US3065333A - Fluorescent lighting fixture - Google Patents

Description

Nov. 20, 1962 J. H. SPAULDING ET AL 3,065,333

FLUORESCENT LIGHTING FIXTURE Filed March 13, 1961 4 Sheets-Sheet 2 Nov. 20, 1962 .1. H. SPAULDING ETAL 3,065,333

FLUORESCENT LIGHTING FIXTURE 4 Sheets-Sheet 5 Filed March 13, 1961 mm 2'; ATTORNEY Nov. 20, 1962 J. H. SPAULDING ETAL 3,065,333

FLUORESCENT LIGHTING FIXTURE 4 Sheets-Sheet 4 Filed March 13, 1961 "yam? IR AKER mm ON ATTORNE United States Patent )fiice 3,065,333 Patented Nov. 20, 1962 3,ea,da3 FLUGRESCENT LEGHTING FIXTURE Joseph H. Spa-raiding, Gerald M. Rodmaker, and Wiliiam R. Wedding, Cincinnati, Chin; said Rodmalrer and said Wedding assignors to said Spanlding Fiied Mar. 13, 15 61, 521'. No. 95,295 14 Claims. (Cl. 240-6) This invention relates to a lighting fixture, and more particularly to a cantilever type illuminator such as, by way of example, may be used as an overhead lighting fixture for indoor or outdoor use to illuminate floor or ground areas to predetermined light intensities.

An object of the invention is to provide an illuminator of the character mentioned, which includes means for increasing the overall efiiciency, and materially reducing the operating and maintenance costs without increasing the initial cost of the device.

Another object of the invention is to provide a cantilever type illuminator which comprises a pair of laterally spaced transverse end housings which are rigidly interconnected by means of an elongate, rigid spine element, one end of which is securely anchored to a mounting plate whereby an illuminator up to three feet wide and eight and one-half feet long, when subjected to winds up to 100 miles per hour, will remain intact, undamaged, operable and free of destructive vibration.

A further object of the invention is to provide an illuminator having the hereinabove described characteristics, in which a plurality of fluorescent light tubes are securely though releasably mounted in spanning relationship between sockets disposed at opposite ends of the fixture, and in a substantially common plane, thereby providing a minimum height dimension to the illuminator.

Another object of the invention is to provide an illuminator wherein the fluorescent light tubes are disposed centrally of the illuminator and wherein the ballasts are located outboard, and remote from the light tubes, in such a manner as to eifectively permit dissipation of the ballast-generated heat without transferring said heat to the light tubes; and wherein the heat from the light tubes is isolated from the ballast.

A further object of the invention is to incorporate in an illuminator of the class mentioned, structural improvements which eliminate undesirable leakage of light, and the entry of flying insects to the lamp and reflector compartment; and further, to strengthen the structure against damaging effects of high winds and inclement weather.

These and other objects are attained by the means described herein and as disclosed in the accompanying Y drawings, in which:

FIG. 1 is a bottom view of an illuminator embodying the teachings of the present invention.

FIG. 2 is an elevational view of the left end plate or head element or" the illuminator of FIG. 1.

FIG. 3 is an elevational view of the rightend plate of the illuminator of FIG. 1.

FIG. 4 is a transverse cross-section taken on line 4-4 of FIG. 1.

FIG. 5 is a transverse cross-section taken on line 5-5 of FIG. 1.

FIG. 6 is an enlarged, partial view of the tion of FIG. 4.

PEG. 7 is a fragmentary cross-sectional view taken on line 7-7 of FIG. 1.

FIG. 8 is a bottom plan view similar to FIG. 1, showing a modification of the illuminator.

FIG. 9 is an end elevation of the FIG. 8 modification, looking from left to right.

FIG. 10 is a perspective view of a head bracket constituting a structural element of the present invention.

middle por- FIG. 11 is an end view of the cantilever beam 8 of FIG. 6.

At the outset it should be noted that fluorescent light tubes require a source of high voltage electricity which is made available by means of a ballast, or inductance. Ballasts, of necessity, undergo an appreciable increase in temperature during operation, and the underwriter laboratories have prescribed 90 C. as the optimum safe operating temperature for ballasts of illuminators of the general type to which this application is: directed.

The life of commercially available ballasts is shortened by if the operating temperature of the ballast is increased by as little as 10% over 90 C.; and although 90 C. is the allowable maximum ballast temperature acceptable by the underwriters, it is commonplace and the rule, rather than the exception, for ballast temperatures to greatly exceed 90 C. in commercial fluorescent outdoor lighting fixtures.

It has been established that the lift of a ballast will be increased by at least 50% if it is operated at temperatures which are 10% below 90 C.; and although this fact. has been well-known to the industry for a number of years, the industry has, prior to our invention, been unable to provide a fluorescent outdoor type lighting fixture with means for permitting the ballast to continuously operate at temperatures which are substantially below the 90 C. approved by the underwriters laboratory.

It is therefore a primary object of the present invention to provide an illuminator with means whereby the operating ballast will run cool when continuously operated, that is, the maximum temperature of the ballast will be substantially below, and in excess of 10% less than 90 C.

In the prior art fixtures with which we are familiar, the ballasts have been disposed interiorly of, above, and in some instances below the tube-containing compartment of the fixture; and in all instances the operating tempera ture of the ballasts has equaled or substantially exceeded 90 C., with the result that the life of the ballast and the efficiency and useful life of the fluorescent tubes have been materially reduced.

With particular reference now to the drawings, the numeral l2 denotes generally a plurality of elongate fluorescent light tubes to which high voltage. electric current is supplied from one or more ballasts or transformers 14 wired in the usual manner not relevant to the present invention.

The numeral M denotes generally the fixture housing which, in the preferred embodiment of the invention, cornprises a pair of laterally spaced transverse end housings 40 and 52, wherein end housing 40 may be considered the head or mounting element which, as best illustrated in FIG. 2, includes a central hub 42 from which integrally formed arms 44 project.

As illustrated in FIGS. 6 and 7, arms 44 of the head element are circumferentially bounded by a continuous, laterally extended flange or shelf 48 upon *whichthe end of cover sheet or panel 16 may be received and-to which said sheet may be anchored by means of fastening elements 50. In the same manner end housing 52 is provided with a continuous flange or shelf 54 which is en gaged by the other end of sheet or panel 16 to which it may be secured by means of fastening elements 56. Uniformly satisfactory results have been obtained in those instances wherein the- transverseend housings 40 and 52 have been fabricated from cast aluminum or the like.

With particular reference now to FIGS. 6, 7 and 10,

the numeral 56 denotes a rigid end, head or mounting bracket which includes an upright base portion 58 having a plurality of drilled and internally threaded lugs 60 formed therein for thereception of bolts 62 the shanks mercially available adapter unit by which of which pass through complementary holes 164 of hub 142 of an adapter plate 143, and through holes 64 of hub 42 to rigidly secure the bracket relative to the transverse end housing 40 and adapter plate 143.

It should be understood that the present invention is not directed to nor concerned with the structural details of the adapter plate 14-3, which comprises part of a comthe fixture of the present invention may be suitably mounted relative to a pole or other support means.

The upright base 58 is provided with a central opening 66 to provide access for wiring. Apair of laterally spaced, substantially parallel tongues 68 and 68A extend in a common direction at right angles with said base.

In the preferred embodiment of the invention said tongues are each substantially U-shaped and include adjacent inner side faces 71A and 73A and outer side faces 81A and 83A, respectively, said tongues being drilled transversely as at 70.

The numeral 76, FIGS. 6, 7 and 11, denotes an elongate, rigid cantilever beam which may be suitably fabricated from sheet steel formed whereby to provide a central U-shaped channel portion defined by bottom wall 75 and upstanding, laterally spaced side Walls 71 and 73 which comprise, respectively, the inner side walls of a pair of outer, inverted, U-shaped channel portions which include top walls 77 and 79 and outer, downturned side walls 81 and 83.

As illustrated in H6. 6, the central U-shaped channel is receivable between tongues 68 with side walls 71 and 73 engaging the adjacent inner faces 71A and 73A, respectively, of the tongues; and with top walls 77 and 79 spanning the inner and outer faces of the tongues for disposing the outer side walls 81 and 83 of the beam downwardly over and along the outer side faces 81A and 83A, respectively, of tongues 68.

Transverse connector elements, such as, by way of example, long bolts 74, may be passed through holes 70 in the tongues and aligned openings, not illustrated, in the side walls of the beam channelways for securely and rigidly locking the beam to the mounting bracket 56.

The cantilever beam 76 constitutes an elongate, rigid spine which supports the entire weight of those portions ofthe fixture forwardly of bracket 56.

Transverse end housing 52 is secured to, carried by and suspended from the free outer end of the beam 76 by means of fastening elements 56 which interconnect upper walls 77 and 79 of said spine to mounting lugs 88 integral with housing 52, as best illustrated in FIGS. and 7.

With reference to FIG. 7, the numeral 80 indicates a socket carrier plate, secured by means of screws 82 to the forward faces 184 of forwardly projecting, side wings 84 of the mounting bracket, which faces are drilled and tapped as at 86 to receive the screws 82. The socket carrier plate 80, as shown in FIG. 4, reaches nearly to the opposite sides 20 of the illuminat-or housing, and is of suflicient length to accommodate the sockets for one end of all the fluorescent tubes incorporated in the lighting fixture. A second socket carrier plate 88, secured to the transverse end housing by screws 90, FIG. 5, carries the sockets for the opposite ends of the tubes. Plates 80 and 88 may be polished to provide light reflective surfaces, if desired.

An additional reflector is indicated at M, which extends the full length of the housing above the lighting tubes. In addition to the screws 82, other screws 94 (FIG. 4) may be anchored into the drilled bosses 96 (FIG. 6) flange 48 of transverse end housing 40, to obtain adequate support for socket plate 80.

As illustrated in the drawings, the tubes T and 12 and ballasts 14 are encased within an elongated, substantially flat housing comprising a top panel 16 having a substantially planar upper surface 18, with marginal longitudinal.

edge portions wrapped downwardly and inwardly to provide opposite laterally spaced side edges 20-20. The open underside of the housing may be closed by a hinged glazed door 22, the hinges of which may be disposed along one edge of the door at the location 24, providing for access to the light tubes and ballasts. The access door preferably is gasketed circumferentiall by means of gasket material 26, to exclude insects, dust, and other foreign materials from the housing interior. The door may be normally held closed by suitable means, such as removable thumb screws or the like 28 threadedly engaging a portion of the housing.

The elongate flattened housing is of opaque material such as sheet metal, and at the side edges 2tl-20 the housing depth is minimal so that the outer surfaces of the ballasts 14 are in close proximity to the housing material, the purpose of this being to carry off and dissipate to atmosphere the heat generated incident to operation of the ballasts. It may here be noted that a pair of light reflectors 30-31) disposed lengthwise of the housing near the side edges thereof, serve to divide the housing into three chambers. The central chamber 34 is the light chamber which confines the fluorescent tubes 12, and this light chamber is flanked by two opposed widely separated ballast or radiation chambers 32, in which the ballasts 1 are housed.

Due to the substantially flat nature of the illuminator housing, the light tubes may be arranged in a common plane which is substantially parallel to the top wall of the housing. All of the light tubes T or 12 are located between the side reflectors Boll-36, and the ballasts 14, isolated from the tube group by the reflectors, are outboard of the tube group and arranged in substantially the same mean plane.

By reason of this arrangement, the ballast heat is afforded maximum opportunity to radiate through the cool extensive walls of the elongate marginal chambers 32, to atmosphere, without directing any appreciable heat to the fluorescent light tubes. Thus, the tube life is ma= terially extended. On the other hand, the ballasts are adequately protected from the heat thrown off by the light tubes, with the result that a materially extended ballast life is ensured. This is of prime importance, due to the high cost of the ballasts and of the skilled labor generally employed in the replacement thereof.

In prior illuminator constructions, the ballasts were invariably located above or beneath the tube group, resulting in overheating both the ballasts and the tubes, and rendering diflicult any servicing of the illuminator and particularly the replacement of ballasts. In the present construction, ballast replacement is no problem, as the ballasts are easily accessible by swinging open the door 22, and removing the side reflectors 30 upon withdrawal of screws 36. In FIG. 7, the characters 38 indicate the customary sockets for mounting the tube lamps.

It may here be noted that the marginal longitudinal edges of the cover panel, turned downwardly and inwardly at the side edges of the fixture as previously explained, may be formed beneath the ballast chambers to provide longitudinal drip ribs 98, the purpose of which is to divert water from the gasketed edges of access door 22. Entry of insects, dust, and other foreign material is effectively precluded by the gasketed connection, as will be understood. It is noteworthy also that the entire illuminator is tightly closed against entry of insects, dust, and the like, because no ventilation for the ballasts is required when they are disposed outboard of the light tube chamber and exposed so fully to the heat dissipating effects of the wrap-around edges of the fixture housing as taught herein.

With respect to FlGS. 1 and 8, it will be observed that the illuminator of FIG. 8 differs from that of FIG. 1 in that it includes but three fluorescent tubes T, requiring only a single ballast 14 at one side chamber of the housing. In FIG. 1, the greater number of fluorescent tubes employed requires two ballasts rather than one, so bal lasts 14 are indicated at both sides of the illuminator housing.

The ballasts, as indicated upon FIG. 4, may be secured within their respective chambers by means of screws or other fasteners 99 passing through the sheet metal of the housing and engaging a mounting flange such as 100, of the ballasts. The screws or fasteners are easily accessible for removal and replacement of the ballasts when necessary, and as previously explained, the reflectors 30 are readily detachable at fasteners 36 for exposing the ballasts in the process of inspection or replacement.

Under numerous tests for safety and efiiciency, the herein disclosed illuminator has been proven far superior to others current in use. For example, whereas according to national standards, fluorescent tube illuminators are considered safe and reasonably efficient as long as the ballast temperature does not exceed 90 degrees C. at an ambient temperature of 80 degrees F., the improved illuminator of the present invention has established a record of only a 57 degree C. ballast temperature under similar conditions. This being well under the 90 degree maximum generally considered safe and acceptable, the illuminator as herein disclosed may be expected to remain safe under extreme high temperature conditions that ould soon disable the prior illuminators. Moreover, the successful reduction of operating temperature as above indicated, assures under normal conditions an extension of ballast and tube life greatly in excess of 50 percent beyond the average life period thereof. As a result, the improved illuminator is much less expensive to operate, and maintenance costs are reduced to a practical minimum.

What is claimed is:

1. In a cantilever type fluorescent lighting fixture, the combination of a rigid end bracket including an upright base and a pair of laterally spaced, substantially parallel tongues extending in a common direction at right angles from one side of said base, an elongate, rigid cantilever beam including channels which are snugly receptive of the spaced tongues of said bracket, means anchoring an end of said cantilever beam to the tongues of said bracket, an elongate, transverse end housing secured to and carried by the other side of the base of said bracket from said tongues, and an elongate, transverse end housing secured to, carried by and suspended from that end of the cantilever beam remote from said bracket.

2. In a cantilever type fluorescent lighting fixture, the combination of a rigid bracket including an upright base and a pair of laterally spaced, substantially parallel tongues extending in a common direction from and at right angles with said base, each of said tongues including a laterally spaced, substantially parallel, inner and outer side face, an elongate, rigid cantilever beam comprising a central U-shaped portion the side walls of which are snugly receivable between the adjacent inner side faces of the tongues of said bracket, the side walls of said central U-shaped portion comprising the inner side walls of a pair of inverted, outer, U-shaped channel portions the outer side walls of which project downwardly over and along the outermost side faces of said tongues, transverse connectors projecting through the overlapping side walls of said cantilever channels and said tongues for rigidly interconnecting said cantilever beam to said bracket, an elongate, transverse end housing secured to and carried by the base of said bracket remote from said tongues, and an elongate, transverse end housing secured to, carried by and suspended from that end of the cantilever beam remote from said bracket.

3. In a tube-lamp type illuminator, the combination of a head element comprising a middle portion and a pair of substanitally coplanar arms extending therefrom in opposite directions, said arms each having a free outer end, an end cap for the illuminator having free outer ends and an intermediate portion, a housing sheet having opposed end edges and opposed side edges, means securing one end edge of the housing sheet to the arms of the .head element, and meanssecuring the opposite end 'edge of said sheet to the end cap, with the end cap and the arms of the head element arranged in substantial parallelism, a head bracket fixed to the middle portion of the head element, and a cantilever beam having one end fixed to the head bracket in position to dispose the opposite end of the beam in close proximity to the end cap of the illuminator, with the housing sheet overlying the beam, and means including the side edge portions of the housing sheet, to provide spaced ballast chambers located one each near'the outer free end of a head element arm.

4. The device as set forth in claim 3, wherein the combination includes means for the support of elongate tube lamps intermediate the ballast chambers aforesaid.

5. In a tube-lamp type illuminator, the combination of a head element comprising'a middle portion and a pair of substantially coplanar arms extending therefrom in opposite directions, said arms each having a free outer end, an end cap for the illuminator having free outer ends and an intermediate portion, a housing sheet having opposed end edges and opposed side edges, means securing one end edge of the housing sheet to the arms of the head element, and means securing the opposite end edge of said sheet to the end cap, With the end cap and the arms of the head element arranged in spaced substantially parallelism, means securing the opposite side edges of the housing sheet to the end capends and to the ends: of the arms of the head element, with the side edges of the housing sheet turned downwardly and inwardly toward one another to form opposed closed sides of the illuminator, a movable access door spanning the closed sides of the illuminator at the inturned side edges of the housing sheet, a head bracket fixed upon the middle portion of the head element, and a cantilever beam having one end fixed to the head bracket in position to dispose the opposite end of the beam in proximity to the end cap of the illuminator, with the housing sheet overlying the beam, a pair of spaced divider members extending lengthwise of the beam, from the head bracket to the end cap, for dividing the space between the closed sides of the illuminator into a pair of spaced ballast chambers and an intermediate light chamber, and means for the support of elongate tube lamps in the intermediate light chamber segregated from the ballast chambers.

6. The device as set forth in claim 5, wherein the side edges of the housing sheet in the vicinity of the access door are deformed longitudinally, to provide inverted ribs serving as drip lips diverting water from the access door.

7. A tube-lamp type illuminator comprising a frame including a head element having a middle hub portion and a pair of substantially coplanar arms extending from the hub portion in opposite directions, a head bracket fixable to the hub portion and comprising a rigid one-piece casting, said casting having an upright base apertured to receive fasteners connecting the base to the hub portion of the head element, a pair of spaced substantially parallel tongues extending in a common direction laterally from the upright base, a double-channel rigid elongate cantilever beam of substantially greater length than the tongues, the channels of the beam being snugly receptive of the spaced tongues of the head bracket, and means for securing corresponding ends of the channels to the tongues.

8. The device as set forth in claim 7, wherein the combination includes an end cap secured in suspension upon the remaining end of the elongate rigid beam.

9. A tube-lamp type illuminator comprising a frame including a head element having a middle hub portion and a pair of substantially coplanar arms extending from the hub portion in opposite directions, a head bracket comprising a rigid one-piece bracket, said bracket having an upright base, means securing the base of said bracket to the hub portion of the head element, a tongue extending laterally from the base at approximately a right angle thereto, a rigid elongate cantilever beam of substantially greater length than the tongue, and means for securing one end of the beam to the tongue lengthwise thereof to form a spine for the illuminator.

10. In a cantilever type fluorescent lighting fixture, the combination of a rigid mounting bracket including a base and a tongue extending from and at right angles with said base, an elongate, rigid cantilever beam including portions which are receivable in the tongue of said bracket, transverse connectors rigidly interconnecting said cantilever beam to the tongue of said bracket, an elongate, transverse end housing secured to and carried by the base of said bracket, and an elongate, transverse end housing secured to, carried by and suspended from that end of the cantilever beam remote from said bracket.

11. A tube-lamp type illuminator comprising a frame including a head element having a middle hub portion and a pair of substantially coplanar arms extending from the hub portion in opposite directions, a head bracket comprising a rigid upright base and a tongue extending at right angles therefrom, a rigid elongate cantilever beam of substantially greater length than the tongue, means for securing an end of the channel to the tongue, and means securing the head element to said head bracket.

12. The fluorescent lighting fixture as defined in and by claim 10 and wherein the casing is divided into a central compartment extending substantially throughout the length thereof wherein a plurality of fluorescent light tubes in substantial side-by-side relationship are disposed and at least one ballast compartment isolated from the tubes and outboard of the tubes.

13. In an elongate, cantilever, fluorescent lighting fixture for outdoor area-lighting use, the combination of a pair of rigid, transverse end members having top, side and bottom portions; an elongate, rigid cantilever beam providing a mounting for the fixture; means securing said transverse end members to said beam in longitudinally spaced relation; an elongate, wide, flat housing for the fixture having top, side and inturned bottom walls; means securing opposite ends of the top, side and inturned bottom walls of said housing to and embracing corresponding portions of said end members with the marignal, longitudinal edge portions of the housing extending around the sides of said end members and inwardly one toward the other to form elongate, enclosed radiation chambers freely projecting into the atmosphere at the sides of the housing; the spacing of the inner edges of the bottom walls of said radiation chambers terminating in opposed, aligned, spaced relationship providing a central chamber therebetween adapted to receive fluorescent light tubes; means attached within and at opposite ends of the central chamber to support fluorescent light tubes longitudinally of the housing and in substantial transverse alignment with said radiation chambers; longitudinally extending wall closure means within said housing on opposite sides of said beam extending along and spaced inwardly from the side walls and engaging the top wall and the said inner-edge-adjacent portions of the bottom walls of the housing for defining opposed sides of the elongate central chamber; elongate electrical ballast means having major heat radiating surfaces within at least one of said radiation chambers; and means securing said ballast means in a radiation chamher with major heat radiating surfaces of the ballast in substantially close heat-conducting relationship with the enclosing walls of said radiation chamber.

14. A fluorescent lighting fixture as defined in and by claim 13, wherein the housing overlies the cantilever beam, and wherein the interior height dimension of the radiation chambers closely approaches the height dimension of a ballast received therein.

References Cited in the file of this patent UNITED STATES PATENTS 2,511,440 Long June 13, 1950 2,717,307 Bjontegard Sept. 6, 1955 2,835,788 Phillips May 20, 1958 2,886,699 Harling May 12, 1959 2,914,657 Akely et al Nov. 24, 1959 2,932,728 Thomas Apr. 12, 1960 3,009,054 Thomas Nov. 14, 1961 3,013,146 Florence Dec. 12, 1961

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