Background of the invention

[0001] The invention relates to a method and/or an apparatus for producing extractable closures, and an extractable closure usable, in particular, to close a mouth of a container, like for example a bottle.

[0002] Specifically, but not exclusively, the invention relates to extractable closures, known also as ring-pull closures, or pull-off closures, generally made of a metallic material (for example aluminum) and provided with an element (for example a ring) that can be pulled by a user to detach the closure and open the container.

[0003] Patent publications US 2019/0263570 Al, JP 2008-174266 A, JP Hl 1115937 A, JP 4065690 B2, EP 3037361 Al and US 1,005,046 show embodiments of pull-off closures that are usable to close a container.

[0004] Certain aspects of the prior art are improvable.

[0005] Firstly, it is desirable to make the operation easier and more convenient with which a consumer pulls the gripping element to open the container, whilst guaranteeing a seal of the container with great security before opening.

[0006] Secondly, it is desirable to make a closure that, whilst ensuring the necessary hermetic seal, is simple and cheap to make, in particular owing to a reduced use of construction material.

Summary of the invention

[0007] One object of the invention is to provide a method and/or an apparatus for producing pull-off closures that can overcome one or more of the aforesaid limits and drawbacks of the prior art.

[0008] One object of the invention is to provide a pull-off closure for containers that is alternative to the pull-off closures of the prior art.

[0009] One advantage is to make available a ring-pull closure the opening of which is particularly easy and convenient and which at the same time ensures high sealing security of the closed container.

[0010] One advantage is to make a simple and cheap manufacturing closure, in particular owing to a reduced use of construction material.

[0011] In one embodiment, a method for producing ring-pull closures provides for a sheet of metallic material being cut and drawn to obtain a plurality of shells each with a central closing wall and a peripheral skirt wall and in which each shell, after drawing, is scored to obtain at least one circumferentially extended score line that forms a preferential breakage line by tearing by pulling a gripping element applied to the shell.

[0012] The invention can be better understood and implemented with reference to the attached drawings that illustrate some non-limiting examples thereof, in which:

Figure 1 is a side view of an embodiment of an extractable closure for containers made in accordance with the present invention;

Figure 2 is a section of the closure of Figure 1;

Figure 3 is a view from the left of Figure 1 ;

Figure 4 is a section of the shell that is part of the closure of Figure 1 before the application of the gripping element to the shell;

Figure 5 is a view from the right of Figure 4;

Figure 6 shows a diagram of the step of scoring the circumferential scoring lines of the manufacturing method for manufacturing the closure of Figure 1;

Figure 7 shows a diagram of the step of forming the protuberances on the tab portion of the shell by plastic deformation in a first embodiment;

Figure 8 shows a diagram of the step of forming the protuberances on the tab portion of the shell by plastic deformation in a second embodiment;

Figure 8 A shows an enlargement of Figure 8;

Figure 9 shows a diagram of the step of forming the protuberances on the tab portion of the shell by plastic deformation in a third embodiment;

Figure 9 A shows an enlargement of Figure 9.

Detailed description

[0013] With reference to the aforementioned figures, 1 indicates overall an extractable closure, which is usable, in particular, to close a mouth of a container, like for example a bottle (made of glass, PET, aluminum, etc).

[0014] The extractable closure 1 may comprise, in particular, a closure of the ring- pull, or pull-off type. At least one part of the extractable closure 1 may be made, in particular, of metallic material (for example aluminum). The extractable closure 1 is provided with a gripping element 2 (for example a pull tab or ring) that can be pulled by a user to detach the closure and open the container. The gripping element 2 may be made, in particular, of plastics (for example PE).

[0015] The extractable closure 1 may comprise, in particular, a shell 3, or conch, comprising a closing wall 4. The shell 3 may be made, in particular, of metallic material (for example aluminum). The closing wall 4 may be, in particular, configured to close an upper mouth of the container. The shell 3 may comprise, in particular, a skirt wall 5. The skirt wall 5 may be, in particular, a cylindrical wall.

[0016] The skirt wall 5 may, in particular, extend downwards from a periphery of the closing wall 4 and may be configured, in particular, for coupling (for example of known type) with a neck of the container.

[0017] The shell 3 may comprise, in particular, a connecting portion 6. The closing wall 4 and the skirt wall 5 may be, in particular, joined by the connecting portion 6. The gripping element 2 may, in particular, extend from or be applied to the skirt wall 5 and may be, in particular, configured to be pulled (upwards) by a consumer so as to detach the shell 3 and open the container. The gripping element 2 may comprise, in particular, a pull ring. The gripping element 2 may comprise, in particular, an upper end portion attached to a lower edge of the skirt wall 5. The gripping element 2 may, in particular, extend downwards from a lower edge of the skirt wall 5.

[0018] The extractable closure 1 may comprise, in particular, preferential detachment means arranged on the shell 3 to promote the detachment of the shell 3 when the gripping element 2 is pulled. The preferential detachment means may comprise, in particular, at least one circumferential score line 7 arranged on a surface of the connecting portion 6, in particular on a convex external surface of the connecting portion 6. The circumferential score line 7 may, in particular, extend in length for at least one sixth, or for at least one fifth, or for at least one fourth, of a rotation angle, so as to ensure the detachment of the shell 3 after breakage of the preferential detachment means (by pulling the gripping element 2).

[0019] The gripping element 2 and the preferential detachment means are so configured that, by pulling the gripping element 2, the closing part that detaches and is lifted through the effect of the tear and the breakage of the preferential detachment means comprises at least one part of the closing wall 4 arranged above.

[0020] The extractable closure 1 may comprise, in particular, sealing means 8 arranged on an inner side of the shell 3 (in particular below the closing wall 4) and configured to make a seal on the mouth of the container. The sealing means 8 may comprise, in particular, a seal applied and molded directly inside the shell 3 by compression moulding of plastics (for example PE, EVA, or other PVC-free materials).

[0021] The circumferential score line 7 may be, in particular, arranged in a radially more peripheral position with respect to sealing means 8 such that the circumferential score line 7 is not superimposed on the sealing means 8.

[0022] This arrangement of the circumferential score line 7 (on the connecting portion

6 and/or in a radially more peripheral position with respect to the sealing means 8) enables tear opening to be facilitated and a high degree of hermetic seal of the container before opening to be maintained. In particular, the operation of tearing to detach the opening can be performed without interfering substantially with the sealing means 8 arranged inside the shell 3.

[0023] The preferential detachment means may comprise, in particular, at least one further circumferential score line 9 arranged on the (outer and convex) surface of the connecting portion 6. The further circumferential score line 9 may be, in particular, spaced in a circumferential direction from the circumferential score line 7. The further circumferential score line 9 may be, in particular, arranged in a radially more peripheral position with respect to sealing means 8 such that the further circumferential score line 9 is not superimposed on the sealing means 8. The further circumferential score line 9 may, in particular, extend in length for at least one sixth, or for at least one fifth, or for at least one quarter, of a rotation angle, so as to ensure the detachment of the shell 3 after breakage of the preferential detachment means (pulling the gripping element 2).

[0024] The further circumferential score line 9 and the circumferential score line 7 may be, in particular, arranged symmetrically to one another with reference to a vertical plane of symmetry passing through the gripping element 2. The circumferential score line

7 may be, in particular, arranged on the connecting portion 6 (in particular on the outer and convex surface thereof) over the entire circumferential extent thereof or anyway over most of the circumferential extent thereof. The further circumferential score line 9 may be, in particular, arranged on the connecting portion 6 (in particular on the outer and convex surface thereof) over the entire circumferential extent thereof or anyway over most part of the circumferential extent thereof.

[0025] The preferential detachment means may comprise, in particular, at least one vertical score and/or connecting line 10 arranged on an (outer) side of the shell 3. The vertical score and/or connecting line 10 may be, in particular, arranged on the skirt wall 5 ending near the gripping element 2. The vertical score and/or connecting line 10 may be arranged, in particular, to join the gripping element 2 to the circumferential score line 7. The preferential detachment means may comprise, in particular, at least one further vertical score and/or connecting line 11 arranged on an (outer) side of the shell 3, in particular to join the gripping element 2 to the further circumferential score line 9.

[0026] A method is disclosed for producing extractable closures for containers, in particular for producing the extractable closure 1.

[0027] The production method may comprise, in particular, the step of providing a sheet of metallic material (for example aluminum). The production method may comprise, in particular, the step of cutting the aforesaid sheet to obtain a plurality of sheet-like bodies. The production method may comprise, in particular, the step of drawing the aforesaid sheet-like bodies to obtain, from each of the bodies, a shell 3 with a central closing wall 4 and a peripheral skirt wall 5.

[0028] The production method may comprise, in particular, the step of scoring the aforesaid shells 3, after the aforesaid step of drawing, to obtain, on each of the shells 3, at least one score line extending circumferentially. The aforesaid scoring step may be in particular so run that the circumferentially extended score line is arranged on a convex external side of the connecting portion of the shell 3 that joins the central closing wall to the peripheral skirt wall.

[0029] The production method may comprise, in particular, the step of applying, to an inner side of the shell 3, the sealing means 8 intended to make a seal on a mouth of a container. The circumferentially extended score line may be, in particular, arranged in a position that is radially more peripheral than the aforesaid sealing means 8, such that the circumferentially extended score line is not superimposed on the aforesaid sealing means.

[0030] The aforesaid steps of cutting and drawing may be run, in particular, in a press by a movement of cutting means along a cutting axis and a movement of drawing means along a drawing axis coinciding with the aforesaid cutting axis. This press could comprise, in particular, an inlet zone of the sheet to be processed, a pressing zone (cutting and drawing), a discharge zone for discharging the scrap metal sheet, a zone for collecting the shells. This press could comprise, in particular, a press of known type. [0031] The production method may comprise, in particular, the step of forming one or more protuberances 12 on one side of each of the aforesaid sheet-like bodies or of the aforesaid shells. It is in particular possible to form two protuberances 12 for each sheet-like body or shell. The formation of one or more protuberances 12 may be achieved, in particular, by plastic deformation without generating scrap, i.e. portions of material that detach integrally from the aforesaid sheet-like bodies or from the aforesaid shells and that then have to be removed.

[0032] The formation of one or more protuberances 12 may be made, in particular, by plastic deformation performed with punch means 13, 17 (drawing and/or punching and/or cutting means).

[0033] The formation of one or more protuberances 12 on one side of the object may entail, in particular in the case of drawing, the simultaneous formation of one or more depressions on an opposite side of the object.

[0034] The plastic deformation that is suitable for forming the protuberances 12 may be such as not to generate scores or through openings on the material as, for example, in the case of simple drawing, or may be such as to generate scores or through openings (without scrap) as, for example, in the case of punching with cutting.

[0035] The formation of a protuberance 12 may comprise, in particular, also a step of cutting material with punch means 17 provided with an “open” cutting profile (i.e. not in the form of a closed ring) so that the deformed material remains attached without releasing scrap.

[0036] The formation of a protuberance 12 may comprise, in particular, the formation of a side opening or slit and is achieved by punching that cuts the material, for example, only on one side, giving rise in particular to a protuberance in the shape of a half cone (a sort of nose) or the like.

[0037] The punch means with blade (combined effect of punching and cutting) may be configured, in particular, so as to deform the material to give rise to a protuberance and also so as to cut the material and thus generate with a relative opening, hole or score, in a similar manner, by way of example, to machining a metal sheet to form the teeth and holes of a grater, or the teeth and the holes of a slip-proof grilled metallic floor.

[0038] It is noted that punching with partial cutting by a non-closed cutting profile (without formation of scrap), can further permit formation of a protuberance that defines an undercut, in particular owing to the formation of a score or opening or hole on the material. The undercut is defined by the inner surface of the protuberance that bounds the aforesaid score, opening or hole.

[0039] The formation of one or more protuberances 12 may comprise, in particular, a plastic deformation performed with punch means 17 provided with at least one blade and configured to form a cut, with the formation of at least one protuberance 12 and, further, the formation of an opening or hole or through score, with plastic deformation without formation of scrap.

[0040] The production method may comprise, in particular, the step of applying a gripping element 2 on each of the aforesaid sheet-like bodies or of the aforesaid shells by engaging the end of the gripping element 2 with each protuberance 12. This step of applying may comprise, in particular, the step of overmoulding the gripping element 2 (for example by injection or compression overmoulding of plastics) directly on the respective sheet-like body or shell 3. This step of applying may comprise, in particular, the step of joining, for example by interlocking and/or mechanical forcing of an end of the (previously formed) gripping element on the respective protuberance 12.

[0041] As said, the protuberance 12 may define, in particular, at least one opening hole or score in the material. The protuberance 12 may define, in particular, at least one undercut that can promote the subsequent operation of applying the gripping element 2, improving solid and tenacious gripping of the element.

[0042] The aforesaid step of forming one or more protuberances 12 (and one or more respective depressions) may be run, in particular, during the aforesaid step of drawing the sheet-like bodies, or after the aforesaid step of drawing the sheet-like bodies, or during the aforesaid scoring step of scoring the shells, or after the aforesaid scoring step of scoring the shells. Each protuberance 12 may be made, in particular, on a tab portion 14 of the shell, by punch means 13, 17 that may comprise, in particular, a small punch and a corresponding small die operating on the tab portion 14. Each protuberance 12 may protrude from an outer side of the tab portion 14 (as in the embodiment of Figures 4 and 5), or from an inner side of the tab portion 14 (as in the embodiments of Figures 7-9).

[0043] In particular, as in the embodiment of Figures 4-5, each protuberance 12, that comprises at least one drawn portion of material without any through opening, may be made by punch means for drawing (for example like the punch means 13 in Figure 7). In the embodiments of Figures 8-9 each protuberance 12, that comprises at least one cut and deformed portion of material with a through opening, may be made by punch means per punching and cutting (like for example the punch means 17 in Figure 8).

[0044] The gripping element 2 may be, in particular, attached to the tab portion 14 of the shell 3. The tab portion 14 may be arranged, in particular, so as to protrude downwards from the skirt wall 5.

[0045] An apparatus is disclosed for producing extractable closures, in particular an apparatus that is usable for producing the extractable closure 1 and for actuating the production method disclosed above.

[0046] The production apparatus may comprise, in particular, means for supplying a sheet of metallic material (for example aluminum sheet). The aforesaid supplying means may comprise, in particular, supplying means of known type (for example, a roller, belt or mat or magnetic or yet other type of conveyor) and is not disclosed here in greater detail.

[0047] The production apparatus may comprise, in particular, cutting means for cutting the sheet supplied by the supplying means. The cutting means for cutting may be configured, in particular, to cut a plurality of sheet-like (for example disc- shaped) bodies. The production apparatus may comprise, in particular, means for drawing the sheet-like bodies cut by the cutting means. The drawing means may be configured, in particular, to make, from each drawn sheet-like body, a shell 3 with a central closing wall 4 and a peripheral skirt wall 5. The central closing wall and the peripheral skirt wall may be joined together, in particular, by a connecting portion 6.

[0048] The cutting and drawing means may comprise, in particular, a single action (cutting and drawing) mechanical press for moulding caps, in particular suitable for multitool moulds, in particular configured to use precut (aluminum) sheets, in particular of known type.

[0049] The production apparatus may comprise, in particular, means for applying, to an inner side of the shell 3, the sealing means 8 (gasket) intended to make a seal on a mouth of a container. The means for applying the sealing means 8 may comprise, in particular, a lining machine, for example of known type.

[0050] The production apparatus may comprise, in particular, means for scoring a side (in particular the outer side) of the shells 3 made by the aforesaid drawing means. The scoring means may be configured, in particular, to make, on each shell, at least one circumferential score line 7 and/or 9. The scoring means may be configured, in particular, such that the circumferential score line is arranged on the connecting portion 6, in particular on a convex surface of the connecting portion (on the outer side of the shell 3).

[0051] The scoring means (see diagram of Figure 6) may comprise, in particular, at least one scoring tool 15 and at least one supporting counter- tool 16. The scoring tool 15 may be configured, in particular, to impose at least one circumferential score (in particular, a non-through score) on one side of the shell 3 (in particular, on the outer side of the shell). The supporting counter- tool 16 may be configured, in particular, to receive and support the shell 3. The scoring tool 15 and the supporting counter-tool 16 may be, in particular, movable in relation to one another to adopt at least one closed position, in which the scoring tool 15 imposes at least one circumferential score 7 or 9 on the outer side of the shell, and at least one open position, in which the shell 3 may be inserted into and/or removed from the supporting counter-tool 16. In particular, it is possible for each scoring tool 15 to be movable upon command in an operating direction F in both directions to move towards or away from the shell 3.

[0052] The scoring means may be configured, in particular, so as to form on one side (outer side) of the shell at least one circumferential score line 7 and/or 9 and/or at least one vertical score line and/or connecting line 10 and/or 11 that joins the circumferential score line/s 7 and/or 9 to the gripping element 2.

[0053] The production apparatus may comprise, in particular, applying means for applying a gripping element 2 to the skirt wall 5 of the shell 3. The production apparatus may comprise, in particular, a processing line along which the aforesaid applying means and the aforesaid scoring means are arranged. The applying means may be arranged, in particular, downstream of the scoring means.

[0054] The cutting means and the drawing means may be arranged, in particular, on the same press. The scoring means may be arranged, in particular, on a rotary machine.

[0055] The production apparatus may comprise, in particular, means for forming one or more protuberances 12 on one side of each of the aforesaid sheet- like bodies or of the aforesaid shells 3, together with the formation of one or more corresponding depressions on an opposite side of the sheet-like body or shell 3. The forming means may be configured, in particular, for forming protuberances 12 and corresponding depressions by plastic deformation with punch means 13 or 17 (for example, by a punch and a drawing or punching/cutting die).

[0056] The production apparatus may comprise, in particular, means for engaging an end of the gripping element 2 with a respective protuberance 12. This engaging means may comprise, in particular, means for overmoulding the gripping element 2 on the respective sheet-like body or shell 3. This engaging means may comprise, in particular, means for joining by interlocking and/or forcing the end of the gripping element 2 on the respective protuberance 12.