US1743851A - Lighting fixture - Google Patents

Description

Jan. 14, 1930. GUTH 1,743,851

LIGHTING FIXTURE Filed Nov. 23, 1927 ATTORNEY Patented Jan. 14, 1930 UNITED STATES EDWIN F. GUTH, OF ST. LOUIS, MISSOURI,

LIGHTING FIXTURE Application filed November 23, 1927. Serial No. 235,187.

My invention relates to that class of fixtures of the well known Brascolitetype, as covered by my Reissue Patent No. 14,680. I

My invention has for its object, to construct a fixture of that type which will have a higher efficiency than is at present obtainable; and this I accomplish by making the enclosing bowl very much smaller than is possible under existing conditions. My invention has for its further object, so to shape the bowl, and to construct it of such material. that it will be free from glare, which is well known to be one of the most detrimental features of lighting units. As is also well known, the intensity of the light is much greater as the shield nears the source, andas a consequence the glass must not be close to the lamp bulb.

As illustrated, I have overcome this by constructing my bowl ofparabolic shape, and of materially greater density Where the bowl is closest to the lamp. This may be accomplished by materially thickening the glass of the bowl at its lower portion where it i near the lamp bulb, but it may be found desirable in practice to employ some medium which will reduce the brightness to the desired amount. Such a construction, however, would be most ineliicient, in so far as the working plane is concerned; and I avoid this by providing a large opening in the bottom of the bowl, so that a direct light of great intensity is distributed onthe working plane, iminediately below the fixture, over an area of a 25 radius.

A further advantage resulting from the use of a bowl with this large opening in the bottom is, that although it enables the fixture to deliver tothe useful-plane a direct light which can be controlled within an area of 50-25 each side of the nadir, yet the filament is shielded from' theeye, so that no deleterious effects are produced by the light coming to the user, notwithstanding the high intrinsic brillianey' of the filament of the a high-powered lamp. The provision of this opening also enables me to avoid a very seriously objectionable feature present in all units of this ty e, i. e.,

drop of elficiency'through service, for the ciency, for I can use a reflector of smaller diameter, and still control all the upwardly directed light rays, within the area of the reflecting plane. This reduction in size, withoutsacrifice of eiiiciency, enables the production ofa very inexpensive unit which is free from objectionable glare.

My invention has for its further object, to provide a socket which will adjustably sup- 7 port the fixture, and will also electrically insulate it therefrom. My construction will also provide for complete protection for the lead-in wires.

My means of accomplishing these objects may be more readily understood by having reference to the accompanying drawings, which are hereunto annexed and made a part of this specification, in which-- v Fig. 1 is a vertical sectionalelevat-ion; and

Fig. 2 is a fragmentary-bottom plan view.

Similar reference numerals refer to similar parts throughout the entire description.

As shown in the drawings, I provide a socket 1, which is preferably made of suitable 35 insulating material. (As' illustrated, this socket is the one described in my co-pendlng application, Serial No. 184,873.) From this socket 1 is suspended at reflector 2, of the canopy type, the lower surface. 3, of which is preferably porcelain-enameledv The socket 1 has a thread 4 on its outer surface, which supports the fixture. A cap 5 is mounted at the top of the socket 1, and is screwed on to the centralstud G of the standard junction or 5 outlet box 7. In the drawings I have shown a plurality of loops 8, formed out of the reflector 2 adjacent the socket 1, to. which loops.

8 are attached rods or wires 9 which support the bowl 10, which is preferably formed of translucent glass; but it will be obvious that any desired form of fastening for these rods 9 may be employed. An electric lamp bulb 11 is mounted in the socket 1 and depends downwardly therefrom. As clearly seen in the sectional view, the bowl is formed with a very large opening 12 in its bottom, and the side wall is very thick at its lower portion 13, tapering to a point 14 as the surface gets farther from the light source and can be thinned without producing glare. A suitable switch 15 is mounted on the upper part of the refiector canopy 2, and has depending from it the usual chain pull 16, for switching the current on and ofi'as desired.

For the purpose of full disclosure of my invention I have described in some detail a specific embodiment thereof; but it Will be apparent that numerous changes might be made in the physical embodiment of my invention within the scope of the claims, and I do not 4 desire, therefore, to be understood as limiting myself, in the broader aspect of my invention, to the specific construction shown and described.

Having described my invention, what I regard as new, and desire to secure by Letters Patent of the United States, is:

1. In a lighting fixture, a source of light,

a bowl formed of light diffusing material surrounding said light source, the thickness of the material in said bowl decreasing with the distance from the light source whereby substantially uniform-brightness of the bowl is obtained.

2. In a lighting fixture, a source of light, a bowl formed of light difl'using material surrounding said light source, the thickness of the material in said bowl decreasing with the distance from the light source whereby substantially uniform brightness of the bowl is obtained, there being a large opening in the bottom of the bowl.

EDWIN F. GUTH.

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