US3470862A

US3470862A - Atmospheric flat-top stove

Info

Publication number: US3470862A
Application number: US679035A
Authority: US
Inventors: Richard G Darrow; William F Morse; Edward A Reid Jr
Original assignee: Columbia Gas Syst
Current assignee: Columbia Gas System Service Corp
Priority date: 1967-10-30
Filing date: 1967-10-30
Publication date: 1969-10-07
Anticipated expiration: 1986-10-07

Description

OCL 7 1969 R. G. DARRow ETAL ATMOSPHERIC FLAT-'TOP STOVE Filed 001;. 30. 1967 .OE RRSJ, mRRD NAom or mruFA. DMD MAR IA HI.. www RWE V. B

United States Patent C) U.S. Cl. 126-39 4 Claims ABSTRACT OF THE DISCLOSURE A kitchen range is disclosed having a smooth top of heat-resistant glass, beneath which'there are infrared gas burners. Heating is by infrared radiation and by conduction. The products of combustion are exhausted through an outlet at the rear of the range.

This invention relates to gas ranges or stoves of the flattop type, and more in particular to stoves which utilize infrared radiant heating. An object of this invention is to provide a thoroughly practical and efficient stove construction which avoids difficulties of the prior art and which has advantages which have not been fully attained in the past. A further object is to provide an improved stove or range construction which is adapted to heat by intense infrared radiation and also by conduction. A further object is to provide for the above with structure which is simple, sturdy, relatively inexpensive and readily cleanable, and whereby there are minimum design restrictions. A further object is to provide superior gasfired cooking ranges or stoves of the household and cornmercial types. These and other objects will be in part obvious and in part pointed out below.

In the drawing:

FIGURE 1 is a perspective view with parts broken away of one embodiment of the invention;

FIGURE 2 is a fragmentary top plan view of the embodiment of FIGURE l; and

FIGURE 3 is a sectional View on the line 3-3 of FIGURE 2.

Referring to FIGURE 1 of the drawings, a flat-top, gas-fired cooking range or stove 2 has four burner units 4, 6, 8 and 10. Each of the burner units is formed by an integral sheet metal assembly 12 (see also FIGURE 3) which is supported in a sheet metal tray-like shell 14. Shell 14 has a bottom wall 16 (see also FIGURE 2), a rear Wall 18, side walls 20 and a front structure 22. Structure 22 includes a horizontal top strip 28 and a bottom strip 27, both of sheet metal, and a vertical air inlet grill 24 formed of horizontal louvers. Strip 28 is attached at its ends to the side Walls 20, and at its rear edge there is an angle strip forming a ledge 29. The angle strip also extends along the sides of the shell Where it is attached to the tops of the side walls. At the rear of the shell there is an air outlet grill 26 which rests upon an angle strip 31 attached to wall 18 and a cross strip 33 which provides a supporting ledge and which also provides an extension of ledge 29.

Resting upon ledge 29 is a plate 30 of heat-resistant glass which has its top surface flush with the top surface of shell 14 and grill 26. Plate 30 provides a removable closure for the top of the shell, with there being the air inlet grill 24 at the front through which air may enter, and the air outlet grill 26 at the rear through which hot gases and air are exhausted. Each of the burner units 4, 6, 8 and 10 has an annular flange 35 which is in alignment with ledge 29 so that plate 30 presses tightly against the flange, and effectively closes the top of the burner unit. As will be more fully discussed below, plate 30 ice transmits infrared radiation very eiciently, and during use it is heated to a relatively high temperature. Hence, the disc portion above each burner unit provides a smooth cooking surface upon which utensils or materials may be placed to be heated by the combined action of infrared radiation heating and conduction heating.

Each of the burner units has a plenum chamber 36 at the bottom to which Ia mixture of gas and air is delivered through a tangential supply duct 38. A plurality of adjustable angle bracket assemblies 45, mounted on the bottom of shell 14, support the burner assemblies. The upper portion of the burner unit is enlarged to provide an annular ledge 39 upon which rests a Wire mesh infrared burner element 41. Burner element 41 provides a cornbustion surface throughout the top of the cylindrical plenum chamber 36. Above burner element 41 the cylindrical hot gas chamber 43 provides a heating zone from which the infrared radiation and the heat of conduction pass through the disc portion of plate 30.

Mounted in the side wall of plenum chamber 36 is a tangential supply duct 38 which has a flared open end 40` Spaced from and aligned with the open end 40 of the duct is a gas supply valve 42 which receives gas from a supply pipe 48, and which has a control knob 44 and a gas discharge nozzle 46. Knob 44 has a stern 47 extending through grill 24. Gas from the valve is discharged horizontally toward the flared open end 40 of its duct 38, thus forming venturi assembly by which the gas entrains the desired amount of fresh air for proper combustion. The turning of the knob 44 to open a valve 42 also energizes an ignitor 49 mounted in ledge 39 above the burner surface so as to ignite the burner. The burner element 41 is of a wire mesh which produces infrared radiation when the burner unit is ignited.

Extending rearwardly from each of the hot gas chambers 43 is a rectangular gas outlet duct 50 which terminates beneath grill 26 and has a top gas outlet opening 52, and an end wall 54 which deflects the gas upwardly through the grill. Hence, when a burner unit is operating, the hot gases are discharged through opening 52, and there is sufficient jet effect to cause a circulation of fresh air into the front of shell 14 through grill 24 and thence rearwardly around the burner units and upwardly through grill 26. At grill 26, t-he fresh air mixes with the hot gases so that the fresh air dilutes the hot gases and reduces the temperature of the air passing upwardly from the grill. The circulation of the fresh air through shell 14 Wipes away any leakage from the burner units, and it also prevents excessive heating of the walls of the burner units.

When a burner unit is ignited, the infrared radiation is transmitted through the disc portion 56 of plate 30, which is the portion or zone of the plate directly above the burner unit and is dened by flange 35. Disc portion 56 is also heated primarily by conduction from the hot gases in chamber 43, but there is some heating by the infrared radiation. In this embodiment this disc portion 56 of an ignited burner unit is heated to a temperature of the order of 1000 F. to 1l00 F. A utensil or other material placed upon the disc portion 56 is heated by the combined and direct action of both the infrared radiation from the burner element 41 and the heating by the disc portion 56. The heating by dise portion 56 may be primarily by direct conduction, but there is also substantial radiation from the disc portion.

As indicated above, plate 30 is a heat resistant glass, and it has a very low heat-transfer factor. Hence, while the disc portion 56 is at a very high temperature, there is negligible transfer of beat horizontally along plate 30 beyond the edge of disc portion 56, i.e., at flange 35. Therefore, plate 30 remains at substantially room temperature except for the specic disc areas or portions which are heated by the ignited burner units. It has been pointed out above that the gases which are discharged from an ignited burner produce a jet effect which causes fresh air to circulate from the front of the stove rearwardly and thence upwardly through grill 26. That circulation of fresh air assists in maintaining the room temperature condition of the portions of plate 30 which are not directly above the various burner units.

This tangential duct arrangement for delivering the airgas mixture to the plenum chamber aids in providing a satisfactory pattern of gas-air ow and distribution within the plenum chamber to insure uniform combustion and infrared radiation throughout the combustion surface of the unit. The products of co-mbustion pass horizontally from the hot gas chamber 43 of a burner at a relatively slow rate of flow. That permits the gases to heat the disc portion S6 and then to pass rearwardly, as explained above.

What is claimed is:

1. In a gas range, the combination of: a shell construction forming a horizontal air chamber within which there is substantially ambient air present and through which air may pass freely from an air inlet to an air outlet solely by convection; a gas burner unit positioned within said chamber and comprising, means forming a plenum chamber and a hot gas chamber, and a burner element closing the top of said plenum chamber and forming the bottom of said hot gas chamber and adapted to produce infrared radiation when the burner unit is ignited; a plate of heat-resistant glass which transmits infrared radiation and may transmit heat by conduction, said plate having a bottom surface which extends over the top of said hot gas chamber and contines the hot gases from flowing upwardly; means providing a hot gas discharge passageway from said hot gas chamber to said air outlet to discharge the hot gases and to induce a ow of air through said chamber from said air inlet to said air outlet thereby to provide a jet effect which induces fresh air to circulate through said chamber; and an air and gas supply 'assembly comprising a supply duct connected to deliver a stream of air and gas to said plenum chamber and means to project a stream of gas into said supply duct and to induce a flow of air therewith.

2. A gas range as described in claim 1 which includes a grill assembly along a front edge of said shell construction forming said air inlet, and a grill assembly providing said air outlet upwardly at the side of said shell assembly opposite to said front side, and wherein said means providing a hot discharge passageway projects the hot gases upwardly through said air outlet.

3. A gas range as described in claim 2 wherein said shell construction and said gas burner unit are formed of sheet metal.

4. A gas range as described in claim 2 which includes a plurality of said burner units and said means providing a gas discharge passageway and a corresponding number of said air and gas supply assemblies.

References Cited UNITED STATES PATENTS 2,743,719 5/1956 Reeves 126-299 X 2,960,980 11/1960 Williams et al. 3,241,542 3/1966 Lotter.

EDWARD G. FAVORS, Primary Examiner U.S. Cl. X.R. 126--214