Patent Abstract:
A light fixture including an outer ring, middle ring, and inner ring, each of which having generally a cylindrical shape. The outer ring has a flange at one end and a threaded female portion on an interior surface. The middle ring has a flange at one end and a threaded male portion on an exterior surface. When the outer ring is mated to the middle ring, the male portion is threaded into the female portion. The inner ring has a plurality of grooves on an exterior surface. The threaded male portion of the middle ring includes a plurality of openings for receiving a plurality of securing members, with each of the plurality of securing members capable of moving in each of the plurality of grooves and capable of securing the middle ring to the inner ring.

Full Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to the field of light fixtures and more specifically, to a recessed light fixture.  
         [0003]     2. Background of the Invention  
         [0004]     Various recessed downlight light fixtures have been designed for use in ceilings. Usually such fixtures create problems when it is necessary to relamp or reballast the fixture because of the difficulty encountered in removing the light fixture from the ceiling or gaining access to the light fixture&#39;s internal components.  
         [0005]     Recessed ceiling light fixtures known in the art use different means of securing their components to each other and to a ceiling structure. For example, U.S. Pat. No. 5,567,041 discloses a recessed ceiling light having an outer housing, which includes an integral flange, and an inner housing, which is secured in position in the outer housing by spokes. The outer housing includes a cylindrical support ring to which the outer lens is secured to the outer housing by a threaded arrangement. Thus, the components of this light fixture are held in place by a complex combination of spokes and threaded fittings.  
         [0006]     U.S. Pat. No. 5,826,970 discloses a recessed ceiling light fixture that includes an outer housing, which is supported in the sheet rock of the ceiling by support arms, a conical cup, which includes a peripheral flange, and an inner member, which is inserted into the conical cup. The inner member is supported within the outer housing by springs, while the conical cup is supported on the outer housing by a friction fit. Thus, the components of this light fixture are held in place in the ceiling by a combination of support arms, spring members, and a friction fit.  
         [0007]     U.S. Pat. No. 5,738,436 discloses a modular lighting fixture that uses a spring member to secure the reflector module to the housing. U.S. Pat. No. 5,941,625 discloses a recessed light fixture that uses a spring clip to secure the light fixture to its housing and to a ceiling structure. U.S. Pat. No. 5,609,414 discloses a recessed lighting fixture that uses a pair of retaining clips and other components to secure the light fixture to its housing and to a ceiling structure.  
         [0008]     In addition to the above, there are known light fixtures that are difficult to assemble and disassemble due to the intricate connecting means of their components. In such instances, the sheet rock and layer of spackle abutting the light fixture are damaged when a user has to pull on the light fixture or inordinately twist the light fixture to assemble or disassemble it. In addition, other known light fixtures are preset for use in ceilings or similar structures containing ½-inch, ¾-inch or 1-inch sheet rock.  
         [0009]     Thus, the prior art does not teach or suggest a recessed light fixture that includes a structure that makes assembly and disassembly of the light fixture simple.  
       SUMMARY OF THE INVENTION  
       [0010]     It is an object of the present invention to provide a recessed light fixture that includes features that make assembly and disassembly of the light fixture simple.  
         [0011]     It is another object of the present invention to provide a recessed light fixture that includes features that make relamping and reballasting of the fixture simple.  
         [0012]     It is another object of the present invention to provide a light fixture that can be used with sheet rock of different sizes.  
         [0013]     According to one aspect of the present invention, the light fixture includes an outer member, a middle member, and an inner member, each of which has a generally cylindrical shape in the form of a ring. The outer member has a peripherial circular flange at one end and a threaded interior surface. The middle member has a similar flange at one end and a threaded male portion on its exterior surface. The outer member is connected to the middle member by threadedly engaging their respective thread surfaces.  
         [0014]     The inner member has an exterior surface on which a plurality of grooves are formed therein, with the grooves extending transversely on its cylindrical wall. The middle member includes a plurality of openings for receiving a plurality of securing members, e.g. set screws, with each of the plurality of securing members having inner ends and being located such that these ends will be respectively received in the grooves, for securing the middle member to the inner member.  
         [0015]     The above and other objects, features and advantages of this invention will be apparent to those skilled in the art from the following detailed description of illustrative embodiments of the invention, which is to be read in connection with the accompanying drawings, wherein:  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is an exploded perspective view of a light fixture constructed in accordance with the present invention;  
         [0017]      FIG. 2  is a perspective view of an assembled light fixture constructed in accordance with the present invention;  
         [0018]      FIG. 3  is a side view showing the light fixture installed in a rectangular support assembly in a ceiling; and  
         [0019]      FIGS. 4 and 5  are elevational views of the light fixture taken approximately 90° from each other. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     As mentioned above, the present invention is directed to a recessed light fixture, and in particular, to a light fixture including an outer ring, a middle ring, and an inner ring. The light fixture can be used in a variety of applications, but is preferably secured in a housing mounted in a ceiling, in a down-light application.  
         [0021]     Referring now to the drawings in detail, and initially to  FIG. 1 , the light fixture  10  includes an outer ring  12 , a middle ring  14 , and an inner ring  16 .  
         [0022]     Outer ring  12  is cylindrically shaped and has a circular peripheral flange  18  formed at one end  20  thereof. Cylindrical ring  12  has a threaded inner surface  22  which is adapted to receive a corresponding externally-threaded outer surface  24  of middle ring  14 . The outer cylindrical surface portion  26  of ring  12  is generally smooth. Flat springs  28  having front and rear edges  30 ,  32 , and top and bottom edges  34 ,  36 , are secured to the outside surface of ring  12  by screws  45 , rivets, welding or other securing means known by those skilled in the art. Such securing means should be selected so as not to impede the threading of middle ring  14  into outer ring  12 .  
         [0023]     Each spring  28  is preferably flat and has a general wing-shape. As seen in  FIG. 1 , front and rear edges  30 ,  32  of springs  28  taper towards the flange  18 . These springs are preferably used in pairs, with each pair preferably being located on diametrically opposed sides of outer ring  12 . As seen in  FIGS. 3-5 , springs  28  serve to retain ring  12  and thus the entire lamp  10  in a protective sheet metal box  90  mounted in the ceiling  92  above the ceiling sheet rock  94  by supporting ring  12  on the edge of a circular hole  96  formed in the based  97  of box  90 . The box  90  is positioned in the ceiling so hole  96  aligns with a slightly larger hole  98  in sheet rock  94 . It protects the fixture  10 , ballast  100  and associated wiring from dust, heat and the like. The internal diameter of outer ring  12  is preferably 3-inches, but in any case is large enough to allow the fixture&#39;s light bulb  29 , electrical connections, wiring and ballast  100  to pass through the internal diameter of outer ring  12  for relamping and reballasting.  
         [0024]     Middle ring  14  is also cylindrical in shape and has a circular peripheral flange  40  formed at its lower end  42 . As noted above, the outside surface of ring  14  is threaded to engage the threads on the inside surface of outer ring  12 . This threading feature allows the light fixture to be used with sheet rock of different sizes, preferably in the range of ½″ to 1{fraction (l/4)}″. Thus, as seen in  FIGS. 3-5 , when ring  14  is threaded into ring  12  the thickness of the sheet rock is captured between the flange  40  of the ring  14  and the base  97  of box  90  to conceal the hole  98  and flange  18  of ring  12 .  
         [0025]     Ring  14  has an inner surface  43  which is preferably smooth. Transverse, radial openings  44  are formed in the cylindrical portion of ring  14 . These openings  44  preferably comprise at least two circular ¼-inch threaded openings for respectively receiving set screws  45 , whose inner ends serve to secure the inner ring  16  in the fixture as described hereinafter. The inside diameter of middle ring  14 , like the inside diameter of outer ring  12  described above, also must be large enough to allow the fixture&#39;s light bulb  29 , electrical connections and wiring, and ballast  100  to pass through its internal diameter for relamping and reballasting.  
         [0026]     Inner ring  16  is also generally cylindrical and has an outer surface  52 , an inner surface  54 , and top and bottom edges  56 ,  58 . Inner ring  16  preferably does not have any flanges. The internal diameter of inner ring  16  is preferably not less than 2¾″. Inner surface  54  includes an internal circular ridge  55  (seen in  FIG. 3 ) that the outer rim of the light bulb  29  rests on. Outer surface  52  has a first surface portion  53  and a second surface portion  59  of smaller outside diameter connected by a chamfered edge  57 . Surface  53  has a plurality of L-shaped grooves  60  formed therein. The upper end  61  of leg  62  of the grooves start at the chamfered edge  57  and extend on outer surface  53  of inner ring  16  toward its lower end  63  to the horizontal leg  66  of the L. Each groove has a second vertical leg  67 , shorter than the first leg  62 , joined to the other end of the horizontal leg  66  thereby to define a first elbow and second elbows in the grooves. The upper end of the second vertical leg  67  in each groove defines a stop or a secured position  72  for ring  16  in ring  14 . More specifically, when ring  16  is inserted into ring  14 , as seen in  FIG. 1 , the upper ends of two legs  62  at chamfer  57  are aligned with the inner ends of the set screws  45  mounted in ring  14  so that upon insertion of the ring  16  those ends travel in the leg  62  of the groove to elbow  68 . At that position further insertion is prevented. The installer will then rotate ring  16  to allow the ends of the set screw  45  to travel in leg  66  to elbow  70 , where further rotation is prevented. By pulling the ring  16  downwardly at that point the set screw  45  will enter leg  67  and engage the stop surface  72 . At that position the inner ring  16  is supported on the set screws  45  and cannot fall out of the fixture. The width and depth of each groove  60  is preferably ¼-inch and {fraction (1/16)}-inch, respectively. However, a person of ordinary skill in the art will readily understand that the length, width, and size of these grooves and the other components of this light fixture may vary to fit a particular application.  
         [0027]     Installation of light fixture  10  in the rectangular support structure or a sheet metal box  90  (as seen in  FIG. 3 ), is performed by first slipping one of the springs  28  of outer ring  12  through the hole in the sheet metal box  90 , and then squeezing the other flat spring  28  to curve against the cylindrical position of the outer ring  12  to allow it to slip through the hole in the sheet metal box  90 . In that position the outer ring  12  can be pushed into the sheet metal box&#39;s housing  90  until flange  18  blocks further movement. The springs  28  open to their flat position once past hole  96  and lock outer ring  12  in place in housing  90 . Next, as seen for example in  FIGS. 3-5 , middle ring  14  is threaded into outer ring  12  to a desired depth based on the thickness of the sheet rock. Then, to install inner ring  16 , grooves  60  are aligned with the ends of the set screws  45 . Inner ring  16  is pushed in until the set screws  45  move forward into first elbow  68  of the leg  62 . Then, middle ring  14  is held for example in one&#39;s left hand and inner ring  16  is rotated clockwise by one&#39;s right hand until the set screws  45  reach second elbow  70  of leg  64 . By gently pushing inner ring  16  downwardly, the set screws  45  move to the stop or secured position  72 , thereby locking inner ring  16  in middle ring  14 . An assembled light fixture  10  is seen in  FIGS. 2, 4  and  5 .  
         [0028]     Disassembly of light fixture  1  to relamp or reballast is done by performing the steps described above in reverse order. To remove inner ring  16  from its engagement with middle ring  14 , this apparatus uses a “lift and shift” movement. This is done by manually pushing ring  16  inwardly, thereby “lifting” it until the ends of the set screws  45  reach elbow  70  of leg  67 . The inner ring  16  is then rotated, i.e., “shifted” counterclockwise until it stops in first elbow  68  of the leg  62 . Inner ring  16  is then gently pulled downwardly, thereby releasing it from middle ring  14 . When inner ring  16  is released and pulled down further, the light bulb  29  is exposed, thereby allowing it to be changed. In addition, the wiring and ballast  100  can be pulled further downward through the opening in middle ring  14  thereby allowing the ballast  100  to be changed or repairs to be made to the fixture&#39;s internal components without removing the entire fixture from the ceiling.  
         [0029]     Although an illustrative embodiment of the present invention has been described herein with reference to the accompanying drawings, it is to be understood that various changes and modifications may be effected therein by those skilled in the art without departing from the scope or spirit of this invention.

Technology Classification (CPC): 5