Abstract:
A flexible member is fabricated with side walls forming a chamber which is coupled to a liquid source on one side and has a slit through an end wall on the other side. The end wall is generally curved toward the chamber on its interior surface. The exterior surface of the end wall has ridges adjacent to the slit that extends through the end wall. Deformation of the side walls of the flexible member as by biting causes the end wall with the slit to deform and open the slit which otherwise is retained closed by the walls of the flexible member. This action establishes fluid dispensing from the source through the slit. The thickness of the end wall varies over its distance creating weaken areas in the end wall. These weakened areas create areas in which the end wall deforms opening the slit. In addition to the foregoing, the interior surface forming the chamber has a minimal surface area. The surface is smooth, allowing easier cleaning of the chamber.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The present invention relates to the field of liquid replenishing hydration systems. In particular the present invention relates to a liquid dispensing valve of a hydration system that improves performance in sustaining a column of liquid and improved liquid delivery flow and is easily cleaned and sanitized.  
           [0003]    2. Discussion of Relevant Art  
           [0004]    Hydration systems are used to supply liquid and re-hydrate a person that is generally losing body moisture as a result of heavy physical exertion, heat or a combination of the two. Hydration systems are generally constructed to hold water or a water based drink in either a rigid or flexible container. A rigid container generally denotes a plastic bottle or canteen while a flexible container generally denotes a bota bag or bladder type system. A rigid container is generally transported in lumbar packs worn around the waist or backpacks and the flexible container is generally transported in a small backpack situated high on the back between the shoulder blades. In both systems the container may be connected to a flexible tube and at the opposite end of the tube, a liquid dispensing valve is secured. Since the liquid dispensing valve is remotely connected to a liquid reservoir the user can hydrate their body without stopping an activity. The liquid dispensing valve is generally opened with a biting action and fluid is removed by a sucking action on the liquid dispensing valve while it is open. Once the biting pressure is discontinued the opening closes stopping fluid flow. If a liquid reservoir is transported or located at an elevation lower than the liquid dispensing valve a negative static head is created in the liquid dispensing valve. This negative pressure attempts to equalize the liquid draining it from the liquid dispensing valve back into the reservoir. If a liquid reservoir is transported or located at an elevation higher than the liquid dispensing valve a positive static head is created in the liquid dispensing valve. This positive pressure also attempts to equalize the liquid wanting to drain the liquid reservoir into the liquid dispensing valve. If the liquid dispensing valve is unable to hold a sufficient negative static head, liquid will drain from the liquid dispensing valve and tube back to the liquid reservoir. If the liquid dispensing valve is unable to hold a sufficient positive static head, liquid will drain through the liquid dispensing valve eventually emptying the liquid reservoir.  
           [0005]    U.S. Pat. Nos. 5,085,349, 5,730,336, 5,816,457, 6,070,767 and 6,032,831 describe a liquid dispensing valve that is connected to a liquid reservoir. U.S. Pat. No. 5,085,349 describes a liquid dispensing valve with a positive static flow to the fluid dispensing unit with the capability of maintaining an eight feet positive column of liquid with a 0.350 inch material thickness at the through slit area. U.S. Pat. No. 5,730,336 describes a liquid dispensing valve that is designed to resist distortion by positive pressure from within the container and intentionally deforms and opens under negative pressure within the container. U.S. Pat. No. 5,816,457 describes a liquid dispensing valve that is designed to maintain a seal under positive pressure within the container but the design is inherent to fail with a negative pressure in the container.  
           [0006]    In U.S. Pat. No. 5,791,510 FIG. 1. shows a partial diagram of a cyclist with a liquid container at or below the liquid dispensing valve. In actual use this liquid dispensing valve must incorporated an inline check valve to hold the liquid at the level of the liquid dispensing valve due to the liquid dispensing valve cannot accomplish this task separately. The check valve and liquid dispensing valve are sold through a company named Check Water located in California.  
           [0007]    U.S. Pat. Nos. 5,730,336 and 5,791,510 are made of a relatively thin uniform elastic or pliable material. In conjunction with the resiliency of the material both patents teach of an additional member to act as a spring to help force the through slit in a closed position. U.S. Pat. No. 5,085,349 is made of a elastic or pliable material with varying wall thickness. In conjunction with the resiliency of the material it also relies on a pressure angle that increases the seal but also increases material thickness at the through slit area and decreases flow through the valve. The material thickness at the through slit may be as thick as the pressure angle will allow creating a liquid dispensing valve that is to rigid to comfortably open with the mouth by a biting action. The aforementioned U.S. patents show art to liquid dispensing valves that will maintain a positive static head but no prior art shows a liquid dispensing valve capable of maintaining a negative static head in a personal hydration system.  
           [0008]    U.S. Pat. Nos. 5,085,349, 6,070,767 and 6,032,831 show the outer and inner surface of the through slit wall flexing outward when a biting action is applied. As previously mentioned this biting action is used to open the valve in order to draw liquid from a reservoir. In U.S. Pat. Nos. 6,032,831 and 6,070,767 a drawing designated as FIG. 8. Shows the dispensing face of a liquid dispensing valve being forced outward into the user&#39;s mouth as the through slit opens. This outward flexing of the through slit wall increases the overall length of the bite valve portion inserted into the user&#39;s mouth often touching the tongue during use. This incident will interfere and hamper the flow of water through the liquid dispensing valve. Also, in FIG. 8. through slit wall, designated as number  50 , shows a tremendous amount of external exposure to the sealing surface ( 50 ) when the dispensing face is forced into an open position. This external exposure allows dirt, sand and foreign particles to adhere to the sealing surface ( 50 ) hindering the seal of the liquid dispensing valve in a relaxed state. It is preferred that the liquid dispensing face of a liquid dispensing valve flex inward away from the tongue during operation, insuring unrestricted water flow. It is also preferred that a liquid dispensing face flex inward protecting the through slit wall from external contamination insuring a reliable seal.  
           [0009]    Liquid dispensing valves are also difficult to clean and sanitize especially the interior cavity formed by the side walls and liquid dispensing wall. Many liquid dispensing valves are difficult to remove from the flexible tube, and after removal, difficult to thoroughly clean. The surfaces of the interior cavity will accumulate bacteria, germs and dirt in general, which is common in this application. The more intricate the inner surfaces facing the cavity, the more difficult is it to thoroughly clean the interior cavity and the liquid dispensing valve. The accumulation of bacteria, germs and dirt in a liquid dispensing valve presents a heath hazard. Current methods of cleaning a liquid reservoir, flexible tubes and liquid dispensing valve are laborious and ineffective if not performed correctly and continuously.  
           [0010]    U.S. Pat. Nos. 5,085,349, 5,730,336, 6,070,767, 5,816,457 and 6,032,831 show liquid dispensing valves that contain interior cavities with multiple angles, curves, small surfaces, undercuts and areas that are difficult to access. These areas and surfaces are extremely difficult to clean and sanitize especially when the inlet opening of these valves are small, making it difficult to insert proper cleaning utensils. Two methods currently exist for proper cleaning liquid dispensing valves. The first method is a mechanical removal of interior contaminants with a brush. This requires special brushes such as CamelBaks multiple brush cleaning kit. Often these cleaning utensils are not purchased or available for a particular liquid dispensing valve. The second method is a chemical cleaning agent. These agents are effective in sanitizing the liquid dispensing valve but great care must be taken to thoroughly rinse the chemical completely from the liquid dispensing valve. A mechanical removal of build up contaminants is often necessary in conjunction with a chemical cleansing agent. Many times the end user is simply unaware of the steps necessary to properly clean their liquid dispensing valve. All liquid dispensing valves need to be cleaned but a valve that has a minimum of complex surfaces, angles and inaccessible areas in the interior cavity is much easier to clean and less likely to accumulate contaminants. It is preferred that a liquid dispensing valve is easily removed and easily cleaned on all surfaces with minimal effort.  
           [0011]    Based on the above and other problems with the relevant art, it is the object of the present invention to create a liquid dispensing valve that will flex inward and maintain liquid in the valve being subjected to either a high positive static or a high negative static head.  
           [0012]    Another objective of the present invention is to create a liquid dispensing valve that has a relatively thin wall at the area of the through slit for improved fluid flow and is an assembly without the need of an additional spring-like member.  
           [0013]    Another objective of the present invention is to create a liquid dispensing valve that has a minimum interior cavity surface shape to minimize accumulation of contaminants making cleaning easier and in less intervals. This can be accomplished by a liquid dispensing valve constructed of elastic or pliable material using the mechanics of properly located external hinge points for calculated movement and stress of material.  
         SUMMARY OF INVENTION  
         [0014]    The above discussed and other problems with the relevant art are overcome by the liquid dispensing valve of the present invention. The present invention comprises a liquid dispensing valve that is constructed of elastic or a pliable polymer that remains flexible over a wide temperature range. The present inventions is generally attached to a flexible tube which, in turn, is attached to a reservoir that generally holds water or a water based drink. As the liquid dispensing valve is deformed by a biting action and outside negative pressure is created by a sucking action on the liquid dispensing valve, liquid is drawn from a reservoir through a tube and through a deformed slit of the liquid dispensing valve. After the user has received a sufficient quantity of liquid he discontinues exerting a sucking pressure and biting action to the liquid dispensing valve. The liquid dispensing valve returns to a neutral state forcing the through slit to close stopping fluid movement. It is preferred that liquid remain in the tube and the liquid dispensing valve to avoid a delay in obtaining liquid and additional effort required to draw liquid through the tube again. A delay in liquid delivery is frustrating to a user as he attempt to re-hydrate during a strenuous activity. It is also preferred that the liquid dispensing valve does not leak which would empty the container denying the user necessary hydration.  
           [0015]    If the liquid reservoir is located at a significantly lower elevation than the liquid dispensing valve the fluid will have a propensity to drain back into the container. For this to happen the through slit of the liquid dispensing valve must momentarily loose its seal allowing air to enter the slit and occupy the area vacated by the draining fluid. If the through slit seal remains intact the fluid will maintain its position in the tube and liquid dispensing valve and the pressure in the liquid dispensing valve will be less than in the reservoir. The present invention utilizes hinge lines to the through slit on the outer surface of the outlet side of the liquid dispensing valve to effectively increase the seal during this situation. The hinge lines are parallel to the through slit and a hinge line exists equal distance on each side of the through slit. This enables the pliable material to flex and swing about the through slit to the hinge line, similar to two cabinet doors that open from the center and minimize the gap between when closed. To aid in the controlled manner in which the through slit is forced open the outer surface of the outlet end may be scalloped on both sides transverse of the through slit between the hinge lines. This scalloped detail is an area where material has been removed from the outer surface forming a weakened line through the outer surface. As the liquid dispensing valve is compressed by biting, the outer surface flexes inward. The scalloped areas provide an external void in the liquid dispensing face for material to compress and fold onto itself and lessen the biting force required to open the through slit.  
           [0016]    If the reservoir is located at a significantly higher elevation than the liquid dispensing valve the liquid will increase pressure in the liquid dispensing valve. This is due to the fluid equalizing to the lowest level. At this time the pressure in the liquid dispensing valve is greater than the liquid reservoir. To contain this increase in pressure the present invention has a curved surface on the inner wall of the dispensing face of the liquid dispensing valve. The curve is directed toward the inner chamber of the liquid dispensing valve. The seal of the through slit of the inner curved surface increases as a curved surface inherently resists distortion and the minimal distortion encountered forces the curved surface to increase the seal, much like a keystone is the focal point of pressure in an arched structure. The liquid dispensing valve may be rectangle-like when viewed from a transverse cross section. The opposing side walls constructed parallel to the hinge lines have a substantial wall thickness. This wall thickness forms a foundation for the liquid dispensing valve and will flex less than remaining wall structures of this device.  
           [0017]    These opposing walls form a strong support for the attachment of the inner curved surface of the outlet dispensing wall member and strong support for the parallel hinge line to the through slit on the outer surface of the outlet dispensing wall side. These walls, being straight or nearly straight, exert a force opposite of the biting action required to open the through slit and return the slit to a closed position when the biting action is removed. Parallel to the length of these walls may be voids located about midway in the exterior surface. The void act as hinge line along the length of the wall enabling the wall flex with less effort. The adjacent opposing side walls are of substantially less thickness than the previously mentioned walls. These opposing walls are the thinnest of the wall structure including the wall structure that forms the outlet side of the liquid dispensing unit. The thinner construction of these walls causes them to flex before all other walls encountering same pressure. Under a positive static head of pressure these walls will flex outward effectively creating a greater seal to the through slit. Under a negative static head of pressure these walls will flex inward effectively creating a greater seal to the through slit.  
           [0018]    Surfaces forming the interior cavity of the present invention are large smooth curved surfaces with minimal projections, comers or angles. This creates an uninterrupted interior cavity that is easy to clean and has less of a propensity to accumulate contaminants. The present invention locates flex points, comers, projections and smaller interrupted surfaces on the outer surface of the liquid dispensing valve. The outer surface of a liquid dispensing valve is much easier to clean and maintain so the addition of such flex points, comers and projections does not hinder performance or ability of the present invention to be cleaned.  
           [0019]    The liquid dispensing valve attaches to a flexible tube on the inlet side of the valve. Two methods are used; one provides a unitary liquid dispensing valve with an annular opening at the inlet side of the liquid dispensing valve being smaller in dimension than the outer diameter of the joining annular tube. The pliability of material of the liquid dispensing valve allows the inlet side of the device to be stretched and placed over the outer surface of the tube. Friction between the outer surface of the tube and inlet side of the present invention maintains the position of the liquid dispensing valve to the tube.  
           [0020]    The other method of attachment to the flexible tube consists of an intermediate structure which attaches to the second end of the flexible tube at one portion and at a second portion attaches to the liquid dispensing valve of the present invention. This structure allows continuity of liquid from a liquid reservoir to the liquid dispensing valve. The liquid dispensing valve must be stretched and deformed at the inlet side to be place over the second portion of the intermediate structure engaging mating seals. The liquid dispensing valve must have a larger inlet side to engage the intermediate structure than the previously mentioned friction fit method. The larger inlet opening allows the interior cavity of the liquid dispensing valve to be readily exposed when the valve is removed. The larger inlet opening makes cleaning of the interior surfaces much easier.  
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0021]    The accompany drawing, which constitute a part of the specifications, illustrate a preferred embodiment of the invention and together with the general description and the detailed description serve to explain the principles of the invention.  
         [0022]    [0022]FIG. 1 shows a general overview of a flexible reservoir as it pertains to a hydration system. The liquid dispensing valve of this illustration is positioned at an elevation lower than liquid in the reservoir with +X denoting a positive static head in the liquid dispensing valve.  
         [0023]    [0023]FIG. 2 shows a general overview of a rigid reservoir as it pertains to a hydration system. The liquid dispensing valve of this illustration is positioned at an elevation higher than liquid in the reservoir with −XX denoting a negative static head in the liquid dispensing valve.  
         [0024]    [0024]FIG. 3 shows a view of the liquid dispensing valve of the present invention.  
         [0025]    [0025]FIG. 4 shows a view of an alternate embodiment of the present invention of FIG. 3.  
         [0026]    [0026]FIG. 5 shows a view of an alternate embodiment of the present invention of FIG. 3 with an intermediate mounting structure between the present invention and the secondary end of the flexible tube.  
         [0027]    [0027]FIG. 6 shows a cross section view of FIG. 3 as shown by a through line and arrows denoted as  6 - 6 . This view also shows the movement and sealing of the through slit in the end wall as the liquid dispensing valve is placed under internal positive static pressure.  
         [0028]    [0028]FIG. 7 shows a view of FIG. 6 with movement and sealing of the through slit in the end wall as the liquid dispensing valve placed under internal negative static pressure.  
         [0029]    [0029]FIG. 8 shows an alternate embodiment of the present invention as viewed in FIG. 6. The outer surface of the liquid dispensing wall is serrated.  
         [0030]    [0030]FIG. 9 shows a view of FIG. 3 as shown by a view line and arrows denoted as  9 - 9 .  
         [0031]    [0031]FIG. 10 shows an alternate embodiment of FIG. 9 with voids located on the outer angled flat wall surface and projections on opposing wall members.  
         [0032]    [0032]FIG. 11 shows an alternate embodiment to FIG. 9 with voids as described in FIG. 10 and wall members being curved.  
         [0033]    [0033]FIG. 12 shows the preferred embodiment of the present invention of FIG. 3 under a compressed biting force, as denoted by arrows, showing the liquid dispensing valve compressing opening the through slot.  
         [0034]    [0034]FIG. 13 shows a cross section view of FIG. 12 as shown by a though line and arrows denoted as  13 - 13 .  
         [0035]    [0035]FIG. 14 shows a cross section view of FIG. 12 as shown by a through line and arrows denoted as  14 - 14 .  
         [0036]    [0036]FIG. 15 shows an alternate embodiment to FIG. 12 with a void extending along external wall surface forming a flex line.  
         [0037]    [0037]FIG. 16 shows a cross section view of FIG. 15 as shown by a through line and arrows denoted as  16 - 16 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0038]    Turning now to the drawings, wherein like components are designated by like reference numerals. FIG. 1 depicts a flexible or bladder liquid reservoir assembled as a hydration apparatus. Number  2  references the flexible hydration system and  4  references the liquid dispensing valve, of the present invention, attached to flexible tubing  6  on one end and flexible tubing  6  is connected to flexible reservoir  8  on the other end. Liquid dispensing valve  4  is shown in a relative accurate position to flexible reservoir  8  when being worn on the back of a user. Liquid level  10  is shown about midway in flexible reservoir  8  and distance +X shows a relative elevation difference between liquid level  10  and liquid dispensing valve  4 . Distance +X may be greater or smaller due to the positioning of liquid dispensing valve  4  in relation to flexible reservoir  8  and liquid level  10 . The distance +X denotes a positive static head of pressure in liquid dispensing valve  4  and if liquid dispensing valve  4  is unable to maintain a positive static head of pressure, liquid will drain out of liquid dispensing valve  4  draining liquid reservoir  8 .  
         [0039]    Referring now to FIG. 2 shows an assembled rigid liquid reservoir hydration system denoted as  12 . One end of flexible tube  6  is connected to liquid dispensing valve  4  and the other end is attached to a rigid reservoir  14 . Liquid level  16  is shown about midway in rigid reservoir  14 . The relative position of liquid dispensing valve  4  and rigid container  14  is an accurate representation of a position in actual use with elevation distance −XX generally denotes a distance maintained by liquid dispensing valve  4  and liquid level  16  while being transported and operated by the user. If liquid dispensing valve  4  is unable to maintain this negative static pressure denoted as −XX the through slit seal will fail and liquid will drain into reservoir  14 .  
         [0040]    In FIG. 3 of the drawings, numeral  4  broadly indicates the present invention. The liquid dispensing valve  4  is connected to the proximal end of partially shown flexible tube  6  by an annular friction fit between the external surface of flexible tube  6  and internal surface of area  36 . Area  36  is annular in shape and open on one end to the ambient surroundings  40  creating an inlet side of liquid dispensing valve  4 . Flexible tube  6  is connected to a liquid reservoir (not shown) at a distal end. Annular area  36  is joined to a rectangle-like chamber, in cross section, comprising opposing surfaces  18 ,  20  and at an approximate right angle surface  22  and  24 . At the other end of this chamber is an outlet wall that comprises an inner and outer wall surface. The outer wall surfaces is comprised of hinge point  28  and  30 , scalloped area  32  and  34 , and surface  42  and  44 , which will be discussed in later drawing descriptions. Approximately centered in the outlet wall through slit  26  connects the internal void of liquid dispensing valve  4  to the outside area  40  when a significant opposing force is applied to surface  18  and  20  distorting liquid dispensing valve  4  causing through slit  26  to open. Through slit  26  is normally forced into a closed position by tension exerted by the outlet wall and opposing surfaces  22  and  24 . Surfaces  22  and  24  exert a column tension to the outlet wall as shown by arrows denoted as Y-Y thus aiding through slit  26  to maintain a closed position.  
         [0041]    [0041]FIG. 4 is an alternate embodiment of the present invention. It functions identical to FIG. 3 with the exception that scalloped area  32  and  34  are not present and void  70  on wall surface  22  and void  72  on wall surface  24  are present. Void  70 ,  72  creates a weakened area in wall member  22  and  24  respectfully. This weakened area creates a hinge line for wall member  22  and  24  to flex about. In the absence of scalloped area  32 , 34  and the addition of void  70 , 72  force required on surface  18  and  20  to distort liquid dispensing valve  4 , opening through slit  26  is somewhat equivalent to the force required for the same action in the embodiment of FIG. 3.  
         [0042]    [0042]FIG. 5 is an alternate embodiment to FIG. 3 where liquid dispensing valve  4  is connected to intermediate component  64  and intermediate component  64  is connected to outlet end of flexible tube  6 . Liquid dispensing valve  4  is connected to intermediate component  64  by annular sealing structures  66 . Sealing structures  66  mate with internal sealing structures (not shown) in liquid dispensing valve  4 .  
         [0043]    [0043]FIG. 6 is a cross section of FIG. 3 being viewed by arrows denoted as  6 - 6 . Liquid dispensing valve  4  is shown under positive internal static pressure with outlet wall flexing and increased pressure denoted by the direction of the arrow. Outlet wall has inner surface  54  and  56  that is bisected by through slit  26 . Inner wall surface  54 ,  56  form a curved surface that projects inward toward the inlet side and is joined to inner surface  52  and  50  respectfully. Four chamber walls along with the outlet surface  54  and  56  forms internal cavity  48 . Cavity  48  has continuity to liquid stored in a liquid reservoir through the inlet side of the liquid dispensing valve  4 , flexible tube  6  and liquid reservoir.  
         [0044]    Positive static pressure in cavity  48  exerts equal pressure on all surfaces that define cavity  48 . Liquid dispensing valve  4  is constructed of a flexible pliable material and the surfaces defining cavity  48  will flex under pressure. Positive static pressure on inner curved surface  54  and  56  will cause surface  54  and  56  to be forced tightly together at through slit  26  thus increasing the sealing of through slit  26 . Inner cavity  48  has a slight annular projection  58  on the inlet side dividing cavity  48  and annular surface  46 . Projection  58  acts as a tactile stop for engaging flexible tube  6  into annular area  36 .  
         [0045]    [0045]FIG. 7 is a view of FIG. 6 showing the liquid dispensing valve  4  with negative static internal pressure. The arrow indicates direction of pressure and material flexing. When cavity  48  encounters a negative static pressure all surfaces defining cavity  48  equally experience the pressure and flex with a thinner wall flexing more than a wall of greater thickness. The inner surface  54  and  56  of the outlet wall containing through slit  26  bisecting both inner and outer surfaces becomes the most flexible wall, due to being attached by only three sides, and will flex more than the remaining walls. The outer surface of the outlet wall designated as  42  and  44  are ridges and are designed to maximize sealing of through slit  26  while under negative static pressure. This sealing action of ridge  42  and  44  against each other prevents outside air  40  entering into chamber  48 . As shown, inner surface  56  and  54  are slightly separated by the pressure differential on the outlet wall.  
         [0046]    The outer surface of the outlet wall contains areas of reduced wall thickness. This void forms a weaker more flexible area in the pliable material and creates a hinge point. At equal distance adjacent to through slit  26  is hinge point  28  and  30 . Hinge point  28  and  30  are formed parallel to through slit  26  and create a controlled pivot of ridge  42  and  44  to its respected hinge point as surface  42  and  44  cantilever under negative pressure. Ridge  42  and  44  pivot inward toward cavity  48  increasing the seal of through slit  26 . Scalloped area  32  and  34  creates a weaker outlet wall at the midline, perpendicular to through slit  26  and hinge point  32  and  34  which will be discussed further in FIG. 12.  
         [0047]    [0047]FIG. 8 shows an alternate embodiment of the present invention of FIG. 7 showing the liquid dispensing valve  4  with negative static internal pressure. The arrow indicates direction of pressure and material flexing. When cavity  48  encounters a negative static pressure all surfaces defining cavity  48  equally experience the pressure and flex with a thinner wall flexing more than a wall of greater thickness. The inner surface  54  and  56  of the outlet wall containing through slit  26  bisecting both inner and outer surfaces becomes the most flexible wall, due to being attached by only three sides, and will flex more than the remaining walls. The outer surface of the outlet wall designated as  74  and  76  maximizes sealing of through slit  26  while under negative static pressure. This sealing action of outlet wall  74  and  76  against each other prevents outside air  40  entering into chamber  48 . As shown, inner surface  56  and  54  are slightly separated by the pressure differential on the outlet wall.  
         [0048]    The outer surface of the outlet wall contains areas of reduced wall thickness. These voids create weaker more flexible areas in the pliable material and form multiple hinge points. At equal distance adjacent to through slit  26  on each side are multiple hinge points  28  and  30 . Hinge points  28  and  30  are formed parallel to through slit  26  and create a controlled pivot of surface  74  and  76  to its respected hinge point as surface  74  and  76  cantilever under pressure. Surface  74  and  76  pivot against each other increasing the seal of through slit  26 .  
         [0049]    [0049]FIG. 9 is a view of FIG. 3 as viewed by arrows denoted as  9 - 9 . This cross section defines cavity  48  with surface  50 ,  52 ,  60  and  62 . The chamber defining cavity  48  can now be seen to be rectangle-like in design. The straight walls defined by surface  22 ,  50  and  24 ,  52  provide the column strength to the outlet wall as mentioned in FIG. 3. Walls defined by surface  18 ,  60  and  20 ,  62  are thinner in cross section than walls that provide column strength. Wall thickness generally defined by surface  24  and  52  will be denoted as “A” and the wall thickness generally defined by surface  20  and  62  will be denoted as “B”. The elastic material of wall thickness “A” provides the main force to return the liquid dispensing valve  4  to its original shape after being distorted and provides additional tension on the outlet wall at all times to seal through slit  26 . When liquid dispensing valve  4  encounters pressure or distortion of any nature walls with thickness “A” will be the last to flex and the first to recover. The two walls defined by surface  22 ,  50  and  24 ,  52  provide structure and a secure joining area of both surfaces of the outlet wall. Walls with thickness “B” will flex before and recover after walls with a thickness of “A” recover. The general relationship of wall thickness is, “B” is generally 40% to 75% of wall thickness “A”.  
         [0050]    [0050]FIG. 10 shows an alternate embodiment of FIG. 9 with void  70  in wall surface  22  and void  72  in wall surface  24 . Void  70  and  72  weakens its respective wall member creating a location for flexing of wall members and projection  78 ,  80  strengthen opposing wall surfaces  18 ,  20  respectfully.  
         [0051]    [0051]FIG. 11 shows an alternate embodiment of FIG. 9 with wall surface  22 , 50  and  24 , 52  are curved outward away from cavity  48 . Void  70  in wall surface  22  and void  72  in wall surface  24  weakens its respective wall member creating a fixed location for flexing of wall members. All specifications of FIG. 9 also apply in FIG. 11.  
         [0052]    [0052]FIG. 12 shows a view of the invention while being compressed by a biting force on surface  18  and  20  as denoted by arrows. Force applied to surface  18  and  20  exerts a force to collapse the outlet wall opening through slit  26 . Ridges  42  and  44  fold inward about a lateral line denoted by dash line M-M. Scalloped area  32  and  24  form a void in the outer surface allowing  42  and  44  to flex inward as noted.  
         [0053]    [0053]FIG. 13 shows a cross section of FIG. 12 as viewed by arrows denoted as  13 - 13 . A biting action on surface  18  and  20  compresses inner surface  60  and  62  to decrease volume in cavity  48 . The biting action forces the liquid dispensing wall to flex inward toward cavity  48 . Through slit  26  is forced open allowing liquid to pass through liquid dispensing valve  4 . Sealing surface  68  of through slit  26  can now be viewed as it flexes inward protecting sealing surface  68  from exposure to dirt and foreign objects.  
         [0054]    [0054]FIG. 14 shows a cross section of FIG. 12 as viewed by arrows denoted as  14 - 14 . This view shows through slit  26  opening toward cavity  48  and sealing surface  68  pivoting inward toward cavity  48 . The arrow depicts direction of liquid flow as liquid moves through liquid dispensing valve  4  into outside area  40 .  
         [0055]    [0055]FIG. 15 shows an alternate embodiment of FIG. 12. Void  70  and  72  are present in wall surface  22  and  24  respectfully. Wall surface  22  and  24  are shown flexing about the void present in each surface.  
         [0056]    [0056]FIG. 16 shows a cross section view of FIG. 15 as viewed by arrows denoted as  16 - 16 . Wall members  22 ,  50  and  24 , 52  are seen flexing outward from cavity  48 . Void  70  and  72  are extended as wall members  22 ,  50  and  24 ,  52  force void  70  and  72  open under pressure. Wall members  22 ,  50  and  24 ,  54  flex about dashed line denoted as M-M which bisects void  70  and  72 .  
         [0057]    The present invention has been described and depicted in terms of the preferred embodiment. The invention is not limited, however, to the embodiment described and depicted. Rather the invention is defined by the claims.