Abstract:
A switch system wherein the housing consists of a spatially injection-molded conductor support (MID technique). The switch system is designed such that it can be largely adapted to the requirements of automotive technology. To that end, the top of the housing has a surface which can be equipped as desired with electrical and/or mechanical components and its underside has pin-like projections which are connected to strip conductor and act as plugs.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to a switch system operating by the MID technique. It concerns a three-dimensional injection-molded conductor support in which the wires are inserted directly into a three-dimensional housing. 
     2. Description of the Art 
     By this method, several layers of conductors can be encapsulated within the housing. It is also possible to encapsulate conductor track-like plastic structures in a housing which subsequently can be metal-plated and insulated. With this method, the conductor tracks run on the surface of the housing which extends in three directions in space (3D). Further details of said method are described in the magazine “Elektronik,” Vol. 15, of Jul. 20, 1990 (pages 28-31). Further information is provided in an announcement by Forschungsvereinigung räumliche elektronische Baugruppen 3-D MID e.V. [Research organization for three-dimensional electronic components 3-D MID, registered]. The present invention deals with applying these techniques to a switch system, in particular, in the field of automotive engineering. 
     Because of the steadily growing number of electronic and electrical driving aids used in motor vehicles, the demand for switches has increased accordingly. Conventional switches essentially are comprised of a button, housing, contact system, mechanical detent, base plate, and cable connector. It is the object of the invention to simplify the design of this type of switch, while reducing its spatial dimensions. 
     SUMMARY OF THE INVENTION 
     A possible application of the MID technique to switches is described in DT-OS 44 26 350.3. The invention, therefore, starts out from a switch system. In principle, the present invention thus comprises the switch housing which is so designed that at one side it allows a simple automatic fitting of the switch housing with electronic and/or mechanical components, while making full use of the advantages offered by the MID technique. By this method, a switch system is created which can be flexibly equipped and, having been provided with conductor track supports, can be flexibly connected. This type of system offers special advantages in that the inventive housing offers extremely variable uses, as a result of which the large quantity essential for the MID technique can be achieved, in order to guarantee an efficient production of switches. 
     In addition, the inventive housing offers the option of operating by the MID technique insofar as, at the same time, the cable connector is developed as a molded plastic component in which the plastic projections serving as cable connectors are metal-plated. 
     Of course, it is also within the scope of the invention if, in special cases, electrical or mechanically-stressed parts are molded into the plastic housing. This, for example, can be achieved in that the plug section of the housing is provided with molded pins in order to guarantee a permanent contact even if it is necessary to plug in the plug several times, or otherwise, the conductor tracks forming the plug would be subjected to excessive electrical or mechanical stress. 
     Because the component surfaces are located at the upper side of the housing, while the switch section is arranged at the underside of the housing, the usual feed through connections will, as a rule, be necessary to provide a cable connection from the upper to the lower side of the housing. 
     This type of feed through connection also allows connection changes in the switch system in that some contact openings are designed to be conductive, while others have no conductive connections. 
     However, it is possible not only to modify the protective circuits in the housing, but also to form various switch types. Microswitches can be so selected that, when actuated, close or open a circuit or switch to a different circuit or, after having been actuated, execute several of these processes simultaneously. These various microswitch types may be installed simultaneously in multiple locations into the inventive housing and be combined among one another. In addition to a microswitch or instead of a microswitch, it is also possible to use an LED which in automotive engineering informs the driver either of the position of the switch (during darkness) or of the status of the switch (on or off). 
     Ultimately, the inventive housing can be so equipped that no microswitch is provided and that the housing performs indicator functions only by means of the LED. 
     It is also possible to actuate the microswitch manually or by mechanical operating devices directly, or to form the indicator surface directly by means of the surface of the inventive housing. In many cases, however, the electric circuit on the surface of the housing is protected or covered for aesthetic reasons. Thus, the housing is placed onto a cover which shields the protective circuits on the housing and prevents mechanical access. For example, by inserting lenses into the cover or by installing windows, which could be provided with symbols, the motor vehicle operator is provided with an aid. 
     A simple form of operating the microswitch fitted at the upper side of the housing can also be achieved. By this method, the cover serves as a button for the switches, in that the cover can be actuated manually or mechanically. By this method, it is necessary to take into consideration that the contact travel must meet various requirements. If, for example, the cover represents the button of a pushbutton, a comparatively small contact travel is adequate. This also applies if the circuit is to be activated only when the button is pressed. On the other hand, however, it may be desired that the position of the button also indicates the switching status of the switch. With a pushbutton, for example, this may be the down position of the pushbutton, or with a toggle switch it may be the tilt position of the switch. Therefore, this requires considerable contact travel for the motor vehicle operator to clearly identify the position of the button. In order to also meet this requirement with the inventive housing, an attachment is placed onto the housing, which, as a result of a corresponding seating of the cover, ensures an extended push or toggle path. The cover is preferably latched onto the housing. However, there are other options of attaching said cover, such as gluing, welding, or the like. 
     If the cover is to be tiltable with respect to the adapter and the housing, it is recommended that the point of rotation is placed as high as possible, so that the cover achieves the highest angle of rotation before it is stopped by the housing. 
     Within the scope of the invention, however, it is also possible that the cover itself be produced by applying the MID technique and thus acts as a movable contact element. Further, said cover can act both as a contact element in a pushbutton and as a toggling element in toggle switch. These switching functions may be selected in addition to actuating the microswitches located on the housing or instead of these microswitches. 
     In order to achieve a permanent switching status, and to fix the position of the cover corresponding to the switching position of the actuated switch, it is recommended to have the adapter and the cover form a latch configuration as an improvement of the invention. This offers the essential advantage that the latching configuration can simply be adapted by selecting the adapter and the cover for the selected switch. In connection with the button, the adapter ensures that the desired latching positions are provided at the same time. As a result, further means are provided to adapt the inventive housing to the changing requirements of switches. 
     A particularly simple latching option has a latching curve in the adapter and a detent cam, which both elastically interlock, formed of a stop bolt which is spring-loaded at the cover. At the same time, the latching positions are provided essentially by the adapter, so that by selecting a corresponding adapter it also is possible to obtain the desired latching positions, without having to replace the cover. By developing the cover with the MID technique with an injection-molded conductor support, the inventive switch system provides a number of additional advantages. For one thing, as mentioned above, the cover itself can serve as a contact element. In special cases, it is also possible to fit the cover with a metal-plated contact element, which, for example, can be molded in order to improve the switching quality of the cover. By inserting the conductor tracks into the cover, a lamp (for example, an LED) can be installed in the cover itself, so as to avoid the use of special light guides. By this method, it must be ensured that the lamp is supplied with power, which, for example, can be done via the latching device, or with a movable cover via the bearing enabling the movement. There is also the basic possibility of molding, at suitable locations, components in the housing (or the cover) which achieve the desired properties, so that improvements can be achieved in the mechanical or electrical field. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The embodiments of the invention are explained in the following by means of the drawing. Shown are: 
     FIG. 1 is a first embodiment of the inventive housing with a tiltable cover; 
     FIG. 2 is an elevated form of the housing with a solidly latched cover; 
     FIG. 3 is a front view of the housing according to FIG. 2; 
     FIG. 4 shows the housing according to FIG. 2 with a tiltable cover; 
     FIG. 5 shows the housing according to FIG. 4 with a latching configuration; 
     FIG. 6 is a sectional front view of the housing according to FIG. 4, with inserted adapter and a mounted tiltable cover; 
     FIG. 7 shows a top view of the housing according to FIG. 2, with the arrangement of the prepared solder contacts; 
     FIG. 8 is the view of the housing according to FIG. 7, provided with LEDs and microswitches; 
     FIG. 9 is a sectional front view of the housing according to FIG. 6, also showing the formation of the cover as an injection molded conductor support, and a lamp inserted into the cover with power being supplied via the swivel bearing; and 
     FIG. 10 is a sectional front view of the housing according to FIG. 6, also showing the formation of the cover as an injection molded conductor support, and a lamp inserted into the cover with power being supplied via the latch devices. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a housing  1  which is produced according to the MID technique. This means that within the molded housing, the conductor tracks and electrical connections are already embedded or brought out at the surface. The housing  1  is provided with at least one level component surface  3  on the housing interior or housing top surface  2  onto which components according to the SMD technique (Surface Mounted Device) can be mounted and soldered by means of automatic machines. In this case, microswitches  4  and an LED  5  are provided as components. 
     The housing  1  at its underside has molded projections  6 , the surfaces of which are developed as electrically conductive conductor tracks, so that the projections  6  as a whole function as switches. Further provided at the housing  1  are stop ends  8  for-limiting the tilting motion of a cover  9 , which is tiltable via pivot pins  10  of a pivot bearing (not shown in detail). A window  11  is installed in the cover  9  through which the light of the LED  5  is visible. On the top surface of the cover  9  there also is provided a gripping surface  12 . 
     FIG. 2 shows a slightly modified design of the housing  1  in which the modifications serve to adapt the shape of the housing to the shape of commonly used switches. In terms of the invention, it is important that with the embodiment according to FIG. 2, the cover  9  is latched onto the housing  1  (also refer to FIG.  3 ), and thus is solidly mounted onto the housing  1 . The housing also has two windows  13 ,  14  which, in an appropriate manner, can be inserted or even molded into the cover. Through these windows  13 ,  14  emerges the light of the LEDs  15 ,  16  which are placed onto the component surfaces  17 ,  18  according to the SMD technique. The component surfaces  17 ,  18  are elevated in order to use automatic machines for installation that are able to reach the flat component surfaces. 
     The cover  9  in FIG. 2 has a partition  19  which separates the light of the two LEDs  15 ,  16 . It is also possible to arrange an additional diode in a socket  20  on the housing  1 , in which, however, two partitions must be provided. 
     FIG. 3 shows a partial section of a front view of the housing according to FIG. 2 which clearly indicates that the cover is attached to the housing  1  via latching devices  21 ,  22 . 
     In FIG. 4, the cover  9  according to FIG. 2 is tiltable at the housing via a pivot bearing  23 . For this purpose, corresponding side walls can be constructed at the housing. However, an adapter according to FIG. 6 may also be used which subsequently will also be explained in greater detail. FIG. 4 also shows bore holes  24  for the purpose of the feed through connections, thus connecting the conductor tracks on the upper side of the housing  2  with the lower side of the housing  25 . By this method, the connections for microswitch diodes and other electrical components can be connected with the projections  6  that function as switches  7 . 
     FIG. 5 shows the housing according to FIG. 4 in which a latching configuration is provided. Moreover, the housing  1  is provided with a latching curve  27  which acts upon a stop bolt  28  which is spring-loaded in the cover  9 . 
     FIG. 6 shows the housing according to FIG. 4 in which, however, an adapter  29  was used. The adapter  29  has the function of relocating the point of rotation of the cover  9  via the component surface  2 . By this method, it is possible to keep the housing  1  relatively flat if, according to FIG. 2, said housing is needed purely as an indicator. With a number of component insertion machines, in particular, if a large number of adjacently configured housings are to be fitted simultaneously, it is not possible for the component insertion machine passing over the housing  1  to dip into lower-lying component surfaces. With respect to the housing  1 , the component surfaces, therefore, should be located on the upper surface. In this case, however, it would not be possible to relocate the point of rotation of the cover  9  beyond the component surface without an adapter  29 . However, to still achieve a wide contact travel for the cover  9 , the components are fitted first, and then the adapter  29  with the cover  9  is placed onto the fitted housing  1 . As is obvious from the comparison of FIGS. 3 and 6, the latching devices  21 ,  22  for the adapter  29  and the cover  9  are identical, so that instead of the cover  9  in FIG. 3, the adapter  29  can be inserted into the latching devices  21 ,  22 . 
     Moreover, FIG. 6 shows a latching means corresponding to the latching means  26 ,  27  in the front view. Further, the latching curve can be arranged both at the housing  1  and the adapter  29  in which the second option preferably is used for the reasons stated above. 
     As is shown in FIG. 6, two latching means are prepared in the cover  9 , so that by turning the cover  9 , it is possible to achieve a deviating latching path. 
     FIG. 7 shows a top view of the housing  1  and especially the component surfaces  3  of the upper side of the housing  2 . In this view, the prepared soldering points  3 , which serve as connecting points for the electrical components, can be identified. These, for example, may be the microswitches  33  through  35 , and/or the LEDs  15 ,  16 ,  36  (see FIG.  8 ). By this method, a combination is also possible in that the toggle switch is only provided with a central LED  36  located on the base, while the two LEDs  15 ,  16  are omitted. FIGS. 7 and 8 also show the option of configuring microswitches of varying class and shape on the component surface  3 , so that these microswitches can be fitted randomly in any combination. 
     FIGS. 9 and 10 each show a sectional front view of the housing with an inserted adapter and a mounted tiltable cover. The cover  9  is shown as an injection molded conductor support, including a lamp  37  inserted into the cover. In FIG. 9, power is being supplied through conductive material  38  via the swivel bearing  30 . In FIG. 10, power is being supplied through conductive material  39  via the latching devices  21 ,  22 .