|Publication number||US3457399 A|
|Publication date||Jul 22, 1969|
|Filing date||Feb 25, 1966|
|Priority date||Feb 25, 1966|
|Publication number||US 3457399 A, US 3457399A, US-A-3457399, US3457399 A, US3457399A|
|Inventors||Milroy Philip R|
|Original Assignee||Gen Electric|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (6), Referenced by (16), Classifications (22)|
|External Links: USPTO, USPTO Assignment, Espacenet|
P. R. MILROY July 22, 1969 LUMINAIRE 5 Sheets-Sheet 1 Filed Feb. 25, 1966 PMpZ 11M? July 22, 1969 M|LROY 3,457,399
LUMINAIRE Filed Feb. 25, 1966 3 Sheets-Sheet 2 MJW July 22, 1969 P. R. MILROY 3,457,399
LUMINAIRE Filed Feb. 25, 1966 3 Sheets-Sheet L,-
States 3,457,399 LUMINAIRE Philip R. Milroy, Hendersonville, N.C., assignor to genital Electric Company, a corporation of New Filed Feb. 25, N66, Ser. No. 530,214 Int. Cl. F215 13/10 U.S. Cl. 240-25 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to luminaires, and more particularly concerns luminaires having sealed optical systems protected from the entry of contaminating materials in the atmosphere.
Luminaires of known type, such as those used for street lighting and other purposes, are subject to the disadvantage that when installed in an industrial or other environment having atmospheres containing impurities or contaminants of various kinds, the illuminating and optical systems of the luminaires become dulled or degraded by deposits of the impurities on their surfaces, resulting in a reduced level of illumination produced thereby. Even when gaskets are used between the joints of the luminaire parts, the contaminated air passes into and out of the interior of the optical system. Such movement of the air may be due to the differential pressures which are built up between the interior and the exterior of the optical system by variation in temperature within the luminaire during the operating and non-operating cycles. On the other hand, providing a completely hermetic seal for known types of luminaire optical systems involves practical and economic difliculties due to the elevated temperatures of modern luminaires, the differential pressures which develop therein during operation and other factors.
It is an object of the invention to provide lighting devices, especially luminaires, having improved protection for their illuminating and optical components from the effect of impure atmospheres in which they operate, and to thereby prolong the effective life of the optical system and maintain a high illumination level thereof.
It is a particular object of the invention to provide luminaires of the above type having a sealed optical system and means for purifying the air which passes into the optical system.
It is another object of the invention to provide in luminaires or the like a sealed, filtered optical system of the above type which is economically manufactured, is
easily assembled, and is readily maintained, and which avoids the need for frequent servicing and cleaning thereof.
Still another object of the invention is to provide a combined filter and sealing system of the above type which is readily adaptable for application to a wide variety of illuminating devices.
Other objects and advantages will become apparent from the following description and the appended claims.
With the above objects in view, the present invention in one of its aspects relates to a luminaire comprising, in combination, a reflector and a refractor separably secured together and forming a closed optical system, a lamp aratent O 3,457,399 Patented July 22, 1969 ranged within the closed optical system, resilient sealing means between the reflector and refractor forming an airtight seal for the closed optical system, and air-permeable purifying filter means inserted into the closed optical system for filtering the air passing thereinto by removal of solid and gaseous impurities contained therein, the lamp during operation heating the air in the closed optical system to an elevated temperature, whereby heated air is expelled outwardly through the filter during operation of the lamp, and cool air is drawn inwardly through the filter and purified thereby when the lamp is not operating.
The invention will be better understood from the following description taken in conjunction with the accom' panying drawings, in which:
FIGURE 1 is a view in elevation, partly broken away, of a street lighting luminaire embodying the present invention;
FIGURE 2 is an enlarged detailed view in cross section of a portion of the FIGURE 1 luminaire showing the seal between the luminaire reflector and refractor of th FIGURE 1 device;
FIGURE 3 is a plan view of the rear portion of the refractor showing the refractor retaining means;
FIGURE 4 is a detailed view in cross section of a portion of the FIGURE 1 luminaire showing the sealing and air filter means arranged in accordance with the invention;
FIGURE 5 is a perspective view of the rear portion of the structure shown in FIGURE 4;
FIGURE 6 is a perspective view of the filter device employed in the FIGURE 1 luminaire;
FIGURE 7 is a perspective view of a different type of luminaire, partly broken away, which may embody the present invention;
FIGURE 8 is an enlarged fragmentary view, partly in section, of the FIGURE 7 luminaire showing the sealing arrangement for the optical system; and
FIGURE 9 is a detailed view of a rim portion of the FIGURE 7 luminaire showing the seal arrangement and latch means for the transparent closure.
Referring now to the drawings, and particularly to FIG- I URE 1, there is shown a street lighting luminaire comprising an elongated upper housing 1 adapted to be mounted at its rear end on a pipe support 7 and having secured therein at its front portion a concave reflector 2, typically of aluminum, having a specular interior reflecting surface facing downwardly towards the bottom opening of housing 1. The housing opening is closed by a bowlshaped light transmitting globe or refractor 3 mounted in a ring-shaped retaining frame 4 which is swingably connected at its rear end to housing 1 by hinge means 5 which pivots on transverse support member 25, and is releasably attached at its front end to housing 1 by latch means 6. The particular hinge connection of refractor retaining frame 4 to housing 1 and other structural features (which do not form a part of the present invention) are shown in greater detail in co-pending application Ser. No. 533,054, filed Mar. 4, 1966, now Patent 3,353,015 issued Nov. 14, 1967 and assigned to the same assignee as the present invention.
Reflector 2 is secured to housing 1 by means of screws at its front end, such as screw 2a threadedly engaging a depending boss 1a in housing 1. At its rear end, reflector 2 is releasably mounted by means of rearwardly projecting tangs 2b (see FIGURES 4 and 5) which are inserted into slots in transverse support member 25 secured to housing 1, as more fully described and shown in the abovementioned co-pending application.
Upon release of latch 6, refractor ring 4 with refractor 3 retained therein may be swung downwardly about hinge 5 to provide access to the interior of the luminaire housing for re-lamping or other servicing operations. Upon closing refractor 4 and latching it to housing 1, re-
fractor 3 is brought into tight sealing engagement with reflector 2 as more fully described below.
As seen in FIGURE 2, refractor 3 is formed with a flange 3a extending around its rim and resting upon annular ridge 4b of ring 4 which extends around the opening in the latter in which refractor 3 is received. The front end of refractor 3 is held in place on ring 4 by a plurality of inwardly projecting retaining members 9 integral with outer ridge 4:: of ring 4 and engaging portions of flange 3a of refractor 3. Formed on the upper edge of refractor 3 is an annular bead 3b which in the closed position of refractor retaining ring 4 engages and compresses gasket 7 attached to reflector 2.
As seen in FIGURE 3, refractor retaining ring 4 has a refractor retaining clip 8 pivotally secured therto adjacent the rear portion of refractor 3. After refractor 3 is inserted into ring 4 with its annular flange 3a resting on supporting ridge 4b, and with the front end portion of flange 3a inserted beneath retaining members 9, clip 8 is turned from the open position (shown in broken lines) to the locking position (shown in continuous lines) in which it overlaps flange 3a of refractor 3, thereby retaining the refractor in assembly with ring 4.
Reflector 2 is formed with a peripheral flange 2a (see FIGURE 2) which overlies the rim of refractor 3 in the closed position. Gasket 7 which provides a seal between reflector 2 and refractor 3 is an annular member of suitably resilient material resistant to high temperatures, such as ethylene-propylene-terpolymer elastomer material or the equivalent. As seen in cross-section, the gasket has an upper U-shaped portion 7a which slips snugly over reflector flange 2a around its circumference, and has intergral therewith a tubular portion 7b which is compressed by bead 3b of refractor 3 in the closed assembly, as seen in FIGURE 2. Preferably, the refractor engaging surface of gasket portion 7b is formed with a series of spaced integral ribs (not shown) extending continuously around its length to provide optimum sealing engagement with refractor 3.
Reflector 2 is formed with an opening at its rear which is closed by a cup-shaped housing 10 in which a lampholder or socket 11 is adjustably secured for holding lamp 12, such as a mercury vapor, sodium vapor, or other type of lamp. The structure providing the adjustable mounting of socket 11 within housing 10 is shown and described in detail in co-pending application Ser. No. 530,213, filed Feb. 25, 1966, now Patent 3,348,035 issued Oct. 17, 1967, and assigned to the same assignee as the present application, and does not constitute a part of the present invention. Housing 10 has a flange portion 10a at its front end (see FIGURE and is secured to reflector 2 around its rear opening by means of rivets 13 spaced around the flange portion. The surface of flange portion a facing the reflector wall is formed with an annular recess (see FIGURE 4) surrounding the rim of housing 10, in which resilient gasket 14 is received and compressed between flange 10a and the rear wall of reflector 2. The outermost edge of flange portion 10a is in contact with the rear surface of reflector 2, and the depth of the annular recess in flange portion 10a is so dimensioned with respect to the thickness of gasket 14 that the gasket is under limited uniform compression in the riveted assembly of housing 10 to reflector 2, and provides a tight permanent seal at the joint therebetween.
In acordance with a significant aspect of the invention, a permeable air purifying filter is arranged in the otherwise air-tight optical system of the luminaire to permit passage of air into and out of the optical system and to remove dust, dirt, and other contaminants of gaseous or particulate nature which may be contained in the air and which would adversely affect the illuminating level of the optical system, such as by forming dulling films, depositing materials corrosive to or discoloring the reflecting surface of reflector 2, or otherwise interfering with the function of the refractor, reflector and lamp. In the em- 4 bodiment shown in FIGURES 1-5, the air purifying means is constituted by a filter cartridge 15 (see FIGURE 6) comprising a bonded cylindrical mass 16 of activated charcoal particles contained within a tubular holder 17 of resilient materials such as that of the gaskets previously described, and plugging rear opening 10b in housing 10. Holder 17 is open at opposite ends and is formed at one end on its outer surface with concentric annular lips 17a, 17b defining an annular groove therebetween in which the edges of housing 10 defining rear opening 10b are snugly received and grasped by lips 17a, 17b in sealing relation. Filter cartridge 15 may thereby be readily attached and removed from the rear opening in socket housing 10.
Insulated lead wires 18, 19 (see FIGURES 4 and 5) connected to the terminals of socket 11 pass through a small aperture in housing 10 which is plugged by a resilient plug or bushing 20 having a pair of holes through which lead wires 18, 19 extend. Bushing 20 tightly fits within and is radially compressed by the edges of aperture of 100 and thereby in turn tightly compresses lead wires 18, 19, thus providing an air-tight bushing.
As a result of the described arrangement, the only means available for air to flow into and out of the interior of the closed illuminating and optical assembly, which includes reflector 2, refractor 3 and lamp 12, is through the low resistance path provided by the filter mass 16. All other possible paths for passage of air are of very much higher resistance to low velocity air flow. By virute of such a low resistance path provided by the filter, there will be no sustained difference in pressure between the inside and outside of the optical assembly. Any pressure differences which may arise by operation of the luminaire or for other reasons are rapidly equilized.
When the lamp in the luminaire is turned on, the elevated temperature which develops inside the optical assembly may rise as high as C. As a result, the air therein expands and flows outwardly at a very slow rate through filter 16. When the lamp is turned off, the interior of the opictal assembly cools off and air is drawn back into the optical assembly, also at a Very slow rate. During this period when air enters the optical assembly, filter 16 acts to remove any organic and inorganic contaminants in the air, both of gaseous and particulate type. Particles have above about .1 micron in size will be screened by the activated charcoal out of the air as it passes through the filter. contaminates of gaseous type, such as found in industrial fumes, smog, auto exhaust products such as hydrocarbons, and the like, will be removed by adsorption by the filter particles. The relative dimensions of filter mass 16 should preferably be such that its diameter is large enough to aflord low resistance to the volume of air passing through the filter, while its thickness is large enough to provide adequate mechanical strength for handling without risk of breakage. In a typical case, the diameter would be about 1% and the thickness about In a commercially available activated charcoal filter product satisfactory for the purposes of the invention, the charcoal particles have a size within U.S. sieve sizes 20 to 50 and are bonded by a thermally resistant binder material.
Initial tests made using street lighting luminaires equipped with activated charcoal filters in accordance with the invention compared to standard unfiltered luminaire units indicate that even in a moderately contaminated atmosphere over a period of 11 months of the loss of light transmission through the refractor in the filtered units is only about 10% as compared to about 30% loss for the standard unfiltered units.
While filters composed of bonded activated charcoal particles are particularly suitable for the purposes of the invention, other types of filter materials which purify air by a combination of screening out solid particles and removal of gaseous contaminants by absorption may alternatively be employed, as for example, activated alumina,
clays, magnesia, gels and silicates. However, activated charcoal is preferred because it specifically adsorbs hydrocarbon vapors in preference to water.
FIGURE 7 shows a different type of luminaire in which the present invention may be embodied. This luminaire is adapted for indoor use, as for example, in factory areas where the atmosphere may adversely affect the optical and illuminating system of the luminaire. As seen in FIG- URES 7 and 8, the luminaire comprises a bell-shaped reflector 30 which has an interior specular reflecting surface and is secured to an intermediate support housing 31, which in turn is supported from ballast housing 32 and separated therefrom for thermal insulating purposes by spacers 51. Lamp 33, such as a mercury vapor or other gas discharge lamp, is removably held in socket 34 secured to the top of housing 31, and extend down into the interior of reflector 30'. Ballast housing 32, which contains electrical ballast components (not shown) for operating discharge lamp 33, is releasably secured to upper support member 40 by means of hinge 41 and latch 42, support member 40 being normally secured to a pipe conduit for supporting the luminaire unit therefrom and having an opening in the top for passage of electrical conductors therethrough (not shown).
Housing 31 is formed with a series of circumferentially spaced openings 31a which are closed by an annular transparent window 35 such as glass which is mounted within housing 31 just inside openings 31a and encircling the upper portion of lamp 33. Light from lamp 33 is thus transmitted upwardly out of the luminaire through window openings 31a (so-called up light), as well as downwardly through the bottom opening of reflector 30. The bottom opening is closed by a glass pane 36 having a peripheral molding strip 37 which is hingedly connected to the reflector 30 by hinge 38. As seen in FIGURE 9, latch 39 which serves to releasably secure window pane 36 to reflector 30 in closed position comprises plate members 39a, 39b secured respectively to window pane 36 and reflector 30, and screw 39c which interconnects members 39a, 3% by threaded engagement with member 39a.
In accordance with the present invention, this luminaire is provided with a sealed optical system in which air from the atmosphere is permitted to pass only through a purifying filter. To this end, the annular joint between the upper part of glass window 35 and window housing 31 is sealed by gasket 43 which is of tubular, air core type. The seal between the bottom edge of glass window 35 and the surface of reflector 30 on which it rests is provided by an annular flat gasket 44. The upper end of support housing 31 adjacent the bottom of ballast housing 32 is sealed by means of a resilient plug or bushing 45 having two aperture for passage of insulated lead wires 46, 47 connected to socket 34, in which apertures the latter wires are tightly gripped by the radial compression on plug 45 due to its tight fit in the aperture at the top of housing 31.
Bottom window 36 is sealed to reflector 30 by means of gasket 48 (see FIGURE 9) which comprises, in cross section, a U-shaped portion 48a interposed between edge molding 37 and glass pane 36, and a tubular portion 48b interposed between the upper surface of edge molding 37 and the bottom surface of reflector flange 30a. In the closed position of window 36, tubular gasket portion 48b is compressed as shown in FIGURE 9 to provide an airtight seal around the bottom opening of reflector 30. Each of gaskets 43, 44, 48 and plug 45 are preferably made of a resilient thermally-resistant material such as the ethylene-propylene-terpolymer elastomer material mentioned previously, or equivalent materials.
Filter cartridge 15 (see FIGURE 7) identical to filter device 15 shown in FIGURES 4-6 is inserted in an aperture in reflector 30 and is securely but removably held therein in the same manner as filter device 15 is mounted in housing of the FIGURE 1 luminaire. The interior of the optical system of the FIGURE 7 luminaire is thus sealed except for the passage provided through filter which serves to purify air entering the optical system substantially as described in connection with the FIG- URE 1 luminaire.
It will be understood that filter 15 may be inserted in the optical system of luminaires at locations other than as shown and described herein, as dictated by the particular structure and needs of the luminaire unit in which it is used.
There is thus provided by the invention a luminaire which breathes only purified air, from which both solid and gaseous contaminating materials have been removed. As a result, the deleterious effects of corrosive impurities and dulling films on the luminaire optical system are reduced to a remarkable degree, and the initially high level of illumination produced by the luminaire is maintained over a long period of time, even in heavily contaminated atmospheres in industrial, smog and similar environments. There is also avoided thereby the frequent cleaning of the optical system such as heretofore found necessary with ordinary luminaires installed in such environments. At the same time, the filter-sealed arrangement of the invention is readily and economically manufactured, is applicable to a wide variety of luminaire and other lighting devices, and makes use of filter devices which are easily removable and replaceable, and can be used interchangeably in different optical systems.
While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art without actually departing from the scope of the invention. Therefore, the appended claims are intended to cover all such equivalent variations as come within the true spirit and scope of the invention.
What I claim as new and desire to secure by Letters Patent of the United States is:
1. In a luminaire, a housing, a reflector and light transmitting closure means secured together in sealed relation forming a closed optical enclosure, means for mounting a lamp in said enclosure, and air-permeable, gas-adsorbent filter means arranged on said closed optical enclosure communicating with the interior thereof for filtering the air passing thereinto by removal of solid and gaseous impurities contained in the air, said filter means constituting the sole passageway for heated air expelled outwardly from said enclosure and for air drawn into the enclosure when the latter is cooled, said housing closing an opening in said reflector and said filter means communicating with the interior of said enclosure through an aperture in said housing.
2. In a luminaire, a housing, a reflector and light transmitting closure means secured together in sealed relation forming a closed optical enclosure, means for mounting a lamp in said enclosure, and air-permeable, gas adsorbent filter means arranged on said closed optical enclosure communicating with the interior thereof for filtering the air passing thereinto by removal of solid and gaseous impurities contained in the air, said filter means constituting the sole passageway for heated air expelled outwardly from said enclosure and for air drawn into the enclosure when the latter is cooled, said filter means communicating with the interior of said enclosure through an aperture in said reflector.
3. A device as defined in claim 2, said reflector having a bottom opening and an upper opening, said housing having an annular portion surrounding said upper refiector opening and having window openings therein, said light transmitting closure means comprising a first transparent closure closing said bottom reflector opening and a second transparent closure closing said housing window openings for transmitting light upwardly from said lamp means to the exterior of the luminaire.
4. A device as defined in claim 3, including resilient gasket means sealing said reflector, said light transmitting closure means and said annular housing portion to each other in air-tight relation.
57 In aluminaire, a reflector and a transparent closure therefor separably secured together and forming a closed optical system, sealing means between said reflector and said transparent closure forming an air-tight seal for said closed optitcal system, and air-permeable purifying filter means inserted into said closed optical system for filtering the air passing therethrough .by removal of solid and gaseous impurities contained therein, lamp means arranged in said closed optical system, said lamp means during operation heating the air in said closed optical system to elevated temperature, whereby heated air is expelled outwardly through said filter means during operation of said lamp means, and cool air is drawn inwardly through said filter means and purified thereby when said lamp means is not operating, said reflector being concave and having an annular rim, said transparent closure being bowl-shaped and having a peripheral edge portion in mating relation with said reflector rim, said sealing means comprising a resilient thermally-resistant gasket secured to one of said reflector and said transparent closure and interposed in sealing relation therebetween, said reflcetor having an opening in a wall thereof, said opening benig closed by a housing, lamp socket means mounted in said housing for holding said lamp means, said housing being sealed to said reflector wall and having an aperture therein, said filter means being inserted in and closing said aperture, said housing having a second aperture, resilient plug means closing said second aperture, and elongated conducting means connected to said lamp socket means and passing outwardly through said resilient plug means in air-tight sealing relation therewith.
6. In a luminaire, a reflector and a transparent closure therefor separably secured together and forming a closed optical system, sealing means between said reflector and said transparent closure forming an air-tight seal for said closed optical system, and air-permeable purifying filter means inserted into said closed optical system for filtering the air passing therethrough by removal of solid and gaseous impurities contained therein, lamp means arranged in said closed optical system, said lamp means during operation heating the air in said closed optical system to elevated temperature, whereby heated air is expelled outwardly through said filter means during operation of said lamp means, and cool air is drawn inwardly through said filter means and purified thereby when said lamp means is not operating, said filter means communicating with the interior of said optical system through an aperture in said reflector, said reflector having a bottom opening closed by said transparent closure and having an upper opening, window housing means enclosing said upper opening and being transparent in at least a portion thereof for transmitting light upwardly from said lamp means to the exterior of the luminaire, and lampholder means secured to said window housing means for holding said lamp means extending into said optical system.
7. A device as defined in claim 6, said window housing means comprising an annular member secured to the top of said reflector extending around said upper open ing thereof and having window openings spaced therearound, an annular transparent window arranged concentrically within said annular member closing the window opening thereof, and resilient gasket means sealing said reflector, said annular housing member and said annular transparent window to each other in air-tight relation.
8. A device as defined in claim 7, said annular housing member having a top wall, an upper housing overlying and secured to said top wall and adapted to contain electrical components for operating said lamp means, said top wall having an aperture leading to the interior of the adjacent upper housing, resilient plug means closing said aperture, and elongated conductor means connected to said lampholder means and passing into said upper housing through said resilient plug means in airtight sealing relation therewith.
9. A device as defined in claim 7, said sealing means between said reflector and said transparent closure comprising an annular gasket of thermally-resistant resilient material, said transparent closure being hingedly connected at one side to said reflector and having latch means on its opposite side attachable to said reflector for releasably holding said transparent closure in closed, airtight sealing relation with said reflector.
10. In a luminaire, a reflector and a transparent closure therefor separably secured together and forming a closed optical system, sealing means between said reflector and said transparent closure forming an airtight seal for said closed optical system, and air-permeable purifying filter means inserted into said closed optical system for filtering the air passing therethrough by removal of solid and gaseous impurities contained therein, said reflector having a wall portion associated therewith forming a part of the enclosure for the optical system, said wall portion defining an aperture, said filter means comprising air-filtering material held in a tubular holder, said tubular holder being formed on its outer surface with juxtaposed resilient lip portions extending around said holder and defining an annular groove therebetween, said holder fitting within said aperture with its annular groove receiving the edges defining said aperture, so that said resilient lip portions respectively engage opposite sides of said wall portion for tightly but removably mounting said filter holder in said wall portion.
References Cited UNITED STATES PATENTS 3,350,860 11/1967 Grassel et al. -387 3,376,695 4/1968 Muckley 55387 1,900,330 3/1933 Chartrand 24025 3,089,025 5/1963 Brisco 240-25 3,315,072 4/1967 Harling 24025 FOREIGN PATENTS 575,976 3/ 1946 Great Britain.
JOHN M. HORAN, Primary Examiner RICHARD M. SHEER, Assistant Examiner US. Cl. X.R.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,457 ,399 July 22, 1969 Philip R. Milroy It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:
Column 2, line 72 "refractor 4" should read refractor ring 4 Column 3 line 33, "intergral" should read integral Column 4, line 30, virute should read virtue line 34, "equilized should read equalized line 40, "opictal should read optical line 45 cancel have"; line 47, "Contaminates" should read Contaminants line 66, "months of the loss" should read months the loss line 74, "absorption should read adsorption Column 7 line 5, optitca1" should read optical line 21, "reflcetor" should read reflector line 22, "benig should read being Signed and sealed this 14th day of April 1970.
WILLIAM E. SCHUYLER, JR.
Commissioner of Patents Edward M. Fletcher, Jr.
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|U.S. Classification||362/267, 55/385.1|
|International Classification||F21V15/00, F21V23/02, F21S8/08, F21V31/03, F21V31/00, F21V17/00, F21V17/10, F21V15/06, F21V7/00|
|Cooperative Classification||F21V23/026, F21V31/03, F21V17/107, F21W2131/40, F21V7/0016, F21W2131/103, F21V15/06, F21S8/086|
|European Classification||F21S8/08H2, F21V31/03, F21V23/02T|