Gas burner, gas hob and gas cooking appliance

Abstract

A gas burner for a gas hob of a gas cooking appliance. The gas burner comprises a gas crown (1) and a cap (14) configured for covering the gas crown (1), wherein the gas crown (1) comprises a central gas distribution chamber (5) confined by a circumferential wall (4) which comprises a peripheral outer surface inclined downwards to the outside, and a plurality of gas outlet ports (6) implemented in the circumferential wall (4) as upwardly opened grooves passing through the circumferential wall (4) and opening into the slanted outer surface, wherein lower outer edges of the grooves (6) are sloped towards the gas distribution chamber (5) and define a groove perimeter (12) corresponding to or larger than the outer cap perimeter (13).

Claims

1. Gas burner for a gas hob of a gas cooking appliance comprising: a gas crown and a cap configured for covering the gas crown, wherein the crown comprises a gas distribution chamber confined by a circumferential wall which comprises a peripheral, slanted outer surface inclined between 20 and 70 degrees relative to a horizontal plane, an outer circumferential edge of the slanted outer surface defining an outer perimeter of the gas burner and a plurality of gas outlet ports implemented in the circumferential wall as upwardly opened grooves passing through the circumferential wall, wherein a base of each groove has an angle ranging from 10 to 30 degrees relative to the horizontal plane and the gas outlet ports open into the slanted outer surface, the gas crown being formed as a single-piece part, wherein lower outer edges of the grooves define a groove perimeter corresponding to or being larger than an outer perimeter of the cap, and the cap comprising a first horizontal, level surface area facing the gas crown and covering the grooves at an upper end of the gas crown, respective openings of the grooves extending through an upper portion of the slanted outer surface, the gas crown including a lower portion extending from the groove base of the grooves to a bottom of the gas crown wherein a length of the upper portion measured along the slanted outer surface is less than a length of the lower portion measured along the slanted outer surface and the lower portion of the slanted outer surface implements a closed truncated cone envelope.

2. Gas burner according to claim 1, wherein the slanted outer surface in lateral cross section of the circumferential wall has a homogenous, linear shape.

3. Gas burner according to claim 1, wherein the cap comprises a second level surface area which, in the assembled state, covers the distribution chamber, wherein the first and second surface areas are stepped relative to each other, and a stepped edge between the first and second surface areas in the assembled state faces an upper, inner perimeter of the circumferential wall.

4. Gas hob comprising at least one gas burner according to claim 1.

5. Gas cooking appliance comprising a gas hob according to claim 4.

6. Gas cooking appliance according to claim 5, wherein the slanted outer surface in lateral cross sections of the circumferential wall has a homogenous, linear shape.

7. Gas burner according to claim 5, wherein the cap comprises a second level surface area which, in the assembled state, covers the distribution chamber, wherein the first and second surface area are stepped relative to each other, and a stepped edge between the first and second surface areas in the assembled state faces an upper, inner perimeter of the circumferential wall.

8. Gas burner according to claim 5, wherein the crown has the shape of a truncated cone.

Description

(1) Exemplary embodiments of the invention will now be described in connection with the annexed figures, in which

(2) FIG. 1 shows a perspective view of a first variant of a gas crown;

(3) FIG. 2 shows a side view of the gas crown of FIG. 1;

(4) FIG. 3 shows a top view of the gas crown of FIG. 1;

(5) FIG. 4 shows a cross-sectional view of the gas crown along line A-A in FIG. 3;

(6) FIG. 5 shows detail C of FIG. 4;

(7) FIG. 6 shows the detail of FIG. 5 together with a burner cap;

(8) FIG. 7 shows a perspective view of the lower side of a burner cap;

(9) FIG. 8 shows a top view of the cap;

(10) FIG. 9 shows a cross-sectional view of the cap along line B-B in FIG. 8;

(11) FIG. 10 shows a perspective view of a second variant of a gas crown;

(12) FIG. 11 shows a side view of the gas crown of FIG. 10;

(13) FIG. 12 shows a top view of the gas crown of FIG. 10;

(14) FIG. 13 shows a cross-sectional view of the gas crown of FIG. 9 along line D-D in FIG. 12;

(15) FIG. 14 shows detail E of FIG. 13;

(16) FIG. 15 shows a side view of a gas burner in the second variant;

(17) FIG. 1 shows a perspective view of a first variant of a gas crown 1 of a gas burner. The crown 1 in the present case has a truncated cone or frustoconical shaped crown body 2.

(18) The crown 1 comprises a bottom wall 3 and a circumferential wall 4. The bottom wall 3 and the circumferential wall 4 make up a single integral part, and as such essentially make up the crown body 2.

(19) The bottom wall 3 and circumferential wall 4 together define a gas distribution chamber 5. The gas distribution chamber 5 in the present case has a circular base and essentially vertical walls, and hence has a cylindrical shape. The gas distribution chamber 5 is open at the top.

(20) In the circumferential wall 4, there are provided a plurality of upwardly opened grooves 6 passing through the circumferential wall 4 and opening at an outer surface 7 of the crown 1.

(21) During operation, the crown 1 and also the gas grooves 6 are covered by a cap (see FIG. 6), such that the grooves 6 together with the cap define gas outlet ports. Gas which enters during operation via a gas inlet port 8 is distributed in the gas distribution chamber 5 to the grooves 6 and can exit the crown 1 to be burnt at the groves outlet, i.e. at the outlets or openings of the grooves or gas outlet ports.

(22) In the present case, the crown body 2 has a rotationally symmetric shape, and the grooves 6 cut the circumferential wall 4 in radial direction.

(23) It shall be noted, that the upper face of the circumferential wall 4, except for the grooves 6, is even or planar, such that an even or planar cap (see FIG. 6) may be positioned on the crown 1 in order to cover the gas distribution chamber 5 and the grooves 6.

(24) From FIG. 2, which shows a side view of the gas crown 1 of FIG. 1 a further detail of the proposed crown 1 can be seen. The detail relates to the outer surface 7, and it can be seen that the lateral outer surface 7 is inclined downwards relative to a direction radially outwards. The inclination relative to the horizontal may be between 20 and 70 degrees.

(25) Implementing the lateral outer surface 7 as a uniformly inclined, in cross sections linear declining lateral face has the advantage that heat generated at the gas outlet ports i.e. grooves 6, during operation can be efficiently reflected to the top or upwards such that the energy loss can advantageously be reduced in particular as compared to burners with different shaped lateral outer surfaces.

(26) Note that the lateral outer surface 7 is configured to implement a truncated cone envelope, in particular is free from bucklings and kinks.

(27) FIG. 3 shows a top view of the gas crown 1 of FIG. 1. From FIG. 3 it can be seen in particular that the grooves 6 pass through or groove the circumferential wall 4 in radial direction.

(28) FIG. 4 shows a cross-sectional view of the gas crown along line A-A in FIG. 3, wherein line A-A passes through a pair of grooves 6 lying on opposite sides of the circumferential wall 4.

(29) What can be deduced from FIG. 4 and by far better from FIG. 5 showing detail C of FIG. 4, is that the groove bases 9 or groove roots are inclined upwards in a direction radially outwards. Such an inclination may contribute to a more upward or vertical direction of the flames at the output port during operation, which is advantageous for the energy efficiency of the gas burner.

(30) The inclination of the groove bases 9 may lie in the range between 10 and 30 degrees, relative to the horizontal. In the present embodiment shown in FIG. 5, the inclination of the groove bases 9 is about 20 degrees.

(31) In FIG. 5, an exemplary inclination angle of the outer surface 7 is indicated, which is about 50 degrees to the horizontal in this embodiment.

(32) In FIG. 5, two further exemplary dimensions of the grooves 6 are indicated. The given dimensions relate to the radial depth of the grooves in radial direction, i.e. in a direction along the groove bases 9. As can be seen from FIG. 5, the upper outer edges 10 of the grooves 6 lie radially inside of the lower outer edges 11 of the grooves 9. Or in other words, the radial depth (5.3 mm) of the circumferential wall at the level of the upper outer edge 10 is smaller than the radial depth (6.9 mm) at the level of the lower outer edge 11 relative to the radial direction.

(33) In accordance with the present invention, the design of the grooves 6 at the outer surface 7 is such that a groove perimeter 12 defined by the lower outer edges 11 corresponds or matches a cap perimeter 13 of the cap 14 covering the crown 1 during ordinary operation.

(34) In other words, the lower outer edges 11 of the grooves 6, and thereby the flame ports or gas outlet ports of the crown 1, are drawn out to the cap perimeter 13.

(35) In doing so, the heat generated by flames at the gas outlet ports can be more efficiently delivered upwards to the cooking face where pots, pans and the like are positioned during cooking. In particular a more vertical direction of the flames can be obtained as compared to known solutions in which the flame ports are not drawn out.

(36) Drawn out flame ports in particular in combination with the inclined outer surface 7, and the inclined groove bases 9 leads to enhanced burner efficiency, in that heat energy generated by gas flames can be efficiently guided upwards to cookware placed on the gas burner.

(37) FIG. 7 shows a perspective view of the lower side of the burner cap 14; FIG. 8 shows a top view of the cap 14; and FIG. 9 shows a cross-sectional view of the cap along line B-B in FIG. 8. As can be seen from a combination of FIG. 7 to FIG. 9, the lower side of the cap 14 comprises a first even, i.e. level, surface area 15 and a second level surface area 16. Level or even in particular shall mean that respective surface areas are planar or flat.

(38) The first and second level surface areas 15, 16 are stepped relative to each other, which in the present embodiment is implemented by different cap thicknesses. The cap thickness in the region of the second level surface area 16 is thicker than the region of the first level surface area 15. The second level surface area 16 is designed such that it can cover the gas distribution chamber 5 and that a stepped edge 17 between the first and second level surface area 15 and 16 in the assembled state faces or abuts an inner perimeter of the gas distribution chamber 5, in particular circumferential wall 4. In the assembled state, the first level surface area 15 covers the grooves 6 to make up the gas outlet ports or flame ports.

(39) In the present example, the upper outer edge of the cap 14 is rounded off, which may mean that the outer perimeter of the cap 14 slightly moves inward (see for example FIG. 9).

(40) The stepped edge 17 may act as a positioning guide for the cap 14, and also provides some retaining functions preventing the cap 14 from slipping off the crown 1 during ordinary use.

(41) As the cap 14 comprises as much as possible even, i.e. level or flat, surfaces, the cap 14 can be manufactured at comparatively low costs. Note, due to the fact that the upper face of the circumferential wall 4 also is essentially flat and that the gas outlet or flame ports are implemented as radial grooves covered by the cap, the gas burner, comprising cap 14 and crown 1, can be manufactured at comparatively low costs, and, as has been discussed, has improved energy efficiency.

(42) FIG. 10 shows a perspective view of a second variant of a gas crown, which is referred to as further crown 18. The difference to the crown 1 shown in FIG. 1 is that the further crown 18 is implemented as a triple crown, with an inner first crown 19, a second middle crown 20 and an outer third crown 21.

(43) Regarding the outer third crown 21, this third crown 21 is designed and implemented essentially like the crown 1 of the first variant, shown in particular in FIG. 1. Hence, the same reference signs are used. The description relating to the grooves 6, groove bases 9, their inclination, the outer surface 7 and its inclination, as well as the design of the upper outer edges 10 and lower outer edges 11 of the grooves 6 and the like apply mutatis mutandis. A separate description is omitted and it is referred to the description related to FIG. 1 through FIG. 9.

(44) FIG. 11 shows a side view of the further gas crown 18. As can be seen, the inner first crown 19 protrudes, relative to the vertical, over the outer third crown 21. The inner first crown 19, i.e. the grooves, lateral wall and the like, does/do not implement all the features related to the invention described herein. In particular, the outer surface of the inner first crown 19 is running vertically, i.e. is not inclined. This resembles a conventional design. However, it shall be mentioned, that the inner first crown 19 may be designed and implemented in accordance to the outer third crown 21 or the crown 1 as described in connection with FIGS. 1 to 9, i.e. in accordance with the invention as proposed herein.

(45) FIG. 12 to FIG. 14 show further details of the further crown 18, which details essentially relate to the design and construction of the outer third crown 21. From FIG. 12 to FIG. 14 it can be seen, that the grooves 6 and outer surface 7 of the outer third crown 21 are implemented in accordance with the crown in FIG. 1.

(46) In particular, the lower outer edges 11 define a groove perimeter 12 (see FIG. 12), wherein this groove perimeter 12 matches with or corresponds to the cap perimeter 13, i.e. the outer cap perimeter 13. This in particular can also be seen from FIG. 15 showing a side view of a gas burner in the second variant.

(47) From FIG. 15 it can be seen that the inner first crown 19 is also covered by a cap; but the grooves are not designed and implemented such that the lower outer edges of the grooves are drawn out to the outer perimeter of the cap.

(48) From FIG. 14 exemplary groove dimensions are indicated, wherein the depth of the upper side of the grooves 6 in radial direction at the level of the upper outer edges 10 is about 7.3 mm, and a radial depth at the level of the lower outer edges 11 of the grooves 6 is about 5 mm. The inclination angles of the groove bases 9 and outer surface 7 in the present example are 20 and 40 degrees, respectively.

(49) As becomes clear, the gas burner of second variant (see FIG. 15) also provides improved energy efficiency, in particular as the outer third crown 21 is implemented in accordance with the crown as shown and described in FIGS. 1 to 9, in particular corresponding to a favourable embodiment of the invention described herein.

(50) As can be seen, the invention as proposed herein is able to provide a gas burner that has improved energy efficiency as compared to known gas burner constructions, and at the same time allows production and manufacture at comparatively low costs.

LIST OF REFERENCE NUMERALS

(51) 1 crown 2 crown body 3 bottom wall 4 circumferential wall 5 gas distribution chamber 6 grooves 7 outer surface 8 gas inlet port 9 groove base 10 upper outer edge 11 lower outer edge 12 groove perimeter 13 cap perimeter 14 cap 15 first level surface area 16 second level surface area 17 stepped edge 18 further crown 19 inner first crown 20 middle second crown 21 third outer crown