US3359415A

US3359415A - Lighting fixture with nested reflectors

Info

Publication number: US3359415A
Application number: US486136A
Authority: US
Inventors: Martin L Lasker
Original assignee: Moldcast Manufacturing Co
Current assignee: NEW MWY Inc; Prescolite Inc; Moldcast Manufacturing Co
Priority date: 1965-09-09
Filing date: 1965-09-09
Publication date: 1967-12-19
Anticipated expiration: 1984-12-19
Also published as: GB1084843A; DE1497316A1

Description

Dec. 19, 1967 M. L. LASKER 3,359,415

LIGHTING FIXTURE WITH NESTED REFLECTORS Filed Sept. 9, 1965 I 4 Sheets-Sheet l MARTHQ L. LASKER ATTORNEY Dec. 19, 1967 L. LASKER LIGHTING FIXTURE WITH NESTED REFLECTORS 4 Sheets-Sheet 3 Filed Sept. 9, 1965 Fig.6

INVENTOR. MAR'nM L. LASKER Dec. 19, 1967 1.. LASKER IGHTING FIXTURE WITH NESTED REFLECTORS 4 Sheets-Sheet 4.

Filed Sept. 9, 1965 INVENTOR. MART! N L LA5KER ATTORNEY United States Patent 3,359,415 LIGHTING FIXTURE WITH NESTED REFLECTORS Martin L. Lasker, Metuchen, N.J., assignor to Moldcast Manufacturing Company, Newark, N.J., a corporation of New Jersey Filed Sept. 9, 1965, Ser. No. 486,136 8 Claims. (Cl. 240-103) ABSTRACT OF THE DISCLOSURE A light reflector made of two or more sections which are stacked and connected to one another in axially aligned nested relationship, with the lower section overlapping the section immediately above it. Each section of the reflector has a wall portion tapered inwardly from the bottom end toward its top edge. The inner sides of the sections have light reflecting surfaces and the outer side of a section at the area where it overlaps the section above it has a light reflecting surface.

The invention relates to lighting fixtures of the hidden source type, and is more particularly directed to improve- :ments in reflectors for such type of lighting fixtures.

The glare zone of a reflector for a lighting fixture is the sight angle most common to viewers approaching the fixture. The illumination zone is the area of desired illumination. It is desirable to produce a reflector for a hidden source lighting fixture which can produce near total darkness throughout the glare zone regardless of the beam spread, focusing angle, or lamp recessed position. Further, it is desirable to produce a lighting fixture whose beam spread, focusing angle, or lamp recessed position can be simply and easily adjusted.

In producing a hidden source lighting fixture to accomplish the above objectives, it also is desirable that the reflector possess minimal dimensions. The outside diameter of a reflector is the dimension of prime importance since any increase in this diameter necessitates an increase in the fixture housing diameter, a condition objectionable on both aesthetic and economic grounds. As shall be discussed below, an increase in the outside diameter of the reflector also requires an increase in the height thereof, and this increase is objectionable where the recessing of the fixture in a shallow ceiling plenum is desired, as well as for aesthetic and economic reasons.

Two prior art types of reflectors are being used to minimize light in the glare zone-a baffiing reflector and a bell-shaped reflector. The baffling reflector is made with horizontally extending opaque rings spaced vertically beneath the light source in such positions that the inside wall of the fixture housing is completely in the shadow cast by the rings. The bell-shaped reflector, which is adapted to be placed beneath the light source, has a curvature such that light striking it is reflected downwardly or away from the glare zone. Both the baflling and bellshaped reflector systems posses serious shortcomings.

With the bafliing reflector, much of the light emanating .from the source is =baflled or cut off. The baflled light is totally wasted with a resultant loss in the efficiency of the fixture including such type of reflector. Moreover, in

order to cast a shadow of suflicient length on the walls of the fixture housing to minimize light in the glare zone,

the width of the horizontally extending baflling rings must be at least as great as the spacing between adjacent rings.

In order to reduce the overall diameter of this type of reflector and still allow suflicient aperture clearance for the removal and insertion of a lamp, the spacing between adjacent rings must be reduced. However, when the rings are closely spaced, the edge of each baflling ring appears as a brightly illuminated line to observers in the glare zone. The resultant series of illuminated lines is aesthetically objectionable.

There is another problem when the batfling rings are closely spaced. The upper surface of each horizontally extending ring receives light from the source and acts as a reflector which tends to light up the shadow cast by the ring above it. This condition may be checked by painting the rings with a light absorbing paint to reduce reflection and then spacing the rings so that the distance between the reflecting surface and the shadowed under surface of the ring above it is large enough to allow sufficient secondary dissipation of that portion of the light which is reflected. However, when the baffling rings are closely spaced, secondary dissipation cannot take place to the necessary degree and a marked lighting up of the shadow occurs.

The bell-shaped reflector operates by presenting a mirror surface to the light at such an angle that the light will be reflected downwardly. To operate properly, however, the bell-shaped reflector must have a parabolic curvature whereby the angle between the tangent of the surface adjacent the upper edge of the parabolic surface and the horizontal top edge of such surface is quite shallow. In order to achieve the desired shallow angle, the lower end of the reflector is necessarily quite large in diameter; that is, close to twice the diameter of the lamp to be positioned with respect to the reflector. In order to maintain a constant cut-oft angle, coupled with a large bottom diameter, it becomes necessary to increase the depth of Lhe1 kdevice. As a result, the bell-shaped reflect-or is unduly Further, and with regard to the bell-shaped reflector, a large portion of the light is trapped outside the reflector and lost between the reflector and the housing for the reflector when the lamp is tilted in the deep recessed position required by this type of reflector. Efficient beam angle control is not possible with this type of reflector. Also, since the source of light must be fixed in a deep recessed position for the reflector to operate properly, variable depth recessing of the light source is not possible. t

In order to obviate the foregoing and other limitations of the prior art devices, it is the general object of the invention to provide an improved reflector.

Another object of the invention is to provide an improved hidden source lighting fixture.

A further object of the invention is to provide an improved reflector for a hidden source lighting fixture which affords near total darkness throughout the flare zone regardless of the beam spread, the focusing angle, or recessed position of the lamp associated with the reflector.

Still another object of the invention is to provide an improved reflector having a minimum outside diameter coupled with minimum height to there-by minimize the size of the lighting fixture in which it is mounted.

Still a further object of the invention is to provide an improved reflector which need not be removed from the lighting fixture in which it is mounted when relamping, the reflector however also being constructed to permit a lamp to be easily removed and replaced for cleaning purposes if necessary.

Still another object of the invention is to provide an improved hidden source lighting fixture wherein the light source may be angularly adjusted for any beam angle and the light sources may be readily adjusted for recessing at a plurality of different positions.

These, and other objects and advantages of the invention will be apparent from the following description, taken in conjunction with the drawings illustrating a preferred embodiment of the invention, in which:

FIG. 1 is a vertical cross-sectional view, on a reduced scale, of a lighting fixture including the reflector of the present invention;

FIG. 2 is a vertical cross-sectional view taken approximately in the plane of line 2-2 of FIG. 1;

FIG. 3 is a vertical cross-sectional view of the reflector, this view also showing a lamp mounted in uppermost position with respect to the reflector, and further illustrating the light pattern furnished by the reflector;

FIG. 4 is a bottom plan view of a bracket which may be used to adjustably support a lamp with relation to the reflector;

FIG. 5 also is a bottom plan view of the bracket, this view however showing the position of the bracket adjusted to furnish a beam angle of ten degrees;

FIG. 6 is a side elevational view of the bracket shown in FIGS. 4 and 5;

FIG. 7 is a vertical cross-sectional view of the reflector similar to the showing of FIG. 3, this view, however, showing a lamp mounted in the lowermost position with respect to the reflector; and

FIG. 8 is also a vertical cross-sectional view of the reflector, this view showing a lamp angularly mounted with respect to the reflector.

As shown in FIG. 1, a hidden source lighting fixture A has a reflector B mounted therein. The reflector is made to provide a highly specular inner surface and is designed to direct all light striking it away from the glare zone. FIG. 3 illustrates the light pattern afforded by the reflector when a lamp C is associated with the reflector, the lamp being shown in its uppermost position.

Referring to FIG. 3, the glare zone, designated a, is defined by the sight angles most common to viewers approaching the reflector or the lighting fixture within which the reflector is mounted. The glare zone a is the area defined by the angle subtended between the cut-off line b of the reflector and a horizontal plane. The cut-ofl. line defines beams of light which may extend from a point at the upper edge 20 to a point 22 on the lower edge of the reflector farthest from the point 20. The illumination zone is designated i.

The reflector B is made of two or more annular sections, each having a wall portion which is tapered inwardly from the bottom toward the top end of the section. The larger and smaller diameters of a section are respectively substantially equal to such diameters of the adjoining section. Preferably, each section is in the form of a short truncated cone.

In the form of the invention illustrated, the reflector is made of three sections, 24, 26 and 28. The reflector sections are formed so that when stacked and connected to one another in axially aligned, nested relationship, a lower section overlaps an upper section, or the section immediately above it. The area of overlap, together with a return segment provided to extend downwardly from the inclined wall of the upper section furnish reflecting surfaces for directing light back to a lamp reflector for the redirection of the light into the illumination zone. The inner sides of the reflector sections and the outer side of that portion of a section at the area where it overlaps an upper section are provided with a specular or reflecting surfaces. For convenience in manufacturing, the entire outer side of each reflector section, as well as its inner side, are provided with specular surfaces.

In greater detail, and as shown in FIG. 3, each reflector section has a taper which extends inwardly from the sections point 29 of widest diameter toward the top edge of the respective section, the angle of taper being designated 0. For the lowermost section 24, the point of widest diameter is the aforementioned point 22. The major diameters of the

sections

26 and 28 at the points 29 and of the section 24 at the point 22 are substantially equal. Preferably, the angle of taper c is approximately 71. In the three section embodiment of the reflector illustrated, the

sections

26 and 28 are respectively secured to the

sections

24 and 26 by the flanges 30 and 32. The flanges 3t and 32 extend substantially parallel and in spaced relation to the inwardly tapered walls 31 and 33 of the

sections

26 and 28, respectively. Preferably, the

reflector sections

24 and 26 are indented or reduced in diameter at their

upper portions

34 and 36 to receive the overlying flanges 3t), 32. The

sections

26 and 28 are respectively connected to the

sections

24 and 26 in any desired manner. Any suitable adhesive may be used to adhere the flanges 3t), 32 to the adjacent portions of the walls of the sections which they overlie. If desired, the connection of one reflector section to a section immediately beneath the same may be accomplished by spot welding. Also, the sections may be connected to one another by friction or force fit.

As also shown in FIG. 3, there is a return segment 38 intermediate the inwardly tapered wall 31 and the flange 30. Similarly, a return segment 40 is provided between the inwardly tapered wall 33 and the flange 32 of the section 28. Preferably, the return segment and flange of a reflector section are made integral with the inwardly tapered wall of the section.

Preferably, the

return segments

38 and 46 are each at an angle d of approximately to the plane of their respective inwardly tapered walls 31 and 33. As will be apparent from FIG. 3, the geometry of the annular reflector sections and their relationship to one another is such that the top edges 42 and 44 of the

sections

24 and 26, respectively, extend above the lower ends of the

return segments

38 and 40. As a result, there is an overlap 46 between

adjacent sections

24 and 26 and an overlap 48 between the

sections

26 and 28. As previously indicated, these overlap areas are provided with reflecting surfaces on their outer sides. The minor diameters of the

sections

24, 26 and 28 at the points 42, 44 and 2t respectively are substantially equal.

The reflector sections are preferably made of a light, strong material such as aluminum. Other materials such as steel or molded plastic may be used. In the preferred embodiment of the invention, the reflector sections are each coated on their inner and outer surfaces with a highly specular black anodized coating. It will be understood, however, that any other highly reflecting or specular surface may be provided. For example, if the reflector sections are made of aluminum, they may be anodized gold or silver. If steel or a plastic material is used for the reflector sections, ahighly polished chromium coating may be applied thereto.

The number of reflector sections used will depend upon the angle of the cut-off line b desired. With more reflector sections stacked one upon another, the effective illuminated area, or illumination zone 1, will become smaller in diameter, assuming that the lamp C will bt located in its uppermost positon. Since the height of each reflector section is comparatively small, on the order of approximately two inches for a major diameter of approximately six inches, the angles of the direct reflecting surfaces are shallow without increasing the diameter of the reflector. The reflector therefore is much smaller in size than may be achieved with the baffle or bell-shaped type of reflector of the prior art.

This may be illustrated as follows: With the standard commercial bell-shaped reflector designed for use with a R-40 lamp (5.130" maximum diameter), the bottom major diameter is approximately 8 /2 and the height is approximately 6 /2". Light control and cut-otf on a bellshaped reflector of this size is comparable to that of a three-tiered reflector as shown in FIG. 3 which has a major diameter of only 6" and a height of The standard commercial bell-shaped reflector, therefore, requires a significantly larger fixture with the same light source. The minor diameter for both types of reflectors is approximately 5.25 to allow relamping without removal of the reflector.

As shown in FIG. 3, light striking the direct reflecting surfaces on the inner side of the

sections

24, 26 and 28 is reflected downwardly at an angle closer to vertical than the cut-off line as defined by the line b. The inner surfaces of the reversely angled,

annular return segments

38 and 40 are reflective and are positioned so that the light striking these surfaces is returned to the lamp reflector C at the proper angle to be redirected downwardly. As a result, little light is lost. Since the

reflector sections

24, 26 and 28 are stacked in a way so that they are nested or telescoped, they form a light baflling overlap at the

aforementioned areas

46 and 48. Light strikin the lower end of the wall 33 of section 28 would normally be reflected into the glare zone; similarly, light striking the lower end of the wall 31 of section 26 would also be reflected into the glare zone. However, the

overlap portions

46 and 48 catch the light and redirect it back to the lamp C for rereflection approximately along its path of incidence. Moreover, the

overlap portions

46 and 48 terminate at the edges 42 and 44, respectively. The edges are positioned away from rather than facing the viewer approaching in the glare zone. Thus, a person approaching from the glare zone a will not see rings formed by the illumination of the top edges 42 and 44. As a result,

one of the essential disadvantages of the bafiiing type of reflector is obviated.

FIG. 1 illustrates the described reflector B included as part of a fixture A. In the preferred embodiment of the invention, the fixture comprises a housing 50 and common means for supporting the reflector and a bracket for adjustably positioning a lamp C.

The housing 50 is tubular and preferably cylindrical in shape in conformity with the preferred annular contour of the reflector. As shown, the housing is open at the bottom and has positioned in the lower part thereof the reflector B. The reflector is resiliently maintained within the housing by a pair of spring members 52, 52' extending between the top edge 54 of the reflector and the support bracket 56. The lower end of the reflector B is provided with an outwardly extending flange 58 which abuts the lower edge 60 of the housing 50. The support 56 is in the form of a ring in conformity with the preferred cylindrical contour of the housing. The support 56 is secured to the inner surface of the housing at the upper end thereof by a series of set screws 62 which are extended through circumferentially spaced, downwardly extendingears 64. If desired, the support member 56 and associated parts may be cast integrally with the housing 50. Where thehousing is made of aluminum, set screws of steel will bite into the wall of the housing to furnish the connection of the support 56 to the housing. The support 56 is provided with

ears

63, 63 to which the upper ends of the springs 52, 52' are secured by screws 65.

As shown in FIGS. 1 and 2, a cover plate 66 is positioned over the support 56 within the housing 50 with a close fit. The cover plate is provided with openings through which screws 68 are extended and threaded into the support 56. The cover member is positioned flush with the top edge of the housing as shown in FIGS. 1 and 2. A ring gasket 70 is positioned between the cover member 66 and the support 56. The cover member is provided with openings to permit the passage of wires (not shown) to extend to the base of a socket 72 mounted on a lamp adjusting bracket D. The cover member 66 may be provided with any suitable means (not shown) such as a series of holes with slotted extensions to enable the fix- 6 ture to be mounted to a ceiling by screws or headed studs, as is well known in the art. Where it is desired that the fixture be mounted on a wall or on a J-box, or be provided with means suitable for mullion mounting, the fixture may be provided with mounting means 74 on the side thereof, as shown in FIG. 1.

As shown in FIG. 1, the lamp adjusting bracket D is suspended within the housing 50 of the fixture from the same support means 56 which serves to support the reflector C. The support means 56 is provided with a depending boss 76 located adjacent the wall of the housing StlyThe bracket D has a longitudinally extending arm 78, the upper end 80 of which is secured to the boss 76 as by a pair of screws 82. The arm 78 lies adjacent the Wall of the housing, and extends vertically in the housing when oriented as shown in FIG. 1.

The lamp adjust bracket D is constructed to provide means for adjusting the position of the lamp in a vertical plane or to a desired recessed position and means for adjustment of a lamps angularity.

As shown in FIGS. 1 and 6, the socket 72 is adjustably mounted upon an arcuate member 84. The socket is secured to a clamp bar 86 positioned on the underside of the arcuate member 84. A clamp bar 86' overlies the member 84. A pair of screws 88, 88' are extended through the clamp bars 86, 86' near their ends and clearing the edges of the arcuate member 84. Upon tightening the screws, the socket is maintained in fixed relationship in desired adjusted position upon the arcuate member 84. When the screws are loosened, the position of the socket 72 may be adjusted along the length of the arcuate member.

As shown in FIGS, 1, 4, 5 and 6, the arcuate member 84- extends from the center of another arcuate member 90, which is preferably semicircular in contour. The arcuate member 90 lies in a plane parallel to the plane of the wall of the cylindrical housing 50. The arcuate member 84 extends radially of the housings wall. For convenience, the memer 84 will be referred to as the radial arcuate member and the member 90 as the circumferential arcuate member. When oriented within the fixture A, as shown in FIG. 1, the radial arcuate member 84 has its arc of curvature extending in a downward direction. The inner end of the radial arcuate member is connected to the center of the circumferential arcuate member. Preferably, the members are integrally connected in a single casting, the casting preferably being of aluminum. The assembly for angular adjustment is designated 92.

As shown in FIGS. 4- and 5, the radial arcuate member is provided on its underside with indicia to indicate the position of angularity for the adjusted position of the socket along such member. The circumferential arcuate member is also provided with indicia to indicate its angular position, together with its rigidly connected radial ar cuate member with respect to the arm 78.

As shown in FIG. 4, the arm 78 is provided with means for adjusting the position along its height of the assembly 92, and also for adjusting the angular position of such assembly circumferentially with respect to the arm 78. For these purposes, the arm 78 is provided with a series of vertically spaced connecting

means

94, 94' and 94" ranging respectively from the uppermost to the lowermost position for the socket-carrying assembly 92. Each of the spaced connecting means comprises a pair of

wedge members

96, 96 spaced apart a distance to receive the circumferential arcuate member. As shown in FIG. 1, the wedge members 96 may be laterally spaced to extend from each side of the arm 78 in pairs. The wedge memers 96 may extend from the front side of the arm for the width of the arm. The wedge members 96" are each provided with a threaded bore through which a set screw 98 is extended. The members 96 are preferably angled to overlie the circumferential arcuate member which is matingly angled to be received beneath the extension 96. By tightening on a screw 98, the assembly 92 is secured in a selected connecting

means

94, 94' or 94"along the height of the arm 78. By rotating the circumferential arcuate member to the desired position with respect to the arm 78, the desired angular position of the assembly 92 is achieved. Such adjustment, of course, is made before tightening up on a screw 98. The angularity indicia on the radial and circumferential arcuate members indicate the desired position of the socket, and the lamp, for the desired beam and focusing angle for a selectively adjusted recessed position of the lamp. The adjustability of the socket along the radial arcuate member and the adjustability of the circumferential arcuate member with respect to the arm 78 will be apparent from a comparison of FIGS. 4 and 5. v

The described lamp adjust bracket D including the assembly 92 furnishes simple and easy adjustability of lamp recessed posit ion, beam spread and focusing angle. Angular adjustment up to 20 in either direction from center and rotational adjustment of 360 for any size lighting fixture is now possible with a lamp adjust bracket of the invention.

The rnulti-position lamp recessing adjustment means afforded by the bracket of the invention permits selection of optimum cut-off for specific illumination requirements at the site of installation. Proper utilization of the full range of beam characteristics offered by different lamps may be achieved in cylindrical source lighting by virtue of the selective combination of beam spread and recessing positions afforded by the described lamp adjust bracket. For example, in the uppermost position of the lamp C with respect to the reflector B, as shown in FIGS. 1 and 3, an intense narrow beam for accent lighting or general illumination from very high ceilings is afforded. In such position, a full 45 cut-otf angle is afforded.

In the lowermost position of the lamp, as shown in FIG. 7, and when utilizing a R-40 flood lamp or a PAR- 38 flood lamp, there is produced a wide angle, even illumination ideal for general lighting. In such lowermost position, with a PAR-38 lamp, up to 25 cut-off is achieved, and up to 20 cut-off is obtained with a R-4O lamp.

The middle recessed position, as shown in FIG. 8, may be utilized with all lamps where intermediate values are desired, and where angled beam focusing is desired. Thus, with a PAR-38 amp, up to 40 cut-off is achieved in such position. Up to 35 cut-off can be achieved with R40 lamps and A lamps with optional reflectors.

It will be readily apparent that lamp recessing adjustment is easily achieved without removal of the reflector B, and no readjustment is necessary upon relamping.

The fixture A may be recessed in a ceiling with the lip 58 flush with the ceiling, whereby the fixture becomes a recessed ceiling lighting fixture. The reflector of the invention frees cylindrical source lighting design from the limitations of rigid, vertical beam installations. Cylindrical sources may now be used where they were never applicable before a sharply spotlight specific facades, to wash walls with aimed and controlled light, and to throw illumination upon horizontal areas remote from the fixture.

It will be apparent that various changes and modifications may be made with regard to the preferred embodiment of the invention as herein illustrated and specifically described. The reflector may be used in conjunction with other housings and the described lamp adjust bracket may be used in conjunction with other reflector structures, although the lamp adjust bracket described is particularly suitable for use in conjunction with the reflector of the invention. The reflector of the invention may be used with other types of lamp mounting means including non-adjustable lamp mounting means. Also, for outdoor lighting, the lower end of the housing may be provided with a protective grill, whereby the reflector would be raised a commensurate amount within the housing and secured in fixed position with respect to the housing by any suitable means. These, and other changes and modifications are within the scope of the invention as sought to be defined in the following claims.

I claim:

1. A reflector for a lighting fixture comprising an upper annular section and a lower annular section connected to one another in axially aligned, nested relationship, each of the sections having a wall portion tapered inwardly from the bottom end toward the upper edge thereof, the diameters of the tapered wall portions of the upper and lower sections at their respective bottom ends being substantially equal and the diameters of tapered wall portions of the upper and lower sections at their respective top edges being substantially equal, said upper section having a return segment extending from the bottom end of its tapered wall portion to the outer side of the lower section below the top edge thereof to provide an overlap, the inner sides of said sections having reflecting surfaces, and the outer side of the lower section at said overlap having a reflecting surface.

2. A reflector as set forth in claim 1, wherein the upper and lower annular sections are each in the form of a truncated cone.

3. A reflector as set forth in claim 1, wherein the tapered wall portion of each section is disposed at an angle of approximately 71.

4. A reflector as set forth in claim 1, wherein the return segment is at an angle of approximately with respect to the plane of the tapered wall portion of the upper section.

5. A reflector as set forth in claim 1, wherein the lower end of the return segment has a flange extending therefrom, said flange extending downwardly substantially parallel to the tapered wall portion of the upper section, said flange engaging the tapered wall portion of the lower section and connected thereto; and wherein said tapered wall portion, return segment and flange of the upper section are integrally formed.

6. A reflector as set forth in claim 1, wherein the upper and lower annular sections are each in the form of a truncated cone; wherein the tapered wall portion of each section is disposed at an angle of approximately 71; wherein the return segment is at an angle of approximately 105 with respect to the plane of the tapered wall portion of the upper section; wherein the lower end of the return segment has a flange extending therefrom, said flange extending downwardly substantially parallel to the tapered wall portion of the upper section, said flange engaging the outer side of the tapered wall portion of the lower section and connected thereto; and wherein said tapered wall portion, return segment and flange of the upper section are integrally formed.

7. A reflector for a lighting fixture comprising upper, intermediate and lower annular sections connected to one another in axially aligned, nested relationship, each of the sections having a wall portion tapered inwardly from the bottom end toward the upper edge thereof, the diameters of the tapered wall portions of the upper, intermediate and lower sections at their bottom ends being substantially equal and the diameters of tapered wall portions of the upper, intermediate and lower sections at their top edges being substantially equal, said upper and intermediate sections each having a return segment extending from the bottom end of their respective tapered wall portions to the outer sides of the intermediate and lower sections respectively below the top edges thereof to provide an overlap between the upper and intermediate sections and an overlap between the intermediate and lower sections, the inner sides of said sections having reflecting surfaces, and the outer sides of the intermediate and lower sections at said overlaps having reflecting surfaces.

8. A reflector as set forth in claim 7, wherein the upper, intermediate and lower annular sections are each in the form of a truncated cone; wherein the tapered wall portion of each section has an angle of approximately 71;

9 10 wherein the return segments of the upper and intermediate return segment and flange of each of the upper and intersections are each dispose-d at an angle of approximately mediate sectlons are mtegrally formed. 105 with respect to the tapered wall portions; wherein References Cited the lower end of each return segment has a flange extend- UNITED STATES PATENTS 1ng therefrom, sa1d flanges each extendlng downwardly 5 substantially parallel to the tapered wall portions, said 1625948 4/1927 Lang 240*403 flanges respectively engaging the outer sides of the tapered 2465248 3/1949 Mccandless 240 78 wall portions of the intermediate and lower sections and NORTON ANSHER, U Examinerconnected thereto; and wherein the tapered wall portion, M. H. HAYES, Assistant Examiner.