Abstract:
A light fixture allows individual light bulbs to be arranged in compact fashion to maximize the number of bulbs per given area in the fixture. To facilitate replacement or exchange of the bulbs, the bulbs are mounted in alternating succession on a pair of separately movable supports, reorientation of which serves to remove the bulbs from the tight packed arrangement, to one in which the bulbs are sufficiently separated from one another to allow hand access for removal and installation of the bulbs. A distinct aspect of the aforementioned feature of the invention independent of the movable supports resides in the ability to utilize two of more of the fixtures to multiply the light produced. Advantageously, the fixtures can be arranged in direct physical series, side by side, or to form an array extending in orthogonal directions.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/641,243 filed Jan. 3, 2005 entitled LIGHT FIXTURE AND LIGHTING METHOD. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a light fixture, and more particularly to a light fixture suited for use in size-restricted areas, such as for example in lighting an aquarium or a plant bench, and which can provide light of greater intensity than many conventional fixtures, including a standard linear fluorescent fixture, and a method of providing lighting. 
   Many types of light fixtures are available for providing artificial light in connection with a number of diverse activities. These conventionally use various types of light sources, including incandescent, fluorescent, metal halide and sodium lamps. Each of these light sources have particular advantage and disadvantage, and selection of a particular type is dependent in large part on the desired application. For example, incandescent bulbs can be dimmed, but are the least light efficient, generating greater heat and less light per watt consumed than the remaining type lamps. Metal halide and sodium lamps require a ballast to operate. Magnetic ballasts, which can generate noise, are generally required, at present, for larger output bulbs. Fluorescent bulbs, while having greater efficiency than incandescent bulbs, cannot be dimmed. 
   Often, the level of light and spectral range emitted is the factor of greatest importance to a user. Particularly in the fields of aquaria and horticulture, wherein photosynthetic processes are involved, selection of a type of light is predicated upon production of sufficient levels of light intensity within a usable spectrum. While fluorescent lights, which are readily available and relatively inexpensive to buy and operate, and which output light in a spectral range usable in photosynthesis, they have heretofore not generally provided a sufficient level of light required by many plants and simulated reef environments. For this reason, metal halide lighting, while much more expensive that fluorescent lighting, is generally the lighting of choice for many applications requiring high intensity light. 
   Compact fluorescent bulbs are available, which are intended for replacement of less efficient incandescent bulbs, and which have an integral ballast and, optionally, a standard screw base. These bulbs can, according to present design, emit up to about four times the amount of light than a standard incandescent bulb using the same power, and therefore, because of their greater light efficiency, run much cooler while outputting comparable levels of light of other types of lighting sources. However, a light fixture for housing these lights has heretofore not delivered a suitable intensity of light for many applications. 
   It would therefore be desirable to provide a light fixture that could utilize any light source, including fluorescent, in a manner which increases the light provided thereby. 
   Accordingly, it is an object of the invention to provide a light fixture which overcomes the drawbacks of the prior art. 
   It is a further object of the invention to provide a light fixture in a compact size suitable for use in defined spaces, and which would maximize light density. 
   It is an additional object to provide a light fixture in a form that is economical and functionally versatile. 
   It is still a further object of the invention to provide a light fixture in which light elements can be installed easily for exchange or replacement, and which optionally accepts compact fluorescent bulbs having a standard incandescent type screw base. 
   It is yet a further object of the invention to provide a method of replacement or exchange of light bulbs in a fixture. 
   SUMMARY OF THE INVENTION 
   In accordance with these and other objects of the invention, there is provided a light fixture in which individual light bulbs are arranged in compact fashion to maximize the number of bulbs per given area in the fixture. The lights are movable from a use orientation to another, bulb replacement position in which the bulbs are accessible for hand replacement. 
   Briefly stated, a light fixture includes at least one support to which light bulbs or other light sources are mountably receivable. When installed to the support, the lights are energizable from a power source to emit light in a desired direction, for example, downward, when in a use orientation. The support is movable from the use orientation to a service orientation in which the bulbs are hand-accessible for replacement or substitution by a user. Advantageously, the support is supportably mounted to a suitable retaining structure in both orientations, and more advantageously continuously remains supportably mounted to the retaining structure also while moved between the respective orientations. 
   According to an embodiment of the invention, a light support is pivotably mountable to a supporting structure, provided, for example, in the form of a housing, and which is conveniently adapted for mounted support to a retaining structure. The light support with lights installed is suitably oriented in one retained position to the supporting structure for active use in providing light, i.e., a use orientation, and is rotatable from such use orientation to a service orientation while remaining mounted to the supporting structure. The lights may be simply arranged along a single row or, alternatively, plural rows, with all of the lights of a given row being disposed codirectionally. Alternatively, and more advantageously, individual lights can be arranged in a row, the lights being directed along respective mutually parallel planes running crosswise the row of lights, adjacent ones of the lights being positioned at an angle to one another, whereby such angularly offset arrangement provides greater accessibility to the lights for facilitated hand replacement notwithstanding a laterally close arrangement. 
   In accordance with another embodiment of the invention, in order to facilitate replacement or exchange of the bulbs, while concomitantly conveniently allowing the bulbs to be placed in a tightly-packed arrangement when in use, the individual bulbs are mounted in alternating succession on a pair of supports, at least one of which is movable independently of the other, reorientation of which serves to remove the bulbs from the tight packed arrangement, to one in which the bulbs on the respective supports are sufficiently separated from one another to allow facilitated hand access for removal and installation of the bulbs. 
   In accordance with an embodiment of the invention, a light fixture conveniently employs a pair of optional access panels, advantageously, though not necessarily, provided in the form of hinged doors, located more advantageously in an upward facing position of the fixture when oriented for use in emitting light in a downward direction, to allow access to the bulbs from above, rather than below, as in most, if not all, enclosed conventional fixtures designed to project light downwardly. The light bulbs (also referred to interchangeably herein as “light elements”) are mounted to inwardly facing sides of respective ones of the doors, such that when the doors are opened upwardly (or panels removed, when not hingably mounted), each door (or panel) includes at least one of the bulbs mounted thereto, and which are made accessible by such movement. After replacement or exchange, the doors are returned to the closed position, thereby restoring an advantageously, but not necessarily, closely packed bulb arrangement, and preventing excessive upward escape of light. 
   In a particularly advantageous embodiment, a fixture in accordance with the invention utilizes self-contained, high efficiency output, compact fluorescent lights of the conventional type mentioned above, and which each have their own integral ballast, located generally between a base adapted for screw connection to a socket and the light emitting portion thereof. The bulbs are arranged with bases of alternate bulbs facing in a horizontal direction, or having a horizontal vector when arranged in a vertically tilted orientation, opposed to that of an adjacent bulb. A pair of supports, advantageously embodying at least one door, is provided at a top of the fixture Each bulb facing in one of the directions is mounted to one of the supports, and each bulb facing in the opposite direction is mounted to a remaining one of the supports, such that the bulbs are arranged in alternating fashion between one another, and extend in a sideways direction of the light fixture when supports are oriented in a use position. 
   Whether or not equipped with an access from above to bulbs contained in the fixture, as hereinbefore described, a distinct feature of the invention, providing independent advantage from the features mentioned above, includes an optional configuration allowing use of the fixtures as plural light emitting sources. Such feature has particular advantage in use, for example, in applications requiring greater light intensity over an extended defined region of given area, such as in connection with aquariums, terrariums, hydroponics and agriculture. Additionally, use of plural (two or more) fixtures allows selection of different bulbs for each fixture to suit, perhaps, different needs over different regions illuminated thereby. In a particularly advantageous embodiment, the light fixtures optionally include electrical coupling structure for transmitting power from one fixture to another connected therewith, thereby allowing multiple fixtures to be connected one to the other, and requiring only one to be powered directly to an external power outlet. 
   While virtually any light source can be used in the above described arrangements, use of compact fluorescent light elements is considered particularly advantageous, since each light can be selected to emit a desired spectrum of light for a given application. Additionally, since each light has its own ballast, the fixture is light weight, maintenance-free, and lights of different wattage can be freely substituted without requiring a change in ballast, as would be otherwise required in a fixture utilizing standard fluorescent bulbs. 
   The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1   a  is a cross-sectional view taken along line  1   a - 1   a  of  FIG. 2  of a light fixture according to an embodiment of the invention, depicted in a use orientation; 
       FIG. 1   b  is a cross-sectional view of the embodiment of  FIG. 1   a , depicted in a service orientation; 
       FIG. 2  is a bottom plan view of the embodiment of  FIGS. 1   a  and  1   b  depicted in the use orientation; 
       FIG. 3  is a bottom plan view of another embodiment of the invention depicted in a use orientation; 
       FIG. 4   a  is a cross-sectional view taken along line  4   a - 4   a  of  FIG. 3  in the use orientation; 
       FIG. 4   b  is a cross-sectional view of the embodiment of  FIG. 4   a  depicted in the service orientation; 
       FIG. 5  is a top plan view of another embodiment of a light fixture in accordance with the invention; 
       FIG. 6   a  is a cross-sectional view taken along line  6   a - 6   a  in  FIG. 5 ; 
       FIG. 6   b  is a cross-section view taken along line  6   b - 6   b  in  FIG. 7   b;    
       FIG. 7   a  is plan view of the light fixture of  FIG. 5 , shown with one of a pair of access doors moved to a bulb replacement position; 
       FIG. 7   b  is plan view of the light fixture of  FIG. 7   a , shown with both doors moved to respective bulb replacement positions; 
       FIG. 8  is a perspective view of the light fixtures shown in  FIGS. 5-7   b , depicted with the access doors closed to a use oriented position; 
       FIG. 9  is a perspective view depicting an embodiment employing a series of light fixtures according to the invention used atop an aquarium; 
       FIG. 10  is a front elevational view of another embodiment employing plural light fixtures according to the invention for use in lighting a reptile terrarium; 
       FIG. 11   a  is a plan view of another embodiment of a light fixture in accordance with the invention shown in condition of operation; and 
       FIG. 11   b  is a plan view of the embodiment of  FIG. 11   a  depicted in an opened condition for servicing of the light elements. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the figures, and in particular  FIGS. 1   a ,  1   b  and  2 , a light fixture in accordance with an embodiment of the invention is shown, generally at  10 . Light fixture  10  includes a housing  1 , and which optionally includes a light transmissive panel  2  through which light is directed generally in the direction of the arrows shown in  FIG. 1   a . Light sockets  3  for receiving light elements  4  are mounted to a rotatable support  5  that is pivotably received to the housing  1  for rotatable positional reorientation about a pivot axis A. A reflector  6  is advantageously provided to focus or increase the intensity of light directed in the desired direction, and as appropriately indicated by the desired application. It is noted that details of internal wiring within fixture  1 , as well as external powering of the fixture  1 , are omitted from the figures for simplifying illustration, and as being deemed unnecessary since the electrical configurations to be employed are well within the purview of one of ordinary skill in the art. 
     FIGS. 1   a  and  1   b  depict, respectively, a use orientation and service orientation. In particular, as shown in  FIG. 1   a  (and  FIG. 2 ), the light elements  4  are vertically positioned for light emission in a downward direction. When the light elements  4  require replacement, or alternatively, exchange of the light elements  4  is desired, for example, to alter a spectral output, the rotatable support is rotated about pivot axis A to the service orientation shown in  FIG. 1   b . In this position, the light elements  4  are exposed above the housing  1  and can be readily accessed by the user. When servicing is complete, the rotatable support  5  is pivoted back to the use position of  FIG. 1   a.    
   Advantageously, suitable structure is optionally provided that allows retained positioning in two discrete orientations corresponding respectively to the aforementioned use and service orientations. In the depicted example, shown essentially in simplified schematic form, this feature is provided conveniently in the form of a rest  7  and a stop  8  which engage edges of the rotatable support  5  to prevent rotation thereof past a roughly 180 degrees range of travel. 
   Referring now to  FIGS. 3 ,  4   a  and  4   b , another embodiment of a light fixture is depicted generally at  20 . While having a different shape than the previous embodiment, the overall functioning of the present embodiment is analogous with that of  FIGS. 1   a ,  1   b  and  2 . Light fixture  20  includes a housing  21 , which also optionally includes a light transmissive window  22  which, while having a curved, rather than planar, configuration, corresponds in function and advantage to panel  2  of the previous embodiment. Light sockets  3  for receiving light elements  4  are mounted to a rotatable support  25  that is pivotably received to the housing  21  for rotatable positional reorientation about a pivot axis A′. A reflector  26  is also optionally and advantageously provided. 
     FIGS. 4   a  and  4   b  depict, respectively, a use orientation and service orientation, the further description of which is omitted as duplicative of the analogous description relating to the functioning of the previous embodiment of  FIGS. 1   a ,  1   b  and  2 . However, it is noted that the embodiment differs in the fact that light sockets  3  are mounted in an alternating angularly offset manner such that adjacent light elements are tilted at an angle α with respect to one another. Such feature further facilitates access to individual light elements  4  during servicing. 
   Turning now to  FIGS. 5-8 , a light fixture in accordance with another embodiment of the invention is shown, generally designated  30 . Light fixture  30  includes a housing  31 , and which optionally includes a light transmissive panel  32  through which light is directed generally in the direction of the arrows shown in  FIG. 6   a . Light sockets  3  for receiving light elements  4  are mounted to a pair of supports that are engageable with the housing  31  in a suitable manner as to allow reorientation with respect to, or removal from, the housing  31  to allow installation or substitution of the light elements  4 , as will be explained below. While the arrows indicative of light rays transmitted through light transmissive panel  32  are shown as being parallel in  FIG. 6   a , it will be understood that the beam of light alternatively can be divergent or convergent depending on the nature (curvature) of a reflector  36  disposed behind the light bulbs. 
   The aforementioned supports for receiving the light elements  4  are provided in the present embodiment conveniently in the form of a first door  35  and a second door  36 , both hingably mounted to the housing  31  to allow pivotable movement about respective axes A 1  and A 2 . The reflector  36  is conveniently mounted to first door  37 . The second door  38  is mounted inward of the first door  37  such that the first door  37  partially overlaps the second door  38  when the light fixture  30  is closed, in the use position, as shown in  FIGS. 5 ,  6   a  and  8 . When installed, light elements  4  advantageously extend codirectionally with a width direction of the fixture  10 , i.e. orthogonal to a direction of light emission from the fixture, or, as shown in  FIGS. 6   a  and  6   b , at a slight tilt from a horizontal plane, to minimize a required height of the fixture  10 . The light elements  4  can, however, be oriented in any suitable orientation if height is not a particular issue, for example vertically, with bases of the light elements  4  facing opposite to the direction light transmitted from the light fixture  30 . In the depicted example, four sockets  3  are provided for receiving up to four light elements  4 , wherein two of the sockets  3  are mounted to the first door  37  and the remaining two of the sockets are mounted to the second door  38 . It will be understood, however, that any number of sockets  3  and light elements  4  (odd or even) can be installed to a light fixture  30  of suitable length. 
   In the depicted embodiment of  FIGS. 5-8 , the light elements  4  are arranged with bases of alternate light elements  4  facing in a direction roughly opposed to that of an adjacent one of the light elements  4 . However, the direction of the light elements  4  need not be reversed with each successive light element, i.e., every other light element, but instead, for example, could be reversed every two light elements, i.e. alternating pairs, or a combination of either pattern or other patterns. 
   As mentioned above, the second door  38  is mounted inward of the first door  37  such that the latter advantageously overlays a portion of the second door  38  when the light fixture  30  is in a closed, light illuminating orientation, as shown in  FIGS. 5 ,  6   a  and  8 . Therefore, while the first door  37  in the outer position can be a full panel, the second door must be suitably configured to provide suitable clearance to allow the sockets  3  carried on the first door  37  (and light elements  4  installed therein), to be received between the other light elements  4  and sockets  3  carried on the second door  38 . 
   When the light elements  4  are to be replaced, the first and second doors  36 ,  37  are opened as shown in  FIGS. 6   b  and  7   b . The intermediary step of initially opening the first door  37  is shown in  7   a . When the light elements  4  have been replaced, the light fixture  30  is returned to a closed, use position ( FIGS. 5 ,  6   a  and  8 ) by reversing the above steps. To further facilitate opening of the first door  37 , a finger cutout  37   a  can optionally be provided as shown in  FIG. 8 . 
   Power is supplied to the fixture  30  by a power cord  35 . A particularly advantageous option is to provide the power cord as a removable (cheater) cord which couples to a male plug  39  external of the fixture  30 . The advantage of such feature will be apparent from the description which follows pertaining to a further embodiment. 
   Whether or not equipped with an access from above to bulbs contained in the fixture, as hereinbefore described, a distinct feature of the invention providing independent advantage from those pertaining to placement and reorientation of the light elements in a fixture is directed to an optional configuration allowing use of the fixtures as plural light emitting sources. Such feature has particular advantage in use, for example, in applications requiring greater light intensity over an extended defined region of given area, such as in connection with aquariums, terrariums, hydroponics and agriculture. 
   An example of such plural arrangement is depicted, for example in  FIG. 9 , and in which a plurality of light fixtures  30  of the general design as shown in  FIGS. 5-8  are placed in adjacent positions atop an aquarium  41 . Unlike standard fixtures of conventional design which are dimensioned to extend along a longitudinal direction of an aquarium tank, and which are generally supported by resting engagement of opposed ends of the fixture with the top edge of either side end of the aquarium, the feature of the present invention instead provides a dimension of the fixtures  30  which allows the fixtures to extend front to back of the aquarium  41 , wherein the fixtures are supported on the top edges corresponding to the front and back walls of the aquarium. Suitable dimensioning of the fixtures  30  will advantageously allow a length extent of the aquarium to be subdivided into an appropriate number of fixtures, the latter which can then be placed atop the aquarium  41  to collectively extend over a substantial length portion of the aquarium, for example, as depicted in  FIG. 9 . 
   In a particularly advantageous variation, the light fixtures  30  of  FIG. 9  optionally include electrical coupling structure for transmitting power from one fixture to another connected therewith, thereby allowing fixtures to be connected one to the other, and requiring only one to be powered directly to an external power outlet. As previously mentioned in connection with  FIGS. 5-8 , power is advantageously supplied to the fixture  30  by a power cord  35  which removably couples to a male plug  39  external of the fixture  30 . Referring back to  FIGS. 4-8 , and as best seen in  FIGS. 5 and 8 , fixture  30  further includes a female connecter  49  positioned such that it aligns with male plug  39  of an adjacent fixture  30  when power cord  35  is removed. Such feature allows the following operation of adjacently abutted fixtures  30 , as shown in  FIG. 9 . When the leftmost fixture  30  of  FIG. 9  is powered by power cord  35 , power is transferred to the female connector on the opposite side of the fixture  30  (the position of which is seen in the rightmost fixture  30  which is identical in construction) by suitable internal wiring (not shown). The aligned male plug  39  of the middle fixture  30  plugs into the female connector  49  of the leftmost fixture  30 , and the male plug  39  of the rightmost fixture  30  in turn plugs into the female connector of the middle fixture. Power is therefore transferred from fixture to adjacent fixture, obviating the need for individual power cords for each of the plurality of fixtures. 
   In addition to the above advantages associated with a modular arrangement of two or more fixtures, use of plural (two or more) fixtures allows selection of different bulbs for each fixture to suit different light requirements over different regions illuminated thereby. For example, as shown in the embodiment of  FIG. 10 , two light fixtures  30 ′ and  30 ″ received atop a terrarium enclosure  41 ′ have different light elements (not shown) installed therein selected to emit light of the type desired to meet environmental light requirements for reptile husbandry. In the depicted example, light fixture  30 ′ contains light elements designed to emit light in the ultraviolet range for basking animals in order to meet metabolic requirements for vitamin D production, and light fixture  30 ″ is equipped with heat lamps to selectively create a temperature gradient along a longitudinal extent of the terrarium enclosure  41 ′ to aid digestion when the reptile is under the light fixture  30 ″ by raising body temperature. 
   It is noted that a light fixture within the broad embrace of the contemplated invention can be designed to accommodate virtually any type of light having any size or configuration. For example, while the above embodiments are directed to light elements of compact shape and having a standard screw base, the invention can be also practiced in a fixture adapted for use with linear fluorescent tubes. In such instance, the individual tubes would be mounted on separate supports, at least one of the supports being movable with respect to the remaining support such that the tubes could be placed side by side with minimal space therebetween during use, and reoriented to a service orientation in which the tight packed arrangement of the light tubes on the respective supports would be relieved. 
   While, as noted above, virtually any light source can be used in the above described arrangements, use of compact fluorescent light elements is considered particularly advantageous, since each light can be selected to emit a desired spectrum of light for a given application. Additionally, since each light has its own ballast, the fixture is relatively light weight, virtually maintenance-free and permits lights of different wattage to be freely substituted without requiring a change in ballast, as would be otherwise required in a fixture utilizing standard fluorescent bulbs. 
   Furthermore, while the above-described embodiments each involves some form of pivotable movement of a light element receiving support relative to a housing, any type of movement can be employed without departure from the invention. For example, as shown in  FIGS. 11   a  and  11   b , a light fixture is depicted, generally designated  50 , in which slidable movement is employed. 
   As depicted, light fixture  50  includes a housing  51  having an optional light transmissive panel  52 , and a pair of slidably movable supports provided in the form of drawers  53  and  54  to which light sockets  3  are mounted for receiving light elements  4 .  FIGS. 11   a  and  11   b  show, respectively, use and service orientations. As shown in  FIG. 11   b , by moving drawers  53 ,  54  in opposed directions indicated by the arrows, light elements  4  are brought out of a tight packed arrangement, from the use orientation of  FIG. 11   a , and exposed from the housing for hand replacement in the service orientation, in analogous fashion with the other embodiments described herein. Handles  53   a ,  54   a  are optionally provided to facilitate movement of the drawers  53 ,  54 . 
   It is noted that, in accordance with an advantageous embodiment of the invention, the light elements are optionally exposed to a region of the housing other than that corresponding the light transmissive panel, thereby obviating removal of the panel, and allowing the panel to be readily sealed in a waterproof or water resistant fashion to the housing. Such feature provides particular advantage when used for gardening and aquarium applications, where water presents a potential threat to the internal workings of the fixture. 
   Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.