WO2007148993A2

WO2007148993A2 - Threaded cap with tamper band having different handed threads

Info

Publication number: WO2007148993A2
Application number: PCT/NZ2007/000158
Authority: WO
Inventors: Michael Patrick Noonan
Original assignee: Alto Packaging Limited
Priority date: 2006-06-21
Filing date: 2007-06-18
Publication date: 2007-12-27
Also published as: WO2007148993A3

Abstract

A tamper evident screw cap and complementary container, each having two thread formations, one below the other, and each of different handedness, whereby rotation of the screw cap relative to the container for the purpose of the breaking of the seal and screw cap removal has the effect, using that thread engagement and/or contact furtherest from the outlet, of winding the tamper band of the cap further down the neck prior to frangible separation from the screw cap. There is a lost motion providing region integrally connecting said screw cap and said tamper band such region being as moulded or as modified post moulding. The tamper banded screw cap is adapted to bump fit the tamper band thread at least in part over its thread complement.

Description

"TAMPER EVIDENT SCREW CLOSURE" TECHNICAL FIELD

The present invention relates to tamper evident screw closures or to a closure system involving a reverse thread tamper band. More particularly, the present invention relates to a tamper evident capped container assembly of a kind where rotation of the part of the cap (i.e. a screw cap frangibly removable from a tamper band) has the effect of leaving the tamper band retained by the neck, such tamper band being retained by interengagement and/or contact between complementary thread regions skeletal or otherwise).

BACKGROUND ART

The present invention in preferred forms recognises an advantage in requiring tamper band separation from a screw removable cap to occur prior to the loss of the seal of the outlet of the necked container (irrespective of whether or not such sealing is by means of a cone seal or other seal type).

The present invention also is directed to a tamper banded closure of a kind having two thread formations or complements for thread formations, or hybrid of either or both, which has each thread formation or the equivalent separated from the other by a post mould provided region of frangibility and/or has the thread formation(s) or complement(s) in opposite handedness. In an object of the present invention to provide a sealed assembly of a kind whereby rotation for the purpose of cap removal has the effect of a holding on, and/or a ramped winding of a frangibly detachable tamper band further, onto the neck of the container.

It is an object of the present invention to provide a post modified moulded cap arrangement which as a consequence of the post mould modification thereof has a frangibly detachable tamper band, the tamper band being screw thread engageable in the opposite sense to which the screw cap region of that cap itself can be screwed.

It is another or alternative object to the present invention to at least provide the public with the useful choice.

As used herein the term "formation" or "formations" has the effect of encompassing any profile able to co-act with a complement to effect a screw on, a screw hold and/or a screw removal. It can even, in the case of the tamper band, ramp to a conclusion (e.g. as if an extended lead in bayonet fit).

As used herein the term "and/or" means "and" or "or", or both. As used herein the term "(s)" following a noun includes, as might be appropriate, the singular or plural forms of that noun. As used herein "tamper band" or any equivalent encompasses any ring or like part of a cap able to be removed by a disruption from the removable screw cap. This is irrespective of whether or not it can also be removed as a tabbed tear band.

The terms "below", "above", "top", "bottom" and "underlaying" each envisages the tamper banded screw cap with its tamper band below the screw cap.

The "rotational axis" referred to hereafter is that for either or both thread formations.

As used herein the term "bump" or "bump on" envisages any engagement and/or contact between thread formations that results other than from a direct feed in screw arrangement i.e. usually as a result of an impact and/or force the formation of one component overrides the formation of the other.

DISCLOSURE OF INVENTION

In an aspect the invention is a tamper banded screw cap ("cap") for a container, wherein the screw cap has a single or multiple lead in and the underlying tamper band has a single or multiple lead in thread formation.

The thread formation of the tamper band in use is adapted to override the thread of a container to engage the thread of said screw cap.

Preferably it is a moulded item having a post mould provided region of frangibility.

Preferably the thread formation of the tamper band is a left hand thread. Preferably the thread formation of the tamper band is tapered inwardly from its bottom to its top. The taper is preferably up to 30° with respect to the rotational axis of the cap. The taper most preferably is from 5° to 15° with respect to said rotational axis.

It is preferred that at least one of the top and bottom of the thread(s) of the thread formation of the tamper band is(are) angled to facilitate one or both of bump off tooling and/or bump on at least part engagement with a complementary thread or complementary threads of a suitable container. Preferably the top of the thread(s) of the thread formation of the tamper band is(are) angled downwardly at from 45° to 80° with respect to the rotational axis. More preferably said angle in the range from 45° to 80° is about 60°.

Preferably the bottom of the thread(s) of the thread formation of the tamper band is(are) angled upwardly at from 30° to 60° with respect to the rotational axis. More preferably said angle in the range from 30° to 60° is about 45°.

Optionally the thread formation of the tamper band has multiple lead ins or is adapted to engage a multiple lead in thread formation of a complementary container. Preferably the post mould provision of a region of frangibility has involved peripheral cutting or erosion. Preferably said cutting or erosion is externally of the skirt. Preferably that peripheral cutting or erosion is fully peripheral i.e. not intermittent.

Optionally moulded inward projections remain as bridging regions spaced about the skirt of the cap after such peripheral cutting or erosion.

Preferably such bridging regions are angled.

Preferably said bridging regions are angled in die range 30 to 60° with respect to die rotational axis (most preferably).

Preferably die bridging regions can distort to a greater angle with respect to die rotational axis when die screw cap thread formations is screw engaged and tightened on the thread formation of die complementary container.

Preferably the bridging regions, prior to rupture, will become more upright (i.e. the angle lessens with respect of the rotational axis) as die screw cap starts rotation for its removal from a complementary thread formation of a suitable container and the tamper band starts its wind further on to its complementary thread formation of a suitable container.

Preferably screw cap rotation for its removal causes rupture in tension of each bridging region when each bridging region is at an angle less to the rotational axis than it was when moulded.

The invention is also a tamper banded screw cap substantially as herein described with reference to any one or more of the accompanying drawings.

In another aspect the invention is a container having a necked oudet for association with a tamper banded screw cap of die present invention, the neck having axially spaced diereon two thread formations, each of different handedness.

Preferably the container is adapted for a tamper banded screw cap as previously defined. The invention is also a necked container substantially as herein described or the neck of which is substantially as herein described, with reference to any one or more of die accompanying drawings.

In another aspect the invention is a tamper evident capped container assembly of, or combination of a container with an oudet from a neck, the neck having two thread formations, one below die odier, and each of different handedness, and a tamper banded screw cap (A) capable of sealing or sealing the oudet and (B) capable of engaging and/or contacting or engaging and/or contacting wiui each of two thread formations, one of the diread formations of the container, - A - wherein rotation of the cap for the purpose of the breaking of the seal and screw cap removal using that thread formation engagement and/or contact nearest the outlet has the effect, using that thread engagement and/or contact furtherest from the outlet, of winding the tamper band of the cap further down the neck prior to frangible separation from the screw cap. Preferably the tamper banded screw cap is a cap of any one of claims 1 to 24.

Preferably bridging regions connect the screw cap from the threaded tamper band of the screw cap. Preferably such bridging regions are angled with respect to the rotational axis of the tamper banded screw cap on the container.

Preferably the screw formation of the tamper band can be bump fitted over all of the upper most thread formation and at least part of the lower most formation.

Preferably there are multiple lead ins of the thread formation of the tamper band or the container to engage the tamper band, or both.

Preferably the thread formation of the tamper band is tapered inwardly from its bottom to its top. Preferably the taper is up to 30° with respect to the rotational axis of the cap.

Preferably the taper is from 5° to 15° with respect to said rotational axis.

Preferably at least one of the top and bottom of the thread(s) of the thread formation of the tamper band is(are) angled to facilitate one or both of bump off tooling and/or bump on at least part engagement with a complementary thread or complementary threads of a suitable container.

Preferably the top of the thread(s) of the thread formation of the tamper band is(are) angled downwardly at from 45° to 80° with respect to the rotational axis.

Preferably said angle in the range from 45° to 80° is about 60°.

Preferably the bottom of the thread(s) of the thread formation of the tamper band is(are) angled upwardly at from 30° to 60° with respect to the rotational axis.

Preferably said angle in the range from 30° to 60° is about 45°.

Preferably said bridging regions are angled in the range 30 to 60° with respect to the rotational axis.

Preferably the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container.

Preferably in the bridging regions, prior to rupture, will become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal from a complementary thread formation of a suitable container and the tamper band starts its wind further on to its complementary thread formation of a suitable container. Preferably screw cap rotation for its removal causes rupture in tension of each bridging region when each bridging region is at an angle less to the rotational axis than it was when moulded.

In another aspect the invention is a tamper evident capped container assembly of, or combination of a container with an outlet from a neck, the neck having two thread formations, one below the other, and each of different handedness, and a tamper banded screw cap (A) capable of sealing or sealing the outlet and (B) capable of engaging and/or contacting or engaging and/or contacting widi each of two thread formations, one of the thread formations of the container, wherein rotation of the cap for the purpose of the breaking of the seal and screw cap removal using that thread formation engagement and/or contact nearest the oudet has the effect, using that thread engagement and/or contact furtherest from the oudet, of winding the tamper band of the cap further down the neck prior to frangible separation from the screw cap, and wherein there is a lost motion providing region connecting said screw cap and said tamper band.

Preferably in combination or assembly, the tamper banded screw cap and the container that complements that tamper banded screw cap does so in a manner substantially as herein described with reference to any one or more of the accompanying drawings. In another aspect the present invention consists in a tamper banded screw cap for or suitable container, having a post mould provided region of frangibility in the skirt between the tamper band and screw cap, the tamper band and the screw cap each having a thread formation of different handedness. A thread formation can include one or more lead in.

Preferably the thread formation of the tamper band region has multiple lead ins or is adapted to engage a multiple lead in thread formation of a complementary closure.

Preferably the post mould provision of a region of frangibility has involved peripheral cutting or erosion. That cutting or erosion is externally of the skirt.

Preferably that peripheral cutting or erosion is fully peripheral i.e. not intermittent.

Preferably moulded inward projections remain as bridging regions spaced about the skirt of the cap after such peripheral.

Preferably such bridging regions are angled (e.g. from say 30 to 60° {most preferably about 45°}) with respect to the rotational axis.

Preferably the bridging regions can distort to a greater angle with respect to the rotational axis when die screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container (thereby to have the tamper band thread formation bump over part of its complementary thread formation).

Preferably the bridging regions prior to rupture become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal and the tamper band starts its wind furdier on to its complementary thread formations.

In still a further aspect the present invention consists in a container having a necked outlet for association with a tamper banded screw cap of the present invention, the neck having axially spaced thereon two thread formations, each of different handedness.

Preferably that thread formation closest to the outlet is a more robust thread than die thread further from die oudet. Nevertiieless, they can be the same robustness or can have the reverse. Preferably at least the thread formation further from the oudet is provided with a multiple lead in feature. In other forms they can be die same i.e. single or multiple.

In another aspect the invention consists in a tamper evident capped container assembly having a container widi an oudet from a neck of die container, the neck having two diread formations, one below die odier, and each of different handedness, and a tamper banded cap or closure ("cap") sealing die oudet and engaging and/or contacting widi each of its two diread formations one of die thread formations of the container, die cap defining a screw cap and a tamper band, wherein rotation of the cap for the purpose of the breaking of the seal and screw cap removal using that thread formation engagement and/or contact nearest the oudet has the effect, using diat diread engagement and/or contact furtherest from the oudet, of winding the tamper band of the cap further down the neck.

Preferably the cap has been moulded and post moulding cut, slit, split or eroded to provide a region of frangibility. Preferably the post mould provision of a region of frangibility has involved peripheral cutting or erosion. That cutting or erosion is externally of the skirt.

Preferably moulded inward projections remain as bridging regions spaced about the skirt of the cap after such peripheral. Preferably such bridging regions are angled (e.g. from say 30 to 60° {most preferably about 45°}) with respect to the rotational axis.

Preferably the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container (thereby to have the tamper band thread formation bump over part of its complementary thread formation).

Preferably the bridging regions prior to rupture become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal and the tamper band starts its wind further on to its complementary thread formations. Preferably screw cap rotation for its removal causes rupture in tension of each bridging region when each bridging region is at an angle less to the rotational axis than it was when moulded.

In yet a further aspect the present invention consists in a tamper evident capped container assembly having a container with an outlet from a neck of the container, the neck having two thread formations, one below the other, and each of different handedness, and a tamper banded screw cap or closure ("cap") sealing the outlet and engaging and/or contacting with each of its two thread formations one of the thread formations of the container, wherein at the commencement or immediately after the commencement of rotation of the cap for the purpose of screw cap removal that thread engagement and/ or contact furtherest from the outlet as the effect of enhancing screw cap and tamper band separation.

Preferably the cap has been moulded and post moulding cut, slit, split or eroded to provide a region of frangibility.

Preferably the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container (thereby to have the tamper band thread formation bump over part of its complementary thread formation). - Preferably the bridging regions prior to rupture become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal and the tamper band starts its wind further on to its complementary thread formations.

In still a further aspect the invention consists in a tamper evident capped container assembly having a container with an outlet from a neck of the container, the neck having two thread formations, one below the other, and each of different handedness, and a tamper banded screw cap or closure ("cap") sealing the outlet and engaging and/ or contacting with each of its two thread formations one of the thread formations of the container, one of its thread formations being of its tamperband.

Preferably the arrangements is such that tamperband and screw cap will show mutual disruption prior to breaking of die seal by die screw cap.

Preferably the tamper banded cap or closure has been wholly or in part bump fitted onto the neck of the container.

In one option the bump fitting is in respect only of die thread formation to diread formation contact of the tamper band region of die cap. In anodier option die bump fitting is in respect of both diread formations of die tamper banded cap.

Preferably that thread formation closest to die oudet is a more robust thread dian the thread further from the oudet. Nevertheless, diey can be die same robustness or can have the reverse. Preferably at least the thread formation furdier from the oudet is provided widi a multiple lead in feature.

Preferably die thread formation to thread formation interengagement closest to the oudet is of a diread formation having a single or fewer lead ins than die thread formation to diread formation engagement and/or contact of the tamper band region. In a preferred form of die present invention die tamper banded cap has been provided with a region of frangibility between the tamper band region thereof and the remainder of die cap by post mould slitting, cutting, splitting, eroding or odier post mould processing.

Preferably the post mould provision of a region of frangibility has involved peripheral cutting or erosion. That cutting or erosion is externally of die skirt. Preferably diat peripheral cutting or erosion is fully peripheral i.e. not intermittent. Preferably moulded inward projections remain as bridging regions spaced about the skirt of the cap after such peripheral.

Preferably such bridging regions are angled (e.g. from say 30 to 60° {most preferably about 45°}) with respect to the rotational axis. Preferably the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container (thereby to have the tamper band thread formation bump over part of its complementary thread formation).

Preferably the bridging regions prior to rupture become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal and the tamper band starts its wind further on to its complementary thread formations.

Preferably screw cap rotation for its removal causes rupture in tension of each bridging region when each bridging region is at an angle less to the rotational axis than it was when moulded. In still a further aspect the invention consists in a tamper evident capped container assembly having a container with an outlet from a neck of the container, the neck having two thread formations, one below the other, and each of different handedness, and a tamper banded screw cap or closure ("cap") sealing the outlet and engaging and/or contacting with each of its two thread formations one of the thread formations of the container, one of its thread formations being of its tamper band, wherein the cap is bridged intermittendy to its tamper band.

Preferably moulded inward projections remain as bridging regions spaced about the skirt of the cap after such peripheral. Preferably such bridging regions are angled (e.g. from say 30 to 60° {most preferably about

45°}) with respect to the rotational axis.

Preferably the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the diread formation of the complementary container (thereby to have the tamper band thread formation bump over part of its complementary thread formation). Preferably the bridging regions prior to rupture become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal and the tamper band starts its wind further on to its complementary thread formations.

In yet another aspect the invention is a tamper banded screw closure having a thread engaging profile internally of the tamper band of multiple lead ins to threads of smaller size to that or those of the screw cap thereof. Preferably the cap has been moulded and post moulding cut, slit, split or eroded to provide a region of frangibility.

Preferably the post mould provision of a region of frangibility has involved peripheral cutting or erosion'. That cutting or erosion is externally of the skirt.

Preferably that peripheral cutting or erosion is fully peripheral i.e. not intermittent. Preferably moulded inward projections remain as bridging regions spaced about the skirt of the cap after such peripheral.

Preferably the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container (thereby to have the tamper band thread formation bump over part of its complementary thread formation). Preferably the bridging regions prior to rupture become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal and the tamper band starts its wind further on to its complementary thread formations.

In still another aspect the invention is a necked container having a thread or thread engaging feature(s) for complementary features(s) of a tamper band of a tamper banded screw closure.

In still another aspect of the invention consists in a container having a necked outlet, the neck having axially spaced thereon two thread formations, each of different handedness, In still a further aspect the present invention consists in a tamper banded screw cap or closure substantially as herein described with reference to any one or more of the accompanying drawings.

In still a further aspect the present invention consists in a necked container having features of its neck substantially as herein described with reference to one or more of die accompanying drawings.

In still a further aspect the present invention consists in, in combination, a tamper banded screw cap or closure in accordance with the present invention and a necked container in accordance with the present invention. In still a further aspect of the present invention consists in a method of ensuring evidence of tampering prior to loss of a seal of a screw capped container, said method involving the provision of a tamper band engaged by a thread of a different handedness to that of the screw cap.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will now be described with reference to the accompanying drawings in which

Figure 1 shows a first embodiment and is a perspective view of a cutaway assembly of the cap on a neck of a container (the body of the container not being shown for convenience as it can be of any form), there being a cone seal from the screw cap part of the overall cap and a threaded tamper band below the skirt of the screw cap,

Figure 2 is an elevational view of the arrangement shown in Figure 1 ,

Figure 3 shows the neck of a container (the body of the container not being shown for convenience) showing the more aggressive (both rib size and pitch) thread nearer the oudet for engaging the screw cap and the less aggressive and with more or multiple lead in for the other handed thread of the tamper band,

Figure 4 is a view of the overall moulding showing the post moulding preferred slitting thereof to provide a line of frangibility (preferably intermittently connections remaining) between the screw cap and the tamper band, Figure 5 shows the reverse side of die cap of Figure 4,

Figure 6 shows the neck of Figure as part of a blow moulded bottle,

Figure 7 shows the axial separation of the screw up screw cap from its screw down tamper band and the broken bridges of the slitted line of frangibility of the post mould stilted cap moulding on a neck of a container, Figure 8 shows in elevation the arrangement of Figure 7 after more unscrewing of the separated screw cap,

Figure 9 shows in the view of Figure 1 the retained tamper band on the tamper band reverse thread of the neck and the removed tamper band-less screw cap, Figure 10 shows the arrangement of Figure 9 in elevation,

Figure 11 shows another perspective of the arrangement of Figures 9 and 10,

Figure 12 shows the bottom view of a second embodiment in accordance with the present invention, this embodiment having a post mould continuous cutting, slitting, splitting or erosion from the outside which has the effect of leaving small bridges as the sole connections between the tamper band and the screw cap, the tamper band having multiple lead in threads of smaller size than the single or multiple feed in thread(s) of the screw cap, each thread formation being of opposite sense e.g. as shown clockwise tightenable of the screw cap and anti-clockwise downwardly windable of the tamper band,

Figure 13 is a sectional prospective of the arrangement shown, Figure 14 is a sectional elevation of the cap in its outright condition, the cap being as shown in Figures 12 and 13, and

Figure 15 is a shaded version of Figure 14 better to show the projection provided bridging left post slitting.

It is envisaged that the cap and container neck of the present invention will be moulded in suitable plastics materials enabling bump location of the threaded tamper band onto the thread or complementary thread formation of the neck of the container.

Suitable plastics materials inside HDPE or polypropylene for the cap and HDPE, polypropylene, PET/PLA, PVC or polycarbonate for the container and thus the neck.

It is envisaged that the whole cap 1 (i.e. the tamper banded screw cap or closure) has, as part of its integral moulding, a screw cap region 2 and a tamper band region 3. Post mould, preferably a line of frangibility 4 to enable screw cap 2 and tamper band 3 separation is provided by appropriate slitting. This provides slits 4A and rupturable bridges 4B.

An alternative to post mould slitting is a more complex moulding process for the overall cap 1 to ensure frangibility. What is necessary however, by whatever means, is that there be some weakening whereby the tamper band 3 can be retained on the neck when the screw cap 2 is removed from the container.

Reference to unscrewing of cap 2 hereafter means or includes initial rotation of overall cap 1 thereby to initiate axial separation of the tamper band 3 from the cap 2 and on going unscrewing of the released cap 2. The complementary neck for a cap as shown in the accompanying drawings can be the neck shown in Figure 3. This neck 5 has its outlet 6 capable of being sealed by the cone seal 7 of the screw cap 2. The screw cap 2 has a first thread formation 8 adapted to co-act with the thread formation 9 of the neck 5. The tamper band 3 has a thread formation 10 adapted to co-act with the thread formation 11 of the neck.

Preferably the thread formation 9 is a single lead in thread but it can be of multiple lead ins. Preferably the thread 11 is of multiple lead ins and is of small profile in that of the thread formation 9.

Preferably each of the threads 9 and 11 are in line and preferably arranged such that there can be a bumping over of the thread 10 onto the thread 11 during the capping process whether by screwing on of thread 8 on the formation 9 or by simple bumping on of the thread 8 over the thread formations 9.

It is a feature of the present invention that the co-acting threads 8 and 9 and the co-acting threads 10 and 11 are of different handedness. It is also preferably but not essential that that thread inter-engagement 10/11 is of a smaller pitch than the more aggressive and stronger mechanical thread interengagement 8/9. This still should ensure the effect of ensuring that during any unscrewing of the cap 2, the seal of the cone seal 7 on inside of the necked outlet is not broken prior to there being some separation at the line of frangibility 4.

By way of example only, there can be 1.0 to 4.0 pitch and one to six start thread formations for one or both of the 8/9 and 10/11 thread combinations. Other pitches and arrangements however can be used.

Another feature of the threads is the prospect that unscrewing rotation of the cap 2 (e.g. by left hand screwing if there is a right hand thread) may lead to some lost motion prior to a ramping inter-engagement of thread 8 with thread 9 thereby ensuring some wind down of the tamper band 3 with its other handed thread 10 on the other handed thread 11.

If therefore the thread 9 is to accommodate a right hand screw close cap, the thread 11 is adapted for a left handed screw down of the tamper band as any person attempts a left hand removal of the cap 2. The opposite arrangement of handedness can in fact be used i.e. left hand screw on for the cap 2 and right hand screw down of the tamper band. A number of features arise from the present invention:

The tamper band is retained notwithstanding removal of the cap. Both or one of the threads can be bumped on. Any form of suitable thread interengagement is possible. A lost motion can be provided for the cap removal thread interengagement to maximise separation of the tamper band prior to removal of the seal provided by screw cap. Cone seal or other seal doesn't disengage until ring frangibly detaches. The connected threaded tamper band helps hold the cap hard down. A larger than usual separation is immediate upon any rotation particularly where there is loss motion for the screw cap removal thread interengagement. - A simple moulding technique for the cap can be used in conjunction with a simple post moulding slitting procedure.

The inline nature of the thread allows a necked container suited for a screw closure of the present invention to be used with other skirted screw closures such that the tamper band engaging thread 11 can be covered for aesthetic and/ or hygienic purposes. A preferred embodiment is that depicted in Figures 12 through 15 which, unlike the embodiment previously described, does not rely on intermittent slitting to provide (as a consequence of the post mould procedure) the provision of the bridging regions 4b flanked by slits 4a as the line of frangible separation. Instead, in the arrangement of Figures 12 through 15, the mould is or can be subject to slitting by a continuous slitting in a post mould process. Such slit penetration however is limited such that angled structures 6 as remnants of projections inwardly of the skirt remain sufficiendy intact as angled frangible connections (i.e. bridging regions) between die screw cap region 6 and die frangible detachable tamper band 7.

The angular disposition of diese tamper evident frangible bridges (for example at an angle of from say 30 to 60° (most preferably about 45°) with respect to the rotational axis of the cap is in die same direction as a reverse diread of die tamper evident band 7.

Figure 15 shows clockwise tightenable thread 8 and anticlockwise downwardly windable direads 9 on the screw cap skirt 6 and the tamper band 7 respectively. The peripheral slitting is only as deep as shown at 10.

Ideally such an angle of such bridging portions 6 is at about 45° with respect to die rotational axis. This angle could be from say 30 to 60° or even wider e.g. 15 to 85°. Nevertheless the angle is to be reducable on any attempt to remove die screw cap.

When a material such as HDPE, such angled connections 6, on capping, means that die tamper band 7 is energised into the cap skirt tiius helping bump die direads 9 of the tamper band 7 over formations of the container diereby to establish a diread formation to thread formation engagement of the tamper band. On removal the same angle helps with separation. The angled bridges help drive the tamper evident band down on the reverse thread thereby to enhance separation. The frangible bridges 6 eventually become vertical for a time before tension is introduced by die furdier screw cap anticlockwise unscrewing. The separation as a result of the un-screwing action of die screw cap results in severance in tension after a notable gap between die screw cap 6 and the tamper band 7 has been established. Replacement of die screw cap to its tightened condition no longer can hide the damage done even were the tamper band to be wound upwardly in an attempt to hide prior opening.

Another feature of the cap of Figures 12 through 15 as with the first embodiment is the preferred continuous nature of the main thread 8 of the screw cap 6 and the continuous nature, albeit with multiple lead ins, of the screw thread(s) 9 of the tamper band.

A cap as depicted in Figures 12 to 15 is able to be moulded and to be removed from a simple moulding tool by a simple removal process non-destructive of the tamper evident feature nor of the threads. Such removal can involve some measure of unscrewing from one part of the tooling, if appropriate, as well as riding over some of the thread forming formulation of the tooling.

The present invention preferably uses a full thread (single or multi start) and the thread owing to "angled sides" (whether straight or curving, or otherwise) does allow the bumping on. Such angled sides, if straight, we understand have a critical angle of not less than 25°.

Bumping off can also be critical in the moulding process itself as the moulding can be made and be emptied from a two part mould without two stage ejection.

An advantage of the arrangement is the fast cycle times of the moulding process. A mere delay of a couple of seconds before the multi cavity mould is open to dump out the caps is a determinate as to whether or not money can be made by the cap manufacture process.

The arrangement with its post mould slitting is very much quicker and allows a product to be made that is cost competitive in the market place.

It is believed that procedures in accordance with the present invention will lead to widespread adaptation of a new tamper evident screw cap arrangement. The present invention envisages containers necked for the capability of the interengagement described irrespective of whether or not a conventional cap might sometimes be used. Likewise the present invention relates to a screw cap in accordance with the present invention with its threaded tamper band irrespective of whether or not that cap is used with other necked bottle forms.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

Claims

I . A tamper banded screw cap ("cap") for a container, wherein the screw cap has a single or multiple lead in and the underlying tamper band has a single or multiple lead in thread formation.

2. A cap of claim 1 wherein it is a moulded item having a post mould provided region of frangibility.

3. A cap of claim 1 or 2 wherein the thread formation of the tamper band is a left hand thread.

4. A cap of any one of the preceding claims wherein the thread formation of the tamper band is adapted to override the thread of a container to engage the thread of said screw cap.

5. A cap of any one of the preceding claims wherein the thread formation of the tamper band is tapered inwardly from its bottom to its top.

6. A cap of claim 5 wherein the taper is up to 30° with respect to the rotational axis of the cap.

7. A cap of claim 6 wherein the taper is from 5° to 15° with respect to said rotational axis.

8. A cap as claimed in any one of the preceding claims wherein at least one of the top and bottom of the thread(s) of the thread formation of the tamper band is(are) angled to facilitate one or both of bump off tooling and/or bump on at least part engagement with a complementary thread or complementary threads of a suitable container.

9. A cap of any one of the preceding claims wherein the top of the thread(s) of the thread formation of the tamper band is(are) angled downwardly at from 45° to 80° with respect to the rotational axis.

10. A cap of claim 9 wherein said angle in the range from 45° to 80° is about 60°.

I I. A cap of any one of the preceding claims wherein the bottom of the thread(s) of the thread formation of the tamper band is (are) angled upwardly at from 30° to 60° with respect to the rotational axis.

12. A cap of claim 11 wherein said angle in the range from 30° to 60° is about 45°.

13. A cap as claimed in any one of the preceding claims wherein the thread formation of the tamper band has multiple lead ins or is adapted to engage a multiple lead in thread formation of a complementary container.

14. A cap as claimed in any one of the preceding claims wherein the post mould provision of a region of frangibility has involved peripheral cutting or erosion.

15. A cap as claimed in claim 14 wherein said cutting or erosion is externally of the skirt.

16. A cap as claimed in claim 15 wherein that peripheral cutting or erosion is fully peripheral i.e. not intermittent.

17. A cap as claimed in claim 16 wherein moulded inward projections remain as bridging regions spaced about the skirt of the cap after such peripheral cutting or erosion.

18. A cap as claimed in claim 17 wherein such bridging regions are angled.

19. A cap as claimed in claim 18 wherein said bridging regions are angled in the range 30 to 60° with respect to the rotational axis.

20. - A cap as claimed in claim 19 wherein the bridging regions are angled at about 45° with respect to the rotational axis.

21. A cap as claimed in claim 18, 19 or 20 wherein the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container.

22. A cap as claimed in any one of claims 17 to 21 wherein the bridging regions, prior to rupture, will become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal from a complementary thread formation of a suitable container and the tamper band starts its wind further on to its complementary thread formation of a suitable container.

23. A cap as claimed in claim 21 or 22 wherein screw cap rotation for its removal causes rupture in tension of each bridging region when each bridging region is at an angle less to the rotational axis than it was when moulded.

24. A tamper banded screw cap substantially as hereinbefore described with reference to any one or more of the accompanying drawings.

25. A container having a necked outlet for association with a tamper banded screw cap of the present invention, the neck having axially spaced thereon two thread formations, each of different handedness.

26. A container of claim 25 adapted for a cap of any one of claims 1 to 24.

27. A necked container substantially as hereinbefore described or the neck of which is substantially as hereinbefore described, with reference to any one or more of the accompanying drawings.

28. A tamper evident capped container assembly of, or combination of a container with an outlet from a neck, the neck having two thread formations, one below the other, and each of different handedness, and a tamper banded screw cap (A) capable of sealing or sealing the outlet and (B) capable of engaging and/or contacting or engaging and/or contacting with each of two thread formations, one of the thread formations of the container, wherein rotation of the cap for the purpose of the breaking of the seal and screw cap removal using that thread formation engagement and/or contact nearest the outlet has the effect, using that thread engagement and/or contact furtherest from the outlet, of winding the tamper band of the cap further down the neck prior to frangible separation from the screw cap.

29. An assembly or combination of claim 28 wherein the tamper banded screw cap is a cap of any one of claims 1 to 24.

30. An assembly or combination of claim 28 or 29 wherein bridging regions connect the screw cap from the threaded tamper band of the screw cap.

31. An assembly or combination of claim 31 wherein the screw formation of the tamper band can be bump fitted over all of the upper most thread formation and at least part of the lower most formation.

32. An assembly or combination of claim 30 wherein such bridging regions are angled with respect to the rotational axis of the tamper banded screw cap on the container.

33. An assembly or combination of any one of claims 28 to 31 wherein there are multiple lead ins of the thread formation of the tamper band or the container to engage the tamper band, or both.

34. An assembly or combination of claim 33 wherein the thread formation of the tamper band is tapered inwardly from its bottom to its top.

35. An assembly or combination of claim 34 wherein the taper is up to 30° with respect to the rotational axis of die cap.

36. An assembly or combination of claim 35 wherein the taper is from 5° to 15° with respect to said rotational axis.

37. An assembly or combination of any one of claims 33 to 36 wherein at least one of the top and bottom of the thread(s) of the thread formation of the tamper band is(are) angled to facilitate one or both of bump off tooling and/or bump on at least part engagement with a complementary thread or complementary threads of a suitable container.

38. An assembly or combination of any one of claims 33 to 37 wherein the top of the thread(s) of the thread formation of the tamper band is(are) angled downwardly at from 45° to 80° with respect to the rotational axis.

39. An assembly or combination of any one of claims 33 to 38 wherein said angle in the range from 45° to 80° is about 60°.

40. An assembly or combination of claim 39 wherein the bottom of the thread(s) of the thread formation of the tamper band is(are) angled upwardly at from 30° to 60° with respect to the rotational axis.

41. An assembly or combination of claim 40 wherein said angle in the range from 30° to 60° is about 45°.

42. An assembly or combination of claim 32 wherein said bridging regions are angled in the range 30 to 60° with respect to the rotational axis.

43. An assembly or combination of claim 32 or 42 wherein the bridging regions can distort to a greater angle with respect to the rotational axis when the screw cap thread formations is screw engaged and tightened on the thread formation of the complementary container.

44. An assembly or combination of claim 32, 42 or 43 wherein in the bridging regions, prior to rupture, will become more upright (i.e. the angle lessens with respect of the rotational axis) as the screw cap starts rotation for its removal from a complementary thread formation of a suitable container and the tamper band starts its wind further on to its complementary thread formation of a suitable container.

45. An assembly or combination of claim 32, 42, 43 or 44 wherein screw cap rotation for its removal causes rupture in tension of each bridging region when each bridging region is at an angle less to the rotational axis than it was when moulded.

46. A tamper evident capped container assembly of, or combination of a container with an outlet from a neck, the neck having two thread formations, one below the other, and each of different handedness, and a tamper banded screw cap (A) capable of sealing or sealing the outlet and (B) capable of engaging and/or contacting or engaging and/or contacting with each of two thread formations, one of the thread formations of the container, wherein rotation of the cap for the purpose of the breaking of the seal and screw cap removal using that thread formation engagement and/ or contact nearest the outlet has the effect, using that thread engagement and/or contact furtherest from the outlet, of winding the tamper band of the cap further down the neck prior to frangible separation from the screw cap, and wherein there is a lost motion providing region connecting said screw cap and said tamper band.

47. In combination or assembly a tamper banded screw cap and a container that complements that tamper banded screw cap in a manner substantially as herein described with reference to any one or more of the accompanying drawings.