Gas burner assemblies, methods for assembling, and gas fired appliances employing same

[0001] This invention relates generally to gas fired appliances, and more specifically, to gas burner assemblies for gas fired appliances.

[0002] Gas fired appliances such as vented gas fireplace heaters have gained widespread popularity recently. Typically, a vented gas fireplace heater includes a housing having a glass front, a gas burner assembly, and a plurality of ceramic logs. The vented gas fireplace heater can be a stand-alone unit with legs, and/or be installed in an existing fireplace.

[0003] Conventionally, the gas burner assembly includes a flat stainless steel top plate connected to a cast iron bottom base with bolts. Assembly requires drilling vertically-extending holes in the cast iron bottom base which holes are then tapped to form screw threads for receiving the bolts. The stainless steel top plate requires drilling vertically-extending holes which correspond and align with the threaded holes installed in the cast iron bottom base. Thereafter, the bolts are typically manually tightened to attach the stainless steel top plate to the cast iron bottom base. Other techniques for assembling a gas burner assembly include attaching a flat ceramic top plate to the bottom base using an adhesive such as a high temperature resistant silicone adhesive.

[0004] There is a need for further gas burner assemblies and methods for assembly of gas burner assemblies for use in gas fired appliances.

[0005] In a first aspect, the present invention provides a gas burner assembly which includes a top plate having at least one port for discharging fuel and a downwardly-depending, peripheral edge having a plurality of spaced-apart slots, a bottom base having a peripheral edge disposed within the downwardly-depending, peripheral edge of the top plate, and wherein the top plate is attached to the bottom base by displacing a portion of the downwardly-depending, peripheral edge adjacent to the slots to form a plurality of spaced-apart, inwardly-extending tabs disposed under the peripheral edge of the bottom base.

[0006] In a second aspect, the present invention provides a gas burner assembly which includes a top plate having at least one port for discharging fuel and a downwardly-depending, peripheral edge having a plurality of spaced-apart slots, a bottom base having a peripheral edge disposed within the downwardly-depending, peripheral edge of the top plate, a gasket disposed between the bottom base and the top plate, a venturi tube assembly, and a tube holder for attaching the venture tube assembly to the bottom base. Additional features of the gas burner assembly may include the distance between adjacent slots being greater than a length of the slots. The top plate may be attached to the bottom base by expanding a portion of the downwardly-depending, peripheral edge under the slots to form a plurality of spaced-apart, inwardly-extending tabs disposed under the peripheral edge of the bottom base. The gasket and the bottom base are sandwiched between a bottom surface of the top plate and the tabs and operable to maintain a gas tight seal between the top plate, the bottom base, and the gasket.

[0007] In a third aspect, the present invention provides gas fired appliances which include a housing, and the above-described gas burner assemblies. At least one ceramic log may also be disposed in the gas fired appliances.

[0008] In a fourth aspect, the present invention provides a method for assembling a gas burner assembly in which the method includes positioning a bottom base having a peripheral edge within a top plate having at least one port and having a downwardly-depending, peripheral edge with spaced-apart slots adjacent to the periphery of the top plate. Portions of the downwardly-depending, peripheral edge of the top plate adjacent to the slots are displaced to form a plurality of spaced-apart tabs under the peripheral edge of the bottom base to attach the top plate to the bottom base.

[0009] In a fifth aspect, the present invention provides an attachment means which includes a first member having a downwardly-depending, peripheral edge having a plurality of spaced-apart slots, a second member having a peripheral edge disposed within the downwardly-depending, peripheral edge of the first member, and wherein the first member is attached to the second member by displacing a portion of the downwardly-depending, peripheral edge under the slots to form a plurality of spaced-apart, inwardly-extending tabs disposed under the peripheral edge of the second member, and the first member and the second member are formed from different materials having different rates of thermal expansion. The first member may be attached to the second member by expanding a portion of the downwardly-depending, peripheral edge under the slots to form a plurality of spaced-apart, inwardly-extending tabs disposed under the peripheral edge of the second member. A gasket may be disposed between the first member and the second member adjacent to the peripheral edge.

[0010] In a sixth aspect, the present invention provides a method for attaching a first member to a second member. The method includes positioning the second member having a peripheral edge within the first member having a downwardly-depending, peripheral edge with spaced-apart slots adjacent to the periphery of the first member, and expanding portions of the downwardly-depending, peripheral edge of the first member adjacent to the slots to form a plurality of spaced-apart tabs under the peripheral edge of the bottom base to attach the first member to the bottom base.

[0022] FIG. 1 illustrates one embodiment of a gas fired appliance such as a vented gas fireplace heater 10 in accordance with the present invention. Vented gas fireplace heater 10 generally includes a housing 12 having a chamber 14 therein and supported by a plurality of feet 15, a pair of doors 16 having glass panels, a gas burner assembly (not shown in FIG. 1) disposed in chamber 14, and at least one ceramic log 18 disposed in chamber 14 above the gas burner assembly.

[0023] FIG. 2 illustrates an exploded view of a gas burner assembly 20 in accordance in the present invention prior to assembly, and which after assembly, may be installed in vented gas fireplace heater 10 (FIG. 1). Gas burner assembly 20 generally includes a top plate 30, a gasket 40, a bottom base 50, a venturi tube 60, and a tube holder 70.

[0024] As explained in greater detail below, the attachment technique of the present invention incorporates the use of tabs, eliminates the use of bolts, compensates for the use of materials with different rates of thermal expansion, and allows for automated and/or uniform assembly.

[0025] Top plate 30 may include a generally planar member 32 having a plurality of ports 33 extending therethrough through which fuel such as natural gas or propane may be discharged resulting in a desired flame picture or pattern. Top plate 30 may be initially formed and cut out from a flat planar member. Thereafter, the plurality of ports 33 may be drilled or stamped therethrough, a plurality of spaced-apart slots 34 adjacent to a peripherally-extending edge 36 cut or punched therethrough, a rounded notch 38 removed, and the corners between the adjacent sides of the flat planar member notched or removed. Next, the peripherally-extending edge may be bent downwardly to form a downwardly-depending, peripheral edge 39 having the plurality of space-apart slots 34 disposed therein as shown in FIG. 2. The top plate may be formed from stainless steel and coated with a high temperature black paint.

[0026] Gasket 40 generally includes a planar member 42 having a central cutout and a peripheral edge sized and configured for being received along the bottom surface of top plate 30 adjacent to downwardly-depending, peripheral edge 39. The gasket may be formed from a fiberglass material such as 1200 MANNIGLASS insulator available from Lydall Industrial Thermal Solutions of Hartford Connecticut or formed from other suitable materials.

[0027] Bottom base 50 includes a generally flat central portion 52 having an opening 54 for receiving a flow of fuel, and a peripheral edge or raised lip 58 which is sized and configured for being received along the bottom surface of top plate 30 adjacent to downwardly-depending, peripheral edge 39 with gasket 30 disposed therebetween. The raised lip forms a chamber within the gas burner assembly for distributing the gas and air mixture to the ports. The bottom base may be may be formed from cast iron.

[0028] Venturi tube assembly 60 includes a venturi tube 62 and a cap 64 which is attached to an end of venturi tube 62 to define a first aperture 66 for receiving a flow of fuel and a pair of second apertures 68 for receiving a flow of air for mixing with the flow of fuel. Tube holder 70 is attached to bottom base 50 using screws 72 receivable within threaded apertures (not shown). The venturi tube and cap may be formed from aluminum, and the tube holder may be formed from cast iron.

[0029] FIG. 3 illustrates assembled gas burner assembly 20 prior to securing top plate 30 to the bottom base. For example, venturi tube assembly 60 may be attached to the bottom base with tube holder 70 using the screws, and thereafter, the bottom base may be nested in top plate 30 with the gasket sandwiched therebetween.

[0030] As shown in FIGS. 4 and 5, thereafter a suitable number of tabs 35 may be formed in top plate 30 to securely and sealably attach top plate 30 to bottom base 50. As best shown in FIG. 6, a portion of the downwardly-depending, peripheral edge under the slot is displaced or extended to form an inwardly-extending tab 35 disposed under peripheral edge 58 of bottom base 50 to sandwich the edge or lip 58 of bottom base 50 and the gasket between the plurality of tabs and the bottom surface of top plate 50. The slot in the edge of the top plate is desirably positioned from the distal most edge of the top plate so that the various components may be compressed and/or sandwiched while the tab is formed resulting in the gasket remaining compressed between the top plate and the bottom base. For example, desirably, the gasket is resilient and may be deformed upon assembly to form a gas tight seal between the top plate and the bottom base.

[0031] For example, the portion of the downwardly-depending, peripheral edge under the horizontally-extending slot may be deformed or expanded to form inwardly-extending tab 35. The plurality of inwardly-extending tabs 35 may include a plurality of spaced-apart, generally inwardly extending V-shaped tabs, or a plurality of spaced-apart, generally inwardly-extending trapezoidally-shaped tabs. From the present description, other configurations of the tabs, such as square, rectangular, curved, cut, other configurations, and combinations thereof, may be suitably employed. In addition, the portion of the downwardly-depending, peripheral edge under the slot may be twisted, e.g., the lowermost middle section may be forced downwardly toward the bottom base.

[0032] In addition, the distance between adjacent slots may be greater than the length of the slots, and a suitable number of tabs may be formed to provide a gas tight seal with or without a gasket.

[0033] The tabs may be manually formed. Alternatively, the tabs may be formed using a hydraulically operated device having a tool such as jaws conforming to the shape of the tab and operable to apply a constant force for uniformly forming the tabs.

[0034] As illustrated in FIG. 7, a method 80 for assembling a gas burner assembly may be represent by the steps of forming a top plate having a plurality of spaced-apart slots adjacent to the periphery of the top plate, at 82, and forming a downwardly-depending, peripheral edge with the spaced-apart slots, at 84. At 86, a bottom base having a peripheral edge is provided, and at 88, the bottom base is positioned within the downwardly-depending, peripheral edge with the slots. Thereafter, at 90, portions of the downwardly-depending, peripheral edge of the top plate are displaced or extended to form a plurality of spaced-apart tabs under the peripheral edge of the bottom base to attach the top plate to the bottom base. Desirably, the components are pressed together prior to and during the forming of the tabs.

[0035] Further, the attachment technique of the present invention may be used on applications which require the attachment of a first member to a second member. For example, the first member may have a downwardly depending, peripheral edge having horizontally- and/or vertically-extending slots which allow a portion of the downwardly depending, peripheral edge to be displaced and/or expanded under a peripheral edge of the second member. This technique is desirably suitable where the first member and the second member have different thermal properties such as thermal expansion rates. The distance between adjacent slots may be greater than the length of the slots, and a suitable number of tabs may be formed to provide a gas tight seal with or without a gasket.

[0036] FIGS. 8–13 illustrate alternative embodiments of the present invention for use in a burner assembly and/or connecting a first member to a second member. For example, FIG. 8 illustrates a downwardly-depending peripheral edge 136 having a horizontally-extending slot 134 and a vertically-extending slot 137 connected to one end of horizontally-extending slot 134. As shown in FIG. 9, a portion 135 of the downwardly-depending peripheral edge can be displaced or bent inwardly under a second member 158.

[0037] FIGS. 10 and 11 illustrates a downwardly-depending peripheral edge 236 having a horizontally-extending slot 134 and a vertically-extending slot 137 connected to the middle of horizontally-extending slot 134. As shown in FIG. 11, portions 235 of the downwardly-depending peripheral edge can be displaced or bent inwardly under a second member 258.

[0038] FIGS. 12 and 13 illustrates a downwardly-depending peripheral edge 336 having a pair of vertically-extending slots 337. As shown in FIG. 13, a portion 335 of the downwardly-depending peripheral edge can be displaced or bent inwardly under a second member 358.

[0039] From the present description, it will be appreciated by those skilled in the art that first member may have a plurality of spaced-apart individual vertically-extending slots employed to form the tabs. One or more of the vertical edges may be displaced or extended over or under the second member, e.g., by being bent on a 45-degree angle.

[0040] Furthermore, the location, size and/or configuration of the slots may vary so that when the various components are assembled, an interference type fit connection will occur along the engaging surface portion of the slot and the bottom base.

[0041] The attachment technique of the present invention utilizing tabs also allows for independent rates of expansion to occur between the top plate and the bottom base, thereby effectively eliminating thermal stresses that could result in deformation of the various materials and reduced service life of the gas burner assembly compared to conventional techniques for attaching the top plate to the bottom base of the gas burner assembly. With dissimilar materials such as dissimilar materials having different rates of thermal expansion, the attachment technique results in generally self adjusting pressure between the top plate, the gasket, and the bottom base. In addition, the present invention provides a generally fastener-less and tool-less assembly process which eliminates the need for drilling and tapping holes in the base, and drilling holes in the top plate while providing a structurally reliable assembled gas burner assembly. Thus, the gas burner assembly may be readily assembled without the use of conventional fasteners such as bolts. The technique for assembling the gas burner assembly may also be automated for a uniform assembly compared to manual hand assembly of attaching bolts.

[0042] While the gas burner assembly of the present invention has been described in connection with use in gas fired appliances such as vented gas fireplace heaters, it will be appreciated that the gas burner assemblies may also be used in barbeques, outdoor and indoor gas cooking grills, gas furnaces, gas boilers, gas fireplaces, gas fired space heating appliances, and other applications requiring a gas burner assembly.

[0043] Thus, while various embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.