Tamper evident closure

Abstract

A tamper-evident closure for a container comprises a shell having a break line along which it is separated during a first opening of the closure. The shell further comprises a first shell portion on one side of the break line, a second shell portion on the other side of the break line, and a distortable portion, which is distorted during the first opening of the closure. The distortable portion is spaced from and separate to the break line.

Claims

1. A tamper-evident closure for a container, the tamper-evident closure comprising a shell having a line of weakness along which the shell is separated during a first opening of the tamper-evident closure, the shell having at least a first shell portion on one side of the line of weakness and at least a second shell portion on the other side of the line of weakness, in which the shell further comprises a distortion zone which is distorted during the first opening of the tamper-evident closure to provide visual evidence that the tamper-evident closure has been opened at least once, the distortion zone being spaced from and separate to the line of weakness, wherein the distortion in the distortion zone is caused by an axial stretching of the shell during the first opening.

2. The tamper-evident closure as claimed in claim 1, in which the tamper-evident closure comprises a means for limiting the extent of the axial stretching of the distortion zone.

3. The tamper-evident closure as claimed in claim 2, in which the means for limiting the extent of the axial stretching of the distortion zone comprises an insulating bead on the shell.

4. The tamper-evident closure as claimed in claim 1, in which the first and second shell portions are connected to each other along the line of weakness by frangible bridges.

5. The tamper-evident closure as claimed in claim 4, wherein a solid intermediate band connects the frangible bridges to the distortion zone.

6. The tamper-evident closure as claimed in claim 1, in which the shell is formed from metal.

7. A container in combination with the tamper-evident closure as claimed in claim 1.

8. The tamper-evident closure as claimed in claim 1, wherein the distortion zone comprises a hidden notch line with alternating upper and lower slots.

9. The tamper-evident closure as claimed in claim 1, in which the distortion is caused in the distortion zone prior to the separation of the shell along the line of weakness.

10. A tamper-evident closure for a container, the tamper-evident closure comprising a shell having a line of weakness along which the shell is separated during a first opening of the tamper-evident closure, the shell having at least a first shell portion on one side of the line of weakness and at least a second shell portion on the other side of the line of weakness, in which the shell further comprises a distortion zone which is distorted during the first opening of the tamper-evident closure to provide visual evidence that the tamper-evident closure has been opened at least once, the distortion zone being spaced from and separate to the line of weakness, in which the shell comprises a top plate and a sidewall depending from the periphery of the top plate, and in which a free end of the sidewall is tucked under a bead on a container neck.

11. The tamper-evident closure as claimed in claim 10, in which the shell is formed from metal.

12. A container in combination with the tamper-evident closure as claimed in claim 10.

13. The tamper-evident closure as claimed in claim 10, in which the distortion is caused in the distortion zone prior to the separation of the shell along the line of weakness.

14. The tamper-evident closure as claimed in claim 10, in which the first and second shell portions are connected to each other along the line of weakness by frangible bridges.

15. A tamper-evident closure for a container, the tamper-evident closure comprising a shell having a line of weakness along which the shell is separated during a first opening of the tamper-evident closure, the shell having at least a first shell portion on one side of the line of weakness and at least a second shell portion on the other side of the line of weakness, in which the shell further comprises a distortion zone which is distorted during the first opening of the tamper-evident closure to provide visual evidence that the tamper-evident closure has been opened at least once, the distortion zone being spaced from and separate to the line of weakness, wherein the shell is separated during the first opening of the tamper-evident closure into a first, removable shell portion and a second, captive shell portion that remains on the container in use, and wherein the distortion zone is formed within the second, captive shell portion.

16. The tamper-evident closure as claimed in claim 15, wherein when the first, removable shell portion is removed and replaced, there is a gap between the first, removable shell portion and the second, captive shell portion.

17. The tamper-evident closure as claimed in claim 15, in which the shell is formed from metal.

18. A container in combination with the tamper-evident closure as claimed in claim 15.

19. The tamper-evident closure as claimed in claim 15, in which the distortion is caused in the distortion zone prior to the separation of the shell along the line of weakness.

20. The tamper-evident closure as claimed in claim 15, in which the first and second shell portions are connected to each other along the line of weakness by frangible bridges.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a side view of a closure formed according to an embodiment of the present invention shown in a sealed, unopened position;

(3) FIGS. 2A to 2D show the opening sequence of the closure of FIG. 1;

(4) FIG. 3A is a side view of a closure formed according to an alternative embodiment and shown in an unopened condition;

(5) FIGS. 3B to 3E show the opening sequence of the closure of FIG. 3A;

(6) FIG. 4A is a section of the closure of FIG. 3A; and

(7) FIGS. 4B to 4E show the opening sequence in sectional form of the closure of FIG. 4A i.e. corresponding to FIGS. 3B to 3E respectively.

DESCRIPTION

(8) Referring first to FIG. 1 there is shown a tamper-evident closure generally indicated 10 attached to a container (in this embodiment a bottle) neck 15.

(9) The closure 10 comprises a generally circular top plate 20 having a generally cylindrical side wall 25 depending from its periphery.

(10) The side wall 25 includes a knurled zone 30 adjacent the top plate 20. Adjacent the knurled zone 30 a screw thread profile 35 is provided and corresponds to screw thread formations formed on the neck 15; the profile 35 is formed by rolling the side wall 25 on to the neck 15.

(11) Towards the open end of the side wall 25 a line of weakness 40 is formed by a plurality of frangible bridges 45. On one side the line 40 defines a tamper-evident band 50 the free end of which is turned under a bead (not shown) on the neck 15 at a tuck under 52. At the other side of the line 40 a top cap 55 is defined.

(12) Referring now to FIGS. 2A to 2D the closure 10 is shown during opening.

(13) The top cap 55 is turned and the screw thread profile 35 begins to rise up the screw thread formations 36 on the neck (see FIG. 3A). The band 50 is prevented from lifting by the tuck under 52.

(14) The band 50 has a distortion zone 70 formed within it. More specifically, the frangible bridges 45 are not directly connected to the distortion zone 70 but rather a solid intermediate band 80 connects the bridges 45 to the distortion zone 70.

(15) As shown best in FIG. 2B, the distortion zone 70 comprises a hidden notch line with alternating upper and lower slots 85b, 90b which are defined by respective alternating upper and lower fixed points 85a, 90a, with the upper fixed points 85a connected to the solid band 80 and the lower fixed points 90a connected to the tuck under 52.

(16) Upon opening, the distortion band 70 is pulled and stretched into a zig-zag shape shown in FIG. 2B. The bridges 45 then break and the top cap 55 is removed and the distorted band 50 drops down, as shown in FIG. 2C. The band 50 remains on the glass finish. Upon re-application of the top cap 55 the zig-zag distorted area 70 remains as visual evidence the closure has been opened at least once, as shown in FIG. 2D, with a gap G between the top cap 55 and the drop band 50 and the distorted band itself.

(17) Referring now to FIGS. 3A and 4A there is shown a closure 110 formed according to an alternative embodiment.

(18) The closure 110 is quite similar to the closure 10, with a top cap 155 and drop band 50 part forming an outer shell (in this embodiment formed from metal). The band 50 is longer and includes an insulating bead 154 below the break line 140 and above the distortion zone 170.

(19) The insulating bead is rolled into the shell so as to be spaced from an undercut 117 formed on the neck finish 115. The finish 115 also includes a step 118 below the undercut 117.

(20) Referring now also to FIGS. 3B to 3E and 4B to 4E, when the closure 110 is first opened the tuck under 152 prevents any axial movement of the band. The band 150 is stretched against the tuck under 152 until the insulating bead 154 engages the undercut 117. Accordingly, the notched distortion zone 170 is stretched to the position shown in FIGS. 3C and 4C.

(21) Continued turning of the top cap 155 now causes the main bridges 145 to break. The top cap 155 can now be screwed off and the band 150 drops down, as shown in FIGS. 3D and 4D, until the bead 154 rests on the step 118.

(22) When the top cap 155 is replaced there is a gap G between the cap 155 and the band 150, as shown on FIGS. 3E and 4E.

(23) In other embodiments (not shown) a further gap generating mechanism may be included, for example as described in WO2005/049443.

(24) Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.