Household cooking appliance

Abstract

A household cooking appliance, in particular an oven, comprises a cooking chamber defined by a muffle having a flue with a fume outlet at an upper wall of the muffle, and a front door, for opening and closing the cooking chamber. The appliance further comprises a delivery channel, defined by a duct body that extends above the upper wall of the muffle, the duct body having an outlet of the delivery channel that is substantially at a front region of the appliance, above an upper portion of the door, and having a fume inlet in a lower wall of the duct body, which is in fluid communication with the fume outlet of the muffle and with the delivery channel. Operatively associated to the duct body is a ventilation assembly, so as to draw in fumes from the fume outlet of the muffle and expel them from the outlet of the delivery channel, the ventilation assembly being in a rear end region of the duct body that is generally opposite to the outlet of the delivery channel. The ventilation assembly comprises a radial fan with a centrifugal impeller inside the duct body, the centrifugal impeller being positioned above the fume inlet of the duct body substantially coaxial thereto and to the fume outlet of the muffle in such a way that at least the fumes are drawn in from the fume outlet substantially in the direction of the axis (X) of the impeller and forced in a radial direction into the delivery channel for being expelled from the corresponding outlet. The rear end region of the duct body has a generally rounded peripheral profile so as to form a volute of the radial fan, the duct body preferably having a shape generally tapered towards its rear end region and comprising a lower half-shell and an upper half-shell. Provided inside the duct body, within the boundaries of the delivery channel, is a flow-deflector element configured for rendering the flow forced by the centrifugal impeller into the delivery channel uniform.

Claims

1. A household cooking appliance, in particular an oven, comprising a cooking chamber defined by a muffle having a flue with a fume outlet at an upper wall of the muffle, and a front door, for opening and closing the cooking chamber, the household cooking appliance also comprising: a delivery channel, defined by a duct body that extends above the upper wall of the muffle, the duct body having an outlet of the delivery channel that is substantially at a front region of the household cooking appliance, above an upper portion of the front door, and having a fume inlet in a lower wall of the duct body, which is in fluid communication with the fume outlet of the muffle and with the delivery channel; a ventilation assembly, operatively associated to the duct body so as to draw in fumes from the fume outlet of the muffle and expel them from the outlet of the delivery channel, the ventilation assembly being in a rear end region of the duct body that is generally opposite to the outlet of the delivery channel; wherein the ventilation assembly comprises a radial fan with a centrifugal impeller thereof within the duct body, the centrifugal impeller having an axis and being positioned above the fume inlet of the duct body substantially coaxial thereto and to the fume outlet of the muffle in such a way that at least the fumes are drawn in from the fume outlet substantially in a direction of the axis of the centrifugal impeller and forced in a radial direction into the delivery channel for being expelled from the fume outlet; wherein the rear end region of the duct body has a generally rounded peripheral profile so as to form a volute of the radial fan, the duct body preferably having a shape generally tapered towards the rear end region of the duct body and comprising a lower half-shell and an upper half-shell; wherein inside the duct body, within boundaries of the delivery channel, a flow-deflector element is provided, configured for rendering a flow forced by the centrifugal impeller into the delivery channel uniform; and wherein the flow-deflector element has two converging side surfaces, a first side surface substantially forming a prolongation of a first generally concave stretch of a side of the duct body and a second side surface substantially forming a prolongation of a second generally concave stretch of the side of the duct body, the flow-deflector element being set up against the side in a generally convex transitional stretch thereof between the first generally concave stretch and the second generally concave stretch in a position comprised between the centrifugal impeller and the outlet of the delivery channel.

2. The household cooking appliance according to claim 1, wherein the duct body has at least one air intake in fluid communication with the delivery channel, the at least one air intake comprising at least one passage at an upper wall of the duct body; and the centrifugal impeller of the radial fan has an upper impeller section and a lower impeller section, prearranged for drawing in air from said at least one passage and the fumes from the fume outlet of the muffle, respectively, with a lower section of the centrifugal impeller being positioned above the fume inlet of the duct body substantially coaxial thereto and to the fume outlet of the muffle.

3. The household cooking appliance according to claim 2, wherein the radial fan has a structure for its support at an opening of an upper wall of the duct body that is substantially coaxial to the centrifugal impeller, at least one of said opening of the upper wall of the duct body and said structure defining said at least one passage.

4. The household cooking appliance according to claim 2, wherein the centrifugal impeller has a set of substantially radial blades with an upper edge and a lower edge, and one or more partitions that extend transversally with respect to the axis of the centrifugal impeller in an intermediate position with respect to the upper and lower edges of the set of substantially radial blades, for defining the upper and lower impeller sections of the centrifugal impeller.

5. The household cooking appliance according to claim 1, wherein the flue is formed from one or more of (A) a drawn part of the upper wall of the muffle that generally projects towards the lower wall of the duct body and (B) a drawn part of the lower wall of the duct body that generally projects towards the upper wall of the muffle.

6. The household cooking appliance according to claim 5, wherein the flue is formed from the drawn part of the lower wall of the duct body that generally projects towards the upper wall of the muffle, and the drawn part of the lower wall of the duct body includes the fume inlet.

7. The household cooking appliance according to claim 6, wherein the flue is further formed from the drawn part of the upper wall of the muffle that generally projects towards the lower wall of the duct body, and the drawn part of the upper wall includes the fume outlet.

8. The household cooking appliance according to claim 5, wherein the one or more of the drawn part of the upper wall of the muffle and the drawn part of the lower wall of the duct body that forms the flue houses a fume filtering element.

9. The household cooking appliance according to claim 7, wherein a fume filtering element is disposed between the drawn part of the lower wall of the duct body and drawn part of the upper wall of the muffle.

10. A household cooking appliance, in particular an oven, comprising a cooking chamber defined by a muffle having a flue with a fume outlet at an upper wall of the muffle, and a front door, for opening and closing the cooking chamber, the household cooking appliance also comprising: a delivery channel, defined by a duct body that extends above the upper wall of the muffle, the duct body having an outlet of the delivery channel that is substantially at a front region of the household cooking appliance, above an upper portion of the front door, and having a fume inlet in a lower wall of the duct body, which is in fluid communication with the fume outlet of the muffle and with the delivery channel; a ventilation assembly, operatively associated to the duct body so as to draw in fumes from the fume outlet of the muffle and expel them from the outlet of the delivery channel, the ventilation assembly being in a rear end region of the duct body that is generally opposite to the outlet of the delivery channel; wherein the ventilation assembly comprises a radial fan with a centrifugal impeller thereof within the duct body, the centrifugal impeller having an axis and being positioned above the fume inlet of the duct body substantially coaxial thereto and to the fume outlet of the muffle in such a way that at least the fumes are drawn in from the fume outlet substantially in a direction of the axis of the centrifugal impeller and forced in a radial direction into the delivery channel for being expelled from the fume outlet; wherein the rear end region of the duct body has a generally rounded peripheral profile so as to form a volute of the radial fan, the duct body preferably having a shape generally tapered towards the rear end region of the duct body and comprising a lower half-shell and an upper half-shell; wherein inside the duct body, within boundaries of the delivery channel, a flow-deflector element is provided, configured for rendering a flow forced by the centrifugal impeller into the delivery channel uniform; wherein the flow-deflector element has two converging side surfaces, a first side surface substantially forming a prolongation of a first generally concave stretch of a side of the duct body and a second side surface substantially forming a prolongation of a second generally concave stretch of the side of the duct body, the flow-deflector element being set up against the side in a generally convex transitional stretch thereof between the first generally concave stretch and the second generally concave stretch in a position comprised between the centrifugal impeller and the outlet of the delivery channel; wherein the duct body has an upper wall and at least one intermediate wall which is set between, and generally faces, the lower and upper walls of the duct body, for defining in the duct body both the delivery channel and an intake channel that extends underneath the delivery channel; wherein the intake channel has an inlet substantially at the upper portion of the front door, underneath the outlet of the delivery channel; and and wherein the at least one intermediate wall has an opening substantially coaxial to the centrifugal impeller in such a way that the radial fan draws into the delivery channel both the fumes from the fume outlet of the muffle and air from the inlet of the intake channel, to force a mixed fume/air flow into the delivery channel towards the outlet.

11. The household cooking appliance according to claim 10, wherein the front door comprises at least one outer door panel, one inner door panel, and one intermediate door panel, the door panels defining between them a plurality of gaps, amongst which at least an external gap and an internal gap, each having a lower inlet and an upper outlet, at a lower portion and an upper portion of the front door, respectively, for passage of a respective flow of cooling air.

12. The household cooking appliance according to claim 11 further comprising: a deflector mounted upon an upper end of one or more of the door panels that shield the inlet of the intake channel from the outlet of the delivery channel, in such a way that the air drawn in by the radial fan from the inlet of the intake channel comprises the cooling air exiting from the upper outlet of the internal gap.

13. The household cooking appliance according to claim 12, wherein the deflector shields the upper outlet of the internal gap from the upper outlet of the external gap in such a way that the aforesaid mixed fume/air flow from the outlet of the delivery channel produces a draught effect with respect to the external gap causing a difference of pressure between the lower inlet and the upper outlet of the external gap so as to induce the flow of cooling air into the external gap.

14. A household cooking appliance, in particular an oven, comprising a cooking chamber defined by a muffle having a flue with a fume outlet at an upper wall of the muffle, and a front door, for opening and closing the cooking chamber, the household cooking appliance also comprising: a delivery channel, defined by a duct body that extends above the upper wall of the muffle, the duct body having an outlet of the delivery channel that is substantially at a front region of the household cooking appliance, above an upper portion of the front door, and having a fume inlet in a lower wall of the duct body, which is in fluid communication with the fume outlet of the muffle and with the delivery channel; a ventilation assembly, operatively associated to the duct body so as to draw in fumes from the fume outlet of the muffle and expel them from the outlet of the delivery channel, the ventilation assembly being in a rear end region of the duct body that is generally opposite to the outlet of the delivery channel; wherein the ventilation assembly comprises a radial fan with a centrifugal impeller thereof within the duct body, the centrifugal impeller having an axis and being positioned above the fume inlet of the duct body substantially coaxial thereto and to the fume outlet of the muffle in such a way that at least the fumes are drawn in from the fume outlet substantially in a direction of the axis of the centrifugal impeller and forced in a radial direction into the delivery channel for being expelled from the fume outlet; wherein the rear end region of the duct body has a generally rounded peripheral profile so as to form a volute of the radial fan, the duct body preferably having a shape generally tapered towards the rear end region and comprising a lower half-shell and an upper half-shell; wherein inside the duct body, within boundaries of the delivery channel, a flow-deflector element is provided, configured for rendering a flow forced by the centrifugal impeller into the delivery channel uniform; wherein the flow-deflector element has two converging side surfaces, a first side surface substantially forming a prolongation of a first generally concave stretch of a side of the duct body and a second side surface substantially forming a prolongation of a second generally concave stretch of the side of the duct body, the flow-deflector element being set up against the side in a generally convex transitional stretch thereof between the first generally concave stretch and the second generally concave stretch in a position comprised between the centrifugal impeller and the outlet of the delivery channel; and wherein the front door comprises at least one outer door panel, one inner door panel, and one intermediate door panel, the door panels defining between them a plurality of gaps, amongst which at least an external gap and an internal gap, each having a lower inlet and an upper outlet, at a lower portion and an upper portion of the front door, respectively, for passage of a respective flow of cooling air.

15. The household cooking appliance according to claim 14, wherein: the duct body has at least one air intake in fluid communication with the delivery channel, the at least one air intake comprising at least one passage at an upper wall of the duct body; and the centrifugal impeller of the radial fan has an upper impeller section and a lower impeller section, prearranged for drawing in air from said at least one passage and the fumes from the fume outlet of the muffle, respectively, the lower impeller section of the centrifugal impeller being positioned above the fume inlet of the duct body substantially coaxial thereto and to the fume outlet of the muffle.

16. The household cooking appliance according to claim 15, wherein the centrifugal impeller has a set of substantially radial blades with an upper edge and a lower edge, and one or more partitions that extend transversally with respect to the axis of the centrifugal impeller in an intermediate position with respect to the upper and lower edges of the set of substantially radial blades, for defining the upper and lower impeller sections of the centrifugal impeller.

17. The household cooking appliance according to claim 14 further comprising: a deflector mounted upon an upper end of one or more of the door panels that shield an inlet of an intake channel of the duct body from the outlet of the delivery channel, in such a way that air drawn in by the radial fan from the inlet of the intake channel comprises air exiting from the upper outlet of the internal gap.

18. The household cooking appliance according to claim 17, wherein the deflector shields the upper outlet of the internal gap from the upper outlet of the external gap in such a way that mixed fume/air flow from the outlet of the delivery channel produces a draught effect with respect to the external gap causing a difference of pressure between the lower inlet and the upper outlet of the external gap so as to induce a flow of cooling air into the external gap.

Description

BRIEF DESCRIPTION

(1) Further aims, characteristics, and advantages of the present invention will emerge clearly from the ensuing detailed description, with reference to the annexed schematic drawings, in which:

(2) FIG. 1 is a schematic view in front elevation of a cooking appliance according to the present invention;

(3) FIG. 2 is a schematic cross section according to the axis II-II of FIG. 1;

(4) FIG. 3 is a sectioned perspective view of the appliance of FIG. 1;

(5) FIG. 4 is a schematic perspective view of a muffle of the appliance of FIG. 1, with a corresponding duct body associated to its upper wall;

(6) FIG. 5 is a schematic perspective view of the muffle of FIG. 4;

(7) FIGS. 6 and 7 are views from different angles of a duct body with a corresponding ventilation assembly associated thereto;

(8) FIG. 8 is a schematic top plan view of the duct body of FIGS. 6 and 7;

(9) FIGS. 9 and 10 are exploded views, from different angles, of the duct body of FIGS. 6-7;

(10) FIG. 11 is a detail at a larger scale of FIG. 2;

(11) FIG. 12 is a schematic cross section similar to that of FIG. 11, with a different plane of section;

(12) FIG. 13 is a detail at a larger scale of the appliance of FIG. 3; and

(13) FIGS. 14 and 15 are views similar to those of FIGS. 9 and 10, but regarding a duct body with corresponding ventilation assembly according to a possible variant embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(14) Reference to an embodiment or one embodiment in the framework of the present description is intended to indicate that a particular configuration, structure, or characteristic described in relation to the embodiment is comprised in at least one embodiment. Hence, phrases such as in an embodiment or in one embodiment, and the like, that may be present in different points of this description do not necessarily refer to the same embodiment of the oven forming the subject of the present invention. Furthermore, particular conformations, structures, or characteristics may be combined in any adequate way in one or more embodiments, even different from the ones represented. The references used herein are provided merely for convenience and hence do not define the sphere of protection or the scope of the embodiments. Furthermore, the cooking appliance will be described in what follows limitedly to the elements necessary for an understanding of the invention, taking for granted that it includes all the other components normally known and necessary for its operation.

(15) With initial reference to FIGS. 1-5, designated as a whole by 1 is a household cooking appliance according to the invention, here represented by a built-in oven. The invention may in any case be applied also to free-standing ovens and to kitchen ranges integrating an oven. The oven 1 has a load-bearing structure or body, designated by 2, associated to the front of which in a stationary way is a control panel 3, comprising control means and/or display means for control of the functions of the oven, these means not being represented herein. Associated to the front part of the body 2 is a front door 4, in particular hinged in a lower region thereof, provided with a handle 4a. In a preferred embodiment, the structure of the door 4, which is preferably made at least in part of metal, comprises a plurality of door panels 4b, 4c, 4d, and 4e, which define between them a series of cooling chambers, as described hereinafter. The lower edge of the control panel 3 and the upper end of the door 4 are separated from one another by a space or gap, designated by G: the presence of this gap prevents the panel 3 from constituting a hindrance to opening of the door itself andas will emerge hereinafterenables passage of at least one forced flow of air from a fan.

(16) Housed within the body 2 is a muffle, designated as a whole by 5. The muffle 5 has a rigid metal body, for example obtained using sheet metal, having an upper wall, a lower wall, a rear wall, and two side walls (only one of which is visible), designated by 5a, 5b, 5c, and 5d, respectively. The muffle 5 is preferentially thermally insulated via an insulation jacket, of a conception in itself known (not represented). The body of the muffle 5 defines a cavity or cooking chamber 6, which can be opened and closed at the front by means of the door 4. For this purpose, associated to the muffle 5 are means for heating the cooking chamber (here not represented). For this purpose, electrical resistances may, for example, be provided, two of which are partially visible, one underneath the lower wall of the muffle and the other associated to its rear wall.

(17) Designated as a whole by 10 is a duct body, with a ventilation assembly 20 associated thereto, forming part of a system for extraction of fumes from the cooking chamber 6. As will emerge from what follows, the duct body 10 defines a delivery channel, at least one air intake in fluid communication with the aforesaid delivery channel, and possibly an intake channel.

(18) With reference in particular to FIG. 4, visible therein is the body of the muffle 5, which may be made of a single piece of sheet metal or of a number of parts of sheet metal fixed together. Associated to the upper wall 5a of the muffle 5 is the duct body 10, which extends over said wall approximately parallel thereto so that its front part, which here has a width comparable to the width of the muffle 5, is substantially located at the front of the appliance, in the vicinity of the gap G and of the upper portion of the door 4 (see, for example, FIGS. 2 and 3). In FIG. 4, the ventilation assembly 20 is not represented, but an opening of the upper wall of the body 10 is visible, present in the rear region of the latter, where the ventilation assembly is to be mounted.

(19) Visible in FIG. 5 is just the body of the muffle 5, defined in the upper wall of which is a fume outlet 7. The fume outlet 7 comprises a through hole or opening of the upper wall 5a, which is preferentially defined in a central area of the wall itself. In an advantageous embodiment, such as the one exemplified, the fume outlet 7 is located in an area corresponding to a drawn part 8 of the wall 5a, which generally projects upwards. As will emerge from what follows, this upper drawn part 8 of the muffle provides at least a portion of a flue for extraction of fumes from the cooking chamber 6. In a particularly advantageous embodiment, the drawn part 8 is shaped so as to define a housing 8a, in which a filtering element can be positioned at least in part, as described hereinafter.

(20) The duct body 10, with the ventilation assembly 20 associated thereto, is visible in different views in FIGS. 6-8. From these figures, there may be appreciated the generally tapered shape of the body 10, starting from its front part towards its rear end region, where the ventilation assembly 20 is mounted.

(21) In a preferred embodiment, the body 10 is made up of a number of parts, comprising a lower half-shell 11, which defines the lower wall 10a of the body 10, and an upper half-shell 12, which defines the upper wall 10b of the body 10. In the embodiment currently considered, the body 10 defines both an intake channel and a delivery channel so that the body itself preferably comprises an intermediate wall 13, having a tapered profile in top plan view that substantially corresponds to the profile in top plan view of the half-shells 11 and 12. The various parts in question of the body 10, as well as the ventilation assembly 20, are clearly visible in the exploded views of FIGS. 9 and 10.

(22) As may be seen, the half-shells 11 and 12 preferentially define, in addition to the lower wall 10a and the upper wall 10b, also respective portions of the sides of the body 10, said portions of the sides being designated herein by 11a and 12a, respectively. The half-shells 11, 12 and the intermediate wall 13 may be obtained from sheet metal, via simple operations of shearing and stamping and/or drawing, with modalities in themselves known. As may be noted, preferentially, the half-shells have respective peripheral edges, not represented here, which project substantially orthogonally from the side portions 11a and 12a and are used for coupling the half-shells themselves to one another, with a technique in itself known, for example clinching, welding, or riveting. Advantageously, when also the intermediate wall 13 is provided, the latter has a respective peripheral edge (not shown), which is set between the peripheral edges of the half-shells 11 and 12 for the purposes of the aforesaid coupling. Regardless of the specific mode of coupling, in the assembled configuration, the opposite major faces of the wall 13 generally face the lower wall 10a and the upper wall 10b so that in the body 10 both a delivery channel and an intake channel, described hereinafter, will be defined.

(23) From FIGS. 9 and 10 it may be noted how, in the rear region of the body 10, and specifically in its upper wall 10b an opening 10c, which is preferably substantially circular, is defined, where the ventilation assembly 20 is to be mounted. From the aforesaid figures, as well as from FIG. 7 it may be noted how defined in the lower wall 10a of the body 10 is a fume inlet 10d. The fume inlet 10d of the body 10 comprises a through hole or opening in its wall 10a, which preferentiallybut not necessarilyhas a section of passage or diameter smaller than that of the fume outlet 7 of the muffle 5.

(24) In an advantageous embodiment, such as the one exemplified, the fume inlet 10d is located at a drawn part 9 of the wall 10a, whichin the mounted condition of the body 10generally projects downwards, i.e., towards the upper wall of the muffle 5. As will emerge from what follows, this lower drawn part 9 of the body 10 provides at least one portion of a flue for extraction of fumes from the cooking chamber 9. In a particularly advantageous embodiment, the drawn part 9 is shaped so as to define a housing 9a, in which a filtering element, designated as a whole by 14 in FIG. 9, may be positioned at least in part.

(25) The intermediate wall 13 has in its rear region a respective through opening 13a, which is preferably but not necessarily circular. Once again preferentially, the diameter of the opening 13a is larger than that of the opening 10d of the body 10. In the assembled condition of the body 10, the opening 10c of the upper wall 10b is at least approximately coaxial or in any case aligned to the fume inlet 10d of the lower wall 10a, and, when the intermediate wall 13 is provided, also the corresponding opening 13a is at least approximately coaxial or in any case aligned to the fume inlet 10d, and hence also to the opening 10c.

(26) Once again from FIGS. 9-10 it may be noted how, at the front end of the walls 10a and 10b defined by the half-shells 11 and 12, as well as of the intermediate wall 13, positioning bosses are provided that co-operate with one another, which also perform functions of spacers. In the example of embodiment, the upper half-shell 12 has two bosses 12b that project downwards, whereas the lower half-shell 11 has a boss 11b that project upwards, in a position generally intermediate with respect to the bosses 12b; on the other side, the intermediate wall 13 has two lateral bosses 13b that project upwards, designed to co-operate with the two bosses 12a of the upper half-shell 12, as well as a central boss 13c that projects downwards, designed to co-operate with the boss 11b of the lower half-shell 11. As has been said, these bosses basically have the function of ensuring positioning and the distances between the front parts of the half-shells 11, 12 and of the wall 13 in order to define precisely the outlet and the inlet, respectively, of the delivery and intake channels referred to previously. The aforesaid outlet and inlet are visible, for example, in FIGS. 6 and 7, where they are designated by 30a and 31a, respectively.

(27) The ventilation assembly 20 forming part of the system for extraction of the fumes from the cooking chamber 6 comprises a radial fan having a centrifugal impeller, designated, respectively, by 21 and 22 in FIGS. 9 and 10. In the preferred embodiment exemplified, the assembly 20 also includes a structure or support 23 for the fan 21. The support 23, preferably made of metal, here has a generally annular configuration so that it can be coupled and fixed to the upper wall 10b of the body 10, at the opening 10c. Preferentially, the diameter of the opening 10c is larger than the diameter of the impeller 22 in order to enable easy insertion of the latter within the body 10, in the production stage. In the example illustrated, the support 23 has an annular peripheral part, which rests and is substantially fixed along the edge of the opening 10c, and a series of substantially radial uprights for supporting the motor 24 of the fan 21 on the outside of the body 10. The annular part of the support 23 is fixed, at the opening 10c of the body 10, preferably via threaded members or rivets, possibly with the aid of brackets. The motor 24 has a single shaft that identifies the axis of rotation of the impeller 22. This shaft (not shown), projects downwards from the body of the motor 24 for rotatably supporting the impeller 22 within the body 10.

(28) As already mentioned, the body 10 has at least one air intake, which in the example illustrated comprises at least one passage at the upper wall 10b of the body itself. In the example, the support 23 has a structure that is in part annular and in part spoked so as to define a series of passages, designated by 23a in FIGS. 6, 8 and 9, which, together with the opening 10c of the upper wall 10b, form an upper air intake.

(29) The centrifugal impeller 22 has an upper impeller section and a lower impeller section, prearranged for drawing in air from the aforesaid passage and for drawing in fumes from the fume outlet 7. In one embodiment, such as the one illustrated in FIGS. 9-10, the impeller 22 has a set of substantially radial blades 22a and a set of partitions 22b that extend in a transverse direction with respect to the axis of rotation of the impeller itself, in an intermediate position between the upper and lower edges of the blades 22a. The partitions 22b, which may also be replaced by a single partition transverse to the blades 22a, hence define in the impeller 22 an upper section and a lower section. The division of the impeller into two different generally coaxial intake sections can also be obtained with a different configuration, for example by providing two distinct sets of appropriately shaped and oriented blades.

(30) Regardless of the specific embodiment, the upper section of the impeller 22 is provided for drawing in air from the outside of the body 10 through the passages 23a, i.e., from an internal area of the structure of the appliance that extends over the muffle 5. Installed in one such area, designated by S in some figures, are electrical/electronic components of the appliance, which typically include an electronic control card of the appliance. Provided in the structure 2 are inlet openings for air coming from outside (not visible) in such a way that the upper section of the impeller 22 induces within the area S a flow of airfrom the aforesaid openings to the passages 23athat laps the aforesaid electrical/electronic components in order to cool them. The aforesaid inlet openings may for example be defined in the panel 3 and/or in a wall (not represented) that closes the space S at the top and/or in the sides and/or the back of the structure 2, or once again in areas of joining between the aforesaid parts. This air that penetrates into the body 10 through the passages 23a can mix with the fumes, thereby reducing their concentration and their temperature.

(31) The condition of the body 10, along with the ventilation assembly 20, assembled on the muffle 5 is visible in the cross-sectional views of FIGS. 11 and 12. It is to be noted that these cross sections have a merely explanatory and schematic nature, having been created artificially for highlighting parts of interest. In these figures, it may clearly be noted how the duct body 10 is mounted so as to extend above the upper wall 5a of the muffle 5. Defined within the body 10, via the intermediate wall 13, are the delivery and intake channels already referred to, designated by 30 and 31, with the respective outlet 30a and inlet 31a substantially at the front of the appliance, where the intake channel 31 extends underneath the delivery channel 30. From these figures, and in particular from FIG. 12 it may clearly be noted how the centrifugal impeller 22, and in particular its lower section, is positioned above the fume inlet 10d of the body 10, at a distance therefrom and substantially coaxial thereto and to the fume outlet 7 of the muffle 5. As may be noted, in the example represented, the axis of rotation X of the impeller 22 substantially coincides with the axes of the aforesaid fume inlet 10d and fume outlet 7. The fume outlet 7 is in fluid communication with the fume inlet 10d and with the delivery channel 30, through the opening 13a of the intermediate wall 13, which is substantially at the centrifugal impeller 22 and preferably completely underneath its lower section.

(32) In this way, the fumes are drawn in from the lower section of the impeller 22 through the corresponding outlet 7 substantially in the direction of the axis X of the impeller itself in order to be forced by the latter in a radial direction, into the delivery channel 30, for then being expelled from the corresponding outlet 30a. It will be appreciated that the fumes are drawn in from the lower section of the impeller 22, together with air taken in from outside through the intake channel 31, the inlet 31a of which provides an air intake from the outside of the structure 2. In this way, forced into the delivery channel 30 is a mixed fume/air flow, also including the air drawn in through the passages 23a. As explained previously, the use of the radial fan 22 enables important advantages to be achieved, as a result of the effect of direct draught that makes possible, among other things, a fume-outlet passage also of restricted dimensions and possibly with a filtering element associated thereto. By way of indication, the fume-outlet passage (hole 10d and/or hole 7) may have a maximum diameter even smaller than 10 mm, for example 8 mm, decidedly smaller than the diameters of traditional ovens with a tangential fan provided with pyrolytic function and associated filter (approximately 35 mm) or not provided with pyrolytic function (approximately 20 mm).

(33) As has been said, the fan is mounted in the rear region of the body 10, which is shaped so as to form the volute for the impeller 22. For this purpose, as highlighted in FIGS. 6-10, the aforesaid rear end region of the body 10 has a generally arched peripheral profile.

(34) Once again from FIGS. 11 and 12 it may clearly be noted how the upper drawn part 8 of the muffle 5 and the lower drawn part 9 of the body 10 provide respective parts of a flue, with the fume outlet 7 defined in an upper end portion of the drawn part 8 and the fume inlet defined in a lower end portion of the drawn part 8, said end portions facing one another. In this way, at least a substantial portion of the flue can be defined integrally by a component that must be in any case mounted on the muffle, i.e., the duct body 10. Very advantageously, this makes it possible to also produce the remaining part of the flue integrally with another component that is in any case necessary, i.e., the muffle 5. The proposed solution hence avoids the need to produce and install a distinct tubular element that provides the flue, as typically occurs in known solutions. As previously shown, the entire flue could possibly be obtained via a deeper drawing of the lower wall 10a of the duct body 10 or else of the upper wall 5a of the muffle 5.

(35) In one embodiment, such as the one exemplified, the aforesaid end portions have respective substantially plane parts that bear upon one another and that have respective holesnot indicated but visible, for example, in FIGS. 5 and 7for elements for mutual fixing, such as for example screws or similar threaded members.

(36) FIG. 12 clearly highlights how between the upper end portion of the drawn part 8 and the lower end portion of the drawn part 9 there may be operatively arranged a filtering element 14, designed to contain emission of undesirable substances from the cooking chamber. The filtering element 14 may advantageously be a catalytic ceramic filter of a conception in itself known, suitable for catalysing nitrogen oxides (NOx) when a temperature of the fumes of approximately 370 C. is exceeded, which is in any case a temperature lower than the one that the fumes at outlet from the muffle 5 typically have during pyrolytic cleaning functions.

(37) As mentioned previously, at least one of the two drawn parts 8 and 9, and preferably both, define respective portions 8a and 9a of a housing for the filtering element 14, without the need for specific additional components. In the example, the filtering element is substantially cylindrical, and the corresponding portions 8a and 9a of its housing are hence basically cylindrical. These portions 8a and 9a of the housing for the filtering element 14 are substantially in the form of recesses defined in the end portions of the drawn parts 8 and 9, respectively.

(38) Once again in FIGS. 11 and 12, it may clearly be noted how the motor 24 of the fan 21 is carried by the support 23 substantially on the outside of the body 20, with its centrifugal impeller 22 completely housed in the delivery channel 30. The flow of air induced from the upper section of the impeller 22 into the passages 23a enables also cooling of the motor 24 to be obtained.

(39) In a preferred embodiment, such as the one exemplified, provided inside the duct body 10 is a flow-deflector element, configured for rendering the forced flow of the centrifugal impeller 22 along the delivery channel 30 uniform. A deflector element of this sort is designated as a whole by 35 in FIGS. 8-10. The deflector element 35 has two converging side surfaces, designated by 35a and 35b in FIGS. 9 and 10, which substantially form a prolongation of a first generally concave stretch and a second generally concave stretch of the side of the duct body 10, respectively. The aforesaid lateral stretches are designated by 10e and 10f in FIG. 8, in which it may likewise be noted how another face 35c of the deflector element 35 is set up against the side in question in a generally convex transitional stretch thereof 10g, which is located between the stretches 10e and 10f. From the same figure, it may be noted how the element 35 is positioned in an area generally comprised between the centrifugal impeller 22 and the front of the body 10, where the outlet of the delivery channel is located. As has already been pointed out, the presence of the deflector element 35 proves advantageous from the fluid-dynamic standpoint in order to render the flow pushed by the impeller along the delivery duct more homogeneous. The element 35 is here constituted by a body having a simple structure, for example made of plastic material, the upper and lower faces of which are approximately triangular and designed to be, on one side, set up against and coupled to the upper wall 10b of the body 10 and, on the other side, set up against and coupled to the upper face of the intermediate wall 13. When the wall 13 is not present, as in an embodiment described hereinafter, the lower face of the element 35 is set up against and coupled to the lower wall 10a of the body 10. The height of the element 15, i.e., the distance between its upper and lower faces, hence substantially corresponds to that of a corresponding portion of the delivery channel 30, i.e., slightly greater than the height of the blades 22a of the impeller 22. Preferentially, provided in one or both of the aforesaid upper and lower faces of the deflector element 35 are projecting engagement elements (not indicated but visible in FIGS. 9-10), which are designed to couple in a unique way in respective seats present in the upper wall and in the intermediate wall (or else in the lower wall) of the body 10 in order to ensure a fixed and unique positioning of the deflector element itself, without any possibility of error in the assembly step.

(40) In the embodiment exemplified in the figuresobserving the duct body from above, such as for example in the view of FIG. 8the impeller 22 is operated in rotation in a clockwise direction, given that the deflector element 35 is set on the left-hand side of the body. It will be appreciated that, in the case of use of a fan with impeller turning in a counterclockwise direction, the deflector element 35 may be positioned on the opposite side, with the corresponding rear portion of the duct body that defines the volute of the fan modified accordingly (i.e., substantially with a shape specular to the one represented in FIG. 8).

(41) As mentioned in the introductory part of the present description, in the appliance 1 the fume-extraction system, including the duct body 10 and the fan 21, can be used for contributing to cooling of the door 4.

(42) As already pointed out with reference to FIG. 3, and as may be seen also in FIGS. 11, 12 and 13, the door 4 comprises a series of panels, preferably but not necessarily panels made of transparent glass or similar material, between which respective gaps are defined. In the embodiment exemplified in the figures an external panel 4b, an internal panel 4e, and two intermediate panels 4c and 4d are provided, which define between them three gaps, of which an external one, i.e., set further away from the cooking chamber 6, an internal one, i.e., set closer to the cooking chamber 6, and one set in an intermediate position. In FIGS. 11-13, the external gap is designated by 40a, the internal gap is designated by 40b, and the intermediate gap is designated by 40c. In other embodiments, the door 4 may comprise just three panels, and hence only the external gap and the internal gap, or possibly just two panels that define between them just one gap. As may be appreciated from FIG. 2 (where only the gaps are indicated) and from FIG. 3 (where only the panels are indicated), the various gaps provided have a lower inlet and an upper outlet, substantially at the lower portion and at the upper portion of the door, respectively.

(43) With reference in particular to FIGS. 11-13, it may be noted how the inlet 31a of the intake channel is substantially located at the upper portion of the door 4 in a position generally facing the upper portion and close to the upper outlets of the gaps 40b-40c. The outlet 30a of the delivery channel 30 is instead set at a height greater than the inlet 31a, in a position generally facing the space or gap G in order to be able to expel the fume/air mixture directly into the external environment.

(44) At the upper portion of the door are deflector means, designated as a whole by 40. In the example, these means are constituted by a profile belonging to the structure of the door, mounted at the upper ends of at least some of the door panels (here the panels 4c-4e). The aforesaid profile 40 has a base, here generally inclined downwards towards the cooking chamber, which overlies the upper outlets at a certain distance therefrom, as well as a series of lower projections for positioning with respect to the panels and the gaps 40b and 40c. The configuration of the profile 40 is such that at least the upper part thereof shields the inlet 31a of the intake channel 31 with respect to the outlet 30a of the delivery channel 30, with at least the upper outlet of the internal gap 40b and the upper outlet of the intermediate gap 40c (if the latter is envisaged), which are in any case set in fluid communication with the inlet 31a of the intake channel 31. In this way, as may be appreciated, the air drawn in by the radial fan 21 from the inlet 31a comprises air exiting from the upper outlet of the internal gap 40b and, in the case exemplified, also from the upper outlet of the intermediate gap 40c. In this way, the action of suction of the fan 21 along the intake channel 31 induces a flow of relatively fresh air, taken in from the inlets of the gaps 40b, 40c that are located at the lower part of the door. The aforesaid air flows upwards along the gaps 40b, 40c, thereby cooling the door 4, in its part generally facing the cooking chamber 6. This air then passes into the intake channel 31, for mixing with the fumes drawn in from the flue 8-9. The fumes are then diluted with relatively pure air, and then pass into the delivery channel 30. It will be appreciated that in this way there is also obtained a corresponding abatement of the temperature of the fumes that traverse the impeller 22 and a dilution thereof in air, such as to limit deposit of fats.

(45) With reference to the embodiment exemplified, the deflector means, here represented by the profile 40, are also configured for shielding the upper outlet of the external gap 40a with respect to the upper outlet of the internal gap 40b and of the intermediate gap, when this is envisaged. In the case exemplified, this function is basically obtained by the base part of the profile 40, the inclined upper surface of which is here used for delimiting a bottom of the gap G in an area corresponding to the gaps 40b and 40c. Instead, the upper opening of the external gap 40a opens substantially at the upper end of the door 4, and hence of the gap G. In this way, the mixed fume/air flow that is forced by the radial fan 21 out of the outlet 30a of the delivery channel 30 induces a draught effect with respect to the external gap 40a; i.e., it induces a difference of pressure between its lower inlet and its upper outlet. Also in this case, then, in the external gap 40a a flow of relatively fresh cooling air is induced, which traverses the gap from its lower inlet to its upper outlet. This flow of air, which enables cooling of the outer side of the door 4, mixes with the flow at outlet from the delivery channel 30, thereby also contributing to reducing the temperature of the latter.

(46) It will be appreciated that, in a different embodiment, the draught effect that can be obtained via the flow at outlet from the channel 30 could be exploited for inducing a flow of air also in the intermediate gap 40c, in which case the profile 40 will be modified accordingly. As explained previously, the concepts set forth can be applied also to the case of a door with just two gaps, and possibly also in the case of a door with just one gap. In this latter case, the flow of cooling air in the single gap can be induced via the flow at outlet from the channel 30 or via the flow at inlet to the channel 31, when this is present.

(47) The presence of the intake channel 31, in fact, albeit preferable, is not indispensable for the purposes of implementation of the invention. The channel 31 may also be present in embodiments in which the door of the appliance 1 does not have gaps traversed by corresponding cooling flows, in particular when it is desired in any case to obtain a mixing of the fumes with air drawn in from the outside of the appliance, prior to the corresponding expulsion into the environment. Instead, the channel 31 may be absent in the aforesaid case of doors without gaps traversed by cooling flows, or when in any case the duct body principally performs functions of extraction of the fumes without them being mixed with air taken in from the outside of the appliance.

(48) In this perspective, shown in FIGS. 14 and 15 is a variant embodiment of the duct body 10 in the case where it defines only the delivery channel. In these figures, the same reference numbers are used to designate elements that are technically equivalent to the ones already described above.

(49) In the example embodiment, the duct body has in this case only the upper half-shell 12, already described previously, and a lower half-shell, designated here by 11, which has a configuration broadly corresponding to that of the intermediate wall 13 illustrated previously. The only substantial difference regards the presence of the corresponding lower drawn part 9, which is to form totally or partly the flue. In the case illustrated, the aforesaid lower drawn part 9 has a lower end portiondesigned for coupling with the upper end portion of the upper drawn part 8 of the muffle 5which is without the corresponding housing for a filtering element. It will be appreciated in any case that, if desired, such a housing can be directly made in the course of the operation of drawing of the part 9, as in the embodiment illustrated previously. It will be appreciated then that the production of a duct body including the delivery and intake channels and the production of a duct body including just the delivery channel implies for the most part similar operations, the only differences basically regarding the modalities of stamping/drawing of the half-shell 11 (on the other hand, it is clear that the die used to obtain the wall 13 can be appropriately tooled to obtain the half-shell 11).

(50) From the foregoing description, the characteristics of the present invention emerge clearly, as do its advantages. It is likewise evident to a person skilled in the art that numerous variations may be made to the cooking appliance described by way of example herein, without thereby departing from the scope of the invention as defined by the ensuing claims.