US3415405A

US3415405A - Cap

Info

Publication number: US3415405A
Application number: US590090A
Authority: US
Inventors: Rausing Anders Ruben; Ignell Rolf Lennart
Original assignee: Sobrefina SA
Current assignee: Sobrefina SA
Priority date: 1965-11-09
Filing date: 1966-10-27
Publication date: 1968-12-10
Anticipated expiration: 1985-12-10
Also published as: FI49579C; DK113973B; BR6684426D0; NL6615694A; CH466065A; GB1091837A; FI49579B; BE689410A; CY510A; NO118830B; NL153494B; DE1270483B

Description

Dec. 10, 1968 A. R. RAusMG ETAL 3,415,405

CAP

Filed Oct. 27, 1966 F 1'9 .1 u. 48 2 M 1.1.

31. l 11 3b 43 P S 12 I 9 a \AS United States Patent 0 14,423/ 65 5 Claims. (Cl. 215-48) ABSTRACT OF THE DISCLOSURE A bottle having an inwardly turned lip at its opening is provided with a tear-oif cap having an outer tubular plug portion designed to sealingly engage said lip and remain in the bottle opening, an inner tubular plug portion having a dome-shaped closed end attached to said outer tubular plug portion at a tear-off connection, and a slot extending upwardly between said outer and inner tubular portions to said tear-off connection which is sealingly closed when the cap is inserted into said bottle opening by inward deflection of said outer tubular portion and/or outward deflection of said inner tubular portion, the latter deflection being promoted by pressure within the bottle and/ or by a disc inserted into said inner tubular portion.

The present invention refers to a cap in combination with a container having an inner over-pressure or sub-atmospheric pressure and which container is provided with an inwardly turned lip in the region of its opening.

A cap of this kind has previously been suggested in the Belgian Patent No. 666,263 granted July 30, 1965, and which corresponds to United States Patent No. 3,251,499. The container shown in this patent has, as is also the case according to the present invention, an inwardly turned lip in the region of its opening. Further, the cap has a lid portion and a tubular plug portion, which on its end turned to the interior of the container is provided with a flange in a way corresponding to a preferred embodiment of the present invention. The tightening of the container is intended to be obtained by the pressure of engagement between a sharp edge of the lip and said flange.

So as to increase the tightness of the closing device still further it has been proposed in Belgian Patent No. 678,159 granted Apr. 31, 1966, and which corresponds to United States Patent No. 3,317,070 to associate with the tubular portion a sealing ring having a section in the form of a triangle, which with sealing action is arranged to engage a surface of the inturned lip. Due to this provision one has been able to eliminate leakage, i.e. to prevent the gas from escaping between the cap and the inner surface of the container neck.

Preferably the cap is intended to be made of polythene or a similar kind of plastic material. As most gases have a certain ability of diffusing through polythene, as for example carbon dioxide, one always has to assume a certain loss of gas however effective the tightening means are made. By tests one has discovered that a rather great portion of the diffusing gas passes through two small regions of the cap, which have a reduced thickness. These regions are defined on one hand by the said sealing ring, probably especially the apex portion of the sealing ring, and on the other hand by the region of an opening indication.

There is therefore a first object of the present invention to reduce the said diffusion at the same time as the virtues of the previously proposed constructions are maintained. Another object is to produce a cap which is at least in some measure reclosable. These demands may be satisfied by a cap that includes the following combination:

"ice

(a) a first tubular plug portion inserted into the container opening to a position of fixation;

(b) a second tubular plug portion on the inner side of the said first tubular portion, said second portion in its upper part being connected with said first portion and in its lower part being provided with a lid portion closing the container opening;

(c) a narrow slot between the said first and second tubular portions,

(d) means for forcing the said first and second tubular portions into an effective mutual pressure contact eliminating the breadth of the slot within an annular region.

Further features and advantages of the invention will be apparent from the following specification with reference to the accompanying drawings, in which FIG. 1 shows a section throgh a cap according to a first preferred embodiment of the invention;

FIG. 2 shows the same cap inserted into a container opening; and

FIG. 3 in a somewhat larger scale shows a portion of a cap according to a second preferred embodiment of the invention.

In FIGS. 1 and 2, 2 generally designates a cap having an axis A. The cap consists of two separable parts, namely an outer tubular plug portion 5 intended to be fixed in the mouth of the container opening, see FIG. 2, and a part capable of being torn ofli and including the

portions

3a, 3b, 3c and 4. The connection between the two separable parts is designated 12. To facilitate the tearing operation and to ensure that the tearing is carried out at the desired region a tearing indication is provided in the form of a notch 11 in the connection 12. The notch 11 runs around i the periphery of the connection 12.

The container which the cap is intended to close preferably consists of a plastic bottle with a filling material which causes an inner over-pressure such as beer or other carbonated beverages. In FIG. 2 a portion of the container has been designated by 1. The cap is intended, in the preferred embodiment of the invention, to cooperate with the upper part of the container, i.e. the part nearest the opening which is designed in a special way. This is therefore included together with the cap in the closing device. FIG. 2 shows, how the upper part of the container, hereinafter called the bottle, extends inwardly towards the centre of the bottle opening and downwardly towards the interior of the bottle, so that a lip 6 is formed. To be able to take up existing stresses the lip 6 is designed] thicker than the rest of the bottle wall. 40 designates a reinforcement of the sealing part of the lip. To prevent the cap from being damaged at the capping operation the part of the lip 6 against which sliding between the cap and the lip will preferably take place is furthermore rounded. The rounding is designated 41.

The sealing of the closing device occurs both between a point 7 on the lip 6 and a surface 23 of a flange 8 associated with the outer tubular part 5, and above all between a sealing ring 30 of triangular cross-section on. the said tubular part 5 and a surface 20 of the inturned lip 6.

Of the remaining details shown in the figures a slot between the tubular part 5 which is intended to be fixed in the bottle opening and the inner tubular plug part 3b on the tear-off part of the cap has been designated 43 and a depression at the end of the slot 43 in the region of the pulling handle 4 has been designated 34. The function of the depression 34 and the function of a notch (not shown in the figures) provided in the portion 30 and extending from the handle 4 towards the depression 34 is to create a concentration of the pulling forces to a limited region of the connection 12 at the initiation of the opening of the package.

In order that the stress in the connection 12 may not be too great at the capping operation there has further been formed a ledge portion 44 in the notch 11 and to reduce the necessary capping pressure a recess 45 in the material has been provided. designates an annular flange intended, together with the flange 8 to retain the tubular part 5 in the bottle mouth when the tear-off part of the cap is removed.

As has been mentioned in the introduction of the specification the diffusion of gas through the region 12 will be considerable if nothing is done to prevent it. According to the invention the diffusion is prevented by blocking the gas flow through the slot 43. This blocking is done in connection with the capping operation by making the diameter of the tubular portion 312 such that the outer tubular portion 5 is pressed inwards into contact with the inner tubular portion 311. Thanks to the fact that the lip 6 is rather stiff, the deformation of the lip will be unimportant. Instead the main deformation will take place in the said outer tubular portion 5. The deformation includes on one hand a general radially directed compression and on the other hand a folding-in of the lower part of the tubular portion 5. The last phase of the capping operation takes place under the counter-action of pressure forces between the annular portion 3c of the lid and the top of the bottle in the region 13. When the cap has been inserted so far in the bottle neck that the lower edge 7 of the lip 6 has snapped above the flange 8, the remaining deformation is so great that the space in the notch 43 at least in the lower part thereof has been eliminated, and the tubular portion 3b, which is included in the tear-off part of the cap, is caused tightly to engage with its lower part the inner wall 47 of the tubular part 5 fixed in the bottle neck. By this compression the necessary initial pressure between the sealing ring 30 and the surface is also obtained.

As earlier mentioned, the part which is intended to be torn off in connection with the opening of the bottle consists of the

portions

3a, 3b, 3c and 4, the portions 312-0 forming a lid which is united with a pulling handle 4. The lid consists of the central substantially dome-shaped portion 3a and the annular portion and the tubular transition portion 3b between the portions 3a and 3c. The central portion 3a is, similarly as the cap as a whole, made from an elastic but yet relatively stiff material, such as HD- or MD-polyethylene. The portion 3a and the tubular portion 3b further have a diameter which is of such size that when the tubular part 5 has been shrunk in connection with the capping, the ridge 46 will well engage the inner wall 47 of the part 5. Furthermore, the portion 30 is slightly thicker in its central part so as to be substantially lens shape. The annular portion 30 is connected to the pulling handle 4. The transition between the annular portion 30 and the tubular one 3b is designated 48.

If the interior of the bottle is subjected to an overpressure i.e. a pressure greater than the surrounding atmosphere, the cap 2 will be subjected to a certain resilient deformation, which has been indicated in FIG. 2 by dash lines. Under the influence of the axially directed components of the pressure the dome-shaped central portion 3a of the cap will tend to be flattened. By this flattening action the diameter of the central portion will expand, whereby the engagement pressure between the

surfaces

46 and 47 increases. As the cap preferably is so shaped that the engagement region between the

surfaces

46 and 47 and the apex of the triangle 30 are in the same plane, designated B in FIG. 2 the increased engagement pressure will be transferred directly via the material in the tubular part 5 to the triangular sealing ring 30. Hereby an upwardly directed, axial pressure action is transformed into an outwardly directed, radial one which highly increases the sealing action at the circumferential edge of the sealing ring 30 and thanks to the compression of the sealing ring, reduces the diffusion of gas through said ring.

The lid of the cap, i.e. the part which has been defined by the portions 3a-c and 4, may according to the preferred embodiment be reused for reclosing the bottle at least when not too great demands are made on the durability and tightness of the closure. However, it could be established that the reclosing cap according to the present embodiment of the invention, such as it appears from the drawings, holds to an over-pressure as high as about 0.6 kp./cm. The reclosability may, however, be further improved, if the tubular portion 312 of the lid is considerably extended so as to pass beyond the lower edge of the part 5. Thereby an appreciable friction hold is obtained between the

parts

3b and 5 at the lower edge of the part 5.

In those cases where the bottle presents an inner subatmospheric pressure in relation to the surroundings, it is also possible according to the invention to modify the cap so that the central dome-shaped portion thereof will instead turn its convex surface outwards, whereby the pressure difference in this case also may be utilized for the sealing.

The embodiment according to FIG. 3 differs from the cap according to FIGS. 1 and 2 substantially therein that the closure means also includes a disc 51, the diameter of which is somewhat greater than the inner diameter of the lower portion 50 of the tubular portion 312 in the free state of said portion, and which disc 51 is pressed into the center of the cap. The disc 51 is made of a stiff material, e. g. metal. Preferably, however, the disc consists of a piece that has been punched out of the container opening in connection with the manufacture of the container. Hereby no extra costs are involved for producing the discs. As should be apparent from the figure the disc acts upon the inner tubular portion 3b so as on one hand to make the blocking of the passage 43 more effective and on the other hand to increase the pressure between the sealing ring and the bottle lip. In FIG. 3 the original shape of the lid portion 3a has been shown by dashed lines. In order to make the radical expansion possible without strongly stretching the lid material, the lid has, referring to the dashed lines, been made somewhat dome-shaped, however, not necessarily so pronouncedly cup-shaped as the lid portion 3a according to the previous embodiment.

We claim:

1. A tear-off cap type closure member for use with a container provided with a pour opening having an inturned lip, said closure member being made from an elastic material and comprising an outer tubular plug portion which sealingly engages said lip and remains connected with said container, a removable inner tubular plug portion located within said outer plug portion and having a closed inner end and which is joined to said outer plug portion by a relatively narrow annular tear-off portion therebetween located at the outer ends of said plug portions, the tubular parts of said plug portions being initially spaced radially from one another to establish a circular slot therebetween and the inner end of said slot being closed off by contact established between said inner and outer plug portions as said closure member is inserted into said pour opening to effect engagement between said outer plug portion and said inturned lip.

2. A closure member for a container as defined in claim 1 wherein said outer plug portion includes an integral sealing ring terminating in a circular edge which engages said inturned lip, said sealing ring being located intermediate two spaced flanges which engage said inturned lip and serve to retain said outer plug portion connected to said inturned lip when said inner plug portion is torn off.

3. A closure member for a container as defined in claim 1 wherein said closed end of said inner plug portion is dome-shaped, the convex side of which faces in the direction presenting the higher gas pressure, the axially directed force applied to said dome-shaped end as a result of the pressure differential existing on opposite sides thereof being converted by distortion of said dome-shaped end into an outwardly directed radial pressure thereby to effect an increase in the sealing pressure between said outer plug portion and said inturned lip.

4. A closure member for a container as defined in claim 3 wherein said outer plug portion includes an integral sealing ring terminating in a circular edge which engages said inturned lip, and wherein said circular sealing edge is located in the plane of pressure which is directed radially outward by said dilferential pressure induced distortion of said dome-shaped inner end of said inner plug portion, said circular sealing edge being located intermediate two spaced flanges which engage said inturned \lip and serve to retain said outer plug portion connected to said lip when said inner plug portion is torn off.

5. A closure member for a container as defined in claim 1 and which further includes a relatively rigid disc pressed into said inner tubular plug portion and which exerts a References Cited UNITED STATES PATENTS 3/1946 Moore 215-5l X 10/1966 Amesbury et al 220--24.5

10 DONALD F. NORTON, Primary Examiner.

U.S. Cl. X.R. 21552