Display lighting system with uplight

[0002] This is a continuation-in-part of copending, commonly assigned U.S. patent application Ser. No. 10/174,211, filed Jun. 17, 2002, which is a continuation-in-part of U.S. patent application Ser. No. 09/922,957, filed Aug. 6, 2001, now U.S. Pat. No. 6,431,721, which is a continuation of U.S. patent application Ser. No. 09/500,882, filed Feb. 9, 2000, now U.S. Pat. No. 6,270,232, all of which are incorporated by reference herein in their entirety.

[0003] This invention relates to cantilevered display lighting systems. More particularly, this invention relates to cantilevered display lighting systems that include uplighting units as well as downlighting units.

[0004] Many known display lighting systems include lighting units held out either above or below displayed objects by cantilever arms secured to display shelving or a nearby structure, such as a wall. The lighting unit typically includes a light source, ballast, reflector, one or more lampholders, and electrical wiring and connectors. Assembling and installing such lighting systems are often both mechanically and electrically tedious and time consuming because of numerous parts, fasteners, and electrical connections. Moreover, such lighting systems typically include bare-lamp strip lights mounted to a mounting board. The strip lights and mounting board are then typically hidden behind a valance board and pass under the cantilever arms. Accordingly, access to electrical wiring and components is cumbersome.

[0005] Furthermore, many known display lighting systems ineffectively illuminate objects on display shelving because the light source is typically not set back sufficiently from the shelves. “Setback” is the horizontal distance measured from the outside edge of a shelf to a light source. Sufficient setback permits emitted light to more completely illuminate the vertical faces of displayed objects. Attaining sufficient setback is usually impractical, however, because the obtrusive sizes of the lighting unit, valance, and cantilever arms holding the lighting unit and valance add clutter, thus distracting attention away from the displayed objects. One known display lighting system reduced the size of the lighting unit by moving the lamp ballast to one of the supporting arms. However, any benefit provided by the smaller lighting unit was offset by the increased size of the arm. Generally, most display lighting systems reduce the distraction by using lighter (i.e., smaller) arms, which consequently limits the amount of setback possible.

[0006] Still further, many known display lighting systems that provide downlighting cannot easily include an additional uplighting unit that can be installed in a luminaire at different positions.

[0007] In view of the foregoing, it would be desirable to provide a display lighting system in which luminaires can be easily assembled and installed.

[0008] It would also be desirable to provide a display lighting system in which rows of luminaires can be easily wired to a power source with wiring and components that are substantially out of view and easily accessible.

[0009] It would further be desirable to provide a wireway enclosure for a display lighting system that conceals from view and provides easy access to wiring and components.

[0010] It would still further be desirable to provide a display lighting system in which light sources can be sufficiently setback from a display to provide effective illumination with little distraction.

[0011] It would yet further be desirable to provide a display lighting system in which an uptight can be easily installed at selectable positions in a luminaire.

[0012] It is an object of this invention to provide a display lighting system in which luminaires can be easily assembled and installed.

[0013] It is also an object of this invention to provide a display lighting system in which rows of luminaires can be easily wired to a power source with wiring and components that are substantially out of view and easily accessible.

[0014] It is a further object of this invention to provide a wireway enclosure for a display lighting system that conceals from view and provides easy access to wiring and components.

[0015] It is still a further object of this invention to provide a display lighting system in which light sources can be sufficiently setback from a display to provide effective illumination with little distraction.

[0016] It is yet a further object of this invention to provide a display lighting system in which an uptight can be easily installed at selectable positions in a luminaire.

[0017] In accordance with this invention, a display lighting system for illuminating objects and areas is provided. The system includes at least one luminaire, which includes at least one lamp housing, a wireway enclosure, and first and second arms. Each arm has first and second ends. The lamp housing includes two endplates, a reflector attached to the endplates, and at least one lampholder. The lamp housing is preferably oriented to provide uplighting. The wireway enclosure is dimensioned to include electrical wiring and at least one electrical component, such as a lamp ballast or transformer. The lamp housing is positioned between the first and second arms and is attachable to the arms between the first and second ends. The wireway enclosure is positioned between the first and second arms adjacent the second ends. A second lamp housing can be positioned between and attached to the arms at the first ends. This second lamp housing is preferably oriented to provide downlighting, but can alternatively provide uplighting in either the same or a different direction than the first lamp housing.

[0018] Wireway enclosures of the invention, which can also be used with lighting systems other than those described herein, preferably have two longitudinal portions hinged together along one edge and removably attachable along another edge to form an enclosed longitudinal structure having open ends. The open ends are covered with sideplates or sidecovers that together with the longitudinal portions form an enclosure having a cavity therein. One of the longitudinal portions hinges open to provide access to the cavity. Both portions are preferably formed by an extrusion process.

[0019] In one preferred embodiment of the display lighting system, the first and second arms at the second ends can be mounted to a structure, such as, for example, display shelving. Furthermore, each arm has a support structure extending outward from the second end that supports the wireway enclosure.

[0020] In a second preferred embodiment of the display lighting system, the wireway enclosure can be mounted to a structure, such as, for example, a wall, and the first and second arms at the second ends are attachable to respective sides of the enclosure.

[0021] Advantageously, electrical wiring (e.g., power conductors) can be run to adjacent luminaires preferably through nipple connectors connecting adjacent wireway enclosures. Moreover, wiring unrelated to the display lighting system can be run conveniently and inconspicuously through one or more adjacent wireway enclosures. For example, power conductors for electrical outlets on other circuits, emergency lighting circuits, computer lines, telephone lines, and burglar alarm wiring can also be run through wireway enclosures. Also, any necessary system separation barriers can be installed within each enclosure. The embodiments of the wireway enclosure that have at least one removable cover permit access to the interior of the enclosure. These features simplify electrical connections when installing rows of luminaires and keep the wiring out of view.

[0022] By providing a separate wireway enclosure for electrical components and wiring, lamp housings can be small, permitting small arms to be used to support a housing at sufficient setbacks from objects displayed on shelving. This improves the illumination of the vertical face of the displayed objects, while reducing distraction to the objects caused by the arms and housings.

[0023] The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:

[0024] FIG. 1 is a simplified elevational view of a first preferred embodiment of a display lighting system deployed in a retail setting according to the invention;

[0025] FIG. 2 is a perspective view of a first preferred embodiment of a luminaire of the display lighting system of FIG. 1 according to the invention;

[0026] FIG. 3 is a perspective view of a portion of the luminaire of FIG. 2;

[0027] FIG. 4 is a perspective view of another portion of the luminaire of FIG. 2;

[0028] FIG. 5 is another perspective view of the portion of the luminaire of FIG. 4;

[0029] FIG. 6 is a perspective view of a portion of the wireway enclosure of the luminaire of FIG. 2;

[0030] FIG. 7 is also a perspective view of the portion of the wireway enclosure of FIG. 6 with the front cover, sideplate, and optional uptight unit removed;

[0031] FIG. 8 is a cross-sectional view of a portion of the luminaire of FIG. 2 taken from line 8—8 of FIG. 2;

[0032] FIG. 9 is a perspective view of a second preferred embodiment of a portion of a luminaire of a display lighting system according to the invention;

[0033] FIG. 10 is a perspective view of the luminaire of FIG. 2 with optional accent lighting according to the invention;

[0034] FIG. 11 is a perspective view of a portion of the luminaire of FIG. 10 taken from line 11—11 of FIG. 10;

[0035] FIG. 12 is a perspective view of another preferred embodiment of a wireway enclosure according to the invention;

[0036] FIG. 13 is a perspective view of a further preferred embodiment of a wireway enclosure according to the invention;

[0037] FIG. 14 is a perspective view of a portion of the enclosure of FIG. 12 without the sideplate;

[0038] FIG. 15 is an exploded perspective view of a portion of the enclosure of FIG. 13 with the enclosure opened and the sideplate removed;

[0039] FIG. 16 is a perspective view of a sideplate of the enclosure of either FIG. 12 or 13;

[0040] FIG. 17 is a perspective view of a portion of the enclosure of FIG. 13;

[0041] FIG. 18 is a perspective view of a portion of another preferred embodiment of a luminaire of a display lighting system according to the invention;

[0042] FIG. 19 is a perspective view of a portion of the luminaire shown in FIG. 18;

[0043] FIG. 20 is a side elevational view of the luminaire of FIG. 18;

[0044] FIG. 21 is a side elevational view of the uptight of FIG. 18;

[0045] FIGS. 22 and 23 are perspective views of an embodiment of a pair of endplates of the uptight unit of FIGS. 18-21;

[0046] FIG. 24 is a perspective view of a portion of two luminaires of FIG. 18 being arranged side-by-side in an embodiment of a display lighting system according to the invention; and

[0047] FIG. 25 is a perspective view of the same portion shown in FIG. 24 of the two luminaires of FIG. 18 arranged side-by-side.

[0048] The invention provides a display lighting system for illuminating objects preferably displayed on gondola-type shelving. Alternatively, walls, wall-mounted objects, signs, billboards, books, artwork, hospital patient areas, and work areas (such as desks, benches, and assembly lines), for example, can also be illuminated with the invention. The display lighting system can be mounted to display shelving, walls, and other structures. The display lighting system provides primarily task lighting, but can also provide ambient and accent lighting. Each luminaire of the system can effectively (i.e., more completely) illuminate the vertical face of displayed objects. Individual luminaires are easily assembled and installed, and rows of luminaires are easily wired to a power source with easily accessible, yet substantially out of view, electrical components and wiring. The entire system is easily maintained.

[0049] FIG. 1 shows a first preferred embodiment of a display lighting system deployed in a retail setting in accordance with the invention. Display lighting system 100 advantageously provides what is known as “task-ambient” lighting. System 100 includes at least one luminaire. Each luminaire includes a lamp housing, which provides task lighting. As shown in FIG. 1, lamp housings 102a-dare held out and above display shelving 103 and 105 with respective arms 104a-d. Lamp housings 102a-dare each sufficiently setback from the outside edges of display shelving 103 and 105, as illustrated by setbacks 107b,d, to provide more complete illumination (i.e., task lighting 109a-d) of the vertical faces of objects on shelving 103 and 105. Setbacks for gondola-type shelving typically range from about 12 inches (30.5 cm) to 18 inches (45.7 cm). However, this can vary depending on the height and spacing of shelves. System 100 also preferably provides optional uplighting 111 and 113 (i.e., ambient lighting).

[0050] FIG. 2 shows a first preferred embodiment of a luminaire of display lighting system 100 in accordance with the invention. Luminaire 200 includes lamp housing 202, arms 204a,b, wireway enclosure 206, and optional uptight unit 208. Each arm 204a,bhas a respective first end 210a,band a respective second end 212a,b. Wireway enclosure 206 is dimensioned to include electrical wiring and at least one electrical component such as a lamp ballast or transformer, and is positioned between arms 204a,badjacent second ends 212a,b. The lengths of lamp housing 202 and wireway enclosure 206 preferably are substantially equal.

[0051] As better seen in FIG. 3, lamp housing 202 includes endplates 314a,bfastened respectively to each side of reflector 316. While endplate 314ais shown fastened to reflector 316 with screws 318, other known methods can be used to fasten endplates 314a,bto reflector 316. Alternatively, endplates 314a,band reflector 316 can be integrally formed as a single reflector unit. Also, reflector 316 can be of different cross-sectional sizes or shapes than that shown in FIGS. 2, 3, 9, 10, 18, and 20.

[0052] First ends 210a,bof arms 204a,bare each attachable to respective endplates 314a,bpreferably with hex-head bolt 320, which may be screwed into a threaded hole, self-clinching nut, or separate nut. Alternatively, other known methods of attaching first ends 210a,bto endplates 314a,bcan be used. The direction in which light is emitted from lamp housing 202 alternatively can be adjustable (i.e., emitted light can be directed upward or downward at various angles) or fixed. If fixed, lamp housing 202 preferably includes pin 322 positioned in slot 324, which sets the direction in which lamp housing 202 emits light, and prevents unintentional movement of lamp housing 202. Furthermore, first ends 210a,beach preferably includes a boss 325 that bulges toward the endplate to provide screw head clearance between arms 204a,band screws 318. Boss 325 also allows the outer surfaces of adjacent luminaire arms 204a,bto be placed side by side along their entire lengths without interference from bolts 320 or pins 322.

[0053] Lamp housing 202 also includes at least one lampholder (not shown) preferably attached to reflector 316. Lampholders, as are known, hold lamps in place and electrically connect them to conductors that deliver power. Lamp housing 202 may include a lens, diffuser, filter, baffle, or other modifier (none shown).

[0054] Preferably, lamp housing 202 further includes a T-5 fluorescent lamp (not shown). A T-5 fluorescent lamp has a diameter of about ⅝ inch (1.6 cm) and can have a length of about 46 inches (116.8 cm) (other lengths available). A lamp-length of about 46 inches (116.8 cm) advantageously permits rows of adjacent luminaires 200 to be used with rows of gondola-type shelving, which typically has 48-inch (121.9 cm) units.

[0055] Alternatively, other types of fluorescent lamps can be used in lamp housing 202. Also, one or more incandescent lamps of different types or shapes alternatively can be used. For example, a longitudinal array of incandescent lamps can be used. Preferably, incandescent lamps used in housing 202 have axial filaments, such as, for example, certain tubular tungsten halogen and showcase lamps. Also, lamp housing 202 alternatively can include lamps that are single-ended or double-ended.

[0056] Lamp housing 202 preferably does not, however, include a lamp ballast or transformer. Accordingly, lamp housing 202 can be of a small preferably slim design, thus presenting less of a distraction to a display than larger lamp housings that include such electrical components.

[0057] Arms 204a,bpreferably are brackets or bracket-like structures that can perform a cantilever function of supporting lamp housing 202 at first ends 210a,b. Alternatively, arms 204a,bcan be of other types of support structures capable of performing the cantilever function, such as, for example, straight, waved, or curved tubular-type members; trusses; perforated plate or sheet metal structures; and very lightweight cantilever arms used with suspension cables. Because lamp housing 202 preferably does not include a lamp ballast or transformer, thus reducing the weight of lamp housing 202, arms 204a,badvantageously can be smaller in size and thus less noticeable than those arms supporting lamp housings that include such components. Arms 204a,bare therefore less distracting.

[0058] Second ends 212a,bof arms 204a,bcan each be mounted to, for example, a respective shelving structure, such as a vertical post. As better seen in FIG. 4, second ends 212a,bpreferably include notched-tabs 426 and 428. Notched-tabs 426 and 428 are sized and spaced such that they can be inserted and secured within vertical elongated holes common in vertical posts of many shelving systems and other structures. For example, second ends 212a,bcan be mounted to a workstation cubicle having such elongated holes. Advantageously, second ends 212a,bcan be mounted without tools or fasteners, thus simplifying and shortening the installation process.

[0059] Second ends 212a,beach includes at least one hole 430 through which electrical wiring can pass, or through which a nipple connector or other known fitting can be installed to permit electrical wiring to pass, for example, between adjacent wireway enclosures of adjacent luminaires. Alternatively, arms 204a,bcan be provided with knockouts. As is known, a knockout is a portion of a surface that can be readily removed with usually one or more tools to provide a hole.

[0060] At least one arm 204a,bpreferably has a double-bend trough 532 preferably running along the inside bottom of the arm, as best seen in FIG. 5. Trough 532 inconspicuously carries electrical wiring between wireway enclosure 206 and lamp housing 202. Alternatively, other supporting structures can be used. For example, hook-like structures periodically spaced along the inside of one or both arms 204a,bcan be used to carry wiring between enclosure 206 and lamp housing 202.

[0061] Trough 532 preferably is also used to support wireway enclosure 206. As shown in FIG. 6, enclosure 206 preferably has a tab 634 at each longitudinal end that rests inside trough 532 when enclosure 206 is positioned between arms 204a,b. Alternatively, other support structures on arms 204a,bcan be used to support enclosure 206 between arms 204a,b. For example, a simple ledge-like structure extending outward from inside an arm 204a,bat second end 212a,bcan be used to support a longitudinal end of enclosure 206.

[0062] While shown in FIGS. 1 and 2 to be generally horizontal and parallel to display shelving and displayed objects when installed, arms 104a-dand 204a,balternatively can be installed such that they are angled upward or downward with respect to the display shelving or displayed objects.

[0063] Referring to FIGS. 6 and 7, wireway enclosure 206 preferably is rectangular (alternatively, other cross-sectional shapes can be used). Preferably, extruded aluminum is used to fabricate enclosure 206, but sheet metal or other appropriate materials can be used instead. Enclosure 206 has a preferably removable front cover 636 and a preferably removable sideplate 638 at each longitudinal end of enclosure 206 (a second preferably removable sideplate 638 is on the longitudinal end of enclosure 206 opposite that shown in FIGS. 6 and 7). Sideplate 638 is attached to enclosure 206 preferably with four screws 644 screwed into respective extruded screw holes or tracks 646. Extruded screw holes 646 advantageously permit long lengths of enclosure 206 to be fabricated, which can then be cut to specified lengths, each cut length having screw holes 646 immediately available. Alternatively, other known methods of attaching sideplate 638 to enclosure 206 can be used. For example, tabs having screw holes at each corner of each longitudinal end of enclosure 206 can be used.

[0064] Sideplate 638 includes at least one hole 648 through which electrical wiring can pass, or through which a nipple connector or other known fitting can be installed to permit electrical wiring to pass, for example, between adjacent wireway enclosures of adjacent luminaires. Alternatively, sideplate 638 can be provided with one or more knockouts. Hole 648 can be aligned with hole 430 in an adjacent arm 204a,b. Installation of nipple connectors or other known fittings through adjacent pairs of holes 648 and 430 preferably aligns adjacent enclosures.

[0065] Removable front cover 636 permits access to the interior of the wireway enclosure. This facilitates installation and connection of electrical components and wiring. Alternatively, or in addition to front cover 636, one or more other sides (e.g., top cover 642) can be removable. Front cover 636 is fastened to wireway enclosure 206 preferably with thumbscrews 850 screwed into threaded standoffs 852, as shown in FIG. 8. Alternatively, other known methods of removably attaching front cover 636 to enclosure 206 can be used (e.g., hinges, friction fit, and tabs with screw holes).

[0066] Wireway enclosure 206 is dimensioned to enclose therein electrical wiring and at least one electrical component, such as a lamp ballast or transformer. An individual luminaire or the first luminaire of a row of luminaires can be wired with either “hardwire” or “softwire.” Hardwire usually refers to relatively permanent insulated wires in either a flexible or rigid metal conduit. Softwire usually refers to a flexible electric cord such as that with a plug for insertion into an electrical outlet. Softwire is preferable for temporary display lighting in which portability without tools is advantageous.

[0067] Wireway enclosure 206 provides display lighting system 100 with increased wiring flexibility, advantageously permitting rows of luminaires 200 to be easily wired. For example, a first luminaire 200 can be connected to a nearby power source. Hardwire power conductors can then be easily run through aligned holes 430 and 648 of adjacent luminaires 200 to connect power to those adjacent luminaires. Furthermore, if advantageous, ballasts or transformers for several adjacent luminaires 200 can be placed in a single enclosure 206 from which electrical wiring can then be run to connect to lampholders in the other luminaires. Removable front cover 636 provides easy access to the interior of each wireway enclosure 206, further facilitating electrical connections.

[0068] Moreover, wireway enclosure 206 conveniently provides a wireway for other wiring and any necessary barrier elements (barrier elements separate wires of different systems from each other). For example, power conductors from another circuit can be run through adjacent enclosures 206 to provide electrical outlets along a row of luminaires. Similarly, emergency lighting circuits, telephone lines, computer lines, burglar alarm wiring, and closed-circuit video lines can be easily, conveniently, and inconspicuously run through wireway enclosures, simplifying electrical connections of other equipment.

[0069] Luminaire 200 installs easily in several ways. For example, luminaire 200 can be shipped fully assembled, or can be assembled at a job site, and then simply mounted without tools to a shelving structure. Alternatively, arms 204a,bcan be mounted to a shelving structure, wireway enclosure 206 can be placed between arms 204a,bat second ends 212a,b, and lamp housing 202 can then be attached to arms 204a,bat first ends 210a,b. Or still further, arms 204a,bcan be attached to lamp housing 202 and then mounted to a shelving structure, and wireway enclosure 206 can then be dropped in place between arms 204a,bat second ends 212a,b. Electrical connections can then be made by removing front cover 636. Power can usually be coupled via conductors in flexible or rigid conduits brought up to luminaire 200 through or adjacent to vertical shelving posts.

[0070] FIG. 9 shows a second preferred embodiment of a luminaire of a display lighting system in accordance with the invention. Luminaire 900 includes wireway enclosure 906, shown without a front cover and sideplates, that mounts to a structure (e.g., a wall) located preferably near display shelving or other area or object to be illuminated. Enclosure 906 preferably includes a plurality of predrilled holes 962 in back cover 964 through which preferably a plurality of screws 966 are screwed into anchors set in the structure. The number of screws 966 and location of holes 962 primarily depend on the strength of the material used to fabricate enclosure 906. For example, thinner gauge material will likely require at least one screw and screw hole positioned closer to each longitudinal end of enclosure 906, as well as, perhaps, one or more additional screws and screw holes there between, to prevent torsional twisting of enclosure 906 when arms 904a,bare attached. Alternatively, other known methods of mounting enclosure 906 to a structure can be used. For example, enclosure 906 can have notched-tabs (the same as or similar to the notched-tabs of arms 204a,b) that can be inserted and secured within elongated holes.

[0071] Enclosure 906 preferably does not include sideplates. Arms 904a,b(arm 904ais not shown for clarity) are attached directly to the longitudinal ends of enclosure 906 with four screws 944 (not shown) screwed into extruded screw holes or tracks 946 (similar to the manner in which sideplate 638 attaches to enclosure 206). Arms 904a,bare otherwise similar to arms 204a,band their alternative embodiments. For example, arms 904a,bhave holes 430 and at least one trough 532, and attach to lamp housing 202 in the same manner as arms 204a,b. Arms 904a,bmay also have notched-tabs 426 and 428.

[0072] Similar to luminaire 200, luminaire 900 also installs easily in several ways. For example, luminaire 900 can be shipped fully assembled, or can be assembled at a job site, and then mounted to a structure. Alternatively, wireway enclosure 906 can be mounted to a structure (e.g., a wall), arms 904a,bcan be attached, and then lamp housing 202 can be attached to arms 904a,b. Or further still, arms 904a,bcan be attached to enclosure 906, the assembly of enclosure 906 and arms 904a,bcan be mounted to a structure, and then lamp housing 202 can be attached to arms 904a,b.

[0073] Optional uptight unit 208 provides uplighting and mounts preferably on top of wireway enclosure 206 or 906. As shown in FIG. 5, uptight unit 208 includes a reflector 554, at least one lampholder 556, and a preferably fluorescent lamp 560. Alternatively, one or more incandescent lamps can be used instead of a fluorescent lamp. Lampholder 556 can be mounted directly to a wiring enclosure as shown in FIG. 5, or alternatively, can be preferably mounted to a mounting bracket 658, which is mounted to a wiring enclosure as shown in FIG. 6.

[0074] Reflector 554 preferably prevents direct viewing of lamp 560 and reflects emitted light generally upward. As shown in FIG. 5, reflector 554 is one-sided and can be used, for example, with a luminaire mounted to a wall or back-to-back with another luminaire also having an uptight unit 208. Alternatively, reflector 554 can be two-sided, as shown in FIGS. 8 and 10, and can be used, for example, with a luminaire mounted back-to-back with another luminaire having no uplighting. Still further, a luminaire mounted to a wall can have a two-sided reflector 554 that distributes uplighting asymmetrically. The side of reflector 554 closest to the wall is oriented substantially straight up while the other reflector side is flared out as shown in FIG. 5.

[0075] FIG. 10 shows luminaire 200 with an optional accent lighting unit 1070 in accordance with the invention. Although shown with luminaire 200, optional accent lighting unit 1070 can also be used with luminaire 900. Accent lighting unit 1070 directs accent lighting to a particular display area or displayed object, and preferably is a low voltage device. A step-down transformer (not shown) coupled to unit 1070 preferably is located in wireway enclosure 206.

[0076] As shown in FIG. 11, accent lighting unit 1070 includes a preferably stainless steel spring clip bracket 1172 that clips on to lamp housing 202 across the light-emitting side of housing 202. An accent lamp housing 1174 is attached to bracket 1172. Housing 1174 preferably is cylindrical, but alternatively can be of other shapes (e.g., rectangular, oval, and hexagonal). Accent lighting unit 1070 preferably includes an MR-16-type lamp 1176 attached to lampholder 1178. Alternatively, other types of lamps 1176 can be used. Lamp 1176 preferably is held in place by a gimbal-ring mechanism 1180, which is attached to housing 1174. Gimbal-ring mechanism 1180 (known in the art) permits lamp 1176 to pivot preferably about more than one axis. Alternatively, lamp 1176 can be fixedly held in place directly by housing 1174.

[0077] FIG. 12 shows another preferred embodiment of a wireway enclosure in accordance with the invention. Wireway enclosure 1206, shown attached to or resting on arms 1204a,b, has two sideplates 1238a,b, a first one-piece longitudinal portion including an integrally-formed top 1242 and front 1236, and a second one-piece longitudinal portion including an integrally-formed back and bottom. Top 1242 and front 1236 and the back and bottom of enclosure 1206 are preferably formed by an extrusion process, and are preferably extruded aluminum. Together, top 1242 and front 1236, the back and bottom, and sideplates 1238a,bform an enclosure having a cavity therein. The enclosure is dimensioned to enclose and substantially conceal from view at least one ballast or transformer and luminaire wiring and preferably other components and other wiring. The longitudinal length of enclosure 1206 can be fabricated to substantially equal a lighting unit held between arms 1204a,b. Such a lighting unit can be the same as or similar to lamp housing 202 and includes at least one lampholder and a lamp reflector. For example, enclosure lengths of about 2 feet to about 10 feet can be made. Optionally, top 1242 includes a notch or hole 1282 that can be used with luminaires having, for example, a plug and cord.

[0078] FIG. 13 shows still another preferred embodiment of a wireway enclosure in accordance with the invention. Wireway enclosure 1306, which preferably includes all the characteristics of wireway enclosure 1206, includes lighting unit 1308 mounted on top 1342. Lighting unit 1308 preferably provides uplighting and includes at least one lampholder 1356 and lamp reflector 1354.

[0079] FIG. 14 shows a portion of enclosure 1206 without sideplate 1238. Top 1242 and front 1236 are integrally formed as a single piece and form a substantially 90° angle between them. Back 1464 and bottom 1484 are also integrally formed as a single piece and also form a substantially 90° angle between them. Top 1242 and front 1236 are longitudinally shorter than back 1464 and bottom 1484 in order to accommodate the embodiment of sideplate 1238 described below. Front 1236 is hinged to bottom 1484 at hinge 1486, and top 1242 is removably attachable to back 1464 with clip 1488. Enclosure 1206 and 1306 each have at least two clips 1488, one positioned near each longitudinal end of the enclosure. Alternatively, other types of fasteners or clips can be used to removably attach top 1242 to back 1464. Hinge 1486 allows top 1242 and front 1236 to hinge forward in the direction of arrow 1490 to provide access to the interior of the enclosure. Hinge 1486 is designed such that wires will not be pinched or damaged as the top and front piece is hinged open and closed.

[0080] Enclosure 1206 also preferably includes several screw tracks 1446. Screw tracks 1446 are operative to receive and hold fasteners such as screws, and can be used to attach lighting components such as ballasts or transformers to the inside of the enclosure. Front 1236 preferably has a screw track 1446arunning longitudinally inside of enclosure 1206. Screw track 1446apreferably runs the entire longitudinal length of front 1236. Back 1464 also preferably has a screw track 1446brunning longitudinally inside of enclosure 1206, which also preferably runs the entire longitudinal length of back 1464. Preferably, screw tracks 1446aand b run parallel to each other and to top 1242. Back 1464 preferably has a second screw track 1446crunning longitudinally along its top edge on the outside of enclosure 1206. As shown, this screw track can be used to secure screws holding clips 1488, among other things. Screw track 1446calso preferably runs the entire length of back 1464. Top 1242 preferably has a screw track 1446drunning longitudinally on the outside of enclosure 1206, which preferably runs through the entire longitudinal length of top 1242.

[0081] Either or both screw tracks 1446cand d can be used to mount lighting unit 1308 to top 1242, thus transforming enclosure 1206 into enclosure 1306. This is advantageous because an enclosure 1206 can easily be converted to enclosure 1306 in the field after enclosure 1206 has been installed.

[0082] FIG. 15 shows an exploded view of a portion of enclosure 1306 with top 1342 and front 1336 hinged open to provide easy access to the inside of the enclosure. As shown, a ballast 1592 can be enclosed inside enclosure 1306 using screw track 1446b. Lighting unit 1308 can be mounted to top 1342 by using fasteners 1544 (e.g., screws) secured to screw track 1446d. Lighting unit 1308 can optionally include a specular insert 1594 for those applications in which, for example, lighting unit 1308 involves non-white surfaces.

[0083] FIG. 16 shows sideplate 1238 in accordance with the invention. Sideplate 1238 can be used with either enclosure 1206 or 1306 and is dimensioned to cover the opening at each longitudinal end of the enclosure formed by the top and front and the back and bottom. Sideplate 1238 can be fabricated from stamped and bent sheet metal or from a zinc or aluminum die casting, and has a preferably flat face 1696 which is substantially perpendicular to the top, front, back, and bottom of the enclosure. Flat face 1696 allows adjacent enclosures to butt against each other without noticeable gaps.

[0084] Sideplate 1238 preferably has at least one hole 1648 through which electrical wiring can pass, or through which a nipple connector or other known fitting can be installed to permit electrical wiring to pass, for example, between adjacent wireway enclosures. Alternatively, a knockout can be used in place of hole 1648. Hole 1648 is preferably aligned with hole 430 in an adjacent arm 204a,b. Installation of nipple connectors or other known fittings through adjacent pairs of holes 1648 and 430 preferably aligns adjacent enclosures.

[0085] Sideplate 1238 preferably also includes top tab 1697 and front tab 1698. When the sideplate is attached to the top, front, back, and bottom of the enclosure, tabs 1697 and 1698 are preferably flush with the top and front of the enclosure, respectively. Front tab 1698 preferably has a cutout 1699 that forms a hole with the front of the enclosure to allow wiring to pass between the inside of the enclosure and, for example, a lamp housing. The wiring can be routed along, for example, an arm attached to both the enclosure and the housing, as described earlier. A tab 1634 similar to or the same as tab 634 is preferably also provided with sideplate 1238.

[0086] Sideplate 1238 is preferably fastened to back 1464 and bottom 1484 with fasteners 1644 (e.g., the three screws shown in FIG. 16). Alternatively, sideplate 1238 can be fabricated with additional tabs along its back and bottom (not shown) to be friction fit over the side edges of the bottom and back of the enclosure.

[0087] FIG. 17 shows a portion of enclosure 1306 and an arm 1704. Note the substantially flush fit of tabs 1697 and 1698 with top 1342 and front 1336, respectively. Also note the hole formed by cutout 1699 that can be used to route wire inconspicuously to and from the enclosure along arm 1704.

[0088] Although shown as generally rectangular in shape, wireway enclosures of the invention can be of other shapes, such as, for example, cylindrical, triangular, pentagonal, and so on, and need not be necessarily longitudinal.

[0089] Also, although sideplate 1238 is shown, wireway enclosures of the invention can have other types of sidecovers to enclose or cover the open longitudinal ends of the enclosures formed by the first and second portions (e.g., the top and front and the back and bottom). For example, alternative to flat faces, sidecovers can have curved or rounded faces. Further, they need not have top and front tabs 1697 and 1698, in which case the first portion (e.g., the top and front) of the enclosure is preferably the same longitudinal length as the second portion (e.g., the back and bottom) of the enclosure.

[0090] FIG. 18 shows a portion of another embodiment of a luminaire of a display lighting system in accordance with the invention. Luminaire 1800 includes lamp housing 202, arms 1804a,b, wireway enclosure 1806, and uptight lamp housing 1808. Each arm 1804a,bhas a respective first end 1810a,band a respective second end 1812a,b. At least one of arms 1804a,bincludes a trough 1832, which can be identical or similar to trough 532. Trough 1832 is shaped and dimensioned to carry wiring 1833 between enclosure 1806 and lamp housing 1808, as well as wiring between enclosure 1806 and lamp housing 202. Enclosure 1806 is dimensioned to enclose electrical wiring and at least one electrical component such as a ballast or transformer. Enclosure 1806 can be, for example, either of enclosures 206, 906, 1206, or 1306. As described above, lamp housing 202 includes endplates 314a,bfastened to respective ends of reflector 316. In this embodiment, lamp housing 202 is preferably oriented to provide downlighting. Alternatively, however, lamp housing 202 can instead provide uplighting.

[0091] Uplight lamp housing 1808 includes endplates 1814a,band a reflector 1854 attached at each end to a respective endplate 1814a,b. Alternatively, endplates 1814a,band reflector 1854 can be integrally formed as a single unit. Lamp housing 1808 also includes a lampholder 1856, which is operative to hold preferably a fluorescent lamp and more preferably a T-5 fluorescent lamp 1860. Alternatively, lampholder 1856 can hold an incandescent lamp.

[0092] Note that luminaire 1800 need not include lamp housing 202 and may accordingly be sold without lamp housing 202. This advantageously gives a user the option of selecting and installing other styles or types of lighting units between ends 1810a,bof arms 1814a,b.

[0093] FIG. 19 shows lamp housing 1808 mounted to another embodiment of an arm in accordance with the invention. Lamp housing 1808 preferably mounts to the top edges of arms 1904a,b, which are perforated plate structures, with preferably a pair of hook structures 1915 (described in more detail below) on each endplate 1814a,b. Alternatively, only one sufficiently-sized hook structure may be used instead of the pair of hook structures 1915. Lampholder 1856 is attached to bracket 1958, which is attached to reflector 1854. Alternatively, bracket 1958 can be attached to one of endplates 1814a,b, or lampholder 1856 can be attached directly to reflector 1854 or one of endplates 1814a,b.

[0094] As shown in FIG. 20, lamp housing 1808 is oriented to provide uplighting in the general direction of arrow 2017, while lamp housing 202 is preferably oriented to provide downlighting in the general direction of arrow 2019. Advantageously, lamp housing 1808 can be mounted to arms 1804a,bat different positions (represented by double-headed arrow 2021) along the length of arms 1804a,b. For example, lamp housing 1808 can be mounted very close to enclosure 1806, very close to lamp housing 202, or substantially anywhere in between. Hole 2030 in arm 1804aand an aligned hole in enclosure 1806 are preferably provided to allow wiring to run conveniently through adjacent enclosures as described above. Similar or identical holes are also preferably included in arm 1804band the other end of enclosure 1806. Arms 1804a,balso preferably include an embossment or boss 2025 identical or similar to boss 325 at ends 1810a,bto allow luminaires of the invention to be arranged side-by-side with little to no space required between adjacent arms because of screw heads or other protruding hardware.

[0095] FIG. 21 shows a profile view of an embodiment of lamp housing 1808 designed for a T-5 fluorescent lamp 1860. Preferably, lamp housing 1808's vertical profile 2023 measures no more than about 1.8″ (4.6 cm). Reflector 1854 is shaped to output a preferably asymmetric light distribution pattern. Such a pattern is preferred when illuminating a plane (e.g., a sign) from one edge. As shown, endplate 1814apreferably has is hook structures 1915a,bthat are positionally offset on endplate 1814afrom the positions of hook structures 1915c,don endplate 1814b. The space between a pair of hook structures is preferably at least as wide as one of the hook structures. The advantage of this feature is shown in FIGS. 24 and 25.

[0096] FIGS. 22 and 23 show a pair of endplates that can be used with lamp housing 1808. Endplate 2214 can be used at one end of lamp housing 1808, while endplate 2314 can be used at the other end of lamp housing 1808. Endplate 2214 preferably includes a tab 2227 and a pair of spaced apart hook structures 2215a,b. The space between hook structures 2215a,bis preferably wider than the width of one of hook structures 2315c,dof endplate 2314. Hook structures 2215a,bare preferably shaped and dimensioned to hook over a top edge of any one of the cantilever arms of the invention. Alternatively, a single hook structure of sufficient size may be used instead of the pair. Tab 2227 can be used to attach endplate 2214 to reflector 1854 via, for example, set screws through screw holes 2229a,b. Endplate 2214 also preferably includes a screw hole 2231 that can be used with a set screw to secure the position of lamp housing 1808 on, for example, arms 1804a,b, after lamp housing 1808 has been mounted on the cantilever arms.

[0097] Similarly, endplate 2314 preferably includes a tab 2327 and a pair of spaced apart hook structures 2315c,d. The space between hook structures 2315a,bis preferably wider than the width of one of hook structures 2215a,bof endplate 2214. Hook structures 2315c,dare also preferably shaped and dimensioned to hook over a top edge of any one of the cantilever arms of the invention. Alternatively, a single hook structure of sufficient size may be used instead of the pair. Tab 2327 can be used to attach endplate 2314 to reflector 1854 via, for example, set screws through screw holes 2329a,b. Endplate 2314 also preferably includes a screw hole 2331 that can be used with a set screw to secure the position of lamp housing 1808 on, for example, arms 1804a,b, after lamp housing 1808 has been mounted on the cantilever arms.

[0098] As shown in FIGS. 22 and 23, hook structures 2215a,bare preferably positioned at an offset along the top of endplate 2214 with respect to the positions of hook structures 2315c,don the top of endplate 2314 such the hook structures do not interfere with each other upon a mounting of endplates 2214 and 2314 on opposite sides of the same cantilever arm. In other words, a projection of hook structures 2215a,balong fixture longitudinal axis 2200, which runs from one endplate to the other endplate through lamp housing 1808 (not shown in FIGS. 22 and 23) substantially perpendicular to both endplates, toward the other endplate results in no overlap of any hook structure with any other said hook structure. The advantage of this feature is shown in FIGS. 24 and 25.

[0099] Furthermore, hook structures 2215a,band 2315c,dare each preferably shaped and dimensioned to hook over two adjacent side by side cantilever arms simultaneously.

[0100] Note that hook structures can be alternatively shaped and dimensioned differently than shown herein and need not extend outward from the top edge of the endplate.

[0101] FIG. 24 shows a portion of two luminaires being arranged side by side in accordance with the invention. Luminaire 2400aincludes uptight lamp housing 2408abeing mounted to both arms 2404aand 2404bwith endplate 2214. Luminaire 2400bincludes uplight lamp housing 2408bmounted to both arms 2404aand 2404bwith endplate 2314. Arms 2404a,bare arranged adjacent each other.

[0102] FIG. 25 shows the luminaires 2400a,barranged side by side. Advantageously, offset hook structures 2215a,band 2315c,dpermit uptight lamp housings 2408a,bto be in alignment with each other and allow arm 2404ato be flush against arm 2404bthroughout substantially their entire lengths.

[0103] Thus it is seen that a display lighting system is provided that assembles and installs easily, and allows the easy installation of an uptight at selectable positions. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow.