Patent Description:
During the performance of cooking activities under use of a cooking hob, cooking vapours are generated, which are distributed over the cooking area. In order to avoid these cooking vapours to be spread throughout the entire kitchen space, an arrangement of an extraction device, particularly an extractor hood, is common. Said extraction device is operated in parallel to the cooking hob, thereby sucking in those cooking vapours in order to filter out particles and tiny droplets from the vapours and/or to blow the vapours to the outside of the building. While it has been common to arrange such an extractor hood above the cooking area, in recent years downdraft extraction devices have been finding a growing market. Such kind of extraction device is usually arranged below a worktop of the related cooking hob and it comprises at least one fan for sucking air from the cooking area through an opening arranged in the worktop. Such a configuration of a cooking hob and an extraction device being connected together in a combined arrangement is commonly called a combination appliance.

There are combination appliances known, in which the airstream is directed across the cooking hob in a vertical direction towards a lower area where the fan is located. The airstream is guided through a recess that commonly houses a filter unit. Said recess is shielded by an initial channel section unit, which separates the airflow from the interior of the cooking hob, notably in order to protect components, in particular electronic components, from getting into contact with the aspirated air that comprises cooking vapours. In order to keep the aspirated air including cooking vapours and respective moisture entirely away from the cooking hob components, the channel is sealed against casing parts of the cooking hob or of the combination appliance, respectively. To this end it is known to provide a sealed joint by using extra components like sponges squeezed between the top plate of the cooking hob and the initial channel section unit. According to the known solution, the sealing level is located above the upper surface of the top plate and a circumferential edge of the initial channel section unit compresses the sealant from above. This type of channel section installation from above, results in a loss of an unobstructed mobility of cookware during cooking activities, because of an absence of a flat cooking surface.

<CIT> discloses the preamble of claim <NUM>, disclosing a downdraft extractor hood with an air conveying channel having a box-shaped design and being positioned below a cooking surface. The air conveying channel is vertically arranged and includes two channel halves, which each communicate in a lower lateral area with an exhaust air suction chamber. A bottom wall of the air conveying channel is arranged in close proximity to a bottom wall of the exhaust air suction chamber.

<CIT> discloses a filter unit for a fume extraction device of a combination appliance, also comprising a cooktop. The fume extraction device includes a filter unit with a filter element and a collection region partially surrounding the filter unit for collecting a liquid. The collection region is formed in an overflow container, which is fixedly connected to the cover plate of the cooktop. Between the overflow container and the cover plate of the cooktop, a sealing ring is provided, which is received in a sealing slot on an upper edge of the overflow container.

<CIT> discloses an extractor hood for the extraction of fumes below a hob plate through a suction opening. An air conveying channel is positioned below the suction opening. The air conveying channel includes a filter element for the filtration of the air stream. After passing the filter element, the air stream leaves the air conveying channel through an air outlet opening at a lower section of a channel side wall and is forwarded to a fan, which is configured to produce the airflow.

It is an object of the present invention to provide a combination appliance of the above-described nature that has a design allowing unhindered movements of cookware, specifically sliding motions, during cooking processes. According to a further object, a method for assembling a combination appliance shall be proposed, which provides a simple structure and an easy and inexpensive manufacturing.

The object is achieved for a combination appliance according to the preamble of claim <NUM> by the features of the characterizing part of claim <NUM>.

A combination appliance, in particular for domestic use, comprises a cooking hob and an extraction device. The cooking hob, configured for cooking a food item thereon, is covered by a top plate or a worktop, which may be a glass plate. The top plate or worktop includes an opening or a recess that is formed therein providing a passage through the top plate or worktop. The extraction device is arranged below the top plate or worktop and comprises at least one fan for sucking air from an area above the cooking hob through the opening or recess of the top plate or worktop and for conveying the air through an air channel of the extraction device. The air channel of the extraction device includes a channel section, which is arranged downstream of the opening or recess and upstream of the fan. The channel section is further arranged adjacent to components, in particular electrical and/or electronic components, of the cooking hob. More specifically because of an impenetrable wall, the channel section forms a barrier for the prevention of the conveyed air to get in contact with the components of the cooking hob. The channel section comprises an upper portion and a lower portion. The upper portion, which is particularly a top edge or top surface, abuts a surface zone of the top plate or worktop, particularly of the bottom of the top plate or worktop. Moreover, the lower portion, which is particularly a bottom surface, abuts and/or is supported by a wall section of the cooking hob. Said wall section is in particular a bottom wall section or a side wall section or an intermediate wall section.

The cooking hob being the source for the aspirated cooking vapours may be of any type including electric or gas cooking hobs. In particular, the electric cooking hob is an induction cooking hob. The cooking hob may further be an autarkic cooking appliance, particularly integrated in a countertop of kitchen furniture, or it may be part of a stove.

A top surface of the top plate or worktop, which is accessible to a user, may be used for putting cookware thereon, specifically in order to perform a cooking process. To this end, the cooking hob preferably comprises at least one heating element defining a cooking zone on the worktop or, specifically, the glass plate, which is favourably made out of glass ceramics.

One particular advantage of the solution according to the present invention is the fact that the top surface of the top plate or worktop is entirely kept in a flat execution and there are no obstacles provided to the user of the appliance, when moving the cookware along the cooking surface.

Said channel section, particularly also further sections of the air channel, may be made in plastic or any other suitable material, e. sheet metal.

More specifically, in order to provide an air discharge for conveyed air, the extraction device comprises an exhaust opening for blowing out the air into the atmosphere. Said exhaust opening is notably arranged at the end of the air channel downstream of the fan. Moreover, in order to purify the conveyed air from particles inside of the aspirated cooking vapours, at least one filter element or a filter unit may be arranged in the extraction device, more specifically in the path of the air stream, particularly inside of the air channel.

A preferred embodiment of the present invention provides for a sealing means, which is arranged or arrangeable at the upper portion of the channel section, in particular between the upper portion and the surface zone of the top plate or worktop. Additionally, or alternatively, the sealing means may be arranged or arrangeable at the lower portion of the channel section, in particular between the lower portion and the wall section of the cooking hob. Said sealing means are adapted to hermetically seal the cooking hob, in particular components of the cooking hob, off from the air conveyed through the air channel. This allows an entire aspiration of the cooking vapours through the opening or recess and prevents any air bypass.

One specific solution for the sealing means comprises a layer of glue, which is particularly a circumferential glue bead applied on or contacting the upper portion of the channel section. The upper portion of the channel section preferably surrounds a cross-sectional area of the interior space of the channel section. More preferably, the upper portion of the channel section surrounds a wall of the channel section. An entirely circumferential glue spread surrounding the interior of the channel section not only cares for a fixed connection between the top plate or worktop and the channel section, but also avoids any air bypass and allows to skip any specific additional sealing means.

The upper portion of the channel section may comprise a circumferential rim or collar laterally protruding from the channel section wall. The circumferential rim or collar and the bottom of the top plate or worktop are preferably aligned parallel to one another. Additionally, or alternatively, the circumferential rim or collar are preferably arranged or arrangeable spaced from the bottom of the top plate or worktop. The space between the circumferential rim or collar and the bottom of the top plate or worktop particularly forms a receiving space for the layer of glue. That way, the layer of glue is not squeezed out at any point of the area or its application, which would entail the risk of air leakage at a point without gluing.

According to an embodiment, the channel section comprises a pipe section, which includes an insertion space for housing a filter element or a filter unit. The channel section and/or pipe section may have any shape with an arbitrary cross section, however, a rectangular cross section, is a preferred solution for such section(s).

The channel section may comprise a supporting means, notably a first supporting means, or a fixation means for a, preferably releasably, fixed positioning of a filter element or a filter unit. In addition to that, or as an alternative solution, a supporting means, notably a second supporting means, for supporting a grid or a lid adapted to cover the opening or recess may be included. Said second supporting means is particularly a supporting surface or supporting frame or supporting element.

The extraction device according to the present invention may also be characterized by an outlet port of the channel section, which opens out into a suction compartment arranged downstream thereof and upstream of the fan. By this means, after having passed the channel section, the conveyed air is supplied, particularly directly supplied, to the fan.

According to embodiments, a circumferential protection edge is arranged at the upper portion of the channel section, which protection edge abuts lateral edges of a cutout of the top plate or worktop, wherein the cutout is specified by the opening or recess. In particular, the cutout is rectangular, specifically when also the channel section is of a rectangular shape. More specifically, the protection edge is arranged at an inlet port located at the opening or recess, thus protecting the edges of the cutout from any mechanical damages.

The combination appliance is advantageously characterized by a wall of the channel section, which comprises a double-walled structure including an inner channel section wall and an outer channel section wall. Moreover, the inner channel section wall opens out into a suction compartment arranged downstream thereof and upstream of the fan and particularly penetrates the bottom wall. The outer channel section wall is preferably supported by the bottom wall section of the cooking hob.

Supporting ribs may be arranged between the inner channel section wall and the outer channel section wall. Said supporting ribs are particularly orthogonally arranged to the inner and outer channel section walls.

According to the present invention, a lower portion, which is a lower end surface, of the channel section wall is supported by a bottom wall section of the cooking hob. Said bottom wall section is more specified by a protrusion of the bottom wall protruding from a box or a compartment defined by walls, which comprise the bottom wall and a side wall adjacent to the channel section wall. As an alternative, the bottom wall section is a circumferential edge of a cutout in the bottom wall.

A sealing function may be integrated at the lower portion as well. This may be designed in that way that a suction effect of the fan only affects the interior of the channel section, while no suction effect affecting the interior of the cooking hob is performed. Therefore, the lower sealing means are designed in a way that no or at least a very low bypass air suction is established. This is particularly received by respective surfaces and/or edges of both walls, i. the inner channel section wall and the outer channel section wall, of the double-walled channel section, which abut at least one cooking hob wall. This way of two contacting areas with only small gaps implemented in series increase the sealing effect. Additionally, or alternatively, the double-walled concept may include a labyrinth sealing.

The object is further achieved for a method for assembling a combination appliance comprising a cooking hob and an extraction device according to the features of claim <NUM>.

A method for assembling a combination appliance comprising a cooking hob and an extraction device, comprises at least a first and a second assembly step. In the first step, a channel section of an air channel of the extraction device is connected to a top plate or worktop of the cooking hob in a way that an inlet port of the channel section is assigned to an opening or recess formed in the top plate or worktop. The connection between channel section and top plate or worktop is preferably performed in an airtight, i. hermetical, manner. More preferably, the channel section is glued on the top plate or worktop. In the second step, the top plate or worktop is positioned on a substructure, in particular on a lower hob box, of the cooking hob. In doing so, the channel section is arranged alongside the substructure or penetrates the channel section, so that, as a result, the channel section extends from the opening or recess of the top plate or worktop to or through a bottom wall, in particular to or through a cutout in the bottom wall, of the cooking hob. Moreover, an outlet port of the channel section opens out or is provided to open out into a suction compartment of a fan of the extraction device. Said fan is configured for sucking air from the area above the cooking hob through the opening or recess of the top plate or worktop and for conveying the air through an air channel of the extraction device. The suction compartment of the fan is arranged beneath the cooking hob in an assembly step prior to the first step, between first and second steps or after the second step. The first assembly step may be performed at an installation location different from that one of the second assembly step. In particular, the first assembly step may be executed on a pre-assembly line.

According to a specific embodiment of the method according to the present invention, the channel section is connected during the first step to the top plate or worktop in a way that the central axis of the channel section passes through the centre of the opening or recess. That way, full alignment between the two involved components is established.

Prior to or at the beginning of the first step, a glue bead may be circumferentially applied on an upper portion, in particular on a top surface or top edge, of the channel section. The upper section preferably surrounds a cross-sectional area of the interior space of the channel section. More preferably, the upper section surrounds a wall of the channel section. Alternatively, the glue bead may by circumferentially applied on a border around the opening or recess of the bottom side of the top plate or worktop. More specifically, after said application of the glue bead, a glued joint is established between the upper portion of the channel section and the top plate or worktop. Said glue bead is not only provided for establishing a fixed connection, but also works as a sealing means for preventing air to pass through the respective junction.

In order to establish a particular compact structure and, more specifically, in order to further increase airtightness between the interior of the channel section and the interior of the cooking hob, the lower portion of the channel section is set down during the second step on the bottom wall of the cooking hob. This joining of the two components is performed in particular in a final stage of the second step. On this occasion an at least approximately airtight junction is preferably established at the contact zone. Said lower portion may be a bottom surface or bottom edge of the channel section.

The present invention will be described in further detail with reference to the drawings, in which.

In all figures the same or equivalent part are marked with the same reference numbers.

<FIG> illustrates a combination appliance <NUM> comprising a cooking hob <NUM> and a downdraft extraction device <NUM> installed in a kitchen cabinet <NUM>. The cooking hob <NUM> is implemented in a cutout of a kitchen countertop <NUM> forming a top cover plate of the kitchen cabinet <NUM>. The downdraft extraction device <NUM> is configured to take away cooking vapours occurring during cooking processes, in particular when cooking with uncovered cookware. The cooking hob <NUM> comprises cooking regions 20a, 20b arranged on a left half and a right half of a cooktop <NUM> of the cooking hob <NUM>, which left and right halves are separated from each other by a suction opening <NUM> for an intake of the cooking vapours, the suction opening <NUM> being arranged alongside a cooktop centreline. The suction opening <NUM> is covered by a cover grid <NUM> for preventing items, e. cookware, to fall into the suction opening <NUM>. Instead of the cover grid <NUM> a lid may be used for entirely covering the suction opening when the extraction device <NUM> is out of use, but for the operation of the extraction device <NUM> the lid is pivotable into an upright open position.

A casing <NUM> of the extraction device <NUM> is shown in <FIG> in transparent illustration. Said casing <NUM> provides a closed outer shell or channel segment for a flow of the sucked-in cooking vapours on their way from the suction opening <NUM> to an exhaust opening <NUM> in a base area <NUM> of the kitchen cabinet <NUM>. Said exhaust opening <NUM> is also covered, namely by an outlet grille <NUM>.

The flow of the sucked-in cooking vapours through the extraction device <NUM> is driven by the operation of an extraction fan <NUM> arranged inside of the casing <NUM>. Said extraction fan <NUM> comprises a bottom-sided intake opening <NUM> for sucking the cooking vapours from the interior space of the casing <NUM>.

A rear-sided fan outlet (not shown) is arranged for a horizontal exit of the air blown out backwards from the extraction fan housing <NUM>. The fan outlet is connected to a first end of an air duct <NUM> designed as a rectangular tube and forms a second channel arranged downstream the above-mentioned first channel. Directly at the passage from the fan outlet to the air duct <NUM>, an air duct bending by <NUM> degrees is implemented, which redirects the air flow from horizontal to vertical downwards. The air duct <NUM> may be guided alongside a rear side of the kitchen cabinet <NUM> and may be bent again by <NUM> degrees close to a rear lower edge of the kitchen cabinet <NUM> in order to direct the airflow towards exhaust opening <NUM> in the base area <NUM> of the kitchen cabinet <NUM>. Accordingly, the second end of the air duct <NUM> is connected to the exhaust opening <NUM>. The embodiment illustrated in <FIG> shows a solution of the air duct <NUM> with an inclined section of its downwardly directed portion, directed slightly to the right. Naturally, a solution with said portion arranged in an exact vertical direction is considerable as well.

The course of the cooking vapours from the cooking area through the extraction device <NUM> to a re-entry into ambient air is illustrated in <FIG> by dotted arrows <NUM><NUM> to <NUM><NUM>. On their way through the extraction device <NUM>, the cooking vapours pass through a filter assembly <NUM>, which is arranged downstream directly behind the suction opening <NUM> for providing a purification of the conveyed air. Said filter assembly <NUM> includes a filter carrier <NUM> supporting a filter element (not shown) that is usually configured for filtering out grease particles and droplets.

The cross-sectional view of <FIG> further shows two power boards <NUM>, one for the left cooking region 20a and one for the right cooking region 20b, the power boards <NUM> providing cooking zones in the left and right cooking regions 20a, 20b with electrical power. In the present embodiment, the cooking hob <NUM> is an induction cooking hob and the cooking zones are defined by induction coils (not shown) that are arranged below the cooktop <NUM> of the cooking hob <NUM>. Attached to the bottom side of the power board <NUM> assigned to the right cooking region 20b, a further circuit board is arranged forming a control electronics <NUM> for the combination appliance <NUM>.

<FIG> illustrates a cross-sectional view of the upper section of the combination appliance <NUM> representing the area of localisation of the cooking hob <NUM>. This means, that the combination appliance section beneath the cooking hob <NUM> is cut away. The viewing direction providing the illustration of <FIG> is shown in <FIG>. It is to be noted that the presentation according to <FIG> represents the status of the filter assembly <NUM> being removed from its operating position according to <FIG> and <FIG> and shows a vertical cross-section through an initial channel section <NUM>. The initial channel section is formed as a pipe section with a rectangular horizontal cross-section, which is defined by its front and rear (from user's perspective) channel walls 58a as well as its lateral channel walls 58b, the channel walls 58a, 58b forming a cuboid tube, with an inlet opening directly downstream of the suction opening <NUM> and an outlet opening opening out into the interior of the casing <NUM>, which is a subsequent air channel segment directly downstream of the initial channel section <NUM>. In addition, the casing <NUM> also works as a suction compartment, which provides the conveyed air to the fan <NUM> that aspirates the air through the intake opening <NUM>. As previously mentioned, in <FIG> the filter assembly <NUM> is not present, however, the suction opening <NUM> is covered with grid <NUM>.

On its bottom side, defining also the outlet opening, the initial channel section <NUM>, more precisely the channel walls 58a, 58b of the channel section <NUM>, rests on a bottom wall <NUM> of the cooking hob <NUM>.

The top sides of the channel walls 58a, 58b of the initial channel section <NUM> abut with their upper front faces a border around the suction opening <NUM> on the bottom surface of the cooktop <NUM>. That way, the initial channel section <NUM> is sandwiched between the upper side of the bottom wall <NUM> of the cooking hob <NUM> and the bottom side of the cooktop <NUM>.

In order to provide a hermetical sealing of the conveyed air in the interior of the initial channel section <NUM> against the interior of the cooking hob <NUM>, more precisely against the electrical and electronic components arranged in the interior of the cooking hob <NUM>, in particular on the power boards <NUM> and control electronics <NUM>, sealing means are arranged between the initial channel section <NUM>, on the one hand, and the bottom surface of the cooktop <NUM> as well as the bottom wall <NUM> of the cooking hob <NUM>, on the other hand.

As is shown in more detail by the enlarged detail view according to <FIG>, the sealing means on the top side of the initial channel section <NUM> is realized by a circumferential glue bead <NUM> continuously surrounding the upper front faces of the channel walls 58a, 58b of the initial channel section <NUM>. In order to provide a receiving space for the glue bead <NUM>, the upper portion of the initial channel section <NUM> comprises a circumferential rim <NUM> laterally protruding from the upper end of the channel walls 58a, 58b. The circumferential rim <NUM> and the bottom surface of the cooktop <NUM> are aligned parallel to one another and the circumferential rim <NUM> is arranged spaced from the bottom surface of the cooktop <NUM>, wherein the space between the circumferential rim <NUM> and the bottom surface of the cooktop <NUM> forms said receiving space for the glue bead <NUM>.

The sealing on the bottom side of the initial channel section <NUM> according to the embodiment of <FIG> and <FIG> is simply realized by a firm touching or pressing of the lower front faces of the channel walls 58a, 58b of the initial channel section <NUM> onto the upper side of the bottom wall <NUM> of the cooking hob <NUM>, or more precisely, on a border around a cutout in the bottom wall <NUM> adjacent to the outlet opening of the initial channel section <NUM>, which cutout provides a passage for the conveyed air from the initial channel section <NUM> to the interior of the casing <NUM>.

<FIG> and <FIG> illustrate a second example of the initial channel section <NUM>. In contrast to the first example according to <FIG> and <FIG>, the initial channel section <NUM> comprises a double-walled structure including an inner channel section wall 66a and an outer channel section wall 66b. Naturally, as in the first example above, both inner and outer channel section walls 66a, 66b comprise four single walls, analogous to front and rear walls 58a and lateral walls 58b of the above-described first example. The inner channel section wall 66a opens out into the casing <NUM> and penetrates the bottom wall <NUM> of the cooking hob <NUM>, thereby protruding somewhat from the lower surface of the bottom wall <NUM>. In this example, the outer channel section wall 66b rests on the bottom wall section of the cooking hob <NUM>.

While the first example according to <FIG> and <FIG> relies on a simple sealing in its bottom region by said firm touching or pressing of the lower front faces of the channel walls 58a, 58b against the bottom wall <NUM>, the sealing effect of the second example is increased by an arrangement of two such minimized gaps in series, i. both the inner channel section wall 66a and the outer channel section wall 66b of the double-walled channel section about the bottom wall <NUM> of the cooking hob <NUM>, either on the top surface of the bottom wall <NUM> (see outer channel section wall 66b) or laterally against the cutout edge (see inner channel section wall 66a). This way of two contacting areas with only small gaps implemented in series increase the sealing effect.

Moreover, in order to provide both inner and outer channel section walls 66a, 66b in a straight design and parallel to one another, supporting ribs <NUM> are arranged between the inner channel section wall 66a and the outer channel section wall 66b. Said supporting ribs <NUM> are orthogonally arranged to the inner 66a and outer 66b channel section walls. Further supporting ribs <NUM> are arranged at the outer surface of the outer channel section wall 66b, which are adapted to rest against an inner wall <NUM> of the cooking hob <NUM>.

Claim 1:
A combination appliance (<NUM>) comprising
- a cooking hob (<NUM>), which is covered by a top plate or a worktop (<NUM>), in particular a glass plate, having an opening (<NUM>) or a recess formed therein,
and
- an extraction device (<NUM>), which is arranged below the top plate or worktop (<NUM>) and comprises at least one fan (<NUM>) for sucking air from an area above the cooking hob (<NUM>) through the opening (<NUM>) or recess of the top plate or worktop (<NUM>) and for conveying the air through an air channel of the extraction device (<NUM>),
wherein the air channel of the extraction device (<NUM>) includes a channel section (<NUM>), which is arranged downstream of the opening (<NUM>) or recess and upstream of the fan (<NUM>), which channel section (<NUM>) is arranged adjacent to components, in particular electrical and/or electronic components, of the cooking hob (<NUM>), the channel section (<NUM>) thereby forming a barrier for preventing the conveyed air to get in contact with the components of the cooking hob (<NUM>),
and wherein the channel section (<NUM>) comprises
- an upper portion, particularly a top edge or top surface, abutting a surface zone of the top plate or worktop (<NUM>), particularly of the bottom of the top plate or worktop (<NUM>),
and
- a lower portion, particularly a bottom surface, abutting and/or being supported by a wall section, in particular a bottom wall section (<NUM>) or a side wall section or an intermediate wall section, of the cooking hob (<NUM>),
characterized in that
a lower end surface of the channel section wall (58a, 58b, 66b) is supported by a bottom wall section (<NUM>) of the cooking hob (<NUM>)
- by a protrusion of the bottom wall (<NUM>) protruding from a box or a compartment defined by walls, which comprise the bottom wall (<NUM>) and a side wall adjacent to the channel section wall (58a, 58b, 66b),
or
- by a circumferential edge or border of a cutout in the bottom wall (<NUM>).