Patent Publication Number: US-9403304-B2

Title: Centerset faucet body and method of making same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 13/087,586, filed Apr. 15, 2011, which claims priority from U.S. Provisional Patent Application Ser. No. 61/451,944, filed Mar. 11, 2011, the disclosures of which are hereby expressly incorporated by reference herein. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates generally to plumbing fixtures and, more particularly, to a faucet including a molded waterway assembly and to a method of making the same. 
     Faucets are generally controlled by either a single handle which utilizes a mixing valve to proportion the flow of hot water and cold water to a delivery spout, or dual handles which utilize two separate valves to independently control the flow of hot water and cold water. In a conventional dual handle faucet, the hot water and cold water valve bodies, which house the respective hot water and cold water valves, are each typically connected to an upstream waterway through a conventional mechanical connection, such as mating threads. Further, each valve body is typically connected to a separate downstream waterway. In certain examples, the valve bodies and the downstream waterways are sand cast from brass, or are machined from brass components and combined through brazing. Sand casting is typically a manual low-tech process that if not controlled properly may lead to failures through pin holes or porosity. One of the potential problems with a brazing connection is that undesirable materials, such as harmful metals, may be communicated from the brazing material into the water passageway through the brazed connection. Further, brazing is often a variable process that may lead to failures. Additionally, brazing often requires an etching operation to be performed subsequent thereto. 
     According to an illustrative embodiment of the present disclosure, a method is provided for forming a waterway for use with a centerset faucet, the faucet including a first water supply, a second water supply, a first valve, a second valve, and an outlet tube. The method comprising the steps of: molding a central body of a coupler having an outlet channel that is configured for fluid communication with the outlet tube; providing a first flexible tube including opposing proximal and distal ends, the first flexible tube configured for fluid communication with the first water supply; providing a second flexible tube including opposing proximal and distal ends, the second flexible tube configured for fluid communication with the second water supply; overmolding a first body of the coupler around the central body of the coupler and around the first flexible tube, the first body of the coupler defining at least a portion of a first valve interface for communicating with the first valve; and overmolding a second body of the coupler around the central body of the coupler and around the second flexible tube, the second body of the coupler defining at least a portion of a second valve interface for communicating with the second valve, the second valve interface being in spaced relation to the first valve interface. 
     According to another illustrative embodiment of the present disclosure, a method is provided for forming a waterway for use with a centerset faucet, the faucet including a first water supply, a second water supply, a first valve, a second valve, and an outlet tube. The method includes the steps of: molding a central body of a coupler, the central body of the coupler defining a first intermediate channel, a second intermediate channel, and an outlet channel, the first intermediate channel configured to direct fluid from the first valve to the outlet channel, the second intermediate channel configured to direct fluid from the second valve to the outlet channel, and the outlet channel configured to direct fluid to the outlet tube; providing a first flexible tube including opposing proximal and distal ends, the first flexible tube configured for fluid communication with the first water supply; providing a second flexible tube including opposing proximal and distal ends, the second flexible tube configured for fluid communication with the second water supply; overmolding a first body of the coupler around the central body of the coupler and around the first flexible tube, the first body of the coupler defining a first inlet channel configured to direct fluid from the first flexible tube to the first valve; and overmolding a second body of the coupler around the central body of the coupler and around the second flexible tube, the second body of the coupler defining a second inlet channel configured to direct fluid from the second flexible tube to the second valve. 
     According to yet another illustrative embodiment of the present disclosure, a waterway assembly is provided for use with a centerset faucet, the faucet including a hot water valve, a cold water valve, and an outlet tube. The waterway assembly includes a hot water inlet tube including opposing proximal and distal ends, a cold water inlet tube including opposing proximal and distal ends, and a coupler including a central body that defines a hot water intermediate channel, a cold water intermediate channel, and an outlet channel, the hot water intermediate channel configured to direct fluid from the hot water valve to the outlet channel, the cold water intermediate channel configured to direct fluid from the cold water valve to the outlet channel, and the outlet channel configured to direct fluid from the hot and cold water intermediate channels to the outlet tube, a hot water body overmolded onto the central body and the proximal end of the hot water inlet tube, the hot water body defining a hot water inlet channel configured to direct fluid from the hot water inlet tube to the hot water valve, and a cold water body overmolded onto the central body and the proximal end of the cold water inlet tube, the cold water body defining a cold water inlet channel configured to direct fluid from the cold water inlet tube to the cold water valve. 
     Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description of the drawings particularly refers to the accompanying figures in which: 
         FIG. 1  is a perspective view of an illustrative faucet of the present disclosure mounted to a sink deck and fluidly coupled to hot and cold water supply lines; 
         FIG. 2  is an exploded perspective view of a portion of the illustrative faucet of  FIG. 1 , the faucet including an illustrative molded waterway including a hot water body, a cold water body, a central body, and hot and cold inlet tubes; 
         FIG. 3  is a top plan view of the molded waterway of  FIG. 2 , the molded waterway shown without the hot and cold inlet tubes; 
         FIG. 4  is a bottom plan view of the molded waterway of  FIG. 3 ; 
         FIG. 5  is a cross-sectional view of the molded waterway of  FIG. 3 , taken along line  5 - 5  of  FIG. 3 ; 
         FIG. 6  is a flow chart of an illustrative method of forming the molded waterway of  FIG. 2 ; 
         FIG. 7  is a partial rear perspective view of the central body of the molded waterway during a first molding step; 
         FIG. 8  is a cross-sectional view of the central body of  FIG. 7 , taken along line  8 - 8  of  FIG. 7 ; 
         FIG. 9  is a cross-sectional view of the central body of  FIG. 8 , taken along line  9 - 9  of  FIG. 8 ; 
         FIG. 10  is a rear perspective view of the central body following the first molding step of  FIG. 7 ; 
         FIG. 11  is cross-sectional view of the central body of  FIG. 10 , taken along line  11 - 11  of  FIG. 10 ; 
         FIG. 12  is a partial rear perspective view of the central body of the molded waterway before a second molding step; 
         FIG. 13  is a partial rear perspective view of the molded waterway during a second molding step; and 
         FIG. 14  is cross-sectional view of the molded waterway of  FIG. 13 , taken along line  14 - 14  of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The embodiments of the invention described herein are not intended to be exhaustive or to limit the invention to precise forms disclosed. Rather, the embodiments selected for description have been chosen to enable one skilled in the art to practice the invention. 
     Referring initially to  FIGS. 1 and 2 , an illustrative embodiment faucet  10  is shown mounted atop sink deck  14 . The illustrative faucet  10  includes base  12  and escutcheon  13 , which may be attached to sink deck  14  with plastic shanks, threaded bolts, or other suitable fasteners (not shown). 
     Faucet  10  is fluidly coupled to hot water supply  16  and cold water supply  18  through conventional stops (not shown). Hot and cold water fluid transport components are provided in the form of inlet tubes  20  and  22 . Hot water inlet tube  20  includes proximal end  20   a  and an opposing distal end  20   b . Similarly, cold water inlet tube  22  includes proximal end  22   a  and an opposing distal end  22   b . Illustratively, inlet tubes  20  and  22  are flexible such that the distal ends  20   b  and  22   b  may be manipulated relative to the respective proximal ends  20   a  and  22   a . For example, inlet tubes  20  and  22  may be formed of a polymer, such as an olefin or a polyethylene. In one illustrative embodiment, inlet tubes  20  and  22  are formed of a polyethylene which has been cross-linked to form cross-linked polyethylene (PEX). However, it should be appreciated that other suitable materials may be substituted therefor. 
     While the illustrative inlet tubes  20  and  22  define a circular cross-section, it should be noted that the cross-sectional shape of inlet tubes  20  and  22  may vary. For example, to facilitate subsequent molding operations, the cross-section of proximal ends  20   a  and  22   a  of inlet tubes  20  and  22  may be oval-shaped or D-shaped. 
     As shown in  FIG. 1 , fluid coupling  24  is provided at distal end  20   b  of hot water inlet tube  20  for connecting with hot water supply  16 , and fluid coupling  26  is provided at distal end  22   b  of cold water inlet tube  22  for connecting with cold water supply  18 . It should be appreciated that inlet tubes  20  and  22  may be directly coupled to the respective hot and cold water stops through corresponding fluid couplings  24  and  26  or, alternatively, to intermediate hot and cold water risers (not shown). 
     The illustrative faucet  10  also includes a centrally-disposed delivery spout  40  that is supported above escutcheon  13 , as shown in  FIG. 1 . Delivery spout  40  receives outlet tube  42  for delivering a mixed water stream to a sink basin or a tub basin (not shown), for example. As shown in  FIG. 2 , faucet  10  may include sealing ring  44  to provide a seal beneath collar  46  of outlet tube  42 . Sealing ring  44  may be in the form of an elastomeric O-ring, for example. 
     Between inlet tubes  20  and  22  and outlet tube  42 , the illustrative faucet  10  further includes hot water valve  30  and cold water valve  32 . Hot water valve  30  is fluidly coupled to hot water inlet tube  20  to deliver hot water to outlet tube  42 , and cold water valve  32  is fluidly coupled to cold water inlet tube  22  to deliver cold water to outlet tube  42 . 
     Hot water valve  30  includes valve member  31  that is movable between a first “on” position where hot water from hot water inlet tube  20  is in fluid communication with outlet tube  42 , and a second “off” position where hot water from hot water inlet tube  20  is not in fluid communication with outlet tube  42 . Valve member  31  may also be movable to a plurality of intermediate positions between the first “on” position and the second “off” position to at least partially restrict the flow of hot water from hot water inlet tube  20  to outlet tube  42 . In one illustrative embodiment, valve member  31  of hot water valve  30  is a rotatable disc that may be rotatably adjusted through a hot water user input, such as handle  34 . As shown in  FIG. 1 , handle  34  generally extends above escutcheon  13  of faucet  10  and is rotatable in the direction of arrow  35 . It should be appreciated that handle  34  may be replaced with another type of user input, such as a lever. 
     Similarly, cold water valve  32  includes a valve member  33  that is movable between a first “on” position where cold water from cold water inlet tube  22  is in fluid communication with outlet tube  42 , and a second “off” position where cold water from cold water inlet tube  22  is not in fluid communication with outlet tube  42 . Valve member  33  may also be movable to a plurality of intermediate positions between the first “on” position and the second “off” position to at least partially restrict the flow of cold water from cold water inlet tube  22  to outlet tube  42 . In one illustrative embodiment, valve member  33  of cold water valve  32  is a rotatable disc that may be rotatably adjusted through a cold water user input, such as handle  36 . As shown in  FIG. 1 , handle  36  generally extends above escutcheon  13  of faucet  10  and is rotatable in the direction of arrow  37 . As with handle  34  of hot water valve  30 , handle  36  of cold water valve  32  may be replaced with another type of user input, such as a lever. 
     In one illustrative embodiment, valves  30  and  32  of faucet  10  may be of the type disclosed in International Patent Publication No. WO 2009/155529, entitled “Valve Assembly for a Two Handle Faucet.” Additional exemplary rotatable valves are disclosed in U.S. Pat. Nos. 3,645,493; 4,453,567; 4,577,835; and 4,700,928. 
     With reference to  FIGS. 2-5 , coupler  100  is provided to convey water through faucet  10 . The illustrative coupler  100  includes hot water body  102  on one side, cold water body  104  on the other side, and central body  106  extending therebetween. As shown in  FIG. 2 , hot water body  102  and cold water body  104  may be positioned at least partially rearward of central body  106  to provide adequate space for drain lift rod  15  of faucet  10  ( FIG. 1 ) behind central body  106 . 
     Referring to  FIG. 5 , hot water body  102  of coupler  100  defines hot water inlet channel  110  and cold water body  104  of coupler  100  defines cold water inlet channel  112 . Between inlet channels  110  and  112 , hot water body  102  and central body  106  of coupler  100  cooperate to define an L-shaped, intermediate hot water channel  114 , and cold water body  104  and central body  106  of coupler  100  cooperate to define an L-shaped intermediate cold water channel  116 . The L-shaped intermediate hot water channel  114  includes a vertical portion  114   a  and a horizontal portion  114   b , and the L-shaped intermediate cold water channel  116  includes a vertical portion  116   a  and a horizontal portion  116   b . In the center of coupler  100 , between intermediate channels  114  and  116 , central body  106  defines outlet channel  118 . 
     In operation, hot water from hot water inlet tube  20  (shown in phantom in  FIG. 5 ) flows upwardly through hot water inlet channel  110  of coupler  100  along arrow H 1 , and cold water from cold water inlet tube  22  (shown in phantom in  FIG. 5 ) flows upwardly through cold water inlet channel  112  of coupler  100  along arrow C 1 . Next, the hot and cold water exits coupler  100  and flows through valves  30  and  32  (shown in phantom in  FIG. 5 ) along arrows H 2  and C 2 , respectively. Then, the hot and cold water re-enters coupler  100  and flows through intermediate hot water channel  114  and intermediate cold water channel  116  of coupler  100  along arrows H 3  and C 3 , respectively. Finally, the hot and cold water combines to form a mixed water stream that flows upwardly through outlet channel  118  of coupler  100  along arrow O and into outlet tube  42  (shown in phantom in  FIG. 5 ) for delivery to a sink basin or a tub basin (not shown), for example. 
     To provide leak-resistant, fluid communication between coupler  100  and inlet tubes  20  and  22  (e.g., along arrows H 1  and C 1  of  FIG. 5 ), coupler  100  may be overmolded about inlet tubes  20  and  22 . Specifically, hot water body  102  of coupler  100  may be overmolded about proximal end  20   a  of hot water inlet tube  20 , and cold water body  104  of coupler  100  may be overmolded about proximal end  22   a  of cold water inlet tube  22 . An illustrative method for overmolding coupler  100  about inlet tubes  20  and  22  is discussed further below. 
     To provide leak-resistant, fluid communication between coupler  100  and valves  30  and  32  (e.g., along arrows H 2  and C 2  of  FIG. 5 ), coupler  100  may support and interface with valves  30  and  32 . In the illustrative embodiment of  FIG. 5 , hot water body  102  extends over central body  106  of coupler  100  to define first valve interface  120  for receiving and supporting hot water valve  30  and, on the other end of coupler  100 , cold water body  104  extends over central body  106  of coupler  100  to define second valve interface  122  for receiving and supporting cold water valve  32 . It is also within the scope of the present disclosure that hot water body  102  and central body  106  may cooperate to define first valve interface  120  and that cold water body  104  and central body  106  may cooperate to define second valve interface  122 . 
     Each valve interface  120  and  122  of the illustrative coupler  100  includes an upwardly projecting inlet wall  124  that surrounds and defines a portion of the corresponding inlet channel  110  and  112  and an upwardly projecting outlet wall  126  that surrounds and defines a portion of the corresponding intermediate channel  114  and  116 . When assembled, inlet walls  124  of each valve interface  120  and  122  direct fluid into respective inlets of valves  30  and  32 , and outlet walls  126  of each valve interface  120  and  122  receive fluid from respective outlets of valves  30  and  32 . In the illustrative embodiment of  FIG. 2 , inlet wall  124  and outlet wall  126  of each valve interface  120  and  122  are substantially D-shaped to provide adequate support for and sealing with valves  30  and  32 . Between and around each inlet wall  124  and outlet wall  126 , each valve interface  120  and  122  may include a recess or trench  128  for receiving a suitable gasket  129  ( FIG. 5 ). Also, as shown in  FIG. 2 , each valve interface  120  and  122  may include one or more peripheral locating notches  130  for receiving corresponding locating tabs  132  on valves  30  and  32 , respectively, to facilitate orientation therebetween. 
     To provide leak-resistant, fluid communication between coupler  100  and outlet tube  42  (e.g., along arrow O of  FIG. 5 ), coupler  100  may support and interface with outlet tube  42 . For example, in the illustrative embodiment of  FIG. 5 , outlet tube  42  is sized for fluid-tight receipt within outlet channel  118  of coupler  100 . This coupling may be enhanced by the presence of counterbore  140  for receiving sealing ring  44 , which is described above with respect to  FIG. 2 , between collar  46  of outlet tube  42  and coupler  100 . 
     Returning to  FIG. 2 , base  12  may define recess  60  that is sized and shaped to receive and support coupler  100  in faucet  10 . The underside of coupler  100  may include suitable locating notches  62  ( FIG. 5 ) and base  12  may include corresponding pegs (not shown) to properly locate coupler  100  within recess  60  of base  12 . Also, faucet  10  may include sealing rings  64  to provide a seal between coupler  100  and base  12 . Each sealing ring  64  may be in the form of an elastomeric O-ring, for example. Base  12  may be configured to engage threaded bonnet nuts (not shown) for tightening valves  30  and  32  onto coupler  100 . 
     Additional information regarding faucet  10  and coupler  100  may be found in International Patent Publication No. WO 2009/126887, entitled “Molded Waterway for a Two Handle Faucet,” the entire disclosure of which is expressly incorporated by reference herein. 
     As further detailed herein, and as shown in  FIG. 5 , coupler  100  is constructed of a flowable material which is molded in a two-step process to form hot water inlet channel  110 , cold water inlet channel  112 , intermediate hot water channel  114 , intermediate cold water channel  116 , and outlet channel  118 . While any suitable material may be used to form coupler  100 , a polymer, including thermoplastics and thermosets, is utilized in the illustrative embodiment. Specifically, polyethylene is utilized in the illustrative embodiment to form coupler  100 , and the polyethylene is then subsequently cross-linked. It should be noted that reinforcing members, such as glass fibers, may be provided within the polyethylene of coupler  100 . 
     The basic principles of overmolding plumbing connections on tubes are shown in U.S. Pat. Nos. 5,895,695; 6,082,780; 6,287,501; and 6,902,210. U.S. Pat. No. 7,766,043 and U.S. Application Publication No. 2007/0044852 also disclose illustrative overmolding about water inlet tubes. 
     With reference now to  FIGS. 6-14 , an illustrative method  200  is provided for forming the waterway assembly  90  of the present disclosure. In  FIGS. 7-9 and 12-14 , one side (i.e., the cold water side) of coupler  100  is illustrated, but it will be understood that similar steps may be performed to construct the opposite side (i.e., the hot water side) of coupler  100 . 
     In a first molding step  202  of the illustrative method  200 , central body  106  of coupler  100  is formed. Step  202  is performed using a suitable first mold  300  (shown in phantom in  FIG. 7 ) to define the exterior shape of central body  106  and core pins  250 ,  252 , and  254  to define the interior shape of central body  106 . As shown in  FIGS. 7 and 8 , first core pin  250  may be oriented vertically in the mold  300  and second core pin  252  may be oriented horizontally in the mold  300  (i.e., perpendicular to first core pin  250 ) to cooperatively define the L-shaped intermediate cold water channel  116  in central body  106 . More specifically, first core pin  250  may be oriented vertically in the mold  300  to define the vertical portion  116   a  of intermediate cold water channel  116  and second core pin  252  may be oriented horizontally in the mold  300  to define the horizontal portion  116   b  of intermediate cold water channel  116 . On the opposite side of coupler  100 , a similar first core pin  250  and second core pin  252  may be used to form intermediate hot water channel  114  in central body  106 . As shown in  FIGS. 7 and 8 , third core pin  254  may extend vertically in the mold  300  (i.e., parallel to first core pin  250 ) to define outlet channel  118  in central body  106 . Although referred to herein as the first, second, and third core pins  250 ,  252 , and  254 , the core pins  250 ,  252 , and  254  may be inserted into the mold  300  in any order. 
     To prevent material from leaking into intermediate channels  114  and  116  during the molding process, especially at the elbow or bend where each vertical portion  114   a  and  116   a  meets its respective horizontal portion  114   b  and  116   b , each first core pin  250  may at least partially straddle the corresponding second core pin  252 , as shown in  FIG. 9 . Such leakages could lead to obstructions or blockages within intermediate channels  114  and  116 . 
     During step  202 , a flowable material, illustratively a polymer such as polyethylene, is injected into inlet  301  of the first mold  300  and around core pins  250 ,  252 , and  254 . Then, the material is allowed to cool. Finally, central body  106  is removed from the mold  300  and core pins  250 ,  252 , and  254  are removed or withdrawn. Exterior openings  150  will be visible in each side of central body  106  in the space once occupied by second core pins  252 , as shown in  FIGS. 10 and 11 . 
     In a second molding step  204  of the illustrative method  200 , hot water body  102  and cold water body  104  of coupler  100  are overmolded around the previously formed central body  106  of coupler  100  and around inlet tubes  20  and  22 . In certain embodiments, bodies  102  and  104  of coupler  100  may be formed substantially simultaneously. In other embodiments, bodies  102  and  104  of coupler  100  may be formed in series. 
     Step  204  is performed using one or more suitable second molds  302  (shown in phantom in  FIG. 13 ) to define the exterior shape of bodies  102  and  104  and core pins  256  and  258  to define the interior shape of bodies  102  and  104 . Core pins  256  and  258  may be distinct components or, as shown in  FIG. 12-14 , core pins  256  and  258  may be interconnected. Fourth core pin  256  may be oriented vertically in the mold  302  to receive proximal end  22   a  of cold water inlet tube  22  and to define cold water inlet channel  112  in cold water body  104  of coupler  100 . On the opposite side of coupler  100 , a similar fourth core pin  256  may be used to receive proximal end  20   a  of hot water inlet tube  20  and to define hot water inlet channel  110  in hot water body  102  of coupler  100 . Fifth core pin  258  may also be oriented vertically in the mold  302  (i.e., parallel to fourth core pin  256 ) to define the remainder of the vertical portion  116   a  of intermediate cold water channel  116  that extends through cold water body  104  of coupler  100 . Also, fifth core pin  258  may at least partially fill intermediate cold water channel  116  while leaving opening  150  in central body  106  of coupler  100  exposed. On the opposite side of coupler  100 , a similar fifth core pin  258  may be used to define the remainder of the vertical portion  114   a  of intermediate hot water channel  114  that extends through hot water body  102  of coupler  100  and to at least partially fill intermediate hot water channel  114  while leaving opening  150  in central body  106  of coupler  100  exposed. Although referred to herein as the fourth and fifth core pins  256  and  258 , the core pins  256  and  258  may be inserted into the mold  302  in any order. 
     During step  204 , a flowable material, illustratively a polymer such as polyethylene, is injected into inlet  303  of each second mold  302  and around core pins  256  and  258 . Then, the material is allowed to cool. Finally, coupler  100  is removed from the molds  302  and core pins  256  and  258  are removed or withdrawn. The resulting molded waterway assembly  90  is shown in  FIGS. 2 and 5 . Because openings  150  in central body  106  of coupler  100  were exposed to the flowable material in the molds  302 , bodies  102  and  104  of coupler  100  now fill openings  150 . 
     Optionally, in step  206  of method  200 , the molded waterway assembly  90  is cross-linked. For example, if the molded waterway assembly  90  is constructed of polyethylene during the first and second molding steps  202  and  204 , the polyethylene of inlet tubes  20  and  22  and coupler  100  (which have not been cross-linked or have been only partially cross-linked) may be cross-linked during step  206  to form cross-linked polyethylene (PEX). While it is envisioned that any form of suitable cross-linking may be utilized to form the PEX of inlet tubes  20  and  22  and coupler  100 , in one illustrative embodiment the polyethylene is cross-linked by bombarding it with electromagnetic (gamma) or high energy electron (beta) radiation. 
     In the illustrative embodiment, no subsequent machining operations are required to finish coupler  100 . For example, no subsequent machining operations are required to prepare first valve interface  120  of coupler  100  to receive hot water valve  30  or to prepare second valve interface  122  of coupler  100  to receive cold water valve  32 . Also, no subsequent machining operations are required to prepare outlet channel  118  of coupler  100  to receive outlet tube  42 . 
     The illustrative method  200  involves overmolding hot water body  102  and cold water body  104  of coupler  100  around a previously formed central body  106  of coupler  100  and around inlet tubes  20  and  22 . While the precise composition of inlet tubes  20  and  22  and coupler  100  are not required to be of any specified polymer, in general, there are several guidelines which are applicable in the practice of the illustrative embodiment. It is of course, recognized that the precise operating conditions utilized in the overmolding process are well-known in the art and are specific to each molded polymer. It is well within the skill of the art to determine the applicable conditions which will result in the appropriate inlet tubes  20  and  22  and coupler  100 . Inlet tubes  20  and  22  and coupler  100  may be a thermoplastic or a thermoset. Illustratively, the polymer overmolded bodies  102  and  104  of coupler  100  should be capable of forming leak-proof bonds, either chemical or physical, with the polymer of the underlying inlet tubes  20  and  22  and with the polymer of the underlying central body  106  of coupler  100 . 
     Illustrative and non-limiting examples of the polymers which may be used in various combinations to form the underlying inlet tubes  20  and  22  and central body  106  of coupler  100 , as well as polymers which may be used in the overmolding process to form bodies  102  and  104  of coupler  100 , include: polyacetals, typically highly crystalline linear thermoplastic polymers of oxymethylene units; poly(meth)acrylics, typically belonging to two families of esters, acrylates and methacrylates; polyarylether ketones containing ether and ketone groups combined with phenyl rings in different sequences and polyether ketones; polyacrylonitrile resins wherein the principal monomer is acrylonitrile; nylons or polyamides, including various types of nylon-6, nylon-6/6, nylon-6/9, nylon-6/10, nylon-6/12, nylon-11, nylon-12; polyamide-imides formed by the condensation of trimellitic anhydride and various aromatic diamines; polyacrylates of aromatic polyesters derived from aromatic dicarboxylic acids and diphenols; polybutene resins based on poly(1-butene); polycarbonates, typically based on bisphenol A reacted with carbonyl chloride; polyalkylene terephthalates typically formed in a transesterification reaction between a diol and dimethyl terephthalate; polyetherimides, based on repeating aromatic imide and ether units; polyethylene homopolymers and copolymers, including all molecular weight and density ranges and degrees of crosslinking; polypropylene homopolymers and copolymers; ethylene acid copolymers from the copolymerization of ethylene with acrylic or methacrylic acid or their corresponding acrylate resins; ethylene-vinyl acetate copolymers from the copolymerization of ethylene and vinyl acetate; ethylene-vinyl alcohol copolymers; polyimides derived from the aromatic diamines and aromatic dianhydrides; polyphenylene oxides including polystyrene miscible blends; polyphenylene sulfides; acrylonitrile butadiene styrene terpolymers; polystyrenes; styrene-acrylonitrile copolymers; styrene-butadiene copolymers thermoplastic block copolymers; styrene maleic anhydride copolymers; polyarylsulfones; polyethersulfones; polysulfones; thermoplastic elastomers covering a hardness range of from 30 Shore A to 75 Shore D, including styrenic block copolymers, polyolefin blends (TPOS), elastomeric alloys, thermoplastic polyurethanes (TPUS), thermoplastic copolyesters, and thermoplastic polyamides; polyvinyl chlorides and chlorinated polyvinyl chlorides; polyvinylidene chlorides; allyl thermosets of allyl esters based on monobasic and dibasic acids; bismaleimides based generally on the condensation reaction of a diamine with maleic anhydride; epoxy resins containing the epoxy or oxirane group, including those epoxy resins based on bisphenol A and epichlorohydrin as well as those based on the epoxidation of multifunctional structures derived from phenols and formaldehyde or aromatic amines and aminophenols; phenolic resins; unsaturated thermoset polyesters including those of the condensation product of an unsaturated dibasic acid (typically maleic anhydride) and a glycol, wherein the degree of unsaturation is varied by including a saturated dibasic acid; thermoset polyimides; polyurethanes containing a plurality of carbamate linkages; and urea and melamine formaldehyde resins (typically formed by the controlled reaction of formaldehyde with various compounds that contain the amino group). 
     The combination of the above polymers illustratively satisfy at least two simultaneous conditions. First, the underlying inlet tubes  20  and  22  and central body  106  of coupler  100  illustratively do not soften and begin melt flow to the point where they lose structural integrity. Thus, according to the illustrative embodiment, the underlying inlet tubes  20  and  22  and central body  106  of coupler  100  are capable of maintaining structural integrity during the overmolding conditions during which the overmolded polymer is in melt flow. Second, the overmolded bodies  102  and  104  of coupler  100  are illustratively capable of forming an essentially leak-proof interface with the underlying plastic, preferably through either a chemical and/or physical bond between the overmolded plastic and the underlying plastic. 
     While using polymer compositions which have differing softening points is one way to achieve the above objectives, there are alternatives, one of which would include the use of two compositions which have the same softening point, but which are of different thickness. Through manipulation of the time, temperature, and pressure conditions experienced during the molding operation, the underlying inlet tubes  20  and  22  and central body  106  of coupler  100  would not experience melt flow, even though they had a similar softening point or range. It is also possible that, through the incorporation of various additives in the polymeric compositions (e.g., glass fibers, heat stabilizers, anti-oxidants, plasticizers, etc.), the softening temperatures of the polymers may be controlled. 
     In an illustrative embodiment of the invention, the composition of the overmolded bodies  102  and  104  of coupler  100  will be such that they will be capable of at least some melt fusion with the composition of the underlying inlet tubes  20  and  22  and central body  106  of coupler  100 , thereby maximizing the leak-proof characteristics of the interface between the underlying inlet tubes  20  and  22  and the overmolded bodies  102  and  104  of coupler  100  and the interface between the underlying central body  106  of coupler  100  and the overmolded bodies  102  and  104  of coupler  100 . There are several means by which such melt fusion may be effected. One of the simplest procedures is to ensure that at least a component of the underlying inlet tubes  20  and  22  and central body  106  of coupler  100  is the same as that of the overmolded bodies  102  and  104  of coupler  100 . Alternatively, it would be possible to ensure that at least a portion of the polymer composition of the underlying inlet tubes  20  and  22  and central body  106  of coupler  100  is sufficiently similar or compatible with that of the overmolded bodies  102  and  104  of coupler  100  so as to permit the melt fusion or blending or alloying to occur at least in interfacial regions. For example, the polymer composition of the underlying inlet tubes  20  and  22  and central body  106  of coupler  100  and the polymer composition of the overmolded bodies  102  and  104  of coupler  100  may be miscible. 
     In another illustrative embodiment of the invention, composites of rubber/thermoplastic blends are useful in adhering to thermoplastic materials used in inlet tubes  20  and  22 . These blends are typically in the form of a thermoplastic matrix containing rubber nodules functionalized and vulcanized during the mixing with the thermoplastic. Composite bodies  102  and  104  of coupler  100  may be formed by overmolding the vulcanized rubber/thermoplastic blend onto the thermoplastic inlet tubes  20  and  22 . In this manner, the cohesion at the interface between these two materials is generally higher than the tensile strength of each of the two materials. 
     Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the spirit and scope of the invention as described and defined in the following claims.