Abstract:
Disclosed are systems and methods for a unitary diaphragm assembly is for use in flush valves. The diaphragm assembly may have a flexible diaphragm which includes a seating portion and a mounting portion at the outer peripheral edge. A flow ring may be positioned adjacent to the seating portion of the diaphragm. An elongated barrel member may extend from the diaphragm in a longitudinal direction and may include a plurality of radial supports positioned circumferentially around the outer surface of the barrel member and along a portion of the length of the barrel member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 62/088,236 filed Dec. 5, 2014, the contents of which are hereby incorporated by reference for all purposes as if set forth in their entirety herein. 
       STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
     
    
     BACKGROUND 
       [0003]    This disclosure relates, in general, to improvements in flush valves for toilets, urinals, and other plumbing equipment. More particularly, this disclosure relates to an improved diaphragm for use in flush valves. 
         [0004]    Flush valves in toilets, urinals, and other plumbing devices may utilize a flexible diaphragm to both establish and seal off the connection between the inlet and outlet within a hollow brass body. In some flush valves, a barrel forms the connection between the inlet and outlet and the top of the barrel may include an annular main valve seat. This main valve atop the barrel may be normally closed by a flexible diaphragm which may extend across the hollow body of the flush valve and define an upper chamber. The flexible diaphragm may be clamped in place by an annular clamping rim on the flush valve body. The center of the flexible diaphragm may connect the upper chamber with the outlet, and a relief valve may be located in the center of the flexible diaphragm to normally seal off the upper chamber from the outlet. 
         [0005]    Diaphragm assemblies may include the diaphragm, a relief valve, a stem, a guide member, wing members, a retaining disc, and a flow ring. The guide member in the barrel may move with the diaphragm and include outwardly extending radial wing members, which engage the inner surface of the barrel to guide the guide member and attached diaphragm. The guide member may be attached to the diaphragm with a retaining disc using brass threading. The diaphragm may be formed of rubber which may be bonded to the brass parts in order obtain acceptable seating surfaces. 
         [0006]    In general, a normally closed flush valve may operate to seal off the upper chamber from the outlet using the water pressure from the inlet. The water under pressure at the inlet may communicate with the upper chamber of the flush valve through a bypass in the flexible diaphragm. Since the upper side of the diaphragm has a greater surface area, the water pressure forces the diaphragm down onto the valve seat on top of the barrel, thus preventing water from flowing into the outlet from the upper chamber. When a user moves a handle of the flush valve, a plunger may move inwardly toward the axis of the barrel and tilt a stem of the relief valve. This may break the seal the relief valve has established and allow water to flow through a guide member within the barrel and to the outlet. The opening of the relief valve may relieve the pressure within the upper chamber and the water pressure from the inlet may force the diaphragm upward and off of the main valve seat, allowing water to flow from the inlet through the barrel to the outlet. When moving upward, the diaphragm may reset the relief valve located in its center such that it again seals off the upper chamber from the outlet. Water from the inlet may then flow through the bypass into the upper chamber until the diaphragm is again forced against main valve seat, thereby closing the valve. 
       SUMMARY 
       [0007]    According to one aspect, a one-piece unitary diaphragm assembly for use in a flush valve is disclosed. The one-piece unitary diaphragm assembly includes an elongated barrel member, an annular flexible diaphragm, a radial support, and a relief valve seat. Constructed of a first predetermined material, the elongated barrel member has a body defining a passageway and the annular flexible diaphragm disposed about it. Constructed of a second predetermined material different from the first, the annular flexible diaphragm has a mounting portion at its peripheral edge for mounting the diaphragm assembly within the flush valve. Extending along some longitudinal length of the barrel member, the radial support is positioned circumferentially around the outer surface of the barrel member. The relief valve seat is located at the upper end of the barrel member and adapted for receiving a relief valve. In some forms, the assembly may further include a relief valve having a stem with a sealing member disposed at its upper end. The lower surface of the sealing member may have a sealing material disposed it, adapted for sealing against said relief valve seat. 
         [0008]    According to another aspect, a flush valve diaphragm kit for use in a flush valve is disclosed. The diaphragm kit includes a one-piece unitary diaphragm assembly, an annular flexible diaphragm, a radial support, relief valve seat, and a relief valve, which are all arranged and constructed as described above. 
         [0009]    The assembly and the kit may vary in form. In some forms, a flow control ring may be positioned about the barrel member and configured to be supported by the radial support. In some forms, a bypass orifice may be disposed through the annular flexible diaphragm. 
         [0010]    According to yet another aspect, a method of molding a one-piece unitary diaphragm assembly is disclosed. The method includes first, heating a first thermoplastic material until molten, and then delivering the first molten thermoplastic material to a mold&#39;s first cavity having an elongated tube shape. The method then includes heating a second thermoplastic material until molten, and delivering the second molten thermoplastic material to the mold&#39;s second cavity, having an annular shape and fluidly communicating with the first cavity. The next step in the method is holding the first and second thermoplastic materials in the mold for a predetermined period of time to form a one-piece unitary diaphragm, and finally, ejecting the one-piece unitary diaphragm from the mold. In some forms, the first and second cavities may fluidly communicate at an interface between the exterior of the elongated tube shape and the interior of the annular shape. In other forms, the exterior of the elongated tube shape may fluidly communicate with a ring-shaped third cavity positioned about the elongated tube shape via a radial passage, which may be configured to form a radial support. The radial support may be configured to support a flow control ring formed from the ring-shaped third cavity. 
         [0011]    The first and second predetermined materials forming an integral unitary diaphragm assembly may vary according to different forms. In some forms, the first and second predetermined materials may be co-formed. In other forms, the second predetermined material may be overmolded onto the first. In some forms, the first and second predetermined materials may be different thermoplastics. In other forms, the first and second predetermined materials may be acrylonitrile butadiene styrene (ABS) and a thermoplastic elastomer (TPE). 
         [0012]    There are many potential benefits of a one-piece unitary diaphragm assembly as described herein. A one-piece unitary diaphragm assembly may control the flow parameters of a flush valve which may flush, rinse, and refill toilets and urinals in a consistent, quiet, quick and effective manner. A diaphragm assembly may be designed as a unitary diaphragm molded from thermoplastic and thermoplastic elastomer resins. Using thermoplastic elastomer materials for a diaphragm assembly may combine the compressibility and sealing characteristics of rubber with the moldable and rigid structural characteristics of plastic, which may meet and exceed the performance required in flush valves. A unitary diaphragm assembly may be interchangeable with older multi-part diaphragm assemblies used in common valve assemblies, flush valves, and flushometer valves. The unitary diaphragm design of the disclosure may improve the consistency, reliability, and expected life of the diaphragm unit by reducing the number of parts and eliminating parts which cause undesirable wear and corrosion. The unitary diaphragm assembly may extend the life of the product by preventing both the separation of the diaphragm tab from the diaphragm rubber and the creation of rubber particles which may clog parts of the assembly, including the bypass. A unitary diaphragm may allow for reduced unit costs due to a decrease in part manufacturing costs and the elimination of assembly costs. A unitary diaphragm may allow for improved control of tolerances which may result in improved performance valve to valve, as well as reduced part scrappage. Finally, lower inventory costs may result due to a reduction in the total number of parts for a unitary diaphragm design. 
         [0013]    These and still other advantages of the invention will be apparent from the detailed description and drawings. What follows is merely a description of some preferred embodiments of the present invention. To assess the full scope of the invention the claims should be looked to as these preferred embodiments are not intended to be the only embodiments within the scope of the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  shows an example of a common flush valve assembly. 
           [0015]      FIG. 2  shows a perspective view of an example of a unitary diaphragm assembly design and a relief valve extending through the center of the diaphragm assembly. 
           [0016]      FIG. 3  shows a cross sectional view of another example unitary diaphragm assembly as it would be seen along line L-L of the assembly of  FIG. 2  with the sealing relief valve in an open position. 
           [0017]      FIG. 4  shows a cross sectional view of the unitary diaphragm assembly of  FIG. 3  with the sealing relief valve in a closed position. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIG. 1  shows an example of a flush valve and diaphragm assembly. This type of flush valve may have a hollow body  10 , generally made of brass, which may include an inlet  12 , an outlet  14 , and a handle connection  16 . A barrel  18  may be located within the flush valve such that the connection between inlet  12  and outlet  14  is through the barrel  18 . An annular main valve seat  20  may be formed on the top of the barrel  18 . The annular main valve seat  20  may be normally closed by the diaphragm  22  which may extend across the hollow body  10  and define an upper chamber  24 . The diaphragm  22  may have a bypass  26  which provides fluid communication between the inlet side of the flush valve and the upper chamber  24 . The diaphragm  22  may be attached at its outer edge to the valve body and may be clamped in place by an annular clamping rim on the outer cover  28  of body  10 . The center of the diaphragm  22  may have an opening  30  which allows for fluid communication between upper chamber  24  and the outlet  14 . A relief valve  32  may normally close the opening  30  at the center of the diaphragm  22 . 
         [0019]    In general, a normally closed flush valve may operate to seal off the upper chamber  24  from the outlet using the water pressure from the inlet  12 . The water under pressure at the inlet  12  may communicate with the upper chamber  24  of the flush valve through a bypass  26  in the flexible diaphragm. Since the upper side of the diaphragm  22  may have a greater surface area, the water pressure from the inlet  12  may force the diaphragm  22  down onto the valve seat  20  on top of the barrel  18 , thus preventing water from flowing into the outlet  14  from the upper chamber  24 . When a user actuates a handle  34  of the flush valve, a plunger  36  may move inwardly toward the axis of the barrel  18  and tilt a stem  38  of the relief valve  32 . This may break the seal the relief valve  32  has established and allow water to flow through a guide member  40  within the barrel  18  and through to the outlet  14 . The opening of the relief valve  32  may relieve the pressure within the upper chamber  24  and the water pressure from the inlet  12  may force the diaphragm  22  upward and off of the main valve seat  20 , allowing water to flow from the inlet  12  through the barrel  18  to the outlet  14 . When moving upward, the diaphragm  22  may reset the relief valve  32  located in its center such that the relief valve  32  may again seal off the upper chamber  24  from the outlet  14 . Water from the inlet  12  may then flow through the bypass  26  into the upper chamber  24  until the diaphragm  22  is again forced against main valve seat  20 , thereby closing the valve. 
         [0020]    The guide member  40  may move with the diaphragm  22  and may include outwardly extending radial wing members  42 . The radial wing members may engage the inner surface of the barrel  18  to guide the guide member  40  and attached diaphragm  22  as the diaphragm  22  moves up and down. 
         [0021]      FIG. 2  shows an example of a unitary diaphragm assembly  50  which may be designed to be utilized in flush valves of the type illustrated in  FIG. 1 , which may replace the complicated diaphragm assemblies of older devices. The unitary diaphragm assembly  50  may be molded as a single piece from a thermoplastic and a thermoplastic elastomer. The unitary diaphragm assembly  50  may include an integral diaphragm  52  which has a mounting portion  54  at the outer peripheral edge. 
         [0022]    Referring to  FIGS. 2-4 , a sealing surface  56  may be located on the underside of the integral diaphragm  52  at a position radially inward relative to integral diaphragm  52 , so as to cooperate with the main valve seat  20  of a flush valve. An integral retaining disc  58  may extend upward from the diaphragm  52  above the portion of the diaphragm  52  having the sealing surface  56 . The retaining disc  58  may include a relief valve seat  60 , which may be configured to receive a sealing relief valve  62 . The sealing relief valve  62  may include a valve stem  64  projecting downward and a sealing material  66  disposed on the underside of the sealing relief valve  62 . The sealing material  66  may form an annular lip configured to establish a seal with the relief valve seat  60 . Alternatively, the sealing material  66  may cover the entire underside of the sealing relief valve  62  rather than only an annular lip. Radial supports  68  may extend from a barrel member  70  to support a flow ring  72  and to maintain the diaphragm assembly  50  in the proper alignment as it moves up and down inside the barrel  18 . 
         [0023]    The relief valve seat  60  may be positioned on the upper end of barrel member  70 . The barrel member  70  may cooperate with the barrel  18  of a flush valve and may extend substantially coaxially along the length of the barrel  18 . The flow ring  72  may control the flow of water when the diaphragm assembly  50  is in the open position. 
         [0024]    The unitary diaphragm assembly  50  may also include a bypass orifice  74  positioned within the diaphragm  52 . The unitary diaphragm assembly  50  may operate in an analogous manner to the diaphragm assembly of  FIG. 1 . 
         [0025]    The unitary diaphragm assembly  50  may be molded as a single piece from a thermoplastic and a thermoplastic elastomer via plastic injection molding. The two materials may be co-molded according to known techniques. Alternatively, a first material may be overmolded onto a second material to construct the unitary diaphragm assembly  50 . As an example, the barrel member  70 , retaining disc  58 , radial supports  68 , and flow ring  72  may be molded from a thermoplastic, such as acrylonitrile butadiene styrene (ABS), and the integral diaphragm  52  may be overmolded or co-molded from a thermoplastic elastomer to the thermoplastic making up the barrel member  70 , integral retaining disc  58 , radial supports  68 , and flow ring  72 . In this way, the unitary diaphragm assembly  50  may be constructed as a single piece from two different materials. 
         [0026]    The unitary diaphragm assembly  50  may be constructed from more than two different thermoplastic materials by using multi-shot plastic injection molding methods, where different parts may be constructed from different materials. As an example, the barrel member  70 , radial supports  68 , and flow ring  72  may be molded from a thermoplastic, such as acrylonitrile butadiene styrene (ABS). While the retaining disc  58  and the diaphragm  52  may be overmolded or co-molded from a first thermoplastic elastomer and a second thermoplastic elastomer, respectively, to the thermoplastic of the barrel member  70 , radial supports  68 , and flow ring  72 . In this way, the unitary diaphragm assembly  50  may be constructed as a single piece from three different materials. 
         [0027]    It should be appreciated that various other modifications and variations to the preferred embodiments can be made within the spirit and scope of the invention. Therefore, the invention should not be limited to the described embodiments. To ascertain the full scope of the invention, the following claims should be referenced.