EP3074317B1

EP3074317B1 - Device for opening a container for pourable products

Info

Publication number: EP3074317B1
Application number: EP14828522.4A
Authority: EP
Inventors: Arne MOHN
Original assignee: Ipi SRL
Current assignee: Ipi SRL
Priority date: 2013-11-28
Filing date: 2014-11-28
Publication date: 2018-01-10
Anticipated expiration: 2034-11-28
Also published as: ITPG20130058A1; BR112016011955A2; WO2015079416A1; MX2016006837A; EP3074317A1; ZA201603057B; CN105939938A

Description

FIELD OF THE INVENTION

The present invention relates to a device for opening a container suitable for containing pourable products. In particular, the opening device of the present invention is positioned at the punchable portion of a multilayer container and comprises a collar, couplable right at the above mentioned punchable portion, and a cutting element movable inside the collar, once the device has been assembled, in a way constrained by helical guide means interposed between said cutting element and said collar. In particular, the cutting element has a plurality of teeth having a substantially triangular section and each provided with an upper ending portion having a vertex adapted to cut the punchable portion when the cutting element helically slides with respect to said collar, as the container is opening.
Basically, in the cutting elements of the prior art, such upper ending portion is a segment defined by two flat flanks of the triangular tooth intersecting the two side faces thereof. Therefore, such upper ending portion has a very sharpened vertex.
The term vertex means, in the present invention, the point at which the sides of a polygon, or angle, intersect, that is to say the point at which edges and faces of a polyhedron or a solid angle converge. As it can be noted, vertex substantially indicates the tip of the tooth itself, i.e. the most protruding part of the tooth.
It should be noted that the tip, or vertex, or free end of the upper ending portion is therefore the tooth portion which first contacts the punchable portion and undergoes the greatest stresses, also and especially because the cutting element travels along a path not exactly perpendicular with respect to the punchable portion, but along a substantially helical path.
Closing devices of this type are known in the art. For example, the European Patent EP1088764 B1 in the name of Tetra Laval describes an opening device of the above described type wherein, in particular, the cutting element is formed in one piece with the collar, thereby forming a single pre-assembled body. It should be noted that this type of closing devices is provided with a cutting element having a plurality of teeth provided with an ending portion having a perfectly sharpened vertex.
Moreover, further closing devices provided with a more sharpened cutting edge have been developed. For example, the International Patent Application WO 2010/128302 A1 in the name of Elopak System AG describes an opening device wherein the cutting element is constituted by tooth having a cutting blade whose edge extends from the tooth tip towards the collar. In particular, the edge of the cutting blade is bevelled on two sides that define the inner and outer faces of the tooth. Furthermore, WO2008049249 discloses an opening device according to the preamble of claim 1. However, such kind of opening devices is not free from drawbacks, because of the increasing difficulty in easily opening the punchable portion of the container on which they are applied. In particular, it should be recalled that such opening devices are applied to containers made of a laminar material, i.e. obtained by coupling several layers of different materials, each dedicated to a specific task. Generally, the layers forming the container at the punchable portion comprise a first outer layer made of a thermoplastic material, a layer made of aluminum and one or more inner layers made of thermoplastic material. An adhesive layer is arranged between the aluminum layer and the thermoplastic layers so as to allow the two layers to be coupled. Such laminar, or multilayer, material, provides a good structural stiffness at the punchable portion and is further studied to create a barrier preventing pathogenic substances and also, especially, oxygen from entering into the container. This prevents the product stored in the container such as, for example, milk or other beverages, from deteriorating within few days. In the field, increasingly reliable thermoplastic materials have been developed and introduced, causing, however, an increase of the characteristics of overall mechanical strength of the multilayer material, due in particular to the increased toughness thereof, therefore resulting in a greater and gradually increasing difficulty in carrying out the first cut of the punchable portion by means of the cutting elements of the known art. In fact, the blends of thermoplastic materials contain materials such as, for example, LLDPE and LDPE which, although on one hand have improved the sealing characteristic of the punchable portion, on the other hand have extremely increased the toughness of the whole material. In particular, the Proprietor further noted that, with these types of multilayer materials, the teeth of the known cutting elements are no longer able to effectively cut off the punchable portion of the container and, anyway, the operation for opening the container results in an excessive effort for the tooth of the cutting element, especially at the sharpened vertex thereof. As a result, during the opening operation, the sharpened vertex of the tooth bends, such that the ability of punching and opening the container is compromised.
It should be noted that with LLDPE (the English acronym of Linear Low Density Polyethylene) is meant an ethylene alpha-olefin copolymer polymerized in the presence of a metallocene, also called metallocene polyethylene, known by the symbol m-PE, which is usually a linear low-density polyethylene. Furthermore, with LDPE (the English acronym of Low Density Polyethylene) is meant a low density polyethylene. According to the known art, characteristics of LLDPE are high shear strength and puncture resistance, whereas LDPE has the advantage of allowing an efficient and safe heat welding and provides, among other functions, the moisture-barrier function.
It is an object of the present invention to provide an opening device equipped with a cutting element allowing to easily and effectively opening the punchable portion of a multilayer container.
It is another object of the present invention to provide an opening device not requiring an undue modification of the general structure of the opening devices of the known art.
These and other objects are obtained by the opening device according to appended claim 1. In practice, said at least one vertex, instead of being sharpened, as provided in the known art devices, is substantially rounded so that the vertex of the tooth, although still able to punch the punchable portion, cannot be bent as the cutting element roto-translates with respect to the collar, i.e. the former helically moves with respect to the latter. In this way, the proprietor experienced that the vertex of the tooth is no longer subject to any kind of bending caused by the excessive stress applied thereto during the opening of the container due to the increased toughness of the multi-layer materials used nowadays. In practice, once the vertex of the tooth has punched the punchable portion, it contacts the cutting edge of the tooth itself, thus making easy the following cutting step of the punchable portion.
In particular, the ending portion extends among said at least two flanks and said at least one side face in order to increase the overall stiffness of the ending portion itself.
Furthermore, said at least one portion extends obliquely with respect to said at least one side face such as to allow the vertex to more easily penetrate the punchable portion. The angle defined between the axis lying on said at least one ending portion and the vertical axis lying on said at least one side face is comprised between 20° and 50°.
Moreover, the cutting element is made of polypropylene.
According to the embodiment described herein, the tooth is provided with two flanks, an outer side face and an inner side face opposite to one another, at least one cutting edge defined by the intersection of one of the two side faces with at least one of the two flanks, the cutting edge being connected over the ending portion, next to the vertex.
In particular, the cutting edge is defined by the intersection of the outer side face with at least one of the two flanks.
Therefore, once the vertex of the tooth has punched the punchable portion at the outer side face, it contacts the cutting edge of the tooth itself, thus making very easy the following cutting step of the punchable portion.
According to the invention, said at least one ending portion has a curvature radius between 0.15 and 0.30 mm at least next to said at least one vertex. The proprietor has experienced that this value range of the curvature radius allows to obtain a good balance among the feasibility in realizing the mould, the tooth effectiveness in punching and the elimination of vertex bends of the ending portion of the tooth.
According to the embodiment herein described, the opening device further comprises an upper cap couplable by screwing with said collar. This cap, as apparent to the field technician, drives the helical displacement of said at least one cutting element with respect to said collar as the container is opening.
According to a further embodiment of the opening device, said cutting element has at least one second tooth having triangular section and provided with at least one upper ending portion having a sharpened vertex, to punch said at least one punchable portion, wherein said at least one second tooth is arranged, with respect to said at least one first tooth, in such a way that said at least one second tooth is meshed with said punchable portion before said at least one first tooth as said cutting element helically moves with respect to said collar. In practice, such second tooth, unlike said at least one tooth, has at least one sharpened vertex and is designed to mesh the punchable portion so as to prevent the rounded vertex of said at least one tooth from sliding on the punchable portion thus causing the laminate, constituting the punchable portion, to yield.
Finally, said at least one punchable portion comprises at least one aluminum layer, one or more layers made of thermoplastic material arranged on the inner and/or outer surface of said aluminum layer, and at least one adhesive layer arranged between said one or more thermoplastic layer and said at least one aluminum layer.
The objects of the present invention are further obtained by a multilayer container for pourable products defined by a laminate comprising a paper layer and provided with a punchable portion at a zone of the container provided with a hole in the paper layer, the container is characterized by comprising an opening device according to the invention and what has been previously described, the opening device being constrained at the punchable portion.
These and other aspects of the present invention will become more apparent to the one skilled in the art from the following description of various preferred embodiments of the present invention, given by way of non-limiting example, with reference to the attached figures, in which:

figure 1 shows an opening device applied on a container for pourable products;
figure 2 shows a section of the container of figure 1 without the opening device and at its punchable portion;
figure 3 is an axonometric, longitudinal sectional view of the opening device according to the invention;
figure 4 is an axonometric view of the cutting element of figure 3;
figure 5 is a particular view of the teeth of the cutting element of figure 4;
figure 6 is a particular view of a general first tooth of the cutting element of figures 4 and 5.
figure 7 is a particular view of a second tooth of the cutting element of figures 4 and 5.

Referring particularly to such figures, an opening device according to the invention is referred to with the numeral 1.
Figure 1 shows an opening device 1 according to the invention and constrained to a multilayer container 2 for pourable products at a punchable portion 3 thereof (figure 2). It should be noted that, according to the embodiment herein described and according to figure 2, said punchable portion 3 of the multilayer container 2 is located at a zone of the container 2 where the paper layer 49, included in the laminate, has a hole 49a. In particular, this punchable portion 3 comprises an aluminum layer 50 arranged inside the laminate, a layer 51 of thermoplastic material, arranged outside the container on the outer surface of the aluminum layer, two layers 52 and 53 of thermoplastic material arranged inside the container 2 on the inner surface of said aluminum layer 50, and an adhesive layer 54 arranged between the aluminum layer 50 and the layers 52 and 53 of thermoplastic material directly contacting said aluminum layer 50. However, it should be said that an embodiment in which the laminate is different, or rather in which the number of layers of thermoplastic material, or else adhesive or aluminum layers, are in different number, or arranged in a different way with respect to each other, is still within the protection scope of the present invention.
Such opening device 1 made of polypropylene, or similar plastic material, comprises a collar 4 couplable around the aforesaid punchable portion 3 and a cutting element 5 moving inside the collar 4 in a way constrained by helical guide means 60 interposed between the cutting element 5 and the collar 4. Such helical guide means 60 comprise, in a known way, threaded elements 30 and 31 arranged on the outer surface 5a of the cutting element 5 and on the inner surface 4a of the collar 4, respectively. In practice, the cutting element 5 moves inside the collar 4 along a helical guide path up to reach the punchable portion 3 of the container 2 in order to cut it as the container 2 itself is used for the first time.
The cutting element 5 comprises a plurality of first teeth 6 each provided with two flat flanks 8 and 9, two side faces 10, an outer one 10a and an inner one 10b opposite to one another, in which the outer side face 10a comprises, in common with one 8 of the two flanks 8 and 9, a cutting edge 11 substantially defined by the intersection of the side face 10a with one 8 of the two flanks 8 and 9. This cutting edge 11 causes the tear of the punchable portion 3 of the container 2 as the cutting element 5 helically moves with respect to the collar 4. Moreover, each first tooth 6 is provided with an ending portion 7 having a vertex 7a to punch the punchable portion 3 as the tooth contacts the latter. Thus, the vertex 7a of the ending portion 7 is the part of the first tooth 6 first contacting the punchable portion 7. Advantageously, said ending portion 7 is rounded next to said vertex 7a. In more detail, said ending portion 7 has a curvature radius r (see figure 6) of 0.22 mm next to said vertex 7a.
However, it should be noted that an embodiment of the opening device 1 having the curvature radius r of the ending portion 7, next to the vertex 7a, comprised between 0.15 and 0.30 mm, is still within the protection scope of the present invention.
As shown in figures 4 to 6, such cutting edge 11 is connected to the ending portion 7, at the vertex 7a. In practice, the first tooth 6, although still having a cutting edge 11, has a vertex 7a no longer sharpened, as taught in the opening devices of the known art, but slightly rounded, nevertheless the tooth still allows to punch and then tear the punchable portion by means of the vertex 7a of the tooth 6 and the cutting edge 11, respectively.
As shown in figures 4 to 6, said ending portion 7 extends among said two side flanks 8 and 9 and said side faces 10a and 10b thereby being shaped as a rounded surface having a curvature radius equal to or substantially similar to the curvature radius of the vertex 7a along its whole extent. In particular, the X axis lying on said ending portion 7 forms an angle of about 36° with respect to the Y axis lying on the outer side face 10a of the first tooth 6. In practice, said ending portion 7 extends obliquely with respect to the outer side face 10a at an angle A of 36°. In other embodiments, this angle A can range from 20° to 50° without thereby departing from the protective scope of the present invention. However, in this way there is a vertex 7a which, while having a rounded shape, is still able to punch the punchable portion 3.
According to further embodiments (not shown) according to the present invention, the tooth can be provided with more than two flanks. Similarly, the tooth also can be provided with only one side face, as well as with more than two side faces. In this case, the cutting profile is defined by the intersection of a side face with one of the flanks and is connected over the ending portion next to the vertex.
According to a further modification and unlike what described about the preferred embodiment, the cutting edge is defined by the intersection of the inner side face, or a side face other than the inner side face, with at least one of the flanks.
Finally, although in the embodiment illustrated in the attached figures the flanks 8, 9 are flat, they can have different shapes, for example they can be concave or convex with respect to the hypothetical ray extending from the base of the tooth 6 to the vertex 7a.
According to the embodiment described in figure 1, the opening device 1 further comprises an upper cap 12 couplable by screwing on said collar 4. Essentially, as known to the field technician, the cap 12 actually drives the helical displacement of the cutting element 5 with respect to the collar 4, as the container 2 is opening. However, it should be noted that an opening device 1 without said cap 12 is still within the protective scope of the present invention.
According to the embodiment herein described, said cutting element 5 comprises a second tooth 20 having triangular section and provided with at least one upper ending portion 21 having a sharpened vertex 21a, just alike the known art devices.
Such second tooth 20 is arranged in such a way that, with respect to the above described teeth 6, it first meshes with said punchable portion 3 with respect to said first teeth 6 having a rounded vertex 7a as the cutting element 5 helically moves relative to said collar 4.
However, it should be noted that a second embodiment without said second tooth 20, or provided with two or more second teeth, is still within the protective scope of the present invention.
It should be noted that this second tooth 20, unlike the first teeth 6, has a sharpened vertex 21a and is designed to mesh the punchable portion 3 such that the latter is properly stretched. On one hand, this solution prevents the rounded vertexes 7a of the first teeth 6 from sliding on the punchable portion 3 thus causing the laminate constituting the punchable portion 3 itself to yield and, on the other hand, it allows to more easily cut the punchable portion 3.

Claims

Opening device (1) of the type constrainable to a multilayer container (2) for products pourable at one punchable portion (3) thereof, said opening device comprising a collar (4) couplable to said punchable portion, and a cutting element (5) moving inside said collar (4) in a way constrained by helical guide means (60) interposed between said cutting element (5) and said collar (4), said cutting element (5) comprising at least one first tooth (6) having a substantially triangular section, said tooth is provided with at least two flanks (8,9), at least one side face (10), at least one cutting edge (11) defined by the intersection of said side face (10) with at least one of said flanks (8) and provided with at least one ending portion (7) having a vertex (7a), to punch said punchable portion, said cutting edge (11) being connected to said ending portion at said vertex (7a), characterized in that said ending portion is rounded at least at said vertex.
Device according to claim 1, wherein that said ending portion extends among said two flanks and said side face.
Device according to claim 1 or 2, wherein said ending portion extends obliquely with respect to said side face.
Device according to claim 3, wherein the angle between the axis (X) lying on said at least one ending portion and the vertical axis (Y) lying on said at least one side face is comprised between 20° and 50°.
Device according to one or more of claims 1 to 4, wherein said tooth is provided with two flanks (8, 9), an outer side face (10a), and an inner side face (10b) opposite to one another, at least one cutting edge (11) defined by the intersection of one of said side faces (10a, 10b) with at least one of said flanks (8), said cutting edge (11) being connected over said ending portion, next to said vertex (7a).
Device according to claim 5, wherein said cutting edge (11) is defined by the intersection of said outer side face (10a) with at least one of said flanks (8).
Device according to one or more of claims 1 to 6, wherein said ending portion has a curvature radius between 0.15 and 0.30 mm, at least next to said vertex.
Device according to one or more of claims 1 to 7, comprising at least one upper cap (12) couplable by screwing on said collar (4), said cap (12) driving the helical displacement of said at least one cutting element (5) with respect to said collar as the container is opening.
Device according to one or more of claims 1 to 8, wherein said cutting element (5) comprises at least one second tooth (20) having triangular section and provided with at least one upper ending portion (21) having a sharpened vertex (21a), to punch said at least one punchable portion, said at least one second tooth being arranged, with respect to said at least one first tooth, in such a way that said at least one second tooth is meshed with said punchable portion before said at least one first tooth as said cutting element helically moves with respect to said collar.
Multilayer container (2) for pourable products defined by a laminate comprising a paper layer (49) and provided with a punchable portion (3) at a zone of said container provided with a hole (49a) in said paper layer (49), said container is characterized by comprising an opening device (1) according to one or more of claims 1 to 9, said opening device (1) being constrained at said punchable portion (3).