Abstract:
An assembly comprised of at least one fixed panel and at least two moveable panels is provided. The moveable panels are capable of being controllably shifted relative both to each other and to the fixed panel such that first and second aligned and non-aligned positions can be achieved. The assembly is further comprised of two or more drive links which are, in turn, comprised of a center pivot which engages with the fixed panel and two or more outer pivots which engage with the movable panels.

Description:
[0001]    This invention relates to a unique type of panel assembly. The application claims priority benefit of U.S. Provisional Application No. 61/162,901, filed Mar. 24, 2009. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The façade of a building plays a central role in a building&#39;s environmental performance, influencing energy usage by determining how light, heat and air are exchanged with its surroundings. As one example, the interlocking systems that comprise curtain walls for high-rise buildings: structural, glazing, insulation, ventilation and shading, all play a role in managing the energy flows between interior and exterior. 
         [0003]    One key strategy to achieve sustainable performance is for buildings to actively adapt and respond to changing climatic conditions. This strategy may be applied to facades in different ways. For example, an adaptive façade may have operable elements such as shades that extend and retract automatically. Those devices can respond to environmental data (i.e. temperature, light intensity and wind flow) gathered from sensors, and, utilizing computational intelligence, the building can optimize its environmental configuration for different environmental conditions. 
         [0004]    This concept of a responsive facade has been termed “intelligent skin” indicating the analogy with natural systems. 
         [0005]    A significant portion of the façade is comprised of windows—or more generally, glazed areas. Static methods are often used to set the light transmissivity of glass. Ceramic fritting is widely utilized where a graphic pattern is applied to glass in order to block some light transmission, yet still allowing sufficient transparency for viewing. However, standard ceramic fritting is static and does not respond to changing conditions. 
         [0006]    By integrating responsive controls with fritted glass surfaces, improved light control and decreased energy usage can be achieved. 
         [0007]    An adaptive window could, for example, allow solar gain during cold weather, yet block the sun when it is warm. Natural light within the building can be maintained at desirable levels. Controllable transparency can also be used to allow visual contact when needed, yet provide privacy under other circumstances. 
         [0008]    Beyond transparency control, a physical surface that can adjust its permeability, thereby controlling the passage of air, moisture or heat, provides additional benefits. Utilizing an exterior layer having controllable permeability, energy from the environment may be accepted or blocked as needed. 
         [0009]    Currently, such adaptive control within the facade is achieved with standard products such as blinds, shades or curtains. Beyond traditional devices, a new generation of adaptive glass technology is available such as ‘switchable’ and ‘electrochromic’ glass. However, these technologies have not received wide acceptance to date. 
         [0010]    The invention disclosed herein provides new methods to provide surfaces having controllable properties. Such properties include transparency, permeability and acoustic performance. Surfaces that are formulated according to the disclosed invention may then be integrated into building façades as an ‘adaptive layer’ providing enhanced environmental performance. 
       SUMMARY OF THE INVENTION 
       [0011]    An assembly comprised of at least one fixed panel and at least two moveable panels is provided. The moveable panels are capable of being controllably shifted relative both to each other and to the fixed panel such that first and second aligned and non-aligned positions can be achieved. 
         [0012]    The assembly is further comprised of two or more drive links which are, in turn, comprised of a center pivot which engages with the fixed panel and two or more outer pivots which engage with the movable panels. 
         [0013]    Also disclosed are fixed and movable panels that can be constructed from perforated sheets, or from transparent sheets which can have an applied graphic pattern. When the panel assembly is in its first position, these perforations, or graphic patterns, are aligned from sheet to sheet, providing a surface that is largely transparent and/or permeable. When the panel assembly is in its second position, the perforations or graphic patterns belonging to the different panels are not aligned, thereby providing a surface that is largely opaque and/or impermeable. 
         [0014]    Accordingly, it is an object of the invention to provide surfaces having controllable properties. 
         [0015]    Another object of the invention is to provide an improved surface in which the transparency, permeability and acoustic performance can be selectively controlled. 
         [0016]    Still, other objects and advantages of the invention will, in part, be obvious and will, in part, be apparent from the following description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    For a fuller understanding of the invention, reference is made to the following drawings in which: 
           [0018]      FIG. 1  shows an exploded view of a drive link of the invention; 
           [0019]      FIG. 2  shows a perspective view of the inventive drive link; 
           [0020]      FIG. 3  shows a perspective view of a second drive link of the invention; 
           [0021]      FIG. 4  shows an exploded view of a first panel assembly of the invention; 
           [0022]      FIGS. 5-8  shows perspective views of the inventive panel assembly of  FIG. 4  as it is transformed from an initial position to a final position; 
           [0023]      FIG. 9  shows an exploded view of a third drive link of the invention; 
           [0024]      FIG. 10  shows a perspective view of the inventive drive link of  FIG. 9 ; 
           [0025]      FIGS. 11-13  show successively a plan and two sectional views of the drive link of  FIG. 9 ; 
           [0026]      FIG. 14  shows a fourth drive link of the invention having a handle element; 
           [0027]      FIGS. 15-18  show plan views of four panels of the invention; 
           [0028]      FIGS. 19-20  show perspective views of drive links of the invention in accordance with  FIGS. 9 and 10 ; 
           [0029]      FIG. 21  shows an exploded view of a second panel assembly of the invention; 
           [0030]      FIGS. 22-24  show plan views of the panel assembly of  FIG. 21  as it is transformed from an initial position to a final position; 
           [0031]      FIGS. 25-26  show a sectional view and a detail plan view respectively of the panel assembly of  FIG. 21 ; 
           [0032]      FIGS. 27-29  shows perspective views of the panel assembly of  FIG. 21  as it is transformed from an initial position to a final position; 
           [0033]      FIGS. 30-33  show plan views of four other panels of the invention, each with circular perforations; 
           [0034]      FIG. 34  shows an exploded view of a third panel assembly of the invention; 
           [0035]      FIGS. 35-37  shows perspective views of the panel assembly of  FIG. 34  as it is transformed from an initial, aligned position to a final non-aligned position. 
           [0036]      FIGS. 38-40  shows cutaway views of the panel assembly of  FIG. 34  as it is transformed from an initial, aligned position to a final non-aligned position. 
           [0037]      FIGS. 41-43  shows plan views of the panel assembly of  FIG. 34  as it is transformed from an initial, aligned position to a final non-aligned position; 
           [0038]      FIGS. 44-47  show plan views of four additional panels of the invention which are transparent and have an applied graphic pattern; 
           [0039]      FIG. 48  shows an exploded view of a fourth panel assembly of the invention; 
           [0040]      FIGS. 49-51  shows perspective views of the panel assembly of  FIG. 48  as it is transformed from an initial, aligned position to a final non-aligned position; 
           [0041]      FIGS. 52-54  shows cutaway views of the panel assembly of  FIG. 48  as it is transformed from an initial, aligned position to a final non-aligned position; 
           [0042]      FIGS. 55-57  shows plan views of the panel assembly of  FIG. 48  as it is transformed from an initial, aligned position to a final non-aligned position; 
           [0043]      FIGS. 58-59  show exploded and perspective views, respectively, of a fourth drive link of the invention; 
           [0044]      FIG. 60  shows an exploded view of a fifth panel assembly of the invention; 
           [0045]      FIG. 61  shows a sectional view of the panel assembly of  FIG. 60 ; 
           [0046]      FIGS. 62-65  show detailed perspective views of the panel assembly of  FIG. 60  as it is transformed from an initial, aligned position to a final non-aligned position; and 
           [0047]      FIGS. 66-69  show plan views of the panel assembly of  FIG. 60  as it is transformed from an initial, aligned position to a final non-aligned position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0048]      FIG. 1  shows an exploded view of drive link  10  which is comprised of sub-links  14  and  16 . Also shown are outer pivot pins  19  and  17 , as well as center pivot pin  11   a  which is co-linear with center pivot pin  11   b.    
         [0049]      FIG. 2  shows a perspective view of drive link  10  in assembled form. It may be seen that outer pivot pins  19  and  17  span between sub-links  14  and  16 . Also shown is center pivot pin  11   a  which is co-linear, yet discontinuous, with pivot pin  11   b . Center pivot pin  11   a  is connected to a handle element  12 . 
         [0050]      FIG. 3  shows drive link  20  which is comprised of sub-links  24  and  26  which, in turn, are connected by outer pivot pins  29  and  27 . Sub-link  24  and sub-link  26  lie in different planes relative to one another. Outer pivots  29  and  27  span the depth of link  20 . Also shown is center pivot pin  21   a  and center pivot pin  21   b  which are co-linear yet discontinuous. 
         [0051]      FIG. 4  shows an exploded view of panel assembly  30  which is comprised of two fixed panels  40  and  70  and two movable panels  50  and  60 . 
         [0052]    Front panel  40  has two pivot holes  42  and  44 . Back panel  70  has two pivot holes  72  and  74  which are respectively aligned with and correspond to pivot holes  42  and  44 . Center pivot pins  11   a  and  21   a  belonging to drive links  10  and  20  respectively are aligned with pivot holes  42 , 44  respectively; center pivot pins  11   b  and  21   b  belonging to drive links  10  and  20  respectively are aligned with pivot holes  72 , 74  respectively. 
         [0053]    Panel  50  has two clearance slots  52  and  54  providing clearance for outer pivot pins  19  and  29  respectively. Panel  60  has two clearance slots  62  and  64  providing clearance for outer pivot pins  17  and  27  respectively. 
         [0054]    Outer pivot pin  17  of drive link  10  is aligned with pivot hole  55  on panel  50 . Outer pivot pin  19  of drive link  10  is aligned with pivot hole  65  on panel  60 . 
         [0055]    Outer pivot pin  27  of drive link  20  is aligned with pivot hole  57  on panel  50 . Outer pivot pin  29  of drive link  20  is aligned with pivot hole  67  on panel  60 . 
         [0056]      FIG. 5  shows panel assembly  30  in an initial position where movable panel  50  is in an upper location and movable panel  60  is in a lower location. Links  10  and  20  are pivotally connected to front panel  40  by center pivot pins  11   a  and  21   a  respectively. 
         [0057]      FIGS. 6 and 7  show panel assembly  30  in two intermediate positions whereby the relative locations of movable panels  50  and  60  are translated relative to their location in  FIG. 5 . Clearance slots  54  and  64  allow for outer pivot pins  27  and  29  to slidably move in an unobstructed manner. 
         [0000]    It may be seen in  FIGS. 5-7  that as panel  50  is successively lowered, panel  60  is successively raised. Thus, the movement of panel  50  counterbalances the movement of panel  60 , thereby ensuring that the force needed to turn handle  12  is minimized. 
         [0058]      FIG. 8  shows panel assembly  30  in a final position where movable panel  50  is in a lower location and movable panel  60  is in an upper location. 
         [0059]      FIG. 9  shows an exploded view of a drive link  80  which is comprised of a center pivot pin  81  and four sub-links  91 ,  92 ,  93  and  94 . Sub-links  91 , 93  share outer pivot pin  83 ; sub-links  93 , 94  share outer pivot pin  84 ; sub-links  94 , 92  share outer pivot pin  82 . Center pivot pin  81  has a hexagonal profile which mates with hexagonal openings in sub-links  91 ,  92 ,  93  and  94 . 
         [0060]      FIG. 10  shows a perspective view a drive link  80  wherein center pivot pin  81  is engaged in the hexagonal openings of the four sub-links, thereby fixing them to one another. 
         [0061]      FIG. 11  shows drive link  80  in plan view. 
         [0062]      FIG. 12  shows a sectional view of drive link  80 . Outer pivot pin  83  connects sub-links  91  and  93 ; outer pivot pin  82  connects sub-links  92  and  94 . Sub-link and sub-link  92  lie in different planes relative to one another. Likewise, outer pivot pins  82  and  83  each lie in different planes. Center pivot pin  81  spans the depth of link  80 . 
         [0063]      FIG. 13  shows a second sectional view of drive link  80 . Outer pivot pin  84  connects sub-links  93  and  94 . 
         [0064]    It may be seen that center pivot pin  81  extends from the topmost to bottommost level of link  80 , whereas outer pins  82 ,  83  and  84  extend only between adjacent sub-links  92 , 94  and  94 , 93  and  93 , 91  respectively. 
         [0065]      FIG. 14  shows a drive link  85  which is similar to drive link  80 , however, it also has a handle element  89 . 
         [0066]      FIG. 15  shows a panel  140  having four pivot holes  141 ,  142 ,  143  and  144 . 
         [0067]      FIG. 16  shows a panel  150  having four pivot holes  151 ,  152 ,  153  and  154  and four slots  155 ,  156 ,  157  and  158 . 
         [0068]      FIG. 17  shows a panel  160  having four pivot holes  161 ,  162 ,  163  and  164  and four slots  165 ,  166 ,  167  and  168 . 
         [0069]      FIG. 18  shows a panel  170  having four pivot holes  171 ,  172 ,  173  and  174  and four slots  175 ,  176 ,  177  and  178 . 
         [0070]      FIGS. 19 and 20  show drive links  80   a  and  80   b  which are essentially identical to drive link  80 . 
         [0071]      FIG. 21  shows an exploded view of panel assembly  190  which is comprised of two fixed panels  140  and  180  and three movable panels  150 ,  160  and  170 . 
         [0072]    Panel assembly  190  is further comprised of four drive links  80 ,  80   a ,  80   b  and  85  which are also shown in exploded view. 
         [0073]    Outer pivot pin  83  of drive link  80  is aligned with pivot hole  151  of panel  150 . Outer pivot pin  84  is aligned with pivot hole  161  of panel  160 . Outer pivot  82  is aligned with pivot hole  171  of panel  170 . 
         [0074]    Center pivot pin  81  aligns with pivot holes  181  and  141  belonging to panels  180  and  140  respectively. Center pivot pin  81  is positioned such that it can slidably pass through slots  155 ,  165  and  175  allowing clearance for unobstructed movement. 
         [0075]    Similarly, outer pivot pin  83   a  of drive link  80   a  is aligned with pivot hole  152  of panel  150 . Outer pivot pin  84   a  is aligned with pivot hole  162  of panel  160 . Outer pivot  82   a  is aligned with hole  172  of panel  170 . 
         [0076]    Center pivot pin  81   a  aligns with holes  182  and  142  belonging to panels  180  and  140  respectively. Center pivot pin  81   a  is positioned such that it can pass through slots  156 ,  166  and  176  allowing clearance for unobstructed movement. 
         [0077]    In a similar manner, drive links  80   b  and  85  align with the respective holes and slots belonging to panels  140 ,  150 ,  160 ,  170  and  180 . 
         [0078]      FIG. 22  shows panel assembly  190 . Drive links  80 ,  80   a ,  80   b  and  85  have a consistent rotational position relative to fixed panels  140 ,  180 , thereby setting a first location of movable panels  150 ,  160  and  170 . Handle element  89  belonging to drive link  85  is in a raised position. 
         [0079]      FIG. 23  shows panel assembly  190  in a second position wherein drive links  80 ,  80   a ,  80   b  and  85  have been further rotated relative to panels  140 ,  180 , thereby providing a translated location of movable panels  150 ,  160  and  170  relative to  FIG. 22 . Handle element  89  is in an intermediate position. 
         [0080]      FIG. 24  shows panel assembly  190  in a third position wherein drive links  80 ,  80   a ,  80   b  and  85  have been further rotated relative to panels  140 ,  180 , thereby translating the locations of movable panels  150 ,  160  and  170 . Handle element  89  is in a lower position. 
         [0081]    It may be seen in  FIGS. 22-24  that as panels  150 ,  160  and  170  are successively moved, the degree to which each movable panel is lowered or raised is essentially counterbalanced by the movements of the other panels. This ensures that the force needed to turn handle  89  is minimized. 
         [0082]      FIG. 25  shows a sectional view of panel assembly  190  wherein center pivot pins  81  and  81   a  may be seen to span between fixed panels  140  and  180 . Outer pivot pins  82  and  82   a  engage moveable panel  170 ; outer pivot pins  84  and  84   a  engage moveable panel  160 . 
         [0083]      FIG. 26  shows a detailed view of panel assembly  190  in its second position. 
         [0084]      FIG. 27  shows a perspective view of panel assembly  190  in its first position where fixed panel  140  is shown in cutaway to reveal movable panels  150 ,  160  and  170 . 
         [0085]      FIGS. 28 and 29  show perspective views of panel assembly  190  in its second and third position respectively. 
         [0086]      FIG. 30  shows panel  210  which is perforated with a pattern of circular holes. Panel  210  has a similar outer profile to panel  140 . It has four holes  211 ,  212 ,  213  and  214  which are located in a similar position relative to its outer profile to holes  141 ,  142   143  and  144  belonging to panel  140 . 
         [0087]      FIG. 31  shows perforated panel  220 . Also in  FIG. 31  is profile  151 , shown in dashed line, which corresponds to the outer profile and slots of panel  150 . Panel  220  may be seen to align with profile  151 . Holes  253 ,  254 ,  255  and  256  have identical locations. Holes  153 ,  154 ,  155  and  156  are in a similar position relative to profile  151 . However, it may be seen that some material is removed from panel  220  relative to profile  151 . 
         [0088]      FIGS. 32 and 33  show panels  230  and  240  respectively. Panels  230  and  240  may be seen to align with profiles  161  and  172  (shown in dashed line) respectively, which in turn correspond to the outer profiles and slots of panels  160  and  170  respectively. 
         [0089]      FIG. 34  shows an exploded view of panel assembly  200 , which is comprised of two fixed panels  210  and  250 , three movable panels  220 ,  230  and  240  as well as four drive links  80 ,  80   a ,  80   b  and  85 . Panel assembly  200  may thus be seen to be mechanically identical to panel assembly  190 . The essential difference is that the panels belonging to assembly  200  are perforated whereas the panels belonging to assembly  190  are not perforated. 
         [0090]      FIG. 35  shows panel assembly  200  is in a first position. Movable panels  220 ,  230  and  240  are located such that their perforations are aligned with the perforations of fixed panels  210  and  250 . In this position, assembly  200  is in an open, non-opaque state. 
         [0091]      FIG. 36  shows panel assembly  200  is in a second position. Movable panels  220 ,  230  and  240  are located such that their perforations are partially aligned with the perforations of fixed panels  210  and  250 . In this position, assembly  200  is in a partially opaque state. 
         [0092]      FIG. 37  shows panel assembly  200  is in a third position. Movable panels  220 ,  230  and  240  are located such that their perforations are not aligned with the perforations of fixed panels  210  and  250 , thereby blocking those perforations. In this position, assembly  200  is in a fully opaque state. 
         [0093]      FIG. 38  shows a cutaway detail of panel assembly  200  in a first position, wherein the perforations of moveable panels  220 ,  230  and  240  are aligned with those of fixed panels  210 ,  250 . Handle element  89  belonging to drive link  85  is in an upper position. 
         [0094]      FIG. 39  shows a cutaway detail of panel assembly  200  in a second position, wherein the perforations of moveable panels  220 ,  230  and  240  are partially aligned with those of fixed panels  210 ,  250 . Handle element  89  belonging to drive link  85  is in an intermediate position. 
         [0095]      FIG. 40  shows a cutaway detail of panel assembly  200  in a third position, wherein the perforations of moveable panels  220 ,  230  and  240  are not aligned with those of fixed panels  210 ,  250 . Handle element  89  belonging to drive link  85  is in a lower position. 
         [0096]      FIGS. 41 ,  42  and  43  show plan views of panel assembly  200  in its first, second and third position respectively. It may be seen that panel assembly  200  may be reversibly transformed from a non-opaque, permeable state to an opaque, non-permeable state by raising and lowering handle element  89 . 
         [0097]      FIG. 44  shows a panel  310  having the same profile and hole locations as panel  140 . Panel  310  is made of a transparent material upon which a graphic pattern of opaque circles has been applied. 
         [0098]      FIGS. 45-47  show panels  320 ,  330  and  340  whose profiles, holes and slot locations are essentially identical to panels  150 ,  160  and  170  respectively. Panels  320 ,  330  and  340  are made of a transparent material upon which graphic patterns of opaque circles have been applied. 
         [0099]      FIG. 48  shows an exploded view of panel assembly  300 , which is comprised of two fixed panels  310  and  350 , three movable panels  320 ,  330  and  340  as well as four drive links  80 ,  80   a ,  80   b  and  85 . Panel assembly  300  may thus be seen to be mechanically identical to panel assembly  190 . The essential difference is that the panels belonging to assembly  300  are transparent, and have a graphic pattern of opaque circles are applied whereas the panels belonging to assembly  190  are not transparent. 
         [0100]      FIG. 49  shows panel assembly  300  is in a first position. Movable panels  320 ,  330  and  340  are located such that their circles are aligned with the circles of fixed panels  310  and  350 . Due to the alignment of these circles, the majority of the surface of assembly  300  is transparent. 
         [0101]      FIG. 50  shows panel assembly  300  is in a second position. Movable panels  320 ,  330  and  340  are located such that their circles are partially aligned with the circles of fixed panels  310  and  350 . In this position, assembly  300  is in a partially opaque state. 
         [0102]      FIG. 51  shows panel assembly  300  is in a third position. Movable panels  320 ,  330  and  340  are located such that their circles are not aligned with the circles of fixed panels  310  and  350 . In this position, assembly  300  is in a largely opaque state. 
         [0103]      FIG. 52  shows a cutaway detail of panel assembly  300  in a first position, wherein the opaque circles on moveable panels  320 ,  330  and  340  are aligned with those of fixed panels  310 ,  350 , thereby creating a largely transparent surface. Handle element  89  belonging to drive link  85  is in an upper position. 
         [0104]      FIG. 53  shows a cutaway detail of panel assembly  300  in a second position, wherein the perforations of moveable panels  320 ,  330  and  340  are partially aligned with those of fixed panels  310 ,  350 . Handle element  89  belonging to drive link  85  is in an intermediate position. 
         [0105]      FIG. 54  shows a cutaway detail of panel assembly  300  in a third position, wherein the perforations of moveable panels  320 ,  330  and  340  are not aligned with those of fixed panels  310 ,  350 , thereby creating a largely opaque surface. Handle element  89  belonging to drive link  85  is in a lower position. 
         [0106]      FIGS. 55 ,  56  and  57  show plan views of panel assembly  300  in its first, second and third position respectively. It may be seen that panel assembly  300  may be reversibly transformed from a largely transparent state to a largely opaque state by raising and lowering handle element  89 . 
         [0107]      FIG. 58  shows a drive link  410  which is comprised of three sub-links  414 ,  416  and  418 . Drive link  410  is further comprised of center pivot pins  411   a ,  411   b  and outer pivot pins  417  and  419 . 
         [0108]      FIG. 59  shows a perspective view of drive link  410 . Center pivot pin  411   a  is co-linear, yet discontinuous, with center pivot pin  411   b . Sub-links  414 , 416  share outer pivot pin  417 . Sub-links  416 , 418  share outer pivot pin  419 . 
         [0109]      FIG. 60  shows an exploded view of panel assembly  400  which is comprised of fixed panels  440 , 470  and movable panels  450 , 460 . Panel assembly  400  has an essentially triangular perimeter. Panels  440 , 450 , 460  and  470  have triangular perforations. 
         [0110]      FIG. 61  shows a sectional view of assembly  400 . Center pivot pin  411   a  engages fixed panel  440 ; outer pivot pin  417  engages movable panel  450 ; outer pivot pin  419  engages movable panel  460 ; center pivot pin  411   b  engages fixed panel  470 . Sub-link and sub-link  414 ,  416  and  418  lie in different planes relative to each another. Likewise, outer pivot pins  417  and  419  lie in different planes. 
         [0111]    None of the four pivot pins  411   a ,  417 ,  419  or  411   b  spans beyond the particular panel with which they engage. Therefore, it is unnecessary to provide clearance slots in the fixed or movable panels to allow unobstructed movement. Further, drive link  410  can be rotated a full three-hundred and sixty degrees in a continuous manner. 
         [0112]      FIG. 62  shows a detailed perspective view of panel assembly  400  in its aligned position. Drive link  410  shown in dashed line may be seen to engage panels  440 , 450 , 460  and  470 . 
         [0113]      FIGS. 63 and 64  show panel assembly  400  in a successive partially aligned positions where drive link  410  has been successively rotated relative to its position in  FIG. 62 . 
         [0114]      FIG. 65  shows panel assembly  400  in a non-aligned position. 
         [0115]      FIGS. 66 through 69  show four views of panel assembly  400  as it transforms from an aligned, largely permeable condition to a non-aligned largely non-permeable condition. 
         [0116]    Assembly  400  has three drive links  410 ,  410   b  and  410   c  which are located near the perimeter of the assembly. It has one drive link  410   a  which is located at the center of assembly  400 . 
         [0117]    Not shown, but possible, are panel assemblies that are comprised of sheets having different acoustical properties, whether absorptive or reflective.