US2305722A

US2305722A - Lighting fixture

Info

Publication number: US2305722A
Application number: US352732A
Authority: US
Inventors: John F Livers
Original assignee: FARIES Manufacturing CO
Current assignee: FARIES MANUFACTURING Co
Priority date: 1940-08-15
Filing date: 1940-08-15
Publication date: 1942-12-22
Anticipated expiration: 1959-12-22

Description

Dec. 22, 1942. J? F. LIVERS 2,305,722

' LIGHTING rlxwunn Filed Au 1'5, 1940 FIG. 1

INVENFOR. Jamv f. LIVERS ATTORNEY Patented Dec. 22, 1942 LIGHTING FIXTURE John F. Livers, Decatur, 111., assignor to Faries Manufacturing Company, Decatur, 111., a corporation of Illinois Application August 1940, Serial No. 352,732

1 Claim.

My invention relates to that class of lighting flxtures which employ the recently developed fluorescent tubes as their light source.

The general acceptance by the public of this type of lighting has resulted in the production of fixtures to employ such a light source, in which, no doubt due to the haste in which they were designed, there is present an amount of glare which is considerably above the standard requirements.

It is now recognized that fixtures possessing glare above the minimum have a deleterious effect upon the eyesight of the user, which results in undue fatigue, etc.

My invention has for its principal object to produce a fluorescent lighting fixture. which will reduce the glare below'the minimum requirements of the I. E. S. without sacrifice of efllciency.

A further object is to construct such a fixture so that almost all of the output of the light source shall be availabl for useful illumination.

A further object is to so construct the fixture that it will (although attaining a high degree of efficiency) have easy accessibility. and produce a pleasing quality of light.

A further object is to permit the majority of the lumens, emitted by the source, to pass to the working plane without producing glare and to reflect and redirect a majority of the remaining lumens downwardly.

A further object is to utilize the remaining Iumens to illuminate the walls and ceiling.

My means of accomplishing the foregoing objects may be more readily understood by reference to the accompanying drawing which is hereunto annexed and forms a. part of this specification in which:

Fig. l is a cross sectional view of my device;

Fig. 2 is a bottom plan view. Similar reference numerals refer to similar parts throughout the entire specification.

As shown in the drawing my fixture comprises a frame I I, which carries a pair of curvilinear reflectors Ill and I2, which are mounted above and parallel to the fluorescent light source I, which is mounted in the frame ll. These reflectors Ill and I2 are preferably designed to receiv and redirect by reflection the lumens emitted from approximately 125 degrees of the circumference of the light source It.

Extending longitudinally of the fluorescent tubes I4, I mount reflectors I6 and I1. They may be secured to the frame I|,'in any suitable or desired manner. These longitudinal reflectors l8 and I! are angular in cross section and have their surfaces I 8 and 20 coated with a reflecting medium. In practice I have found it preferable to mount these longitudinal angular reflectors l6 and I1, with the apex of the angle in the plane of the axis of the fluorescent tube ll. Obviously.

this may be varied according to the amount of light flux it is desired to reflect into the upper or lower hemisphere.

Below the plane of the light source l4, and parallel thereto, I mount a plurality of shields or screens 22. These screens are preferably coated with a mat reflecting surface, having a low absorption quality. If desired they may be made adjustable. I have found in practice that in the majority of cases, it is not necessary. It sufllces if they shield the light source H. from the ey of an observer except at a point directly below the fixture.

In ractice it has been found that this construction allows all of the lumens emitted from degrees of the circumference of the light source I4, to pass downwardly to the working plane.

The remainder of the light rays, not reflected or passing downwardly as described, will pass without obstruction or reflection to the walls, lighting them with a softly diffused light entirely free from glare.

It will be apparent to persons skilled in the art that by varying the curvature of the reflectors l0 and I2, with relation to the position of the light source 14, it will be possible to distribute, in any desired direction, that portion of the light flux which is controlled by these reflectors.

Referring to Fig. i it will be seen that the reflector I2 is so shaped that its lower edge projects perpendicular for the distance of the diameter of the fluorescent lampsthen outwardly in a gradual arc until a point directly above the apex of one of said angular reflectors, then continuing parallel to the working plane in a horizontal direction beyond the said angular reflector. While reflector III is so shaped that its lower edge projects perpendicular for the distance of the diameter of the fluorescent lamps then outwardly in a gradual arc until it reaches a point directly above the apex of one of said angular reflectors where it curves sharply and downwardly to a point beyond said angular reflector. This construction provides a novel means of intensifying a portion of the lume'ns directly on the working plane by gathering an redirecting the rays as in reflector l0 while at the same time providing adequate illumination as in reflector l2.

Preferably the ends 24 and sides 26, of the fixture are opaque. If it is desired to avoid the contrast caused thereby, they can be formed 01' translucent glass or of a translucent plastic.

Although I have described a specific shape for the fixture, such description is solely to supply an illustration of the preferred embodiment of the invention, and I do not desire to be understood as being limited to such specific shape or construction, except as such limitations may appear in the hereinafter contained claim.

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

In a fluorescent lighting flxture, a frame having side and end walls, a pair of fluorescent lamps having their ends mounted on the end walls of said frame and in spaced parallel relationship, their axes being in the same horizontal plane, a pair of reflectors angular in cross section mounted on the inside of a side wall, each of which comprises two flat surfaces meeting at an apex in the plane of the axis of the adjacent lamp,

said reflectors extending longitudinally of and parallel to said lamps, a plurality of parallel shields mounted below said lamps which shield the eye 01' an observer but permit direct and reflected rays to reach the working plane, and a pair of curved reflectors one for each lamp mounted above said lamps to redirect the direct and part of the reflected rays outwardly and downwardly, one of said curved reflectors being shaped so that its lower edge projects perpendicular for the distance of the diameter of the fluorescent lamps, then outwardly in a gradual are until a point directly above the apex of one of said angular reflectors, then curving sharply downwardly to a point beyond said angular reflector, the other of said curved reflectors being shaped so that its lower edge projects perpendicular for the distance of the diameter of the fluorescent lamp, then outwardly in a gradual arc until a point directly above the apex of the other of said angular reflectors, then continuing parallel to the working plane in a horizontal direction beyond the said angulanreflector, whereby varying intensity of illumination falls on the working plane.

JOHN F. LIVERS.