US2093165A - Lighting fixture - Google Patents

Description

Sept. l4, 1937. c, w, FLOOD, JR 2,093,165

LIGHTING FIXTURE Filed Feb. 15, 1936 INVENTOR Charles M27000,

Patented Sept. 14, 1937 ,7 UNITED STATES PATENT OFFICE LIGHTING FIXTURE Charles W. Flood, Jr., Philadelphia, Pa. Application February 15, 1936, Serial No. 64,041

2 Claims. (01. 240- 78) The object of the invention is to provide improvements in lighting fixtures broadly, but more particularly in the type which is hereinafter described in detail.

Primarily, another and more specific object is to provide a novel support for a fixture, which will preclude the casting of shadows by such support, especially in the case of the holder of the usual bowl or globe, such as is present in practically all forms of indirect and semi-indirect lighting. However, the immediate need for such an improved fixture is brought about by the relatively recent perfection of the so-called high intensity mercury vapor lamp, and particularly as the same becomes more widely used in domestic, oifice, auditorium and similar illumination, as compared with the illumination of factories, arenas, and the like, wherein the presence of a different color in the secondary light within the limits of a shadowarea are of less importance.

While the improved fixture is by no means limited to use with the above-mentioned high intensity mercury vapor lamp, its adaptability in combination with such a lamp is so marked, that certain characteristics of the samewill be referred to, as they relate to or multiply the ad.- vantages arising from the use of such fixture. This lamp is primarily a mercury vapor unit, with its long recognized characteristic of emitting light, which while aiding vision with lessened eye-strain, and thereby, it is said, reducing nervous tension such as is caused by eye-strain,

nevertheless is rich in blue rays but is practically entirely deficient in red, orange and/or yellow rays. To be even more exact, the light emitted from the lamp is substantially all produced in the center of the visible spectrum, that is, in the yellowish green area and extending into the blue.

This being the case, it has been found highly advantageous to combine a plurality of common metal filament or similar lamps, which are high in red, orange and yellow rays, in the same unit with a high intensity mercury vapor lamp, except that it is advisable to space the zones of most intense heat in the former as far as practicable from the latter, in order that said former will permit the cooling of the said latter, as quickly as possible following cessation of the current supplied, so that the vapor lamp will be reconditioned as soon as possible for again starting, it being a characteristic ofsuch a lamp that it cannot again startyuntil the mercury vapor within it has been first condensed, and this requires variously from five to fifteen minutes.

ging form. It .is also preferable that such ,sup-

thereto. 7, v

Having thus obtained a lamp group, which as'a unit emits practically a full daylight range of ray color values, it becomes advisable that there shall be no shadow from which the rays from the mercury vapor lamp are excluded, as such shadow especially upon some surfaces will be distinctly off color, as compared with the remainder of the illuminated area. a .7 a

More fully stated, the object of the'invention is therefore to provide av lighting fixture, in which 1 a high intensity mercury vapor or other form of light from onesource iscombined with metal filament or other form of light from a second source, and in which the color or colors emitted by the first differs substantially from that of the second, one of said light sources being centrally or axially positioned, while the other source is spaced radially away from the first, and the two are suspended within a common nether-imposed bowl or globe, which reflects practically all, or at least a substantially portion of the rays from the combined light sources radially upwardly.

In order to fulfill this object, an immediate supporting element for the fixture unit has been provided, which, instead of being substantially rectilinear and in a geometric plane with the axis of thefcentral. light source, extends angularly with respect to such axis, as in the case of a in a regular path, or in the case of one or more diagonally extending elements not confined 'to such a regular geometric figure as that of a spiral, as for instance an alternating or zig-za'gporting element, regardless ,of shape, shall be closely positioned with respect to the preferably singie, centrally positioned light source, in order that even the penumbra of a shadow which would be cast by saidelement from one point of 40 saidsource is totally obliterated by the unim paired illumination-from other points upon the same source, either or both above and below such shadow-casting point.

With the objects of the invention, thus stated, 5 the embodiment herein shown comprises further details of construction, which are hereinafter fully brought out in the following description, when read inconjunction with the accompanying drawing, in which Fig. .1 is avertical diametrical section through a fixture of the improved type, and Fig. 2 is a diagrammatic view, including the central light source within such fixture and a portion of the supporting. element as related Referring to Fig. 1, there is here shown an embodiment of the invention which may comprise any suitable type of lamp-supporting member, but which member is here shown as comprising an annular portion I, surrounding a depressed central portion 2, in which latter is positioned any desired form of lamp receptacle 3, while radially outwardly said annular portion is preferably deflected downwardly to provide a substantially conical portion 4, to which are secured any desired number of lamp receptacles 5, beyond which said supporting member terminates in an outwardly extending preferably planular flange 6.

Beneath, and removably secured to said supporting member by any suitable means I, is any desired form of ornamental cover 8 for said supporting member, and this cover also comprises a laterally deflected marginal portion 9, which is adapted, when in operative position, to cooperate with the fiange 6 of said supporting member, so as to grip or clamp between them the inner annular edge portion Ill of a bowl or globe ll, which may be of any desired shape and construction whether transparent, semi-transparent, or opaque, or a combination thereof.

That portion of the fixture thus described may obviously be supported either in upright position, as from the fioor, or other suitable foundation, or it may be inverted and suspended from the ceiling or other superposed body. In either case, the fixture is designedto operatively support a preferably single source of light, with the axis of said source coincident with the axis of the fixture, and said source being illustrated by a tubular high intensity mercury vapor lamp H, in so-called base-down position within the central receptacle 3, while surrounding said lamp and in radially spaced relation therewith preferably a plurality of lamps 13 of another type are positioned, these last-mentioned lamps being preferably of the well-known metal filament form, and with their axes extending diagonally outward from said first-mentioned lamp, or in other words, the outer positioned lamps being within the confines of the bowl or globe H, but with their hottest portions spaced as far from the mercury vapor lamp as may be feasible. This is in order that the said outer positioned lamps will not seriously delay the cooling of the mercury vapor lamp, following a short period during which the current to said lamps may be extinguished. In such a case, with the restoration of the electric current, the outer lamps would light immediately, and if more closely grouped would tend to prevent the cooling of the central lamp, which latter condition is necessary in order to condense the mercury vapor within the same, before it can again become lighted, or illuminated, and at present such cooling requires a substantial lapse of time of from approximately five to fifteen minutes duration.

Now, it will be obvious that this fixture may be used as hereinbefore referred to in either upright or inverted position, but for purposes of illustration, it is shown in the drawing as being in inverted position. In this instance, and also for purposes of illustration, there is shown a tubular pipe or conduit [4, which represents any available service outlet extending downwardly from the ceiling, as above mentioned, and being provided with a downwardly directed cap E of any suitable form, except that said cap is provided with a preferably diagonally extending bore 75 It, in which is secured in any suitable manner one end of a spirally shaped tube or rod l1, the opposite end of which is normally secured to the annular portion l of said. lamp supporting member. While said support element I1 may comprise a rod, it preferably comprises a tube through which may extend the current conducting wires, which lead into the space between the lamp sup porting member and the cover 8, when such wires lead to the receptacles 3 and 5 in well-known approved manner.

Of particular note is the fact that said tubular, or similar supporting element, extends co-axially about the central lamp l2, and in relatively close proximity thereto, and is preferably of considerably less diameter or transverse width than said lamp, for the purpose hereinafter described. It should also be noted that instead of said supporting tube comprising a regularly progressive spiral or similar geometrical figure, it may comprise any suitable shape by which it progresses between the supporting pipe or other element I l, and the said lamp supporting member l-6.

Referring to Fig. 2, there is here diagrammatically illustrated the result of providing said supporting tube of a diameter or transverse measurement substantially less than that of the lamp 92, which it surrounds or is at least adjacent to. In this diagram, it will at once be apparent that the region l8 of complete shadow, or in other words the umbra, is so small as to be practically insignificant, while the penumbra, or region I9 of partial shadow, such as may be cast upon a surface 25, is characterized by such an extremely small diminution of illumination, as to be entirely negligible.

In addition to the foregoing, is the fact that by extending the tube ll diagonal1y,.the light emitted by other portions of the lamp l2, either or both above and below the portion partially screened by said tube at a given point, also directly illuminates the area H! of the penumbra upon the surface 28, so that by reason of this additional fact, it can be truthfully said that the fixture is adequately supported, but by means of a supporting element which casts no shadow at all.

In the case of a mercury vapor lamp which notoriously emits rays only from the yellowishgreen through the blue end of the spectrum, the shadow cast by supporting means heretofore in use presents an area, which when being illuminated only by the metal filament lamp l3, produces an undesirable and inharmonious color contrast of relatively distinct yellow or yellowish tint, Whereas with the present device, the blending of the light rays, emitted from the two sources I2 and I3, normally cooperates to produce a balanced illumination, which can be made to very closely approximate, if not actually duplicate, the true white nature of daylight. In other words, it produces a synthetic white light.

So far as the improved fixture is itself concerned, it can function in any position. Therefore, mention hereinbefore of upright or inverted position is merely representative of any position which may be desirable and feasible.

, Having thus described my invention, what I claim asv new and desire to protect by Letters Patent of the United States is:-

1. A lighting fixture, comprising a superimposed suspension support, a depending spirally shaped tubular wire-conducting element attached to said support, a. member carried by a lower portion of said element, a bowl carried by said member, a substantially tubular lamp suption of said element, a bowl carried by said member, a substantially tubular non-filament lamp 7 supported within the spiral of said element, and a plurality of filament lamps also carried by said member radially outwardly from the spiral of said element, all of said lamps being within said how].

CHARLES W. FLOOD, JR. I

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