P. Finally, a cap 11' placed on the tank allows protection of the distribution member.

The other end of the casing 10 is open. It is closed off from the ambient air by a scraper piston 100'. This has peripheral sealing lips 101' which rest tightly against the inner wall of the casing 10. The piston 100' also has reliefs 102 and 103' in the shape of a crown with the same axis as the tank R. A relief 103' is arranged on the side of the product 80. This minimizes the remaining internal volume when the tank is empty (see Figure 22). The other relief 102' protrudes on the opposite side. When the distributor is full, it determines the end of the stroke of the piston 100' by abutting against a cover 16'. In the embodiment of Figure 21, this cover is clamped between the free end of the casing 10 and a sleeve 12' which is pushed around the latter. The cover 16' finally has an air hole 17 to allow the stripping piston 100' to rise again within the casing 10.

Figures 22 and 23 show the same tank as Figure 21, but this time not only without its cap 11', but also without its pump.

However, it already contains the cover 16' and the sleeve 12', which were previously assembled by the manufacturer of the tanks. It is now at the manufacturer of the product to be packaged, for example the pharmacist or the manufacturer of cosmetic products, who wants to subject it to a preliminary filling operation, which has just begun in Figure 22 and is carried out in Figure 23. For this purpose, for example, a stopper 202 is brought into contact with the neck 15' and pressed against it. An injection nozzle 200 passes through this stopper 202. The product 80 is filled under pressure through this injection nozzle 200. It first fills the space inside the crown 103' of the scraper piston 100' (see Figure 22) and reaches by pushing the piston 100' towards the free end of the casing 10 (see Figure 23). This method makes it possible to fill practically the entire casing 10 (except for the space 82 corresponding to the original internal volume of the neck 15 and the crown 103') without the risk of trapping air bubbles.

After this filling and after removing the plug 202 and the injector 200, a pump is squeezed onto the tank, for example, according to the vacuum packaging process described above. This creates a distributor according to Figure 21 described above. The product 80 it contains is thus protected from air. The dispensing by the distributor pump P is made possible by the scraper piston 100' which moves in the casing 10 and adapts the capacity of the tank R to the remaining quantity of product.

Finally, another way of obtaining a variable capacity dispenser consists in filling a tank R of the bottle or container type with a propellant gas which is to be placed, for example, above a liquid product to be dispensed. To form such a dispenser, the rigid tank is first filled. This is done, for example, by means of an injector which rises in the tank as more product is poured in. In fact, the tip of the injector remains at the level of the surface of the product, which minimizes the entrapment of air bubbles. A pump of the type shown in Figures 24 and 25 is then squeezed in accordance with the vacuum packaging process described above. Once the product is thus hermetically sealed in the dispenser, propellant gas can be poured into the tank by such a pump.

This is a pre-pressure metering pump P of the known type, as described in the French patent application No 88-08653 filed by the applicant. It comprises two movable pistons 40' and 60', which arranged one above the other inside a pump body 50' with a first open end and a second end, narrowed in the form of a tube, to be placed in the tank R. The outer piston 40' is hollow with an internal delivery channel 41' and also acts as a piston, while the peripheral sealing lips 42' rest tightly against the inner wall of the pump body 50'. The inner piston 60' is a differential piston and cooperates with the outlet and inlet valve flaps. To this end, it comprises, on the one hand, a needle 61' which fits into the delivery channel 41' to rest against a terminal throat of the latter, and, on the other hand, a sleeve 62' which can be pushed tightly onto a sleeve 52' which projects from the bottom of the pump body 50' and communicates with the tank R.

These two pistons 40' and 60' act together, on the one hand, thanks to a spring 70' arranged between the pump body 50' and the differential piston 60' and, on the other hand, thanks to a ferrule 30' fixed, for example, to the open end of the pump body 50' by means of a crimp collar 20'. The pressing of the hollow piston 40' first causes the differential piston 60' to descend so that its skirt 62' comes into contact with the sleeve 52' and closes the inlet valve flap. From this, the pressure of the product enclosed in the annular space between the pump body 50' and the sleeve 52' and the skirt 62', space which is nothing other than the pump chamber, increases. When it reaches a value sufficient to cause the lowering of the differential piston 60' with respect to the hollow piston 40' against the force of the spring 70', the product can be dispensed with a pre-pressure effect through the open passage between the needle 61' and the end constriction of the outlet channel 41'.

The output continues as long as the piston 40' descends. When it reaches the end of its stroke, the user stops applying force so that the spring 70' relax and cause the pistons 40' and 60' to rise again. The pump chamber defined above increases its volume again and a vacuum is created. Finally, when the jacket 62' leaves the sleeve 52', thereby opening the inlet valve flap, the vacuum is such that product is sucked from the tank R into the chamber.

In order to allow the tank R to be filled with propellant gas by the pump P, the design and function of the components just described also includes the following special features:

* the tip of the needle 61' has a small recess 66' to accommodate a needle tip. This is, for example, part of a machine for filling with propellant gas. It is then inserted into the delivery channel 41' to push the needle 61' back with respect to the hollow cylinder 40'. In Figure 25, the needle tip (not shown) has pushed the differential piston 60' all the way down to the sleeve 52';

* at the base of its needle 61', the differential piston 60' includes ridges 65' which maintain a minimum distance between the two pistons;

* the inner wall of the pump body 50' is provided with an annular shoulder 51' directed towards its open end. As shown in more detail in Figure 5, it is intended to form a stop for the sealing lips 42' of the hollow cylinder 40', and this after such a stroke that the differential piston 60' can penetrate even deeper into the pump body 50';

* Finally, at the outer root of the sleeve 52', ribs 53' protrude, some of which rise up along the sleeve 52'. In this way, the sealing lip 63' of the casing 62' can rise up on the ribs 53' as soon as the differential piston 60' has sunk all the way down. If necessary, teeth 54' at the upper end of the sleeve 52' prevent the underside of the casing 62' from resting too tightly on the sleeve 52'. This leaves a passage to connect the pump chamber and the inside of the tank.

Filling with propellant gas is therefore carried out by pushing back the differential piston 60' with the aid of a needle which rests in the recess 66', until the casing 62' rises onto the ribs 53'. At the same time, the hollow piston 40' can either not be moved at all or also come into contact with the shoulder 51'. In all cases, the outlet valve flap is thus kept open. In other words, there is now a passage from the outside into the tank, with the pump chamber being in communication with the tank via the cavities remaining between the ribs 53' and between the teeth 54'.

When the propellant gas is inside the tank, it not only pressurizes the product to be dispensed, but also expands as more product is dispensed. Thus, the distributor equipped with such a pump can contain a rigid tank.

Such vacuum-packaged distributors are mainly useful for preserving products for which contact with ambient air is harmful. What they have in common is that they use a tank with a variable capacity. Since it is filled when its capacity is at its maximum, the present process allows any air to be removed from it before sealing a distributor without re-intake of air. In addition, this is carried out in a room so that the vacuum is created both inside and outside the tank. This therefore avoids the emptying of product from the tank during packaging. And it is actually the entire maximum capacity of the tank that is occupied by the product when the packaged distributor is finally placed on the market.

Claims (25)

1. Process for vacuum packaging a product with a consistency ranging from that of a liquid to that of a paste in a tank (R) of variable capacity closed by a distribution member without air intake, the process comprising at least one phase of sealingly fixing the member to the tank (R) filled with the product (80), characterized in that the sealing of the member is carried out when the tank (R) is located in a space (1, 3) in which an air vacuum is maintained. 2. Method according to claim 1, wherein the distribution member is a pump (P) with a hollow actuating rod (40) which, when pressed, communicates with a pump chamber (55), the inlet into the chamber (55) being controlled by a non-return valve (52), characterized in that after the pump (P) has been tightly secured, the hollow rod (40) is pressed and a gas is injected into the hollow rod (40) while the tank (R) and its pump (P) secured to it are still in the space (1, 3) kept under vacuum, the gas being injected at a pressure sufficient so that after the atmospheric pressure around the tank (R) has been restored, the pressure there is lower than in the pump chamber (55) so that the product cannot penetrate into it. 3. Process according to claim 2, characterized in that the gas is air injected at atmospheric pressure. 4. Method according to claim 2, characterized in that the Gas is nitrogen, which is injected at a pressure higher than atmospheric pressure. 5. Method according to claim 1, in which the tank (R) has a deformable shell (10), characterized in that before fixing the member in the vacuum chamber, the tank (R) is filled at atmospheric pressure while its shell (10) is kept deformed so that the tank has its maximum capacity. 6. Method according to claim 1, in which the tank (R) has a rigid shell (10, 10e) and means for varying its capacity, characterized in that before fixing the member in the vacuum chamber, the tank (R) is filled at atmospheric pressure while its rigid shell (10, 10e) is mechanically held. 7. Method according to claim 6, characterized in that the means for changing the capacity of the tank (R) consist of a flexible casing (10i) firmly connected to the rigid casing (10e) and arranged in it, the rigid casing (10e) having a ventilation hole (17). 8. Method according to claim 6, characterized in that the rigid casing (10) is a cylinder having a neck (15) at one end while its other end is open, and in that the means for varying the capacity of the tank (R) consist of a scraper piston (100') which seals the open end and can rotate from a low position in which the tank (R) is full to a high position in which the tank (R) has been emptied. 9. Method according to claim 8, characterized in that the stripping piston (100') has a crown (103') which projects on the side of the product (80) and has such a shape, that the distribution member is arranged in the crown (103') when the stripping piston (100') is in the high position, thus reducing the amount of product (80) remaining in the emptied tank (R). 10. A method according to claim 8 or claim 9, characterized in that the stripping piston (100') has, on the side opposite the product (80), a crown (102') which projects far enough to abut against a lid (16') with a vent hole (17) held on the open end of the tank (R) to close it. 11. Method according to any one of claims 8 to 10, characterized in that, before fixing the distribution member on the tank (R), the product (80) is introduced under pressure into the tank (R) by means of an injection nozzle (200) passing through a plug (202) arranged on the neck (15), the scraper piston (100') being in the high position in the tank (R), which is emptied at the start of the introduction of the product (80). 12. Method according to claim 6, characterized in that the means for varying the capacity of the tank (R) consist of a propellant gas arranged above the product (80), the distribution member then being a pre-compression metering pump (P) having a differential piston (60') having on one side a needle (61') for fitting into a hollow piston (40') in a discharge channel (41') and forming with it an outlet valve, and on the other side a skirt (62') for telescopically and tightly fitting around a sleeve (52') fixed to a pump body (50') and forming with it an inlet valve, the sleeve (52') having projections (53', 54') capable of breaking the seal between the skirt (62') and the sleeve (52') when the differential piston (60') is pushed to the bottom. of the pump body (50'). 13. Device for applying the method according to any one of the preceding claims, in which the tank (R) has a neck (15) on which the distribution member can be tightly fixed and, before the phase of tightly fixing the member, at least the phases of 1/ Fixing the tank (R) in a cup (110) having an open top so that the neck (15) sits on the top, and 2/ filling the tank (R) with the product through the neck (15), after which the device is placed on the neck (15), characterized in that the device (3) has a crown (300, ..., 308) which can be placed tightly on the bottom of the top of the cup (110) to form the space (1, 3), means (308, 318) being provided for sucking the air out of the space (1, 3), and in that the device (3) is provided with means (320, ..., 329) for fastening the distribution element, which are arranged in the middle of the crown (300, ..., 308). 14. Device according to claim 13, characterized in that the crown (300, ..., 308) rests tightly on the top of the cup (110) by means of an annular sealing lip (307) which bears against a circular edge (115) firmly connected to the cup (110). 15. Device according to claim 13 or claim 14, characterized in that the cup (110) is movable and that the device (3) is moved downwards onto the cup (110) by the actuation of a first cylinder (310) when the cup (110) is vertically below the device (3). 16. Device according to claim 15, characterized in that the cup (110) is arranged on a circular conveyor (100). 17. Device according to any one of claims 13 to 16, characterized in that the means (320, 329) for fixing the member comprise a centering device (317) compatible with the member and ending in a support serving as a stop for a fixing element (20) of the member, the centering device (317) being integral with a head (310, ..., 318) of the device (3), the crown (300, 308) of the device (3) being connected to the head (310, ..., 318) by a system of the leakage damper type, so that when the crown (300, ..., 308) rests on the cup (110), the centering device (317) can be slowly lowered onto the member until the support exerts a suitable pressure on the fixing element (20) of the member exercises. 18. Device according to claim 17, characterized in that the fastening element (20) of the member is a ring with an internal relief (22), the pressure exerted by the support being sufficient to cause the relief (22) to snap into place around the neck (15) of the tank (R). 19. Device according to claim 17, characterized in that the element (20) for fixing the member is a clamping collar, the pressure exerted by the support being sufficient to cause compression of a seal (23) arranged between the collar and the neck (15) of the tank (R), and in that the means (320, ..., 329) for fixing the member also comprise clamps (320) firmly connected to the head (310 318) of the device (3) and capable of being clamped onto the clamping collar by a closure cone (325) which a second cylinder slides around the clamps (320). 20. Device according to claim 17, characterized in that the element (20) for fixing the member is a clamping shell, the pressure exerted by the support being sufficient to place the clamping shell on the neck (15) of the tank (R), and in that the means (320, ..., 329) for fixing the member also comprise clamps integral with the head (310, ..., 318) of the device (3) which can be spread against the shell below the neck (15) by a cam which a second cylinder moves with respect to the clamps (320). 21. Device according to any one of claims 17 to 20, in which the distribution member is a pump (P) with a hollow actuating rod (40) communicating with a pump chamber (55) when it is depressed, the inlet into the pump chamber (55) being controlled by a check valve (52), characterized in that the centralizer (317) comprises a rod (331) of a diameter comparable to that of the actuating rod (40) of the pump (P), has an axial channel (333) and is integral with a piston (332) which causes it to rotate axially in the centralizer (317). 22. Device according to claim 21, characterized in that the piston (332) is arranged in a recess of the centering device (317) where it tightly delimits an upper chamber (373) and a lower chamber (371), a channel (334) drilled into the rod (331) opening into the upper chamber (373), while a return spring (336) is arranged around the rod (331) in the lower chamber (371). 23. Device according to claim 22, characterized in that an upper part (337) slides tightly onto the centering device (317) and provides a stop for the piston (332) at the level of a shoulder (330) of its rod (331) against the action of the spring (336). 24. Device according to any one of claims 13 to 23, characterized in that the cup (110) has two jaws (120, 130) forming a vice (1) for securing the tank (R). 25. Device according to claim 24, characterized in that one of the jaws (120, 130) is fixedly connected to a rod (131) projecting from the cup (110), a return spring (134) surrounds the rod (131) in such a way as to oppose the approach of the jaws (120, 130) of the vice (1), and a roller (133) is fixed to the end of the rod (131), a ramp (101) being further provided against which the roller (133) can roll when the cup (110) moves, the ramp (101) then being arranged with respect to the cup (110) in such a way that the jaws (120, 130) remain approached against the action of the spring (134).