Patent Application
20230090849
The present invention concerns a captive closure comprising a screw cap which has at least one cylindrical cap skirt having a female thread and a peripherally extending tamper-evident band at the lower open end of the cap skirt, wherein the tamper-evident band is connected to the lower edge of the cap skirt by way of at least one easily tearable weakening line, wherein after tearing along the weakening lines the tamper-evident band remains connected non-detachably to the cap skirt by way of holding bands. The present invention also concerns a combination comprising a container neck having a male thread and a corresponding screw cap.
Plastic products and corresponding plastic waste, in particular in the form of so-called microplastics, which are formed by abrasion and decay from plastic waste are increasingly the subject of focus of public attention. Screw closures to which the present invention relates also comprise plastic, typically polyethylene or polypropylene. The deposit system which was also introduced for disposable bottles of plastic admittedly reduces the number of plastic bottles ending up in residual waste, which instead are passed for recycling, but that does not prevent the situation whereby in many cases the closures of the bottles after being emptied are not screwed on to the bottle again but are discarded or disposed of separately and thus pass uncontrolledly into the environment and for example at riverbanks and beaches into the sea.
There were and there are therefore endeavours to design closures on bottles, in particular on drinks bottles, in such a way that even after opening of a bottle they remain connected to the bottle neck. Such a property is also referred to as “captive”.
Captive closures are known in principle.
Particularly in the case of disposable bottles the so-called tamper-evident bands which are connected to the lower edge of a cap skirt by way of weakened locations remain hanging from the bottle neck under a so-called pilferproof ring and already form a captive part of the closure. In that respect it is only necessary to ensure that, even after opening and release of the screw cap from the bottle neck thread the screw cap remains connected to the tamper-evident band by way of at least band portion or the like, referred to herein as a holding band, the tamper-evident band in turn being held fast to the bottle neck by way of the so-called pilferproof ring. A pilferproof ring is typically an annular projection which extends peripherally beneath the bottle neck thread and which has a substantially flat or slightly conical underside, behind which radially inwardly projections or parts of a tamper-evident band hookingly engage so that when a screw cap is unscrewed the tamper-evident band is held fast by the pilferproof ring while the weakened locations between the tamper-evident band and the cap skirt tear.
It is then only necessary to ensure that the connection remaining by way of the at least one holding band between the tamper-evident band and the cap skirt is sufficiently long to lift the screw cap completely off the mouth opening of the bottle neck and to be able to move it laterally or tip it away from the opening of the bottle neck.
It will be noted however that these captive screw caps are frequently found to be highly disruptive in use as the caps, for example when pouring liquid out of a corresponding bottle, move back in front of the opening of the bottle or under the action of the force of gravity turn on the bottle neck and move into the jet of liquid when it is being poured out.
In particular if a user wants to drink directly out of a bottle corresponding screw caps which are still joined to the bottle neck are often in the way and are a nuisance. The conventional captive closures can also cause disruptions when closing bottles in high-output closure installations.
In practice therefore captive closures have not yet gained acceptance to a desirable extent. Therefore the object of the present invention is to design a captive screw cap with tamper-evident band in such a way that the screw cap after unscrewing and release from the bottle neck opening is tipped or pivoted away into a position which does not interfere with further use of the bottle and drinking from or pouring out of the bottle and can remain there without additional measures. Here the screw cap is also referred to for brevity as the “cap”.
That object is attained by a screw closure according to the present invention as defined in claim 1.
In the screw closure according to the invention holding bands are formed by two weakening lines which are respectively interrupted at least once in the peripheral direction and which extend at an axial spacing relative to each other and in the peripheral direction partially overlap alternately, wherein interruption portions of both weakening lines are bridged over by the respective other weakening line at an axial spacing. The weakening lines can be produced by cuts or also by separating lines with strips, which are already formed in the injection moulding arrangement.
The above-mentioned interruption portions in the weakening lines are referred to hereinafter as “separating strips”. The separating strip of the upper weakening line effectively forms an axial extension of the cylindrical cap skirt, that is limited to a peripheral sector. The separating strip of the lower weakening line forms an axial extension of a lower tamper-evident band portion which is held stationarily to the bottle neck.
In conventional closures in which tamper-evident band and cap skirt are connected together along a single peripherally extending weakening line, which tears open when the closure is opened for the first time, the term “tamper-evident band” is used to denote all portions at the lower edge of a closure cap skirt, that lie axially beneath or from the cap thread beyond the level of the weakening line which corresponds to the line referred to here as the upper weakening line.
The expression “axially beneath” here also includes the inwardly and upwardly angled portion of a so-called flexband which in production of the closure cap forms an axial prolongation of the outer tamper-evident band portion, even if parts of that angled flexband portion in the upwardly folded state can extend on the cap inside above the level of the upper weakening line.
To simplify the description herein the foregoing definition of the term “tamper-evident band” is retained, that is to say both separating strips are viewed as part of the tamper-evident band insofar as they lie below the level of the upper weakening line, even if the separating strip of the upper weakening line remains fixedly connected to the lower edge of the cap skirt and is only detached along the lower weakening line from the part of the tamper-evident band, that remains stationarily on the bottle neck. That similarly also applies to the holding bands which when the closure is closed also lie below the level of the upper weakening line, but nonetheless upon and after opening do not remain in that position.
The above-defined tamper-evident band comprises a part which remains stationarily on the bottle neck and which—apart from a rotation—remains immobile relative to the bottle neck, and moveable parts like the holding bands and the upper separating strip which upon opening are moveable relative to the stationary part and the bottle neck, but remain connected to the stationary part.
In that way the closure remains overall non-detachably connected to the bottle neck.
The separating strips have ends in the peripheral direction which over their axial width are respectively connected to one of the ends of the holding bands. The separating strips are of at least the same inside radius as the cap skirt. The axially downwardly facing free end face of the upper separating strip is referred to as the lower edge while the axial end region of the upper separating strip, that includes the edge, is referred to as the “rim”.
The peripherally overlapping portions of the weakening lines define the holding bands as strip-shaped portions of the tamper-evident band, that extend between the weakening lines in the peripheral direction.
The cylindrical cap skirt with the female thread defines an axis of the closure and the bottle neck on to which a corresponding screw cap is screwed defines an axis of the bottle neck. Those axes coincide in the closed state.
A sufficient axial spacing of the weakening lines of for example at least 2 mm in the overlap region thereof leads to sufficiently strong holding bands which do not tear up to a tensile force of 30 N and generally even up to 40 N. For an average consumer and in particular for children it is therefore not readily possible to tear the screw cap off the part of the tamper-evident strip which is held fast under the pilferproof ring, by tearing the holding bands. As a result the cap including the tamper-evident band remains constantly connected to the bottle neck.
Suitable matching of the peripheral extent of the separating strips and the spacing (measured in the axial direction) of the weakening lines can provide that a screw cap, after being unscrewed and lifted off and being folded over at a sufficient spacing relative to the container neck opening, is moved into a sufficiently stable position in which it remains after opening and after being folded over and does not move into a disruptive position in front of the container neck mouth opening even under its own weight, independently of the orientation of the associated container or bottle neck.
The terms “container” and “bottle” are used synonomously in the context of the present invention as in regard to the invention the precise kind of container is not an important consideration as long as it has only one neck with male thread, on to which the closure or the screw cap of the closure fits.
Desirably each of the two weakening lines has precisely one separating strip and the centre points of the two separating strips are in mutually diametrally opposite relationship. The weakening lines are at any event at an axial spacing relative to each other in their overlap regions. In an embodiment when the closure is unopened the two weakening lines remain along the entire peripheral extent thereof at the same respective axial position which however is different between the two weakening lines. The axial position of the weakening lines however can also vary along the extent thereof in the peripheral direction as long as the holding bands do not become too narrow as a result and retain a sufficient tearing strength of at least 30 N to preferably at least 40 N.
In regard to the separating strips of the weakening lines such an axial spacing is admittedly not important and the respective other weakening line which is not interrupted there could in this example transition into an axial position which otherwise corresponds to the interrupted weakening line or which is at an even larger axial spacing therefrom.
The upper weakening line defines a separating line between the lower rim of the cap skirt and the tamper-evident band. The lower weakening line separates the tamper-evident band along a peripheral portion into a lower and an upper tamper-evident band portion, wherein the upper tamper-evident band portion is fixedly connected to the cap skirt in the region of the interruption in the upper weakening line and otherwise defines a portion of the separating line between holding bands and the lower tamper-evident band portion.
In an embodiment the tamper-evident band is a so-called flexband which has a first outer tamper-evident band part which extends as an axial prolongation of the cylindrical cap skirt and a second tamper-evident band part which is folded over from the lower edge of the first tamper-evident band part radially inwardly and upwardly and whose free upwardly facing end has engagement elements for engagement with the underside of the pilferproof ring.
The terms “upper” and “lower” are used here as ensues upon orientation of the closure when fitted on to the bottle neck opening of a vertically disposed bottle.
Separation of the tamper-evident band along the entire length of the weakening lines means that in the overlap region of the weakening lines, by virtue of the axial spacing thereof, strip-shaped portions of the tamper-evident band are produced, which are referred to herein as holding bands. Those holding bands connect the respective separating strips of the upper and lower weakening lines, wherein those separating strips in turn form a connection to the cap skirt and to the first anti-tamper band part respectively, which is intended to remain stationarily on a bottle neck. The separating strip of the lower weakening line is also determining for the length of the holding bands but does not have any function going beyond that, in terms of the stability of the opened cap position. The separating strip of the upper weakening line (upper separating strip) in contrast, depending on the respective configuration thereof, contributes substantially to stabilisation of a widely opened state of the cap. Insofar as reference is made hereinafter to “separating strip” without more detailed identification, this therefore always means that upper separating strip. That separating strip forms an axial extension of the cap skirt and is fixedly connected thereto.
The ends of that separating strip in the peripheral direction are respectively connected to one of the ends of the holding bands, while the other end of the holding bands is respectively connected to the ends of the lower separating strip in the peripheral direction.
After the screw cap is unscrewed and then pivoted away or folded over, remaining connected to the bottle neck by way of the separating strips and by the holding bands, the cap after a pivotal movement through about 90° moves into a position in which the lower rim of the separating strip, that is pivoted with the cap, is moved radially inwardly towards the bottle neck and the upper rim of the separating strip, directly adjoining the cap skirt, is moved radially outwardly away from the bottle neck.
The holding bands between the two separating strips are thereby twisted and hold the cap or the separating strip which axially prolongs the cap in contact with the bottle neck. The lower rim of the separating strip or its lower edge is in contact with the bottle neck in that situation and forms a pivot point on the bottle neck, that however is displaced in the axial direction during the pivotal movement on the bottle neck.
Apart from a slight return force of the twisted holding bands the tamper-evident band does not initially oppose any noteworthy resistance during the folding-over movement of the screw cap and the pivotal movement of the lower rim of the separating strip, radially towards the bottle neck.
As the holding bands are connected to the ends of the separating strip over the entire width the portions of the holding bands, which directly adjoin the upper end of the separating strip, are stretched somewhat more greatly than the portions adjoining the lower end of the separating strip. The axial height of the separating strip between the pivot point and the upper attachment of the holding bands thus forms a lever for the pulling force on the holding bands, which lever when a dead centre point in respect of the pivotal movement at about 90° is exceeded assists with the further opening movement of the cap. As a result the cap reaches a stable opening angle of about 140° with respect to its starting position. In addition the holding bands extend over the pilferproof ring by virtue of the upward movement of the screw cap with the upper separating strip, and that contributes to stretching and tensile stressing in the holding bands. The fact that the separating strip extends over a certain peripheral angle of for example 20-60° also has the result, when folding over the cap, because of the arcuate configuration of the separating strip along the periphery and with the radius of the cap skirt, of producing an increase in the spacing of the ends of the separating strip from the bottle neck and thus a corresponding increase in the tensile force in the holding bands which thus hold the cap in the wide-opened position by pulling the turned-over separating strip to the bottle neck.
In principle however the holding bands, that is to say the length of the overlap regions of the two weakening lines, and also the axial height and peripheral length of the separating strip, are such that stretching of the bands remains in the elastic range and does not reach the yield point.
This means that, by virtue of the engagement between the lower edge of the separating strip and the bottle neck by the holding bands, a varying force is exerted on the separating strip, which initially rises upon tipping of the screw cap, then goes beyond a dead centre point and then decreases again, more specifically when the screw cap and therewith the upper separating strip are tipped through more than about 90° with respect to the closed position thereof, in which case the holding bands extending between the two separating strips are turned in themselves. Because of a comparatively small wall thickness of for example 0.3 to 0.6 or 0.8 mm and a moderate width (measured in the axial direction) of the holding bands of for example 3 mm the elastic return forces by virtue of the twisting of those holding bands are relatively slight in comparison with the force which the holding bands exert in the direction of the bottle neck on the upper separating strip.
As a result the folded-over position of the closure, that is reached after passing beyond the dead centre point, remains substantially stable and the screw cap does not move in front of or too close beside the bottle neck opening, which causes problems.
So that the screw cap does not cause a problem in particular when drinking out of the bottle neck opening in an embodiment the axis of the closure cap which in the closed state of the closure coincides with the axis of the bottle neck is to assume a stable position after opening and lateral pivoting of the closure, in which position it is pivoted with respect to the starting position or with respect to the axis of the bottle neck through at least 120°, preferably at least 140°.
In consideration of the mode of operation of the captive closure during and after the screw cap being folded over it will be clear that the specifically produced return and stabilising forces depend on a whole series of interacting parameters, which include inter alia a certain axial width and the peripheral extent of the upper separating strip fixed to the cap skirt, the difference between the outside radius of the bottle neck and the inside radius of the separating strip, which is the same as the inside radius of the cap, and the peripheral extent of the weakening lines and the lower separating strip (and thus the length of the holding bands).
The above-mentioned parameters can be matched to each other in different combinations in such a way that the folding-over movement of the screw cap takes place beyond a dead centre point so that the screw cap overall has a bistable position, wherein the screw cap in the completely opened stable position does not interfere with access to the bottle neck mouth. Preferred and practically functional values for the above parameters are set forth hereinafter and in the appendant claims.
In principle it is desirable even if not necessary that each weakening line has precisely one separating strip and the centre points of the separating strips are in diametrally opposite relationship. The separating strip of the lower weakening line which is fixedly connected to the other part of the tamper-evident band delimits in a direction the overlap between the upper and lower weakening lines and the overlap of the weakening lines determines the length of the holding bands which connect the tamper-evident band remaining on the bottle neck to the screw cap skirt.
Desirably the separating strip of the upper weakening line extends over a peripheral angle between 10° and 75°, preferably in the range between 20° and 60°. An angle in that range ensures that the separating strip in itself is stable and is folded over together with the cap skirt and upon opening not just the cap skirt is bent over with respect to the separating strip while on the other hand that also provides for an adequate force which holds the folded-over closure in its completely open position, for which the separating strip must be of a certain minimum length in the peripheral direction.
The separating strip of the lower weakening line which is diametrally opposite the separating strip of the upper weakening line can extend over a peripheral angle of between for example 120° and 200°, preferably between 170° and 190°, wherein the difference in the peripheral angle of the upper and lower separating strips defines the length of the holding bands which extend between the remaining part of the tamper-evident band and the cap skirt.
The width of the separating strip remaining on the cap skirt should preferably be at least half the width of the total, intact tamper-evident band, that is to say which is not divided along the weakening lines, so that the twisting of that relatively wide portion in relation to the rest of the tamper-evident band causes a corresponding difference in diameter and length between the radially inner lower edge of the separating strip and the upper rim of the separating strip, that attaches to the screw cap.
Expressed in numbers the width as measured in the axial direction (in the intact state) of the separating strip remaining on the cap skirt is at least 1.5 mm, preferably at least 2 mm and in particular about 3 mm or more. The wall thickness of the tamper-evident band in contrast is in a range between 0.3 and 0.8 mm so that it is clear that the forces produced in the band by twisting of the separating strip with respect to the rest of the band are governed inter alia by the different inside and outside radii of the twisted tamper-evident band portions (consisting of the holding bands and the upper separating strip), which is correspondingly greater the wider the twisted portion is.
The minimum width of the holding bands, measured in the axial direction, depends inter alia on the plastic material specifically used and also on the wall thickness of the holding bands. The minimum spacing of the weakening lines, that defines the minimum width of the holding bands, should accordingly in an embodiment be greater than 1 mm, preferably greater than 2 mm and in particular greater than 2.3 mm. An upper limit is respectively established by the width of the tamper-evident band. The holding bands which are effectively formed as portions of the tamper-evident band, that extend between the separating lines, are then of a sufficient tearing strength to prevent the screw cap from being forcibly torn off the tamper-evident band—at least by the hands of a child. Preferably the holding bands are tear-resistant up to a tensile force of at least 30 N, preferably at least 40 N.
The combination according to the invention comprising a bottle neck with a male thread and a closure as was described hereinbefore is characterised in that the outside diameter of the bottle neck above a pilferproof ring, the inside diameter of the tamper-evident band and the width, the peripheral extent and any thickening of the upper separating strip are so matched to each other that after being released and when the screw cap is then folded over the free lower edge of the separating strip comes into engagement with the bottle neck. In that situation the holding bands are twisted somewhat. When a tipping angle of about 90° is exceeded the cap with the separating strip is moved beyond a dead centre point so that thereafter the outside of the separating strip is towards the outside of the bottle neck and the screw cap is stabilised by virtue of a certain tensile stress in the holding bands in that position of being turned over through more than 90°.
The folding-over or tipping angle is defined here as the angle between the axis of the bottle neck (which coincides with the closure axis when the bottle or container neck is closed by the closure) and the closure axis in the turned-over state.
The difference between the outside diameter of the bottle neck in a region above the pilferproof ring, in which after opening of the closure the upper separating strip of the tamper-evident band is arranged against the bottle neck, should be at most 2.5 mm, preferably at most 1.5 mm smaller than the nominal inside diameter of the tamper-evident band. The term “nominal inside diameter” is used to denote the inside diameter of the tamper-evident band without any flexband portion which in particular also corresponds to the inside diameter of the cap in the region of the upper separating strip before the weakening lines are separated.
In the variant discussed hereinafter a slight difference in diameter between the relevant portion of the bottle neck or the pilferproof ring, along which the lower edge of the separating strip slides, and the diameter of the tamper-evident band is ensured by adaptation of the bottle neck diameter or the pilferproof ring profile and thus also its diameter.
A small difference in diameter provides that the lower edge of the separating strip which is fixedly connected to the upper rim of the cap skirt and which after the screw cap is released is disposed above the pilferproof ring already comes into engagement with the bottle neck upon a relatively small tipping angle and even after passing beyond the dead centre point a force caused by such engagement between the bottle neck and the separating strip is acting, which holds the folded-over screw closure in the wide-opened position and stabilises it.
In a variant of the combination according to the invention comprising container neck with screw thread and closure the pilferproof ring is of a profile defined by a lower flank which extends in an axial section at at least 80° relative to the bottle neck axis, a region of maximum diameter and an upper flank which extends at an angle of inclination <90° relative to the bottle neck axis and transitions beneath the thread on the bottle neck into the outer bottle neck diameter. In that case the upper flank or a portion of the bottle neck above the upper flank of the profile of the pilferproof ring extends at least into or as far as an axial position which at a maximum folded-over position of the screw cap is reached by the lower edge of the upper separating strip. That portion is of a larger outside diameter than the bottle neck without thread profile or in the thread bottom.
This means that when unscrewing and folding over the screw cap, the upper separating strip is firstly lifted over the region of the maximum diameter of the pilferproof ring and its lower edge slides on to the upper flank thereof, wherein the bottle neck diameter which is enlarged in that region over which the lower edge of the separating strip passes urges the separating strip further radially outwardly than would be possible with the bottle neck diameter because otherwise it would be present between the pilferproof ring and the thread and also at the thread bottom. That causes further twisting of the holding bands and thus rotates the separating strip and the screw cap into a still further tipped position.
The difference in the outside diameter of the upper flank or the portion above same and the bottle neck diameter without thread profile, that is to say at the thread bottom, should be at least 0.1 mm, preferably at least 0.3 mm and up to 1 mm in the above-described variant.
In particular in the combination according to the invention of container neck with screw thread and closure the pilferproof ring is of a triangular profile or a trapezoidal profile, the lower flank of which extends at an angle of 80° or more, that is to say perpendicularly or almost perpendicularly to the axis of the container neck, and the upper flank of which extends at an angle of about 30° or less relative to the axis of the container neck. Upon opening of the container by unscrewing the closure the separating strip slides over the ridge between the flanks of the pilferproof ring, whereafter firstly the upper flank of the pilferproof ring comes into contact with the separating strip. By virtue of the small angle of the upper flank the flank has a large axial extent and the region defined by that flank of a diameter greater than the above-mentioned bottle neck diameter thereabove can readily extend over the region over which the lower edge of the separating strip passes when the closure cap is opened and folded over.
In addition the cylindrical neck portion of the container neck, on which the cylindrical male thread is provided, can generally be of a slightly larger diameter (by about 0.3-0.8 mm) below the thread and above the pilferproof ring, than above same, which leads to an even stronger engagement between the lower edge of the upper separating strip and the bottle neck and thus tends to further increase the tipping angle between the bottle neck axis and the axis of the closure.
Many established bottle neck standards are not to be modified at short notice and otherwise only with the involvement and with discussions of many participating parties so that as a result the diameter of a bottle neck or pilferproof ring and the profile thereof are initially to be deemed invariable. A further configuration of a closure is presented for that purpose, which is provided for use on standard bottle necks which have a thread depth by standard of 1.3 mm or more. An example of this is the bottle neck in accordance with the PCO standard 1881.
With a deeper thread the inside radius of the cap skirt also involves a larger difference in relation to the outside radius of the bottle neck than in a thread which is less deep as the inside radius of the cap skirt corresponds at least to the radius of the thread bottom of the screw cap, which in turn is somewhat larger than the outside radius of the bottle neck thread.
That correspondingly applies to the lower edge region of the cap skirt and the separating strip attached thereto.
For such deeper threads it is possible to consider a further parameter of the closure in order to ensure a sufficiently large and stable pivotal angle for the closure in the open state, more specifically the radial thickness of the upper separating strip at its lower rim.
The lower rim of the upper separating strip in the intact state of the tamper-evident band extends along the lower weakening line and is delimited thereby.
In an embodiment intended in particular for closure and bottles which have a thread depth beyond 1.2 or 1.3 mm it is provided that the separating strip of the upper weakening line has a radial thickening at least at its free lower rim.
In particular that lower edge (in the closed state) is radially outwardly thickened. More specifically that thickening after opening and folding-over of the screw cap lies above the pilferproof ring against the bottle neck. That thickening at the separating strip compensates at least for a part of the difference in radius between the bottle neck and the inside radius of the upper separating strip which, as explained above, is also increased because of the deeper thread.
The radial thickening is provided on the outside of the separating strip and at least at one or two positions in the region of its lower edge. After the cap is pivoted over through more than 90° the radial thickening bears against the bottle neck or however the upper flank of the pilferproof ring. The radial thickening on the separating strip thus forces the region of the separating strip, that—in relation to the cap—is radially within the thickening radially further outwardly in particular at its lower rim, which effectively amounts to the part of the separating strip which is notionally considered without the thickening assuming precisely the same position and angular arrangement as in the case of a smaller radius difference between the bottle neck and the inside radius of the separating strip.
In a variant the wall thickness of the separating strip by virtue of a radial thickening of its lower rim is up to 1 mm, wherein the term “thickening” means the radial protrusion of that region beyond the surface of the tamper-evident band, which surface is otherwise cylindrical. With a wall thickness of the rest of the tamper-evident band of about 0.3 to 0.8 mm that thickening is between 0.2 and 0.7 mm, in particular 0.2 to 0.4 mm. Without that thickening the wall thickness of the tamper-evident band—apart from the weakening lines—is substantially constant and equal to the wall thickness of the cap skirt.
The thickening however can also extend over the entire tamper-evident band portion beneath the separating strip, that is to say to the lower rim of the tamper-evident band, and in particular also along the entire periphery of a lower tamper-evident band portion below a line and between the upper and the lower weakening lines and at a spacing relative to same. That simplifies production in an injection moulding mould and in particular production of the lower weakening line, in comparison with a variant which has a radial thickening restricted only to a region along the lower rim of the separating strip.
The radial thickening of the upper separating strip makes itself noticeable in particular in relation to greater thread depths on the bottle neck beyond 1.3 mm, like for example in the case of threads of the wide-spread standard type PCO1881. The thickening has a stabilising action on the pivoted position of the opened closure cap and holds the axis of the screw cap tipped in the opened state through more than 120°, preferably more than 140°, with respect to the bottle neck axis.
The axial dimensions of all parts below the cap skirt jointly, which conventionally form a tamper-evident band, are in practice limited to overall about 5 to 6 mm. On the one hand the requirement for saving material and the specifications involving suitably adapted container necks already limit that axial dimension upwardly. That dimension is limited downwardly by a sufficient functional stability. A tamper-evident band must on the one hand be secured to the bottle neck in such a way that in practice it cannot be removed without damaging the bottle neck. On the other hand it also has to withstand the forces involved in applying the closure to a bottle neck thread, in particular while it is being moved over the pilferproof ring. Those conditions can no longer be met if substantial parts of the tamper-evident band are axially shorter than for example 2 mm (apart from easily frangible bridges which can be distributed along a weakening line).
If as in the present case the closure part is additionally divided beneath the cap skirt into the elements, stationary part, holding bands and separating strips, there is only little scope available for a variation in the axial width of the holding bands and the axial height of the separating strips. In practice both dimensions are in the range of 2-3 mm. In the peripheral region of the holding bands and the upper separating strip an axial width of about 2-3 mm then remains for the stationary outer tamper-evident band portion. Any axial variation in the configuration of the weakening lines along their peripheral extent would therefore also be limited to an axial range of at most 1 mm in width for practical reasons. That would not change anything in terms of the fundamental function of a closure according to the invention and is therefore not discussed in detail here.
Moreover in an embodiment of the invention the stationary part forms a flexband with the outer stationary portion already described above and a part which is folded over inwardly and upwardly and which comes into engagement with the pilferproof ring of a bottle neck.
In a further variant the closure is designed for use on an opening spout of a carton pack.
Such a screw closure for carton packs has a closure lower part having a peripherally extending flange which can be connected to the surface of a carton pack in sealed relationship and a cylindrical pouring spout portion which adjoins the flange and which has an upper outer and a lower inner opening, a screw cap having a female thread which can be screwed on to a male thread on the pouring spout portion, a cutting ring which is arranged in the pouring spout portion and which at its lower rim has at least one axially inwardly projecting cutting edge, and an axial lift and entrainment device on the cutting ring and the screw cap which includes an entrainment means mounted at the inside of the screw cap and an axial lift device which upon rotation of the screw cap in the opening direction moves the cutting ring axially in the direction of the lower opening and in the peripheral direction and thereby produces an at least partially circularly extending cut in the container surface.
The object of the invention is also attained for such a closure in that at the lower rim of its cap skirt the screw cap has a peripherally extending tamper-evident band which with an inner projection engages behind a pilferproof ring at the outside of the pouring spout portion beneath the male thread, wherein the tamper-evident band is partially divided by two cuts which are separate from each other and which partially extend peripherally and which partially overlap in the peripheral direction and which do not cross and is partially separated from the skirt of the screw cap so that in the regions of the cuts that overlap in the peripheral direction a respective holding band is formed from parts of the tamper-evident band, which holding band holds the screw cap when released from the male thread fixedly to the lower part of the tamper-evident band, which part remains subdivided on the closure.
This variant may also have all features of appendant claims 2 to 12, wherein in regard to the combination of bottle neck and closure in claims 13 to 17 the respective bottle neck would be replaced by the closure lower part fitted to a drinks carton.
In such a closure the cutting ring on its outside has a second male thread in opposite relationship to the male thread of the pouring spout portion and which engages with a second female thread, matching same, on the inside of the pouring spout portion.
In this variant the second female thread and the second male thread can be of a greater pitch than the female thread of the screw cap and the male thread of the pouring spout portion wherein preferably the factor between the different pitches is at least 1.5.
In addition in that respect the entrainment means of the screw cap can be in the form of a lift cam with an edge or surface which is inclined relative to the closure axis and an element of the cutting ring can be in the form of a cam follower and mutually radially overlapping guide elements can be provided on the outside of the cutting ring and on the inside of the pouring spout portion, wherein at the beginning of an opening rotational movement of the screw cap the guide elements permit only an axial movement of the cutting ring and it is only after a predetermined axial position of the cutting ring is reached that they allow entrainment of the cutting ring in the peripheral direction and limit further axial movement.
Further advantages, features and possible uses of the present invention will be apparent from the description hereinafter of a preferred embodiment and the accompanying Figures in which:
In the perspective view in
Conventional screw caps with a tamper-evident band have only one single weakening line which, unlike the weakening line 13 shown here, extends without an interruption along the entire periphery of the screw cap 10 and represents the separation line between the screw cap 10 and the tamper-evident band 3.
A weakening line can generally be a peripherally extending uniform weakening of material which can be produced for example by a cut which does not extend completely through the material of the tamper-evident band 3 or the transition to the cap skirt 2, but it may also involve a cut which passes completely through the wall thickness of the tamper-evident band 3 but which is interrupted at individual points by easily frangible bridges.
The present invention differs from that conventional form of screw caps with tamper-evident band insofar as it has two weakening lines 13, 14 which on the one hand are spaced from each other in the axial direction and which on the other hand do not extend over the entire periphery of the tamper-evident band but are interrupted in an upper separating strip 11 of the upper weakening line 13 and in a lower separating strip 12 of the lower weakening line 14.
The interruptions 13, 14 are of differing lengths but are so arranged that they overlap the separating strip 11 and 12 respectively of the respective other weakening line. In that respect it is desirable if the centre points of the separating strips 11, 12 are in mutually diametrally opposite relationship as in the present case at 0° and 180° in
If after opening or unscrewing of the screw cap from a bottle neck the weak connection which initially still occurs along the weakening lines 13, 14 is completely severed the holding bands 15, 16 formed in the overlap region of the weakening line form a substantially tear-resistant connection between the interruption regions 11, 12. In that case the interruption region 11 is connected to the lower rim of the screw cap and the interruption region 12 is connected to the part of the tamper-evident band 3 which remains at its original position, being disposed beneath the weakening line 14.
The part of the tamper-evident band 3 remaining beneath the weakening line 14 together with the interruption region 12 in total still form a completely peripherally extending fixing band in engagement with the bottle neck, between the screw cap and the neck of the container. The interruption regions 12 and 11 are respectively connected together by remaining holding bands 15, 16 which are produced by the overlapping portions of the two weakening lines 13, 14 so that effectively the screw cap 10 remains connected by way of the holding bands 15, 16 to the lower portion of the tamper-evident band and thus the bottle neck and accordingly is captive.
By virtue of the thread pitch the cap skirt moves axially upwardly while the tamper-evident band is retained to a so-called pilferproof ring 21 which can only be seen by way of indication in the Figures.
As soon as the screw cap in
In that respect particular significance is attributed to the interruption region 11 which by virtue of of the connection to the cap skirt simply represents a relatively stable axial prolongation of the cap skirt 2. By tipping of the screw cap as shown in
In that case the lower edge 11a of the separating strip 11 comes into engagement with the outside of the bottle neck 20 as the edge 11a, by virtue of of the tipping of the screw cap and also by virtue of of its axial displacement is forced over the pilferproof ring 21 and because of the twisting of the holding bands 15, 16 is forced to a smaller radius than in the
The upper rim of the separating strip 11 which is fixedly connected to the lower rim of the cap skirt 2 correspondingly moves on to a larger radius than in the starting state shown in
That lower edge 11a of the separating strip 11 therefore comes into contact and frictional engagement with the outside of the bottle neck 20, wherein the force occurring between the bottle neck 20 and the separating strip 11 or the edge 11a becomes a maximum when the separating strip 11 is oriented approximately horizontally, that is to say perpendicular to the bottle neck axis 50. The holding bands 15, 16 are then under a tensile stress.
Upon a further tipping movement of the screw cap and the separating strip 11 the tensile stress in the holding bands which have a certain elasticity is reduced somewhat again so that the horizontal position of the separating strip 11 defines a dead point. As soon as that dead centre point has been exceeded the engagement between the separating strip 11 and the bottle neck 20 effectively causes a force which tends to move the screw cap into the further turned-over position against elastic return forces in the holding bands 15, 16. Accordingly the cap skirt 2 and thus the screw cap 10 overall assumes a sufficiently stable position beyond the dead centre point. The screw cap thus remains in a state of being widely opened out even if the bottle neck is rotated or inclined in any direction.
In that position the cap skirt is sufficiently far away from the bottle neck opening so that liquid can be both poured out of the bottle and also drunk directly out of the bottle without the screw cap which is still held fast to the bottle neck being a nuisance in that case.
Preferably the screw cap 10 is tipped in such a way that it is in a sufficiently stable position and the cap skirt 2 is at a distance which is of the maximum possible extent relative to the bottle neck opening. To permit that the pilferproof ring 21 on the bottle neck 20 in accordance with the invention can inter alia be of such a configuration that the screw cap 10 on being folded over is urged radially outwardly and this therefore involves a greater twisting of the holding bands 15, 16 and consequently an increase in the tipping angle.
As shown in
When the screw cap 10 is unscrewed the upper separating strip 11 is now lifted over the ridge 23 at which the pilferproof ring 21 is of its maximum diameter. In the subsequent tipping movement the holding bands 15 and 16 are twisted and the lower edge 11A of the separating strip 11 slides on to the upper flank 24 of the pilferproof ring 21. In that case the separating strip 11, by virtue of the diameter D of the upper flank 24, that is greater in relation to the outer bottle neck diameter d, in the region over which the lower edge 11A of the separating strip 11 passes, is held further radially outwardly than would be possible in relation to the bottle neck diameter d, as it is otherwise present between the pilferproof ring 21 and the thread 25 and also on the thread bottom. By virtue of that effect the holding bands 15, 16 shown in
In the embodiment shown in
A further profile of a pilferproof ring 21 is shown in
By virtue of such a profile of the pilferproof ring 21 as shown in
A further alternative is shown in
The screw cap 10 in
The purpose of the thickening 11b at the lower rim of the separating strip 11 is to hold the opened screw cap wide open, as shown for example in
The upper weakening line 13 is not present in the region of the separating strip 11 because of the sectional plane in
The fixing part of the tamper-evident band is formed by a flexband. It comprises a radially inner, upwardly folded-over part 3a and a radially outer flexband portion 3b which even after opening of the closure remains stationarily on the bottle neck.
As can be seen from
The flange 1 is welded or glued on to a carton 45, the welding operation presupposing that the carton material 45 is provided with a suitable surface coating (for example polyethylene).
The lower part 40 of the closure has a male thread 42, on to which the female thread 41 of a screw cap 10 can be screwed.
The pouring spout portion 40 also has a further female thread 31 into which engages a corresponding male thread of a cutting ring 35 which also has axially projecting cutting elements 33 which in the closed state as shown in
Upon further rotation of the screw cap 40 in the opening direction the easily frangible bridges of the cut lines also tear, which however does not lead to complete separation of the screw cap from the tamper-evident band as more specifically the upper interruption portion 11 remains connected by way of the holding bands 15, 16 (only a respective one is visible in the Figures) to the lower interruption portion 12 which in turn remains connected to the peripherally extending stationary lower part of the tamper-evident band 30, which in turn is held fast to the pilferproof ring 35 at the closure lower portion 10.
The length of the holding bands 15, 16, that is to say the length of the overlap regions of the cut lines, is set as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 128 886.7 | Nov 2018 | DE | national |
| 10 2019 120 725.8 | Jul 2019 | DE | national |
The present application is a continuation of pending U.S. patent application Ser. No. 17/280,787, filed Mar. 26, 2021, which is the national phase of International Application PCT/EP2019/080338, filed Nov. 6, 2019, which claims the benefit of German Application 10 2019 120 725.8 filed Jul. 31, 2019, and German Patent Application 10 2018 128 886.7 filed Nov. 16, 2018, which are incorporated herein in their entireties by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17280787 | Mar 2021 | US |
| Child | 17994210 | US |
