US2199014A

US2199014A - Lamp

Info

Publication number: US2199014A
Application number: US157902A
Authority: US
Inventors: Stitt Charles Monroe
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-08-07
Filing date: 1937-08-07
Publication date: 1940-04-30
Anticipated expiration: 1957-04-30

Description

April 3o, 1940.

C. M. STITT LAMP Filed Aug. '7. 1937 2 Sheets-Sheet l 'Illlll/ April 3o, 1940. C, M ST." 2,199,014

l LAMP Filed Aug. '7, 1937 Q 2 Sheets-Sheet 2 ma ,a

l VVshown in Figs. and 6;

Patented Apr. 30, 1940 elaine Monroe stm. Hmmm, onu. Application Augusta 1931, serial No. 151,902

2 Claims.

- This invention relatesto lamps and more particularly pertains to electric lamps of the Vcharacter employed in the production'oi illuminating beams, flood lights, and other illuminators 'for producing white light or lsubstantially white light. v .v An object of the invention is `to provide 'a lamp which is especially applicable for use as a head light for vehicles where it is desired to obtain eirective illumination without excessive glare.

Another object is to 4provide a lamp which, while projecting a beam of white or near white iight, is so constructed and operated that when viewed from the front thereof and proximate thereto and particularly from points forward of but to either side thereof will present to the observer an illuminated eld comprising areas cornposed of a plurality of colors andwith `the absence of blinding glare, but which when viewed from points remote from the lamp will appear as a white or nea-r' white light free'of excessive glare.

A further object is to provide a lamp of the above character which is simple in construction and in which the parts may be readily assembled.'

With the foregoing objects in view, together with such other objects and advantages as may subsequently appear, the invention is carried into eiiectas illustrated by way of example in the accompanying drawings in which:

Fig. 1 is aperspective, view of the lamp as viewed from the front and to one side thereof;

Fig.' 2.is a detail in vertical section of the lamp with parts of the-housing broken away;

Figg is a detail in elevation as viewed on the line 3 3 of 1ig.2;

Fig. 4 is a sectional view as seen v 'on menne 4--4 africa;

' Fig. 5 is a diagrammatic viewv inv elevation 'of one form of color screen employed in the lamp; Fig. -6 is a viewin side elevation of the screen shown in'Fig. 5;`

Fig. 'I is a perspective view of one -of "the screen segmentsv employed in 'the' construction Fig. 8 is a view'in elevation of the front ofthe lamp shown in Fig'. 42 with the colvervlens removed showing another form of the screen;

Fig. 9 isa diagram in perspective` depicting the mode of operation of the invention.v

Referring to thej drawings more specifically, A indicates generally 'a lamp housing having an openend fitted with a reflector B having fa rim VIII which seats on an internalshoulder' Il on the housing. The reflector may be of any; suitable type; being here shown as comprising the ordinary parabolic reiiector employed in 'motor v ehicle head lights havingk a central sleeve Il'car4 f5 rying a socket il. An electric lamp C fitted with an illuminating filament il is niounted'inthe socket and is adapted to be adjusted tof proper focus by shifting the socket I3 longitudinally'in thesleeve l2." 'V

While various types .of lamps may be employed as a source of light orlight aenerating means I have found that highly satisfactory 'results are obtained by the use of an electric lamp having a glass bulb formed with a transparent I5 area' I5 on its outer end wall iv and'ha'vingl translucentsidewallsl.

` A color screen D is'disposed across the reflector B. in front of the lamp C which screen 'embodies at least three sectioned, b,'and"c formed 20 Ito transmit light rays lof different colors'such as red, violet and green respectively; so as rto propagate red, violet and green rays which when co-mingled with and superimposed upon each other will produce a beam of white or near white light. I

Theformation ofthe sections a, b and c to have the desired color screening and colored ray producing properties `may be eiected eitherby forming the sections of glassA embodying the requisite pigmentation, or by the employment ofany other transparent or translucentsheet'material such as the `phenol-resin products orfCellonhane and similar materialsforby the use of transparent or translucent Ymaterial applied upon plates of y The sections a, b, and c, maybe formed in one piece or may comprisevsepa'rate segments'. vWhere 'segmental` sections are employed as shown in Figs." `2, 3,4; and 8-they areucarried oninter'con- 40 nected 'radiating channeledfmmbers 6, j, and if linterposedv between the 'contiguous edges of the segmental sections with A the'f latterfse .ted in the channels thereof as particularly showniin Fig. 4.

The outer ends'jof themeinbers enff; 'a'ndig arev45 formed with tongues l1 'which qverlithefmargini0 of the reflector Bi'a'nd' are engagedA collectively with the latter-Lto theshoulder I'I by f screws *Il Preferably convexoconcave "l with fthe -margirr-V of its concave vfaire 4opposite and concentric xwith .the weer. rae. E ...Sea-is, 455

2l having an inturned marginal flange 2i en-A gageable with the rim of the lens. The lens E is transparent but is preferably formed with a translucent marginal portion 22.

Interposed between the screen D and the lamp C is a concave reflector F which overlies the transparent outer end portion Il of the lamp bulb in slightly spaced relation thereto and which reflector F connected to the interconnected portion of the members e, j and g by a screw 22 which passes through the intersecting portion of the members and is threaded into engagement with a hub 24 on the reflector. The purpose of the reflector F is to direct rays emitted from the transparent end II of the lamp bulb back through the translucent wall It thereof so as to augment the intensity of the light beam projected by the reflector B.

The reflectors B and F and the lens E are disposed with their principal axes in axial alignment with each other and with the center of the filament I4, and the color screen segments a, b and c extend radially from the axial line of the reflector.

The color screen sections a, b and c are formed of practically corresponding light absorptive properties so that the intensity of light propagated by the sections will be equal or atleast nearly equal.

In the operation of the invention as illustrated in Figs. 2 and 9 on illuminating the lamp C by directing electrical current through the filament Il, a portion of the resultant rays pass directly through the translucent side wall I6 of the lamp bulb, while another portion of the rays pass through the transparent end portion l5 Aof the bulb and are reflected by the reflector F back through thetranslucent wall I6 of the bulb. In this fashion all the rays emitted from the lamp are scattered and diffused and directed against the reflector B so as to be' reflected. in most part by the latter and directed through thescreens a, b and c and through thel refraction lens E thus propagating a beam of light which diverges according to the designed contours of the reflector B and lens E.

By disposing the lamp C in proper focal posi- ,tion relative to the reflector B the propagated beam, by reason of its being composed of red, violet and green rays superimposed and comingied, will be white or near white, and will effect illumination of bodies accordingly.

Inasmuch as it is diilicult to form the reflector B as to avoid the formation of a. fringe of colored rays around the major beam, such fringe is eliminated at least in most part by the provision of the formation of the translucent margin 22 on the lens E which acts to scatter and diffuse the color rays of the fringe.

In the modified form of the color screen shown in Figs. 5, 6 and 7, the segments a, b and c are prismatic so as to effect refraction of the screened rays in a fashion yto cause superimposing of the groups of rays propagated by the several segments and thereby produce the desired white or near white light free of excessive glare. By thus forming the screen segments to have the refractive properties of prisms they may be employed either with or without a supplemental refracting lens E.

An important feature of the invention resides in the fact that whiiea beam of light is propagated to produce sight sensation of whiteness when viewing a bodyonwhich the beam is incident, the rays emitted from the lamp incident on the retina of the eye produce color sensations so that a person viewing the lamp from the front or diagonally from the front thereof will discern within limits the luminous colored segments a, b and c. In other words, -an observer lviewing the illuminated lamp will observe the luminous red, violet and green segments a, b and c free of blinding glare. However, such condition prevails within limits of distance or server and the lamp the 'color sensations developwith gradually increasing intensity to a maximum at close proximity to the lamp.

In order to produce a beam of white or near white light by means of the present invention it is essential that the color screen sections collectively transmit light of various wave lengths ranging from low to high value, and accordingly it is necessary that the screen include at least one red section for propagation of light of long wave length, at least one violet section for propagation of lightl of short wave length, and at least one section capable oi propagating light of intermediate wave lengths, which latter section is preferably green since it transmits composite rays of intermediate wave lengths. It ismanifest, however, that in some instances it may be desirable to produce a beam which is slightly tinged with color, such'as to have, for example, a reddish-yellow tinge,' or greenish tinge, or blue- Vish tinge, in-which event the color screen will be formed with a section or sections of a character to aord the desired excess of color constitutent, as by varying the shade of the green section to render it capable of transmitting an excess of yellow rays, or an excess of blue rays.

Where it is desired to produce a beam which is clear white or having a blueish tinge, it is necessary that the source of light C be clear white, that is, one which emits light containing waves of all wave lengths with their relative intensity such that the color sensation produced by their incidence on the retina is that of whiteness. However, though electrically operated filament or glow lamps are defective in blue, such does not preclude their .use in my lamp, since suchdeilciency does not suillciently detract from the whiteness of the beam as to affect the practicability of the lamp for general purposes of illumination, as for example in the head lights of vehicles, and flood lights on aircraft landing fields, and in general for any transmitted light of whatever character or purpose as may be required.

While I have set forth specific embodiments of my invention I do not limit myself to the constructions shown, and-the invention embraces such modifications asy come within the purview of the accompanying claims. For example, while I have shown the lamp as equipped with a refracting cover lens E there are occasions where such lens may be disp'ensed with it having been found in practice that in applying the lamps as headlights for a vehicle sumcient intermingling of the colored rays as directed through the screens a, b and c is eifected as to producea satisfactory beam of the character set forth.

I claim:

Atransparent end `wall portion, a color screen ad- I 1. In a lamp. an electric nlament lamp including a bulb having a translucent side wall portion and a transparent end wall portion, a'

color screen adjacent said electric lamp extend- '5' ing in front of the transparent end wall portion thereof, said color screen embodying a plurality of segmental sections of different colors including a red section. a violet section and a section for transmitting light rays intermediate 10. red and violet rays; a renector for projecting light emanating from said electric lamp through said screen, a second reflector extending over the transparent end portion of said bulb for reiiecting rays from said electric lamp onto said ll ilrst named reilector through the translucent side walls of said bulb, a reiracting lens extending over said screen, said refracting lens and first named reflector cooperating to eilect superimposition and commingling of colored rays emit- I) ted from said screen to produce a white or nearwhite illumination. and means on said retracting lens for diffusing fringe rays.

2. In a lamp, the combination of an electric ilJament lamp including a bulb having a trans- I lucent light diffusing side wall portion and a jacent said electric lamp extending in front of the transparent end wall portion thereof, said color screen embodying a plurality of sections of different colors including a red section, a violet section and a section for transmitting light rays intermediate red and violet rays; said screen sections having similar or like light absorptive properties to propagate rays oi' similar or like intensity; a parabolic reflector encompassing said bulb and arranged to project light emanating from said bulb co/inciden'tly through the several sections-of said screen to form a beam, a

second reflector extending over the transparent end portion of said bulb arranged to reect rays emitted from the outer end of said electric bulb back ontov said iirst named reiiector through the translucent side walls of said bulb, and a reiracting lensextending over said screen cooperating with said ilrst named reflector to effect superimposition and commingling of colored rays emitted from said screen to produce a white or near white illumination.

CHARLES MONROE S'ITIT.