JPH04242555A - Plastic screw-in cap to seal mouth of container - Google Patents

Abstract

PURPOSE: To provide a plastic screw cap for sealing a port of a container in which a predetermined tearing position of a guarantee strip is not damaged when the cap is screwed into the port and a security function is applied when the cap is removed for the first time. CONSTITUTION: A guarantee strip 3 of a screw cap 1 has a predetermined tearing position 11. The guarantee strip can be cut and separated over its entire height at the predetermined tearing position 11. In addition to the predetermined tearing position, there is provided in particular, a window-shaped load bearing opening 12. The load bearing opening 12 may improve an extending characteristic of the guarantee strip when the cap is screwed into the container at the first time. The predetermined tearing position is comprised of at least two material bridges, the lower of the two material bridges is arranged at a lower end edge of the screw cap. At first, when the cap is to be removed, a certain force may act in the guarantee strip and this force may not act against the load bearing opening when the force is applied.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a plastic screw-on cap for sealing the mouth of a container according to the preamble of claim 1. Such screw-on caps have a security function in that the initial removal of the cap is indicated by tearing the security band. Screw-on caps of this type are known and commonly used, particularly in the area of soft drinks.

0002

BACKGROUND OF THE INVENTION A problem with known caps is, inter alia, that when sealing the mouth of a container, the retaining element has to be extended somewhat in order to be able to move over the ridge of the mouth of the container. Since the screw cap simultaneously carries out a rotational movement, there is a risk in this case that the predetermined breaking point will already be torn off or that the security band will remain deformed in such a way that it can no longer perform its function. On the other hand, the predetermined breaking point must have such dimensions that it is possible to remove the cap without applying excessive force when the cap is first removed.

0003

[Problem to be Solved by the Invention] Therefore, it is possible to extend the guarantee band without damaging the predetermined breaking point when sealing the mouth of the container, so that the guarantee function is not affected when the cap is first removed. It is an object of the invention to provide a screw-on cap of the type mentioned in the opening paragraph, where there is no such screw-on cap. This problem is solved according to the invention with a screw-on cap having the features of claim 1.

0004

The invention is based on the recognition that the force exerted on the security band during initial screw-on is not the same as during initial removal of the cap. The load-relieving opening here serves particularly advantageously so that when the cap is first screwed on, the security band can be stretched in the circumferential direction without the material bridge at the predetermined break point being damaged. On the other hand, the lower material bridge at the predetermined breaking point acts as a force transmission line when screwing the cap, which force transmission line does not actually touch the load relief opening and therefore when removing the cap the extension of the security band is first It works to a much lesser extent than when screwing on a cap. As a result of this, the security band is actually torn and this indicates the removal of the first cap.

[0005] Depending on the application, the load relief openings can have completely different shapes. They may, for example, be in the form of a slit extending over a portion of the security band and opening approximately vertically towards the lower edge of the security band. The load relief aperture may also be formed as a window spaced relative to the lower edge of the security band. In this case, the lower edge of the guarantee band is uninterrupted all around the circumference, which can improve the guarantee function. The window may be formed approximately rectangular, or polygonal,
It may also have a circular or other shape. In certain cases an adjacent arrangement of multiple load relief openings may also be possible.

[0006] The security band has a peripheral portion that is connected on all sides with the lower edge of the cap, and the lower edge of the cap has a complementary portion that is connected via a tearable bridge, thereby providing a gap between the portions. It is particularly preferred that the predetermined breaking point is arranged in one or each of the two boundary areas. In this case, the load relief opening is arranged in particular in a peripheral part that is relatively firmly connected to the cap. If the guarantee band is provided with reinforcing retaining elements on the inside of the complementary part, for example in the form of a ridge, then when removing the cap the bridge between the guarantee band and the cap is first torn, while the lower material bridge in the predetermined breaking position is still retained at that time. Upon further removal of the cap, the lower material bridge is also torn, and in this case there is no significant elongation. The material bridges may run parallel or obliquely to the circumferential direction of the security band. Particularly good results may be obtained with two adjacent load relief openings.

Other individual features and advantages will become apparent from the following description of the exemplary embodiments with reference to the drawings.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a plastic screw-on cap 1 having an internal thread 5 which, together with an external thread 6, is intended for sealing the mouth 2 of a container. Such screw-on caps are used in particular for sealing bottles containing soft drinks, and in this case, as a rule, recycled glass bottles with standard-sized bottle openings are in question. However, this cap can also be used for disposable glass and plastic bottles. In contrast to plastic disposable bottles, it is particularly important in this case that the security band 3 does not remain under the ridge 4 of the neck of the bottle. The reason for this is that the retention of the security band means a considerable expenditure of effort when cleaning the bottles. It will also be easier to recycle plastic bottles. Therefore, the guarantee band has a predetermined breaking point 11 in the circumferential direction,
The predetermined breaking point 11 serves to ensure that the security band remains connected away from the bottle mouth, especially with the screw cap. However, a thin film connection 22 for a tearable connection with the remaining cap is also conceivable.

The security band 3 consists of a peripheral part 9 which is relatively firmly connected to the lower cap edge and a complementary part 10 which is tearable or not firmly connected. On the inside 7 of the security band, in particular on the complementary part 10, a retaining element 8 in the form of a ridge is provided, which retains the ridge 4 of the bottle mouth 2 when the cap is first screwed on.
forms a snap fit with the underside of the cap and provides the necessary pulling force to tear the security band when first removing the cap.

Details of the screw cap are shown in FIGS. 2 to 5.
is shown in detail. The cap bottom 15 is provided with an inner seal 16 that engages the inside of the mouth of the container. However, instead of such an inner seal, the screw-on cap may also be provided with a sealing insert. The bottom wall 17 of the cap is provided with peripheral indentations to improve gripability.

The security band 3 is connected to the lower edge 18 of the cap via a bridge 20 in the region of the complementary part 10. In this complementary part the reinforced ridge 8
A ridge 8 is also provided, the ridge 8 serving as a retaining element. From FIG. 5 it can be seen that the bulge 8 extends approximately over an angle α and in this case transitions at both ends into complementary angle portions 21 which are arranged in a peripheral portion 9 which is firmly connected to the cap edge. I know that there is.

[0012] The predetermined breaking position 11 is formed by two parts 9 and 1.
Exists within the boundary region between 0 and 0. The predetermined breaking point 11 is formed by an upper material bridge 13 and a lower material bridge 14, the lower material bridge 14 being arranged at the lower edge 19 of the security band. As can be seen from FIGS. 3 and 4, the two material bridges 13 and 14 are vertically offset from each other in cross section, and the inner wall of the upper material bridge 13 has approximately the same diameter as the outer wall of the lower material bridge 14. offset as shown. This arrangement facilitates the removal of the sealing cap from the injection mold, in which case no damage to the material bridges 13 and 14 occurs. The security band runs approximately wedge-shaped at the upper edge in a manner known per se in the complementary part 10, the shape likewise serving to improve the release from the mold. In the peripheral part 9 the security band is relatively firmly connected to the lower edge 18 of the cap, which can be seen particularly well from the right side of FIG.

A window-like load relief opening 12 could be formed as well as an intermediate space between the material bridges 13 and 14. It will be clear that if the total height of the security band is approximately 5 mm, the load relief opening has very small dimensions. The optimum arrangement and shape of the load relief opening, in particular its position relative to the predetermined break point 11, depends on various parameters. In this case, the elasticity of the material, the dimensions of the predetermined breaking point, and the thickness of the guarantee band are important factors.

From FIGS. 6 to 9, the operation of the load relief opening at various stages can be seen. Figure 6 shows the guarantee band with no load on it, especially before the cap is screwed in for the first time. Material bridge 13 at predetermined breaking position
and 14 are unstressed and the window-like load relief opening 12 has a rectangular shape without distortion.

[0015] When sealing the mouth of the container, the cap is turned in the screwing direction a. It is clear that in this case the inner ridge 8 of the security band slides over the ridge 4 around the entire circumference of the mouth of the container, which causes a circumferential rotation of the security band. The material bridges 13 and 14 are extended;
These are slightly distorted in this case. However, the extensibility is improved by the load-carrying opening 10, and the load-relieving opening 12 is also strained in this case, as is clear from FIG. After the retaining element 8 has engaged the underside of the bulge 4, the security band again assumes the stress-relieving position shown in FIG.

When the cap is first removed, it is rotated in the opposite direction of arrow b. Retaining element 8
can no longer slide over the ridge 4, so the bridge 20 of the complementary part 10 is torn apart. In this uncapping phase, the predetermined breaking point is stretched considerably, as can be seen from FIG. 8, but the two material bridges 13 and 14 have not yet been torn apart. Starting from the end of the holding element 8, various lines of action c run circumferentially on the one hand and obliquely to the lower cap edge 18 on the other hand, which lines of action in this case extend towards the load relief opening 1.
There is no contact with 2. This therefore results in the tensile force acting entirely within the predetermined breaking point without any significant elongation.

FIG. 9 shows another stage of the decapping process, in which case the upper material bridge 13 has already been torn off. The complementary part 10 then still runs at a steep angle with respect to the lower cap edge 18 or the peripheral part 9 which is firmly connected to the cap edge. The line of force action then runs only through the lower material bridge 14, but at the same time runs obliquely so that the load relief opening is not affected at the end of the tearing process. Further rotation of the screw-on cap in the direction of cap removal direction b also tears the lower material bridge 14, thereby causing the
The situation will be as shown below.

FIG. 10 shows a modification of the invention having a load relief opening in the form of a downwardly opening slit 22. FIG. This effect is similar to that of a window-like loaded state opening, but in this case the action of the force in the circumferential direction is interrupted at the lower edge of the security band.

Finally, FIG. 11 shows another variant with two load relief openings 12 and 12', which are designed as elongated rectangles. Surrounding parts 9 that are tightly connected
Further load relief openings may also be provided, especially at the other end.

[Brief explanation of the drawing]

1 is a view of the mouth of the container and the cap with the security band torn after removal of the cap; FIG.

2 shows a particularly highly enlarged sectional view of the screw cap according to the invention; FIG.

FIG. 3 is a further enlarged cross-sectional view of a predetermined breakage position in the direction of the arrow II.

FIG. 4 is a cross-sectional view of a predetermined fracture position along arrow direction II-II.

FIG. 5 is a view from below of the screw-on cap shown in FIG. 2;

FIG. 6 is a plan view of a predetermined breakaway position with a load relief opening in the snap-fit security band before screwing on the cap or removing the cap; FIG.

FIG. 7 is a view of the predetermined breaking position shown in FIG. 6 when sealing the mouth of the container.

8 is a view of the predetermined break position shown in FIG. 6 at a first stage during initial removal of the cap; FIG.

9 is a view of the predetermined fracture position shown in FIG. 8 at a further stage in which the upper material bridge has been torn; FIG.

FIG. 10 shows a variant with a slit-shaped load relief opening;

FIG. 11 shows another embodiment with two adjacent load relief openings.

[Explanation of symbols]

1 Screw-in cap 2 Container mouth 3. Guarantee band 4 Raised part 7 Inside the warranty band 8 Holding element 9 Surrounding area 10 Complementary part 11 Predetermined breaking position 12 Load removal opening 13 Upper material bridge 14 Lower material bridge 18 Lower edge of cap 19 Lower edge of warranty band 20 Separable bridge 22 Slit

Claims (12)

[Claims] Claim 1: A security band (3) disposed on the lower edge of the cap and formed integrally with the cap.
) a plastic screw-on cap (1) for sealing the mouth (2) of a container having a security band (
3) is for engaging the annular ridge (4) of the mouth of the container when the cap is put on and comprises for this purpose at least one retaining element (8) on the inside (7); , said retaining element (8) is movable on the ridge (4) when first putting on the cap and acts to tear the security band when first removing the cap;
In the plastic screw-on cap (1), wherein the security band has at least one predetermined break point (11) in the circumferential direction, in which the guarantee band is separable over its entire height: a predetermined break point (11); The rupture location (11) is located in at least two material bridges (1
3, 14) and the material bridge (13, 14)
14) connects the opposite ends of the security band, where a lower material bridge (14) is provided on the lower edge of the security band; and besides the predetermined breaking position (11), first the cap is at least one load relief opening (12) is provided in the security band (3) to improve the stretchability of the security band (3) during donning;
A plastic cap for sealing the mouth of a container. 2. The screw-on cap of claim 1, wherein the load relief opening comprises a slit extending over a portion of the security band and opening generally vertically towards the lower edge of the security band. 3. Screw-in device according to claim 1, characterized in that the load relief opening is formed as a window (12), said window (12) being arranged at a distance from the lower edge (19) of the security band. cap. 4. Screw-on cap according to claim 3, characterized in that the window (12) is formed as a substantially rectangular or substantially polygonal shape. [Claim 5] The guarantee band is attached to the lower edge of the cap (18
); and a complementary part (10) in which the security band is connected to the lower edge of the cap via a separable bridge (20); Here, one or each of the two boundary areas between the parts (9, 10) is located at a predetermined rupture position (11
5. The screw-in cap according to claim 1, further comprising: ). 6. Screw-on cap according to claim 5, characterized in that the security band is provided with a reinforced retaining element (8) on the inside (7) of the complementary part (10). [Claim 7] The reinforced retention element is a ridge,
7. The threaded cap of claim 6, wherein the ridge extends over a majority of the complementary portion. [Claim 8] The load relief opening (12) is connected to the peripheral portion (9).
) Claims 5 to 7 are characterized in that
One of the screw-on caps. 9. Threaded cap according to claim 8, characterized in that each of the ends of the peripheral part (9) is provided with a load relief opening. 10. Threaded cap according to claim 1, characterized in that, in addition to the predetermined breaking point (11), two load relief openings are provided. 11. The method according to claim 1, wherein the two material bridges (13, 14) at the predetermined breaking point (11) are arranged vertically offset from each other in the cross section. Screw-on cap. [Claim 12] Two material bridges (13, 14)
12. Screw-on cap according to claim 1, characterized in that at least one of the is oriented obliquely to the circumferential direction of the security band (3).