GB1571897A

GB1571897A - Cap for a bottle

Info

Publication number: GB1571897A
Application number: GB5206876A
Authority: GB
Original assignee: Daiwa Can Co Ltd
Current assignee: Daiwa Can Co Ltd
Priority date: 1975-12-16
Filing date: 1976-12-14
Publication date: 1980-07-23
Also published as: FR2335414B1; AU2059476A; AU504311B2; FR2335414A1; DE2657092A1

Description

(54) A CAP FOR A BOTTLE (71) We, DAIWA CAN COMPANY, LIMITED, a corporation organised under the laws of Japan of No. 1-10, 2-chome, Nihombashi, Chuo-ku, Tokyo, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a cap for a bottle which, in order to remove the cap from the bottle a part of the cap fixed to the mouth of the bottle is torn so that the inside of the bottle becomes open to the atmosphere and negative pressure inside the bottle is thereby released, whereafter the whole cap is removed from the bottle.

One example of a cap and bottle of this kind is disclosed in a Japanese patent gazette, Laid-Open Specification No.

38275/72 (Serial No. 1402177), now described with reference to Figure 1 of the accompanying drawings. The cap consists of a top wall 105 and a skirt portion 106 depending therefrom. In said skirt portion, there are provided four separating lines 101, 102, 103 and 104 ascending substantially verically from its lowermost edge 108.

The term separating line as used herein includes a score line which is weakened so as to be easily torn, and a cut line which has already been cut. A seal member (not shown) is provided annularly on the inner side of the circumference of the top wall.

Of the four separating lines, two lines 103 and 104 are arranged diametrically opposite one another, while the remaining two lines 101 and 102 are arranged with a relatively small distance therebetween, approximately centrally between said lines 103 and 104. In order to open the inside of the bottle to the atmosphere when a part of the skirt between the line 101 and the line 102 is lifted, there is provided a projected or recessed strip 107 or without two lines in the peripheral part of the top wall which extends from the skirt side to the centre side of the cap.

After this cap is caused to cover the mouth of the bottle, the lower end of said skirt portion is bent inwardly toward the centre of the cap so that it is engaged with the underside of the rim of the mouth of the bottle and fixed thereto. When it is desired to remove this cap from the bottle, the narrow bent part of the skirt portion between two lines 101 and 102 is first stretched out so as to release it from engagement with said rim. Then the skirt portion between the lines 101 and 102 is lifted up by grasping said stretched part whereby the negative pressure inside the bottle can be released by virtue of said projected or recessed strip 107 or without its deformation. Thus the negative pressure by which the cap is retained on the bottle is removed and thereafter the skirt portion grasped as above is further lifted up.As a result, the engagement of the skirt portion with the rim of the bottle between the lines 103 and 104 is released while the line 103 and line 104 of the diameter direction are separated, respectively, whereby the cap and bottle are eventually disengaged over half the circumference of the mouth of the bottle.

Thereafter, the remaining half engagement between the periphery of the bottle and that of the cap can be released by pushing the cap outwardly from the diameter line of the bottle, so that the cap is completely detached from the mouth of the bottle.

However, this type of cap has the disadvantage that it has a projected or recessed strip 107 extending from the skirt side 106 to the centre side which results in an incomplete seal of the bottle.

It is therefore an object of the present invention to overcome the above dis advantage that it has a projected or recessed strip 107 extending from the skirt side 106 to the centre side which results in an incomplete seal of the bottle.

It is therefore an object of the present invention to overcome the above disadvantage.

It is another object of the invention to provide a cap wherein a negative pressure inside the bottle can be released by lifting a part of the cap from the lower edge of the skirt.

According to the invention, there is provided a cap made of a material capable of being torn and adapted for use on a bottle having a negative pressure inside, said cap having a top wall provided with a central circular flat portion, an annular raised portion for receiving a sealing member, and a sloping wall portion connecting said central circular flat portion with said annular raised portion; a skirt portion depending downward from the outer peripheral edge of said raised portion; and a tab member depending downward from a part of the lower edge of said skirt portion; said cap further having a pair of first separating lines extending toward said top wall from the vicinity of the intersection of the peripheral edge of said tab member and the lower edge of said skirt portion; and a pair of second separating lines extending to the vicinity of the upper end of said skirt portion from the lower edge thereof; said second separating lines being arranged diametrically opposite each other with respect to said top wall and spaced respectively equally distant from said first separating lines; wherein the character of said material is selected such that in the absence of said separating lines it is nevertheless readily tearable by manual lifting of said tab member, and the spacing between and respective orientation of said first separating lines are chosen relative to the dimensions of said cap such that grasping and manually lifting said tab member produces tear lines coinciding at least at their beginning with said first separating lines and terminating at points in said raised portion of said top wall substantially on a tangent to the circle at the top of said sloping wall portion, the distance between such points being such that the resistance imposed by said points is sufficient to interrupt further tearing of said top wall along projections of said tear lines whereby further lifting of said tab member causes separation of said second separating lines and folding back of half of said cap along the line joining said second separating lines.

In the accompanying drawings: Fig. l(a) is a side view of an examples of a conventional cap used for releasing the negative pressure inside a bottle.

Fig. l(b) is a plan view of Fig. l(a).

Fig. 2 is a front view partly broken illustrating one embodiment of the cap of this invention mounted on the mouth of a bottle.

Fig. 3 is a right side view of Fig. 2 including broken lines indicating removal of the cap of Fig. 2.

Fig. 4 is a partial perspective view from the left of the cap of Fig. 2.

Fig. 5 is an explanatory view of the position of the internal peripheral circle on the annular projected part of the top wall.

Fig. 6 is a front view illustrating a second embodiment of this invention.

Fig. 7 is a front view, partly broken, illustrating a third embodiment of this invention similar to that of Fig. 2.

Fig. 8 is a partial perspective view from the left of the cap of Fig. 7.

In Figs. 2 to 5 is shown a cap El made of a thin metallic sheet capable of being torn, comprising a top wall 1; a central flat portion 2 of the top wall; an annular raised portion 3 on the peripheral edge of the top wall; a sealing member 10 arranged inside thereof; a slope 4 connecting the flat portion 2 and the projected part 3; a skirt portion 5 depending downwardly from the peripheral edge of the top wall; a portion 6 bent toward the centre of the cap and engaged with the underside of a rim 21 of the mouth of a bottle 20; a tab 7 depending downwardly from a bottom edge 11 of the skirt portion 5, a pair of first separating lines or score lines 8 and 8' which extend upwardly and vertically toward the top wall from the vicinity of the intersection of the peripheral edge of the tab 7 and the lower edge 11 of the skirt portion and which reach the vicinity of an arcuate portion 12 connecting the skirt portion 5 and the annular raised portion 3; and a pair of second separating lines or score lines 9 and 9' which are positioned symmetrically with respect to the centre of the top wall and at substantially the same distance from the lines 8 and 8' respectively, and which extend upwardly and vertically from the bottom edge 11 of the skirt portion with substantially the same length as that of 8 and 8'. In Fig. 4, there is shown an internal peripheral circle 33 inside the raised portion 3, which circle is given, as shown in Fig. 5, by connecting points 33B.

These points 33B are intersections of an arcuate portion 38 connecting the projected part 3 and the slope 4 with oblique lines 36 extending at an angle of 0=45 with respect to said projected part from the centre P of said arcuate portion.

When it is desired to remove the cap El from the mouth of the bottle 20 on which it has been mounted, the tab 7 is lifted so as to tear the skirt portion along the pair of first separating or score lines 8, 8'. When the tab is further lifted, the break proceeds substantially along the extensions 30 of the lines 8, 8', whereby the skirt portion is torn up to the upper end thereof, and further proceeds to tear the annular projected part at 31, 31' as shown in Fig. 4.

If the distance A between the upper ends 13 and 13' of said lines 8 and 8' is preliminarily designed so that said terminal ends of the tearing 32, 32' are positioned on a tangent 34 of the internal peripheral circle 33, a line connecting the points 32 and 32' becomes naturally consistent with said tangent 34. When the line connecting these terminal ends 32 and 32' comes to accord with the tangent 34 of the internal peripheral circle in the above way, it is no longer possible for the whole part between the tearing lines made beyond the upper ends of the separating lines 8, 8' to proceed further, which ends the tearing.It is be cause (1) there is the slope 4 between the raised portion 3 and the flat portion 2; (2) a middle point 35 between 31 and 31', which is a contact point of the tangent 34 with the internal peripheral circle 33, is positioned near said slope 4; (3) said middle point 5 thus tend to go down along the slope 4; (4) while the terminal points 32, 32' of the tearing still remain on the flat surface of the raised portion 3 and tend to keep on proceeding thereon. At the time that the tearing stops proceeding as above, the approximate position of the tab is shown as A in Fig. 3.If, at this time, the terminal points 32, 32' of the tearing parts 31, 31' are designed to be positioned in about the middle of the radial width of the raised portion 3, the aforesaid tearing will accurately stop and the initial force required to lift up the tab can also be reduced to a relatively small amount with a desirable result. When, however, the width of the annular projected part is greater, the distance between lines 8 and 8' may be such that the terminal points approach nearer the side of the internal peripheral circle 33 than the middle position of the radial width of the raised portion 3. In any case, all that is necessary is that the tearing parts 31, 31' terminate within the annular raised portion.

The tearing so far described can be done with a relatively small force since it is not affected by the negative pressure inside the bottle and it is thus a simple tearing of the cap material. If the tearing proceeds to the above degree and yet the negative presure does exist inside the bottle, the removal of the cap which must be done from this stage will require a considerably larger force, since it must not only overcome the negative pressure inside the bottle but also release engagement of the cap with the bottle. However, as shown in this embodiment, if the tab is bent at the position of the tangent 34, the inside of the bottle becomes open to the atmosphere in the vicinity of the point 35 as shown in Fig. 2 so that the negatitve pressure inside the bottle can be released and accordingly the force by which the cap has been retained on the mouth of the bottle is also released.

As a result, the only thing that has to be done is to release the engagement of the bottle with the lower part of the skirt.

Thus, when the tab 7 is still lifted, the tearing does not proceed any longer but the engagement of the bent portions 6 between the lines 8 and 9 and between the lines 8' and 9' respectively with the expanded portion 21 is gradually released from the side of the first separating lines toward the second separating lines. At the same time the tearing along the second separating lines 9, 9' begins to proceed.

At this stage the condition of the tab 7 is as shown at B in Fig. 3, and the whole cap can be easily removed from the mouth of the bottle by simply pushing the cap in the direction of the arrow C in Fig. 3.

In the embodiment described above, the cap El is made of an aluminium sheet having a thickness of 0.2 mm; the diameter of the internal peripheral circle of the annular raised portion is about 36 mm; the distance between the first separating lines is 18 mm; and the outside diameter of the mouth of the bottle is about 46 mm.

The maximum stress in the first tearing, that is, that caused until it reaches the position 32, 32' is about 2 kg, and the maximum stress in the second tearing, that is, that caused until the tab 7 reaches the position B as shown in Fig. 3 by breaking the second separating lines 9, 9' is about 2.5 kg.

In the above description, the separating lines are the score lines 8, 8' and 9, 9', but they may all be cut lines or a combination of both. A cap E2 as shown in Fig. 6 is a second embodiment of the invention, which is different from the one shown in Fig. 2 in that it has small notches 41, 41' in the lower edge 11 of the skirt portion 5 on both sides of the tab 7 and that the first separating or score lines 42, 42' diverge upwardly, starting from the notches 41, 41'. In this embodiment, if the distance ' between the upper ends 44 and 44' of the first separating lines 42 and 42' is equal to the distance A between the upper ends 13 and 13' of the first separating lines 8 and 8' in Fig. 2, the position where the tearing stops in the annular raised portion 3 is substantially the same as that in the embodiment of Fig. 2.In this case, however, the distance between the lower points 45 and 45' of the first separating lines 42 and 42' is naturally less than is the case in Fig. 2.

Accordingly, the force required to release the engagement of the mouth of the bottle with the lower end 11 of the skirt portion between the lines 42 and 42' by pulling up the tab 7 can be made smaller. It is thus particularly effective when the diameter of the bottle or the cap is large.

In Figs. 7 and 8 is shown a third embodiment of the invention. Figs. 7 and 8 are similar to Figs. 2 and 4, respectively, the same reference numerals indicating the same parts.

The point in which the cap of this embodiment differs from that of Figs. 2 and 4 is that the first separating lines 18 and 18' extend out in the annular raised portion 3 of the top wall 1 of a cap E3 and that the upper ends thereof 17, 17' are already positioned on the tangent 34' of the internal peripheral circle 33 on the centre side of the top wall of said projected part 3. Consequently, it is obvious that the distance A" between the upper ends 17 and 17' of the first separating lines 18 and 18' is designed such that when the separating lines are torn, the terminal ends of the tearing lie on said internal peripheral circle.

Since the lines 18, 18' run parallel with each other, the distance A" between the upper ends 17, 17' is equal to the distance L between the starting ends 37, 37' of said separating lines. In the cap of this embodiment, the first separating lines themselves extend up to the terminal ends of the first tearing, that is, up to 17, 17'. Therefore, the tearing can be done more easily than in the case of the embodiment of Figs. 2 and 6. In the structure as shown in Figs.

2 and 6, since the first separating lines are short so that the tearing must be continued on the area where the separating lines no longer exist after the tearing of the separating lines themselves is over, it sometimes happens, though rarely, that a part departing from the extension of the separating lines is torn depending upon the particular material used for the cap.

When such material has to be used, the structure as shown in Fig. 8 is particularly suitable. The above mentioned upper ends 17 17' do not have to lie accurately on said tangent 34' and can be positioned in the vicinity thereof.

In this embodiment, the cap E3 is made of an aluminium sheet having a thickness of 0.22 mm; the diameter of the internal peripheral circle of the raised portion is about 35 mm; the distance between the first separating lines is 18 mm; and the outside diameter of the mouth of the bottle is about 46 mm. The maximum stress in the first tearing is about 1.8 kg while the maximum tearing in the second tearing, where the second lines 9, 9' are broken and the tab 7 is brought to the condition shown as B of Fig. 3, is 2.5 kg.

The cap of this invention has such effects and advantages that since it has no projected nor recessed strip on the annular raised portion of its top wall, the sealing of a bottle can be done accurately; that since the distance between the upper ends of the first separating lines is designed such that the terminal ends of the tearing of the first separating lines themselves, or of the tearing effected beyond said first separating lines, are positioned on the tangent of the internal peripheral circle of said annular raised portion, the tearing can accurately stop within the annular raised portion and release the negative pressure inside the bottle when it stops; and that owing to the release of the negative pressure the following operation for removing the cap is made very easy.

WHAT WE CLAIM IS: - 1. A cap made of a material capable of being torn and adapted for use on a bottle having a negative pressure inside said cap having a top wall provided with a central circular fiat portion, an annular raised portion for receiving a sealing member, and a sloping wall portion connecting said central circular fiat portion with said annular raised portion, a skirt portion depending downward from the outer peripheral edge of said raised portion; and a tab member depending downward from a part of the lower edge of said skirt portion; said cap further having a pair of first separating lines extending toward said top wall from the vicinity of the intersection of the peripheral edge of said tab member and the lower edge of said skirt portion; and a pair of second separating lines extending to the vicinity of the upper end of said skirt portion from the lower edge thereof; said second separating lines being arranged diametrically opposite each other with respect to said top wall and spaced respectively equally distant from said first separating lines; wherein the character of said material is selected such that in the absence of said separating lines it is nevertheless readily tearable by manual lifting of said tab member; and the spacing between and respective orientation of said first separating lines are chosen relative to the dimensions of said cap such that grasping and manually lifting said tab member produces tear lines coinciding at least at their begining with said first separating lines and terminating at points in said raised portion of said top wall substantially on a tangent to the circle at the top of said sloping wall portion, the distance between such points being such that the resistance imposed by said points is sufficient to inter

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Claims

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45' of the first separating lines 42 and 42' is naturally less than is the case in Fig. 2.

Accordingly, the force required to release the engagement of the mouth of the bottle with the lower end 11 of the skirt portion between the lines 42 and 42' by pulling up the tab 7 can be made smaller. It is thus particularly effective when the diameter of the bottle or the cap is large.

In Figs. 7 and 8 is shown a third embodiment of the invention. Figs. 7 and 8 are similar to Figs. 2 and 4, respectively, the same reference numerals indicating the same parts.

The point in which the cap of this embodiment differs from that of Figs. 2 and 4 is that the first separating lines 18 and 18' extend out in the annular raised portion 3 of the top wall 1 of a cap E3 and that the upper ends thereof 17, 17' are already positioned on the tangent 34' of the internal peripheral circle 33 on the centre side of the top wall of said projected part 3. Consequently, it is obvious that the distance A" between the upper ends 17 and 17' of the first separating lines 18 and 18' is designed such that when the separating lines are torn, the terminal ends of the tearing lie on said internal peripheral circle.

Since the lines 18, 18' run parallel with each other, the distance A" between the upper ends 17, 17' is equal to the distance L between the starting ends 37, 37' of said separating lines. In the cap of this embodiment, the first separating lines themselves extend up to the terminal ends of the first tearing, that is, up to 17, 17'. Therefore, the tearing can be done more easily than in the case of the embodiment of Figs. 2 and 6. In the structure as shown in Figs.

2 and 6, since the first separating lines are short so that the tearing must be continued on the area where the separating lines no longer exist after the tearing of the separating lines themselves is over, it sometimes happens, though rarely, that a part departing from the extension of the separating lines is torn depending upon the particular material used for the cap.

When such material has to be used, the structure as shown in Fig. 8 is particularly suitable. The above mentioned upper ends 17 17' do not have to lie accurately on said tangent 34' and can be positioned in the vicinity thereof.

In this embodiment, the cap E3 is made of an aluminium sheet having a thickness of 0.22 mm; the diameter of the internal peripheral circle of the raised portion is about 35 mm; the distance between the first separating lines is 18 mm; and the outside diameter of the mouth of the bottle is about 46 mm. The maximum stress in the first tearing is about 1.8 kg while the maximum tearing in the second tearing, where the second lines 9, 9' are broken and the tab 7 is brought to the condition shown as B of Fig. 3, is 2.5 kg.

The cap of this invention has such effects and advantages that since it has no projected nor recessed strip on the annular raised portion of its top wall, the sealing of a bottle can be done accurately; that since the distance between the upper ends of the first separating lines is designed such that the terminal ends of the tearing of the first separating lines themselves, or of the tearing effected beyond said first separating lines, are positioned on the tangent of the internal peripheral circle of said annular raised portion, the tearing can accurately stop within the annular raised portion and release the negative pressure inside the bottle when it stops; and that owing to the release of the negative pressure the following operation for removing the cap is made very easy.

WHAT WE CLAIM IS: - 1. A cap made of a material capable of being torn and adapted for use on a bottle having a negative pressure inside said cap having a top wall provided with a central circular fiat portion, an annular raised portion for receiving a sealing member, and a sloping wall portion connecting said central circular fiat portion with said annular raised portion, a skirt portion depending downward from the outer peripheral edge of said raised portion; and a tab member depending downward from a part of the lower edge of said skirt portion; said cap further having a pair of first separating lines extending toward said top wall from the vicinity of the intersection of the peripheral edge of said tab member and the lower edge of said skirt portion; and a pair of second separating lines extending to the vicinity of the upper end of said skirt portion from the lower edge thereof; said second separating lines being arranged diametrically opposite each other with respect to said top wall and spaced respectively equally distant from said first separating lines; wherein the character of said material is selected such that in the absence of said separating lines it is nevertheless readily tearable by manual lifting of said tab member; and the spacing between and respective orientation of said first separating lines are chosen relative to the dimensions of said cap such that grasping and manually lifting said tab member produces tear lines coinciding at least at their begining with said first separating lines and terminating at points in said raised portion of said top wall substantially on a tangent to the circle at the top of said sloping wall portion, the distance between such points being such that the resistance imposed by said points is sufficient to inter

rupt further tearing of said top wall along projections of said tear lines whereby further lifting of said tab member causes separation of said second separating lines and folding back of half of said cap along the line joining said second separating lines.
2. A cap as claimed in claim 1, wherein the first separating lines extend to the top end of the skirt portion.
3. A cap as claimed in claim 2, wherein the first separating lines diverge upwardly toward the top end of the skirt portion.
4. A cap as claimed in claim 1, wherein the first separating lines extend inwardly in the annular raised portion.
5. A cap, substantially as herein described with reference to Figures 2 to 5, 6 or 7 and 8 of the accompanying drawings.
6. A cap as claimed in any preceding claim wherein said material capable of being torn is a thin metallic strip.