Abstract:
The invention relates to a photovoltaic insulating glazing comprising a multi-layer glazing with a photovoltaic module. The glazing is further characterized in that two contact strips for contacting the photovoltaic module are led out from an intermediate space between the glass layers and a spacer spaces the glass layers apart, thereby forming the intermediate space.

Description:
This application is the national stage of PCT/EP02/10620 filed on Sep. 20, 2002 and also claims Paris Convention priority of DE 101 46 498.3 filed on Sep. 21, 2001. 
     BACKGROUND OF THE INVENTION 
     The invention concerns a photovoltaic insulating glazing comprising a multi-layer glazing with a photovoltaic module, wherein contact strips contact the photovoltaic module and are led out from the photovoltaic module, and with a spacer, formed e.g. as a shaped bar, which spaces apart glass layers to form an intermediate space. 
     Photovoltaic modules are integrated into insulating glazing via a glass layer e.g. of a double glass structure, into or onto which the solar cells are embedded or disposed. The module generally constitutes one layer of the insulating glazing. The other layer is formed by a glass pane. An intermediate space is provided between the sheet of glass and the photovoltaic module which can be filled with gas to effect an insulating glazing. The invention also concerns other types of photovoltaic modules. 
     The production of photovoltaic insulating glazing requires an electric connection between the photovoltaic module of the insulating glazing and the outer side of the insulating glazing. In particular, processing of photovoltaic modules whose electric connections, the so-called “contact strips”, exit the photovoltaic module through bores on the rear-side of the module cover causes problems, since this contact strip passes through the space between panes of the insulating glazing. The contact strips consist is a thin metal strip. The electric connection to external terminals must, in particular, meet the following requirements:
         Gas and water vapor impermeability,   Tension relief of the module connections,   Small size on the rear side of a maximum of 5 mm corresponding to the usual sealing material cover of an insulating glazing,   Cable outlet should be tangential to the insulating glazing edge,   Optimum integration of assembly process in insulating glazing production.       

     Conventionally, a cable bushing is provided, wherein the connecting cables are soldered or crimped to the contact strips in the space between the panes of the insulating glazing and are then guided out of the pane region via bores in an insulating glazing spacer. The above-mentioned requirements are thereby not met or only to an insufficient extent. 
     It is therefore the underlying purpose of the present invention to provide a photovoltaic insulating glazing with which the electric connections are connected to the contact strips in a simple manner to satisfy the above-mentioned requirements. 
     SUMMARY OF THE INVENTION 
     This object is achieved in accordance with the invention by a photovoltaic insulating glazing having at least one opening in the spacer in which the contact strips and external connecting elements are fixed via a bolt which is inserted into the at least one opening, wherein the contact strips cooperate with electric connecting elements, in particular, an external connection cable, which are disposed outside of the glass layers. 
     The spacer may comprise, in particular, individual elements and connecting elements, wherein the individual elements are connected via the connecting elements, and the openings may be bores in the connecting elements. The connecting elements may be conventional linear or corner connections for insulating glazing spacers with bores to avoid additional production expense. 
     Alternatively, the spacer itself may have one or more bores. 
     The bore may also simultaneously serve as a gas filling opening for the insulating glazing. 
     In particular, the bore may have a thread for screwing in the bolt. The bolt can also optionally be pressed into the bore. 
     In accordance with a first alternative, the contact strip may extend through the bore and be clamped via the bore thread. The contact strip is guided out of the bore on the other side where it is in direct contact with the electric connecting element. The electric connecting element may be e.g. a connecting cable with a cable lug, wherein the contact strip is directly connected to the cable lug. The bolt may e.g. have a nut or a bolt head by means of which the cable lug is clamped between the wall of the connecting element and/or the spacer and the bolt head, and is thereby held in a force-locking fashion to fix the external connecting element. The contact strip and the module connection itself are then tension-relieved and the opening in the spacer and/or connecting element is/are simultaneously closed to keep the gas, which is filled into the insulating glazing, confined within the space between the panes. 
     In accordance with a second alternative, the contact strip may also be connected to a cable lug and the cable lug is fixed below a corresponding bolt head such that the cable lug is clamped between the bolt head and the surface of the spacer and/or the connecting element, and electrically cooperates with the bolt, wherein the bolt projects to the outside through the bore and the electric connecting element is fixed to the bolt in a force-locking fashion using a nut (described above) and is also electrically connected to the bolt. In this case, the contact strip cooperates only indirectly with the electric connecting element, e.g. with an external cable. 
     Depending on the design, the bolts may be made from electrically conducting or non-conducting material of different embodiments, such as e.g. blind rivets, expansion bushings or the like. 
     In a further embodiment, an elastic sealing nipple may be provided in the bore to seal the space between the glass panes from the outer side of the glass layers. In this fashion, gas and vapor tightness is ensured to an even greater degree. 
     The connecting elements may be made from plastic material. The spacers which are formed e.g. of hollow aluminum members, are pushed onto and clamped on the connecting elements. In particular, press fitting may be provided. The electric connecting element may be a cable lug with fitted connecting cable. 
     If the spacers are made from electrically conducting material, non-conducting washers can be used to prevent electric contact between the bolt and the spacers, thereby preventing short-circuits. 
     If the openings are provided in the spacer itself and should the spacer be made from conducting material, electric insulation is always required. Hollow plastic shaped spacers require no insulation. 
     The contact strip can be guided out of the photovoltaic module through a bore in the rear module cover as well as laterally from the module layers. In this case, the spacer can be disposed either between the inner module cover and the glass pane or between the outer module cover and the glass pane. 
     If the spacer is disposed in accordance with the second alternative, the inner module cover must be shorter than the outer. The contact strip is fixed as described above. 
     If the spacer is disposed in accordance with the first alternative, the contact strip does not exit into the space between the panes, but completely outside of the insulating glazing. In this case, it is also fixed “from the outside” like those of the external connecting element, either through fixing via a cable lug or clamping between bore wall and bolt. 
     In a particularly preferred fashion, the bore in the spacer and/or connecting element does not penetrate through to the space between the panes, but only the outer side has an opening. The sealing of the space between the panes is thereby not impaired. In the finished pane, the contact strip is then finally also enclosed by the insulation. 
     In a particularly preferred fashion, the electric connection is no longer visible in the finished window or when the window is installed, since bores projecting into the space between the panes can be omitted. 
     In order to prevent the connecting cables, which penetrate at an angle outwardly through the sealing material of the insulating glazing, from being pulled out of the sealing material up to that location where the cable lug is mounted by the bolt on the spacer when the connecting cable is pulled, which would destroy the photovoltaic insulating glaze, a block, e.g. of plastic material can be provided at the cable outlet which has approximately the width of the insulating glass, i.e. a width corresponding approximately to the width of the glass panes enclosing the space between the panes, and the space between the panes itself. This block can be glued onto the non-hardened insulating glazing sealing material. 
     The block may be a conventional glazing block of a thickness of preferably 0.5 to 8 mm which may also serve as glazing block in addition to its function of protecting the cable outlet. 
     Such a block can also prevent crushing of the connecting cables between substructure and glass during installation. 
     A block of this type may comprise grooved recesses along the glass edge to receive the cable, which offer the additional advantage of increased sealing material coverage in the region of the electric connection. Moreover, the side of the block facing the glass may have projections in the form of e.g. barbs which press into the sealing material when the block is glued and which provide additional positive locking between block and sealing material after the sealing material has hardened. 
     The bores may be stepped bores. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The invention is explained in more detail below with reference to embodiments. 
         FIG. 1  shows an inventive photovoltaic insulating glazing; 
         FIG. 2  shows assembly of the electric connection in accordance with a first embodiment; 
         FIG. 3  shows a second embodiment of an electric connection; and 
         FIG. 4  shows a further embodiment of a PV insulating glazing. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows an insulating glazing which consists of two external glass panes  12  and  14 . The pane  14  forms the outer cover of a photovoltaic module  16 . The pane  15  forms the inner cover. Solar cells are disposed between the panes  14 ,  15 . 
     The photovoltaic module  16  has a contact strip  18  to provide an electric connection. The contact strip  18  is thereby guided in the space  20  between the panes through a bore in the inner cover  15 . 
     A conventional spacer  22  is provided to define a space  20  between the pane  15  and glass pane  12 , which has an insulating function and by means of which the electric connection can be guided through the space  20  between the panes to the outside where it can contact an electric connecting element  26 , in most cases an external cable. The space  20  between the panes is filled with gas, as is typical for insulating glazing. The electric connection must therefore be gas and vapor-tight. 
     The spacers  22  comprise of hollow aluminium, shaped elements which are held via connecting elements  28  of plastic material (shown in  FIG. 2 ) by pushing a hollow aluminium element onto both sides of a connecting element  28 , where it is frictionally held. The connecting elements  28  thereby have a bore  30 . 
     To provide electric contact to the photovoltaic modules  16 , the connecting element  28  may have a stepped bore  30 , which is shown in  FIG. 2   a ).  FIG. 2   a ) shows a section of the corresponding connecting element  28  and its lower side. The hollow spacer elements  22  are pushed onto the connecting element  28  in the direction of arrow  32 . 
       FIG. 2   b ) shows insertion of a special sealing nipple  34  of elastic material with integrated threaded nut  36  into the stepped bore  30 . A threaded bolt  38  (shown in  FIG. 2   c ) screws, with the integrated nut  36 , the sealing nipple  34  to the shaft of the threaded bolt  38  and to the connecting element  28  in a gas-tight fashion. 
     During screwing, a conventional cable lug  40  is fixed to the threaded bolt  38  and provides electric contact to a contact strip  18  of the photovoltaic module  16 . Such a connecting element  28  is installed in the insulating glazing spacer  22  using one connecting element  28  per contact strip  18 . 
     For insulating glazing production itself, i.e. joining of the individual panes, the additional production step merely involves provision of the clamping connection between contact strip and cable lug. For sealing of the insulating glazing, the contact points are initially left open or provided with a suitable cover. 
     In the installed state (shown in  FIG. 2   d ), the external connecting cable (electric connecting element  42 ) is also provided with a cable lug  44 , and is fixed to the threaded bolt  36  using a threaded nut  46  to ensure gas-tight electric connection between the contact strips  18  and the electric connecting element  42  via the bolt  38 . 
     Tensile forces on the electric connecting element  42  are introduced into the connecting element  28  and not into the contact strip  18  such that no tensile loads act on the latter. Gas and water vapor tightness is also ensured and the space  20  between the panes is independent of environmental influences. 
     After mounting of the external connecting cable, the connection is sealed with sealing material and thereby also electrically insulated. 
     Electrically non-conducting washers are moreover used below the cable lugs  44 ,  40  to prevent electric contact between bolt  38  and spacers  22  when the spacers  22 , which may consist of a metallic material, are assembled with the connecting elements  28 , to avoid possible short-circuits. 
       FIG. 3  shows three illustrations a) through c) of an alternative embodiment of the electric contact wherein the same parts have the same reference numerals. 
     The connecting element  28  has a bore  30  through which the contact strip  18  is guided. A blind rivet  48  serves as bolt, wherein a cable lug  44  is pushed under its head  50 . The cable lug  44  is again connected to the electric connecting element  42 . The blind rivet  48  is inserted into the bore  30  from the outside and mounted there (shown in  FIGS. 3   b  and  3   c ). 
     The cable lug  44 , which surrounds the blind rivet  48 , is fixed under the head  50  of the blind rivet  48  and at the same time, the contact strip  18  is clamped between the wall of the bore  30  and the rivet  48 . Transmission of tensile forces no longer acts on the contact strip  18 . The contact strip  18  is directly contacted with the electric connection  42  and, as clearly shown in  FIG. 3   c ), the bore is closed. The electric conductivity of the bolt or blind rivet is thereby not important. 
     In contrast to the alternative shown in  FIG. 2 , this solution has the advantage that mounting of the rivet  48  is possible after assembly of the insulating glazing. The bores  30  may at the same time serve as gas filling opening of the insulating glazing. 
     Alternatively, two bores may be provided in the structure of  FIG. 1 , wherein the contact strip  18  is led out of the space  20  between the panes via a first bore  30 , wherein the bore  30  completely penetrates through the spacer  22  and is closed by a stopper when the contact strip  18  has been guided through, and a second bore is provided next to it which is formed in particular as a blind hole from the outer side of the spacer. The strip  18  can be fixed in this second bore (see  FIG. 4 ) to facilitate contact. 
       FIG. 4  shows a variant, wherein the contact strip  18  is guided to the electric connection from the outside. 
     The spacer  22  is disposed between the inner module cover  15  and the glass pane  12 . The cable strip exits between inner  15  and outer module cover  14  and is fixed “from the outside” in the spacer  22 , analogously to the above-described fixing. 
     To ensure safe contact between contact strip  18  and cable lug  44 , they can be soldered to each other. To prevent damage to the spacer  22 , in particular if it is made from plastic material, soldering should be preferably carried out before mounting of the cable lug  44  and strip  18  to the bolt, which leads to the following preferred assembly steps:
         If required ( FIG. 1 ), the strip  18  is guided through the bore  30  until it projects outwardly by a few centimeters;   The strip  18  is soldered to the cable lug  44  of the electric connecting cable  26  at a separation of a few centimeters from the spacer  22 ;   The cable lug  44  with soldered strip  18  is fixed with the bolt to the spacer  22 .       

     The projecting strip  18  is thereby pushed back into the bore or folded together and put on the back of the spacer  22 . 
     Further advantages and features can be extracted from the remaining application documents. The features may be essential to the invention either individually or collectively.