Patent Publication Number: US-2021171253-A1

Title: Assembly for Dispensing Liquids

Description:
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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be further described, by way of example only, with reference to the following drawings in which: 
         FIGS. 1 and 2  show side and perspective views of an assembly for dispensing liquids, in accordance with an embodiment of the present invention; 
         FIGS. 3 and 4  are exploded views corresponding to  FIGS. 1 and 2 , respectively, of the assembly; 
         FIGS. 5  shows a capsule body for use in making an assembly in accordance with an embodiment of the invention; 
         FIG. 6  is a sectional view through the assembly of  FIG. 1 , with the cap in the loaded position; 
         FIG. 7  is a sectional view corresponding to the right hand side of the assembly shown in  FIG. 6 , with the cap in the dispensing position; 
         FIGS. 8 and 9  show partial sectional views of apparatus for mixing liquids, according to an embodiment of the present invention; 
         FIGS. 10 and 11  are perspective views of apparatus for mixing liquids according to a further embodiment of the invention, with the lever in the first position and the second position; and 
         FIGS. 12 and 13  are, respectively, a side elevational and a top plan view of the base member of the assembly of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     The assembly  2  for dispensing liquids shown in  FIGS. 1-4  comprises a base member  8 , a cap  4  which is axially slidable 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 . In this embodiment the capsule includes a flange  24  at the second end of the capsule body, which sits on an annular seat  26  in the base member  8 . In this embodiment, the flange  24  is interrupted by a production key detail  36  which is used to locate the capsule during filling and sealing operations. 
     The capsule body  7  has at least one wall  20  defining a first cavity  38  and at least one wall  22  defining a second cavity  40  ( FIG. 5 ). The cavities  38 ,  40  have first and second openings, respectively, at the first (dispensing) end  16  of the capsule. Each cavity contains a liquid and is covered by a seal member  64  which seals the contents of each cavity from the other cavity. Each cavity  38 ,  40  may be provided with a separate seal member, or a single seal member  64  may 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 member  64  and the peripheral wall around the base  34  of the capsule body. 
     The walls of the first cavity  38  and the second cavity  40  are collapsible, concertina-style, if pressure is applied to the walls of the cavities from the second end  18  of the capsule body  7 . The cap  4  includes a plunger  54 , which in this embodiment is at the bottom of an opening  28  in the cap. The plunger  54  will bear against and cause progressive collapsing of the walls of the first cavity and the second cavity if the cap  4  is made to slide by an external force to a dispensing position in which the walls  20 ,  22  of the cavities  38 ,  40  are sufficiently collapsed to cause unsealing of the first opening and the second opening. In the embodiment shown in  FIG. 5 , a single seal member (not shown) may cover substantially the entire lower surface  34 . A dividing member  30  is disposed between two internal projections  32  at the first end. A depression  56  helps reduce adhesion of the seal member at one end of the dividing member  32 . As pressure increases within the cavities, a critical pressure is reached at which the bond between the seal member and the dividing member  30  breaks, 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 base  34  remains 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 cavities  38 ,  40  have respective burst pins  42 ,  44 . As pressure is increased, further collapse of the walls  20 ,  22  of the cavities  38 ,  40  brings the tips of the burst pins into contact with the seal member  64  and 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 body  7  to 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 member  8  in this embodiment has an outer wall  46  and an inner wall  50  which defines an opening. The capsule  6  sits in the space defined by the inner wall  50 . A screw thread  48  is provided on an inner-facing surface of the outer wall  46 , for securing the assembly to the neck of a vessel. 
     The base member  8  is provided with a cup member  15  (best shown in  FIGS. 12 and 13 ) for receiving liquids discharged from the capsule  6  when the seal  64  has 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 member  15  via drain openings  9  in one or more side walls adjacent the cup member  15 . 
     The cap  4  and the base member  8  are provided with first mutually interengageable locking members arranged and adapted to prevent or inhibit removal of the cap  4  from the base member  8  when the cap is in a loaded position with the plunger  54  over the first cavity  20  and the second cavity  22  with the cavities sealed. In this embodiment, the base member  8  is provided with three external axial grooves  10  (two of which are visible in  FIG. 4 ) each of which has a projecting ridge  12 . For each groove  10 , the cap  4  has a corresponding inward-projecting catch or detent  52 . The detent  52  is hook-like and has a bevelled or chamfered inner-facing edge  53 . As the cap  4  is pushed onto the base member  8 , the chamfered edge  53  passes over the ridge  12  and the detent  52  flexes outwardly. When the trailing edge of the detent  52  passes over the ridge  12 , the detent  52  snaps into place at a location  13  within the groove  10  beneath the ridge  12 , as best shown in  FIG. 6 . In this loaded position, the assembly resists removal of the cap, which would require simultaneous outward flexing of each detent  52 . The cavities remain sealed in the loaded position. 
     Application of sufficient further force to the cap  4  will cause the plunger  54  to 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 detent  52  travels over a ramp portion  14  and flexes outwardly. At the dispensing position ( FIG. 7 ) the detent snaps into place against a lower surface  17  of the base member  8 . Here, the detent  52  and surface  17  comprise 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 shoulder  19  on the cap bears against an upper surface of the ridge  12  when the cap is in the dispensing position, preventing further downward travel of the cap. The assembly is fixed in the dispensing position. 
     Referring now to  FIGS. 8 and 9 , an embodiment of an apparatus for mixing liquids comprises a vessel  58  having a primary chamber  62  and a neck  60  in which is disposed the assembly  2 . The seal member  64  is in fluid communication with the cup member  15  and the primary chamber  62 . In this example, the assembly  2  is releasably secured to the neck  60  by the screw thread  48  on the base member  8  and a complementary screw thread on the neck  60 . In  FIG. 8 , the cap  4  is in the loaded position and the seal  64  is intact. Application of external pressure on the cap  4  pushes the cap to the dispensing position shown in  FIG. 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 pins  42 ,  44  on the sealing member  64 . Liquids  66  from the cavities enter the cup member  15 , 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 cup  15  produces 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 cup  15 , the user inverts or shakes the vessel  58 , causing water in the primary chamber  62  to enter through drain openings  9  and mix with the contents of the cup  15 . The vessel  58  may 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 vessel  58  is a bottle, and chlorine dioxide solution is dispensed by unscrewing the assembly  2  to 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 in  FIGS. 10 and 11 , the vessel  58  is a trigger sprayer, for example of a type described in WO 2014/064414. The assembly  2  is secured to a neck of the sprayer bottle with the cap  4  in the loaded position. The trigger sprayer is provided with a lever  68  which is pivotable between a first position ( FIG. 10 ) in which the lever  68  does not bear against the cap  4 , and a second position ( FIG. 11 ) in which the lever bears against the cap in the dispensing position. The lever  68  is manually pivoted by the user about a hinge  72  until it is in contact with a surface  70  on the vessel  58 . 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.