Abstract:
A closure ( 10 ) is provided for a water bottle of the type used in conjunction with a water fountain. The closure ( 10 ) comprises a body ( 20 ) having an open feed cylinder ( 50 ) and a sealing cap ( 30 ) which is movable between a sealing position and an open position and is adapted to seal the feed cylinder when in a sealing position. The sealing cap is biased towards a sealing position by biasing means which preferably comprise a plastics spring ( 70 ) that anchors the sealing cap ( 30 ) to the body ( 20 ). The form of the spring ( 70 ) and the arrangement of the sealing cap ( 30 ) and the feed cylinder ( 50 ) are such as to minimize and compensate for creep in the plastics material of the spring ( 70 ) in use of the closure ( 10 ) to ensure resealing of the feed cylinder ( 50 ) if and when the water bottle is removed from the water fountain.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to a closure and particularly to a closure for a water bottle of the type used in conjunction with a water fountain. The neck of this type of bottle is closed by the closure to seal it and so that it can be turned upside down before being lowered onto a water fountain spike. The closure must in some way allow entry of the water fountain spike into the interior of the bottle to allow the removal of water. 
     It is known to provide a closure with a central feed cylinder which is blocked by a sealing cap. As the bottle is lowered onto the water fountain spike the spike pushes the sealing cap out of the feed cylinder. The sealing cap is formed so that it can attach to the water fountain spike as it is pushed out of the feed cylinder. However, it has been found that the sealing cap does not always attach itself to the spike and very often floats up to the top of the bottle. This is particularly common if the spike is not inserted straight into the closure but rather at a slight angle. Precise positioning of the bottle on the spike is not an easy operation, particularly due to the weight and bulk of the bottle. 
     Whilst in general once the water bottle has been placed on the water fountain it should not need to be removed before the bottle has been fully emptied, there may be circumstances in which removal of the bottle is required. In the prior art system discussed above the sealing cap does not reseal the feed cylinder as the water bottle is removed from the water fountain spike so that water can escape freely from the feed cylinder as the water bottle is removed. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided a water closure for a water bottle of the type used in conjunction with a water fountain, comprising a body having an open feed cylinder, and a sealing cap movable between a sealing position and an open position and adapted to seal the feed cylinder when in a sealing position, in which the sealing cap is biased towards a sealing position by biasing means. 
     In a preferred embodiment the sealing cap is anchored to the body by the biasing means, and is movable between a lower sealing position and a raised open position, whereby to allow water to flow through the feed cylinder when the water bottle is placed on a water fountain spike or the like and to reseal the feed cylinder when the water bottle is removed. 
     It can be seen that a closure with a sealing cap that is anchored to the body has the advantage that the cap cannot float off the body into the water bottle and, due to the biasing means, when the bottle is lifted off the water fountain spike the sealing cap will automatically reseal the feed cylinder. This feature has the additional benefits of preventing refilling of the water bottle and preventing contamination if the water bottle is removed from the water fountain spike for any length of time, for example, if repairs are required to the water fountain. 
     The biasing means may comprise a spring such as a tension or torsion spring. Other forms of biasing means such as a linearly extending elastic element are not beyond the scope of the invention. 
     The closure body will generally be formed from a plastics material. The form of any biasing means is of particular importance and it is necessary to consider any effect the choice of material may have on the contents of the water bottle. For example, it is well known that if metals, such as stainless steel, come into contact with water that the taste of the water may be adversely affected. The use of a metal spring, whilst not impossible, is seen as unsatisfactory. 
     The use of a plastics spring such as a coil spring is preferred but brings with it specific problems which the present invention also seeks to overcome. One of the major considerations when using a plastics spring is the relationship between the spring coefficient and the characteristic known as creep. The higher the spring coefficient the greater the tendency for the plastics material to creep which will reduce the ability of the spring to return. In addition, it is known that chlorine, often present in bottled water, also affects the creep characteristics of plastics. 
     The spring preferably serves to return the sealing cap even when there is very little or no water left in the bottle. The present invention has been designed to work even if the bottle is not inverted so that the spring is strong enough to return the sealing cap with no additional help in the form of pressure of the water above it. 
     The present invention accepts that some creep is inevitable given the requirement for it to return the cap even if the bottle is not inverted, and addresses this by optimising the design of the spring and compensating for creep. 
     The section of the spring material is preferably as close to a circle as possible to minimize creep, whilst allowing for easy moulding. It has been found that material with a substantially square cross section is useful for minimising creep of such a spring whilst being easy to mould. 
     In addition, the spring may be formed in a substantially unstressed state, to be stressed only when the water fountain bottle is in use, this avoids the possibility that the spring will creep during extended periods of storage before use. However, alternatively the spring may be pre-stressed to some extent to improve its ability to return following stretching. The preferred level of pre-stressing may be a compromise between improving the ability of the spring to return and the level of creep suffered as a result. 
     Other useful features for a spring include a small cross-sectional area and increased length, both of which reduce stress and therefore creep. 
     The form of the spring is not of particular importance to the present invention although the use of a coil spring having a conical shape has been found to be particularly advantageous. A conical spring is particularly stable when it is extended, does not twist as it is stretched and does not reduce in diameter as it is stretched. In addition it has been found that this configuration is easy to mould. The use of the conical spring is therefore seen as preferable over, for example, a cylindrical spring. 
     Whilst the sealing cap of the present invention may of course take the form of an inner or outer cap, i.e. its relationship with the open feed cylinder is as a cover or a plug, in a preferred embodiment the sealing cap takes the form of a stopper element adapted to plug the feed cylinder. In the preferred embodiment the inner sealing cap and feed cylinder are arranged such that the distance the cap is moved by the water fountain spike is greater than the distance the cap must be returned by the spring to reseal the feed cylinder. In other words, at least part of the sealing cap in its lower sealing position must be within the feed cylinder. This may be achieved for example by using an elongate sealing cap. As the water bottle is lowered onto the water fountain spike the spike engages the sealing cap and pushes it through the feed cylinder a distance before the sealing cap emerges from the end of the feed cylinder whereby to unblock it. Over the period of time the sealing cap is raised out of the feed cylinder to allow escape of the contents of the water bottle the plastics material of the spring will inevitably creep to a certain extent. It can be seen, however, that if the water fountain spike is subsequently withdrawn, the distance the sealing cap must be returned by the spring before it blocks the feed cylinder is less than the distance it was originally moved by the water fountain spike. 
     In a typical closure the displacement is approximately twice the distance required for resealing. In a specific embodiment the closure is arranged so that the bottom of the sealing cap is pushed up through and out of the feed cylinder approximately 25 mm against the action of the biasing means as the bottle is placed on the water cylinder spike, and in its uppermost open position the bottom of the sealing cap is held approximately 15 mm from the feed cylinder opening, such that a return of 10 mm or more provided by the biasing means is sufficient to reseal the feed cylinder. 
     It is noted by the inventors that there is no particular need for the closure to be removed from the bottle by the end user. Refilling of the container by the user may be unwanted and the manufacturer may wish to prevent this. In addition, because the sealing cap is anchored to the closure body and cannot float into the bottle, there will be no tendency for a user to try to remove the closure in order to access a cap which has floated into the bottle. The closure of the present invention may therefore be permanently secured to the bottle. In this context the term “permanently” means that it is not removable by hand or by a non-specific tool and for example may only be removable using a specific machine. For this purpose the securing means may comprise a hinged annulus which is adapted to be upturned to engage a bead or the like on the bottle. 
     The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a water bottle closure according to the present invention; 
         FIG. 2  shows a perspective view of an axial section taken through the closure of  FIG. 1  when inverted; 
         FIG. 3  is an axial section of the closure shown secured to a water bottle; 
         FIG. 4  shows the closure of  FIG. 3  as it is first positioned over a water fountain spike; 
         FIG. 5  shows the closure of  FIG. 4  in which the water bottle has been fully lowered onto the water fountain spike so that the closure feed cylinder is open; 
         FIG. 6  is an axial section through a closure formed according to an alternative embodiment shown secured to a water bottle; and 
         FIG. 7  is a cross-section through part of a conical coil spring formed as part of an alternative embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to  FIGS. 1 and 2  there is shown a closure generally indicated  1  which is intended to be connected to a water bottle of the type used in conjunction with a water fountain. The closure  1  comprises a body  20  and a cylindrical sealing cap  30 . 
     The body  20  comprises an annular skirt  40  which is partially closed at one end by an annular top panel  45 . A feed cylinder  50  depends from the central opening  46  defined by the annular top panel  45 . The feed cylinder  50  narrows slightly at a shoulder  55  and a ring pull element  60  is attached to the interior of the cylinder  50  at the shoulder  55 . The ring pull element  60  is frangibly attached to the shoulder  55  and serves to seal the closure  1  before first use. 
     Radially inwardly of the annular skirt  40  an upstanding wall  65  depends from the annular top panel  45 . Together the annular skirt  40  and the upstanding wall  65  define a channel  66 . 
     The sealing cap  30  is slidably mounted in the feed cylinder  50 . The main body  35  of the sealing cap  30  extends from the shoulder  55  of the feed cylinder  50  to the end  51  of the feed cylinder  50  at which point a circumferential abutment band  31  projects radially outwardly from the sealing cap cylinder  30 . The sealing cap  30  is closed by a panel  33  at its lower end level with the circumferential abutment band  31 . It can be seen that the sealing cap  30  is a stopper element which is adapted to plug the feed cylinder  50 . 
     The exterior dimensions of the sealing cap  30  are approximately equal to the interior dimensions of the feed cylinder  50  to allow relative sliding movement but sealed at all relative positions. The circumferential abutment band  31  defines a first end position of the sealing cap  30 . An upstanding collar portion  32  extends away from the circumferential abutment band  31 . The circumferential abutment band  31  also serves as a point of connection for one end of a substantially conical spring  70 . 
     In practice the conical spring  70  may be injection moulded in-line and opposite corners of the square spring section will line up along a diagonal line along which the mould breaks open. The resulting spring is inclined at approximately 45°, as shown in the drawing. In order to fit within the dimensions of the cap the vertical distance from the circumferential abutment band  31  to the annular top panel  45 , to which the spring  70  must be secured, must be bridged because such a spring does not extend the full distance in this unstressed, as-formed state. A spring  70  having a rectangular cross section could bridge the vertical distance; however, this has been shown to result in increased creep of the plastics material and it is therefore preferred to use a spring with a square cross-section. Accordingly the other end of the spring  70  is attached to a tubular bridging portion  71  which bridges the gap between the lower end of the spring and the annular top panel  45 . The spring  70  is secured to the annular top panel  45  by virtue of an interference fit of the bridging portion  71  within the upstanding wall  65 . 
     An annular flap  80  is hingedly connected to the free end of the annular skirt  40  by a film hinge  81 . The annular flap  80  has a plurality of circumferentially spaced wedge-shape elements  85  which, when the closure  1  is secured to a bottle and the annular flap is upwardly turned, are adapted to engage a rim of the bottle neck so as to secure the closure to the bottle as is shown in  FIGS. 3 to 5 . 
     The working of the closure will now be described in relation  FIGS. 3 to 5 . 
       FIG. 3  shows the closure  1  secured to the neck  90  of a water bottle, typically a 5 gallon bottle. The bottle neck  90  is received in the channel  66  formed between the upstanding wall  65  and the annular skirt  40 . The width of the channel  66  is such that the bottle neck  90  is slightly wider. As a result, when the closure is applied the wall  65  is forced inwards. The bridging portion  71  is therefore held more tightly in place. 
     The annular flap  80  is turned upwardly so that the wedge elements  85  engage a bead rim  95 . It will be appreciated that because the flap  80  is folded flat against the skirt  40  and because of the now inwardly directed elements  85 , it is extremely difficult to lever the flap  80  back to its starting position. 
     The ring pull element  60  is shown still attached and it can be seen that the sealing cap  30  cannot therefore be pushed upwardly in this state. In this inoperative position the spring  70  is substantially unstressed. 
     Referring now to  FIG. 4  the ring pull element  60  has been removed and the opening  46  of the annular top panel  45  has been aligned with a water fountain spike  100 . The dimensions of the feed cylinder  50  below the shoulder  55  are such that the spike  100  can slide freely through it. The widest point of the spike  100  is of substantially the same circumferential dimensions as the interior of the feed cylinder  50  so that it contacts the lower end  36  of the sealing cap  30  as shown in the drawing. 
     Referring now to  FIG. 5  it can be seen that as the water bottle  90  is lowered on to the water fountain spike  100  the spike  100  pushes the sealing cap  30  through the feed cylinder  50  against the biasing action of the spring  70 .  FIG. 5  shows the spike  100  fully inserted and it can be seen that in this second end position the sealing cap  30  no longer plugs the feed cylinder  50  so that water can escape from the bottle. 
     The spring  70  is now in a stressed condition and over a period of time will inevitably creep, consequently its ability to return the sealing cap  30  will be diminished. 
     Because the sealing cap  30  is formed as a stopper it will seal the feed cylinder  50  as soon as the end  36  of the main body  35  is withdrawn into the feed cylinder  50 . The sealing effect of the sealing cap  30  is not therefore dependent on a complete withdrawal back to the point at which the circumferential abutment band  31  prevents further movement. It can be seen therefore that the distance the end  36  of the main body  35  is moved by the spike  100  is much greater than the distance it is from the end  51  of the feed cylinder  50  when the water fountain spike  100  is fully inserted. Therefore the distance the spring  70  must return the sealing cap  30  in order for it to seal the feed cylinder  50  is much less than the distance it was initially moved. This design thereby compensates for creep of the plastics material when the closure  10  is in use. 
       FIG. 6  is an axial section through a closure  101  formed according to an alternative embodiment. The closure  101  is shown attached to a bottle neck  190  in the same position as  FIG. 4  in which the bottle has been positioned over a water fountain spike  200 . Like reference numerals refer to like parts. 
     In this embodiment the conical spring  170  is exactly the same. However, the length of the bridging portion  171  is decreased. This means therefore that in order to bridge the distance between the circumferential abutment band  131  to the annular top panel  145  the spring  170  must be stretched to allow the bridging portion  171  to be pressed within the upstanding wall  165 . The spring  171  is therefore quite significantly pre-stressed. Although this adversely affects the level of creep, when the spring  171  is further extended during use the force provided by the spring to return the cap  130  is increased. 
     In this embodiment the inner surface of the main body  135  of the sealing cap  130  has a plurality of axial ribs  136  which project inwardly and are positioned so that they are contacted by the domed head portion  101  of the spike  200 . This means that there is additional contact between the spike  200  and the sealing cap  130 . This alternative embodiment also has an additional tamper-prevention feature. As discussed with respect to  FIG. 3 , the annular flap  180  is turned upwardly and wedge elements  185  engage a bead rim  195 . This helps prevent removal of the closure from the bottle neck. To help prevent the possibility of placing a tool between the annular skirt  140  and the bottle neck  190  and attempting to lever the two apart to try to flip the flap  180  back down, the annular skirt  140  is joined to the channel  166  by a strengthening strut  167 . 
     As previously discussed, precise positioning of a water bottle over a water fountain spike is a difficult operation. The shoulder  55  of the feed cylinder  50  of  FIG. 4  is joined to the annular top panel  45  by a straight cylindrical sleeve  51 . In this alternative embodiment the sleeve  51  is conical. This conical sleeve  51  acts as a guide surface for the incoming spike  200  so that precise positioning is not required. If the bottle is mis-positioned it can still be lowered onto the spike  200  because the spike can slide up the guiding surfaces of the sleeve  51 . 
       FIG. 7  is a cross section through part of a conical coil spring  70   a  which could be used as an alternative to the spring  70  shown in  FIGS. 3 to 5 . As discussed, a circular cross section is optimal for reducing creep. However, if the spring is to be moulded in line to have its conical shape in the as-moulded condition, it is preferable to have undercuts in the region of the break line of the mould. Accordingly the section of the spring  70   a  is generally square and has diagonally opposed corners  71 ,  72  along the break line  75  of the mould. However, the opposite diagonally opposed corners  73 ,  74  are rounded, tending more towards a circle. The result is a section which is practical to mould and creeps less than an absolute square section. 
     Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined by the appended claims.