Abstract:
A burner for a cooking range includes a burner base disposed on the range top, a burner body extending upwardly through aligned openings in the range top and the burner base to a threaded rim, a venturi having a threaded annular flange secured to the threaded rim of the burner body and a venturi tube depending from the flange through the burner body to a lower end. The burner base is sandwiched between the annular flange of the venturi and the range top and is thereby mounted to the range top by means of the venturi. A gas orifice is disposed beneath the bottom end of the venturi tube for ejecting gas upwardly into the venturi tube and a ported burner ring and burner cap rest on the burner base overlying the venturi tube. The burner is easily assembled and disassembled from the top without special tools and without raising or removing the range top. Components of the burner may be individually removed from the top of the range for maintenance or replacement. The venturi and the burner body cooperate to secure the burner base to the range top, thereby minimizing the need for additional fasteners and special tools. The burner provides a suitable gas-air mixture for efficient and clean combustion under a wide variety of circumstances without adjusting the venturi or an associated shutter.

Description:
TECHNICAL FIELD 
     This invention relates generally to gas ranges for home cooking and more particularly to upshot gas burner assemblies for gas ranges. 
     BACKGROUND 
     An upshot gas burner assembly for a gas range typically includes a base on the range top, a burner body beneath the range top in communication with a gas supply line for delivering gas to the burner, an orifice in the body for ejecting a metered amount of gas upwardly, a venturi above the orifice for receiving gas from the orifice and mixing it with air to form a gas-air mixture, a ported burner head overlying the venturi on the range top for discharging the gas-air mixture in a generally radially fingered pattern, and an igniter for igniting the gas-air mixture to produce a cooking flame. In many traditional burners, the base and the body are formed from a single piece of cast metal with a central opening, the body extending through an opening in the range top into the space below and the base resting on the range top. The gas line and orifice then connect to the base below the range top and a separate venturi mounts within the central opening. The base is secured to the range top with appropriate fasteners, such as screws. In many cases, adjustable vents or shutters or venturi position adjustments are provided for controlling the flow of air into the venturi to adjust the gas-air mixture ratios in the venturi. While such designs are functional, they nevertheless are relatively complex to assemble and even more troublesome to disassemble for cleaning and maintenance. 
     Many prior upshot burners also have included multi-piece venturi assemblies that include adjustments for regulating the gas-air mixture in the venturi. A set screw usually is provided for fixing the position of the adjustable portion of the venturi or an associated air regulation shutter when proper adjustment is obtained. The adjustability of the venturi in traditional burners is problematic because, among other things, it requires a relatively complex adjustment mechanism, is not easily removable for cleaning or maintenance, usually requires re-adjustment after removal, and is prone to being improperly adjusted, resulting in inefficient combustion in the cooking flame. 
     Accordingly, a need exists for an upshot burner for a gas range that provides for convenient removal and replacement of the venturi from the top without removing or raising the top tray of the range, convenient replacement of the gas orifice from the top without removal of the top tray, and easy and convenient cleaning of the burner base, ring, and cap. A burner that provides proper gas-air mixture within the venturi for efficient combustion under a wide range of conditions without the need for a multi-piece or adjustable venturi assembly is needed as is a burner that produces a stable flame and uniform distribution of heat over the heated area. Complete combustion, high flame controllability, quiet operation at all times, ease of ignition, and the ability to operate with a variety of gas compositions and pressures is desired. It is to the provision of a burner that meets these and other needs that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     Briefly described, the present invention, in a preferred embodiment thereof, comprises an upshot gas burner for a cooking range. The burner has a disc-shaped base that rests on the range top. The base has a central opening that aligns with a corresponding opening in the range top. A burner body has a generally cylindrical upper section that extends upwardly through the aligned openings in the range top and base to a threaded top rim. The body also is formed with a generally L-shaped hollow arm that depends from the upper section. The L-shaped arm has a threaded seat into which a gas orifice is threaded. The orifice, when threaded into the port, is centrally disposed beneath the cylindrical upper section. A gas supply line couples to the end of the arm to supply gas to the orifice, which is oriented to eject a metered flow of gas in an upward direction. 
     A single piece venturi has an elongated venturi tube with a lower end and an upper end. The upper end of the venturi is formed with a radially projecting annular flange that includes an internally threaded annular recess on its bottom side. The recess is sized to receive the threaded top rim of the cylindrical upper section of the burner body with the internal threads of the recess engaging the threads on the top rim of the body. With this arrangement, the burner may be mounted easily in the range top by moving the top section of the body upwardly through the aligned openings in the range top and base, inserting the venturi tube through the cylindrical upper section of the body, and threading the annular flange of the venturi tightly onto the top rim of the body. A burner ring and burner cap are then positioned on the base overlying the exit opening of the venturi tube to complete the assembly of the burner. To remove the venturi for cleaning, maintenance, or replacement, the burner ring and cap are removed and the venturi is simply unthreaded and removed from the base, all without removing or raising the range top itself. Further, with the venturi removed, the gas orifice is easily accessible through the top section of the body and can be removed for cleaning or replacement with a socket, again without removing or raising the range top. 
     The venturi tube of the venturi is carefully sized and configured such that, when the burner is mounted in the range top as described, the bottom end of the venturi tube is positioned at the appropriate distance above the gas orifice. This distance is predetermined to insure that the proper volume of air is drawn into the venturi tube with the gas flow, where it is mixed with the gas in the appropriate mixture for complete and efficient combustion under a variety of gas composition and line pressure conditions. 
     Thus, an upshot gas burner for a cooking range is now provided that successfully addresses the problems and shortcomings of traditional burners. The burner is easily installed in a range top and the venturi and orifice may be removed quickly and easily from the top for cleaning or replacement. Due to the careful positioning and-configuration of the single piece venturi tube, the gas-air mixture is optimized for a wide variety of conditions without the need for any venturi adjustment mechanism or movable shutters. Accordingly, the venturi tube is fixed and not subject to mis-adjustment as in the prior art. The burner produces a stable flame that is easily ignited, provides uniform heat, and operates quietly at all flame intensities. These and other features, objects, and advantages of the burner of this invention will become more apparent upon review of the detailed description set forth below, when taken in conjunction with the accompanying drawing figures, which are briefly described as follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view of a portion of a range top and a sealed upshot burner assembly embodying principles of the present invention. 
     FIG. 2 is an exploded perspective view of a range top and burner assembly according to the invention. 
     FIG. 3 is a perspective partially transparent view of the burner body illustrated in FIGS. 1 and 2. 
     FIG. 4 is a side elevational partially transparent view of the venturi illustrated in FIGS.  1  and  2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-4 illustrate in detail a preferred embodiment of the present invention that represents what is considered to be the best mode of carrying out the invention. In FIG. 1, a sealed upshot burner is indicated generally by reference numeral  100 . The burner  100  is shown installed in the top  200  of a cooking range, which generally is indicated by reference numeral  1 . The range top  200  includes a top surface  210  and a burner support  220 , which is secured beneath the top surface  210 . Gas is supplied to the burner through a gas pipe  300  from a gas supply (not shown). As illustrated in FIGS. 1 and 2, the burner  100  comprises multiple, removable components. More specifically, the burner  100  includes a burner body  101 , a removable gas orifice  120 , a removable burner base  130 , a removable venturi  140 , a removable ported burner ring  160  supported on the burner base  130 , and a removable burner cap  180  supported on the burner ring  160 . It should be understood that the term “removable” to describe certain components of the burner indicates that these components may be individually removed from the burner  100 . The construction of the burner  100  will now be described in greater detail. 
     Referring to FIGS. 1 and 3, the burner body  101  generally comprises a substantially cylindrical top section or venturi tube housing  102  formed with an annular flange  107  disposed around its lower end portion. The body  101  is further formed with a substantially L-shaped arm  108  that depends from the housing  102  with a horizontal section of the arm disposed below the venturi tube housing  102 . The venturi tube housing  102  is formed with an externally threaded, reduced-diameter upper rim  103  having external threads  103   a  and a mid-section  104  having a greater outer diameter than that of the upper rim  103 . An upper annular shelf  105  defines the junction between the threaded upper rim  103  and the mid-section  104 . A cylindrical interior passage  106  extends through the venturi tube housing  102 . The L-shaped arm  108  extends downwardly and then transversely from the annular flange  107  and includes a threaded orifice seat  109  that communicates with a gas flow passageway  110 . According to one embodiment of the invention, the burner body  101  is constructed of cast aluminum, although other suitable materials may be used. The range top  200 , which includes the top surface  210 , the support  220 , and the mount  212 , is formed with aligned openings for receiving the body  101 . The burner base  130  also has a central opening that is aligned with the openings in the range top  200 . 
     When the burner body  101  is installed in the range top  200 , as shown in FIG. 2, the venturi tube housing  102  extends through the central openings  211  and  221  of the top surface  210  and burner support  220 , respectively, and the annular flange  107  engages and is secured to the burner support  220  about its opening  221 . The annular flange  107  and burner support  220  may include screw holes  107   a  and  222 , respectively, and screws or other fasteners (not shown) may extend through the holes  107   a  and  222  to secure the burner body  101  to the burner support  220 . The L-shaped arm  108  of the burner body connects at its distal end to the gas pipe  300  such that the gas inlet  110  communicates with the gas pipe  300 . 
     A gas orifice  120 , shown best in FIG. 2, is provided to direct and meter the flow of gas into the venturi tube  140 . The orifice  120  preferably is constructed of brass, but may be constructed from another suitable material. The orifice  120  includes a central bore  121  through which gas is expelled and has external threads  122  that engage the threaded seat  109  to mount the orifice in the arm  108  underlying and spaced from the venturi tube. According to one embodiment, the orifice  120  is formed with a hexagonal top  123 , so that the orifice  120  can be gripped by a socket or wrench for mounting or removing the orifice from its seat from the top of the range. 
     As best illustrated in FIGS. 1 and 2, the burner base  130  supports the burner ring  160  and the burner cap  180  rest atop the burner ring. The burner base  130  is substantially disk-shaped and includes a central opening  131 , a top side  132 , a raised annular ledge  133  protruding from the top side  132 , and an annular bottom side  134 , including a recessed middle area  135 . The burner base  130  is formed with an igniter hole  137  for receiving an igniter  190 . According to one embodiment, the burner base  101  is constructed of aluminum, but other suitable materials may be used. 
     As shown in FIG. 1, when the burner  100  is installed in the range top  200 , a gasket  136  is fitted within the recessed middle area  135  of the burner base  130 , and the burner base rests on the burner mount  212  of the top surface  210 . The gasket provides a seal against spills and other contaminants. The burner base  130  is positioned such that the bottom side  134  of burner base  130  rests on the burner mount  212  with its central opening aligned with the openings in the range top elements. The threaded rim  103  of the burner body  101  extends upwardly through and protrudes from the central opening  131  of the burner base  130 . The igniter hole  137  in the burner base is aligned with an igniter hole  213  of the burner mount  212  and the igniter  190  is received in the igniter hole  137  of the burner base, igniter hole  213  of the burner mount, and igniter hole  223  of the burner support  220  as shown. 
     The venturi  140  will now be described with reference to FIGS. 1 and 4. The venturi  140  comprises an elongated venturi tube  141  having a bottom end portion and a top end portion and an integral annular flange  142  extending radially outwardly from the top portion of the venturi tube  141 . According to one embodiment of the invention, the venturi  140  may be constructed of brass, however other suitable materials may be used. The annular flange  142  has a top side  143  and a bottom side  144 . An internally threaded annular recess  145  is formed in the bottom side  144  of the annular flange  142 . The recess  145  has an outer annular wall  146  with interior threads  146   a.  The interior threads  146   a  are sized to engage the external threads  103   a  on the top rim of the burner body  101  to secure the venturi  140  to the burner body  101 . More specifically, the venturi  140  is threaded onto the top rim of the burner body  101  with the interior threads  146   a  of the venturi engaging the external threads  103   a  of the burner body  101 . 
     Referring to FIG. 4, a venturi throat P extends through the venturi  140  from a bottom opening O 1  to a top opening O 2 . The bottom opening O 1  is aligned with and overlies the orifice  120  when the burner is installed as shown in FIG. 1 such that an air space resides between the two. The throat P includes a lower section P 1  extending from the opening O 1  to a lower midpoint M 1  of the throat, a middle section P 2  extending upward from the lower midpoint M 1  to an upper midpoint M 2  of the throat, and an upper section P 3  extending upward from the midpoint M 2  to the top opening O 2  . The openings O 1  and O 2  each have a diameter D max , which is the maximum diameter of the throat P. The midpoints M 1  and M 2  each have a diameter D min , which is the minimum diameter of the throat P. The diameter of the lower section P 1  decreases from the bottom opening O 1  towards the lower midpoint M 1 . The diameter of the middle section P 2 is substantially constant, and corresponds to the minimum diameter D min . The diameter of the upper section P 3  increases from the upper midpoint M 2  to the top opening O 2 . 
     Referring again to FIG. 1, when the burner  20  is assembled in a range top, the venturi  140  is threaded securely onto the top rim of the burner body sandwiching and securing the base  130  onto the range top. The venturi tube  141  of the venturi  140  resides within and extends downwardly through the interior passage  106  of the burner body  101 , and the annular flange  142  of the venturi  140  is secured to the threaded top rim  103  of the burner body  101 . When the venturi  140  is fully and securely threaded on the burner body  101 , the bottom side  144  of the venturi&#39;s flange  142  engages the top side of the burner base  132 , and the upper annular shelf  105  of the burner body  101  engages the recessed middle area  135  on the bottom of the burner base. The venturi tube  140 , the burner body  101  and the burner base  130  are thus secured together such that the burner base  130  is sandwiched between the range top and the annular rim of the venturi. Accordingly, the venturi  140  and the burner body  101  cooperate to secure the burner base  130  to the top surface  210  of the range top  200  and generally to mount the entire burner assembly in the range top without the need for any other fasteners. 
     As shown in FIG. 1, when the venturi  140  is secured within the burner  100 , its throat P is coaxially aligned with the opening  121  of the orifice  120  and the bottom opening O 1  of the throat is spaced from the orifice  120  forming air gap  150 . The orifice  120  meters and directs the flow of gas from the gas inlet  110  upwardly through the air gap  150 , and this gas flow draws air into opening O 1  according to the venturi effect. The gas and air mix within the venturi throat to produce a gas-air mixture that flows upwardly through the throat P of the venturi  140 . 
     The dimensions of the air gap  150  and the venturi throat P are selected such that the burner is efficient and effective without requiring adjustment of the position of the venturi tube  140  or the air gap to adjust air flow through venturi  140 . In other words, the venturi tube  140  is secured in a fixed, non-adjustable position. According to one preferred embodiment of the invention, the air gap  150  has a length L g , extending from the orifice  120  to the venturi tube  140 , of 0.080-0.140, the lower section P 1  has a length L 1  of 0.600-0.750, the middle section P 2  has a length L 2  of 0.800-0.950, the upper section P 3  has a length L 3  of 0.600-0.750, the diameter D max  is 0.500-0.625 and the diameter D min  is 0.450-0.490. 
     The ported annular burner ring  160  will now be described with respect to FIGS. 1 and 2. The burner ring  160  is formed with a top surface  161  and an annular outer wall  163  extending at an angle downwardly from the top surface  161 . The top surface  161  is formed with a raised annular ledge  162  for supporting and centering the burner cap  180 . The outer wall  163  includes a recessed notch  164  and a plurality of flame ports  165  are formed through and arrayed about the annular wall for expelling the gas-air mixture in a radially fingered pattern, which is ignited to form the cooking flame. According to one embodiment of the invention, the burner ring  160  is constructed of brass, although other appropriate materials may be used. 
     When the burner ring  160  is properly positioned for use, it rests on top of the burner base  130  such that the recessed wall portion  164  engages the raised annular ledge  133  of the burner base  130  to position and center the burner ring. A plenum  170  is defined between the top side  132  of the burner base  130  and interior surfaces  166  of the burner ring  160 . The plenum  170  communicates with the flame ports  165 . The annular flange  142  of the venturi  140  is disposed within the plenum  170  such that the throat P communicates with the plenum  170 . The plenum  170  receives the gas-air mixture from the throat P and the gas-air mixture is expelled through the flame ports  165  of the burner ring for ignition by the igniter  190 . 
     The burner cap  180 , shown in FIGS. 1 and 3, includes a convex disc-shaped top portion  181  and a lower annular extension  182  extending from the top portion  181 . The burner cap  180  rests on top of the burner ring  160  forming the top of the plenum  170  and cooperates with the igniter  190  to generate a spark for igniting the gas-air mixture expelled from the flame ports  165 . More specifically, the lower annular extension  182  rests on the top surface  161  of the burner ring  160  and is laterally centered by the raised annular ledge  162 , which has an outer diameter that is slightly smaller than the inner diameter of the lower annular extension  182 . According to preferred embodiments of the invention, the burner cap  180  can be constructed from enameled steel or enameled cast iron, although other suitable materials may be used. 
     The method of assembling the burner  100  will now be described with reference to FIGS. 2 and 3. The burner body  101  is coupled to the gas pipe  300  as shown. The burner body  101  is secured to the range top  200  by inserting the cylindrical venturi tube housing  102  through the central openings  221  and  211  of burner support  220  and the top surface  210 , respectively, and securing the lower annular flange . 107  to the burner support  220  with screws (not shown). The gas orifice  120  is threaded into the seat  109  of the arm  108 . It should be noted that the orifice  120  can be mounted before or after the burner body is secured to the burner support  220 . As best seen in FIG. 2, the orifice  120  is accessible through the openings  221  and  211 , so that it can be installed and removed from the top of the range without removing the burner body  101  from the range top  200  or lifting the range top itself. 
     Once the burner body is positioned in the range top  200 , the burner base  130  (with the gasket  136  installed therein) is positioned on the top surface  210  such that the central opening  131  and igniter hole  137  of the burner base are aligned with the central opening  211  and igniter hole  213  of the top surface  210 , respectively. The igniter  190  is received into the igniter holes  135  and  213 . 
     When the burner base is placed on the top surface  210 , the venturi  140  is positioned in the burner body and securely threaded in place as described above. More specifically, the venturi tube  141  of the venturi  140  is inserted through the interior passage  106  of the burner body  101  and the threaded annular flange  142  of the venturi tube is threaded onto the upper rim  103  of the burner body  101 . Thus, the venturi  140  can be installed in and removed from the burner from the top without special tools and without removing or raising the range top. 
     With the venturi installed, the burner ring  160  is placed on the burner base  130  such that the recessed wall portion  164  of the burner ring  160  engages the raised annular ledge  133  of the burner base  130 . The burner cap  180  is then placed on the burner ring  160  such that lower annular extension  18 . 2  of the burner cap rests on the top surface  161  of the burner ring  160  and is laterally centered by the raised annular ledge  162 . 
     The operation of the burner  100  will now be discussed in greater detail. When the burner is turned on (i.e., gas is a allowed to flow through the gas pipe  300  to the burner  100 ), gas flows from the gas pipe  300  into the gas inlet  110  of the burner body  101 . Gas then flows from the gas inlet  110  upwardly through the orifice  120  and across the air gap  150 . As the gas flows across the air gap  150  and into the throat of the venturi, it creates a venturi effect that draws air into the venturi throat creating a gas-air mixture. The gas-air mixture mixes and flows upwardly through throat P of the venturi  140 , and eventually exits the throat and enters the plenum  170 . The gas-air mixture then flows through the flame ports  165  of the burner ring  160  and exits in a radially fingered pattern where it is ignited by a spark generated between the igniter  190  and the burner cap  160 . Thereafter, gas-air mixture continues to flow as described above to fuel the cooking flame. 
     The burner  100  is easily assembled and disassembled with minimal usage of tools and from the top of the range. The venturi  140  and burner body  101  function as fasteners that mount the burner to the range. Components of the burner can be individually removed for maintenance or replacement. Therefore, damaged or worn components can be easily replaced without requiring replacement the entire burner assembly. Furthermore, with the exception of the burner body  101 , the individual components of the assembly  100  can be replaced without uninstalling the entire burner  100 . The venturi  140  and orifice  120  can be removed from and installed in the burner  100  all from the top without requiring removal or raising of the range top. Additionally, variations of each component can be made such that the burner can be adapted to fit many different types of range tops, without requiring a redesign of the entire burner. 
     It will be understood by those skilled in the art that while the foregoing invention has a been disclosed with reference to preferred embodiments or features, various modifications, changes and additions can be made to the illustrated embodiments without departing from the spirit and scope of the invention as set forth in the claims.