US20260176026A1 · App 19/126,731
SCREW CAPS FOR CONTAINERS
Publication
Application
Classifications
IPC Classifications
CPC Classifications
Applicants
Crown Packaging Technology, Inc.
Inventors
Adam Stephenson
Abstract
A screw cap for a container. The cap comprises an inner member having an annular sidewall with an internal screw thread for screwing the cap onto a threaded opening of a container; and an outer member having a skirt enclosing the sidewall of the inner member, the outer member being coupled to the inner member to prevent displacement of the outer member relative to the inner member parallel to an axis defined by the screw thread. The cap has a first configuration in which the outer member is rotatable with respect to the inner member to prevent the cap from being unscrewed and a second configuration in which the skirt engages with the sidewall of the inner member so that the cap can be unscrewed by rotating the outer member.
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Description
TECHNICAL FIELD
[0001]The present invention relates to screw caps for containers, and in particular, although not exclusively, to child-resistant screw caps.
BACKGROUND
[0002]Many products benefit from child-resistant (CR) packaging, which inhibits young children from accessing potentially harmful products or substances yet enables access for adults who are aged or have disabilities. Several standards have been developed for CR packaging including: ISO 8317 “Child-resistant packaging” for requirements and testing procedures for reclosable packages, ISO 13127 “Packaging—Child resistant packaging” for mechanical test methods for reclosable child resistant packaging systems”; ASTM D3475, “Standard Classification for Child-Resistant Packages.” BS EN ISO 8317:2004 “Child-Resistant Packaging” is the international standard covering reclosable packaging for any contents.
SUMMARY OF THE INVENTION
[0003]According to a first aspect of the invention there is provided a screw cap for a container. The cap comprises an inner member having an annular sidewall with an internal screw thread for screwing the cap onto a threaded opening of a container and an outer member having a skirt enclosing the sidewall of the inner member. The outer member is coupled to the inner member to prevent displacement of the outer member relative to the inner member parallel to an axis defined by the screw thread. The cap has a first configuration in which the outer member is rotatable with respect to the inner member to prevent the cap from being unscrewed and a second configuration in which the skirt engages with the sidewall of the inner member so that the cap can be unscrewed by rotating the outer member.
[0004]The skirt may be spaced apart from the sidewall of the inner member in the first configuration and the second configuration may be obtained from the first configuration by deflecting one or more sections of the skirt towards the axis. The skirt is preferably resilient such that the cap returns to the first configuration upon removal of a force or forces used to deflect the section(s) of the skirt. Thus, the default (i.e. “resting”) state of the cap may be for the skirt to be disengaged from the sidewall of the inner member. In some implementations, the outer member may be cylindrical or frustoconical, e.g. wider at the base of the skirt than at the top of the skirt.
[0005]In some implementations, the outer member has a predefined rotational orientation with respect to the inner member that enables the skirt to engage with the sidewall of the inner member. Thus, if the cap is left with the outer member in a different rotational orientation with respect to the inner member then, to unscrew the cap, a user may be required to rotate the outer member about the inner member to bring it into the predetermined rotational orientation. Manipulating the cap in this way may be outside the capabilities of young children, making the cap child-resistant. Alternatively or additionally, in some implementations, the force(s) required to deflect one or more sections of the skirt towards the axis may be too great for small children to achieve. In some implementations, the cap and/or the container may be provided with markings to indicate the correct rotational orientation to users. The outer member may have multiple rotational orientations (e.g. 2, 3, 4, 5, 6 or more) with respect to the inner member that enable the skirt to engage with the sidewall of the inner member. However, it may be preferable to minimise the number of such orientations to make it harder for the cap to be unscrewed, e.g. to reduce the likelihood that rotating the outer member arrives at a correct orientation fortuitously.
[0006]The sections of the skirt may comprise respective features that engage with corresponding features on the sidewall of the inner member when the one or more sections of the skirt are deflected towards the axis with the outer member in the predefined rotational orientation. The features may be engaged such that rotation of the outer member in either a clockwise or an anticlockwise direction rotates the inner member in the same direction to screw or unscrew the cap from a container. For example, each of the features of the skirt may interlock with a corresponding feature on the sidewall of the inner member when the cap is in the second configuration, so that the outer member and the inner member can be rotated in unison. Alternatively or additionally, each of the features on the skirt may comprise a portion of the interior surface of the skirt that has an increased surface roughness compared to other parts of the interior surface of the skirt, with the opposing surface of the inner member having corresponding portions of increased surface roughness. In some cases, friction between the portions of increased roughness on the skirt and the inner member may be sufficient to rotationally couple the outer member to the inner member when the one or more sections of the skirt are deflected. Preferably, there is a one-to-one correspondence between the features on the skirt and the features on the inner member, as this may minimise the number of rotational orientations for the outer member relative to the inner member that allow the second configuration to be obtained (i.e. to “unlock” the cap). However, in some implementations there may be a many-to-one or one-to-many correspondence between the features, which may facilitate unscrewing the cap from a container (or screwing it back onto the container) by providing more rotational orientations that allow the cap to be unlocked. The features may be provided at a lower portion of the skirt and sidewall.
[0007]The feature(s) of the skirt may comprise one or more recesses extending away from the axis and the feature(s) on the sidewall of the inner member comprise a corresponding one or more protrusions extending away from the axis, the or each of the recesses being configured to receive a respective one or more of the protrusions when the sections of the skirt are deflected towards the axis with the outer member in the predefined rotational orientation. Thus, when the outer member has the correct rotational alignment with respect to the inner member and the sections of the skirt are then deflected radially inwards, the protrusions on sidewall extend into the recesses on the skirt, thereby rotationally coupling the inner member to the outer member.
[0008]The feature(s) of the skirt may comprise one or more protrusions extending towards the axis defined by the screw thread of the inner member and the feature(s) on the sidewall of the inner member may comprise a corresponding one or more recesses extending towards the axis with the outer member in the predefined rotational orientation. The or each of the recesses is configured to receive a respective one or more of the protrusions when the sections of the skirt are deflected towards the axis. Thus, when the outer member has the correct rotational alignment with respect to the inner member and the sections of the skirt are then deflected radially inwards, the protrusions on skirt extend into the recesses on the sidewall, thereby rotationally coupling the inner member to the outer member
[0009]The feature(s) of the skirt may comprise one or more protrusions extending towards the axis and the feature(s) on the sidewall of the inner member may comprise a corresponding one or more protrusions extending away from the axis. The or each of the protrusions on the skirt may be configured to contact (e.g. abut) the corresponding protrusion on the sidewall of the inner member along a tangent to the sidewall when the sections of the skirt are deflected towards the axis with the outer member in the predefined rotational orientation. Thus, rotation of the outer member may cause the protrusions to exert a torque on the inner member through the contacting surfaces of the protrusions on the skirt and the sidewall.
[0010]The feature(s) on the skirt and the corresponding feature(s) on the sidewall of the inner member (e.g. recesses and/or protrusions) may be formed by deforming (e.g. bending, pressing and/or stamping) the skirt and/or the sidewall of the inner member. For example, pressing or stamping may be used to form indentations on one side of the skirt and/or the sidewall of the inner member together with corresponding protrusions on the other side of the skirt and/or the sidewall of the inner member. Such an approach may be preferred when the skirt and/or the sidewall of the inner member are made of metal, for example.
[0011]The features on the skirt may be angularly spaced apart around the skirt with an (e.g. approximately) equiangular spacing, e.g. spaced apart around a perimeter of the skirt with an equiangular spacing. The outer member (and/or the inner member) may therefore have a rotational symmetry that makes it easier for a user to select a correct rotational orientation for the outer member to allow the cap to be unscrewed. Tolerances in how the features engage with one another (i.e. in the relative sizes of the features) may permit there to be small deviations in the spacing between the features. In some implementations, the features may be irregularly spaced around the skirt, at least to some extent, to reduce the number of rotational orientations that allow the skirt to engage with the sidewall so that the cap can be unscrewed.
[0012]In some implementations, there may be two features on the skirt (and corresponding features on the sidewall of the inner member) that are spaced apart by 180 degrees at least approximately, e.g. spaced apart by from 170 to 180 degrees, or from 175 to 180 degrees. The features may be diametrically opposed to one another. In such cases, it may be easier for users to apply the force(s) necessary to deflect the sections of the skirt by gripping the skirt across the diameter of the cap. In other implementations, there may be three features on the skirt (and/or on the sidewall of the inner member) that are spaced apart by 120 degrees, and so on. However, smaller numbers of features may be preferable to avoid making it difficult for the user to deflect the sections of the skirt in the correct manner.
[0013]In other implementations, only a single feature may be provided on the skirt and/or a single corresponding feature on the sidewall of the inner member. In some examples, there may be only a single rotational orientation for the outer member relative to the inner member that allows the cap to be unscrewed.
[0014]The inner member may comprise a panel, from which the sidewall descends, for covering an opening of a container onto which the cap is screwed. The outer member may comprise a shoulder portion from which the skirt descends, the shoulder portion extending towards the axis to partially cover the panel. The panel may comprise a raised circular portion (i.e. a circular portion that extends away from the parts of the panel covered by the shoulder portion in a direction along the axis) having a radially inwardly extending groove (i.e. a groove that extends towards the axis) in which a rim of the shoulder portion is located. Displacement of the outer member relative to the inner member along a direction parallel to the axis may therefore be prevented by the rim of the shoulder portion contacting the panel or the underside of the circular raised portion. The circular raised portion and the radially inwardly extending groove may be formed by folds in the panel. The groove may be configured to allow rotation of the outer member about the inner member. The groove may enclose a rim (edge) of the shoulder portion of the outer member to prevent users from contacting the rim of the shoulder portion, which may avoid the need for a curl to be provided at the rim for this purpose. As the circular raised portion protrudes above the shoulder portion of the outer member, it may provide a lip onto which a container having a base with a corresponding recess to allow the container to be stacked on top of the screw cap. The raised portion may be decorated e.g. with text, a logo, an image etc.
[0015]Alternatively, the outer member may comprise a panel from which the skirt descends for covering an opening of a container onto which the cap is screwed. The inner member may comprise a shoulder portion from which the skirt descends, the shoulder portion extending towards the axis. The panel may comprise a circular recessed portion having a radially inwardly extending groove that receives a rim of the shoulder portion. Displacement of the outer member relative to the inner member along a direction parallel to the axis may therefore be prevented. The circular recessed portion and the radially inwardly extending groove may be formed by folds in the panel. The groove may be configured to allow rotation of the outer member about the inner member. The groove may enclose a rim (edge) of the shoulder portion of the outer member to prevent users from contacting the rim of the shoulder portion, which may avoid the need for a curl to be provided at the rim for this purpose. The recessed portion may be decorated e.g. with text, a logo, an image etc.
[0016]In some other implementations, the outer member and the inner member may each comprise a panel for covering an opening of a container onto which the cap is screwed. However, such implementations may require more material (e.g. metal) for their manufacture compared to implementations with only a single panel.
[0017]The outer member and the inner member may be made of the same (or similar) materials, which may facilitate recycling of the cap. In some implementations, the outer member and the inner member may be made of a metal material, preferably the same metal material (although the metal materials can be different in some examples). In other implementations, the outer member and the inner member may each be made of a plastics material, preferably the same plastics material. The inner and outer member may be manufactured by injection moulding in some cases.
[0018]An exterior surface of the skirt may be patterned/textured and/or a coating may be applied to the exterior surface of the skirt to assist with gripping, e.g. the surface may be knurled or otherwise comprise a non-smooth surface having indentations or ridges.
[0019]The cap may include a gasket adapted for forming a seal with a rim of a container.
[0020]According to a second aspect of the present invention, there is provided a container package comprising a container having a threaded opening and a screw cap according to the first aspect. The screw cap is configured to screw onto the threaded opening of the container.
[0021]The screw cap and the container are preferably made of the same metal material, which may facilitate recycling of the container package.
[0022]The container may comprise an end fixed inside the opening that forms a primary seal for the container. The end may be attached to the container by a double seam in some implementations.
[0023]In some implementations, at least a portion of the end may be removable to break the primary seal and thereby enable access to a product inside the container by a user. For example, the end may include a disposable tearaway portion that is adapted for discarding by a user after the user removes the tearaway portion from the opening of the container body. The end may include the tearaway portion and a ring permanently affixed to the inside of the opening of the container body. The tearaway portion of the end may include a metal panel and a tab affixed to the tearaway panel, and the ring may be affixed to rim the opening by a double seam. The end may include a score separating the metal panel from the ring, and the tab may be affixed to the metal panel by a rivet. The tearaway panel may be a foil or film in some cases.
[0024]In some implementations, the container may be a two-piece or a three-piece can.
[0025]The container package may be configured to prevent damage or degradation of a product stored in the container from one or more of light, moisture and air.
[0026]The container may comprise a base that is able to at least partially accommodate the top of the screw cap so that the container packages are stackable, i.e. a top of a screw cap of a first container package may be received by the base of a container of a second container package provided on top of the first container package. For example, as described above in connection with the first aspect, the inner member may comprise a panel having circular raised portion that can be received by a recess in the base of a container stacked on top of the screw cap.
[0027]In some implementations, the screw cap according to the first aspect and/or the container package according to the second aspect may be child-resistant. In this regard, the term “child resistant” refers to a package that is “constructed to be significantly difficult for children under five years of age to open, and not difficult for normal adults to use properly,” which is consistent with California and US federal definitions. It is preferred that, when the screw cap is used to seal a container, the sealed container is in compliance with child resistant packaging regulations, such as ISO 8317 “Child-Resistant Packaging” for requirements and testing procedures for re-closable packages, ISO 13127 “Packaging—Child resistant packaging” for mechanical test methods for re-closable child resistant packaging systems”; ASTM D3475 “Standard Classification for Child-Resistant Packages”; and BS EN ISO 8317:2004 “Child-Resistant Packaging” for international standard covering re-closable packaging for any contents; and California regulations, such as 16 CCR 5307 & 5413(d).
BRIEF DESCRIPTION OF THE DRAWINGS
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
DETAILED DESCRIPTION
[0035]
[0036]The container 102 comprises an enclosed base 108 and a sidewall 110 extending upwardly from the base 108, which has a sidewall 112 with an external screw thread 113 onto which the screw cap 106 is screwed. The base 108 and the sidewall 112 may be formed from a metal blank by a drawing process, for example. The screw cap 106, the enclosed base 108 and the sidewall 110 are (substantially) rotationally symmetric about a central axis Z defined by the screw thread 113 of the sidewall 112 and the thread of the screw cap 106.
[0037]The container 102 comprises a rim 114 formed at an uppermost portion of the sidewall 112 that defines the opening 104 covered by the cap 106. As can be best appreciated from
[0038]
[0039]The screw cap 104 also comprises an outer member 416 comprising a skirt 418 that surrounds (encircles) the sidewall 408 of the inner member 402 and comprises a shoulder portion 420 that extends radially inwards (i.e. towards the Z-axis) to cover the shoulder portion 406 of the inner member 402 and a portion of the panel 404 of the inner member 402. The panel 404 of the inner member 402 comprises a circular raised portion 422 that extends radially outwards, over the shoulder portion 420 of the outer member 416, thereby trapping the innermost edge of the shoulder portion 420 of the outer member 416 in a radially inwardly extending groove 426 formed under the raised portion 422. The outer member 416 is therefore coupled to the inner member 402 to prevent relative axial movement between them (i.e. movement in a direction parallel to the axis). The raised portion 422 and the innermost edge of the shoulder portion 420 are (substantially) circular so that the outer member 416 can be rotated about the inner member 402 (i.e. it is rotatable around the Z-axis independently of the inner member 402), at least in the configuration shown in
[0040]The sidewall 408 of the inner member 402 is inaccessible to users because it is covered by the skirt 418 of the outer member 416. For example, in the implementation shown in
[0041]The skirt 418 comprises a pair of pips 304 that correspond to the pips 302 provided on the sidewall 408 of the inner member 402, i.e. the pips 304 on the skirt 418 are formed at the same height as the pips on the sidewall 408 of the inner member 402 and are similarly diametrically spaced apart from one another. Each of the pips 304 extends radially outwards from the skirt 418 such that a respective recess is created on the interior surface of the skirt 418 that is configured to accommodate a corresponding one of the pips 302 on the sidewall 408 of the inner member 402 when the pips 304 on the skirt 418 are deflected towards the sidewall 408 of the inner member 402.
[0042]
[0043]The configurations of the cap 104 shown in
[0044]The second (unlocked) configuration (shown in
[0045]
[0046]Another difference between the container package 600 of
[0047]
[0048]For each of the embodiments mentioned above, the inner member 402, 602 may comprise a gasket (not shown) between the underside of the panel 404 and the rim 114 of the container 102, 602. Alternatively or additionally, the underside of the panel 404 may comprise a channel (not shown) in which a sealing compound may (optionally) be provided. In some instances, the gasket and/or the sealing compound may avoid a need for an end 116 to be provided. In some instances, there may be no gasket, sealing compound and channel, or end 116.
[0049]It is understood that the container packages 100, 600 and other embodiment container packages disclosed herein may also include one or more tamper evident features (not shown in the figures), such as an overwrap and/or other indicators or barriers to entry which, if breached or missing, can reasonably be expected to provide visible evidence to consumers that tampering has occurred.
[0050]The container packages 100, 600 in the embodiments of the figures are also re-sealable, which refers to the ability to re-close the package after initial opening such that the re-closed package is child-resistant, regardless of whether the re-closed provides a freshness seal (that is, a seal that is hermetic or inhibits air or vapour transmission through the seal).
[0051]The present invention is described by illustrating embodiments and aspects of the container packages and components thereof as well as materials therefor. The present invention is not limited to the particular structure and function of the container packages and components disclosed herein. The terms “such as” and “for example” are understood the implicitly include “without limitation.” Further, the features of any of the embodiments may be applied to or combined with any other embodiment.
Claims
1. A screw cap for a container, the cap comprising:
an inner member having an annular sidewall with an internal screw thread for screwing the cap onto a threaded opening of a container; and
an outer member having a skirt enclosing the sidewall of the inner member, the outer member being coupled to the inner member to prevent displacement of the outer member relative to the inner member parallel to an axis defined by the screw thread,
wherein the cap has a first configuration in which the outer member is rotatable with respect to the inner member to prevent the cap from being unscrewed and a second configuration in which the skirt engages with the sidewall of the inner member so that the cap can be unscrewed by rotating the outer member.
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17. A container package comprising a container having a threaded opening and a screw cap according to
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