Title:
Indirect lighting fixture
United States Patent 2303747


Abstract:
This invention relates to that type of llumina. tion in which the bulb has its lower portion coated with a reflecting medium such as silver to a cut-off line approximately to the level of the light source (filament) so that the greater portion of the light from the source will be directed to...



Inventors:
Kuhl, Frank P.
Application Number:
US34908240A
Publication Date:
12/01/1942
Filing Date:
08/01/1940
Assignee:
SILVRAY LIGHTING INC
Primary Class:
Other Classes:
362/241, 362/305, 362/408, 362/414
International Classes:
F21S13/00
View Patent Images:



Description:

This invention relates to that type of llumina. tion in which the bulb has its lower portion coated with a reflecting medium such as silver to a cut-off line approximately to the level of the light source (filament) so that the greater portion of the light from the source will be directed to the ceiling to give light distribution which is entirely indirect.

This type of illumination has the characteristic of distributing the light laterally throughout the space to be illuminated so as to give, in a selected working plane thereof, and within the lateral limits of such space (which is dependent upon the lumen strength of the light source) a uniform distribution in said selected working plane.

It is to be distinguished from an illuminating arrangement employing a clear bulb beneath a curved reflector which receives only the rays radiated upwardly directly from the source and reflects these downwardly and substantially vertically so as to concentrate only these reflected radiations in the space immediately below the fixture.

My invention can be embodied into fixtures in 2 the same way regardless of whether the bulb is supported base up or base down. The main distinction between the two structurally is that where the bulb is supported base up it is the spherical surface which is coated with the re- t flecting medium to a cut-off line approximately to the level of the light source, whereas when the bulb is supported base down it is the neck of the bulb that is coated to approximately the aforementioned cut-off line. FIctionally the 3 two differ in that there will be less obstruction where the bulb is supported base down and therefore increased illuminating efficiency.

Illumination employing only a reflecting bulb of the character referred to, gives a brilliant light 4( concentration on the bulb surface above the reflecting cut-off line and an objectionable glare to an observer. The Perree Patent 1,596,725 and the Howell Patent 2,102,462 are examples of arrangements for eliminating this glare in such illumination, comprising a translucent bowl supported in close adjacency to said bulb cut-of line with the bowl extending generally outwardly or laterally into the path of the line of vision to the bulb. The bowl in both of these patents is con- so toured and dimensioned so as to encroach slightly upon the light distribution curve so as to avail itself of some of the lumens to illuminate the bowl which is made translucent to effect this purpose.

It is the general object of my invention to proviae with a reflecting bulb of the aforementioned character, a shielding means which does not present any horizontally or laterally extended secS tons so that thereby the shielding function is attained without the interposition of an obstruetion to ventilation and to pull chain operation and without presenting a surface upon which dust may settle, as is the case where a bowl is employed.

SI attain the general objects of my invention by aWsociating with the reflecting bulb to give the aforementioned type of illumination, shielding means which are generally vertically directed. In the embodiment herein disclosed, these shielditg means take the form of one or more relatively thin annular members spaced from the bulb and from each other (where a plurality of such members are employed) and so related as to their number, their depth or height, their position relatively to and spacing from the cut-off ilhe of the bulb and from each other, as to effect the shielding function and additionally provide for improved ventilation and convenient pull 5 chain operation and all this without requiring that the shielding means encroach upon the light distribution curve or that the effect of an illuminated shielding means be dispensed with.

The general object of my inventio is the proo vision In a lghting fixture Of a simle, inexpensive construction giving effective illumination.

. Among the more particular objects of my invftion are the provision in a lighting fixture c.plrsing a silvered bulb, of means for Prevent5 Irk glare from such a bulb without interfering with the effective light distribution therefrom, ald the provision in a lighting fixture of shieldng means that will not collect dirt and dead insits, that provides excellent ventilation, that Sdoes not present a dark appearance when viewed from the underside, that can be relamped from below without disturbing the fixture and in which a pull chain on the lamp socket is directly accessible from below the fixture.

These objects and such other objects, as will hereinafter appear or be pointed out, are attained in the illustrative embodiments of my invention shown in the drawings, in which: Figure 1 is an elevational view, partly n section, of one embodiment of my invention wherein the bulb is supported base up; Figure 2 is a diagrammatic view showing a light distribution curve of a silvered bowl bulb which determines certain constructional features of my invention; Figure 3 is an elevational view, similar to Figure 1 of a% second embodiment of my invention wherein the bulb is supported base up; Figures 4 and 5 are sectional elevational views of other embodiments illustrating the principles of my invention; Figure 6 is an elevational view of an embodiment of my invention wherein the bulb is supported base down in a lighting fixture, portions being broken away to disclose the underlying construction;.Figure 7 is an elevational view of an embodiment of my invention showing the application of my invention to a floor lamp, the bulb being broken away to disclose the underlying construction; Figure 8 is a bottom plan view of a multiple lamp lighting fixture In which the bulbs are supported base up and in which provision is made for direct lighting as well as for indirect lighting; and Figure 9 is a side elevational view of the fixture of Figure 8, with portions broken away to disclose the underlying construction substantially on the line $-9 of Figure 8, looking in the direction of the arrows.

In the illustrative embodiment of my invention shown in Figure 1, the numeral 10 denotes a lamp socket supported from the ceiling C within which is mounted, base up, an incandescent bulb II provided with a filament having its center of luminosity at 12, which point is positioned near, but slightly above the center of a spherically curved portion of the glass encasement of the bulb II. The lowermost outer surface areas of this spherical portion carry a reflecting coating S1, which prevents passage of light from the luminous center 12 in a downward direction and reflects such light back toward the luminous center 12 and against the ceiling and upper portions of the walls in which the fixture is located.

The center of curvature of this spherically curved portion of the bulb encasement and the reflecting coating thereon is indicated at 14, and it will be observed that the upper boundary 15 of the reflecting coating 12 is shown by way of example as positioned slightly above the center of curvature 14, while the center of luminosity is shown positioned slightly above both the boundary 15 of the casting and the center 14. B( This construction assures a free passage of the reflected rays around the filament of the bulb 1, and minimizes bombardment of the filament by these reflected rays.

The distribution curve of a bulb such as the 5 bulb II, which type of bulb is commonly known as the "silvered bowl" type of incandescent bulb, is shown in Figure 2 at P. This figure is a light distribution chart of conventional form in which the candle power is laid off radially ( along lines radiating at different vertical angles from the luminous center of the bulb. It will be observed that the spread of light is approximately 180%.

Experience has shown that if a bulb such as i the bulb II is positioned below a ceiling, as in Figure 2, so that the ceiling and wall act as reflectors serving to redistribute the light from the bulb, the resulting illumination in the working plane, for a room of ordinary dimensions, 7 is substantially uniform.

It is also found however that if a silvered bowl bulb such as the bulb II is used without shielding, that the glare from the uncoated parts of the bulb is very annoying. This glare is due 7 mainly'to secondary reflections at the glas surface of the uncoated portions of the encasement of the bulb. In order to prevent the same I have provided a system of louvers and shields.

The louvers in the embodiment of Figure 1 are in the form of concentric cylindrical surfaces arranged at appropriate levels so as to cut off direct view of the glass surface of the bulb from points of view at which such glare would be annoying. The level of the louvers is also arranged with a view toward keeping their size as small as possible consistent with adequate shielding effects, and with the requirements of proper ventilation, and the surfaces are vertically disposed so as to offer no obstruction to downwardly directed light and to a pendent pull chain and no places where dust can collect. At the same time those surface portions of the louvers which are illuminated by the bulb are so disposed that such illumination is substantially uniform for the respective louvers.

The system of louvers just described is shown at 16, IT and 18 and as will be observed their upper edges 19, 20 and 21 respectively are arranged at different levels, that is to say in stepwise relation and they are so disposed that the said upper edges lie in the light distribution curve P' which is characteristic of the bulb II and which is drawn to an appropriate scale. By so arranging the louvers it will be observed that those points thereof that receive the strongest illumination are spaced at a greater distance than those points that receive the lesser illumination. The relation of the candle power to the distance of the point at which it is received is in inverse proportion, so that the brightness of the inner surface of the louvers receiving this light is substantially the same for all louvers.

As an additional safeguard against glare I Shave shown an inverted truncated conical shield 22 surrounding the neck portions of the bulb and coaxial therewith and this shield is disposed substantially in the direction of the rays proceeding from the filaments of the bulb 1i, so Sthat it has no obstructive effect on the passage of such Iras, while at the same time it shields the neck portions of the bulb from view.

if a fixture provided with a system of louvers and shields as has just been described is positioned in an ordinary sized room it will be obvious that no matter at what point the observer is positioned he cannot obtain a direct view of any of the uncoated portions of the bulb II, except where he is positioned almost immediately Sbelow the fixture. In these last named positions portions of the uncoated bulb surface, are, it is true, visible, but the angles at which such surface portions are viewed is such that the glare. if any, is negligible. Furthermore the eye of an observer situated almost directly beneath the fixture is seldom turned upward into the position necessary in order to obtain a view of the uncoated portions of the bulb.

It will be observed that the louvers 16, IT, 18 offer no obstruction to the passage of vertical rays of light from the ceiling and further that they offer no surface on which dust or dead insects con collect. The shield 22 on the other hand while it does offer some obstructive action 0 to downward rays is of such small size and is positioned so closely to, the bulb II that its obstructive effect is negligible. Relamping is possible through the louver 16 and a pull chain, where used, is readily hung within the shield 22 and the louver 16. Ventilation is ample, because the spacing of the louvers is sufficiently wide for the purpose.

In order to support the system of louvers and shields that I have just described I may use rods or braces 23 interconnecting the louvers 16, 17 and 18 as indicated. At an intermediate point these braces are connected by a suitable fitting 24 with arms 25 connected to a collar 26 provided with bayonet slots 27 adapted to engage pins 28 projecting inwardly from a socket cover 29. It will be observed that the fitting 24 is shown as in threaded engagement with the ends 'of the arms 25, and thereby the height of the rods 23 may be adjusted, and the position of the louvers so controlled that the most effective illumination results.

The fitting 24 for this purpose will be provided with an opening through which the lower ends of the arms 25 may pass and an opening at right angles to this threaded opening through which the arms 23 pass, and it may be locked in position on the threaded ends of the arms 25 by means of a pair of lock nuts 30.

It will be understood that this manner of mounting the louvers 16, 17 and 18 is illustrative of one of the many ways of mounting them.

The socket 10 is shown supported from the ceiling C in the conventional manner, as by various fittings 31, and an outlet box 32, the details of which need not be described beyond saying that they serve, in addition to supporting the socket, to support the socket cover 29, and by means of arms 33 to support a canopy 34, also of conventional type.

It will be understood that the canopy 34 has primarily an ornamental function, but that if desired its surface may be treated so as to reflect light striking it. Preferably of course such reflection should be diffusing as otherwise it might result in objectionable glare at this point.

The louvers 16, 17 and 18 may be of opaque materials, such as metal, in which case they completely obstruct the light, or they may be of translucent material, so that they transmit some light, but not enough to result in glare. By using translucent materials of various coefficients of transmission the brightness of the outer louver surfaces may be made to vary and may be made of any desired intensity.

It will also be understood that while the louvers 16, 17 and 18 have been shown as cylindrical, that louvers of other configurations may be found suitable and, for particular purposes, even preferable.

In Figure 3 a second preferred embodiment of my invention is disclosed. In this figure I have shown a bulb III, also of the silvered bowl type, supported from the ceiling in a neck up position by being mounted in a socket 110. The luminous center of the bulb is indicated at 112. The center of curvature of its lower spherical portions as well as of the reflecting coating 113 is shown at 114, and the boundary of the reflecting surface is shown at 115.

A system of concentric cylindrical louvers 116, 117 and 118 is shown disposed similarly to the louvers 16, 17 and 18 of the first embodiment, with their upper edges 119, 120 and 121 disposed in the distribution curve P2 of the bulb I , whereby the size of the louvers may be reduced and whereby the illuminating effect already mentioned in connection with the first embodiment is attained.

The louvers 116, 117 and 118 are shown interconnected by rods or arms 123 and certain of 7 these arms are provided with brackets 124, into a slot 124a to which is fastened one end of a chain 125, the other end of which chain is connected in any suitable or preferred manner to a socket cover 128.

The socket 110 and the socket cover 128 are supported from the ceiling 133 in a more or less conventional manner by fittings designated collectively by the numeral 131, which extend into o1 a box 132 of conventional type mounted in the ceiling 133. The fittings 131 also serve to support a canopy 134, by means of arms 135 secured to the canopy and to the said fittings.

The functioning and the advantages of this embodiment of my invention are in general the same as those of the first embodiment. It will however be noted that this embodiment does not include anything corresponding to the shield 22 of the first embodiment, wherefore it Is not so well adapted for large sized rooms In which the bulb might be viewed at an angle very near the horizontal.

It will further be observed that adjustability of the louvers may be effected by lengthening or shortening the chain 125. For this purpose the opening 124a in each bracket 124 may be of keyhole conformation, as shown, permitting ready detachment and insertion of the chain, and a catching thereof at any desired point between adjacent balls of the chain.

The principles upon which my invention is based will be more readily understood by a reference to Figure 4 in which I have shown an embodiment of my invention in which a silvered bowl bulb 211, mounted neck up in a socket 210 has its reflecting portion 213 surrounded by a single cylindrical louver 216, this louver being supported in any suitable or preferred manner as by chains 217 extending from the ceiling, or a part of the fixture mounted in the ceiling.

When the eye of an observer is located at the point marked a, it will be observed that the lines of vision b, c, drawn toward the upper and lower edges of the louver 216 respectively, bound a region within which the eye is completely shielded from glare from the uncoated portions of the bulb 211. In fact, if the position a were the only point of observation, the dotted line of vision d, drawn from the eye to the upper boundary of the reflecting surface, might serve to limit the lower edge of the louver 216. However, other positions of the eye must also be considered. For instance, if the eye is positioned at the point e it will be found that in order for the uncoated portion of the bulb 211 to be invisible from this point of view, the limiting of the lower edge of the louver by the line b is required, this limiting being the same as that for the line g which runs from e to the upper boundary of the reflecting surface.

It will be apparent that complete shielding is 30 effected when the eye is either at a, at e, or at any point therebetween. For lines of vision of less inclination than that from a, the neck portions of the bulb become visible, and therefore this fixture is unsuitable for all but rooms of very 5 small extent. For angles approaching the vertical more nearly than the position e, that is, for portions of the eye directly underneath the fixture, there is also no shielding, but, as already Sexplained in connection with the first embodiment, no shielding is necessary at these points.

In order to adapt a fixture such as shown in Figure 4 for rooms of greater extent a second louver must be added. The effect of this is to '5 add to the shielded region a number of positions which are limited by the position of the eye Indicated at h.

It will be unnecessary to describe the details of the embodiment of Figure 5. The parts thereof corresponding to the embodiment of Figure 4 have been numbered and lettered similarly to the parts of the fixture of that figure, except that the numerals and letters have been primed.

It is to be observed, however, that the second louver 217' has its upper edge portion raised above the upper edge portion of the louver 216', as a result of which raising the same shielding effect may be obtained with a louver of relatively small radius, whereas if the upper edge portion of the louver 217' were at the same level as the' upper edge of the louver 216' a much greater radius would be required for the louver to shield the vision through the same angle. This will be obvious from an inspection of Figure 5.

For reasons already mentioned in connection with the embodiments of Figures 1 and 3 the upper edges of the louvers 216' and 217' are preferably disposed in the light distribution curve P3.

The lighting fixture shown in Figure 6, which is also of the ceiling type, comprises a socket 260 within which is mounted an incandescent bulb 261 in a base down position. The luminous center of this bulb is at 212 and a reflecting coating 263 is shown on the lower or neck portion of the bulb. The boundary of the reflecting surface is shown at 265 and it will be observed that it is slightly below the luminous center 212.

A system of louvers 266, 267 and 268 corresponding in structure and function to the louvers 16, 17 and 18 of the first embodiment is shown surrounding the bulb 261. A system of supports 213 is shown uniting the louvers and the socket cover 218 within which the socket 260 seats. The louver system is shown carried from a stem 281 by chains or the like 280. The stem 281 is shown mounted in the ceiling 284 as by means of an outlet and ceiling plate construction 285 to which the stem 281 is connected through a bayonet joint 282 so that the fixture can be readily attached as a unit to the ceiling. The details of this mounting are not illustrated as a unit and need not be described, as they may be of any conventional type.

It is to be understood that the socket 260 is suitably wired by conductors which may pass through the stem 231, the details of such wiring not being shown.

A pull chain 283 adapted for the operation of the socket is shown by way of example as depending from the socket and passing through an opening at the base of the socket cover 278.

The system of louvers 266, 267 and 268 are related positionally, as are the corresponding louvers of the, previous embodiments, by having their upper edges positioned in the light distribution curve P4 of the bulb 261, drawn to an appropriate scale, and it will be understood that their location and extent is determined according to the principles enunciated hereinabove in connection with the said other embodiments.

Since the operation of this arrangement is substantially similar to that of the previously described embodiments, detailed description thereof would appear to be superfluous. However it may be pointed out that due to the absence of a shadow thrown on the ceiling by the base of the bulb where the bulb is mounted base up, somewhat greater illuminating efficiency is obtained than in the preceding embodiment, In Figure 7 I have shown my invention applied to a floor lamp, the illuminating system of which comprises a bulb 311, mounted base down in a socket positioned in the canopy 328, and having a reflecting surface 313 and surrounded by the system of louvers 316, 311 and 318, substantially identical with the corresponding parts of the embodiment of Figure 6, and further description is therefore unnecessary. This system is carried on a stem 330 mounted in a pedestal or base 331. The upper edges of the louvers 316, 317 and 318 are arranged in the light distribution curve or surface Ps of the bulb, as indicated in the drawings.

Obviously this embodiment will function similarly to the preceding embodiments, the only important distinction lying in the manner of supporting the luminous structure, this being in one case a support from and below the ceiling, and in the other case a support above the floor.

In the embodiment of Figures 8 and 9 I have shown a multi-lamp ceiling fixture in which indirect and direct illumination are combined.

The central element of the fixture is constituted by an assembly comprising a socket 410 within which is mounted an incandescent bulb 411. Surrounding this bulb is a reflector 412.

The bulb 411, as will be observed, is not provided with a reflecting coating and it is mounted Wo base up so that, with the aid of the reflector 412 all of its light is directed downwardly. Glare is prevented by a system of louvers 413 shown in the form of concentric rings mounted in the Smouth of the reflector 412. The socket 410 is 15s shown mounted within a socket cover or husk 410a.

The assembly just described, which constitutes the direct illumination element of the fixture is shown carried by a support 414, mounted from 0n the ceiling 415 in any suitable or preferred manner, as for example, by the arrangement designated in general by the numeral 416, and which may be of conventional type.

Suitably supported from the arrangement 416, 43 as by supports 416a disposed around the socket 410 are a plurality of sockets 417, enclosed if desired, as shown, by socket husks 417a, three such sockets being shown, although it will be understood that any desired number may be used. Mounted within the sockets 417 are shown silvered bowl bulbs 418, these being mounted in the dependent or base up position.

Supported from the socket husk 410a, as for example, by brackets 419 having a bayonet joint connection with a ring carried by said socket husk, is a system of louvers 420, 421 and 422 of progressively increasing diameter and arranged in stepped relation. The main portions of these louvers, as can be seen in Figure 8, are contoured cylindrically and are coaxial with the bulbs 418, and the portion concentric with-each of the bulbs merges with the similar portions associated with the other bulbs, as shown in Figure 8. It is unnecessary to describe the exact configurations of these louvers, which are influenced, aside from their utilitarian functions, by considerations of artistic design. In general, whatever the exact configuration of these louvers 70 they follow the principles hereinabove enunciated in connection with the other embodiments.

Their upper edges are shown located in the light distribution curve or surface P6 of the bulb they surround.

The louvers 420, 421 and 422 are shown connected together into a unitary structure by braces 423.

It will be understood that the fixture is wired in the conventional manner and that suitable controls of conventional type are provided.

These have not been illustrated.

While I have herein disclosed several embodiments of my invention it will be understood that the same may be embodied in other forms without departing from the spirit thereof, as will 1 be obvious to those skilled in the art.

It will further be understood that the disclosure herein is by way of illustration and is not to be interpreted in a limiting sense and that I do not limit myself other than as called 1 for by the prior art and the terms of the appended claims.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent, is: 2 1. An indirect lighting fixture utilizing ceiling reflection, said fixture comprising an incandescent bulb of the silvered bowl type having a silvered reflecting area thereon extending from its tip to a cut-off line approximately at the level of the filament, whereby the light beam emitted by said bulb has a spread of approximately 180", a mounting for said bulb whereby it is supported with its base uppermost and its 3 silvered bowl lowermost in spaced relation to a ceiling, said mounting being of a character to offer no appreciable obstruction to the passage of light from the bulb to the ceiling, and shielding means supported on the fixture at the level 3* of and in spaced relation to the bulb so as not to obstruct the passage of air currents upwardly over the bulb, said shielding means including a plurality of cylindrically arched surface portions coaxial with the vertical axis of the bulb, and 4C each of said arched surface portions consisting only of vertical surface elements that offer no appreciable obstruction to the passage of light or air in a vertical direction, and will not collect dust, and will serve to prevent glare from the 4Z bulb reaching the eye of an observer positioned to the side of and below the level of the fixture, and said arched surface portions being spaced from each other and from the bulb in a radial direction, with their upper edges at progressively 5o higher levels as the radii thereof increase and so that the upper portion of each receives light directly from the bulb, and the said arched surface portions being at a level so that their upper edge portions intercept only a relatively small ;.s portion of the marginal light rays of the light beam emitted by the bulb, whereby the spread of said light beam will not be materially reduced, the upper edge of each arched surface portion being at a higher level than the lower edge of Co the next surrounding arched portion, and there being no obstruction to the passage of light from the bulb to the ceiling other than that due to the mounting, and substantially no obstruction by the fixture to the vertical passage of light from the ceiling downward, whereby when the fixture is hung below a ceiling, the wide spread of the light beam emitted by the bulb will result in the illumination of a substantial area of the ceiling, and substantially all the light reflected from the ceiling will be utilized in illumination of the working plane.

2. An indirect lighting fixture utilizing ceiling reflection, said fixture comprising an incandescent bulb of the silvered bowl type having a silvered reflecting area thereon extending from its tip to a cut-off line approximately at the level of the filament, whereby the light beam emitted by said bulb has a spread of approximately 180°, a mounting for said bulb whereby it is supported with its base uppermost and its silvered bowl lowermost, said mounting being of a character to offer no appreciable obstruction to the passage of light from the bulb to the ceil0 ing, and shielding means supported on the fixture at the level of and in spaced relation to the bulb so as not to obstruct the passage of air currents upwardly over the bulb, said shielding means including a plurality of rings coaxial with the 5 vertical axis of the bulb, and each ring consisting only of vertical surface elements that offer no appreciable obstruction to the passage of light or air in a vertical direction, and will not collect dust, and will serve to prevent glare from the 0 bulb reaching the eye of an observer positioned to the side of and below the level of the fixture, and said rings being spaced from each other and from the bulb in a radial direction, with their upper edges at progressively higher levels 5 as the diameters of the rings increase and so that the upper portion of each receives light directly from the bulb, and the rings being at a level and so positioned as to intercept only a small portion of the marginal light rays of the Slight beam emitted by the bulb, whereby the spread of said light beam will be substantially unaffected, the relative levels of the upper edges of said rings lying in the light distribution curve of said bulb drawn to an appropriate scale, 5 whereby the illumination of the upper portions of said rings will be substantially the same for all the rings, the upper edge of each ring being at a lower level than the lower edge of the next surrounding ring, and there being no obstruction to the passage of light from the bulb to the ceiling portion other than that due to the mounting, and substantially no obstruction to the vertical passage of light from the ceiling downward, whereby when the fixture is hung below a ceiling, a substantial area of the ceiling will be illuminated as a result of the wide spread of the light beam emitted by the bulb, and whereby substantially all the light reflected from the ceiling will be utilized in illumination of the working plane.

3. An indirect lighting fixture utilizing ceiling reflection, said fixture comprising an incandescent. bulb of the silvered bowl type having a silvered reflecting area thereon extending from its tip to a cut-off line approximately at the level of the filament, whereby the light beam emitted by said bulb has a spread of approximately 1800, a mounting for said bulb whereby it is supported with its base uppermost and its silvered bowl lowermost, said mounting being of a character to offer no appreciable obstruction to the passage of light from the bulb to the ceiling, and shielding means, said shielding means consisting of a plurality of cylindrical louvers, coaxial with the vertical axis of the bulb supported substantially at the level of the silvered bowl of the bulb, and further consisting of an inverted conical baffle surrounding the neck portion of said bulb, said cylindrical louvers having their upper edge portions at levels rising progressively outward in a radial direction and said baffle being positioned at a higher level than said louvers, while the upper edge of each louver is at a higher level than the lower edge of the next surrounding louver, and there being substantially no obstruction to the passage of light from the bulb to the ceiling other than that due to the bulb mounting, and substantially no obstruction to the vertical passage of light from the ceiling downward, whereby when the fixture is hung in properly spaced relation below a celling, a substantial area of the ceiling will be illuminated as a result of the wide spread of the light beam emitted by the bulb, said louvers and safd baffle forming a system of shields for preventing glare from reaching the eye of an observer below and at the side of the fixture, and said fixture being free of light obstructing elements other than those enumerated, whereby substantially all of the light reflected from the ceiling will be utilized for illumination of the working plane.

FRANK P. KUHL.