Abstract:
A heat trap assembly for a hot water tank includes a housing and a sealing member disposed in the housing. The sealing member includes a first portion that is adapted to restrict rotational movement of the sealing member in at least two perpendicular axes. The sealing member includes a second portion that is adapted to restrict rotational movement in a third axis perpendicular to both of the at least two perpendicular axes.

Description:
This application claims priority under 35 U.S.C. 119(e) from provisional application Ser. No. 60/411,912 filed Sep. 19, 2002, which is incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   This invention relates to a heat trap assembly for hot water tanks. More specifically, this invention relates to a heat trap assembly including a non-rotating sealing member that is received in the heat trap assembly. It is also appreciated that the heat trap assembly is also amenable to other applications. 
   Referring to  FIG. 1 , a hot water heater assembly  10  generally includes a tank  12  including a heating element (not shown), a cold water inlet pipe  14  and a hot water outlet pipe  16 . As the hot water is turned on, for example the hot water spigot in a household, hot water exits through the hot water outlet pipe  16  while cold water flows through the cold water inlet  14  into the tank  12 . The amount of hot water leaving the tank equals the amount of cold water replaced and heated in the tank. 
   Considerable heat is lost through the water inlet and outlet piping of a water heater. The heat loss is due primarily to thermal circulation and not as a result of conduction through the piping itself. 
     FIG. 2  displays a prior art attempt to control the heat lost through the water inlet and the water outlet piping of the water heater. A prior art cold water inlet heat trap assembly  20  includes a nipple  22 , a seat  24 , a cage  26 , and a ball  28 . The nipple  22  is received in the inlet  30  of the tank  12  and also received in the outlet  32  of the cold water inlet pipe  14 . The nipple provides the housing for the heat trap assembly  20 . The seat  24  is formed inside the nipple. The seat includes an opening having a diameter smaller than the diameter of the ball  28 . The cage  26  is a cage-like structure that traps the ball inside the nipple as water from the inlet pipe  14  flows through the nipple  22  into the tank  12 . The ball  28  has a specific gravity less than 1.0 so that when no water is flowing through the cold water inlet pipe and the nipple into the tank the ball floats up to cover the opening at the seat. 
   In use, the hot water is turned on somewhere in the household, or wherever the tank is located. Almost simultaneously, hot water exits the hot water tank  12  through the hot water outlet pipe  16  and cold water enters the tank  12  through cold water inlet pipe  14 . As cold water flows through the nipple  22 , the water dislodges the ball  28  from the seat  24  and the ball moves toward the cage  26 . The cage  26  catches the ball and retains the ball inside the nipple. The cage has openings to allow the water to flow around the ball and enter the tank  12 . When the hot water is turned off, the ball  28  floats upwardly back towards and into engagement with the seat  24  trapping heat below it. 
   A similar hot water heat trap assembly  40  is provided on the hot water outlet pipe  16 . The heat trap assembly  40  includes a nipple  42 , a seat  44 , a cage  46 , and a ball  48 . The nipple  42  is received in the inlet  50  of the hot water outlet pipe  16  and in the outlet  52  of the tank  12 . The seat  44  and the cage  46  are of the same or similar construction of the seat  24  and the cage  26  of the cold water heat trap assembly  20 . In the hot water heat trap assembly  40 , the seat  44  and the cage  46  are disposed on opposite ends of the heat trap assembly as compared to the cold water heat trap assembly  20 . The ball  48  of the hot water heat trap assembly  40  has a specific gravity greater than 1.0. Accordingly, when the hot water exits the tank  12  into the nipple  42 , the ball  48  is dislodged from the seat  44  and retained by the cage  46 . The cage has openings to allow water to pass around the ball and through the nipple. When the hot water is turned off in the household, no hot water is flowing through the nipple  42  and the hot water outlet pipe  16  so that the ball  48  sinks toward and into engagement with the seat  44  trapping heat below. 
   The problem with the above-mentioned energy saving device involves “chatter” of the balls  28  and  48  inside the nipples  22  and  42 . Because the diameter of the nipple required to allow the ball to float freely inside the nipple and the influence of water flowing through the nipple, the balls tend to rotate at a relatively high speed. The high speed rotation of the balls allows the ball to contact the nipple and “chatter” making an audible sound that is noticeable to those standing near the water heater. To some consumers, this is considered objectionable, although it does not represent a defect in the heat trap. Accordingly, it is desirable to provide a heat trap assembly that provides the same or better energy efficiency of the prior art heat traps while also eliminating the “chatter” that accompanies such heat trap assemblies. 
   SUMMARY OF THE INVENTION 
   A heat trap assembly for a hot water tank includes a housing having a fluid inlet and a fluid outlet and a sealing member disposed in the housing. The sealing member includes a tail portion and a portion that is dimensioned to at least substantially cover the inlet of the housing to prevent loss of heat through the fluid inlet when no fluid is running through the inlet and allow fluid to pass around the sealing member when fluid is flowing through the outlet. 
   According to another aspect of the invention a heat trap assembly for a hot water tank includes a cage, a seat and a sealing member. The cage includes an opening that defines a fluid outlet. The seat attaches to the cage and includes an opening that defines a fluid inlet. The sealing member includes a post. The sealing member is trapped between the opening that defines the fluid outlet and the opening that defines the fluid inlet. 
   According to yet another aspect of the invention, a heat trap assembly for a hot water tank includes a housing and a sealing member disposed in the housing. The sealing member includes a first portion that is adapted to restrict rotational movement of the sealing member in at least two perpendicular axes. The sealing member includes a second portion that is adapted to restrict rotational movement in a third axis perpendicular to both of the at least two perpendicular axes. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view of a prior art hot water heater assembly. 
       FIG. 2  is a sectional view with parts in elevation of the upper portion of the hot water heater assembly of  FIG. 1  disclosing a prior art heat trap assembly. 
       FIG. 3  is a side cross-section view of a heat trap assembly according to the present invention. 
       FIG. 4  is an end view of the heat trap assembly of  FIG. 3  taken from the left side of FIG.  3 . 
       FIG. 5  is an exploded cross section view of the heat trap assembly of FIG.  3 . 
       FIG. 6  is a side cross-section of a portion of the heat trap assembly of  FIG. 3  with water flowing through the assembly. 
       FIG. 7  is a side cross-section view of a portion of the heat trap assembly of  FIG. 3  with no water flowing through the assembly. 
       FIG. 8  is a side cross-section view of a portion of the heat trap assembly of  FIG. 3  with water flowing through the assembly. 
       FIG. 9  is a side cross-section view of a portion of the heat trap assembly of  FIG. 3  with water flowing through the assembly. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   It is to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific examples and characteristics relating to the embodiments disclosed herein are not to be considered as limiting. 
   Furthermore, for ease of illustration and comprehension the orientation of the heat trap assemblies is disclosed for a hot water heater assembly having inlet and outlet pipes located at the top to the heater. The heat trap assembly can also be used on hot water heater assemblies where the water enters at an alternative location, however the orientation and configuration of the components may need to be altered. The flow of the water through the heat trap assembly will control the location of certain components and the description that follows should not be deemed limiting as to certain hot water or cold water heat trap assemblies. 
   Referring to  FIG. 3 , a heat trap assembly  100  includes a nipple  102 , a seat  104 , a cage  106 , a sealing member  108 , and an insert  110 . The seat, cage, sealing member and insert of the heat trap assembly are made of a durable material, which in the preferred embodiment is plastic. The nipple is also made of a durable material, which in the preferred embodiment is metal. 
   The nipple  102  receives the seat, the cage, the sealing member, and the insert. In an alternative embodiment, the nipple can include at least one of the seat, the cage or the insert. In the preferred embodiment, the nipple includes threads (not shown) to attach to the pipes  14  and  16  ( FIGS. 1 and 2 ) and the tank inlet  30  and the tank outlet  52  (FIG.  2 ). The diameter of the nipple  102  is slightly larger than the diameter of the sealing member  108 . 
   Referring to  FIG. 5 , the seat  104  defines an opening  112  having a diameter smaller than the sealing member  108 . The opening  112  can define a fluid inlet for the water that will flow through the assembly. The seat also includes a beveled ledge  114  surrounding the opening. The beveled ledge allows a more secure fit for the sealing member  108  when it is seated on the seat. In a cold water heat trap assembly the seat is situated at the top of the heat trap assembly. In a hot water heat trap assembly the seat is situated at the bottom of the heat trap assembly. In the preferred embodiment, the seat  104  attaches to the cage  106 . The seat in combination with the cage can provide a housing for the sealing member  108 . The seat is shown as a separate component from the nipple  102 , the cage  106  and the insert  110 , however it is contemplated that the seat could be a unitary piece with any of the aforementioned components. 
   The cage  106  defines an opening  116  having a diameter larger than the sealing member  108 . The opening  116  can define a fluid outlet for the assembly. The cage includes trapping members or ribs  118  that interrupt the opening  116 . Each rib  118  includes a curved surface to catch the sealing member  108 . As seen in  FIG. 4 , the ribs  118  are situated 120° apart from one another giving the ribs a Y configuration in cross-section. The exact number, shape and orientation of the ribs is not critical. The cage need only retain the sealing member while water is flowing through the assembly, and also allow water to flow around the sealing member and through the opening  116 . The distance between the ribs of the cage and the ledge of the seat is limited by the length of the sealing member  108 , which will be described in greater detail below. The cage is depicted as a separate piece, however it could be of unitary construction with the nipple, the seat and/or the insert. In a cold water heat trap assembly the cage is situated at the bottom of the heat trap assembly. In a hot water heat trap assembly the cage is situated at the top of the heat trap assembly. 
   The sealing member  108  includes a spherical portion  130 , a tail portion  132 , and a post or stud  134 . The sealing member is designed so that it will rotate very little or not at all when water passes through the assembly. In a hot water heat trap assembly, the sealing member has a specific gravity greater than 1.0. In a cold water heat trap assembly the sealing member has a specific gravity less than 1.0. The spherical portion  130  of the sealing member has a diameter less than the diameter of both the nipple  102  and the cage opening  116 . The spherical portion  130  of the non-rotating sealing member has a diameter larger than the diameter of the opening  112  of the seat  104 . In lieu of having a spherical configuration, the spherical portion could take another configuration. An alternative configuration would allow the sealing member  108  to at least substantially cover the inlet or the outlet of the assembly  100  so that heat is not lost from the hot water tank into the water held in the attached piping. 
   The tail portion  132  extends from the spherical portion  130  of the sealing member  108 . The tail portion  132  is frusto-conical in configuration tapering away from the spherical portion  130 . Alternatively, the tail portion can be cylindrical, or another suitable shape. As seen in  FIGS. 6 and 9 , the length of the tail portion is such that an end  138  of the tail portion  132  of the sealing member  108  can still rest against the seat  104  when the sealing member  108  contacts the ribs  118  of the cage  106 . 
   The post  134  is positioned slightly off-center from a central axis  136  of the sealing member  108 . The post is a protruding stud disposed substantially opposite the tail portion  132 . The length of the post is such that the post will catch or engage one of the ribs  118  when water is flowing through the nipple  102  as seen in  FIGS. 4 and 9 . 
   Referring to  FIG. 3 , the insert  110  is interposed between the nipple  102  and the cage  106 . The insert  110  retains the cage in place inside the nipple with a resilient friction fit. 
   Referring to  FIGS. 6-9 , the sealing member is trapped between the opening  112  of the seat  104  and the opening  116  of the cage  106  by the beveled ledge  114  and the ribs  118 . Referring now to  FIG. 7 , with no water flowing through the assembly  10 , the sealing member  108  is seated on the seat  104 , thus trapping heat below. Referring now to  FIG. 6 , as the water enters the assembly  100  the sealing member  108  moves towards the ribs  118  of the cage  106 . As seen in  FIGS. 4 ,  8  and  9 , the ribs  118  of the cage  106  retain the sealing member as water flows through the assembly. The tail portion  132  of the sealing member does not exit the opening  112  of the seat when the sealing member contacts the ribs of the cage. 
   The sealing member  108  is restricted from rotation and inhibited from rattling against the cage  106  when water is flowing through the assembly causing an unwanted “chatter”. As seen in  FIG. 3 , the tail portion  132  of the sealing member  108  restricts rotation about the Y-axis and the Z-axis. Rotation about the Y-axis and the Z-axis maybe further restricted by the end  138  of the tail portion  132  resting against the seat  104 . Rotation about the X-axis is restricted by the post  134  engaging the rib  118  of the cage  106 . Thus, the tadpole shape of the sealing member  108  limits rotational movement of the sealing member in the Y and Z axes. The protruding post  134  of the sealing member  108  contacting the rib  118  restricts rotation about the X-axis. 
   A heat trap assembly having the desired energy efficiency is provided without having the accompanying unwanted “chatter” as found in the prior art. The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention described be construed to include all reasonable modifications and alterations that come within the scope of the appended claims.