Abstract:
A mechanism to check fluid flow from a tube or spigot when it is disconnected from a downstream conduit is provided. The mechanism includes a duckbill check valve that has its bills pointed in the upstream direction. To keep the bills apart for the fluid flow to continue, the downstream conduit has to be inserted against the underside of the bills. Once the downstream conduit separates from the valve, the valve closes itself.

Description:
TECHNICAL FIELD 
     The invention generally relates to check valves, connectors, and fittings that can be used in connection with any fluid conduit. 
     BACKGROUND OF THE INVENTION 
     Many types of fluid conduits can benefit from a re-closeable outlet end, especially if such re-closure is automatic. For example, for many bag-in-box types of storage and dispensing systems, a drainage tube or spigot typically extends out of the bag to deliver the fluid content of the bag. Whether the drainage tube or spigot delivers directly to a separate receptacle, e.g., a drinking cup, or is further connected to a second conduit for further processing, it would be desirable to have a mechanism to close the outlet end when delivery is not needed, e.g., when switching bags out of the box. For economical reasons, it is often advantageous that such a mechanism be provided in the form of a reusable device: a connector or fitting that can be attached and detached from various conduits&#39; outlet ends. 
     SUMMARY OF THE INVENTION 
     The present invention relates to various features of an improved valve or closure device. The valve automatically closes itself and stops further delivery or drainage of the fluid when a downstream object, e.g., another conduit, is withdrawn from the valve. 
     In one aspect, the invention provides a method for closing an outlet of a fluid conduit. The method includes the step of providing a one-directional valve near the outlet of the fluid conduit. The valve has a pointed portion that points upstream and the pointed portion is biased to remain closed, thereby shutting off fluid flow. In one embodiment, the method further includes the step of providing a tubular body that houses the one-directional valve wherein the tubular body is detachable from the rest of the conduit. And the method may also include sealing the tubular body against the fluid conduit, e.g., by providing an annular barb on the outside of the tubular body to form a seal with the fluid conduit. In one feature, the method further includes inserting a downstream conduit from the outlet of the fluid conduit to push open the valve, thereby opening up fluid flow. The method can further include the step of attaching the outlet of the fluid conduit to the downstream conduit and forming a seal where the two come into contact. 
     In another aspect, the invention provides a device that includes a tubular body having an upstream inlet end and a downstream outlet end, and a one-directional valve inside the tubular body. The valve includes a pointed portion that points towards the upstream inlet end and the pointed portion is biased to remain closed. In one embodiment, the device further includes a retainer that retains the valve inside the tubular body of the device. In one feature, the pointed portion of the valve includes multiple lips that are biased to remain closed but can be forced open by an elongated object inserted through the downstream outlet end. In one embodiment, the lips include a pair of substantially flat portions facing each other. In one embodiment, the upstream inlet end has an annular barb. In one feature, the upstream inlet end of the device is configured to attach onto an upstream conduit. The upstream inlet end of the device forms a seal where it comes into contact with the upstream conduit. In another feature, the downstream outlet end of the device is configured to attach onto a downstream conduit; they may form a seal where they come into contact. 
     In a further aspect, the invention provides a method of making a device, 
     which includes the steps of: 
     (a) providing a tubular body having an upstream inlet end and a downstream outlet end; and 
     (b) enclosing a one-directional valve inside the tubular body, the valve having a pointed portion that points towards the upstream inlet end and wherein the pointed portion is biased to remain closed. 
     In one embodiment, the pointed portion has multiple lips biased to remain closed. In one feature, the method may further include providing a retainer that retains the valve inside the tubular body of the device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing, and other features and advantages of the invention, as well as the invention itself, will be more fully understood from the description, drawings and claims that follow. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views and various embodiments. 
         FIG. 1  is a perspective view of a dispenser with its front door removed and with part of the production line inside the dispenser in an exploded view on the right. 
         FIG. 2  is a perspective cut-away view of a valve fitting according to the present invention. 
         FIG. 3  is a cross-section view of the valve fitting depicted in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Features of the invention may work by themselves or in combination as shall be apparent to one skilled in the art. The lack of repetition is meant for brevity and not to limit the scope of the claim. Unless otherwise indicated, all terms used herein have the same meaning as they would to one skilled in the art of the present invention. 
     The present invention can be used in and with any fluid conduit, e.g., tubes, manifolds, pipes, spigots, and so on. The present invention is particularly useful where a downstream conduit needs to be connected to an upstream one for fluid delivery, but when the two are disconnected, it is desirable to stop the fluid flow from the upstream conduit. 
     Referring to  FIG. 1 , an example where the present invention may be practiced is provided. A postmix beverage dispenser  50  is shown here with the front door removed, and one of the two parallel production lines is depicted in a partly exploded view on the right side. The dispenser  50  mixes a concentrate, e.g., orange juice concentrate, with a diluent, e.g., potable water, inside a mixing chamber  52  before dispensing the product into a receptacle  54  through a nozzle  56  that is housed, in part, inside the mixing chamber  52 . The concentrate is delivered through a bag-in-box system where a sealed bag of the concentrate (not shown) is placed inside a holder  58 . A drainage tube  60  extends from the bag and out of the holder  58 , and the tube&#39;s outlet  61  is eventually attached to a tube adapter  62  on the top of a pump head  64 . The pump head  64  houses a piston (not shown) that transfers the delivered concentrate into the mixing chamber  52  into which pressurized water is delivered as well. When the drainage tube  60  is removed from the tube adapter  62 , e.g., to change the flavor of the concentrate for the dispenser  50 , it would be desirable if the drainage tube  60  automatically closes or seals off its outlet end  61  so that the content does not spill out or drip. Further details of the postmix beverage dispenser  50  is provided in co-owned international application no. PCT/US2005/045087 filed on Dec. 12, 2005, the entire disclosure of which is hereby incorporated by reference to the extent permitted by relevant patent laws. 
     Referring now to  FIGS. 2 and 3 , a connector or fitting  70  is provided with a one-directional valve or check valve  72  housed inside a tubular housing or body  74 . The tubular body  74  has an upstream inlet end  76  and a downstream outlet end  78 . The fitting&#39;s upstream inlet end  76  attaches to an upstream conduit, such as the drainage tube  60  ( FIG. 1 ) from a bag of concentrate. The fitting&#39;s downstream outlet end  78  attaches to a downstream conduit, such as the tube adapter  62  ( FIG. 1 ) of a pump head. Therefore, the direction of fluid flow inside the fitting is from end  76  to end  78 , as indicated by the arrow  81 . On both ends of the fitting  70 , which can be sized to fit onto their corresponding connecting conduits, structures may be provided to ensure a seal is formed with the upstream or downstream conduit. In one embodiment, the upstream inlet end  76  has an annular barb  80  on the outside wall, and the downstream outlet end  78  has an annular ring  82  on the inside wall, to engage and seal against the corresponding conduit. 
     The valve  72  has a pointed portion  84  that points towards the upstream inlet end  76 . The pointed portion  84  can have a variety of configurations that, in general, taper towards a closure point or slit  86 . The pointed portion  84  is biased to remain closed or checked at the closure slit  86 , preventing fluid flow through the fitting  70 . The pointed portion  84  includes multiple lips  88  biased to remain closed. The pressure from the fluid inside the fitting  70 , especially if the fitting is positioned in a vertical orientation with its inlet end  76  on top as shown in  FIG. 2 , helps to push the valve lips  88  shut. Accordingly, in some embodiments, the valve lips  88  do not need to be preloaded. Those lips  88 , for example, can be a pair of substantially flat portions resembling duckbills facing each other. Such duckbill check valves are commercially available from manufacturers such as Red Valve Co., Inc. of Carnegie, Pa., Clippard Instrument Laboratory, Inc. of Cincinnati, Ohio, and Vernay Laboratories, Inc. of Yellow Springs, Ohio. The valves may be made of a variety of materials such as elastomeric compounds including rubber. In one embodiment, the valves are made by liquid silicone injection molding—valve manufacturers that use such technique include Liquid Molding System, Inc. of Midland, Mich. The valve  72  can also use other configurations and structures, such as umbrella valves, for the purpose of the present invention. 
     To open the valve  72 , an elongated object, e.g., a downstream conduit (not shown), is inserted into the fitting  70  through its outlet end  78 , in the direction opposite the arrow  81 . Once the downstream conduit contacts the underside of the valve&#39;s pointed portion  84 , the operator can use the conduit to apply the necessary pressure to force open the lips  88 . In one way to use the invention, the operator thrusts the conduit past the lip&#39;s closure slit  86  until it lodges in the portion of the tubular body  74  that is upstream to the valve. Fluid flow in the direction of the arrow  81  will proceed from the fitting  70  into the downstream conduit. 
     When the downstream conduit is withdrawn or otherwise separates from the fitting  70 , the valve lips  88  will close automatically, effectively shutting off the fluid flow. For fluids of relatively low viscosity such as some types of juice concentrates, it is preferred that the lips of the duckbill check valve be elongated and/or thin so that they remain checked in the closed position and little or no leakage or dripping results. The valve can be reopened when the downstream conduit is inserted back in and past the valve. A retainer  90  ( FIG. 3 ) can be found downstream from the valve  72 , resting against the annular ring  82 , to prevent the valve  72  from being removed with the downstream conduit from the tubular body  74 . 
     Still referring to  FIGS. 2 and 3 , the fitting  70  may also have an integrated collar  92  to aid in the removal and connection to the upstream and downstream conduits. The collar  92  can also act as a locator to prevent abnormal insertion. 
     The fitting  70  can be made integrally with the upstream conduit, of course, such that the tubular body  74  is simply an integral portion of the conduit and constitutes part of its discharging/outlet end. A detachable fitting  70 , as depicted in  FIGS. 2 and 3 , however, allows reuse of the check valve  72  for different conduits and connections. Other aspects of making and using the invention, the embodiments of which have been described, would be obvious to one skilled in the art. 
     While the invention has been described with certain embodiments so that aspects thereof may be more fully understood and appreciated, it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the scope of the invention as defined by the appended claims.