US1373845A - Lighting device - Google Patents

Description

E. D. TILLSON. LlGHTiNG DEVICE.

APPLICATION FILED JULY 8. 191a.

Patented Apr. 5, 1921.

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Be it known that I, EDWIN D. T1LLso a subject of the King of Great Britain, residingat Evanston, Cook county, Illinois, have invented a new and useful Improvement in stores factories, etc., where comparatively brilliant general lightingv is required and yet where it is desirable, if not imperative, to protect the eyes of the persons beneath and within close range. My invention is especially desirable in connection with the so called. nitrogen lamps which are ordinarily extremely bright and 'in which the filament occupies but a small compass usually considered as constituting a point source.

The general object of the invention is to produce a lighting fixture or device appropriate for the conditions above mentioned, and to facilitate an understanding of the in vention reference is made to the accompanying'drawing which is a side elevation chiefly in axial section showing the complete appa ratus. Incarrying out my object, I have employed a comparatively flat reflector abovethe light source which, in the completest form, is combined with a plurality of. coaxial bands or rings of translucent substance. These bands are arranged at different levels and placed in such manner as to cut off, from the eye of the observer, all direct rays emanating from the filament. The translucent bands impart the cheerful appearance desired in such places as the ones mentioned and yet they shield the eye from the direct rays. My device also has the advantage of not showing an image of the source to anyone directly under or near the device. It will be understood that, with a so called point source of light, especially when of reat brilliance, a reflector is apt to show 1; e image in such a way as to be ungrateful to the. eye; and my device is" so constructed thatsuch image will not be seen rema ritsoirfornvnfisroir', ref ners, mmune ib'nvion. f

1918. Serial No. 243,982.

buildings, especially factories there is apt to be a considerable amount 0 dust. When ordmary bowls .are employed beneath the l ght source for the'purpose of eye protectlon, the dust accumulates all too rapidiy and, unless the bowls are frequently cleane the light is dimmed and the bowl presents an unpleasant appearance. It is one of my objects to provide a lurality of annular bandsor rings which w1ll possess the advantages of a bowl-and yet have sheer sides to which Specification of Letters Patent. Pat htd Apr. 1921 Ap1ilication filed m s,

' the dust will practically be unable to adhere.

Another object of the invention is to make the translucent bands separately removable so that if only one needs cleaning, the other.

need not be disturbed.

I obtain my objects by the construction llustrated in the-accompanying drawing in which the light source is in the form of an electric bulb 1, preferably of the gas filled or nitrogen filled type. This has a filament 2 which forms the source proper and usually occupies a small space so that the li ht practically emanates from a point.- 'l he lamp screws into a socket 3 which is'supported by any appropriate type of'fixture 41 A refiector 5 is also supported from said fixture I by any suitable means which form no essential part of my present invention and need not be described in detail.

The reflector has a central opening 6 of somewhat larger diameter than the neck of the bulb, thus affording ventilation. While the exact form-is immaterial, the reflector is, ingeneral, comparatively flat and near enough to the level of the'filament to insure that a considerableportion of the rays reflected from it will be distributed at wide an les.

elow the reflector, preferably'about on a .level with the filament, is an annular band or ring 8 oftranslucent'material arranged A concentric with the: vertical "line passing through'the filament and so placed and dimensioned that its upper edge'will intercept the rays which would otherwise escape be low edge 5 of the reflector 5. This translucent element 8 is, in the present case, supported upon the hooks 10 formed at the outer ends of rods 11 which hang from hooks 12 secured to'the reflector.

. Coaxial with the element 8 is a second translucent annular band M: which, in the present case, is entirely below the filament and is securedto a ring 15 by means of set screws 16 or other suitable devices. Ring (15 is supported by the rods '11, although any appropriate type of suspending means may be employed. This second translucent element is of considerably smaller diameter than the first translucent element 8 and its upper edge is so located as to' intercept the rays which would esca e beneath the lower edge of the element 8. urthermore the surfaces of both the elements 8 and 14 are sheer enough to prevent the 10d ing of any considerable amount of dust. y preference, the upper element converges toward the top while the lower one converges toward the bottom. This enables the translucent elements to cover a greater spherical area centered at the filament.

While not essential, it is desirable to provide a reflector 17 directly beneath the bulb, its diameter being sufiicient to intercept the rays which would otherwise escape past the lower edge of the translucent element 14. This reflector is suspended by arms 18 supported by the ring 15.

In practice, the only light rays which will reach the reflector direct are those which will be thrown outward at a wide angle as illustrated by the ray BB. Persons observing these rays will be so far away horizontally that the eyes will not be bothered by direct reflection. All of the other rays, except those between the lines AA will be diffused and softened before reaching the eye of those within the illuminated area. In the present case, a small spot directly beneath the device will be shaded from direct rays, although on account of the flaring shape of the upper translucent element 8, even this spot will receive illumination in proper degree.

From the foregoing it would be seen that the device is capable of illuminating a wide area and presents a cheerful appearance and yet it effectually protects the eyes of all persons. Those persons far away ma receive a directly reflected light butthey must be at a distance sufiicient to prevent any unpleasant effect upon the eyes. The light which will reach persons nearer to the device will be reflected and diflused in such manner as to prevent any ungrateful effect and the appearance of any direct image reflected from the reflector. Anotheradvantage is that the two translucent elements are individually removable, and on account of the outward flaring shape of the uppermost translucent element it will seldom be necessary to take it down for cleaning purposes. The lower element 14 having slightly converging sides may need cleaning occasionally but it can be removed without disturbing the element 8 above it. Thus the device is convenient as well as efiicient as a li hting device.

1 aving thusdescribed my inventionwhat I claim as new and desire to secure by Letters Patent, is

1. A lighting device having a light source, a reflector above said source, an upper annular translucent element, open top and bottom, surrounding said source and having its upper edge high enough to intercept the 'rays which would escape the edge of the reflector, a lower and smaller annular translucent element open top and bottom, surrounding said source and having its upper edge high enough to intercept the rays which would escape beneath the lower edge of the upper translucent element, said lower element having a substantially sheer inner concave surface facing inward and upward, and said upper element having a concave inner surface facing inward and downward.

2. A lighting device having a light source, a reflector above said source, and a plurality of annular translucent elements arranged at different levels below saidreflector, the upper translucent element being of smaller diameter than the reflector and the second translucent element being of smaller diameter than the first translucent element; the upper edge of the upper translucent element being high enough to intercept the rays which would escape the edge of the reflector and the upper edge of the lower translucent element being high enough to intercept the rays which would escape the lower edge of the upper translucent element, and an opaque disk directly beneath the light source and having a diameter great enough to intercept the rays which wouldescape the lower edge of the lower translucent element, the upper translucent element lfaving a concave inner surface facing inward and downward, and the second translucent element having a concave inner surface facing inward and upward, and the radii vectores of both the upper and the second translucent elements lying entirely within-the respective elements. EDWIhl D. TILLSON.

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