Gas cooking assembly and a hob comprising the same

Abstract

A gas cooking assembly comprises: (a) a base part (10) comprising: (a1) a burner body (14) for installation in a cooktop surface (16); (a2) a gas outlet (20) in the burner body (14); and (a3) an ignition source (22) in the burner body (14); and (b) an upper part (12) comprising: (b1) at least one foot (36) for supporting the upper part (12) on the cooktop surface (16); (b2) a grate (26) for supporting a cooking vessel; (b3) an annular flame spreader (28); and (b4) a gas inlet (46) at the bottom side of the flame spreader (28); wherein the upper part (12) is an integral unit that is removable from the base part (10), wherein when the upper part (12) is connected to the base part (10), the gas inlet (46) of the upper part (12) connects to the gas outlet (20) of the base part (10).

Claims

1. A gas cooking assembly comprising: (a) a base part comprising: (a1) a burner body for installation in a cooktop surface; (a2) a gas outlet in the burner body; and (a3) an ignition source in the burner body; and (b) an upper part comprising: (b1) at least one foot for supporting the upper part on the cooktop surface; (b2) a grate for supporting a cooking vessel; (b3) an annular flame spreader; and (b4) a gas inlet at a bottom side of the flame spreader; wherein the upper part is an integral unit that is removable from the base part, wherein when the upper part is connected to the base part, the gas inlet of the upper part connects to the gas outlet of the base part, wherein the gas inlet of the upper part comprises a duct protruding downwards from the upper part and the gas outlet of the base part protrudes upwards from the base part so that an upper edge of the gas outlet is located above the cooktop surface, and wherein said gas inlet duct and said gas outlet are slidingly engageable so as to establish fluid communication therebetween when so engaged.

2. The gas cooking assembly of claim 1, wherein the grate comprises an annular disk which interposes the flame spreader and which carries a plurality of bars for supporting a cooking vessel.

3. The gas cooking assembly of claim 2, wherein a plurality of legs are attached to the annular disk, each said leg having a foot for supporting the upper part on the cooktop surface.

4. The gas cooking assembly of claim 3, wherein the bars extend outwardly beyond the annular disk and merge into the legs.

5. The gas cooking assembly of claim 3, wherein the legs are sized to provide for a distance between the flame spreader and the cooktop surface.

6. The gas cooking assembly of claim 1, wherein the flame spreader has a generally U-shaped cross-sectional shape having inner and outer annular walls with a plurality of recesses along an upper edge of the inner and/or outer wall.

7. The gas cooking assembly of claim 6, wherein the flame spreader directly abuts against a bottom side of the grate.

8. The gas cooking assembly of claim 6, further comprising a cap ring interposed between the flame spreader and the grate, wherein the cap ring rests on the upper edge of the inner and outer walls of the flame spreader.

9. The gas cooking assembly of claim 1, wherein the flame spreader is attached to the grate by a plurality of clamps or bolts.

10. The gas cooking assembly of claim 9, wherein the flame spreader comprises a plurality of lugs extending outside of the annular shape of the flame spreader and which are located below bars of the grate, wherein bolts extend through the lugs into the bars.

11. The gas cooking assembly of claim 1, wherein the duct and the gas outlet are shaped to allow insertion of the duct into the gas outlet only at a predetermined orientation of the upper part with respect to the base part.

12. The gas cooking assembly of claim 11, wherein the duct and the gas outlet have a cross-sectional shape which has a single axis of symmetry, so as to allow insertion of the duct into the gas outlet only at two predetermined orientations of the upper part with respect to the base part.

13. The gas cooking assembly of claim 1, wherein the base part further comprises an adjustable Venturi assembly for control of a gas-air mixture that is passed to the gas outlet.

14. The gas cooking assembly of claim 1, wherein the base part further comprises a thermocouple for providing a flame signal indicating that a burner flame is ignited, and a safety valve for shutting off a gas supply if the thermocouple no longer provides the flame signal.

15. A hob comprising at least two gas burners, at least one of which is the gas cooking assembly as defined in claim 1, the base part of which is positioned at a distance to at least one further gas burner, so that the upper part can be selectively positioned either at close proximity or at a larger distance to the at least one further gas burner.

16. A burner assembly comprising: a base part adapted to be mounted at or adjacent to a cooktop surface and having a vertical duct extending upward, a thermocouple and an ignition source, the vertical duct having a substantially symmetrical cross-section and being in communication with a gas source; and an upper part comprising a grate, a flame spreader and a cap ring all fixedly connected together as a single assembled element, the flame spreader comprising inner and outer annular walls spaced apart from one another and defining an annular distribution chamber therebetween, at least one of the inner and outer annular walls having a plurality of flame ports therein, a gas inlet duct extending downward from an underside of said flame spreader and being in fluid communication with said annular distribution chamber, the grate comprising a plurality of bars adapted to support a cooking utensil placed thereon, said cap ring being interposed between the grate bars and the flame spreader such that an underside surface of said cap ring rests on upper edges of the first and second annular walls so as to define an upper wall of said annular distribution chamber, a plurality of legs being attached to or formed with said grate bars and extending downward therefrom and adapted to support the upper part on said cooktop surface; said gas inlet duct having a shape and a cross-section that are complementary to said vertical duct such when said gas inlet duct and said vertical duct are registered and said legs of said upper part are resting on said cooktop surface, said gas inlet duct and said vertical duct are slidingly engaged so as to establish fluid communication between said gas source and said distribution chamber; said upper part being reversibly positioned on said cooktop as said single assembled element so as to establish said fluid communication between said gas source and said gas distribution chamber.

17. The burner assembly according to claim 16, said upper part being positionable in opposing positions relative to said vertical duct corresponding to respective orientations of said upper part that are 180° rotationally offset with one another, said gas inlet duct and said vertical duct being registered and slidingly engaged in both said opposing positions to establish said fluid communication between said gas source and said gas distribution chamber, said upper part being thereby adapted to selectively and reversibly define either: a common cooking zone together with another adjacent burner assembly on the cooktop, or two distinct cooking zones, one each for the burner assembly and said adjacent burner assembly on the cooktop.

18. The burner assembly according to claim 17, said gas inlet duct and said vertical duct being registrable in only said opposing positions of said upper part relative to said vertical duct on account of their shape and cross-sectional symmetry, said cap ring and said grate being supplied as separate components that are connected together.

Description

(1) The present invention is described in further detail below by reference to the drawings in which:

(2) FIG. 1 is a perspective view of a gas cooking assembly in accordance with the present invention;

(3) FIG. 2 is a side view illustrating the gas cooking assembly shown in FIG. 1;

(4) FIG. 3 is a perspective view illustrating the upper part of the gas cooking assembly shown in FIGS. 1 and 2;

(5) FIG. 4 is a perspective view illustrating an alternative embodiment of the upper part of the gas cooking assembly shown in FIGS. 1 and 2;

(6) FIG. 5 shows the gas connection between the upper part and the base part;

(7) FIGS. 6A and 6B show the gas connection between the upper part and the base part when viewed from above in different positions of the upper part;

(8) FIG. 7 illustrates rotation of the gas cooking assembly in accordance with the present invention;

(9) FIGS. 8A and 8B illustrate a hob or a portion thereof, with two gas cooking assemblies in different operating positions;

(10) FIGS. 9A and 9B illustrate a hob or a portion thereof, with three gas cooking assemblies in different operating positions; and

(11) FIGS. 10A and 10B illustrate a further embodiment hob or a portion thereof, with three gas cooking assemblies in different operating positions.

(12) FIG. 1 illustrates in perspective view a gas cooking assembly in accordance with the present invention. The gas cooking assembly comprises a base part 10 and an upper part 12. The base part 10 which may be part of a hob comprises a burner body 14 which is installed from the bottom side of a cooktop surface 16, which may be for example a glass ceramic plate. In its base portion that is located below cooktop surface 16, the burner body comprises means for controlling gas flow, such as a an adjustable Venturi assembly 18 that is configured to control the air flow to the burner, so as to control the amount of air feed in order to control the mixing ratio of fuel gas and air. As schematically illustrated in FIG. 2, the adjustable Venturi assembly 18 preferably is oriented horizontally in the burner body 14, so as to control the flow of gas that is fed to the adjustable Venturi assembly 18 via a gas line 52 to a vertical duct 54 which feeds a gas outlet 20 that is provided in an upper portion of the burner body 14. As can be seen in FIGS. 1 to 4, in addition to the gas outlet 20, the base part 10 comprises an ignition source 22, such as a piezoelectric spark plug, and a thermocouple 24 for sensing temperature, which elements all are mounted so as to project upwardly beyond the level of the cooktop surface 16.

(13) Upper part 12 comprises a grate 26 for supporting a cooking vessel and an annular flame spreader 28 which is mounted at the bottom side of an annular cap element 30 that is integrally connected with the grate 26. In the embodiment shown in the drawings, grate 26 comprises four bars 32 which are arranged in a cross-like fashion and which extend outwardly beyond the cap element 30 so as to provide for a stable support for a cooking vessel. At their outer ends, bars 32 merge into downwardly extending legs 34 each of which terminates in a foot 36 having a flat horizontal bottom surface with which the foot rests in the cooktop surface 16.

(14) The cap ring 30 and the grate 26 can be formed as an integral part, and thus for example can be formed as a cast iron part which is provided with an enamel coating. Flame spreader 28 can be made of the same or a different material than the grate. In the embodiments shown herein, flame spreader 28 is a U-shaped aluminum ring which as can be best seen in FIGS. 3 and 4 has a plurality of recesses 38 along the inner and outer walls 40, 42. The space between inner wall 40 and outer wall 42 forms a gas distribution chamber 44, via which a fuel gas-air mixture is passed from a gas inlet 46 to the plurality of recesses 38.

(15) While in the embodiment shown in FIG. 3, the flame spreader 28 directly abuts with the upper faces of the inner and outer walls 40, 42 against the bottom side of cap ring 30 of the grate 12, in the embodiment shown in FIG. 4 a separate cap ring 48 is interposed between the flame spreader 28 and the grate 12. The cap ring 48 rests on the upper edges of the inner and outer walls 40, 42 of the flame spreader 28 and thus forms a top wall for the gas distribution chamber 44.

(16) As further can be best seen in FIGS. 3 and 4, the flame spreader 28 and the grate 12 are fixedly connected to each other by means of a plurality of bolts 50 which extend through the flame spreader 28 into threads that are formed in bars 32 of the grate 12. Of course the flame spreader 28, the grate 12 and optionally the separate cap ring 48 also can be fixed to each by other releasable or permanent fixing means, such as by clamps, by form-fit or by welding or brazing. In case that bolts are used for providing for the connection, the flame spreader can be provided with lugs that extend outside of the annular shape of the flame spreader 28 and which are located below the bars 32 of the grate 12, so that the bolts do not obstruct the gas flow within the gas distribution chamber 44.

(17) FIG. 5 illustrates in detail the gas connection between base part 10 and upper part 12. Flame spreader 28 of upper part 12 has a gas inlet duct 46 protruding downwards from the flame spreader 28. With gas inlet duct 46 having an oblong cross-sectional shape, burner body 14 of the base part 10 comprises a receptacle 56 of corresponding oblong inner cross-sectional shape for insertion of the gas inlet duct 46. As shown in FIGS. 6A and 6B the gas inlet duct 46 and the receptacle 56 which comprises the gas outlet 20 of the base part 10 have an oblong shape, the longer side of which has a curvature that corresponds to the shape of the inner wall 40. In order to allow rotation of the upper part 12 by 180°, so that the upper part 12 can be rotated from the position shown in FIG. 6A by 180° so as to assume the orientation shown in FIG. 6B, the gas inlet duct 46 and the receptacle 56 with the gas outlet 20 also along the outer wall 42 has a curvature that corresponds to the shape of the inner wall 40, so that the duct has a shape that is symmetric both about an axis that extends along the longitudinal direction of the duct as well as about an axis that extends along the short direction of the duct. For use in a standard domestic cooking hob, the gas inlet duct typically will have a length of about 20 to 28 mm and a width of 3 to 9 mm, which provides for an open cross-sectional area that is well sufficient for implementing gas throughput rates as they are typical for gas burners of cooking hobs.

(18) While ignition source 22 and thermocouple 24 can be integrated into burner body 14, FIG. 5 shows an embodiment, in which to facilitate installation of ignition source 22 and thermocouple 24, burner body 14 is provided with clamps 58 that are located on both sides of receptacle 56.

(19) As will be readily understood from the above, the present invention provides for an easy to use burner assembly in which the flame spreader is joined with the grate to form an integral unit which can be completely removed from the cooking top, while the spark plug and the thermocouple remain installed in the cooktop, as is also illustrated in FIGS. 6A and 6B.

(20) When setting upper part 12 onto base part 10, gas inlet duct 46 and receptacle 56 serve as locator elements which assist the user in locating the correct position for installation of the burner assembly upper part 12. That is, with gas inlet duct 46 and receptacle 56 in the installed position of the upper part 12 at the base part 10 overlapping for a certain distance, when installing the burner upper part 12, it is held above the base at the position where the gas inlet duct 46 overlaps the receptacle 56, which position can be easily found since both these parts protrude towards each other, and then the upper part 12 is lowered so as to insert gas inlet duct 46 into the receptacle 56. Due to the symmetric cross-sectional shape of gas inlet duct 46 and receptacle 56, the upper part 12 can be selectively set onto the base part 10 in one of two positions, as it is illustrated in FIG. 7. When used in combination with at least one further gas burner, the burner assembly thus allows varying the size and shape of the cooking zones provided by these burners.

(21) FIGS. 8A and 8B illustrate an example of employing a gas cooking assembly as it suggested herein as a rotatable burner 60 in combination with a further burner assembly 62, which either may be a fixed burner or also a rotatable burner. In the situation shown in FIG. 8A the upper part 12 of burner assembly 62 is positioned such that it is positioned on its base part in the position shown in FIG. 7 as “burner right position”, in which the gas inlet 64 is located on a line that extends through the centers of rotatable burner 60 and of the further burner assembly 62, wherein the gas inlet 64 is located to the left of the center of rotatable burner 60. In this position rotatable burner 60 and the further burner assembly 62 are located at a distance to each other so as to constitute two separate cooking zones which in FIG. 8A are marked by circles 66 and 68.

(22) By removing upper part 12 of rotatable burner 60, turning it by 180° and again placing it onto the gas outlet so that the gas inlet 64 is located to the right of the center of rotatable burner 60, the grates of rotatable burner 60 of further burner assembly 62 are located adjacent to each other, so that these burners form a combined cooking zone 70 for heating larger lengthy cooking vessels.

(23) Similarly, in a hob having at least three gas burners, as is illustrated in FIGS. 9A and 9B, the three gas burners can be selectively combined into one large lengthy cooking zone (see FIG. 9A), or, by turning the middle burner assembly 72 by 180° about its gas inlet 74, the three burner assemblies can be separated from each other so as to constitute three independent cooking zones or one large triangular cooking for heating a large cooking vessels that is set on all three burners (see FIG. 9B).

(24) When further also the left burner assembly 76 and the right burner assembly 78 are configured as rotatable burner assemblies, wherein the gas inlet 80 of the left burner assembly 76 and the gas inlet 82 of the right burner assembly 78 are located in the position shown in FIG. 10A on a line that extends through the centers of left burner assembly 76 and of right burner assembly 78, wherein in the situation shown in FIG. 10A the gas inlet 80 of the left burner assembly 76 is located to the right of the center of left burner assembly 76 and the gas inlet 82 of the right burner assembly 78 is located to the left of the center of right burner assembly 78, by turning left burner assembly 76 by 180° about gas inlet 80 and turning right burner assembly 78 by 180° about gas inlet 82, the three burner assemblies 72, 76 and 78 can be combined into a triangular cooking zone for the heating of larger circular vessels in which the three burner assemblies 72, 76 and 78 are located close to each other as it is illustrated in FIG. 10B.

(25) As will be readily understood, there are various further options of providing for flexible cooking zones by combining one or more of the rotatable burner assemblies suggested herein one or more further burner assemblies, which either also can be rotatable burner assemblies or the location of which is fixed with respect to the cooktop surface.

LIST OF REFERENCE SIGNS

(26) 10 base part 12 upper part 14 burner body 16 cooktop surface 18 adjustable Venturi assembly 20 gas outlet 22 ignition source 24 thermocouple 26 grate 28 flame spreader 30 cap element 32 bar 34 leg 36 foot 38 recess 40 inner wall 42 outer wall 44 gas distribution chamber 46 gas inlet 48 cap ring 50 bolt 52 gas line 54 vertical duct 56 receptacle 58 holder 60 rotatable burner 62 additional burner 64 gas inlet of 60 66 left cooking zone 68 right cooking zone 70 combined cooking zone 72 middle burner assembly 74 gas inlet of 72 76 left burner assembly 78 right burner assembly 80 gas inlet of 76 82 gas inlet of 78