Management of light fixture surface temperature

Description

FIELD OF THE INVENTION

[0001] This invention relates to management of light fixture surface temperature.

BACKGROUND OF THE INVENTION

[0002] A bollard light fixture is a type of outdoor lighting encased in a vertical post at ground level. Bollard light fixtures are commonly used for ground illumination. Generally, bollard light fixtures include a bollard housing, wherein a light source is located within the bollard housing. A cap is then affixed to the top of the bollard housing. A gasket is typically located at the junction of the cap and the bollard housing. Bollard light fixtures may have a variety of sizes, shapes, and capabilities.

[0003] In a typical bollard design, the light source emits heat that travels via convection to the inner surface of the cap. The heat then transfers via conduction to the outer surface of the cap, such that the touchable surface temperature of the cap exceeds maximum allowable safety standards.

[0004] Accordingly, there is a need for a thermal management device to control the amount of heat transferred to the touchable outer surface of the bollard housing cap, so that the touchable upper surface temperature is below the maximum allowable temperature for such fixtures.
Patent document (DE19920669) describes a lantern with a roof, walls and base. A heat shield 15 is intended to prevent light emitted by the lamp going into the roof.
Patent document GB1038866 describes a beacon comprising a base portion, means for supporting a light source or sources in the base portion, a head portion having a light-reflecting surface, and a flexible body portion between the head portion and the base portion, said body portion having a light-transmitting duct through which light may pass from the base portion to the head portion.

SUMMARY

[0005] The present invention is as set out in the appended claims. Embodiments of the present invention are directed to management of light fixture housing temperature. In one embodiment, a light fixture includes a housing with a top end having an aperture, a light source, a membrane, and a cap. The membrane has an outer perimeter that substantially conforms to the outer perimeter of the top end of the housing and substantially covers the aperture in the top end. The membrane is formed of a translucent material and is disposed to create a luminous highlight at the junction of the top end and the cap. The membrane may be a silicone-containing material. In some embodiments, additional insulating material is placed in an area formed between the cap and the membrane.

[0006] The membrane may be installed in existing light fixtures, where the existing light fixture comprises a housing with a top end having an aperture, a light source, a gasket, and a cap. The method of installation includes the steps of removing the cap, removing the gasket, providing a membrane that substantially conforms to the outer perimeter of the top end of the housing and substantially covers the aperture in the top end, placing the membrane over the top end of the housing, placing the cap over the membrane, and securing the cap to the top end of the housing. The membrane is formed of a translucent material and is disposed to create a luminous highlight at the junction of the top end and the cap. In some embodiments, the method further comprises removing material from the membrane so that the membrane comprises an outer perimeter that is configured to substantially conform to the outer perimeter of the top end of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] 

Figure 1 is an exploded perspective view of a bollard light fixture according to one embodiment of the present invention.

Figure 2 is an assembled perspective view of the bollard light fixture of Figure 1.

Figure 3 is a cross-sectional view taken along line 3-3 in Figure 2..

Figure 4 is a cross-sectional view of a bollard light fixture with a traditional gasket.

Figure 5 is a cross-sectional view taken along line 5-5 in Figure 3.

Figure 6 is a perspective view of a bollard light fixture according to an alternative embodiment of the present invention.

Figure 7 is an exploded perspective view of a bollard light fixture according to another alternative embodiment of the present invention.

DETAILED DESCRIPTION

[0008] Embodiments of the invention provide components that manage the touchable surface temperature of a light fixture. While the components are discussed for use with bollard light fixtures, they are by no means so limited. Rather, embodiments of the temperature-management components may be used in light fixtures of any type.

[0009] Figures 1-3 and 5 illustrate an embodiment of the bollard light fixture 10 having a light source 12, a bollard housing 14, a cap 16, and a membrane 18. The light source 12 is located within the bollard housing 14. The light source 12 may be located anywhere within the bollard housing 14. The light source 12 may be any suitable light emitting source including, but not limited to, fluorescent, metal halide, high pressure sodium lamps, light emitting diodes ("LEDs"), or organic light emitting diodes ("OLEDs").

[0010] In one embodiment, the bollard housing 14 surrounds the light source 12. The bollard housing 14 has a generally elongated shape along its vertical axis. The cross-sectional shape of the bollard housing 14 may be any appropriate shape that provides sufficient interior space for the location of the light source 12. Examples of such cross-sectional shapes include but not limited to circular, rectilinear, oval, triangular, clover-leaf, or other similar shape. The bollard housing 14 may be formed of any material suitable for use in close proximity to a light source including, but not limited to, aluminum, iron, steel, composite material, acrylic, polycarbonate, polystyrene, or copolymers thereof, or other similar material. In some embodiments, the bollard housing 14 itself is light-transmissive. The bollard housing 14 has two ends - a base end 20 and a top end 22. The base end 20 is configured to be mounted to a surface such as the ground. The top end 22 has an aperture 24 to allow access to the light source 12.

[0011] In some embodiments, the bollard housing 14 includes at least one refractive lens 26. The at least one refractive lens 26 may be formed from glass, plastic, or other similar material that provides suitable optical properties, as well as allowing visible light to escape the bollard housing 14. In some embodiments, as shown in Figure 6, multiple refractive lens 26 are located on the surface of the bollard housing 14.

[0012] The cap 16 is located adjacent the top end 22 of the bollard housing 14. The cap 16 encloses an area 28 surrounding the top end 22 to prevent introduction of contaminants into the bollard housing 14. The cap 16 is connected to the top end 22 via any appropriate mechanical fasteners 29 including, but not limited to, clips, screws, bolts, or other similar devices. The cross-sectional shape of the cap 16 may have any shape that complements the shape of the housing 14, including, but not limited to, circular, rectilinear, oval, triangular, clover-leaf, or other similar shape. Moreover, the surface contour of the cap 16 may have a domed, flat, or other contoured shape. The cap 16 may be formed of any material suitable for use in close proximity to a light source including, but not limited to, aluminum, iron, steel, composite material, acrylic, polycarbonate, polystyrene, or copolymers thereof, or other similar material.

[0013] The membrane 18 is located between the light source 12 and the cap 16. The membrane is positioned on the top end 22 of the housing 14 to cover aperture 24. The outer perimeter of the membrane 18 is shaped to substantially conform to the outer perimeter of the top end 22. When the membrane 18 is shaped to substantially conform to the outer perimeter of the top end 22 it may be sandwiched between the bollard housing 14 and the cap 16 such that the membrane 18 is visible from the outside of the bollard light fixture 10 during normal use. Accordingly, the membrane 18 may have any shape including, but not limited to, circular, rectilinear, oval, triangular, clover-leaf, or other similar shape. As shown in Figure 5, the presence of the membrane 18 in place of a gasket 34 impedes the convection flow of heat from the light source 12 to the cap 16 by creating a barrier between the heat source and the cap 16. The membrane 18 may be formed of silicon or any other suitable material that reduces the amount of heat transmitted to an area 28 encapsulated between the membrane 18 and the cap 16.

[0014] The membrane 18 imparts optical properties to the bollard light fixture 10. The membrane 18 is be formed of a translucent material that creates a luminous highlight at the junction of the top end 22 and the cap 16. In other embodiments, the color of the luminous highlight at the junction of the top end 22 and the cap 16 may be altered by forming the membrane 18 of a color-tinted translucent material or by incorporating a colored light source to impart a colored appearance to the luminous highlight.

[0015] The membrane 18 may have any appropriate thickness that allows the membrane 18 to sufficiently impede heat transfer to the area 28. In some embodiments, the thickness of the membrane 18 is at least approximately 0.0508 cm (0.02 inches), but may range from 0.0508 cm (0.02 inches) to 2.54 cm (1.0 inches) depending on the type of material used to form the membrane 18. The area 28 is filled with any suitable insulating material including, but not limited to, air, fiberglass, foam insulation, or other similar components that has the effect of further reducing the amount of heat transfer from the light source 12 to the cap 16. The membrane 18 and/or the insulating material of area 28 maintain the surface temperature of the cap 16 below 60 °C, and preferably below 45 °C. The membrane material, membrane thickness, or type of insulating material in area 28 may be adjusted as need to achieve a desired maximum surface temperature of the cap 16.

[0016] Optionally, the refractive lens 26 may also include louvres 30, as shown in Figure 7. In one embodiment, the louvres 30 are located within the bollard housing 14 adjacent the at least one refractive lens 26. As shown in figure 7, the louvres 30 may be placed behind the refractive lens so that in use, the louvres 30 are located between the light source 12 and the refractive lens 26. Furthermore, the louvres may be formed as a separate component to the lens 26 such that the separate component comprises one or more louvres 30, the component being removably attachable to the light fixture 10. The louvres may be removably attachable to the housing 14 or the refractive lens. In other embodiments, the louvres 30 are placed adjacent the external surface of the at least one refractive lens 26. In either embodiment, the angle of louvres 30 may be adjusted to control the distribution of light exiting the at least one refractive lens 26. The louvres 30 may have any shape including, but not limited to, rectilinear, cylindrical, hemicylindrical, or any other shape that complements the shape of the refractive lens 26 to allow adjustment of the angle of the louvres 30.

[0017] In some embodiments, a reflector 32 may surround the light source 12 (see Figure 3). The reflector 32 may have any shape that directs light emitted from the light source 12 toward the at least one refractive lens 26, including, but not limited to, rectilinear, frustoconical, cylindrical, and dome-shaped. The reflector 32 may be formed from aluminum or other similar material. The inner surface of the reflector 32 preferably has extremely high surface reflectivity, preferably, but not necessarily, between 96%-99.5%, inclusive and more preferably 98.5-99.5%. To achieve the desired reflectivity, in one embodiment the inner surface of the reflector 32 is coated with a highly reflective material, including, but not limited to, paints sold under the tradenames GL-22, GL-80 and GL-30, all available from DuPont ®. Other embodiments may utilize textured or colored paints or impart a baffled shape to the reflector surface to obtain a desired reflection.

[0018] The membrane 18 may be installed in an existing bollard light fixture 10. In the existing light fixture 10, as shown in Figure 4, the gasket 34 may be positioned at the junction between the cap 16 and the bollard housing 14. As an initial step in the installation process, the cap 16 must be removed from the top of the bollard light fixture 10. In some embodiments, the existing gasket 34 is then removed from the top end 22 of the bollard housing 14. The outer perimeter of the membrane 18 is compared to the outer perimeter of the now-removed gasket 34. If necessary, excess material may be trimmed from the new membrane 18 to achieve an outer perimeter shape that substantially conforms to the outer perimeter of the top end 22. Alternatively, any excess material may be trimmed from the new membrane 18 after installation. In some embodiments, additional insulating material may be added to the area 28 between the cap and the membrane 18. The new membrane 18 is then placed over the top end 22 and the cap 16 is re-connected to the top end 22.

[0019] The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Further modifications and adaptations to these embodiments will be apparent to those skilled in the art.

Claims

1. A light fixture (10) comprising:

a. a housing (14) that comprises a top end (22) having an outer perimeter, wherein the top end comprises an aperture (24);

b. a light source (12), wherein the light source is located within the housing;

c. a cap (16) positioned adjacent the top end; and

d. a membrane (18) positioned between the cap and the light source and having an outer perimeter, wherein the outer perimeter of the membrane substantially conforms to the outer perimeter of the top end of the housing and substantially covers the aperture in the top end

characterised in that:

the membrane (18) is formed of a translucent material and is disposed to create a luminous highlight at the junction of the top end (22) and the cap (16).

2. The light fixture (10) as claimed in claim 1, wherein the cap (16) is configured to enclose an area (28) between the cap and the membrane (18).

3. The light fixture (10) of claim 2, wherein the area (28) between the cap (16) and the membrane (18) is filled with fiberglass, or foam insulation.

4. The light fixture (10) as claimed in any preceding claim, wherein the light source (12) comprises a fluorescent lamp, a metal halide lamp, a high pressure sodium lamp, or a light emitting diode.

5. The light fixture (10) as claimed in any preceding claim, wherein the light fixture comprises at least one refractive lens (26) coupled to the housing (14).

6. The light fixture (10) of claim 5, wherein the refractive lens (26) comprises a set of louvres (30).

7. A method of making a light fixture (10) as claimed in any of claims 1-6 from an existing light fixture (10), the existing light fixture comprising:

(i) a housing (14) that comprises a top end (22) having an aperture (24) and an outer perimeter:

(ii) a cap (16) positioned adjacent the top end;

wherein the method comprises:

a. removing the cap from the top end of the housing;

b. providing a membrane (18) with an outer perimeter that substantially conforms to the outer perimeter of the top end of the housing;

c. positioning the membrane over the top end of the housing to substantially cover the aperture in the top end of the housing;

d. positioning the cap over the membrane to enclose an area (28) between the cap and the membrane; and

e. securing the cap to the top end of the housing;

characterised in that:

the membrane (18) is formed of a translucent material and is disposed to create a luminous highlight at the junction of the top end (22) and the cap (16).

8. The method of claim 7, wherein the existing light fixture (10) further comprises a gasket (34) positioned between the cap (16) and the housing (14); wherein the method further comprises the step of:

removing the gasket from the top end (22) of the housing.

9. The method of claims 7 or 8, or the light fixture (10) as claimed in any of claims 1-6 wherein the membrane is sandwiched between the bollard housing (14) and the cap (16) such that the membrane (18) is visible from the outside of the light fixture (10).

10. The method as claimed in any of claims 7 to 9, or the light fixture as claim in any of claims 1-6 and 9 wherein the membrane (18) comprises a thickness of at least 0.0508 cm.

11. The method as claimed in any of claims 7 to 10, further comprising adding an insulating material to the area (28) between the cap (16) and the membrane (18).

12. The method of claim 11, wherein the insulating material comprises fiberglass, or foam insulation.

13. The method as claimed in any of claims 7 to 12, or the light fixture (10) as claimed in any of claims 1 to 6 and 9, wherein the membrane (18) comprises silicon.

14. The method of any of claims 7-13 or light fixture (10) of any of claims 1 to 6, 9 and 13,, wherein the translucent material is colour-tinted.

15. The method as claimed in any of claims 7 to 14, or a light fixture (10) as claimed in any of claims 1-6, 9 and 13-14 wherein the cap (16) has a surface temperature of less than 60 degrees Celsius when the light source (12) is activated.

Ansprüche

1. Beleuchtungskörper (10), umfassend:

a. ein Gehäuse (14), der ein oberes Ende (22) mit einem Außenumfang umfasst, wobei das obere Ende eine Öffnung (24) umfasst;

b. eine Lichtquelle (12), wobei die Lichtquelle innerhalb des Gehäuses angeordnet ist;

c. eine Kappe (16) das obere Ende angrenzend angeordnet ist; und

d. eine Membran (18) zwischen der Kappe und der Lichtquelle und mit einem äußeren Umfang angeordnet ist, wobei der äußere Umfang der Membran im Wesentlichen mit dem äußeren Umfang des oberen Endes des Gehäuses und im wesentlichen bedeckt die Öffnung in dem oberen Ende

dadurch gekennzeichnet, dass:

die Membran (18) aus einem lichtdurchlässigen Material gebildet ist und angeordnet ist, einen Licht highlight an der Verbindung des oberen Endes (22) und der Kappe (16) zu schaffen.

2. Die Leuchte (10) nach Anspruch 1, wobei die Kappe (16) konfiguriert ist, eine Fläche (28) zwischen der Kappe und der Membran (18) zu umschließen.

3. Die Leuchte (10) nach Anspruch 2, wobei der Bereich (28) zwischen der Kappe (16) und der Membran (18) mit Glasfaser gefüllt, oder Schaumisolierung.

4. Die Leuchte (10) nach einem der vorhergehenden Ansprüche, wobei die Lichtquelle (12) eine Leuchtstofflampe umfasst, eine Metallhalogenidlampe, eine Hochdruck-Natriumlampe oder eine Leuchtdiode.

5. Die Leuchte (10) nach einem der vorhergehenden Ansprüche, wobei die Leuchte an dem Gehäuse zumindest eine Brechungslinse (26) gekoppelt (14) aufweist.

6. Die Leuchte (10) nach Anspruch 5, wobei die Brechungslinse (26) eine Reihe von Lamellen (30) aufweist.

7. Verfahren eine Leuchte der Herstellung (10) nach einem der Ansprüche 1-6 aus einer vorhandenen Leuchte beansprucht (10), die vorhandene Leuchte umfasst:

(i) ein Gehäuse (14), der ein oberes Ende (22) aufweist, die eine Öffnung (24) und einen Außenumfang;

(ii) eine Kappe (16) positioniert benachbart zu dem oberen Ende;

wobei das Verfahren umfasst:

a. die Kappe von dem oberen Ende des Gehäuses zu entfernen;

b. eine Membran (18) mit einem Außenumfang, vorausgesetzt des oberen Endes des Gehäuses an dem äußeren Umfang entspricht im wesentlichen;

c. die Membran über dem oberen Ende des Gehäuses positioniert, um im wesentlichen die Öffnung in dem oberen Ende des Gehäuses bedecken;

d. Positionieren der Kappe über der Membran eine Fläche (28) zwischen der Kappe und der Membran zu umschließen; und

e. die Kappe mit dem oberen Ende des Gehäuses zu sichern;

dadurch gekennzeichnet, dass:

die Membran (18) aus einem lichtdurchlässigen Material gebildet ist und angeordnet ist, einen Licht highlight an der Verbindung des oberen Endes (22) und der Kappe (16) zu schaffen.

8. Verfahren nach Anspruch 7, wobei die bestehende Leuchte (10) ferner eine Dichtung (34) aufweist, die zwischen der Kappe (16) und dem Gehäuse (14); wobei das Verfahren ferner den Schritt umfasst:

entfernen der Dichtung von dem oberen Ende (22) des Gehäuses.

9. Verfahren nach den Ansprüchen 7 oder 8, oder der Leuchte (10) nach einem der Ansprüche 1-6, wobei die Membran zwischen dem Poller Gehäuse (14) und der Kappe (16), so dass die Membran (18) sandwichartig angeordnet ist, ist von der Außenseite der Leuchte (10) sichtbar ist.

10. Verfahren nach Anspruch 7 bis 9 in einem der Ansprüche oder der Leuchte nach Anspruch einem der Ansprüche 1-6 und 9, wobei die Membran (18) eine Dicke von mindestens 0,0508 cm aufweist.

11. Verfahren nach umfassend in einem der Ansprüche 7 bis 10, ferner beansprucht ein isolierendes Material auf den Bereich (28) zwischen der Kappe (16) und der Membran (18) hinzugefügt wird.

12. Verfahren nach Anspruch 11, wobei das isolierende Material Fiberglas umfaßt oder Schaumisolierung.

13. Verfahren nach 7 bis 12 in einem der Ansprüche oder der Leuchte (10) nach einem der Ansprüche 1 bis 6 und 9 beansprucht, wobei die Membran (18) Silizium umfaßt.

14. Verfahren nach einem der Ansprüche 7-13 oder Leuchte (10) nach einem der Ansprüche 1 bis 6, 9 und 13,, wobei die durchscheinenden Material Farbe getönt ist.

15. Verfahren nach 7-14 in einem der Ansprüche oder einer Leuchte (10) nach 1-6 in einem der Ansprüche, 9 und 13-14, wobei die Kappe (16) eine Oberflächentemperatur von weniger als 60 hat Celsius Grad, wenn die Lichtquelle (12) aktiviert wird.

Revendications

1. Appareil d'éclairage (10) comprenant:

a. un boîtier (14) qui comporte une extrémité supérieure (22) ayant un périmètre externe, dans lequel l'extrémité supérieure comprend une ouverture (24);

b. une source de lumière (12), dans lequel la source lumineuse est située à l'intérieur du boîtier;

c. un capuchon (16) positionnée adjacente à l'extrémité supérieure; et

d. une membrane (18) placée entre le capuchon et la source de lumière et ayant un périmètre externe, dans lequel le périmètre extérieur de la membrane se conforme sensiblement au périmètre externe de l'extrémité supérieure du boîtier et recouvre sensiblement l'ouverture dans l'extrémité supérieure

caractérisé en ce que:

la membrane (18) est formée d'un matériau translucide et est disposée pour créer un point culminant lumineux à la jonction de l'extrémité supérieure (22) et le capuchon (16).

2. L'appareil d'éclairage (10) selon la revendication 1, dans lequel le capuchon (16) est configuré de façon à entourer une zone (28) entre le couvercle et la membrane (18).

3. L'appareil d'éclairage (10) selon la revendication 2, dans lequel la zone (28) entre le capuchon (16) et la membrane (18) est rempli de fibres de verre, ou une isolation en mousse.

4. L'appareil d'éclairage (10) selon l'une quelconque des revendications précédentes, dans lequel la source de lumière (12) comprend une lampe fluorescente, une lampe aux halogénures métalliques, une lampe au sodium à haute pression, ou une diode émettrice de lumière.

5. L'appareil d'éclairage (10) selon l'une quelconque des revendications précédentes, dans lequel le dispositif d'éclairage comprend au moins une lentille de réfraction (26) couplé au boîtier (14).

6. L'appareil d'éclairage (10) selon la revendication 5, dans lequel la lentille de réfraction (26) comprend un ensemble de lamelles (30).

7. Procédé de fabrication d'un appareil d'éclairage (10) selon l'une quelconque des revendications 1-6 à partir d'un appareil existant de lumière (10), l'appareil d'éclairage existant, comprenant:

(i) un boîtier (14) qui comporte une extrémité supérieure (22) ayant une ouverture (24) et un périmètre extérieur;

(ii) un capuchon (16) positionnée adjacente à l'extrémité supérieure;

dans lequel le procédé comprend:

a. enlever le capuchon de l'extrémité supérieure du boîtier;

b. fournir une membrane (18) avec un périmètre extérieur qui est sensiblement conforme au périmètre extérieur de l'extrémité supérieure du boîtier;

c. le positionnement de la membrane au-dessus de l'extrémité supérieure du boîtier pour couvrir sensiblement l'ouverture dans l'extrémité supérieure du boîtier;

d. positionner le capuchon sur la membrane pour entourer une zone (28) entre le couvercle et la membrane; et

e. fixer le capuchon à l'extrémité supérieure du boîtier;

caractérisé en ce que:

la membrane (18) est formée d'un matériau translucide et est disposée pour créer un point culminant lumineux à la jonction de l'extrémité supérieure (22) et le capuchon (16).

8. Procédé selon la revendication 7, dans lequel l'appareil d'éclairage existant (10) comprend en outre un joint d'étanchéité (34) positionné entre le capuchon (16) et le boîtier (14); dans lequel le procédé comprend en outre l'étape consistant à:

enlever le joint d'étanchéité de l'extrémité supérieure (22) du boîtier.

9. Procédé selon la revendication 7 ou 8, ou l'appareil d'éclairage (10) selon l'une quelconque des revendications 1-6, dans lequel la membrane est prise en sandwich entre le boîtier de borne (14) et le capuchon (16) de sorte que la membrane (18) est visible depuis l'extérieur de l'appareil d'éclairage (10).

10. Procédé selon l'une quelconque des revendications 7 à 9, ou dispositif d'éclairage selon l'une quelconque des revendications des revendications 1-6 et 9, dans lequel la membrane (18) présente une épaisseur d'au moins 0,0508 cm.

11. Procédé selon l'une quelconque des revendications 7 à 10, comprenant en outre l'addition d'un matériau isolant à la surface (28) entre le capuchon (16) et la membrane (18).

12. Procédé selon la revendication 11, dans lequel le matériau isolant comprend des fibres de verre, ou une isolation en mousse.

13. Procédé selon l'une quelconque des revendications 7 à 12, ou l'appareil d'éclairage (10) selon l'une quelconque des revendications 1 à 6 et 9, dans lequel la membrane (18) comprend du silicium.

14. Procédé selon l'une quelconque des revendications 7-13 ou appareil d'éclairage (10) selon l'une quelconque des revendications 1 à 6, 9 et 13,, dans lequel le matériau translucide est teinté en couleur.

15. Procédé selon l'une quelconque des revendications 7 à 14, ou un appareil d'éclairage (10) selon l'une quelconque des revendications 1-6, 9 et 13-14, dans lequel le capuchon (16) présente une température de surface inférieure à 60 degrés Celsius lorsque la source lumineuse (12) est activé

Drawing