Abstract:
A bracket for use in mounting a safety switch in series with a thermocouple provides improved positioning of the switch to detect conditions causing safety concerns. The bracket includes adjustable support members for providing connection of the safety switch to a thermocouple and maintaining the position of the safety switch for improved detection. The bracket provides for mounting the safety switch connected in series to the thermocouple within a water heater for detection of overheat conditions.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to residential water heaters, and more particularly to a bracket for use in mounting a safety switch in series with a thermocouple in a water heater. 
     BACKGROUND OF THE INVENTION 
     A residential water heater, and in particular a gas-fired water heater uses a gas burner to heat water within the tank of the hot water heater. A thermostat is typically provided to control the temperature of the water inside the tank and typically may be set within a particular range (e.g., warm, hot or very hot). In order to ignite the burner, either for the first time or if the burner flame goes out, a pilot flame is used to provide that ignition. Further, gas water heaters typically include a thermocouple device to detect whether a flame is present. The heat of the flame creates a current in the thermocouple that keeps a gas valve open. When the flame goes out, the circuit is broken (i.e., no current flow through the thermocouple), causing the gas valve to close. 
     Recently gas water heaters have also incorporated safety devices, including energy cutoff switches (ECO), which detect excessive heat conditions and open the switch to provide an open circuit to thereby close the gas valve. In particular, the ECO is connected in series with the thermocouple so that it interrupts the current flow keeping the gas valve open, causing the gas valve to close, when excessive heat is detected. Thus, ECO switches for use with hot water heaters interrupt the electrical current flow from the thermocouple and cause the burner and pilot flame to extinguish during conditions of excessive heat. 
     It has been difficult to incorporate ECOs and other similar sensors into hot water heaters because of the necessity that they be connected in series with the thermocouple. This necessity makes it difficult to position the ECO in the best place to detect excessive heat conditions and therefore reduces the effectiveness and reliability of the ECO. Further, assemblies for use in attempting to connect and mount these ECOs in a good location for detecting excessive heat conditions are, very specialized (e.g., manufactured for a particular application or hot water heater), which results in added cost to manufacture such assemblies. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a bracket for mounting a thermocouple and safety device (e.g., ECO), and to a thermocouple and safety device (e.g., ECO) assembly that positions the thermocouple and the safety device while also providing connection of the safety device in series with the thermocouple. In particular, the present invention provides a bracket that supports the safety device and connects to the outer portion of a conductor of a standard thermocouple to provide grounding, while allowing the inner portion of the conductor to be connected in series with, for example, a thermally actuated safety switch, such as an ECO switch. Thus, mounting of the bracket in a particular desired location in the gas fired appliance (e.g., hot water heater) is provided. 
     Specifically, in one embodiment of the present invention a bracket for mounting a safety switch (e.g., ECO) in connection with a thermocouple of a water heater includes a first and second support member for maintaining the position of the safety switch in connection with the thermocouple, and a mounting portion for mounting the bracket to a hot water heater. The support members may be configured for adjustment for use in supporting the thermocouple thereto and/or to allow for connection of the safety device in series with the thermocouple. Further, the bracket may provide continuous electrical connection through the thermocouple when connected in series with the safety device. 
     In another embodiment of the present invention a bracket for mounting a safety switch in connection with a thermocouple includes means for connecting the safety switch to the thermocouple to provide continuous electrical connection and grounding through the thermocouple and configured to maintain the position of the safety switch. The bracket also includes means for mounting the bracket within a water heater. 
     In still another embodiment of the present invention a combined thermocouple and ECO assembly for a water heater includes a thermocouple having a conductor with internal and external leads divided into proximal and distal sections and a bracket having first and second portions engaging and electrically connecting the leads to provide electrical connection between the external leads of the proximal and distal sections. Further, the ECO includes first and second leads connected between the internal leads of the proximal and distal sections. The first and second portions may be configured for adjustable engagement. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 is an elevation view of an exemplary thermocouple; 
     FIG.  2 ( a ) is a top perspective view of a bracket constructed according to the principles of the present invention for mounting a safety device within a gas-fired appliance; 
     FIG.  2 ( b ) is an elevation view of another embodiment of a bracket of the present invention; 
     FIG. 3 is a rear elevation view of the bracket of FIG.  2 ( a ); 
     FIG. 4 is a top plan view of the bracket of FIG.  2 ( a ); 
     FIG. 5 is a cross-sectional view of the bracket of FIG. 4 taken along the line  5 — 5 ; 
     FIG. 6 is a front elevation view of the bracket of FIG.  2 ( a ); 
     FIG. 7 is a side elevation view of the bracket of FIG.  2 ( a ) showing the support members in an uncrimped position; 
     FIG. 8 is an front elevation view of the bracket of FIG.  2 ( a ) showing a safety device connected in series with a thermocouple; 
     FIG. 9 is a front perspective view of the bracket of FIG.  2 ( a ) connected to a burner unit; 
     FIG. 10 is a side perspective view of the bracket of FIG.  2 ( a ) connected to a burner unit; 
     FIG. 11 is a back plan view of the bracket of FIG.  2 ( b ) showing a safety device connected in series with a thermocouple; and 
     FIG. 12 is a top perspective view of the bracket of FIG.  2 ( b ) in connection with a burner unit. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Although the present invention is described in connection with a bracket having a particular configuration for mounting a specific safety device for a gas fired appliance, it is not so limited, and different configurations may be provided to mount different safety devices. 
     Before describing in detail a bracket of the present invention, a brief description of a thermocouple for use with a gas fired application, such as a hot water heater, will be provided. As shown in FIG. 1, a typical thermocouple  20  includes a tip  22  and an integrated conductor  24  (e.g., connection wires) to provide electrical connection to the coil operator of, for example, a hot water heater. Typically the conductor  24  includes an outer portion that provides ground and an inner portion that is connected to dissimilar materials in the tip  22  that generate an electric flow when exposed to heat. The thermocouple  20  develops a voltage when heated based upon the thermoelectric properties of the two electrically connected portions of dissimilar composition. Essentially, the heat creates an electron flow from the one material to the other in the tip  22 . Electrical current is thereby provided through the conductor  24  that is connected to the coil operator in the gas valve of the hot water heater to thereby activate the operator to provide a supply of gas (i.e., open the gas supply valve). When connected to the coil operator using threads  26 , as shown in FIG. 1, the threads  26  provide an electrical ground and a connection member  28 , which is electrically connected to the inner portion, provides current flow. 
     In operation, and for example, when igniting a hot water heater, the electrical current generated from the tip  22  of the thermocouple  20  when heated by a pilot flame creates an electromagnetic field which magnetically holds in an open position a rubber valve member to provide gas flow to the burner of the hot water heater. The pilot flame is typically initiated by manually depressing a valve and igniting the pilot flame, and holding the valve until the thermocouple  20  is heated to a certain temperature (i.e., until electrical current flows through the tip  22 ). 
     Having described an exemplary thermocouple  20  for use with a hot water heater, a bracket of the present invention will now be described that may be used for mounting a safety device, and in particular, an ECO in series with the thermocouple  20 . The ECO may be, for example, a re-settable thermal switch, part number C01-150 .25-0011 available from Thermik corporation. It should be noted that the bracket may be used for initial installation of an ECO or for retrofit applications. Specifically, and as shown in FIGS. 2 through 7, a bracket  30  of the present invention generally includes first and second support members  32  and  34  for supporting an ECO mounted in series with a thermocouple  20 , and a mounting portion  36  for mounting the bracket  30  within the hot water heater. In particular, the support members  32  and  34  are integrally formed, as part of a longitudinally extending base portion  38  for supporting the conductor  24  of the thermocouple  20 . Support members  32  and  34  are preferably configured for crimping and/or rolling to provide for support of an ECO in a gap  40 , which allows for further adjustment of the position of an attached ECO. The support members  32  and  34  essentially create a channel  42  for passage therethrough of the conductor  24  of the thermocouple  20 . 
     As shown in one embodiment in FIG.  2 ( a ), the mounting portion  36  is configured as a tab offset from the center of the bracket  30  and extending vertically and perpendicular from the base portion  38  and includes a mounting hole  44  for mounting the bracket  30  to a hot water heater, for example, to an existing standard pilot burner/thermocouple bracket  48  as shown in FIGS. 9 and 10. In another embodiment, and as shown in FIG.  2 ( b ), a bracket  30 ′ may be provided with the mounting portion  36  provided at about the center of the bracket  30 ′ and includes two mounting holes  44  for mounting the bracket  30 ′ to a hot water heater as shown in FIG.  12 . Further, and as shown in FIG.  2 ( b ), the mounting bracket  30 ′ may be provided without the longitudinally extending base portion  38  extending through the gap  40 . 
     It should be noted that the brackets  30  and  30 ′ may be mounted in any location within the hot water heater and are not limited to a particular location. Further, and as shown for example in FIG. 12, the bracket  30 ′ may be used to connect an ECO  60  in series with a thermocouple  20  without mounting the bracket  30 ′ within the hot water heater. In such as case, the thermocouple  20  supports the bracket  30 ′. The bracket  30  may also be used in this manner. The brackets  30  and  30 ′ are preferably mounted in a location to allow for detection of overheat conditions by the ECO. 
     As shown in FIG. 7, the bracket  30  may be constructed as a single stamped piece (e.g., metal stamp bracket) with the support members  32  and  34  crimped or formed to accommodate a particular size of conductor  24  for a specific thermocouple  20 . 
     In operation, and as shown more specifically in FIGS. 8 and 11, the brackets  30  and  30 ′ of the present invention provide support for mounting an ECO  60  in series with a thermocouple  20 , thereby maintaining continuous electrical connection through the thermocouple  20 . In particular, the ECO  60  is connected to an inner portion  62  of the conductor  24 , to provide electrical flow. Further, the bracket  30  provides continuous electrical grounding of the outer portion  61  of the conductor  24  using the threads  26 . It should be noted that the support members  32  and  34  may be provided with openings  50  and  52  which may be used, for example, for injecting solder to connect the outer portion  61  to the support members  32  and  34 . 
     As shown in FIGS. 9,  10  and  12 , the brackets  30  and  30 ′ allow for mounting of an ECO  60  in series with a thermocouple  20  within a hot water heater and in particular, the burner unit  70  of a hot water heater. For example, and as shown in FIG. 9, the bracket  30  may be mounted to a standard pilot burner/thermocouple bracket  48  below the burner  72  of the hot water heater. In particular, the ECO is connected (e.g., spliced) in series with the thermocouple  20  and mounted in close proximity to and below the thermocouple tip  22  and burner  72  to detect overheat conditions. Further, and as shown in FIG. 9, the ECO also may be mounted below a pilot gas flow tube  74  and a gas igniter, which may be, for example, a hot surface igniter  76 . Thus, and for example, if air flow is restricted to the burner  72  and flames begin to turn downward, and/or lint below the burner and/or vapor begins to ignite, the ECO  60  is mounted in a location to detect such overheat condition and shut off the burner  72  (i.e., shut off the burner flame). 
     Thus, the present invention provides a simpler, less costly bracket for mounting an ECO within a hot water heater in a desired location. The present invention allows for adjustment of the mounted ECO and provides for ease in retrofit installations. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention e invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.