Outdoor light fixture including passive and / or active cooling modules

Abstract

A lighting fixture (100) is disclosed that includes a mounting plate (11), one or more lighting modules (15) coupled to the mounting plate (11), and a heatsink (12). The heatsink includes a plurality of fins (12a) and one or more horizonal / vertical sections. The heatsink (12) is coupled to the mounting plate (11). The mounting plate (11) and the heatsink (12) are formed to include one or more apertures (14) near or around the one or more lighting modules (15). The one or more horizonal / vertical sections (12b) are positioned covering all or some portions of the one or more apertures (14) while still allowing for air flow (16) through the apertures (14) and past the one or more fins (12a). The lighting fixture (100) may be retrofit in the field to include an active cooling module (20). The active cooling module includes a fan unit (22) and a shroud (21). The shroud (21) covers at least a portion of the plurality of fins (12a).

Description

[0001] Outdoor light fixture including passive and / or active cooling modules

[0002] FIELD OF THE INVENTION

[0003] The invention relates generally to lighting fixtures, and in particular, to an outdoor lighting fixture including a passive cooling module that can be retrofit to include an active cooling module designed to facilitate heat dissipation.

[0004] BACKGROUND

[0005] Configurable luminaires are typically used for outdoor environmental lighting, including, for example, streetlamps, parking lighting, pathway lighting, rural settings, farmlands, and general security and so forth. Such conventional outdoor or high mast luminaires include three main sub-assemblies: mast structure, headframe (or housing), and lighting module. The headframe can be configured to include one or more lighting modules to provide different light distribution as required for the particular application.

[0006] Outdoor luminaires may include features that try to reduce heat-related lumen depreciation. For example, heatsinks may be used to reduce excess electrical heat and keep it away from the electrical components such as drivers and the LED modules. Traditional heatsinks are limited to a certain max lumen output and wattage of luminaire. Accordingly, such conventional heatsinks may not be sufficient to address the all heat related issues. Excess heat may cause problems associated with the durability of the outdoor luminaire associated with thermal dissipation and high-temperature problems, which end up affecting the light intensity and service life.

[0007] Using fans for active cooling in the high-power luminaires may be beneficial to help with excess heat dissipation. However, active cooling add cost to the luminaries and customer acceptance for the use of active cooling is still a challenge. Customers may prefer passive cooling for certain applications to reduce cost when active cooling is not needed. In other applications when high-power luminaires are required, active cooling may be used. However, retrofitting a luminaire that only includes passive cooling to active cooling may be complicated and costly to do because the luminaire is not designed for such retrofitting.

[0008] Accordingly, an alternate approach is needed that allows the luminaire to be used with both passive and active cooling and allow for retrofitting of such luminaire. US 2015 / 070911 Al relates to a first heat sinking path formed in a forming direction of a heat sink unit disposed radially in a housing where a light emitting module is mounted. A second heat sinking path is formed along an edge of the light emitting module. By providing a light engine concept in which a light emitting module, an optical member, and a heat sink unit are included and a bottom surface is gradually widened from one side to the other side.

[0009] US 2017 / 352605 Al relate to a heat sinking technology, adaptive to LED lighting devices in a generally LED array format containing multiple openings on the heat sink's base portions and optionally fin portions providing “short path cooling” technology.

[0010] WO 2022 / 179968 Al relates to a lighting device having wireless resonant coupling includes a wireless power transmitter unit and a light module that includes a light source. The wireless power transmitter unit is configured to provide power to the light module wirelessly by transmitting a power waveform to the light module. An amplitude of a fundamental frequency component of the power waveform equals an amplitude of a third harmonic frequency component of the power waveform.

[0011] SUMMARY OF THE PRESENT INVENTION

[0012] Aspects, objects, and embodiments of the present invention address the shortcomings discussed above.

[0013] In this regard, a standard luminaire is provided with passive cooling using natural air convection and smart air flow features between critical components and a ungraded luminaire is provided with active cooling as an option for higher lumen or power option.

[0014] One aspect of the present invention is related to a luminaire that has an optimized heatsink that has air flow channels in critical areas between critical components allowing for natural convection and helps to maximize how much power can be put in luminaire with passive cooling. In this regard, the design of the luminaire allows air flow channels in strategically placed apertures in the LED mounting plate and the heatsink casting.

[0015] Another aspect of the present invention is related to a luminaire that can be retrofit with an active cooling module in the field to help maximize power and lumen levels. The active cooling module can easily be retrofit directly to an existing heatsink and allows for easy wiring to drivers. This allows for the luminaire to operate at higher peak lumen outputs with better thermal management. One embodiment of the present invention is directed to a lighting fixture that includes a mounting plate, one or more LED lighting modules coupled to the mounting plate and a heatsink coupled to the mounting plate. The heatsink includes a plurality of fins and one or more horizonal / vertical sections. The mounting plate and the heatsink are formed to include one or more apertures near or around the one or more lighting modules. The horizonal / vertical sections are positioned covering all or some portions of the apertures while still allowing for air flow through the apertures and past the fins. The plurality of fins may form a V-like configuration on the mounting plate.

[0016] Another embodiment of the present invention is directed to a method for retrofitting a lighting fixture with a passive cooling module with an active cooling module in the field. The lighting fixture includes a mounting plate, one or more lighting modules coupled to the mounting plate and a heatsink. The heatsink includes a plurality of fins and one or more horizonal / vertical sections wherein the heatsink is also coupled to the mounting plate. The mounting plate and the heatsink are formed to include one or more apertures near or around the lighting modules. The horizonal / vertical sections are positioned covering the one or more apertures while still allowing for air flow through the apertures and past the fins.

[0017] The lighting fixture also includes a wireless power transmitter, a driver and a preassembled connection via a wire from the driver for a fan unit. The active cooling module includes a fan unit including a wireless power receiver and a shroud. The method includes the steps of positioning the shroud to cover at least a portion of the plurality of fins, positioning the fan unit so that the wireless power receiver is in proximity to the wireless power transmitter, coupling the fan unit to the driver using the wire and adjusting an output power level of the lighting fixture.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further details, aspects, and embodiments of the invention will be described, by way of example only, with reference to the drawings. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. In the figures, elements which correspond to elements already described may have the same reference numerals. In the drawings,

[0020] Figs, la and lb illustrates perspectives views, respectively, of an example lighting fixture with a passive cooling module and an example of another lighting fixture retrofit with an active cooling module, in accordance with example embodiments of the present disclosure; Fig. 2 illustrates top view of an LED / optics plate assembly of the luminaire in Figs, la and lb (the plate is shown with a top half partially transparent to show the placement of certain components relative to other components on the opposite side of the plate assembly);

[0021] Fig. 3 illustrates a partial perspective view of the example lighting fixture of Fig. la showing additional details in accordance with certain example embodiments;

[0022] Fig. 4 illustrates a partial perspective view of the example lighting fixture of Fig. lb showing additional details in accordance with certain example embodiments;

[0023] Fig. 5 illustrates a side view of the example lighting fixture of Fig. lb showing additional details therein in accordance with certain example embodiments;

[0024] Fig. 6 illustrates a partial perspective view of the example lighting fixtures of Fig. la and lb showing additional details in accordance with certain example embodiments; and

[0025] Fig. 7 illustrates a partial perspective view of the example lighting fixture of Fig. lb showing additional details in accordance with certain example embodiments.

[0026] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0027] While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will herein be described in detail one or more specific embodiments, with the understanding that the present disclosure is to be considered as exemplary of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described.

[0028] In the following, for the sake of understanding, elements of embodiments are described in operation. However, it will be apparent that the respective elements are arranged to perform the functions being described as performed by them.

[0029] Further, the invention is not limited to the embodiments, and the invention lies in each and every novel feature or combination of features described herein or recited in mutually different dependent claims.

[0030] In the following paragraphs, the present disclosure will be described in further detail by way of examples with reference to the attached drawings. In the description, well known components, methods, and / or processing techniques are omitted or briefly described so as not to obscure the disclosure. As used herein, the "present disclosure" and / or “present invention” refers to any one of the embodiments of the disclosure described herein and any equivalents. Furthermore, reference to various feature(s) of the "present disclosure" is not to suggest that all embodiments must include the referenced feature(s).

[0031] The example embodiments discussed herein are directed to high mast luminaires such as the luminaires mounted above roadways. While the example embodiments described herein are in the context of outdoor or high mast luminaires, it should be understood that the embodiments described herein can apply to a variety of luminaires. For example, the embodiments can be used with luminaires located in any environment (e.g., indoor, outdoor, hazardous, non-hazardous, high humidity, etc.). Further, the luminaires described herein can use one or more of a number of different types of light sources, including but not limited to various light-emitting diode (LED) light sources such as discrete LEDs, LED arrays, chip on board LEDs, and organic LED light sources, as well as other types of light sources. Therefore, the example luminaires described herein should not be considered limited to a particular type of light source.

[0032] Any luminaires, or components thereof (e.g., housings), described herein can be made from a single piece (e.g., as from a mold, injection mold, die cast, 3-D printing process, extrusion process, stamping process, or other prototype methods). In addition, or in the alternative, a luminaire (or components thereof) can be made from multiple pieces that are mechanically coupled to each other. In such a case, the multiple pieces can be mechanically coupled to each other using one or more of a number of coupling methods, including but not limited to epoxy, welding, fastening devices, compression fittings, mating threads, and slotted fittings. One or more pieces that are mechanically coupled to each other can be coupled to each other in one or more of a number of ways, including but not limited to fixedly, hingedly, removably, slidably, and threadedly.

[0033] A coupling feature (including a complementary coupling feature) can allow one or more components and / or portions of an example housing or other component of a light fixture to become coupled, directly or indirectly, to another portion of the example housing or other component of a light fixture. A coupling feature can include, but is not limited to, a snap, Velcro, a clamp, a portion of a hinge, an aperture, a recessed area, a protrusion, a slot, a spring clip, a tab, a detent, and mating threads. One portion of an example housing can be coupled to a light fixture by the direct use of one or more coupling features.

[0034] In addition, or in the alternative, a portion of a luminaire can be coupled using one or more independent devices that interact with one or more coupling features disposed on a component of the housing. Examples of such devices can include, but are not limited to, a pin, a hinge, a fastening device (e.g., a bolt, a screw, a rivet), epoxy, glue, adhesive, tape, and a spring. One coupling feature described herein can be the same as, or different than, one or more other coupling features described herein. A complementary coupling feature (also sometimes called a corresponding coupling feature) as described herein can be a coupling feature that mechanically couples, directly or indirectly, with another coupling feature.

[0035] Terms such as “first”, “second”, “top”, “bottom”, “side”, “distal”, “proximal”, and “within” are used merely to distinguish one component (or part of a component or state of a component) from another. Such terms are not meant to denote a preference or a particular orientation, and are not meant to limit the embodiments described herein. In the following detailed description of the example embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0036] Referring to Figs, la and lb, perspective views of example luminaires 100 and 110 in accordance with embodiments of the present invention are shown. The example luminaires 100 and 110 include a housing 101. The housing 101 may include various electrical components (some of which are shown in Fig. 5) needed for proper operation of the luminaire such as light module drivers, dimming controls, digital wireless control systems and surge protection circuitry. The luminaires 100 and 110 may be attached to a pole (not shown) for mounting, for example, above a roadway.

[0037] The luminaires 100 and 110 may provide a scalable, variable configurable lighting using one or more lighting modules 15 as shown in Fig. 2. The one or more lighting modules 15 may be coupled to, or contained in, the housing 101 with a portion of the one or more lighting modules 15 exposed outside the housing 101 to allow light generated by the one or more lighting modules 105 to radiate / exit therefrom. The one or more lighting modules 15 may also include optics and refractors. The luminaires 100 and 110 may utilize a “mix and match” type system of different sets of the one or more lighting modules 15 to meet a plurality of different lighting requirements. The one or more lighting modules 15 may be adjustable to allow for different levels of light output. For example, the one or more lighting modules 15 may be LED light modules which includes a plurality of LED light elements disposed to generate light outwardly from the one or more LED lighting module 15.

[0038] As noted above, a major concern when designing an LED outdoor fixture or other types of luminaires is effective heat management. Heat at the semiconductor domain junctions is a primary determinant in the life of the LED and in maintaining a consistent wavelength. LEDs function better and last longer at cold or cool temperatures, and deteriorate more rapidly with increased heat. The design effort to draw heat away from the junctions has often resulted in the LED circuit boards being attached to a finned heat sink, with natural air convection or fans used for cooling. In an outdoor light fixture, however, the ambient temperature may at times be relatively high.

[0039] Fig. la shows the luminaire 100 that includes a passive cooling module 10. The passive cooling module 10 design utilizes passive cooling with air convection and one or more apertures 14 (shown in more detail in Fig. 2) in critical areas to provide maximize thermal management. The passive cooling module 10 includes a heatsink 12, an LED mounting plate 11 and the one or more of the LED lighting modules 15. The one or more apertures 14 are formed in the heatsink 12 and the LED mounting plate 11 to allow for enhanced cooling / heat dissipation by air convection.

[0040] The heatsink 12 may be manufactured by cast molding or assembled from various components coupled together. The heatsink 12 may be constructed from copper or aluminum or other material that has a high thermal conductivity such as compounds made from copper, zinc oxide, aluminum, silicon oil, ceramic, or graphite. This will allow for the rate of heat transfer through the heatsinkl2 to be high. As shown in the embodiment of Fig. 3, the heatsink 12 may include a plurality of fins 12a that form one or more channels 13 and / or one or more horizontal / vertical sections 12b that are positioned in locations above or near the LED lighting modules 15. The heatsink 12 and / or the one or more horizonal / vertical sections (12b) may also be formed integral with the LED mounting plate (11). The channel 13 and the one or more apertures 14 allow for air flow 16 to help passively dissipate heat created by the luminaire 100.

[0041] The one or more apertures 14 are strategically located near and around the one or more LED lighting modules 15 to allow for enhanced cooling while meeting Dark sky’s requirements of no through light above the heatsink 12. The Dark-sky requirements are defined by the approval of outdoor lighting ordinances through the IDA Fixture Seal of Approval program. To meet these requirements, a fixture must be fully shielded and emit no light above the horizontal plane. As shown in Fig. 3, the horizontal / vertical sections 12b of the heatsink 12 are designed / positioned to prevent light from emitting above the horizontal plane while allowing for the air flow 16. In this regard, the one or more horizontal / vertical sections 12b are positioned covering all or some portions of the one or more apertures (14) while still allowing for air flow (16) through the apertures (14) and past the one or more fins (12a). In addition, the one or more LED lighting modules 15 may be located on the LED mounting plate 11 on top (proximal to the LED mounting plate 11) of the fins 12a so that there is no trapped hot air in the air flow 16 channels. To help illustrate this feature, Fig. 2 is shown with a portion of the LED mounting plate 11 having a transparent section I la and a non-transparent section 1 lb. Sections of the fins 12a can be seen via the transparent section I la. The one or more LED lighting modules 15, the one or more apertures 14 and the fins 12a are positioned to prevent or reduce the possibility of hot air being trapped in a cavity formed by the heatsink 12.

[0042] There are lighting applications that may require active cooling because passive cooling may not meet the heat dissipation demands. For example, active cooling may be required for lighting installations in regions with higher ambient 50 or 65C. Another application when active cooling may be needed is when there is a need for increased lumen or wattage levels. With a higher power load, passive cooled systems will thermally run hotter and active cooling will help lower the overall system temperatures.

[0043] Fig. 4 illustrates features of the active cooling module 20 in accordance with one embodiment of the present invention. In this embodiment, the active cooling module 20 may be retrofit to the luminaire 100 with the passive cooling module 10 to form the luminaire 110 with the active cooling module 20. The active cooling module 20 includes one or more fan units 22 and a shroud 21. The shroud 21 is positioned to cover at least a portion of the plurality of fins 12a. In a preferred embodiment, the shroud 21 covers a distal edge section 12c of at least two of the plurality of fins 12a to form a tunnel-like path for the air flow 16. This extends the air flow 16 through the fin’s 12a length and reduces air leaks by forming the tunnel -like path via the fins 12a. The cool air inside the channel 13 flows over the fins 12a. In operation, the one or more fan units 22 pull cool air from outside the housing 101 into the channel 13 formed by the plurality of fins 12a and the shroud 21. While the air begins at ambient temperature, it extracts heat from the plurality of fins 12a. This further ensures improved heat dissipation through the fins 12a.

[0044] It should be understood by one of ordinary skill in the art that configuration of the heatsink 12 may vary. For example, as shown in Fig. 5, the fins 12a have generally a linear organization with one input port (at the fan units 22 coupling) and two output ports, e.g., a V-configuration. This configuration may be varied such as a non-linear orientation, e.g., as S-, W-, or semicircular-shaped, with a different number of input and output ports. The number of the fins 12a may also vary depending on the application. The active cooling module 20 can be coupled to the luminaire 100 by a coupling means 23. For example, in a preferred embodiment the coupling means 23 are one or more magnets 23 that couple to metallic portions of the luminaire 100. This allows for the active cooling module 20 to be easily installed / retrofit in the field without the need for additional tools. The one or more magnets 23 secure the active cooling module 20 in its proper location. An alignment means 23 a may be used to ensure proper placement of the one or more magnets 23 and the shroud 21. In this embodiment, the alignment means 23a are slots 23a that mate with the one or more magnets 23. Fig. 6 illustrates an exploded view of a portion of the luminaries 100 and 110 showing the alignment means 23 a. It will be appreciated by one of ordinary skill in the art that other coupling means may be used to secure the active cooling module 20 to the luminaire 100.

[0045] In one embodiment, the one or more fan units 22 are powered with use of wires to a power supply. However, this could be cumbersome for retrofit applications because the one or more fan units 22 need to be wired to a driver 28 (shown in Fig. 5) and to the power supply (not shown).

[0046] In another embodiment of the present invention, the one or more fans units 22 may include wireless power technology. This allows for the one or more fan units 22 to be powered without the need of any additional wiring to the power supply. This further allows for ease of installing especially on retrofit application in the field. Wireless power technology is the transmission of electrical energy without wires as a physical link. As shown in Fig. 5, an electrically powered transmitter device 24 generates a time-varying electromagnetic field that transmits power across space to a receiver device 25 in proximity to the transmitter device 24. The receiver device 25 extracts power from the field and supplies it to an electrical load, i.e., the one or more fan units 22.

[0047] In more detail, as shown in the embodiment of Fig. 5, the transmitter device 24 is coupled to the LED mounting plate 11. The transmitter device 24 includes a transmitter coil 24a and a full bridge MOSFETs that converts DC to a high frequency square wave. The receiver device 25 is coupled to the one or more fan units 22. The receiver device 25 includes a receiver coil 25a, a high frequency rectifier and a high frequency capacitor.

[0048] The transmitter device 24 can also run at different speeds by modulating the transmitted power, thereby controlling the power the one or more fan units 22. The transmitter device 24 is coupled to the driver 27 via a wire 26. The wire 26 may be preinstalled in the housing 101 so that it would already be present from the driver 27 to easily allow for the connection that can be made in field to connect the one or more fans units 22 for retrofit applications. For retrofit applications, the driver 27 may be reprogrammed in the field for higher power output levels.

[0049] Fig. 7 shown another embodiment of the active cooling module 20. The coils 24a and 25a may be sealed to protect the coils from damage and / or weather using one or more covers 30. The one or more covers 30 may be made from plastic or other similar weather-proof / durable material to protect the coils 24a and 25a. In the embodiment shown in Fig. 7, the cover 30 is a box-like structure that surrounds the coil 25a of the receiver device 25. The coil 24a of the transmitter device 24 is inset in a cavity 31. The cover 30 for the coil 24a of the transmitter device 24 fits into a gasket grove 32 around the cavity 31.

[0050] The foregoing detailed description has set forth a few of the many forms that the invention can take. The above examples are merely illustrative of several possible embodiments of various aspects of the present invention, wherein equivalent alterations and / or modifications will occur to others skilled in the art upon reading and understanding of the present invention and the annexed drawings. In particular, regard to the various functions performed by the above described components, the terms used to describe such components are intended to correspond, unless otherwise indicated to any component, such as hardware or combinations thereof, which performs the specified function of the described component (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the illustrated implementations of the disclosure.

[0051] Although a particular feature of the present invention may have been illustrated and / or described with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, references to singular components or items are intended, unless otherwise specified, to encompass two or more such components or items. Also, to the extent that the terms "including", "includes", "having", "has", "with", or variants thereof are used in the detailed description and / or in the claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0052] The present invention has been described with reference to the preferred embodiments. However, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the present invention be construed as including all such modifications and alterations. It is only the claims, including all equivalents that are intended to define the scope of the present invention. In the claims references in parentheses refer to reference signs in drawings of exemplifying embodiments or to formulas of embodiments, thus increasing the intelligibility of the claim. These references shall not be construed as limiting the claim.

Claims

CLAIMS:

1. A lighting fixture (100), comprising: a mounting plate (11); one or more lighting modules (15) coupled to the mounting plate (11); and a heatsink (12) including a plurality of fins (12a) and one or more horizonal / vertical sections (12b) wherein the heatsink (12) is coupled to, or integral with, the mounting plate (11), a wireless power transmitter (24), wherein the mounting plate (11) and the heatsink (12) are formed to include one or more apertures (14) near or around the one or more lighting modules (15), wherein the one or more horizonal / vertical sections (12b) are positioned covering all or some portions of the one or more apertures (14) while still allowing for air flow (16) through the apertures (14) and past the one or more fins (12a) and, an active cooling module (20) that includes a fan unit (22) including a wireless power receiver (24) and a shroud (21), wherein the shroud (21) covers at least a portion of the plurality of fins (12a), and wherein the shroud (21) and at least some of the plurality of fins (12a) for a tunnel-like channel (13).

2. The lighting fixture (100) of claim 1, wherein the plurality of fins (12a) form a V-like configuration on the mounting plate (11).

3. The lighting fixture (100) of claim 2, wherein the V-like configuration is coupled on a side of the mounting plate (11) opposite of another side of the mounting plate on which the one or more lighting modules (15) are coupled.

4. The lighting fixture of claim 1, wherein the one or more lighting modules (15) are LED lighting modules (15).

5. The lighting fixture (100) of claim 4, wherein the lighting fixture (100) is a high mast luminaire (100).

6. The lighting fixture (110) of claim 1, further comprising an active cooling module (20).

7. The lighting fixture (110) of claim 6, wherein the active cooling module (20 includes a fan unit (22) and a shroud (21) that covers at least a portion of the plurality of fins (12a).

8. The lighting fixture (110) of claim 7, wherein the shroud (21) and at least some of the plurality of fins (12a) form a tunnel-like channel (13).

9. The lighting fixture (110) of claim 6, wherein the coupling feature is a magnet.

10. The lighting fixture (110) of claim 1, wherein the wireless power transmitter (24) includes a coil (24a) that is protected by a cover (30).

11. The lighting fixture (100) of claim 1, further comprising a driver (27) and a preassembled connection via a wire (26) from the driver (27) for a fan unit (22).

12. The lighting fixture (110) of claim 1, wherein wireless power receiver (25) includes a coil (25a) that is protected by a cover (30).

13. A method for retrofitting the lighting fixture (100) of claim 11 comprising the steps of positioning the shroud (21) to cover at least a portion of the plurality of fins (12a); positioning the fan unit (22) so that the wireless power receiver (25) is in proximity to the wireless power transmitter (24); coupling the fan unit (22) to the driver (27) using the wire (26); and adjusting an output power level of the lighting fixture (110).

Images