ES2280726T3 - OPENING DEVICE, WHICH CAN BE CLOSED AGAIN, FOR HERMETICALLY CLOSED CONTAINERS OF LAMINARY MATERIAL OF VERTIBLE FOOD PRODUCTS. - Google Patents

Abstract

An opening device (2, 2 ''), which can be closed again, for a hermetically sealed sheet container (1) of a pourable food product, whose device (2, 2 '') comprises: - a frame ( 10) defining a pouring hole (11), installed around a perforable part (4) of said container (1), and having at least a first thread (20); - a removable plug (12) having a second thread (22) that engages with said first thread (20) to thread the plug (12) on said frame (10) in order to close said pouring hole (11); - tamper-proof means (28) attached to said plug (12) by joining means (29 (breakable and detachable from said plug (12) after the first rotation of the plug; and - cutting means (13, 31) controlled by said cap (12) and which, after the breakage of said breakable joining means (29), shears said pierceable part (4) to open said container (1); - characterized in that one (20) of said threads (20, 22) comprise, in one part engaged by the other (22) of said threads (20, 22) in the transition phase between the separation of said means (28) tamper-proof and the initial shear of said pierceable part ((4) by the action of said cutting means (13, 31), successive thread parts (40, 41) separated by a distance (D1) smaller than the distance (D) from the rest of said one (20 ) of said threads (20, 22), in order to eliminate the clearance between threads 820, 22) in said part.

Description

Opening device, which can be returned to close, for hermetically sealed containers of sheet material of pourable food products.

The present invention relates to a device opening, which can be closed again, for closed containers Hermetically sealed sheet food products poubles

As is known, many food products pouring, such as fruit juices, treated milk to ultra high temperature (hereinafter UHT milk), wine, juice tomato, tomato sauce, etc., are sold in containers made of a packaging material of sterilized sheet.

A typical example of this type of packaging is the parallelepiped shaped container for food products vertibles or liquid products known as aseptic Tetra Brik (registered trademark), which is manufactured by folding and closing Hermetically a continuous band of laminated packaging material. The packaging material has a structure multi-strata comprising a layer of material fibrous, for example paper, coated on both sides with strata of heat-sealing plastic material, for example polyethylene, and, in the case of aseptic containers for products of Long-term storage, such as UHT milk, comprises also a layer of oxygen protection material, defined, for example, by an aluminum film, which overlays on a layer of closing plastic material heat-tight, and in turn is coated with another layer of heat-sealing plastic material that eventually defines the inside of the container that will be in contact with the food product.

Such containers are normally produced in fully automatic packaging machines, in which a continuous tube from strip-fed packaging material keep going; the continuous band of packaging material is sterilized in the packaging machine itself, for example, by applying a sterilizing chemical, such as a solution of hydrogen peroxide, which, once the sterilization, is eliminated, for example by vaporizing it by heating, of the surfaces of the packaging material; and the continuous band of packaging material thus sterilized is maintained in a closed, sterile environment, and folds and closes tightly to form a vertical tube.

The tube is filled with the food product sterilized or subjected to sterilization treatment, and tightly close and cut along sections crosswise equally spaced to form briquettes, which then they fold mechanically to form the finished containers, by example, substantially parallelepipedically.

Alternatively, the packaging material is could cut into starting pieces, which fold into containers on  shaping spindles, whose containers are then filled with the food product and close tightly. An example of This type of package is the so-called "two cover" waters "known by the trade name Tetra Rex (brand registered commercial).

To open these containers, they have been proposed various solutions a first of which, described in the US patents Numbers 4,655,387 and 4,410,128, comprising the corner formation of a flap of the container, a line of preferential tearing defined by a succession of perforations that extend through the outer strata from the packaging material to the layer of protective material, and the container is opened by lifting the flap and cutting or tearing at through the perforations. Once opened, the packaging of this type obviously cannot be closed, and therefore must be handled carefully to avoid involuntary discharge until it has been consumed all the food product contained in the package.

To eliminate this inconvenience, the packaging of the aforementioned type have devices of opening that can be closed again, which substantially they comprise a frame that defines an opening and installed around a hole or pierceable or removable part in a wall of the container and a cap articulated to the frame. The cap normally it has been integrally molded with the frame, and initially it is tightly closed with respect to it, along an edge peripheral surrounding the opening, through a thin annular part and breakable union. Once opened, the cap can move between a closed position, and an open position. Alternatively, it they also use screw caps, separated from and initially threaded to the frame.

A problem that arises with the devices of opening of the aforementioned type is that the cap must be detachable from the frame with virtually no effort when open the container For this reason, the opening devices are made of an easy-to-break plastic material, normally polyethylene.

However, polyethylene has the inconvenient of being a poor protection against oxygen. Therefore, the face of the packaging material that eventually define the inside of the container must be installed over the hole with an additional "patch" element defined by a foil of heat seal plastic material, and face opposite of the packaging material must be provided with an element of oxygen protection, for example, a removable tongue by traction, which is tightly sealed by heat with respect to the patch element and is provided with an aluminum layer.

The provision to the packaging of elements of protection and patch implies additional material treatment  of packing before sterilizing, folding and closing it tightly to form the vertical tube, thereby increasing the production time and the cost of the packaging.

Also, once the cap has opened, the user must also remove the protection element to access to the contents of the container

Therefore, devices have been proposed opening that can be closed again, by means of which it opens the container in one operation, while at the same time acting as effective protection against oxygen.

In the solutions described in the applications WO 95/05996 and EP-A-1088764 and EP 1262412, about which is based on the preamble of claim 1, the opening devices of this type substantially comprise a frame defined by a cylindrical collar that defines an opening of pouring, and by a base tab installed around a perforable part of the container; a removable cap that threads on the outside of the frame collar to close the opening; and a substantially tubular cutting member that threads into the frame collar, and comprises, at one end, a cutting edge with one or more teeth that cooperate with the pierceable part of the container to separate it incompletely from the respective wall, it is say, everything except a small angle part.

The cap has normally been molded so integral with a relatively tamper-proof ring undue coaxially attached to the plug by some junction points Radial and breakable.

The described cap is pressed on the frame in such a way that the tamper-proof ring improperly clicks past the threaded part of the frame very close to the base tab.

The cutting member is actuated by the plug by means of unidirectional transmission means of the type ratchet, which are activated when the cap is disengaged from the collar. The cutting member moves in a spiral, with respect to the frame, from an elevated resting position, in which its cutting edge looks at the pierceable part, up to positions successive lower cutters, in which the cutting edge interacts with the pierceable part.

When previously type packages are opened cited, the force exerted by the user on the plug therefore It is discontinuous and relatively annoying. More specifically, it requires a force of maximum intensity at the beginning of the phase of opening to remove the tamper-proof ring from the cap undue, and much less considerable force is needed in the subsequent phase of rotation, in which, due to the inevitable axial clearance between the threads of the plug and the frame, the plug rotates substantially free or "empty", and again a maximum intensity force is required to start the shear of the pierceable part by the cutting member.

In other words, when the container is opened, the user experiences two maximum force values separated by a substantially free rotation phase, the effect of which is annoying. Is say, after the first maximum value of the force, the user you have the impression that the container is already open, just to come back to realize that you have to exert extra effort to really complete the operation.

In addition, to store the containers consumed and reduce the amount of plastic used, the height of the opening devices applied to the packaging is maintained as low possible.

This is currently done using threads of frame and plug of multiple initiation, which also help the user in the opening and closing of the container. That is, while single initiation solutions require a full turn of the plug or a little more, the threads of long passage and of initiation Multiple allow the cap to be completely removed, or tightened completely, turning it approximately 180º.

However, brief opening devices with multiple initiation threads, they are unsuitable for containers that contain carbonated beverages, because the threaded passage junction length does not adequately retain the cap as opposed to pressure produced inside the container by the gas contained in the product.

Therefore, the gas contained in the product could cause the cap to pop off and detach from the container when the pierceable part is sheared.

An object of the present invention is to provide a opening device that can be closed again for packaging hermetically sealed pourable food products, designed to eliminate the aforementioned inconveniences typically related to opening devices known.

In accordance with the present invention, a opening device that can be closed again for packaging Hermetically sealed spillage food products, according to It is claimed in Claim 1.

Two embodiments are described below. Examples of the present invention, by way of example with reference to the attached drawings, in which:

Figure 1 presents a perspective view of a top of a tightly closed container for pourable food products, equipped with a device opening that can be closed again according to the teachings of the present invention;

Figure 2 presents a side view to scale enlarged and exploded view of the opening device of the Figure 1 before applying it to the respective container;

Figure 3 shows a view from below to enlarged and perspective scale of an opening device of the plug of Figure 1;

Figures 4 and 5 show views in axial section on an enlarged scale of the opening device of Figure 1 installed in the respective container and in two configurations different operating;

Figure 6 shows a section through the line VI-VI of Figure 4;

Figure 7 shows an enlarged detail of an externally threaded frame of the opening device of Figure 5, in which the parts of the frame thread that gear with the respective parts of the plug thread have cut along the central lines;

Figure 8 is similar to Figure 4, and presents an alternative embodiment of an opening device of according to the present invention;

Figure 9 shows the same view as in the Figure 7, of the opening device of Figure 8.

In Figure 1, the number 1 indicates as a whole a tightly sealed aseptic container for products pourable food, for example a container in the form of parallelepiped known as Tetra Brik Aseptic (trademark registered), which has been manufactured from sheet material for packaging, as described in detail above, and is provided with a opening device 2 that can be closed again made of a plastic material and applied to container 1 in a manner conventional, for example using sealing methods with adhesives, with microllama or with laser.

The packaging material has a structure of multiple strata, and comprises, in a top wall 3 of the container 1, a perforable circular part 4 of axis A (Figures 2, 4 and 5), which in use it is covered externally by an opening device 2 and separates at least partially from the wall 3 to allow the product is poured out of container 1.

In the example shown, the packaging material it comprises a layer of fibrous material 5, usually paper, coated on their inner and outer faces with respective sheets laminates 5, 7 normally defined by one or more layers of heat-sealing plastic material, for example, polyethylene. When the packaging material is used to produce aseptic containers of products with long storage periods,  such as UHT milk, the inner laminated sheet 7 comprises also a layer of protective material interposed between the layers of heat-sealing plastic material.

The pierceable part 4 is defined in this case by respective parts of the outer and inner laminated sheets 6, 7 that cover a hole 8, of axis A, practiced in the stratum of fibrous material 5.

When there is no material layer of protection, for example, in the case of non-aseptic containers of pasteurized products (for example, yogurt, cream, and other products cold storage), the pierceable part is defined by a preferential tearing line (not shown) formed in the stratum of fibrous material and defined by a succession of perforations An example of this solution is described in the EP-A-1088764 patent application, whose content is considered included herein by title reference.

With reference to Figures 1 to 6, the opening device 2 comprises a frame 10 defining a through hole 11 of axis A, through which the food products, and fixed to wall 3 of container 1, around the pierceable part 4; a plug 12 formed separately from frame 10 and coaxially installed to frame 10 to close hole 11; and a tubular cutting member 13, of axis A, which is couples to hole 11 in an axially and angularly movable manner, and it is activated by the plug 12 to interact with the pierceable part 4 of the wall 3 in order to open the container 1.

More specifically, the frame 10 comprises a flange 14 of circular annular base, of which a surface of end is fixed to the wall 3 of the container 1, around the part perforable 4, and whose radially inner edge protrudes axially a cylindrical collar 16, of axis A, which defines the hole 11.

On the respective lateral surfaces opposite, the collar 16 comprises an external thread 20 and a thread internal 21, which, in use, meshes with the respective threads 22, 23 of the cap 12 and the cutting member 13, and are inclined in opposite directions with respect to the A axis.

On the outside, the collar 16 comprises an annular flange 24 interposed axially between one end of the thread 20 and flange 14, and located at a constant axial distance from tab 14.

The collar 16 also has one or more windows lateral 18 to release any gas contained in the product food, and therefore reduce the pressure inside container 1, when the cap 12 is unscrewed from the frame 10 and the shear of the pierceable part 4.

The plug 12 is defined by a body hollow cylindrical limited by a circular upper wall 25 for close the hole 11, and by a cylindrical side wall 26, which protrudes from a peripheral edge of the upper wall 25, is internally provided with thread 22, and thread on collar 16 of the frame 10.

The upper wall 25 has an annular nerve protruding 27 adjacent to the side wall 26 and defining, with the side wall 26, a seat to receive the end edge top of collar 16.

Cap 12 has normally been molded so integral with a ring 28 relative handling tamper undue coaxially attached to an end edge of the plug 12, opposite the upper wall 25, by a series of joining points breakable radials.

The plug 12 is initially fixed to the frame 10 in a tightly closed position, in which it is completely  threaded on collar 16, with its lower end edge and ring 28 tamper proof still attached between yes, on opposite sides of nerve 27 of collar 16 (Figure 4).

Once opened, the cap 12 is movable between an open position, in which it is unscrewed at the height of the collar 16 and separates from frame 10, and a closed position that the hole 11 is closed. The initial rotation of the plug 12, when open the container 1, break the junction points between the cap 12 and the ring 28 tamper-proof, which relies on the base tab 14. More specifically, the junction points are they break by the spiral rotation of the plug 12 separating from the nerve 24 of frame 10, and by the action of nerve 24 that simultaneously retains tamper-proof ring 28 improper

With reference to Figures 2, 4, 5 and 6, the cutting member 13, which has a thread 23 on its surface outside, is installed in a known way inside the collar 16 of the frame 10 by the thread 23 that meshes with the thread 21, and it comprises an end edge 30 having cutting means 31 with a front face - in the example shown, a cutting tooth - that cooperates with the pierceable part 4 to open the container 1. The union from collar 16 of frame 10 to cutting member 13, and the operation of the cutting member 13 by the action of the plug 12, They are described below only as necessary to understand clearly the present invention. Details can be found Additional in the patent application EP-A-1088764, whose content is considers included in this report by way of reference.

Threads 21 and 23 define, when the container 1, a helical path, of axis A, of the member shear 13 through the pierceable part 4, from a position of raised rest (Figure 4) to a lower open position (no shown). More specifically, in the elevated rest position, the cutting member is completely housed within collar 16, with the cutting means 31 facing the pierceable part 4, and, in the lower open position, the cutting member 13 protrudes axially with respect to collar 16, it has penetrated a distance determined inside container 1, and has completely cut the part perforable 4, leaving it attached to the wall 3 by an angle part small.

The movement of the cutting member 13 from the raised position until the lower position is controlled by the plug 12 by means of angular transmission means 32 unidirectional (Figures 3 and 6), which are selectively deactivated once the cutting member 13 reaches the open position lower.

More specifically, means 32 of transmission comprise a number of first teeth 33-four in the example shown- that they have a sawtooth profile, which they protrude from the upper wall 25 of the plug 12, and also angularly spaced around the A axis; and a number of second teeth 34 - eight in the example shown - which also have a sawtooth profile, and protruding radially from an inner surface of the cutting member 13, and engage a integral way angularly and axially free with teeth 33 along the release path of cap 12 of collar 16 when container 1 is opened. More specifically, the path of release of the cap 12 has been shown in Figure 1 by a left rotation R of the plug 12 around the A axis.

More specifically, each tooth 33 is defined, towards the side wall 26, on two oblique sides 36, 37, converging out; the side (36) that has an inclination greater, with respect to the radial direction that joins a tooth respective 33 to axis A, defines a stop for a respective tooth 34 in the direction of rotation R of the plug 12; and the other side (37) allows teeth 34 to slide angularly in the direction of counter rotation.

Each tooth 34 extends over the entire height axial of the cutting member 13 and has, in cross section. he same profile as teeth 33, defined by two oblique sides converging 38, 39; and the side (38), which has one more slope inclined, with respect to the radial direction joining the tooth 34 to axis A, look at side 36 of a respective tooth 33.

According to an important aspect of present invention, the thread 20 of the frame 10 comprises, in a part engaged by the thread 22 of the plug 12 in the phase of transition between ring 28 separation proof improper manipulations and the initial shear of the part perforable 4 by the action of the cutting means 31, parts successive threads 40, 41 separated by a distance D1 less than the distance D from the rest of the thread 20, in order to eliminate, in said part, the clearance between threads 20 and 22. This feature allows perfect control of plug rotation 12 when the container is opened, to minimize the risk that the Stopper 12 pop out and escape in the case of products with gas. Even more, by eliminating the clearance between threads 20 and 22 in the transition phase between the separation of ring 28 proof improper manipulations and the initial shear of the part punishable 4, the user experiences only a force of prolonged maximum intensity when opening the container.

In the example shown, nut 20 is of the type of three initiations, and the thread parts 40, 41 are part of independent threads.

In an alternative embodiment not shown, the thread 20 could be a type of a single initiation, and the parts of thread 40, 41 could be defined by spaced, facing parts, of the same thread.

The distance between the thread parts 40, 41 is reduce to D1 by altering the course of one (40) of the two parts of thread in such a way that it converges towards the other (41).

The number 2 'of Figures 8 and 9 indicates in its a whole different embodiment of an opening device in accordance with the teachings of the present invention, and that described below insofar as it differs from device 2 opening, and using the same reference numbers for parts components corresponding or equivalent to those already described.

The 2 'opening device differs from the opening device 2 in which the distance D1 has been reduced forming one (40) of the two thread parts to carry it further close to each other (41). More specifically, the thread part 40 defines a projection 42 protruding towards the thread part adjacent 41.

The opening device 2, 2 'is assembled, before attaching to the pierceable part 4 of the container 1, by means of the insertion of cutting member 13 in an angular position predetermined within collar 16, and simultaneously raising or subsequently the plug 12 to the frame 10.

More specifically, when the cutting member 13 inside collar 16, threads 21 and 23 engage each other, and teeth 34 slide axially along pairs on opposite angular sides of the sides 36, 37 of a respective tooth 33.

The plug 12 is preferably pressed into the axial direction on the frame 10, after first placing the plug 12 in a predetermined angular position with respect to the cutting member 13. At this stage, threads 20 and 22 engage each other, and the tamper-proof ring 28 makes a "click" past the annular nerve 24 of collar 16 towards the tab 14. Alternatively, cap 12 could be pressed axially on the frame and then threaded on the collar 16 from frame 10 to a final angular position that allows full use of the screw-out route of the cap 12 when the container 1.

At the end of the previous operations, the cutting member 13 is in the raised rest position inside the collar 16, and defines, together with the cap 12 that closes hole 11, a tightly closed configuration of opening device 2, 2 'in container 1 (Figures 4, 6).

In actual use, based on said configuration tightly closed, the container 1 is opened by turning the cap 12 in the R direction with respect to the A axis to unscrew it from the collar 16.

As the plug 12 is turned in the direction R around axis A, the engagement of threads 20 and 22 simultaneously displaces the plug 12 axially separating it from the wall 3, thus breaking the radial points that join the ring to tamper proof 26, which is retained by support axially in rib 24 of collar 16.

Once the proof ring is separated improper handling 28, a part of the thread 22 of the plug 12 slides between thread portions 40 and 41 of collar 16 separated by a smaller axial distance (D1), such that the movement of the cap 12 is perfectly guided in this stage.

The teeth 22 of the plug 12 are positioned with the sides 36 leaning against sides 38 of the respective teeth 34 of the cutting member 13, which thereby also rotates around the A axis in the R direction.

Given the opposite inclination of the pairs mutually engaged of threads 20, 22 and 21, 23, the axial displacement of the cap 12 separating from the wall 3 of the container 1 corresponds to a simultaneous axial movement of the member shear 13 towards wall 3. More specifically, the member Shear 13 is rotated by the plug 12 by the action of the teeth 33 and 34 coming into contact on the respective sides 36, 38, which simultaneously slide axially relative to each other by the spiral movement imparted on the cap 12 and member shear 13 by the respective pairs of threads 20, 22 and 21, 23.

The initial rotation of the cap 12 around the A axis in R direction produces equal rotation of the member shear 13 and, simultaneously, an axial penetration of the part perforable 4 by cutting means 31 (Figure 5).

In the transition phase between the separation of tamper-proof ring 28 and shear initial of the pierceable part 4 by the media action sharp 31, the user must still exert a force relatively intense on cap 12 to continue the action of opening and overcome the resistance found by thread 22 to pass through the constriction between thread parts 40 and 41 of collar 16.

In this phase, the gas contained in the product food is released through windows 18 to reduce quickly the pressure exerted on the cap 12 from within the container 1.

Once the constriction has expired, and after the initial penetration of the pierceable part 4 by the cutting member 13 and the release of any gas contained in the food product, normal axial clearance is restored between threads 20 and 22, which therefore slide with more freedom.

The cutting means 31 advances angularly to through the pierceable part 4 to separate it along its perimeter of the wall 3.

The opening is completed by disengaging axial teeth 33 and 34, followed by the complete release of the cap 12 of collar 16 to free hole 11 of spill.

Once container 1 has been opened, it is prevented that the cutting member 13 moves from the open position lower, because the teeth 33 of the plug 12 are not capable of reach an axial position that engages with teeth 34 of the cutting member 13. In said position, the sheared part of the pierceable part 4 is retained within the cutting member 13 to keep hole 11 free.

The container 1 is closed simply by returning to put the cap 12 on the collar 16.

The advantages of opening devices 2, 2 'according to the present invention will be clear from The following description.

In particular, as indicated, the clearance clearance between threads 20 and 22 in the phase of transition between tamper-proof hoop separation undue 28 and the initial shear of the pierceable part 4 allows optimal control of the rotation of the cap 12 in the most phase delicate, that is, when container 1 is opened, minimizing that so the risk that the cap 12 pops out and comes off in the case of Products containing gas. In this case, the window or windows 18 practiced in the collar 16 of the frame 10 allows / allows the fast gas release to quickly reduce pressure exerted on the cap 12 from inside the container 1, and restore normal axial clearance between threads 20 and 22 in the next opening phase, without any risk of detachment of the plug 12.

Moreover, under the feature before mentioned of the threads 20 and 22, the user, when opening the package 1, experience a single prolonged maximum force, compared to both successive maximum forces typical of opening devices known. In other words, the annoying sensation of discontinuity when the container is opened.

Of course, changes can be made to the opening devices 2, 2 'that have been described and illustrated herein, however, without departing from the scope of the Claims
attached.

Claims (7)

1. An opening device (2, 2 '), which can be closed again, for a sheet container (1) Hermetically sealed of a pourable food product, whose device (2, 2 ') comprises:

-

             a frame (10) defining a pouring hole (11), installed around a perforable part (4) of said container (1), and that it has at least a first thread (20);

-

             a removable cap (12) having a second thread (22) that gear with said first thread (20) to screw the plug (12) into said frame (10) in order to close said pour hole (eleven);

-

             tamper proof means (28) attached to said plug (12) by breakable joining means (29) and separable from said cap (12) after the first rotation of the cap; Y

-

             cutting means (13, 31) controlled by said stopper (12) and that, after the breaking of said joining means (29) breakable, shear said pierceable part (4) to open said container (1);

-

characterized in that one (20) of said threads (20, 22) comprises, in one part engaged by the other (22) of said threads (20, 22) in the transition phase between the separation of said means (28) under test of improper manipulations and the initial shear of said perforable part (4) by the action of said cutting means (13, 31), successive thread parts (40, 41) separated by a distance (D1) smaller than the distance (D) of the rest of said one (20) of said threads (20, 22), in order to eliminate the clearance between the threads (20, 22) in said part.

2. A device as claimed in Claim 1, characterized in that the course of one (40) of said thread parts (40, 41) is altered so that it converges towards the other mentioned thread part (41). 3. A device as claimed in Claim 1, characterized in that one (40) of said thread parts (40, 41) defines a projection (42) projecting towards the other mentioned thread part (41). 4. A device as claimed in any one of the preceding Claims, characterized in that said thread parts (40, 41) form part of independent threads. 5. A device as claimed in any one of the preceding claims, characterized in that said thread parts (40, 41) form part of the same thread (20). A device as claimed in any one of the preceding claims, characterized in that said cutting means comprise a tubular cutting member (13) that engages said pouring hole (11) in an angular and axially movable manner, angularly attached to said cap (12) at least along a path of release of the cap (12) from said frame (10) when said container (1) is opened, and it has at least one cutting end tooth (31); connecting means (21, 23) being provided between said frame (10) and said cutting member (13) to define a spiral path of the cutting member (13) through said pierceable part (4). A device as claimed in any one of the preceding Claims, characterized in that said frame (10) has at least one side window (18) to aid in the release of any gas contained in the food product when said cap (12 ) is unscrewed from the frame (10) and after the initial shearing of said perforable part (4) by the action of said cutting means (13).