US2004183A - Lighting fixture - Google Patents

Description

June 11, 1935. R. B. BENJAMIN LIGHTING FIXTURE Original Filed Feb 16, 1931 3 Sheets-Sheet 1 /zdn w June 11, 1935. R. B. BENJAMI'N LIGHTING FIXTURE Original Filed Feb. 16, 1931 3 Sheets-Sheet 2 L June 11, 1935.

R. B. BENJAMIN LIGHTING FIXTURE Original Filed Feb. 16, 1931 3 Sheets-Sheet 3 Patented June 11, 1935 LIGHTING FIXTURE Reuben Benjamin, Chicago, 111., assignor to Benjamin Electric Mfg. Company, Des Plaines, 111., a corporation of Illinois Application February 16, 1931, Serial No. 515,933 Renewed August 5, 1933 I 8 Claims. This invention relates to lighting fixtures and has special reference to floodlights.

More particularly, this invention rel-ates to enclosed 'floodlights whereby a widely divergent beam is projected through a relatively small opening in such a manner as to illuminate large areas with substantially uniform intensity.

A desirable feature of the invention is the provision of a comparatively small, compact, lighting unit in which all direct rays are directed through a relatively small opening to provide a widely divergent beam, and all reflected rays are caused to converge and be directedthrough the opening to effect a widely divergent beam of reinforcing rays, the combined effect of all of the rays causing substantially uniform intensity over a large area.

A further object is to provide a fixture hav: ing a small opening in one side thereof through which is emitted a widely divergent beam of inter-- secting rays, and comprises a housing having a light source therein with a main reflector portion positioned about the rear of thelight source and a second reflector portion having a diameter not substantially greater than that of the main reflector portion positioned forwardly thereof for reflecting substantially all the light rays which are not directly reflected by the main reflector portion or opening and directing them back against the main reflector which latter reflects all the rays intercepted thereby out through the small open-' ing, the use of the small openingbeing made possible by the combination of the two reflector portions.

The front reflector is so formed and positioned that the double-reflected rays which are first re flected by the front reflector and then again by the main reflector portion strengthen and reinforce the divergent beam of light at the outer portion of the beam so that the center of the beam does not have a high intensity which gradually diminishes towards the outer portion, but instead a fixture of this type gives forth a beam of comparatively uniform intensity andv even distribution throughout. Such a construction is unusually eflicient and is particularly suitable for lighting large areas with a substantially uniform intensity.

It is common practice in the construction of floodlights where a fairly wide angle of distribution is required, to use the same form of housing and reflector as is employedwherea narrow beam is desired, such as. in.a,spotlight or automobile headlight, and to spreadthelight directly emitted out through the small beam by means of a s1 PATENT OFFICE glass lens either by stippling or other deformation which serves to ac complish this purpose.

In all such devices the front opening must be made'with a diameter at least equal to thelargest diameter of the re.-

flector employed in order cient. V

A floodlight embodying that the unit be enthe present invention has many advantages over and accomplishes results not possible in the use of the ordinary floodlight. By employing two reflector portions, substantially all the light from the light source may be reflected through an aperture which may be made very small as compared with the usual or conventional type, while, at the same time, the

diameter of the reflectors and the length of the fixture may be kept within a reasonable size.

As only a comparatively small light emitting opening is required, the lens'or glass cover, there fore, may be made with a one-half as great as diameter substantially that of the lens, which would ordinarily be requlred, andthis means substantially one-fourth as little as one-sixth of the the area and perhaps weight. Furthermore,

thelength of the seal between the lens and the casing is cut in half, the

the lens is materially lessened and of breakage of the cost of and danger labor in mounting the lens is greatly reduced.

As a lens. of i a small ture, particularly the seal the casing, may weather-proof. For this are adapted for use size is employed, the fixbetween the lens and be made more completely.

reason the floodlights around athletic fields, especially baseball and football fields where it is necessary tothrow the light upward so as to illuminate the underside of above the eye level.

the ball after itrises This type of unit is also" suitable as an exploe sion-proof fixture for us tions, may be be substantially gas tight Explosions are prevent keeping gas out of e in hazardous-- loca-' as such fixtures having only a small lens made to withstand greatfor-ce and also ed not by absolutely the enclosure but by making the fixture destruction-proof and of such a construction that if the enclosure ignites the bustion will escape so that they will become point before reaching the from any cause 'the'gas within hot productsof com slowly fro'mthe fixture cooled below the danger outside of the casing and will not,, therefo're, ignite the gas in the surrounding atmosphere. withstand a much greater tively larger lens,'it is vantage isderived in cons As a small .lens may force than a compara-j evident thata great ad:

tructing an explosion proof fixture with a comparatively small open ing in which the lens or glass front may be positioned and through which .substantially all the light from the light source is projected.

It is also an object of the present invention to provide a fixture of the type hereinabove referred to which may be so constructed that it may be easily placed and supported in a position to direct the light therefrom in the most efficient manner.

Further objects and advantages will be apparent from the following description when taken in connection with the accompanying drawings, in which latter:

Figure 1 is a front elevational view of an adjustable floodlight embodying the present invention.

Fig. 2 is a central vertical cross sectional view taken on the line 2-2 of Figure 1;

Fig. 3 is a central vertical cross sectional View of another form of floodlight embodying the present invention having a handle for carrying the same and legs or supporting members upon which the fixture rests or by which it may be hung;

Fig.4 is a side elevational view of the construe" tion shown in Fig. 3 suspended from a wall;

. Fig. is aside elevational view similar to Fig. 4 showing the fixture resting on the floor;

Fig. (Sis a front shown in Figs. 3, 4, and 5 with the axis of the reflectors in a horizontal position;

Fig. 7 is a central vertical cross sectional view of an explosion-proof fixture embodying the present invention; and

Fig- 8 isa central vertical cross sectional View of a ceiling fixture embodying the present invention.

Referring more the construction casing consisting particularly to the drawings, shown comprises a two-part of a rear portion 4 having a hood 2 extending therefrom and a front portion 3 pivotally secured to the rear portion i. The front portion 3 is provided with a central opening 3a which is comparatively small as compared to the inside diameter of the casing. A socket 4 is secured in the hood and provided with the usual threaded shell portion 5 in which a lamp 6 is threaded to extend into the casing formed by the rear. portion I and the front portion 3, the light source of said lamp being preferably no further forward than the front of the rear casing portion I.

A main reflector portion 1 which is shown in Fig. 1 as being substantially spherical in form, but which may be parabolical, is positioned within the rear easing portion I, being attached thereto by a screw 8 which threads into the casing portion I. and having a peripheral flange portion Ia which fits into a peripheral notch 'Eb in the forward portion tion I. An opening 9 is provided in the reflector through which the stem of the lamp 6 may be inserted for threading it into the socket =3. The lamp is preferably positioned so that when the lamp is inserted in the socket the junction of the neck and globular portion of the lamp lies close to the opening 9 in the reflector. The reflector I and lamp support are so designed that the position of the lightsource lies between the center or centers of curvature of the reflector and the focal pointsthereof so that the rays, reflected by the reflector 7 intersect and pass through a small area a short distance in front of the cenof each is drawn elevational view of the fixture of the rear casing portral portion of the reflector thereby forming a widely diverging beam of intersecting rays.

A front converging reflector portion I0 is mounted in the front casing portion 3 and is secured thereto by screws I i which thread into the casing portion 3. This reflector portion I 9 is sub stantially a continuation of the rear reflector portion 1, although in Fig. l the two are not shown as meeting. This is to allow for manufacturing variations. The front reflector portion I0 which is shaped so as to lie substantially adjacent the inner surface of the casing portion 3 is provided with two substantially spherical concentric reflecting surfaces 82 and i 3. The radius with the light source of the lamp as a center or substantially thus, so that all the rays intercepted thereby are reflected back against the main reflector portion 7 from whence they converge and are projected outwardly in a widely diverging beam through the small opening 3a. The outer reflecting surface i2 lies adjacent the inner surface of the casing portion 3 and intercepts substantially all the rays which otherwise would strike the casing surface, while the reflecting surface I3 lies substantially within and to the rear of the sides of the opening 3a and intercepts all the rays of the light projected forwardly of the reflecting surface I2 and not directly emitted'through the opening to. With such an arrangement of reflectors substantially all the light from the light source of the lamp is projected through the small opening 3a and this is accomplished while at the same time decreasand employing opening small in comparison to the diameter of the reflectors used.

As shown in the figures the globular portion of the lamp 6 extends substantially as far forward as theopening 3a in the casing and for this reason a spherical shaped front lens 54 is employed thereby allowing sufficient distance between the'lamp and the lens without increasing the length of the casing. The lens it is provided with a flat peripheral ring E5, the front portion of which lies adjacent the inner front surface of the casing portion 3 where it is held by means of spring clips I6 which are secured to the casing portion 3 by means of the screws ii. A packing I5a is positioned between the edge #5 of the glass front It and the front casing portion 3.

The two casing portions I and 3 are securely held together by means of eye bolts I! and I8, the eye portions of the eye bolts I'i being pivotally mounted in the downwardly extending members I9 of the rear casing portion I about the pivots-20. The threaded ends of the eye bolts extend forwardly through openings provided therefor-in the ear portions 2i extending downwardlyfrom the front casing portion 3 so that the front casing portion 3 may be pivoted forwardly about the pivots 28. Thumb nuts 22 are threaded onto the free end of the eye bolts I? so that the casing portions may be tightly clamped together. The eye portion of the eye belt I 8 is pivotally mounted about the pivot 23 so that the free end, which extends forwardly through the slot 24 in the upper part 25 of the front casing 3, may be moved vertically in and out of the slot 24. A thumb nut 25 is threaded on to the end of the eye bolt I8 and engages the sides of the slot 24 so as to tightly clamp the casing. portions together. To pivot the front tion I, the thumb nuts 22 'Iheeyebolt I8 is then swung upwardly out of The stem 29 is formed vertically adjusted.

to the ends of the bolts 31 which, when tightened, desired vertical position.

to the lower side of the hood the slot 24 and the front casing portion 3 may then. be pivoted about the pivots 2D. In order to provide a tight seal between the casing portio'ns,an annular ring 26ais inserted in the annular groove 26b in the front casing portion 3 which, when the two casing portions are tightly secured together, presses tightly against the rear casing portion l to form a tight seal.

The whole fixture ispivotally mounted on a stationary pipe or support 21 by the following means: i

A Y shaped supporting member 28 is formed with .a cup shaped stem 29 which is adapted to be placed over the end of an upright pipe 21. with a longitudinal slot 30 which connects with the circumferential slot 31. outwardly extending projecting members 32 are provided adjacent the sides of the slot 30 so that the stem portion may be tightly clamped about the pipe 21. A bolt 33 extends through openings provided therefor in the projecting portions 32 and a thumb nut 34 is threaded on the end of this bolt. By this means the Y shaped supporting member 28 may be rotated on the upper end of the pipe 21 and may be secured in any desirable position by tightening the thumb nut 34. The ends of the arms 35 of the Y shaped member 28 are adapted to fit over and against the ears 35 which are formed on the rear casing portion I. Openings are provided in the ends of the arms 35, which openings register with openings in the ear portions 36. Bolts 31 extend horizontally throughthe openings in the ears 36 and the arms 35 so that the'whole fixture may be Nuts 38 are threaded on will hold the fixture in If desired, a guard39 may be secured over the front glass or lens [4 and held in position by means of screws 40. a

The constructions shown in the remainder of the figures are substantially the same as that described in connection with Figure 1. In Figs. 3, 4, Sand 6, the front casing portion 3 is provided with a peripheral annular threaded portion 4! for threading into the inner threaded surface 42 provided on the forward portion of the rear casing I so that to secure the two casing portions l and 3, it is merely necessary to thread the front casing portion 3 into the rear portion I. An annular portion 43 is provided on the periphery of the front casing portion 3 which engages the rear portion 1 and limits the distance the front portion may be; threaded in the rear portion and also makes a tight fit between the two.

A handle 44 is secured to the apertured projecting members 45 provided on the top of the casing l and hood 2 whereby the fixture may be easily carried from place to place. Legs 46 are provided on the lower side of the casing portion I and an apertured leg or tail-piece 41 is secured member 2 so that a three-point support is provided for the fixture. The legs and tail-piece are so formed that when the fixture is resting on the floor, as shown in Fig. 5, the beam of light from the fixture extends substantially between the vertical and the horizontal, the axis thereof extending upwardly about 45 fromthe horizontal.

Fig. 4 shows the fixture hung from a wall with the aperture inthe tail-piece 41 placed over a support in the wall. When in this position the beam of light from the fixture is also substantially between the-vertical and the horizontal but the axis of the beam extends about 45 down from the horizontal. If it is desired to position the fixture so that the axis of the beam is horizontal, the fixture may be placed, as shown in Fig. 6. It has been found desirable in the forms of the fixture shown in Figs. 1 to 6, inclusive, to use a main reflector portion I which is substantially spherical, although, if desired, the same may be parabolical. In Fig. 3 an annular washer 48 is positioned between the bottom of the socket 4 and the inner end of the hood 2 to form a tight seal therebetween. With the construction shown in Fig. 3 in whichthe fixture is substan-' tially air-tight except for the in-and-out breathing 3 due to the change in temperature, the fixture may be used as an explosion-proof fixture.

The form of fixture shown in Fig. "I is alsovery eificient as an explosion-proof fixture. In this form the main reflector portion 1 and the front reflector portion I l are beaded together as shown at 49 to form a continuous reflector. The front reflector I l is shown withonly the one spherical reflecting surface l2, the second reflecting surface l3 being omitted. However, if desired, the front reflector maybe provided with two reflecting surfaces, as shown in Figs. 1 to 6. In the device shown in Fig. 7, the main reflector portion 1 is shown as. "being substantially parabolical with the light source placed within the focal point of the parabola.

The front lens or shown inFig. 3, is made of stand great shock. The lens shield 50 by cementing, or any, other desirable means for forming a tight fit therebetween, and the shield with the lens is threaded into the small opening in the front casing portion 3. The two parts of the casing are held together by screw bolts 5| which extend through apertures in the peripheral portion 52 of the front casing 3 and thread into the peripheral portion 53 of the rear casing portion l. Thus a tight fit between the two casings'is insured. A space 54 is left between the inner portion of the front reflector H and the front casing portion 3 to provide for ventilationso that the heat thrown off by the lamp 6 may escape through the opening 54 and be radiated off by the casing. This will prevent excessive heat within the reflectors.

As all the parts of the casing are tightly sealed together, in case an explosion occurs therein, the gases will be cooled below the danger point before they may escape into the atmosphere, thus preventing any danger of igniting the gases in the surrounding atmosphere.

A form of ceiling fixture embodying the present invention is shown in Fig. 8. In this form, no casing whatsoever is used. A hood 55 which is suspended from the ceiling is provided at the lower end thereofwith a flange 56 and is secured to the main reflector I by means of screws 51 glass l4, as in the device heavy glassto withpassing through the reflector 1 and the flange 56, on the end of which screws, nuts 58 are threaded.

The front reflector portion H is provided with a threaded flange 59 extending inwardly therefrom into which the lens 14 may be threaded. An annular diffusing glass member 60 is slid down over the hood 55 so that the lowerend thereof? engages the notches 6| in the main reflector 1. A slidable ring 62 is then slid down over the hood and over the upper end of the glass portion 60 which thereby forms a dustproof protection about the jointure of the hood 55 and the main reflector I. Apertures 63 are formed in the upper portion of the reflector 1 I4 is mounted in the its rear edge adjacent the front which is covered by the dilTusing-gla'ss portion 60 through which light may escape upwardly through the diffusing glass portion 6 0 against the ceiling. Thus, there is formed a dust proof, eflicient, and inexpensive ceiling feature having a few parts and which may be easily assembled or taken apart. t I

While I have shown and described various embodiments of the present invention, it will be apparent to thoseskilled in the art that various modifications thereof may be made withoutdeparting fromthe spirit and scope of this invention, and therefore, I wish to be limited-only by the prior art and the scope of the appended claims.- e

l. 'A light projecting constructioncomprising a concave reflector, means for supporting an electric bulb with its light source between the center or centers of curvature and the focal points of the reflector whereby the reflected rays converge and cross each other, a zonal spherical reflector in front of said concave reflector having its center substantiallyat the light source whereby light from the zonal reflector will be reflected back onto the concave reflector and re-reflected as converging crossing rays, said zonal reflector having edge of the concave reflector, and a protecting outwardly convex spherical glass cover in front of the bulb, said glass cover being substantially nearerthe light source than is the zonal reflector, the outside diameter of said glass'cover being materially less than the smaller diameterof the zonal reflector;

2. A light projecting construction comprising a concave reflector, means for supporting anelec tric bulb with its light source between the center or centers of curvature and the focal points of the reflector whereby the reflected rays converge and cross each other, a zonal spherical reflector in front of said concave reflector having its center substantially at the light source whereby light from the zonal reflector will be reflected bacl onto the concave reflector andre-reflected as converging crossing rays, said zonal reflector having its rear edge adjacent the front edge of the concave reflector, a protecting outwardly convex spherical glass cover in front of the bulb, said glass cover being substantially nearer the light source than is the zonal reflector, the outside diameter of said glass cover being materially less than the smaller diameter of the zonal reflector, and a two part casing for said reflectors separable substantially on the plane of junction of the concave reflector and zonal reflector. v

3. A light projecting construction comprising a concave reflector, means for supporting an electric bulb with its light source between the center or centers of curvature and the focal points of the reflector whereby the reflected rays converge and cross each other, a zonal spherical reflector in front of said concave reflector having its center substantially at the light source whereby light from the zonal reflector will be reflected back ontothe concave reflector and re-reflected as converging crossing rays, said zonal reflector having its rear edge adjacent the front edge of the concave reflector, and a protecting outwardly convex spherical glass cover in front of the bulb, said glass cover being substantiallyn'earer the light source than is the zonal reflector, the outside diameter of said glass cover being materially less than the smaller diameter of the zonal reflector, said concave reflector havingan openingin the rear for the passage of the neck of the bulb.

4. A light projecting construction comprising a concave reflector, means for supporting an electric bulb with its light source between the center or centers of curvature and the focal points of the reflector whereby the reflected rays converge and cross'each other, a zonal spherical reflector in front of said concave reflector'having its center substantially at'the light source whereby light from the zonal reflector will be reflected back onto the concave reflector and re-reflected as converging crossing rays, said zonal reflector having its rear edge adjacent the front edge of the concave reflector, a protecting outwardly'convex spherical glass cover in front of the bulb, said glass cover being substantially nearer the light source than is the zonal reflector, the outside diameter of said glass cover being materially less than the smaller diameter of the zonal reflector, said concave reflector having an opening in the rear for the passage of the neck of the bulb, and a hood for housing the neck of the bulb and the bulb supporting means.

5. A light projecting construction comprising a concave reflector, means for supporting an electric bulb with its light source between the center or centers of curvature and'the focal points of the reflector whereby the reflected rays converge and cross each other, a zonal spherical reflector in front of said concave reflector having its center substantially at the light source whereby light from the zonal reflector will be reflected back onto the concave reflector and re-reflected as converging crossing rays, said zonal reflector having its rear edge adjacent the front edge of the concave reflector, a protecting outwardly convex spherical glass cover in front of the bulb, said glass cover being substantially nearer the light source than is the zonal reflector, the outside diameter of said glass cover being materially less than the smaller diameter of the zonal reflector, said concave reflector having an opening in the rear for the passage of the neck of the bulb, and a two part casing for said reflectors separable substantially on the plane of junction of the concave reflector and zonal reflectonftherea'r housing portion being provided with a hood for housing the neck of the bulb and the bulb supporting means.

6. An explosion-proof fixture comprising a casing capable of withstanding the internal pressure due to an explosion within said casing'and sufficiently gas-tight so that the hot gaseous products, due to explosion, will be cooled'in escaping sufficiently to prevent ignition outside of the casing, means for supporting a light source in said casing, said casing having a light aperthirty degrees at its apex'forming a spreading,

beam outside of the casing, 'a rear concave reflecting surface for reflecting all light rays falling thereon in a convergent direction and through said light aperture forming a spreading beam outside of the casing having an angle of at least thirty degrees at its apex, and'a front concave annular reflector surface for'reflec'ting the light rays falling thereon from the light source onto the rear reflectin'g'surface to be rereflected in a convergent direction and'through the light aperture, said light aperture being sub stantially smallerin diameter than the maximum diameter of the rear reflectorsurfa'ce.

7. An explosion-proof fixture comprising a casing capable of withstanding the internal pressure due to an explosion Within said casing and sufficiently gas-tight so that the hot gaseous products, due to explosion, will be cooled in escaping sumciently to prevent ignition outside of the casing, means for supporting a light source in said casing, said casing having a light aperture and a cover glass extending across said light aperture of suflicient diameter for the passage therethrough of a divergent cone, of direct rays from the light source having an angle of at least thirty degrees at its apex forming a spreading beam outside of the casing, a rear concave reflecting surface for reflecting all light rays falling thereon in a convergent direction and through said light aperture forming a spreading beam outside of the casing having an angle of at least thirty degrees at its apex, and a front concave annular reflector surface for reflecting the light rays falling thereon from the light source onto the rear reflecting surface to be re-reflected in a convergent direction and through the light aperture, said light aperture being substantially smaller in diameter than the maximum diameter of the rear reflector surface, the intersections of the converging rays from the rear reflecting surface lying within the space within said casing, thus preventing dangerously high temperatures outside of the casing.

8. An explosion-proof fixture comprising a casing capable of withstanding the internal pressure due to an explosion within said casing and suiflciently gas-tight so that the hot gaseous products, due to explosion, will be cooled in escaping sufficiently to prevent ignition outside of the casing, means for supporting a light source in said casing, said casing having a light aperture and a cover glass extending across said light aperture of sufllcient diameter for the passage therethrough of a divergent cone of direct rays from the light source having an angle of at least thirty degrees at its apex forming a spreading beam outside of the casing, a rear concave reflecting surface for reflecting all light rays falling thereon in a convergent direction and throughsaid light aperture forming a spreading beam outside of the casing having an angle of at least thirty degrees at its apex, and a front concave annular reflector surface for reflecting the light rays falling thereon from the light source onto the rear reflecting surface to be rereflected in a convergent direction and through the light aperture, said light aperture being substantially smaller in diameter than the maximum diameter of the rear reflector surface, said front reflecting surface having a minimum diameter substantially smaller than the maximum diameter of the rear reflector surface.

REUBEN B. BENJAMIN.

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