US 3448260 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
June 3, 1969 v. s. WINCE ET AL 3,448,260
LUMINAIRE Filed April 6, 1966 Y Sheet oi 4 I 1 l 2/ 1U."-
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. LUMINAIRE Filed April 6, 1966 Sheet 3 INVENT Rs MEAPL S. livcfi ATTORNEYS June 3, 1969 v. s. WINCE ETAL LUMINAIRE Sheet 4 of 4 Filed April 6, 1966 INVENTORS 14-1424 ,5? h m/az yzleaierfl. 0.045 %%#M ATTORNEYS United States Patent US. Cl. 240-93 14 Claims ABSTRACT OF THE DISCLOSURE A luminaire for mounting upon a wall and having a refractor providing front, bottom and end panels for redirecting light from a light source within the luminaire and from a reflector positioned behind the light source. The prismatic elements of the panels include curvilinear prisms and flutes on the front panel, these being concentric and formed about a center below the panel, curvilinear prisms on the side panels intermediatte horizontal and vertical prisms thereon, and curvilinear prisms on the bottom panel for exploding down light. The side panels also include .a fluted lower section. The reflector in vertical section provides parabolic contours and in horizontal section arcuate sections, the inner ends of which lie along a common are of a circle. The inner surfaces of said panels being provided with prisms and flutes to assist in the efiicient redistribution of light from the luminaire.
The present invention relates generally to an improved luminaire, and in particular to a luminaire for mounting to the outside vertical wall of .a building, to illuminate the area adjacent the building, such as parking, loading, play areas, etc.
It is a general object of this invention to provide an improved refractor offering improved light distribution over the desired area.
The use of the inventive refractor in combination with a reflector results in the light being directed into a useful, substantially rectangular area of light distribution, and away from the non-useful areas, over which much of the light was distributed by prior art luminaries.
It is a further object of the present invention to provide a luminaire which affords economical and different utilization of light energy, for illuminating relatively large outdoor areas.
It is yet a further object of this invention to provide comfortable and uniform illumination over the desired area by a specially designed reflector, and through the use of a novel prismatic design of the refractor of the luminaire.
In accordance with these objects the present invention provides a reflector arranged within the luminaire which intercepts substantially all the light which is not otherwise directed to the refractor, which is disposed adjacent the reflector. This combination is adapted for use with an elongated light source such as a mercury lamp and directs the light produced thereby outwardly and downwardly from the building to provide illumination over the desired area.
The refractor includes a front face which comprises curved prisms on the upper section of the front panel thereof which concentrates the light in the beam direction by providing light re-direction having both vertical and lateral components. The lower portion of the front face of the refractor receives light at beam angle from the reflector as well as direct light from the light source. This lower portion is provided with concentric flutes which do no redirecting of the light, but serve to diffuse the light to eliminate streaks and striations.
The inner wall of the refractor front face comprises vertical fluted prisms which spread the light rays incident thereon to make the refractor completely luminous when viewed from any normal viewing angle.
The refractor end panels are provided with internal vertical flutes for horizontal diffusion of light, and outside horizontal prisms at the upper portion thereof for concentrating the direct light into beam direction, which proceed through a series of curvilinear prisms to a series of vertically oriented prisms at the lower section, for concentrating direct and reflected light away from the building wall. The end panels further comprise horizontal flutes in the lower forward corner which receives and diffuse the reflected light incident thereon.
The inner surface of the refractor bottom panel comprises curved prisms which direct reflected and direct light both laterally and away from the wall, and then explode or push out the light in all directions.
The reflector comprises, in vertical section, at least two sections, the lower section being substantially parabolic to concentrate reflected light into a parallel beam at about 70 degrees from the vertical onto the lower portion of the refractor while the upper section spreads light vertically from the beam direction to nadir, and directs this spread beam onto the lower portions of the refractor.
The reflector, in horizontal section, includes at least two arcuate sections which serve to laterally spread the light so that .at almost any viewing angle the luminaire appears to be filled with light.
In another possible embodiment of the present invention, the reflector is adapted to be used with an elongated light source, in which configuration the reflector comprises in horizontal section more than two arcuate sections, which laterally spread the light.
The objects .and attendant advantages obtained by the use of this invention will be better understood by reference to the following detailed specification when considered in connection with the accompanying drawings, in which:
FIG. 1 is an elevational view of the front panel of the refractor, with the dashed portion indicating various sections of prisms and flutes;
FIG. 2 is a top plan view, partly in section, of the luminaire, showing the horizontal cross section of the reflector and typical ray paths of light emanating from the light sources as reflected by the reflector;
FIG. 3 is a side view, in section, of a luminaire showing the reflector in vertical section, and indicating typical ray paths of light;
FIG. 4 is a side elevational view of a luminaire showing the prismatic construction of the outside surface of the end panel;
FIG. 5 is an elevational view of the inner surface of .an end panel of the refractor;
FIG. 6 is an elevational view of the prism construction of the inner surface of the front panel of the refractor;
FIG. 7 is a top plan view showing the prismatic structure of the bottom panel of the refractor;
FIG. 8 is a detailed view, in section, taken across lines 8-8 of FIG. 7;
FIG. 9 is a sectional view, in detail, taken along lines 9-9 of FIGS. 5 and 6;
FIG. 10 is a view, in section, taken along lines 1010 of FIG. 1;
FIG. 11 is a view, in horizontal section, showing another embodiment of a reflector which may be used with an elongated light source in a luminaire of the type described;
FIG. 12 is a vertical section of the reflector shown in FIG. 11; and
FIG. 13 is a photometric chart showing typical illuminating distribution patterns which may be achieved by the use of two embodiments of the inventive luminaire.
Referring now to the figures and in particular to FIGS. 1-10, the luminaire comprises a glass refractor and a metallic reflector 12 which is disposed rearwardly of the refractor.
The reflector shown in FIGS. 2 and 3 consists, in vertical section, of lower sections 14 and upper section 16.
'Lower section 14 is substantially parabolic in vertical section. The light from light source LJC. is reflected from section 14 into a parallel beam at main beam direction, i.e. approximately 70 from nadir, as illustrated by rays f-f' and j-j'. This parallel beam of light is reflected onto an area I of refractor '10 shown in FIG. 1 which shall be more fully discussed below.
Section 16 of reflector 12 operates as a fill-in section and distributes the light by spreading it vertically between the beam angle down to nadir. This section of the reflector is so designed to reflect the light from the light source, as illustrated by the ray traces e-e and aa' shown in FIG. 3, onto the bottom panel 29 of the refractor 10, and onto lower portion J of front panel 20.
The reflector comprises, in horizontal section (see FIG. 2) two symmetrical arcuate sections 18 and 18a, which operate to distribute the light from light source LC. laterally over a wide angle. The lateral action of the reflector concentrates most of the light on the lower portion of the front panel and on the lower forward portions of the end panels 22 of refractor 10. As shown by the typcial ray traces a-a', and d-d' (FIG. 2), the operation of reflector 12 spreads the downwardly reflected light through as wide a lateral angle as possible, so that at almost any normal viewing angle, the luminaire appears to be completely filled with light.
The refractor 10 includes a downwardly and inwardly sloping front panel 20 which is divided into sections A, B, C and J. A series of prisms 20a are located in the top section of panel 20 at sections A, B and C, as shown in FIG. 1. Prisms 20a receive direct light from the light source LC. and lower the light into beam direction (about 70). Prisms 20a are shown in discrete sections A, B and C, because of the varying depths of these prisms. Since the light from the light source strikes the front panel 20 at sections B and C .at greater angles with respect to the normal, than the light striking the front panel at section A, the depth of prisms 20 is made greatest in section A, of intermediate depth in section B, and shallowest in section C.
A feature of the present invention is that the prisms 20a are not horizontally disposed, but rather are curved about a center point, which, in the embodiment shown, is calculated to concentrate the emergent light in beam direction of about 70 from the vertical, while simultaneously providing a lateral redirection of the direct light. In one construction of a refractor, designed according to the present invention, and having a front panel width of six inches, the optimum center point was found to be 9% inches below the flange 21.
The vertical action of prisms 20a is illustrated by typical ray paths g and h. It can be appreciated that the horizontal action of these prisms varies along the curved paths thereof to pull in light which would otherwise'be directed into non-useful corner areas typical of the horizontal light patterns for such luminaires.
Area I comprises a section of concentric flutes 20b which lie in circular paths generated about the same center point as prisms 20a. Flutes 20b receive and pass the reflected light from section 14 of the reflector, which is already at beam angle, and serve to diffuse such light without changing the vertical angle of the beam, as shown by rays f and j in FIG. 3. Moreover, flutes 20b in zone I also receive radiant emission of direct light at beam angles and lower angles than beam, and then spread reflected light at beam direction and lower from section 16 of the reflector. It can be appreciated that the diffusion, because of the curvature of the prisms, is effected in both vertical and lateral directions.
Refractor 10 also includes opposing end panels 22 which are substantially identical in construction. The outer surface of end panel 22, as shown in FIG. 4, includes prisms 24 which lie substantially horizontal at the upper section of the panel where they act to vertically depress direct light. Prisms 24, as they proceed towards the rear of panel 22, form arcuate or curvilinear prisms 24a which then proceed to form vertical prisms 24b at the rear, lower portion of end panel 22. The light directing action of prisms 24, 24a and 24b is shown by the direction of the arrows in FIG. 4. The overall effect of these prisms is to provide uniformally changing light redirection from vertically to forwardly along the curved portions 24a to the vertical portions 24b.
The remaining portion of end wall 22 comprises horizontal flutes 30 which receive the Wide, laterally spaced reflected light such as that indicated by ray b and direct light indicated by ray d and diffuse the same.
The inner surface 23 of the end walls 22, as shown in FIG. 5, have vertical flutes 32 which horizontally dilfuse the incident light indicated by rays a" and d prior to the action of the prism 24 and flutes 30 on the outer surface of the end panel.
The prism construction of the inner wall 25 of the front panel comprises, as shown in FIG. 6, double-action V-type prisms 34 with varying miters and which principally serve to laterally spread the light from the source. This action is indicated by ray paths a and d in FIG. 2.
FIG. 7 shows the prism consstruction of the inner surface 27 of bottom panel 29 of refractor 10. Prisms 36 which are longitudinally parallel toward the rear of the panel, direct incident light in lateral directions on either side of nadir. Prisms 36 become curvilinear at 36a where the light redirection action changes along the curved paths to push the light forward and away from the wall, by exploding the light in all lateral forward directions. The light directing characteristics of prisms 36, 36a are indicated by the direction of the arrows in FIG. 7.
The prismatic construction of the outer surface of bottom panel 29, as shown in section in FIG. 10, comprises, mainly, parallel horizontal prisms 29a toward the rear of the panel and horizontal flutes 31 which contribute to the exploding action of the bottom panel by contributing forward redirection of the light via the prisms 29a opposite the laterally light directing parallel portions of prisms 36, as well as forward and rearward diffusion toward the front of the panel via the flutes 31 opposite the curved portions 36a of the internal prisms. The light redirection of the prisms on bottom panel 29 is shown by the typical ray paths a and b" in FIG. 3.
FIGS. 11 and 12 show another embodiment of a reflector for use with a refractor as described herein, for particular use with an elongated light source such as a mercury lamp (not shown) mounted approximately horizontally. The refractor shown in FIGS. 11 and 12 is substantially identical to that shown in FIGS. l-l0, except for a greater horizontal dimension across the front panel.
In FIG. 11 a reflector 40 is shown in horizontal section, while FIG. 12 illustrates the reflector 40 in vertical section.
This shape of the reflector 40, as seen in the sectional view of FIG. 11, provides for a maximum light output and a maximum lighted appearance across the entire front face of the refractor. This is accomplished by designing the basic curvature of the section as an arc length (dotted portion in FIG. 11) upon which is superimposed a series of reflecting surfaces 42 which are in the form of sections of circles. The action of the circular reflecting surfaces 42 is shown in FIG. 11 by typical rays paths, k-k', i-i, [Hr-"1 nn, 00', p-p', q-q and r-r', which show how light emitted from a typical light point source LC, is reflected in a broad lateral distribution across the front face of the refractor 44. The reflector 40, as shown in the vertical section of FIG. 12, reflects light, as shown by typical ray paths s-s' and t-z', spreading it into paths which strike the lower section of the front panel of refractor 44. Ray paths u, v and w are direct light paths, which are refracted and diffused by refractor 44 as shown in FIG. 2 and as described in the discussion of the refractor embodiment of FIGS. l-10.
FIG. 13 is a photometric chart showing the light distribution which may be obtained by the use of the inventive refractor-reflector combination as disclosed herein. Charts A and A illustrate the lateral distribution of light, while charts B and B represents the vertical distribution. The A and B plots are those obtained by the use of a luminaire according to the embodiment shown in FIGS. 2 and 3, while the A and B plots represent the distribution obtained by the use of a luminaire according to the embodiments shown in FIGS. 11 and 12.
With respect to the horizontal distribution charts A and A of FIG. 13, the effect of the curvilinear front prisms is shown by the increased illumination at the extreme left and right hand section of the patterns.
It has been found that a luminaire constructed according to the foregoing specification, when mounted to a building wall, will provide substantially rectangular distribution of light defined by a distance of approximately six times the luminaire mounting height along the building, and three times the mounting height away from the building.
What is claimed is:
1. A luminaire for use with a light source comprising a refractor for receiving light from said light source, said refractor comprising a substantially vertically oriented front panel disposed forwardly of said light source and including prisms lying in concentric paths generally above said light source and having their common center below the bottom edge of said front panel, and below said light source, said prisms constituting means for redirecting light emitted at and above a horizontal plane through the source vertically downwardly centrally thereof and vertically downwardly and at varying lateral angles laterally of the center thereof, said prisms being deeper at the center of said front panel than at the side sections of said front panel.
2. A luminaire according to claim 1, wherein a reflector is disposed rearwardly of said light source and said front panel further comprising a series of concentric flutes below said prisms, the common center of said flutes being the same as the common center of said prisms.
3. A luminaire according to claim 2, wherein said reflector comprises, in vertical section thereof, a substantially parabolic segment for reflecting incident light in parallel rays at beam direction.
4. A luminaire according to claim 2, wherein said front panel is relatively flat and said luminaire further includes a central light source, said reflector comprises, in horizontal section, a plurality of arcuate sections, each of which are generated about sections of circles, the inner ends of said sections lying along a single arc of a circle of a radius greater than that of said arcuate sections, said arcuate sections and said single arc of a circle being concave in the direction of said front panel whereby said arcuate sections of said reflector constitute means for directing light from said central source laterally across said front panel.
5. A luminaire for use with a light source comprising a refractor for receiving light from said light source, said refractor comprising a front panel including prism means lying in concentric paths for redirecting light vertically centrally thereof and vertically and at varying lateral angles outwardly of the center thereof, said refractor further comprises two end panels, each of which contain first prism means for imparting light lowering action for light incident at the upper portion of said side panel,
second prism means disposed at the rear lower portion of said side panel for redirecting incident light in the forward direction, curvilinear prism means intermediate said first and second prism means, and light diffusing means on the front lower section of said side panel.
6. A refractor for use in combination with a light source and for disposition forwardly thereof, comprising a generally vertically oriented front panel having prisms for lowering and laterally spreading incident light striking the same at and above a horizontal plane through the source and occupying the upper portion of the outer surface thereof, said prisms lying in relatively wide concentric arcs defined by radii originating from a center point substantially in the plane of the light source at a predetermined distance below the light source and below the bottom edge of said front panel, said prisms constituting means for receiving light at increasingly smaller lateral angles of incidence along points laterally of the vertical center line of said front panel and for depressing the light and laterally redirecting the same at varying lateral angles laterally of the vertical center line.
7. The refractor as claimed in claim 6, wherein said prism means lie at various depths with respect to the surface of said front panel.
8. The refractor as claimed in claim 6, further comprising opposing end panels ench of which comprise laterally extending prisms along the top portion thereof, longitudinally extending prisms along the rear lower portion thereof, and diffusing means at the lower forward portion thereof.
9. The refractor as claimed in claim 6, wherein said refractor further comprises a bottom panel comprising on the upper surface thereof arcuately formed prisms disposed at the front end thereof, and longitudinally extending prisms at the rear portion thereof for laterally spreading incident light thereon.
10. The refractor as claimed in claim 6, wherein the inner surface of said front panel comprises V-type light spreading prisms of varying miters.
11. The refractor of claim 6 including light diffusing means located at the lower portion of said front panel.
12. A luminaire for use with a light source comprising a reflector having an upper and a lower section disposed rearwardly of said light source, and a refractor receiving light reflected from said reflector, said refractor comprising a front panel having a series of prisms receiving direct light from said light source lying in concentric paths at the upper section thereof, constituting means for redirecting incident light into beam direction centrally thereof and vertically and into beam direction at varying angles outwardly of the center thereof, and a series of concentric flutes originating from the same center point as the radii which define said series of prisms constituting means for diffusing light reflected from the lower section of said reflector at beam direction, said refractor also comprising a pair of opposing end panels, each comprising a first series of horizontal prism means disposed at the upper section thereof for lowering light incident thereon, a series of vertical prism means disposed at the rear, lower section thereof for redirecting incident light thereon in a forward direction, and curvilinear prism means intermediate said horizontal and vertical prism means for directing incident light in both the downward and forward directions.
13. The luminaire of claim 12, wherein it is provided with a bottom panel extending between the lower edges of the front and sides, and prism means are exposed thereon for exploding the light incident thereon downwardly and forwardly, said prisms including curvilinear prisms on one side and laterally acting prisms on the other.
14. In a luminaire having a central light source, a reflector disposed rearwardly of said light source, said reflector comprising in horizontal section, a plurality of arcuate reflecting sections wherein the innermost extensions of each of said arcuate sections lies along a single section of a circle said reflecting sections and said single from the central source laterally.
7 8 section of a circle being outwardly concave, said arcuate 3,233,096 2/ 1966 Schrnitt 240-10 3 reflecting surfaces constituting means for directing light 3,340,393 9/1967 Franck et a1. 240-93 FOREIGN PATENTS References Cited 484,428 5/1938 Great Britain.
UNITED STATES PATENTS NORTON ANSHER, Primary Examiner.
gf iffi MQLFEiA RICHARD M. SHEER, Assistant Examiner. Dorey 240-106 US. Cl. X.R. English 240-25 10 240 45, 103, 106