FR2835806A1 - MACHINE FOR CLOSING THERMOSCELLARIZED VARIOUS CONTAINERS - Google Patents

Abstract

The invention relates to a machine that is used to seal different containers comprising: a frame (12) which can move between a release position and a standby closed position; and a mechanism (40) for moving the mobile frame (12) between the standby closed position and a closed position. According to the invention, the movement mechanism (40) comprises at least one magnetic-field-producing coil (41) such that, when the frame is in the standby closed position, the magnetic field created by the coil acts on a circuit (43) that closes the magnetic field. Moreover, the frame (12) and the base (2) are designed to comprise means for positioning said frame (12) in the standby closed position, so that the magnetic field can be closed during the excitation of the coil.

Description

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 The object of the present invention relates to the technical field of packaging of various products and, more particularly, food products in the context of consumer products, artisanal or semi-industrial.

 The object of the invention more specifically relates to the packaging of products using containers of the tray type, of different shapes and sizes which should be closed after filling, in order to preserve their entire contents.

 The present invention relates more specifically to a machine for closing, sealing or generally, closing a tray by heat sealing a closure member such as a film, a cover, a seal or the like.

 In the state of the art, various machines have been proposed for performing a heat sealing operation of a closure member on a container. For example, it is known a machine comprising a base arranged to delimit a housing for receiving a container. This machine also comprises a movable chassis connected to the base by means of a connection system making it possible to ensure the passage of the chassis between a release position of the reception housing and a waiting position for closing the container. Such a chassis is equipped with a means for fixing a closure member to the container placed in the housing. For example, such a fixing means can be produced by heating means.

This machine is also provided with an additional mechanism of indirect force ensuring a displacement of the movable chassis between a closing standby position and a closed position in which the heating means are pressed against the shutter member in order to '' secure it on the container.

 It therefore appears that the mobile chassis must be maneuvered on the one hand, over a relatively large stroke between the release and waiting positions for closure to allow easy access to the container receiving housing and on the other hand, on a limited stroke with application on the sealing member of a relatively high sealing pressure for a determined period. The intensity of the sealing pressure and the heating time are important parameters for the quality of the seal, poor closure can lead to degradation of the product packaged in the container.

 It therefore appears the need to have a machine designed to ensure the movement of the mobile chassis while respecting the sealing parameters while

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 making it possible to produce a simple machine using a minimum of parts and optimizing the energy efficiency between the installed power and the sealing pressure obtained.

 Another object of the invention is to propose a reliable machine, easy to maintain, at low cost and with limited space.

- un socle aménagé pour délimiter un logement de réception d'un contenant, - un châssis mobile entre une position de dégagement et une position d'attente de fermeture, équipé d'un moyen de fixation d'un organe d'obturation sur un contenant placé dans le logement, - un système de liaison entre le châssis et le socle autorisant le passage du châssis mobile d'une position à l'autre, - et un mécanisme de déplacement du châssis mobile entre la position d'attente de fermeture et une position de fermeture dans laquelle le moyen de fixation assure la solidarisation de l'organe d'obturation sur le contenant. Selon l'invention : le mécanisme de déplacement comporte au moins une bobine de production d'un champ magnétique, montée sur le socle ou le châssis de manière qu'en position d'attente de fermeture du châssis, le champ magnétique créé par la bobine agisse sur un circuit de fermeture du champ magnétique aménagé respectivement sur le châssis ou le socle, en périphérie du logement de réception, "le châssis et le socle sont aménagés pour comporter des moyens pour positionner le châssis, en position d'attente de fermeture, de manière à déterminer avec le socle un entrefer adapté pour permettre, lors de l'excitation de la bobine, la fermeture du champ magnétique par le circuit afin de créer une force d'attraction assurant le déplacement du châssis jusqu'à la position de fermeture du contenant. The object of the invention therefore aims to meet these needs by proposing a machine for closing various containers, comprising:

- a base arranged to delimit a housing for receiving a container, - a movable frame between a release position and a closing standby position, equipped with a means of fixing a shutter member to a container placed in the housing, - a connection system between the chassis and the base allowing the mobile chassis to pass from one position to another, - and a mechanism for moving the mobile chassis between the waiting position for closing and a closed position in which the fastening means secures the closure member to the container. According to the invention: the displacement mechanism comprises at least one coil for producing a magnetic field, mounted on the base or the chassis so that in the standby position for closing the chassis, the magnetic field created by the coil acts on a circuit for closing the magnetic field arranged respectively on the chassis or the base, on the periphery of the receiving housing, "the chassis and the base are arranged to include means for positioning the chassis, in the closed standby position, so as to determine with the base an air gap adapted to allow, during the excitation of the coil, the closing of the magnetic field by the circuit in order to create a force of attraction ensuring the movement of the chassis to the closed position of the container.

 Another object of the invention is to propose a machine for closing by heat-sealing containers, also designed to create an air depression and possibly inject a neutral gas.

 To achieve such an objective, the machine under the invention comprises a chassis and / or a base provided with sealing means making it watertight in the waiting position for

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closing the receiving housing delimited by a tank, such a receiving housing communicating with a device for suction and / or injection of a various fluid.

Figure 1 is a longitudinal sectional elevation view of an exemplary embodiment of a machine according to the invention.

 Figure 2 is a cross-sectional view taken essentially along lines II-II of Figure 1.

 FIG. 3 is a top view of the machine taken substantially along lines III-III of FIG. 2.

 Figure 4 is a perspective view showing a machine according to the invention equipped with a reel of heat-sealable film.

 FIG. 5 is a partial section view showing a characteristic detail of the machine illustrated in FIG. 4.

 Figure 6 is a plan view showing another embodiment of the movement mechanism.

 FIG. 7 is a partial section taken substantially along the lines A-A of FIG. 6.

 Figure 8 is a longitudinal sectional view of another embodiment of a machine according to the invention.

 FIG. 9 is a cross-sectional view taken essentially along lines B-B of FIG. 8.

 FIG. 10 is a view of a characteristic detail of the machine illustrated in FIGS. 8 and 9.

 In the embodiment illustrated in Figures 1 to 3, the machine according to the invention and designated as a whole by the reference 1 comprises a base 2 defining a housing 3 for receiving a container 4 intended to be closed by a shutter member not shown, by a heat sealing operation. In the example illustrated, the container 4 is in the form of a substantially parallelepiped-shaped container provided with a wing or a peripheral surface 5 for sealing the closure member such as a film, a cover or a cover for example. The housing 3 arranged on the base 2 is delimited in a cradle 6 on the edge of which rests the peripheral surface 5 of the container.

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 The peripheral cradle 6 is supported on either side by legs 8 connected at their ends to form a base 9 equipped with feet 10 for bearing on a support. The cradle 6 thus extends to a determined height of the support to allow positioning inside the housing 3 of containers 4 of various heights. Preferably, the base 9 constitutes a stacking surface for the closure members to be heat-sealed on the containers 4.

 The machine 1 according to the invention also comprises a mobile chassis 12 equipped with a fixing means 13 for the closure members of the container. Preferably, the fixing means 13 is designed for heat sealing a thermoplastic sealing member on the container 4. For example, the fixing means 13 is formed by a pressure plate 14 equipped with an element heating 15 such as for example, an electrical resistance. This pressure plate 14 has a closed outline of dimensions adapted to the peripheral area 5 of the container 4. In a preferred and known manner, the heating element 15 is connected to a regulation block, not shown, which is connected to a temperature sensor. temperature mounted in relation to the pressure plate 14. The pressure plate 14 is intended to come into contact on the closure member perpendicular to the peripheral area 5 of the container, which in the example illustrated, rests on a rubber bead 7 mounted on the edge of the cradle 6. Of course, it can be envisaged that the peripheral area 5 of the container 4 rests on a metal sealing imprint forming part of the cradle 6 or attached to the cradle 6.

 Figs. 4 and 5 illustrate more particularly a machine 1 ensuring the sealing as a shutter member, of a film F wound in the form of a reel mounted on a pin 16 supported at its ends by the legs 8 of the base 2 As is known, the base 2 is provided on its rear part with a roller 161 for passing the film F intended to hold the film against the cradle 6 of the base. According to this alternative embodiment, the machine 1 is equipped with a system 17 for cutting the film F to the length of the container 4. In the example illustrated, the cutting system 17 is mounted on the movable frame 12 upstream of the housing 3 with respect to the stretching direction of the film. The cutting system 17 comprises a knife 171 mounted transversely on the movable frame 12, and on either side of which extends a film clamp 172 mounted vertically movable. Film clamp 172 is requested for

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 extend projecting from the movable frame 12 by means of springs 173 in order to press the film against the cradle, on either side of a groove 174 for the knife 171, arranged on the base 2.

 The chassis 12 is movable relative to the base 2 between a position for releasing the housing 3 shown in phantom in Figure 1 and a closed standby position shown in solid lines in Figure 1. For this purpose, the chassis 12 and the base 2 are connected to each other by means of a connection system 18 authorizing the passage of the mobile chassis 12 from one position to another. In the illustrated embodiment, the connection system 18 consists of two rods 19 fixedly mounted on either side of the movable frame 12. The other end of each of the rods 19 is equipped with a hinge pin 21 authorizing the pivoting of the movable frame 12 around this articulation axis 21. According to an advantageous characteristic of the invention, each articulation axis 21 is mounted with a possibility of vertical movement allowing the approximation between the chassis 12 and the base 2 in a substantially vertical direction.

 To this end, the hinge pin 21 is mounted inside a slide 23 guided in vertical movement inside a groove 24 arranged in a tab 26 extending at the rear and towards the low from the cradle 6. Each slide 23 is resiliently returned by means of a spring 27, in the high position, that is to say in separation from the movable frame 12 relative to the base 2.

 The movable frame 12 is therefore able to occupy the release position in which it occupies a position substantially perpendicular to the extension plane of the housing 3 for receiving the container 4. This release position is defined by opening stops 29 carried by the tabs 26 on which the rods 19 come to bear. In this open position, it should be noted that the housing 3 is made easily accessible for carrying out the operations of placing and removing the container 4 as well as the filling the container 4.

 From this release position, the mobile chassis 12 can be moved manually by pivoting around its articulation axes 21 so as to bring it into a closed standby position in which the mobile chassis 12 determines with the base 2, an air gap E. In this closing standby position, the movable frame 12 and the base 2 are found in superimposed position. Of

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 more precisely, the fixing means 13 and the cradle 6 extend in planes substantially parallel to each other and distant from the air gap E, the function of which will appear more precisely in the following description. The waiting position for closing the movable chassis 12 is defined by a closing stop 31 carried by the cradle 6 and on which abuts a connecting cross member 32 carried by the rods 19.

 According to another advantageous characteristic of the invention, the machine 1 comprises a mechanism 40 ensuring the movement of the movable frame 12 between the closing standby position and a closing position in which the fixing means 13 ensures the joining of the shutter member on the container 4. The displacement mechanism 40 comprises at least one coil 41 for producing a magnetic field, mounted in the example illustrated on the base 2 so that in the standby position for closing the movable frame 12, the magnetic field created by the coil can close on a closing circuit 43 arranged in the example illustrated on the movable frame 12. According to an advantageous characteristic of embodiment, the field production coil 41 is associated with a magnetic circuit 44 called magnetic field channeling. In the standby closing position, the magnetic pipe circuit 44 extends in proximity relation and opposite the closing circuit 43. Thus, it must be understood that the total magnetic circuit for the circulation of the magnetic field created by the coil 41 has a fixed part (pipe circuit 44 in the example illustrated) and a movable part (closing circuit 43 in the example illustrated).

 The coil 41, the channeling circuit 44 and the closing circuit 43 of the magnetic field are adapted so that when the coil is excited, the magnetic field created by the coil can close in order to create a direct force of attraction ensuring the movement of the movable frame 12 from its standby closing position to its container closing position. Of course, this movement is possible insofar as the movable frame 12 is mounted with the possibility of vertical sliding by means of the hinge pins 21 guided in vertical translation. The air gap E delimited between the movable frame 12 and the base 2 is adapted to allow, for a given excitation of the coil, the closing of the magnetic field by the closing circuit 43 placed on the movable frame 12.

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 In the example illustrated in FIGS. 2 and 3, the magnetic field production coil 41 extends over the entire periphery of the housing 3. Similarly, the closing circuit 43 extends around the periphery of the housing 3 when the movable chassis 12 occupies its standby position closing. In the example illustrated, the cradle 6 is provided with a groove 45 extending along a closed contour surrounding the housing 3, and designed to receive the excitation coil 41 and the magnetic pipe circuit 44.

As can be seen from the figures, the pipe circuit 44 which is made of a non-magnetic material, for example of mild steel, has a cross-section in a "U" shape, the branches of which face the closing circuit 43 made of non-material magnetic. On this pipe circuit 44 which has a toroid shape, that is to say closed on itself, is wound an electrically conductive wire insulated dielectrically to form the coil 41 which is housed inside the pipe circuit 44. Of course, the electrical installation of the coil 41 can be completed or ensured by a coating such as silicone filling the "U" circuit.

 As illustrated in fig. 6 and 7, it is clear that it can be envisaged to use several coils for producing a magnetic field 41 and magnetic circuits 43, 44 at various point locations in the cradle 6. For example, provision could be made to mount at least one coil / circuit assembly, on each side of the housing 3. Thus, each excitation coil 41 and its associated magnetic circuit 43, 44 has a similar embodiment but with reduced dimensions. Thus, each magnetic pipe circuit 44 which is constituted in the form of a toroid of cross section in "U" shape allows the winding of a wire to obtain the coil 41 for producing the magnetic field. In relation to each magnetic pipe circuit 44, the mobile chassis 12 is equipped with a closing circuit 43. It should be noted that provision could be made to reverse the relative position between the coil producing the magnetic field 41 and the closing circuit 43 so that the coil 41 would be mounted on the movable frame 12 while the closing circuit 43 would be arranged on the base 2 extending over all or part of the periphery of the housing 3.

 The operation of the machine 1 according to the invention follows directly from the above description.

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 In the raised position of the movable frame 12, a container 4 can be placed inside the housing 3 and be filled with products, for example food. A shutter member such as a cover, film or cover is placed on the container 4. The movable frame 12 is then moved manually so as to pivot and come to occupy its closed standby position determined by the support of the movable chassis 12 on the stop 31. In this position for awaiting closure, the movable chassis 12 extends substantially parallel to the cradle 6 with a spacing corresponding to the air gap E.

 The excitation coil 41 is then electrically supplied to create a magnetic field which closes by the closing circuit 43. The attraction force thus created is applied to the movable frame 12, so that the pressure plate 14 comes to bear on the cradle 6 and more precisely, on the closure member which is superimposed on the peripheral area 5 of the container resting on the rubber cord 7. It should be noted that in the variant embodiment of the machine illustrated in FIGS. 4 and 5, the pressing of the pressure plate 14 leads to the cutting of the film by the knife 17}.

 The time of application of the pressure plate 14 which corresponds to the time of electrical supply to the excitation coil 41 on the one hand, and the intensity of the attraction force which depends on the value of the excitation on the other hand, are determined so as to obtain an effective heat-sealing of the closure member on the container 4. After the coil 41 has been de-energized, the movable frame 12 which returns under the action of the springs 27 in its closed standby position, can be raised to remove the filled and closed container in order to allow another operating cycle to be restarted.

 The machine 1 according to the invention which is of simple design and of limited size requires a low electrical power insofar as the attraction force acts directly, without additional mechanical system, on the mobile chassis, on the periphery of the housing 3 .

 Figures 8 and 9 illustrate another alternative embodiment of a machine according to the invention adapted to create a vacuum inside the container 4 and, optionally ensuring the injection of a neutral gas inside the container. This machine designated by the reference 1, has all the characteristics already

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 described in relation to Figures 1 to 3 which are not repeated in the following description. Compared to the machine described in relation to Figures 1 to 3, this machine 1 further comprises a sealed tank 50 arranged on the base 2 and adapted to delimit the receiving housing 3. In the embodiment, the base 2 is provided with sealing means 51 adapted to seal in a waiting position for closing, the receiving housing 3. These sealing means 51 are constituted by a peripheral seal 52 extending outside the receiving edge of the peripheral area 5 of the container 4. It should be noted that the movable frame 12 also has a sealed character, at least for its part delimited inside the seal 52 in order to obtain a sealed receiving housing 3 .

 The machine 1 also comprises, as illustrated in FIG. 10, support stops 53 which are elastically deformable under the action of bringing the mobile chassis 12 closer to the base 2, thus making it possible to delimit an intermediate position for waiting for closing of the chassis 12 in which the housing 3 is made completely sealed. As can be seen more precisely in FIG. 10, the support stops 53 for example, four in number distributed around the periphery of the housing 3 and carried by the movable frame 12, are constituted by a sheath 54 movable inside from which a spring 55 is mounted.

 According to a characteristic of the invention, the excitation of the coil 41 for creating a magnetic field is controlled by a control unit making it possible to control the coil according to a so-called weak excitation mode to ensure the limited displacement of the mobile chassis. 12 to bring it into an intermediate position for awaiting closure so as to make it watertight by the sealing means 51, the tank 50 delimiting the receiving housing 3. In this position, the waterproof mobile chassis 12 is brought closer to the base 2 so that the seal 52 is deformed while leaving the closure member free on the container 4. In this position, provision may be made to control a pump, not shown as suction of the air contained inside the tank 50, that is to say of the housing 3 and consequently of the container 4. For this purpose, the suction pump can be mounted on the base by communicating with the interior of the tank 50 per l 'through a pipeline fitted with a controlled shutter. In some applications, it can be provided

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 injecting inside the housing 3, a fluid such as a neutral gas. The coil for creating a magnetic field can then be controlled in its so-called normal excitation mode, to ensure the consecutive displacement of the movable frame 12 so as to ensure the heat-sealing operation of the container as described above.

 It should be noted that in the example illustrated in FIG. 8, the machine comprises means 59 for detecting the movable frame 12, in its position for awaiting closure. This detection means 59 is connected to the control unit of the coil 41 making it possible to control its excitation when the movable chassis 12 occupies its position for awaiting closure. Of course, this detection means 59 can equip the machine illustrated in FIGS. 1 to 3.

Claims (11)

1-Machine for closing various containers, comprising: - a base (2) arranged to delimit a receiving housing (3) of a container (4), - a movable frame (12) between a release position and a closing standby position, equipped with a fixing means (13) of a shutter member on a container (4) placed in the housing (3), - a connection system (18) between the chassis ( 12) and the base (2) authorizing the passage of the movable chassis from one position to another, - and a mechanism (40) for moving the movable chassis (12) between the standby position for closing and a position for closure in which the fixing means (13) secures the closure member to the container, characterized:. in that the displacement mechanism (40) comprises at least one coil (41) for producing a magnetic field, mounted on the base (2) or the chassis (12) so that in the closed standby position of the chassis, the magnetic field created by the coil acts on a circuit (43) for closing the magnetic field arranged respectively on the chassis or the base, on the periphery of the receiving housing (3), and in that the chassis (12 ) and the base (2) are arranged to include means for positioning the chassis (12), in the standby closing position, so as to determine with the base (2) an air gap (E) adapted to allow, during excitation of the coil, closing of the magnetic field by the circuit (43) in order to create a force of attraction ensuring the movement of the frame (12) to the closed position of the container.  2-machine according to claim 1, characterized in that the displacement mechanism (40) comprises at least one coil (41) for producing a magnetic field, mounted on the base (2) at least partially surrounding the housing of reception (3) and a circuit for closing the magnetic field (43) arranged on the mobile chassis (12). <Desc / Clms Page number 12>  3-Machine according to claim 1 or 2, characterized in that the movement mechanism (40) comprises a coil for producing a magnetic field (41) surrounding the entire periphery of the receiving housing (3).  4-Machine according to one of claims 1 to 3, characterized in that the magnetic field production coil (41) is associated with a magnetic field channeling circuit (44) extending in the closed standby position , in proximity relation to the closing circuit (43).  5-machine according to claim 1, characterized in that the means for positioning the frame in the closed standby position, consist of at least one stop (31) for limiting the movement of approach of the movable frame (12) relative to the base (2).  6-Machine according to one of claims 1 to 5, characterized in that the movable frame (12) and / or the base (2) comprise sealing means (52) sealing, in a waiting position for closing, the receiving housing (3).  7-Machine according to claim 6, characterized in that it comprises a suction device and optionally injection of a communicating fluid, with the receiving housing (3).  8-Machine according to claims 6 and 7, characterized in that it comprises: has abutment stops (53) elastically deformable under the action of approximation of the movable frame (12) relative to the base (2) allowing delimit an intermediate waiting position for closing the chassis,. and a unit for controlling the excitation of the coil creating a magnetic field (41), comprising on the one hand a weak mode of excitation of the coil to ensure the limited displacement of the movable frame to bring it into an intermediate position so as to seal, by the sealing means (52), the receiving housing (3), and on the other hand a normal mode of excitation of the coil to ensure the consecutive movement of the chassis (12 ) so as to ensure the closure by the closure member, of the container (4).  9-machine according to claim 1, characterized in that the connection system (18) between the chassis (12) and the base (2) consists of rods (19) fixed <Desc / Clms Page number 13>  each on a hinge pin (21) mounted with a possibility of vertical displacement allowing the approximation between the chassis and the base.  10-machine according to claim 9, characterized in that the hinge pins (21) of the rods (19) are guided in vertical translation on the base (2).  11-Machine according to one of claims 1 to 10, characterized in that it comprises a means (59) for detecting the movable frame (12) in the standby closing position for controlling the operation of the coil ( 41) for producing a magnetic field.