Multi-format lidding machine with blades nested in the upper tooling and associated process

Abstract

The present invention relates to a machine (10, 11) for sealing containers (22) for thermally sealing a sealing film (30) on a container (22) of products, in particular food products, the sealing machine (10, 11) comprising: - a lower tool (12, 14) comprising a base (20) for receiving a container (22), - an upper tool (24) arranged to allow the passage of the sealing film (30) between the lower tool (12, 14) and the upper tool (24), the upper tool (24) comprising a heating block (32) arranged to heat the film (30), the machine (10, 11) being characterized in that the upper tool (24) comprises a first retractable blade (34) for cutting the film (30), the first blade (34) being movable through a groove (56) arranged in the thickness of the heating block (32). Figure for the abstract: 3

Description

Title of the invention: Multi-format sealing machine with blades nested in the upper tooling and associated method Technical field of the invention

[0001] The present invention relates to the sealing of containers which consists of thermally sealing a film on a container,

[0002] The invention relates more particularly to a multi-format lidding or thermoforming machine. Throughout the text, the expression "lidding machine" covers all simple lidding machines and thermoforming machines.

[0003] The invention also relates to a method of sealing using a machine according to the invention. Technical background

[0004] Conventionally, capping is carried out by a capping machine or by a thermoforming machine. The thermoforming machine allows the thermoforming, capping and cutting of containers.

[0005] In a manner known per se, a container sealing machine comprises a lower tool and an upper tool arranged to allow the passage of the sealing film between the lower tool and the upper tool. The lower tool comprises a base for receiving a container. The upper tool comprises a heating block comprising a support surface arranged to press the film onto a rim of the container in a position for welding the tools.

[0006] A first type of sealing concerns sealing using a technology called "skin packaging", the sealing film is placed on the container and the product it contains in order to fit the shape of the product, like a second skin. To do this, the film is placed under the heating block brought to a predetermined temperature to soften the film and thus allow it to deform, then, a depression in the lower tool allows the film to be placed on the product, the film thus perfectly fitting the shape of the product.

[0007] A second type of sealing involves modified atmosphere sealing, which includes standard vacuum sealing. In this case, the container and the product it contains are placed in the lower tooling. Then, the lower tooling and the upper tooling are pressed against each other to form a closed enclosure, and then the enclosure is placed in a modified atmosphere to allow better preservation of the product. The film is then placed over the container and the product is then sealed to the rim of the container by heat sealing.

[0008] Multi-format tray sealing machines are known in which the upper tooling comprises a multi-format heating block comprising a support surface for each format. Such multi-format sealing machines also comprise a series of lower tools, each lower tooling comprising a welding base and a film cutting blade adapted to a container format.

[0009] However, the positioning of the film cutting blade in the lower tooling does not allow for quality film cutting, particularly in the case of “skin packaging” type sealing. In addition, a film cutting blade in the lower tooling is located in the work area, which leads to cleaning and safety constraints. Summary of the invention

[0010] The invention proposes a container sealing machine for thermally sealing a sealing film on a container of products, in particular food products, the sealing machine comprising: - lower equipment comprising a base for receiving a container, - an upper tool arranged to allow the passage of the sealing film between the lower tool and the upper tool, the upper tool comprising a heating block arranged to heat the film, the upper tool comprising a first retractable blade for cutting the film, the first blade being movable through a groove arranged in the thickness of the heating block.

[0011] According to other characteristics of the invention:

[0012] - the upper tooling comprises an actuator arranged to move the first blade between a cutting position in which the blade projects from a lower face of the heating block and a retracted position in which the blade does not project from the lower face of the heating block;

[0013] - the first blade is mounted on a first frame by means of fixing elements, the first frame being an intermediate piece between the first blade and the actuator;

[0014] - the upper tool further comprises a second blade on the periphery of the block of heating;

[0015] - the sealing machine is such that: - the first blade has a continuous annular shape, and - the groove is non-through at least in places and is arranged in a lower face of the heating block, the groove having a shape complementary to the shape of the first blade such that the first blade is contained within the thickness of the heating block in the retracted position;

[0016] - the elements for fixing the first blade to the first frame comprise at least at least one tab arranged to slide in a through hole provided in the thickness of the heating block between the groove and an upper face of the heating block;

[0017] - the upper tool is movable in rotation around a horizontal axis between a operating position and a blade maintenance position;

[0018] - the upper tooling has a side window for access to the fixing elements from the first blade to the first frame;

[0019] - the machine has several nested retractable blades, each blade retractable being movable through a groove specific to the blade and arranged in the thickness of the heating block;

[0020] - the first blade corresponding to a first sealing format and the second blade corresponding to a second sealing format, the lower tooling comprises at least a first base corresponding to the first format and a second base corresponding to the second format;

[0021] - each base is mounted in a drawer capable of being inserted longitudinally in the machine to a sealing position in which the base is opposite the heating block;

[0022] - the machine includes a means of automatic detection of the base format.

[0023] The invention also proposes a sealing method using a sealing machine comprising: - a lower tool comprising at least a first base corresponding to a first format and a second base corresponding to a second format, - an upper tool arranged to allow the passage of the sealing film between the lower tool and the upper tool, the upper tool comprising: - a heating block designed to heat the film, - a first retractable film cutting blade, the first blade corresponding to the first format and being movable through a groove provided within the heating block, - a second blade on the periphery of the heating block and corresponding to the second format, the process comprising the following steps: - placing a base among the first base and the second base in the sealing position in which the base is opposite the heating block, - detecting the format of the base which is in the sealing position, - carrying out a sealing cycle including the following steps: - selection of the blade to be used based on the format detected in the previous step, - cutting the sealing film using the blade selected in the previous step. Brief description of the figures

[0024] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0025] [Fig-1] is a general perspective view of a sealing machine according to a first embodiment of the invention comprising two sealing formats;

[0026] [Fig.2] is a schematic and partial view in vertical section of the machine of [Fig.l];

[0027] [Fig.3] is a perspective view showing the underside of the two heating blocks of the machine of [Fig.l] equipped with two cutting blades per heating block;

[0028] [Fig.4] is a side view of the heating blocks of the machine 1 showing the actuators of the blades;

[0029] [Fig.5] is a perspective view from above of the heating blocks of Figures 3 and 4 showing the frames on which the blades are fixed;

[0030] [Fig.6] is a perspective and cross-sectional view of a heating block of Figures 3 to 5, showing the arrangement of the first blade within the thickness of the heating block;

[0031] [Fig.7] is an exploded view showing the interlocking of the two blades and the heating block;

[0032] [Fig.8] is a bottom view of an upper tool of a sealing machine according to a second embodiment of the invention comprising three sealing formats;

[0033] [Fig.9] is a side view of the upper tooling of the machine according to the first embodiment of the invention showing access to the means for fixing the first blade to the frame;

[0034] [Fig. 10] is a perspective view of the machine according to the first embodiment of the invention showing the upper tooling pivoted upwards in the blade maintenance position;

[0035] [Fig. 11] is a perspective view of the lower tooling of the machine according to the first embodiment of the invention showing the means for automatically detecting the format of the lower tooling;

[0036] [Fig. 12] is a perspective view of the base of the lower tooling of the machine according to the first embodiment of the invention showing an adjustable bottom in depth by means of positioning notches and comprising an orifice for the passage of the centering stud of the lower tool relative to the upper tool. Detailed description of the invention

[0037] For the description of the invention and the understanding of the claims, the vertical, longitudinal and transverse orientations according to the reference V, L, T indicated in the figures, the longitudinal L and transverse T axes of which extend in a horizontal plane, will be adopted as a non-limiting example and without limiting reference to Earth's gravity. By convention, the vertical axis is oriented from bottom to top, the longitudinal L axis is oriented from back to front and the transverse T axis is oriented from left to right.

[0038] In the following description, identical, similar or analogous elements will be designated by the same reference numbers.

[0039] [Fig.l] illustrates a multi-format sealing machine 10 according to a first embodiment of the invention. The machine 10 comprises two sealing formats, including a first format and a second format.

[0040] Thus, the machine 10 comprises two lower tools 12, 14, including a first lower tool 12 contained in a first drawer 16 and corresponding to the first format and a second lower tool 14 contained in a second drawer 18. Each lower tool 12, 14 is configured to receive two containers to be sealed, such as two trays, juxtaposed transversely.

[0041] The first lower tool 12 and the first drawer 16 are in one piece. Similarly, the second lower tool 14 and the second drawer 18 are in one piece.

[0042] The machine incorporates in its lower part two storage areas located one above the other and each capable of receiving the first drawer 16 or the second drawer 18. In the example shown, the second drawer 18 is placed in the lower storage area.

[0043] The drawer corresponding to the container format to be sealed is inserted into a sealing zone by sliding along rails. In the example shown, the first drawer 16 is placed on the rails.

[0044] Alternatively, the lower tooling 12, 14 and the drawer 16, 18 may not be in one piece. In this case, the machine 10 comprises, for example, a drawer dedicated to the sealing area and at least one drawer dedicated to the storage area. Consequently, the lower tooling is placed in the drawer dedicated to the sealing area if it corresponds to the format of the container to be sealed or in the drawer dedicated to the storage area otherwise.

[0045] Alternatively, the machine may have only one drawer dedicated to the sealing area which remains on the slides and in which the lower tooling 12, 14 corresponding to the format to be sealed is positioned before the sealing operation. The lower tool 12, 14 then mainly consists of a base. The machine may then not have a second drawer in the storage area. The storage area then directly receives the lower tools 12, 14 which are, for example, simply placed in the storage area.

[0046] [Fig. 2] schematically represents a vertical sectional view of the machine 10 in which the first lower tool 12 is placed. The first lower tool comprises two bases 20 for receiving a container 22 juxtaposed transversely. Each base 20 comprises an upper edge 21 of annular shape on which the container rests at the level of its peripheral edges 23.

[0047] The machine 10 comprises an upper tool 24 capable of cooperating with the lower tool 12, 14 to form an enclosure. In the example shown, the upper tool 24 is designed to be moved in a vertical translation by means of a jack 26 between an open position of the enclosure and a closed position of the enclosure.

[0048] The machine 10 also comprises means 28 for unwinding a sealing film 30. In the closed position of the enclosure, the film 30 is pinched at the interface between the lower tooling 12, 14 and the upper tooling 24.

[0049] The upper tool comprises two heating blocks 32 respectively facing the two bases 20.

[0050] In an embodiment not shown, the heating blocks 32 can be moved vertically between a rest position and a welding position by an actuator such as a jack.

[0051] Alternatively, the film 30 may be clamped between the heating blocks 32 and an intermediate frame. This allows the film to be clamped before being sucked in and heated to begin stretching. The frame is actuated by four pneumatic cylinders at the four corners of the upper tooling 24. The upper tooling 24 equipped with the frame then descends towards the lower tooling 12 to close the enclosure.

[0052] The upper tool 24 also comprises two film cutting blades 30 per heating block 32, including a first blade 34 and a second blade 36, as well as a system 38 for actuating the blades.

[0053] Each first blade 34 corresponds to the first sealing format. Each second blade 36 corresponds to the second sealing format.

[0054] Figures 3 to 5 show the heating blocks 32 equipped with the first blades 34 and the second blades 36 as well as the system 38 for actuating the blades.

[0055] Each heating block 32 comprises a lower face 40 comprising an annular bearing surface 42 arranged to press the film 30 along a weld bead onto a rim 23 of the container 22 in a welding position of the heating block 32. The bearing surface 42 has a shape similar to that of the upper edge 21 of the base 20 opposite the corresponding heating block 32.

[0056] It should be noted that the mechanical welding step is optional in the case of film plating. Indeed, in the case of film plating, a vacuum is created in the enclosure and the film is softened under the effect of the heat from the heating blocks 32. Then the upper part is returned to atmospheric pressure, which has the effect of pressing the film 30 against the product and the container 22. The film 30 being hot, it sticks to the entire surface of the container 22 not covered by the product.

[0057] Each blade 34, 36 has a retracted position in which the blade does not protrude from the lower face 40 of the corresponding heating block 32 and a cutting position in which the blade protrudes from the lower face 40 of the heating block 32.

[0058] The blade actuation system 38 comprises, for each first blade 34, two first cylinders 44 and a first frame 46 fixed on the one hand to the pistons 48 of the corresponding first cylinders 44 and on the other hand to the first blade 34. Thus, for each first blade 34, the set of two first cylinders 44 constitutes an actuator 45 arranged to move the first blade 34 between the retracted position and the cutting position.

[0059] Each first frame 46 has a rectangular shape hollowed out in its center. For information purposes, the width L of the edges of the first frame 46 is approximately twice as large as the thickness E of the edges of the first frame 46.

[0060] Similarly, the blade actuating system 38 comprises a second frame 50 on which the second blades 36 are mounted juxtaposed in the transverse direction. The blade actuating system 38 also comprises two second cylinders 52, the second frame 50 being fixed to the pistons 54 of the second cylinders 52. The assembly of the second frame 50 and the second cylinders 52 is arranged to actuate the second blade 36 between the retracted position and the cutting position.

[0061] The second frame 50 has a generally rectangular shape comprising two transversely juxtaposed recesses having the same horizontal dimensions as the heating blocks 32 apart from the mounting clearance in order to allow the heating blocks 32 to slide in the second frame 50. At the interface between the two heating blocks 32, the second frame 50 comprises a crosspiece 64 on which the pistons 54 of the second cylinders 52 are fixed respectively at the two ends of the crosspiece 64. For information purposes, the thickness E2 of the second frame 50 is substantially equal to the thickness E1 of the first frames 46 and the width L2 of the second frame 50 is approximately half as large as the thickness E2 of the second frame 50.

[0062] According to a characteristic of the invention, and as shown more specifically in [Fig. 6], each first blade 34 is movable through a groove 56 arranged in the thickness of the corresponding heating block 32.

[0063] The first blade 34 has a continuous annular shape. In the example shown, the perimeter of the first blade 34 describes a rectangle in a horizontal plane having rounded corners.

[0064] The groove 56 has a shape complementary to the shape of the first blade 34 so that the first blade is contained within the thickness of the heating block 32 in the retracted position.

[0065] In the example shown, the heating block 32 has a generally parallelepiped shape with a slight flare 58 in the vicinity of the lower face 40.

[0066] The lower face 40 of the heating block 32 is hollowed out in its center with a dome 60 arranged to receive contents protruding from the container 22. The dome 60 has a flared shape at its base and extends in the lower part by a fillet in an interior portion 66 of the bearing surface 42 tangent to the horizontal plane.

[0067] The heating block 32 comprises through-orifices 62 opening into the dome 60 and making it possible to inject or suck in gases during the sealing cycle, in particular to carry out sealing under a modified atmosphere or under vacuum. The through-orifices 62 make it possible to press the film 30 firmly against the heating blocks 32 so that the film 30 softens uniformly in contact with the heating blocks 32.

[0068] The groove 56 opens into the lower face 40 of the heating block 32 at the periphery of the inner portion 66 of the bearing surface 42. Thus, the groove 56 extends along the bearing surface 42 between the inner portion 66 of the bearing surface 42 and an outer portion 68 of the bearing surface 42. For information purposes and in no way limiting, the groove 56 extends over approximately ¾ of the height of the heating block 32. The groove 56 has a constant width L3 over the entire height of the groove 56 except in the vicinity of the inner portion 66 where the groove 56 has a narrowing 68 corresponding to a widening of the portion of the heating block 32 forming the dome 60. Thus, the groove 56 is non-through at least in places and is arranged in the lower face 40 of the heating block 32. 32.

[0069] With particular reference to [Fig.7], the first blade 34 is mounted on the first frame 46 by means of fixing elements 70. The fixing elements 70 of each first blade 34 to the corresponding first frame 46 comprise eight tabs 72. Each tab 72 is arranged to slide in a through-orifice 74 made in the thickness of the heating block 32 between the groove 56 and an upper face 76 of the heating block 32.

[0070] By way of illustration, the fixing element 70 comprises two tabs 72 per side of the corresponding first frame 46. Each tab 72 is a rectangular metal plate made of the same material as the first blade 34 and extending above the blade in a vertical plane parallel to the side of the first frame 46 to which the tab 72 is fixed. Still by way of illustration, each plate 72 is positioned at % of the length of a side of the first frame 46 relative to a corner of the first frame 46. Alternatively, the fixing element 70 could comprise a different number of tabs 72 per first blade 34, for example 2 tabs 72. The tabs 72 could have another shape, for example a tubular shape.

[0071] The tabs 72 are an integral part of the blade 34 and are made from the same sheet metal or are added and welded.

[0072] The fixing element 70 of the first blade 34 to the first frame 46 also comprises screws 78 arranged to screw the transverse tabs 72 to the transverse sides of the first frame 46.

[0073] The fixing element 70 of the first blade 34 to the first frame 46 further comprises plates 80 screwed onto a lateral face of a longitudinal side of the first frame 46 and making it possible to maintain the longitudinal tabs 72 embedded in the longitudinal sides by embedding the tab 72 between the side of the first frame 46 and the plate 80.

[0074] Alternatively, the fixing element could include other fixing means such as welding, strong glue or a force fit.

[0075] In the example shown, the second blade 36 has a tubular shape of rectangular section with rounded corners corresponding to the perimeter of the heating block 32 in a horizontal plane to within a mounting clearance. The second blade is directly screwed to the second frame 50.

[0076] According to a variant of the invention shown in [Fig. 8], the multi-format machine 11 can comprise three sealing formats. In this case, the upper tool 24 comprises two blades movable through respectively two grooves 56 arranged in the thickness of the heating block 32. It should be noted that the heating block 32 shown in [Fig. 8] is flat and does not comprise a dome. The multi-format machine 11 of [Fig. 8] is therefore designed to seal products that do not exceed the height of the tray or container.

[0077] According to another variant not shown, the multi-format machine can comprise N sealing formats. In this case, the upper tool 24 comprises (N1) blades movable through respectively (N1) grooves 56 arranged in the thickness of the heating block 32.

[0078] With reference to [Fig.9], the upper tooling comprises at least one lateral window 82 for access to the elements for fixing the first blade 34 to the first frame 46. The window 82 is for example an opening cut out in the metal casing of the machine 10 opposite the fixing elements 70. The window 82 advantageously comprises a means for closing the opening to guarantee the sealing of the enclosure and to limit the risks linked to the handling of the blades.

[0079] With reference to [Fig. 10], the upper tool 24 is rotatable about a transverse horizontal axis located at the rear of the upper tool 24 between an operating position shown in [Fig.l] and a blade maintenance position shown in [Fig. 10] in which the upper tool 24 is pivoted through an angle of up to approximately 135°. Thus, in the blade maintenance position, the blades are accessible from below the upper tool 24, which is oriented upwards. Alternatively, the upper tool 24 can be pivoted through any angle of up to 360°.

[0080] With reference to [Fig. 11], the machine 10 comprises means 84 for automatically detecting the format of the base 20. In the example of [Fig. 11], the first drawer 16 is being inserted longitudinally into the machine 10 to a sealing position in which each base 20 is opposite the corresponding heating block 32.

[0081] The machine 10 comprises a first detector 86 intended to detect the base 20 corresponding to the first format and a second detector 88 intended to detect the base 20 corresponding to the second format.

[0082] The first drawer 16 comprises a lug 90 positioned opposite the first detector 86 in the sealing position of the first drawer 16. The second drawer 18 comprises a lug 90 positioned opposite the second detector 88 in the sealing position of the second drawer 18. Thus, if a lug 90 is detected by the first sensor 86, then the first format is selected and it is the first blades 34 which are implemented during the sealing cycle. If a lug 90 is detected by the second sensor 88, then the second format is selected and it is the second blades 36 which are implemented during the sealing cycle.

[0083] In order to adjust the positioning of the lower tooling 12, 14 relative to the upper tooling 24 when inserting a drawer into the machine 10, each lower tooling 12, 14 comprises positioning orifices 92 configured to receive positioning studs projecting from a lower face of the upper tooling 24.

[0084] The machine 10 may also comprise a film pinching plate in the upper tooling which can be lowered independently of the position of the heating block and making it possible to hold the film along a contour, in particular during the suction phases in the skin-type sealing cycles.

[0085] With reference to [Fig. 12], the base 20 may comprise a bottom 94 adjustable in depth. The bottom 94 is a removable plate comprising fingers 96 laterally. The base 20 comprises on an inner lateral face positioning notches 98 arranged in a staircase pattern and intended to receive a finger 96 in the case where the container depth corresponding to the positioning notch 98 in question is selected.

[0086] To allow the insertion of the bottom 94 into the base 20 for several positioning notches 98 offset longitudinally relative to each other, the bottom 94 can be turned horizontally “upside down” or pivoted 180° around a vertical axis.

[0087] Thus, the machine corresponding to [Fig. 12] is a container sealing machine 22 making it possible to thermally seal a sealing film 30 on a container 22 of products, in particular food products, the sealing machine comprising: - a lower tool 12, 14 comprising a base 20 for receiving a container 22, - an upper tool 24 arranged to allow the passage of the sealing film 30 between the lower tool 12, 14 and the upper tool 24, the upper tool 24 comprising a heating block 32 arranged to heat the film 30, the machine being such that the base 20 comprises a bottom 94 adjustable in depth.

[0088] Advantageously, the bottom 94 is a removable plate laterally comprising fingers 96.

[0089] Advantageously, the base 20 comprises on an inner lateral face positioning notches 98 offset longitudinally relative to each other and intended to receive a finger 96.

[0090] Advantageously, the positioning notches are arranged in a staircase pattern.

[0091] Advantageously, the bottom 94 can be turned horizontally by 180° around a vertical axis.

[0092] According to a variant of the invention not shown, the lower tooling could comprise a lower actuator arranged to move the base in a vertical translation between a low rest position and a high welding position.

[0093] The invention also relates to a sealing method using a sealing machine 10 according to the invention comprising:

[0094] - a lower tool 12, 14 comprising at least one first base 20 corresponding to a first format and a second base 20 corresponding to a second format,

[0095] - an upper tool 24 arranged to allow the passage of the sealing film 30 between the lower tool 12, 14 and the upper tool 24, the upper tool 24 comprising:

[0096] - a heating block 32 comprising a bearing surface 42 arranged to press the film 30 on an edge of the container 22 in a welding position,

[0097] - a first retractable blade 34 for cutting the film 30, the first blade 34 corresponding to the first format and being movable through a groove 56 provided within the heating block 32,

[0098] - a second blade 36 on the periphery of the heating block 32 and corresponding to the second format.

[0099] The method comprises the following steps.

[0100] The first step corresponds to the placement of a base 20 among the first base and the second base in a sealing position in which the base 20 is opposite the heating block 32. Typically, the first step corresponds to the insertion of a drawer among the first drawer 16 and the second drawer 18 into the machine up to a sealing position.

[0101] The second step corresponds to the detection of the format of the base which is in the sealing position. In this case, the second step corresponds to the detection by the first sensor 86 or by the second sensor 88 of the lug 90 present in the inserted drawer, this detection allowing the selection of a sealing format thanks to the determination of the format of the base 20 inserted in the machine. If a lug 90 has been detected by the first sensor 86, then the first format is selected. If a lug 90 has been detected by the second sensor 88, then the second format is selected.

[0102] The third step corresponds to the performance of a sealing cycle. The sealing cycle includes the selection of the blade to be implemented according to the format detected in the previous step. If the first format has been selected, then the first blade(s) 34 are selected. If the second format has been selected, then the second blade(s) 36 are selected.

[0103] The sealing cycle traditionally includes modifications to the atmosphere present in the enclosure of the machine 10, for example a vacuum and / or an injection of protective gases. The sealing cycle may also include a rise in temperature of the heating block and a welding step corresponding to a downward translation of the heating block.

[0104] The sealing cycle also includes cutting the sealing film 30 by the blade selected in the previous step.

[0105] The invention has several technical advantages presented below.

[0106] The invention makes it possible to obtain a versatile machine for sealing several container formats.

[0107] The machine also allows for clean welds to be produced for several types of sealing, including modified atmosphere sealing and “skin” type sealing.

[0108] The versatility of the machine both in terms of formats and type of sealing makes it possible to reduce the size and cost of sealing installations for a user while allowing a variety of packaging.

[0109] In the case of the invention in which the blade is positioned above the film, when the blade is actuated for cutting, the blade tends to press the film even more against the container whereas for a blade of the prior art located in the lower tooling, the blade tends to detach the film from the container by lifting the film above the container, which explains why the cuts in the prior art are of lower quality, in particular in the case of skin sealing in which the film is not necessarily welded to the container along a weld bead.

[0110] The invention also makes it possible to limit the risks for the operator of cut injuries linked to the cutting blades insofar as the blades are not located in a handling zone, in particular during the format change. Indeed, for a format change, the operator simply changes drawers, the drawers presenting no danger of cuts for the operator.

[0111] The invention also allows ergonomic handling for format change since the drawers have a lighter weight compared to the prior art and since the format detection is automated.

[0112] The invention also allows for easier maintenance thanks to the blade access window, the simple attachment of the blades to the actuators and the pivoting nature of the upper tooling.

[0113] Legend 10 machine 2 formats 11 machine 3 formats 12 first lower tool 14 second lower tool 16 first drawer 18 second drawer 20 base 21 upper edge 22 container 23 ledge 24 upper tools 26 cylinder 28 ways to unfold the film 30 lidding film 32 heating blocks 34 first blade 36 second blade 38 blade actuation system 40 lower face 42 support surface 44 first cylinder 45 actuator 46 first frame 48 piston of the first cylinders 50 second frame 52 second cylinder 54 piston of the second cylinders 56 groove 58 flare 60 dome 62 through holes 64 crosses 66 inner portion 68 outer portion 70 fixing elements 72 tab 74 through hole 76 upper face 78 screws 80 plate 82 window 84 automatic detection methods 86 first sensor 88 second sensor 90 spur 92 positioning hole 94 background 96 finger 98 positioning notch

Claims

Claims

1. Machine (10, 11) for sealing containers (22) for thermally sealing a sealing film (30) on a container (22) of products, in particular food products, the sealing machine (10, 11) comprising: - a lower tool (12, 14) comprising a base (20) for receiving a container (22), - an upper tool (24) arranged to allow the passage of the sealing film (30) between the lower tool (12, 14) and the upper tool (24), the upper tool (24) comprising a heating block (32) arranged to heat the film (30), the machine (10, 11) being characterized in that the upper tool (24) comprises a first retractable blade (34) for cutting the film (30), the first blade (34) being movable through a groove (56) arranged in the thickness of the heating block (32), and in that the upper tool (24) further comprises a second blade (36) on the periphery of the heating block (32).

2. A sealing machine (10, 11) according to claim 1, characterized in that the upper tool (24) comprises an actuator (45) arranged to move the first blade (34) between a cutting position in which the blade projects from a lower face (40) of the heating block (32) and a retracted position in which the blade does not protrude from the lower face (40) of the heating block (32).

3. Sealing machine (10, 11) according to the preceding claim, characterized in that the first blade (34) is mounted on a first frame (46) by means of fixing elements (70), the first frame (46) being an intermediate part between the first blade (34) and the actuator (45).

4. Sealing machine (10, 11) according to any one of the preceding claims, characterized in that: - the first blade (34) has a continuous annular shape, and in that - the groove (56) is non-through at least in places and is arranged in a lower face (40) of the heating block (32), the groove (56) having a shape complementary to the shape of the first blade (34) so ​​that the first blade (34) is contained in the thickness of the heating block (32) in the retracted position.

5. Sealing machine (10, 11) according to the preceding claim when it itself depends on claim 3, characterized in that the fixing elements (70) of the first blade (34) to the first frame (46) comprise at least one tongue (72) arranged to slide in a through orifice (74) provided in the thickness of the heating block (32) between the groove (56) and an upper face (76) of the heating block (32).

6. A sealing machine (10, 11) according to any one of the preceding claims, characterized in that the upper tool (24) is rotatable about a horizontal axis between an operating position and a blade maintenance position.

7. Sealing machine (10, 11) according to any one of the preceding claims, characterized in that the upper tool (24) comprises a lateral window (82) for access to the fixing elements (70) of the first blade (34) to the first frame (46).

8. Sealing machine (10, 11) according to any one of the preceding claims, characterized in that it comprises several nested retractable blades, each retractable blade being movable through a groove (56) specific to the blade and arranged in the thickness of the heating block (32).

9. Sealing machine (10, 11) according to any one of the preceding claims, characterized in that, the first blade (34) corresponding to a first sealing format and the second blade (36) corresponding to a second sealing format, the lower tooling (12, 14) comprises at least a first base (20) corresponding to the first format and a second base (20) corresponding to the second format.

10. Sealing machine (10, 11) according to the preceding claim, characterized in that each base (20) is mounted in a drawer (16, 18) capable of being inserted longitudinally into the machine (10, 11) up to a sealing position in which the base (20) is opposite the heating block (32).

11. Lidding machine (10, 11) according to one of claims 9 or 10, characterized in that it comprises an automatic detection means (84) of the format of the base (20).

12. A method of sealing using a sealing machine (10, 11) comprising: - a lower tool (12, 14) comprising at least a first base (20) corresponding to a first format and a second base (20) corresponding to a second format, - an upper tool (24) arranged to allow the passage of the sealing film (30) between the lower tool (12, 14) and the upper tool (24), the upper tool (24) comprising: - a heating block (32) arranged to heat the film (30), - a first retractable blade (34) for cutting the film (30), the first blade (34) corresponding to the first format and being movable through a groove (56) formed within the heating block (32), - a second blade (36) at the periphery of the heating block (32) and corresponding to the second format,the method comprising the following steps: - placing a base (20) among the first base and the second base in the sealing position in which the base (20) is opposite the heating block (32), - detecting the format of the base (20) which is in the sealing position, - carrying out a sealing cycle comprising the following steps: - selecting the blade to be used according to the format detected in the previous step, - cutting the sealing film (30) by the blade selected in the previous step.,

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