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Publication numberUSRE13600 E
Publication typeGrant
Publication dateJul 22, 1913
Filing dateMay 15, 1907
Publication numberUS RE13600 E, US RE13600E, US-E-RE13600, USRE13600 E, USRE13600E
InventorsOtis A. Mttoatt
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
my gatt
US RE13600 E
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)




Reissued July 22, 1913. 1 3,660.




Reissued July 22, 1913.

'o'rrs .A. iu YGA'r'r, or NEW YORK, N. Y.


Specification of Beissued Letters Patent. Reigsued July 22, 1 913,

Original No. 804.254, dated November 14, 1905, Serial No. 210,978. Application for reissue filed May 15,

- 1907. Serial No.B73,8B2-.

shade having a part acting as a reflector and an opposite part acting as'a lightdirecting, distributing o'r softening shade.

The invention consists in a structure having av )'art,. usually about one-half its surface, covered with a specular surface, such as reflecting-prisms, constructed to reflect back into theshade a large portion of the light-rays which emanate within the reflector.

The other side of the reflector-shade has on' its outer surface a series of light-d1- recting or distributing surfaces, such as prisms or ribs. which prisms direct the light in any desirable direction and at the same time soften the light-rays. ()n this directing side the interior surface of the shade may also be covered with diffusing-ribs,

which soften the lightrays before they re'ach the final light-reflecting surfaces.

Figure 1 is a side elevation of a shade- .retlector embodying the principles of the present 'invelitiong-l ig. 2 is a vertical sec:

.tion of the rear side of said device; Fig. 3

is a vertical sectionof the front side thereof; Fig. 4 is a broken horizontal section at the rear side of the shade-reflector"; and

Fig. 5 is a broken horizontal section at the front slde of the shade-reflector in any plane in which the prisms appear. Fig. '(i

is a side elevation of a modified form of shadsreflectorg Fig. 7 is a side elevation of a further modification; Fig. 8 is a rear elevation of Fig. 7; Fig. 9 a broken section on line .2- z. y

My shade-reflectors are made of pressed glass and in all.co1nmon sizes are in a single piece. That side A-of the body of. the structure which'is to act as a specular reflector 'may be substantially. covered by external prisms B. These prisms areof the character, termed by me doiible-refiectingi prisms thatis, the light from within the reflector encounters a smooth interior surface K and is deflected very little or not at all tl1ereby. Passing to the outer inclined face of a prism-B a light-ray encounters this face at an angle of forty-five degrees, (for best results). The ray is reflected'at a right angle directly across the prism and strikes the second.- inclined face also at an angle of fcrty-fiye degrees, thereto, (see Fig. 4,) ,wherein 1 2 indicates alight ray thus reflected twice. The light-ray is thus returned on a' line substantially parallel with its line of radiation. This direction of a light-ray may be somewhat modified by the form of the body, as at 3 4, Fig. 2.

For ordinary consideration it. may be calculated that from seventy to eighty per cent.

of'the light will be thrown back toward and through. a lamp inclosed in the reflector and toward the shade or light. distributing or radiating side of the device.

The shade-refiectors are shown in vertical position in. Figs. 1 and 6, but can be turned to any position desired. For convenience of description the specular reflecting surfaces which are here illustrated in the form of prisms will be described in the positions they occupy when the reflector-shades are in the position of Figs. 1 and 6. Thus it will be seen that the. prisms B extend in genc1ally vertical direction with reference to the body of the shade-reflector. In a spherical reflector the.reflecting-prisms are substantially in the form of lanes. Some light will pass through the prismatic reflector, and the external appearance of a lighted reflector will be that of a darkened snrface'with bright lines thereof. To main"- tain the proper reflective angles of their plane surfaces, the retlecting-prisms must varyin width and height with their position onthe body of the reflector.

The front or light-diffusing side C of the shade-reflector is preferably covered internally with small vertical or lunar prisms or ribs D. These internal prisms will not reflect the light back toward its source, but

will simply deflect the light-rays more or less in horizontal directions as theyf-pass through the glass. The surfaces not be planes, but may be merely rounded flutings for this purpose.


The amount of light received by the front face C or shade .part of the. device will be something less than twice the amount which-would be-theie received were the-reflector part. of the device v l [10 i rays. Y

. vice The outer surfsceof the shade C is substam tially eovered with light-directing surfaces, preferably horizontal directing or distributing surfaces, such as prisms E.. These prisms are of various characters, according to the ill'nminaltions desired. These prisms may be single-reflecting prisms or light-db recting prisms and. do not reflect light to any considerable extent back into the interior of the shade-reflector, but direct the rays in calculated. directions or in all direcs tions.

The upper prisms-seyfor one-fourth the height of thesliade-snay be made to direct the ligl1t-rays ln'a direction inclined downwardly at a considerable angle. The prism along the central part of the face C may be made to direct the rays rlownwsrdly at a lesser angle, and part of the face C may be made to direct the rays about horizontally. Such directions 'for li lit-rays are indicated by'lines 6, 7 8,9 l Fig.3. Such an arrangement for prisms will give a concentration of light along a horizontal band near the. shade-face. Other arrangement of constrnction'of the prisms B may be made to concentrate therays or to diffuse tliem, as desired. The dirooting-planes of these prisms are deter mined by the mold, which is made on care fully-calculated lines.

By continuing thercfiector side of the defor something more than half the circumference a very considerable concentration of lightrrays' may be effected over a limiteolaree at the front of "the reflectorshade. In my Patent No. 736,535, of August 18, 1903, the construction of verticelreflecliingprisms on the outer face of the reflector is explained; These latter prisms I term doublercfiecting prisms.,- While the horizonlal "prisms E, ii refleclors at all, are single-refiecbingor light-.clistributing prismsand may-serve merely to diffuse the light- By light-distributing l prisms I refer to prisms having their plane faces at calcnlated' angles with referenceto the source, of light, so that a'large proprtion of light passing through the prisms'collectivelyshall .be by the prisms- 'd irectecl in definite quantities in predetermined j directions. .By lightdiflusing zl mean the breaking up ofz the of she rays without attempt to control the 5 i lightrays and'tbe scattering and softeifing' quantity of lighs in a given direction.

Figs we see mam may hav unar: refi'ectln r mating I may bedirecting-pnsms. If

' as in the present invemfiion. the prisms at the lower ,plan'es, comprising planes, comprising an integral as understood in this the directional light} determined directions. softening or blending direction.

In my Pafieni; No. 736,535 a slimle is dewith no special relation to scribed wherein the upper part of the globe is a reflector and the lower part is sur rounded by circumferential prisms, which .tliis globe Were turned at a righteangle, it would have the effect-of directing the light in rings or circles insteacl'of the transverse cli'scribution of the light-rays in a plane or planes,

Q The reflector-shade a. portion A Whicli reflects light interiorly across the reflector shade. It has also 2. transmitting" portion C, transyersely-distributive of light, which transmits the light reflected across the (levice out through {using or directing-portion.

' Of the specular reflecting surfaces, probthe plane transverse (lifably the best results are secured by using double-reflecting prisms of about' fi specular reflecting portions are meant surfaces having opproximatelylzotsl eficcb ing properties. The &onble -reflecting prisms herein described are cxarnples of such speelllar surfaces.

I claim: v

1 A reflector-shade for the asymmetric distribution of light in straight parallel-35 an integral glass inclosure having upon one sicle a. reflectcr portion and upon the other side a series of asymmetric light distributing ribs lying in parallel planes transver ely cross ng substantially zit-right angles of the reflector opposite the reflector-portion.

2. A reflector-shade for she asymmetric distribution of light in straight parallel inclosure ha ving upon one skis a prismatic re Hector-portion and uponnthe other side a series of asymmetric light clistriblitii' g ribs lying in 'parallel planes transversely cross mg substantially at right angles the body of signature orrs A. Mrs-Arr.

no the reflector opposite the reflector-portion.

In testimonywhereofl. afiix I ingtlie presence oftwosnbscribing witnesses.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5095415 *Oct 30, 1989Mar 10, 1992Minnesota Mining And Manufacturing CompanyLight fixture for externally illuminated sign