Abstract:
A cooktop has a metal support plate upon which heating equipment can be mounted and a control casing for housing or attaching a control unit or electronics. Fasteners allow for detachable connection of the metal support plate and the control casing to each other, and comprise fastenings formed on the metal support plate and corresponding slots on the control casing, whereby the fastenings are designed for attachment into the slots in an attachment orientation whereby movement of the two parts relative to each other results in the final assembled state. There is a moveable protrusion on the control casing and a recess or catch on the metal support plate that mates with the protrusion. During movement of the support plate and control casing into the final assembled position, the protrusion interacts with the catch or recess to lock the metal support plate relative to the control casing.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to German Application Number 20 2007 001 432.5 filed on Jan. 22, 2007, the contents of which are incorporated by reference. 
     FIELD OF THE INVENTION 
     The invention concerns a cooktop, and more specifically, a means for fastening two portions of a cooktop in a lockable, but yet releasable, manner. 
     BACKGROUND OF THE INVENTION 
     Usually with cooktops, such as induction cooktops, heating equipment is attached to the cooktop&#39;s metal support plate. Under this metal support plate, a control casing is affixed, which holds the controls or electronics for the cooktop. Fasteners are provided to connect the metal support plate and control casing as two detachable parts during assembly of the cooktop. Usually the control casing is screwed onto the metal support plate, for example with four metal screws at the corners of the control casing as fasteners. This step of screwing the parts together is relatively time consuming, which slows down and makes assembly of cooktop more difficult. 
     The invention addresses the problem of creating the type of cooktop named at the beginning, with which problems of the present assembly technology can be avoided and especially with which the assembly of the cooktop is made quicker and easier, and allows the detachment of the metal support plate and control casing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An example embodiment of the invention is presented schematically in the drawings and will be more closely described as follows, wherein: 
         FIG. 1A  illustrates a part of a cooktop in the form of a metal support plate and a control casing not yet attached; 
         FIG. 1B  illustrates an enlargement of a portion from  FIG. 1A ; 
         FIG. 2A  illustrates both parts from  FIG. 1A  in an attached state; 
         FIG. 2B  illustrates an enlargement of a portion from  FIG. 2A ; 
         FIG. 3A  illustrates both parts from  FIG. 2A  through the movement from the end orientation into the end position, and 
         FIG. 3B  an enlargement of a portion from  FIG. 3A . 
     
    
    
     DETAILED DESCRIPTION 
     One embodiment of a solution of this problem can be found in a cooktop with characteristics of claim  1 . Advantageous as well as preferable designs for the invention are subject to further claims and will be explained more closely below. The wording of the claims will be used in the description of the content through express reference. 
     According to one embodiment of the invention, fastenings and appropriate slots (or cuts formed in the shape of slits) are provided for the metal support plate and the control casing respectively. Fastenings are provided on one part, and cuts or slots on the other part. In some embodiments, both parts can have both fastenings and slots. The fastenings are equipped for attachment on or in the slots of the other part, whereby the attachment of both parts is carried out in a so-called attachment orientation. Furthermore, the fastenings and slots are also equipped so that both parts can be moved relative to each other into a final assembly orientation. In this way, the actual connection is produced when both parts are oriented towards each other in the final assembled position. In order to prevent movement in the reverse direction, or in other words, movement of the metal support plate and the control casing so as to disassemble the two components, there are provided, one on each respective part, a moveable protrusion and a catch. The catch can take the form of a recess or projection for the protrusion. During the movement of both parts into the end position, the protrusion moves to, or into the catch, in the case of a recess, or over and above the catch, in case of a projection. In this way, the end position effects a sort of locking mechanism with the catch. Preferably, the moveable protrusion is located on the control casing and the catch is located on the metal support plate, particularly as a projection. 
     Essentially, the control casing and the metal support plate can be arranged in the attachment orientation in an embodiment of the invention, whereby the fastenings grip into the slots. Through movement in the end position, the fastenings and the slots connect and lock into position. Once both parts are in the final position of the assembly or connection, the moveable protrusion and the catch forms a locking system that prevents the parts from detaching. This type of locking is reversible allowing for repairs, for example, particularly by bending back the protrusion from the catch. This allows other means of attachment such as screws to be foregone, at least for producing the connection itself. 
     It is possible to prepare the protrusion to be pre-stressed or flexible so that it works together with the catch on its own. Particularly, it can slide into the lock, for example, upon movement of both parts into the final assembled position. Especially advantageous is preparing the moveable protrusion as a kind of long flexible tongue. The catch can come out from a projection standing out from the other part or a further protrusion. When attaching both parts to each other in the attachment orientation, the moveable protrusion can be in front of the projection and then be moved over the projection and grasp behind it with a type of locking. For this to occur, the direction of movement of the moveable protrusion is most advantageously diagonal or perpendicular to the end orientation. For such independent movement of the moveable protrusion over the projection, the projection can have a beveling on the side, onto which the protrusion rests once attached and then upon movement of both parts in the end orientation over the projection, by bending away so to speak. On the other side, on which the moveable protrusion in the end position rests, the projection should be straight, or not have any beveling, so that a reverse movement is only possible by bending the tongue away. 
     In a further embodiment of the invention, in addition to an automatic (under the circumstances) connection between the catch and the moveable protrusion, detachable means of fastening can be provided, for example screws or bendable plates with which the moveable protrusion can be attached on, or behind the catch, to prevent reverse movement. 
     In a further embodiment of the invention, a locking between the moveable protrusion and the catch is provided so that it is only accessible from the side of the metal support plate opposite the control casing. Here, it is especially advantageous that the catch is a recession or depression in the metal support plate and the moveable protrusion is pressed into this for locking and can be forced out manually or with machine, in case the locking does in fact need to be undone in order to detach the two parts from each other. 
     Preferably, the fastenings are provided on the metal support plate and the respective slots on the control casing, particularly on a wide edge that stands out from the control casing and rests flat against the metal support plate. It is preferable to have several slots on two sides of the control casing and the respective fastenings, for a secure and generally stable attachment of the metal support plate onto the control casing. It is advantageous to have the fastenings on one part and the slots on the other, whereby the fastenings and slots can be identically prepared. 
     In order to further simplify the assembly and make it more secure, the fastenings and respective slots are distributed and arranged so the control casing can only be attached to the metal support plate in a single possible position. This helps avoid mix-ups during assembly and possible later repairs. 
     In further embodiment of the invention, it can be provided that the fastenings and the slots are prepared so that the slit-shaped cuts have a certain leeway when sliding in the fastenings, which enables a certain tolerance (or lack thereof) of precision during the attachment process. Particularly, the slots can be somewhat wider and a good bit longer than the fastenings. Furthermore, they should be so prepared that when moving the two parts from the end orientation into the final position the leeway becomes less, or at least ensures stability in the final assembled position. This is possible through slants and thickened portions (“thickenings”) in the area behind the cuts on which the fastenings rest during movement into the end position. 
     In further embodiment of the invention, it is possible that the moveable protrusion comes to rest against a projection as a catch when the fastenings are sliding into the slots or, in other words, when the control casing is being attached to the metal support plate. The tension of the protrusion can be overcome during attachment, so that the protrusion bends back appropriately. If the control casing in the end orientation is then moved to the metal support plate in the end position, the moveable protrusion grasps or snaps behind the projections and forms the lock. 
     The metal support plate can be larger than the control casing, two to five times larger, for example. Furthermore, it is advantageous to attach the control casing somewhat in the middle or center of the metal support plate and to have it in the same shape. Both parts can be produced most advantageously out of metal, but particularly the metal support plate. 
     These and further characteristics are found not only in the claims, but also from the description and drawings, whereby the individual features can be carried out alone or in combination with other features in the invention. The division of the application into separate sections as well as sub-headings does not restrict the general applicability of the statements made under them. 
       FIG. 1A  shows the cooktop, during the assembly of a metal support plate  13  and a control casing  20 . The metal support plate  13  has a rim  14  crimped downward, that surrounds an underside  15 . The underside  15  has a central opening  16  for connections between a control in the control casing  20  and heat equipment or induction spools that are laid on top of the metal support plate  13 , which are not shown here in the figure. Furthermore, the underside  15  on the metal support plate  13  has several exposed fastenings  17  that point towards the right as well as a projection  18 . From the enlargement in  FIG. 1B , it can be seen that the fastenings  17  are designed with the same shape and are similarly positioned for a particular direction. Furthermore, it can be recognized that the projection  18  has a slant  19  on the right side, while on the left it stands out at a right angle from the metal support plate  13 . 
     Around the control casing  20 , with a likewise rim  21  that stands out from the side, there are slots  23  in the form of slits cut in the rim  21  near the control casing  20 , namely six cuts  23  along the two longer sides of the control casing  20 . To the right next to the cuts  23 , the rim  21  has thickenings  24 . This is easy to see in  FIG. 1B . This will be discussed further later. 
     On the control casing&#39;s  20  right-pointing facing there is a flexible tongue  26 . This is bendable along the dotted line from the other rim  21  and divided from the rim  21  by the solid line. This is more clearly visible in  FIG. 2B . 
     The control casing  20  is arranged in the attachment orientation A according to  FIG. 1A  on the metal support plate  13  or the other way around. In the control casing  20  is the control or electronics. 
     In  FIG. 2A , it is shown how the control casing  20  is attached to the metal support plate  13  in the attachment orientation A according to in  FIG. 1A . All fastenings  17  grasp through the respective slots  23  into the control casing  20  or into its rim  21 . As seen in enlargement in  FIG. 2B , when attaching the flexible tongue  26 , it comes to rest exactly on the projection  29  or with the upper left edge shown in  FIG. 2B  in the area of the slanting. For this reason, it is bent on the lower right end of the rim  21  (at the dotted line). 
     Now the control casing  20  is moved along the direction E according to  FIG. 2A  after it contacts the metal support plate  13  or vice versa. After this movement, the cooktop is positioned in the final assembly position, according to  FIG. 3A . Viewing the enlargement of  FIG. 3B , it can be recognized how the fastenings  17  do not just grasp any area of the rim  21  on the end of the slots, but instead grasp right at the thickenings  24 . This secures a good attachment of the control casing  20  to the underside  15  of the metal support plate  13 , especially when the thickenings  24  from the slots  23  become thicker. 
     Furthermore, it can be recognized in  FIG. 3B  that the flexible tongue  21  snaps into position behind the projection  18 , or rests next to it, and the flexible tongue essentially rests flat against the metal support plate  13 . Since the projection  18  has no slants, the flexible tongue  26  cannot slip over the projection  18  when the control casing  20  is moved against the end orientation  26  and in this way a lock is formed that cannot detach automatically. This prevents the two parts from detaching by merely being pushed against each other. The projection  18  forms the lock described above. 
     It is recognized from  FIGS. 2B and 3B  that the rim  21  of the control casing  20  has a certain flexibility or bendability in the location of a separate flexible tongue  26 . This allows the tongue  26  to be bent when the control casing  20  is being attached to the metal support plate  13 . This allows the tongue to ride over the projection  18  during assembly and to snap into its regular position behind the projection  18  to lock the control casing  20  in position. 
     Detaching the control casing  20  can be carried out by bending the flexible tongue  26  away from the metal support plate  13  and thereby no longer letting it rest against the projection  18  (essentially unlocking it). A hole through the metal support plate  13  can additionally be provided, next to the projection  18 , through which the flexible tongue  26  can be pushed away from the projection  18  with a penetrating tool. 
     Likewise in  FIG. 3B , those skilled in the art may see that instead of the projection  18 , a larger opening in the metal support plate  13  could be provided on which the flexible tongue  26  rests. This flexible tongue  26  can be pressed or slid upwards into the recess of the metal support plate  13  either of its own accord or with a tool so that there the lock will not detach on its own. A disadvantage would be circumstances under which the flexible tongue extends over the upper edge of the metal support plate  13  and is in the way. 
       FIG. 3A  represents a glass ceramic plate  12  using dashed lines. This is brought up for the cooktop  11  on the metal support plate  13  when the induction spools are brought up on the upper side of the metal support plate  13 . A mainly mechanical linkage between the glass ceramic plate  12  and the metal support plate  13  can be produced with a outer rim, clamp or other mechanism not shown here. 
     In  FIG. 3B  it is likewise easy for those skilled in the art to see how the flexible tongue  26  can be connected to the metal support plate  13 , for example, by means of a metal screw, either from above first through the metal support plate  13  or from underneath first through the flexible tongue  26 . Further means of fastening are easily viable. 
     The advantage of attaching the fastenings  17  to the metal support plate  13  or accordingly to its underside  15  and the cuts  23  to the rim  21  or accordingly to the control casing  20  lies in the fact that the upper side of the metal support plate  13  can be made completely even and without extending parts. This allows the addition of heating equipment, especially induction heating equipment, to be particularly simple.