Abstract:
The invention relates to a switch for a door, a flap or a door handle of a motor vehicle, having a base body with a receptacle; a first contact area and second contact area, both areas provided in the receptacle; a snap-action plate arranged in the receptacle having a curved region situated above the first contact area, and at least three support elements, with at least one support element contacting the second contact area, the curved region undergoing elastic deformation by operation of the snap-action plate, thereby achieving an electrical connection between the two contact areas and therefore generating a switching signal, with the second contact area, which is at a distance from the first contact area, extending at least in regions around the first contact area such that at least one support element touches the second contact area in every possible position of the snap-action plate within the receptacle.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to German application no. DE 10 2010 037 511.9 filed on Sep. 15, 2010, which is hereby incorporated by reference in its entirety. 
     SEQUENCE LISTING 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not Applicable 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The invention relates to a switch for a door, a flap or a door handle of a motor vehicle, having a base body which has a receptacle, a first contact area and a second contact area, which are provided in the receptacle, and a snap-action plate which is arranged in the receptacle, with the two contact areas being electrically connected to one another by means of operation of the snap-action plate, as a result of which a switching signal can be generated. 
     (2) Background Art 
     DE 10 2007 062 907 B3 describes a snap-action plate which can be used in a switch. It has disadvantageously been shown that the production of such switches with a snap-action plate can be complex since corresponding adjustment of the snap-action plate to the contact areas of the receptacle is required so that reliable functioning is ensured when the switch is in the assembled state. Specifically, it is necessary to ensure that the snap-action plate is placed in the receptacle in such a way that an electrical connection is always established between the two contact areas, which are arranged within the receptacle, when the snap-action plate is operated. 
     BRIEF SUMMARY OF THE INVENTION 
     The object of the present invention is to avoid the above-mentioned disadvantages, in particular to provide a switch which can be produced in a simple and cost-effective manner. 
     The object of the present invention is achieved by all the features of patent claim  1 . Advantageous developments are cited in the dependent claims. 
     According to the invention, provision is made for the switch to be formed with a base body which has a receptacle. Furthermore, a first contact area and a second contact area are located in the receptacle, with the snap-action plate being arranged in the receptacle. In addition, the snap-action plate has a curved region, which is situated above the first contact area, and at least three support elements, with at least one support element making contact with the second contact area, with the curved region undergoing elastic deformation by means of operation of the snap-action plate, so that an electrical connection between the two contact areas can be achieved and therefore a switching signal can be generated. In this case, it is essential to the invention that the second contact area, which is at a distance from the first contact area, extends at least in regions around the first contact area in such a way that at least one support element touches the second contact area in every position of the snap-action plate. A particular advantage of this invention is that the snap-action plate has to be introduced only into the receptacle of the base body, without it being necessary to orient the snap-action plate within the receptacle depending on the position of said receptacle since the arrangement of the first contact area and of the second contact area according to the invention ensures that the snap-action plate always touches the second contact area at least by way of one support element. Readjustment of the snap-action plate within the receptacle is therefore no longer necessary, as a result of which the complexity of production of a switch can be considerably simplified. 
     According to the invention, provision can be made for the receptacle to be of circular, oval, square, rectangular or triangular design. The snap-action plate, by way of its support elements, should be adapted depending on the geometrical design of the receptacle. 
     It may be advantageous for the first contact area to be arranged centrally in the receptacle and/or the second contact area to extend along the edge region of the receptacle. If the switch is operated, the curved region of the snap-action plate undergoes elastic deformation, and therefore contact is made with the first contact area, as a result of which the snap-action plate, which is composed of metal, electrically connects the first contact area and the second contact area to one another. In contrast, the second contact area runs on the edge region of the receptacle and has a defined length, so as to ensure that one of the support elements makes contact with the second contact area in every location and every position of the snap-action plate within the receptacle. 
     In an advantageous embodiment of the invention, the snap-action plate can have n support elements, with each support element being oriented at an angle α=(360/n)° relative to the adjacent support element. It is therefore feasible for the snap-action plate to have three, four or more support elements, said support elements likewise serving as “contact legs” in this case in order to make contact with the second contact area. 
     If the receptacle is of circular design, one possible design variant of the invention makes provision for the second contact area to extend on a circular path, with the length L of the second contact area being L&gt;arc(α)×r, where r is the radius of the circular path. As a result, it is possible to ensure that a support element of the snap-action plate always rests on the second contact area, without complex adjustment of the snap-action plate being necessary during assembly of the switch. 
     It is likewise feasible for the second contact area to be made up of individual contact areas which are spaced apart from one another. Therefore, a large number of individual contact areas can form the second contact area within the receptacle, said individual contact areas being geometrically arranged in relation to one another in such a way that at least one support element makes contact with one individual contact area in every possible position of the snap-action plate within the receptacle. 
     In one possible embodiment of the invention, the first contact area and the second contact area can be composed of metal, in particular the first contact area and/or the second contact area can be coated with gold. One advantage of the gold coating is that the corrosion resistance of the contact areas can be significantly increased, as a result of which the service life of the switch can be increased. 
     In order to further simplify assembly of the switch, the receptacle can have an obliquely running wall region which tapers in the direction of the snap-action plate. In this case, the wall region, which runs obliquely, serves as a mounting aid for the snap-action plate which is to be inserted. In this case, the wall region is formed in a funnel-like manner, with the obliquely running wall region becoming narrower in the direction of the receptacle. During the mounting and the insertion of the snap-action plate, the snap-action plate slips and/or slides along the oblique wall region and approaches the receptacle. The snap-action plate then breaks contact with the oblique wall region and falls onto the second contact area by way of at least one of the support elements. 
     In one feasible embodiment of the invention, a cover, which is composed of plastic and is attached to the base body, can close the receptacle in a sealing manner, with, in particular, the cover being attached to the base body in an interlocking and/or force-fitting and/or cohesive manner. For example, it is possible to attach the cover to the base body by means of an adhesive connection or a clip connection. The cover can likewise be attached to the base body by laser welding. In a further cost-effective alternative, provision is made for the base body to have latching elements which project into mating latching elements of the cover. The cover can have, for example, one or more openings into which latching elements of the base body project in an interlocking and/or cohesive manner and therefore constitute a reliable and cost-effective alternative for attaching the cover to the base body. As a result, the snap-action plate is reliably covered within the receptacle. 
     In order to prevent unnecessary movement of the support elements during operation of the switch or of the snap-action plate, during which the curved region undergoes elastic deformation in the direction of the first contact area, the cover has a foot element in one possible embodiment of the invention, said foot element projecting into the receptacle and making contact with the support elements, as a result of which the snap-action plate can be reliably fixed. The foot element therefore reliably holds each of the support elements in its position on the second contact area. There is no risk of the support element losing contact with the second contact area even when the snap-action plate is operated. 
     The foot element can advantageously run in an encircling manner, in particular the foot element can be of annular design. The foot element can at the same time perform a sealing function for the cover. In the case of a circular receptacle, the foot element has a circular design which projects into the receptacle in the manner of a projection and at the same time makes contact with the support elements. 
     In a measure which improves the invention, provision can be made for the cover to have a seal which has a first seal region and a second seal region, with the first seal region being a radial seal and the second seal region being an axial seal, with, in particular, the seal being L-shaped in a cross-sectional view of the cover. In this case, the foot element can be a constituent part of the second seal region which acts as an axial seal. 
     The receptacle can advantageously be surrounded by a collar element of the base body, with the cover resting on the collar element, with, in particular, the seal making contact with the collar element. In this case, the collar element can protrude out of the base body in the manner of a projection, with the collar element bounding the receptacle at the same time. The first seal region and the second seal region can rest against the collar element when the cover is in the attached state. It is likewise feasible for the obliquely running wall region to be arranged on the collar element or even be integrated in the collar element. Furthermore, the collar element can be designed with corresponding latching elements in order to ensure a reliable clip connection to the cover. 
     In one possible embodiment of the invention, the cover can be a two-component plastic part, with a first region of the plastic part being produced from a first plastic and a second region of the plastic part being produced from a second plastic, with the first plastic being softer than the second plastic. In one possible embodiment of the invention, it is feasible for the first and/or the second seal region to be at least partially formed with the first plastic. It is likewise feasible for the foot element to be formed with the first plastic. Manufacturing tolerances can advantageously be compensated for by virtue of the use of the softer plastic, and therefore reliable attachment of the cover to the receptacle is ensured. 
     The first region of the cover can advantageously be formed with an internal contact element which extends in the direction of the curved region of the snap-action plate. This provides improved haptic behavior of the switch, it being possible for the internal contact element, which extends in the direction of the snap-action plate in the manner of a projection, to be at a distance from the snap-action plate or to rest on the curved region of the snap-action plate when the switch is not operated. The two last-mentioned design variants of the contact element make it possible, inter alia, to influence the haptic behavior of the switch and to influence the travel of the switch. If the contact element rests on the snap-action plate without the switch being operated, the travel can be considerably reduced, as a result of which the switch can be constructed to be compact overall. 
     Provision can likewise be made for the second region of the cover to surround the first region of the cover, with the second region of the cover being attached to the base body. The second region of the cover, which is composed of a relatively hard plastic, can be used to actually attach the cover to the base body, it being possible for the second region to also perform the sealing functions at the same time. In contrast, the first, softer region of the cover serves to provide corresponding haptics for the user. 
     In a further embodiment of the switch according to the invention, the mating latching element of the cover can be formed with a latching hook which is held in the latching element of the base body, with the latching element of the base body being in the form of an opening. In this case, the mating latching element can be integrated in the second region of the cover. The second region of the cover can have a plurality of mating latching elements which are reliably held on the base body by means of a latching connection. In one possible embodiment of the invention, the cover has two latching hooks, with the snap-action plate being located between the two mating latching elements of the cover. One advantage of this embodiment is that the cover can be easily mounted on the base body by means of the latching hooks. 
     It is likewise feasible for the second region of the cover to have an edge on the lower face of the cover, with the edge having a sealing means which is formed from the first plastic, with, in particular, the first region being integrally connected to the sealing means. Therefore, in addition to a first seal region and a second seal region, the cover can have a further sealing means on the edge of the cover, said sealing means creating an additional sealing effect for the switch. 
     In addition, the first contact area and the second contact area can respectively be a constituent part of a first contact element and of a second contact element, with the first contact element and the second contact element extending out of the receptacle. The sealing means of the edge of the cover provides reliable sealing of the first contact element and of the second contact element, it being possible for said contact elements to further extend outside the cover. In contrast, the first seal region and the second seal region, which provide radial and axial sealing, serve mainly to ensure that the constituent parts within the receptacle are reliably sealed off. 
     In order for the cover, which is in the form of a two-component plastic part in one possible embodiment, to represent a stable overall construction, the first region and the second region can have a common contact area which is formed, in particular, in a stepped and/or staircase-like manner. The corresponding geometric design of the contact areas of the first region of the cover and of the second region of the cover additionally has the effect that good haptics are ensured when the first region is operated, without there being a risk of the first region becoming detached from the second region. The stepped and/or staircase-like contact areas therefore likewise make a contribution to reliable connection of the first region to the second region. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Further advantages, features and details of the invention can be gathered from the following description. Several exemplary embodiments of the invention are described in detail with reference to the drawings. In this case, the features mentioned in the claims and in the description may each be essential to the invention individually in their own right or in any desired combination. In the drawings: 
         FIG. 1  shows one possible exemplary embodiment of a switch according to the invention with a snap-action plate, a cover and contact areas on which the snap-action plate rests, 
         FIG. 2  shows a further exemplary embodiment of a switch with a snap-action plate, contact areas and a cover, 
         FIG. 3  shows a plan view of a receptacle of the switch, it being possible for the snap-action plate according to  FIG. 1  to be inserted into said receptacle, 
         FIG. 4  shows the receptacle according to  FIG. 3 , with the snap-action plate inserted in said receptacle, 
         FIG. 5  shows a further alternative embodiment of a receptacle according to  FIG. 3 , 
         FIG. 6  shows the switch according to  FIG. 2  in a further, three-dimensional view, 
         FIG. 7  shows a further exemplary embodiment of a switch with a snap-action plate, contact areas and also a cover, 
         FIG. 8  shows a further exemplary embodiment of a switch with a snap-action plate, contact areas and also a cover, and 
         FIG. 9  shows a further view of the switch according to  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     All the exemplary embodiments according to  FIG. 1  to  FIG. 9  show a switch according to the invention which can be used in a door, in a flap or in a door handle of a motor vehicle. The switch has a base body  10  which is designed with a receptacle  11  into which a snap-action plate  40  can be inserted. The receptacle  11  has a first contact area  31  and a second contact area  32 , said contact areas being at least partially illustrated in  FIG. 1  to  FIG. 5 . According to the shown exemplary embodiments, the first contact area  31  is arranged centrally in the receptacle  11 . In contrast, the second contact area  32  extends along the edge region of the receptacle  11  and is at a defined distance from the first contact area  31 . In this case, the receptacle  11  is of circular design. The first contact area  31  is likewise of circular form, with the second contact area  32  extending along a circular path. 
     According to  FIG. 1 ,  FIG. 2 ,  FIG. 4  and  FIGS. 7-9 , the snap-action plate  40  has a curved region  41  which is situated above the first contact area  31 . In addition, the snap-action plate  40  has a plurality of support elements  42 , with the snap-action plate  40  and also the second contact area  32  being geometrically matched to one another in such a way that at least one support element  42  makes contact with the second contact area  32 . This ensures that reliable functioning of the switch, in the case of which the two contact areas  31 ,  32  can be electrically connected by means of operation of the snap-action plate  40 , is ensured in every feasible installation position of the snap-action plate  40  in the receptacle  11 . It is not necessary, during production of the switch, after the snap-action plate  40  has already been inserted into the receptacle  11 , to readjust the snap-action plate  40  relative to the second contact area  32  or to rotate it about an axis which runs perpendicular to the plane of the drawing according to  FIG. 3  or  FIG. 4  and extends through the first contact area  31 . 
       FIG. 3  shows one possible exemplary embodiment of the geometric design of the second contact area  32  which extends along a circular path around the first contact area  31 . In addition to this,  FIG. 4  shows the snap-action plate  40  which is inserted into the receptacle  11  according to  FIG. 3 . In this exemplary embodiment, two support elements  42  make contact with the second contact area  32 . However, according to the invention, it would be sufficient if the second contact area  32  were only to have a length, in particular an “arc length”, in the case of which only one support element  42  would rest on the second contact area  32 , this not being explicitly illustrated. This means that the length L of the contact area  32  can be described in accordance with the following equation: L&gt;arc(α)×r, where r is the radius of the circular path and α=(360/n)°, where n is the number of support elements. 
       FIG. 5  shows a further exemplary embodiment in which a second contact area  32  is provided, said second contact area being made up of three individual contact areas  32  which are spaced apart. It goes without saying that it is feasible to vary the number of individual contact areas and also the respective lengths of the individual contact areas  32 . It is possible to ensure, as a function of the geometry of the snap-action plate  40  and also the individual contact areas  32 , that contact with at least one support element  42  and one individual contact area  32  is always ensured in every location and position of the snap-action plate  40 , this not being explicitly illustrated in the figures. 
       FIG. 7  schematically shows the receptacle  11  which has an obliquely running wall region  12 . The wall region  12  is in the form of a funnel. In this case, the wall region tapers in the direction of the snap-action plate  40  which rests on the second contact area  32  by way of its support elements  42 . One advantage of an obliquely running wall region  12  is that the snap-action plate  40  can be simply “thrown” into the receptacle  11  during production of the switch and insertion of the snap-action plate  40 , with the wall region  12  at the same time ensuring that the snap-action plate  40  reliably finds its way into the receptacle  11  and onto the contact areas  31 ,  32 . In the process, the snap-action plate  40  slides along the wall region  12  by way of its support elements  42 , until the snap-action plate  40  falls into the receptacle  11 . The wall region  12  therefore serves as a mounting aid for the snap-action plate  40 . 
     As illustrated in  FIGS. 1 and 2  and  FIGS. 7-9 , the cover  20  has a foot element  22  which projects into the receptacle  11  and makes contact with the support elements  42 . This results in the snap-action plate  40  being reliably held in the installed state, without the risk of one or more support elements  42  breaking contact with the second contact area  32  when the switch is operated. In this case, the foot element  22  is formed in an encircling, annular manner. 
     As can be seen in  FIG. 1 ,  FIG. 2  and also  FIG. 7  in particular, the receptacle  11  is surrounded by a collar element  14  of the base body  10 . The collar element  14  constitutes a kind of wall in this case.  FIG. 1  illustrates one possible exemplary embodiment for attaching the cover  20  to the base body  10 . In this case, the cover  20  is laser-welded to the collar element  14 , as a result of which the encapsulated receptacle  11  is reliably sealed off. In a further exemplary embodiment, it is likewise feasible for the cover  20  to be attached to the collar element  14  by means of an adhesive connection. 
     A further exemplary embodiment for attaching the cover  20  to the base body  10  is illustrated according to  FIG. 2 ,  FIG. 6  and also  FIGS. 7-8 , with the cover  20  being attached to the base body  10  by means of a clip connection. In this case, the base body  10  has hook-like latching elements  13  which engage in mating latching elements  21 , in particular openings  21  in the cover  20 , and therefore ensure reliable attachment of the cover  20  to the base body  10 . In order to ensure reliable sealing of the inner region of the receptacle  11 , the cover  20  has a seal  23  which has a first seal region  23 . 1  and a second seal region  23 . 2  according to  FIG. 2 . The seal  23  is of L-shaped design in the cross section of the cover  20 . In this case, the cover  20  is a two-component plastic part, with the seal  23  being composed of a first plastic. In this case, the cover  20  has a first region  24  which is arranged centrally on the cover  20 . The second region  25  surrounds the first region  24 , with the second region  25  of the cover  20  being harder than the first region  24 . In addition, the first region  24  of the cover is formed with an internal contact element  26  which extends in the direction of the curved region  41  of the snap-action plate  40 . In the following exemplary embodiment, the first region  24  of the cover  20  is produced from the same first plastic as the seal  23 . 
       FIGS. 8 and 9  show a further variant of an exemplary embodiment, with the cover  20  being a two-component plastic part. The first region  24  of the cover  20  serves as a pushbutton for the snap-action plate  40  in this case. The second region  25  of the cover  20  is formed with a mating latching element  21 , with the mating latching element  21  being formed with a latching hook  21 . 1  at its free end. In the present exemplary embodiment, the cover  20  has two mating latching elements  21  with a latching hook  21 . 1  in each case, with each mating latching element  21  projecting through a latching element  13  of the base body  10 . The latching element  13  of the base body  10  is in the form of an opening in which the mating latching element  21  of the cover  20  is held in a reliable manner. 
     This connection of the cover  20  to the base body  10  constitutes a reliable and simple latching connection. In this case, the second region  25  of the cover  20  is produced with the relatively hard second plastic, so as to ensure that the cover  20  is reliably fixed to the base body  10 . In contrast, the first region  24  of the cover  20  is formed with the first plastic which is softer than the second plastic. As in the other exemplary embodiments according to  FIG. 1  to  FIG. 7  too, the first region  24  of the cover  20  serves as a pushbutton in order to correspondingly deform the snap-action plate  40  which is situated beneath said cover. 
     As can be clearly seen in  FIG. 9 , the second region  25  of the cover  20  has an edge  25 . 1  on the lower face  27  of the cover  20 . This edge  25 . 1  has a sealing means  28  which is formed from the first plastic. In this case, the first region  24  is integrally connected to the sealing means  28 . The first contact area  31  and the second contact area  32  are respectively a constituent part of a first contact element  31 A and of a second contact element  32 A. In this case, the first contact area  31  and the second contact area  32  are located in the receptacle  11  of the base body  10 . The first contact element  31 A and the second contact element  32 A extend from the receptacle  11  and leave the cover  20  at the point which is provided with reference symbol  29 . In a further alternative embodiment which is not explicitly illustrated, the two contact elements  31 A and  32 A can extend perpendicular to the plane of the drawing according to  FIG. 8 . In order to ensure the cover  20 , which is formed from two components, has good haptics properties and a long service life, the first region  24  and the second region  25  are formed with a common contact area  24 . 2 ,  25 . 2  which has a staircase-like geometry. 
     It goes without saying that further embodiments of a snap-action plate  40  can be used in this invention, it being possible for said further embodiments to have three or more than four support elements  42 . The idea of the invention likewise also covers the possibility of the receptacle  11  having a geometric shape which differs from the circular design which is shown in the exemplary embodiments. The arrangement of the first contact area  31  and of the second contact area  32  can also vary within the receptacle  11 . In order to increase the service life of the switch, the first contact area  31  and the second contact area  32  and also the snap-action plate  40 , in particular the curved region  41  and the support elements  42 , can have a coating which, in particular, comprises at least Au and/or Ni and/or Ag and/or Sn. 
     It is likewise feasible for the cover  20  to be composed entirely of the soft plastic, like the first region  24 , according to all the exemplary embodiments. 
     LIST OF REFERENCE SYMBOLS 
     
         
         
           
               10  Base body 
               11  Receptacle 
               12  Wall region 
               13  Latching element 
               14  Collar element 
               20  Cover 
               21  Mating latching element, opening 
               21 . 1  Latching hook 
               22  Foot element 
               23  Seal 
               23 . 1  First seal region 
               23 . 2  Second seal region 
               24  First region of the cover 
               24 . 2  Contact area 
               25  Second region of the cover 
               25 . 1  Edge 
               25 . 2  Contact area 
               26  Internal contact element 
               27  Lower face 
               28  Sealing means 
               29  Position, location, point 
               31  First contact area 
               31 A First contact element 
               32  Second contact area 
               32 A Second contact element 
               40  Snap-action plate 
               41  Curved region of the snap-action plate 
               42  Support element