EP0062571A1 - Process and device for piercing the lid of a recipient, and manufacturing appliance for the device - Google Patents

Abstract

This piercing device for cover made of a flexible and tearable material consists of a rigid tongue (101) substantially planar on which there is a hinge pin (109) dividing the tongue into a piercing arm (107) and a operating arm (108), the hinge pin (109) being fixed to the cover (102). To materialize the axis (109), there is provided a second flexible tongue (106) having at least approximately the same extension as the rigid tongue (105) and fixed, on one side to the drilling arm (107) of the rigid tongue (105) and, on the other side, at least in the area covered by the operating arm (108) of the rigid tongue (105), on the cover. This device is particularly suitable for being produced during the forming, filling and sealing of thermoplastic containers.

Description

The invention relates to a method for providing covers for receptacles with lever tabs for piercing, said covers being made of a flexible and tearable material.

Many lid opening devices are known.

Thus, it has been proposed to cover pre-embrittlement with an element which is grasped and pulled to cause the rupture of the cover along its lines of embrittlement. This opening system is generally inconvenient and requires a pre-impression which is not compatible with the conservation of certain products (oxidation and / or bacteriological contamination at the bottom of the pre-imprint lines, for example when the bottom of the pre-imprint reaches a oxidizable and / or non-sterile layer of a multilayer cover sterilized on the surface).

Another solution has been proposed, consisting of preforming a hole in the cover and covering it with an adhesive element which is easy to remove. However, this system has also not been satisfactory with regard to the conservation guarantees for certain products.

A peelable cover device has been very well received by manufacturers and users. Generally associated with an installation for manufacturing thermoformed containers, it has led to a safe and economical opening system.

However, there are products for which the latter solution cannot be used, in particular in the case of long-term or sterile packaging requiring perfect sealing at the level of the lid which can only be obtained with sealing by autogenous welding therefore non-peelable.

French patent 2,241,466 also discloses cover opening devices using lever-piercing tongues, but on the one hand, these tongues are glued directly flat to relatively rigid covers, in material thermoplastic; on the other hand, these opening devices are necessarily associated with a cover having weakening lines and operate the opening more by shearing at the weakening lines than by real drilling of the cover. These known devices have the drawback either of not offering the tongue a precise articulation, in which case the device malfunctions or even the tongue can come off the cover; or to require the presence on the cover itself of the independent means of the tongue ensuring the tongue a certain articulation. But, in the latter case, the manufacture of these additional means - when it is possible - complicates and slows down the production line for sealed containers; moreover, this then forces the tongues to be positioned in a very precise position predetermined as a function of said additional means, which is not always easy and compatible with a high production rate.

The invention aims to propose a new type of simple and economical opening device, which can be adapted to many types of lids and in particular to those generally used in equipment for manufacturing and packaging thermoformed containers with welded lids which are cut from strips with lids, and not having the aforementioned drawbacks. The manufacturing and packaging equipment particularly targeted are of the so-called type FFS (abbreviated designation of three English verbs meaning: to form, to fill, to seal).

• - on réalise des languettes rigides sensiblement planes,
• - on matérialise sur les languettes un axe d'articulation divisant les languettes en un bras de perçage et un bras de manoeuvre,
• - on fixe lesdits axes d'articulation sur les couvercles.

The objects of the invention are achieved by the fact that:

• - substantially flat rigid tongues are produced,
• - a hinge pin dividing the tongues into a drilling arm and an operating arm is produced on the tongues,
• - Said hinge pins are fixed on the covers.

The invention also relates to a piercing device consisting of a substantially planar tongue on which is formed an articulation axis dividing the tongue into a drilling arm and an operating arm, the articulation axis being fixed to the cover.

The invention also relates to an installation for manufacturing a drilling device, comprising means for producing substantially planar tongues, means for materializing on the tongues an articulation axis dividing the tongues into a drilling arm and into operation, and means for fixing said hinge pins on the lids of the containers.

According to a first embodiment, the hinge pin is materialized by a rib on the tongue.

Thus, the piercing device comprises a substantially planar tongue, provided on one of its faces with a rib fixed on the outside face of the container cover, the rib separating the tongue into two arms for maneuvering and drilling, whereby a manual lifting of the operating arm initially causes the tongue to tilt around the rib and the cover to be pierced by the piercing arm, and subsequently tears off part of the cover from drilling.

Thanks to the device according to the invention, it is entirely possible to dispense with a pre-impression. Naturally, it can however be used, especially when one wishes to obtain a tear along a given line or when the cover is particularly thick.

The opening system according to the invention has, apart from its simplicity, other advantages: it does not require a powerful and / or sudden movement (which may lead to the product contained in the container being overturned); if the tab is slightly pulled, the container can be closed temporarily by putting it back in position; the tab being able to be pulled out and remaining attached to the partially torn cover, a separate pollution-generating element is not created when it is thrown away.

Advantageously, the rib is formed integrally with the tongue. More specifically, the rib is formed by a deformation of the tongue obtained for example by stamping.

Advantageously, the operating arm comprises on the face of the tongue turned towards the cover, a spacer pin to facilitate gripping of the tongue.

Advantageously, the cover is made of an aluminum-based material, and in particular of a polyethylene / aluminum, polypropylene / aluminum or similar composite material.

Advantageously, the tongue is based on rigid plastic material, and in particular on the plastic material constituting the container itself.

In the context of the manufacture of thermoformed containers from a thermoplastic strip, provided with a welded and cut cover, it is advantageous to form the drilling tabs in the ther strip. moplastic used to make the containers.

Advantageously, the tongues are cut from the thermoplastic strip in the free zones situated between the zones for forming the containers.

Advantageously, the tabs are cut when the containers are cut.

An installation for manufacturing the device according to the invention, in the context of equipment for packaging thermoformed containers from a thermoplastic strip, provided with a welded cover and cut out at a cutting station, comprises ribs forming means, tongues of cutting means, means for entry and means for transferring tabs to a gluing station, transfer means of the _tongues from the glueing station to the container lids, and means for applying the tabs to the lids.

According to a second embodiment of the invention, still more advantageous, the articulation axis of the rigid tongues is materialized by providing them contiguously with a flexible tongue having at least the same extension approximately as the rigid tongues, fixed on one side with the rigid tabs only on the side of the drilling arm, and fixed on the other side with the covers, at least on the side of the operating arm of the rigid tabs.

In this way, the articulation of the rigid tongue on the cover is materialized by the line of separation between the part of the flexible tongue, part fixed on the rigid tongue, and the part of flexible tongue free relative to said rigid tongue but attached to the cover. By tilting upwards the operating arm of the rigid tongue, the drilling arm of the latter necessarily pivots downwards by tearing the cover at this point up to the line of articulation. Then pulling the rigid tab towards the end- rear of the flexible tongue secured to the cover, the cover is torn at the same time along lines following at least approximately the edges of the flexible tongue. Thus, also in this embodiment, it is not necessary to provide the cover with weakening or tearing lines.

For fixing the flexible tongue to the rigid tongue and / or to the cover, a hot glue or a lacquer or a fusible varnish or other sticky substance is generally used.

Although the cover can be made of any tearable material, it is advantageous to make it out of a metal sheet, in particular of aluminum, provided if necessary with a heat-bonding film.

The rigid tongue and the flexible tongue can be made of any suitable material, but when the containers are produced from a thermoplastic sheet and the cover from an aluminum strip, if necessary provided with a film. iron-on, it is advantageous to manufacture the rigid tabs from the thermoplastic strip and the flexible tabs from the aluminum strip.

In this case, it is recommended to use rigid tabs and flexible tabs for the manufacture. The zones of thermoplastic strip and aluminum strip located between the curvilinear or rounded edges of the thermoplastic containers when cutting the containers from the container strip and cover strip.

For this purpose, it is possible at the time of sealing the cover strip to the edges of the filled containers and still attached to the thermoplastic container strip, to seal part of the cover strip, part corresponding to that of the tab. flexible, intended to be fixed on the rigid tab and then, preferably after advancement sealed containers at least one step, is set cutting rigid and flexible tabs in underground areas _- wind star-shaped, included between the edges of the containers which at this time are not yet or are only partially cut from the container strip - cover strip assembly, the cutting zone of the rigid and flexible tabs superimposed being chosen so that it coincides with the prior sealing area which must then correspond to the piercing arm of the cut rigid tongue.

Of course, the cut and sealed assemblies of the rigid and flexible tongues are recovered and the entire face of the flexible tongue, face turned away from the rigid tongue, is preferably glued to the lid of a container sealed in the zone located at the plumb with the opening of a container. Preferably, the flexible tongue is glued to the cover - which is made of the same material as the latter - so that the piercing arm of the rigid tongue is located near the edge and, if necessary, near a corner of the container opening.

To ensure bonding of the flexible tab on the cover, the external free face of the latter can be glued with an appropriate adhesive and then apply the rigid tongue - flexible tab assembly with the face glued against the corresponding cover, but it is also possible to glue the cover zone intended to receive the free face of the flexible tongue which on its other face adheres firmly to the drilling arm of the rigid tongue.

An installation for manufacturing this piercing device, having a flexible tongue and a rigid tongue superimposed, comprises in particular means for sealing a flexible strip on a rigid strip in zones corresponding subsequently to the drilling arms of the various rigid tabs, means for cutting the rigid and flexible tabs superimposed, means for transferring the cut and sealed assemblies of flexible tabs and rigid between the cutting station and the place of their installation on the lids of the sealed containers, sizing means either on the free face of the flexible tab or on the cover zone intended to receive the assembly of rigid and flexible tab as well as means for applying the sets of flexible and rigid tabs to the corresponding covers so that the free face of the flexible tab adheres firmly to the cover.

When the drilling device is applied to thermoformed and heat-sealed containers, the various means of the installation for manufacturing the drilling devices can advantageously be integrated into packaging equipment of the F.F.S. type. that is to say, which thermoforms the containers from a thermoplastic strip, which fills them with a product and which seals them with a strip with lids and which finally cuts the sealed containers from the thermoplastic strip and the strip to covers.

In this case, the station for sealing the cover strip on the thermoplastic container strip also comprises the means for sealing the flexible strip on the rigid strip and the means for cutting the sets of rigid and flexible tabs can be provided either in the partial cutting station for sealed containers is just upstream of it.

• - la figure 1 est une vue en plan d'un r.é- cipient et de son couvercle muni d'un premier mode de réalisation du dispositif de perçage de l'invention ;
• - la figure 2 est une vue de face du récipient de la figure 1 ;
• - la figure 3 est un détail agrandi du dispositif de la figure 2 ;
• - la figure 4 est une vue en plan de récipients formés dans une bande thermoplastique et montrant l'emplacement de découpe des languettes du premier mode de réalisation du dispositif ;
• - la figure 5 est un détail agrandi de la figure 4 ;
• - la figure 6 est une vue schématique latérale partielle d'une installation de fabrication du premier mode de réalisation du dispositif de l'invention ;
• - la figure 7 représente une pince élastique utilisée dans l'installation de la figure 6 ;
• - la figure 8 est une vue en coupe verticale à travers un récipient dont le couvercle est muni d'un second mode de réalisation de dispositif de perçage de l'invention ;
• - la figure 9 est une vue agrandie du dispositif de la figure 8 mais en position de perçage.
• - la figure 10 est une vue en plan d'une bande à couvercles scellée à une bande thermoplastique à récipients, cette figure montrant à la fois les contours de découpe des récipients et des languettes, dans le cadre du second mode de réalisation de l'invention ;
• - la figure 11 est une vue schématique latérale d'une installation de fabrication du second mode de réalisation du dispositif de perçage de l'invention ;
• - la figure 12 est une vue de dessus de l'installation de la figure 11.

The invention will be better understood by the description which follows, made with reference to the appended drawings in which:

• - Figure 1 is a plan view of a container and its cover provided with a first embodiment of the piercing device of the invention;
• - Figure 2 is a front view of the container of Figure 1;
• - Figure 3 is an enlarged detail of the device of Figure 2;
• - Figure 4 is a plan view of containers formed in a thermoplastic strip and showing the cutting location of the tongues of the first embodiment of the device;
• - Figure 5 is an enlarged detail of Figure 4;
• - Figure 6 is a partial side schematic view of a manufacturing installation of the first embodiment of the device of the invention;
• - Figure 7 shows an elastic clamp used in the installation of Figure 6;
• - Figure 8 is a vertical sectional view through a container whose cover is provided with a second embodiment of the piercing device of the invention;
• - Figure 9 is an enlarged view of the device of Figure 8 but in the drilling position.
• FIG. 10 is a plan view of a strip with lids sealed to a thermoplastic strip with receptacles, this figure showing both the cutting contours of the receptacles and of the tongues, in the context of the second embodiment of the invention;
• - Figure 11 is a schematic side view of a manufacturing installation of the second embodiment of the drilling device of the invention;
• - Figure 12 is a top view of the installation of Figure 11.

The first embodiment of the piercing device of the invention (FIGS. 1 to 7) comprises a substantially planar tongue 1 provided with a hinge pin in the form of a rib 2 on one 3 of its two faces.

The tongue 1 is glued to the location of the rib 2 with non-brittle glue 4 on the cover 5 of a container 6.

The rib 2 separates the tongue 1 into two arms: one 7 said to maneuver, and the other 8 said to be drilling.

By lifting upwards (arrow 9, FIG. 3), the operating arm 7 of the tongue 1, the latter swivels around the rib 2 so that the end of the drilling arm comes to touch the cover 5 (FIG. 3, dotted position). This tilting is possible because of the flexibility of the cover 5 which deforms slightly, and, if necessary, because of the flexibility of the glue 4.

The lifting of the operating arm continuing, the end of the piercing arm 8 starts and pierces the cover 5. In order to facilitate this operation, the end of the piercing arm 8 is angular (tip 10).

Continuing the pivoting of the tongue 1 around the rib 2 until it is placed in a position substantially perpendicular to the plane of the cover 5, the piercing arm widens the tear in the cover until appreciably the width 1 of tongue 1 at the rib 2. The piercing arm 8 gradually widens from the tip 10 towards the rib 2 so as to facilitate the gradual widening of the tear.

Once the cover is pierced and torn over the width 1, it suffices, if one wishes to extend the opening, to pull the tab 1 by the operating arm 7 in the direction opposite to the drilling arm, so as to continue the tear.

The tear continues generally on the width 1. This operation is particularly easy if, in the case of a composite cover comprising a plastic material, the tear takes place in the direction in which the plastic has been extruded : it is therefore preferable in this case to place the tongue with its rib 2 perpendicular to the orientation, ion of the plastic film.

Naturally, if the cover has weakening lines, made for example by pre-impression, the tongue can be placed so that, during the pivoting of the latter causing the piercing and the beginning of tearing of the cover, the tear meets the lines of embrittlement and, by continuing to pull the tab, the tearing continues along the lines of embrittlement. These can be provided so as to obtain an annular tear which goes all around the cover and making it possible to remove the latter almost entirely.

The rib 2 of the tongue 1 can be constituted by an insert fixed to the tongue; it can be formed by the bead of glue 4 itself even if the latter is fairly large.

Preferably, the rib 2 is formed integrally with the tongue 1 and can be, in the case where the tongue is made of plastic material, a simple deformation (FIG. 3) obtained hot or cold by stamping.

The height of the rib 2 is not critical, and can be chosen to be 1 to 2 mm for example. From it, and the length of the piercing arm, depends the angle at which the point 10 of the piercing arm 8 attacks the cover 5, an angle related to the ease of piercing.

In order to be able to drill the cover 5 manually without difficulty, it is preferable that the length of the lever arm a of the drilling arm is less than that b of the gripping arm (FIG. 2), for example in a ratio of one quarter or a third.

In order to facilitate manual gripping of the gripping arm 7, the latter is provided with a spacer stud 11 on its face 3. This stud can be obtained like the rib 2 by stamping.

The stud 11 can be very slightly glued to the cover 5, so as to oppose a fortuitous lifting of the operating arm 7 resulting in accidental drilling. The bonding is however weak enough to yield under the effort of the operator during the intentional manual lifting of the tongue 1. Although the tongue 1 can be placed, which is of any size depending on the type of opening that is desired practice, at very numerous locations on the cover, it is advantageous to place it, as shown in Figures 1 to 3, so that the end 10 of the drilling area 8 is located in the immediate vicinity of the edge 12 from the edge of the container 6 on which the cover 5 is placed. In this way, when the tongue 1 has pivoted and the point 10 begins to attack the cover 5, the point of attack 13 of the bore is very close (for example from 1 to 3 mm) from the edge 12 of the edge of the container, so that this region of the cover is supported by the presence close to the edge, and slightly deformed and the drilling is thus facilitated (shearing effect).

The invention applies to any kind of tear-off cover under the action of a rigid wedge piece, the tear of which can be possibly extended by pulling the torn part.

In particular, the invention applies to the opening of thermoformed containers with a heat-sealed non-peelable lid. This is particularly the case for thermoformed containers from a polystyrene 14 / polyethylene 15 composite strip provided with an aluminum 16 / polyethylene 17 composite cover sealed by autogenous welding on the edges of the container.

In the context of such receptacles, it is particularly advantageous, when the shape chosen for the tongues 1 is suitable, to form them in the thermoplastic strip 18 (FIGS. 4.5) for forming the receptacles in star waste. (Figures 4, 5) remaining between the containers.

We will explain (Figures 4.7) in what follows an example of manufacture and implementation of the opening tabs 1 in the context of conventional equipment for packaging thermoformed containers comprising downstream of a whole chain of thermoforming stations, filling, sealing of a cover strip, a station 19 for cutting containers.

The containers are cut in a known manner by means of dies and punches not shown, over the entire width of the strip 18 and in steps of two containers for example. These techniques are known to those skilled in the art and will not be further described.

The tongues 1 are advantageously formed in the stars situated between the containers, at the level of the cutting station 19 for the containers. At this level, the strip 18 carries the thermoformed containers 6 and is covered with the cover strip (for example in aluminum / polyethylene composite): consequently, by being cut at this station 19, the tongues 1 will be formed from a structure comprising, on the one hand, this thermoplastic composite and, on the other hand, the cover strip, which will allow, by an adequate printing of the cover strip, to make appear on the tongue 1 the desired indications (such as arrows or codified opening instructions) or patterns any.

In order to cut the tongues 1 simultaneously with the cutting of the containers 6, the lower cutting tool 20 used for cutting the containers 6 is provided with embossed punches 21 in the shape of the tongues 1 and located in the inter-container zones . The punches 21 cooperate with dies 22, the inlet section of which coincides with the section of the punches 21 so as to allow the tongues 1 to be cut by shearing. These have been previously stamped at the container forming station to form their surface the rib 2 and the stud 11, so that these are perfectly formed tongues which pile up as they are cut in the dies 22 (this stacking of tongues 1 has only been shown on the right matrix of Figure 6).

In order to limit the friction of the tongues on the walls of the dies, which could lead to a blockage, the walls of the matrix are, in general, wider than at their entry section.

The tongues 1 are led to the outlet of the dies 22 by guides 23 which can in particular be guides produced from several filiform guides enclosing the tongues, which can be specially shaped for this purpose by having concave edges, or even notches, allowing easy guidance by this type of guide.

At the outlet of the guides 23, each tongue is taken up by an elastic clamp 24 mounted on a rotary drum 25 around an axis 26 perpendicular to the direction of advance 27 of the strip 18.

The elastic clamps 24 can be produced as shown in FIG. 7 by a plate 28 carried by a foot 29 capable of sliding to enter more or less into the drum 25. The plate 28 is provided with elastic retaining elements 30 which allow a tongue 1 to snap into place and bear against the plate 28.

During a rotation of the drum 25, the tongues 1 pass in front of a gluing station 31 where the ribs 2 (and the spacer pins 11, if any) are glued.

After having again rotated a suitable angle, the pliers 24 come to deposit the tongues 1 on the lids of the pots 6a, 6b situated above the recovery belt 32, by means of an expulsion rod 33 slidably mounted in each clamp 24.

It should be noted that, as can be seen in FIGS. 4 and 5, the tongues are taken from the regions between the containers and deposited on the containers at a location generally offset transversely to the location of the removal. It is therefore necessary to take account of this lateral offset, either at the level of the guides 23, or by a device associated with the clamps 24 allowing them to carry out during the rotation of the drum 25 a small lateral transfer.

In order to ensure exact placement of the tongue, on the containers 6a, 6b, it is good that the position of these is itself very precise.

To this end, provision is made. at the cutting station 19, not to completely detach the containers 6c (FIG. 4) in the cutting station 19 from the containers 6e immediately upstream, and to maintain them by an uncut portion on their common side 34 ; thus, after advancing one step during which the containers 6c, 6d have taken the position 6a, 6b in which they receive the tongues, the containers 6a, 6b are perfectly positioned since they are still connected to the containers upstream.

They will be separated from it by the cutting tools of the station 19 which include means for cutting the last remaining fastener (that is to say the common side 35 corresponding to the side 34 advanced by one step). The containers are then free to be taken up by the belt 32 for storage or the like.

FIGS. 8 to 12 show a second embodiment of the piercing device 101 fixed to the lid 102 of a container 103, the upper edge 104 of which is made integral, for example by sealing, with the edge of the lid 102. piercing 101 is applied to lids which are tearable and which, preferably, cannot be separated easily from the container, for example by peeling.

The piercing device 101 comprises a rigid upper tongue 105 and a flexible lower tongue 106 which are superimposed and have substantially the same contours, seen in plan (see FIG. 10). In its front part, the flexible tongue 106 is firmly fixed to the corresponding part of the rigid tongue 105 which must form the drilling arm. The area of attachment of the flexible tongue 106 to the rigid tongue 105 is generally smaller than the free area of the rigid tongue 105. The other face of the flexible tongue 106, that is to say the face lower, diverted from the rigid tongue 105 is fixed, preferably over its entire surface and, in any case, along a surface larger than the area for fixing the flexible tongue 106 on the rigid tongue 105, on the cover 102 in particular of such that the attachment zone between the flexible tongue 106 and the rigid tongue 105 faces the edge of the opening of the container 103.

Thanks to this kind of fixing between the rigid 105 and flexible 106 tongues and the flexible tongue 106 on the cover, the 102, a drilling arm 107 and an operating arm 108 are produced on the rigid tongue 105 which preferably is more larger than the drilling arm 107.

There is thus produced at the inner rectilinear limit of the zone for fixing the rigid 105 and flexible tabs 106 one on the other and being located below the zone for fixing the flexible tab 106 on the cover 102, an axis d hinge 109 which is itself firmly fixed both to the rigid tongue 105 and to the flexible tongue 106 and thereby to the cover 102 and which allows the pivoting of the operating arm 108 upwards (see arrow F1, FIG. 9 ) and of the drilling arm 107 downwards so that the latter tears the cover 102. Then by pulling the operating arm 108 backwards in the more or less horizontal direction indicated by the arrow F2, the following cover can be torn the contours determined by those of the flexible tongue 106.

The material of the container or the rigid tongue is immaterial provided that the latter can be fixed properly on the flexible tongue. It is the same with regard to the materials of the cover and the flexible tongue provided that the cover can be torn by the rigid tongue and that the flexible tongue can be fixed firmly on the rigid tongue and on the cover and that this fixing resists the forces applied to the various connections.

When using the piercing device 101 with thermoformed containers and covered with covers of aluminum foil or strip or of a sheet or complex strip comprising a metallic film, it is advantageous to manufacture the rigid tongue 105 from the thermoplastic container strip and the flexible tabs 106 from the aluminum strip.

FIG. 10 shows a plan view of a portion of cover strip 110 covering the container strip. The opening 111 of the containers is shown in broken lines, the cutting lines 112 of the edges of the containers with their sealed lids being shown in solid lines. Several grouped receptacles can be separated from each other along the lines of weakness 113.

The cover strip 110 is sealed on the edges of the containers in the annular zones 114 lying between the lines 112, 113 on the one hand and the openings 111 on the other.

It can be seen in FIG. 10 that the cutting lines 112 between four containers delimit an intermediate star-shaped zone 115 which, in principle, constitutes waste. According to a feature of the invention, this intermediate zone 115 is used for the manufacture of the assembly - rigid tongue 105 flexible tongue 106 -. To this end, the front part of flexible tongue 106 (part of aluminum strip provided with a heat-bonding film located in the intermediate zone 115) is sealed (under pressure and hot) on the corresponding part of the ' container strip and subsequently constituting the rigid tongue 105, this sealing preferably being carried out at the same time as the sealing of the covers on the edges of the containers in the annular zones 114. The sealing zone 116 of the flexible tongue 106 has been indicated on the rigid tongue 105 by hatching and the internal limit of this zone 116 by a straight line 117 extending perpendicular to the longitudinal axis of the rigid tongue 105.

. After this partial sealing of the flexible tongue 106. on the rigid tongue 105, the rigid tongue assembly 105 is cut flexible tongue 106 - along the contours 118 and then preferably glued the entire free face of the flexible tongue 106 before applying it, in the inverted state, against the cover, preferably such that the pointed part (piercing arm 107) of the rigid tongue is located near the opening 111 of the container. In other words, the outside face of the cover and the outside face of the flexible tongue 106 are glued back to back one on the other, these faces having been in the same plane and on the same side in the strip of covers 110 before the cutting of the rigid 105 and flexible 106 tabs (see reference 119 in FIG. 13).

The installation for manufacturing the piercing device 101 comprises the means mentioned above which are obviously adapted to the shape of the tongues and to the places of their application.

It is self-evident that the sealing zone 116 corresponds to the zone of the rigid tongue 105, zone forming the piercing arm 107 and the straight 117 will later constitute the right articulation 109 when the piercing device is fixed on the cover 102 of container 103.

FIGS. 11 and 12 show an installation for manufacturing a piercing device according to the invention, this installation being associated with or preferably incorporated in packaging equipment 120 of the type which thermoforms containers 103 from a thermoplastic strip 121 which fills them with a product, which seals the filled containers using a flexible strip with lids 110 and which, finally, cuts the filled and sealed containers 103 from the thermoplastic strip 121 and the strip to covers 110. The packaging equipment 120 is of a known structure so that it is not necessary to describe it in detail. This equipment 120 successively comprises a heating station not shown in the thermoplastic strip 121, a thermoforming station not shown in which are made cells constituting the containers 103 which remain still attached to said strip 121, a filling station in which the containers 103 _- are filled with a product, a sealing station 122 in which the strip of lids 110 previously placed on the thermoplastic strip 121 so as to cover the openings 111 of the containers 103 and the edges surrounding them is sealed hot and under pressure, along annular sealing zones 114 on said edges, and a cutting station 123 in which the sealed containers 103 are cut, either individually or in groups, from the thermoplastic strip 121 and the cover strip 110 to outside the sealing areas 114 along cutting lines 112 before being evacuated, for example using a conveyor belt t 124 to an overpacking station not shown.

In the present case, the thermoplastic strip 121 is advantageously used for reci pins and cover strip 110 for producing the two-arm lever comprising the rigid tongue 105 and the flexible tongue 106 when there are sufficiently large intermediate free zones 115 between the sealing zones 114 of several neighboring containers belonging to two successive rows of containers. Of course, it is also possible to produce the lever assembly constituted by a rigid tongue 105 and a flexible tongue 106 by using two superimposed tapes, one of which is made of rigid thermoplastic material and the other of which is made of a flexible material, foldable and heat-sealable, that is to say capable of being heat sealed and pressurized on the strip of rigid thermoplastic material.

As can be seen in FIGS. 11 and 12, the installation for manufacturing the drilling device comprises sealing means 125 comprising a heated upper punch 126 and a lower counter-punch 127, the working faces of which have a configuration identical to that of the sealing zones 116 of the tongues 105 and 106 (see also FIG. 10). In the case of the embodiment shown in FIGS. 10 to 12, the punches 126 and the counter punches 127 are provided in the sealing station 122 and carried respectively by the punches 128 and counter punches 129 used to seal the strip of cover 110 on the thermoplastic container strip 121 along the annular zones 114.

The rigid tongue 105 - flexible tongue 106 assemblies are then cut either from the above-mentioned pair of ribbons, or from the set of superimposed bands consisting of the container strip 121 and the cover strip 110, this cutting being carried out according to the predetermined shape 118 of the pairs of overlapping tabs 105, 106 and so that the sealing area 116 of each pair of tabs 105, 106 is located to the right of the drilling arm 107 and is separated from the unsealed area by the separation line 117 which will later materialize the hinge pin 109 of the drilling device. The cutting of the superimposed and partially heat-sealed tongues one on the other 105, 106 is carried out using cutting means 130 of the type comprising a cutting punch 131 and a fixed bottomless die 132 arranged on either side of the pair of overlapping ribbons or bands 110,121. The pairs of cut tabs 105, 106 are discharged through the bottom of the dies 132 either in transfer means 133 constituted either by removable storage cartridges, or by guide slides. When the pairs of tabs 105, 106 are cut from a pair of superimposed ribbons, their storage is carried out in cartridges connected to the open bottom of the dies 132 and preferably provided with a return spring subsequently facilitating expulsion one by one. one of the pairs of tongues 105, 106 above a determined location of a flat cover 102 sealed on the edge of the corresponding container 103, said determined location having been previously coated with a tiny layer of glue or a drop of glue 134 from an appropriate glue dispenser 135.

In the case of the exemplary embodiment shown in FIGS. 11 and 12, the die 132 is arranged above the pair of strips 110, 121 and the corresponding punch 131 is placed below said pair of strips at the predetermined locations 136 for cutting. pairs of tabs 105,106. The cutting means 130 can be provided either in the cutting station 123 of the sealed containers or one or several tape feed steps upstream of said station 123, the tape feed step being equal to the width of a cut container, width taken in the direction of advance F ₁ of the pair of strips 110,121. Of course, the punches 131 are controlled synchronously with the cutting elements of the station 123.

In the present case, the guide rails 133 can be produced by tubes having a cross section adapted to the configuration of the pairs of tongues 105, 106 and shaped so as to present a semi-circular central part 136 and two vertical lateral parts 137, 138 of which l one (137) opens at its lower end above the bottom of the matrix 132 and the other (138) is closed at its lower end by a window pusher 139 of a known type (for example of the kind buttons used in slide projection devices). and is arranged near the place of deposit of a pair of tabs 105, 106 on the area of the previously glued cover. The window pusher 139 is in a horizontal position and spaced from the cover strip 110 by a distance at least slightly greater than the thickness of a pair of tabs 105, 106 which during its transfer into the slide 133 has been turned over 180 °. When the window part of the pusher 139 is laterally extended from the slide 133, the latter is located below an applicator piston t40 which after having pushed a pair of tabs 105, 106 out of the window where it has been retained on its edges by elastic means, apply it against the previously glued area of the cover strip 110, area situated directly above the opening of a container 103. It will be noted in FIGS. 10 and 11 that the sealing means 125 , the sizing means 135 and the application means 140 of the pairs of tongues 105, 106 are arranged one behind the other (with the appropriate lateral offset) in the direction of advance of the strips 110,121 and that the cutting means 130 are arranged downstream of the application means 140. When the transfer slide 133 is completely filled with a pair of tongues 105,106, each punching movement 131 will automatically introduce a pair of tabs 105,106 into the window of the pusher 139 at the other end of the slide 133. It should also be noted that the type of slide 133 cooperating at one end with the open bottom of a cutting die and at the other end with a window pusher 139 can also be used when the cutting means 130 do not cooperate with a pair of strips 110,121, but with a pair of strips independent of said pair of strips. This could in particular be the case when the free zones 115 between the edges of containers 103 are too small to allow the pairs of tongues 105, 106 to be cut at these locations.

Claims (17)

1. Method for providing lids with receptacles with lever tabs for piercing, said lids being made of a flexible and tearable material, characterized in that - Rigid, substantially planar tongues (1; 101) are produced; - There is materialized on the tongues a hinge pin (2; 109) dividing the tongues (1; 101) into a drilling arm (8; 107) and an operating arm (7 ', 108); - Said hinge pins are fixed on the covers (5; 102). 2. Method according to claim 1, characterized in that the tongues (1; 101) are produced from a sheet of rigid thermoplastic material (18; 121). 3. Method according to any one of claims 1 and 2, in the context of the manufacture of thermoformed containers from a rigid thermoplastic strip (18; 121), characterized in that the tongues (1; 101 ) in said thermoplastic strip (18; 121). 4. Method according to any one of claims 1 to 3, in the context of the packaging of thermoformed containers (6; 103) from a rigid thermoplastic strip (18; 121) and closed by a cover (5; 102) made from a cover strip (110) superimposed on the thermoplastic strip (18; 121) comprising the containers, characterized in that the tongues (1; 101) are fixed by their hinge pins (5; 102) to the covers (5; 102) when these are in the closed position on the containers (6; 103). 5. Method according to claim 3, in which the thermoplastic strip (18; 121) comprises areas for forming containers, and free areas (115) outside said areas for forming, characterized in that the tongues are cut out ( 1; 101) in said free zones (115). 6. Method according to any one of claims 1 to 5, characterized in that the articulation axis (2) materializes by forming a rib (2) on the tongue (1) and the tongues (1 ) by their rib (2) on the covers (5). 7. Method according to any one of claims 1 to 5, characterized in that materializes the articulation axis (109) of the rigid tongues by providing them contiguously with a flexible tongue (106) having at least approximately the same extension as the rigid tongues (105), fixed on one side to the rigid tongues (105) only on the side of the drilling arm (107) and fixed on the other face to the covers (102) at least on the side of the arm for operating (108) rigid tongues (105). 8. Method according to claim 7, characterized in that the rigid tongues (105) are produced in a rigid thermoplastic material and the flexible tongues (106) in a flexible and heat-bonded composite material, and in that the tongues are fixed flexible (106) on the drilling arm (102) of the rigid tongues (105) by heat sealing, and in that the flexible tongues (106) are fixed on the covers (102) using a sticky substance. 9. Method according to any one of claims 7 or 8, in the context of the manufacture of thermoformed containers (103) in a rigid thermoplastic strip (121) and closed by a cover made from a cover strip (110 ) superimposed to the thermoplastic strip (121) comprising the containers (103) and heat-sealed on the edges (114). said containers (103), characterized in that the cover strip (110) is heat-bonded to the thermoplastic strip (121) in zones (116) intended to subsequently form the drilling arm (107) of the rigid tongues (105 ) is cut in the superimposed strips (121,110) sets of rigid tabs (105) / flexible tongue (106) comprising in particular said zones (116) and said assemblies are bonded by the flexible tongue (106) to the covers. 10. The method of claim 9, characterized in that, at each step, is hot melt glue at a first station the strip cover (110) on the thermoplastic strip (121) on the edges (114) of reci _- tainers and in zones (116) intended to subsequently form a drilling arm (107), a small amount of adhesive (134) is deposited at a second station on the container lids (103), rigid tab assemblies are applied to a third station ( 105) / flexible tongue (106) ur the covers, rigid tongue (105) / flexible tongues (106) are cut at a fourth station for transfer to the third station and then cut to a fifth station (123) finished containers. 11. Device for piercing the lid of containers by leverage, this lid being made of a flexible and tearable material, characterized in that it consists of a rigid tongue. (1; 101) substantially planar on which there is a hinge pin (2; 109) dividing the tongue into a drilling arm (8; 107) and an operating arm (7; 108), the axis of articulation (2; 109) being fixed to the cover (5; 102). 12. Device according to claim 11, characterized in that the articulation axis (2) is cons formed by a rib (2) of the tongue (1). 13. Device according to claim 11, characterized in that it comprises a second flexible tongue (106) having at least approximately the same extension as the rigid tongue (105) and fixed, on one side on the drilling arm (107 ) of the rigid tongue (105) and, on the other side, at least in the area covered by the operating arm (108) of the rigid tongue (105), on the cover. 14. Installation for manufacturing a device for piercing a container lid by leverage, this lid being made of a flexible and tearable material, characterized in that it comprises means (20,21,22; 131,132) for producing substantially planar tongues, means for materializing on the tongues an articulation axis dividing the tongues (1; 101) into a drilling arm and an operating arm, and means (31; 135) for fixing said axes of hinge on container lids. 15. Installation according to claim 14, characterized in that it is associated with packaging equipment of the type which thermoforms containers from a thermoplastic strip, which fills them with a product and which seals them with a strip of lids and which finally cuts the sealed containers from the thermoplastic strip and the cover strip. 16. Installation according to any one of claims 14 or 15, characterized in that the installation comprises means for forming ribs (2), means (20,21,22) for cutting tabs (1), gripping means (30) and means for transferring (23,24,25) the tongues (1) to a gluing station (31), means for transferring (25,24) the tongues (1) from the station glue (31) up to the covers container keys, and means for applying (33) the tongues (1) to the lids. 17. Installation according to any one of claims 14 or 15, characterized in that it comprises means for sealing a flexible strip (110) on a rigid strip (121) in zones (116) corresponding subsequently to the arms. drilling. different rigid tabs (105), cutting means (131,132) of the rigid and flexible tabs superimposed, transfer means (133) of the cut and sealed assemblies of flexible and rigid tabs (105,106) between the cutting station (130) and the place of their placement on the lids of the sealed containers (103), sizing means (135) either of the free face of the flexible tongue or of the cover zone intended to receive the assembly (105,106) rigid and flexible tabs as well as means for applying (139,140) the sets of flexible and rigid tabs on the corresponding covers so that the free face of the flexible tab adheres firmly to the cover.

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