Abstract:
A flush mounted installation unit in which an operating portion of the installation unit such as the supporting plate, the covering or switch unit is designed as an antenna so that the unit can perform the dual function of housing and mounting the components for use in a control system and providing an antenna for a radio link between the central control unit and the components.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an installation unit, in particular an electric flush-mounted installation unit. 
     2. Description of the Prior Art 
     Installation units of the type mentioned in the introduction are used in a control system for a building or for one or more rooms in a building. Such control systems are provided with at least one central control unit and with at least two components connected to the central control unit via a radio link. Such control systems serve inter alia for regulating temperature. 
     With the aid of the installation unit mentioned in the introduction, the central control unit and also the components of the control system which are connected to the central control unit via a radio link are installed e.g. on walls of the rooms whose temperature level is to be regulated. Such an installation unit must therefore enable simple installation of a central control unit or a component of the control system. 
     SUMMARY OF THE INVENTION 
     Taking this as a departure point, the present invention is based on the problem of providing an installation unit for control systems which has been developed further and enables novel functions. 
     In order to solve this problem, the installation unit mentioned in the introduction is characterized by the fact that an assembly, in particular a metallic or metalized supporting plate, of the installation unit is designed as an antenna. A switch attachment of the installation unit may also be designed as an antenna. 
     As already mentioned, at least one central control unit of the control system for a building is connected to further components via a radio link. Accordingly, the signals are transmitted between the central control unit and the components. By virtue of the fact that an assembly of the installation unit is designed as an antenna, it is possible for the actual transmitting and receiving devices of the central control unit or components of the control system that is or are to be installed with the aid of the installation unit not to have to have a separate antenna. The antenna function is accordingly performed directly by the installation unit. It is accordingly the intention of the invention to supply the installation unit with a new function. Accordingly, the installation unit no longer serves merely for installation of the central control unit or components of a control system, rather the installation unit, in particular a metallic or metalized supporting plate thereof, participates in the signal transmission between the central control unit and the components of the control system. 
     Preferred developments of the invention emerge from the subclaims and the description. An exemplary embodiment of the invention is explained in more detail below with reference to the drawing, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a metallic supporting plate—configured according to the invention—of an installation unit according to the invention in plan view. 
     FIG. 2 shows the metallic supporting plate as shown in FIG. 1 in a cross section together with a sheet for electrical adaptation of the supporting plate, and 
     FIG. 3 shows an electrical equivalent circuit diagram of the installation unit according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The elements of an installation unit, namely an electric flush-mounted installation unit, which are illustrated in the drawing serve for installation of a central control unit and also components of a control system which are connected to the central control unit via a radio link. Signals are transmitted between the central control unit and the components. 
     An electric flush-mount installation unit is provided inter alia with a metallic supporting plate  10 . The metallic supporting plate  10  is designed as a frame as shown in FIG.  1 . The frame is formed by a total of four limbs  11 ,  12 ,  13 ,  14 , mutually opposite limbs  11 ,  13 , and  12 ,  14  running parallel to one another and adjacent limbs  11 ,  12 , and  12 ,  13  and  13 ,  14  and  14 ,  11  being arranged at right angles to one other. The limbs  11 ,  12 ,  13 ,  14  of the supporting plate  10  accordingly form a frame having an approximately rectangular configuration. 
     Instead of the metallic supporting plate  10 , a metalized supporting plate may also be provided. This may be e.g. a supporting plate made of plastic which is provided at least in regions with a metallic layer. Thus, such a supporting plate, made of plastic maybe subjected e.g. to metallic vapour deposition. For the sake of simplicity, only the metallic supporting plate  10  is referred to below, but a metalized supporting plate can also be used. 
     The metallic supporting plate  10  of the electric flush-mount installation unit is, according to the invention, designed as an antenna. To that end, the metallic supporting plate  10  designed as a frame is provided with a slot  15  extending at least in regions along the periphery of the frame. 
     As shown in FIG. 1, the slot  15  runs centrally within the limbs  13  and  12 ,  14  of the supporting plate  10 . The slot  15  accordingly extends across three limbs, in which case it extends only in regions across the limbs  12 ,  14  running parallel to one another. By contrast, the slot  15  extends continuously across the limb  13  which connects the limbs  12 ,  14 . 
     The limbs  12 ,  13  and  14  are accordingly subdivided in the region of the slot  15 , namely into an outer limb  16  and an inner limb  17 . 
     As shown in FIG. 1, the slot  15  is directed to the outside in a section  18  of the metallic supporting plate  10  designed as a frame. In this section  18 , the slot  15  breaks through the frame, namely the outer limb  16  of the limb  12 , to the outside. 
     A metallic supporting plate configured in this way already fulfils the function of an antenna. In order to adapt the antenna to the specific requirements, in particular in order to adapt the complex input impedance, a sheet  19  is assigned to the supporting plate  10  as shown in FIG.  2 . The sheet  19  covers the slot  15  in regions in the region of the limb  12 , namely in direct proximity to the section  18 . 
     According to the invention, the sheet  19  comprises a metallic layer, namely a copper layer  20 , which is enclosed by two insulator layers  21 . With its lower insulator layer  21 , the sheet  19  bears on the outer limb  16  and inner limb  17  of the supporting plate  10  in the region of the limb  12  and covers the slot  15  in this region. Between the outer limb  16  and the sheet  19 , on the one hand, and the inner limb  17  and the sheet  19 , on the other hand, a capacitor is formed in each case, with the aid of which the supporting plate  10  designed as an antenna can be electrically adapted. This adaptation can be effected on the one hand by way of the width of the sheet  19 , and on the other hand by way of the thickness of the insulator layers  21  or the choice of material for the insulator layers  21 . 
     As shown in FIG. 2, the sheet  19  bears on the outer limb  16  and inner limb  17  without electrical contact. In the region of an end  22  of the sheet  19 , the copper layer  20  makes contact with a printed circuit board  23 , e.g. via soldering, it being possible for the printed circuit board  23  to bear assemblies of a transmitting and/or receiving device. The contact between the printed circuit board  23  and the copper sheet  20  is illustrated as connecting point  24  in FIG.  2 . 
     FIG. 3 shows an electrical equivalent circuit diagram of the antenna with adapting circuit, said antenna being formed from the metallic supporting plate  10  and from the sheet  19 . In terms of DC voltage, the supporting plate  10  and the sheet  19  are at a ground potential. The capacitance formed between the outer limb  16  and the sheet  19 , on the one hand, and the capacitance formed between the inner limb  17  and the sheet  19 , on the other hand, are illustrated as capacitors  25 ,  26  in FIG.  3 . The capacitance of the capacitors  25 ,  26  can be adapted by suitable selection of the material for the insulator layers  21 . This adaptation can also be effected by way of modification of the thickness of the insulator layers  21 . Furthermore, it is possible to adapt the width of the covering of the slot  15  by the sheet  19 . Such modifications enable the complex input impedance Z of the unit-acting as an antenna—comprising the supporting plate and the sheet to be adapted to the specific requirements. The complex input impedance Z is ideally 50 ohms. 
     The above-described unit comprising the supporting plate  10  configured according to the invention and the sheet  19  operates as a shortened λ/4 antenna at a signal transmission frequency of 433 MHz. 
     In a departure from the exemplary embodiment illustrated it is also conceivable for a covering (not illustrated) of the installation unit to be designed as an antenna. Thus, a switch unit, pushbutton unit or operating unit of the installation unit can perform the antenna function. 
     List of Reference Symbols: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 10 
                 Supporting plate 
               
               
                 11 
                 Limb 
               
               
                 12 
                 Limb 
               
               
                 13 
                 Limb 
               
               
                 14 
                 Limb 
               
               
                 15 
                 Slot 
               
               
                 16 
                 Outer limb 
               
               
                 17 
                 Inner limb 
               
               
                 18 
                 Section 
               
               
                 19 
                 Sheet 
               
               
                 20 
                 Copper layer 
               
               
                 21 
                 Insulator layer 
               
               
                 22 
                 End 
               
               
                 23 
                 Printed circuit board 
               
               
                 24 
                 Connecting point 
               
               
                 25 
                 Capacitor 
               
               
                 26 
                 Capacitor