US2977460A - Lighting unit - Google Patents

Description

March 28, 1961 K. FRANCK LIGHTING UNIT Filed June 12, 1957 M a a T 7m P 2 LIGHTING UNIT Filed June 12, 1957, Ser. No. 665,245

8 Claims. c1. 240-9 .This invention relates to a supporting member, having a cross-sectional shape substantially resemblingan inverted T, used to support light refracting plates.

It is an object of this invention to provide a transparent supporting member that will support adjacent refracting plates and will refract light passing through it.

It is a further object of this invention to provide the vertical light incident surfaces of the supporting member with light refracting means so that light fallingon the vertical light incident surfaces will be emitted from the vertical light emitting surfaces of the supporting member in directions low enough to prevent glare.

It is yet another object of this invention to provide a horizontal cross member integrally connected to the vertical member with light incident surfaces that are smooth and with light emitting surfaces having light spreading means.

Other objects of my invention will hereinafter appear in the specification taken in connection with the following drawings in which the same numerals, with prime marks added, indicate like parts.

Fig. 1 is a plan view showing the invention in use;

Fig. 2 is a perspective view of one embodiment of my invention;

Fig. 3 is a fragmentary bottom view of the invention illustrated in Fig. 2;

Fig. 4 is a perspective view of a modification of the invention;

Fig. 5 is a fragmentary bottom view of the supporting member illustrated in Fig. 4;

Fig. 6 is a fragmentary sectional view taken along line 66 of Fig. 4 in the direction of the arrow;

Fig. 7 is a perspective view of a further embodiment of the invention; and

Fig. 8 is a fragmentary bottom view of the structure illustrated in Fig. 7.

In Fig. 1 the light source, illustrated as a series of fluorescent lamps 10, is suitably mounted to ceiling 12. By means of brackets 14, rods 16, clamping members 18 and support members 20, a series of refracting plates 21, 22 and 23 are suspended from the ceiling to rest upon the flanges or base 24 of the support member 20. Since the detailed construction of plates 21, 22 and 23 do not form any part of this invention, no detail de-v scription of them will be herein included.

The supportmember 20 (Fig. 2) has a substantially horizontal base 24, a substantially vertical body portion 26 integrally connected to the base, and a knob portion 28 at the upper extremityof body 26 integrally connected to the body and extending the full length of member 20. Referring to Fig. 2, it is seen that the cross-sectional shape of this supporting member substantially resembles an inverted T wherein the horizontal base 24 corresponds to the cross member of the T and the vertical body 26 corresponds to the vertical member of the T.

Body 26 (Fig. 2) is formed by a series or plurality of super-imposed prisms 40 extending laterally the full length of member 20. The upper extremity 42 of body 26, below the knob 28, is smooth, however, for apurpose to be hereinafter described.

Light entering one side of body 26from the light source 10 will be refracted downward by prisms 40 and emitted from the opposite side of body 26 in directions low enough to prevent glare. Thus, the light, depressed by prisms 40, is pre-controlled near the flanges or plates 21 and 22 (i.e., where they rest on the T-bar surface 48) through which the light might escape directly through the vertical portions of the flanges.

The flange member or base 24 of support member '20 has a smooth light incident surface 48 upon which-the refracting plates 21, 22 and 23 will rest. In order that anyone taking a direct view from beneath one of these support members upwardly towards the light source will not receive the direct glare of light source 10, the light emitting surface 50 of base 24 has a plurality of prisms 52 arranged parallel to the long axis of the support member. These prisms act to distribute light passing through base 24, so as to reduce the glare. i

The clamping member 18 is composed substantially of two U-shaped members 60 and 61 (Fig. 1) adapted to be connected by means of a screw 64 extending through members 60, 62.

The lower extremities 62 and 63, upon loosening of the screws 64, will fit over the knob 28 (Fig. 2) of the support member 20 and engage the surface 42 of body 26. When tightened, the knob 28 will be held upon' the extremities 62, 63 of clamping member18. It being understood that other means other than that-described hereinabove for securing the upper extremity of support member 20, could also be employed.

Another embodiment of my invention is illustrated in Figs. 4, 5 and 6. tions or flutes have been formed upon the body 26' of support member 20'. larly to the prisms 40 hereinabove described in that they spread the light passing through the body 26. The light emitting surface 50' likewise has a plurality of prisms 52, however, in this modification, these prisms run substantially perpendicular to the body 26- so as to give a If desired, in addilongitudinal spreading of the light. tion to prisms 52 and in the ridges formed by prisms 52, a second row of prisms 72 (Fig. 5) may be added,

rib projections rather than running vertically, up and down the side of the body 26" run substantially horizontally one above the other, the full lateral length of the body 26" and scatter or spread the light over the light incident surfaces of refracting plates 21, 22, 23.

Likewise, on the light emitting surface 50" of this modification is a plurality of prisms 52", similar to the prisms 52 of Fig. 2 hereinabove described, to spread light emerg f ing from light emitting surface 50".

A material of manufacture giving excellent results has been found to be clear acrylic plastic, however, other clear plastic or transparent materials could be used with out departing from the spirit of this invention. The plastic support members themselves can be made from a mold or, if desired, formed by an extrusion process.

I have hereinabove described what I consider to be the best embodiments of my inventions. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. In a lighting unit including a light source, a

In Fig. 4, a series of convex rib por- These rib portions 70 act simi- I amass transmitting member below said light source, and a supporting clamp member extending downwardly adjacent an edge of said light transmitting member, the improvement comprising a transparent support member for said light transmitting member having a cross sectional shape substantially resembling an inverted T and including a substantially horizontal base portion supporting an edge of said light transmitting member, a substantially vertical body portion extending upwardly from said base portion intermediate the width thereof, and a widened knob portion at the upper end of said body portion held by said clamp member, said vertical portion including prism means on the side adjacent said light source and said base portion including prism means on the bottom face thereof,.said prism means on said body portion and said base portion being arranged to direct light incident thereon in directions low enough to prevent glare.

2. A support member as in claim 1, wherein said prism means includes a plurality of parallel prisms on said base portion formed parallel to the plane of the vertical body portion and running the full length of said base portion.

3. A support member as in claim 1, wherein said prism means includes a plurality of parallel prisms on said base portion extending perpendicularly to the plane of the vertical body portion.

4. A support member as in claim 3, wherein said prism means on the base portion includes an additional single row of prisms positioned between the ridges of two rows of said plurality of parallel prisms, said second single row of prisms on the light emitting surface being parallel to the plane of said vertical body portion.

5. In combination with a light source, a light transmitting plate below said light source, and a depending clamping member, a transparent substantially T-shaped supporting and retracting member, said member including a substantially horizontal base portion supporting an edge of said light transmitting member and a substantially vertical body portion joined to said base portion intermediate the width thereof and substantially coextensive in length therewith, said vertical body portion including a widened knob portion at the top held by said clamping member, said body portion and said base portion having glare reducing surfaces including prism means thereon to direct light incident on said surfaces in directions to prevent glare in a location beneath said member.

6. In the combination according to claim 5 wherein said prism means includes a plurality of rows of prisms on the bottom face of said base portion.

7. In the combination according to claim 5 wherein said prism means includes a plurality of substantially horizontal rows of prisms on said body portion.

8. In the combination according to claim 5 wherein said prism means includes prisms arranged to spread light in lateral directions.

References Cited in the file of this patent UNITED STATES PATENTS Cullen June 17, 1958

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