US 2192019 A
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Description (OCR text may contain errors)
.JOC- f D Search Room Feb. 27, 1940.
LIGHTING FIXTURE Filed May 1, 193'.' 2 Sheets-Sheet 1 INVENTOR l/vosLer SCHEPMOES [Qing/0MM ,M/
ATTORNE S Feb. 27, 1940.
L. SCHEPMOES LIGHTING FIXTURE Filed May 1, 1937 2 Sheets-Sheet 2 INVENTOR UNDSLEY Sc//gPMoE BY @4). ai@ @wf WJ ATToRNE'l Patented Feb. 27, 1940 UNITED STATES PATENT ori-ice LIGHTING FIXTURE Application-May 1, 1937, serial No. 140,126
This invention relates to a lighting fixture and more particularly to a lighting fixture and lens for illumination of a railroad car or the like.
In accordance with the seating arrangement of 5 modern railroad cars, busses and similar vehicles, it is often desirable to provideA lighting fixtures which not only harmonize with the interior decoration of the vehicles but which effectively provide localized illumination. Many such vehicles are provided with aligned pairs of seats over which a baggage rack extends and which are more eectively illuminated by light sources which illuminate generally the entire interior of the vehicle. Such illumination is often too weak to l5 provide sufficient reading light but is, nevertheless, productive of glare and light streaks which cause eye strain. When such xtures are increased in illuminating power, the resulting glare is still more bothersome. Still other fixtures which attempt to provide localized illuminaiton,
for each pair of seats do so indifferently because of improper location, poorlens structure, and
numerous other reasons. These fixtures also very often cause an atmosphere of gloominess in the upper portions of the car and accordingly detract from rather than enhance the interior decoration thereof.
It is accordingly among the objects of this invention to provide a lighting fixture for a railroad car or similar vehicle which is reasonably inexpensive, sturdy, durable under conditions of "rigorous use,.which effectively illuminates the' reading plane in the car without creating a condition of glare and finally which enhances the general appearance of the car interior.
The invention accordingly consists, in the features of construction, combinations of elements, and arrangements of parts, all .as will be illustratively described herein, and the scope of the 40 application of which will be indicated in the following claims.
In the accompanying drawings in which are shown two of the various possible embodiments of my invention,
Figure 1 is a longitudinal sectional elevation of my light fixture;
Figure 2 is a bottom plan view of the fixture;
Figure 3 is a sectional elevation taken along the line 3--3 of Figure 2;
Figure 4 is a diagrammatic view showing .the
distribution of light from the lens in my fixture;
and l Figure 5 is a sectional elevation of a modified form of my fixture.
Similar reference characters refer to similar (CL 24o-7.35)
parts throughout the several views of the drawings.
Referring rst to Figure 1, my light fixture comprises generally a housing indicated at I9 which mounts an electric bulb socket II holding a bulb I2, casing II) having removably mounted therein a lens generally indicated at I3.
Still referring to Figure l, casing I0 is preferably an integral die-casting or stamping of suitable material such as aluminum and com lo prises a dome-like reflector. portion I4, 'the inside I5 of which is suitably coated or finished to reiiect light rays from bulb or light source. I2. An opening I6 is provided in refiector I4 through which the open end of socket II extends in bulb- 15 receiving position. Casing I0 also includes substantially vertical side portions Il (Figure 3) 1 which join refiector I4 with a flange portion I8 (see also Figure 1) which forms a mounting surface for the casing. I also provide an integral 20 socket mounting plate I9 provided with a sub-. stantially U-shaped opening 20 by which socket II may be mounted in any suitable manner.
A pair of bosses 2| (Figure 1) are provided along one transverse end of casing I0 and on 25 these bosses I secure a bracket 22 'as by screws 23 for a. purpose hereinafter described. On the other transverse end of casing III I provide a similar pair of bosses 2l (Figures 1 and 3) on which are secured similar brackets 25 as by screws 26 30 (Figure 1).
As is more clearly shown in Figure 2, casing iiange I3 has a. suitable number of screws 21 extending therethrough which may be threaded into 4a portion 28 (Figure 1) of the baggage rack I (for example) or the ceiling of a railroad car or the like to mount the casing therein.
Brackets 22 and 25 are provided respectively with horizontal portions 22a and 25a having suit-y able hbles formed therein through which extend n respectively lens supporting hooks 29 and 30. As all of these hooks are substantially the same, only one will be described. 'I'hus hook 29 (Figure 1) has a. collar 3| suitably secured thereto and between this collar and casing flange I8 a spring 32 is coiled about hook 29. Spring 32 is an expansion spring and accordingly thrusts against collar 3l to force hook 29 upwardly to cause lens supporting arm 29a thereof to pull against'the bottom of one edge of lens I3 thus l, f holding the lens against casing flange I8 in proper operative position. Similarly lens hooks 30 are provided with springs 33 which force hook arms 30a against the bottom of the opposite edge of lens I2 to hold it in position.
side portions 34 resting against casing ange I8. The outer surfaces of side and bottom portions 34 and 35 preferably are corrugated, i. e. they have parallel ridges 36 formed thereon (Figure 2) which are suitably treated so as to have a diffusing surface rather than a clear surface.
It may now be seen that lens I3 may be readily installed or detached from casing I .bythe manipulation of hooks 29 and 30 as these hooks may be pulled downwardly against the action of springs 32 and 33 and thence twisted to swing hook arms 29a and 30a away from the bottom of the lens. l y l Positioned substantially, centrally of lens bottom portion 35 (Figure 2) is a twin-'condenser lens generally indicated at 31. As is better shown in Figure 1, twin condenser lens 31 comprises two lens portions 38 and 39 (Figure 1) lying in the same general plane. As each of these lens portions is substantially similar to the other, only onel will be described hereinafter. Lens portion 38 accordingly has an upper convexsurface 40 (see also Figure 3) which extends from a point 4I where it joins the bottom 35 of lens I3 to a point 42 where it joins the upper convex surface 43 of lens portion 39, point 42 being equidistant from the lcenters o.f lenses 38 andv 39 andrpreferably being aligned with the center of source I2. With reference, to Figure 3, the bottom surface of lens portion 38 is formed in a'series of concentric prisms 44, 45 and 46, the lower surfaces of each of which are preferably concentrically convex. The central portion 41 of the bottom surface of lens 38 is also preferably convex. Lens portion 39 is similarly provided with concentric prisms 48, 49 and 50 having convex surfaces and with a convex lower surface I. Thus condenser lens 31 comprises in general`a pair of inverted so-called Fresnel lenses 38 and 39 lying in the same gleneral plane, each of the Fresnel lenses in turn having a segment cut therefrom and the two lenses 38 and 39 joined along their respective chords, i. e. along the line or chord 53 (Figure 2). As shown in Figure 1, lower lens surfaces 41 and 5I join at a point 52 directly'below the point -42 where upper convex surfaces 40 and 43 jon 40 and 43 which are wholly convex are adjacent y light source I2 and preferably center point 42 of lensl 31 is positioned'in alignment with vthe center portion I2a of light source I2. This positioning of the lens not only facilitates cleaning thereof but also places the main body of the lens above the bottom horizontal plane of lens portion 35 which considerably lessens the production of light streaks and glare therefrom and increases the intensity of the condensed light.
Referring now to Figure .4 wherein I show diagrammatically the distributionof light from lens 31, it will be seen that light -rays A emanating from source I2C. strike the upper convex surfaces 40 and 43 of the lens and are distorted by lens 31 so as to. emanate therefrom-Ain two relatively distinct beams B and C which are suitably divergent toyprovide spot illumination for a pair/of'seats; for example, when the lens is asymmetrically positioned thereover. Beams of light B and C thus amply illuminate the seats toward which they are directed but do A not cause glare outside of their locality. A sumcient diffusion of light, however, emanates from portions 34 and 35 (Figure 1) of the lens to provide a soft illumination in the upper portion of thev car or enclosure in which the fixture is installed thus to dispell an otherwise gloomy atmosphere. Furthermore, this soft diffusion of light eliminates to a considerable extent the glare which would otherwise be noticeable when the vision is directed straight at the lens as the brightness of light emanationis graduated be-f. tween the brilliant part of lens I3, i. e. con-1 denser lens 31 and the relatively darker sur;-A rounding portions thereof, i. e. diffusing portion 35.
Referring now to Figure 5 in which I show my above-described lens mounted in a baggage rack support, the baggage rack includes a supporting arm 54 suitably secured to a side 55 of the car and extending therefrom to terminate in an upwardly curved portion 56. On opposite sides of arm 54 I provide substantially yvertical -side walls 51k (only one of which is shown) and these side walls with a. pair of partitions 58 and 59 form an enclosure 60 in which the several parts of the lighting xture are disposed. An upper support 6I is pivotally connected to the upper end of partition 58 by a hinge 62, support 6I being provided with downwardly projecting arms 63 and 64 and being held in rclosed position by a screw 16. Support arms 63 and 64 have secured thereto in any suitable manner a reector 65 which surrounds a light source 66 mounted in a socket 61 secured in any suitable manner to partition 58. Partition 58 has an opening 68 formed therein to accommodate elec-v tric conductors 69 which are connected tol socket 61.` It will appear that support 6I may be pivoted to the dotted line position to permit access to socket 61 and the lens therebelow.
An opening is formed on the bottom of supporting arm 54 through which a lens generally indicated at 1I extends. Lensr1I is substantially similar to lens I3 (Figure 1) except that lens 1I is provided with a flange 12 which rests upon a gasket 13 adjacent the edges of opening 10. A suitable number of clips 14 are secured as by screws 16 to arm 54 and these clips bear against lens flange 12`to hold the lens in its proper operative position.
As has been noted hereinabove, it is desirable to distribute light uniformly over thel reading plane in the car, this reading plane being approximately 33 inches above the fioor of the car and at an angle of about 45 thereto. It is, however, quite difIicult to illuminate' this reading plane uniformly when the light source is positioned asymmetrically with regard thereto. However, by utilizing my above-described ler/is 1I (Figure 5) which throws the twin beams or spots B and C Y eicient manner.
As many possible embodiments may be made of 'thev above invention and as many changes might be made in the embodiment above set forth, vit is to be understood that all matter hereinbefor set forth, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.
1. A lighting fixture for a railroad car or the like provided with a line of pairs of seats, said xture being asymmetrically disposed over a pair of said seats and with respect to the reading planes related thereto, said ixture comprising, in combination, a reilector adapted to be con-Y nected to the upper part of the car, a source of light adjacent said re'iiector, and a light-transmitting and diusing member adjacent said source of light and having a generally fiat bottom facing generally downwardly of said car, a portion of said bottom being translucent and adapted to effect a general diffusion of light in the upper portion of said car, the central portion of said member comprising a pair oi' CODCaVO-COIIVSX Condenser 1eI1SeSaCh arranged xture being asymmetrically disposed over a pair of said seats and with respect to the reading planes related thereto, said fixture comprising, in combination, a reilector adapted to be connected to the upper part of the car, a source of light adjacent said reflector, and a light-transmitting and diiusing member adjacent said source of light and having a generally iiat bottom facing generally downwardly of said car, a portion of said bottom being translucent and adapted to effect a general diiusion of light in the upper portion of said car, the central portion of said member comprising a pair of concavo-convex condenser lenses, each arranged to direct a spot beam of light of uniform intensity over one of said reading planes, the concave portions of said lenses extending upwardly from the plane of said bottom wall, said bottom wall including a plurality of corrugations or the like, and spring' source.