Abstract:
A lighting fixture for a heat generating light bulb which includes a pair of heat sinks to assist in dissipating heat and also an airflow path that extends through the lighting fixture that causes air to flow past the light bulb and the heat sinks with the heated air to pass through louvers and openings formed within the housing shell of the light fixture into the ambient.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The field of this invention relates to lighting fixtures and more particularly to a lighting fixture which is designed to dissipate heat in order to substantially prolong the life of the light bulb and also permit the lighting fixture to use higher wattage light bulbs. 
     2. Description of the Related Art 
     The use of lighting fixtures for light bulbs has long been known. The single most destructive thing in conjunction with lighting fixtures is the heat that is generated by the light bulb. This heat that is generated not only causes the lighting fixture to be raised to an excessively high temperature but will also cause the light bulb to prematurely fail. As a result, many light fixtures are designed to be used with lower wattage light bulbs. Lower wattage light bulbs do not give off a substantial amount of light. In certain installations, a greater amount of light is required. There is a need to construct a lighting fixture which readily dissipates heat that is generated from the light bulb which will keep the overall body of the lighting fixture at a decreased temperature and will also permit usage of a higher wattage bulb with the heat that is generated by the bulb being dissipated into the ambient substantially extending the life of the light bulb. 
     SUMMARY OF THE INVENTION 
     A first basic embodiment of lighting fixture which utilizes a light bulb mounted in conjunction with a socket. Surrounding the socket is a first heat sink with there being a second heat sink surrounding the first heat sink. A ring-shaped shell surrounds the second heat sink with this ring-shaped shell having a plurality of openings. A forward housing shell is mounted on the ring-shaped shell. The forward housing shell surrounds the light bulb in a spaced relationship forming an annular chamber. A rear housing shell is mounted adjacent the ring-shaped shell and located opposite the forward housing shell. The rear housing shell has a base which is adapted to be electrically connected to the light socket. The rear housing shell has a series of louvers. Heat that is generated by the light bulb is dissipated by air flowing through the forward housing shell, past the first heat sink and the second heat sink and into the ambient through the openings and the louvers. 
     A further embodiment of this invention is where the first basic embodiment is modified by having the first heat sink mounted on the socket. 
     A further embodiment of this invention is where the first heat sink is defined as comprising a metallic sleeve with a plurality of outwardly extending radial fins. 
     A further embodiment of this invention is where the first basic embodiment is modified to include a mounting ring on which is mounted electronic components and is located within the annular chamber of the forward housing shell. 
     A further embodiment of this invention is where there is insulation located within this annular chamber. 
     A further embodiment of this invention is where there is an outer cover mounted in conjunction with the forward housing shell. 
     A further embodiment of this invention is where the outer cover includes aligning tabs with these aligning tabs to engage with the light bulb to properly align and support the light bulb within the light socket within the lighting fixture. 
     A second basic embodiment of this invention is where there is a light bulb mounted in conjunction with a socket. Surrounding the socket is a heat sink assembly. A ring-shaped shell surrounds this heat sink assembly with this ring-shaped shell including a plurality of openings. A forward housing shell is mounted on the ring-shaped shell with the forward housing shell surrounding the light bulb in a spaced relationship forming an annular chamber. A rear housing shell is mounted adjacent to the ring-shaped shell and located opposite the forward housing shell. The rear housing shell has a base which is adapted to electrically connect with a light socket. The rear housing shell has a series of louvers. Heat that is generated by the light bulb is dissipated by air flowing through the forward housing shell, past the heat sink assembly and into the ambient through the openings and the louvers. 
     A further embodiment of this invention is where the second basic embodiment is modified by the heat sink assembly being mounted on the socket. 
     A further embodiment of this invention is where there is a mounting ring mounted within the annular chamber of the forward housing shell with this mounting ring having mounted thereon electronic components. 
     A further embodiment of this invention is where the la annular chamber includes insulation to protect the electronic components of the mounting ring from over heating. 
     A further embodiment of this invention is where there is mounted an outer cover in conjunction with the forward housing shell with this outer cover surrounding the light bulb. 
     A further embodiment of this invention is where the outer cover includes aligning tabs which engage with the light bulb to support the light bulb and keep it properly aligned within the lighting fixture. 
     A further embodiment of this invention is where the second basic embodiment if modified by the heat sink assembly including in part a metallic sleeve with a plurality of outwardly extending radial fins. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is to be made to the accompanying drawings. It is to be understood that the present invention is not limited to the precise arrangement shown in the drawings. 
     FIG. 1 is an external side view of the lighting fixture of the present invention; 
     FIG. 2 is a transverse cross-sectional view of the lighting fixture of the present invention taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a longitudinal cross-sectional view through the lighting fixture of the present invention taken along line  3 — 3  of FIGS. 2; and 
     FIG. 4 is a transverse cross-sectional view through the lighting fixture of the present invention taken along line  4 — 4  of FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring particularly to the drawings, there is shown the lighting fixture  10  of this invention. Lighting fixture  10  has a screw base  12  which is designed to be screw threadingly received within a conventional lighting socket, which is not shown. The screw base  12  is fixedly mounted on a rear housing shell  14 . The rear housing shell  14  is primarily hollow, it has an exterior configuration which comprises a cylindrical shaped section  16  located between truncated cone-shaped sections  18  and  20 . The truncated cone-shaped sections  18  and  20  both include a series of louvers  22 . The louvers  22  are basically elongated slots. 
     Integrally formed with the rear housing shell  14  and located within the internal chamber of the rear housing shell  14  are four in number of spaced apart mounting posts  26 . Each mounting post  26  is designed to receive a screw fastener  28 . Mounted within the upper open end of the rear housing shell  14  is a baseplate  30 . Baseplate  30  is basically flat. The baseplate  30  is located between the screw fasteners  28 . Mounted against the baseplate  30  and externally of the mounting posts  26  is a ring-shaped shell  32 . Formed within the ring-shaped shell  32  are a series of elongated openings  34  and a series of elongated slots  35 . There are four in number of the slots  35 . The ring-shaped shell  32  has an internal chamber  36 . Integrally connected with the ring-shaped shell  32  and located within the internal chamber  36  are four in number of short posts  38 . A short post  38  is to align with a mounting post  26 . Each short post  38  has a center hole  40 . Each screw fastener  28  is to be located through a center hole  40  prior to connection with a mounting post  26 . 
     A light bulb  42  is plugged into a socket  44 . The light bulb  42  is centrally located within an internal chamber  46  of a forward housing shell  48 . The forward housing shell  48  has an enlarged access opening  50 . The forward housing shell  48  will normally be constructed of a thin sheet material, such as aluminum. 
     The socket  44  has electrical wires  52  and  54  connecting thereto. The electrical wires  52  and  54  pass through a first heat sink  56 . The socket  44  is fixedly secured to the first heat sink  56  by means of bolt fasteners  58 . The first heat sink  56  takes the form of a sleeve from which there is outwardly extending in a radial manner a plurality of fins  60 . Each electrical wire  52  and  54  connect to a separate socket hole  62  with there being two in number of such socket holes  62  formed within the socket  44 . The light bulb  42  is to have a pair of prongs, which is not shown, each of which is to engage with a socket hole  62 . Thereby one prong electrically connects with electrical wire  52  and the other prong engages with electrical wire  54 . 
     The wires  52  and  54  pass through respective through openings  64  and  66  formed within the first heat sink  56 . The first heat sink  56  is fixedly mounted by appropriate screw fasteners, which are not shown, onto a second heat sink  68 . Second heat sink  68  includes a baseplate  70  on which the first heat sink  56  is mounted. Extending outwardly from baseplate  70  are a plurality of L-shaped posts  72 . The posts  72  are unattached at their outer end. Between each pair of L-shaped posts  72  is located a connecting post  74 . The connecting posts  74  are integrally connected to an annular ring  76 . The annular ring  76  includes four in number of cut-outs, which are not shown. Within each cut-out is to be located a short post  38 . In this way, the second heat sink  68  is locked to the rear housing shell  14 . 
     The first heat sink  56  will normally be constructed of aluminum material as aluminum is readily conductive of heat. The second heat sink  68  is to be constructed of any material that facilitates conducting of heat which again would probably be of aluminum. The heat sinks  56  and  68  can be constructed of any material that facilitates the conducting of heat. 
     Mounted directly against the wall of the internal chamber  46  is a plastic or ceramic annular mount  78 . This annular mount  78  is mounted directly against annular-shaped inwardly extending flange  80  which is formed integral with the forward housing shell  48 . Extending in an inward direction from the inwardly extending flange  80  are four in number of extensions  82 . Each extension  82  is to connect with a short post  38 . Each extension  82  has a hole  84  formed therein. Each screw fastener  28  is to extend through a hole  84  of an extension  82 . This fixedly mounts in position the forward housing shell  48  relative to the rear housing shell  14 . Mounted against the annular mount  78  is a mounting ring  86 . The mounting ring  86  will normally be constructed of a plastic material. Mounted on the mounting ring  86  is to be a plurality of electrical components  88 . Some of the components  88  extend from the mounting ring  86  and are fixedly mounted on the wall of the interior chamber  46 , as is clearly shown in FIG. 3 of the drawings. 
     Mounted within the internal chamber  46  is a ceramic or plastic collar  90 . Collar  90  has an upper annular flange  92 . The peripheral edge of the upper annular flange  92  abuts against the wall of the interior chamber  46 . The collar  90  also includes a bottom wall  94 . The bottom wall  94  has exteriorly mounted thereon a plurality of small protrusions which form feet, which are not shown. These feet are to rest against the annular ring  76 . These feet will locate the bottom wall  94  slightly spaced from the annular ring  76 . Collar  90  also includes four in number of posts  98 . There is to be post  98  which is to align with a short post  38 . Each post  98  includes a through hole  100  through which a screw fastener  28  is to be conducted. Therefore, by tightening of the screw fasteners  28 , it can thusly be seen that the collar  90  is fixed to the rear housing shell  14 . 
     The portion of the internal chamber  46  located between the exterior surface of the collar  90  and the internal wall  46  is to include a wad of fibrous material  102 . The fibrous material  102  is to function as a heat insulator protecting the electronic components  88  that are mounted on the mounting ring  86 . 
     Collar  90  also includes a center sleeve  104  that extends from the bottom wall  94 . The center sleeve  104  surrounds and is spaced from the socket  44 . 
     Mounted on the forward housing shell  48  is an outer cover  106 . The outer cover  106  will normally be constructed of sheet metal and has a slight dome shape with the general overall configuration being that of a disc with the exception that there is a center hole  108  formed within the outer cover  106 . The outer cover  106  is to be snapped onto the forward housing shell  48  and is removably secured thereto. Removal of the outer cover  106  is required in order to replace the light bulb  42 . A typical light bulb would be a twelve volt, sixty-five watt Halogen bulb. Mounted to the outer cover  106  and extending within the center hole  108  are three in number of equally spaced apart tabs  110 . Each tab  110  is fixed to the outer cover  106 . The inner edge of the tab  110  is designed to engage with the annular peripheral lip  112  of the light bulb  42 . Therefore, the tabs  110 , in conjunction with outer cover  106 , provide support for the light bulb  42  to keep the light bulb  42  in its established position and also to insure that the light bulb  42  is correctly aligned within the lighting fixture  10 . 
     During use of the lighting fixture  10 , heat that is generated from the light bulb  42  will be dissipated radially toward the collar  90 . Let it be assumed that the lighting fixture is mounted in a vertically oriented position with the screw base  12  being located above the outer cover  106 . Heat has a tendency to rise, so as the heat rises toward the second heat sink  68 , air is to flow into the annular gap  114  which is formed by the center hole  108  relative to the annular peripheral lip  112  of the light bulb  42 . This air flow will push the heat in contact with both heat sinks  56  and  68  and heat that is accumulated by these heat sinks  56  and  58  will be free to pass into the air through elongated openings  34 , elongated slots  35  and louvers  22 . During operation of the light bulb  42 , there will be created a constant air flow through the openings  34 , slots  34  and the louvers  22 . This constant air flow does an effective job of dissipating created heat by the lighting fixture  10  thereby substantially prolonging the life of the light bulb  42  while also permitting use of a substantially increased wattage of light bulb  42  than was previously possible.