Abstract:
A dispenser including a base unit with an actuation mechanism for dispensing liquid and a refill unit insertable into the base unit in an inverted configuration with its outlet lowermost for the supply of liquid to the base unit. The refill unit includes an annular wall projecting into the refill unit and defining an outlet from the refill unit, the annular wall being closable at its innermost end by a valve element biased onto the annular wall. The base unit includes a hollow spigot and an annular seal surrounding and spaced from the top of the spigot whereby insertion of the refill unit into the base unit causes the spigot to enter the annular wall and to lift the valve element from the annular wall to define a flow path from the refill unit, and the annular seal to seal between the spigot and the annular wall.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 13/129,164, filed 12 Sep. 2011, which is a US National Stage of International Application No. PCT/GB2009/002682, filed 17 Nov. 2009, which claims the benefit of GB 0820981.9, filed 17 Nov. 2008, each of which are herein fully incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a dispenser for dispensing a liquid soap or the like. 
     BRIEF SUMMARY OF THE INVENTION 
     The dispenser has a base unit into which a refill unit containing the material to be dispensed is fitted in an inverted configuration, namely with its outlet at the lowermost end. The present invention has been specifically designed for a free-standing soap dispenser suitable for use in a domestic environment. However, it could also be applicable to a wall-mounted unit and could be used for larger scale devices such as public lavatories. The unit may have a manually operated pump to dispense the liquid, but is preferably provided with a proximity sensor which senses the presence of the user&#39;s hand and has a pump to automatically dispense liquid. 
     As the device is primarily intended for the domestic market, it is essential that a consumer can replace a refill unit in a manner which is very easy, foolproof and without mess which is at best an annoyance for the consumer and at worst could destroy the dispensing mechanism. 
     According to the present invention, a dispenser comprises a base unit with an actuation mechanism for dispensing liquid and a refill unit insertable into the base unit in an inverted configuration with its outlet lowermost for the supply of liquid to the base unit, the refill unit comprising an annular wall projecting into the refill unit and defining an outlet from the refill unit, the annular wall being closable at its innermost end by a valve element biased onto the annular wall, the base unit comprising a hollow spigot and an annular seal surrounding and spaced from the top of the spigot, whereby insertion of the refill unit into the base unit causes the spigot to enter the annular wall and to lift the valve element from the annular wall to define a flow path from the refill unit, through at least one cut-out portion formed in the top of the spigot and/or the bottom of the valve element and down the hollow spigot, and the annular seal to seal between the spigot and the annular wall, wherein the activation mechanism comprises a pump selectively operable to pump a metered dose of liquid along a dispensing tube and out of a dispensing head; a proximity sensor in the form of a capacitive sensor; and control circuitry to react to a signal from the proximity sensor to activate the pump. 
     Such an arrangement provides a mechanism by which the refill unit can simply be lowered onto the spigot. This causes the flow path to be opened up. During the opening process, the annular seal forms a seal with the annular wall thereby preventing leakage even during the opening process. 
     The present invention therefore provides a simple and mess free way of replacing the refill unit even when the refill has not been completely emptied. 
     The cut-out portion could be formed in the bottom of the valve element. However, this would also require the valve seat to be shaped to match the cut-out portion on the valve element. It is therefore preferable for the cut-out portion to be on the top of the spigot. Preferably, there is more than one cut-out portion to provide a plurality of flow paths. In the preferred example, the cut-out portions effectively take the form of castellations on the top of the spigot. 
     The valve element could be biased by a spring which is on the opposite side of the valve element from the annular wall. However, preferably, the valve element is biased by at least one resilient member which is preferably joined at one end to the valve element and at the other end at a location radially outwardly of and below the innermost end of the annular wall, the or each resilient member being configured so that when the valve element is lifted from the annular wall, a flow path is present between the valve element and the annular wall. 
     By using at least one resilient member anchored outside of the annular wall, the structure of the device can be greatly simplified as the resilient elements themselves and the means by which they are anchored can be integrated into the existing structure of the refill unit. If the valve element was to be resiliently supported on its opposite side, then an additional structure would be required to support this, thereby complicating the design. 
     This forms an independent aspect of the present invention which can be defined in its broadest sense as a refill unit for a dispenser, the unit comprising an opening at one end which, in use, is the lowermost end, the opening comprising an annular wall projecting into the unit and being closable at its innermost end by a valve element biased onto the annular wall, wherein the valve element is biased by at least one resilient member with joined at one end to the valve element and at the other end to a location radially outwardly of and below the innermost end of the annular wall, the or each resilient member being configured so that, when the valve element is lifted from the annular wall, a flow path is present between the valve element and the annular wall. 
     If only a single biasing element is used, it could not be a continuous annular component, but would have to have holes in or be a helical structure, or similar, so that the flow path could be present. Preferably, there are a plurality of resilient elements with gaps therebetween to provide the flow path. 
     The or each resilient member may be manufactured separately from the valve element and fixed together. However, preferably, the valve element is manufactured integrally with the or each resilient member. 
     The or each resilient member preferably extends into a surrounding valve plate which is secured to the cap of the refill unit. 
     The valve plate may simply be glued, adhered or otherwise fixed within the cap. However, preferably, the valve plate is sandwiched between the cap and a fixing plate. Preferably, one or more fixing posts are provided in one of the cap, valve plate or fixing plate in order to locate the various elements with respect to one another. 
     The opening in the refill unit may be a liquid outlet or an air relief inlet. The structure of the annular wall, valve element and resilient member is equally applicable to either. 
     These and other objects, features and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  is a cross-section through a dispenser with an infrared sensor in place of the capacitive sensor of the invention; 
         FIG. 2  is a cut-away perspective view of the refill being introduced into the dispenser but not yet being engaged; 
         FIG. 3  is a view similar to  FIG. 2  showing the refill in an intermediate position; 
         FIG. 4  is a view similar to  FIGS. 3 and 4  showing the refill in its fully engaged position; 
         FIG. 5  is a perspective view of the cap assembly prior to assembly; 
         FIG. 6  is a perspective view of the cap assembly after assembly; 
         FIG. 7  is a cross-section showing the engagement between the bottle neck and cap assembly; 
         FIG. 8  is a perspective view of the cap with the frangible members intact; 
         FIG. 9  is a view similar to  FIG. 7  after the bottle has been removed from the cap; 
         FIG. 10  is a view similar to  FIG. 8  after the frangible members have broken off; 
         FIG. 11  is an exploded perspective view of a cap of a second refill unit; 
         FIG. 12  is a view similar to  FIG. 11  showing the assembled cap; 
         FIG. 13  is a cross-sectional view through the pressure relief valve of the second example; and 
         FIG. 14  is a view similar to  FIG. 13  showing the pressure relief valve in an open configuration to allow the flow of air. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below. Although exemplary embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the exemplary embodiments, specific terminology will be resorted to for the sake of clarity. 
     It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named. 
     Also, in describing the exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
     Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and/or to the other particular value. 
     Similarly, as used herein, “substantially free” of something, or “substantially pure”, and like characterizations, can include both being “at least substantially free” of something, or “at least substantially pure”, and being “completely free” of something, or “completely pure”. 
     By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named. 
     It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified. 
     The materials described as making up the various elements of the invention are intended to be illustrative and not restrictive. Many suitable materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention. 
     The dispenser is a hands-free dispenser which is generally suitable for domestic use. The dispenser is primarily intended to dispense liquid soap, but may also be used to dispense other liquid or semi-liquid products (ideally with a viscosity greater than water), such as hand cream, body lotion, moisturizer, face cream, shampoo, shower gel, foaming hand wash, shaving cream, washing up liquid, toothpaste or a sanitizing agent such as alcohol gel. 
     The dispenser comprises two main parts, namely a refill  1  and a base unit  2 . The refill  1  provides a reservoir of liquid to be dispensed and is fitted to the base unit  2  as set out below. 
     The base has an interface  3  into which liquid is dispensed from the refill unit. The interface  3  is in fluid communication with a dispensing tube  4 . A pump  5  is selectively operable to pump a metered dose of the liquid along dispensing tube  4  and out of dispensing head  6 . 
     The base has an infrared transmitter  7 A which transmits an infrared beam through a window  8  to a receiver  7 B to sense the presence of a user&#39;s hands in the vicinity of the dispenser. Control circuitry reacts to a signal from the proximity sensor to activate the pump. The illustrated sensor is a break beam sensor, but may also be a reflective sensor. Although an infrared sensor is shown and described, this is replaced by a capacitive sensor in the present invention. The device may be mains powered or battery powered. 
     The interface between the refill  1  and base unit  2  will now be described in greater detail with reference to  FIGS. 2 to 10 . 
     The base unit  2  comprises a cowling  10  which forms a cup-shaped housing surrounding a significant portion of the refill to protect and support it. A spigot  11  projects through the base of the cowling  10  and is sealed to the cowling  10  by an O-ring seal  12 . The spigot has a plurality of castellations  13  in its top surface. A second O-ring seal  14  surrounds the spigot  11  beneath the castellations  13 . 
     The refill  1  comprises a bottle  20  to which a cap  21  is fixed. The bottle  20  has a neck  22  which fits over and seals with an annular flange  23  within the cap  21 . The cap  21  has an upwardly depending skirt  24  (when in the inverted orientation shown in the drawings) which forms the outer surface of the cap. Working inwardly from the skirt  24 , the next feature of the cap is an outer annular wall  25  which is generally co-axial with the skirt  24 . 
     This is shown in detail in  FIGS. 5 to 10 . 
     The outer annular wall  25  consists of a pair of retaining members  26  and a pair of support members  27  which alternate with one another and each extend for approximately a quarter of the circle as shown in  FIGS. 5 ,  6 ,  8  and  10 . The profile of the support members  27  is as shown in  FIG. 2 . These members extend directly up from the lower wall of the cap, are parallel sided and have an inclined upper surface  28 . The profile of the retaining members  26  is shown in  FIGS. 7 and 9 . Unlike the support members  27 , these are not fixed to the wall of the cap. Instead, they are fixed at either end to the support members  27  by frangible members  29  as best shown in  FIGS. 6 and 8 . The retaining members  26  are parallel sided and have an inclined upper surface  35  as shown in  FIGS. 7 and 9 . 
     As shown in  FIGS. 7 and 9 , the neck  22  of the bottle has an inclined outer surface  36  which is complimentary to the inclined surfaces  28  and  35  of the annular wall  25 . Behind the inclined outer surface  36  is a shoulder  37  which faces the main body of the bottle  20 . This inclined outer surface  36  and shoulder  37  is only present in the vicinity of the retaining members  26  and not in the vicinity of the support members  27 . Adjacent to the support members  27 , the neck  22  has a parallel sided configuration as shown in  FIG. 2 . 
     In order to insert the bottle  20  into the cap  21 , the bottle  20  is pushed down with its neck fitting over the annular flange  23 . The inclined outer surface  36  of the bottle co-operates with the inclined surfaces  28 ,  35  to displace the retaining members  26  radially outwardly until the shoulder  37  snaps into place behind the retaining members  26  as shown in  FIG. 7 . When the bottle  20  is pulled off of the cap  21 , the shoulders  37  bear against the retaining members  26 , thereby breaking frangible members  29  so that the retaining members  26  become detached from the cap  21  as shown in  FIGS. 9 and 10 . Once this has happened, it is no longer possible to retain the cap on a bottle, thereby preventing subsequent use of the refill  1 . 
     It should be noted that it is not necessary for both of the retaining members  26  to become fully detached from the lid. It is possible that only one of these becomes detached, or that one or both are simply displaced to a location at which they can no longer engage with the neck of the bottle. 
     Returning now to  FIGS. 2 to 4 , the liquid outlet and associated valve will now be described. 
     The liquid outlet from the reservoir is provided by an annular wall  30  surrounding a central opening  31 . At the top of the annular wall  30  is an inclined surface  32  (see  FIG. 4 ) which provides a valve seat for outlet valve element  33 . This is shown in the form of a U-shape cup-like member, but may equally be a solid member or a hollow ball-like member. The outlet valve element  33  is biased into its closed position by a plurality of biasing elements  34 . These are attached at their upper end towards the top of the valve element  33  and are attached at their lower ends at a location radially outward of the annular wall  30  and below the top of the annular wall  30 . They are preferably formed integrally with the valve element  33 . 
     As shown in  FIGS. 2 to 4 , when the refill  1  is lowered into the base unit  2 , the spigot  11  engages with the lower surface of the valve element  33  as shown in  FIG. 3 . Further downward movement of the refill causes the valve element  33  to be lifted from its seat, and also brings the O-ring  14  into sealing engagement with the annular wall  30 . The valve element  33  is lifted to the position shown in  FIG. 4 . In this position, liquid in the bottle  20  can flow around the biasing elements  34 , and enter the spigot via the castellations  13  and hence flow into the base unit  2 . Liquid is prevented from escaping between the spigot  11  and annular wall  30  by the O-ring seal  14 . This arrangement offers a simple and mess-free way for a consumer to insert a refill regardless of the fill level of the refill. 
     In order to remove a refill, the consumer lifts it out of the base whereupon the biasing elements  34  cause the valve element  33  to return to the seat  32 . During this movement, the seal between the spigot  11  and annular wall  30  is maintained by the O-ring seal  14 . A spent refill is then replaced by a new one following the above procedure. 
     The cap is provided with a pair of pressure relief valves  40 . Each is formed by an annular boss  41  integral with the cap  21 . A pressure relief valve element  42  is seated on the top of the annular boss  41  and is biased in place by a pair of biasing elements  43  (as shown, for example, in  FIG. 5 ). The biasing force is such that, under normal conditions, the pressure relief valve element  42  forms an air tight seal on the boss  41 . However, when the pressure within the bottle  20  drops below a certain level, the pressure differential across the relief valve element  42  is sufficient to overcome the force exerted by biasing elements  43  and to allow air into the bottle  20 . This reduces the pressure differential thereby restoring the air tight seal without leakage of fluid. 
     Each pressure relief valve  40  is surrounded by an annular barrier  44  which extends axially to a level axially above the level of the top of the annular wall  30 . Thus, when the valve element  33  is open, any air entering the relief valve  40  will not become entrained in the outgoing liquid stream. In practice, this means that the relief valve can be placed closer to the outlet, thereby resulting in a more compact cap. Although two relief valves are shown, a single valve, or more than two valves could be provided if necessary. 
     The manner in which the cap is assembled is illustrated in  FIGS. 5 and 6 . 
     The assembly is a three-part structure consisting of the cap  21 , a valve plate  45  and a fixing plate  46 . The cap has a number of molded features including the annular flange  23 , annular wall  25  and annular bosses  41 . In addition, the cap  21  has a plurality of fixing posts  47 . 
     The valve plate  45  is an elastomeric material and is integrally formed with the valve element  33 , biasing elements  34 , relief valve element  42  and biasing elements  43 . The valve plate has a plurality of locating holes  48  which correspond to the fixing posts  47 . 
     The fixing plate  46  is made of a rigid plastics material and is integrally formed with the annular barrier  44 . As with the valve plate  45 , the fixing plate  46  is also provided with a plurality of locating holes  49  which correspond to the fixing posts  47 . 
     To assemble the cap, the three components are placed on top of one another as shown in  FIG. 6  with the fixing posts entering the locating holes to ensure that the components are correctly aligned. Heat or adhesive is then applied to the top of the fixing posts  47  to secure the fixing posts to the fixing plate  46 . The elastomeric valve plate  45  is thereby sandwiched between the cap  21  and fixing plate  46  which holds the valve elements  33  and  42  in position. 
     A second example of a cap for a refill unit will now be described with reference to  FIGS. 11 to 14 . 
     The structure of the outlet valve element  33  in the second example is essentially the same as the first example, and will not be described again in relation to the second example. 
     As can be seen from  FIG. 11 , the cap  21  is integrally molded with a number of features, such as the annular walls  25  and  30  and a conical part  50  of the pressure relief valve which will be described below. A resilient lip  53  (described in more detail below) for the pressure relief valve is provided integrally molded with the valve plate  45 . The fixing plate  46  is also provided with a shield  57  for the relief valve. This is equivalent to the barrier  44  in  FIG. 2 , but only extends around the side of the relief valve facing the outlet valve element  33 . The barrier  44  and shield  57  could be used interchangeably in the two examples. 
     The cap assembly is assembled in the same manner as in the first example. 
     The pressure relief valve  60  is illustrated in  FIGS. 13 and 14 . 
     The valve has the conical part  50  which is an integral part of the cap  21  as mentioned above. At the top of the conical part  50  is a cylindrical post  61 . The resilient lip  53  is effectively a hollow frustoconical extension of the valve plate  52  of resilient material which extends along the conical part  50  from which it diverges slightly and is a tight fit against the post  61 . At least one air inlet  62  (also shown in  FIG. 11 ) passes through the wall of the conical part  50  and is normally covered by the resilient lip  53  as shown in  FIG. 11 . When the pressure in the bottle  20  falls as liquid is emptied the pressure differential across the resilient lip  53  will eventually become sufficient to displace the lip  53  to a sufficient degree to allow air A into the bottle  20  as shown by the arrows in  FIG. 8 . It should be noted that the degree to which the resilient lip  53  lifts from the conical element  50  has been exaggerated in  FIG. 8  and that, in practice, this will be almost imperceptible. 
     Instead of sealing against the post, the resilient lip  53  may seal against the conical part  50 . In this case, the lip will not diverge from the conical part as shown. Instead, it would actually have an angle of incline less than the angle of the conical part  50  so as to be naturally biased onto the conical part. 
     Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. While the invention has been disclosed in several forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions, especially in matters of shape, size, and arrangement of parts, can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims. Therefore, other modifications or embodiments as may be suggested by the teachings herein are particularly reserved as they fall within the breadth and scope of the claims here appended.