US2305723A

US2305723A - Luminaire

Info

Publication number: US2305723A
Application number: US397694A
Authority: US
Inventors: John F Livers
Original assignee: FARIES Manufacturing CO
Current assignee: FARIES MANUFACTURING Co
Priority date: 1941-06-12
Filing date: 1941-06-12
Publication date: 1942-12-22
Anticipated expiration: 1959-12-22

Description

Dec. 22, 1942. vE 5 2,305,723

LUMINAIRE Filed June 12, 1941 2 Sheets-Sheet 1 ATTORNEY Dec. 22, 1942. w s 2,305,723

LUMINAIRE Filed June 12, 1941 2 Sheets-Sheet 2 F IG. 2

I 8 a: W- as A d h j I I I I I 1 f 2 o 5 BALLAST 5" STAmNG M'IISITOR ATTORNEY Patented Dec. 22, 1942 LUMINAIRE John F. Livers, Decatur, 111., assignor to Furies Manufacturing Company, a corporation of 11- linois Applicationjune 12, 1941, Serial No. 397,694

3 Claims.

My invention is designed primarily for fluorescent lighting and more specifically to the illumination of library or study tables accounting desks or similar workingplanes.

One of the greatest difficulties in such illumination is due to veiling glare or where the lamp is not properly shielded, light from the direct ray of the lamp produces such glare upon the surface of the table or on the work as to induce undue fatigue and eyestrain. Another objection is that there is nearly always present acyclic flicker upon the illuminated arcs which impairs the usefulness of the luminaire.

My invention has for its principal object to provide reflectors of both specular and diffuse types arranged so that they will both receive the direct light rays emitted by the lamps and to cause the reflected light rays from the specular reflector to be intermingled with the difluse reflection with the result that the reflectors are balanced. The diffused rays serving to soften the specular reflected rays, thereby providing corresponding eye ease to the user.

A further object is to combine and reflect the light rays from both lamps from a single reflector. I accomplish this by a combination of duplicate dual balanced reflectors each of which is provided with specular and diffuse surfaces and fluorescent lamps arranged so that each reflector will receive not only the direct and reflected rays emitted from one lamp, but will also receive direct rays from the adjacent side of the adjoining lamp.

I have found in practice that a lamp embodying this structure will substantially overcome the cyclic flicker which is so objectionable.

In the operation of fluorescent lamps the auxiliaries are so constructed that one lamp is kept out of phase (when operating on A. C. current); This is referred to as lagging, but actually one lamp is always burning while the other is out. By my novel arrangement of dual reflectors I am able to almost entirely eliminate this objectionable efiect. A further object of my invention is to eliminate veiling glare.

A further object is to combine the control of the light rays by a specular reflecting surface so as to distribute the lumens over precise areas but to soften the characteristics of such specular reflection by mixing them with rays from a diffuse reflecting surface.

My means of accomplishing the foregoing objects may be more readily understood by reference to the accompanying drawings which are hereunto annexed and form a part of this specification in which:

Fig. 1 is a side elevation of a luminaire embodying my improvement;

Fig. 2 is an enlarged end view partly in section to show the interior construction; and

Fig. 3 is a modification of the structure shown in Figs. 1 and 2.

As shown in the drawings I have illustrated my invention as applied to a table lamp, though it will be obvious to persons skilled in the art that it is not confined to such type of lighting but may be, found useful wherever the problem which it is designed to solve is present.

I mount two fluorescent lamps l and 2 parallel to each other on the same plane but spaced from each other. As the mounting of these lamps is standard construction, a detailed description thereof is not necessary. These lamps may be mounted adjacent the top of a standard 3 having a base 4. The standard may, if desired, be provided with a central tube 5 which may extend through the top of a table 6 only fragmentary portion of whichis shown as obviously it forms no part of my invention.

The tube 5 leads to the operating auxiliaries comprising ballast 5' and starting compensator 5" and wiring connections which are standard parts and hence are well known.

About the lamps i and 2 are mounted two sets of my improved reflectors I and 8; as they are duplicates I shall only describe one set of them. The lower reflector 1 consists of a base portion 9 and an upwardly and outwardly flaring portion Ill. The upper edge of this flaring portion extends above the axis of the lamp I so that at no time is the lamp visible to the user, when seated normally at a table or a desk.

The inner surface of the lower reflector I is coated with a suitable reflecting surface, either diffuse or specular as desired.

The upper reflector comprises a curvilinear portion II the lower inner lip or edge ll' of which is spaced above the lamps l and 2, and is located midway between the lamps. This space allows the direct rays; emitted from the side of lamp 2 adjacent lamp l, to pass through the space below the lip II and above lamp l and mingle with the rays from that lamp, while the opposite action takes place with the rays emitted from the side of lamp I adjacent lamp 2. This curved portion II is provided with a specular reflecting surface. By the use of a specular reflector it will be clear that I. can obtain accurate distribution of the light rays. The reflector 8 I has a plane portion I 2 which slants outwardly and downwardly. The edge H of the plane portion I! is located in line with the top edge of the lower reflector I. The inner surface of the plane portion I2 is coated with a diffuse reflecting surface.

Due to this arrangement the direct rays from the lamps are allowed to impinge upon both the diffuse and specular reflectors. It will be clear to those familiar with the art that unless provision is made for this function the operating characteristics of the auxiliaries would be nullifled. Those rays which pass in a downward direction will strike the lower reflector and be redirected to that portion of the upper reflector provided with the specular reflecting surface. The specular reflector will redirect the light rays, which impinge upon it, outwardly causing them to meet and mingle with the rays redirected by diffuse reflection from the plane portion I 2 of the upper reflector. The result is to produce upon the working plane a soft glareless illumination as the specular reflector provides for accurate and scientific control of the light rays while the diffuse reflector, which is preferably white, breaks up and softens the light distribution.

In the detail view Fig. 3, I show the base of a portable lamp which is not intended to be attached to a piece of furniture. In this structure I provide a base or housing 20 which may be secured to the lower end 2| of the tube by means of a suitable nut 22 and washer 23, the end 2| of the tube 5 being threaded for that purpose. A starting compensator 24 and ballast 25 of standard construction are mounted in the housing 20 in any suitable or desired manner. Although I have illustrated my invention in connection with a desk or table lamp I do not wish to be understood as limiting myself thereto. for it will be clear to persons skilled in the art that it can be used on any kind of a luminaire, where the results are desirable.

It will also be apparent that where it is desirable the difiuse reflector may be used for color correction by the addition of certain dyes or pigments to the coating.

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

l. A luminaire comprising a pair of fluorescent lamps, means to support said lamps in spaced relation and parallel to each other, a lower trough-shaped reflector mounted below and extending in front of said lamps to shield said lamps from the eyes of the user and to reflect light rays upwardly, transversely elongated curved specular reflectors mounted back to back, one above each lamp, to redirect both direct and reflected rays in predetermined distribution, and

a diffuse flat reflector, mounted above and in front of each lamp, extending downwardly from each specular reflector to a horizontal plane passing through the upper edges of the lower reflector, each difluse reflector being positioned so as to receive direct rays from both lamps and redirect them downwardly to intercept and mingle with the rays reflected by its adjacent specular reflector, the lower inner edge of each specular reflector being spaced above the lamps and located midway between them so that rays from each lamp may reach both diffuse reflectors.

2. A luminaire comprising a pair of fluorescent lamps, means to support said lamps in spaced relation and parallel to each other, transversely elongated curved specular reflectors mounted back to back, one above each lamp, to redirect both direct and reflected rays in predetermined distribution, and a diffuse flat reflector, mounted above and in front of each lamp, extending downwardly from each specular reflector to a horizontal plane passing through the horizontal axes of the lamps, each diffuse reflector being positioned so as to receive direct rays from both lamps and direct them downwardly to intercept and mingle with the rays reflected by its adjacent specular reflector, the lower inner edge of each specular reflector being spaced above the lamps and located midway between them so that rays from each lamp may reach both diffuse reflectors.

3. A luminaire comprising a pair of fluorescent lamps, means to connect said lamps to auxiliaries, which when operated on A. C. current will keep one lamp out of phase with the other, means to support said lamps in spaced relation and parallel to each other, a lower trough-shaped reflector mounted below and extending in front of said lamps to shield said lamps from the eyes of the user and to reflect light rays upwardly, transversely elongated curved specular reflectors mounted back to back, one above each lamp, to

redirect both direct and reflected rays in predetermined distribution, and a difluse flat reflector mounted above and in front of each lamp, extending downwardly from each specular reflector to a horizontal plane passing through the upper edges of the lower reflector, each difluse reflector being positioned so as to receive direct rays from both lamps and redirect them downwardly to intercept and mingle with the rays reflected by its adjacent specular reflector, the lower inner edge of each specular reflector being spaced above the lamps and located midway between them so that rays from each lamp may reach both diffuse reflectors.

JOHN F. LIVERS.