Abstract:
A directional lighting fixture can receive an elongated lamp. The fixture has a spaced pair of connective devices each having a barrel with an electrical contact adapted to connect to opposite ends of the lamp. A tubular lamp cover has a light transmissive section and a light reflective section. Each section is contiguous to the other and trough-shaped. The lamp cover is rotatably mounted around the barrels of the connective devices.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to directional lighting fixtures and in particular, to fixtures having rotatable reflective devices. 
     2. Description of Related Art 
     Lamp fixtures ought to be convenient and adaptable to various situations. For elongated lamps such as fluorescent lamps, a fixture may be designed as a single assembly with connectors that connect to the opposite ends of the fluorescent lamp. Such lamp fixtures are designed to be attached to ceilings, walls or other surfaces such as the underside of cabinets over a work surface. 
     Lamp fixtures often include a lamp cover that may have a diffuser to soften the light and avoid shadows with sharp edges. Such covers can also prevent dust collection inside the lamp fixture and also prevent individuals from touching the lamp or its electrical connectors. Because lamp life is limited, lamp fixtures should also be designed to facilitate lamp replacement. Therefore, lamp covers should be easily removed and reinstalled for the purpose of replacing lamps. 
     Such lamp fixtures may be manufactured as a single unit with an integral power switch and with connectors for bringing power to the fixture either through a power cord or other adapters. Also, power connectors can be designed to connect a number of lamp fixtures in series, daisy-chain style. 
     It is often desirable to direct light output to a desired location. For example, one may wish to balance the lighting in a room or workspace by adjusting the direction of the light from individual fixtures. In some cases the fixture may provide accent lighting or be designed to illuminate an area of interest such as a painting. Also, a lighting fixture may be mounted under a cabinet over a work surface but offcenter. In that case one may wish to redirect the light from the fixture to the center of the work surface. Moreover, one may wish to periodically readjust the direction of the lighting depending on what portion of the work surface requires the most lighting. 
     SUMMARY OF THE INVENTION 
     In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a directional lighting fixture adapted to receive an elongated lamp. The fixture has a spaced pair of connective devices each having a barrel with an electrical contact adapted to connect to opposite ends of the lamp. A tubular lamp cover has a light transmissive section and a light reflective section. Each section is contiguous to the other and trough-shaped. The lamp cover is rotatably mounted around the barrels of the connective devices. 
     In a disclosed embodiment a light fixture will have a relatively long housing attached at either end to a connective device supporting a barrel containing contacts that can connect to an elongated lamp, such as a fluorescent lamp. In this embodiment a collar is rotatably mounted on the barrel of each of the connective devices with ridges in striations that allow the collars to rotate but with the feel of having many detents. 
     A pair of trough-shaped sections snap together on the collars to form a lamp cover. In particular, a reflective section has a pair of longitudinal lips that can snap into longitudinal grooves on the collars. A light transmissive section has a pair of longitudinal channels that can snap over the longitudinal lips of the light reflective section to form a tubular lamp cover. 
     The direction of light emanating from the fixture can be adjusted by rotating the tubular lamp cover and the collars. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a side view of a directional lighting fixture in accordance with principles of the present invention; 
         FIG. 2  is an exploded, perspective view, partly in section, of a portion of the fixture of  FIG. 1 ; 
         FIG. 3  is in an end view of the collar of  FIG. 2 ; 
         FIG. 4  is a side view of the connective device of  FIG. 2 ; 
         FIG. 5  is an inside end view of the connective device of  FIG. 4 ; 
         FIG. 6  is a separate end view of the light transmissive section and light reflecting section of the lamp cover of  FIG. 1 ; 
         FIG. 7  is similar to  FIG. 6  but showing a lamp installed; 
         FIG. 8  is an outside end view of the connective device of  FIG. 1  fitted with a male power connector; 
         FIG. 9  is an outside end view of the connective device of  FIG. 4  fitted with a female power connector; 
         FIG. 10  is in an end view of the tubular housing of  FIG. 1 ; 
         FIG. 11  is in an end view of a tubular housing that is an alternate to that of  FIG. 10 ; and 
         FIG. 12  is an end view of a dual-lamp connective device that is an alternate to that of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1-10 , a directional lighting fixture is shown as a pair of connective devices  10  and  12  interconnected by a tubular housing  14  and fitted with an optional electrical switch  16 . Connective devices  10  and  12  are substantially the same and device  12  is shown comprising a hollow casing  12 A having an upper portion  12 B supporting a cylindrical barrel  18  with longitudinal ridges  20 . 
     Barrel  18  has a twist-type electrical contact  22  or a spring loaded socket. Specifically, the pins (not shown) on an elongated fluorescent lamp L can slide through slot  24  and then swing into openings (not shown) in slot  24  to reach electrical contact  22 . 
     An inwardly directed stub  26  projecting from casing  12 A has an open end providing access to the inside of casing  12 A. Visible in  FIG. 5  through stub  26  is a reinforcing column  28  inside casing  12 A. Also visible are a pair of dividers  30  in the form of cantilevered tabs designed to act as separating guides for wires (not shown) routed through connective device  12 . 
     The back of connective devices  10  and  12  have power connectors  32  and  34 , respectively (see  FIGS. 8 and 9 ). Power connector  32  is shown as a twin or trio of male connecting pins  32 A located inside recess  36 . Power connector  34  is shown as a trio of female connecting sockets  34 A recessed in cavities in embossment  38  which is itself recessed inside well  40 . 
     A plug (not shown) formed much like the embossment  38  (with sockets  34 A) can be inserted into recess  36  ( FIG. 8 ) to connect to pins  32 A and supply power to connective device  10 . Plug  41  ( FIG. 4 ) is a shell designed to fit over embossment  38  ( FIG. 9 ). Internal pins (not shown) inside the shell of plug  41  slip into sockets  34 A. Plug  41  is intended to transmit power from sockets  34 A to a similar lamp fixture or other device. 
     In some cases the present lamp fixture can be mounted end to end with a similar lamp fixture. The two lamp fixtures can be interconnected by an adapter  43  ( FIG. 1 ) whose left end is designed to fit over the embossment  38  ( FIG. 9 ) and connect to sockets  34 A. The right end of adapter  43  is designed to plug into the recess  36  ( FIG. 8 ) and connect to the pins  32 A. Accordingly, the lamp fixtures can be daisy-chained together, end to end. 
     Collar  42  has a uniform inside diameter and an outside diameter that is uniform for the proximate 150° of sector  42 A. Axial striations  52  exist over 360° of the inside of collar  42 . Sector  42 B has a smaller outside diameter except for flange  44  whose outside diameter is the same as that of sector  42 A. Two longitudinal grooves  46  mark the transition between sector  42 A and  42 B. A short access gully  48  extends on the outside of collar  42  and reaches the center of the inside edge of sector  42 A. Projecting axially from the inside edge of sector  42 A are a pair of guide tabs  50  located on either side of and equidistant from gully  48 . 
     A tubular lamp cover  50  comprises a light transmissive section  52  and a light reflective section  54 . Section  54  is an aluminum extrusion painted white and or other finishes to enhance its reflecting capabilities. Section  54  is substantially frustro-cylindrical and extends approximately 210°. Section  52  is also substantially frustro-cylindrical and extends approximately 150°. Section  52  is a transparent plastic with an inside surface that is corrugated in order to make this section diffusive. The two longitudinal edges of section  52  are formed into a pair of channels  58 . The two longitudinal edges of section  54  are formed into a rounded, inwardly directed pair of lips  56  designed to snap into channels  58 . 
     Previously mentioned tubular housing  14  is an aluminum extrusion designed to slide over stubs  26  on each of the connective devices  10  and  12 . As shown in  FIG. 10 , the top of housing  14  has a gutter-shaped surface  14 A designed to accommodate the curvature of lamp cover  50 . It will be appreciated that stubs  26  and housing  14  may, in other embodiments, have different outlines. Housing  60  of  FIG. 11  is an example of such an alternate outline. 
     To facilitate an understanding of the principles associated with the foregoing fixture, its operation will be briefly described. The fixture can be wired in a conventional manner with wiring running through housing  14 , and the devices  10  and  12  to deliver power to the electrical contacts  22 , which by themselves are conventional. The fixture can be mounted to a surface by using mounting hardware such as a C-clip (not shown). 
     Housing  14  can also contain a conventional ballast/starter circuit, which is typically a solid-state circuit, although the more traditional inductive coil and switching contacts may still be used in some embodiments. In still other embodiments, a self-starting lamp may be employed in which case no starter circuitry will be necessary. 
     Collars  42  will be fitted over the barrels  18  of connective devices  10  and  12 . With the gully  48  down, the lips  56  of reflective section  54  can be snapped into the grooves  46  of the collars  42 . The collars  42  can then be rotated to bring the reflective section  54  down. Next the pins of lamp L can be slid through slot  24  before rotating lamp L approximately 180° in order to make connection with contacts  22 . (It will be appreciated that the foregoing is a twist-type connector but that other embodiments can use different types of connectors.) 
     The channels  58  of light transmissive section  52  can now be snapped onto the lips  56  of reflective section  54 . When properly positioned, the two ends of section  52  will rest on the tabs  50  of the collars  42 . If the lamp L needs to be replaced, a user can remove section  52  by inserting a fingernail through gully  48  and under section  52  in order to lift this section. 
     With light transmissive section  52  installed, power can be supplied by inserting the plug of a power cord (not shown) into the power connector  32  ( FIG. 8 ) to make contact with pins  32 A. Switch  16  can then be operated to turn the lamp L on. If desired, a number of fixtures can be connected together by using the power output connector  34  of  FIG. 9 . 
     The light emanating from portions of lamp L adjacent to light transmissive section  52  follows a direct path, although some diffusion occurs due to the corrugations on the inside surface of section  52 . Light emanating from portions of lamp L adjacent to reflective section  54  will reflect one or more times off the inside of section  54  and the outside of lamp L as suggested by multiply reflected ray B 1  (moving clockwise) and multiply reflected ray B 2  (moving counterclockwise). 
     A user can change the direction of the beam of light emerging through light transmissive section  52  by rotating section  52  and  54  in unison with collars  42 . As collars  42  rotate, their striations  52  will interact with the ridges  20  on barrels  18 . This will give the user the feel that the lamp cover  50  has a large number of detents. 
     In the embodiment of  FIG. 12  components corresponding to those previously illustrated bear the same reference numerals except for being increased by either 100 or 200. In particular, housing  114  snaps into C-shaped clip  62 , which is fastened by screw  64  onto mounting surface  66 . It will be appreciated that similarly shaped C-clamps can be used to support the housings of the previously mentioned embodiments. 
     Longitudinal housing  114  is attached to a connective device having two casing branches  112 A and  212 A both terminating in casing section  112  and  212  supporting barrels  118  and  218 , respectively. As before, barrels  118  and  218  contain lamp contacts accessible through slots  124  and  224 , which the pins of a fluorescent lamp. 
     A complementary set of connective devices similar to that illustrated in  FIG. 12  are attached to the opposite end of housing  114  in order to support a lamp at either end. Also, collars similar to that previously illustrated (collars  42  of  FIG. 2 ) are mounted on barrels  118  and  218 . Moreover, lamp covers identical to those previously illustrated (cover  50  of  FIG. 6  comprising section  52  and  54 ) are mounted onto the collars on the barrels  118  and  218 . 
     It is appreciated that various modifications may be implemented with respect to the above described, preferred embodiments. While the foregoing embodiments employed elongated lamps such as T4 or T5 fluorescent lamps other embodiments may operate with different types of gaseous discharge lamps, incandescent lamps, halogen lamps, LED, CCFL, EEFL, etc. Accordingly, the dimensions of the fixture will be adjusted to accommodate the specific lamp being handled. While power connectors were illustrated, in some embodiments these can be eliminated and the fixture can be hardwired. While the foregoing reflective section was a metal extrusion painted white (or other finishes), other embodiments may employ other materials that may be fitted with a reflective tape or by a separate reflector. Also, the two sections of the lamp cover can be connected by a hinge or may not be connected to each other and simply rely on the end collars to hold the two sections together. Also, while the lamp cover was illustrated with a cylindrical shape, in other embodiments its cross-section may be polygonal, oval, or shaped otherwise. In addition, light diffusion can be achieved through the lamp cover by corrugations, roughening of the surface, or by using a material that is inherently diffusive. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.