Easily operable closure cap

Abstract

Closure cap primarily for bottles or containers for beer or carbonated drinks comprising a cover member and a crimping ring, a seal being cast on the inside and covering the junction between said two members. The crimping ring is provided on its upper part with several incisions which permit the crimping ring to be ruptured segment-wise. The seal, which terminates in a thin lip in its lower part, adheres only to the cover member, and forms a valve flap.

Description

The present invention concerns a closure device more particularly intended for closing bottles or containers for containing a pressurized liquid such as beer or carbonated drinks.

A closure of this kind requires absolute fluid-tightness, even when subjected to high pressure in the container. Nonetheless, it must be possible easily to open the closure, preferably without resorting to a tool. Ideally, it should be possible to open the container gradually, in order to prevent explosive emission of the contents of the container.

It is an object of this invention to produce a cap which meets with all these requirements while providing for easy opening of the container which makes it possible gradually to reduce the pressure inside the container, without any liquid or foam spurting therefrom.

In order to achieve this aim, use is made of a combination of several features, each of which is an improvement in itself but the totality of which gives quite an exceptional result. These features concern the metal cap itself on the one hand, and the seal on the other hand.

The metal cap, according to the invention, is formed of a disc-shaped cover member, the edge portion of which is possibly adapted to the edge of the mouth opening of the container, said cover member being held on the container by means of an annular member which can be crimped onto the collar of the mouth of the container. Once set in position, this member has a substantially C-shaped cross-section, that is to say, it comprises a vertical portion which is parallel to the collar on the container neck, a bent-over upper portion which holds the cover member in place, and a bent-over lower portion which is crimped under the collar on the neck of the container. The above-mentioned bent-over upper portion is extended at one position by a web portion which terminates in a gripping ring which is laid on the cover member. A line of low resistance, also referred to as a tear line, extends from one of the junction points of the web portion with the bent-over edge portion, and terminates at the free edge of the lower crimpable portion, thus permitting the annular member to be torn radially. The invention comprises adding one or more radial low-resistance lines which are distributed over the semi-circular segment of the member, which will be the first to be disengaged, said lines being essentially limited to the bent-over upper portion of said circular member.

Preferably, at least one of said partial lines is at an angle approaching a right angle, to the axis of symmetry of the cap.

In this way it becomes possible to remove the annular member in small segments, until the annular member has been disengaged over an angle of 180.degree.. A last partial tear line at about this position, for example on the axis of symmetry of the cap, permits total and final disengagement of the annular member.

In order to arrive at such disengagement of the annular member, with a gradual reduction in the internal pressure in the container, without any liquid or foam being sprayed from the container, it is also necessary in accordance with the invention to provide a second feature; the disc-shaped cover member is covered on its face which is directed inwardly, with a varnish which promotes adhesion of a cast seal, while the annular member is covered on its inward face with a varnish which prevents such seal adhering thereto.

The seal so extends that it covers, on the one hand, the free edge of the disc-shaped cover member, and also a part of the vertical wall of the annular member, the thickness of the seal being reduced towards its free end.

The invention will be described hereinafter with reference to a non-limitative embodiment illustrated in the accompanying drawings, in which

FIG. 1 is a cross-sectional view taken along a diagonal of the metal disc-shaped cover member;

FIG. 2 is a top plan view of the blank for the annular member;

FIG. 3 is a top plan view of the annular member ready to be joined to the cover member;

FIG. 4 is a cross-sectional view of the annular member taken along the line IV--IV of FIG. 3;

FIG. 5 is a cross-sectional view taken along the same line, of the two components of the cap which are joined together and provided with a seal; and

FIG. 6 is a cross-sectional view taken along the same line of the cap crimped onto a container.

The disc-shaped cover member 1 (FIG. 1) can be made, for example, of electrolytic tin plate, covered with a varnish which permits firm adhesion of the seal to the cover member. The cover member has a circular recess 2 of curvilinear shape which is disposed in the peripheral marginal portion of the cover member and which substantially corresponds to the edge of the mouth of the container on which it is to be fitted. The recess 2 is connected to the flat central portion 3 by a circular groove 4.

The second metal member 5 is shown first of all in FIG. 2 in the condition in which it is discharged as a blank from the cutting press. It has a central aperture 6 which is surrounded by an annular segment 7 separated from the crimping edge portion 9 by a slot 8 over an angular distance of approximately 270.degree..

The crimping edge portion 9 is provided with a plurality of incisions which reduce the thickness of the metal at the positions of such incisions, by a little more than half, in order to facilitate tearing of the metal at the desired moment and at precisely determined positions. This member can be made of a metal which lends itself readily to making this member, such as aluminum. The internal surface of the member 5 will be covered with a varnish to which the seal cannot adhere.

The first incision 10 extends from one end of the slot 8 up to the external edge of the crimping edge portion 9. From the other end of the slot 8, an incision 11 is directed firstly so as to converge to a greater or lesser degree with the incision 10, but without going as far as the free edge of the member 5. The incision 11 terminates in a substantially semi-circular reverse loop 12.

Two other incisions are directed perpendicularly to the slot 8 towards the outside edge of the member 5, the first incision 13 forming a right angle to the axis of symmetry X--X of the slot 8, while the second incision 14 is disposed on said axis. The length of these incisions depends on the height of the collar on the neck onto which the cap will be crimped. That is to say, the length of the incisions will generally be less than half the width of the crimping edge portion 9. The position selected for the line 13, in the embodiment illustrated, is not limiting, since this angle can vary within certain limits. However, on the one hand the incision should not be too close to the loop 12, for if these two lines are too close together, the intermediate part could suffer tearing when opening the cap. On the other hand, if the distance between the two incisions 12 and 13, for causing partial rupturing of the ring, is excessive, the desired effect, which will be referred to hereinafter, would be less effectively achieved.

The precise manner of determining the width of the two incisions 13 and 14 will be understood from considering FIG. 3 which shows the second metal member 5 ready to be joined to the cover member 1.

The edges of the annular segment 7 have been bent over to form a gripping ring 15 which is connected by a web portion 16 to the crimping edge portion 9. The web portion 16 comprises two stiffening ribs 17 which are positioned substantially at the level of the beginning of the incisions 10 and 11 and which make it easier to begin the tearing action of the cap. The bent-over part 9' (FIG. 4) of the crimping portion or ring 9 has a diameter equal to that of the mouth of the container to be capped. Forming the ring 15 has enlarged the slot 8 and increased the size of the central aperture 6'.

In FIG. 5 the two metal members 1 and 5 have been joined together and a seal 18 has been run into the peripheral recess, and extends over a portion 18' of the part 9' of the crimping edge portion 9, thus covering the junction between the two metal members 1 and 5. For the seal, it is essential to use a flexible material, so as to retain a high degree of elasticity at the lip portion 18'. After the cap crimping operation (FIG. 6), the seal 18 is spread out so that the cap sealingly closes the container. The cap can be opened in the following manner: the consumer raises the ring 15 to which he applies a pulling force to cause the member 5 to tear along the incision 10. The incision 11 is also torn, but due to the configuration thereof, the radial pulling movement is slightly deflected. The ring 15 remains attached to the collar 19 and a first part of the lip portion 18', which is between the incision lines 10 and 11, is freed. Becuase of the flexibility of the material used, the lip portion 18' forms a masking flap which permits the gas, forming an increased pressure within the container, to escape, particularly as the crimping edge portion or ring 9 will be rapidly disengaged up to the following incision 13. The position of the incision 13, substantially perpendicularly to the axis of symmetry X--X of the cap, makes it necessary for the consumer to stop a short while, as the movement of his hand must change in direction; the hand moves away and continues to go away until disengagement of the ring 9 reaches the incision 14.

Once the incision 14 has been torn, the crimping edge portion or ring 9 can be completely released, by pulling tangentially thereon. The member 5 remains in the consumer's hand, and the cover member 1 which is retained by the lip portion 18' of the seal 18 is removed. All the cap removal movement occurs therefore in one plane, as the vertical part 9' rolls away from the collar 19 by segments, from one incision to another.

It will now be understood why it is desirable for the segments of the lip portion 18' to be gradually disengaged; this is to achieve a certain balance between the internal pressure in the container, and the atmosphere, before rupturing the incision 14, permits the second half of the crimping ring 9 to be totally and instantaneously disengaged. Thus, in the embodiment illustrated, the three lip segments are respectively disposed at an angle at the center of 40.degree., 70.degree. and 90.degree.. This also explains that the selection as regards positioning of the incision 14 is not limited strictly to positioning it in the axis of symmetry of the cap; it is only necessary for it to be disposed at least at an angle of 180.degree. to the total and final rupture line 10.

Claims

We claim:

1. A metal cap assembly for closure of containers having a collar about the open mouth of the container, said metal cap assembly comprising a two-part assembly in which one part comprises a disc-shaped cover member dimensioned to overlie at least a portion of the collar, the second part comprising an annular member having a central body portion and an integral peripheral portion adapted to be crimped onto the collar at the mouth of the container, said central body portion having a central aperture and a slot spaced outwardly of and extending about the central aperture to provide a gripping portion between said aperture and slot and a web portion connecting the gripping portion with the peripheral portion, a first line of weakness extending in a radial direction from one end of the slot to the edge of the annular member to permit the member to be drawn along the line of weakness in a radial direction, and at least one second line of weakness extending from the slot at an angle which is no greater than 90.degree. to the axis of symmetry of the cap and confined to the central body portion of the annular member, a coating on the surface of the one part facing the second part in the assembled relation to promote adhesion of a sealing material between the parts, a coating on the surface of the second part facing the first part in the assembled relation, which minimizes adhesion of said sealing material, and a sealing material at the junction between the disc-shaped cover member of the one part and the peripheral portion of the annular member of the second part to establish a sealing relationship therebetween when in the assembled relation.

2. A cap assembly as claimed in claim 1 in which the slot extends about the central aperture over an angular distance of approximately 270.degree..

3. A metal cap assembly for closure of containers having a collar about the open mouth of the container, said metal cap assembly comprising a two-part assembly in which one part comprises a disc-shaped cover member dimensioned to overlie at least a portion of the collar, the second part comprising an annular member having a central body portion and an integral peripheral portion adapted to be crimped onto the collar at the mouth of the container, said central body portion having a central aperture and a slot spaced outwardly of and extending about the central aperture to provide a gripping portion between said aperture and slot and a web portion connecting the gripping portion with the peripheral portion, a first line of weakness extending in a radial direction from one end of the slot to the edge of the annular member to permit the member to be drawn along the line of weakness in a radial direction, and a second line of weakness extending from the other end of the slot in the direction to converge towards the first line of weakness but terminating short of the edge of the annular member.

4. A cap assembly as claimed in claim 3 in which the second line of weakness terminates in a reverse loop.

5. A cap assembly as claimed in claim 4 in which the reverse loop is substantially semi-circular.

6. A cap assembly as claimed in claim 3 which includes a third line of weakness extending from the slot into the body portion at an angle of about 90.degree. to the axis of symmetry of the slot.

7. A cap assembly as claimed in claim 6 in which the third line of weakness extends substantially perpendicularly from the slot.

8. A cap assembly as claimed in claim 6 in which the third line of weakness extends for a distance less than one-half the distance from the slot to the edge of the annular member.

9. A cap assembly as claimed in claim 6 which includes a fourth line of weakness extending from the slot in alignment with the axis of the slot.

10. A cap assembly as claimed in claim 9 in which the fourth line of weakness extends for a distance less than one-half the distance from the slot to the edge of the annular member.

11. A cap assembly as claimed in claim 3 in which the central aperture is circular and the gripping portion defined by the central aperture and the slot is in the form of an annular segment.

12. A cap assembly as claimed in claim 11 in which a portion of the annular segment, opposite the web, is bent over to form a gripping ring.

13. A cap assembly as claimed in claim 3 which includes stiffening ribs in the web portion between the first and second lines of weakness in crosswise alignment with the beginning of the first and second lines of weakness.