US2220298A - Luminaire - Google Patents

Description

Nov. 5, 1940. J STAlR ET AL 2,220,298.

LUMINAIRE Filed Nov. 16, 1938 I INV-ENTORS: 1/4605 1.5mm 4N EARL C.M -/mw o or," x

ATTEY.

Patented Nov. 5, 1940 UNITED STATES LUMINAIRE Jacob L. Stair, Chicago, and Earl C. McKinnie, Oak Park, Ill.

Application November 16, 1938, Serial No. 240,768

Claims.

This invention relates to lighting fixtures or luminaires, and it has especial reference to a structure of this character wherein a reflecting device is employed for directing light rays in a 5 given direction and wherein means are also provided for directing light rays in another direction to illuminate, for example, a translucent globe that envelops the lamp and the reflecting device. Furthermore, through the medium of the elements of the luminaire, the character and intensity of the resultant illumination is controlled.

The improved luminaire embodies a more or less translucent globe or exterior bowl that has a comparatively wide opening in its bottom through which a proportion of the light rays are adapted to pass in a downward direction. Means within the globe, and surrounding the bulb or other light source, reflect a proportion of the light rays through the bottom opening in the globe, so that both direct and reflected rays pass down out of the luminaire. The reflecting means has an annular outlet or gap of substantial width through which direct light rays from the bulb emerge in a direction that is preferably lateral to the axis of the luminaire for the purpose of permitting these rays to impinge upon the globe or bowl to illuminate the latter. Interposed in the path of these lateral light rays is an annular diffuser element that is adapted to break up or scatter the direct rays thereby tending to evenly distribute such rays upon the globe. The character and the quantity of these lateral rays are determined by the density of the difiuser element so that any intensity of illumination from brilliant down to a dull glow may be secured. The direct rays from the bulb and the reflected rays from the reflector means, which emerge through the bottom opening in the globe affect brilliant illumination upon objects within a given zone below the luminaire, and the light rays emitted through the globe produce a difiused illumination upon the Walls and the ceiling of the room. Light control means in the form of louvers are positioned below the light source in order that the downward rays may be directed in the manner desired and the eyes of persons below the fixture are shielded from direct or reflected rays from the lamp. Thearrangement of the parts of this luminaire is such that the diffuser means and the louvers are supported 7 by the reflector means, and the latter is supported by the globe. All of these elements are arranged through the bottom opening in the globe, and the difiuser element is conveniently supported upon a portion of the reflecting device, as are also the control louvers.

One of the principal objects of this invention is to provide a luminaire that is novel in both construction and assembly. Other objects are to provide a structure that is convenient to install and performs its required functions with the highest degree of efficiency. The luminaire is economical to produce so that it may be sold at a reasonable retail price to the user. And the parts are readily accessible for inspection, repair, and replacement.

The various objects of the invention are accomplished by means of the structure hereinafter fully described and as more or less particularly pointed out in the appended claims. For a better understanding of the construction and arrangement of the parts of the luminaire, reference is made to the accompanying drawing that forms a part of this specification.

In the drawing:

Figure 1 is a view, half in elevation and half in vertical axial section of this novel luminaire.

Figure 2 is an elevation of the reflecting means or unit removed from the luminaire.

Figure 3 is plan of the louver unit detached from the fixture.

The drawing is to be understood as being somewhat schematic and is for the purpose of disclosing a typical or preferred form in which the invention may be produced. In the drawing the same reference characters are used to designate like parts in the different views.

The structure herein disclosed consists of an electric socket I0 carrying an electric light lamp or bulb II, and said socket is enveloped by a metal shield I2, that is of annular form and slightly tapered or frusto-conical in form. The shield l2 has an outwardly and downwardly flared portion at its lower end 13 that terminates at its outer edge in a depending flange M which provides an annular seat to receive a flared lip I5 surrounding an opening in the top of the globe It. A plurality of thumb screws 17, screwed into eyelets IB in the flange It are employed to maintain the flared lip of the globe or body detachably in position,

This globe l6 above referred to is preferably a hollow body made partly or wholly of translucent material such as glass or the like, and in the type shown in Figure 1 the body is somewhat spherical in shape, but it will be understood this globe or body member may be ornamental if desired. At its bottom the globe or body is provided with a relativelylarge opening [9 through which light rays from the bulb may pass. These rays are either direct, or reflected or both.

The manner of illuminating the globe or body of the fixture, as Well as for emitting a considerable volume of the light rays out of said body through the opening i9, is in the form of a lightdirecting device such as shown in Figure 2. This device is especially adapted for use in a direct lighting fixture, and, as shown, it embodies an annular upper portion or collar 20 that is located,

so that it surrounds the neck of the bulb II and is positioned adjacent or in the lower portion of the shield 52. Radially disposed, spring bracket arms 2!, having down turned outer portions, are secured to this annular portion or collar 20 and they project over and rest, upontheupper edge of flared lip l5 of the globe or body. These bracket arms aiio-rd the means for supporting the light reflecting means upon the top of and within.

the globe or body it. Below the collar 20 there is the upper section of a two-part reflector, which section consists of somewhat conical- shaped portions 22 and 23 that flare outwardly as shown,

and the lower edge of the portion 23 has its base or lower edge in a plane above the horizontal plane of the concentrated light point 24 of the bulb. The lower section of this two-part reflector consists of a somewhat conical-shape section 25 that flares outwardly in a downward direction and at its upper edge it is spaced from the upper section of the reflector and is also below the horizontal plane of the concentrated light point 24. These reflector sections 25 and 22-23 are maintained in vertically spaced relation to each other by straps 28 so that an annular light gap or light passageway 2'! is provided between the proximate edges of. the reflector sections. Thus, a certain proportion of the direct light rays from lamp I I is emitted; laterally and passes transversely through gap 2,? of the two-part reflector or light directing device towards the walls of theglobe or body of the fixture.

In order to diffuse or scatter the direct rays that pass transversely through the light directing device, a translucent ring difiuser orcylinder 28 is interposed between the bulb and the globe or body. This difiuser 28 is preferably supported 0 by a suitable portion of the reflector or light directing device so as to. extend vertically across the gap 27 in a position where it intercepts the light rays that are emitted through said gap. This difiuser ring or cylinder is of slightly greater diameter than the lower portion of the upper section of the light directing device, and in order to maintain said diffuser 29 in position a ledge or shoulder 29 is formed near the top of the reflector section 25 to provide a seat on which the diffuser removably rests. The diffuser is made preferably from opal glass or any other light transmitting medium.

The bottom of the reflector section 25 is disposed in the wide opening 22 in the globe or fixture body, and its lower margin is flared outwardly and turned upwardly to provide a lip 30 that engages the margin of the globe surrounding the lower opening I!) therein.

From the foregoing it will be seen that the opening 19 in the bottom of the globe or body permits direct rays from. the bulb H to pass out of the fixture in a downward direction, and the inner surfaces of the light directing device reflect other light rays out of the fixture also 75 through said opening IS. The light-gap or passageway 2'! between the spaced upper and lower sections of the light directing device permit direct rays from the bulb to pass transversely through the reflector to the globe orbody of the fixture and such rays are broken up by the diffuser cylinder 28 so that they are spread upon the globe. Thus, the translucent walls of this fixture body are illuminated and the light rays pass laterally out of the fixture in a horizontal or nearly horizontal direction. The density of translucency of the difiuser cylinder 28 controls the intensity of the illumination of the outer globe or shade IS. A somewhat opaque diffuser will create a rather dull illumination of the globe,

whereas a diffuser which is only slightly opaque will result in a brilliant illumination of the globe. This manner of control of the light rays is quite essential in many places where the luminaire is installed, and a given result is simple to accomplish and may be done in a variety of different ways, such as for example, by the use of divers thicknesses of glass cylinders, or by using several concentric cylinders of the same density of light filtration, or by the use of tints applied to one or both surfaces of the diffuser cylinder.

For the purpose of reducing the glare incident to the downward passage of light rays through the bottom of the globe or shade suitable control means are provided which are preferably in the form of the louver unit shown in plan in Figure 3. As shown this unit comprises concentric rings 3| and 32 that are maintained in desired relation by means. of narrow cross-bars 33, and are suspended in the lower opening of the luminaire by narrow hangers 34 having hooks 35 at their upper ends to engage the upper margin of reflector member 25 as shown in Figure 1. The rings 3i and 32 are preferably metal bands and may be either cylindric or frusto-conic in section depending upon the service desired. The hangers may be narrow metal bands or a suitable gauge of wire so that their hooked ends 35 will not interfere with the emission of light rays through the gap 21 between the reflector members 2223 and 25. The position of the louvers may be adjusted vertically with respect to the lamp and the lower opening of the luminaire in which they aredisposed by shortening the hangers 3.5 whenever desired.

It will be noted the light source is in such position that the downward light rays (both direct and reflected) passing downwardly out of the fixture prevents glare in the eyes of persons beneath or near the fixture. Access'to the interior of the fixture is readily obtained by first removing the louvers and bulb, and then loosening one or more of the thumb-screws H from the. lip l5 and lowering the'body downward to remove it from the holder structure at the bottom of the shield I2. One or more of the spring arms 2l' may be lifted and swung to one side which permits the light directing, member to be removed downward through the opening 22 in the body thereby affording access to the inside of the body as well as permit the difiuser cylinder 28 to be lifted from its seat or shoulder 29 and removed.

What we claim is:

1. A lighting apparatus comprising a light source; a light-directing device around said light source adapted for reflecting light rays in a downward direction, said device embodying an upwardly converging concave reflector the lower margin of which is above the horizontal plane of .said light source, and a lower upwardly congreater diameter than the first named reflector, said lower reflector provided with an opening in its upper portion through which reflected light rays from the upper reflectors pass in a downward direction, said reflectors disposed in vertically spaced relation whereby an annular light gap is provided between said reflectors, said gap having substantial dimension in a vertical direction; an annular diffuser registering'with said light gap; and a translucent shade outside said reflectors, said light source, and said diffuser, said shade provided with an opening alined with the lower rim of the lower reflector and through which pass the reflected light rays from said upper reflector.

2. A lighting apparatus comprising a light source; a light-directing device around said light source, said device embodying an upwardly converging reflector member of irusto-conic section disposed wholly above the horizontal plane of the light source, a lower upwardly converging reflector member of frusto-conic section disposed wholly below the horizontal plane of the light source and spaced below the base of the upper member whereby a light gap of substantial width is provided for emission of direct light rays between adjacent margins of said members; a translucent shade outside said light source and said reflector members, said shade provided with a light egress opening in its bottom; said reflector members both adapted to reflect light rays in a downward direction through the egress opening in said shade; and diffusing means disposed in the path of the direct rays that pass through said light gap, whereby to distribute light rays upon the interior of said shade.

3. A lighting apparatus comprising a translucent shade provided with top and bottom openings; a light source within said shade; and a light directing device interposed between said shade and said light source and adapted to reflect the major portion of the light rays downward through said bottom opening in the shade, said device embodying upper and lower reflectors that are spaced apart a substantial distance to provide a wide light gap, said reflectors comprising upwardly converging elements having openings in their top portions, the said upper reflector adapted to reflect light rays 'down through the top opening in said lower reflector and out through the bottom opening in said shade; means for difiusing the direct light rays passing through said light gap, the bottom of said lower reflector fitting the margin of the bottom opening in said shade, and the top of said upper reflector extending into the top opening in said shade, the

remaining portions of said light directing device including said difiusing means having diameters less than the diameter of the bottom opening in said shade whereby to permit bodily removal of the device as a unit through said opening.

4. A luminaire comprising a holder; a translucent body having an opening at its top and secured to said holder, said translucent body also having an opening'in its bottom for downward passage of light rays; a light source supported by said holder and disposed within said body; and light directing means within said body around the light source, and extending from the lower opening up into the top opening, said means embodying an upwardly converging reflector device having spaced opaque upper and lower concave portions and an intermediate light transmitting portion, the opaque concave portions of said device having top openings accommodating the light source whereby the upper portion of said device is adapted to reflect light rays down through the-lower portion past said intermediate light transmitting portion of the device, the said opaque portions as a unit adapted to reflect light rays down through the bottom opening of the body and the intermediate light transmitting portion of said device being translucent whereby lateral light rays direct from the light source pass transversely through the reflector device and are diffused upon the walls of said body. f

5. A luminaire embodying a light bulb, a shade holder supporting said bulb; a translucent globe supported by said holder, said globe having an opening in its bottom; an upwardly converging reflector surrounding the lower portion of said bulb and disposed in the opening in said globe, said reflector adapted to reflect light rays downwardly through said opening; an upwardly converging supplementary reflector surrounding the upper portion of said bulb, said supplementary reflector adapted to reflect light rays downwardly through the first-named reflector and through the opening in the bottom of said globe, the proximate margins of said reflectors being vertically spaced a substantial distance from each other, the said margins disposed in planes respectively above and below the horizontal plane of the light source in said bulb whereby to provide a relatively wide light gap through which direct rays from said bulb emerge to illuminate said globe; and a louver structure in the opening in said globe and disposed within the first-named reflector.

' JACOB L. STAIR.

EARL C. McKINNIE.

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