Abstract:
A solar light enclosure is provided with a light receiving top opening and a light emitting bottom opening. The enclosure also includes lateral light extraction panels for emitting light from the sides of the enclosure. The panels may incorporate lens structures, prisms, baffles and reflector elements to transmit light in selected lateral directions. The panels may be attached to the enclosure by hinges and be tiltable away from the enclosure to further enhance illumination toward selected side areas. The enclosure interior may include light control partitions to direct portions of light toward the light extraction panels while simultaneously transmitting other portions of light downwardly and out the enclosure bottom opening. The partitions may be sized, shaped and adjusted angularly to create patterns of light for illuminating specified work areas, hallways and architectural structures.

Description:
This application claims priority from provisional application No. 60/137,192 filed Jun. 2, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to interior lighting utilizing natural lighting fixtures. In particular, the invention concerns a skylight enclosure adapted to receive solar light and distribute the received light to selected areas of a building interior. 
     2. Description of Related Art 
     The idea of converting a skylight dome in one&#39;s roof to a more useful item that will effectively distribute light and illuminate desired areas of an interior, has resulted in the creation of a wide variety of elaborate and complicated solar lighting systems. For example, U.S. Pat. No. 5,099,622 discloses a roof mounted skylight from which extends a tubular structure that terminates about flush with the ceiling of a room. The domed portion of the skylight extending above the roof is transparent and includes a reflector. The reflector captures a portion of sunlight that would otherwise pass through the dome and directs it into the underlying tubular structure. The reflected light exits the structure through a concave diffuser which scatters the captured light throughout a room. 
     The above system is inefficient because all light entering the tubular structure can only exit through the downward facing diffuser. Therefore, no matter how concave the diffuser is, there will still be dark areas around the room. Additionally, the reflector will also shield some of the sunlight during certain times of every day. As a result, less sunlight will enter the structure causing diminished illumination. 
     U.S. Pat. No. 5,175,967 seeks to overcome the above deficiency by placing a reflective surface at an inner lower terminal end of the tubular housing. The mirror is positioned at a 45° angle to direct light through a window placed in the side of the housing. An objection to this arrangement is that the mirror itself blocks out a substantial portion of light that could otherwise be directed out of the bottom of the structure. Thus, while light is directed out one portion of the housing, the area directly beneath the structure is severely deficient in illumination. Further, the side window through which reflected light exits, has no means for adjustment or for inhibiting sunlight glare. 
     A more sophisticated passive lighting system using a glass dormer structure for a roof is shown in U.S. Pat. No. 5,408,795. This elaborate system allows light to pass through openings in the glass dormer and become softened and diverted by passing through layers of diffusers, mirrors and fresnel lens panels. A primary function of the system is to enable an inside person to view outdoor images, while also dispersing ambient daylight. This, of course, results in lower amounts of overall illumination and defeats the purpose of most skylight assemblies. 
     SUMMARY OF THE INVENTION 
     A significant attribute of the present invention is the ability to enhance light captured in a solar lighting enclosure and transmit the light out the sides of the enclosure in a controlled manner without glare and with minimal loss to the light intensity. The system provides a housing having light reflecting interior surfaces between a light admitting top opening and a light emitting bottom opening. The enclosure includes a lower wall portion within which is incorporated light directing means comprising side extraction panels through which light, collected from within the enclosure, passes outwardly in predetermined directions. 
     One or more side extraction panels may be used depending on the location of the interior building areas to be illuminated. When the system is used to illuminate hallways or aisles, the side extraction panels can be positioned on sides of the enclosure that face the above areas. 
     If even more light is desired for specific work areas or selected decorative areas of a room, the side extraction panels may be provided with light guide means incorporated into the panels to direct light specifically to those areas. Conversely, if more indirect lighting is desired, the guide means can transmit light toward a reflective ceiling. The panels may also be equipped with tilt adjustment mechanisms for rotating the panels away from the enclosure lower wall portion. This permits light to be directed at a more downwardly inclined angle than is possible with internal guide means. 
     In cases where it is more important to direct most of the light outwardly through the side extraction panels, the interior of the enclosure may be provided with light control means. The light control means transmits a portion of the enclosure light to an underlying diffuser while simultaneously reflecting other portions of the light toward the side extraction panels. The light control means may comprise flat, curved or fluted light control partitions that are sized to be equal to, or less than, the entire area of the enclosure light emitting bottom opening. More than one partition may be used and each partition may be fixed in place or be rotatable. 
     The light control partitions may also have varying shapes such as triangular, polygonal, round, oval and trapezoidal. Still further, as with the side extraction panels, the light control partitions may be equipped with angular adjustment means such as slotted brackets, pawl and rachet assemblies, piston/shaft air or hydraulic devices, jack screw and related apparatus known in the art. When the size and shape of the light control partitions are coordinated, they may operate together to create variable sized open areas to allow light to pass unobstructed out the enclosure bottom light emitting opening. This feature may be used to delineate emitted light patterns for special illumination needs. 
     The efficiency of the overall system is improved by utilizing a light collimator over the enclosure light admitting top opening. This will allow better alignment and reflection of the light rays within the enclosure and will diminish the effects of sun glare. It is also advantageous to provide a light diffuser sheet over the light emitting bottom opening to further reduce glare and to enhance the distribution of light in a downward direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric front view of the overall light enclosure of the present invention with portions of the front and right sidewalls broken-away to show side extraction panels about the lower portion of all sidewalls. 
     FIG. 2 is an isometric view of the enclosure shown in FIG. 1 with a portion of the front wall broken-away to reveal a side extraction panel on a left side wall of the enclosure and with light control partitions added to the enclosure interior. 
     FIG. 3 is an elevational cross-section view taken along lines  3 — 3  of FIG.  2 . 
     FIG. 4 is a cross-sectional plan view taken along lines  4 — 4  of FIG.  2 . 
     FIG. 5 is a cross-sectional view taken along lines  5 — 5  of FIG.  3 . 
     FIG. 5 a  is a first variation of the light control partitions shown in FIG.  5 . 
     FIG. 5 b  is second variation of the light control partitions shown in FIG.  5 . 
     FIG. 6 is a bottom plan view taken along lines  6 — 6  of FIG.  3 . 
     FIG. 7 is a fragmentary side elevational view taken along lines  7 — 7  of FIG. 2 illustrating a tilting mechanism for rotating a light control partition. 
     FIG. 8 is a corner fragmentary view similar to FIG. 7 showing a different angular position of the light control partition. 
     FIG. 9 is a fragmentary view similar to FIG. 7 showing outward tilting of a side extraction panel and including a reflector shield extending angularly above the tilted side extraction panel. 
     FIG. 10 is a cross-sectional view taken along lines  10 , 10  of FIG. 5 a.    
     FIG. 11 is a cross-sectional view taken along lines  11 , 11  of FIG. 5 b.   
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference now to the drawings, the overall solar light enclosure system is shown generally by reference  10 . The system is depicted as having a polygonal cross-section circumscribed by a rigid framework  12 . Depending on the specific application, the enclosure could have a triangular or round cross-section The height of the structure will be dictated by the building roof height and how close one wishes to position the solar light emissions to specified areas. Also, the total cross-sectional area of the enclosure will be a matter of choice in relation to the total amount of light one wishes to distribute. 
     The basic framework  12  consists of four upstanding angle members comprising face member  13  and side member  14 . The members are located at each corner of the enclosure and connect at their uppermost points with a mounting structure  20 . At their lowermost points they connect with respective bottom side plates  17  and bottom face plates  18 . The bottom plates extend inwardly to inner plate edges that define light emitting bottom opening  42 . 
     In the lower half portion of framework  12  are cross-pieces that interconnect the upstanding members. As shown in FIG. 1, mid-side pieces  15 , 15  extend between corresponding face members  13 , 13 . Similarly, lower side pieces  15 ′, 15 ′ extend across the framework bottom and interconnect opposing side members  14 , 14 . Lower face pieces  16 ′, 16 ′ interconnect opposing face members  13 , 13 . 
     The areas below mid-side pieces  15 , 15  and mid-face pieces  16 , 16  and above lower pieces  15 ′, 15 ′ and  16 ′, 16 ′ between respective portions of the upstanding members  13 , 14 , comprise panel openings for placement of light directing means shown as side extraction panels. The panels are referenced as front panel  50 , back panel  52 , left panel  54  and right panel  56 . In FIG. 2, it will be noted that the cross pieces  15 , 16  have been omitted whereby only left and right side extraction panels  54 , 56  are shown. 
     The upper ends of the upstanding frame members  13 , 14  are interconnected by the aforementioned mounting structure  20 . The mounting structure also provides a means to disperse any accumulated condensation and vent air as needed during daily and seasonal heat and cooling cycles. Additionally, it connects protective dome  26  and collimator  28  to the framework  12 . 
     The mounting structure comprises a gutter plate  21  that projects outwardly from the top end of each upstanding frame member  13 , 14 . It extends around the entire periphery of the enclosure. Extending upwardly from the gutter plate outward from the upstanding frame members, is a spacer part  22 . The spacer part includes a flattened free end portion for engaging the underside of overlaped peripheral margins of dome  26  and collimator  28 . At the outermost end of the gutter plate is a skirt  23  that flares downwardly a distance sufficient to provide a peripheral weather shield for the overall mounting assembly. 
     Overlapping a portion of the skirt and the dome and collimator margins, is L-shaped bracket  24 . The bracket includes gasket and/or sealant materials to help insure a strong weatherproof connection. 
     It will be noted that the foregoing description of the mounting structure and its connection to the enclosure has been simplified for ease of understanding of the overall system. It does not form a part of the present invention. It will also be appreciated that additional means will be required to sealingly engage the enclosure or mounting structure to the roof of a building. 
     To complete the enclosure, the framework open areas above the extraction panel openings are covered with wall structures shown as frontwall  30 , backwall  32 , left sidewall  34  and right sidewall  36 . Preferably, the wall structures comprise a rigid flat insulative material  38 , such as foamed resin or plastic. They include an inner layer  39  of reflective metalized film or a polished sheet of metal. The wall structures are sealingly fixed, by mechanical fasteners and/or adhesives, to the inner surfaces of the upstanding frame members and cross pieces. Their top ends will preferably be straight and about coextensive with gutter plate  21  to define enclosure light admitting top opening  40 . 
     As shown in FIG. 1, there are four light extraction panels located above the light emitting bottom opening  42 . They may be fixed in place and emit light from all four sides of the enclosure. This version is suitable for positioning in the center of a room to provide ambient 360° light. The FIG. 2 embodiment, with left and right side extraction panels  54 ,  56 , is best suited for positioning above narrow halls or aisles. 
     In both embodiments, the guide means for the side extraction panels is shown as comprising multiple horizontally aligned lectilinear lens structures. Depending on the type of lens material and it&#39;s configuration, the light transmitted will be distributed outwardly at a wide angle less than 180°. If it is desired to direct the light in a predetermined direction, the panels may comprise a variety of other guide means such as internal light deflecting baffles, pre-aligned prisms, polarized or holographic light film, interior reflectors, shutters and other types of lens designs. 
     The guide means includes another alternative for directing light. This involves mounting the panels so that they can tilt outwardly from the enclosure walls. To accomplish the above, selected panels may be attached to corresponding upper or lower cross pieces with hinges. With each extraction panel having a top edge  60  and bottom edge  61 , the hinge can be attached preferably to either edge and rotate upwardly to direct light toward a ceiling or downwardly to illuminate specified lower areas. As best shown in FIGS.  3  and  7 - 9 , hinge  58  is attached to lower side and face pieces  15 ′, 16 ′ and to edge  61  of left and right side extraction panels  54 , 56  by fastening means such as pins, bolts, screws, rivets and adhesives. 
     The hinged panels may include a tilt adjustment mechanism for releasably securing the panels in a selected angular position. As shown in FIG. 9, an adjustable bracket  63  is illustrated which is externally mounted beneath hinge  58 . In ways known in the art, the bracket will be hinged and include notched guideways, rachet mechanisms or simple hinge shaft tightening means known in the art for fictionally inhibiting rotation of the bracket (and panel). Other tilt adjustment mechanisms could also be used in place of the bracket. Examples are rotatable screw jacks, pneumatic/hydraulic piston assemblies and electro/mechanical solenoid systems. 
     To ensure that a maximum amount of light will be directed downwardly when the panel is tilted outwardly, an optional reflective shield  65  may be used as shown in FIG.  9 . The shield may be flat or curved and may be angularly adjustable. It extends outwardly from the housing framework to overlie that portion of the space between panel top edge  60  and the enclosure wall. In this way, any light that might escape out of the aforementioned space will be reflected downwardly in the desired direction. 
     When the panels are provided with a tilt adjustment mechanism, it is preferable to provide an enclosure abutment seal for at least the panel top edge  60 . Thus, when the panel is in a closed position coextensive with a corresponding side wall, as depicted in FIG. 8, a gasket seal  66  is positioned along a portion of mid-side cross piece  15 . 
     To further enhance the performance and effectiveness of the light extraction panels, light control means may be incorporated into the enclosure interior. The light control means preferably comprises one or more light control partitions located to extend at an angle starting from below the extraction panels and extending inwardly into the enclosure interior. The partitions are preferably flat rigid structures having variable light transmitting and reflecting characteristics. They may comprise composites of glass, plastic and metal. Clear plastics such as acyclics and polycarbonates, along with pre-formed metal sheets, all may be used alone or in combination. A particularly suitable material useful with the invention for both transmitting and reflecting light, is LEXALITE by Lexalite International Corp. This material comprises a laminate of clear acrylic with a perforated polished aluminum film. 
     The light control partitions are preferably angularly adjustable. For this purpose the lower end of each partition is provided with a hinge  74  which interconnects the partition with corresponding bottom side and face plates  17 ,  18 . 
     To secure each partition at a selected angular position, releasable adjustment means known in the art may be used. For illustrative purposes only, FIGS. 2 and 7 show a slotted bracket  76  that is mounted to framework lower face piece  16 ′ and upstanding face member  13 . Housing front wall  30  is provided with a corresponding slot and a side edge of partition  70  includes a guide pin  78  that extends laterally through the wall slot and bracket. The end of the guide pin is threaded to accommodate a lock washer (not shown) and wingnut  80  for loosening and tightening the guide pin to the bracket. Tightening the wing nut will fix the partition at a selected position by frictional compression engagement. 
     It can be seen that the partitions, in combination, can create a variety of emitted light patterns by changing their size, shape and relative positions. With particular reference to FIGS. 2,  3  and  5 , leading edges  71 ,  73  of respective partitions  70 ,  72  are shown spaced-apart a short distance. The space between the edges creates a slot opening  84  for allowing light to pass directly to diffuser sheet  44  and then downwardly to a selected area. The farther apart the partition leading edges are, the more direct light will be available for downward illumination. 
     In general, the light opening may be varied by the angle of each partition with respect to the other and by the length of each partition. Additionally, the partitions themselves may be narrower than the width of the enclosure interior. This construction creates openings about the side edges of the partitions and results in more downwardly directed light and less light directed toward the side extraction panels. 
     The partitions may also have varying geometrical shapes which can be used to create a selected downwardly directed light pattern. For example, FIGS. 5 a  and  10  illustrate four corresponding trapezoidal shaped partitions shown by references  87 - 90 . The partitions are connected to respective portions of the bottom plates  17 ,  18  with hinges  74   a . When the partitions are brought together, their leading edges create a polygonal shaped light opening  86 . 
     FIGS. 5 b  and  11  show that if it is desired to create an elongated direct light pattern, rectangular front and back partitions  93 ,  94  may be secured to respective bottom face plates  18 ,  18  by hinges  74   b . The partitions extend lengthwise along the entire length of the enclosure. Depending on the width and angular position of the partitions, a longitudinal light opening  92  will be created. When light from within the enclosure passes directly through the opening  92  and diffuser sheet  44 , a bright elongated narrow light pattern will be emitted downwardly. It is expected that each of the FIGS. 5 a  and  5   b  embodiments will include releasable securement means, such as the bracket assembly  76  shown in FIG. 7, or equivalent means known in the art. 
     In consideration of all the above enumerated variations, it can be seen that the enclosure of the invention is adaptable for a wide variety of applications and has sufficient versatility to be a replacement for, or at least a strong environmentally desirable supplement to, electrical light fixtures during daylight hours. Therefore, while the above descriptions set forth illustrative embodiments in detail, it will be apparent that still further variations and modifications may be made without departing from the spirit and scope of the invention. As such, the invention is intended to encompass all of such variations that come within the purview of the appended claims and should not be limited by the aforementioned illustrative embodiments.