Cooking appliance

The present invention relates to a household appliance comprising a fastening system for an attachment of a component or an assembly to a casing wall or to a frame or support part according to the preamble of claim 1 .

In order to support persons in performing domestic work, household appliances of di f ferent kinds are known . In particular, cooking processes are performed using cooking appliances . For example , cooking hobs comprise cooking zones for placement of cookware receiving the food to be cooked . The cooking zones are generally arranged on a cooktop, in particular a glass ceramic cooktop, which forms an upper wall of the cooking hob . Moreover, there are cooking hobs known, in which a cooking fumes extraction functionality is integrated . More speci fically, such kind of a combination appliance comprises a cooking hob and an integrated downdraft extraction device with an extraction opening in the cooktop of the cooking hob . With such a combination of a cooking hob and an extraction device , a compact solution is provided . On the other hand, each type of household appliance , but particularly such a combination appliance , requires a plurality of mechanical fastening solutions , which are exposed to di f ferent mechanical stress situations during the li fetime of the household appliance , especially during its transportation and/or installation, where vibrations or shocks usually occur .

It is an obj ect of the present invention to provide a household appliance comprising a fastening system for an attachment of a component or an assembly to a casing wall or to a frame or support part , having a, preferably cost-ef ficient , solution for such a fastening system, which is designed to ensure prevention of damages to the household appliance under the impact of a mechanical stress situation usually occurring during the li fetime of the appliance .

The obj ect is achieved for a household appliance comprising a fastening system for an attachment of a component or an assembly to a casing wall or to a frame or support part by the characteri zing features of claim 1 .

A household appliance comprises a fastening system for an attachment of a component or an assembly at a casing wall or at a frame or support part . The fastening system according to the present invention includes at least a first fastening means and a second fastening means . The first fastening means is configured to be plastically deformed under the influence of a first force exceeding a first force threshold and the second fastening means is configured to be plastically deformed under the influence of a second force exceeding a second force threshold . The first and second forces are directed orthogonally to the mounting plane . The first force threshold is lower than the second force threshold .

The household appliance is particularly a cooking appliance , more particularly a cooking hob or a combination appliance comprising a cooking hob . Further, said mounting plane is particularly the area of attachment of the component or assembly at the casing wall or frame or support part , e . g . the area of the component or assembly abutting against or touching the casing wall or frame or support part .

With such dimensioning of first and second fastening means , it may be provided that a plastic deformation of the first fastening means occurs at a force level , speci fically arising from a particular shock impulse , which force level will at most cause an elastic deformation or displacement of the second fastening means .

The second force threshold is preferably higher than a predetermined force value , the fastening system is required to withstand throughout the entire li fetime of the household appliance . This entire li fetime particularly includes the transportation and/or installation of the household appliance , during which it usually receives the maj or mechanical impact , e . g . stress situations like vibrations and/or shocks . On the other hand, the first force threshold may be lower than said predetermined value , which may cause the first fastening means to undergo a plastic deformation in case of occurrence of a force , e . g . sourcing from a shock impulse , with a force level that may appear, during the li fetime of the appliance , speci fically during transportation or installation .

In some implementations , the first fastening means is configured to absorb a shock by an elastic deformation, i f this shock includes a force within a first force value range , and by a plastic deformation, i f this shock includes a force within a second force value range . The second force value range is speci fically above the first force value range , i . e . a lower limit value of the second force value range is higher than the upper limit value of the first force value range . More speci fically, the lower limit value of the second force value range abuts the upper limit value of the first force value range .

Moreover, the fastening system may include a shock absorption capacity within the second force value range , which is increased in comparison with the first force value range . Said increased shock absorption capacity is preferably induced by absorption of mechanical deformation energy associated with plastic deformation . According to an embodiment , the first fastening means and the second fastening means are located in close proximity to each other . With such positioning, the first and second fastening means may closer cooperate with each other, speci fically in dependence of the force that is applied . However, a more distant positioning may work as well , what may also depend on the exact location of the respective fastening means , e . g . a positioning close to a centre of gravity of the entire system .

One speci fic solution for the household appliance according to the present invention provides that the fastening system comprises a plurality of first fastening means and a plurality of second fastening means . Preferably, one of each of the plurality of first fastening means and one of each of the plurality of second fastening means form a pair of first and second fastening means , so as to have provided a plurality of pairs of first and second fastening means . In such construction, each pair includes one first and one second fastening means , which are located close to each other .

According to a particularly speci fic embodiment , the first fastening means comprises at least one fastening flap, preferably a plurality of fastening flaps . Additionally, or alternatively, the second fastening means comprises at least one fastening hook, preferably a plurality of fastening hooks .

In some implementations , a main direction of extent of the fastening flap is oriented parallel to the mounting plane , the fastening flap preferably being formed as a flat element . With such orientation of the fastening flap in combination with its preferred flat design, a low level of the force value , at which plastic deformation starts to occur, is reali zed . Moreover, a main direction of extent of the fastening hook may be oriented orthogonally to the mounting plane . Likewise , the fastening hook is preferably formed as a flat element .

In some implementations , the fastening hook is configured to be inserted in an opening of the casing wall or of the frame or support part . The opening is preferably a slit-shaped opening . A hook end portion of the fastening hook is configured to engage behind the casing wall or the frame or support part . Preferably, the engagement is provided after the fastening hook, more speci fically the component or assembly, has performed a sliding movement in a direction parallel to the mounting plane .

According to a speci fic embodiment , the hook end portion is arranged at a rear surface of the casing wall or of the frame part at least directly after fastening the component or the assembly at the casing wall or the frame part . Said rear surface faces away from the component or assembly . Further, a gap is formed between the hook end portion and the rear surface and is configured to allow at least a movement of the component or assembly relative to the mounting plane , i . e . relative to the casing wall or to the frame or support part , within the force value range , in which elastic deformation of the first fastening means takes place , or, as preferred, to allow even a movement of the component or assembly relative to the mounting plane within the force value range , in which plastic deformation of the first fastening means takes place . Accordingly, the gap between the hook end portion and the rear surface of the casing wall or of the frame part may define a maximum level of plastic deformation of the first fastening means and/or a maximum relative movement between the component or assembly and the casing wall or the frame or support part . One speci fic solution according to the present invention is characteri zed in that the first fastening means and/or the second fastening means is/are integrally formed with a housing or a supporting structure of the component or the assembly . That way, no additional component or part is needed, supporting the task of providing a cost-ef ficient solution .

Moreover, it may be provided that at least one of the first fastening means and the second fastening means is a metal part , which is preferably produced by a sheet metal punching and forming process . Certainly, also other material , notably any material usually used in the manufacturing of household appliances , may find use as well . More speci fically, such material is selectable from a group of plastic, fibre or any similar materials . In order to reali ze plastic deformation of the first fastening means , it is preferred to use material of low brittleness , or even flexible plastic or fibre material , even though it may not be excluded that a speci fic shock absorption will be performed by causing fine cracks on the first fastening means . In some implementations , di f ferent materials for first and second fastening means are applied, for example using more flexible material for the first fastening means than for the second fastening means . Even more , due to the fact that the household appliance shall be constructed in that way that mechanical stress situation usually occurring during the li fetime of the appliance do not ef fect any plastic deformation or damage of the second fastening means , it may be possible to use material of high brittleness for this element .

More speci fically, the household appliance is a combination appliance comprising a cooking hob and the component or assembly is an extraction device or a component or assembly of the extraction device , preferably an extraction fan . The component or assembly is particularly attached to a bottom wall of the cooking hob .

Novel and inventive features of the present invention are set forth in the appended claims .

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

FIG . 1 is a perspective view of a combination appliance comprising a cooking hob and a downdraft extraction device installed in a kitchen cabinet ;

FIG . 2 is a cross-sectional perspective view of the disassembled combination appliance of FIG . 1 with a frontal surface cut away and including a removable filter device ;

FIG . 3 is a partial side view of a combination appliance similar to the illustration of FIG . 2 ;

FIG . 4 is a perspective view of a detached housing of the cooking hob of the combination appliance of FIG . 3 ;

FIG . 5 is a perspective view of a detached motor plate forming a top wall of a fan housing of the downdraft extraction device of the combination appliance of FIG . 3 ; and

FIG . 6 is an enlarged view of detail VI according to FIG . 4 .

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

FIG . 1 illustrates a general setup of a standard combination appliance 10 comprising a cooking hob 12 and a downdraft extraction device 14 installed in a kitchen cabinet 16 . The cooking hob 12 is implemented in a cut-out of a kitchen counter- top 18 forming a top cover plate of the kitchen cabinet 16 . The downdraft extraction device 14 is configured to take away cooking vapours occurring during cooking processes , in particular when cooking with uncovered cookware . The cooking hob 12 comprises cooking regions 20a, 20b arranged on a left hal f and a right hal f of a cooktop 22 of the cooking hob 12 , which left and right halves are separated from each other by a suction opening 24 for an intake of the cooking vapours , the suction opening 24 being arranged alongside a cooktop centreline . The suction opening 24 is covered by a cover grid 26 for preventing items , e . g . cookware , to fall into the suction opening 24 . Instead of the cover grid 26 a lid may be used for entirely covering the suction opening when the extraction device 14 is out of use , but for the operation of the extraction device 14 the lid is pivotable into an upright open position .

A housing 28 of the extraction device 14 is shown in FIG . 1 in transparent illustration . Said housing 28 provides a closed outer shell or channel segment for a flow of the sucked-in cooking vapours on their way from the suction opening 24 to an exhaust opening 30 in a base area 32 of the kitchen cabinet 16 . Said exhaust opening 30 is also covered, namely by an outlet grille 34 .

The flow of the sucked-in cooking vapours through the extraction device 14 is driven by the operation of an extraction fan 36 arranged inside of the housing 28 . Said extraction fan 36 comprises a bottom-sided intake opening 38 for sucking the cooking vapours from the interior space of the housing 28 .

A rear-sided fan outlet is arranged for a hori zontal exit of the air blown out backwards from the extraction fan housing 42 . The fan outlet is connected to a first end of an air duct 44 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 44 , an air duct bending by 90 degrees is implemented, which redirects the air flow from hori zontal to vertical downwards . The air duct 44 may be guided alongside a rear side of the kitchen cabinet 16 and may be bent again by 90 degrees close to a rear lower edge of the kitchen cabinet 16 in order to direct the airflow towards exhaust opening 30 in the base area 32 of the kitchen cabinet 16 . Accordingly, the second end of the air duct 44 is connected to the exhaust opening 30 . The embodiment illustrated in FIG . 1 shows a solution of the air duct 44 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 14 to a re-entry into ambient air is illustrated in FIG . 1 by dotted arrows 46 ¹ to 46 ⁵ . On their way through the extraction device 14 , the cooking vapours pass through a filter assembly 48 , which is arranged downstream directly behind the suction opening 24 for providing a puri fication of the conveyed air . Said filter assembly 48 includes a filter carrier 50 supporting a filter element (not shown) that is usually configured for filtering out grease particles and droplets .

The structure of the combination appliance 10 with the air duct 44 inside of the kitchen cabinet 16 and the exhaust opening 30 on the front of the cabinet 16 as shown in FIG . 1 is only one installation option . In other exemplary installations , the illustrated air duct 44 may be replaced by a direct blow-out opening at the cabinet rear side through an opening in the rear- sided cabinet wall or by an air channel guided through a wall of the installation location of the combination appliance 10 , e . g . for an air exhaust outdoors .

The cross-sectional view of FIG . 2 further shows two power boards 54 , one for the left cooking region 20a and one for the right cooking region 20b, the power boards 54 providing cooking zones in the left and right cooking regions 20a, 20b with electrical power . In the present embodiment , the cooking hob 12 is an induction cooking hob and the cooking zones are defined by induction coils (not shown) that are arranged below the cooktop 22 of the cooking hob 12 . Attached to the bottom side of the power board 54 assigned to the right cooking region 20b, a further circuit board is arranged forming a control electronics 56 for the combination appliance 10 . A cooking hob housing 58 encloses the components of the cooking hob 12 , speci fically said power boards 54 and said control electronic 56 . As illustrated in FIG . 3 in dotted lines , the cooking hob housing 58 is fixed to the cooktop 22 by screws via brackets 62 , which themselves are attached to the bottom side of the cooktop 22 by gluing .

Furthermore , the combination appliance 10 is shown in parts in FIG . 3 with a presentation method similar to that one of FIG . 2 . In contrast to the illustration of FIG . 2 , the presentation of FIG . 3 includes the frontal surface of the combination appliance 10 . Moreover, the extraction device housing 28 and the filter assembly 48 are removed for an increased focus on the present inventive concept .

The extraction fan 36 is attached to a bottom wall 60 of the cooking hob housing 58 , which attachment forms a hanging arrangement when the combination appliance 10 is installed in the kitchen cabinet 16 , by means of fastening elements illustrated in FIG . 3 with dotted lines . These fastening elements include hooks 66 and flaps 68 , which are arranged at di f ferent lateral edges of a motor plate 64 . The motor plate 68 , which is shown in isolated illustration in FIG . 5 , forms an integral element , more precisely a top plate , of the fan housing 42 and provides a supporting structure for the entire extraction fan 36 . The top surface of the assembled motor plate 64 entirely abuts against the bottom surface of the bottom wall 60 of the cooking hob housing 58 .

The fastening details are generally provided with FIG . 4 , presenting the cooking hob housing 58 isolated from the cooking hob 12 , as well as with detailed illustration according to FIG . 6 showing an enlarged view of detail VI indicated in FIG . 4 . Rectangular openings 70 and slits 72 are implemented in the bottom wall 60 of cooking hob housing 58 , which are configured to receive the hooks 66 and the flaps 68 that are integrally formed, more speci fically received by a punching and bending process of a sheet metal , with lateral edges of the motor plate 64 . The flaps 68 are in a stepped arrangement to the main plane of the motor plate 64 , so that the flaps 68 are configured to engage behind the bottom plate 60 of the cooking hob housing 58 . In a similar way, also the hooks 66 engage behind said bottom plate 60 after their insertion in the related slits 72 and a displacement of motor plate 64 alongside the bottom surface of bottom wall 60 . In contrast to the engagement of the flaps 68 , which provides a touching support on the top surface of the bottom wall 60 at contact surfaces 76 , the lower edges of the hooks 66 are spaced from said top surface by forming a gap 74 in between after fixation of the entire extraction fan 36 to the bottom wall 60 . That way, in normal condition, e . g . directly after the assembly of the combination appliance 10 , and without any shock impact thereon, the hooks 66 do not perform any supporting function . Instead, only after any shock impact onto the appliance 10 such supporting function comes into ef fect , as will be described in more detail further down below . The enlarged detail view according to FIG . 6 further illustrates that an easy insertion of the flaps 68 is provided by an angled free edge 78 forming a lead-in chamfer during the assembly process .

The general working concept of the fastening system herein disclosed is as follows . Due to the fact that the combination appliance 10 comprises heavy components like the extraction fan 36 , which are attached to other components like the cooking hob wall 60 , there is a risk of damages speci fically during transportation or installation of the combination appliance 10 , especially in case of an unintended drop of the appliance 10 causing shocks and related displacement forces acting on the individual components . Rigid connections of these components directly transmit emerging forces caused by these shocks to the parts or components that are connected to them . In the speci fic case of the cooktop 22 comprising a glass ceramic plate , more speci fically having a cutout forming or comprising the suction opening 24 , there is a high risk for damages on the glass material because cut surfaces and edges of glass material provide weak points of the entire element . Usually, such kind of shocks with an impact on glass elements will cause glass breakage . In order to avoid such damages , the herein disclosed combination of flat flaps 68 and rigid hooks 66 dampens such shocks , on the one hand, and, on the other hand, except slight but acceptable displacements , the components stay in their original positions .

In other words , the principal purpose of the speci fic fastening system provides a combination of one or more flat flaps 68 and one or more very strong hooks 66 with orientation orthogonally to the mounting plane , which are arranged on a connection part , speci fically on the motor plate 64 of the extraction fan 36 . Said hooks 66 and flaps 68 may be positioned in a central area or in a side area of the connection part , or in any position therebetween . There is no limitation or speci fic preference as to the number of hooks 66 and flaps 68 . In case of shocks , the flat flaps 68 are deformed elastically within the limits of the material properties of the used material , which is preferably a metal . Depending on the shock intensity causing a related relative movement of the component , the result may be only an elastic deformation of the flaps 68 . A more enhanced shock intensity inducing a higher relative movement , however, leads to a plastic deformation of the flaps 68 , which plastic deformation process includes an increased shock absorption capacity . On the other hand, the vertically oriented hooks 66 allow said relative movement of the component and the related elastic and plastic deformation of the flat flaps 68 within the predefined distance , corresponding to the provided gap 74 , only . Moreover, the vertical hooks 66 are suf ficiently rigid for keeping the relative movement within said predefined distance . To this end, it is provided that no such shocks and related forces shall be taken into account , which would end up with any plastic deformation of the hooks 66 . More speci fically, the fastening system is preferably designed in such a way, that drop tests , as required by standards in the household business , will at most lead to plastic deformation of the flaps 68 , but will not lead to any plastic deformation of the hooks 66 . In the same manner, the shocks during transport and installation may be compensated by elastic and plastic deformation of the flat flaps 68 , while the vertically oriented hooks 66 ensure a proper retaining positioning of all components . The included gap 74 is dependent on the maximum elastic deformation level of the material as well as the distance of the hooks 66 to the flaps 68 .

As already indicated above , the fixation system may include a plurality of pairs of cooperating flaps 68 and hooks 66 in a way that the motor plate 64 is entirely attached by these means to the bottom wall 60 of the cooking hob housing 58 . Alternatively, the motor plate 64 may be fastened to the bottom wall 60 of the cooking hob housing 58 on only one side , while the other side of the motor plate 64 may comprise fastening means , e . g . screws and related holes , for a rigid connection to the bottom wall 60 after said displacement of the motor plate 64 alongside the bottom surface of the bottom wall 60 , so that the inventive concept will operate only one-sided, which may reduce the protective ef fect of the fastening system but may nevertheless be a suf ficient solution .

All in all , with the disclosed combination of soft first fastening means , which absorb hard shocks , and rigid second fastening means , which keep the attached component in almost unchanged position, the fastening system can be downsi zed and the number of involved parts can be reduced . No flexible parts like silicone , rubber or springs are necessary as it is provided in solutions known from the prior art . Naturally, in order to further increase the ef fect as provided by the present invention, such flexible or soft parts might be used in addition . Moreover, the packaging of the entire combination appliance 10 for its safe transportation may be designed less complex and in a more cost-ef ficient way .

Finally, although a combination appliance 10 with speci fic dimensions is presented by FIGs . 1 to 6 , the herein described setups of combination appliance 10 may be applicable to all known si zes of cooking hobs 12 and respective combination appliances 10 with a width of at least 580 mm . Two , three or four cooking zones may be provided, speci fically depending on the si ze of the cooking hob 12 .

Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings , it is to be understood that the present invention is not limited to these precise embodiments , and that various other changes and modi fications may be af fected therein by one skilled in the art without departing from the scope or spirit of the invention . All such changes and modi fications are intended to be included within the scope of the invention as defined by the appended claims .

Moreover, features which are described in the context of separate aspects and embodiments of the invention may be used to- gether and/or be interchangeable . Similarly, features described in the context of a single embodiment may also be provided separately or in any suitable sub-combination .

List of reference numerals

10 combination appliance

12 cooking hob

14 downdraft extraction device

16 kitchen cabinet

18 kitchen countertop

20a, 20b cooking regions

22 cooktop

24 suction opening

26 cover grid

28 extraction device housing

30 exhaust opening

32 base area

34 outlet grille

36 extraction fan

38 intake opening

42 fan housing

44 air duct

4 gl to 5 arrows indicating air flow

48 filter ass emb 1 y

50 filter carrier

54 power boards

56 control electronics

58 cooking hob housing

60 bottom wall

62 bracket

64 motor plate

66 hooks

68 flaps

70 rectangular opening

72 slit

74 gap

76 contact surface

78 angled free edge