GB2094276A - Reclosable metal top-end for a container for carrying liquids - Google Patents

Abstract

An imperforate crown (5) of the top-end (4) of a container (1) has at least one aperture zone (8) which is weakened in comparison to the remainder of the crown (5). A piercing member (13) for puncturing the aperture zone (8) is provided on the top-end (4) outside the aperture zone (8) and serves to reclose the hole so created. The piercing member (13) is held fast by means of a flexible strip (12) to the top-end. The fastening can be by means of a rib (6) which encircles the aperture zone (8). The piercing member can be retained ready for use on a projecting stud (48, see Fig. 12) or in a lipped recess (15, see Fig. 1) in the crown. Alternatively, the piercing member (13) can be held within an intermediate ring (53) which is snapped on to the rib (6). Between the intermediate ring (53) and the piercing member (13) one can provide at least one fracturable element (55) which is preferably gas-tight. The opening up of the aperture zone (8) is made easier by providing various lines e.g. see Fig. 4, or areas of weakness in the aperture zone (8). A tapering portion of the base (18) of a further container (19) is arranged to stack within the double seam (3) of the first container (1). <IMAGE>

Description

SPECIFICATION Reclosable metal top-end for a container for carrying liquids This invention relates to a metal top-end for closing a container, e.g. a can, for carrying liquids, the top-end comprising an imperforate crown surrounded by a rolled seam and havng at least one aperture zone, wherein the or each aperture zone is weaker than the remainder of the crown, and wherein there is provided for the or each aperture zone, on the top-end outside said at least one aperture zone, a piercing member for puncturing the aperture zone, and for closing the hole so created.

In one known top-end of this general type, as described in German published patent application OLS 21 04 956, the piercing member is formed as a snap ring or snap lid which can be coupled to the rolled seam. However, in both cases the snap portion is removable from the top end. The piercing member with its cutter or sharp tip can thus be removed from the container, which means that it can then inadvertently be lost and become a danger to man and beast. The piercing action is carried out against the resilient restoring force of the snap ring or snap lid.This restoring force prevents one achieving the desirable seal between the punch and an annular bead which encircles each aperture zone, and this gives rise to an unsatisfactory reclosing of the hole in the top-end which has been created.

It is an object of the present invention to prevent any envirnnmental hazard caused by parts which are removable from the container, and also to facilitate the opening of the aperture zone or zones and to improve the method of reclosing the hole or holes thus created.

In accordance with the present invention this is achieved by the fact that the piercing member is held retained on the top-end by a flexible strip.

In the case of liquid contents, such as condensed milk, edible oil and the like, the top-end is preferably provided with two dia metrically opposed aperture zones. In the case of a drinking container on the other hand one aperture zone only is sufficient. The top-end can be made for example of aluminium or, preferably, tinplate. The flexible strip of the or each piercing member is preferably held fast on the crown of the top-end. The strip retains the piercing member on the top-end, but nevertheless enables a simple and reliable handling of the piercing member. The aper ture zones can be circular, oval, teardropshaped, or of any other suitable form.Preferably, the aperture zone or zones are positioned close to the edge of the top end in order to make it easier to pour out the liquid contents or to drink directly from the aperture zone wiithout the need for drinking straws or the like. In the case of drinking containers, a separate pressure equalising hole is superfluous since at the beginning of the penetration of the tip of the piercing member into the aperture zone the internal excess pressure within the drinking container can equalise with the atmosphere through the then comparatively small annular gap which opens between the tip and the edge of the aperture zone. The weakening of the aperture zone is such that the force needed to puncture the aperture zone by means of the piercing member can Bse exerted even by children.Because the piercing member is retained on the topend and consequently on the container, the piercing member cannot become detached from the container and therefore cannot give rise to any danger. The piercing member can be made for example of plastics material, or alternatively of tinplate, for example the same tin-plate as is used for the making of the crown and/or the body of the container.

A comparatively simple and in all cases suitable arrangement is achieved if one end of the strip is held retained on a stud formed from the material of the crown.

Alternatively, the or each aperture zone can be surrounded by an upstanding rib formed from the material of the crown and one end of the strip can be held fast on the rib. With this arrangement one avoids the need for any separate fastening point.

Preferably, the piercing.member is provided with a recess which is releasably engageable with a retaining projection on the top-end. In this way the piercing member is held securely on the topbend until it has to be used. An uncontrolled movement of the piercing member relative to the top-end in the range of movement of the strip is thus avoided. Alternatively, the same result can be achieved if the piercing member normally is releasably held by retaining means, such as a lipped recess, on the top-end.

In one preferred embodiment, the or each aperture zone is surrounded by an upstanding rib formed from the material of the crown, an intermediate ring is coupled to the rib and extends out beyond the rib, and the piercing member is connected to the intermediate ring by means of at least one fracturable element prior to the time that the aperture zone is penetrated. The intermediate ring is preferably coupled to the rib by means of a retaining snap fastening. The intermediate ring with its said at least one fracturable element serves on the one hand as a retainer for the piercing member until the time that it is used, and on the other hand serves as a spout or mouthpiece for the pouring of the liquid contents or the drinking of the liquid contents from the container.The fracturable element may be formed for example as a plurality of webs divided around the circumference.

Preferably, the or each fracturable element is formed as a gas-tight annular membrane.

This makes it possible to create hermetic sealing of the internal chamber of the intermediate ring up until the time that the container is opened. This means in particular that the aperture zone and the portion of the piercing member which overlies it can be maintained hygienically clean without any difficulty up until the time that the container is opened.

Preferably, the intermediate ring, the fracturable element or elements, the piercing member and the flexible strip are formed as one piece from plastics material. This arrangement is particularly desirable from the point of view of ease of manufacture.

In order to facilitate the opening of the container the piercing member may comprise a cone having a central tip, and the or each aperture zone may be provided with a recessed puncture point which co-operates with the cone tip.

Preferably, lines of weakness which intersect at this puncture point are provided in the or each aperture zone. This means that in a simple way one can create the desired weakening of the aperture zone. The puncture point can be recessed more deeply than the lines of weakness in order thereby to facilitate the initial fracturing of the aperture zone. The provision of the puncture point means that it is easier to carry out the central location of the tip of the piercing member in the aperture zone.

In a preferred embodiment, the or each aperture zone comprises an outer ring of at least approximately the same thickness as the remainder of the crown and surrounding a central region, with the central region being thinner than the rest of the crown. This arrangement provides another convenient method of weakening the aperture zone. For example, the central region can be enabled to open with comparatively little pressure exerted thereon, while the outer ring opposes the penetration of the piercing member with a greater resistance.

Preferably, the lines of weakness, if extended, would intersect at the puncture point provided in the central region. The orientation of the lines of weakness in this way facilitates the fracturing of the aperture zone.

Additionally, a hinge line of weakness can be provided to extend between the outer ends of two adjacent lines of weakness. Such a hinge line can be straight or curved to correspond to the outer edge of the aperture zone.

The more straight hinge lines are provided the more the polygon which is thereby created approaches a continuous curve, for example a circle.

In one embodiment of the invention, the piercing member includes a spreading portion extending axially from the cone, and a sealing portion axially beyond the spreading portion, the sealing portion extending transversely of the longitudinal axis of the piercing member beyond the outermost periphery of the cone and co-operating with a sealing wall surface formed from the material of the crown. With this arrangement, upon penetration of the piercing member, the sectors of the aperture zone of the top-end which separate from one another are forced particularly far apart and thus create a comparatively large discharge hole in the top-end.

This latter advantage can alternatively be achieved in another way if a spreading portion is provided between the outermost contour of the cone in the transverse direction of the piercing member and a sealing region of the piercing member which co-operates with a sealing wall surface formed from the material of the crown.

In order that the invention may be fully understood a number of embodiments of topend in accordance with the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a longitudinal sectional view through parts of two drinking containers which are stacked one upon the other; Figure 2 is a schematic longitudinal sectional view showing the manufacture of an aperture zone in the top-end of Fig. 1; Figure 3 schematically illustrates the puncturing of the aperture zone by means of a piercing member; Figure 4 is a plan view of another type of aperture zone; Figure 5 is a sectional view taken along the line 5-5 of Fig. 4; Figure 6 shows the puncturing of the aperture zone of Fig. 5; Figure 7 is a plan view of another form of aperture zone; Figure 8 is a sectional view taken along the line 8-8 of Fig. 7; ; Figure 9 is a longitudinal sectional view through an aperture zone with a piercing member having a spreading portion; Figure 10 is a longitudinal sectional view through an aperture zone with a different piercing member, and showing two different positions in the sequence; Figure ii is a plan view of a part of the top-end showing the aperture zone and piercing member; Figure 12 is a sectional view taken along the line 12-12 of Fig. 11; Figure 13 is a sectional view taken along the line 13-13 of Fig. 11; and, Figure 14 is a longitudinal sectional view corresponding to Fig. 1 but through a further embodiment of top-end in accordance with the invention.

Fig. 1 shows a container 1, formed as a drinking container, comprising a tin-plate body 2 which is connected in a gas-tight fashion in known manner by means of a double seam 3 to a tin-plate top-end 4. Inwardly of the double seam 3 of the top-end there is a domed crown 5 from which an upstanding metallic rib 6 is formed. The rib 6 has an inner cylindrical sealing wall 7 whose lower edge becomes an aperture zone 8 of the crown 5.

The aperture zone 8 is of lesser thickness than the remainder zone 9 of the crown 5, and is therefore weakened.

A stud 10 is formed in the centre of the crown 5 out of the material of the remainder zone 9, and an eyelet 11 at one end of a strip 1 2 of plastics material is retained on the stud.

The other end of the plastics strip 1 2 is fixed to a piercing member 1 3 which comprises a disc 14 which is held seated tightly in a lipped recess 1 5 formed in the crown 5.

The piercing member 1 3 comprises a conical portion 1 6' which has a tip 1 6 for punching through the aperture zone 8, and it is also provided with a cylindrical sealing region 1 7 which is complementary to the sealing wall 7.

The piercing member 1 3 is formed from a suitable plastics material.

A tapering portion of the base 1 8 of a further container 1 9 is arranged to stack within the double seam 3 of the first container 1. It will be appreciated from Fig. 11 that all the aforementioned elements of the crown 5 of the lower container 1 are spaced from the external contour 20 of the base 1 8 of the upper container 1 9 when they are in their inoperative positions shown in Fig. 1 so that it is possible to stack the containers 1 and 1 9 on top of one another, as shown in Fig. 1, without any difficulty.

Fig. 2 shows the manufacture of the reduced thickness aperture zone 8. A hydraulic press ram 21 is moved in the direction of arrow 22 relative to a hydraulic press die 23 which for its part can be moved in the direction of arrow 24 towards the aperture zone 8.

By means of the pressure forces acting between the two press elements 21 and 23 the tin-plate is thinned to the desired value in the aperture zone 8. In the centre the hydraulic press ram 21 has a conical projection 25 which, during the pressing operation, creates a complementary recessed puncture point 26 in the aperture zone 8. Simultaneously, the sealing wail 7 is formed to shape by the hydraulic press ram 21.

In order to open the container 1, the piercing member 1 3 is loosened from its seated position in the lipped recess 1 5 from the position which it occupies as shown in Fig. 1, is pivoted through about 180 by means of the strip 1 2 with continuing retention of the piercing member on the top-end 4, and the tip 1 6 of the piercing member 1 3 is pushed into the puncture point 26.The tip 1 6 of the piercing member 1 3 penetrates through the aperture zone 8 in the region of the puncture point 26 when a certain pressure is exerted on the piercing member 13, and this creates from this instant an outward equalisation of the excess pressure prevaiiing within the con tainer 1. With further progressive exertion of pressure on the piercing member 13, the piercing member 1 3 finally is pushed into its deepest position, as shown in Fig. 3, in which the aperture zone 8 is opened up more and more into sectors connected to the bottom edge edge of the sealing wall 7.In this way a hole 27 is created in the aperture zone 8 through which the liquid contained within the con tainer 1 can be poured or drunk after removal of the piercing member 1 3. In pauses between drinking the piercing member 1 3 can be fitted back into the hole in the position shown in Fig. 3, in which position its sealing portion 1 7 contacts the complementary seal ing wall 7 with sufficient sealing force to prevent any foreign bodies or insects from entering the container through the hole 27.

In the following Figures of the drawings the same or equivalent elements are shown with the same reference numbers as in Figs 1 to 3.

In Fig. 4 the aperture zone 8 is shown as having at least approximately the same thick ness as the remainder zone 9, and is also shown as being provided with lines of weak ness 28 to 31. These lines of weakness 28 to 31 are each formed as straight lines and intersect at the centre of the aperture zone 8 at the puncture point 26.

As Fig. 5 shows, the puncture point 26 is recessed to a greater depth than the lines of I weakness 28 to 31, in order on the one hand to facilitate the centred insertion of the tip 1 6 of the piercing member 1 3 into the aperture zone 8 and on the other hand to facilitate the initial penetration of the aperture zone 8.

In Fig. 6 there is shown the position of deepest penetration of the piercing member 1 3 into the interior of the container 1. In this position the aperture zone 8 has fractured into segments along the lines of weakness 28 to 31 and has formed a downwardly projecting sealing wall 7 around the periphery of the aperture zone 8 where it merges into the remainder zone 9 of the top-end. The sealing wall 7 co-operates with the sealing zone 1 7 of the the piercing member 1 3 in a manner which gives a sufficient sealing action.

Fig. 7 shows another form of aperture zone 8. it Here, lines of weakness 32 to 38' are only provided in an outer ring 40 encircling a central region 39. The lines of weakness 32 to 38' would, if extended, pass through the puncture point 26 in the centre of the aper ture zone 8. The outer ring 4Q is of at least approximately the same thickness as the re mainder 9 of the crown, while the central region 39 has a lesser thickness. These differ ent thicknesses can be seen particularly clearly in Fig. 8. In this embodiment also the puncture point 26 is formed as a recess in the central region 39.

Fig. 7 shows one special feature, in that in this embodiment the outer end points of the lines of weakness 35 and 36 are connected to one another by a linear weakened hinge line 41 and the outer end points of the lines of weakness 36 and 37 are connected to one another by a corresponding weakened hinge line 42 which is arcuate and follows the periphery of the aperture zone 8. By this means the opening up of the sectors of the aperture zone 8 defined by the lines of weakness 32 to 38' is facilitated when the piercing member 1 3 is pushed into place.

In Fig. 9 a spreading section 50 is provided at the base of the conical portion 16' of the piercing member 1 3 and extends in the axial direction. The sealing region 1 7 of the piercing member 73 is formed adjacent to the spreading section 50 and extends transversely of the longitudinal axis of the piercing member 13 beyond the outermost contour 51 of the conical portion 16'. When the piercing member 1 3 has its tip 1 6 pushed into the aperture zone 8, the aperture zone 8 increasingly breaks into sectors as shown in Fig. 9 which initially rest against the conical portion 16' as shown in Fig. 6.When the piercing member 1 3 is pushed still further into the interior of the container 1, then the outermost contour 51 causes an outward spreading of the fractured sectors of the aperture zone 8 as shown in Fig. 9, where the spreading portion 50 is shown at its lowest position, until the plate 14 comes up against the rib 6 which acts as a stop. This end position is shown in Fig. 9. In this position the sealing zone 1 7 of the piercing member 1 3 is in contact with the sealing wall 7 of the top-end 4.

In the embodiment shown in Fig. 10 a circular cylindrical portion with diameter equal to the maximum diameter 51 of the conical portion 1 6' is provided adjacent to the conical portion 1 6' of the piercing member 13. This circular cylindrical portion constitutes both the spreading portion 50 and the sealing portion 17.

If, as shown in Fig. 10, the conical portion 1 6' is increasingly pushed into the aperture zone 8, then initially, in the same manner as described in the embodiment shown in Fig. 9, the broken sectors of the aperture zone 8 lie in contact with the external surface of the conical portion 16', until an intermediate state is reached which is shown by the left-hand half of Fig. 1 0. In this intermediate state the spreading portion 50 overlies the sealing wall 7.If then from this intermediate state the piercing member 1 3 is pushed further into the interior of the container 1, an increased spreading of the sectors of the aperture zone 8 occurs due to the lower edge of the spreading portion 50 which corresponds to the outermost contour 51 of the cone 16', until one reaches the end position which is shown in the right-hand haif of Fig. 1 0. In this end position the sealing portion 1 7 sealingly contacts the sealing wall 7. The plate 1 4 rests against the upper edge of the upstanding rib 6. The spreading of the aperture zone 8 in the direction of the arrow 52 leads to an enlargement of the hole 27 in the top-end 4 in a similar manner to that described above in relation to the embodiment shown in Fig. 9.

In Fig. 11 the aperture zone 8 and the piercing member 1 3 are shown in their rest positions immediately next to one another close to the double seam 3.

As is shown in Fig. 12, the piercing member 1 3 is made of plastics material and is provided with a recess 47 by means of which it can be releasably snapped on to a retaining stud 48 which projects up from the crown surface 9. The flexible strip 1 2 is connected at its one end to the edge of the plate 14 and at the other end is fastened by means of the eyelet 11 into a circumferential rebate 49 of the rib 6 as shown in Fig. 1 3.

In the embodiment shown in Fig. 14 an intermediate ring 53 with a lower reinforced bead 54 is snapped fast into a circumferential rebate 49 of the rib 6. The eyelet 11 of the flexible strip 1 2 is again snapped into place in the circumferential rebate 49 between the bead 54 and the crown 5. Alternatively, the strip 1 2 could be formed integrally with the intermediate ring 53.

The other end of the strip 1 2 is connected to the centre of the plate 14 of the piercing member 1 3. The plate 14 is connected to the intermediate ring 53 by means of a fracturable element 55 which is formed as a gas-tight annular membrane. In this case, the intermediate ring 53, the fracturable element 55, the piercing member 1 3 and the flexible strip 1 2 with its eyelet 11 are made as one piece from plastics material.

In order to open the container 1, as shown in Fig. 14, it is only necessary to exert pressure downwardly on the plate 14 of the piercing member 1 3. This causes the tip 1 6 of the cone 16' to penetrate the puncture point 26 of the aperture zone 8. Simultaneously, the thin fracturable element 55 breaks.

The piercing member 1 3 penetrates increasingly into the interior of the container 1 and thus opens up the aperture zone 8 in the manner described above in relation to the other embodiments.

Fig. 14 also shows how the containers 1 and 1 9 can be stacked above one another, since the piercing member 1 3 the intermediate ring 53 and the flexible strip 1 2 are arranged beneath the external contour 20 of the base 18 of the upper container 19.

Claims (16)

1. A metal top-end for closing a container for carrying a liquid, the top-end comprising an imperforate crown surrounded by a rolled seam and having at least one aperture zone, wherein the or each aperture zone is weakened in comparison with the remainder of the crown, wherein there is provided for the or each aperture zone, on the top-end outside said at least one aperture zone, a piercing member for puncturing the aperture zone and for closing the hole so created, and wherein the piercing member is held retained on the top-end by a flexible strip.

2. A top-end as claimed in claim 1, in which one end of the strip is held retained on a stud formed from the material of the crown.

3. A top-end as claimed in claim 1, in which the or each aperture zone is encircled by an upstanding rib formed from the material of the crown, and in which one end of the strip is held fast on the rib.

4. A top-end as claimed in any preceding claim, in which the piercing member is provided with a recess which is releasably engageable with a retaining projection on the topend.

5. A top-end as claimed in any of claims 1 to 3, in which the piercing member normally is releasably held by retaining means on the top-end.

6. A top-end as claimed in any of claims 1 to 3, in which the or each aperture zone is surrounded by an upstanding rib formed from the material of the crown, in which an intermediate ring is coupled to said rib and extends outwardly beyond the rib, and in which the piercing member is connected to the intermediate ring by means of at least one fracturable element prior to the penetration of the aperture zone.

7. A top-end as claimed in claim 6, in which the or each fracturable element is formed as a gas-tight annular membrane.

8. A top-end according to claim 6 or 7, in which the intermediate ring, said at least one fracturable element, the piercing member and the flexible-strip are formed as one piece from plastics material.

9. A top-end as claimed in any preceding claim, in which the or each piercing member comprises a cone having a central tip, and in which the or each aperture zone is provided with a puncture point recessed to co-operate with the cone tip.

10. A top-end as claimed in claim 9, in which the or each aperture zone is provided with lines of weakness which intersect at the puncture point.

11. A top-end as claimed in claim 9, in which the or each aperture zone comprises an outer ring which surrounds a central zone and which is of at least approximately the same thickness as the rest of the crown with lines of weakness extending towards the central zone, and in which the central zone is thinner than the remainder of the crown.

12. A top-end as claimed in claim 11, in which the lines of weakness, if extended, would intersect at the puncture point provided in the central zone.

1 3. A top-end as claimed in any of claims 10 to 12, in which a hinge line weakness extends between the outer ends of two adjacent ones of said lines of weakness.

14. A top-end as claimed in any of claims 9 to 13, in which the piercing member includes a spreading portion extending axially from the cone, and a sealing portion axially beyond the spreading portion, said sealing portion extending transversely of the longitudinal axis of the piercing member beyond the outermost periphery of the cone and co-operating with a sealing wall surface formed from the material of the crown.

1 5. A top-end as claimed in any of claims 9 to 13, in which a spreading portion is provided between the outermost contour of the cone and a sealing region of the piercing member which co-operates with a sealing wall surface formed from the material of the crown.

16. A metal top-end for a container substantially as hereinbefore described with reference to any one of the Figures of the accompany drawings.