EP0752375A1 - Easy-opening device for a package made of a sheet of tearable foil, method and machine for providing a package with such a device - Google Patents

Abstract

The packaging is formed from a tearable synthetic film which envelopes an object (1). A straight incision (3) is made across the film (2) and an opening tab (5), comprising a fastening portion (6), is welded or stuck onto the film external face (3) covering the incision. A gripping tab (8) extends freely from the fastening portion. The opening tab is orientated and positioned on the film with its gripping tab perpendicular to the main direction of the incision. The incision is closer to the common edge (9) of the fastening portion and the gripping tab than the opposite end edge (11) of the fastening portion. The opening tab is formed from an adhesive label and the fastening portion is also provided with adhesive. The gripping tab is formed from a portion of the label where the adhesive is suppressed or neutralised.

Description

The invention relates to an easy opening device for packaging objects or groups of objects in at least partially enveloping film of tearable synthetic film. In particular, the invention relates to the packaging of articles of everyday consumption such as articles offered for sale in large distribution areas (food products, books, cassettes, discs, cigarettes, etc.).

Many objects or groups of objects are wrapped in films that are at least partially enveloping, that is to say generally totally enveloping or sometimes only partially enveloping, with a synthetic packaging or overwrapping film which must be torn. by the user. It may, for example, be a film of PVC, polyethylene, polypropylene, etc. In particular, among tearable films, there are packaging films of the mono-oriented type, and in particular heat-shrinkable films placed around the object or group of objects by heat shrinking, or films folded around the object or group of objects.

The known packages under at least partially enveloping film of tearable synthetic film give satisfaction, but pose the problem of the subsequent opening of the package, in particular by the consumer.

In the case of tearable synthetic films, and more particularly in the case of heat-shrinkable films, it has always been abandoned until now to make an incision or a perforation through the film, for several reasons. First of all, such a film is generally applied in close contact with the object or group of objects to be packaged. Consequently, in order not to attack or damage the object or group of objects, it is considered essential to provide a possible incision or perforation before performing the step of heat shrinking or close application of the film to the object. However, during this application, in particular by heat-shrinking, this results in either a prohibitive enlargement of the incision or perforation, or a tear in the film film during application. In addition, the fragility of such films is such that it is estimated that the presence of an incision or a perforation would be liable to damage the packaging or to excessively affect its subsequent resistance to handling.

There are already known packages that are protected from incisions or perforations making tear initiations and / or precuts. However, these incisions or perforations, made before applying the packaging around the object or group of objects, are reserved for resistant packaging materials and whose general dimensions are not changed during application on the object or group of objects (cardboard side, rigid molded plastic, film neither stretched nor heat-shrunk and non-tearable, ...). The manufacture of these packages requires the treatment of long lengths of film or cardboard, before the packaging operation, to spare the incisions or perforations. In addition, it is necessary to precisely position the incisions or perforations on the film or cardboard. The process is therefore inconvenient and inflexible.

With tear-off type films, we have already thought of facilitating the opening, for example by providing a V-cut at the periphery of a marginal strip of the film (packaging of coffee powder, packaging sheets for chocolate bars , ...). However, the cut is not always visible, is not always sufficient to effectively initiate a tear initiation, and is not applicable to packages whose film does not have a marginal strip capable of receiving such a cut. . In the latter case, we generally incorporates a tear strip or cord between the object or group of objects to be wrapped and the film of film covering it. An extreme free portion of the strip or cord is accessible from the outside by the user (pack of cigarettes, cassette, book or disc ...). Such a device is nevertheless delicate and costly to produce, and is reserved for objects or groups of objects of generally simple shape and manufactured and packaged in very large series. In addition, depending on the nature of the packaging film used, the opening is not always convenient, even with the aid of said strip or of said tear cord.

In other cases, the packaging with tear-off synthetic film is not provided with any particular easy opening device, so that the consumer is forced to use a cutting or cutting tool, at the risk of being injured. or damage the packaged product.

Patent US-A-3,442,436 described, in 1967, a method for forming means for easy opening of a film of heat-shrunk film after or before heat-shrinking, in which a punch is brought and applied against the film for the cut or burn it along a broken cut line forming at least one triangle, the apex of each triangle defining a free end and the base of each triangle being connected integral with the film, so that each triangle constitutes a tab which can be pulled to open the film.

Next, a label applying device is provided to apply a label above the cut line. Despite the age of this document, the solution it advocates is not used because it poses many problems. First of all, it is not possible in practice to make the broken cut-off line by applying a punch without damaging the packaged product, except possibly entirely manually. In addition, if the cut is made before laying the film around the product or before shrinking, it will deforms and causes deterioration of the film and of the packaging under the effect of the stresses applied during the laying of the film around the product, in particular in the case of heat shrinkage. Thus, it is not possible to produce in an industrial and automatic manner, precisely, in series, and at a reasonable cost, the easy opening means described in this document.

The invention aims to overcome these drawbacks by proposing a device for easy opening of a packaging formed by a film of tearable synthetic film - in particular heat-shrinkable film - at least partially enveloping an object or group of objects, this device being particularly simple, effective, adaptable to any form or nature of object or group of objects and films, and which can be produced industrially, automatically, in series, without damaging the object or group of packaged objects.

The invention also aims to propose a method for providing an object or group of objects wrapped in at least partially enveloping film with tearable synthetic film - in particular heat-shrinkable film - with an easy opening device, adaptable to any shape or nature. of object or group of objects and films, and which can be produced industrially, automatically, in series, without damaging the object or group of packaged objects.

The invention aims more particularly to propose such a method that can be implemented continuously, at a rate, and while the objects or group of objects are in motion. The invention also aims to propose such a method that can be implemented on a compact automatic machine and operating without interruption, in cadence, similar to an automatic labeling machine.

The invention also aims to propose a machine for implementing this method. The invention aims more particularly to propose such a compact machine capable of operating at high speed, in particular similar to an automatic labeller.

The invention also aims to provide an easy opening device obtained by a method of the invention, a packaging and a packaged object or group of objects provided with an easy opening device according to the invention.

The invention also aims to propose such a method making it possible to provide the packaging with an easy opening device which does not affect the qualities of the packaging thus produced, in particular from the point of view of airtightness, sealing, preservation of packed objects or groups of objects ...

The invention also aims to propose such a method and an easy opening device thus obtained which can be used with all kinds of objects, and in particular with soft objects such as food products (portions of cheese, coffee, etc.). .), or with hard objects (recorded magnetic cassettes, discs, cigarette packs ...) without damaging or polluting the objects.

• l'incision est en forme de portion de droite,
• la languette d'ouverture est orientée et posée sur la pellicule avec sa portion de préhension (8) qui prolonge la portion d'ancrage dans une direction au moins sensiblement perpendiculaire à la direction principale de l'incision.

To do this, the invention relates to a device for easily opening a packaging formed from a film of tearable synthetic film at least partially enveloping an object or group of objects, this device comprising an incision made through the film and an opening tab comprising an anchoring portion welded or glued to the outer face of the film by covering the incision, and a gripping portion extending freely in extension of the anchoring portion, characterized in that:

• the incision is in the form of a straight portion,
• the opening tab is oriented and placed on the film with its gripping portion (8) which extends the anchoring portion in a direction at least substantially perpendicular to the main direction of the incision.

We were able to highlight the fact that a straight incision combined with a tongue placed so as to exert a traction at least substantially perpendicular to the incision makes it possible to obtain an easy and complete opening with divergent tears in the film, and this almost with any kind of film, especially with folded and / or heat-shrunk films. Thus, contrary to what US-A-3,442,436 indicated, the inventors have demonstrated that it is not necessary to form a tab with the cut made in the film in a broken line to pre-orient the tear lines. . In addition, this simplified form of easy opening device according to the invention can be manufactured and placed automatically in series in an extremely simple and inexpensive manner and can be put into practice on an industrial scale.

Advantageously and according to the invention, the device is characterized in that the opening tab is oriented and placed so that the incision is closer to the common edge of the anchoring portion and the gripping portion than the opposite extreme edge of the anchoring portion. In other words, the anchoring portion extends perpendicularly to the incision, and from the incision, over a greater distance opposite the gripping portion than towards the gripping portion. Thus, the part of the anchoring portion extending from the incision, perpendicular to the incision and opposite to the gripping portion corresponds to more than half of the anchoring portion.

The invention also relates to a packaging comprising an at least partially enveloping film of tearable synthetic film -in particular a film of heat-shrinkable film-, characterized in that it is provided with an easy opening device.

The invention also relates to an object or group of objects packed with at least one package according to the invention provided with an easy opening device according to the invention.

The invention also relates to a method for provide a package with an easy opening device according to the invention, that is to say a method of fitting an easy opening device at the end of a process for packaging an object or group of objects by said film.

• on ménage à travers la pellicule l'incision en lui donnant la forme d'une portion de droite,
• on pose et on oriente la languette d'ouverture sur la pellicule avec sa portion de préhension qui prolonge la portion d'ancrage dans une direction au moins sensiblement perpendiculaire à la direction principale de l'incision.

The invention thus relates to a method for providing a packaging formed with a film of tear-resistant synthetic film at least partially enveloping, previously placed and shaped around an object or group of objects, with an easy opening device comprising a incision made through the film and an opening tab comprising an anchoring portion welded or glued to the outer face of the film by covering the incision, and a gripping portion extending free in extension of the portion of anchoring, characterized in that:

• we cut the incision through the film, giving it the shape of a straight portion,
• the opening tab is placed and oriented on the film with its gripping portion which extends the anchoring portion in a direction at least substantially perpendicular to the main direction of the incision.

Advantageously and according to the invention, the opening tab is positioned and oriented so that the incision is closer to the common edge of the anchoring portion and the gripping portion than to the opposite extreme edge of the portion anchor.

Advantageously and according to the invention, the steps of making the incision and of placing the opening tongue are carried out successively on packaged objects or groups of objects which are driven in continuous movement without interruption in translation according to a direction at least substantially perpendicular to the main direction of the incision to be made.

Advantageously and according to the invention, to make the incision, a rotary knife is used around an axis at least substantially parallel to the direction of moving packed objects or groups of objects.

Advantageously and according to the invention, to make the incision, a knife is used comprising a blade mounted on a movable support defining a protective surface capable of coming into contact with the film to limit the penetration height of the blade through the film.

• des moyens d'entraînement et de guidage des objets ou groupes d'objets préalablement emballés par une pellicule de film synthétique au moins partiellement enveloppante, en déplacement continu de translation les uns à la suite des autres,
• un poste de découpe d'une incision en forme de portion de droite à travers la pellicule de chaque objet ou groupe d'objets,
• à l'aval de ce poste de découpe, un poste de pose d'une languette d'ouverture formée d'une étiquette comprenant une portion d'ancrage et une portion de préhension s'étendant en prolongement de la portion d'ancrage, ce poste de pose d'une languette d'ouverture comprenant des moyens automatiques de pose d'une étiquette sur la pellicule de chaque objet ou groupe d'objets avec la portion de préhension qui prolonge la portion d'ancrage dans une direction au moins sensiblement perpendiculaire à la direction de l'incision telle que ménagée par le poste de découpe d'une incision,
• des premiers moyens de détection de la présence d'un objet ou groupe d'objets emballés en regard du poste de découpe d'une incision,
• des seconds moyens de détection de la présence d'un objet ou groupe d'objets emballés en regard du poste de pose d'une languette d'ouverture,
• des moyens adaptés pour actionner le poste de découpe d'une incision lorsque les premiers moyens de détection détectent la présence d'un nouvel objet ou groupe d'objets,
• des moyens adaptés pour actionner le poste de pose d'une languette d'ouverture lorsque les seconds moyens de détection détectent la présence d'un nouvel objet ou groupe d'objets.

The invention also relates to a machine for implementing a method according to the invention, characterized in that it comprises:

• means for driving and guiding objects or groups of objects previously wrapped by a film of synthetic film at least partially enveloping, in continuous translational movement one after the other,
• a station for cutting an incision in the form of a straight portion through the film of each object or group of objects,
• downstream of this cutting station, a station for installing an opening tab formed by a label comprising an anchoring portion and a gripping portion extending in extension of the anchoring portion, station for installing an opening tongue comprising automatic means for applying a label to the film of each object or group of objects with the gripping portion which extends the anchoring portion in a direction at least substantially perpendicular to the direction of the incision as provided by the incision cutting station,
• first means of detecting the presence of an object or group of objects packed next to the incision cutting station,
• second means for detecting the presence of an object or group of objects packed next to the station for installing an opening tab,
• means adapted to operate the incision cutting station when the first detection means detect the presence of a new object or group of objects,
• means adapted to actuate the installation station of an opening tab when the second detection means detect the presence of a new object or group of objects.

A machine according to the invention is extremely compact, simple, inexpensive and can work continuously at high speed. Advantageously and according to the invention, the station for cutting an incision comprises a movable knife actuated by a pneumatic cylinder, and the station for installing an opening tongue comprises an electrical or electropneumatic labeling device.

The machine according to the invention can thus be produced in a similar manner to a simple automatic labeling machine.

The invention also relates to an easy opening device, a packaging, an object or group of objects, a method and a machine, characterized in that they comprise in combination all or part of the characteristics mentioned above or above. after.

• la figure 1 est une vue schématique en perspective d'un objet emballé avec un emballage doté d'un dispositif d'ouverture facile selon l'invention,
• la figure 2 est une vue schématique en perspective de l'objet de la figure 1 dont l'emballage est en cours d'ouverture,
• les figures 3a à 3d sont des vues schématiques en coupe verticale d'une machine selon l'invention représentant respectivement différentes étapes chronologiques d'un procédé selon l'invention,
• les figures 4a à 4d sont des vues schématiques en perspective représentant l'objet emballé respectivement au cours des étapes du procédé représentées aux figures 3a à 3d,
• les figures 5a à 5c sont des vues en élévation représentant les différentes positions du couteau rotatif du poste de découpe d'une incision d'une machine selon l'invention,
• la figure 6 est une vue schématique partielle en perspective de dessous d'une variante de réalisation d'une machine selon l'invention,
• la figure 7 est une vue de détail en coupe selon la ligne VII-VII de la figure 8, par un plan vertical perpendiculaire à l'axe de rotation d'une première variante d'un couteau de découpe d'incision d'une machine selon l'invention,
• la figure 8 est une vue en coupe selon la ligne VIII-VIII de la figure 7,
• la figure 9 est une vue similaire à la figure 7 illustrant une variante de réalisation du couteau de découpe.

Other characteristics and advantages of the invention will appear on reading the following description referring to the appended figures which illustrate a non-limiting example of embodiment of the invention, and in which:

• FIG. 1 is a schematic perspective view of an object packaged with a package provided with an easy opening device according to the invention,
• FIG. 2 is a schematic perspective view of the object of FIG. 1, the packaging of which is being opened,
• FIGS. 3a to 3d are schematic views in vertical section of a machine according to the invention respectively representing different chronological stages of a method according to the invention,
• Figures 4a to 4d are schematic perspective views showing the packaged object respectively during the process steps shown in FIGS. 3a to 3d,
• FIGS. 5a to 5c are elevation views showing the different positions of the rotary knife of the station for cutting an incision of a machine according to the invention,
• FIG. 6 is a partial schematic perspective view from below of an alternative embodiment of a machine according to the invention,
• Figure 7 is a detail view in section along the line VII-VII of Figure 8, by a vertical plane perpendicular to the axis of rotation of a first variant of an incision cutting knife of a machine according to the invention,
• FIG. 8 is a sectional view along line VIII-VIII of FIG. 7,
• Figure 9 is a view similar to Figure 7 illustrating an alternative embodiment of the cutting knife.

In Figure 1, there is shown an article 1 (dotted), of generally parallelepiped shape, wrapped in a film 2 of a tearable synthetic film. The invention is also applicable for packaging objects or articles 1 of any other form, either individually or in groups. The film 2 can form either a primary packaging, or a secondary packaging, or a packaging or an overpack ...

The film 2 is placed and shaped entirely around the article 1, and therefore has the final shape and appearance of the packaging. In the example shown, the film 2 is formed from a heat-shrunk film. The invention is applicable to any tearable synthetic film. Among the tearable synthetic films, mention may be made of mono-oriented synthetic films, and more particularly and advantageously foldable and / or heat-shrinkable films. Such a film 2 is generally applied closely on contact of article 1. This article 1 can be a generally soft food product (portion of cheese, meat ...) or non-food which can be hard and rigid (cassette, book, disc, pack of cigarettes, ...) .

The wrapped article 1 comprises a device 3.5 for easy opening of the packaging formed from the film 2. This device comprises a rectilinear incision 3, that is to say in the form of a straight portion, formed through the film 2 over at least part of its thickness, and in general over its entire thickness in the case of a thin film (conventionally of the order of 10 μm), and an opening tab 5. The tab of opening 5 includes an anchoring portion 6 welded or glued to the outer face 7 of the film 2, covering the incision 3, and a gripping portion 8 allowing the user wishing to open the packaging to grasp the tongue d 'opening 5. The orientation and location of the incision 3 on the film 2 and relative to the object 1 are not important in the context of the present invention and can be arbitrary. The gripping portion 8 is a portion of the tongue 5 which is adjacent to the anchoring portion 6 and which extends freely in extension of the anchoring portion 6, and the opening tongue 5 is oriented and placed on the film 2 relative to the incision 3 with its gripping portion 8 which extends the anchoring portion 6 in a direction at least substantially perpendicular to the main direction in which the right incision 3 is made. Thus, when the user grasps the gripping portion 8 and exerts traction on the opening tab 5 tending to move aside the gripping portion 8 from the film 2, he first takes off the part 12 of the anchoring portion 6 which extends between the incision 3 and the common edge 9 of the anchoring portion 6 and the gripping portion 8. When this separation leads to the incision 3, the two edges facing the incision 3 tend to move apart, which triggers the tearing of the film along generally divergent tear lines, such as shown in Figure 2. The right incision 3 is therefore formed of a single fine straight slot made through the film which forms a primer for two tear lines 14, 15 from the two ends 16, 17 respectively of the incision 3 .

The opening tongue 5 is adapted and associated in such a way that the anchoring portion 6 covers the incision 3 entirely. This preserves the seal between the contents of the packaging (article 1) and the outside.

As an opening tab 5, one can use a label formed of a synthetic film affixed to cover the incision 3. This label is provided with an adhesive or a self-adhesive 10 on at least a portion of its surface so that it can be glued to the film 2 and form said anchoring portion 6. The gripping portion 8 is a portion of the label which is adjacent to the anchoring portion 6, and which is devoid of glue or self-adhesive, or provided with a coating (varnish, paper, film, etc.) neutralizing the glue or self-adhesive, or provided with a repositionable type adhesive, that is to say say allowing easy subsequent manual takeoff. In this way, this gripping portion 8 is not permanently bonded to the film 2 and can be easily gripped by the user with a view to opening the packaging.

The anchoring portion 6 of the opening tab 5 on the film 2 can be fixed by gluing with an adhesive or an adhesive 10 which can be of any kind (thermo-adhesive, contact adhesive, etc.). Also, the anchoring portion 6 can be fixed to the film 2 by heat-sealing or in any other equivalent way.

Anyway, the glue and / or the adhesive and / or the solder used to fix the anchoring portion 6 to the film 2 is adapted to allow the subsequent dissociation of a part 12 of this anchoring portion 6 when the user exerts traction on the gripping portion 8, so that the opening tab 5 is detaches from the film 2 to the incision 3, as described above. But the glue and / or the adhesive and / or the weld are strong enough to hold a residual part 13 of the anchoring portion 6 associated with the film 2, to allow the subsequent tearing initiated by the incision 3, by traction of the user on the tongue 5, the residual part 13 of the anchoring portion 6 remaining attached to the film, as shown in FIG. 2.

Advantageously and according to the invention, the opening tongue 5 is oriented and placed so that the incision 3 is closer to the common edge 9 of the anchoring portion 6 and the gripping portion 8 than to the extreme edge 11 opposite the anchoring portion 6. If necessary, provision may be made for the glue or the adhesive covering the anchoring portion 6 on a part opposite to the gripping portion 8 - in particular on said residual portion 13 - to be more resistant as the glue or the adhesive covering the rest of the anchoring portion 6 -in particular the part 12 of the anchoring portion extending between the incision 3 and the common edge 9-. For example, the gripping portion 8, and the adjacent portion 12 of the anchoring portion 6 up to the incision 3 are provided with a repositionable adhesive while the residual portion 13 is provided with an irreversible permanent adhesive which cannot later be lifted off. In practice, this is generally not necessary since the resistance opposed by the film becomes much less important as soon as the incision 3 is discovered and the tear lines 14, 15 are started.

In the case of a food item, the anchoring portion 6 may have an area of its surface for contact with the film 2 which is free of glue or self-adhesive or provided with a coating (varnish, paper, film ...) neutralizing the glue or the self-adhesive opposite the incision 3. In this way, this zone is chemically and biologically inert so that it can be placed in hygienic contact with a food product. As a variant or in combination, a food-grade glue or adhesive can be used.

Advantageously, the opening tab 5 is formed of an adhesive label whose anchoring portion 6 is provided with an adhesive, the gripping portion 8 being formed of a portion of this label where the adhesive is removed or neutralized. Generally, the labels are associated with a support 46 (FIG. 4d) from which they can be detached (in general, a strip of silicone film). The gripping portion 8 can then also consist of a portion facing which the support 46 detachable from the label is cut and left in place when the opening tab 5 is applied and glued to the film 2.

Advantageously and according to the invention, the length of the anchoring portion 6 in the direction perpendicular to the incision 3 and from the incision 3 opposite the gripping portion 8, that is to say say the length of said residual portion 13 opposite the gripping portion 8, is greater than 5 mm -in particular between 10 mm and 50 mm-. In addition, the length of the incision 3 is between 2 mm and 50 mm, in particular between 5 mm and 15 min. Furthermore, the length of the incision 3 is of the order of 50% to 90% of the width of the anchoring portion 6 in the same direction. It has indeed been observed that these dimensions and proportions are particularly advantageous and effective with the majority of films 2 of tearable film (whatever their nature and dimensions), and with an opening tab 5 formed from a traditional adhesive label. .

In the embodiment shown in the figures, advantageously and according to the invention, the width of the gripping portion 8 parallel to the incision 3 is less than that of the anchoring portion 6. In this way, a saving material, and it facilitates the identification of the gripping portion 8 and the direction in which the traction must be exerted by the user. Thus, the use of the easy opening device according to the invention is particularly simple and intuitive. Also, it is advantageous to provide that the width of the gripping portion 8 parallel to the incision 3 is less than the length of the incision 3 in the same direction. Indeed, in this way, the traction exerted by the user on the gripping portion 8 has the effect of spreading the two edges faster opposite the incision 3 when the latter comes to be discovered. Advantageously, the anchoring portion is centered axially with respect to the incision 3, and the gripping portion 8 is centered axially with respect to the anchoring portion 6 and to the incision 3.

In the figures, an exemplary embodiment of the method and of the machine according to the invention is shown, making it possible to provide a packaging formed with a film 2 of tear-resistant synthetic film at least partially enveloping, previously placed and shaped around an object. or group of objects (item 1) of an easy opening device 3, 5 as described above. It should be noted that the method according to the invention is carried out after having placed and shaped said film 2 around said object or group of objects 1, until it gives its final shape and appearance for the packaging of said object or group. of objects. This process can be integrated into a packaging process, in the final or intermediate phase (in the case where another packaging is then placed), or on the contrary is executed independently and separate from the packaging process itself. object consisting in placing and shaping the film 2 of tearable synthetic film around the object or group of objects. Thus, the machine according to the invention is supplied with objects or groups of objects previously wrapped in film 2, as shown in FIG. 4a. From these objects or groups of previously packed objects, the method according to the invention consists in providing them with an easy opening device 3, 5.

The machine according to the invention shown in the figures is in the general form of an automatic labeling machine. In the example shown, the packaged article 1 is assumed to be of generally parallelepiped shape. However, this form is in no way obligatory and the machine and the method of the invention can also be applied to all other forms of objects or groups of objects. The machine according to the invention essentially consists of a frame 20 carrying a motorized lower conveyor 21, for example by an electric motor 57, capable of driving and guiding the objects or groups of objects 1 previously packed in continuous movement in translation one after the other, at constant speed. The conveyor 21 is advantageously formed of two endless conveyor belts 21a, 21b, of the same width, parallel to each other, and spaced from each other so as to allow the passage of the tools cutting the incision 3 and fitting the opening tab 5.

Under the conveyor 21 is arranged a cutting station 22 of the incision 3 in the form of a straight portion, and, a little further downstream in the direction and the direction of driving of the objects or groups of objects 1, a installation station 23 of the opening tongue 5.

The machine further comprises a first detector 24 for the presence of an object or group of packaged objects 1 facing the cutting station 22, and a second detector 25 for the presence of an object or group of packaged objects 1 opposite the installation station 23. Preferably, the detectors 24, 25 are of the optical type (photoelectric cells).

The packaged articles 1 are guided and maintained on the lower conveyor 21 by means of an upper conveyor 39 with a band and rollers mounted elastically in the vertical direction which comes to apply them against the lower conveyor 21. The conveyor 39 is driven in synchronism with the conveyor lower 21. The upper conveyor 39 extends at least opposite the stations 22, 23 for cutting an incision 3 and laying an opening tab 5. In addition, this upper conveyor 39 is advantageously fixed relative to the frame by means of an adjustment console 40 allowing, thanks to a crank 41 associated with a worm and vertical slides, to adjust the vertical position relative to the lower conveyor 21, according to the thickness of the articles 1 to be treated. Also, lateral guides 42 are provided on each side of the conveyor 21, to laterally guide the articles 1 in movement. These lateral guides are formed by ramps mounted relative to the frame 20 by adjustable fixing means 58 making it possible to vary their relative spacing.

In addition, the machine is equipped with automatic means (electronic and / or computer) adapted to actuate the cutting station 22 when the first detector detects the presence of a new object or group of objects 1, and automatic means (electronic and / or computer) adapted to activate the laying station 23 when the second detector detects the presence of a new object or group of objects 1. A control console 26 makes it possible to carry out the adjustments and to generally control the machine .

FIGS. 5a to 5c illustrate in more detail, the incision cutting station 22. This comprises a knife 27 which can rotate around a horizontal axis 28. This axis 28 is fixed relative to the frame 20 and s' extends parallel to the direction of drive in translation of the articles 1 by the conveyor 21. In this way, the plane of movement of the knife 27 is a vertical plane perpendicular to the direction of movement of the conveyor 21, that is to say a vertical transverse plane. This knife 27 is controlled in its rotational movements around the axis 28 by means of a pneumatic cylinder, the body 29 of which is fixed to the frame 20 and the actuating rod 30 of which is connected to a connecting rod 31, itself connected to a crank 32 secured to the knife 27. The connecting rod / crank mechanism thus formed makes it possible to drive the knife in rotation during the reciprocating movements of translation of the jack. The axis 28 of the knife 27 is placed relative to the conveyor 21, and the whole mechanism is adjusted so that when the rod 30 of the jack deploys (from FIG. 5a to FIG. 5c), the knife 27 describes an arc passing through a slot 33 formed through a central plate 34 of the conveyor 21 mounted fixed relative to the frame 20 and extending longitudinally between the two upper strands of the belts 21a, 21b. In doing so, the knife 27 has its cutting end which protrudes above the upper face of the plate 34, so as to come into contact with the lower face of the article 1 packed opposite to form through the film 2 of this article 1, a straight incision 3 in the transverse direction, that is to say perpendicular to the direction of advance of the conveyor 21. The length of the incision 3 thus formed depends on the length of the knife 27 relative to its axis of rotation 28 and the depth of penetration of the knife into the packaged article 1.

The knife 27 advantageously consists of a blade 35 mounted on a support 36 movable in rotation about the axis 28. The crank 32 is integral with the support 36. For example, it consists of an extension of the support 36. The support 36 is itself rotatably mounted around the axis 28 and defines a protective surface 37 capable of coming into contact with the film 2 to limit the penetration of the blade 35 through the film 2. In the case of a rotary knife, as shown, the protective surface 37 is a portion of surface of revolution around the axis 28, in particular a portion of cylinder of revolution.

The blade 35 is advantageously mounted relative to the support 36 in an adjustable manner so that the height of this blade 35 projecting from the reach 37, and therefore the depth of penetration of the knife 27 into the packaged article 1, can be settled. In addition, the blade 35 is mounted so that it can be changed and replaced. The axis 28 is carried by a support piece 38 itself fixed to the frame 20 by means of height adjustment means for its position (for example two oblong vertical slots crossed by clamping bolts, as shown in FIGS. 5a to 5c).

By adjusting the height of the projecting blade 35 relative to its support 36 and the position of the support 38 relative to the frame 20, it is thus possible to adjust the length of the incision made through the film 2.

It should be noted that the incision 3 is made through the film 2 while the wrapped article 1 is driven in continuous movement without interruption in translation by the conveyor 21 perpendicular to the main direction of the incision 3 thus made (the the operating speed of the jack 29 being very much greater than the speed of advancement of the articles 1 on the conveyor 21).

An exemplary embodiment of the means for adjusting the height of the projecting part of the blade 35 outside of the support 36, appears from FIGS. 7 to 9. The blade 35 is in the general shape of a plate having a straight lower edge. The cutting part of the blade 35 has an acute angle 52 projecting from the support 36 for cutting the incision 3. The support 36 has a central groove 49 for receiving the blade 35 between two sides 59 of the support 36 which is therefore in general form of screed. The groove 49 has a flat bottom 50 receiving the lower edge of the blade 35. This bottom 50 is inclined so that by sliding the blade 35 on this bottom 50, the acute angle 52 cutting the blade 35 projects more or less outside the support 36 relative to the bearing surface 37. A clamping screw 48 is screwed into a thread passing through one of the flanks 59 of the support 36, so that the end of this screw 48 comes pressing against the blade 35 to clamp it in position against the other flank 59. In the alternative embodiment of FIG. 9, the blade 35 can be adjusted in any position relative to the bottom 50. In the alternative embodiment shown in the figures 7 and 8, there is also a drilling through the two sides 59, and a wedge pin 51 allowing, at each blade change 35, to replace a new blade 35 without requiring a new adjustment. Thus, once a first adjustment of the position of the blade 35 determined from the knife shown in FIG. 9, the drilling is carried out and a pin 51 is placed to obtain the variant of FIGS. 7 and 8 making it possible to easily keep this adjustment during the subsequent change of the blade 35 with an identical new blade. The pin 51 also serves as a stop for the rear edge 53 of the blade 35 perpendicular to the bottom 50, so that the blade 35 is better locked in position, without possible rotation, in the support 36.

The slot 33 formed through the plate 34 of the conveyor 21 is of a width such that it lets the blade 35 pass, and the bearing surface 37 of protection. In this way, during the rotation of the knife 27, the protective surface 37 comes into contact with the film 2.

The operation of the cutting station 22 and of the jack is triggered by the first detector 24 as soon as the latter detects the presence of an article 1 facing transversely of this first detector 24. The detector 24 is placed in a longitudinal position with respect to to the slot 33 of the plate 34, and therefore relative to the knife 27, in an appropriate manner to allow the incision 3 to be made at the desired location of the film 2 of the packaged article 1.

As soon as the first detector 24 no longer detects the presence of the article 1 on which the incision 3 has just been made (FIGS. 3c and 4c), the knife 27 is returned to the initial position to make a new incision 3 on a subsequent new article 1, thanks to appropriate programming of said automatic means adapted to actuate the cutting station 22. As a variant, the knife 27 can be of the bidirectional type, so as to be able to make an incision 3 alternately in both directions of rotation around axis 28.

The installation station 23 with a tongue opening 5 includes automatic means for applying labels to the film 2 of each object or group of objects 1, and therefore consists of a labeling device, the general construction and operation of which are known per se same. This laying station 23 is, like the cutting station 22, placed under the lower conveyor 21, and has a presentation and distribution plate 43 for labels arranged under a rectangular light 44 of corresponding dimensions, formed through the plate 34 of the conveyor 21. In a variant not shown, a pneumatic or electropneumatic device can also be provided to collect each label from the support strip 46 and apply it to the film 2. The station 23 for placing the labels forming the opening tabs 5 is powered by an electric motor.

The opening tabs 5 are formed of adhesive labels which are in the form of a roll of labels placed one after the other on a support strip 46 wound on itself in a spiral, in the traditional way . The strip 46 is guided by a series of rollers or rollers to the extreme edge of the plate 43 for presentation and distribution of the labels through the lumen 44. The support strip 46 is folded around this edge, then guided by rollers or rollers up to a motorized receiving drum 47. When the drum 47 is wound, the strip 46 moves along the edge of the plate 43, which has the effect of releasing a new label, that is to say a new opening tab 5 which comes s 'apply and stick against the film 2 of an article 1 passing opposite the light 44 (Figure 4d).

The opening tabs 5 are placed on their detachable support strip 46 so that the gripping portion 8 extends the adhesive anchoring portion 6 in a direction perpendicular to the direction of the incision 3 as it has been formed. beforehand by the cutting station 22. Similarly, the edge of the plate 43 for presenting and distributing the opening tongues 5 is perpendicular to the direction of advance of the conveyor 1 and to the axis 28 of rotation of the knife 27. When the second detector 25 detects the presence of a packaged article 1, said automatic means adapted to actuate the laying station 23 actuate the electric motor for rotating the drum 47, so that an opening tab 5 is applied to the film 2 of article 1 opposite. Again, the detector 25 is placed in the longitudinal direction of drive of the conveyor 21 relative to the plate 43 for presentation and distribution of the opening tabs 5, suitably for affixing the opening tab 5 suitably as described above, compared to incision 3.

In the variant shown in FIG. 6, the cutting station 22 is placed as close as possible, in the longitudinal direction, to the laying station 23. To do this, the plate 43 for presentation and distribution of the labels which is mounted integral of the housing 55 of the labeling device, has a vertical part 54 of height at least equal to that of the cutting station 22 (cylinder 29, 30 and knife 27) so as to be adjacent thereto, and an end portion 56 inclined towards the downstream with respect to the plane of the plate 34 of the conveyor 21 for the application of the opening tabs 5. The rollers or guide rollers of the strip 46 of labels are carried by the plate 43 and / or by the casing 55. The detectors 24, 25 are also brought together in a corresponding manner. In this way, the installation of the opening tongue 5 occurs immediately after cutting the incision 3, which improves the precision of the installation of the opening tongue 5 relative to the incision 3. With this mode embodiment, if a return of the knife 27 to the initial position is provided (step of FIGS. 3c and 4c), this is only carried out after the installation of the opening tongue 5 (step of FIGS. 3d and 4d) .

The entire labeling system is mounted relative to the frame 20 on a common support whose vertical position relative to the plate 34 of the conveyor 21 is adjustable, for example using a crank console, worm and slide, similar to that allowing the adjustment of the upper conveyor 39. In this way, it is possible to adjust the position of the plate 43, in particular of its end portion 56 relative to the lumen 44 and to the packaged articles 1.

The different packaged articles 1 follow one after the other, with a spacing between them sufficient to allow the functioning of the detectors 24, 25 and of the stations 22, 23 for cutting and laying.

In the process according to the invention, a single incision 3 is therefore made through the film 2, giving it the shape of a straight portion and the opening tab 5 is placed and oriented on the film 2 with its gripping portion 8 which extends the anchoring portion 6 in a direction at least substantially perpendicular to the main direction of the incision 3. The steps of cutting the incision 3 and installing the opening tongue 5 are carried out successively on packaged objects or groups of objects 1 which are driven in continuous movement without interruption, in translation in a direction at least substantially perpendicular to the main direction of the incision 3.

Claims (20)

Device for easy opening of a packaging formed by a film (2) of tearable synthetic film at least partially enveloping an object or group of objects (1), this device comprising an incision (3) made through the film ( 2) and an opening tab (5) comprising an anchoring portion (6) welded or glued to the outer face (7) of the film (2) covering the incision (3), and a gripping portion (8) extending freely as an extension of the anchoring portion (6), characterized in that: - the incision (3) is in the form of a straight portion, - The opening tab (5) is oriented and placed on the film (2) with its gripping portion (8) which extends the anchoring portion (6) in a direction at least substantially perpendicular to the main direction of the incision (3). Device according to claim 1, characterized in that the opening tongue (5) is oriented and placed so that the incision (3) is closer to the common edge (9) of the anchoring portion (6) and from the gripping portion (8) as from the opposite extreme edge (11) of the anchoring portion. Device according to either of Claims 1 and 2, characterized in that the opening tongue (5) is formed by an adhesive label, the anchoring portion (6) being provided with an adhesive, the gripping portion (8) being formed of a portion of the label where the adhesive is removed or neutralized or of a portion opposite which a support (46) of the label is cut and left in place. Device according to one of claims 1 to 3, characterized in that the length of the anchoring portion (6) from the incision (3) and opposite the gripping portion (8) is greater at 5 mm - in particular between 10 mm and 50 mm -. Device according to one of Claims 1 to 4, characterized in that the length of the incision (3) is between 2 mm and 50 mm - in particular between 5 mm and 15 mm -. Device according to one of claims 1 to 5, characterized in that the length of the incision (3) is of the order of 50% to 90% of the width of the anchoring portion (6) in the same direction. Device according to one of claims 1 to 6, characterized in that the width of the gripping portion (8) parallel to the incision (3) is less than that of the anchoring portion (6). Device according to one of Claims 1 to 7, characterized in that the width of the gripping portion (8) parallel to the incision (3) is less than the length of the incision (3). Packaging comprising an at least partially enveloping film of tearable synthetic film -in particular a film of heat-shrinkable film-, characterized in that it is provided with an easy opening device (3,5) according to one of claims 1 to 8. Object or group of objects packed with at least one package according to claim 9. Method for providing a packaging formed with a film of tear-resistant synthetic film at least partially enveloping, previously placed and shaped around an object or group of objects, with an easy opening device comprising an incision (3) made to through the film (2) and an opening tab (5) comprising an anchoring portion (6) welded or glued to the outer face (7) of the film (2) by covering the incision (3), and a gripping portion (8) extending free as an extension of the anchoring portion (6), characterized in that: - the incision (3) is cut through the film (2) by giving it the shape of a straight portion, - we put and orient the tongue opening (5) on the film (2) with its gripping portion (8) which extends the anchoring portion (6) in a direction at least substantially perpendicular to the main direction of the incision (3). Method according to claim 11, characterized in that the opening tongue is positioned and oriented so that the incision (3) is closer to the common edge (9) of the anchoring portion (6) and of the gripping portion (8) as of the opposite extreme edge (11) of the anchoring portion (6). Method according to one of claims 11 and 12, characterized in that the steps of cutting the incision (3) and laying the opening tongue (5) are carried out successively on objects or groups of objects (1) packaged which are driven in continuous movement without interruption in translation in a direction at least substantially perpendicular to the main direction of the incision (3) to be made. A method according to claim 13, characterized in that to make the incision, a knife (27) is rotatable about an axis (28) parallel to the direction of movement of the objects or groups of objects (1) packed. Method according to one of claims 11 to 14, characterized in that to make the incision (3), a knife (27) is used comprising a blade (35) mounted on a mobile support (36) defining a protective surface (37) able to come into contact with the film (2) to limit the penetration height of the blade (35) through the film (2). Machine for implementing a method according to one of claims 11 to 15, characterized in that it comprises: - Means (21, 39, 42) for driving and guiding the objects or groups of objects (1) previously wrapped by a film (2) of synthetic film at least partially enveloping, in continuous translational movement with each following the others, a cutting station (22) of an incision (3) in the form of a straight portion through the film (2) of each object or group of objects, - downstream of this cutting station (22), a laying station (23) of an opening tab (5) formed of a label comprising an anchoring portion (6) and a gripping portion (8) extending as an extension of the anchoring portion (6), this installation station (23) of an opening tongue (5) comprising automatic means for applying a label to the film (2 ) of each object or group of objects with the gripping portion (8) which extends the anchoring portion (6) in a direction at least substantially perpendicular to the direction of the incision (3) as provided by the post cutting (21) an incision, - first means (24) for detecting the presence of an object or group of objects packaged opposite the cutting station (22) of an incision, - second means (25) for detecting the presence of an object or group of objects packed opposite the installation station (23) of an opening tab (5), means adapted to activate the cutting station (22) of an incision when the first detection means (24) detect the presence of a new object or group of objects, - Means adapted to actuate the installation station (23) of an opening tab when the second detection means (25) detect the presence of a new object or group of objects. Machine according to claim 16, characterized in that the cutting station (22) of an incision comprises a knife (27) rotatable about an axis (28) at least substantially parallel to the direction of movement of the objects or groups of 'packed objects. Machine according to one of claims 16 and 17, characterized in that it comprises means adapted to replace the position of cutting (22) of an incision in position to make a new incision (3) after cutting an incision (3), when the first detection means (24) no longer detect the presence of the object or group of objects. Machine according to one of claims 16 to 18, characterized in that the drive and guide means (21, 39, 42) comprise a lower conveyor (21), in that the cutting stations (22, 23) of an incision and installation of an opening tongue are arranged under the lower conveyor (21) provided with lights (33, 44) opposite these stations (22, 23), and in that the means of drive and guide comprise, at least opposite the stations (22, 23) for cutting an incision and fitting an opening tab, an upper conveyor (39). Machine according to one of claims 16 to 19, characterized in that the cutting station (22) of an incision comprises a movable knife (27) actuated by a pneumatic jack (29, 30), and in that the station fitting (23) of an opening tab comprises an electrical and / or electropneumatic labeling device.

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