June 10, 1941.
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`1. L. s'rEwART
`LIGHTING FIXTURE
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`2,244,737
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`Filed Dec. 51, 1937
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`5 Sheets‘-Sheet 1
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`Yotrio Ex. YOT—1204, Page 1
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`Yotrio Ex. YOT-1204, Page 1
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`June 10, 1941.
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`|__ L, 5'1-EWART
`LIGHTING FIXTURE
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`2,24-4,737;
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`Filed Dec. 31, 1937
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`June10,1941?
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`L?L,STEWART
`LIGHTING FIXTURE
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`2244,737
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`June10,1941?
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`L,L,STEWART
`LIGHTTNGFrxTURE
`Filed Dec,31,1937
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`2244737
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`5 Sheets?Sheet 4
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`Yotrio Ex. YOT-1204, Page 4
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`June10,1941?
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`LLsTEwART
`LIGHTING FIXTURB
`Filed Dec?31,1957
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`2244737
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`5Sheets-Sheet,5
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`Patented. June 10, 1941
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`i
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`* 2,244,737
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`UNITED STATES PATENT orricr.
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`2,244,737
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`LIGHTING rrxrvns
`‘Lemuel L. Stewart, Elkhart, Ind., assignor to The
`Adlake Company, a corporation of Illinois
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`Application December 31,1937, Serial No. 182,859
`2 Claims.
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`1
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`2
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`0
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`0
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`Due to limitations in available power, lighting-
`fixtures used on railway cars, buses and the like,
`should provide suiilcient
`illumination at
`the
`reading plane for easy reading, but no more gen-
`eral illumination than is required for practical
`purposes. Highly efllcient, specially designed
`lighting fixtures are necessary to meet specifica-
`tions of this kind, and the principal .object of
`this invention is to provide such fixtures.
`A further object of the invention is to intro-
`duce color into the light which is given off by
`the fixture without materially impairing the em-
`ciency of the fixture as a whole.
`Practicability of fabrication, ease of mainte-
`nance, and cheapness in cost are other desirable
`attributes of the fixtures shown in the accom-_
`panying drawings, in which
`Fig.
`1 is a fragmentary cross-sectional view
`of a railway car equipped with lighting fixtures
`made in accordance with this invention;
`Fig, 2 is a. cross sectional view showing one
`’ of the preferred forms of the invention;
`Fig, 3 is _a bottom plan view of the fixture
`shown in Fig. 2;
`‘
`Fig. 4 ‘is a fragmentary cross-sectional view
`showing fixtures built into the underside of the
`baggage racks;
`Fig. 5 is a cross sectional view through the
`fixture shown in Fig. 4;
`'
`«
`Fig. 6 is a bottom plan view of the fixture
`cover shown in Fig. 5, a portion being cut away,
`as indicated by the section line 6-6 in Fig. 5 ;
`Figs. 7 and 8 show modified forms;
`Fig_ 9 is a cross sectional view of a railway car
`which,
`for
`the purposes of
`illustration,
`is
`equipped on the left side with the fixture shown
`in Figs, 10 and 12, and on the right side with the
`fixture shown inFigs. 11 and 13;
`Figs. 10 and 11 are bottom plan views of the -
`4
`fixtures shown in Figs. 12 and 13, respectively;
`and
`«
`
`(Cl. 240-735)
`power demands‘ are similarly budgeted and then
`the size and electrical characteristics of the gen-
`erator, relays and other electrical equipment are
`determined.
`.
`The recent trend toward light-weight cars ne-
`cessitates cutting down on the weight of the elec-
`trical equipment carried by each car, with the
`result that every effort
`is being made at the
`present time to reduce the amount of power re-
`quired for car lighting. To accomplish this end,
`highly efiicient lighting fixtures must be used.
`-
`Broadly speaking,
`the problem can best be
`handled by using eiilcient spotlight units which
`give the required illumination at the reading
`plane, but no more general illumination than is
`necessary for lighting the aisles and giving a
`general pleasing effect to the car interior.
`The fixtures shown in the drawings and here-
`after described accomplish these objects and
`meet the other requirements of practical design
`by having a minimum number of parts, by being
`easy to maintain, and by being capable or adjust-
`ments which enable the desired lighting char-
`acteristics to be readily obtained after the instal-
`lation oi the fixtures has been completed.
`V
`V
`Referring now to Figs. 1-3 inclusive, lighting
`fixtures generally designated 2|), are shown
`mounted on the ceiling of the lower deck of a
`railway car 2I,«one fixture being mounted above
`each pair of seats 22. The fixtures are recessed
`into the lower deck ceiling, the finish sheet of
`which is indicated at 23 (Fig. 2) and each com-A
`prises a standard lamp 2! screwed into a socket
`'25 which is adjustably supported by a collar 26
`which rests upon and is capable of lateral ad-
`justment relative to a reflector generally desig-
`_ nated 21.
`The reflector is shown as a sheet metal stamp-
`ing having a polished reflecting surface 28, but
`it may be of any approved design and preferably
`is provided with a screw thread 29 adjacent to
`its mouth to receive the threads 30 formed on
`the glass cover, which is generally designated 3|.
`The threads 29 of the reflector may terminate in
`a marginal finish fiange 32.
`Thecollar 26 is split, as indicated at 33, to
`provide a clamping jaw 34 which may be made to
`grip the socket .25 and hold it in any desired
`adjusted position along a vertical axis by the
`tightening of a screw 35.
`lateral adjustment of
`the lamp within. the reflector 21 is accomplished
`by movement of the collar 26 on the top fiat
`surface 36 of the reflector, the desired adjusted
`position being held by a small screw 31 which
`travels in a slot 38 provided in the collar 28.
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`3
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`0
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`O
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`Figs. 12 and 13 are sectional views showing an-
`other type of fixture coming within the broad
`scope of this invention.
`The choice of certain preferred and modified
`forms of the invention for illustration and de-
`scription is for the purpose of complying with
`sec. 4888 of the Revised Statutes, but it should
`be understood that the claims should not be
`limited by these specific embodiments of the
`invention unless required by the prior art.
`,
`In designing the electrical equipment for a
`railway car, the engineer in charge usually allows
`a given number of watts,
`say 1500 watts,
`for the car lighting equipment. Other electrical
`s
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`50
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`Q‘!C)!
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`Yoirio Ex. YOT—1.204, Page 6
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`2,244,737
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`The fixture is preferably ventilated by provid-
`ing openings 39 and 48 in the reflector, or it
`may be made of a suitable heat dissipating ma-
`terial such as aluminum.
`The fixture cover 3! is made of glass or other
`suitable transparent material as for example
`certain plastic material of which
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`C51.
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`In Figs. _4-6 inclusive, a somewhat similar fix-
`ture is shown mounted in the baggage racks ex-
`tending longitudinally of the car. The cover in
`this instance may have a smooth rounded outer
`surface to make‘ it simulate a crystal ball, but”
`' as before, the cover 3! has a lens portion all and
`a light difiusing portion 132. The -glass in the
`diffusing portion 42 may have small bubbles as
`indicated at M which assist in breaking up the
`light rays and increasing the general illumina-
`tion.
`‘Fixture covers of this type have a radiant glow
`which make them distinctive in appearance and
`pleasing to the eye.
`,
`As best shown in Fig. 5, the fixture comprises
`a box £48 having a hinged cover 49 which sup-
`ports an adjustably positioned bracket 59 which
`in turn holds thesocket 5! for the lamp 52. The
`bracket carries at its outer end a refiector 53 so
`"that no matter where the lamp unit is positioned
`- within the box, the reflector is directly behind
`the lamp. The bracket is slidably carried on the
`cover 539 by a pair of screws 54 which are thread-
`ed into the bracket 5A3 and travel in a slot 55 pro-
`vided in the box cover.
`Since the light fixture shown in Figs. 4-6 in- T
`clusive, is closer to the reading plane than the
`fixture shown in Figs. 1-3 inclusive, vertical ad-
`justment of the lamp with respect to the lens :3!
`is relatively unimportant although suitable pro-
`vision may be made at the lower end of the
`bracket 59 to accommodate vertical adjustment.
`As before, a light screen as may be used on the
`inner side wall of the cover 3! for color efiect.
`The fixtures shown in Figs.-7 and 8 are pri-
`marily intended for ceiling installations, the one
`in Fig. 7 comprising a lens cover lit which. is
`threaded into a somewhat elongated depending’
`base $1 in order to give the side or light dil-
`fusing portion 58 a better opportunity to provide
`even ceiling illumination, and the fixture shown
`in Fig. 8 accomplishes somewhat the same re-
`sult by having the cover 59 oi‘ substantially
`spherical Iorm.
`The fixtures shown in Figs. 1-8 inclusive all
`have the novel aesthetic efiect of an illuminated
`crystal and the eiiect is more pronounced when
`at least the side portions of the cover are pro-
`vided with bubbles.
`In Figs. 9--12 inclusive, two further modifica-
`tions of the lighting fixture are shown, the cov-
`ers of which are characterized by having re-
`entrant
`lens portions 69 surrounded by a de-
`pressed annular diffusing portion ti.
`In" Fig. 12,
`the lens is of the optical type and in Fig. 13,
`the lens is of the prismatic -type. In both forms,
`however, the lens serves to collect the light rays
`and concentrate them into a vertical beam to be
`thrown on the reading plane below.
`»
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`The marginal diffusing portion ti may be pro-
`vided with beading, as indicated at $2 in Fig. 12
`to give -the cover an ornate appearance and as»
`sist in the distribution of the light for general
`illumination, or it may be plain-, as shown in Fig.
`13 in which event, the inside annular trough
`53 would be frosted or enameled‘ to give this
`portion of the cover light dlfi’using-character-
`istics.
`In Fig. 12, the fixture itself comprises -a re-
`flector fill having a split neck 55 forming a jaw
`which is adapted to adjustably clamp the lamp
`socket
`555
`in its desired vertical position with
`respect
`to the lens 58. The socket. carries a
`standard lamp 6? and ventilation of the fixture
`is accomplished by convection .with air entering
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`Yoirio Ex. YOT—1204, Page 7
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`Phenol-formaldehyde compounds,
`Urea-formaldehyde compound,
`Methyl—methacrylate resin,
`Cellulose acetate
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`are the most suitable. The cover comprises a
`lens portion 13! and light diffusing portion lit, the
`former having its radius of curvature chosen to
`give the desired distribution of concentrated
`«light on the reading plane immediately beneath
`the fixture. The light diiiusing‘ portion -932 of
`the cover preferably has a plurality of annular
`prisms or ribs £33 which are shaped to provide
`evenly distributed illumination or any other de-
`sired distribution of light.
`.
`'
`The cover Bl
`is readily secured to the fixture
`by screwing it into the reflector 21, the upper
`margin of the cover being serrated as indicated
`at 4:3 to cooperate with a spring pawl dd which
`locks the cover in place and prevents it from ac-
`cidentally being unscrewed by jarring oil
`the
`car.
`It will be observed that the light from the
`lamp 24 is concentrated by the reflector 27 on
`the lens portion ill of the cover and the lens
`serves to collect the light rays and transmit them
`in the form of a beam on the reading plane be-
`low. A certain amount of light, however, will
`pass out laterally through the diffusing portion
`62- of the cover and the prisms $3 will serve to
`distribute these rays according to general
`il-
`lumination requirements. The prisms bend the
`light rays from the source laterally and upward-
`ly to provide general illumination for the upper
`. portion of the car without glare to the passen-
`gers below.
`.
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`It is possible to give the vertical beam ema-
`nating from the fixture a quality of color (the
`lamp 2tl being a source of white light) by
`placing a color screen as along the inner wall
`of the light diffusing portion ‘$32 of the cover.
`The screen may constitute a relatively thin sheet
`of gelatin or other colored translucent or trans-
`parent material, or it may consist of colored
`enamel sprayed on the inner wall by well known
`methods. Some of the light rays which would
`normally pass through the light diffusing por-
`tion of the cover will be defiected byethe screen
`through the lens 4! and when the color screen
`is blue, for example, the vertical beam will have
`a_certain daylight quality which improves it for
`reading purposes.
`‘
`Of course the rays passing through the light
`diffusing portion 432 of the cover will also be
`colored, «and the color in the region will be more
`pronounced because only those rays which cor-
`respond in wave length to the transmission band
`or bands of the color screen will so through the
`screen.
`.
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`It should be noted that the efllciency of the
`vertical beam is not impaired in the least by the
`addition of color since the screen is not placed
`in the path of the main beam, but only inter-
`cepts certain laterally directed rays which other-
`wise would pass through the diffusing portion 612
`or be reflected as white light by the inner sur-
`face of that portion.
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`3
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`10
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`20
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`9,244,737
`portions can be varied to suit conditions, using
`numerous combinations of frosting. enameling.
`color tinting and bubbles in the glass, without
`departing from the spirit of this invention.
`Iclaim:
`'.
`g
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`1. In a lighting fixture. a source of white light,
`‘ a cover below the source through which light
`rays are transmitted for ‘producing a‘ given light
`distribution, said cover having light transmitting
`means for throwing a vertical beam of white un-
`filtered light and a concentric diflusing portion
`for casting light laterally, said diffusing portion
`including annular prisms adapted to bend the
`light rays upwardly, and a color screen inside
`the cover placed with respect to the light source
`and cover» so as to direct colored light from the
`source through the light diflusing portion and to
`diffuse colored light from the’ screen into the
`vertical beam of white light.
`2. In a lighting fixture, a source of white light.
`a cover below the source through which light
`rays are transmitted for producing a given light
`distribution, said cover having light transmitting
`means for throwing a vertical beam or white un-
`filtered light and a concentric diffusing portion
`-for‘ casting light laterally, a reflector behind
`the source reflecting white light through the light
`transmitting means, said diffusing portion in-
`cluding annular prisms adapted to bend the light
`rays upwardly, and a color screen inside the
`cover placed with respect to the light source and
`cover so as to direct colored light from the source
`through the light diffusing portion and to diiluse
`-colored light from the screen into the vertical
`beam of white light.
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`L. STEWART.
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`the reflector through openings 68 and leaving the -
`refiector through openings I9.
`_
`Attached to the mouth of the rim is a retaining
`rim ‘ll provided with screw threads ‘ll into which
`the fixture cover is screwed into place and prefer-‘
`ably the upper edge or the cover is serrated as
`indicated at 12 to cooperate with the locking
`pawl not shown, which is of the same character as
`the pawl 45 shown in Fig. 2.
`-Near the base of the reilector 64 is a band or
`screen 13 which may be color tinted to reflect a
`certain amount of color into the main beam
`transmitted through the lens 60, but a greater
`amount through the light diffusing portion Si or
`the cover.
`"An alternative method of introducing color into
`the light emitted by the fixture is by employing
`a color screen 14 (see Fig. 13) of gelatin, or
`other suitable light filtering material.
`The lamp cover shown in Fig. 13 is supported
`by clips 15 in a retaining ring 16 which is swung
`irom a concealed hinge 11 rigid with the reflector
`64. Ventilation openings 68 and 59 are provided
`as in the fixture shown in Fiz. 12.
`'
`One advantage of the re-entrant lenses which
`‘characterize the fixtures shown in Figs. 12 and 13,
`is that the surrounding diffusing portions 6| tend
`to screen the light source from the eyes oif persons
`who are not directly in the vertical beam given
`out by "the fixture. Another advantage is that
`the total depth of the fixture is held to a mini-
`mum and at the same time, the depressed annu-
`lar diflusing portion 6| provides better general
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