GB2086361A

GB2086361A - An improved container closure

Info

Publication number: GB2086361A
Application number: GB8128442A
Authority: GB
Original assignee: Johnsen and Jorgensen Plastics Ltd
Current assignee: Johnsen and Jorgensen Plastics Ltd
Priority date: 1980-09-26
Filing date: 1981-09-21
Publication date: 1982-05-12
Also published as: GB2086361B

Abstract

In a container closure which has a cap part 1 and a tear band 2, the cap part has a depending plug 5 with a centrally dished recess of more or less conical or frusto-conical shape arranged so that when in use the dished recess is directed towards the inside of the container. The closure may have a hinge 15 and a thumb tab 11. <IMAGE>

Description

SPECIFICATION An improved container closure This invention is concerned with the provision of an improved container closure especially adapted for use as a closure for containers holding carbonated drinks.

In our copending patent application filed today we describe an improved closure of plastics material adapted to take the place of a conventional metal crown closure. One feature which we describe in our copending application is the provision of a centrally dished depending plug on the closure so shaped that when in use the dished part is directed towards the inside of the container. By this construction any gas escaping from a carbonated drink within the container tends to enter the dished part which has the effect of urging the outer annular part of the plug outwardly and to press it against the inside wall of the container. This construction will, we believe, be very effective in the provision of a closure of plastics material for use with a container having a neck of conventional crown-closure-receiving shape.However the closure described in our copending application may have no tamper resistant feature; once the closure has been removed, for example by a conventional bottle opener, it stays open because it is almost impossible to replace. For that reason a tamper resistant feature is not required because it is obvious to all if the closure has been removed. On the other hand in some cases it may be desirable to provide the closure with a tamper resistant feature so that a user can see at a glance if the closure has been tampered with.

According to one aspect of the invention therefore we provide a container closure comprising a cap part and a tear band wherein the cap part has a depending plug with a centrally dished recess of substantially conical or frustoconical shape arranged so that when in use the dished recess is directed towards the inside of the container.

The present invention also includes a hinged closure in which the cap part is constructed as above and in which the cap part is connected by a substantially annular weakened line to an anchor band except at one section of the circumference that is adapted to act as a hinge. The invention also includes a hinged closure including not only a cap part and an anchor band but also a tear band.

These hinged closures have in the past ten years or so achieved a very considerable success commercially and our hinged closures known under the Registered Trade Mark JAYCAP and described in Patent No. 812580 are to be found on many different containers including bottles of still soft drinks such as orange squash. To adapt our JAYCAP for use with carbonated drinks involves problems which are set forth in our Patent No. 1 529795. The construction described in Patent No. I 52795 is effective but we have found that if a carbonated drink be stored over a period there may be a slow imperceptible leakage.

Therefore according to another aspect of the invention there is provided a hinged closure comprising a cap part, a tear band, an anchor band and a hinge to connect the cap part to the anchor band wherein the cap part has a depending plug with a centrally dished part of substantially cone or frusto-conical shape so that when in use the dished part is directed towards the inside of the container. By this construction any gas escaping from a carbonated drink within the container tends to enter the substantially conical dished part which has the effect of urging an outer annular part of the plug outwardly and to press it against the inside wall of the container.The dished part may be wholly of true cone shape but it may be of any other suitable shape e.g. it may be rounded at the apex so long as inclined side walls are provided so that the dished part acts as a chamber to receive gas under pressure in such a way that the outer annular part of the plug acts as a seal plug.

In order that the invention may be clearly understood reference is now directed to the accompanying drawing in which: Figure 1 is a longitudinal sectional view of one embodiment of the invention and Figure 2 is a plan view partly in section on the line A-A of figure 1.

In the drawing the closure comprises a cap part 1, a tear band 2 and an anchor band 3. The cap part 1 also has a depending plug 5 to enter the mouth of the container. The closure also has sundry sealing beads of conventional construction.

The tear band is connected to the cap part 1 by a weakened membrane 12 and to the anchor band 3 by a weakened membrane 13. The hinge by which the cap part 1 is connected to the anchor band 3 is shown at 15, as in a conventional JAYCAP. The depending plug has a central conical dished part 24 of V-shape in longitudinal section and an outer annular part 25 which forms an annular expanding seal plug the outer wall 26 of which is urged against the inside wall of the container if gas under pressure enters the dished part 24. In this way as the gas escapes from the liquid in the container pressure builds up in the dished part 24 and the inclined arms 27 of the plug tend to splay outwards so that the wall 26 presses tightly against the container wall.

Incombination with the~feature described above we may also use the construction described in our Patent No. 1 529795 in which we describe and claim a hinged closure for closing the mouth of a container comprising a cap part, an integral anchor band adapted to embrace the neck of the container or that part of the container wall adjacent the mouth of the container, a tear band between the cap part and the anchor band, a hinge connecting the cap part to the anchor band and a thumb tab diametrically opposite to the hinge, wherein the tear band extends around the closure symmetrically on each side of the thumb tab towards the hinge for a part only of the distance between the respective ends of the thumb tab and the hinge and wherein the part of the closure between the tear band and the hinge at each side of the hinge is spanned by a weakened tear line between the cap part and the anchor band. In our prior patent the closure has a cap part 1, a tear band 2 and an anchor band 3.

The cap part 1 has a depending plug 5 for insertion into the mouth of a container.

The cap part 1 also has annular sealing beads 8 and 9. The tear band 2 in the example illustrated extends for about 900 around the closure, that is 450 on each side of a thumb tab 11 and the tear band 2 is connected to the cap part 1 by a weakened membrane 12 and to the anchor band 3 by a weakened membrane 13. The weakened membrane 12 ends at each end of the tear band 2 but the weakened membrane 13 extends on around the closure to the hinge 15 to form two arcuate weakened lines. The anchor band 3 has a main internal bead 1 6 and a smaller auxiliary bead 17.

At diametrically opposed positions on the weakened membrane 1 3 there are thickened posts which resist tearing so that a portion of the cap flexes upwards to release the pressure in a controlled manner until the thickened posts tear.

In operation when it is desired to open a container which is closed by a closure as illustrated the tear band is torn away by seizing a finger grip and pulling the band 2 around the closure in the usual way. When the band 2 has been torn to the end remote from the finger grip upward pressure is exerted on the tab 11 to push the cap part 1 away from the anchor band 3 so that the rest of the weakened membrane 13 between the ends of the tear band 2 and the hinge 1 5 is broken and the cap part 1 pivots upwardly on the hinge 1 5.

It will be understood that for containers of liquid with a high aeration pressure the are of the tear band will be small e.g. 900 while with lower pressures the arc of the tear band may be longer.

In a preferred embodiment therefore we provide a closure of the kind described with a conical V-section pressure chamber in the plug and with a construction of tear band as described in our prior patent.

It will be understood that our improved container closure is for use with a container having an appropriately shaped neck profile. In the drawing we have shown a closure shaped to fit a container with a neck profile designed for use with our conventional JAYCAP, the closure being forced down on to the container so that the rim of the container around the opening or mouth enters the gap 28 and the top edge seats against the bead 8.

Figures 3 and 4 illustrate, in section and elevation respectively a second embodiment of the invention in which the cap part 1 is not hingedly connected to an anchor band. In the embodiment of Figures 3 and 4 the cap part is connected by a weakened line to a tear band 2 and a second weakened line runs out to the bottom of the band so that the tear band can readily be torn away after which the cap part can be simply pushed off the container. In this embodiment the bead 16 is provided on the tear band instead of on the anchor band.

Claims

1. A container closure comprising a cap part and a tear band wherein the cap part has a depending plug with a centrally dished recess of substantially conical or frusto-conical shape arranged so that when in use the dished recess is directed towards the inside of the container.

2. A container closure comprising a cap part connected to an anchor band by a substantially annular weakened line except at one section of the circumference that is adapted to act as a hinge wherein the cap part has a depending plug with a centrally dished recess of substantially conical or frusto-conical shape so that when in use the dished recess is directed towards the inside of the container.

3. A hinged closure comprising a cap part, a tear band, an anchor band and a hinge to connect the cap part to the anchor band wherein the cap part has a depending plug with a centrally dished recess of substantially conical or frusto-conical shape so that when in use the dished recess is directed towards the inside of the container.

4. A closure according to claim 1 or 2 or 3 wherein the dished recess is curved or rounded at the apex.

5. A closure according to any of the preceding claims wherein the dished recess is substantially square or of other suitable shape at the apex, an inclined side wall being provided.

6. A closure according to any of the preceding claims wherein the dished recess is of V-shape in longitudinal section and has an outer annular part which forms an expanding sealing plug which when in use is urged against the inner wall of the container if gas under pressure enters the dished part.

7. A closure according to claim 3 wherein a thumb tab is provided on the cap part substantially diametrically opposite to the hinge and wherein the tear band extends around the closure symmetrically on each side of the thumb tab towards the hinge for a part only of the distance between the respective ends of the thumb tab and the hinge and wherein the part of the closure between the tear band and the hinge at each side of the hinge is spanned by a weakened tear line between the cap part and the anchor band.

8. A closure according to claim 7 wherein the tear band extends for about 900 around the closure i.e. for about 45" on each side of the thumb tab.

9. A closure according to claim 8 wherein the tear band is connected to the cap part by a first weakened membrane and to the anchor band by a second weakened membrane and wherein the first weakened membrane finishes at each end of the tear band but the second weakened membrane extends on around the closure to the hinge, at diametrically opposed positions on the second membrane thickened posts being provided to resist tearing.

10. A hinged closure comprising a cap part with a top and a skirt, a tear band, an anchor band and a hinge to connect the cap part to the anchor band wherein the cap part includes a centrally disposed plug with a substantially vertically depending side wall to enter the mouth of a container and wherein the plug has a centrally dished recess of substantially conical or frusto-conical shape open at the lower end towards the inside of a container when in use and with an inclined inner wall rising to an apex adjacent to or slightly below the top of the cap part.

11. A closure and container assembly wherein the closure is made in accordance with any of the preceding claims.

12. A closure according to claim 1,2, 3 or 8 substantially as hereinbefore described with reference to the accompanying drawings.