Luminaire bracket

BACKGROUND OF THE INVENTION

This invention relates generally to luminaires for lighting large areas such as roadways and is more particularly directed to a bracket for securing luminaires to a roadway barrier or other mounting surface and which also provides a raceway for the luminaire power cables. _3g

In the illumination of roadways of, for example, freeways or bridges, it is often preferable that the illumination means be at a level relatively close to the road, e.g., slightly below the normal eye level of a driver of a motor vehicle. It is found that this positioning of the illu- 40 mination means results in brighter and fuller illumination of the roadway than does conventional overhead lighting, and yet reduces the glare to vehicle drivers. Roadway luminaires for this type of illumination are commonly mounted on roadway barriers, such as the median barrier 45 between lanes of oppositely directed traffic or the side rails of a roadway. These luminaires are usually elongated and are mounted in end to end abutting relationship to provide continuous illumination of the roadway.

It is to be appreciated that to provide power for the 50 illumination sources of this type of luminaire, cables or wires must lead to each of the luminaires. Thus, some means for accommodating the cables along the length of the barrier must be provided, and it is preferable that such means enclose the cables in a manner protecting them 55 from the elements. If when a roadway barrier is being constructed it is contemplated that luminaires of this type will be installed on it, a wireway or raceway for the cables can be built into the barrier as a part thereof. Most existing barriers, however, do not include a race- 60 way for luminaire power cables, although it is desirable to be able to substitute this type of luminaire for the overhead lights now provided on most existing roadways. Moreover, the space available on many existing barriers is not sufficient to permit mounting of both a wireway 65 and luminaire thereon. Thus, heretofore it has not always been practical to convert existing overhead lighting arrangements to low level lighting. It should be noted that the luminaire housings themselves cannot be used as a wireway since it is desirable to be able to remove or 70 replace each luminaire independent of the others should one become damaged or otherwise in need of repair.

SUMMARY OF THE INVENTION

The instant invention permits luminaires of this type to be installed on existing roadway barriers irrespective of whether such barriers have raceways. The brackets for securing the luminaires to the barrier are adapted, in combination with the luminaires, to provide a continuous raceway from the luminaire cables. More particularly, each bracket includes a channel member adapted to accommodate the power cables and having means for securing a luminaire over its mouth to define an enclosed raceway. The channel member of each bracket meets with the channel member of the adjacent brackets to provide continuity of the raceway for the length of the luminaire assembly.

The combined bracket-raceway provides the luminaire assembly as a generally self-contained unit. The unit takes up only a minimum amount of space and obviates the necessity of modifying existing roadway barriers for the mounting of the low-level roadway luminaires.

BRIEF DESCRIPTION OF THE DRAWING

With reference to the drawing:

FIGURE 1 is a perspective view of a roadway median barrier having luminaires mounted thereon by a combined bracket and raceway of the invention;

FIGURE 2 is an enlarged, cross-sectional view taken on a plane indicated by line 2—2 of FIGURE 1 illustrating constructional details of the luminaire and bracket of the invention;

FIGURE 3 is a fragmentary rear view of a joint between two luminaires illustrating the manner in which adjacent brackets are joined to provide a continuous raceway between them;

FIGURE 4 is an enlarged fragmentary perspective view illustrating a luminaire and a bracket of the invention exploded from one another;

FIGURE 5 is a cross-sectional view similar to FIGURE 2 of another luminaire and bracket of the invention; and

FIGURE 6 is a fragmentary front elevation view of a joint between two luminaires and brackets of the embodiment of FIGURE 5 illustrating the manner in which adjacent brackets of this embodiment are joined to provide a continuous raceway between them.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGURES 1-4, and particularly to FIGURE 1, a roadway barrier 11 is shown which includes a continuous beam 12 supported on a base 14 by a plurality of upwardly extending longitudinally spaced posts 16. The illustrated exemplary barrier 11 is a median barrier adapted to be positioned between lanes of oppositely directed traffic. From the following description, it will be appreciated, however, that the invention is equally applicable to roadway side barriers and other forms and configurations of barriers.

Mounted on beam 12 are a plurality of longitudinally aligned, adjacent luminaire units 17. Since barrier 11 is a median barrier, two sets of luminaire units are provided, one on each side of the barrier. Each luminaire includes a light housing 18 having at one side thereof a plurality of longitudinally spaced light transmitting lenses 19 of plastic or the like backed by a collimator 21 of preferably honeycomb material. The top of each housing is a hinged lid 22 which may be pivoted open to provide ready access to the interior of the housing. This facilitates replacement of the illumination source which can be a fluorescent lamp 23 having ballast 24. Wires 26 are suitably secured to branch circuit conductor cables 25 within the raceway such as by means of split compression connectors and extend upwardly through an aperture 27 in

3,473,017 the bottom of housing 18. Such wires 26 are releasably connected to a terminal block 28 mounted on the housing bottom, and wires 29 connect the terminal block to ballast 24. Because wires 26 are releasably connected to terminal block 28, the luminaire can be easily freed from its connection to the cables in the raceway.

With reference to FIGURE 3, it will be seen that at the joint 31 between adjacent luminaires, a small space is provided to accommodate thermal expansion and contraction of such luminaires. The joint itself is covered by a strap 32 having a quick release catch 33 facilitating separation of one luminaire from the other to permit any one luminaire to be removed from the barrier without disturbing the adjacent ones.

It is to be appreciated that as described to this point, the luminaire assembly is generally conventional. This type of luminaire is also described in Patent No. 3,387,126 issued on Jan. 4, 1968, to Kun S. Lim, one of the present co-applicants, for Roadway Luminaire.

In accordance with the invention, luminaires 17 are secured to barrier 11 by novel brackets generally referred to by the reference numeral 36. Each bracket 36 includes a channel member 37 which extends for substantially the full length of the luminaire and is communicably connected with the channel member 37' of a bracket 36' for the longitudinally adjacent luminaire 17'. The lateral cross sectional area enclosed by each channel member 37 is sufficiently large, e.g., 5 square inches, for the channel member to accommodate a plurality of luminaire power cables. The mouth 38 of each channel member faces upwardly and a luminaire is secured over such mouth in covering relationship to thereby define with the channel member an enclosed raceway for the power cables. More particularly, at each longitudinal edge of the channel member adjacent its mouth there is provided means for securing the luminaire housing to the bracket over the channel. At the forward edge of the bracket such means includes an inwardly curved arcuate flange 39 which extends for the full length of the bracket. Such flange engages with a lip 41 which extends downwardly and outwardly from the luminaire housing adjacent the forward edge of its bottom. Such lip extends longitudinally of the housing for substantially its full length so that when the arcuate flange 39 and such lip 41 are interengaged, a front closure seal for the raceway is provided for substantially the full length of the luminaire. The rear edge of the bracket has a generally U-shaped gutter 42 which extends for the full length of such edge. A complementary L-shaped flange 43 adapted to fit within gutter 42 projects downwardly and outwardly from luminaire housing 17 adjacent the rear edge of its bottom. Flange 43 also extends for the full length of the housing so that when such flange is engaged with gutter 42, a closure seal for the raceway is also provided at the rear side thereof to protect cables therein from the elements.

To provide for quick release securance of each luminaire housing to a bracket 36, a set screw 44 threadably passes through outer flange 46 of gutter 42 and engages the shank of L-shaped flange 43. A jam nut 47 on the free end of set screw 44 locks such screw in position. In the depicted embodiment wherein each bracket 36 is substantially coextensive with one luminaire 17 at least two of the set screws 44 are provided for each bracket with one adjacent each end of the luminaire for securing the luminaire housing to the bracket.

The manner by which the above described complementary engaging elements of the bracket and housing and the set screws provide for quick release of the luminaire housing should be apparent from the above and is fully described in the previously mentioned Patent No. 3,387,126. The set screws employed with the respective brackets can be dissimilar as described in such patent to provide positive locking securance at one end of each housing and longitudinal slippage at the other so that thermal expansion and contraction of the housing is accommodated.

It is to be appreciated that while in the embodiment being described the respective luminaire housings and brackets are substantially coextensive, this is not necessary. Several brackets could be used for each housing, or several housings could be mounted on each bracket, so long as the brackets are longitudinally adjacent one another with the channel members thereof communicably connected so as to provide the continuous raceway. FIGURE 3 depicts the manner in which the raceway defined by two adjacent brackets is continued at the joint between such brackets. An insert 51 bridges the gap between adjacent brackets 37 and 37' and has its respective ends received within the ends of the two channel members 37 and 37'. Insert 51 has a surface configuration which conforms to the interior surface configuration of such channel members at their ends so as to act as a continuation of the raceway between such channel members. One end of such insert is suitably rigidly secured within one of the channel members such as by bolt 52 securing it to channel member 37'. So that thermal expansion and contraction between the brackets will be accommodated, the other end of the insert is slidably connected to the other channel member, channel member 37, such as by means of a flexible grounding strap 53 secured between them by bolts 54 and 55.

The base of each bracket 36 is adapted for securance of the bracket to roadway barrier 11 or other suitable mounting surface. More particularly, the base of channel member 37 is formed with two parallel, outwardly projecting gutter portions 56. Bolt holes 57 extend through the bracket base at suitably longitudinally spaced intervals along such gutter portions and bolts 58 extend through such holes and are threadably received within inserts 59 in the barrier to provide for securance of the bracket to such barrier. Suitable sealing washers 61 on each bolt adjacent its associated hole 57 prevent liquid seepage or leakage into the raceway.

The rear side wall of the channel member of each bracket extends upwardly further than the front wall thereof so that the mounting of the luminaire will be such that light emanating therefrom will be directed downward at a slight angle. It will be appreciated that this construction can be varied depending on the particular surface configuration of the barrier or other mounting surface to which the luminaire is to be secured and depending upon the requirements attendant to the particular use to which the luminaire is to be put.

FIGURES 5 and 6 depict another preferred embodiment of the invention in which the raceway defined by the luminaire bracket is sufficiently large to accommodate the ballast for the lamps. This removal of the ballast from inside the luminaire housing allows the lamps to be placed in each housing end-to-end closely adjacent one another. Thus, a continuous longitudinal beam of light will emanate from the luminaires and no shadows will be caused by the ballast. With particular reference to FIGURE 5, a luminaire assembly of this embodiment of the invention is generally referred to by the reference numeral 61. Assembly 61 is mounted on a roadway side barrier 62 by means of angle brackets 63 which are secured to the rear side of barrier 62 by means of bolt and nut assemblies 64. Desirably, two angle brackets 63 are provided for each luminaire assembly 61, one adjacent each end thereof. Barrier 62 is shown as being of the side rail type to exemplify a different form and configuration of barrier on which the invention permits the installation of low level luminaires.

The upper surface 66 of the outwardly projecting flange 67 of each angle bracket 63 is generally planar and is coextensive with the upper surface of side rail barrier 62. Such flange has two threaded apertures for receiving the threaded end of bolts 69 which mount luminaire bracket 71 of this embodiment to the angle bracket 63.

As previously mentioned, channel member 72 of luminaire bracket 71 defines a raceway of a sufficiently large

3,473,017 cross section to accommodate the ballast 73 for a fluorescent lamp 74 of each luminaire. More particularly, the rear side wall 76 of such channel member is extended upward to a much greater height than the corresponding rear side wall on the previously described embodiment. The base 77 of each luminaire housing 78 is adapted to extend horizontally inward from the upper edge of bracket wall 76 and then angularly downward to meet the relatively short front side wall 79 of the bracket channel member 72. The horizontal portion of luminaire housing base 77 provides a platform upon which are vertically mounted by suitable bolt and nut assemblies 81 vertical end supporting plates 82 for the lamps. Ballast 73 for each lamp 74 depends from the underside of the platform portion of base 77 into the raceway defined by the channel member 72. A suitable aperture 83 in base 77 provides an opening for passage of power wires 84 from the ballast 73 to the lamp 74. As mentioned before, the removal of ballast 73 from the luminaire housing and placement thereof within the raceway permits longitudinally adjacent lamps 74 to be placed close to one another in end-to-end relationship to provide a generally continuous beam in the longitudinal direction and eliminate ballast shadows. The provision of the downwardly extending angular portion of the base assures that the light housing lense 86 can be of a comparable size to that of the previous embodiment without adding to the total height of the luminaire or raising such luminaire appreciably above side barrier 62.

Terminal block 87 for releasably connecting the wires 88 from branch circuit power cables 89 to wires 91 leading into ballast 73 is also mounted in the raceway. More particularly, screws 92 secure such block to the base of channel member 72 interiorly thereof. The placement of the terminal block within the raceway facilitates quick removal of luminaire housing 78 from its bracket by eliminating the necessity of opening the hinged lid 93 of the luminaire housing to release the electrical connection of the lamps from the cables within the raceway. To effect release of such connection, it is only necessary to release wires 91 from the terminal block once the housing has been raised from the bracket.

It will be appreciated that ballast 73 generates heat during lamp operation. For this reason it is desirable to hold branch circuit cables 89 away from such ballast and for this purpose a cable retainer strap 94 is provided at the location of each ballast.

The complementary engaging portions by which the luminaire housing of this embodiment is secured to the bracket over the mouth of the channel member 72 are basically the same as in the previously described embodiment. For this reason they will not be described in detail. However, it should be noted that in this embodiment the U-shaped gutter-L-shaped flange engaging elements are at the front of the assembly rather than at the rear as in the first embodiment, and the inwardly directed flange—outwardly directed lip elements are at the rear thereof.

With reference to FIGURE 6, it will be seen that this embodiment does not include an insert comparable to the insert 51 of the previous embodiment for communicably connecting adjacent brackets to provide continuity of the raceway. In the instant embodiment the strap 96 for covering the joint between adjacent luminaires encircles both the luminaire housing and the bracket to thereby bridge the gap between the adjacent brackets as well as between the adjacent luminaires. Thus strap 96 communicably connects the channel member of one bracket to that of the other and eliminates the necessity for an insert. It will be noted that to permit the strap 96 to encircle both the luminaire housing and the bracket, the exterior surface configuration of the bracket has a smooth contour relative to the bracket of the previously described embodiment and is an extension of the surface configuration of the luminaire housing. More particularly, the outer surface of the luminaire housing and bracket mate with one another at the joint, and the bracket does not include wells or gutter portions at its base. Instead of the wells or gut ter portions of the previously described embodiment to space the base of the bracket from the barrier to which it is mounted, spacing washers 97 are provided on mounting bolt 69 between such bracket and the angle bracket 63.

Strap 96 is releasably secured around the joint between the adjacent luminaire assemblies by means of a bolt and nut assembly 98. This bolt and nut assembly, as well as the set screws 99 for securing the luminaire housings to the brackets, are provided at the front of the luminaire. Individual luminaire housings can then be removed and replaced without it being necessary to have access to the rear of the assembly. This is particularly advantageous when the luminaire is mounted on the side rail barrier of, for example, a bridge on which access to the far side of the barrier is limited.

To ground adjacent luminaire brackets of this embodiment to one another, a sheathed grounding wire 101 passes through collars 102 of grounding lugs 103 secured to each luminaire adjacent the joint. The ends of the ground cable are bared of sheathing and are secured in electrical contact to the respective brackets such as by means of screws 104 which secure the grounding lugs to the brackets.