Abstract:
A modular ballast housing for a track lighting fixture having a universal releasable connector that engages various types of lighting fixtures is disclosed.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention generally refers to a modular ballast housing for track lighting fixtures having a universal connector that engages various types of lighting fixtures.  
         BACKGROUND OF THE INVENTION  
         [0002]    Track lighting systems provide support and a source of electric power for lighting fixtures. Track lighting systems are often utilized in commercial establishments where individual lighting fixtures are utilized to highlight a particular item or area. Typically, it is both necessary and desirable to readjust the aiming of the light from a lighting fixture in both the vertical and horizontal directions. In lighting installations where a multiplicity of lighting fixtures are employed, such as in a retail environment, proper aiming is important to good visual merchandising. However, re-aiming, re-lamping, and cleaning may very likely be done by someone who does not have the requisite skills or appreciation of the art of good lighting.  
           [0003]    Ceramic arc tube metal halide high intensity discharge lamps (CAMH) are a relatively new generation of high intensity discharge (HID) lamps used in track lighting systems and are known for their long life, stable color rendering throughout their life, and energy efficiency. These lamps are often used in environments where relatively powerful levels of illumination are desired, where long term energy cost is an issue, and where frequent re-lamping and re-aiming by unskilled users is undesirable. These lamps are most often used in retail and commercial settings but may also be employed in a residential setting as well. HID lamps require a ballast for initial ignition and ongoing electrical current control. Typically, the ballast is integral with or mounted to the light fixture. Therefore, if either the ballast or the light fixture needs to be re-lamped, both components must be removed from the track and repaired or replaced. Also, re-aiming may be difficult when the ballast is integral with the light fixture. Further, a ballast is typically the most costly component in track lighting systems. Therefore, if a user desires to change the type of light fixture on the track, the user must also purchase another ballast even if the old ballast still functions.  
         SUMMARY OF THE INVENTION  
         [0004]    The foregoing problems are solved and a technical advance is achieved by the present invention. Disclosed is a ballast housing detachably attached to a track having a removable attachment for a lighting fixture. 
       
    
    
       [0005]    BRIEF DESCRIPTIONS OF THE DRAWINGS  
         [0006]    The invention and further features and advantages thereof are explained in greater detail on the basis of the exemplary embodiments schematically shown in the figures.  
         [0007]    [0007]FIG. 1 is a perspective view of a track lighting system having a track, a ballast housing, and a lighting fixture.  
         [0008]    [0008]FIG. 2 is a perspective exploded view of the ballast housing and the male connector of the present invention.  
         [0009]    [0009]FIG. 3 is a top perspective view of the ballast housing of the present invention.  
         [0010]    [0010]FIG. 4 is a bottom perspective view of the base portion and the cover plate of the ballast housing shown in a removed position.  
         [0011]    [0011]FIG. 5 is a cross-sectional view of the male connector releasably engaged with the female connector of the present invention.  
         [0012]    [0012]FIG. 6 is an exploded cross-sectional view of the male connector and female connector of the present invention.  
         [0013]    [0013]FIG. 7 is a top perspective view of the locking element of FIG. 6.  
         [0014]    [0014]FIG. 8 is a bottom perspective view of the adapter element of FIG. 6.  
         [0015]    [0015]FIG. 9 is a top perspective view of the adapter element of FIG. 6. 
     
    
     DETAILED DESCRIPTION  
       [0016]    Referring to the drawings in more detail, FIG. 1 illustrates a track  10  of a track lighting system adapted for mounting on a surface, such as a ceiling (not shown). Electrical conductors line the track  10  to provide a source of electric power (not shown) typically in the form of wires or bus bars. In one embodiment, there are at least two extrusion of the track  10  itself can act as the ground connection, as is customary. In some embodiments, three separate wires or bus bars are provided. The track  10  provides slidable support for at least one lighting fixture  18  which may be moved to any desired position along the length of the track  10 . Particularly, the track  10  provides mechanical support and electrical grounding for the lighting fixture  18 . The track  10  may be made from any type of metal or suitable material, including but not limited to extruded aluminum.  
         [0017]    The lighting fixture  18  contains a lamp receptacle (not shown) for receiving a high intensity discharge (HID) lamp (not shown). The lamp receptacle, lamp, and wiring are not shown, as they are conventional and well known in the art. In one embodiment, the HID lamp is a ceramic arc tube metal halide high intensity discharge lamp (CAMH). The lighting fixture  18  detachably attaches to a ballast housing  20  enclosing a ballast (not shown) which provides the initial ignition and the continuing electrical current needed for HID lamps (FIG. 2). Having a ballast separate from the lighting fixture  18  permits a user to mount and remove the lighting fixture  18  without needing to remove the ballast. The ballast housing  20  may be generally rectangular in shape to substantially align with the track  10  and may be comprised of plastic or metal. In one embodiment, the ballast housing  20  is comprised of polycarbonate lexan  940 .  
         [0018]    Referring to FIGS.  2  to  4 , the ballast housing  20  includes a base portion  22  and a cover plate  24 . The ballast is removably inserted into the base portion  22  of the ballast housing  20  and may be secured therein and electrically connected to a power supply and to the lighting fixture  18  lamp receptacle wiring through easily detachable and reattachable connections, such as crimp connectors, in a manner as is generally known in the art to permit easy replacement of the ballast. The base portion  22  has an interior surface  26  which receives the ballast and an exterior surface  28  which detachably attaches to the lighting fixture  18 . The cover plate  24  is detachably attached to the interior surface  26  of the ballast housing  20 . The cover plate  24  has a plurality of openings  30  that align with a plurality of bores  32  on the interior surface  26  of the ballast housing  20 . Fasteners (not shown), as are generally known in the art, engage the openings  30  and the bores  32  to securely fasten the cover plate  24  onto the base portion  22 . In one embodiment, the cover plate  24  has two components, one covering the ballast and the other covering the electrical components of the female and male connectors  44  and  46 , respectively. The base portion  22  of the ballast housing  20  mechanically and electrically contacts the ballast housing  20  to the track  10  through a set of fingers  36  extending from a post  35  extending from the interior surface  26  of the base portion  22  through the cover plate  24  near a proximal end  42  of the ballast housing  20 . In one embodiment, two fingers  36  extend from the tower through the cover plate to detachably attach to the two electrical conductors  12  and  14  and the post  35  engages the extrusion for grounding on the track  10 . At a distal end  40 , a latch  38 , pivotable on the exterior surface  28 , is affixed to and controls the movement of a tower  37 . When the latch  38  is pivoted, the tower  37  may rotate up to approximately 90 degrees to engage the track  10 . A detent  39  in the exterior surface  28  catches an extension (not shown) on the latch  38  to hold the latch  38  and hence the tower  37  in the engaged position. In this position, the latch  38  is flush with the exterior surface  28  of the base portion  22 . Another embodiment for mounting the fingers  36  and tower  37  in the track is described in U.S. Pat. No. 5,259,774, which is incorporated herein by reference.  
         [0019]    Referring to FIG. 2, near the proximal end  42  of the ballast housing  20 , a female connector  44  extends perpendicularly from the exterior surface  28  of the base portion  22 . The female connector  44  detachably attaches to a male connector  46  which, in turn, may be detachably attached to the lighting fixture  18 . The female connector  44  and the male connector  46  provide the electrical and mechanical connection between the ballast housing  20  and the lighting fixture  18 . The female and male connector  44  and  46 , respectively, may be comprised of plastic or metal. In one embodiment, the female connector  44  and the male connector  46  are comprised of polycarbonate lexan  940 .  
         [0020]    The female connector  44  preferably integrally forms a continuous cylindrical wall  48  from the ballast housing  20 . As depicted in FIGS. 2 and 3, a lower portion  50  of the cylindrical wall  48  has a predetermined radius, A. In one embodiment, the lower portion  50  has preferably two vertical indents or raised lines  51 . At approximately the midpoint of the height of the cylindrical wall  48 , an upper portion  52  of the cylindrical wall  48  has a smaller radius B which forms a ledge  54  at the junction of the lower portion  50  and the upper portion  52  in the cylindrical wall  48 . At least one bayonet slot  56  is formed in the upper portion  52  of the cylindrical wall  48 . In one embodiment, two “L”-shaped bayonet slots  56  are formed in the upper portion  52  of the cylindrical wall  48  and are spaced approximately 180 degrees apart (for example). Additional bayonet slots  56  may be provided as well. The bayonet slots  56  may have a detent  57  in the bottom portion of the “L”. Further, a keyway  58  may be placed on the upper portion  52  of the cylindrical wall  48  to assure a correct polarity of the electrical connection. Inside the cylindrical wall  48  is a cavity  60  of a predetermined depth. In one embodiment, a “Y”-shaped partition wall  62  extends above a floor  64  of the cavity  60  to increase voltage carrying capacity. The partition wall  62  may be angled asymmetrical for reasons described below. Inside each area is a single socket  66 . One skilled in the art would recognize that any number of partitions  62 , including none, and two or more sockets  66  may be employed in the electrical connection.  
         [0021]    Referring back to FIG. 2, the male connector  46  has three separate components which lock the lighting fixture  18  to the ballast housing  20 : a yoke element  68 , a locking element  70 , and an adapter element  72 . The three pieces align with one another in the sequence just described. As depicted in FIGS. 5 and 6, the yoke element  68  has a top face  74  and a bottom face  76  having an outer radius, C. An opening  78  lies in the center of the yoke element  68  to receive the wiring (not shown) of the lighting fixture  18 . In one embodiment, an eyelet (not shown) is non-rotatably mounted in the opening  78  to securedly attach the lighting fixture  18  to the yoke element  68 . A gap  79  (FIG. 2) is cut out of the outer circumference of the yoke element  68 , which provides a guide for the yoke element  68  when the yoke element  68  is aligned with the adapter element  72 . Two enclosed bores  80  extend downward from the bottom face  76  of the yoke element  68 . A rotation ring  82  with a rotation stop  84  extends from the top face  74  around the circumference of the opening  78  (FIG. 2). The bores  80  receive fasteners (not shown) which fasten the yoke element  68  to the adapter element  72  and prevent movement of the yoke element  68  relative to the adapter element  72 . The yoke element  68  rests on the locking element  70  as described below.  
         [0022]    Referring to FIGS. 6 and 7, the locking element  70  has an inner wall  86  and an outer wall  88 . The locking element  70  has an inner radius slightly larger than C to receive the yoke element  68 . At least one bayonet pin  90  protrudes from the inner wall  86 . In one embodiment, two bayonet pins  90  located approximately 180 degrees apart protrude from the inner wall  86 , although different numbers of pins or different angles may be chose, so long as they are arranged complementarily to the bayonet slots  56 . The bayonet slots  56  of the upper portion  52  of the female connector  44  receive the two bayonet pins  90 . The detents  57  retain the bayonet pins  90  in a locked position when the male connector  46  is assembled for use. The outer wall  88  may also have an indent or raised line  89  that aligns with either of the two indents  51  of the lower portion  50  of the cylindrical wall  48  of the female connector  44  to form a continuous indent or line as the locking element  70  is rotated between a locked position and an unlocked position. In one embodiment, the indents  51  are marked “lock” and “unlock” to designate the two positions in which the bayonet pins  90  rest when in the bayonet slots  56 .  
         [0023]    As depicted in FIG. 7, a ledge  92  partially circles above the bayonet pins  90  on the inner wall  86  of the locking element  70  to provide a seat and stop for the yoke element  68 . The locking element  70  has an outer radius equal to the radius, A, so that when the male connector  46  aligns with the female connector  44 , the lower portion  50  of the cylindrical wall  48  is continuous with the outer wall  88  of the locking element  70 . The locking element  70  overlaps the adapter element  72  as described below. In another embodiment, the locking element  70  is threadedly engaged to the female connector  44  rather than engaged by the bayonet pins  92  and bayonet slots  56 . In other embodiments, other releasable connectors as are known in the art are employed to engage the female connector  44  to the male connector  46 .  
         [0024]    Referring to FIGS. 8 and 9, the adapter element  72  has an inner portion  96  and an outer portion  98  in which a flange  100  extends from the outer portion  98  at a top end. The outside circumference of the flange  100  has a radius substantially similar to the yoke element  68  so that the ledge  92  of the locking element  70  rests on the flange  100  to prevent movement of the adapter element  72  through the locking element  70 . Therefore, when all three components of the male connector  46  are placed together, the ledge  92  sits between the yoke element  68  and the adapter element  72 . At least one flange opening  102  of the adapter element  72  permits the bayonet pin  90  of the locking element  70  to bypass the flange  100  of the adapter element  72 . In one embodiment, the two bayonet pins  90  bypass two flange openings  102 . A key  104  extends down the outer portion  98  of the adapter element  72  perpendicular to and continuous with the flange  100 . The key  104  engages the keyway  58  of the female connector  44  to prevent rotation and provide proper alignment of the adapter element  72  relative to the female connector  44 .  
         [0025]    The inner portion  96  of the adapter element  72  has two openings  106  through a horizontal floor  108  to receive and guide fasteners into the bores  80  of the yoke element  68  to clamp the locking element  70  between the yoke element  68  and the adapter element  72  but not so tight as to prevent rotation. As a result, rotational movement of the yoke element  68  relative to the adapter element  72  and the female connector  44  is prevented. Electrical pins  112  extend through the floor  108  of the adapter element  72  to engage the sockets  66  of the female connector  44  (FIG. 6). The floor  108  of the adapter element  72  is complementarily shaped to receive the floor  64  of the female connector  44 . In one embodiment, a “Y” shaped recess  110  receives the “Y” shaped partition wall  62  of the female connector  44 . The recess  110  is similarly asymmetrically angled to permit only the correct alignment of the sockets  66  of the female connector  44  and the respective electrical pins  112  of the adapter element  72 . The opposing side of the floor  108  of the adapter element  72  may include a “Y” shaped partition wall  111  which increases voltage carrying capacity. A post  113  extends from at least one arm of the “Y” shaped partition wall  111  and seats within the gap  79  of the yoke element  68  (FIG. 2). In one embodiment, one of three electrical pins  112  protrude through each of three areas defined by the “Y” shaped partition wall  111  of the adapter element  72 .  
         [0026]    The electrical pins  112  and the sockets  66  may be configured to assist the user in aligning the electrical pins  112  and the sockets  66  and to prevent inaccurate coupling. In one embodiment, the electrical pins  112  may be of different lengths and the sockets  66  of different depths to accommodate only the correct electrical pin  112 . In another embodiment, the vertical positions of the electrical pins  112  may be varied to accomplish the same goal. For example, a ground conductor electrical pin  112  may be the first to engage and the last to disengage its respective socket  66  during the process of engaging or disengaging a lighting fixture  18  resulting in the lighting fixture  18  being grounded before power is applied. Further, the key  104  on the outer portion  98  of the adapter element  72  permits the adapter element  72  to rest in the female connector  44  in only one rotational position which also insures that the electrical pins  112  engage their respective sockets  66 .  
         [0027]    The lamp and lamp receptacle of the lighting fixture  18  connect to the male adapter  46  through conventional wiring which extends through the opening  78  of the yoke element  68  to the electrical pins  112  of the adapter element  72 . As depicted in FIGS. 1 and 2, the lighting fixture  18  has a surface that abuts the yoke element  68  of the male connector  46 . A stop pin (not shown) extends from the surface of the lighting fixture  18  and prevents horizontal movement beyond approximately 358 degrees when the stop pin contacts the rotational stop  84  on the yoke element  68 . The configuration of the lighting fixture  18 , the yoke element  68 , the locking element  70 , the adapter element  72  of the male connector  46 , and the female connector  44  permits vertical and horizontal adjustment of the lighting fixture  18  relative to the ballast housing  20  without unlocking the lighting fixture  18  from the ballast housing  20 . In one embodiment, the lighting fixture  18  rotates approximately 90 degrees vertically and approximately 358 degrees horizontally. Further, the locking element  70 , which is capable of rotation, is mechanically isolated from the electrical pins  112 .  
         [0028]    Any type of lighting fixture  18  may include the male connector  46  of the present invention. Therefore, the ballast housing  20  with the integrally formed female connector  44  may detachably attach to any lighting fixture  18  having the corresponding male connector  46 .  
         [0029]    Referring to FIGS. 1 and 2, to place a ballast in the track  10  mounted on the ceiling or other horizontal, vertical or sloped surface, the ballast is inserted and electrically received in the ballast housing  20 . To connect the ballast housing  20  to the track  10 , the ballast housing  20  is positioned at a 90 degree angle to and below the track  10 . The fingers  36  are aligned with an elongated opening in the track  10  and then the ballast housing  20  is rotated approximately 90 degrees to engage the electrical conductors  12  and  14  and the extrusion of the track  10  to complete an electric connection to the wiring of the light fixture  18 , and thus, to the lamp. The latch  38  on the distal end  42  of the ballast housing  20  is then rotated approximately 90 degrees so that the tower  37  contacts the track  10 . In this position, the latch  38  is placed into the detent  39  and lies flush with the exterior surface  28  of the ballast housing  20  and therefore is hidden from the view below. Engaging the tower  37  with the track  10  mechanically secures the distal end  42  to the track and prevents the fingers  36  on the proximal end  40  from rotating. Once the ballast is affixed to the track  10 , the male connector  46  of the lighting fixture  18  is detachably attached to the female connector  44  of the ballast housing  20 .  
         [0030]    Depicted in FIGS. 2, 3, and  6 - 9 , the male connector  46  is assembled so that the yoke element  68  rests on the ledge  92  of the locking element  70  and the ledge  92  rests on the flange  100  of the adapter element  72 . The post  113  of the adapter element  79  is aligned with the gap  79  of the yoke element  68  to prevent rotation of the yoke element  68  and the adapter element  72  relative to one another. Once the three components are correctly aligned, the fasteners securedly attach the adapter element  72  to the yoke element  68 . The bayonet pins  90  bypass the adapter element  72  through the flange openings  102 . The bayonet pins  90  of the locking element  70  are then aligned with and placed in the bayonet slots  56  on the female connector  44 . Further, the electrical pins  112  are placed in their respective sockets  66 . The locking element  70  is rotated from approximately 10 to approximately 30 degrees to connect and secure the lighting fixture  18  to the ballast housing  20  both mechanically and electrically.  
         [0031]    The light fixture  18  may be constructed either integral with the male connector  46  or detachably attached to the male connector  46 . If the light fixture  18  is detachably attached to the male connector  46 , the light fixture  18  may be attached to the male connector  46  before the male connector  46  detachably attaches to the female connector  44 . The stop pin on the light fixture  18  is aligned with the yoke element  68  so that the stop pin may rotate freely up to 358 degrees around the rotation ring  82  (FIG. 5).  
         [0032]    The male and female connectors,  46  and  44 , respectively, have just been described in a configuration where the female connector  44  is associated with the ballast housing  20  and where the male connector  46  is associated with the lighting fixture  18 . It is to be understood that the respective parts may be reversed as well so that the male connector  46  is associated with the ballast housing  20  and the female connector  44  is associated with the lighting fixture  18 . Also, although the female connector  44  is illustrated as having a cylindrical wall  48 , the wall could be of other configurations, such as rectangular, particularly if locking arrangements other than bayonets slots  56  or threaded connections are utilized, such as other snap locks or latches as are known in the art.  
         [0033]    As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.