EP1007429B1 - Snap-locking closure device for a beer barrel - Google Patents

Description

The present invention relates to a tamper-proof and self-sealing closure cap for container orifices, in particular for beer drums, provided with a filling head carrying the aforementioned orifice on a flange, the cap comprising a cover disc and a adjacent skirt, attached to its periphery and extending from the disc to a distance therefrom and the cap being arranged to be uniquely coupled to said flange.

To protect the barrels against fraud, they are provided with a cap or a so-called tamper-proof closing cap acting as an overcap capsule, the latter being fixed to the flange carrying the filling hole of the barrel and forming a barrel head. When such cover caps are placed on the barrel collar, they can be removed by breaking them which makes visible any fraud or attempted fraud. Barrels provided with such a protective cap are known.

However, a problem arises in the case of these known closure caps residing in the fact that when removing the closure cap placed on the barrel collar, debris is formed which are deposited on the closure seal itself of the barrel. In addition, some protective caps are insufficiently damaged after removal from the collar, so that they can easily be placed on the barrel head. Therefore, the anti-fraud protection thus obtained is not sufficiently reliable.

EP-A-652 160 discloses a cap of the aforementioned type, in which the inner wall of the skirt is provided with peripheral elements consisting of teeth to each of which is attached a tail intended to cooperate to engage against the collar aforesaid under the action of a hinge member attaching each tooth-tail combination to said skirt.

To remove the closure cap, a tear strip is provided in the disk. However, the skirt has axial notches evenly distributed around the periphery thereof which extend over most of the height of the skirt constituting weak portions which indicate an attempt to remove the cap. The presence of these axial notches requires a certain wall thickness of the skirt not allowing a minimization of the thickness of the wall during the manufacture of the cap.

The disclosed cap further has a pull strip, which is separated from the rest of the cap by a slot at its longitudinal edges and is connected by elements that can be broken. This band extends as well in the skirt as in the upper disc of the cap. In the portion of the strip extending into the skirt is attached a pull tab 34 remote from the upper disc of the cap.

The object of the present invention is to provide a protection of the access to the contents of the drum, in particular by the flange and the opening of the barrel thereto, which provides a solution to the aforementioned problem, while providing a satisfactory convenience to the opening, so that the drum is both ready for use, reliable and non-polluting.

For this purpose, it is proposed according to the invention a cap as defined in the main claim. Thus, thanks to the embodiment of the cap according to the invention wherein said tongue is arranged to protrude directly from the circular periphery of the cover disc itself, the tape can be entered more conveniently to tear it off by the tongue.

In addition, the tab being provided in the plane of the cover disc, the tear of the protective cap starts at its upper surface and the skirt can thus keep its wall thickness substantially intact. The cap can be made with a smaller amount of material thanks to the possibility of minimization thus obtained the thickness of the skirt.

The peripheral openings more particularly have a width greater than their height and their number. The limited number of window openings makes it possible to increase their width thus widening the visual field, which makes said control easier, faster and more reliable. In addition, the locking members have substantially the same width as the control openings, which makes them sufficiently wide so that the formation of remaining debris is thus avoided, so as to eliminate any form of pollution of the environment. In addition, the anchoring of the cap to the collar is made more solid

In an advantageous embodiment of the invention, each locking notch has a straight cross section, one end of which is attached to the edge of the skirt and the other end is free and bears against the collar of the skirt. barrel, so as to ensure a good anchoring of the closure cap to the collar.

Preferably, the free end of each locking notch has a profile which is adapted to the geometry of the collar of the barrel. As a result, the clearance between each locking catch and the flange can be reduced to a minimum.

In an advantageous embodiment of the invention, said tear strip is provided with a pull tab, and more particularly said tab is provided protruding from the circular periphery of the cover disc. Thus, the tape can be grasped more conveniently for tearing off the tongue.

Preferably, the tongue is provided in the plane of the cover disc. With this measurement, the tear of the protective cap begins at its upper surface and the skirt keeps its wall thickness intact.

In a particularly advantageous embodiment of the invention, the skirt is slightly flared outwards, the end of the tongue being located inside the diameter of the outer periphery of the skirt. Thus the protective caps can be stored compactly.

Advantageously, said tear strip is limited by two breaking grooves which are provided in at least one of the faces of the cover disc as grooves, preferably on the side facing the barrel collar. Thus, removal of the tear strip is facilitated and, in addition, the formation of dirty dust in the grooves is avoided.

According to a particularly advantageous embodiment of the invention, the two grooves depart divergently from the tongue to the opposite side of the periphery of the disc. Thus one obtains at the same time a regular rupture of the band with respect to the rest of the cap while preventing the rupture of the band itself.

The average width of the tear tape measured perpendicularly to the direction in which it is drawn is such that after removal of the tear strip a drawing operation is possible only after complete removal of the tear tape. remaining part of the protective cap. This greatly enhances the reliability of the anti-fraud protection.

In addition, an unbroken cut can be provided at least on one side of the tongue. This greatly facilitates the detachment of the tongue and thus promotes a perfectly clean detachment of the entire band.

In the skirt is provided a slot at the level of the tongue to initiate the tearing and to further facilitate the grip of the tongue.

It is also possible to provide at least one additional cut in the cover disc on the opposite side of the periphery of the disc relative to the tongue so as to ensure a break that is clear to the end of the strip.

More particularly, said additional notch also extends in the skirt to a predetermined distance from the edge or to the edge of the skirt substantially perpendicularly. Thus after the tearing of the band, the latter does not constitute an obstacle to the operations of withdrawal of the drum.

In addition, an oblong rib is provided substantially in the middle of the tear strip. Said rib prevents early tearing or rupture of the tear strip.

Preferably, said edge has a circumferentially bulge cross section preferably substantially constant, forming a peripheral bead at the leading end of the cap. Thus the skirt is strengthened and its tear along the edge is avoided when accidentally placing the protective cap on the barrel collar. This also allows a reliable use of thinner walls, saving material can be achieved.

Shoulders in the form of pads forming a stop are provided on the inner surface of the skirt to limit the clearance between the collar of the drum and the protective cap.

The invention also relates to a method of manufacturing a protective cap, in which the protective cap is formed by injecting a plastic material into a matrix comprising matrix elements, the matrix elements being supplied to slide one in the other in a direction parallel to the axis, the matrix elements sliding one inside the other having recesses and stamps. This method is particularly suitable for a full realization of the skirt of the protective cap.

The protective cap can also be obtained by first making the skirt in the form of a solid and continuous surface. Then, the locking notches are obtained by folding the free edge towards the inside of the surface of the skirt along a fold line which is between 60% and 90%, preferably between 70% and 80% of the height of the skirt. the skirt, measured from the side of the surface of the skirt associated with the protective cap, the folding being carried out in such a way that at least one of said locking members forms the desired angle with said surface of the skirt.

Moreover, said protective cap can still be obtained by mounting two parts produced separately, in particular an outer protective cap without opening in the skirt and the upper face without openings, and an inner ring with locking members.

Other advantages and features of the protective cap according to the invention will emerge from the description of the exemplary embodiments illustrated below by means of the accompanying drawings.

Figures 1 and 3 show a view from above and respectively from below the closure cap according to the invention.

Figures 2 and 5 show perspective views of the closure cap according to Figures 1 and 3 respectively.

FIG. 4 represents a cross-sectional view along the line IV-IV of FIG. 1 of the closure cap according to the invention.

FIG. 6 represents a partial cross-sectional view along the line VI-VI of FIG. 1 of the closure cap according to the invention.

Figure 7 shows an enlarged detail view of the closure cap according to the invention.

Figures 8 and 9 show further details of the closure cap illustrated in two operating positions.

In general, the beer barrels are provided at their bottom with a flanged tap device which can be connected to a draw-off device. The aforementioned taps must be protected by a cap or overcap as well against dirt as damage that may occur during storage or transport.

FIG. 1 shows a self-sealing closure cap 11 mainly comprising a cover disc 1 and an adjacent skirt 2 which is provided on its inner wall with locking members 5, for example eight, each consisting of an upwardly inclined protrusion forming notch, connected by one end to the free edge 3 of the skirt 2 and the opposite end is free. The free end of each locking notch 5 can be uniquely and irreversibly coupled by a form connection, preferably unidirectional, in particular by snapping to a drum head 30 provided with a flange 31 projecting. In the coupled position each locking notch 5 is resiliently hooked against the projecting flange 31 so that the closure cap is securely anchored to the flange 31.

A tear strip 6 is provided in the cover disc 1 to allow the withdrawal of the closure cap 11 of the flange 31 when the user wishes to have access to the contents of the filled drum still sealed. The barrel is accessible only by tearing the closure cap 1, which in turn covers the closure 32 itself of the barrel, thus effectively protects the barrel on the one hand against impurities, dust etc. and on the other hand, against fraud.

In addition, the tear strip 16 is provided with a pull tab 7, which serves as a gripping member for the tearing of the strip 6. Thus, the tear strip serves as a guarantee strip.

The tear strip 6 extends in the middle of the cover disc 11 preferably over the entire diameter. Two grooves 5 are formed in the cover disc 1, forming two breaking grooves, in which the tear strip 6 can be torn off. To avoid the formation of dust in the grooves 15, they are formed in the inner face of the cover disc 1, which is turned towards the collar of the drum. This greatly facilitates tearing of the tear strip 6 in the pulling direction, indicated by reference F in FIG. 2.

In addition, the extension of the tear strip 16 by the tongue 7 arranged projecting produces a leverage already at the beginning of the drawing operation according to the arrow F of the strip 6. Thus, the initial phase of the draw can take place unfold in the best conditions.

Advantageously, the tongue 7 does not extend beyond the outer diameter of the edge 3. Thus, the free edge of the tongue 7 is located in the annular zone between the periphery 13 of the covering disk 1 and the edge 3 of the skirt 2. This allows a stack with space saving while avoiding that the tongue 7 is damaged during the stacking of several caps 11 or during sudden manipulations. In addition, by providing the tongue 7 in the plane of the cover disc 1, a significant space saving is achieved during the storage of the caps 11.

To facilitate the engagement of the tongue 7, an opening 9 is provided in the skirt 2 at the height of the tongue as clearly illustrated in FIG. 7. In order to allow a more flexible unfolding of the initial phase, respectively the final phase of the operation. tearing of the strip 6, notches 21 upstream and / or downstream 22, for example each V-shaped, are provided upstream respectively downstream of the direction of traction, each time around the periphery 13 of the disk 1 The downstream notches 22 may even advantageously extend further into the skirt 2 to a predetermined distance from the edge 3 or even to the edge 3, transversely thereto.

The two grooves 15 are straight and possibly parallel, although preferably mutually divergent starting from the tongue 7. This results in a progressive and reliable tearing of the strip 6 and the tearing of the strip itself is furthermore avoided, because the leverage, which is superimposed on a constantly applied tensile force and which increases as the band is torn off, is compensated for by an ever increasing width of the tear strip 6.

It goes without saying that the grooves may have another shape, for example, a slightly curved shape, the curvature being directed towards the diameter, so that the aforementioned effect is further enhanced.

The ratio between the circle segment of the tear strip 6 on the pull side, that is to say at the height of the arrow F indicated in FIG. 2, and that on the opposite side is, for example, between 0.5 and 0.9, preferably between 0.6 and 0.8.

Preferably, the width of the tear strip 6 measured perpendicularly to the center line M, more particularly in the central zone of the cover disc 1, is such that after removal of the tear strip 6, effective withdrawal of the barrel will be possible only after complete removal of the remaining portion of the cap 11. In other words, said width is such that in order to be able to place the withdrawal device on the collar 31, the two remaining lateral parts 21 22 of the protective cap on either side of the strip 6 must also be removed, in addition to the withdrawal of the tear tape itself.

Advantageously, at least one oblong rib 16, 18 is provided parallel to the grooves 15, preferably on both sides thereof. They have a constant cross-section and serve to reinforce the groove edges thus preventing the lateral tearing of both the tear strip 6 and the side portions of the cover disc 1 itself, for example, during a sudden tearing of However, in order not to hinder too much the initial phase of tearing off the strip 6, the ribs 16, 18 extend only from a certain distance from the periphery 13 of the disc, as visible on Similarly, in order to facilitate the final phase of the tearing operation, the ribs 16, 18 extend only to a certain distance from the side opposite to the tear strip.

Preferably, an additional analog rib 17 is further provided, preferably having a wider cross-section. This extends in the middle of the tear strip 6 as a reinforcing element and thus avoids premature tearing or even breaking of the strip.

The skirt 2 has for example a conical type of low slope, as shown in Figure 2. In this case a still less bulky stack can be obtained, for example by fitting the caps into each other. The height of the skirt 2 and / or 3, measured along the longitudinal axis L of the cap 11, and their thickness are chosen according to the type of barrel collar 31 to which the cap is intended.

To minimize clearance between barrel cap 30 and guard cap 11, shoulders 28 are provided on the inner surface of the skirt, as shown in FIGS. 3-6.

As shown in FIG. 3, flanges 12 are still provided on the inner surface of the cover disc 1, so that they further limit the clearance between the barrel head 30 and the cap 11 to a bare minimum or even 'eliminate. The flanges 12 thus serving as circular holding elements are oblong and extend in segments with a substantially constant cross section, following the circular periphery of the barrel head 30. Thus the barrel head 30 and the flanges 12 are in mutual contact over the entire length thereof so as to ensure good maintenance. The constant cross-section is advantageously triangular, so as to avoid any "adhesion" of the cap 11 to the barrel head 30. For this purpose, other similar pointed shapes may also be chosen for the cross-sections of the flanges 12.

Furthermore, said locking members 5 are designed to function as spring clips on the barrel collar. The operation of the locking members 5 is represented in FIGS. 8 and 9, each in two positions, respectively A in phantom for the compressed situation of the elastic locking members 5 and B in continuous lines for the relaxed situation. Firstly, the elastic locking members 5 are compressed towards the skirt 2 (position A) by placing the protective cap 11 against the drum head 30. After the installation on the barrel collar (position B), the members locks return elastically inward and return to their original position thus ensuring a unidirectional shape connection including snap of the cap 11 to the flange 31. Thus, the cap 11 can not be removed after the tearing of the strip 6. The locking members 5 abut against the barrel flange and remain under tension, and thus, after tearing the strip 6, the remaining parts 23, 24 of the cap are mutually spaced apart to the side.

The locking members 5 may be made in several ways: by matrix elements provided with recesses and being slid into each other parallel to the axis (L) of the cap without formation peripheral openings in the skirt 2, which thus extends continuously; but by heating and bending inwards clips made in the extension of the skirt or by the composition of two parts made separately, that is to say a cylindrical skirt provided with an edge and a ring provided with locking members and where appropriate also by movable elements perpendicular to the axis L, by making peripheral openings in the surface of the skirt 2.

Another essential function of said locking members 5, however, is also to achieve the fixing of the protective cap 11 on the flange 31 of the barrel. To strengthen the locking members 5 in this function, these are provided with a reinforcement 27, including, for example, a rounded and padded connection area between the right cross section of the locking members and the inner surface of the skirt 2. Preferably, each locking notch 5 also has a continuous uninterrupted wall surface and in particular the base area of each locking notch 5 is also uninterrupted, as shown in FIGS. 4, 5, 6 and 8.

As shown in Figures 2 and 5, the skirt 2 is advantageously full, thus ensuring its rigidity, even for relatively thin walls. An alternative skirt interrupted by peripheral openings 4, each corresponding to the locking members 5 can however also be considered. The peripheral openings 4 constitute at the same time control windows, allowing verification as to the good connection between the locking members 5 and the withdrawal head 30.

In order to be able to control each of the two functions of the locking members 5 described above, it is thus possible advantageously to make use of peripheral openings 4. Thus, the appropriate position of the locking members 5 with respect to the flange 31 can be visualized and adapted if necessary.

Preferably, the number of locking members 5, respectively the number of peripheral openings 4 are at most eight and they extend over most of the edge 3. Thus the locking members 5, respectively openings relatively wide peripherals 4 are obtained, that is to say locking members and / or peripheral openings which extend in a more pronounced manner in the peripheral direction of the skirt 2, rather than in the radial direction of the latter leaving between them only relatively reduced material portions forming radial bridges 20.

For optimum operation, a material combining rigidity and elasticity with a low shear strength is chosen. Thus we obtain that the locking members do not break during installation A on the flange and immediately return to the position B indicated in solid lines in Figures 8 and 9. In order to also allow removal of the tear strip 6 without effort, it has been found that an optimal result is obtained by selecting impact-resistant polystyrene. It is understood that other materials combining the aforementioned qualities may also be considered.

Claims (25)

1. Tamperproof and self-sealing closure cap (11) for container openings, in particular for beer barrels, equipped with a filler head (30) having a flange (31) bearing the aforementioned opening (32), the cap (11) comprising a cover disc (1) and an adjacent skirt (2) joined to its circumference and extending from the disc (1) up to a certain distance therefrom and the cap (11) being adapted to be coupled only once to the said flange (31), the inner wall of the skirt (2) being equipped with at least one locking element (5), peripheral apertures (4) being provided in the cover disc (1) along its circumference (13), a tear strip (6) being provided, which is equipped with a pull tab (7), the said strip (6) serving to permit the removal of the cap (11), characterised in that each locking element (5) consists of an oblique resilient slope oriented towards the disc (1), normally forming an angle (α) with the inner wall of the skirt (2) and engaging, in the closed position, resiliently against the flange (31) so that the cap (11) is solidly anchored to the flange (31), in that the said strip (6) is provided in the disc (1) and extends downstream up to and including the free edge of the skirt and in that the pull tab (7) is arranged to project relative to the circumference (13) of the disc (1), the circumference of the skirt at least in the part of the latter which is close to the tab being continuously solid and all in one piece.
2. Cap according to claim 1, characterised in that the skirt (2) is substantially solid and in that each aperture (4) has a corresponding locking element (5), with corresponding respective widths.
3. Cap according to the preceding claim, characterised in that the width of the peripheral apertures (4) measured along the circumference (13) of the disc is greater than the height of these apertures measured on the axis (L) of the cap (11).
4. Cap according to any one of the preceding claims, characterised in that each locking element forms a catch (5) having a substantially straight cross-section, one end of which is joined to the edge (3) of the skirt (2) and the other end (26) of which is free to bear resiliently against the aforementioned flange (31).
5. Cap according to the preceding claim, characterised in that the free end (26) of each locking catch (5) has a profile adapted to the geometry of the barrel flange (31).
6. Cap according to one of claims 4 or 5, characterised in that the zone in which each catch (5) is joined to the edge (3) is uninterrupted (25) and in that, furthermore, the zone (27) of the included angle (α) between the catch (5) and the skirt (2) is filled out at the level of the vertex of the aforementioned angle (α),
7. Cap according to one of claims 1 or 6, characterised in that the tab (7) is provided in the plane of the cover disc (1).
8. Cap according to any one of the claims, characterised in that the skirt (2) is slightly flared towards the free edge (3) thereof, the free end of the tab (7) being situated within the diameter of the circumference of the free end (3) of the skirt (2).
9. Cap according to one of claims 9 to 11, characterised in that a slot (9) is provided in the skirt (2) at the level of the tab (7) and extending along the latter (7).
10. Cap according to any.one of the preceding claims, characterised in that the said tear strip (6) extends over virtually the entire diameter of the cover disc (1), substantially symmetrically along one of the median lines (M) of the latter, so that the pulling direction of the tear strip (6) is oriented in the direction of the median line of the disc (1).
11. Cap according to any one of the preceding claims, characterised in that the said tear strip (6) is bounded by two tear furrows which are provided as grooves (15) in at least one of the faces of the cover disc (1).
12. Cap according to the preceding claim, characterised in that the two furrows (15) run divergently from the tab (7) to the opposite side of the circumference (13) of the disc.
13. Cap according to any one of claims 10 to 12, characterised in that the average width of the tear strip (6) is such that, after removal of the latter (6), a tapping operation is possible only after complete removal of the remaining part (23, 24) of the closure cap (11).
14. Cap according to any one of claims 7 to 13, characterised in that a notch (21) is provided in the circumference (13) of the disc (1), on at least one lateral side of the tab (7).
15. Cap according to any one of claims 7 to 14, characterised in that at least one additional notch (22) is provided in the circumference (13) of the cover disc (1), on the side opposite the tab (7).
16. Cap according to the preceding claim, characterised in that the said additional notch (22) continues in the skirt (2), at least up to a predetermined distance from the free edge (3).
17. Cap according to one of the preceding claims, characterised in that an oblong and flattened rib (16, 18; 17) is provided on the cover disc (1) along at least one side of the tear strip (6) and/or in the tear strip (6), preferably virtually in the middle of the latter (6).
18. Cap according to any one of the preceding claims, characterised in that the edge (3) of the skirt (2) has an enlarged, preferably substantially constant, cross-section forming a peripheral collar at the leading end of the cap (11).
19. Cap according to any one of the preceding claims, characterised in that shoulders (28) are provided on the inner surface of the skirt (2).
20. Cap according to any one of the preceding claims, characterised in that at least one bead (12) is provided on the inner surface of the cover disc (1), which bead is arranged to extend along the free edge of the flange (31).
21. Barrel, in particular beer barrel, comprising a filler head (30) having an outwardly projecting flange (31), and a seal (32) being provided to close off the barrel, the barrel comprising a tamperproof and self-sealing closure cap (11) according to any one of the preceding claims, characterised in that the latter (11) is for single use and is produced from a recyclable synthetic material possessing suitable rigidity, elasticity and tearability and in that it (11) is coupled to the flange (31) by a unidirectional form-locking connection of the locking catches (5) to the flange (31).
22. Method for manufacturing a cover cap according to any one of the preceding claims, characterised in that the cap (11) is produced by injecting a plastic material into a mould comprising mould elements, the mould elements being caused to slide one into the other in a direction parallel to the axis (L) of the cap, the sliding mould elements being provided with hollows.
23. Method for manufacturing a cap according to any one of claims 1 to 7, characterised in that the cap (11) is produced by injecting plastic material into a mould composed of several mould elements, the mould elements being caused to slide in one another in a direction perpendicular to the axis (L).
24. Manufacturing method according to one of claims 22 or 23, characterised in that the said closure cap (11) is obtained by first producing the skirt (2) as a solid and continuous surface, each locking member (5) then being produced by folding the free edge towards the inside of the skirt (2) along a folding line which is situated at between 60% and 90%, preferably between 70% and 80%, of the height of the skirt (2), measured from the side of the skirt associated with the closure cap (11), the folding being effected in a manner such that the said locking members (5) form the desired angle (α) with the skirt.
25. Method according to the preceding claim, characterised in that the said closure cap (11) is produced by assembling two separately produced parts, notably the outer closure cap (11) without apertures in the skirt and the disc (1), and the peripheral collar (3) forming an inner ring with the locking members (5).

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