US2381630A - Lighting fixture - Google Patents

Description

Aug- -7, 1945- G; P. WAKEFIELD LIGHTING FIXTURE FiIed Sept. 1s, 1942 FIE-.3

INVENTOR. GEORGE RWAKEFIELD ATTORNEYS Patented Aug. 7, 1945 UNITED- STATES PATENT OFFICE LIGHTING FIXTURE GeorgeP. Wakefield, Vermilion, Ohio, assignor to The F. W. Wakefield Brass Company, Vermilion, Ohio, a corporation of Ohio Application September 16, 1942, Serial No. 458,525

"2'Claims. (01.240-78) The present improvements, relating as indicated to lighting fixtures, have more particular regard to lighting fixtures designed tobe fitted with elongated tubular illuminators, such as the so-called fluorescent tubes which are coming into extensive use particularly as a medium for interior illumination.

Most fixtures designed thus to be-fitted with tubular illuminators of the type in question have been merely adaptations of fixtures such as have heretofore, been employed in connection with the more familiar incandescent lamp bulb. This is particularly true as to the means provided for supporting'the illuminating units and the light diffusing elements which take the place of the old-fashioned globe and reflector. A problem is also presented by reason'of the difierence in wiring connections required for fluorescent units, and provision has to be made for various accessory devices. r l

The object of the present improvements accordingly is to provide in the'firstplacea simple, compact, frame or chassis wherein illuminating units of the tubular type may .be readily inserted and removed. A further object is to provide a simplified system of wiring in connection with such frame whereby current may be properly conducted to the units, of which a plurality is generally utilized. Still another object-is to provide a frame or chassisiwhich will be readily adaptable to the support of various-types and constructions of light diffusing means suitable for use in fluorescent lighting. I i

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described1 and particularly pointed out in the claims.

,The annexed drawing and the following de scription set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various-mechanical forms in which the principle of the invention may be used.

In said annexed drawing:

Fig. 1 .is a perspective viewseen from below and to the right of a lighting fixture embodying my present improvements;

Fig. 2 is a broken top plan view of one end of such fixture;

Fig. 3 is partially an end elevation from the inside and partly a transverse section of the portion of the structure shown in Fig. 2, the plane of the section being indicated by the line 3-3, Fig. 2;

Fig. 4

is a simplified diagram of the wiring connections showing the manner in which the circuits to the respective illuminators may be closed in desired sequence, as is necessary where a plurality of fluorescent lighting units is to be supplied from a common source of current; and

Fig. 5 illustrates a detail modification.

The main frame I of my improved fixtur is of elongated trough-like form, as best shown in Fig. 3, and will preferably, although not necessarily, be fashioned of sheet metal, the over-all length of said member being substantially the same as that of the tubular fluorescent units 2. The fixture illustrated, it should be noted, is designed to carry four such units or illuminators, two being located in spacedrelation on each side of such main frame member I. The lower side walls 3 of the latter Will desirably be inclined towards each other and provided with exterior reflecting surfaces. Said main frame member is also provided with a removable upper portion 4 which constitutes a cover, upon removal of which access to the interior of the main frame member maybe readily had. The means whereby the main frame member, and. thus the fixture as a whole, is suspended from the ceiling are not shown since these may be of any desired form' and will vary depending upon whether the fixture is tobe suspended below the ceiling or attached directly thereto. In the latter case the cover member 4 may, if desired, be omitted.

To each end of said main frame member I are secured oppositely extending arms 5, each such pair ofarms constituting, in effect an integral cross-head and preferably'being molded solidly ofa suitable dielectricplastic material. Such paired arms or cross-head may be permanently attached to the ends of main frame member I at the time they are thus molded, or the ends of the latter may be attached thereto by screws or like fastening means (not shown). 'In any event, conductors 6 will be molded in place in such arms 5, such conductors leading from binding posts or screw terminals 1 on that portion of the inner face of the arm which lies within hollow main frame member I, to spaced pairs of contacts 8 on the upper face of the arm. These contacts form seats whereon the terminals za of the corresponding tubular illuminators 2 will rest when the fixture is assembled and thus serve both to support the latter and provide the necessary electrical connections therefor.

Each pair of terminals 2a are secured as usual in the'corresponding end of the illuminator and when in circuit serves to conduct current to a corresponding filament 21). It isconsideredun necessary to show the complete circuit arrangement as this is well illustrated. The current to the several conductors 6, which thus in turn supply to the terminals 20. of the several illuminators, will be brought to the fixture through suitabl leads and the usual thermal starting unit (not shown) which may be conveniently housed in the hollow main frame member I, whether the latter be suspended from or attached directly beneath a ceiling.

In order to facilitat the placement and removal of the illuminators in the fixture with their terminals thu supported on cross arms 5, the

upper portions 9 of the latter are; longitudinally split in a horizontal plane coincident with the seats 8. Such upper portion 9, when held in place by spring clips 9a, or equivalent means, will serve to securely retain the illuminating units against displacement, but by releasing and lifting off such upper portions of the arms the units are immediately rendered accessible for removal.

Since in operation of fiuorescent lighting units thefilaments of the several tubular illuminators will require to be individually preliminarily heat' ed before the high voltage current is supplied to the illuminator, the special switching arrangement diagrammatically illustrated in Fig. 4 is provided. As there shown, a series of paired contacts ID are so arranged, e. g.in a circle, so that a rotatin switch member I I may successively connect pairs of said contacts which are in turn connected by conductors I! with the binding posts I at the respective ends of the main frame member I, the arrangement being such that each pair of conductors 6, which are intended to supply cur rent to the respective illuminating units, are successively thus supplied first with the necessary current for heating the filaments and then with the high voltage current which produces the discharge from one filament to the other,causing the unit to glow.

The switch ll may be conveniently located centrally in the hollow main frame member so as to beperable through an opening l3 in the bottom wall thereof by means of a detachable operating tool M (see Fig. 1). r As previously indicated, my improved lighting fixture is designed to be utilized with various typesand constructions of light diffusing means. By wayof illustration there is shown in dotted utli'nein Fig. 1 and in broken section inFigs. 2 and 3 a familiar formof such light difiusing means comprising translucent side panels l5, endplates IG'and a louver assembly l carried in the lower portion of the box-like structure formed by-said side panels and end plates. While the latter are shown as separate parts held together by frame members 18, they may, if desired,"be moldedout of suitable plastic material in the form of a unitary structure.

In any event, the structure inclusiveof' the elements just described will be of such size and shape that it may be fitted over and enclose the frame of the fixture heretofore described, together with the several illuminators carried by the latter. In order to hold such light diffusing means in place, the component end plates I6 will be detachably secured by screws or like means [8 to the cross arms of thefixture frame. The entire light diffuser member, whatever its particular construction and whether it consists merely of translucent walls or include a louver, reflectors and the'like, may thus be readily attached to and detached from the frame as an independent unit.

In lighting fixtures of the type described where a plurality of tubular illuminators is employed, it is sometimes considered desirable to dispose such illuminators at different elevations. My improved construction of frame may be readily adapted to such arrangement of the illuminators by a modification in the form of the cross arms at the ends of the main frame member. Thus, as illustrated in Fig. 5, such modified. cross arm 20 has its upper face formed with steps 2| and 22 which lie on different levels and. the upper cover portion 23 of the arm is made of complementary form. By locating the contacts 8, vwhereon the ,terminals of the illuminator when in place areseated, on the steps, such illuminators will be held in the fixture frame at correspondingly different elevations.

From the foregoing description of the construction and assembly of my improved fixture, it will be seen that the component elements of the frame are of simple, yet sturdy, construction and that they may be readily fabricated and assembled either in the factory, or, if shipped in knocked-down condition, on the job. When in use the insertion and removal of the tubular lighting units is an extremely simple matter and can be accomplished without'the' use of any tool wherever the fixture is supported so as to be accessible from above. At the most, the light diffusing structure'only will require to b removed in order to get access to the cross arms whereon'the illuminatorsflare supported, Such light diffusing structure, it will be noted, instead of being made up" ofparts separately attached to the frame, constitutes an' independent structure which may be attached and removed in its entiretminclusive of side panels, end'walls and louver, where the latter is utilized.

It is noted that certain general features of construction disclosed but not claimed herein are presented in my co-pending application filed November 15, 1944, Serial No.'563,483,

Other modesof'applying the principle of my invention maybe employed instead of the one ex-' plained, change being made asregards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

' "I therefore particularly point out and distinctly claim as my invention:

l. Ina lighting fixture of the type designed to be fitted with elongated, tubular illuminators having projecting terminals at their respective ends, the combination of an elongated hollow, main frame member approximately th same length as such illuminators, the upper portion of said main fram'emember being in the form of a removable cover to permit access to the interior thereof, a cross arm of solidly'molded di-electric plastic material se'curedto each end of said main member,'spaced seats 'on' the upper faces of said arms constituting electrical contacts adapted di-' rectly to receive th terminals on the corresponding ends of a plurality of such illuminators upon downward placement thereof and thereby support the latter in substantially parallel relation, conductors embedded in said arms and extendin from within th respective ends of said main frame to said seats, respectively, and member removably secured to'saidarms adapted to retain such illuminator terminals in place on their seats. a r 2. In a lighting fixture of the type designed to be fitted with elongated, tubular illuminators,.the combination of an elongated main frame member of approximately the sarne length as such illuminators, laterally extending arms secured to each end of said main frame member and adapted to engage the corresponding ends of such illuminators and thereby support the latter in substantially parallel relation, said arms having upper removable hold-down portions to cooperate with the ends of the illuminators and an independent unitary light difiusing structure including translucent side panels, end walls and a louver, said end walls being adapted to over-lie the ends of said main fram member and said arms, and detachably secured thereto. GEORGE P. WAKEFIELD.

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