Abstract:
An adjustable reflector device for light fixtures is disclosed. The device comprises a reflector sheet made of a resiliently flexible material with at least one reflective surface folded and flexed along two parallel pivot axes into a concave arrangement of one central section and two flexible wings behind a high-intensity discharge lamp, such that the degree of concavity of the reflector can be adjusted to a plurality of predetermined degrees relative to the lamp by flexing or bending the wings radially around the pivot axes without the use of tools, thereby allowing horticulturists in the field to adjust the geometry of the light beam emitted in order to provide plants positioned below the fixture with a uniform pattern of light radiation of different intensities as needed at different stages of plant growth.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application No. PCT/CN2016/096444, filed on Aug. 23, 2016, which claims the benefit of Chinese Patent Application No. 201520693145.4, filed on Sep. 9, 2015, each incorporated by reference herein in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Within the field of indoor horticulture, it is commonly known that adjustable light fixtures offer many advantages, such as allowing horticulturists to customize the intensity and geometry of light radiation emitted from a light fixture to meet the needs of plants at different stages of growth, without adjusting the height at which the light fixture is installed, replacing the fixture, changing the lamp used or making other such changes. 
         [0003]    Typically, a light fixture is installed above a planting tray of standard dimensions: 4 ft×4 ft, 4 ft×6 ft or 4 ft×8 ft. It is commonly known that plants require different intensities of light for optimal results at different phases of growth, creating the need for a light fixture capable of emitting a light beam of uniform intensity which can be easily adjusted to a plurality of selected geometries, which correspond to both the standard dimensions of commonly used planting trays and selected degrees of intensities commonly required for optimal results at different stages of plant growth. 
         [0004]    In the prior art, adjustable light fixtures which comprise at least one arched, concave reflective surface have no end plates along the curved edges of the reflective sheet, thereby failing to reflect light emitted from the central light source toward the sides of the fixture not bounded by the arched sections of the reflective surface. Such arrangements fail to reflect substantial amounts of light radiation into the target area, resulting in a waste of electricity. 
         [0005]    Another shortcoming not addressed in the prior art is the inability to adjust the geometry of the light beam emitted by a light fixture in a single step and without the use of additional tools. Previous art requires multiple steps or the use of tools to adjust the geometry of the emitted light beam. Due to the complexity of the adjustments, horticulturists must spend substantial time and exert substantial effort to carry out the adjustments, which in most practical growing situations must be carried out for a large quantity of light fixtures. In addition, the need for the precise use of hand tools requires a sufficiently high level of visibility in the field. This necessitates the installation and operation of auxiliary lighting sources in the work space, which necessarily incurs additional costs. 
         [0006]    In the prior art, light fixtures with concave reflective surfaces substantially surrounding the light source on five sides are built with substantially heavy frames or housings to support the light source and the reflective surfaces. The weight of the fixtures increases the difficulty of installation and necessitates that the structure or architecture supporting the fixture is able to support a heavy object. A rigid housing comprising a latitudinal surface above the light source and rigid, longitudinal sides surrounding the light source limits the degree to which reflective surfaces installed within the concave structure can be easily adjusted, and the necessary complexity and heaviness of the fixtures increase manufacturing and shipping costs. 
         [0007]    In the prior art, adjusting the concavity of fixtures with arched reflective surfaces requires changing the degree of curvature of the arched surfaces, which may result in sub-optimal geometries of the reflected light beam or sub-optimal uniformity of the radiation intensity of the light beam. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention seeks to provide an adjustable reflecting device which substantially overcomes or at least ameliorates the disadvantages of the prior art. 
         [0009]    Accordingly, it is an object of the invention to provide a light fixture having a concave reflective sheet with movable end plates that maybe adjustably retained to the fixture&#39;s minimal frame in different selected positions, whereby the movable end plates retain the reflective sheet in selected degrees of concavity, thereby enabling the light beam, which is created by reflection of light emitted from a light source positioned substantially centrally within the fixture and substantially in parallel to the apex of the concave reflective sheet, to be of adjustable geometry and intensity. 
         [0010]    Another object of the invention is to provide a light fixture which can be easily adjusted without the use of tools and in environments with low visibility to emit a light beam that is adjustable between a plurality of selected geometries. In an environment with relatively low visibility, a horticulturist can make the adjustments to the device by listening for a clicking sound or by taking note of physical reverberations when the adjustable retention mechanisms are engaged in different selected positions. 
         [0011]    Still another object of the invention is to provide light fixture which can be easily adjusted to emit a light beam that is adjustable between a plurality of selected geometries, which, when the fixture is installed at a height commonly allowed by ceilings or grow-tent hangers of approximately standard height, correspond to the standard dimensions of planting trays used in the indoor horticulture industry, thereby allowing horticulturists to provide uniform light radiation of relatively low intensity to 4 ft×8 ft or 4 ft×6 ft trays of plants during the early and vegetative phases of growth, and then to re-adjust the light beam to a higher intensity of radiation to be projected onto 4 ft×4 ft trays during the plants&#39; flowering phase of growth. These adjustable geometries of the light beam allow horticulturist to re-arrange their plants in grow trays beneath the fixture to minimize the amount of fixtures needed during early and vegetative growth phases and to customize the light beam&#39;s radiation intensity to different growing needs, which allows savings in electricity and equipment costs. 
         [0012]    Still another object of the invention is to provide a method of constructing a reflective surface for application in an adjustable light fixture from a single substantially rectangular sheet of material which is reflective on at least one side, thereby simplifying manufacturing and installation processes, as well as reducing the amount of material required by eliminating the potential need for overlapping sheets in cases in which more than one sheet are attached together. 
         [0013]    Still another object of the invention is to provide a method of constructing a light fixture with reflective surfaces substantially surrounding a light source on five sides in a concave arrangement that does not require a rigid housing or a substantially heavy frame, thereby minimizing manufacturing and shipping costs, while simultaneously optimizing the fixture&#39;s reflectivity and range of adjustable positions. The lack of a rigid housing in the present invention allows it to be manufactured using relatively little material and at a correspondingly low total weight, which subsequently allows the fixture to be supported by relatively weak support structures, thereby increasing its versatility for installation in different situations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The present invention will be more fully understood from the following description of a preferred but non-limiting embodiment thereof, described in connection with the accompanying drawings, wherein: 
           [0015]      FIG. 1  shows a reflector arrangement installed on a light fixture according to an exemplary embodiment; 
           [0016]      FIG. 2  is a perspective view of the reflector arrangement of  FIG. 1 ; 
           [0017]      FIG. 3  is an enlarged perspective view of a reflector unit according to an exemplary embodiment; 
           [0018]      FIG. 4  is a perspective view of a pair of wing frame unit according to an exemplary embodiment; 
           [0019]      FIG. 5  is a cross-sectional view of a connector rod attached to a reflective sheet wing; 
           [0020]      FIG. 6  is a cross-sectional view of a reflective sheet wing having a free edge; 
           [0021]      FIG. 7  is a cross-sectional view of a movable end plate adjustably attached to a fixed end plate; 
           [0022]      FIG. 8A  is a cross-sectional view of a ball catch unit retained in a higher catch position; 
           [0023]      FIG. 8B  is cross-sectional view of a ball catch unit retained in a middle catch position; 
           [0024]      FIG. 8C  is cross-sectional view of a ball catch unit retained in a lower catch position; 
           [0025]      FIG. 9A  is a perspective view of  FIG. 1  in use when the reflector arrangement is retained in the higher catch position, as illustrated in  FIG. 8A ; 
           [0026]      FIG. 9B  is a perspective view of  FIG. 1  in use when the reflector arrangement is retained in the middle catch position, as illustrated in  FIG. 8B ; 
           [0027]      FIG. 9C  is a perspective view of  FIG. 1  in use when the reflector arrangement is retained in the lower catch position, as illustrated in  FIG. 8C ; 
           [0028]      FIGS. 10A-10C  are perspective views of  FIG. 1  in use when the adjustable reflector arrangement is retained the catch positions illustrated in  FIG. 8A - FIG. 8C ; and 
           [0029]      FIGS. 11A-11C  are cross sectional views of the concave reflector sheet in use when retained in corresponding catch positions as illustrated in  FIG. 8A - FIG. 8C . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    Exemplary embodiments of a lighting system according to the present invention are presented with those components of primary interest relative to the inventive apparatus and process. For purposes of clarity, many of the mechanical and electrical elements for attaching and assembling the various components of the lighting system are not illustrated in the drawings. A lighting control panel which provides for the electrical control of an illumination bulb used in the present lighting system is not shown in most of the drawings as such bulbs and their operation are well known within the industry. These omitted elements may take on any of a number of known forms which may be readily realized by one of normal skill in the art having knowledge of the information concerning the mode of operation of the system and of the various components and related processes utilized for horticulture lighting systems as provided herein. 
         [0031]    As used herein, the term “light fixture” refers to a system capable of creation of a flux of radiation by activation of a lighting bulb. The terms “lighting”, “radiation” and “illumination” all refer to electromagnetic energy having a wavelength in the infrared, visible and ultraviolet range. Lighting bulbs for use in the present invention are those having metal halide, high pressure sodium radiation sources and combinations thereof. 
         [0032]    As used in this application, “up”, “down”, “upper”, “lower”, “beneath”, and “above” are intended to facilitate the description of the adjustable reflector assembly. Such terms are merely illustrative of the reflector assembly and do not limit the reflector assembly to any specific orientation. 
         [0033]    As used herein the term concave reflector is to have its broadest meaning, including arched sections of any curve that can be desirable as well as any number of straight sections, especially folded sections between the apex of the convex reflector and the light source which prevent radiation from being reflected off the reflector back at the light source and increase the uniformity of the reflected light. 
         [0034]    Referring to  FIG. 1  to  FIG. 3 , the exemplary embodiment of a winged adjustable reflector unit  1  comprises a substantially rectangular back plate  2 . The winged adjustable reflector unit  1  further comprises two lamp socket housings ( 3 . 1  and  3 . 2 ), two lamp sockets ( 4 . 1  and  4 . 2 ), and two fixed end plates ( 6 . 1  and  6 . 2 ) placed on two ends of the back plate  2 . In one embodiment, each fixed end plate may be attached to one end of the black plate  2 . The winged adjustable reflector unit  1  further comprises movable end plates (such as movable end plates  7 . 1 ,  7 . 2 ,  7 . 3 , and  7 . 4  as shown in  FIG. 1 ).  FIG. 1  also shows resilient reflective sheet  9  and reflective sheet wings ( 12 . 1  and  12 . 2 ). Each reflective sheet wing ( 12 . 1  and  12 . 2 ) may have two wing edges. For instance, as shown in  FIG. 3 , reflective sheet wing  12 . 1  may comprise wing edges  13 . 1  and  13 . 2 . Reflective sheet wing  12 . 2  may comprise wing edges  13 . 3  and  13 . 4 . Each movable end plate ( 7 . 1 ,  7 . 2 ,  7 . 3 , and  7 . 4 ) may be placed along a wing edge of a corresponding reflective sheet wing ( 12 . 1  or  12 . 2 ). For instance, the movable end plate  7 . 1  may be placed along wing edge  13 . 1  of the reflective sheet wing  12 . 1 . In  FIG. 2, 29  refers to an oblong bolt hole. 
         [0035]    With references to  FIG. 1  and  FIG. 4 , the curvature of the reflective sheet wings may be determined by curvature of curved edges of the movable end plates. For instance, the curvature of the reflective sheet wings  12 . 1  may be determined by curvature of curved edges  10 . 1  and  10 . 3  of the movable end plates  7 . 1  and  7 . 4 . As illustrated in  FIG. 4 , each movable end plate, such as  7 . 4 , may have a support strip  25  folded at a 90 degree angle toward the corresponding reflective sheet wing  12 . 1 . With references to  FIGS. 1-4  and  FIGS. 6-7 , the support strip  25  may be welded to the corresponding reflective sheet wings  12 . 1  and  12 . 2 . The support strip  25  may be reinforced by a wing tab  42  protruding from the wing edge of the reflective sheet wing  12 . 1  and positioned to securely interlock with a tab slot  43 , as shown in  FIG. 6 . 
         [0036]      FIG. 5  is a cross-sectional view of a connector rod  8  attached to a reflective sheet wing  12 . The connector rod  8  may have a securing hole  37  on one end through which a securing means may be installed thus to secure a movable end plate to the fixed end plate. The securing means may be a screw, a bolt or any other things that may be used to secure the movable end plate to the fixed end plate. 
         [0037]      FIG. 6  shows that each reflective sheet wing may comprise a free edge. For instance, the reflective sheet wing  12 . 1  may comprise a free edge  11 . 1 . The rigidity of the free edge may be reinforced by a connector rod. For instance, with additional reference to  FIG. 2 , a connector rod  8 . 1  may be configured to reinforce the rigidity of the free edge of the reflective sheet wing  12 . 1  and a connector rod  8 . 2  configured to reinforce the rigidity of the free edge of the reflective sheet wing  12 . 2 . Each connector rod ( 8 . 1  and  8 . 2 ) may connect two movable end plates. For instance, with additional references to  FIG. 1  and  FIG. 4 , the connector rod  8 . 1  may connect two movable end plates  7 . 1  and  7 . 4 . 
         [0038]      FIG. 7  is a cross-sectional view of a movable end plate adjustably attached to a fixed end plate by retaining means. Retaining means may attach the movable end plates and the fixed end plates together strongly enough to resist the force of the resilient reflective sheet&#39;s natural resilience or the force of gravity acting on the reflective sheet wings. The retaining means may comprise a hinge pin and a hinge pin nut. As shown in  FIGS. 6-7 , the hinge pins ( 22 . 1  and  22 . 3 ) and hinge pin nuts ( 24 . 1  and  24 . 3 ) may attach respective movable end plates ( 7 . 3  and  7 . 4 ) to the corresponding fixed end plates  6 . 1  in a loose manner to allow radial rotation around respective hinge pins  22 . 1  and  22 . 3 .  23  refers to a hinge pin hole. The movable end plates may be disengaged and reengaged in a selected position using a relatively small amount of force, such that a person having average strength and skill can easily change the fixture&#39;s degree of concavity with little exertion and without the use of any tools. Each reflective sheet wing of the light fixture may also be flexed independently of the other, enabling horticulturists to adapt use to confined spaces, such as installation in close proximity to a wall on one side, wherein it is advantageous to reflect more light away from the wall on one side while covering a relatively large area on the non-walled side. 
         [0039]    Fastening mechanism may fasten the movable end plates to the fixed end plate. The fastening mechanism may comprise ball bearing catches and spring-loaded ball bearing unit. As illustrated in  FIG. 7 , ball bearing catches  19 . 3 ,  20 . 3 , and  21 . 3  are built into one side of the movable end plate. The movable end plates  7 . 3  and  7 . 4  are attached to the corresponding fixed end plate  6 . 1  in an arrangement allowing the movable end plates  7 . 3  and  7 . 4  to slightly radially rotate around the hinge pins  22 . 1  and  22 . 3 , in such a way as to adjustably engage with a respective spring-loaded ball bearing unit  17 . 1  and  17 . 3  installed in the fixed end plates  6 . 1  through the respective ball bearing unit hole  18 . 1 ,  18 . 3 , wherein the spring-loaded ball bearing units  17 . 1  and  17 . 3  face toward the corresponding movable end plates  7 . 3  and  7 . 4 . 
         [0040]    With additional reference to  FIGS. 6-7 , the ball bearing catches  19 . 1  and  19 . 3 ,  20 . 1  and  20 . 3 ,  21 . 1  and  21 . 3  on the outward facing surfaces of the movable end plates  7 . 3  and  7 . 4  may adjustably engage with the respective spring-loaded ball bearing units  17 . 1  and  17 . 3 , installed on the inward facing surfaces of the corresponding fixed end plates  6 . 1  in a variety of selected positions. 
         [0041]    In exemplary embodiments, three selected positions allow the light fixture to be opened to three different degrees of concavity. The geometries of the light beams emitted by these particular configurations roughly correspond to the three standard dimensions of plant trays (4 ft×4 ft, 4 ft×6 ft and 4 ft×8 ft), but the present invention can be easily adapted to include any number of adjustable positions which may be advantageous for growing situations. 
         [0042]    Each of the movable end plates  7 . 1 ,  7 . 2 ,  7 . 3 , and  7 . 4  is adjustably attached to the corresponding fixed end plate  6 . 1  or  6 . 2  at a plurality of selected angles A, B, and C by using adjustable retainable means. As described above, the adjustable retainable means may comprise hinge pins and hinge pin nuts. The selected angles A, B, and C are illustrated in  FIG. 8A ,  FIG. 8B , and  FIG. 8C , respectively. By adjusting the installation angles, the degree of concavity of the resilient reflective sheet may be adjusted which may enable the lighting fixture to emit a light beam of selectable geometry. The movable end plates  7 . 1 ,  7 . 2 ,  7 . 3 , and  7 . 4  may be placed along wing edge of the corresponding reflective sheet wing  12 . 1  or  12 . 2  in such ways that allow varying degrees of flexibility, securing the reflective sheet wing at a fixed angle or fixed degree of curvature for all or part of the wing edge, thereby allowing the curvature of the reflective sheet to be affected to a greater or lesser degree by the extent to which the fixture is flexed. 
         [0043]    In use, the lighting fixture is generally suspended by using hanging eye bolts  32 . 1  and  32 . 2 , as illustrated in  FIG. 1 , from the ceiling of the grow space or from a hanging bar or other such setup such that the light fixture emits a beam of light down onto the plants positioned below it. The adjustable reflector unit may also comprise adjustable fastening mechanism that adjustably fastens the movable end plates  7 . 1 ,  7 . 2 ,  7 . 3 , and  7 . 4  to the corresponding fixed end plates  6 . 1  or  6 . 2 . 
         [0044]    The adjustable fastening mechanism that adjustably fastens the movable end plates  7 . 1 ,  7 . 2 ,  7 . 3 , and  7 . 4  to the corresponding fixed end plates  6 . 1  or  6 . 2  may take any form, comprising ball catches, magnetic latches, adjustable latches, roller latches, touch latches, loft latches, bolt and hole mechanisms, hook and eye mechanisms, or any other mechanism that adjustably fastens the movable end plates  7 . 1 ,  7 . 2 ,  7 . 3 , and  7 . 4  to the back plate  2  or any other fixed component of the lighting fixture. Adjustable retaining mechanisms may be manually adjusted between pre-determined positions by pushing, pulling or physically manipulating the two free edges of the reflective sheet together or apart. In other words, the adjustable retaining mechanisms may be adjusted without use of any tool. In use, the adjustable fastening mechanism is adjusted by pushing the two free edges of the reflective sheet together or apart without the use of any other tool and which makes an easily audible sound and tactile vibration when the fastener is engaged, thereby enabling the user to make adjustments in environments with little visibility. 
         [0045]    With references to  FIG. 7  and  FIG. 8A , the adjustable fastening mechanism may comprise spring-loaded ball bearing unit and ball bearing catch. For instance, engagement of the spring-loaded ball bearing unit  17 . 1  and  17 . 3  with the lower position ball bearing catch  21 . 1  and  21 . 3  adjustably fastens the movable end plate  7 . 3  and  7 . 4  to the corresponding fixed end plate  6 . 1  such that the selected angle A, which is formed between a line from the hinge pin  22 . 1  to  22 . 3  and the corresponding free edge of the reflective sheet wing is relatively acute compared to other selected positions. The configuration corresponds to a relatively closed arrangement of the resilient reflective sheet, as illustrated in  FIG. 11A , which causes light emitted from double ended lamp  5  incident on the ridged central section  14  and arched reflective sheet wings to be reflected uniformly across the geometry of a light beam that approximately corresponds to a 4 ft×4 ft plant tray, as can be inferred from  FIG. 9A  and  FIG. 10A . 
         [0046]    Similarly, with references to  FIG. 7  and  FIG. 8B , engagement of the spring-loaded ball bearing unit  17 . 1  and  17 . 3  with the middle position ball bearing catch  19 . 1  and  19 . 3  adjustably fastens the movable end plate  7 . 3  and  7 . 4  to the corresponding fixed end plate  6 . 1  such that the selected angle B, which is formed between a line from the hinge pin  22 . 1  to  22 . 3  and the corresponding free edge of the reflective sheet wing is relatively acute compared to selected angle B. The configuration corresponds to a relatively open arrangement of the resilient reflective sheet, as illustrated in  FIG. 11B , which causes light emitted from double ended lamp, not shown in  FIG. 11B , incident on the ridged central section  14  and arched reflective sheet wings  12 . 1  and  12 . 2  to be reflected uniformly across the geometry of a light beam that approximately corresponds to a 4 ft×6 ft plant tray, as can be inferred from  FIG. 9B  and  FIG. 10B . 
         [0047]    Similarly, with references to  FIG. 7  and  FIG. 8C , engagement of spring-loaded ball bearing unit  17 . 1  and  17 . 3  with the higher position ball bearing catch  20 . 1  and  20 . 3  results in the most obtuse selected angle C, which corresponds to the most open configuration of the light fixture, as illustrated in  FIG. 9C  and  FIG. 10C . 
         [0048]      FIGS. 11A-11C  are cross sectional views of the concave reflector sheet in use when retained in corresponding catch positions as illustrated in  FIG. 8A ,  FIG. 8B , and  FIG. 8C . The resilient reflective sheet is folded and flexed to create exemplary arrangements of reflective surfaces. The exemplary arrangements may include any combination of flat, ridged and curved sections. In exemplary arrangements, as illustrated in of  FIG. 11A  to  FIG. 11C , the resilient reflective sheet is folded to feature two symmetrical curved reflective sheet wings (not completely shown), which radially rotate around two parallel pivot axes. The pivot axis is defined by the position of corresponding hinge pins, as described above, and which roughly corresponds to hinge folds  16 . 1  and  16 . 2  on the resilient reflective sheet. Additional folds are made parallel to the hinge folds  16 . 1  and  16 . 2  in the central section  14  of the resilient reflective sheet form a central ridge  15 , which prevents light emitted from the double-ended lamp from being reflected directly back at the double-ended lamp  5 , as shown in  FIGS. 9A-9C . A number of auxiliary ridges  36 . 1  and  36 . 2 , as shown in  FIGS. 11A-11C  are on both sides of the central ridge  15 , which serve the purpose of diffusing the light radiation reflected by the fixture in order to emit a light beam of substantially uniform radiation across its geometry. A peak is formed between the central ridge  15  and an auxiliary ridge. For instance, as shown in  FIG. 11A , peak  39 . 1  is formed between the central ridge  15  and the auxiliary ridge  36 . 1 . Peak  39 . 2  is formed between the central ridge  15  and the auxiliary ridge  36 . 2 .