Patent Publication Number: US-2012031388-A1

Title: Domestic hob

Description:
The present invention relates to a domestic hob comprising a housing with a bottom wall. 
     Domestic hobs of the above-mentioned kind are known in prior art. If such domestic hobs are to be installed in built-in furniture, such as in a floor cupboard, it is to be considered that the temperature within the furniture does not exceed an admissible threshold due to the heat dissipation of the hob in order to prevent a damage of the furniture. 
     In this context DE-A-10 2005 053 173 proposes a domestic hob of the above-mentioned kind comprising two temperature sensors. The sensors detect and monitor the temperature of the furniture or rather the heat yielded to the furniture. However, the detection and monitoring of the temperature is expensive due to the necessary electronic equipment. 
     A further domestic hob of the above-mentioned kind is described in DE-U-20 2005 018 776. This domestic hob is installed in a floor cupboard, wherein a drawer is provided directly beneath the hob. In order to provide a space for stowing the cables of the hob, an intermediate plate is arranged between the upper edges of the drawer and the bottom side of the hob. Moreover, the furniture comprises a heat resistant and/or thermically isolating protection plate or protection layer arranged between the intermediate plate and the bottom side of the hob. This intermediate plate or intermediate layer can be provided directly on the intermediate plate. One draw-back of this solution is that the size of the intermediate plate as well as the size of the protection plate or the protection layer have to be adapted to the dimensions of the floor cupboard when assembling the hob. This adaption makes the assembly of the hob very time-consuming and expensive. 
     It is an object of the present invention to provide a domestic hob of the above-mentioned kind giving the user protection against thermal and/or electrical dangers emanating from the bottom side of the hob, and which is inexpensive to manufacture and to assemble. 
     In order to solve this object the present invention provides a domestic hob of the above-mentioned kind which is characterized in that at least one thermically and/or electrically isolating and/or flame resistant protection plate is attached to the hob underneath the bottom wall, wherein a main plane of the protection plate is spaced apart from the bottom wall by a predetermined distance. 
     Such a domestic hob is inexpensive to manufacture thanks to its simple construction. Moreover, since the protection plate is attacked to the hob its size does not need to be adapted to the dimensions of the furniture in which the hob is to be housed, e.g. to the dimensions of a floor cupboard. Accordingly, the domestic hob according to the present invention is easy and inexpensive to assemble. 
     According to one embodiment of the present invention at least one spacer is provided for maintaining the predetermined distance between the main plane of the protection plate and the bottom wall of the housing. The at least one spacer can be made integral with the protection plate and/or the bottom wall. For example, one or more border areas of the protection plate can form upwardly bent sections, which abut against the bottom wall of the hob and thus maintain the predetermined distance between the main plane of the protection plate and the bottom wall of the housing. Due to the integral configuration of the at least one spacer and the protection plate and/or the bottom wall, the number of components is reduced such that in particular the assembly of the domestic hob can be simplified. 
     Alternatively, the at least one spacer is provided as a separate component, such as a spacer bushing, a spacer pin or the like extending between the main plane of the protection plate and the bottom wall of the housing. Of course it is also possible to use a combination of separate spacers and spacers, which are made integral with the protection plate and/or the bottom wall. 
     According to one embodiment of the present invention the protection plate is screwed and/or riveted and/or bonded to or hooked in the hob. 
     Alternatively, snap-fitting means are provided for fixing the protection plate to the hob. Such snap-fitting means are advantageous in that they form a releasable connection between the protection plate and the hob, which is very easy and fast to assemble and to disassemble. Preferably, the snap-fitting means are made integral with the protection plate and/or the housing in order to reduce the number of components and thus to simplify the assembly of the domestic hob. 
     According to one embodiment of the present invention the protection plate comprises at least one cable opening for feeding through cables. Accordingly, the cables of the hob can be fed out of the clearance present between the main plain of the protection plate and the bottom wall of the housing in a defined manner. The edges of the cable opening are preferably chamfered and/or provided with a cable protecting means in order to protect the cables from being damaged. As a cable protecting means a plastic rail may be clipped on the edges of the cable opening, only to cite an example. 
     Preferably, the protection plate and/or the bottom wall of the housing comprises at least one venting opening for venting the hob. 
     According to an embodiment of the present invention a first protection plate section is provided with at least one venting opening for feeding air and a second protection plate section is provided with at least one venting opening for removing air, wherein the protection plate sections are spacially separated from each other in order to ensure an effective air circulation. 
     For separating the protection plate sections a separation wall and/or sealing means may be provided. 
     Moreover, the present invention provides a protection plate designed to be attached underneath a bottom wall of a housing of a domestic hob such that a main plane of the protection plate is spaced apart from the bottom wall of the housing by a predetermined distance, wherein the protection plate is thermically and/or electrically isolated and/or flame resistant. 
     According to one embodiment of the present invention the protection plate comprises at least one spacer for defining the predetermined distance. 
     The protection plate may be designed to be screwed and/or riveted and/or bonded to or hooked in the hob. 
     Alternatively, the protection plate may comprise snap-fitting means for fixing the protection plate to the hob. 
     Preferably, at least one cable opening for feeding through cables is provided whose edges are preferably chamfered and/or provided with a cable protecting means. 
     Advantageously, a first protection plate section is provided with at least one venting opening for feeding air and a second protection plate section is provided with at least one venting opening for removing air, wherein the protection plate sections are spacially separated from each other. 
    
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
       The detailed configuration, features and advantages of the present invention will become apparent in the course of the following description with reference to the accompanying drawings. 
         FIG. 1  is a perspective, exploded bottom view of a domestic hob according to an embodiment of the present invention. 
         FIG. 2  is an perspective, exploded top view of the hob shown in  FIG. 1 . 
         FIG. 3  is an perspective, exploded bottom view of a domestic hob according to a second embodiment of the present invention. 
         FIG. 4  is a perspective, exploded top view of the hob shown in  FIG. 3 . 
     
    
    
       FIGS. 1 and 2  show a domestic hob  10  according to a first embodiment of the present invention. The hob  10  comprises a conventional ceramic top plate  12  and a housing  14 . In order to accommodate the electronic components of the hob  10  the housing  14  has a box-shape which is defined by a bottom wall  16  and four side walls  18 . Along the upper edges of the side walls  18  angle profiles  20  are arranged for receiving the ceramic top plate  12  and for fixing it to the housing  14 . The bottom wall  16  of the housing  14  is provided with venting openings  22   a ,  22   b  and  22   c  for cooling the interior of the housing  14  by the circulation of ambient air. The circulation is caused by means of a fan (not shown) received in the housing  14 , which sucks in ambient air through the venting openings  22   a  and  22   b  and ejects the air through the venting opening  22   c.    
     Moreover, the hob  10  comprises a protection plate  24  which is made of a thermically and electrically isolating and fire resistant material and which is fixed to the bottom wall  16  of the housing  14  by means of screws  23 . The protection plate  24  includes a square main plane  26  extending essentially in parallel to the bottom wall  16  of the housing  14 , wherein three border areas of the main plane  26  are bent upwardly towards the housing  14  of the hob  10  in order to form spacers  28 . These spacers  28  abut against the bottom wall  16 , such that the main plane  26  of the protection plate  24  is spaced apart from the bottom wall  16  by a predetermined distance. Thus, a clearance is created between the main plane  26  of the protection plate  24  and the bottom wall  16  of the housing  14 . The clearance is devided by a separation wall  34 , which extends between the two opposing spacers  28  and is fixed to the main plane  26  of the protection plate  24 , whereby two protection plate sections  36  and  38  are formed. Within the protection plate section  36  a first venting opening  40   a  is provided underneath the venting openings  22   a  and  22   b  of the housing  14  for feeding air, and in the protection plate section  38  two venting openings  40   b  and  40   c  are provided underneath the venting opening  22   c  of the housing  14  for removing air. Accordingly, ambient air is sucked in by means of the fan through the venting opening  40   a  formed in the protection plate  24 , flows through the venting openings  22   a  and  22   b  into the housing  14 , receives the heat generated by the electric components arranged within the housing  14  and flows out through the venting openings  22   c  of the housing  14  and the venting openings  40   b  and  40   c  of the protection plate  24 . 
     Moreover, the main plane  26  of the protection plate  24  is formed with a cable opening  42  for feeding through the cables of the hob  10 . The edges of the cable opening  42  may be chamfered and/or provided with a cable protection means (not shown), e.g. a plastic protection rail, which can be clipped on the edges of the cable opening  42  in order to protect the user from getting cut. 
     Thanks to the thermically isolated protection plate  24  as well as to the distance between the bottom wall  16  of the housing  14  and the main plane  26  of the protection plate  24  created by the spacers  28  it is prevented that a user, who accidentally comes into contact with the bottom side of the hob  10 , gets burned. Moreover, the electrical isolation of the protection plate  24  prevents that the user receives an electric shock. Since the protection plate  24  is not fixed to the furniture but to the hob  10  itself there is no need to adapt the size of the protection plate  24  to the dimensions of the furniture, e.g. to the dimensions of floor cupboard. Thus, the assembly of the hob  10  can be performed in an easy, fast and inexpensive manner. 
     It should be noted that the spacers  28  can also be provided as separate elements, e.g. in the form of spacer bushings arranged around the screws  23 . 
       FIGS. 3 and 4  show a hob  50  according to a second embodiment of the present invention. The structure of the hob  50  is very similar to the one of the hob  10  shown in  FIGS. 1 and 2  for which reason corresponding components of the hob  50  are designated with the same reference numerals as used in  FIGS. 1 and 2  in order to simplify matters. The hobs  50  and  10  only vary in that the hob  50  comprises snap-fitting means  52  instead of the screws  30  for fixing the protection plate  24  to the housing  14  of the hob  50 . The snap-fitting means  52  are provided at the exterior of the spacers  28  and project upwardly towards the housing  14 . The snap-fitting means  52  comprise snap-fitting projections  54  which project inwards and latch into corresponding snap-fitting openings  56  formed in the side walls  18  of the housing  14 . 
     Thanks to the snap-fitting means  52  the fixation of the protection plate  24  to the bottom wall  16  of the housing  14  can be performed in a very fast and comfortable manner.