TAMPER-INDICATING CLOSURE

Abstract: A tamper-indicating closure serves as a closure for a container (2) which, at its container neck (3), possesses at least one locking surface (5) with which the retaining elements (6) of the tamper-indicating band (7) are able to engage. The tamper-indicating band (7) possesses an upper portion (10) which extends downwards from the cap skirt (12) and which is connected with this by a frangible line (11). A plurality of retaining elements (6) are provided on the upper portion (10) of the tamper-indicating band (7). The retaining elements (6) are in each case connected with the adjacent retaining element by a flexible web (13). Each of the retaining elements (6) possesses at least one wedge shape (8) on its surface oriented towards the container neck (3).

Description: Tamper-Indicating Closure The invention relates to improvements in tamper-indicating closures as well as an integrally molded blank for the manu¬ facture of a tamper-indicating closure. Tamper-indicating closures for various types of containers are widely and numerously known and in use. These types of closure are mainly employed in the beverage and food industry for the most varied of uses. In order to hinder manipulation of such containers, mainly bottles, the closures are provided with a tamper-indicating band which is brought into engage¬ ment with a locking surface on the container neck. A protrud¬ ing bead, one or more ribs, a groove or another shape for an undercutting on the container neck mostly serve as the lock¬ ing surface. One difficulty with the use of known closures is mainly that the tamper-indicating band on the one hand should slip over the container neck and locking surface easily and without da¬ mage to the frangible web or bridges connecting the band to the closure. In addition the tamper-indicating band must be elastic, in order to avoid too great a resistance when clo¬ sing the bottle and, with that, damage to the frangible line. On the other hand, the tamper-indicating band should be formed to be as stiff and resistant as possible, in order to reliably maintain engagement with the locking surface when opening the tamper-indicating closure, so that the tamper- indicating band will tear along the frangible line and thus display the initial opening. These types of closures can be manufactured in one piece, to¬ gether with the tamper-indicating band, by means of plastic injection molding. However, subsequent application of a wea- kened line to the closure blanks, between the closure cap and the tamper-indicating band, is also known. These types of de¬ vices and methods are known from US-PS-3,673,761 (Light/Ciba- Geigy), DE-OS-14 82 603 (Teillac/ALCA SA)" or US-PS-4,895,265 (Luc et al./ The West Co.). However, tamper-indicating closures made of metal are also known on which a tamper-indicating band is subsequently af¬ fixed. The tamper-indicating element is, with that, normally annular in shape with a holding portion, with which it can be brought into interlocking connection with the closure cap. The holder portion - and with that the closure cap - is con¬ nected with the tamper-indicating band by means of connecting bridges or webs. Other methods of manufacture of such tamper-indicating clo¬ sures, such as compression molding, co-injection molding and similar, are also known. A tamper-indicating band is known from US-patent 4,801,031 with which an inwardly folded tamper-indicating band posses¬ ses pleats in its end area, said pleats being directed in¬ wards. On the one hand, this type of tamper-indicating band can be too stiff in its upper edge area, because the tamper- indicating band exists with its full material thickness be¬ tween the individual fold-type protrusions. On the other hand, there is the risk that, during opening of the closure and thus with a vertical pressure being exerted onto the folds, the lower area of the tamper-indicating band will elastically yield and as a result the folds can slip over the retaining surface without tearing of the frangible line. A closure is known from US-PS-4,470,513 (Ostrowsky/Ethyl Mol¬ ded Products), the tamper-indicating band of which possesses a plurality of retaining elements which are provided with wedge shaped protrusions. It is apparent that such a closure can be further improved with reference to the stretching abi- lity of the tamper-indicating band during initial placement and with reference to its engagement properties with the retaining surface. The invention serves the purpose of improving tamper-indica¬ ting closures, in particular the various types of tamper-in¬ dicating closures as previously described, in such a way that the tamper-indicating band on the one hand will slip over a container neck during closure easily and without excessive loading of the frangible line, and on the other hand will achieve firm engagement, as secure against tampering as pos¬ sible, with the locking surface. Economic manufacture shall at the same time remain assured. According to the invention, this purpose is primarily solved according to the patent claims. The invention makes use of a combination of a plurality of known and also new features in order to achieve the set goal. It is based on individual retaining elements arranged at a distance from one another, since these will on the one hand put up less resistance when placing the closure on a contai¬ ner, and on the other hand adapt better to the neck of the container, thus offering greater security. The connection of the retaining elements by means of flexible webs ensures high elasticity of the arrangement during placement on a container neck. At the same time, by the connection of the individual retaining elements it is also ensured that there will be co¬ hesion between the individual elements so that greater secu¬ rity during opening of the tamper-indicating closure will occur. Each individual retaining element locks itself on the one hand against the locking surface and is, on the other hand, supported by adjacent retaining elements. Since each of the retaining elements possesses a wedge shape which in principle extends its whole length, the retaining elements are exceptionally resistant to bending under pres- sure loading. This has the effect that if, during opening of the container, the retaining element is pressed against the locking surface it is reliably ensured that the retaining elements will not simply bend or yield in another way to the pressure loading. Rather, they are, on the basis of the wedge shape, resistant to bending so that the force exerted onto them from the locking surface of the container will be guided in a longitudinal direction immediately into the upper por¬ tion of the tamper-indicating band, which transfers the force as a tensile load onto the frangible line and, with that, re¬ liably initiates tearing of the frangible line. The wedge shape can, with that, be so formed that each wedge tapers away downwards toward the lower edge of the tamper-indicating band. It is, however, also possible to permit the wedge shape to run up to the lower edge, if a particularly stable version is desired. Through raising of the stability as a result of the selected wedge shape, the wall of each retaining element can be of a thinner design, through which greater flexibility will be achieved. If the back side of the retaining element is shaped to be flat, and merely the surface oriented toward the container neck possesses a wedge shape, very high stiffness of the retaining element can be achieved. If, on the other hand, the front side and the back side of the retaining element are formed as a wedge, in cross section an approximately V-shaped retaining element will ensue which can elastically yield du¬ ring placement on a container neck. This is desirable mainly with container necks of small diameter, particularly in the case of beverage bottles. The wedge shape can, depending on the type of use, possess a shape which runs into a tip or a rounded form. The shape which runs into a tip will guarantee particulary good hooking of the retaining elements behind the locking surface. With a rounded form, a wider contact surface will result which, for example, can be advantageous in the case of beverage bottles with beads as a locking surface. Each individual wedge shape can also possess more than one wedge shape on its surface with advantage. Each of these wedge shapes leads to stiffening in the longitudinal direc¬ tion. In so far as particular demands are placed on the expansion of the tamper-indicating band during placement on a container neck, it can be useful if the retaining element is provided with an elastic web at the vertex of the wedge. Additional tamper-indicating security can be achieved if the web between the retaining elements in each case is formed to be thin in such a way that it serves as a frangible line in order to display manipulations. The tamper-indicating closure according to the invention can be manufactured in a particularly simple way if the tamper- indicating band, comprising the upper portion and the adja¬ cent retaining elements, is manufactured as a cylindrical continuation of the cap skirt and if, subsequently, the re¬ taining elements are bent back inwards and upwards in the direction of the cap base. The backwards bending is here facilitated if each retaining element is connected with the cap skirt by means of a hinge element. The hinge element can take the form of a thinning of the material. The elastic expansion of the retaining elements can be fur¬ ther improved if the hinge element possesses a connecting portion which is connected with the lower edge of the upper tamper-indicating band portion and whose wall thickness is thinner than the wall thickness of the upper portion and which runs with a radially inwardly and downwardly directed angle. Since the retaining elements are essentially longer than the connecting portion, these take effect with a rela¬ tively long lever arm on the connecting portion and cause pivoting and deflection of the retaining elements during initial placement, even with relatively slight pressing forces. It is of particular advantage if the angle of the connecting portion in relation to the longitudinal axis of the closure cap amounts, at the same time, to approximately between 30 degrees and 60 degrees, with advantage approximately 45 de¬ grees. Additional elasticity can be at the same time achieved if the lower edge of the upper tamper-indicating band portion possesses an indentation and if the connecting portion is arranged on the side of the indentation lying radially inside. A stiffening of the individual retaining elements against one another can be additionally achieved if the hinge element is provided collectively for a plurality of retaining elements and if the individual retaining elements are connected with the hinge element. This stabilising effect can be still fur¬ ther increased if the hinge element possesses an annular bead directed approximately radially inwards. Examples and embodiments of the invention are more closely described in the following, illustrated by the drawings. Namely: Figure 1 Schematic representation of a tamper-indicating closure with the features of the invention in cross section, Figure 2 the tamper-indicating closure according to figure 1 viewed from below, Figure 3 a section along the line A-A in figure 1, Figure 4 enlarged representation of a partial section along the line B-B in figure 2, Figure 5 an enlarged detail from the sectional representa¬ tion according to figure 3, Figure 6 a partial section in accordance with figure 5 through a modified embodiment of the invention, Figure 7 a partial section along the line A-A in figure 6, Figure 8 a partial section along the line B-B in figure 6, Figure 9 an embodiment of a tamper-indicating closure with modified frangible line, Figure 10 a partial section through the tamper-indicating band of the closure according to figure 9 in the area of the wedge tip and prior to bending back of the retaining element, Figure 11 a partial section through the web in accordance with figure 10, Figure 12 a partial section representing a web with inter¬ ruptions, Figure 13 an embodiment with two part retaining elements, Figure 14 an embodiment with a double wedge shape for each retaining element, Figure 15 an embodiment with rounded wedge shape of the re¬ taining element, Figure 16 sectional representation of a modified embodiment with a connecting portion in sectional represen- tation along the line A-A in figure 17, and Figure 17 a view from below of the tamper-indicating closure according to figure 16. According to figure 1, a tamper-indicating closure 1 for closure of a container 2 is anticipated, a beverage bottle with a container neck 3 being represented as a container. An annular circumferential bead 4 is provided on the container neck 3, the lower edge of which forms a locking surface 5 with which retaining elements 6 of the tamper-indicating band 7 can engage. As can be seen in figures 1 to 5, each of the retaining elements 6 is, through a section running parallel to the cap base 12a, formed to be V-shaped. The surface oriented towards the container neck 3 of each retaining element 6 consequently possesses a wedge shape 8. Apart from that, each retaining element is, on its underside, connected by a hinge element 9 with the upper portion 10 of the tamper- indicating band, said tamper-indicating band being likewise connected along a frangible line 11 with the cylindrical cap skirt 12. The frangible line 11 is formed as a material weak¬ ness of the upper portion 10 of the tamper-indicating band 7. As can be mainly seen in figure 4, the wedge shape 8 of the tamper-indicating band 7 tapers away downwards towards the hinge element 9. The individual retaining elements 6 are connected flexibly with each other by means of webs 13. During initial screwing on of the tamper-indicating closure 1 onto the container neck 3, the retaining elements 6 can slide elastically over the bead 4 without at the same time the frangible line 11 being destroyed. On the one hand, the elasticity of the tamper-in¬ dicating band 7 is assisted by the webs 13. On the other hand, the retaining elements 6 can, because of their wedge shape, be pressed outwards, the wedge shape becoming flat¬ tened and through that the inside diameter becoming enlarged, in order to permit passing over the bead 4. After closure of the container 2, the retaining elements 6, because of the elasticity of their material, will press inwards once again and achieve engagement with the locking surface 5 of the bead 4. Because of the wedge shape, the retaining elements 6 are longitudinally exceptionally stiff, so that, during opening of the container, deformation of the retaining elements 6, or slipping past the bead 4 in another way, is prevented. Apart from that, the webs 13 ensure good cohesion of the entire arrangement of all retaining elements 6. As is evident from figure 3, the tamper-indicating band 7 is connected firmly with the cap skirt 12 by means of a strengthened bridge 14. When opening the tamper-indicating closure the frangible line 11, formed as a thin web, will thus tear and in addition the vertical frangible line 15 will tear, so that the tamper-indicating band 7 will be separated from the cap skirt 12 along the frangible line 11 and will remain connected with the cap skirt solely at the bridge 14. Figure 6 shows a modified embodiment of a tamper-indicating band 7 with retaining elements 6 which are, as a body, in cross section formed as a wedge shape. This cross sectional shape ensures particularly good stiffness of the retaining elements longitudinally. Figure 7 shows a section along the line A-A in figure 6, which runs through the web 13 between two retaining elements 6. Figure 8 shows a section along the line B-B in figure 6, which runs through the thickest point of the wedge shape 8. Figure 9 shows a modified embodiment according to figure 1, with which the frangible line 11 comprises a plurality of bridges 16 which are able to tear away. Apart from that, the hinge element 9, for connection of the upper portion 10 of the tamper-indicating band 7 with the individual retaining elements 6, is formed as a reduction in the material. Through that, the retaining elements 6, after manufacture of the integrally molded blank, can be bent inwards particularly well. Figures 10 and 11 show, with that, partial sections in accor¬ dance with figures 7 and 8, one through the tip of the wedge shape 8 and one through the web 13. Figure 12 shows the embodiment of a tamper-indicating band with which the web 13 comprises individual bridges 13a and 13b. The bridges 13a and 13b are relatively easily damaged so that they can be destroyed during manipulation. Figure 13 shows a partial section through an embodiment with which each retaining element 6 is subdivided by a web 6a. The web 6a ensures high elasticity of the tamper-indicating band during closure. Figure 14 shows an embodiment with which each retaining ele¬ ment is provided with two wedge tips 8a, 8b, which are direc¬ ted inwards. By means of this shape, the number of wedge shapes making contact with a locking surface 5 (Figures 1 and 4) is doubled, without the elastic deformability of the re¬ taining elements 6 being reduced when compared with the embodiments according to the figures 1 to 13. Evidentially, according to the configuration of the container 2 to be closed and the locking surface 5, the individual retaining elements 6 can also be provided with more than just two wedge shapes 8a and 8b, without departing from the framework of the invention. Figure 15 shows an embodiment with which the wedges 8 are rounded off at each tip. By this means, too, the surface engaging with the locking surface 5 can be enlarged. Apart from that, with the embodiment according to figure 15, each of the retaining elements 6, in accordance with the embodi¬ ment according to figure 5, is thicker in the middle area 6c than in the edge area merging into the web 13. This ensures particularly good longitudinal stability of the retaining elements 6. Figure 16 shows a modified embodiment of a tamper-indicating closure 1, which is manufactured by injection molding. No frangible line has yet been provided between the tamper-indi¬ cating band 7 and the cylindrical cap skirt 12. This can be subsequently applied, for example by cutting. A circumfe¬ rential connecting portion 20 is provided as a hinge element 9 which runs off into an approximately radial bead 21 direc¬ ted inwardly. The individual retaining elements 6 are con¬ nected on their underside with the bead 21 and the connecting portion 20. At the same time, a circumferential indentation 22 is provided on the underside of the upper tamper-indica¬ ting band portion 10, said indentation approximately dividing the wall thickness of the portion 10. The connecting portion 20 is provided on the inner side of the indentation 22 and, with that, possesses approximately half the thickness of the tamper-indicating band portion 10. The connecting portion 20 runs, with that, with an angle of approximately 45 degrees to the longitudinal axis of the tamper-indicating closure 1. Evidently the retaining elements 6 can be pivoted relatively elastically when placing of the tamper-indicating closure 1 on a container neck. With that, the entire connecting portion 20, with the bead 21, bends unimpededly inwards. During opening, the forces exerted in the longitudinal direc¬ tion of the retaining elements 6 are, in contrast, lead through an acute angle directly into the wall of the upper tamper-indicating portion 10, and will thus be transmitted to the frangible line 11 (Fig. 1 to 15). The bead 21 streng¬ thens, with that, the connecting portion 20 against deforma¬ tion in the case of forces directed downwards. In addition, the bead 21 hinders manipulation on the retaining elements 6. Inasmuch as the invention is subject to modifications and variations, the foregoing description and accompanying draw¬ ings should not be regarded as limiting the invention, which is defined by the following claims and various combinations thereof:

Claims: Claims 1. Tamper-indicating closure for closure of a container (2), said container possessing at least one locking surface (15) on a container neck (3), characterized by a closure cap with a cap base (12a) and a cylindrical cap skirt (12), and a tamper-indicating band (7) which is connected with the cap skirt (12) and is able to be separated at least par¬ tially from the cap skirt (12) along a frangible line (11), the tamper-indicating band (7) possessing an upper por¬ tion (10) which extends downwards from the cap skirt . (12), and moreover a plurality of retaining elements (6), arranged at a distance from one another, being arranged on the tamper-indicating band (7) , said retain¬ ing elements being in each case connected with the adja¬ cent retaining element by a flexible web (13, 13a, 13b), the retaining elements (6), after placement onto the container (2), projecting radially inwards and upwards in the direction towards the cap base (12a) from the portion (10) of the tamper-indicating band (7), and with that being able to be brought into engagement with the locking surface (5) on the container neck (3) , and the surface oriented towards the container neck (3) of each retaining element (6) possessing at least one wedge shape (8, 8a, 8b) which in principle extends along the entire length of the retaining element (6) . 2. Tamper-indicating closure according to claim 1, wherein the retaining elements (6) possesses a V-shaped cross section in the plane parallel to the cap base (12a). 3. Tamper-indicating closure according to claims 1 or 2, wherein the frangible line (11) possesses a plurality of connecting bridges (16) which are arranged at a distance from one another. 4. Tamper-indicating closure according to claims 1 or 2, wherein the frangible line (11) possesses an area with a weakening of the material. 5. Tamper-indicating closure according to one of the claims 1 to 2, wherein the web (13) is formed as a frangible line. 6. Tamper-indicating closure according to one of the prece¬ ding claims 1 or 2, wherein each of the retaining ele¬ ments (6) is connected by a hinge element (9) with the cap skirt (12) . 7. Tamper-indicating closure according to one of the prece¬ ding claims 1 or 2, wherein the retaining elements (6) are formed as two parts and are provided with a web (6a) in the vertex of the wedge shape (8) . 8. Tamper-indicating closure according to one of the prece¬ ding claims 1 or 2, wherein the surface of the retaining elements (6) oriented towards the container neck (3) is provided with at least two wedge tips (8a, 8b). 9. Tamper-indicating closure according to claim 1, where¬ in the hinge element (9) possesses a connecting portion (20) which is connected with the lower edge of the upper tamper-indicating band portion (10) and whose wall thickness is thinner than the wall thickness of the upper portion (10) of the tamper-indicating band (7) and which runs at a radially inwardly and downwardly directed angle α. 10. Tamper-indicating closure according to claim 9, wherein the angle α amounts to between 30° and 60° in relation to the longitudinal axis of the tamper-indicating clo¬ sure (1) . 11. Tamper-indicating closure according to claim 10, wherein the angle amounts to approximately 45°. 12. Tamper-indicating closure according to claim 10, wherein the lower edge of the upper portion (10) possesses an indentation (22) and that the connecting portion (20) is arranged on the side lying radially inwards from the • indentation (22). 13. Tamper-indicating closure according to claims 1 or 9, wherein the hinge element (9) is collectively provided for a plurality of retaining elements (6) and that the individual retaining elements (6) project radially in¬ wards from the hinge element (9) . 14. Tamper-indicating closure according to claim 13, wherein the hinge element (9) possesses an approximately ra¬ dially inwardly directed, annular bead (21). 15. Integrally molded blank, manufactured in one piece from thermoplastic material, for the manufacture of a closure (1) having a cylindrical cap skirt (12), a tamper-indi¬ cating band (7) and a plurality of retaining elements (6) projecting in principle in the same direction from the cap base (12a) said elements (6) having an inside wedge-shaped surface which, in principle, is formed as an extension of the inner surface of the tamper-indica¬ ting band (7) .

Inventors: KELLY RONALD L, KELLY, RONALD, L.
Applicants: CROWN CORK AG
Application year: 1993
Main classification: B65D41
IPC codes: B65D41