Abstract:
The invention relates to a louver blind having louvers ( 1 ) that can be pivoted about a vertical axis, displaceably held at both ends thereof by louver holders ( 2 ) extending beyond the louver width between an upper and a lower guide track ( 3 ). The louver holders ( 2 ) are hereby connected to each other by carriages ( 4 ) displaceable in the guide tracks ( 3 ) and aligned in parallel to each other, and can be pivoted by synchronously driven drive device disposed in the carriages ( 4 ). In order to make the installation of the louver blind—or optionally the removal thereof—easier, according to the invention, decoupleable permanent magnets ( 16, 18 ) are provided for connecting between the louver mounts ( 2 ) and the carriages ( 4 ). Said arrangement has the further advantage that the connections can automatically release when critical tension or rotational forces are exceeded, so that damage can be prevented in the connecting parts.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national phase of PCT/EP2008/010667 filed Dec. 10, 2008, which claims priority to DE 10 2008 003 718.4 filed Jan. 9, 2008. 
     FIELD OF THE INVENTION 
     The invention relates to a louver blind with louvers that can pivot about a vertical axis and that are held at their two ends by louver holders extending across the louver width so that they can move between an upper and a lower guide track, wherein the louver holders are connected aligned parallel to each other to carriages that can move in the guide tracks and can pivot by means of synchronously driven rotating means arranged in the carriages. 
     BACKGROUND OF THE INVENTION 
     Louver blinds are used in architecture to protect buildings and their users from the undesired effects of intense solar irradiation. Simultaneously, however, a high degree of transparency should remain. For this purpose, the louvers must be mounted in carriages so that they can pivot such that, in the state when they are moved apart from each other, these can each be rotated perpendicular to the incident solar irradiation. 
     Louver blinds of the type named above are known, for example, from DE 75 39 579 U. Here, the louver holders and the gear devices arranged in the carriages are connected rigidly to each other. The production of this connection requires special effort in terms of assembly and also makes any repair work more difficult, for example, when changing out particularly wide louvers, like those being used increasingly for facades with large surface-area glass windows. 
     The task of the invention is to form the connection between the louvers and the carriages so that both the assembly of the louver blinds and also repair work on the louvers can be performed more easily. In addition, the connections should automatically disconnect when critical tensile forces or torques are exceeded, in order to prevent damage to the connecting parts. 
     SUMMARY OF THE INVENTION 
     To achieve this task, it is proposed according to the present invention that the connection between the louver holders and the carriages is produced by permanent magnets that can be decoupled. 
     This can be achieved advantageously in that the rotating means in the carriage are locked in rotation with a rotary plate projecting from the slot of the guide tracks that is open to the louvers, wherein the magnets are mounted in radial alignment on this rotary plate, and a magnet holder is mounted on the louver holders opposite each rotary plate, wherein this magnet holder is equipped with counter magnets of corresponding strength for producing the connection to the magnets of the rotary plate. 
     In this way, not only is the assembly made easier, but it can also be achieved that, for the case of the unintentional appearance of torque or tensile stresses that lead to the detachment of the coupling connection, the magnets easily disconnect from each other and automatically rejoin when the disconnection forces are eliminated. Such stresses can then occur, for example, when a window washer inserts his ladder between louvers that are arranged at a right angle for cleaning large surface-area windows, in order to reach the windowpanes, and, in this way, pushes against the louver holders. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       Additional features of the invention and their advantages follow from the subordinate claims and the explanation of a preferred embodiment of the invention that is shown in the drawings and that shall be described in detail below. Shown herein are: 
         FIG. 1 , a louver blind with louvers moved apart from each other and arranged at an angle to the window; 
         FIG. 2 , the lower guide track with rotary plate when coupled with the magnet plate in a perspective top view; 
         FIG. 3 , the same picture with a decoupled magnet holder; 
         FIG. 4 , the upper guide track with carriages and rotary plates in a perspective diagram with a view into the gear; 
         FIG. 5 , the same picture in side view; 
         FIG. 6 , the same picture in longitudinal section according to line VI-VI in  FIG. 5 ; 
         FIG. 7 , a front view of  FIG. 5 ; 
         FIG. 8 , the upper louver holder with rotary plates and chocks assembled together in a perspective view from above; 
         FIG. 9 , the upper louver holder with decoupled rotary plates in longitudinal section according to line IX-IX in  FIG. 10 ; 
         FIG. 10 , a cross section in this respect according to line X-X in  FIG. 9 ; 
         FIG. 11 , an upper rotary plate in top view with a view of the magnets; 
         FIG. 12 , the rotary plate in section according to line XII-XII in  FIG. 11 ; 
         FIG. 13 , the rotary plate in section according to line in  FIG. 11 ; 
         FIG. 14 , a section through the edge of the plate according to line XIV-XIV in  FIG. 11 ; 
         FIG. 15 , the magnet holder in section according to line XV-XV in  FIG. 16 ; 
         FIG. 16 , the same magnet holder in front view; 
         FIG. 17 , a chock in side view; and 
         FIG. 18 , the same chock in front view with view of the projection. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The louver blind shown in the figures is equipped with louvers  1  that can pivot about a vertical axis. The louvers  1  are held at their two ends by louver holders  2  that usually extend across the entire louver width. These louver holders  2  are held so that they can move and pivot on their side between an upper and a lower guide track  3 , wherein the louver holders  2  are connected to each other with carriages  4  that can move in the guide tracks  3  in a way still to be described by means of permanent magnets  16  and  18 . 
     In  FIGS. 4-7 , the configuration of a carriage  4  with a gear housed in this carriage for pivoting the louvers  1  is shown clearly and shall be explained in detail below—as much as necessary for understanding the invention. 
     The carriage  4  is here guided so that it can move in the guide track  3  by means of laterally mounted track rollers  5 . For movement, in the front carriage  4 , a threaded sleeve  6  with large thread pitch is fit in the longitudinal direction, with a threaded rod  7  with the same thread pitch being guided through this sleeve. The threaded rod  7  is driven by a motor arranged at the beginning of the guide track  3 , in order to move the front carriage  4  in the longitudinal direction. The following carriages  4  are then pulled along by typical spacers. 
     The gear installed in the carriage  4  is made essentially from a toothed wheel  8  that is mounted vertically in the center of the carriage  4  and that projects downward with a rotating rod  9  through an open slot  10  in the guide track  3 , with this rotating rod being locked in rotation, in turn, with a rotary plate  11  or  31 . The toothed wheel  8  engages in vertically mounted pinions  12  that are driven on their side by worms  13  mounted in the carriage  4  at the side of the pinion  12 . 
     Here it has proven useful to drive the toothed wheel  8  by means of two diametrically opposed pinions  12  and two worms  13 , in order to keep the structural height of the carriage  4  as small as possible. 
     The worms  13  are provided with a crossed slot  14  through which a rotating rod  15  is inserted that is shaped corresponding to the profile of the slot  14 . This rotating rod  15  is guided through the worms  13  of several carriages  4  arranged one after the other and is connected to a motor at the beginning of the guide track  3 . Therefore, the rotary plate  11  or  31  of all of the carriages  4  can be pivoted in sync by the same angle. 
     In  FIGS. 2 and 3 , the effect according to the invention of the magnet connection between a lower louver holder  2  and a lower rotary plate  11  locked in rotation with the carriage  4  is shown, with this rotary plate having two diametrically opposed permanent magnets  16  in radial alignment relative to the louver holder  2 . On the bottom side of the louver holder  2 , a magnet holder  17  is mounted above the rotary plate  11 , wherein this magnet holder is equipped with counter magnets  18  of corresponding strength for producing the connection to the magnets  16  of the lower rotary plate  11 . 
     On its edge, the lower rotary plate  11  has—just like the upper rotary plate  31  in  FIGS. 8-10  and  11 - 13 —a ring  19  that is directed toward the magnet holder  17  and that is notched in the radial projection of the magnets  16  up to the plate base  20  at the width of the magnet holder  17 . In this way, the notch faces  21  are directed outward at an angle from the plate base  20 , so that the magnet holder  17  can rotate upward along the inclined faces  21  and in this way can be simultaneously decoupled for an unexpected rotating force on the louver holder  2 . 
     The magnet holder  17  is made from an elongated base body  22 , as can be seen from  FIGS. 15 and 16 , in which the two counter magnets  18  are embedded at the same spacing as the magnets  16  in the lower rotary plate  11 . On its bottom side, the base body  22  has a projection  23  that has a T-shaped cross section and that is inserted into a correspondingly shaped groove  24  on its bottom edge for connecting to the louver holder  2  and that is anchored in the center of the louver holder  2 . 
     In the center of the base body  22 , a circular recess  25  is formed in which engages a round peg  26  fixed on the lower rotary plate  11  in the center between the two magnets  16  in the coupled state. This round peg  26  ensures that, after the appearance of the previously mentioned rotational effect and the decoupling dependent on this effect, the centering of the magnet holder  17  relative to the rotary plate  11  is maintained, so that after the rotational effect is eliminated, the magnet holder  17  can be docked again without a problem. Obviously, the intentional centering effect could then also be achieved when the recess  25  is provided as in  FIG. 13  on the upper rotary plate  31  and the associated round peg  26  as in  FIG. 15  on the magnet holder  17 . 
     While just the force of gravity is responsible for the coupling situation at the lower end of the louvers  1 , in which, after the louver holder  2  drifts away, the magnet holders  17  dock on the rotary plates  11  again due to magnetic forces, additional measures must be taken at the upper end of the louvers  1 , as can be seen from  FIGS. 8-10 , so that the louver holder  2  does not fall downward due to unexpected appearance of tensile or torque forces after the disconnection of the magnet connection. 
     Therefore, on the upper louver holders  2  on both sides of the upper rotary plate  31 , chocks  27  are provided with inward-directed projections  28  that have the same T-shaped projections  23  as the magnet holders  17 . These chocks  27  are pushed with their projections  23  on both sides of the rotary plate  31  into the grooves  24  on the lower edge of the louver holder  2  and anchored in the groove  24  shortly before contact on the rotary plate  31 . In this way it is achieved that the projections  28 , as can be seen from  FIG. 8 , engage behind the rotary plate  31  in the coupled state of the magnets  16  and  18  with a safety spacing “a”. When the upper rotary plate  31  is decoupled from the magnet holder  17  by the unexpected effect of tensile or torque forces, it can fall downward only by the safety spacing “a” and is then held by the projections  28  ( FIG. 9 ). 
     The upper edge  29  of the upper rotary plate  31  is here preferably offset inward by a radial step  30  corresponding to the radial dimension of the projections  28  (see  FIGS. 10 and 13 ). In order to also achieve the most centered position possible here after the decoupling, the radial step  30  of the upper rotary plate  31  is provided underneath the projections  28  with recesses  32  corresponding to the width of the chocks  27  (see  FIGS. 11 and 14 ). 
     Similar to the notch faces  21  in the ring  19 , here the notch faces  33  are also directed outward at an angle from the base of the recesses  32 , while the projections  28  of the chocks  27 , as can be seen from  FIGS. 17 and 18 , have counter faces  35  that are directed inward at an angle corresponding to their engagement edges  34  and that engage in the recesses  32  of the step  30  in the decoupled state of the magnet holder  17 . 
     In addition it shall be noted that the upper rotary plates  31  differ from the lower rotary plates  11  in shape only by the additional formation of radial steps  30  on the upper edge  29  and recesses  32  in the steps  30  that are provided for the interaction with the chocks. 
     It is understood that the upper rotary plates  31  can also be used on the lower end of the louvers  1 , in order to eliminate a second shape for the rotary plate  11  or else in order to be able to also insert the same chocks  27  at the lower end of the louvers  1  in the louver holder  2 , if all that matters is protection against decoupling due to the effect of torque forces. 
     It is further understood that the characterizing features of the invention can also be used in such louver blinds in which the vertically directed louvers  1  are held so that they can move and pivot only at their upper ends with their louver holders  2  on an upper guide track  3 , when a lower guide track can be eliminated or if the upper guide track runs at an angle, because the window frame is beveled at the top. 
     It is also understood that the connection according to the invention between the louver holders  2  and the carriages  4  can also relate completely generally to louver blinds in which the louvers  1  are held so that they can pivot about their louver axis between two parallel guide tracks  3 , regardless of whether the guide tracks are arranged vertically, horizontally, or at an angle in space.