Patent Publication Number: US-7594734-B2

Title: Light fixture diffusor

Description:
TECHNICAL FIELD 
     This invention relates generally to light fixtures, and specifically to the diffusor of a light fixture for a ceiling fans. 
     BACKGROUND OF THE INVENTION 
     Ceiling fans powered by electric motors have been used for years in circulating air. They typically have a motor within a housing mounted to a downrod that rotates a set of fan blades about the axis of the downrod. The fan may also include a light fixture. 
     Ceiling fan light fixtures typically include one or more glass light diffusers which may be in the form of a single globe or a plurality of shades. Each diffusor is retained by a mounting structure affixed to the ceiling fan. The glass light diffusers typically include a lower portion which may include an ornament design and may assume a variety of shapes and configurations, and a substantially cylindrical portion extending upwardly from the lower portion. The light diffusers of conventional ceiling fan light fixtures are typically retained in one of the following two ways. A plurality of circumferentially spaced set screws may be used, with the set screws protruding radially inwardly through a cylindrical flange of the mount structure affixed to the fan, until they are in contacting engagement with the neck portion of the glass light diffusor. The light diffusor is then retained in place by the friction created by the contacting engagement between the set screws and the neck portion of the light diffusor. The force exerted by the set screws may crack the fragile neck of these glass diffusers should they be overly tightened. 
     In other conventional ceiling fan light fixtures, the substantially cylindrical neck portion of the light diffusor includes a helical threaded portion which engages protuberances in an annular flange of the mount structure, as shown in U.S. Pat. No. 6,428,188. The manufacturing of these light diffusers may be difficult due to the multiple protuberances of the neck of those globes or shades which are threaded in place. It has been found that the glass material does not hold tolerances well as the material can shrink or expand in diameter due to variables in the molding process. 
     In view of the foregoing deficiencies associated with known light fixtures in general, and light fixtures for ceiling fans in particular, there remains a need for a light diffusor that is easy to manufacture and which will not break should mounting screws be utilized. It thus is to the provision of such that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     A light diffusor comprises a translucent light diffusing portion having a mounting flange with a plurality of mounting holes therein, a mounting neck having a mounting flange with a plurality of mounting holes therein configured to align with the light diffusing portion mounting holes, and a plurality of mounting bolts coupling the translucent light diffusing portion to the mounting neck. Each mounting bolt extends through one light diffusing portion mounting hole and one neck mounting hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a perspective view of a ceiling fan including a light diffusor embodying principles of the invention in a preferred form. 
         FIG. 2  is a perspective view of the light diffusor of  FIG. 1 . 
         FIG. 3  is a cross-sectional view of the light diffusor of  FIG. 1 . 
         FIG. 4  is a cross-sectional view of a portion of the light diffusor of  FIG. 1 . 
         FIG. 5  is a top view of the neck portion of the light diffusor of  FIG. 1 . 
         FIG. 6  is a top view of the light diffusing portion of the light diffusor of  FIG. 1 . 
         FIG. 7  is a top view of the mounting bracket of the light diffusor of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein like reference numerals have been used for similar elements throughout,  FIG. 1  is a perspective view illustrating a ceiling fan  10  which incorporates a light fixture  11  having a diffusor  12  according to the present invention. It should be understood that the particular features of ceiling fan  10  do not form a part of the present invention and are shown by way of illustration, not of limitation. The light fixture diffusor of the present invention may be advantageously utilized in conjunction with a wide variety of other ceiling fans. Furthermore, the light fixture diffusor according to the present invention may be used in conjunction with ceiling fans having a wide variety of configurations with regard to the included motor housing, blade irons, fan blades, etc. As yet another alternative, the light fixture diffusor according to the present invention may be mounted directly to overhead structures other than those comprising a stationary portion of a ceiling fan. For instance, the light fixture diffusor may be mounted directly to a ceiling of a structure or to a mount plate affixed to the ceiling. Lastly, the light fixture diffusor may be in the form of multiple glass shades rather than a single glass globe. 
     In the illustrative embodiment shown in  FIGS. 1-7 , ceiling fan  10  is suspended from a ceiling (not shown) of a residential or commercial structure, by a canopy  14  and downrod  16  arrangement. A ball  18  is affixed to an upper end of the downrod  16  and is pivotally disposed within a seat (not shown) formed in the canopy  14  to allow the ceiling fan  10  to pivot somewhat, for instance to accommodate a vaulted or sloped ceiling. The downrod  16  supports an electric motor encased within a motor housing  19 . Ceiling fan  10  further includes a plurality of fan blades  20  which are coupled to a rotating portion of ceiling fan motor. 
     The light fixture  11  includes a reflector plate  22  and light bulb assembly, which are mounted to the bottom of the ceiling fan motor housing  19 , and a light diffusor  12 . The light diffusor  12  has a translucent or transparent light diffusing portion  24 , shown in the form of an inverted translucent dome, and a rigid mounting neck  25  coupled to the diffusing portion  24 , the structure is similar to that shown in U.S. Pat. No. 6,428,188 which is specifically incorporated herein. Preferably, the diffusing portion  24  is made from a material such as glass while the mounting neck  25  is made of a material such as metal. 
     The diffusing portion  24  has an inwardly extending flange  27  with a series of mounting hole  28  therein. The mounting neck  25  has a generally cylindrical, upright section  30 , an inwardly extending mounting flange  31 , and three outwardly extending ridges  32  extending from the upright section  30  which are configured to mate with corresponding protuberances extending from reflector plate  22 . The neck inwardly extending mounting flange  31  has a series of mounting holes  33  configured to align with the mounting holes  28  of the diffusing portion  24 . A first annular gasket  35 , made of a resilient material such as silicone, is mounted between the mounting neck flange  31  and the diffusing portion flange  27 . The first gasket  35  has a series of mounting holes  36  which are configured to align with the mounting holes  28  of the diffusing portion flange. A second annular gasket  37 , of similar material, is mounted below the diffusing portion flange. The second gasket  37  also having a series of mounting holes  38  which are alignable with mounting holes  28  of the diffusing portion flange. Lastly, three mounting brackets  40  are mounted below the second gasket  37 . Each mounting bracket  40  has two threaded mounting holes  41  which are configured to align with two adjacent mounting holes  38  of the second gasket  37 . A mounting screw or bolt  43  extends through each neck mounting hole  33 , first gasket mounting hole  36 , diffusor portion mounting hole  28 , and second gasket mounting hole  38 , and threads into a bracket mounting hole  41 . 
     The diffusor metallic neck greatly reduces manufacturing problems with the formation of threading ridges in the neck, a problem associated with necks made of the same glass material as that of the diffusing portion. Furthermore, the metallic neck does not break under the stress exerted by overly tightened set screws. As such, the metal neck provides distinct advantages over the glass necks of the prior art. 
     It should be understood that the present invention is also directed to many different types of ceiling lights and to ceiling fan diffusors in the form of light shades, such as those shown in U.S. Pat. No. 6,350,045, which is specifically incorporated herein. Furthermore, the orientation of the flanges need not be inwardly, as the present invention may also includes light fixtures wherein the flanges of the neck, globe or both, may extend outwardly. The diffusing portion may be coupled to the neck through any conventional means such as clamps, rivets, clasps, brackets, and the like. 
     Lastly, it should also be understood that the metal neck may be adapted to threadably receive the mounting screw, rather than having the mounting brackets  40 . 
     It thus is seen that a ceiling fan light fixture diffusor now is provided which is easier to manufacture and is not susceptible to breakage from mounting it incorrectly, problems which are prevalent with those of the prior art. Although it has been shown and described in its preferred form, it should be understood that other modifications, additions or deletions may be made thereto without departure from the spirit and scope of the invention as set forth in the following claims.