Device for sealing a tank of a liquid product

Abstract

A closure device for a fluid product reservoir (10) having a neck (11), comprising: - a cap (1), - a retaining ring (20) for retaining said cap (1) on said neck (11), said retaining ring having a cylindrical structure (210) comprising wall portions (211) separated by lateral windows (212), each wall portion (211) having at least one internal radial projection (26) for retaining said cap (1) in said retaining ring (20), each lateral window (212) having a lower edge (212') having at least one rigid lug (21) extending radially inward from said lower edge (212'), said rigid lugs (21), in the closure position of said retaining ring (20), being disposed under a neck of said reservoir (10), thus securing said retaining ring (20) on said reservoir (10), - a locking cover (30) comprising a cylindrical wall (34) and an upper wall (35),said locking cap (30) being disposed around said fixing ring (20), to lock said fixing ring (20) in its closing position, the upper surface of said cap (1) having a deformation profile (12) which cooperates, after assembly, with said fixing ring (20).

Description

[0001] The present invention relates to a device for sealing a reservoir of a fluid product, for example, a bottle containing a pharmaceutical fluid. A preferred application of the present invention is that of freeze-drying stoppers that can be pierced with a needle. The present invention also relates to a method for manufacturing such a sealing device.

[0002] In general, a freeze-drying stopper consists of a stopper made of a substantially flexible material, such as an elastomer, which is press-fitted into the neck of the tank. Means for positioning the stopper in an intermediate, partially assembled position, combined with a lateral cutout in the stopper, allow freeze-drying of the tank contents in this intermediate position. After freeze-drying, the stopper is pushed into its closed position, in which it seals the tank airtight, and a metal ring is fitted, typically crimped, around the stopper to secure it to the tank neck.

[0003] This known implementation has several drawbacks.

[0004] Thus, the surface area for heat exchange between the inside and outside of the reservoir during freeze-drying is small, typically less than 25 mm², and it is not possible to increase the dimensions of the side cutout without risking rendering the stopper inoperative in the closed position. Furthermore, prior art stoppers must be silicone-coated, particularly for transport and storage, to prevent them from sticking together, but also during freeze-drying, to prevent the stopper from sticking to the freeze dryer shelf. Another drawback is the risk of the stopper suddenly popping out of the reservoir neck at the end of freeze-drying, before the ring is crimped. Moreover, due to its structure, especially its shape with the side cutout, it is difficult, if not impossible, to apply a coating, such as an ETFE film, to the side of the stopper that comes into contact with the drug in the reservoir.Furthermore, the use of a metal ring, usually made of aluminum, can generate metal particles during the crimping process onto the tank neck, potentially harmful to the fluid inside the tank. More generally, the use of metal parts is disadvantageous in terms of recycling and environmental impact.

[0005] Documents US2021009319 and US2013312373 describe prior art devices. US2012187072A1 discloses a tank sealing device according to the preamble of claim 1.

[0006] The present invention aims to remedy the aforementioned drawbacks.

[0007] The present invention aims in particular to provide a sealing device that is completely free of silicone.

[0008] The present invention also aims to provide a sealing device that is completely free of metal.

[0009] The present invention also aims to provide a sealing device which substantially increases the exchange surface area during freeze-drying.

[0010] The present invention also aims to provide a sealing device which avoids any risk of malfunction between the end of freeze-drying and final assembly.

[0011] The present invention also aims to provide a sealing device which allows the use of a stopper having a coating on the side in contact with the drug.

[0012] The present invention also aims to provide a sealing device that is simple and inexpensive to manufacture and assemble.

[0013] The present invention therefore relates to a device for sealing a fluid product reservoir, comprising: a cap, a retaining ring for retaining said cap on said tank, said retaining ring having a cylindrical structure comprising wall portions separated by lateral windows, each wall portion having at least one internal radial projection for retaining said cap in said retaining ring, each lateral window having a lower edge provided with at least one rigid lug extending radially inwards from said lower edge, said rigid lugs, in the sealing position of said retaining ring, being disposed under a neck of said tank, thus securing said retaining ring to said tank, a locking cover comprising a cylindrical wall and an upper wall, said locking cover being disposed around said retaining ring, for locking said retaining ring in its sealing position,the upper surface of said cap having a deformation profile which, after assembly, cooperates with said fixing ring.

[0014] The said deformation profile includes a peripheral groove provided with a plurality of elastically deformable axial projections.

[0015] Advantageously, said upper wall of said blocking cover comprises flexible wall sections, separated by radial grooves, said flexible wall sections, which surround said central passage, making it possible to guarantee a play-free assembly when fixing said blocking cover onto said fixing ring.

[0016] Advantageously, said stopper is a freeze-drying stopper, said fixing ring being movable on the neck between a freeze-drying position, in which the stopper does not seal said neck hermetically, and its sealing position, in which said stopper seals said neck hermetically, said locking cap being movable on said fixing ring between a freeze-drying position and its locking position, in which it locks said fixing ring in its sealing position.

[0017] Advantageously, each wall portion of said fixing ring comprises at least one first external radial projection and at least one second external radial projection, said first and second external radial projections being axially offset from each other.

[0018] Advantageously, said locking hood has in its cylindrical wall at least one internal radial profile, which, in the freeze-drying position, is wedged between said first and second external radial projections of said fixing ring, so as to maintain said locking hood in its freeze-drying position on said fixing ring.

[0019] Advantageously, said cylindrical structure of said fixing ring has an axially lower edge having radially inward projecting profiles, which, in the freeze-drying position, are arranged under the neck of said tank to retain said fixing ring on said tank in the freeze-drying position.

[0020] Advantageously, said lower edge of each side window has an external radial profile extending radially outwards from said lower edge, said locking cover having in its cylindrical wall at least one internal radial profile, so that in the locking position of said locking cover, said at least one internal radial profile snaps under said external radial profiles of the fixing ring, to hold said locking cover on said fixing ring in its locking position.

[0021] Advantageously, in the freeze-drying position, the exchange surface between the inside and outside of said reservoir is greater than 50 mm², advantageously about 80 mm².

[0022] Advantageously, said fixing ring comprises a substantially flat upper plate including a central opening, said locking cover comprising an upper wall defining a central passage aligned with said central opening of said fixing ring, said device comprising a removable pad fixed on the external surface of said upper wall of said locking cover, for closing said central passage.

[0023] Advantageously, said disc has foldable tabs adapted to fold under an edge of said central passage.

[0024] Advantageously, the device is silicone-free.

[0025] Advantageously, the device is metal-free.

[0026] Advantageously, said cap has on its lower surface facing the inside of said tank a coating, in particular a thin film of ETFE (ethylene tetrafluoroethylene), in order to limit the interactions between said cap and said fluid product.

[0027] The present invention also relates to an assembly comprising a fluid product reservoir including a neck provided with a sealing device as described above to hold a stopper on said neck.

[0028] The present invention also relates to a method for assembling a sealing device as described above, comprising the following steps: to provide a deburring type assembly machine, comprising a die, made in the form of a hollow sleeve, and a punch associated with an ejector cooperating with said die, to mold a fixing ring, and to place said fixing ring on a first side of said die, to mold without silicone a fabric, in particular of rubber, to form plugs, and to place said fabric on a second side of said die, to move said punch together with said ejector relative to said die to cut a plug in said fabric and bring it opposite said fixing ring, to move said ejector relative to said die to push and fix said plug in said fixing ring.

[0029] These and other features and advantages of the present invention will become more apparent from the following detailed description, made with reference to the accompanying drawings, given by way of non-limiting example, and in which: There figure 1 is a schematic side view of a tank equipped with a closure device, The figure 2 is a schematic top-view perspective view of a stopper according to an advantageous embodiment, The figure 3 is a schematic top perspective view of a fixing ring according to an advantageous embodiment, The figure 4 is a view similar to that of the figure 3 From below, The figure 5 is a schematic top-view perspective view of a locking cover according to an advantageous embodiment, and The figure 6 is a view similar to that of the figure 5 , from below.

[0030] The terms "axial" and "radial" refer to the longitudinal central axis of the device. The terms "top," "bottom," "upper," and "lower" refer to the upright position of the device as represented on the figure 1 .

[0031] A reservoir 10, which can be made of plastic or glass, is formed with a neck at its upper part. The reservoir can notably be in the form of a bottle.

[0032] A stopper 1 made of elastically deformable material, such as rubber or any other elastomeric material, is provided to provide a tight seal for the reservoir 10. This stopper 1 has a cylindrical plate which, in the closed position, rests on the upper edge of the reservoir 10. Advantageously, the lower surface of the stopper 1 which comes into contact with the fluid product contained in the reservoir 10, can be provided with a coating, in particular a thin film of ETFE (ethylene tetrafluoroethylene), in order to limit the interactions between the stopper 1 and the fluid product.

[0033] A fixing ring 20 is provided to fix the cap 1 onto the reservoir 10. The ring 20 is movable between a freeze-drying position, in which freeze-drying can be carried out, and a sealing position, in which the cap 1 seals the reservoir 10 in a hermetic manner.

[0034] A locking hood 30 is provided around the fixing ring 20, said locking hood 30 being movable between a freeze-drying position, in which it cooperates with an upper part of the fixing ring 20, and an assembled position, in which it locks the fixing ring 20 in its sealing position on the reservoir 10.

[0035] The plug 1 has an external diameter adapted to the internal diameter of the retaining ring 20, so that it does not move when placed in the ring. The central part of the plug 1 forms a spigot area 11. The upper surface of the plug 1 has a deformation profile 12 which, after assembly, cooperates with the retaining ring 20 to distribute stresses onto the neck of the reservoir 10 while axially compensating for dimensional variations. This deformation profile 12 has a peripheral groove 14 provided with a plurality of elastically deformable axial projections 13.

[0036] The retaining ring 20 has a generally cylindrical shape, with a substantially flat upper plate 200 comprising a central opening 201 aligned with the tapping area 11 of the cap 1. The lower portion axially opposite the upper plate 200 is open to receive the reservoir 10. The upper plate 200 is connected to a cylindrical structure 210, for example by radial struts 205. The cylindrical structure 210 comprises wall sections 211 separated by upward-opening lateral windows 212. In the example of the figures 3 et 4 There are four wall sections 211 and four side windows 212 arranged alternately around the periphery of the cylindrical structure 210. A different number of these elements is possible, for example three. Each wall section 211 may have a cutout 211' open at the bottom.

[0037] The upper plate 200 has at least one axial projection 24, advantageously peripheral, near the central opening 201. The axial projection 24 cooperates during assembly with the deformation profile 12 of the plug 1, to compensate for dimensional variations in the plug 1 and / or the fixing ring 20 and / or the reservoir 10. This also maintains sufficient pressure on the plug 1 to ensure sealing and therefore the integrity of the fluid product contained in the reservoir 10.

[0038] Each wall section 211 has at least one internal radial projection 26 which serves to hold the cap 1 in the retaining ring during the assembly of the sealing device on the reservoir 10. During the assembly of the sealing device, the cap 1 is pushed against the upper plate 200 of the retaining ring, and snaps into place on said internal radial projections 26 of the wall sections 211. The cap 1 is then wedged between the plate 200 and the internal radial projections 26, which holds the cap 1 securely in the retaining ring 20.

[0039] Each wall portion 211 has at least one first external radial projection 27 and at least one second external radial projection 27', which serve to maintain the locking cap 30 in its freeze-drying position on the retaining ring 20. The two external radial projections 27, 27' are axially offset from each other. Advantageously, each wall portion 211 has a first external radial projection 27 surrounded by two second external radial projections 27', as seen in the figures 3 et 4 .

[0040] Each side window 212 has a lower edge 212' provided with at least one rigid lug 21 extending radially inwards from said lower edge 212'. In the example of the figures 3 et 4There are two lugs 21 on each lateral side of said lower edge 212'. Furthermore, said lower edge 212' of each lateral window 212 has an external radial profile 23 extending radially outwards from said lower edge 212'. In the closed position of the retaining ring 20, the rigid lugs 21 of the retaining ring 20 are arranged under the neck of the reservoir 10, thus fixing said ring 20 to said reservoir.

[0041] The axially lower edge 210' of the cylindrical structure 210 has profiles 22 projecting radially inwards. In the freeze-drying position, the inwardly projecting profiles 22 are located below the neck of the reservoir 10, and the rigid lugs 21 are located on the neck of the reservoir 10. This allows the retaining ring 20 to be held on the neck of the reservoir 10 in the freeze-drying position.

[0042] The locking cover 30 comprises a cylindrical wall 34 closed on one axial side by an upper wall 35 defining a central passage 36 which is aligned with the opening 201 of the fixing ring 20 and the spigot area 11 of the plug 1. The upper wall 35 advantageously includes flexible wall sections 37, separated by radial grooves 38. These flexible wall sections 37, which surround the central passage 36, ensure a play-free assembly when the locking cover 30 is fixed to the fixing ring 20.

[0043] A removable disc (not shown) is fixed to the external surface of the upper wall 35 of the locking cover 30, to close said central passage 36. Advantageously, said disc may have foldable tabs adapted to fold under the edge of said central passage 36. When the user wishes to use the fluid product contained in the reservoir 10, he removes the disc from the locking cover 30, in particular by pulling it off, which allows him to access the reservoir 10 with a needle adapted to pierce the stopper 1 after passing through the central passage 36 of the locking cover and the central opening 201 of the fixing ring 20.

[0044] The blocking cover 30 has in the lower part of its cylindrical wall 34 at least one internal radial profile 32. Advantageously, said internal radial profile 32 extends over the entire periphery of the cylindrical wall 34.

[0045] In the freeze-drying position, said internal radial profile 32 is wedged between the first and second external radial projections 27, 27' of the fixing ring 20, so as to maintain the locking cover on the fixing ring 20, in its freeze-drying position.

[0046] After freeze-drying, an axial force is applied to the locking cap 30, which first moves the retaining ring 20 into its sealing position, with the rigid lugs 21 passing under the neck of the reservoir 10. When the retaining ring 20 reaches the sealing position, the stopper 1 is compressed onto the reservoir 10, ensuring a leak-proof seal. Simultaneously, the locking cap 30 is moved into its locking position to secure the sealing device to the reservoir 10.

[0047] In the assembled position of the locking cover 30, i.e., the locked position, with the retaining ring 20 in the closed position, the rigid lugs 21 of the retaining ring 20 are positioned under the neck of the tank. This locks the closure device onto the neck. Furthermore, in this assembled position of the locking cover 30, the internal radial profile 32 of the locking cover 30 snaps into place under the external radial profiles 23 of the retaining ring 20, thus securing the locking cover 30 in its assembled position.

[0048] The assembly process uses a deburring-type assembly machine, comprising a die, made in the form of a hollow sleeve, which receives a fixing ring on one side and a fabric, typically made of rubber, on the other to form the plugs. A punch associated with an ejector cooperates with the die, as explained below.

[0049] The fabric emerges from the silicone-free molding stage and is positioned on the upper edge of the matrix. The fixing ring, previously injected in a cleanroom, is placed on the opposite edge of the matrix.

[0050] The punch and ejector descend together, causing the cap to be cut by shearing with the upper edge of the die.

[0051] When the plug, separated from its fabric, reaches the level of the retaining ring, the punch stops. The ejector continues its descent in the die, carrying the plug with it, until it comes into position in the retaining ring.

[0052] After the plug is assembled in the retaining ring, the punch and ejector return to their initial positions. Internal radial projections hold the plug inside the retaining ring.

[0053] Advantageously, washing of the fixing ring is provided before or after assembly of the cap in said fixing ring.

[0054] The present invention therefore provides, in particular, the following advantages: Because the stopper is not inserted into the neck of the tank during freeze-drying, the exchange surface area is significantly increased, potentially exceeding 50 mm²; in the example shown in the figures, this exchange surface area is 80 mm²; the dimensions of the side windows 212 and the cutouts 211' can be adapted to optimize this exchange surface area; such an increase in the exchange surface area, which can more than double compared to the prior art, significantly accelerates the freeze-drying process; it should be noted that this increase in the exchange surface area is independent of the presence or absence of the deformation profile 12 on the upper surface of the stopper 1; because the stopper 1 is housed in the retaining ring 20 from the moment of manufacture, it is not necessary to silicone the stoppers; indeed, they will never be in contact with each other, nor with the shelf of the freeze dryer;Because, in the freeze-drying position, the cap 1 is fixed in the fixing ring 20, there is no risk of it suddenly coming out of the neck after freeze-drying; Because it is no longer necessary to use a crimpable metal ring, particularly one made of aluminum, it avoids the generation of potentially harmful particles and facilitates the recycling of the device.

[0055] Of course, alternative embodiments are conceivable, without departing from the scope of the present invention, as defined by the attached claims.

Claims

1. Device for blocking a fluid product reservoir (10), comprising: - a cap (1), - a fixing ring (20) to hold said cap (1) on said reservoir (10), said fixing ring (20) comprising a cylindrical structure (210) comprising wall parts (211) separated by lateral windows (212), each wall part (211) comprising at least one inner radial projection (26) to hold said cap (1) in said fixing ring (20), each lateral window (212) comprising a lower edge (212') provided with at least one rigid lug (21) extending radially inwards from said lower edge (212'), said rigid lugs (21), in the blocking position of said fixing ring (20), being arranged under a neck of said reservoir (10), to thus fix said fixing ring (20) on said reservoir (10), - a blocking cover (30) comprising a cylindrical wall (34) and an upper wall (35), said blocking cover (30) being arranged around said fixing ring (20), to lock said fixing ring (20) in its blocking position, the upper surface of said plug (1) comprising a deformation profile (12) which engages, after assembly, with said fixing ring (20), characterised in that said deformation profile (12) comprises a peripheral groove (14) provided with a plurality of elastically deformable axial projections (13).

2. Blocking device according to claim 1, wherein said upper wall (35) of said blocking cover (30) comprises flexible wall parts (37), separated by radial grooves (38).

3. Blocking device according to any one of the preceding claims, wherein said cap (1) is a freeze-drying cap, said fixing ring (20) being movable on the neck (11) between a freeze-drying position, wherein the cap does not block said neck (11) in a sealed manner, and its blocking position, wherein said cap (1) blocks said neck (11) in a sealed manner, said blocking cover (30) being movable on said fixing ring (20) between a freeze-drying position and its blocking position, wherein it locks said fixing ring (20) in its blocking position.

4. Blocking device according to claim 3, wherein each wall part (211) of said fixing ring (20) comprises at least one first outer radial projection (27) and at least one second outer radial projection (27'), said first and second outer radial projections (27, 27') being axially offset from one another.

5. Blocking device according to claim 4, wherein said blocking cover (30) comprises in its cylindrical wall (34) at least one inner radial profile (32), which, in the freeze-drying position, is wedged between said first and second outer radial projections (27, 27') of said fixing ring (20), to thus hold said blocking cover (30) in its freeze-drying position on said fixing ring (20).

6. Blocking device according to any one of claims 3 to 5, wherein said cylindrical structure (210) of said fixing ring (20) comprises an axially lower edge (210') comprising profiles (22) projecting radially inwards, which, in the freeze-drying position, are arranged under the neck of said reservoir (10) to hold said fixing ring (20) on said reservoir (10) in the freeze-drying position.

7. Blocking device according to any one of claims 3 to 6, wherein said lower edge (212') of each lateral window (212) comprises an outer radial profile (23) extending radially outwards from said lower edge (212'), said blocking cover (30) comprising in its cylindrical wall (34) at least one inner radial profile (32), such that in the blocking position of said blocking cover (30), said at least one inner radial profile (32) is snap-fitted under said outer radial profiles (23) of the fixing ring, to hold said blocking cover (30) on said fixing ring (20) in its blocking position.

8. Blocking device according to any one of claims 3 to 7, wherein, in the freeze-drying position, the exchange surface between the inside and outside of said reservoir (10) is greater than 50mm2, advantageously around 80mm2.

9. Blocking device according to any one of the preceding claims, wherein said fixing ring (20) comprises a substantially flat upper plate (200) comprising a central opening (201), said blocking cover (30) comprising an upper wall (35) defining a central passage (36) aligned with said central opening (201) of said fixing ring (20), said device comprising a removable patch fixed on the outer surface of said upper wall (35) of said blocking cover (30), to close said central passage (36).

10. Blocking device according to claim 9, wherein said disc comprises foldable tabs adapted to be folded under an edge of said central passage.

11. Blocking device according to any one of the preceding claims, wherein said device has no silicone.

12. Blocking device according to any one of the preceding claims, wherein said device has no metal.

13. Blocking device according to any one of the preceding claims, wherein said cap (1) comprises a coating on its inner surface rotated inwards from said reservoir (10), in particular a thin ETFE (ethylene tetrafluoroethylene) film, in order to limit the interactions between said cap (1) and said fluid product.

14. Assembly comprising a fluid product reservoir (10) comprising a neck provided with a blocking device according to any one of the preceding claims to hold a cap (1) on said neck.

15. Method for assembling a blocking device according to any one of claims 1 to 13, characterised in that it comprises the following steps: - providing an assembly machine of the trimming type, comprising a matrix, made in the form of a hollow sleeve, and a punch associated with an ejector engaging with said matrix, - moulding a fixing ring (20), and arranging said fixing ring (20) on a first side of said matrix, - silicone-free moulding a sheet, in particular made of rubber, to form caps (1), and arranging said sheet on a second side of said matrix, - moving said punch together with said ejector with respect to said matrix to cut a cap (1) in said sheet and bring it opposite said fixing ring (20), - moving said ejector with respect to said matrix to push and fix said cap (1) in said fixing ring (20).

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