"GAS BURNER" * * * * *
FIELD OF THE INVENTION
The present invention concerns a gas burner for a cooker or an inbuilt cooking surface or hob, wherein the central body supporting the gas injector is able to be attached from outside simply and practically. To be more exact, the central body comprises a plurality of positioning elements, each of which is able to accommodate a clamping screw and to be arranged below an outer wall of a supporting frame. Each screw is screwed from outside so as to clamp the corresponding positioning elements onto the outer wall and thus attach the central body in stable manner. In the case of cooking surfaces, the positioning elements are arranged between the outer wall and the inner wall of the supporting frame and the clamping screws are screwed onto the inner wall .
BACKGROUND OF THE INVENTION
A gas burner is known for a cooking surface or hob, which comprises a supporting central body, or injector-bearing cup, which comprises a vertical sleeve connected to a gas feed pipe. Above the in ector-bearing cup a flame-dividing head is able to be removably located. The injector-bearing cup is attached with a series of screws on a lower inner wall of the cooking surface, and with a second series of screws on an upper outer' wall of the cooking surface.
This known burner has the disadvantage that it is difficult to assemble, because the two series of screws, in order to be tightened, require access both from above and also from below the cooking surface.
To be more exact, the screws which attach the injector- bearing cup to the inner wall are difficult to reach from the outside. In fact, these screws have to be tightened, for
example in the event that they accidentally come loose, or when the injector-bearing cup has to be dismantled for maintenance or replacement. This means that the whole outer wall also has to be removed, which is a great drawback. Applicant has devised and embodied the present invention to overcome this shortcoming of the state of the art and to obtain further advantages .
SUMMARY OF THE INVENTION The present invention is set forth and characterized essentially in the main claim, while the dependent claims describe other innovative characteristics of the invention.
The purpose of the invention is to achieve a gas burner which can be installed both in a cooker and also in an inbuilt cooking surface or hob, which has great stability and safety and which at the same time is easy and simple both to assemble and to dismantle.
In accordance with this purpose, a burner according to the invention comprises a central body provided with a gas injector and a flame-dividing head, able to be removably assembled on the central body, which is able to be assembled and attached by clamping means on a supporting frame which comprises at least an outer wall and also, in the case of cooking surfaces, an inner wall. The central body comprises a plurality of positioning means able to house the clamping means and to be positioned below the outer wall and, in the case of cooking surfaces, between the inner wall and the outer wall. The clamping means comprise screwable elements which can be screwed from above, each of which is able to cooperate with the outer wall and, in the case of cooking surfaces, with the inner wall too, to clamp the positioning means to the supporting frame.
The screwable means comprise screws, for example of the self-threading type. The threaded stem of each screw is
inserted, and easily dis-inserted, from outside, through a corresponding through hole made in the outer wall. Moreover, each screw is screwed onto the positioning means in the case of cookers, whereas in the case of a cooking surface it is screwed into the inner wall of the supporting frame.
In a preferential embodiment, the positioning means comprise bushing elements, of a substantially cylindrical shape, hollow inside, which are arranged in a substantially vertical position and act as a guide in order to insert the screwable elements.
In the case of cooking surfaces, below each bushing element a corresponding spacer element is arranged coaxial, substantially tubular in shape, which is able to guide the insertion of the screwable elements between the outer wall and the inner wall of the cooking surfaces.
Advantageously, the bushing element and the relative spacer element are made in different pieces, easily able to be coupled together .
According to a variant, the bushing element and the relative spacer element are made in a single piece.
The central body advantageously comprises at least three positioning elements arranged radially and equidistant from each other. This arrangement allows to achieve a stable attachment, secure and plane, of the central body, both in the case of a cooker and in the case of an inbuilt cooking surface.
In this preferential embodiment, apart from the positioning elements there are other stability and safety elements. The central body in fact comprises centering feet to center it with respect to the supporting frame and vertical fins to support and accommodate the flame-dividing head.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein: - fig. 1 is a lateral view, in section, of the gas burner according to the present invention, assembled in an inbuilt cooking surface;
- fig. 2 is a lateral view, in section, of the burner in fig. 1, assembled in a cooker; - fig. 3 is a view from below of a central body of the burner in fig. 1;
- fig. 4 is an axonometric projection of the central body in fig. 3. DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF EMBODIMENT OF THE INVENTION
With reference to fig. 1, a burner 10 according to the invention comprises a central body 12, on which a gas injector 14 is centrally and vertically assembled, a flame- dividing head 20, resting on the central body 12, and a cover 22, removably resting on the flame-dividing head 20.
The central body 12 is able to be mounted on a supporting frame 13 of an inbuilt cooking surface (fig. 1) or a cooker (fig. 2). The supporting frame 13 comprises, in the case of a cooker, only an upper wall 18, whereas, in the case of an inbuilt cooking surface, the upper, or outer wall 18, and a lower, or inner wall 19, arranged substantially parallel to each other and at a distance of about 3 cm from each other.
The central body 12 comprises a connector 24, which is provided with an inner end 24a, on which the injector 14 is mounted, and with an outer end 24b, able to be connected to a gas pipe, not shown in the drawings. The central body 12 also comprises three centering feet 26, by means of which it is able to be positioned in corresponding holes 26a made in
the lower wall 19 of the inbuilt cooking surface (fig. 1).
The central body 12 also comprises a horizontal flange 27 and three bushing elements 28 substantially cylindrical in shape (fig. 2) , which are hollow inside and are offset by 120° with respect to each other (figs. 3 and 4) .
In the event that the burner 10 is mounted on an inbuilt cooking surface (fig. 1), each of the bushing elements 28 is able to be selectively coupled coaxially with a corresponding spacer element 29, having a substantially tubular shape and which is interposed between the bushing element 28 and the lower wall 19.
To be more exact, the bushing elements 28 and the spacer elements 29 are suitably sized, so that their overall height is coherent with the distance between the two walls 18 and 19 of the supporting frame 13 of the inbuilt cooking surface.
According to the invention, each bushing element 28 (fig.
1) , and possibly the corresponding spacer element 29 associated therewith (fig. 1) , allows to correctly position the central body 12 with respect to the supporting frame 13.
To be more exact, the bushing elements 28 and the corresponding spacer elements 29 are able to be positioned in correspondence with through holes 30 and 32, made respectively on the walls 18, 19, to guide the insertion of the stem of a screw 34, able to clamp the central body 12 with respect to the supporting frame 13.
To be more exact, in the event that the burner 10 is assembled on a cooker (fig. 2), the screw 34 is of reduced length and is screwed into a corresponding thread 35, made inside the bushing element 28.
On the contrary, if the burner 10 is assembled on a cooking surface (fig. 1), the screw 34, which has a greater length and is of the self-threading type, screws into the
hole 32, thus clamping the central body 12 between the two walls 18 and 19.
Each screw 34 is easily screwed from above, hence from above the upper wall 18, and can easily be unscrewed and removed, in the event that the central body 12 has to be dismantled also from the lower wall 19.
Moreover, the fact that the central body 12 is clamped by means of the three screws 34 arranged at 120° with respect to the longitudinal axis of the central body 12, passing through the center of the injector 14, allows to center the central body 12 with precision and keep it plane with respect to the upper wall 18, both in the case of an inbuilt cooking surface and also of a cooker.
The central body 12 is also provided with three vertical fins 36 to support the flame-dividing head 20. These vertical fins 36 are able to be housed in a hole 37 on the upper wall 18 and protrude upwards to define the plane on which the flame-dividing head 20 rests. The three vertical fins 36 are arranged radially and equidistant with respect to each other, offset by 120°, to define a tubular chamber 38.
According to a characteristic of the present invention, the upper end of each of the three vertical fins 36 (figs. 3 and 4) comprises a surface 36a, substantially horizontal, so that the three surfaces 36a define a single stable area on which the flame-dividing head 20 can rest.
The central body 12 also comprises a lateral fin 40 (figs. 3 and 4) , in which a first pair of hollows 42 is made, open on one side and arranged in a radial direction, in each of which a sparking plug, of a known type and not shown in the drawings, is able to be selectively inserted. On the opposite side of the lateral fin 40 there is a second pair of hollows 44, also arranged in a radial direction, into
each of which a safety thermocouple, of a known type and not shown in the drawings, is able to be selectively inserted. The thermocouple is able to be connected to the gas pipe to block access of the gas to the central body 12 should the flame go out.
The presence of two pairs of hollows 42 and 44 allows to achieve a single central body 12 for two types of burner, for example of the rapid and semi-rapid type. In fact, according to the type of burner, the thermocouple and the sparking plug are inserted into the corresponding hollows 42 and 44 which are further inside or outside.
The flame-dividing head 20 (figs. 1 and 2) also comprises a central sleeve 46 able to be inserted vertically into the tubular chamber 38. The primary combustion air enters from outside the flame-dividing head 20, in the direction of the arrow AP, into the sleeve 46 through the chamber 38 and mixes with the gas arriving from the injector 14. A plurality of channels 50, having a lenght / of about 8 mm, are made in the flame-dividing head 20 in a radial position with respect to the central sleeve 46, and are closed above by the cover 22 in order to define the outlet apertures of the main air-gas mixture.
The cover 22 comprises a lower surface 53 which extends without a break in continuity inside a peripheral edge 54 which protrudes downwards for some millimeters, for example 1.5 to 2.5 mm. In this way, once the cover 22 has been arranged above the flame-dividing head 20, it assumes a very stable position, without being constrained to the sleeve 46 of the flame-dividing head 20, as happens on the contrary in the state of the prior art.
Moreover the edge 54 determines a pre-determined short and constant form of the flame. This strategy allows to obtain another advantage for the safety of the burner, as a short
flame is very stable and allows to obtain and good and constant gas combustion.
It is clear, however, that modifications and/or additions of parts can be made to the burner 10 as described heretofore, without departing from the field and scope of the present invention.
For example, according to a variant, the spacer elements 29 and the relative bushing elements 28 are made in a single piece. It is also clear that, although the present invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of gas burner, all of which shall come within the field and scope of the present invention.