Abstract:
A low-profile lighting fixture particularly suitable for low and medium height mounting installations. The lighting fixture includes a housing assembly comprising a base member and first and second end sections at opposite ends of the base member. The first and second end sections respectively contain a power supply ballast transformer and capacitor for the fixture. An upstanding bracket supporting a horizontally-oriented lamp-receiving socket is attached to the base member intermediate to the first and second end sections, and a generally-rectangular reflector having an opening therein is mounted to the base member in line with and intermediate to the first and second end sections with the lamp-receiving socket extending horizontally into the interior of the reflector via the opening in the reflector. The base member and the first and second end sections of the housing assembly have elongated channel openings formed therein for facilitating the assembly of the elements comprising the housing assembly and for facilitating the mounting of the aforementioned power supply components (ballast transformer and capacitor) within the first and second end sections. Channels openings formed in the base member are also used in conjunction with a wire-retaining clip for establishing and orienting the path of wiring associated with the power supply components.

Description:
BACKGROUND OF THE INVENTION 
     In the manufacture of lighting fixtures, particularly industrial-type lighting fixtures for low and medium height mounting installations, it is desirable that the vertical dimensions of such fixtures be made as small as possible so that the fixtures utilize as little of the vertical space of an installation site as possible and, at the same time, interfere as little as possible with existing equipment such as air-conditioning and heating equipment, fire sprinkler systems and plumbing and electrical equipment. In addition, it is desirable that the fixtures comprise as few parts as possible and be easily and quickly assembled to minimize manufacturing costs. The present invention is directed to a lighting fixture which satisfies the above objectives. 
     BRIEF SUMMARY OF THE INVENTION 
     Briefly, in accordance with the present invention, a low-profile lighting fixture is provided which includes a generally-flat base member and first and second end sections. The first and second end sections are attached to the base member at first and second ends of the base member, respectively, and define first and second housings, respectively. A power supply ballast transformer is contained within the first housing defined by the first end section and, in a similar manner, a power supply capacitor is contained within the second housing defined by the second end section. 
     The low-profile lighting fixture of the invention further includes a lamp-receiving socket, a mounting means for the lamp-receiving socket and a reflector. The mounting means is attached to the base member adjacent to one of the end sections and positions the lamp-receiving socket in a generally horizontal orientation. The reflector is positioned in line with the first and second end sections, intermediate to the first and second end sections, and has an opening therein. In accordance with the invention, this opening communicates with the interior of the reflector for the projection into the interior of the reflector of the lamp-receiving socket. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Various objects, features and advantages of a low-profile lighting fixture in accordance with the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing in which: 
     FIGS. 1 and 2 are perspective and front views, respectively, of a low-profile lighting fixture in accordance with the invention as arranged for use in a direct lighting application; 
     FIGS. 3 and 4 are perspective and front views, respectively, of the lighting fixture of the invention as arranged for use in an indirect lighting application; 
     FIG. 5 is an exploded perspective view of a housing assembly and lamp socket arrangement included in the lighting fixture of the invention and the manner in which a power supply ballast transformer, capacitor and resistor are mounted within the housing assembly; 
     FIG. 6 is a cross-sectional view of the lighting fixture of the invention as taken along line 6--6 of FIG. 3; 
     FIG. 7 is a view illustrating the power supply capacitor as mounted within the housing assembly of the lighting fixture of the invention; 
     FIG. 8 is a schematic diagram illustrating an exemplary wiring arrangement for the electrical components of the lighting fixture of the invention; 
     FIG. 9 is a top view of a reflector employed in the lighting fixture of the invention; and 
     FIG. 10 illustrates an alternative arrangement for mounting a power supply ballast transformer within the housing assembly of the lighting fixture of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1-6, there is shown a low-profile lighting fixture 1 in accordance with the present invention. The lighting fixture 1 may be arranged to illuminate an area with either direct lighting, for example, as shown in FIGS. 1 and 2, or to illuminate an area with indirect lighting, for example, as shown in FIGS. 3 and 4. As shown in FIGS. 1-6, the lighting fixture 1 comprises a housing assembly 2, a generally-rectangular reflector 3 attached to the housing assembly 2, and a screw-type lamp socket 4 extending horizontally through an opening 3a in the reflector 3 and arranged to receive a lamp 5. 
     The housing assembly 2 is shown in detail in FIGS. 5 and 6 and includes a base member 6 and a pair of opposed end sections 7 attached to the base member 6 at opposite ends of the base member 6. The base member 6, typically of extruded metal, comprises a flat portion 6a having a central opening 6g therein and a pair of horizontal side channel portions 6b extending upwardly from the side edges of the flat portion 6a and each including a guide portion 6c and a C-shaped portion 6d defining an elongated channel slot 6e. The purpose of the side channel portions 6c will be described in detail hereinafter. The central opening 6g is used for the passage of wiring external to the fixture 1 to the interior of the fixture 1 to be then joined with wiring associated with the electrical components of the fixture 1, specifically, the power supply components of the fixture 1. 
     The aforementioned end sections 7 are employed in accordance with the present invention to contain the power supply components for the fixture 1. More particularly, and as best indicated in FIGS. 5 and 6, the left-hand end section 7 as shown in the figures is arranged to contain a power supply ballast transformer 8 for the fixture 1 and the right-hand end section 7 as shown in the figures is arranged to contain a power supply ballast capacitor 9 and an associated resistor 9a for the fixture 1. Each of the end sections 7 comprises an end cover 10 and an end cap 11. The end cover 10, typically of stamped metal, includes a pair of flat opposed side portions 10a and a flat portion 10b extending between and integral with the side portions 10a. The portion 10b further has a pair of tabs 10c formed at a pair of adjacent corners thereof, each of the tabs 10c having an opening 10d therein. 
     The end cap 11, typically of extruded metal, includes a flat end portion 11a having openings 11b at a pair of adjacent corners thereof and a pair of vertical side channel portions 11c extending away from the side edges of the end portion 11a and each including a guide portion 11d and a C-shaped portion 11e defining an elongated channel slot 11f. The end cover 10 and the end cap 11 are secured to each other to form the end section 7 by means of a pair of threaded bolts 15 which are inserted through the openings 10d in the tabs 10c of the end cover 10 and threaded into the channel slots 11f in the channel portions 11c of the end cap 11. It will be noted that the channel slots 11f in the channel portions 11c are initially unthreaded but threads are formed therein as the threaded bolts 15 are threaded into the channel slots 11f. The guide portions 11d of the end cap 11 serve to guide the side portions 10a of the end cover 10 during the above-described assembly operation and further serve to contain the end cover 10 between the guide portions 11d. Each of the end sections 7 as described hereinabove is attached to the base member 6 by means of a pair of threaded bolts 17 inserted through the openings 11b in the end cap 11 and threaded into the channel slots 6e of the channel portions 6b of the base member 6. As in the case of the channel openings 11f of the end cap 11, the channel slots 6e of the base member 6 are also initially unthreaded but threads are formed therein as the threaded bolts 17 are threaded into the channel slots 6e. The guide portions 6c of the base member 6 serve to guide the side portions 10a of the end covers 10 during the attachment of the end sections 7 to the base member 6 and further serve to contain the end sections 7 between the guide portions 6c. 
     The manner in which the ballast transformer 8 and the ballast capacitor 9 and resistor 9a are mounted within the left-hand and right-hand end sections 7 of the lighting fixture 1 is shown in FIGS. 5-7. As indicated in FIG. 5, the ballast transformer 8 is mounted to the base member 6, to be then located within the left-hand end section 7, by means including a pair of L-shaped bolts 20 having horizontal and vertical portions 20a and 20b, respectively, and by means of a ballast clamp 21. More particularly, the horizontal portions 20a of the L-shaped bolts 20 are inserted into small openings 6f cut into the elongated channel slots 6e and made to lie along the paths or axes of the channel slots 6e. The horizontal portions 20b of the L-shaped bolts 20, the ends of which are threaded, are then inserted through openings 21a in the ballast clamp 21 and the ballast clamp 21 made to lie across the top of the laminated metal core portion of the ballast transformer 8. A pair of nuts 23 are then threaded onto the threaded ends of the horizontal portions 20a of the L-shaped bolts 20 and tightened until the ballast transformer 8 has been secured against the base member 6. 
     The ballast capacitor 9 and the resistor 9a are mounted within the right-hand end section 7, prior to the end cover 10 and the end cap 11 of that end section being assembled together as previously described, by means of a pair of straps 30. As shown in FIG. 5, each of the straps 30 has a flat central portion 30a, a generally C-shaped curved portion 30b at one end of the central portion 30a and a flat portion 30c normal to the other end of the central portion 30a and having an opening 30d therein. To mount the capacitor 9 (and associated resistor 9a) within the right-hand end section 7, the curved end portions 30b of the straps 30 are manipulated into the elongated channel slots 11f of the end cap 11 of that section and the capacitor 9 (with the associated resistor 9a) is placed between the straps 30 in abutment with the inner surface of the end portion 11a of the end cap 11. The straps 30 are then bent or wrapped around the front of the capacitor 9 until the flat portions 30c of the straps 30 are essentially parallel to each other and the straps 30 embrace and capture the capacitor 9 against the inner surface of the end portion 11a of the end cap 11 as shown, for example, in FIG. 7. A threaded bolt 28 (FIG. 7) is then inserted through the openings 30d in the flat portions 30c of the straps 30 and threaded into an associated nut 28a (FIG. 7) until the capacitor 9 is held tightly in place against the inner surface of the end portion 11a of the end cap 11. 
     The aforementioned lamp socket 4 is properly positioned with respect to the base member 6 so as to receive a lamp 5 by means of a bracket 35. As indicated in FIG. 6, the bracket 35 is secured to the base member 6 by means of a rivet 36 and includes a flat vertical portion 35a having openings 35b and 35c therein and an essentially Z-shaped portion 35d integral with the vertical portion 35a and having a threaded opening 35e therein. The openings 35b are adapted to receive a pair of threaded bolts 38 for securing the lamp socket 4 to the bracket 35 and the opening 35c is provided for the passage of wires from the lamp socket 4 to be connected to the power supply components for the fixture 1, that is, to the ballast transformer 8, the ballast capacitor 9 and the resistor 9a. An exemplary wiring arrangement for the ballast transformer 8, the ballast capacitor 9, the resistor 9a and the lamp socket 4 is shown in FIG. 8. 
     The Z-shaped portion 35d of the bracket 35 is employed together with a similar Z-shaped member 40, secured to the base member 6 by means of a rivet 41 (FIG. 6), to mount the aforementioned reflector 3 to the base member 6. More particularly, after the lamp socket 4 has been inserted through the opening 3a in the reflector 3 so as to enter into the interior of the reflector 3, a pair of threaded bolts 3d such as standard thumb-type bolts (FIG. 6) are simply inserted through corresponding openings 3b in the reflector 3 (see FIG. 9) and threaded into the threaded opening 35e of the Z-shaped portion 35d of the bracket 35 and into a similar threaded opening 40a in the Z-shaped member 40. A lamp 5 as shown in FIGS. 1-4 may then be inserted into the lamp socket 4. The above-described reflector 3 may be of metal with a porcelain enamel coating and have a generally-rectangular or tub-like configuration. It will be noted in this latter respect and as best shown in FIGS. 1-5 that the opposed side portions 10a of the end covers 10 have edge surfaces 10e (FIG. 5) facing the center of the fixture 1 which are curved slightly to conform to the outside contour of the opposing side walls of the reflector 3. As a result, dust or other foreign matter is prevented from entering either of the end sections 7. 
     The aforedescribed elongated channel slots 6e of the base member 6 are also used to establish and orient the path of wiring used in conjunction with the ballast transformer 8 and the ballast capacitor 9. Desirably, this wiring should be arranged within the fixture 1 to have a flat-form profile so as not to interfere with the other parts of the fixture 1, particularly when the fixtue 1 is used in a direct lighting application as shown in FIGS. 1 and 2. As shown in FIGS. 5 and 6, a generally U-shaped wire retaining clip 45 is placed over the wiring with the U-portion of the wire retaining clip 45 being inserted within one of the elongated channel slots 6e of the base member 6 and the free ends of the wire retaining clip 45 being inserted within the other of the elongated channel slots 6e of the base member 6. As a result, the wiring is retained flatly in position, specifically, either over (FIGS. 1 and 2) or under (FIGS. 3 and 4) the reflector 3, and prevented from interfering with the other parts of the fixture 1 or their assembly. 
     Referring now to FIG. 10 there is shown an alternative arrangement by which a power supply ballast transformer 50 of a design differing from the aforedescribed transformer 8 may be mounted within the left-hand end section 7 of the lighting fixture 1. As shown in FIG. 10, the alternative mounting arrangement includes a transformer support tray 51 having a plurality of openings 53 therein. The ballast transformer 50 is securely mounted to the support tray 51 by means of a plurality of threaded bolts 51a which are inserted into the openings 53 in the support tray 51, openings 54 in flanges 50a of the transformer 50, and then threaded into associated nuts 50b. The support tray 51 with the transformer 50 secured thereto may then be slidably and tightly inserted into the opposed channel slots 6e of the base members 6 and retained in position within the channel slots 6e. 
     It will now be obvious that the above-described lighting fixture 1, by virtue of its use of the end sections 7 and the reflector 3 therebetween, all arranged linearly with respect to each other and closely with the base member 6 of the fixture 1, establishes a low profile for the fixture 1 and renders the fixture 1 particularly suitable for low and medium height mounting installations. The low profile of the fixture 1 is further enhanced by the use of the horizontally-oriented lamp socket 4 and the horizontally-oriented lamp 5. In addition, the ballast transformer 8 and the ballast capacitor 9 (and resistor 9a) are neatly and conveniently housed within the end sections 7, with the ballast transformer 8 being spaced away from the lamp 5 so as not to interfere with the lamp 5 or its operation when heat is generated by the ballast transformer 8 in the normal course of its operation. The wiring associated with the ballast transformer 8 and the ballast capacitor 9 is further maintained in a flat, non-interfering, compact position. Finally, the elongated channel slots 6e and 11f in the base member 6 and in the end caps 11, respectively, greatly facilitate the assembly of the housing assembly 3 of the fixture 1 and allow the ballast transformer 8 and the ballast capacitor 9 (and resistor 9a) to be mounted within their respective end sections 7 using simple readily-assembled components. 
     While there has been described what is considered to be a preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as called for in the appended claims.