HUP0300991A2 - Plastic closure cap, with sealing skirt - Google Patents

Abstract

The subject of the invention is a plastic closure cap for the neck of a container, which has an end wall (4) and an outer rim (5) with a device for fastening the closure cap to the neck of the container (9) on its inner side, protruding from the end wall (4) and protruding in the same direction as the outer rim (5), the inner side of the neck the inner collar (8) of the seal that closes the neck has an inner collar (8) in close cooperation with its surface. At least on the outer side of the inner collar (8), it expands like a truncated cone from the base of the inner collar (8) towards the free edge of the inner collar (8), and the outer diameter of the inner collar (8) is the free in the vicinity of its edge is larger than the nominal inner diameter (Di9) of the neck (9) of the tank. The taper of the inner collar (8) is such that it does not prevent the axial separation of the inner collar (8) from the mold. According to the invention, the slope of the truncated cone-like outer surface of the inner collar (8) is between approximately 1° and 5°. HE

Description

76.716/BT

PCT/FR00/02871

PUBLICATION

COPY μ.

Plastic cap with sealing inner collar

BfiRTCÁP, Longvic, FRÍ

The present invention relates to a plastic closure for a container neck, which closure has an end wall and an outer rim projecting from the end wall, on the inner side of which is provided with a means for securing the closure to the container neck, and an inner sealing collar projecting in the same direction as the outer rim and sealing the neck by cooperating with the inner surface of the neck.

Such closures generally have a cylindrical or more complex shaped sealing collar (e.g. a first, expanding frustoconical section followed by a second, narrowing frustoconical section, which also has a cylindrical section and a subsequent outer rim that can be bent towards the end wall of the closure, or cylindrical collars with an outer rim or shoulder at the free edge, with an olive-like profile or the like). The molding of such complex shaped collars is relatively complicated.

The complex shape of the sealing collars serves to improve the seal, especially for pressurized liquids such as carbonated liquids. The seal is preferably formed near the free edge of the collar, which is formed slightly inward of the free edge of the neck, towards the interior of the container. In screw caps with such collars, it is also desirable to reduce the torque required to unscrew the cap.

76.716/ΒΤΊ *2003.04.09.

-2However, the known sealing collars only imperfectly meet all the requirements of easy casting, good sealing and reduced unscrewing torque.

The present invention relates to a closure cap whose collar is designed to optimally meet the above requirements.

The plastic closure cap according to the invention, which is used to close the neck of a container, has an end wall and an outer rim protruding from the end wall, on the inner side of which is provided with a means for fastening the closure cap to the neck of the container, and an inner sealing collar protruding in the same direction as the outer rim, which cooperates tightly with the inner surface of the neck to close the neck. The inner collar widens in a frusto-conical manner at least on the outer side from the base of the collar towards the free edge of the inner collar, and the outer diameter of the inner collar in the vicinity of its free edge is greater than the nominal inner diameter of the neck of the container. The taper of the inner collar is such that it does not hinder the axial molding process of the collar.

This design of the sealing collar allows the sealing effect exerted by the collar relative to the inner surface of the container neck to be concentrated essentially near the free edge of the collar. This ensures a good seal, reduces the unscrewing pressure and optimally positions the collar-neck contact point, so that any gas pressure in the container strengthens the contact between the collar and the container neck. Nevertheless, the taper of the collar is small enough to allow the collar to be produced by simple axial molding and removal from the mold.

Preferably, the slope of the frustoconical outer surface of the collar is between about 1° and 5°, preferably about 2°.

To facilitate the cooperation of the collar and the neck of the container, preferably the free edge of the sealing inner collar has an external cutout, the internal diameter of which is smaller than the nominal internal diameter of the neck of the container.

76.716/BT2“2003.04.09.

-3The inner surface of the collar may be cylindrical or may be truncated conically flared. In this case, it is advantageous if the taper of the inner surface of the collar is equal to or smaller than the taper of the outer surface.

Depending on the design of the container neck rim, the length of the sealing inner collar is between about 3 and 6 mm, preferably about 4 mm.

The closure according to the invention can be made of any type of plastic material commonly used for the production of closures with sealing collars, for example the closure can be molded from polyethylene, polypropylene or similar plastic material.

With reference to the attached schematic drawings, the closure cap according to the invention will be explained in more detail below with the aid of the illustrated exemplary embodiments, where the

Figure 1 is an axial section of the closure cap according to the invention, and

Figure 2 shows detail II of Figure 1 on a larger scale, showing the profile of the sealing collar.

The closure cap 1 shown in Figure 1 has a cap body 2 and an authenticity marking strip 3 molded in one piece with the cap body 2. Since the authenticity marking strip 3 is not the subject of the present invention, it is not necessary to describe it in more detail.

The cap body 2 has essentially an end wall 4 and an outer rim 5 which projects from the end wall 4 along its outer edge. The outer rim 5 has a thread 6 on the inside and a knurling 7 on the outside. The end wall 4 also has an inner collar 8 which projects from the end wall 4 in the same direction as the outer rim 5, concentrically with the latter. The sealing inner collar 8 serves to ensure that when the closure cap 1 is screwed onto the bottle neck 9 schematically illustrated under the closure cap 1 in Figure 1, it cooperates in a sealing manner with the inner surface of the bottle neck 9. The inner surface has a nominal inner diameter Di9.

76.716/BT*3*2003.04.09.

-4As can be seen better in Figure 2, the inner collar 8 of the seal widens in a frustoconical shape, both externally and internally, starting from its base (i.e. the end wall 4) towards its free edge. The outer surface of the inner collar 8 has a slope corresponding to the angle, while its inner surface has a slope β. In the vicinity of the free edge of the inner collar 8, the largest outer diameter De8 max is larger than the inner diameter Di9 of the bottle neck 9. The free edge of the inner collar 8 has an outer cutout 10, the inner diameter of which Di10 is smaller than the nominal inner diameter Di9 of the bottle neck 9.

For example, with the closure shown, a bottle neck 9 with a nominal inner diameter Di9 of 25 mm is closed, the inner collar 8 with a length L8 of 4 mm has a minimum outer diameter De8 min of about 25.48 mm and a maximum outer diameter De8 max of about 25.72 mm, while the radial thickness of the inner collar 8 is about 0.8 mm. The inner diameter DilO of the cut 10 is about 24.50 mm, while the angles a and β are about 2°.

It is understood that the embodiment described and illustrated above is only a non-limiting example and the invention can be implemented in many other modified versions.

In this way, the values of the angles a and β, which define the slope of the outer and inner surfaces of the inner collar 8, may be different from each other, instead of being equal. The angle β may be smaller than the angle a, even having a value of 0§, for example depending on the material of the cap, the length of the inner collar 8, the thickness of the inner collar 8, the diameter of the bottle neck, etc.

76.716/BT*4*2003.04.09.

Claims (6)

-5Patent claims 1. A plastic closure cap for a container neck, comprising an end wall (4) and an outer rim (5) projecting from the end wall (4) and provided with a means for securing the closure cap to the container neck (9) on its inner side, and an inner sealing collar (8) projecting in the same direction as the outer rim (5) and sealing the neck in a clamping manner with the inner surface of the neck, said inner collar (8) expanding in a frustoconical manner at least on its outer side from the base of the inner collar (8) towards the free edge of the inner collar (8), and the outer diameter of the inner collar (8) adjacent to its free edge is greater than the nominal inner diameter (Di9) of the container neck (9), and the taper of the inner collar (8) is such that it does not prevent the axial separation of the inner collar (8) from the mold, characterized in that the slope of the frustoconical outer surface of the inner collar (8) is between approximately 1° and 5° between. 2. A closure according to claim 1, characterized in that the slope of the frustoconical outer surface of the inner collar (8) is approximately 2°. 3. A closure according to claim 1 or 2, characterized in that the free edge of the inner sealing collar (8) has an outer cutout (10) with an inner diameter (DilO) smaller than the nominal inner diameter (Di9) of the container neck (9). 4. The closure cap according to any one of claims 1-3, characterized in that the inside of the sealing inner collar (8) also expands in a frustoconical manner, and furthermore the conicity of its inner surface is the same as or smaller than the conicity of the outer surface. 5. A closure according to any one of claims 1-4, characterized in that the length (L8) of the sealing inner collar (8) is between about 2 and 5 mm, preferably about 4 mm. 6. A closure cap according to any one of claims 1-5, characterized in that it is molded from polyethylene, polypropylene or a similar plastic. r. Tamás Bokor iá·.-,.. ο í i rt x rx nx The authorized person is the SzabaimHÚ-Ug; ±/õi Office H-1062 Budapest, Andrássy út 113. Winter! 461 1000 Fax: 461-1099 76.716/BT*5*2003.04.09.