CLIP-ON BOTTLE MOLD

Description

technical field

[0001] The invention relates to the field of blow molding using a preform to manufacture a container with a neck and an undercut. More particularly, the container is a module of a container composed of a plurality of such containers, arranged axially to one another with a cooperative connection between the bottom of one container and the neck of another axially adjacent container. The invention specifically relates to a mold for the blow molding of a preform to obtain such a container with an undercut in its bottom, the manufacturing process using said mold, and a container composed of a plurality of containers manufactured by implementing this process. Previous technique

[0002] Among containers, we know of bottle-shaped or similar containers designed to hold liquid products, particularly beverages. Such containers have a tubular neck at their proximal end, equipped with easily reversible means, such as screwing, for joining to a removable cap. The neck extends towards the distal end of the container with a flared neck, and then axially with a body that is closed at its base by a bottom formed at its distal end.

[0003] It is common to form such containers by blow molding using a preform installed inside a mold. This molding technique is advantageous for producing thin-walled containers at lower costs and high production rates. The mold is primarily composed of at least two side shells and a base. The shells are laterally movable for opening and closing the mold and have a gripping mechanism at their apex for a collar on the preform, which is then held inside the mold during the blow molding process. The base of the mold may be axially movable to form the open cavity of the container's bottom.

[0004] Containers have been proposed that consist of a plurality of necked containers that can be axially assembled with a cooperative mechanism between the base of an upper container and the neck of a lower container. The base of the upper container has a cavity that houses the extended neck of the flared neck of the lower container. This cavity includes a tubular space for receiving the neck, which is extended by a flared pocket. The assembly between the upper and lower containers is achieved through the cooperative interlocking of axially compatible interlocking elements present in their respective containers. In the assembled position, an interlocking element of the lower container is embedded within a complementaryly shaped interlocking element of the upper container.This interlocking mechanism is achieved through elastic deformation of one or both of the interlocking components, preventing spontaneous separation of the containers under the weight of the lower container, particularly when the container is supported by the upper container. To assemble or separate the containers, the operator applies force to deform one or both of the interlocking components, causing them to either cooperate or, conversely, separate.

[0005] The applicants have developed ( Figures 1 And 2) a modular container (described in WO2012104499A2) composed of necked containers with axial interlocking mechanisms achieved through cooperation between their base and neck. This axial interlocking between containers can be obtained at lower costs and high production rates by blow-molding a preform in thermoplastic material, despite the requirement for the thinnest possible wall thickness to save material, and despite the presence of an undercut used to form an interlocking element within the containers.

[0006] More specifically, said modular container is composed of a plurality of containers 1 with necks that can be axially nested successively one after the other, with cooperation between their base 2 and their neck 3 extended by a flared neck 4. The containers 1 have axial nesting elements 11, 12, 16, 17 with a neighboring container, at least one of which is arranged as a collar 11 formed around the neck 3 of a container 1, and at least one of which is arranged as a recess for receiving the collar 11. This recess includes a cavity 8 open to the outside, formed in the base 2 of the containers 1, and which has a blind tubular space 9 for receiving a neck 3 extended by a flared pocket 10 for receiving the flared neck 4 extending from this neck 3. The recess is formed by the tubular space. 9 which is provided in undercut in the bottom 2 of container 1,this tubular space providing a chamber 9 for receiving the collar 11 in radial freedom and in unidirectional axial grip against a shoulder 12 formed at the base of the chamber 9 opposite its blind face 15.,

[0007] A prior art manufacturing method (WO2012104499A2) exists for blow-molding this undercut container from a preform. This method is compatible with producing a thin-walled container designed to allow reliable and convenient axial interlocking with a similar container to form the modular unit. This manufacturing method uses a mold as shown in the figures 3-5 .

[0008] This mold 101 comprises shells 102 which are laterally movable around an axis A2 of general orientation of the mold 101 corresponding to the axis (A1) of general extension of the container 1 to be obtained, and a base 103 which is axially movable along this axis A2 of general orientation of the mold 101. Each shell 102 has a recessed cavity 104 that forms half a wall of the container 1 to be obtained. Cavities 105 for molding the bosses 17 on the flared neck 4 of the containers 1 to be obtained are provided in the area corresponding to the top of these recessed cavities 104. The shells 102 have at their top a rebate 106 or similar feature for gripping and holding a preform inside the mold 101, by means of a ring provided in the preform for this purpose.The base 103 is equipped with means for forming the cavity 8 in the bottom 2 of the container 1 to be obtained, which combines a raised impression forming a molding wall 109 of the flared pocket 10 and the receiving recesses 16 of the bosses 17, with a radially expanding molding head 110 of the undercut chamber 9. The radially expanding head 110 emerges axially from the molding wall 109 and is a component of a retractable element 111 which is mounted jointly with the base 103 on a common frame 112.

[0009] The retractable member 111, and more specifically the head 110 it comprises, is actuated by a piston 113 through a relative displacement between the retractable member 111 and the piston 113. The retractable member 111 is arranged as a tube mounted on a frame 112, oriented along the axis A2 of general orientation of the mold 101, and passing axially through the base 103. The tubular arrangement of the retractable member 111 provides an axial channel 114 for the movement of the piston 113, enabling its passage between its retracted and extended positions. In the retracted position of the retractable member 111, the expandable head 110 is retracted into a demolding position as illustrated in the fig.4 ; in the deployed position of the retractable member 111, the head 110 is expanded by being axially traversed by the piston 113 in a molded position, as illustrated on the fig.5The piston 113 is supported by a base that can be moved by motorized means, such as an electric actuator or similar drive. These motorized means are used to move the base 103 between the open and closed positions of the mold 101, and more specifically to move the moving assembly 120, which consists of the base supporting the frame 112, itself supporting the base 103 and the retractable element 111 that passes axially through it. The base is equipped with axial guide columns for the frame 112, which supports the base 103 and the retractable element 111. These columns cooperate with bushings provided in the frame 112. Deformable return means 119 are interposed between the frame 112 and the base, where they have opposing grips.Such return means 119 are likely to consist of springs, pneumatic cylinders or any other restraining device against relative displacement between the chassis 112 and the base beyond a predetermined stress threshold.

[0010] This type of mold, although perfectly efficient, has a particularly large axial footprint which makes it difficult to insert into a conventional blow molding line.

[0011] Furthermore, the process using this mold does not allow for production rates equivalent to those obtained with conventional container molding processes.

[0012] Documents EP1321370A1, EP1163996A2 and US4414175A are representative of the technological background and describe bases for molds according to the prior art. Summary of the invention

[0013] Thus the present invention relates in particular to a mold base, for a clip-on container, comprising on its upper face a molding wall, of the bottom of the container to be obtained, from which emerges a head extending along a longitudinal axis A2, said head includes a peripheral surface comprising at least one blind opening, remarkable in that the portion of said peripheral surface in line with said blind opening is movable between an advanced position, where said portion is aligned with the rest of said peripheral surface, and a rear position where said portion is arranged set back from the axis parallel to the axis A2 and passing through the bottom of said blind opening.

[0014] In the context of the present invention, the term "arranged in setback from the axis parallel to the axis A2 passing through the bottom of said blind opening" means that said portion of wall is arranged between the axis A2 and the axis parallel to the axis A2 passing through the bottom of said blind opening.

[0015] The presence of one or more blind openings allows for the creation of the shoulders responsible for clipping the container. The existence of these movable portions directly above these openings allows for the axial removal of the molded container without the shoulders being retained inside said openings.

[0016] According to a preferred embodiment, said head has a cylindrical or truncated conical shape comprising a peripheral surface and a top face.

[0017] According to a preferred embodiment, said head comprises at least two blind openings, arranged in the same plane perpendicular to axis A2, placed opposite each other, at the base of said head.

[0018] According to a preferred embodiment, said head is hollow and contains all or part of a central core, movable in translation parallel to the axis A2, between a high position and a low position, arranged such that the movement of said central core from the high position to the low position causes the displacement of said portion vertically above said blind opening from the advanced position to the rear position.

[0019] According to a preferred embodiment, the central core and the internal surface of the movable portion each have a face inclined outwards from the base, relative to axis A2, in contact with each other and joined by a first sliding joint

[0020] According to a highly preferred embodiment, the first sliding connection is made by a dovetail joint.

[0021] According to a preferred embodiment, said central core extends below the base of said head inside a channel.

[0022] According to a preferred embodiment, said base includes a push button, movable in translation in the direction of axis A2, associated with said central core such that the movement of said push button in the direction of axis A2 causes the movement of said central core to the upper position.

[0023] According to an even more preferred embodiment, said push button and said central core are connected by a second sliding link.

[0024] According to a highly preferred embodiment, said second sliding link is made via at least one guide line inclined, with respect to the plane perpendicular to axis A2, in the direction of said axis A2.

[0025] According to a preferred embodiment, said central core has wings extending outwards from said channel, said wings being associated by said sliding link with said push button.

[0026] The presence of this push button, which drives the central core, allows for a particularly compact base, extending only slightly along its axis compared to the molding device of the prior art. This enables the base according to the invention to be integrated into conventional blow molding lines without modifications.

[0027] According to a preferred embodiment, the free end of said push button extends beyond the periphery of the rest of said base

[0028] The invention also relates to a mold comprising a base according to one of the preceding claims and shells mounted laterally movable around said axis A2, between an open position and a closed position, said shells each having a hollow imprint delimiting a part of the wall of the container to be obtained, characterized in that in the closed position said shells bear against said push button.

[0029] According to a preferred embodiment, said mold comprises two shells mounted pivoting relative to each other. Brief description of the drawings

[0030] There fig.1 is an axial cross-sectional illustration of a modular container composed of a plurality of containers axially assembled by interlocking, according to the prior art. fig.2 is a detail of the container depicted on the fig.1 illustrating the cooperation between the bottom of one container and the neck of a neighboring container. fig.3 is a perspective illustration of a mold, from the earlier art, used to form a container by blowing a preform, as shown on the Fig. 1 to Fig. 2 . THE Fig. 4 and Fig. 5 are cross-sectional illustrations of an expandable molding head in its retracted and expanded positions, respectively, for the formation of an undercut annular chamber within a container shown in the fig.1 And 2 . There figure 6 presents a perspective view of an embodiment of a mold according to the invention. figure 7 presents a perspective view of the basis of the embodiment presented to the figure 6 . There figure 8 presents a perspective view of the association between the central core, the chassis, the push button, and the moving portions of an embodiment of a base according to the invention. figures 9a and 9bpresent a cross-sectional view of an embodiment of a mold according to the invention with the shells in the open (9a) and closed (9b) positions. Description of the implementation methods

[0031] With reference to figures 6-9 The mold according to the invention comprises a base 200 having on its upper face 201 a molding wall 202 forming the hollow impression of all or part of the bottom of the container to be obtained. Preferably, said upper face 201 is circular and comprises successively, from its periphery to its center, a flat annular area 203, suitable for receiving the shells 300 comprising the impression of the rest of the container to be obtained, then the molding wall 202 and the head 204 intended for molding the chamber 9.

[0032] The molding wall 202 and the head 204 can be co-molded or permanently assembled. However, the head 204 can advantageously be a separate part that fits into an opening located in the center of the molding wall 202. In this latter case, the molding wall 202 and the head 204 can be joined by fixing these two parts onto a frame 400.

[0033] The chassis 400 preferably has a cylindrical shape comprising a flat upper surface 401 onto which the various elements of the base 200 (molding wall 202, head 204, etc.) are attached. Furthermore, a peripheral shell 500 can advantageously be used to isolate the space between said chassis 400 and said upper surface 201 from its surroundings.

[0034] The head 204, located at the center of the upper face 201, extends from the molding wall 202 along a longitudinal axis A2, which is also the general orientation axis of the mold according to the invention and of the container to be obtained. This head 204 is preferably cylindrical or frustoconical in shape, with its axis of revolution being the axis A2, and comprises a peripheral surface 205 and an upper face 206. The upper face 206 may advantageously include cavities for forming ribs in the bottom of the container to be molded.

[0035] The head 204 includes on its peripheral surface at least one blind opening 207 intended to form a shoulder 12 within the chamber 9 of the container to be obtained. Advantageously, the peripheral surface 205 includes two or three blind openings 207 distributed regularly at the base of the head 204. Advantageously, the blind openings 207 are arranged in the same plane perpendicular to the axis A2. The blind opening 207 preferably has a parallelepiped shape, but any other shape may be used within the scope of the present invention.

[0036] The peripheral surface 205 of the head 204 comprises movable portions 208 framed by fixed portions 209. The fixed portions 209 extend from the base of the head 204 and advantageously also form the upper face 206 of the head 204.

[0037] Each movable portion 208 is positioned directly above a blind opening 207 and advantageously forms its upper edge and, even more advantageously, all or part of its lateral edges. The movable portion 208 has a width along its entire height at least equal to that of the blind opening 207.

[0038] The movable portion 208 can move between a first position, called the forward position, where the movable portion 208 is aligned with the rest of the peripheral surface 209, and a rear position where the movable portion 208 is set back from the axis parallel to axis A2 and passing through the bottom of the blind opening 207. For clarity, it is specified that in the forward position, the movable portions 208 and the fixed portions 209 of the head 204 are aligned so as to form the footprint of the chamber 9 and the shoulders 12 of the container to be obtained. In the rear position, the movable portion 208 is set back from the bottom of the blind opening 207, which will allow axial clearance of the resulting container without the shoulders 12 being held by the upper edge of the blind opening 207.

[0039] The movement of the movable portion(s) 208 is advantageously guided by at least one guide line 210 (preferably grooves). This guide line is advantageously located on a lateral face of the movable portion 208 and cooperates with a congruent shoulder present on the adjacent surface of the head, or vice versa.

[0040] The radial displacement of the moving portions 208 of the peripheral surface 205 is generated by a central core 211. This core is located wholly or partially inside the head and can move in translation, parallel to the axis A2, between a high position and a low position. For clarity, it is specified that the high and low positions are defined relative to the elevation of the central core 211 with respect to the base of the head 204.

[0041] The base 200 according to the invention can comprise one or more central cores 211. For example, according to a first embodiment each central core 211 can cooperate with a single movable portion 208. According to a second embodiment a single central core 211 can cooperate with all the movable portions 208 of the head.

[0042] The movement of said central core 211 from the high position to the low position causes the movement of the movable portion 208 from the forward position to the rear position.

[0043] A person skilled in the art is capable of considering all means of associating the central core 211 with the moving portion 208 so as to transform the axial displacement of the central core 211 into a radial displacement of the moving portion 208. Devices including rods or cams may be considered.

[0044] According to a preferred embodiment of the invention, the central core 211 and the internal surface of the movable portion 208 each have an inclined face 212,213 in the direction of said base 200, with respect to the axis A2, in contact with each other and joined by a sliding connection obtained by a dovetail joint 214 between the two inclined faces 212,213. In the context of the present invention, the terms "internal" and "external" are chosen with reference to the distance from the axis A2.

[0045] In the raised position, the two inclined surfaces 212 and 213 have maximum contact area. When moving to the lowered position, the central core 211 slides along the inclined surface 212 of the inner surface of the moving portion 208, carrying the latter along axis A2 to its rear position. The return of the central core 211 to the raised position causes the moving portion 208 to retrace its path.

[0046] In addition to its inclined face 213, the central core 211 includes a spar 215 associated with said inclined face 213 and extending into the head 204 along an axis parallel to axis A2. Preferably, said central core 211, and more particularly said spar 215, extends below the base of said head within a channel 216. This latter channel 216 is advantageously formed within a cylindrical part 217 extending the head 204 below the molding wall 202. Advantageously, this cylindrical part 216 is directly associated with the chassis 400 of the base 200.

[0047] Furthermore, the central core 211 may advantageously include at least one wing 218 extending radially outward from the base 200. Preferably, all or part of said wing 218 extends beyond the cylindrical part 217 via an opening. This wing 218 allows the central core 211 to interact with other parts of the base 200 according to the invention and causes the central core 211 to move between its upper and lower positions. When the central core 211 is in its lower position, the wing preferably rests on the upper face 401 of the chassis 400.

[0048] Finally, the base 200 according to the invention may also include at least one push button 220, movable in translation along axis A2, associated with said movable core 211 such that the movement of said push button 220 along axis A2 causes said central core 211 to move to the raised position. Those skilled in the art are capable of determining the means to be used to associate the push button 220 with the central core 211. These means include, in particular, rods and cams.

[0049] Preferably, the push button 220 and the central core 211 are connected by a second sliding joint made via at least one guide line 221 inclined in the direction of said axis A2. It is thus understood that the radial movement of the push button 220 in the direction of the axis A2 will cause the central core 211 to move to the upper position.

[0050] The push button 211 advantageously has a lower face resting on the upper face 401 of the chassis 400 and a free end extending beyond the peripheral wall 500 of the base 20 when the central core 211 is in the lowered position. Furthermore, the push button 220 comprises two blades forming an intercalated space, open at the end opposite said free end, suitable for receiving all or part of the wing 218 of the central core 211. These blades include on their inner face at least one guide means congruent to at least one guide means present on the outer face of the central core providing the second sliding connection. These guide means may, in particular, take the form of a groove and / or a shoulder. Alternatively, said push button 220 may comprise a single blade, extending in the direction of axis A2, and inserted between two wings of the central core 211.

[0051] To allow the elements of the base 200 to return to a position where the central core 211 is in the lower position and the movable portion 208 is in the rear position, the base 200 further includes an elastic means for moving the push button 220 outwards from the base. This elastic means may advantageously take the form of a spring 222 positioned between a first stop 223 attached to the push button 220 and a second stop 224 fixed to the chassis. The spring 222 may be held in position by a rod 225 extending from the first stop 223.

[0052] Preferably, the different elements of the base 200 according to the invention can each include at least one bore forming at least one channel passing through these elements and allowing the circulation of a fluid suitable for cooling the mold during its use.

[0053] The mold according to the invention further comprises shells 300, the inner face of which includes a hollow cavity 301 for forming the walls of the container to be obtained. Moreover, these shells 300 also include a zone 302 congruent to the annular zone of the upper face of the base and to the peripheral wall 500 of the base 200.

[0054] These shells 300 are mounted to move laterally around axis A2, between an open and a closed position. These two shells 300 can be free relative to each other or preferably joined by a pivot joint, around an axis A1 parallel to axis A2.

[0055] In the closed position, the shells 300 clamp onto the base 200 according to the invention, thus forming the mold of the entire container. During this step, the shells 300 press against the push button 220, causing the central core 211 to move to the raised position and the movable portion to the advanced position. The blowing of the preform can then begin, resulting in a container comprising, in particular, shoulders 12 located inside the blind openings 207.

[0056] The movement of the shells 300 from the closed to the open position causes the pushbuttons 220 to move outwards, under the effect of the elastic means 222, and thus the return of the central core 211 to its lower position and the movable portion 208 to its rear position. In doing so, the upper edge of the blind openings 207 no longer obstructs the axial movement of the resulting container, which can then be separated from the head 204.

[0057] The present invention also relates to a method for producing a container comprising the use of a base 300 or a mold according to the invention.

Claims

1. Base (200) for a mould, for a clippable container, comprising on the upper face (201) thereof, a wall (202) for moulding the bottom of the container to be obtained, from which a head (204) emerges extending along a longitudinal axis A2, said head (204) comprises a peripheral surface (205) comprising at least one blind opening (207), characterised in that the portion (208) of said peripheral surface (205) in line with said blind opening (207) can move between a forward position, where said portion is aligned with the rest of said peripheral surface (205), and a rear position where said portion (207) is set back from the axis parallel to the axis A2 and passing through the bottom of said blind opening (207).

2. Base (200) for a mould, for a clippable container, according to the preceding claim characterised in that said head (204) has a cylindrical or tapered shape comprising a peripheral surface (205) and an upper face (206).

3. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said head (204) comprises at least two blind openings (207), arranged along the same plane perpendicular to the axis A2, positioned facing one another, at the base of said head (204).

4. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said head (204) is hollow and contains all or part of a central core (211), movable in translation parallel to the axis A2, between a high position and a low position, arranged such that the movement of said central core (211) from the high position to the low position actuates the movement of said portion (208) in line with said blind opening (207) from the forward position to the rear position.

5. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that the external surface of said central core (211) and the internal surface of said mobile portion (208) each have an inclined side (212, 213) towards the exterior of said base (200), relative to the axis A2, in contact with one another and joined by a sliding link.

6. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said sliding link is embodied by a dovetail assembly (214).

7. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said central core (211) extends below the base of said head (204) inside a channel (216).

8. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said base comprises a push-button (220), movable in translation towards the axis A2, associated with said central core (211) such that the movement of said push-button (220) towards the axis A2 actuates the movement of said central core (211) to the high position.

9. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said push-button (220) and said central core (211) are joined by a second sliding link.

10. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said sliding link is embodied via at least one inclined guiding line (221) towards said axis A2.

11. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that said central core (211) has wings (218) extending towards the exterior of said channel (216), said wings (218) being joined by said sliding link to said push-button (220).

12. Base (200) for a mould, for a clippable container, according to one of the preceding claims characterised in that the free end of said push-button (220) projects from the periphery of the rest of said base (200).

13. Mould comprising a base (200) according to one of the preceding claims and shells (300) laterally movably mounted about said axis A2, between an open position and a closed position, said shells (300) each comprising a hollow cavity (301) defining a portion of the wall of the container to be obtained, characterised in that, in the closed position, said shells (300) bear on said push-button (220).

14. Mould according to the preceding claim characterised in that it comprises two shells (300) pivotally mounted in relation to one another.