Patent Description:
Any discussion of the prior art throughout the specification should in no way be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field.

<CIT> describes a mixing unit comprising a sealed container joined to a second container.

<CIT> describes a refill container that can facilitate refilling work.

Liquid cleaning and hygiene products such as multi-purpose surface cleaner, glass cleaner, or degreaser are often supplied in ready-to-use concentrations in a wide variety of containers, with a wide variety of dispensing systems. Typically, such liquid cleaning products comprise one or more active ingredients diluted with water (or another solvent) to a concentration that is suitable for use in the home or commercial environment.

Cleaning products supplied in a ready-to-use concentration are advantageous in that the products can be supplied in a safe and effective concentration, and can be appropriately labelled. Ready-to-use products are also more convenient for the user, since they do not require dilution or reconstitution before use.

One example of a widely used container system for cleaning products is a spray bottle comprising a trigger actuator. Such systems generally comprise a bottle comprising a body and a neck, the neck being configured to engage a removable spray nozzle. The spray nozzle is generally secured to the neck of the bottle by way of complementary screw threads on the neck and on the nozzle. After use, the container or vessel in which the cleaning product was supplied is typically discarded and a replacement acquired.

Although the spray bottle in which cleaning products are supplied generally have a lifetime that extends beyond the point at which the cleaning product has been depleted, the practice of refilling spray bottles with cleaning product is not widespread in a domestic setting.

In a commercial or industrial setting, spray bottles are sometimes refilled for re-use by diluting a predetermined volume of concentrated liquid with water. The concentrated cleaning liquid may be
supplied in a bottle, which typically has a larger volume than the spray bottles used by cleaning professionals due to the fact that the concentrate vessel is not carried throughout the cleaning process.

However, although it is known to supply concentrated cleaning fluids for dilution prior to use, the practice of refilling spray bottles with water and a concentrated cleaning fluid is not widespread due to the many challenges in safely and effectively managing concentrated products, especially in a home environment.

Handling of concentrated cleaning fluids requires care both during refilling of a spray vessel and with regard to storage of the concentrated liquid. To avoid risks to health, even more so than diluted cleaning fluids, concentrated cleaning fluids should be transported and stored securely, and kept out of reach of children and animals.

Moreover, concentrated (undiluted) cleaning fluids may cause damage to surfaces within the home and spillages should be avoided to avoid damage to clothing and household items.

Further difficulties may be encountered in ensuring that the concentrated cleaning product is diluted to a safe and effective concentration. Over-dilution of a concentrated cleaning fluid with water may lead to inferior cleaning results. Under-dilution of a concentrated cleaning fluid may present a risk to health, damage to household items and excessive consumption of the concentrated cleaning fluid.

Despite a desire to reduce the plastic waste generated by discarding empty bottles, and a desire to reduce the costs and resources required to ship and store ready-to-use cleaning products, refill systems that are suitable and convenient for use in domestic and professional settings are not widely available.

The present inventors have been able to solve many of the problems associated with conventional cleaning product dispensing systems and have been able to develop a refill capsule system for use with spray bottles (and other cleaning product vessels) that can overcome many of the above problems.

An object of the present invention is to provide a refill capsule and an associated plug configured to rupture a seal over the refill capsule that overcome the above mentioned disadvantages associated with current cleaning products that allows vessels or containers for cleaning products to be reused.

It is another object of the invention to provide a refill system comprising a plug that allows a user to safely and reliably deliver a predetermined volume of concentrated cleaning fluid to a spray bottle or similar vessel for dilution.

It is another object of the invention to provide a refill capsule and an associated plug that allows for safe and reliable delivery of a concentrated cleaning fluid to a refillable vessel.

It is yet another object of the invention to provide a refill capsule and a cap assembly comprising a plug that can be simply and reliably coupled to a refillable vessel to discharge the concentrated liquid into the refillable vessel.

These and other objects are accomplished by the invention described in the following text and figures.

In a first aspect of the present invention, there is provided a plug configured to rupture a frangible seal which closes and seal a refill capsule for a concentrated cleaning liquid. The plug comprises an abutment surface for beating against a closure member to break a frangible seal securing the closure member in place. The plug is configured to allow the flow of fluid therethrough.

The plug according to the invention is described in the claims appended herewith. Optional features are described in the dependent claims.

The plug according to the invention allows a volume concentrated cleaning fluid to be safely and conveniently stored and transported. A cap system comprising the improved plug can be engaged, for example by virtue of a threaded engagement, with a refillable vessel. Upon engagement of the system with a refillable vessel, the plug moves within the cap assembly and the frangible seal is configured to break under the influence of the plug, thereby releasing the concentrated cleaning fluid contained in a capsule to flow through the plug into the refillable vessel.

In the following, it should be note that the term 'comprising' encompasses the terms 'consisting essentially of' and 'consisting of'. Where the term "comprising" is used, the listed steps or options need not be exhaustive and further steps or features may be included. As used herein, the indefinite article 'a' or 'an' and its corresponding definite article 'the' means at least one, or one or more, unless specified otherwise.

The terms 'upstream' and 'downstream' as used herein refer to the direction of flow of fluid through the refill system during use, with fluid flowing from an upstream end to a downstream end. In the context of the present invention, fluid flows from an upstream refill capsule system into a downstream refillable vessel. The proximal direction is the upstream direction, whilst the distal direction is the downstream direction.

In specifying any range of values or amounts, any particular upper value or amount can be associated with any particular lower value or amount.

The various features of the present invention referred to in individual sections above apply, as appropriate, to other sections mutatis mutandis. Consequently features specified in one section may be combined with features specified in other sections as appropriate. Any section headings are added for convenience only, and are not intended to limit the disclosure in any way.

The invention is not limited to the examples illustrated in the drawings. Accordingly it should be understood that where features mentioned in the claims are followed by reference numerals, such numerals are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting to the scope of the claims.

The present invention relates to a plug for a refill capsule system. The plug is configured to be secured within a cap assembly, and is configured to move between a first position and a second position with the cap assembly to break a frangible connection therein. The plug according to the invention comprises an improved configuration compared to known seal-rupturing plugs, as will be described in further detail below.

The plug according to the invention generally comprises a tubular body with an open proximal end and an open distal end. The open proximal end is surrounded by a first rim, which defines an opening. The rim further can comprises at least first and second cut-outs extending in a distal direction from the rim, with the proximal surface of the rim providing a proximal-facing abutment surface for bearing against a frangible sealing component. The proximal-facing abutment surface extends in a first plane that is orthogonal to a longitudinal axis A of the tubular body, and has at least two fold rotational symmetry with respect to the longitudinal axis A.

In at least one configuration the plug comprises: a hollow tubular body with an open proximal end and an open distal end, wherein the open proximal end is surrounded by a first rim that provides a proximal abutment surface for bearing against a frangible sealing component of a cap assembly; wherein the proximal abutment surface lies in a plane that is orthogonal to a longitudinal axis of the tubular body, and surface surrounds, in total, at least half of the open proximal end; a skirt extending around the tubular body, and comprising a tubular skirt wall arranged coaxially with respect to the tubular body, the skirt wall being spaced apart from the tubular body in a radial direction to form a plug recess between the skirt wall and the tubular body; wherein the skirt wall extends from a skirt distal end at which the skirt wall is connected to the tubular body, to a free proximal end, wherein the free proximal end of the skirt comprises: an outwardly extending flange comprising a distal facing abutment surface for abutting a rim of a refillable vessel.

The proximal-facing abutment surface of the plug can be provided by a continuous circumferential rim of the tubular body, terminating in a plane Q. Alternatively, the proximal-facing abutment surface can comprise a discontinuous rim comprising a plurality of cut-outs equally spaced circumferentially around the rim of the tubular body, wherein the cut-outs extend in a distal direction from the rim.

By providing a rotationally symmetric abutment surface configured to apply a net force along the longitudinal axis A, and perpendicular to the plane in which the frangible connection extends, the frangible connection can be configured to snap, failing around its circumference, rather than peeling from an initial breach around the seal. Such a circumferential failure of the seal can result in a snap or click sound that is audible to the user, thereby providing positive feedback that the frangible connection has been successfully broken and that the liquid contained in a capsule body can escape.

Moreover, by providing a rim that surrounds at least half of the circumference of the tubular body, the flow of fluid through the plug (and thus through the cap assembly), may be improved.

The plug also comprises an outwardly extending flange comprising a distal-facing abutment surface for abutting a rim of a refillable vessel.

The flange can be provided on a skirt that extends around the tubular body, the skirt comprising a generally tubular skirt wall arranged coaxially with respect to the tubular body, and being spaced apart from the tubular body in a radial direction to form a plug recess between the skirt wall and the tubular body.

Optionally, the skirt wall can be connected to the tubular body at a distal end of the tubular body, and extend proximally from the connection point to circumferentially surround the tubular body. The proximal end of the skirt wall can comprise a free end. The flange can extend from the free end of the skirt wall.

The free end of the skirt wall can further comprises a proximal sealing rim for sealing against a sealing surface of a cap assembly. The sealing rim can be provided on a proximal surface of the flange that provides the distal-facing abutment surface. In some examples, the proximal sealing rim may taper to a peak.

By providing a sealing rim, a seal can be formed between the proximal sealing rim and a corresponding surface of an associated cap assembly, for example, a connection wall joining the inner and outer walls of a dual-walled cap assembly. The sealing rim may be peaked. This can form an improved seal against the sealing surface of the cap assembly. The sealing peak may terminate in the same plane as the proximal-facing abutment surface.

The tubular body can further comprise at least one cut-out or slot in a wall of the tubular body. The cut out or slot can provide a discontinuity in the rim of the plug such that a broken cap part cannot settle over the cap to block the proximal opening of the tubular body because the rim does not extend in the
same plane around the full circumference of the tubular body. This discontinuity may thus improve flow through the tubular body of the plug.

The rim can comprises two or more cut-outs, and preferably, two diametrically opposed cut outs.

The tubular body can further comprise a protrusion or ridge extending around an outer surface of the tubular body. Such a ridge can provide improved engagement of the plug with a cap assembly comprising a similar ridge, a corresponding groove, or solely by way of increasing the contact force between the plug and a cap assembly within a system.

The free proximal end of the skirt wall further comprises at least one claw extending radially from the flange. The at least one claw can comprise a corresponding engagement feature (e.g. a screw thread) in the cap assembly. The claw can be configured to flex to allow movement of the plug in a proximal direction, but to prevent or resist movement of the plug in a distal direction. Optionally, the at least one claw comprises a curved claw with a distal-facing concave surface and a proximal-facing convex surface.

Advantageously, the at least one claw can comprises two claws, preferably three claws, and more preferable four or more claws.

The advantages of the plug assembly are applicable in many combinations of cap assemblies. In at least one exemplary configuration, the plug can be combined with a cap assemble to form a cap system.

The cap assembly can comprise an inner wall defining a conduit through the cap assembly, the conduit extending from an upstream end to a downstream end. An outer wall may surround the inner wall along at least a first portion of its length, wherein the outer wall is spaced from the first portion of the inner wall to define a circumferential void between the inner and outer walls extending from an open downstream end to a closed upstream end. A connecting wall can extend between the inner and outer walls to prevent fluid flow through the void, the connecting wall forming the closed upstream end of the void.

The cap assembly may further comprise a closure member configured to seal the conduit, the closure member comprising an upstream side and a downstream side. The closure member is sealed to the inner wall with a peripheral frangible connection located between proximal and distal ends of the conduit.

Preferably, the frangible connection extends in a plane P, which is orthogonal to a longitudinal axis of the conduit.

In such an exemplary configuration, the plug can be disposed within the cap assembly such that the outer wall of the cap assembly surrounds the plug (preferably extending beyond the distal end of the plug) and the inner wall of the cap assembly extends into the plug recess.

In this position, the proximal-facing abutment surface of the plug is aligned with and opposes the bearing surface of the closure member such that the plug can be moved in a proximal direction, to bear against the bearing surface of the cap, and break the frangible seal.

The frangible connection can be configured in different ways. For example, the frangible connection can be disposed between a first peripheral recess formed between the inner wall and a downstream side of the closure member, and a second peripheral recess between the inner wall and an upstream side of the closure member.

In an alternative configuration, the downstream recess can be omitted and instead inner surface of the inner wall immediately upstream of the frangible connection can be off-set radially from an inner surface of the wall immediately downstream of the frangible connection. Preferably, the upstream inner surface is offset radially outwardly from the downstream inner surface.

Offsetting the inner surface of the inner wall immediately upstream and immediately downstream of the closure member may provide multiple advantages. For example, offsetting the radial position of the inner wall immediately upstream and downstream of the closure member can control the width of the frangible connection at its thinnest part. This provides a well-defined region in which the frangible connection breaks. Moreover, offsetting the radial position of the upstream inner wall compared to the downstream inner wall ensures that the closure member can be pushed into a region of the conduit that has a greater cross-sectional area than the cross-sectional area of the closure member. This can ensure that the closure member is pushed into a region in which it cannot block the conduit.

In plug/cap assembly combinations, the bearing surface of the cap assembly can extend in a plane that is orthogonal to the longitudinal axis of the conduit. Combined with the orthogonal proximal-facing abutment surface of the plug, this can ensure that the frangible connection snaps rather than peels.

The closure member in the cap assembly may be hollow and tapered, and taper from a downstream base to an upstream peak. For example, the closure member may be conical or frustoconical.

The hollow closure member may be open at the base, and is preferably oriented with the peak in an upstream direction and the base in a downstream direction.

The outer wall of the cap assembly can also comprises engagement means, e.g. a screw thread on its inner surface, and wherein the claws of the plug are configured to engage the engagement means of the cap assembly.

In at least some configurations, the inner wall of the cap assembly can comprise a protrusion or ridge extending radially inwardly from an inner surface of the inner wall. The ridge on the cap assembly can be configured to cooperate with a ridge on the plug to reduce the likelihood that the plug moves in the distal direction during transit or storage.

The plug described here may also be combined with the cap assembly in a refill system, which further comprises a capsule body for containing a concentrated cleaning product, wherein the capsule body is engaged with the cap assembly, and wherein an internal volume of the capsule body is in fluid communication with an upstream end of the conduit. The capsule body comprises an opening surrounded by a rim, and wherein the rim is configured to bear against the connecting wall of the cap assembly.

In an exemplary system, a shrink wrap cover extends around at least a portion of the capsule and at least a portion of the cap assembly.

It will be appreciated that the advantages provided by the plug described herein are not limited to the exemplary combinations described below. For example, the plug described herein may be combined with the cap assembly shown in the illustrated examples, or with other compatible cap assemblies. For example, although the illustrated examples include a plug in combination with a dual-walled cap assembly, plugs according to the present invention can also be combined with cap assemblies comprising a frangible seal formed across a single-walled conduit.

As used herein, the term 'refill capsule' refers to a capsule body suitable for a container for concentrated cleaning fluid.

By way of example, the present invention is illustrated with reference to the following figures, in which:.

In the detailed description of the figures, like numerals are employed to designate like features of various exemplified devices according to the invention.

<FIG> shows a refill system <NUM> for containing a concentrated cleaning fluid and configured for use with a refillable vessel. <FIG> shows a cross-sectional view of an assembled refill system comprising a capsule body <NUM>, a cap assembly <NUM>, and a plug <NUM>. As shown in <FIG>, a longitudinal axis A extends from a closed end of the capsule <NUM>, through the cap assembly <NUM>, and the plug <NUM>.

As shown in <FIG>, the capsule body <NUM> comprises a generally hollow receptacle configured to receive a volume of concentrated cleaning fluid. The concentrated cleaning fluid is contained within an internal volume <NUM> of the capsule body <NUM>. The capsule body <NUM> comprises a neck <NUM> comprising an open end surrounded by a rim <NUM>. The neck <NUM> comprises a screw thread <NUM> configured to engage a corresponding screw thread on the cap assembly <NUM>.

The cap assembly <NUM> is configured to seal the capsule and extends from an upstream end to a downstream end. The upstream end of the cap assembly <NUM> is configured to engage the capsule body <NUM>. The downstream end of the cap assembly <NUM> is the end configured to engage a refillable vessel, as will be described in more detail with reference to <FIG>.

The cap assembly <NUM> defines a conduit <NUM> through the cap assembly <NUM> though which fluid can flow to exit the capsule <NUM>. The conduit <NUM> extends through the cap assembly <NUM> from an open upstream end to an open downstream end. A closure member <NUM> seals the conduit <NUM> to prevent fluid communication between the upstream end and the downstream end of the conduit <NUM>. The closure member <NUM> is sealed to the inner wall of the conduit by a frangible seal, which can be broken by applying pressure to the closure member <NUM>.

The plug <NUM> is disposed within the cap assembly <NUM> and is configured to bear against the closure member <NUM> to break the frangible seal as the refill system <NUM> is screwed onto (or otherwise engaged
with) a refillable vessel. The plug <NUM> comprises an internal bore through which cleaning fluid can escape through once the plug <NUM> has been used to rupture the seal in the cap assembly <NUM>.

Advantageously, the refill system <NUM> can be wrapped in a shrink wrap cover. The shrink wrap cover can cover the whole cap assembly <NUM> and the capsule <NUM>, or it may cover only a portion of the capsule <NUM> and the capsule assembly <NUM>. Advantageously, it may extend around the system <NUM> such that the join between the capsule <NUM> and the cap assembly <NUM> is surrounded by a shrink wrap cover. By shrink wrapping the capsule <NUM> and the cap assembly <NUM> together, the likelihood of the cap assembly <NUM> being inadvertently removed from the capsule <NUM> is further reduced.

Referring now to <FIG>, use of the system will be described in more detail.

<FIG> show an enlarged view of the refill system <NUM> comprising cap assembly <NUM>, and plug <NUM>. The capsule <NUM> is omitted for clarity. <FIG> also show the upper portion of a refillable vessel <NUM> with a neck <NUM> that defines an opening in fluid communication with an interior volume of the vessel.

<FIG> shows the system before use with the closure member <NUM> sealed within the conduit <NUM>. As shown in <FIG>, the refill system <NUM> is supplied with the plug <NUM> disposed within the cap assembly <NUM>. In the configuration shown in <FIG>, the plug <NUM> is spaced apart from (i.e. not in direct contact with) the closure member <NUM>. The plug <NUM> is mounted within the cap assembly <NUM> such that it is secured in place against accidental movement (e.g. during transport or storage). However, the plug <NUM> and the cap assembly <NUM> are configured such that the plug <NUM> can be pushed axially towards the closure member <NUM> by bearing on an abutment surface provided on the plug <NUM>.

The plug <NUM> can be secured or mounted within the cap assembly <NUM> in different ways. An exemplary plug and cap assembly combination will be discussed in further detail with reference to Figures <NUM>-<NUM>.

The cap assembly <NUM> comprises a screw thread <NUM> (or other engagement means) configured to engage the corresponding screw thread on a refillable vessel <NUM>. The screw thread <NUM> allows the cap assembly <NUM> to be screwed onto the neck <NUM> of the refillable vessel <NUM>. The screw thread <NUM> is provided on an interior surface of the cap assembly <NUM>, whilst the screw thread <NUM> of the refillable vessel <NUM> is provided on an exterior surface of the vessel <NUM>. Therefore, as the cap assembly <NUM> is screwed onto the neck <NUM> of the vessel <NUM>, the neck <NUM> of the vessel <NUM> and the rim <NUM> with which the neck <NUM> terminates are guided into the cap assembly <NUM>.

Referring now to <FIG>, the plug <NUM> is disposed within the cap assembly <NUM> such that the introduction of the neck <NUM> into the cap assembly <NUM> tends to bear against the plug <NUM>, pushing it in an upstream direction, towards the capsule and into contact with the closure member <NUM>. As shown in.

<FIG>, as the rim <NUM> advances within the cap assembly, the plug <NUM> is first brought into abutment with the closure member <NUM> and then begins to exert a force thereagainst as the rim <NUM> advances further. As the plug bears against the closure member <NUM>, the force exerted against the closure member <NUM> increases to a point at which the frangible seal between the closure member and the conduit <NUM> fails, and the closure member <NUM> is pushed in an upstream direction such that it no longer seals the conduit <NUM>.

Once the seal provided by the closure member <NUM> is broken, concentrated cleaning fluid flow from the internal volume of the capsule, through the conduit <NUM> of the cap assembly, through the internal bore of the plug <NUM>, and into the refillable vessel <NUM> below.

Once the capsule has been emptied, the cap assembly <NUM> can be unscrewed from the neck <NUM> of the vessel <NUM>, and discarded safely.

By providing a refill system as described above, it is possible to provide a safe, convenient, and effective way of delivering a controlled quantity of concentrated cleaning fluid to a refillable vessel.

Several advantages may be provided by the system described here, which may result in an improved refill system.

The cap assembly <NUM> will now be described in more detail with reference to <FIG>, which shows a cross-sectional view of the cap assembly <NUM>. The plug <NUM> is omitted from <FIG>.

The cap assembly described herein includes a number of improvements that may provide enhanced performance. The cap assembly may comprise an improved wall structure, an improved frangible seal, enhanced safety features, and improved audible and tactile feedback to the user. Each of these improvements will be described in more detail below. Moreover, it will be appreciated that the features described below may be incorporated in a refill system alone, or in combination with other features to provide a further improved product.

As shown in <FIG>, the cap assembly <NUM> comprises an inner wall <NUM> that defines a conduit <NUM> extending from an open upstream end to an open downstream end. A closure member <NUM> is positioned within the conduit <NUM> and has an upstream side 208a and a downstream side 208b. The closure member <NUM> is sealed around its periphery to the inner wall <NUM> with a frangible connection <NUM>. The frangible connection is located between the upstream open end and the downstream open end of the conduit <NUM> and will be described as in more detail in <FIG>.

An outer wall <NUM> extends around the inner wall <NUM>. The outer wall <NUM> is connected to the inner wall <NUM> by a connecting wall <NUM> or a connection portion. The connecting wall <NUM> extending between the inner and outer walls <NUM>, <NUM> prevents the flow of fluid through the cap assembly between the inner and outer wall walls <NUM>, <NUM>. The only route through which fluid may flow through the cap assembly is thus through the inner conduit <NUM> when the frangible connection <NUM> has been broken.

The inner wall <NUM> is arranged coaxially within the outer wall <NUM> to form a circumferential void <NUM> between the inner and outer walls <NUM>, <NUM>. In the embodiment shown in <FIG>, the connecting wall <NUM> connects to each of the inner and outer walls <NUM>, <NUM> part way along their length. This forms an upstream void 214a between the inner and outer walls <NUM>, <NUM> upstream of the connection wall <NUM>, and a downstream void 214b between the inner and outer walls <NUM>, <NUM> downstream of the connecting wall <NUM>.

By providing an upstream void 214a, the seal between the capsule <NUM> and the cap assembly <NUM> can be improved because the inner wall <NUM> can be specially adapted for forming a seal between the cap assembly <NUM> and the capsule <NUM> within the neck <NUM> of the capsule, whilst the outer wall can be <NUM> can be specially adapted to form a seal between the cap assembly <NUM> and the capsule around the neck <NUM> of the capsule <NUM>. In at least some examples, the outer wall <NUM> can provide a child-resistant closure with the capsule <NUM>. For example, the outer wall <NUM> can comprise a plurality of ratchet teeth (not shown) that mate with a plurality of ratchet teeth on the capsule <NUM> to allow the cap assembly <NUM> to be screwed onto the capsule <NUM>, but prevent the cap assembly <NUM> from being unscrewed from the capsule assembly. The child resistant closure may prevent the cap assembly <NUM> from being unscrewed from the capsule <NUM> entirely (or at least without breaking the cap assembly <NUM>) or it may be configured to prevent the cap assembly <NUM> from being unscrewed from the capsule <NUM> unless a predetermined axial force is applied to the cap assembly <NUM> in a direction towards the capsule <NUM>.

Moreover, by providing an upstream void 214a to accommodate the neck <NUM> of the capsule <NUM>, the neck <NUM> can be used to provide structural reinforcement to the cap assembly <NUM> to minimise the degree to which is flexes as pressure is applied to rupture the frangible seal <NUM>. By minimising the degree to which the cap assembly <NUM> can flex under pressure from the plug, the frangible seal <NUM> is more likely to fail suddenly under pressure, resulting in a snap or click that provides audible and tactile feedback to the user that the seal is broken and that the concentrated liquid can be dispensed.

By providing a downstream void 214b, at least a portion of the plug <NUM> can be accommodated between the inner and outer walls <NUM>, <NUM>. This can allow the plug <NUM> to be retained within the cap assembly <NUM> during transport and storage, and held securely in place until the user screws the refill system <NUM> onto a refillable vessel.

It will be appreciated that although the provision of an upstream void 214a and a downstream void 214b can be combined to provide enhanced advantages over known systems, in at least some examples the cap assembly can comprise only an upstream void 214a or only a downstream void 214b.

The conduit <NUM> provided by the inner wall <NUM> of the cap assembly can have a variable diameter along its length. For example, the diameter of the conduit <NUM> upstream of the frangible seal <NUM> can be larger than the diameter of the conduit <NUM> downstream of the frangible seal <NUM>. By increasing the diameter of the conduit <NUM> upstream of the frangible seal <NUM>, the closure member <NUM> can be pushed by the plug <NUM> into a region of the conduit <NUM> that has a larger diameter than the closure member <NUM>. This further reduces the likelihood that the closure member <NUM> can occlude the conduit <NUM> to prevent the egress of cleaning fluid from the capsule <NUM> through the cap assembly <NUM> and the plug <NUM>.

In the embodiment shown in <FIG>, the inner wall <NUM> is shaped with a barrel shaped or bulbous upstream end portion to provide a barrel seal for sealing with the neck <NUM> of the refill capsule <NUM>. Instead of comprising a cylindrical shape having sides that are substantially parallel, the upstream end of the conduit <NUM> is barrel shaped, steadily decreasing in transverse cross-sectional diameter (i.e. a cross-section in a plane perpendicular to the longitudinal axis A) from a maximum diameter upstream of the frangible seal <NUM> towards the upstream rim of the conduit <NUM>. By varying the diameter of the conduit <NUM> at the upstream end, variation in manufacturing tolerances can be accounted for and/or a tighter seal can be provided between the capsule <NUM> and the cap assembly <NUM> because the narrower open end of the conduit <NUM> can be inserted into the neck <NUM> of the capsule <NUM>, and a tight seal can be formed between the barrel sealing rim and the neck of the capsule <NUM>.

As shown in <FIG>, the connecting wall <NUM> may further comprise a circumferential notch <NUM> or channel adjacent the inner wall <NUM> on the upstream side. The notch <NUM> reduces the thicnkess of the connecting wall <NUM> at the point where the inner wall <NUM> joins the connecting wall <NUM>. This can increase the degree to which the upstream portion of the inner wall <NUM> can flex inwardly to fit within the neck <NUM> of the capsule <NUM> (as shown in <FIG>).

The inner wall <NUM> downstream of the closure member <NUM> has a generally cylindrical form, with substantially parallel walls. However, as shown in <FIG>, the inner surface of the inner wall <NUM> can comprise a radially inwardly protruding ridge or projection <NUM>. The ridge or projection <NUM> can advantageously engage a corresponding projection on the plug <NUM>, as will be described in more detail below with reference to <FIG>.

As shown in <FIG>, the closure member <NUM> is positioned within the conduit <NUM> formed by the inner wall <NUM> and closes the conduit to prevent the passage of fluid therethrough unless the frangible seal <NUM> is broken.

The closure member <NUM> shown in <FIG> comprises a conical or frustoconical shape, and extends from an upstream peak <NUM> to a downstream base <NUM>. The base <NUM> is preferably open to allow access to the hollow interior of the conical closure member <NUM> from the downstream side. By providing a hollow, peaked closure member <NUM>, the likelihood of the closure member <NUM> settling over the opening formed through the inner conduit after the seal has been broken is reduced. To the contrary, the buoyancy provided by the hollow closure member <NUM> means that the closure member tends to float away from the conduit <NUM>.

The base <NUM> of the closure member provides a bearing surface against which a plug of a cap assembly can bear to apply pressure to rupture the frangible seal. The bearing surface <NUM> preferably extends in a plane R that is orthogonal to the longitudinal axis A of the cap assembly <NUM>.

<FIG> shows an enlarged view of the frangible connection <NUM> formed between the closure member <NUM> and the inner wall <NUM>. As shown in <FIG>, the frangible connection <NUM> extends between the outer perimeter of the closure member <NUM>. The frangible connection <NUM> is preferably between <NUM> and <NUM> thick. However, the skilled person will appreciate that other dimensions may be chosen depending on the materials used and the dimensions of the system <NUM>.

The frangible connection <NUM> is formed between two opposing recesses or notches <NUM>, <NUM>. The recesses or notches <NUM>, <NUM> are shown in <FIG>, which is a cross-sectional view. However, it will be appreciated that for a closure member <NUM> having a circular transverse cross-section, the recesses or notches <NUM>, <NUM> may be formed as circumferential channels.

The first recess <NUM> is formed upstream of the frangible connection <NUM>, between an upstream side 208a of the closure member <NUM> and an interior surface of the inner wall <NUM>. The second recess <NUM> is formed downstream of the frangible connection <NUM>, between a downstream side 208b of the closure member <NUM> and an interior surface of the inner wall <NUM>. By forming a frangible connection <NUM> between two opposing recesses or channels, the thickness (in a longitudinal direction) and the width (in a transverse direction) of the frangible connection <NUM> can be controlled.

The notches <NUM> and <NUM> (or the channels) extend from an open end to a closed end, with the frangible connection forming the closed end in each case. The closed end of each recess or channel may advantageously have a rounded profile, as shown in <FIG>. By providing a frangible connection between opposing rounded notches or channels, the width of the frangible connection at the thinnest part is closely controlled.

It will be appreciated that the transverse width of the thinnest part of the frangible connection <NUM> can be controlled by varying the radius of curvature of the rounded notches. The smaller the radius of curvature of the first notches or recess <NUM> can be chosen to be substantially the same as the second notch or recess <NUM>.

Referring again to <FIG>, the frangible connection <NUM> preferably extends in a plane P that is orthogonal to the longitudinal axis A of the cap assembly <NUM>. By providing a flat seal (with respect to the longitudinal axis A), the frangible connection <NUM> tends to snap arounds its circumference at substantially the same time as the plug <NUM> bears on the bearing surface <NUM>. This is contrast to a frangible connection that extends in a plane extending at a non-perpendicular angle to the longitudinal axis A, which tends to peel from the 'lower' end (the portion of the frangible connection that is first brought into close proximity with the plug) towards the 'upper' end (the portion of the seal that is furthest from the advancing plug).

Once of the advantages of the frangible connection breaking around the perimeter of the closure member <NUM> at the same time is that the frangible connection may fail suddenly, causing a snap or click as the frangible connection <NUM> is broken. The snap or click failure of the frangible connection can provide audible and/or tactile feedback to the user that the component sealing the refill system <NUM> has been broken and that the concentrated cleaning fluid disposed within the capsule body <NUM> will be dispensed.

The plug <NUM> will now be described in more detail with reference to <FIG>, which shows a cross-sectional view of the plug <NUM>.

The plug described herein includes a number of improvements that may provide enhance performance. The plug may comprise an improved wall structure, an improved bearing surface for rupturing the frangible seal, enhanced safety features, and features that contribute to improved audible and tactile feedback to the user. Each of these improvements will be described in more detail below. Moreover, it will be appreciated that the features described below may be incorporated in a refill system alone, or in combination with other features to provide a further improved product.

As shown in <FIG>, the plug <NUM> comprises a generally tubular body <NUM> defining an internal conduit therethrough, with a proximal abutment surface <NUM> (for engaging the bearing surface <NUM> on the closure member <NUM>). The proximal abutment surface <NUM> is provided by the rim surrounding the open proximal end of the generally tubular body <NUM>.

In the embodiment shown in <FIG>, the plug <NUM> further comprises a skirt that extends around the tubular body <NUM>. The skirt comprises a generally tubular skirt wall <NUM> that is arranged coaxially with respect to the tubular body <NUM>, to provide a dual-walled plug. The skirt wall <NUM> is spaced apart from the tubular body <NUM> (in a radial direction) to form a plug recess <NUM> between the skirt wall <NUM> and the tubular body <NUM>.

The skirt wall <NUM> is connected at its distal end to the distal end of the tubular body <NUM>, and comprises a free proximal end. The free proximal end of the skirt <NUM> further comprises an outwardly extending flange <NUM> that provides a distal abutment surface <NUM> for abutting a rim of a refillable vessel <NUM> (see <FIG>).

By providing a plug <NUM> comprising an inner tubular body <NUM> and an outer skirt <NUM>, the plug assembly <NUM> can be more securely retained within the cap assembly <NUM>. For example, the plug recess <NUM> can accommodate a component (e.g. inner wall <NUM>) of the cap assembly to retain the plug <NUM> securely within the cap assembly <NUM> until the user screws the system <NUM> onto a refillable vessel <NUM>.

The distal abutment surface <NUM> at the free end of the skirt wall <NUM> can be configured to provide multiple additional advantages. For example, the free end of the skirt wall <NUM> can comprise a proximal seal <NUM> configured to seal against the connecting wall <NUM> of the cap assembly <NUM>. The proximal seal <NUM> can comprise a circumferential ridge comprising a peak. The peak provides a small surface area to be brought into contact with the connecting wall <NUM>, thereby improving the seal.

The free proximal end of the skirt wall <NUM> comprises one or more claws <NUM> configured to engage the threads <NUM> of the cap assembly <NUM>. The engagement of the claw(s) <NUM> with the thread <NUM> can provide additional security that the plug <NUM> will remain in place within the cap assembly <NUM>.

The claw(s) <NUM> may also retain the plug <NUM> within the cap assembly <NUM> after the product has been used. Since the plug <NUM> must be pushed into the cap assembly <NUM> to rupture the frangible connection <NUM>, the claws are preferably configured to such that they can ride over the threads <NUM> of the cap assembly as the plug <NUM> advances towards the closure member <NUM>. The claw(s) <NUM> may thus comprise a distal facing concave surface and a convex proximal surface.

As shown in <FIG>, the plug <NUM> may further comprise a circumferential ridge or protrusion <NUM> on an outer surface of the tubular body <NUM>. The ridge or protrusion <NUM> can be configured to engage with a corresponding ridge or protrusion (e.g. ridge <NUM>) on a complementary cap assembly <NUM>. This may further improved the retention of the plug <NUM> within the cap assembly before use.

As shown in <FIG>, the plug <NUM> can also comprise one or more cut-outs or slots <NUM> in the wall of the tubular body <NUM>. The cut-outs or slots preferably extend from the proximal rim <NUM> of the tubular body <NUM> partway along the tubular body <NUM>. The discontinuity in the rim <NUM> formed by the cut-outs or slots <NUM> may advantageously improve the flow of fluid through the cap assembly <NUM> and the plug <NUM> after the frangible connection <NUM> has been broken, by ensuring that the closure member <NUM> cannot form a seal against the rim <NUM> of the plug <NUM>.

In the embodiment shown in <FIG>, the plug <NUM> comprises two diametrically opposed cut-outs <NUM> (although only one is visible in the cross-sectional view shown in <FIG>). However, one cut-out may be provided, or three or more cut-outs can be provided in the tubular body <NUM>.

Providing a discontinuity in the rim of the tubular body <NUM> may also provide the additional advantage of reducing the surface area of the abutment surface <NUM> that is brought into contact with the bearing surface <NUM> of the closure member <NUM>, thereby increasing force per unit area exerted on the closure member <NUM>.

Although not illustrated in the drawings, it will be appreciated that the closure member <NUM> may be modified (in addition to or as an alternative to the plug <NUM>) to enhance the flow of cleaning fluid through the plug <NUM> and cap assembly <NUM> in a similar manner. For example, the closure member <NUM> may be modified to provide a discontinuity, such as a cut-out or recess, in the bearing surface <NUM> of the closure member <NUM> that prevents the closure member <NUM> from forming a seal with the plug <NUM> after the frangible connection has been broken.

As will be appreciated, a plug <NUM> comprising a planar rim <NUM> and a closure member <NUM> comprising a planar bearing surface <NUM> may form a seal against each other in the event that the closure member <NUM> settles over the opening of the tubular member <NUM> of the plug <NUM>. Should the planar surfaces align and come into contact to form a seal around the perimeter of the rim <NUM>, the closure member <NUM> could prevent the egress of fluid from the capsule <NUM> after the frangible connection <NUM> has been broken.

However, by providing one or more cut-outs or slots in either (or both) of the rim <NUM> or the bearing surface <NUM>, in the event that the closure member <NUM> settles against the tubular body <NUM> of the plug, fluid contained in the capsule may still flow through the tubular body <NUM> of the plug <NUM> by way of the openings formed by the slots of cut-outs.

As shown in <FIG>, the plug <NUM> may further comprise at least one barrier or beam <NUM> that extends across the distal opening of the tubular body <NUM>. The beam <NUM> may extend across the diameter of the distal opening, or multiple beams can extend across the opening. The beam is configured to allow the flow of fluid therepast, but prevent or restrict the insertion of an object (e.g. a finger) into the conduit formed by the tubular body <NUM>. This minimises the likelihood of the frangible connection <NUM> being broken inadvertently or improperly by way of an object passing through the tubular body <NUM>.

As will now be described with reference to <FIG>, when assembled, the capsule <NUM>, the cap assembly <NUM>, and the plug <NUM> can provide a system <NUM> providing yet further advantages.

<FIG> shows an enlarged view of the distal end of the refill system <NUM>. The neck <NUM> of the capsule <NUM> is clearly shown, and the rim <NUM> that surrounds the opening in the neck <NUM>. The neck <NUM> of the capsule <NUM> also comprises one or more threads <NUM> extending around the neck <NUM> (on an outer surface), which are configured to engage corresponding threads in the cap assembly <NUM>.

The cap assembly <NUM> is also clearly shown. The cap assembly <NUM> comprises the dual walled construction described above with reference to <FIG>. An inner surface of the outer wall <NUM> comprises one or more threads <NUM> that are configured to engage the threads <NUM> on the capsule <NUM>.

The cap assembly <NUM> is screwed onto the capsule <NUM> such that the rim <NUM> of the neck <NUM> is disposed within the upstream void 214a. Advantageously, the rim <NUM> of the neck <NUM> abuts the connecting wall <NUM> of the cap assembly. By engaging the capsule <NUM> with the cap assembly <NUM> such that the rim <NUM> of the capsule <NUM> abuts the connecting wall of the cap assembly <NUM>, the neck <NUM> of the connecting wall <NUM> against flexing as the plug <NUM> bears against the closure member <NUM>. Moreover, by abutting the rim <NUM> of the capsule <NUM> against the connecting wall <NUM> of the cap assembly, additional security against leakage from the capsule can be provided.

The cap assembly <NUM> is further configured such that the upstream end of the inner wall <NUM> (which is optionally configured as a barrel shaped seal, as described above) is disposed within the neck <NUM> of the capsule <NUM>. The inner wall <NUM> thus forms an additional seal with the neck <NUM> of the capsule <NUM>.

The engagement between the plug <NUM> and the cap assembly <NUM> will now also be described with reference to <FIG>. As shown in <FIG>, the plug <NUM> is disposed within the cap assembly <NUM>. The plug <NUM> shown in <FIG> is structurally similar to the plug described with reference to <FIG>.

As illustrated, the plug <NUM> is disposed within the cap assembly <NUM> such that the distal end of the inner wall <NUM> of the cap assembly is disposed within the recess <NUM> formed between the tubular body <NUM> and the skirt wall <NUM>. During assembly, the ridge <NUM> on the plug <NUM> is pushed passed the corresponding ridge <NUM> on the inner wall <NUM> of the cap assembly. The engagement of the two ridges <NUM> and <NUM> may help to retain the plug <NUM> within the cap assembly <NUM> during transport and storage of the system <NUM>.

The one or more claws <NUM> of the plug <NUM> may also help to retain the plug <NUM> within the cap assembly <NUM> by engaging the threads <NUM> on the interior surface of the outer wall <NUM>. Preferably, at least two claws are provided to securely engage the thread(s) <NUM> on of the cap.

The combination of the plug <NUM> and the cap assembly <NUM> described herein may be configured to prevent the closure member <NUM> blocking the flow of fluid through the cap assembly after the frangible connection <NUM> has been broken.

For example, as illustrated in the embodiment shown in <FIG>, the inner wall <NUM> of the cap assembly <NUM> can be configured to have a first diameter downstream of the frangible connection <NUM> and a second, larger diameter upstream of the frangible connection <NUM>. To ensure that the closure member <NUM> is pushed or lifted into a position in which it cannot seal against the inner wall <NUM> of the cap assembly <NUM> after the frangible connection <NUM> has been broken, the plug <NUM> can be configured such that the rim or abutment surface <NUM> can be moved upstream past the point at which the frangible connection <NUM> joins the closure member <NUM> to the inner wall <NUM>. This can be achieved by ensuring that the maximum distance of travel of the plug <NUM> is not limited by the cap assembly until the rim <NUM> has pushed the closure member <NUM> into the increased diameter portion of the conduit <NUM>.

In the example shown in <FIG>, the maximum travel of the plug <NUM> towards the frangible connection <NUM> is the point at which the seal <NUM> on the skirt wall <NUM> abuts the connecting wall <NUM> of the cap assembly <NUM>. In the embodiment illustrated, the rim <NUM> of the tubular body <NUM> and the seal <NUM> terminate in the same transverse plane. To ensure that the travel of the plug <NUM> is not limited until after the closure member has been lifted away from the narrower part of the conduit <NUM>, the frangible connection <NUM> is positioned downstream of the connecting wall <NUM>.

Alternatively (or additionally), the rim or abutment surface <NUM> of the plug <NUM> can extend proximally beyond the sealing surface <NUM> of the skirt wall <NUM>.

The capsule <NUM>, cap assembly <NUM>, and plug <NUM> can be made of any suitable material known in the art. For example, the capsule, cap assembly, and the plug may be made of polyethylene or polypropylene, and may be formed by injection moulding techniques. Advantageously, the capsule <NUM> can be formed of polyethylene, whilst the cap assembly <NUM> and the plug can be formed of polypropylene.

It will be appreciated that aspects of the present invention include embodiments in which the features described above are provided alone or in combination with other features described here. For example, the frangible connection described above can be provided in a refill system having a cap assembly that screws directly onto the neck of a refillable vessel. In such systems, the cap can be configured such that the rim of the refillable vessel bears directly on the closure member to break the frangible connection and allow concentrated cleaning fluid to flow through the cap assembly into the refillable vessel.

Moreover, the plug described herein may be provided in a cap assembly having a different sealing arrangement to the arranged described herein. For example, the cut-outs and slots in the plug assembly
that prevent a closure member sealing against the opening in the plug can be employed in cap assemblies with different structures, and with different closure members.

Claim 1:
A plug (<NUM>) for use in a cap assembly of a refill capsule, the plug (<NUM>) comprising:
- a hollow tubular body (<NUM>) with an open proximal end and an open distal end, wherein the open proximal end is surrounded by a first rim (<NUM>) that provides a proximal abutment surface for bearing against a frangible sealing component of a cap assembly;
- wherein the proximal abutment surface lies in a plane that is orthogonal to a longitudinal axis of the tubular body, and surface surrounds, in total, at least half of the open proximal end, and preferably has at least two fold rotational symmetry about the longitudinal axis;
- a skirt extending around the tubular body (<NUM>), and comprising a tubular skirt wall (<NUM>) arranged coaxially with respect to the tubular body (<NUM>), the skirt wall (<NUM>) being spaced apart from the tubular body (<NUM>) in a radial direction to form a plug recess (<NUM>) between the skirt wall (<NUM>) and the tubular body (<NUM>),
- wherein the skirt wall (<NUM>) extends from a skirt distal end at which the skirt wall (<NUM>) is connected to the tubular body (<NUM>), to a free proximal end,
- wherein the free proximal end of the skirt comprises:
- an outwardly extending flange (<NUM>) comprising a distal facing abutment surface (<NUM>) for abutting a rim (<NUM>) of a refillable vessel (<NUM>); and
- characterized in that the free proximal end of the skirt wall (<NUM>) further comprises at least one claw (<NUM>) radially outwardly of the distal abutment surface (<NUM>).