Assembly for dispensing liquids

An assembly (2) for dispensing liquids comprises: • a base member (8); • a cap (4) on the base member (8); and • a dispensing capsule (6) in the base member (8) and covered by the cap (4). The dispensing capsule (6) comprises: • a capsule body (7) having a first end (16) and a second end (18); • at least one wall (20) defining a first cavity (38) within the capsule body, the first cavity (38) having a first opening at the first end (16) of the capsule body; • at least one wall (22) defining a second cavity (40) within the capsule body, the second cavity (40) having a second opening at the first end (16) of the capsule body; • the first opening and the second opening provided with a seal member (64) which seals the first cavity (38) and the second cavity (40). The walls of the first cavity and the second cavity are collapsible if pressure is applied to the cavities from the second end (18) of the capsule body.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

This patent application claims priority from PCT Patent Application No. PCT/GB2018/053741 filed Dec. 21, 2018, which claims priority from Great Britain Patent Application No. 1800024.0 filed Jan. 2, 2018. Each of these patent applications are herein incorporated by reference in its/their entirety.

BACKGROUND

a. Field of the Invention

The present invention relates to an assembly for dispensing liquids, notably for dispensing a disinfectant composition, and to apparatus including the assembly.

b. Related Art

Many liquid preparations include active ingredients which degrade over time, limiting product shelf life. This is particularly true for disinfectants or sterilising agents such as chlorine dioxide, where the active ingredient is formed in situ when required by mixing two reagents. Examples are disclosed in WO 2005/011756. Chlorine dioxide, for example, may be formed by mixing a chlorite solution and an acid.

It is known to provide a dispensing capsule for location in the neck of a vessel, the capsule having two internal chambers, each containing a reagent. Discharging of the contents of the chambers into the vessel allows the reagents to mix and generate the active ingredient. Examples of such a dispensing capsule are described in WO 2017/060677. The dispensing capsule has two or more sealed dispensing chambers each of which contains a different substance to be dispensed into a primary chamber. Screwing a cap onto the neck of the vessel causes progressive crushing of the walls of the dispensing chambers and breaks an internal seal between the chambers, permitting pre-mixing of the contents of the chambers. Further crushing of the walls as the cap is screwed down results in breaking of an external seal, permitting discharge of the mixture into the primary chamber. The pre-mixing accelerates formation of the active agent, but it is desirable to further accelerate this formation to reduce the time needed to form an adequate concentration of active agent in the primary chamber.

After dispensing of the pre-mixed contents, the user unscrews the cap and must then remove the dispensing capsule from the neck of the vessel. The removal can be difficult as the capsule is typically a tight fit to ensure a good seal. The crushed dispensing capsule should then be properly recycled. However, re-use of the crushed capsule may be attempted, by pushing up the crushed cavity walls, refilling each cavity and resealing the capsule. This re-use is undesirable because the integrity of the cavity walls may have been compromised by the crushing, producing leakage and premature mixing. Also, the new seal may not perform within specification, for example by fracturing or delaminating too soon, or by not permitting sufficient time for pre-mixing. This can reduce efficiency and provide less surface complete disinfection, which is a particular problem in clinical environments.

SUMMARY OF THE INVENTION

Aspects of the invention are specified in the independent claims. Preferred features are specified in the dependent claims.

The invention provides an assembly for dispensing liquids, which provides additional pre-mixing time for concentrated reagents to react together prior to being discharged into the primary chamber.

A preferred embodiment of the invention provides an assembly for dispensing liquids, which may be ergonomically actuated and which is removable from the neck of a vessel by a single action of pulling or unscrewing. The assembly may be locked in a configuration in which re-use is prevented.

DETAILED DESCRIPTION

The assembly2for dispensing liquids shown inFIGS.1-4comprises a base member8, a cap4which is axially slidable on the base member8, and a dispensing capsule6in the base member8and covered by the cap4.

The dispensing capsule6comprises a capsule body7having a first end16and a second end18. In this embodiment the capsule includes a flange24at the second end of the capsule body, which sits on an annular seat26in the base member8. In this embodiment, the flange24is interrupted by a production key detail36which is used to locate the capsule during filling and sealing operations.

The capsule body7has at least one wall20defining a first cavity38and at least one wall22defining a second cavity40(FIG.5). The cavities38,40have first and second openings, respectively, at the first (dispensing) end16of the capsule. Each cavity contains a liquid and is covered by a seal member64which seals the contents of each cavity from the other cavity. Each cavity38,40may be provided with a separate seal member, or a single seal member64may cover both cavities, for example as disclosed in WO 2017/060677, which provides for pre-mixing of the contents of the cavities before breaking of the seal between the seal member64and the peripheral wall around the base34of the capsule body.

The walls of the first cavity38and the second cavity40are collapsible, concertina-style, if pressure is applied to the walls of the cavities from the second end18of the capsule body7. The cap4includes a plunger54, which in this embodiment is at the bottom of an opening28in the cap. The plunger54will bear against and cause progressive collapsing of the walls of the first cavity and the second cavity if the cap4is made to slide by an external force to a dispensing position in which the walls20,22of the cavities38,40are sufficiently collapsed to cause unsealing of the first opening and the second opening. In the embodiment shown inFIG.5, a single seal member (not shown) may cover substantially the entire lower surface34. A dividing member30is disposed between two internal projections32at the first end. A depression56helps reduce adhesion of the seal member at one end of the dividing member32. As pressure increases within the cavities, a critical pressure is reached at which the bond between the seal member and the dividing member30breaks, allowing the seal member to deform into a dome and permit partial mixing of the contents of the cavities while the bond between the seal member and the peripheral wall around the base34remains intact. The contents may, for example, be reagents which when mixed produce a disinfectant composition; for example chlorine dioxide or peracetic acid. Suitable reagents will be well known to those skilled in the art; for example, reagents for producing chlorine dioxide include: chlorite and acid; chlorate, peroxide and acid; and chlorite, hypochlorite, and a suitable buffer. The reagents may be in a concentrated form, providing rapid formation of the active agent when the contents of the chambers are mixed.

In this embodiment, the first and second cavities38,40have respective burst pins42,44. As pressure is increased, further collapse of the walls20,22of the cavities38,40brings the tips of the burst pins into contact with the seal member64and then causes the burst pins to push against the seal member to break the bond at the outer periphery, allowing pre-mixed contents of the capsule body7to be dispensed in a controlled manner. Alternatively, the burst pins could cause rupturing of the seal, or the burst pins could be omitted and application of sufficient pressure alone could be used to cause unsealing or bursting of the seal member, thereby releasing the contents of the cavities.

The base member8in this embodiment has an outer wall46and an inner wall50which defines an opening. The capsule6sits in the space defined by the inner wall50. A screw thread48is provided on an inner-facing surface of the outer wall46, for securing the assembly to the neck of a vessel.

The base member8is provided with a cup member15(best shown inFIGS.12and13) for receiving liquids discharged from the capsule6when the seal64has been displaced or broken. The concentrated reagents from the capsule remain in the cup and can rapidly react to provide the disinfecting agent before the user causes liquid (for example, water) from the primary chamber to wash through the cup member15via drain openings9in one or more side walls adjacent the cup member15.

The cap4and the base member8are provided with first mutually interengageable locking members arranged and adapted to prevent or inhibit removal of the cap4from the base member8when the cap is in a loaded position with the plunger54over the first cavity20and the second cavity22with the cavities sealed. In this embodiment, the base member8is provided with three external axial grooves10(two of which are visible inFIG.4) each of which has a projecting ridge12. For each groove10, the cap4has a corresponding inward-projecting catch or detent52. The detent52is hook-like and has a bevelled or chamfered inner-facing edge53. As the cap4is pushed onto the base member8, the chamfered edge53passes over the ridge12and the detent52flexes outwardly. When the trailing edge of the detent52passes over the ridge12, the detent52snaps into place at a location13within the groove10beneath the ridge12, as best shown inFIG.6. In this loaded position, the assembly resists removal of the cap, which would require simultaneous outward flexing of each detent52. The cavities remain sealed in the loaded position.

Application of sufficient further force to the cap4will cause the plunger54to bear against and cause progressive collapse of the walls of the first cavity and the second cavity as the cap is made to slide to a dispensing position in which the walls of the cavities are sufficiently collapsed to cause unsealing of the first opening and the second opening. As the cap moves from the loaded position to the dispensing position, the detent52travels over a ramp portion14and flexes outwardly. At the dispensing position (FIG.7) the detent snaps into place against a lower surface17of the base member8. Here, the detent52and surface17comprise second mutually interengageable locking members arranged and adapted to prevent or inhibit removal of the cap from the dispensing position on the base member. Also in this embodiment, an inner shoulder19on the cap bears against an upper surface of the ridge12when the cap is in the dispensing position, preventing further downward travel of the cap. The assembly is fixed in the dispensing position.

Referring now toFIGS.8and9, an embodiment of an apparatus for mixing liquids comprises a vessel58having a primary chamber62and a neck60in which is disposed the assembly2. The seal member64is in fluid communication with the cup member15and the primary chamber62. In this example, the assembly2is releasably secured to the neck60by the screw thread48on the base member8and a complementary screw thread on the neck60. InFIG.8, the cap4is in the loaded position and the seal64is intact. Application of external pressure on the cap4pushes the cap to the dispensing position shown inFIG.9. Crushing of the walls of the cavities causes unsealing of the openings of the cavities, in this example by the action of the burst pins42,44on the sealing member64. Liquids66from the cavities enter the cup member15, where they react to form a disinfectant. The liquids may, for example, be an acid and a chlorite solution which react to form a chlorine dioxide solution. Pre-mixing of the concentrated reagents in the cup15produces the active reagent more rapidly than if the reagents are added separately, or after only a relatively short pre-mixing time, to water in the primary chamber.

After waiting a predetermined time for the reagents to mix in the cup15, the user inverts or shakes the vessel58, causing water in the primary chamber62to enter through drain openings9and mix with the contents of the cup15. The vessel58may be at least partially filled with a liquid such as water prior to securing of the assembly on the neck, in a suitable quantity so that the resulting solution has a desired concentration of active agent. When mixing has taken place, the resulting solution (aqueous chlorine dioxide, in this example) may be dispensed. In this example, the vessel58is a bottle, and chlorine dioxide solution is dispensed by unscrewing the assembly2to remove it from the vessel neck, and pouring the solution out through the neck. Alternatively, the assembly could be replaced by a sprayer head with a dip tube, and the contents of the vessel could be dispensed by spraying.

In the further embodiment of the apparatus shown inFIGS.10and11, the vessel58is a trigger sprayer, for example of a type described in WO 2014/064414. The assembly2is secured to a neck of the sprayer bottle with the cap4in the loaded position. The trigger sprayer is provided with a lever68which is pivotable between a first position (FIG.10) in which the lever68does not bear against the cap4, and a second position (FIG.11) in which the lever bears against the cap in the dispensing position. The lever68is manually pivoted by the user about a hinge72until it is in contact with a surface70on the vessel58. In this embodiment, the lever completely covers the cap when the lever is in the second position. This Class 2 lever provides a mechanical advantage, and enables the user to exert greater force via the lever than by applying finger pressure directly to the cap.

In a preferred embodiment the force required to move the cap from the loaded position to the dispensing position is greater than the force required to move the cap to the loaded position. This arrangement can permit the cap to be pushed onto the base member by hand to the loaded position, but prevent or inhibit the accidental pushing of the cap to the dispensing position.

Although the invention has, for convenience, been illustrated with each set of locking members comprising a detent on the cap and one or more ridges or depressions on the base member, the invention is not limited to this arrangement. For example the base member may be provided with a detent, and the cap may be provided with one or more depressions which snap-fit over the detent when the cap is pushed down the base member. In another embodiment, the first (and optionally second or third) locking members may be an annular snap-fit which utilizes hoop-strain to hold the cap in place. Hoop-strain is the expansion of the circumference of the cap (more elastic piece) as it is pushed or twisted onto the base member (more rigid piece).

The invention has been illustrated with axial grooves on the base member. However, it will be understood that the grooves need not be completely straight, providing that the cap can be pushed on the base member. For example, the grooves could have a twist which imparts some rotational movement as the cap is pushed on the base member. In alternative embodiments, the cap may be provided with a groove and the base member with a projection that sits in the groove, or the cap and base member may have complementary screw threads.