Abstract:
The present invention provides an adjustment mechanism by which a luminaire may be adjusted and secured along an arc. The adjustment mechanism includes a mounting bracket, adjustment bolt, adjustment brace, which is attached to the optical housing of the luminaire, and a positioning means, such as an eyebolt. The adjustment bolt is threadably attached to the adjustment brace via a non-rotatable nut. The adjustment bolt, which is disposed through the positioning means, is turned in order to adjust the position of the luminaire. As the adjustment bolt turns, the non-rotatable nut, along with the adjustment brace and optical housing attached thereto, moves along the threaded shaft of the bolt. When the turning of the bolt has ceased, the non-rotatable nut, adjustment brace and optical housing are secured in position by the frictional engagement of the thread of the bolt and the thread of the nut.

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates to lighting fixtures and, more particularly, to adjustment mechanisms for luminaire-type lighting fixtures. 
     2. Description of the Related Art 
     Wall mounted luminaire-type lighting fixtures are often designed to be tiltably adjusted. However, current luminaire adjustment mechanisms tend to be difficult to use. Current adjustment mechanisms often employ exterior rotatable knurled knobs that tend to be obtrusive and require that the luminaire be spaced from the wall in order to accommodate the adjustment mechanism. Some of these adjustment mechanisms also employ lubricating grease within their workings which can produce an unsightly residue on and around the lighting fixture. Set screws or lock washers are often included in these current adjustment mechanisms to lock in place the optical housing of the fixture after adjustment. The use of such securing means requires multiple steps in adjusting and locking the fixture. They also often lead to imprecise adjustment, due to the tendency of the lighting fixture to shift as the securing means is tightened. 
     Thus, there is a need for an adjustment mechanism for a luminaire that provides for easy and precise adjustment, and is less obtrusive than current mechanisms. The novel adjustment mechanism should provide for the precise adjustment of the fixture by the use of a socket driver or other similar tool, without soiling the fixture. The mechanism should also maintain the luminaire in position once it has been so adjusted. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an adjustment mechanism for a luminaire. 
     It is another object of the present invention to provide an adjustment mechanism for a luminaire that allows for the adjustment and securing into position of a luminaire with one movement. 
     It is yet another object of the present invention to provide an adjustment mechanism for a luminaire that is cleaner and less obtrusive than many current mechanisms. 
     It is a further object of the present invention to provide an adjustment mechanism having a floating adjustment bolt that allows for the adjustment of the fixture along an arcuate path. 
     More particularly, an adjustment mechanism of the present invention includes a mounting bracket that attaches the lighting fixture to a wall, pole or similar structure. The mounting bracket includes a substantially arcuate support wall that includes at least one, and preferably three, slots therein. An adjustment brace is also provided which is fastened to the optical housing of the lighting fixture by at least one fastening means, such as a housing bolt. The fastening means, or housing bolt, is preferably disposed in one of the slots included in the mounting bracket, and is free to move along the course of the slot, thereby allowing the adjustment brace and the optical housing to move relative to the mounting bracket. Attached to the adjustment brace is a non-rotatable threaded nut, through which a threaded adjustment bolt is received. The non-rotatable nut is free to move along at least a portion of the threaded length of the adjustment bolt, as the adjustment bolt is axially rotated. The shaft of the adjustment bolt is also disposed through a positioning means, such as an eyebolt, which is attached to the mounting bracket. At least one securing means, such as a washer, nut or combination of both, is attached to the adjustment bolt. The securing means restricts the movement of the adjustment bolt so that the bolt remains in position as the non-rotatable bolt moves along its shaft. 
     In use, the optical housing may be adjusted relative to the mounting bracket by axially rotating the adjustment bolt, preferably with a socket driver or other similar tool. As the adjustment bolt is rotated, a mechanical advantage is gained by the presence of the positioning and securing means which act to restrict the movement of the bolt. More specifically, the adjustment bolt remains in position as it&#39;s being turned, while the non-rotatable nut is able to move along the shaft of the rotating bolt. The adjustment and optical housing brace move with the non-rotatable nut. The adjustment bolt has enough room to shift within the eyelet of the eyebolt, so that the shaft&#39;s angle of inclination shifts with the non-rotatable nut as the nut and the adjustment brace move along the arched support wall of the mounting bracket. Also, the non-rotatable nut is movably attached to the adjustment brace so that the nut may “float” as the it moves along the arched support wall. The housing bolts connecting the optical housing to the adjustment brace move, in conjunction with the adjustment brace, along the slots of the mounting bracket. The optical housing, in turn, moves, along the same arc, defined by the support wall of the mounting bracket, as the housing bolts do, thereby providing for the adjustment of the light emanating from the optical housing. When the optical housing has been adjusted to the desired position, the fixture may be locked into position simply by stopping the rotation of the adjustment bolt. The frictional interaction of the thread of the non-rotatable nut and the thread of the adjustment bolt prevent any further movement of the optical housing. 
     It will become apparent that other objects and advantages of the present invention will be obvious to those skilled in the art upon reading the detailed description of the preferred embodiment set forth hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a preferred embodiment of an adjustment mechanism for a luminaire of the present invention; 
     FIG. 2 is an exploded view of a luminaire including the adjustment mechanism of FIG.1; 
     FIG. 3 is a bottom view of the mounting bracket of the adjustment mechanism of FIG. 1; 
     FIG. 4 is a perspective view of the luminaire of FIG. 2; 
     FIG. 5 is a side view of the luminaire of FIG. 3 shown with the optical housing adjusted away from the mounting surface; 
     FIG. 6 is another side view of the luminaire of FIG. 3 shown with the optical housing adjusted toward the mounting surface; 
     FIG. 7 is a cross-sectional view of selected elements of the adjustment mechanism of FIG. 1, namely, a portion of the support wall of the mounting bracket, the non-rotatable nut, the adjustment brace, the adjustment screw, the securing means, and the eyebolt; 
     FIG. 8 is another cross-sectional view of the selected elements of FIG. 7, wherein the adjustment brace is adjusted toward the head of the adjustment bolt; 
     FIG. 9 is yet another cross-sectional view of the selected elements of FIG. 7, wherein the adjustment brace is adjusted away from the head of the adjustment bolt. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in the figures, an adjustment mechanism  100  for a luminaire is provided. The adjustment mechanism  100  includes a mounting bracket  20 , an adjustment brace  50  attached to a non-rotatable nut  40 , an adjustment bolt  30 , a positioning means, such as an eyebolt  60 , at least one securing means, such as washers  65  and  66  and nut  67 , and at least one fastening means, such as housing bolts  70  and  71 . 
     As shown in FIG. 1, the mounting bracket  20  has a mounting wall  23  that may include at least one hole  29  through which a screw or other fastening device may be disposed, so as to mount the luminaire to a wall, pole or similar structure. In the preferred embodiment, the mounting bracket  20  has a substantially arcuate support wall  21  and at least one substantially arcuate side wall  22 . The support wall  21  has at least one slot  24  included therein, and preferably three slots  24 ,  26  and  27 . Indicia may be included on the support wall that aids in the precise adjustment of the lighting fixture. For example, a scale  25  may be included on the support wall adjacent one of the slots  24 , so that the degree of rotation of the optical housing  200  may be determined. 
     Also shown in FIG. 1, the adjustment brace  50  is positioned adjacent to the support wall  21  of mounting bracket  20 . The adjustment bracket has a first wall  51 , which may be generally U-shaped, that includes at least one hole therein. Extending from the first wall  51  of adjustment brace  50 , preferably at a right angle therefrom, is a second wall  52  that may include a hole or slot therein. This second wall  52  may receive therein, or have attached thereto, a non-rotatable nut  40 . The non-rotatable nut  40  includes an inwardly threaded annular portion through which the shaft  32  of adjustment bolt  30  is threaded. The non-rotatable nut  40  may include a flange projecting therefrom by which the nut  40  may be attached to the second wall  52  of the adjustment brace  50 . 
     The hole(s) included in the first wall  51  of adjustment brace  50  are aligned so that they may receive at least one housing bolt  70  and  71 . The shafts of housing bolts  70  and  71  are disposed through the slots  26  and  27  of the support wall  21  of the mounting bracket  20 , as well as through the holes located in the adjustment brace  50 . The housing bolts  70  and  71  are attached to the optical housing  200 , so that the housing bolts  70  and  71  attach the adjustment brace  50 , the mounting bracket  20  and the optical housing  200  together, while allowing the optical housing  200  and the adjustment brace  50  to move with each other relative to the mounting bracket  20 , as will be explained hereinafter. 
     An additional housing bolt  72  may also be attached to optical housing  200  and be disposed through a third slot  24  located in support wall  21 . Unlike housing bolts  70  and  71 , housing bolt  72  is not attached to adjustment brace  50 . Rather, housing bolt  72  may include an angle indicator  73  and/or at least one washer  74  attached thereto, which thereby secure optical housing  200  to mounting bracket  20 . The wing portions of angle indicator  73  may be aligned so that they may be used as an indicating means by which the position of the optical housing  200  may be judged according to the scale  25  located on the support wall  21 . Other indicating means may also be provided which moves with optical housing  200  and serves to indicate the angle of adjustment of the housing. In the preferred embodiment, the scale  25  will be aligned adjacent to slot  24 , so that the position of the angle indicator  73  may be compared to the scale  25  to determine the angle of adjustment of the optical housing  200 . The scale may include markings representing degrees of adjustment away from an initial position marked  0 . In the preferred embodiment, the optical housing  200  may be adjusted up to 10 degrees away from or up to 5 degrees toward the mounting surface of the structure upon which the lighting fixture is mounted. However, a wider range of adjustment is contemplated by the adjustment mechanism of the present invention. 
     As shown in FIG. 2, the mounting bracket  20  is attached to the optical housing  200  of the lighting fixture by the housing bolts  70 ,  71  and  72  that are disposed through both the slots  24 ,  26  and  27  located in the support wall  20  and a plurality of holes  201 ,  202  and  203  located in the optical housing  200 . Adjustment brace  50  is situated with the first wall  51  disposed adjacent to support wall  21 , while the second wall  52  projects therefrom and is generally perpendicular to support wall  21 . Non-rotatable nut  40  is attached to the second wall  52  by a flange  42 , as shown in FIG. 2, or similar means. Non-rotatable nut is so aligned as to receive the shaft  32  of adjustment bolt  30 . In the preferred embodiment, adjustment bolt  30  includes a thread  33  circumscribing a portion of shaft  32 . Thread  33  mates with the threaded annular portion of non-rotatable nut  40 . 
     A positioning means, such as eyebolt  60 , is disposed within support wall  21 . The eyebolt  60  receives the shaft of adjustment bolt  30 . The eyelet of eyebolt  60  projects away from support wall  21  and is aligned perpendicular to the length of slots  24 ,  26  and  27 . Securing means are disposed on either side of eyebolt  60  along the shaft  32  of adjustment bolt  30 . More particularly, washer  65  is disposed between the head  31  of adjustment bolt  30  and the eyelet of eyebolt  60 , while washer  66  and nut(s)  67  are disposed between the eyelet and non-rotatable nut  40 . These securing means restrict the longitudinal movement of adjustment bolt  30 . 
     A cover  80  is also shown in FIG.  2 . Cover  80  fits over the adjustment mechanism  100  and attaches to the upper edge of side wall  22 . A plurality of washers  74  and spring washers  79  are disposed along the shafts of housing bolts  70 ,  71  and  72 . The washers  74  are used to adjust the spacing between the various components of the lighting fixture and also assist in securing these components to each other. The spring washers  79  are partially compressible and thereby provide for a smoother adjustment of the optical housing  200 . 
     A cylindrical tube  77  may be disposed through both hole  204 , located in optical housing  200 , and slot  24  located in the support wall  21  of mounting bracket  20 . This cylindrical tube  77  may receive the electrical conductors leading to the optical housing  200 . 
     FIG. 3 shows the underside of mounting bracket  20  with slots  24 ,  26  and  27  located in support wall  21 . In the preferred embodiment, slots  26  and  27 , through which housing bolts  70  and  71  are disposed, are aligned parallel to each other, while slot  24  is spaced parallel to, but spaced apart from slots  26  and  27 . 
     FIGS. 4-6 show a luminaire with the adjustment mechanism  100  of the present invention. FIG. 4 shows the optical housing  200  directed parallel to a mounting surface, or, rather, at 0° of adjustment. FIG. 5, however, shows the optical housing  200  directed 10° away from the mounting surface. FIG. 6, on the other hand, shows the optical housing adjusted 5° toward the mounting surface. In the preferred embodiment, the adjustment mechanism  100  allows positioning of the optical housing  200  at any point with a range of 10° away from or 5° toward the mounting surface. 
     As shown in FIGS. 7-9, the shaft  32  of adjustment bolt  30  moves relative to support wall  21  of mounting bracket  20  as the adjustment mechanism  100  is adjusted. More particularly, since the support wall  21  is arcuate and the adjustment brace  50  moves in the arc defined by slots  26  and  27  located in the support wall  21 , the adjustment bolt  30  shifts or floats to accommodate the change in position of the adjustment brace  50  and the non-rotatable nut  40  attached thereto. As the optical housing  200  is adjusted along the arched support wall  21 , the eyelet of eyebolt  60  remains stationary. During the adjustment, the adjustment bolt  30  shifts or floats within the eyelet of eyebolt  60 , while the non-rotatable nut  40  floats relative to adjustment brace  50 . The shifting of both the adjustment bolt  30  and the non-rotatable nut  40  allows for movement of the adjustment brace  50  along the arched support wall  21 , while the non-rotatable nut  40  moves along the shaft  32  of adjustment bolt  30 . 
     In use, the cover  80  is removed from the adjustment mechanism  100 . A socket driver, screwdriver or other similar tool is mated to the head  31  of adjustment bolt  30 . Adjustment bolt  30  can thereby be axially rotated. The securing means  65 ,  66 ,  67  prevent adjustment bolt  30  from moving longitudinally. Instead, non-rotatable nut  40 , which is threadably engaged to thread  33 , moves along shaft  32 . The interattachment of non-rotatable nut  40 , adjustment brace  50 , housing bolts  70  and  71  and optical housing  200  cause these aforementioned components to move along an arc defined by the slots  26  and  27  located in support wall  21  of mounting bracket  20 , as the adjustment bolt  30  is rotated. Housing bolt  72  also moves in unison with these components, and the indicting means attached thereto may be used to determine the angle of inclination of the optical housing  200  by comparing it to the indicia, or scale  25 , located on the support wall  21 . When the proper angle has been attained, the rotation of adjustment bolt  30  is stopped. Thread  33  of adjustment bolt  30  frictionally engages the thread of non-rotatable nut  40 , so that the optical housing  200  is locked in place. Thus, no additional locking means need be provided to secure the fixture in position, once it has been adjusted. 
     The components of the adjustment mechanism  100  may be formed of any metal and/or plastic well known in the art and by any method of manufacture well known in the art. 
     While the invention has been found in one preferred embodiment in respect to the design of the adjustment mechanism of the luminaire-type lighting fixture, it is apparent that various modifications can be made to the present invention without departing from the spirit or scope of the invention as set forth in the claims appended hereto.