US2726319A - Fluorescent lighting fixture - Google Patents

Description

Dec. 6, 1955 L.. c. WILLIAMSON 2,725,319

FLUORESCENT LIGHTING FIXTURE Filed April 24, 1955 2 Sheets-Sheet 1 FIG. 2.

INVENTOR, LESTEIQ 0. W114; I4M80Al,

Dec. 6, 1955 1.. c. WILLIAMSON 2,726,319

FLUORESCENT LIGHTING FIXTURE Filed April 2 1953 2 Sheets-Sheet 2 INVENTOR. LE s TEE 0. WI 4 MMso/v,

United States Patent FLUORESCENT LIGHTING FIXTURE Lester C. Williamson, Indiana, Pa.

Application April 24, 1953, Serial No. 350,922

1 Claim. (Cl. 240-9) This invention relates to lighting fixtures using'lamps of elongated tubular shape, such as fluorescent lamps,

and more particularly to a fixture having a vdetachable cover of resiliently flexible sheet material and means for holding the cover in place relative to the remainder of the fixture.

It is among the objects of the invention to provide an supporting structure, such as a building will or ceiling,

which has end caps of partly conical shape which facilitate mounting the fixtures in multiple to provide various geometrical patterns; which may also include end caps of partly cylindrical shape where it is desired to provide the fixture with an end wall substantially at right angles i to the longitudinal center line of the fixture; which 'includes means for mounting a lamp tube on the mounting strip and supplying electric current to the lamp tube; and which is simple and-durable in construction, economical to manufacture, easy to install and of ornamental appearance.

Other objects and advantages .will become apparent from a consideration of the following description and the appended claimin conjunction with the accompanying drawings, wherein:

Figure 1 is a bottom plan view of a lighting fixture illustrative of the invention;

Figure 2 is a side elevational view of lighting fixture illustrated in Figure 1;

Figure 3 is a transverse cross sectional view on the line 3-3 of Figure 2;

Figure 4 is a fragmentary longitudinal cross sectional view on the line 4-4 of Figure 3;

Figure 5 is a fragmentary longitudinal cross sectional view on the line 5-5 of Figure 1;

Figure 6 is a bottom plan view of a group of lighting fixtures illustrative of the invention arranged in a geometrical pattern;

Figure 7 is a fragmentary longitudinal cross sectional view of a modified form of lighting fixture illustrative of the invention;

Figure 8 is a transverse cross sectional view on the line Y constituting an operative component of either form of lighting fixture;

Figure 12 is a perspective view of an end cap constituting an operative component of the form of the invention shown in Figures 1 to 5, inclusive, and

Figure 13 is a perspective view of an end cap constituting an operative component of the form of the invention shown in Figures 7 and 8. I

With continued reference to the drawings, the lighting fixture comprises a sheet metal mounting strip 10 of elongated, rectangular shape having a flat web 11 and inwardly turned flanges 12 and -13 extending one along each side edge thereof and providing inwardly opening, mutually opposed grooves extending longitudinally of the respectively opposite side edges of the mounting strip. The mounting strip is adapted to be mounted with the side of the web 11 thereof remote from the flanges 12 and 13 disposed against the surface of a supporting structure, such as a building wall or ceiling, and is provided with longitudinally spaced apart apertures, some of which receive screws, as indicated at 14, by means of which forks, as indicated at 15, are secured to the web of the mounting strip and extend perpendicularly from the side of the web adjacent the flanges 12 and 13 one near each end of the fixture to support an associated lamp tube 16 in parallel and spaced relationship to the adjacent side of the web of the mounting strip. The tube is secured to the forks 15 by suitable binders, not illustrated, and connector means, as indicated at 17 in Figure 7, extend through other apertures in the .web of the -mounting strip to carry electric current to the opposite ends of'the tube -16.

As the tube 16, the means for mounting the tubeon the mounting strip and the means for supplying electric current to the tube are well known to the art, a more detailed illustration and description thereof is considered unnecessary for the purposes of the present disclosure.

The fixturealso includes a cover 1-8 which is provided by a rectangular body of resiliently flexible sheet material, such as a cellulose acetate or a synthetic resin material, having-light transmitting properties. This cover-is provided in a flat,channel-sha ped condition, as illustrated in Figure 11, having a flat web 19 and flanges 20 and 21 upstanding from the web one along each longitudinal edge of the web.

In the arrangement illustrated in Figures 1 to "5 inelusive the flat cover 18 is transversely curved to a substantially semi-cylindrical shape with the convex sideof the web portion 19 at the side of this web portion from which the flanges 20 and 21 extend and the flanges 20 and 21 of the cover are engaged in the grooves provided by the flanges 12 and 13 of the mounting strip 10, as

illustrated in Figure 3. The resilient nature of the cover maintains the cover flanges pressed firmly into the grooves provided by the mounting strip flanges to retain the cover in position on the mounting strip and also provides .for the easy removal of the cover from the mounting strip when desired.

The connection between thecover and the mounting strip is further reinforced by resilient sheet metal .bands,

.as indicated at 23 and 24, which extend around the cover 18 at the respectively opposite ends of the cover and have offset end portions engaged in the grooves providedby the mounting strip flanges.

The ends of the fixture are closed by end caps,one of which is generally designated at 25, and the other at 26. The end cap 25 is formed of suitable sheet material, such as sheet metal, and has a portion 27 of partly conical shape and a portion 28 of partly cylindrical shape at the larger end of the partly conical portion 27, i

a stiffening bead formation 29 being provided in the end cap 25 between the portions 27 and 28. The partly Patented Dec. 6, 1955 p 3 cylindrical portion 28 is disposed between the band 23 and the adjacent end portion of the cover 18 so that the band holds the end cap in place on the corresponding end of the cover.

In the arrangement illustrated in Figures 1 to 5 inclusive, the cover is bent to substantially semicylindrical shape, as explained above, and in this form of the invention the web 11 of the mounting strip has a width substantially equal to the diameter of the cylinder of which the shape of the cover constitutes one-half and the end cap 25 has a substantially semicircular transverse cross sectional shape but has its side edges spaced from the plane of the web of the mounting strip 10. A rowel shaped button 30 is disposed adjacent the small end of the end cap 25 and is provided with a central aperture receiving the head portion of a screw fastener 31 by means of which the button is attached to the supporting structure on which the fixture is mounted and held in spaced relation to the surface of such supporting structure. The button has a plurality of spike or petal formations 32 radiating outwardly from the central portion of the button at substantially equal angular intervals around the central portion and angularly oflset relative to the central portion so that they lie substantially in the surface of a flat truncated cone. Each of these spikes has an aperture near its outer end and one of the spikes is disposed in overlapping relationship to the smaller end portion of the end cap 25 and secured to the end cap by a screw 33 extending through the aperture in the button spike and through a registering aperture in the end cap 25 near the smaller end of the latter Both end caps of each fixture may be of the form of the end cap 25, as described above, and the fixtures may be arranged in multiple in geometrical patterns, as illustrated in Figure 6, with the smaller ends of adjacent conical end caps connected together by corresponding buttons 30.

The reinforcing bands 23 and 24 may, if desired, be provided with centrally located small holes, as indicated at 34, for the insertion of a wire probe for testing the condition of cold cathode lamp tubes.

The end cap 26 is of partly cylindrical shape having a fiat end wall 35 provided with a central opening 36 and having a marginal flange 37 disposed substantially perpendicular to the end wall and disposed between the band 24 and the outer surface of the adjacent end portion of the cover 18. The flat end caps 26 are used only when it is desired to provide a flat end wall substantially at right angles to the longitudinal center line of the fixture as where a ballast device or transformer is to be mounted between the opposed ends of two adjacent fixtures or two fixtures are to be disposed with their adjacent ends in abutting relationship. Where the end cap 26 is disposed at one end of a ballast device, a bushing 38 of electrically insulative material is mounted in the opening 36 in the end wall 35 of the end cap and releasably secured in the opening by suitable means, such as the annular flange 39 at the outer side of the end wall and a garter spring 40 disposed in a groove in the bushing at the inner side of the end wall. A suitable connector may extend through the insulating bushing 38 to connect the ballast device to the adjacent end of a lamp tube mounted in the corresponding fixture.

The modified form of the invention illustrated in Fig- 1 ures 7, 8 and 10 is substantially the same as that illustrated in Figures 1 to 5 inclusive and described above except that in the modified arrangement the mounting strip 42 has a width materially less than the width of the mounting strip 10 used in the first described form of the invention and the cover 44 in the modified arrangement is bent to a more nearly cylindrical shape than the semi-cylindrical shape of the cover 18. The conical end caps 45 of the modified form are also transversely curved to a more nearly cylindrical shape corresponding to the transverse cross sectional shape of the cover 44 and the flat end caps, if used, would be correspondingly shaped.

In the modified arrangement the mounting strip 42 has a fiat web portion 46 and inwardly inclined flanges 47 and 48 providing grooves receiving the flanged edges 49 and 50 of the cover 44 in the manner described above, and reinforcing bands, as indicated at 51, extend around the end portions of the cover 44 and around the corresponding end portions of the end caps and are engaged at their ends with the flanges of the mounting strip to reinforce the connection between the cover and the mounting strip and hold the end caps in place relative to the cover. The conical end caps are also secured at their smaller ends to rowel-shaped buttons 30, as described above, secured to the supporting structure by suitable screw fasteners 31.

The metal portions of the fixture, such as the reinforcing band and end caps may be suitably colored or otherwise ornamented to provide an ornamental appearance for the fixture and the covers may be of transparent or translucent material and may be colored, if desired.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claim rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claim are, therefore, intended to be embraced therein.

What is claimed is:

A lighting fixture comprising an elongated mounting strip of channel shape and having an inwardly turned flange extending along each side thereof adapted to be secured to a supporting structure, a cover comprising a rectangularly shaped body of resiliently elastic light transmitting sheet material engaged along its side edges with the inner sides of the flanges of said mounting strip and transversely curved to a partly cylindrical shape, end caps receiving the corresponding ends of said cover, means connecting said end caps to said mounting strip to hold said cover in place on the mounting strip, at least one of said end caps comprising a sheet material body having a portion of partly cylindrical shape receiving the adjacent portion of said cover and a portion of partly conical shape extending from said portion of partly cylindrical shape outwardly of the adjacentend of said cover, and a rowel shaped button disposed adjacent the smaller end of said one end cap having one spike formation thereof secured to said one end cap and the other spike formations thereof capable of securement to end caps of similarly constructed lighting fixtures.

References Cited in the file of this patent UNITED STATES PATENTS 1,963,218 Wakefield June 19, 1934 1,997,687 Hoegger Apr. 16, 1935 2,269,182 Claspy et al Jan. 6, 1942 2,348,930 Schepmoes May 16, 1944

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