GB1579337A

GB1579337A - Closures

Info

Publication number: GB1579337A
Application number: GB30228/76A
Authority: GB
Original assignee: Metal Box PLC
Current assignee: Crown Packaging UK Ltd
Priority date: 1976-07-20
Filing date: 1976-07-20
Publication date: 1980-11-19
Also published as: AU2696677A; AU512687B2; IN146936B; ZA774166B

Description

(54) IMPROVEMENTS IN OR RELATING TO CLOSURES (71) We, METAL Box LIMITED, a Company incorporated under the laws of Great Britain, of Queens House, Forbury Road, Reading EG1, 3JH, England, do hereby declare the invention for which we pray that 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 improvements in closures for containers having externally threaded necks and in particular to a tamperproof closure of the kind which is formed from thin ductile metal and which has a top and a skirt which comprises an upper part adapted to have screw threads formed therein and a lower part which constitutes a collar or locking ring and is connected to the upper part by a series of angularly spaced bridges interrupting a peripheral slit line.

The upper part may be pre-threaded but usually it is thread-rolled into engagement with threads on a bottle neck during application of the closure to the bottle, the collar or locking ring being, during said application, rolled into engagement with a rib or bead on the bottle neck. The upper part of the closure is separated from the collar or locking ring by applying torque in the unscrewing direction. This results in rupturing of the bridges which leaves the upper portion with a ragged edge which may scratch or cut the hand of a user.

It is a main object of the invention to provide a closure of the kind above referred to in which protection is afforded against injury by said ragged edge.

According to the invention there is provided a closure of the kind which is formed from thin ductile metal and which has a top and a skirt which comprises an upper part adapted to have screw threads formed therein and a lower part which constitutes a collar or locking ring and is connected to the upper part by a series of angularly spaced bridges interrupting a peripheral slit line, wherein the upper part of the skirt has, at its lower extremity, a bead comprising an outer layer and an inner layer which are integral and continuous with the upper part of the skirt, the free edge of the bead being located above the lowermost edge of the bead and being connected through the said bridges to the lower part of the skirt, and the outer and inner layers of the bead and the lower part of the skirt are all substantially parallel with the axis of the closure, whereby the bead forms a mask for the ragged edge on the upper part of the skirt which is created by rupturing of the bridges.

Preferably the peripheral slit line is so located that on rupturing of the bridges the ragged edge on the upper part of the skirt is disposed between the opposite ends of the bead. The outer layer of the bead may be provided with knurling.

The bead may be offset outwardly from the upper part of the skirt.

Alternatively the bead may be formed inwardly of the upper part of the skirt and the upper portion of the lower part of the skirt offset inwardly to accommodate the bead.

In another construction, the bead is formed inwardly of the upper part of the skirt and the whole of the lower part of the skirt is correspondingly offset inwardly of the upper part of the skirt.

The invention also comprehends a method of forming a closure of the kind characterised above in which the peripheral slit line is so located that on rupturing of the bridges, the ragged edge is disposed between the opposite ends of the bead, comprising the steps of: (a) folding outwards from the upper part of the skirt a two-sided bead one side of which is preferably substantially normal to the skirt and the other of which forms an acute angle with said one side, (b) forming a series of angularly spaced bridges interrupting a peripheral slit line in the skirt adjacent to and below said one side of the bead, and (c) at least partially collapsing the bead downwardly so that the bead extends down beyond the peripheral slit line and the outer and inner layers of the bead are substantially parallel with the axis of the closure.

In one embodiment the method may include the step of setting the slits back substantially into the plane of the skirt before collapsing the bead downwardly.

If desired, the outer side of the bead may be knurled while collapsing the bead.

The invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is an elevation, partly in section, of a closure according to the invention applied to a bottle neck, Figure 2 is an elevation, partly in section of the closure shown in Figure 1 when removed from the bottle neck, Figures 3 to 7 illustrate, to an enlarged scale, stages in the formation of the closure shown in Figure 1, and Figures 8 and 9 illustrate diagrammatically alternative embodiments of the closure.

Referring to the drawings, the closure is formed from thin ductile metal and has a top 1 and a skirt 2 which comprises an uPper part 3 adapted to have screw threads 4 formed therein and a lower part 5 which constitutes a collar or locking ring and is connected to the upper part 3 by a series of angularlysaced bridges 6 interrupting a penpheralstline 7.closure as thus far described is of a conventional kind and as is customary the screw threads 4 may be preformed in the skirt or, as is more usual, thread-rolled into engagement with threads on the neck 8, Figure 1, of a bottle. When the closure is applied to the bottle neck the collar or locking ring 5 is inturned from the broken line position to the full line position shown in Figure 1.As is usual, the closure may be provided with a cut line 9, Figure 1, to facilitate removal of the collar or locking ring when it is desired to remove the closure from the bottle neck. The closure may, if desired, be provided with a sealing compound 10 or with a disc, a washer, or a wad.

In accordance with the invention the upper part of the skirt is provided with a mask, indicated generally by the reference 11, which when the upper part 3 is separated from the lower part, Figure 2, affords protection against injury from the ragged edge 12 created by rupturing of the bridges 6.

Preferably, as shown in the drawing, the mask 11 is integral with the skirt and is formed, as described below, by folding of a portion of the skirt.

In the embodiment of Figure 1 the mask 11 is formed by a portion of the skirt which is outfolded from the skirt so that on separation of the lower part 5 from the upper part 3 by rupturing at the bridges 6, Figure 2, the outfolded portion forms a bead which extends axially of the closure and then defines the lower edge 13 of the closure. To permit this the peripheral slit line 7 with the bridges 6 is located between the lower edge 13 and the top 1 of the closure. As shown in Figures 1 and 2 the outer layer of the mask may be provided with knurling 14. The method of forming the mask is illustrated in Figures 3 to 7. Referring to Figures 3 to 7, a part of the skirt 2 is folded outwards to form a two-sided bead, Figure 3, one side 15 of which is preferably substantially normal to the skirt and the other side 16 of which forms an acute angle with the side 15.Next the series of angularly spaced bridges 6 interrupting the peripheral slit line 7 is formed in the skirt adjacent to and below the side 15 of the bead, Figure 4. The slits are then, if necessary, set back substantially into the plane of the skirt, Figure 5, and the bead is collapsed downwardly towards the skirt, Figures 6 and 7, so that the bead forming the mask 11 extends substantially parallel with the axis of the closure beyond the peripheral slit line 7 towards the collar or locking ring 5, while being offset outwardly from the upper part 3 of the skirt, as shown.

If desired, setting back of the slits may be effected while the closure is being thread rolled on to the neck 8 of a bottle.

The mask may be provided with knurling 14 and if desired this is done during the final collapsing of the bead. However, knurling of the cap skirt may be provided in the conventional manner adjacent the top 1.

In the alternative embodiment of Figure 8 the mask consists of a flattened bead which is formed inwardly of the upper part 3 of the skirt, and the lower part 5 of the skirt is offset inwardly to accommodate the bead.

The peripheral slit line 7 is formed at the end of the bead nearest the top 1.

In the embodiment of Figure 9, only the upper portion 17 of the lower portion 5 of the skirt is offset inwardly to accommodate the bead. The peripheral slit line 7 is formed at the end of the bead nearest the top 1 of the closure, where it joins the inwardly offset portion 17.

WHAT WE CLAIM IS: 1. A closure of the kind which is formed from thin ductile metal and which has a top and a skirt which comprises an upper part adapted to have screw threads formed therein and a lower part which constitutes a collar or locking ring and is connected to the upper part by a series of angularly spaced bridges interrupting a peripheral slit line,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. (b) forming a series of angularly spaced bridges interrupting a peripheral slit line in the skirt adjacent to and below said one side of the bead, and (c) at least partially collapsing the bead downwardly so that the bead extends down beyond the peripheral slit line and the outer and inner layers of the bead are substantially parallel with the axis of the closure. In one embodiment the method may include the step of setting the slits back substantially into the plane of the skirt before collapsing the bead downwardly. If desired, the outer side of the bead may be knurled while collapsing the bead. The invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is an elevation, partly in section, of a closure according to the invention applied to a bottle neck, Figure 2 is an elevation, partly in section of the closure shown in Figure 1 when removed from the bottle neck, Figures 3 to 7 illustrate, to an enlarged scale, stages in the formation of the closure shown in Figure 1, and Figures 8 and 9 illustrate diagrammatically alternative embodiments of the closure. Referring to the drawings, the closure is formed from thin ductile metal and has a top 1 and a skirt 2 which comprises an uPper part 3 adapted to have screw threads 4 formed therein and a lower part 5 which constitutes a collar or locking ring and is connected to the upper part 3 by a series of angularlysaced bridges 6 interrupting a penpheralstline 7.closure as thus far described is of a conventional kind and as is customary the screw threads 4 may be preformed in the skirt or, as is more usual, thread-rolled into engagement with threads on the neck 8, Figure 1, of a bottle. When the closure is applied to the bottle neck the collar or locking ring 5 is inturned from the broken line position to the full line position shown in Figure 1.As is usual, the closure may be provided with a cut line 9, Figure 1, to facilitate removal of the collar or locking ring when it is desired to remove the closure from the bottle neck. The closure may, if desired, be provided with a sealing compound 10 or with a disc, a washer, or a wad. In accordance with the invention the upper part of the skirt is provided with a mask, indicated generally by the reference 11, which when the upper part 3 is separated from the lower part, Figure 2, affords protection against injury from the ragged edge 12 created by rupturing of the bridges 6. Preferably, as shown in the drawing, the mask 11 is integral with the skirt and is formed, as described below, by folding of a portion of the skirt. In the embodiment of Figure 1 the mask 11 is formed by a portion of the skirt which is outfolded from the skirt so that on separation of the lower part 5 from the upper part 3 by rupturing at the bridges 6, Figure 2, the outfolded portion forms a bead which extends axially of the closure and then defines the lower edge 13 of the closure. To permit this the peripheral slit line 7 with the bridges 6 is located between the lower edge 13 and the top 1 of the closure. As shown in Figures 1 and 2 the outer layer of the mask may be provided with knurling 14. The method of forming the mask is illustrated in Figures 3 to 7. Referring to Figures 3 to 7, a part of the skirt 2 is folded outwards to form a two-sided bead, Figure 3, one side 15 of which is preferably substantially normal to the skirt and the other side 16 of which forms an acute angle with the side 15.Next the series of angularly spaced bridges 6 interrupting the peripheral slit line 7 is formed in the skirt adjacent to and below the side 15 of the bead, Figure 4. The slits are then, if necessary, set back substantially into the plane of the skirt, Figure 5, and the bead is collapsed downwardly towards the skirt, Figures 6 and 7, so that the bead forming the mask 11 extends substantially parallel with the axis of the closure beyond the peripheral slit line 7 towards the collar or locking ring 5, while being offset outwardly from the upper part 3 of the skirt, as shown. If desired, setting back of the slits may be effected while the closure is being thread rolled on to the neck 8 of a bottle. The mask may be provided with knurling 14 and if desired this is done during the final collapsing of the bead. However, knurling of the cap skirt may be provided in the conventional manner adjacent the top 1. In the alternative embodiment of Figure 8 the mask consists of a flattened bead which is formed inwardly of the upper part 3 of the skirt, and the lower part 5 of the skirt is offset inwardly to accommodate the bead. The peripheral slit line 7 is formed at the end of the bead nearest the top 1. In the embodiment of Figure 9, only the upper portion 17 of the lower portion 5 of the skirt is offset inwardly to accommodate the bead. The peripheral slit line 7 is formed at the end of the bead nearest the top 1 of the closure, where it joins the inwardly offset portion 17. WHAT WE CLAIM IS:

1. A closure of the kind which is formed from thin ductile metal and which has a top and a skirt which comprises an upper part adapted to have screw threads formed therein and a lower part which constitutes a collar or locking ring and is connected to the upper part by a series of angularly spaced bridges interrupting a peripheral slit line,

wherein the upper part of the skirt has, at its lower extremity, a bead comprising an outer layer and an inner layer which are integral and continuous with the upper part of the skirt, the free edge of the bead being located above the lowermost edge of the bead and being connected through the said bridges to the lower part of the skirt, and the outer and inner layers of the bead and the lower part of the skirt are all substantially parallel with the axis of the closure, whereby the bead forms a mask for the ragged edge on the upper part of the skirt which is created by rupturing of the bridges.

2. A closure according to Claim 1 wherein the peripheral slit line is so located that on rupturing of the bridges the ragged edge on the upper part of the skirt is disposed between the opposite ends of the bead.

3. A closure according to Claim 1 or Claim 2 wherein the outer layer of the bead is provided with knurling.

4. A closure according to any one of the preceding Claims, wherein the bead is offset outwardly from the upper part of the skirt.

5. A closure according to any one of Claims 1 to 3, wherein the bead is formed inwardly of the upper part of the skirt and the upper portion of the lower part of the skirt is offset inwardly to accommodate the bead.

6. A closure according to any one of Claims 1 to 3, wherein the bead is formed inwardly of the upper part of the skirt and the whole of the lower part of the skirt is correspondingly offset inwardly of the upper part of the skirt.

7. A method of forming a closure according to Claim 2 comprising the steps of: (a) folding outwards from the upper part of the skirt a two-sided bead one side of which is preferably substantially normal to the skirt and the other of which forms an acute angle with said one side, (b) forming a series of angularly spaced bridges interrupting a peripheral slit line in the skirt adjacent to and below said one side of the bead, and (c) at least partially collapsing the bead downwardly so that the bead extends down beyond the peripheral slit line and the outer and inner layers of the bead are substantially parallel with the axis of the closure.

8. The method according to Claim 7 including the step of setting the slits back substantially into the plane of the skirt before collapsing the bead downwardly.

9. The method according to Claim 7 or Claim 8 including the step of knurling the outer side of the bead while collapsing the bead.

10. A closure according to Claim 1 substantially as herein described with reference to Figures 1 to 7 or to~8 or 9 of the accompanying drawings.