Abstract:
A low-profile one-way valve assembly that attaches to a liquid conduit. A valve fitting supports a recessed, bi-leaflet, elastomer valve piece. A compound curvature at a valve base, raised seal forming surfaces at provided leaflets, tapered extension surfaces at the leaflets and a tailored sidewall thickness profile at the leaflets assures a durable watertight sealing action at the flexible valve piece. An O&#39;ring mounted to a threaded fitting surface seals the assembly relative to a supporting conduit. A cover is also provided to protect the valve piece from external damage and significant back pressures.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to an elastomer valve and, in particular, to a one-way, bi-leaflet (e.g. duck-bill shaped) valve assembly that mounts to liquid conduits, such as flow ports located below other elevated system conduits or a reservoir and from which it is periodically necessary to clear latent fluid (e.g. when winterizing water lines for swimming pools, recreation vehicles and vacation properties). 
         [0002]    Numerous one way valve devices are known for use in wide varieties of plumbing applications and systems. The present valve assembly in one construction is used to facilitate and overcome problems encountered when winterizing swimming pools. 
         [0003]    Winterizing swimming pool plumbing lines typically requires the draining of the pool water below the level of the return openings, such as at the skimmers or pool sidewalls, to assure that no water enters or backs-up into the lines as they are seasonally drained, filled with anti-freeze and/or plugged. Such drainage wastes water and treatment chemicals. Reduced water levels can also produce cover damage such as where the pool has an automatic covering system. 
         [0004]    For systems where the water level is not reduced, plugs can be added to the submerged ports as air is blown through the ports, but which can be unpleasant due to the attendant splashing that occurs as the plugs are inserted. 
         [0005]    One valve that can be added to conduits that require seasonal clearing is disclosed at U.S. Pat. No. 6,877,524 and application publication US2004/0177882 to Vasilev. The valve of the subject invention can also be used in the foregoing applications and others where a one-way flow valve is desired. The valve finds particular application at submerged ports to permit expelling latent liquid and prevent backflow from low pressure surrounding water. 
         [0006]    In one preferred form, the valve provides a support fitting having a suitable fastener coupling (e.g. threaded or adhesive) that mounts to an associated conduit. An elastomer duck-bill shaped valve piece mounts in the fitting. The valve piece is shaped to promote a flexing when mounted to the fitting to induce provided leaflets into abutting engagement in a closed condition, except when liquid or air is expelled from the conduit. Under forward pressure, the valve piece flexes open. Otherwise, the leaflets are constructed to resiliently close upon themselves with the release of pressure to maintain a flexible aperture in a closed condition to resist counter flow. A cap that mates with the fitting is provided as a cover to the valve piece to further assure against reverse flow. 
       SUMMARY OF THE INVENTION 
       [0007]    It is a primary object of the invention to provide a one-way valve that opens with suitable liquid or air pressure and self-closes upon the cessation of the pressure. 
         [0008]    It is a further object of the invention to provide a valve assembly that when submerged prevents back flow into an associated submerged conduit. 
         [0009]    It is a further object of the invention to provide elastomeric valves that readily install to ports or openings of a plumbing system that return water to a reservoir (e.g. pool, spa etc.) from a pump and/or filtration equipment below the water line of the reservoir. 
         [0010]    It is a further object of the invention to provide a valve assembly that supports a cover piece for the valve to protect the valve from physical damage, such as with ice movement or other physical abuse. 
         [0011]    It is a further object of the invention to provide a resilient valve piece having a molded configuration that flexes to promote the closure of a flexible aperture defined by valve piece leaflets upon attachment to a fitting. 
         [0012]    It is a further object of the invention to provide an elastomeric valve piece having surfaces of varying contours, thickness profiles and shapes to provide a sharp, clean seal parting line to prevent leakage. 
         [0013]    The foregoing objects, advantages, distinctions and improvements of the invention, along with variously considered improvements and modifications are described with respect to one considered valve assembly having utility for winterizing swimming pools. This assembly provides a low-profile fitting that attaches to a conduit and supports an elastomer, duck-bill shaped valve piece that is recessed into the fitting. A flanged surface at the valve piece and an O&#39;ring at a male, threaded surface of the fitting seals the assembly relative to a liquid conduit. A cover is provided that mounts over the elastomer valve piece to cover and protect the valve piece from external damage. 
         [0014]    Still other objects, advantages, distinctions and constructions of the invention will become more apparent from the following description with respect to the appended drawings. Similar components and assemblies are referred to in the various drawings with similar alphanumeric reference characters. The description should not be literally construed in limitation of the invention. Rather, the invention should be interpreted within the broad scope of the further appended claims. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective drawing shown in exploded assembly to one valve assembly of the invention. 
           [0016]      FIG. 2  is a perspective drawing showing an assembled view of the valve assembly of the invention 
           [0017]      FIG. 3  is a perspective drawing to a duck-bill shaped elastomer valve piece removed from an associated fitting. 
           [0018]      FIG. 4  is a front view to the duck-bill shaped elastomer valve piece of  FIG. 3 . 
           [0019]      FIG. 5  is a section view to the duck-bill shaped elastomer valve piece of  FIG. 2  taken along section lines  5 - 5  of  FIG. 4 . 
           [0020]      FIG. 6  is a side view to the duck-bill shaped elastomer valve piece of  FIG. 3 . 
           [0021]      FIG. 7  is a section view to the duck-bill shaped elastomer valve piece of  FIG. 3  taken along section lines  7 - 7  of  FIG. 6 . 
           [0022]      FIG. 8  is a top view to the duck-bill shaped elastomer valve piece of  FIG. 3 . 
           [0023]      FIG. 9  is a detailed view in enlarged scale to the juncture of the slit and the edge wall of the valve piece of  FIG. 8 . 
           [0024]      FIG. 10  is a bottom view to the duck-bill shaped elastomer valve piece of  FIG. 3 . 
           [0025]      FIG. 11  is a detailed view in enlarged scale to the inside surface of the juncture of the slit and the edge wall of the valve piece of  FIG. 10 . 
       
    
    
       [0026]    Similar structure throughout the drawings is referred to with the same alphanumeric reference numerals and/or characters. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0027]    Referring to  FIG. 1 , a perspective view is shown to a one-way valve assembly  2  that includes a support fitting  4 , an O&#39;ring  6  for sealing the fitting  4  to a mating fitting, conduit, coupler or surface, a resilient elastomer, duck-bill shaped, bi-leaflet valve piece  8  and a valve piece cover  10 . In an assembled condition shown at  FIG. 2 , the valve piece  8  mounts in the fitting  4  and a distal end of the valve piece extends approximately to a octagon tool surface  9  of the fitting  4 . The assembly  2  finds particular application for winterizing liquid conduits such as found in swimming pools, whirlpools, spas or other fixtures and having a submerged conduit port that must be seasonally purged of liquid. The assembly  2  may also be used in other applications, such as winterizing plumbing conduits at recreation properties or the like to facilitate liquid purging and prevent access to the conduit interior by mice or unwanted materials (e.g. dirt, leaves etc.) or the like. 
         [0028]    The fitting  4  is presently constructed as a body piece  12  having external threads  14  that mates with a female outlet port (not shown) that commonly extends from the sidewall of a swimming pool. The body piece  12  is molded from a suitable plastic (e.g. PVC, nylon or other high density material). 
         [0029]    A flange  16  radiates from interior of the body  14  at an aft end of a central bore  18 . The flange  16  couples to an annular groove  20  provided at the valve piece  8 . Upon fitting the valve piece  8  into the fitting  4 , an aft surface  22  of the valve piece  8  acts as a washer to capture the valve piece  8  to the fitting  4  and/or seal against an abutting bore or end surface at a mating coupler fitting, reference  FIG. 2 . The O&#39;ring  6  can enhance the liquid seal with a mating coupler or independently seal the fitting  4  to the mating coupler. Once mounted to the fitting  4 , distal, leaflet edges  24  of the valve piece  8  are nested and recessed into the bore  18  and flex into sealed abutment. The fitting  4  thereby physically protects the valve piece  8 . 
         [0030]    The cover  10  can be mounted and captured to the bore  18  to physically protect the valve piece  8 . A sidewall surface  26  is sized to mount within the bore  18  and a cap surface  28  mounts over the seated valve piece  8 . A peripheral flanged edge surface  30  mates and interlocks with a recess  32  let into the fitting  4 . Collectively, the valve piece  8  and cover  10  effectively seal an associated liquid conduit port, when submerged against backflow and physical damage. 
         [0031]    Turning attention to  FIGS. 3 through 10 , details are shown to the construction of the elastomer valve piece  8  and related unique and novel features. From  FIG. 3 , sidewalls  40  of the valve piece  8  project with a convex taper from the annular groove  20  and annular flanged aft end  22  of the valve piece  8  to the parallel, seal forming leaflet edges  24 . The sidewall surfaces  40  project from the end  22  at intersecting angles in the range of 35 to 45°. 
         [0032]    The valve piece  8  thus presents a duck-bill shape. It is to be appreciated however that other shapes might be adapted into the valve piece  8 , provided the peripheral edges and/or included leaflet surfaces  24  are constructed to expand and contract to a sealed condition. The valve piece  8  can also be constructed with different numbers of leaflets and/or can be constructed with one or more of the following seal enhancing features. 
         [0033]    The ability of the leaflets  24  of the valve piece  8  to flex and return to a closed or sealed condition at the parting line  47  of the leaflet edges  24  is enhanced by forming a concave curvature  42  at the lateral sides of the flanged end  22  and a convex curvature  43  at the front and rear sides of the flanged end  22  of the valve piece  8 , reference  FIGS. 4 through 6 . Upon seating the groove  20  onto the flange  16  of the fitting  4 , the compound curvatures  42  and  43  flatten against the flange  16  and flex the valve piece  8  to induce the edges of the leaflets  24  to flex and flatten in sealed abutment against each other. 
         [0034]    The sealing action is enhanced by providing raised sidewall surfaces  44  along each leaflet edge  24 . The surfaces  44  taper at the end of each leaflet  24  into a point or “beak”  46 . The surfaces  44  increase the effective area of the seal action and the beaks  46  promote the flattening of the surfaces  44  and edges  24  against each other. The dimensions, taper angle and/or shape of the surfaces  44  and beak  46  can be varied to promote sealing and prevent leakage. 
         [0035]    To further enhance the seal action, the tapered beaks  46  at the lateral ends of the parting line or slit  47  are extended downward at surfaces  48  formed into the sidewalls  40 . The surfaces  48  define a V-shape and rise from the groove  20 . The surfaces  48  project at back-to-back angles in the range of 25 to 30°. The enhanced material at the sidewall surfaces  48  accommodate normal open/closing flexion and assure a leak proof seal internally and externally.  FIGS. 9 and 11  respectively show external and internal views to the closed slit or parting line  47 . 
         [0036]    With attention to  FIGS. 5 ,  8  and  10 , the thickness of the sidewalls  40  is also tailored to be thicker at the lower, center portions of the sidewalls  40  in the space bounded by the profile line  50  as the sidewalls  40  rise from the end flange  22 . An exemplary profile line for the valve piece  8  is shown at  FIGS. 5 ,  8  and  10 . The thickened sidewall profile promotes the sealing action at the edges  24  and surfaces  44  in the presence of back pressure on the sidewalls  40 . The thickened sidewalls particularly counter acts sidewall compression or collapse in the presence of back pressure and stabilizes the ends of the leaflets in the beak regions  46 . Collectively, the compound curvatures  42  and  43  of the base flange  22 , the raised edge surfaces  44 , the beak end surfaces  46  and  48 , and the tailored thickness profiles at the sidewalls  40  assures a watertight sealing action at the parting line slit  47 . 
         [0037]    While the invention has been described with respect to a number of preferred constructions and considered improvements or alternatives thereto, still other constructions may be suggested to those skilled in the art. It is to be appreciated that selected ones of the foregoing features can also be used singularly or be arranged in different combinations to provide a variety of improved, detachable valve assemblies. For example, the valve piece can provide overlapping leaflets in a variety of shapes and numbers. The thickness profiles of the leaflets can be varied in a manner different from that disclosed. The base of the valve piece can be constructed without compound curvatures. The foregoing description should therefore be construed to include all those embodiments within the spirit and scope of the following claims which are intended to cover generic and specific features of the invention herein described.