Abstract:
A drip resistant dispensing valve for fluids is disclosed, which provides a dispensing outlet configured to minimize the tendency for residual fluid to collect in and drip from the dispensing outlet while maintaining a simple construction for ease of manufacture. The dispensing outlet face is situated a distance away from the valve body, which tends to prevent, or at least minimize the risk of, contact between potentially contaminating external surfaces with the surfaces of the discharge outlet. Such construction assists in minimizing the retention of fluid on the surfaces of the dispensing outlet, and migration of the fluid to surfaces outside of the dispensing outlet that could tend to promote growth of biological contaminates and/or provide additional surfaces that could pool fluid following a dispensing operation and thereafter drip from the valve. A shell is provided around the dispensing outlet to assist in avoiding contamination of the valve and of the fluid being dispensed through the valve, and to aid in positioning a receptacle for receiving fluid from the dispensing valve.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field Of The Invention 
         [0002]    The present invention relates to fluid dispensing apparatus and, more particularly, to a robust, relatively simple, low-cost, and easily actuatable dispensing valve for dispensing fluid from a source of such fluid, which valve is configured so as to reduce the tendency for residual fluid to collect on and ultimately drip from the valve following a dispensing operation, and to minimize the risk of contamination of the valve and the fluid that is to be dispensed. 
         [0003]    2. Description Of The Background 
         [0004]    Dispensing valves for dispensing fluid from fluid containers, systems, or other sources of such fluid are shown by U.S. Pat. Nos. 3,187,965; 3,263,875; 3,493,146;  3,620,425; 4,440,316; 4,687,123; 5,918,779; 6,491,189; and 6,742,680. Such valves can be used, for example, in a system for dispensing beverages or other liquids used by consumers in the home. Low cost, trouble-free, and reliable valve action are significant considerations in these applications. Low cost is particularly important if the valve is to be sold as a disposable item as, for example, where the valve is provided attached to a filled fluid container and discarded along with the container when the fluid has been consumed. 
         [0005]    Unfortunately, many of the dispensing valve mechanisms available fail to provide a dispensing outlet that does not avoid the collection of liquid on its surfaces, thereby resulting in the unwanted release of liquid from the dispensing outlet after it has been shut off. For instance, during a dispensing operation, fluid from a storage container typically contacts the inside surfaces of a dispensing outlet on a dispensing valve. These inner surfaces can tend to collect liquid during use of the dispensing valve, such that after fluid is dispensed and the user has removed the cup, glass, or other receptacle for receiving the liquid and released the actuation mechanism of the dispensing valve, the collected liquid on the inner surface remains. Thus, not all of the liquid is caught in the receptacle; rather, some accumulates on such inner surfaces and may drip off such surfaces after the dispensing operation. 
         [0006]    Still further, many of the currently employed dispensing valves promote the development of unsanitary conditions in and around the dispensing outlet. This may be due to the configuration of the dispensing outlet, which allows direct contact between the outlet and the user or the receptacle employed by the user. Through such direct contact with the dispensing outlet, various bacteria, pathogens, and the like may be transmitted to the surfaces of the dispensing outlet. Many such pathogens and the like may not be readily ascertainable through visual inspection and may survive cleaning of the dispensing outlet. This may lead to such unwanted organisms traveling further into the dispensing valve, and likewise into a container to which the dispensing valve is attached and contaminating the liquid within. 
         [0007]    In U.S. Pat. No. 3,187,965 to Bourget, a dispensing valve for a milk container is shown having a generally integral valve body connected at one end to the milk container. The valve body has an L-shaped passage formed therein defining an inlet opening at one end in communication with the milk container and a discharge outlet at the opposite end for discharging the milk to the exterior of the container when the valve is opened using a push-button actuator. The discharge outlet is fully exposed to the outside environment, thus promoting contact with potentially contaminated surfaces, and no provision is made to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet. 
         [0008]    Another valve, shown in U.S. Pat. No. 3,263,875 to Lofdahl, has a similarly configured dispensing outlet and a push-button actuator, and once again lacks any provision to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet, and fully exposes the discharge outlet to the outside environment, thus promoting contact with potentially contaminated surfaces. 
         [0009]    Likewise, commercial attempts have been made to provide low-cost dispensing valves for use with disposable containers, but such efforts have met with limited success. For example, Waddington &amp; Duval Ltd. provide a press tap for use with disposable containers (such as wine boxes, water bottles, and liquid laundry detergent containers) under model designations COM 4452 and COM 4458, both of which provide a depressible button actuator operatively connected to a valve closure for moving the valve closure away from a valve seat to dispense fluid through a discharge outlet. As with the examples provided above, the discharge outlet is fully exposed to the outside environment, thus promoting contact with potentially contaminated surfaces, and no provision is made to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet. 
         [0010]    Similarly, the Jefferson Smurfit Group provides a similar tap for use with disposable containers under the model designation VITOP. Once again, the Jefferson Smurfit Group tap construction is configured such that the discharge outlet is fully exposed to the outside environment, thus promoting contact with potentially contaminated surfaces, and no provision is made to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet. 
         [0011]    Moreover, such valve constructions are configured such that undispensed fluid will remain in the valve behind the valve seat after use in a significant portion of the valve body and away from the container to which such valve is attached (and likewise away from any refrigerated environment in which such container is stored). This increases the risk of spoilage of such volume of fluid resting within the valve body after each use. Still further, such valve constructions lack the physical integrity to withstand vigorous sterilization procedures required of many fluid dispensing applications, including irradiation at exposures of up to as high as 5.0 MRAD and high temperature steam and chemical sterilization procedures. 
         [0012]    Thus, although substantial effort has been devoted in the art towards development of low-cost valves of this general type, there remains an unmet need for a disposable valve having a discharge outlet that reduces the tendency for residual fluid to collect in and drip from the dispensing outlet while maintaining a simple construction for ease of manufacture, and that exhibits a configuration that tends to prevent, or at least minimize the risk of, contact between potentially contaminating external surfaces with the surfaces of the discharge outlet. Likewise, there remains an unmet need for a dripless valve that is easier to use than prior known valves and that does not require that the user exert large forces to hold the valve open. This problem is complicated by the fact that the tendency of a spring or other resilient member to maintain the valve in a closed position should provide the force necessary to assure leak-free seating of the valve seal when in such closed position Likewise, there remains an unmet need for a disposable valve that is sufficiently robust so as to be able to withstand vigorous sterilization procedures, that reduces heat transfer through the valve between the interior and exterior of the fluid container, and that does not trap a significant amount of fluid outside of the intended storage vessel between dispensing cycles. 
       SUMMARY OF THE INVENTION 
       [0013]    It is, therefore, an object of the present invention to provide a fluid dispensing valve that avoids the disadvantages of the prior art. 
         [0014]    Accordingly, the present invention provides a drip resistant dispensing valve including a discharge mechanism having decreased liquid retention properties. Further, the discharge mechanism of the drip resistant dispensing valve provides an outer shell that promotes the avoidance of direct contact between a user and/or receptacle and the dispensing outlet. 
         [0015]    It is another object of the present invention to provide a fluid dispensing valve that is drip resistant and avoids the unwanted accumulation of liquids outside of the liquid container to which the valve is attached. 
         [0016]    It is a further object of the present invention to provide a fluid dispensing valve that promotes the avoidance of contaminants contacting and/or inhabiting the dispensing outlet, other interior surfaces of the dispensing valve, and/or the liquid container. 
         [0017]    Disclosed herein is a drip resistant dispensing valve for fluids that provides for ease of use by requiring only a minimal force exerted on the valve actuator to maintain the valve in an open position, and that offers a simple, ergonomic design and robust functionality capable of dispensing a wide variety of products. 
         [0018]    With regard to a first aspect of a particularly preferred embodiment, a valve includes a discharge mechanism having properties that reduce or eliminate the propensity for residual fluid to remain on such discharge mechanism following a discharge or dispensing operation. The discharge mechanism provides an outer shell that promotes the avoidance of direct contact between a user, a receptacle, and/or other potentially contaminating surfaces and the dispensing outlet of the discharge mechanism. 
         [0019]    With regard to another aspect of a particularly preferred embodiment, the valve body and actuator are formed of a polypropylene copolymer with an average wall thickness of approximately 0.06 inches, and the valve seal is formed of a thermoplastic rubber having an average thickness of about 0.03 inches. Such dimensional characteristics and materials allow the drip resistant dispensing valve to withstand the highest aseptic sterilization regimen as outlined by the Food &amp; Drug Administration (FDA) and maintain the sterility of a product as specified by the National Sanitation Foundation (NSF) guidelines. More specifically, the dispensing apparatus is able to withstand either gamma or cobalt irradiation at the maximum dose of 5.0 MRAD (50 Kilogray) in the sterilization process. The dispensing apparatus is able to withstand the high temperatures associated with the steam and chemical sterilization processes required in the filling process. The dispensing apparatus is capable of withstanding these combined sterilization regimens without degrading the valve structure or operation. Thus, the valve of the instant invention may be used to dispense products ranging from aseptic products such as dairy, 100% juice and soy products, to commercially sterile products such as preserved juice and coffee products, to non-sterile fluids such as chemical solvents. 
         [0020]    In order to allow a minimal force for holding the valve in an open position, a resilient valve actuator having the characteristics of a nonlinear spring is provided at an actuator end of the valve body and operatively connected to a plunger, with the opposite end of the plunger having mounted thereon a resilient valve seal. An intermediate discharge outlet is positioned between the actuator end and the valve seal, such discharge outlet being placed in fluid communication with the interior of a fluid container to which the valve is attached when the valve is in an open position. A valve port wall is positioned between the valve seal and the dispensing chamber providing a plurality of ports for controlling the flow of fluid through the valve body when the valve is in an open position. The valve and the valve port wall are positioned such that when the valve is installed on a liquid container, virtually no liquid will be trapped by the valve structure outside of the insulated container, thus preventing the spoilage of a dose of liquid resting in the valve after each dispensing cycle. A push-button is provided for actuating the drip resistant dispensing valve and is exposed to the exterior of a fluid container to which the drip resistant dispensing valve is attached. In one embodiment of the instant invention, the push-button is concentrically mounted within a breakaway circular rim. Upon first using the drip resistant dispensing valve, a user depresses the push-button, dislodging the circular rim from the button, and thereby providing evidence that the valve had been opened, thus providing a tamper-evident actuator. 
         [0021]    Such valve is also preferably configured so as to withstand sterilization procedures including irradiation up to 5.0 MRAD and high temperature steam and chemical sterilization processes without degradation of the integrity of the valve structure or operation, and thus may be used for dispensing a wide variety of products ranging from aseptic products (free from microorganisms) to non-sterile products. 
         [0022]    The simplicity and functionality of the drip resistant dispensing valve of the instant invention enables its manufacture and automatic assembly with multiple cavity tools, which in turn reduce manufacturing costs, and offers the market a low cost dispensing solution. The simplicity and functionality of the design also enables the dispensing apparatus to be easily customized in the manufacturing process to fit a wide range of dispensing packages such as a flexible pouch, flexible bag, or semi-rigid plastic container. The drip resistant dispensing valve of the instant invention is also configured to adapt easily to a wide range of filling machines and filling conditions worldwide. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The above and other features, aspects, and advantages of the present invention are considered in more detail, in relation to the following description of embodiments thereof shown in the accompanying drawings, in which: 
           [0024]      FIG. 1  is an exploded view of a drip resistant dispensing valve in accordance with an exemplary embodiment of the present invention; 
           [0025]      FIG. 2  is an expanded partial cut-away view illustrating the drip resistant dispensing valve shown in  FIG. 1 ; 
           [0026]      FIG. 3  is a side view illustrating the dispensing outlet of the drip resistant dispensing valve shown in  FIG. 1 ; 
           [0027]      FIG. 4  is a cut-away view of the drip resistant dispensing valve taken along line ‘A-A’ of  FIG. 3 ; 
           [0028]      FIG. 5  is an enlarged view of  FIG. 4 , showing the valve plunger, actuator, and seal; 
           [0029]      FIG. 6  is a side view illustrating a sanitary cover for the dispensing outlet of the drip resistant dispensing valve shown in  FIG. 1 ; 
           [0030]      FIG. 7  is a top view illustrating the actuation end of the drip resistant dispensing valve shown in  FIG. 1 ; 
           [0031]      FIG. 8  is a cut-away view of the drip resistant dispensing valve taken along line ‘B-B’ of  FIG. 7 ; 
           [0032]      FIG. 9  is a bottom view illustrating the fluid inlet end of the drip resistant dispensing valve shown in  FIG. 1 ; 
           [0033]      FIG. 10  is a plan view of the valve seal shown in  FIGS. 1 ,  2 , and  5 ; 
           [0034]      FIG. 11  is a cross-section of the valve seal taken along line ‘C-C’ of  FIG. 10 ; and 
           [0035]      FIG. 12  is a side cross-sectional view of an actuator for use with the drip resistant dispensing valve shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0036]    The invention summarized above and defined by the enumerated claims may be understood by referring to the following description, which should be read in conjunction with the accompanying drawings in which like reference numbers are used for like parts. This description of an embodiment, set out below to enable one to build and use an implementation of the invention, is not intended to limit the enumerated claims, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form. 
         [0037]    Referring to the drawings,  FIG. 1  shows a drip resistant dispensing valve  12  in accordance with one embodiment of the present invention. As will be described in greater detail below, valve  12  is configured for attachment to a fluid container (not shown), which may be a rigid container (such as a thermos or plastic bottle), a flexible bag or pouch, or any other fluid container. The drip resistant dispensing valve  12  may be so situated on a fluid container so as to allow dispensing of fluid under gravity flow, or alternately, where the source of fluid is under a head of pressure, provided by a source other than gravity. 
         [0038]    As is shown in the Figures, drip resistant dispensing valve  12  has a generally tubular valve body  13  having an outer wall  13   a  and an inner wall  13   b . The valve body has an inner or inlet end  7 , and an opposite outer or actuation end  9 , and an axial direction extending between these ends. Although the valve body  13  is shown generally in the form of a round cylindrical tube, the valve body may be round, square, octagonal or other shape adapted for the application to which the drip resistant dispensing valve  12  will be applied. Alternately, only a portion of the valve body  13  may have such alternate shape, with the remainder of the valve body maintaining a generally cylindrical shape. For instance, inlet end  7  may have an oblong configuration where it connects to a fluid container, while the remainder of the valve body may maintain a generally cylindrical configuration. Valve body  13  is provided with features  14  for connecting the valve body  13  to a fluid container or other source of fluid to be dispensed so as to bring the inlet opening  15  ( FIG. 2 ) formed in the valve body  13  in communication with the fluid to be dispensed. The particular connecting features  14  depicted in the drawings include ribs encircling the exterior of the valve body near the inlet end  7 . These ribs are arranged to form a fluid-tight, press-fit connection between the exterior of the valve body and the interior of an outlet provided in the container. Other suitable connecting and sealing features may be used in addition to or in lieu of ribs. For example, the valve body  13  can be provided with threads or bayonet-type locking features that can be mated with features of the container. In addition, auxiliary sealing elements such as resilient O-rings or other gaskets can be provided on the container or on the valve body for engagement between the valve body and the container. 
         [0039]    In a preferred embodiment, a discharge mechanism for the drip resistant dispensing valve  12  includes a shell  100  at least partially encompassing a discharge outlet  121 . In a preferred embodiment, the shell  100  and discharge outlet  121  are integrally connected with or formed in the valve body  13  at a position between the inlet end  7  and actuator end  9 . It is to be understood that shell  100  may be connected with valve body  13  through the use of various connection mechanisms, such as a threaded connection, compression lock connection, snap fit connection, friction fit connection, and the like. The shell  100  and discharge outlet  121  are disposed outside of the container or other source of fluid when the valve body  13  is engaged with the container. The shell  100  and discharge outlet  121  are generally in the form of a short tubular member extending in the direction perpendicular to the axial direction of the valve body. Discharge outlet  121  provides communication between an outside environment and the interior of the valve body  13 . 
         [0040]    Discharge outlet  121  is configured so as to prohibit fluid being dispensed from outlet  121  from coming into contact with and/or collecting on the interior of shell  100 . More particularly, discharge outlet  121  includes a wall  125  that forms a projecting surface extending from outer wall  13   a  of valve body  13  so as to direct all flow through an outlet channel  134 . Discharge outlet  121  is configured to substantially prevent fluid from collecting on the interior surfaces of the outlet and remaining there following a dispensing operation. Fluid flowing through the outlet channel  134  may run along the interior of wall  125  of discharge outlet  121 , but when it reaches the outer edge  139  of such discharge outlet  121 , it has no path but to remain on the edge of the discharge outlet  121  or fall from the valve into a container into which the fluid is being dispensed. The wall  125  of discharge outlet  121  extends away from outer wall  13   a , thus creating a distal separation between the open face  140  of discharge outlet  121  and the interior, back wall of shell  100  (formed by the outer wall  13   a  of the body). As shown in  FIGS. 2-5 , wall  125  of discharge outlet  121  forms a small rectangular opening at the open face  140  of the outlet channel  134 . In the current embodiment, the rectangular opening is approximately 0.23 inches on each side. To promote a dripless feature, the wall  125  of the discharge outlet  121  should be as thin as possible (consistent with good molding practices), and should extend outward from the outer wall  13   a  of valve body  13  a distance that is at least three times the thickness of the outer edge  139  of the wall  125 , and will preferably extend outward from the outer wall  13   a  a distance greater than three times the thickness of the outer edge  139  of the wall  125 . The distal separation between the outer edge  139  at the open face  140  of the outlet channel  134  and the outer wall  13   a  of the valve body  13  prevents fluid being dispensed through discharge outlet  121  from contacting the inner surfaces of shell  100 , as the fluid is unable, on its own, to traverse the 180 degree turn that would be necessary in order to migrate to those interior surfaces of shell  100 . In this manner, residual undispensed fluid cannot pool on the inner surfaces of shell  100  and later drip off those surfaces at an undesirable time. Therefore, contamination of the interior of shell  100  (and establishment of sites on those surfaces at which biological contaminates might grow) is minimized, if not prevented altogether. 
         [0041]    In the current embodiment, shell  100  is configured in a flat, generally cylindrical shape having an inner surface  105 . Alternative configurations for shell  100  may be employed, such as in the shape of a square, rectangle, other polygonal shapes, or as a cylinder, oval, oblong, and other shapes as contemplated by those of ordinary skill the art, without departing from the scope and spirit of the present invention. 
         [0042]    Shell  100  further includes a shell channel  114  that provides an open passage through the interior of shell  100 . The boundaries of the shell channel  114  are defined by the shell inner surface  105 . In a preferred embodiment, the shell channel  114  defines the open passage through shell  100  that surrounds the discharge outlet  121 . Shell channel  114 , similar to shell  100 , extends in a perpendicular direction from the axial direction of the valve body  13 . 
         [0043]    The length that the shell  100  extends from the outer wall  13   a  of valve body  13  may increase the ease with which a user may proximally locate a receptacle next to the shell  100  for receiving the dispensed liquid. Further, the size of shell channel  114  may promote the use of the drip resistant dispensing valve  12  with variously sized receptacles, such as cups, water bottles, and the like. For instance, the generally cylindrical shape of the shell  100  may allow for its insertion into the mouth of a water bottle. This may promote a decrease in the amount of “lost” liquid or spillage during operation of the drip resistant dispensing valve  12 . 
         [0044]    An outer edge  116 , which is formed at the opposite end of shell  100  from its connection with the outer wall  13   a  of the valve body  13 , preferably provides a generally flat surface. In some embodiments, the outer edge  116  may provide a concave surface. A removable cover  119 , as best seen in  FIG. 6 , may be temporarily attached to the outer edge  116  during shipment of an unused, new valve  12 . The cover  119  should be removed and disposed prior to use of the valve  12 . 
         [0045]    Further, shell  100  is configured to decrease the risk of contamination of the discharge outlet  121  and possibly a liquid within a container to which the drip resistant dispensing valve  12  may be attached. For instance, sufficient distance is provided between the outer edge  116  of shell  100  and the outer edge  139  at the open face  140  of the outlet channel  134  and laterally between the wall  125  of the discharge outlet  121  and the shell inner surface  105  to reduce the risk of contaminates on the outer edge  116  of the shell  100  traveling or migrating to the outer edge  139  of discharge outlet  121 . Furthermore, the opening  143  at the end of shell channel  114  is substantially larger than the open face  140  of discharge outlet  121 . Thus, the shell  100  provides a guard against the contamination of the discharge outlet  121  through its dimensional structure. 
         [0046]    In operation, when a user activates the valve to dispense the liquid from within the container, fluid is discharged through channel  134  of the discharge outlet  121  in a manner that substantially prevents the liquid from contacting the inner surface  105  of the shell  100 . Thus, while the shell  100  may promote the efficient use of the drip resistant dispensing valve  12  by providing an indicator to the user of where to locate a receptacle to receive the liquid during dispensing, it is generally not directly involved with the dispensing of the liquid itself. This may promote an environment on the inner surface  105  of the shell  100  capable of remaining substantially free from contaminates and/or as previously mentioned, assist in avoiding the travel of contaminates onto or into the discharge outlet  121  and outlet channel  134 . 
         [0047]    The thickness of the walls provided for the shell  100  and discharge outlet  121  may vary to accommodate the needs of various liquids and/or materials to be dispensed through drip resistant valve  12  connected to a container of the liquids/materials, so long as the construction maintains sufficient integrity to undergo the above-described sterilization and irradiation processes. In a preferred embodiment, the outer shell  100  and discharge outlet  121  have wall thicknesses of approximately 0.06 inches. The thickness of the walls assists in promoting the ease of operation and cleaning of the drip resistant valve  12  and the ability of the valve to be subjected to sterilization processes while maintaining its functionality. 
         [0048]    As shown more particularly in  FIGS. 4 ,  5 ,  8  and  9 , a valve port wall  17  extends across the interior of body  13  between inlet opening  15  and discharge outlet  121 . The valve port wall  17  defines a at least one hole or valve port  80 , as well as a valve seat  18  encircling the valve port  80  and facing toward the inlet opening  15 . Preferably, the valve port  80  is located off the centerline of the valve port wall  17 , toward the side of the valve body  13  from which the discharge outlet  121  extends. The fluid flow resistance of the valve  12  in the open position is controlled in large measure by the flow resistance of p valve port  80 . Thus, the fluid flow resistance of the valve can be selected to fit the application by selecting the size of the valve port  80 . The size of valve port  80  can be varied through only slight modification of injection molding apparatus (such as by varying movable pin positions within such a mold structure). This allows the manufacturer to make valves for almost any application with minimal tooling costs. Limited only by the size of discharge outlet  121 , the valve port  80  need not be round or oval; other shapes, including an arcuate port extending partially around the center of the valve body and partially around plunger guide opening  33 , can be made with appropriate interchangeable injection molding components. 
         [0049]    The valve port wall  17  also defines a plunger guide opening  33  adjacent the central axis of the valve body  13 . A tubular plunger guide  20  extends outwardly from the valve port wall  17  toward the actuator end  9  of the valve body  13 . The plunger guide  20  is aligned with the plunger guide opening  33  of the valve port wall  17 . As best seen in  FIGS. 5 and 8 , a plunger guide support wall  5  extends across the valve body  13  just outward of discharge outlet  121 , so that the plunger guide support wall  5  lies between the discharge outlet channel  134  and the actuator end  9  of the valve body  13 . In the embodiment described herein, a portion of the plunger guide  20  combines with portions of the valve port wall  17  and the plunger guide support wall  5  to form boundaries for the discharge outlet channel  134 . 
         [0050]    The valve body  13  may also have a pair of grip wings  30  and  31  projecting outwardly from the remainder of the valve body  13  at actuator end  9 . Grip wings  30  and  31  extend generally in directions perpendicular to the axial direction of the valve body and parallel to the direction of discharge outlet  121 . Valve body  13  desirably is formed from a polymeric material compatible with the fluid to be dispensed as, for example, a thermoplastic such as polypropylene or other polyolefin. In a preferred embodiment, valve body  13  is formed from a polypropylene copolymer. 
         [0051]    A plunger member  21  is slidably mounted in plunger guide  20 . Plunger member  21  desirably is also made of polypropylene or other plastic material. In a preferred embodiment, plunger member  21  is likewise formed from a polypropylene copolymer. 
         [0052]    Plunger member  21  has an inner end  22  that extends through the plunger guide  20  and through the plunger guide opening  33  of valve port wall  17  into the inlet opening  15 . The plunger guide  20  also serves to separate the plunger member  21  from the discharge outlet  121 . 
         [0053]    Referring to  FIGS. 10 ,  11 , and  12 , a resilient valve seal  19  in the form of a shallow conical member is fixedly connected to the inner end  22  of the plunger member, as by a coupling element  22   a  that can be force fitted into engagement with a sized opening  19   a  in the valve seal  19  because of the resilient nature of the materials from which the valve seal  19  and plunger  21  are fabricated. Valve seal  19  can be formed from essentially any resilient material that will not react with or contaminate the fluid being dispensed, and that will not melt or degrade under the conditions encountered in service. For example, a thermoplastic or thermosetting elastomer or other flexible material, typically in the range of about 30 to about 80 Shore A durometer, and more preferably, about 50 to about 80 Shore A durometer, can be employed in typical beverage dispensing applications. In a preferred embodiment, valve seal  19  is formed from a thermoplastic rubber. The periphery of valve seal  19  overlies valve seat  18  and seals against the valve seat when the valve is in the closed position depicted in  FIGS. 2 and 5 . 
         [0054]    The thickness of the valve seal  19  will depend on the material and operating conditions. Merely by way of example, in a valve for dispensing beverages under gravity head (e.g., on the order of 0.5 to 1 pound per square inch pressure), the valve seal is about 1 inch in diameter and about 0.020 to 0.040 inches thick, most preferably about 0.032 inches thick, at its periphery. 
         [0055]    A cylindrical stop member  28  and actuator  24  are formed integrally with the plunger member  21  at the outer end  23  of plunger member  21  remote from the inner end  22 . Actuator  24  has a dome-shaped resilient section  25 , so sized that the perimeter  26  of this dome-shaped section  25  can be mounted or held from escaping by a ledge or groove  27  disposed on the inner wall  13   b  of the valve body  13 , just inward of the actuator end  9  of the valve body  13 . The dimensions of the actuator  24  are selected to provide desired resilient action and force/deflection characteristics as described in U.S. Pat. No. 6,491,189, the specification of which is incorporated herein by reference in its entirety. In one exemplary embodiment, the plunger  21 , stop member  28 , and actuator  24 , including resilient section  25 , are molded as a unit from polycarbonate or similar material. The resilient section  25  is generally conical and about 1 inch in diameter, with an included angle of about 160°. That is, the wall of the conical resilient section lies at an angle Z ( FIG. 12 ) of 10° to the plane perpendicular to the axial direction of the plunger member  21 . The resilient section  25  is about 0.012 inches thick at its perimeter, and about 0.018 inches thick at its juncture with stop member  28 . Stop member  28  is about 0.292 inches in diameter. Thus, the ratio between the axial extent x of the conical resilient section and the average thickness of the resilient section is about 4:1. 
         [0056]    Stop member  28  coacts with a stop shoulder  29  formed by the outer end of the plunger guide  20 . Thus, the distance that the plunger  21  can be moved when force is exerted on the plunger  21  at actuator  24  will be determined by the distance the stop member  28  can travel before contact is made with the stop shoulder  29  (see  FIG. 5 ). 
         [0057]    A positioning flange  10  is preferably provided circumscribing the valve body  13  just above connecting features  14 . When the drip resistant dispensing valve  12  is installed on a fluid container, positioning flange  10  abuts the exterior wall of the container. In its closed position (seated against the port wall  17 ), the valve seal  19  is positioned a short axial distance from positioning flange  10 , preferably not more than about 0.25 inches, so as to limit the amount of fluid contained within the portion of the valve outside of the fluid container to the volume within the inlet end of the valve between positioning flange  10  and the valve seal  19 . By limiting the amount of fluid that may be contained within the valve structure after a dispensing cycle, the risk of subjecting a dose of liquid held within the valve after a dispensing cycle to temperature fluctuations is reduced, in turn reducing the risk of dispensing a dose of spoiled liquid at the start of the following dispensing cycle. 
         [0058]    In operation, the valve  12  is preferably mounted to a fluid container (not shown). The discharge opening preferably points downwardly outside of the container, whereas finger grip wings  30  and  31  project horizontally. The valve  12  normally remains in the fully closed position. In this position, the resilience of actuator  24  urges the plunger  21  outwardly, toward the actuator end  9  of the valve body  13 , and holds the valve seal  19  in engagement with seat  18 , so that the valve seal  19  blocks flow from the inlet opening  15  to port  80  and discharge outlet  121 . In this condition, the pressure of the liquid in the container tends to force the valve seal  19  against seat  18 , thereby closing the valve. 
         [0059]    In the embodiment of the instant invention shown in  FIGS. 2 and 5 , a separate push button element  60  is provided for manual engagement by a user to operate the drip resistant dispensing valve  12 . Push button element  60  is preferably formed as a disk having a generally planar top surface  61  and a bottom surface  62  on the opposite side from the top surface  61 . Extending downward from and centrally located on bottom surface  62  is an engagement pin  63 . In the embodiment of the instant invention depicted in  FIGS. 2 and 12 , the dome-shaped resilient section  25  of actuator  24  is provided with a central opening  64  sized to receive engagement pin  63  therein and to hold the engagement pin  63  in place via a friction fit. Thus, depressing push button element  60  downward likewise causes plunger member  21  and valve seal  19  to move in an opening direction aligned with the central axis of the valve body and transverse to valve port wall  17 . Preferably, engagement pin  63  is provided a circumferential ledge  65  around pin  63  generally parallel to bottom surface  62 . When inserted into actuator  24 , pin  63  thus fits snugly within central opening  64  in actuator  24 , while ledge  65  lies flush against the top face of actuator  24 . Thus, when push button element  60  is pushed downward, only ledge  65  comes in contact with actuator  24 , thus ensuring that the dome-shaped resilient section does not lose its shape or its spring characteristic when the button is actuated. 
         [0060]    In an alternate embodiment of the instant invention, push button element  60  further comprises a detachable tamper indicating ring  70  circumscribing push button element  60 . Tamper indicating ring  70  includes a flat surface sized and configured to seat against the actuation end  9  of the valve body  13  surrounding actuator  24 . The tamper indicating ring  70  is provided with a plurality of tabs  74  extending towards the interior of the tamper indicating ring  70 , each tab  74  having a narrow terminal section attached to the upper and outer edge of push button element  60 . Tabs  74  are preferably configured so as to position push button element  60  substantially below the plane defined by the uppermost extent  72  of the tamper indicating ring  70 , such that when push button element  60  is assembled with actuator  24  within the drip resistant dispensing valve  12 , the outermost point of the actuation end  9  is the uppermost extent  72  of the tamper indicating ring  70 . Thus, by recessing push button  60  into the structure of drip resistant dispensing valve  12  and below the uppermost extent  72  of the tamper indicating ring  70 , inadvertent or accidental actuation of the valve (through bumping against a surface, etc.) may be averted. 
         [0061]    In use, a new drip resistant dispensing valve  12  is provided on an unused container with push button element  60  installed in actuator  24  with tamper indicating ring  70  intact. Upon the first actuation of the valve through depression of push button  60 , movement of tamper indicating ring  70  is blocked by the upper edge of valve body  13 , such that movement of push button element  60  into valve body  13  results in breaking of tabs  74  and tamper indicating ring  70  separating from push button element  60 . Thus, previous actuation of valve  12  may be readily apparent to a user based upon either the presence or absence of tamper indicating ring  70  from push button element  60 . 
         [0062]    The user can open the valve by grasping the finger grip wings  30  and  31  with his or her fingers and pressing his or her thumb against the center section of the push button element  60  so as to intentionally move actuator  24 , plunger member  21 , and valve seal  19  in an opening direction aligned with the central axis of the valve body and transverse to valve port wall  17 . Such movement takes the plunger member  21  and valve seal  19  from the normally closed position towards an open position, in which stop member  28  on the plunger member  21  engages stop shoulder  29  on the plunger guide  20  of the valve body  13 . In this open position, the valve seal  19  is remote from valve port wall  17  and remote from seat  18 , so that the valve seal  19  does not occlude port  80  and hence fluid can flow from a container to outlet channel  134 . 
         [0063]    Because the finger gripping members  30  and  31  extend generally transverse to the discharge outlet  121 , and extend generally horizontally during use of the valve, the user&#39;s fingers will be supported above the bottom end of the discharge outlet  121 , out of the stream of fluid discharged from the opening. Thus, if a hot fluid is being dispensed, it will not harm the user. 
         [0064]    By constructing each of the valve elements as discussed above, namely, forming the valve body from a polypropylene copolymer having a minimum average wall thickness of approximately 0.06 inches, and forming the valve seal from a thermoplastic rubber having an average thickness of about 0.03 inches, the valve structure may be subjected to the vigorous sterilization processes necessary for using the valve in food applications, including irradiating the structure at up to 5.0 MRAD and subjecting the structure to high temperature chemical and steam sterilization processes, without causing the valve structure to become brittle or otherwise jeopardizing the integrity of the valve&#39;s structure or operation. 
         [0065]    Since the drip resistant dispensing valve  12  as above described is made with only a few parts formed by conventional, simple molding techniques, it is relatively simple in operation and inexpensive to manufacture. It is inherently reliable, and does not require extreme precision in manufacture. 
         [0066]    Those skilled in the art of spring design will readily recognize that the resilient element  25  of the actuator  24  may be disposed at the exposed or actuator end  23  of the plunger  21 , so that the resilient section acts as part of the push button and closes the actuator end of the valve body  13 . However, this is not essential, and the resilient element  24  can be disposed within the valve body  13 , at a location inaccessible to the user, as explained in detail above through use of push button element  60 . In addition, although it is highly advantageous to form the resilient element integrally with the plunger member, this is not essential. 
         [0067]    The invention has been described with references to a preferred embodiment. While specific values, relationships, materials and steps have been set forth for purposes of describing concepts of the invention, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the basic concepts and operating principles of the invention as broadly described. It should be recognized that, in the light of the above teachings, those skilled in the art can modify those specifics without departing from the invention taught herein. Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with such underlying concept. It is intended to include all such modifications, alternatives and other embodiments insofar as they come within the scope of the appended claims or equivalents thereof. It should be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein. Consequently, the present embodiments are to be considered in all respects as illustrative and not restrictive.