FR2502590A1 - Pull-tab opening for container lid - has piercing end and lifting end with interposed fulcrum axis fixed to lid - Google Patents

Abstract

The process provides a container lid (5) with a lever-action piercing tongue (1). A plane rigid tongue is fabricated and provided with a fulcrum axle (2), a piercing arm (8) and a handling arm (7). The lever is fixed to the lid by the axle. The tongues may be fabricated from thermoplastic sheet with each axis of articulation being made by a forming rib (2) on the surface of the respective tongue. The tongue is fixed to its container lid by the rib. The containers are also made from the same thermoplastics sheet.

Description

Device for opening a container with a lid, method and installation for manufacturing the device.

 The invention relates to a device for opening a container lid.

 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-emp p You reach a rust-proof and / or non-rusty surface with a multilayer lid sterilized on the surface).

 Another solution has been proposed, consisting of pre-punching 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.

 There are, however, 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 not peelable.

The invention aims to propose a new type of device
simple and economical opening, adaptable to many
types of covers and in particular to those generally used in
manufacturing facilities for thermoformed neck containers
welded lugs which are cut from strips of lids.

 The objects of the invention are achieved by the fact that the opening device comprises a substantially planar opening tongue, provided on one of its faces with a rib fixed on the outside face of the container lid, the rib separating the tongue in two gripping and piercing zones respectively, whereby a manual lifting of the gripping zone causes, initially, a tilting of the tongue around the rib and the piercing of the cover by the piercing zone, at, secondly, the tearing of part of the cover from the hole.

 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 to remain attached to the partially torn cover, a separate element generating pollution 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 grip zone com
door, on the face of the tongue facing the
cover, a spacer nipple to facilitate the pre
hension of the tongue.

Advantageously, the lan drilling area
lookout ends on the far side of the rib with a
angular attack zone.

Advantageously, the length of the lever arm
formed by the drilling area is shorter than the lon
of the lever arm formed by the grip zone.

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

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

Advantageously, the tongue is fixed on the
cover so that the end of the area of
drilling far from the rib is located nearby
immediately from the edge of the container on which the
lid.

The invention also relates to a method of
manufacture of the device according to the invention, in
part of the manufacturing of thermoformed containers
from a thermoplastic strip, fitted with a cover
welded, and cut. This process is characterized in that
we form the opening tabs in the strip
thermoplastic used to make the containers.

Advantageously, the tongues are cut
in the thermoplastic strip in the
areas between reci formation areas
pients.

Advantageously, the tongues are cut
when cutting the containers.

 The invention also relates to an installation for manufacturing the device according to the invention, in the context of an installation for manufacturing thermoformed containers from a thermoplastic strip, provided with a welded cover and cut at a cutting station. The installation is characterized in that it comprises means for forming ribs, means for cutting tongues, means for gripping and means for transferring the tongues to a gluing station, means for transferring the tongues from the gluing station to the lids of the containers, and means for applying the tabs to the lids.

The invention will be better understood from the description which follows, given with reference to the appended drawings in which
- Figure 1 is a plan view of a container and its cover provided with the connection device;
- Figure 2 is a front view of the container of Figure 1;
- Figure 3 is an enlarged detail of the device of the invention;
FIG. 4 is a plan view of containers formed in a thermoplastic strip and show the location for cutting the tongues;
- Figure 5 is an enlarged detail of Figure 4
- Figure 6 is a schematic view of an installation for manufacturing the device of the invention;
FIG. 7 represents an elastic clamp used in the installation of FIG. 6.

 The opening device of the invention comprises a substantially flat tongue 1 provided with 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 zones: one called grip 7, and the other called piercing 8.

 By lifting upward (arrow 9, fig. 3) the gripping zone 7 of the tongue 1, the latter swings around the rib 2 so that the end of the drilling zone 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 gripping area continuing, the end of the piercing area 8 starts and pierces the cover 5. In order to facilitate this operation, the end of the piercing area 8 is angular (tip 10).

 By 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 drilling area widens the tear in the cover until the width t of tongue 1 is substantially obtained. level of the rib 2. The piercing zone 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 across the width, it suffices, if you wish to extend the opening, to pull the tab 1 by its gripping zone 7 in the direction opposite to the drilling zone, so as to continue the tear.

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

Naturally, if the cover has weakening lines, re-aligned for example by pre-impression, the tongue can be placed so that, when 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 tear continues following the lines of embrittlement. These can be provided so as to obtain an annular tear which goes all around the cover and makes it possible to remove the latter almost entirely.
The rib 2 of the tongue 1 can be beech by a patch attached to the tongue; it can be beech formed by the bead of glue 4 luimeme if it is large enough. However, this last solution is less advantageous since it does not make it possible to physically delimit the gluing area.

Preferably, the rib 2 is formed internally.
basically with tab 1 and may other, in the case
where the tongue is made of plastic, a simple
deformation (fig. 3) obtained hot or cold by
stamping.

The height of the rib 2 is not critical,
and can be chosen equal to 1 to 2 mm for example.

Of her, and the length of the lever arm of the area
of drilling depends on the angle at which the tip 10 of the
drilling zone 8 attacks the cover 5, angle in relation
with ease of drilling.

 In order to be able to pierce the cover 5 manually without difficulty, it is preferable that the length of the lever arm a of the drilling area is less than that b of the grip area (fig. 2), for example in a report a quarter or a third.

 In order to facilitate manual gripping of the gripping zone 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 gripping area 7 resulting in accidental piercing. The bonding is however weak enough to yield under the effort of the operator during the intentional manual lifting of the tongue 1.

Although we can place the tongue 1, which is of any size depending on the type of opening that we want to make, at very many locations on the cover, it is interesting to place it, as shown in Figs. 1 to 3, so that the end 10 of the piercing zone 8 is if killed in the immediate vicinity of the edge 12 of 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 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 containers, it is particularly advantageous, when the shape chosen for the tongues 1 is suitable, to form them in the thermoplastic strip 18 (fig. 4, 5) for forming the containers in the waste in star (fig. 4,5) remaining between the containers.

 We will explain (Fig. 4-7) in what follows an example of manufacture and installation of the opening tabs 1 as part of a conventional installation for manufacturing thermoformed containers comprising downstream of a whole rod thermoforming stations, filling, sealing of a cover strip, a station 19 for cutting containers.

The cutting of the containers is done so
known by means of dies and punches not shown, over the entire width of the strip 18 and by steps of two containers for example. These tc'chniues are known to those skilled in the art and will not be further described.

 The tongues 1 are advantageously formed in the stars located 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 made of aluminum composite / polyethylene): consequently, by being cut at this station 19, the tongues 1 will be formed dtunc 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 tab 1 the desired indications (such as arrows or codified opening instructions) or any patterns.

 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 zones. - containers.

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 Fig. 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 more or less enter the drum 25. The plate 28 is provided with elastic retaining elements 30 which allow a tongue 1 to snap in and bear against the tray 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 once again turned a suitable angle, the pliers 24 come to deposit the tongues 1 on the lids of the pots 6a, 6b situated above the take-up 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 pFelbvem * -nt.

 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, it is planned, at the cutting station 19, not to completely detach the containers 6c (fig.) In the cutting station 19 from with the containers 6e immediately upstream, and to maintain them by a part not cut 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 selected therefrom by the cutting tools of the station 19 which include means for cutting the last remaining fastener (that is to say the st - - say I 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.

 The invention is obviously not limited to the particular embodiment which has just been described.

Claims (21)

1. Device for opening a lid (5) of a container (6), characterized in that it comprises a substantially flat opening tab (1), provided on one (3) of its faces with a rib (2) fixed on the outside face of the cover (5) of the container (6), the rib (2) separating the tongue into two gripping (7) and piercing (8) zones respectively, whereby manual lifting (9) of the gripping area (7) causes, at first, a tilting of the tongue (1) around the rib (2) and the piercing of the cover by the piercing area (8) and, in a second time, the tearing of part of the cover (5) from the hole. 2. Device according to claim 1, characterized in that the rib (2) is glued to the cover (5). 3. Device according to one of claims 1 or 2, characterized in that the rib (2) is constituted by an attached part fixed to the tongue. 4. Device according to one of claims 1 or 2, characterized in that the rib (2) is formed integrally with the tongue (1). 5. Device according to claim 4, characterized in that the rib (2) is constituted by a deformation of the tongue (l). 6. Device according to claim 2, charac terized in that the rib (2) is constituted by a bead of glue. 7. Device according to one of claims 1 to 6, characterized in that the gripping zone (7) comprises, on the face of the tongue turned towards the cover, a spacer stud (11) to facilitate the gripping of the tongue. 8. Device according to one of claims 1 to 7, characterized in that the drilling zone (8) of the tongue (1) ends, on the side remote from the rib (2) by an angular attack zone ( 10). 9. Device according to one of claims 1 to 8, characterized in that the length (a) of the lever arm formed by the drilling area (8) is shorter than the length (b) of the lever arm formed by the gripping area (7). 10. Device according to claim 9, characterized in that the length (a) of the lever arm of the drilling area (8) is between about a quarter and a third of that (b) of the lever arm of the area gripping (7). 11. Device according to one of claims 1 to 10, characterized in that the cover (5) is made of aluminum-based material (16). 12. Device according to claim 11, characterized in that the cover (5) is made of composite material (16, 17) polyethylene / aluminum. 13. Device according to any one of claims 1 to 12, characterized in that the tongue (1) is based on plastic. 14. Device according to one of claims 1 to 13, characterized in that the tongue (1) is fixed to the cover (5) so that the end (10) of the drilling area (8) remote from the rib (2) is located in the immediate vicinity of the edge (12) of the container (6) on which the rubber (5) is placed. 15. Device according to any one of claims 1 to 14, characterized in that it is associated with a cover (5) comprising a weakening pre-impression. 16. Device according to any one of claims 1 to 15, characterized in that the tongue (1) supports a graphic.  17. The method of manufacturing the device of claim 1, in the context of the manufacture of thermoformed containers from a thermoplastic strip, provided with a welded cover, and cut out, characterized in that the tongues are formed ( 1) openings in the thermoplastic strip (18) used to make the containers. 18. The method of claim 17, characterized in that the tongues (1) are cut by stamping in the thermoplastic strip (18) in the zones located between the zones of formation of the containers. 19. The method of claim 18, characterized in that the tabs are cut (1) when the containers are cut. 20. The method of claim 19, of the type in which the covers are formed from a strip with a cover, characterized in that the tabs cut the tabs (1) in a strip (1 & covered with the cover strip, this the latter being printed so that the desired graphics appear on the cut tabs, 21. Installation for the manufacture of the device of claim 1-, in the context of an installation for manufacturing thermoformed containers from a thermoplastic strip, provided with a welded cover and cut at a cutting station (19)> 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 transfer (23, 24, 25) of the tabs (1) to a gluing station (31), means of transfer (25, 24) of the tabs (1) from the gluing station (31) to container lids, and means for applying (33) the tabs (1) to the lids.