US570446A - Globe for electric-arc lamps - Google Patents

Description

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GLOBE POR BLBGTBIG ARG LAMPS. No. 570,446. Y Patented Novf 3, 18915l UNITED STATES" PATENT OFFICE.

MARCUS B. BAILEY, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-THIRD TO PAUL IY. I'IFIERMANS, OF BROOKLYN, NEW YORK.

GLOBE FOR ELECTRIC-ARC LAMPS.

SPECIFICATION forming part of Letters Patent No. 570,446, dated November 3, 1896. Application iiled July 1]., 1894. Serial No. 517,207. (No model.)

To all whom it may concern:

Be it known that I, MARCUS B. BAILEY, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Globes for Electric-Arc Lamps, of which the following is a specifica* ion. v

The object of my invention is to produce a reflecting-globe that will throw an even light in a given direction free from shadows and that will maintain such conditions where the arc varies in its position within the globe, as in the case of single-feed lamps. To this end I corrugate in a peculiar manner that part of the globe which is to act as a reflector and of course make it of such material or provide it with such coating or backing as is desirable Where it is made of glass; and in order to readily produce the desired corrugations in a suitable and economical manner, I prefer to make the globe in sections, that is to say, it may be divided longitudinallyin two sections, one of which will be of clear glass and the other of which will be a corrugated reflector. I may further divide the corrugated half hori zontally, or the globe may be divided horizontally in halves and one half corrugated. The parts of the globe so divided will be held in position by the means of attachment to the lamp and the wire-netting ordinarily used, or by any suitable means.

In the accompanying drawings, Figure l is a vertical section on the line l l of Fig. 2, and Fig. 2 a horizontal section on the line 2 2 of Fig. l.

A indicates the half of the globe made of clear glass, while B indicates the other halfv of the globe, which is opaque and may be of any suitable reflecting material or material provided with a suitable reflecting-surface, though 4I prefer to make this half of glass and give it a coating such as is applied to the backs of mirrors to give it a high reflecting capacity. This reflecting half of the globe may, if desired, be formed in two parts, the line ofdivision being a horizontal one. The upper half of the corrugated section is formed with a series of corrugations which are divided or separated by vertical or meridian lines b, there being eight such series.

The lines formed .by the apices of the corrugations, the same being indicated at h', are substantially at about an angle of fortvfive degrees from the vertical or meridian dividn ing-lines. The corrugations in one series run in an opposite direction from those in the adjoining series, and the lines indicating the apices of the corrugations meet at the dividing-lines, that is to say, the lines indicating the corrugations of any two adjoining series are of V shape or inverted-Vshape. The corrugations of the lower section appear asmeridian lines and meet or coincide at the top with the corrugations and meridian divisionlines of the upper section.

The corrugations of both the upper and lower halves of the reflecting-sections of the globe catch the light and reflect it with a dif fused effect, there being no distinct focus behind the carbons, and hence the shadows of the carbons and their carriages or supports are not thrown into or upon the field of light projected by reflection from the globe. This desirable effect results from the fact that the incident rays emitted from a center are reflected from the upper section in different angular directions, said lines of reflection crossing both as regards the horizontal and vertical fields by reason of the reflecting corrugations being angularly arranged relativelyT to one another in the different adjacent sections, and that the curvilinear form of the an gularly-arranged corrugations causes a general downward deiection of the rays, so that the general result is not materially aected bythe gradual lowering of the arc due to the burning away of the lower carbon, and the corrugations in the lower section having primarily a tendencyto throw the reflected light horizontally.

I prefer to provide the different styles of corrugations in the upper and lowersections in order to insure a uniform reflection of the light as the arc descends within the globe as the carbons are consumed in the single-feed lamp. Where the light is to be reilected downwardly from an elevated lamp, the upper half of the globe will be corrugated, as indicated by the lines h o', and the lower half will be without corrugations. I have found by demonstration that with a reflector of this gen- ICO eral character I am enabled to light compar atively laigei` areas with a flat uniform appearance of light characterized by an absence of shadows or dark spots.

I prefer to make the globe in sections, as indicated, because of the facility with which the corrugations may then be formed.

I claim as my inventionl. A globe for an electric-arc lamp having one part thereof opaque and provided with series of reflecting-corrugations divided by meridian lines, the alternate series of corrugations being angularly arranged in opposite directions between the meridian dividinglines, and having the other part opposite the opaque part of such material and form as to permit the passage of the reiiected light, substantially as set forth.

2. A globe for an electric-arc lamp, having one part thereof opaque and provided with series of refleeting-corrugations divided by meridian lines, the alternate series of corrugations being arranged at angles of about forty-live degrees in opposite directions between the meridian dividing-lines, the ends of the corrugations of the adjacent series meeting together at the meridian lines, and having the other part opposite the opaque part of such material and form as to permit the passage of the reii ected light, substantially as set forth.

A globe for electric-arc lights, having one side or portion formed of uncorrugated glass, and the other side or portion opaque and having reecting-corrugations, the upper half of the latter portion being provided With series of corrugations divided by meridian lines from which the corrugations run at an angle of about forty-five degrees, the corrugations in one series running in the opposite direction fromthose in the adjoining series, and meeting them at the meridian lines, and the lower half of said portion being formed with meridian corrugations coinciding at the top with the meridian dividing-lines and corrugations of the upper half.

In testimony whereof I have hereunto subscribed my name.

MARCUS B. BAILEY. lVitnesses:

P. W. HEERMANS, FRANK S. OBER.

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