The present disclosure related to solid state lighting fixtures, and, more specifically, to systems for replacing non-solid state lighting fixtures with solid state lighting fixtures.
High-power Light Emitting Diodes (LEDs) offer many advantages as sources of illumination as compared to other sources of illumination. For example, LEDs are significantly more efficient than incandescent bulbs. Lighting devices that rely on LEDs as the light source therefore consume significantly less power than an equivalent lighting device having one or more incandescent bulbs as the light source. LEDs also contain no mercury, such as found in compact fluorescent lamps (CFLs). Additionally, lighting devices that employ LEDs as the light source are solid-state devices and therefore more physically robust than incandescent, metal halide, sodium vapor lamps or CFLs. LED-based lighting devices also have a long lifetime, thus requiring fewer replacements as compared to most other lighting sources.
Luminaires can be designed around LEDs to make optimal usage of LEDs' advantages. Merely replacing a metal halide lamp in a streetlight with an LED source, for example, will yield less than optimal results due to the different optical and thermal requirements of LEDs as compared to metal halide lamps. However, there is a significant market demand for retro-fitting existing luminaires with LED sources. Optically, the output from an LED is much more directive and can be utilized best when the optical system is optimized around that characteristic. Thermally, LEDs emit far less heat than most other sources, however, the heat they do emit must be removed effectively in order for the LEDs to operate near their full potential.
The present disclosure provides various embodiments of heat dissipation members that are able to effectively conduct thermal energy away from a solid state light engine. In one aspect, an adapter plate is provided that fits in the existing luminaire in place of an existing globe that mounts to the luminaire. A heat sink mates to the adapter plate and also houses a solid state light engine and associated electronics. The heat sink may provide an enclosed, protective volume for the associated electronics, such as a power supply for the solid state light engine. A globe mounting ring (also referred to as a globe mounting plate) allows either an existing globe to be re-mounted or a new globe to be installed. In various embodiments, a mount or mounts for a light redirecting mechanism are provided.
Adapter plates, in an aspect of the disclosure, include adaptor plates that are sized and shaped to accommodate hardware protuberances that may be present in an existing luminaire, and are adapted to accommodate the mounting of a globe or other cover that is associated with a luminaire. One or more heat sinks are mounted between two adaptor plates and facilitate the transfer of heat away from a solid state light engine and associated electronics. Alternatively, one or more adaptor plates or mounting rings may be integrally formed as part of a heat sink.
In one aspect, the present disclosure provides a solid state light fixture, comprising: (a) an adaptor plate that is adapted to be secured to a base to which the light fixture is to be mounted; (b) a heat sink adapted to be secured to the adaptor plate that comprises a light engine mounting surface and a globe adaptor ring mounting surface on a first side thereof, and a plurality of heat dissipating elements on a second side thereof; (c) a light engine mounted to the light engine mounting surface; (d) a power supply mounted to the second side of the heat sink that is electrically connected to the light engine; and (e) a globe adaptor ring adapted to be secured to the globe adaptor ring mounting surface, the globe adaptor ring adapted to receive an optically transmissive globe that encloses the light engine. The adaptor plate, heat sink, and globe adaptor ring are secured together, the heat dissipating elements providing a thermally conductive path between the heat sink and ambient air outside of the globe. In one embodiment, the heat sink further comprises a wall extending from the first side that encloses the light engine mounting surface, and a cover lens may be secured to a top of the wall such that the light engine is enclosed within the cover lens, wall, and light engine mounting surface. The light engine mounting surface may include one or more openings aligned with electrical connection elements of the light engine. In one embodiment, the light engine comprises a plurality of light emitting diodes (LEDs), and may also include a plurality of secondary optics associated with the LEDs. In another embodiment, the light fixture further comprises (f) a reflector support secured to a globe adaptor ring mount; and (g) a reflector secured to said reflector support configures to reflect light from said light engine to a target area. The light fixture of this aspect may be installed with an existing base for a non-solid state light fixture.
In another aspect, the present disclosure provides a system for securing a solid state light fixture to an existing light fixture pole having an existing mounting structure for an optically transmissive globe and a utility power source, comprising: (a) an adaptor plate that is adapted to be secured to the existing mounting structure; (b) a heat sink comprising a light engine mounting surface and a globe adaptor ring on a first side thereof, and a plurality of heat dissipating elements on a second side thereof, the heat sink adapted to be secured to the adaptor plate; (c) a light engine mounted to the light engine mounting surface; and (d) a power supply located on the second side of the heat sink that is electrically connected to the light engine and adapted to be electrically connected to the utility power source. The globe adaptor ring is adapted to receive an optically transmissive globe that encloses substantially all of the first side of the heat sink, and when the adaptor plate and heat sink are secured together to the existing mounting structure, the heat dissipating elements provide a thermally conductive path between the heat sink and ambient air outside of the globe.
Various embodiments, including preferred embodiments, and the currently known best mode for carrying out the invention, are illustrated in the drawing figures, in which:
The present disclosure recognizes that one challenge with retro-fitting LED sources into existing non-solid-state luminaire designs is to provide an effective thermal path from the LED sources to a cooler external environment. The present disclosure describes several embodiments for dissipating heat from an LED source retrofitted into an existing luminaire into the environment external to the luminaire. It is noted that there are very few, if any, present-day LED luminaire retro-fit products that are effective in removing the heat generated by the LEDs to the outside environment. Present retrofit methods place an LED light engine coupled to a heat sink in place of the prior lamp assembly. This may be in an open air luminaire but more commonly is in a luminaire with a globe enclosing the lamp assembly. This globe typically provides protection against the weather but also tends to keep the heat generated by the lamp assembly internal to the globe. This heating was not necessarily an issue with metal halide or other mature technology lamps, but past a certain power range this tendency to trap heat inside of a globe may increase the temperature of LEDs to the point that the LED junction may degrade and decrease the lifetime of the lamp.
The present disclosure provides embodiments that reduce internal heat build-up in LED light engines by providing a sufficient thermal path to the outside of the luminaire. This allows heat to be removed from the LEDs thus enabling longer-life operation. Another issue with LED luminaire retro-fit products is adaptability to existing luminaires. Internal lamp assemblies and their mountings vary from manufacturer to manufacturer and even from model to model from the same manufacturer. Creating a matching adaptor for each of those in a retrofit assembly may be cost-prohibitive. However, each enclosed luminaire has a mounting area for the globe that encloses it. This globe is readily removable on traditional luminaires due to the necessity of regular lamp replacement. This intentional serviceability allows the novel features described herein to be installed readily on nearly any luminaire that has a globe or other similar protective enclosure.
With reference first to
A globe adapter ring 56 is mounted to the heat sink 36. The globe 32 may then be mounted to the globe adapter ring 56 to provide an enclosed, protective volume for the LED light engine 40 and associated power supply 48 (LED driver circuitry). The globe adapter ring 56 allows either an existing globe to be re-mounted, or a new globe to be installed, and also, in this embodiment, includes a mount 60 for a light redirecting mechanism. In the embodiment of
In the exemplary embodiment of
As mentioned, the components as described in
With reference now to
In some exemplary embodiments, the power supply for the LED engine may be either wired or connectorized on the top, in order to mate with a matching connector on the bottom of the LED light engine. The power supply may also be either wired or connectorized on the bottom in order to be connected to the mains from the existing lamp assembly. Fully or partially connectorized power supplies may provide considerable labor savings cost during assembly and installation of a retrofit project. Adapter plates of other embodiments may be made in various heights and diameters to accommodate various sized luminaires. The adapter plates may be stamped, formed, drawn, spun, cast, molded or made by some other method. The adapter plates also may have an angled top to provide for drainage.
With reference to
With reference to
As discussed above, the LED light engine may include one or more connectors that are used to make power and/or data connections. The heat sink 120 of this embodiment includes a connector access opening 136 through which electrical connections between the LED light engine and power supply may be completed. The connector access opening 136 may, of course, have different configurations or multiple openings, depending upon the electrical connections required for the LED light engine of the particular embodiment. The heat sink 120 includes a second mounting surface 140 for mounting a globe adaptor ring. The globe adaptor ring, as discussed above, is configured to secure a globe to the light fixture, and may be one of a number of different configurations depending upon the particular globe that is to be secured to the light fixture. The globe adaptor ring may be secured to the second mounting surface 140 through any appropriate method, such as, for example, through welding, adhesive, screws, pins, braces, dogs, detents, or latches, to name a few. The heat sink of this embodiments includes fins 144 that are arranged in separate sections, with fins 44 of the different sections arranged at different angles than fins 44 of adjacent sections. The different arrangement of the angles of the fins 44 of adjacent sections provides for enhanced air flow.
The bottom side of the heat sink 120 contains the cooling fins 44 in this embodiment, and formed in the cooling fins is a power supply area 148 defined by a wall 152 that creates a volume in which a power supply may be situated. The particular configuration of the power supply area 148 and wall 152 may be altered to accommodate the particular shape of the power supply that is used at the driver for the LED light engine, and may be a circular, square, or rectangular configuration, for example. A power supply may be secured within the power supply area 148 through screws, adhesive, or any other appropriate attachment means. In other embodiments, the power supply is secured to an adaptor plate that is secured to the heat sink 120. In the embodiment of
An adaptor plate may be secured to the bottom of heat sink 120 through any suitable attachment method, such as through screws, welding, or adhesive, for example. In other embodiments, an adaptor plate is secured to an installed base, such as a pole top light fixture, and the heat sink 120 with the globe adaptor ring then mounted to the adaptor plate through any suitable attachment method. In still other embodiments the adaptor plate and globe adaptor ring include complementary clamping-type devices that are used to clamp the heat sink 120 between the adaptor plate and globe adaptor ring. The globe adapter ring that is mounted to the heat sink opposite the adaptor plate may be made in various heights and diameters to accommodate various sized globes or other protective and/or optical enclosures. The adapter rings may be stamped, formed, drawn, spun, cast, molded or made by some other method.
With reference to
While a light engine having LEDs has been described in the above embodiments, it will be understood that other types of solid state lighting elements may be used. Quantum Dots, for example, are semiconductor nanocrystals that possess unique optical properties. The emission color of quantum dots can be tuned from the visible throughout the infrared spectrum. This allows quantum dot LEDs to create almost any output color. Organic light-emitting diodes (OLEDs) include an emitting layer material that is an organic compound. To function as a semiconductor, the organic emitting material must have conjugated pi bonds. The emitting material can be a small organic molecule in a crystalline phase, or a polymer. Polymer materials can be flexible; such LEDs are known as PLEDs or FLEDs.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
This application claims priority to U.S. Provisional Patent Application No. 61/152,850, filed on Feb. 16, 2009, the disclosure of which is incorporated by reference herein in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US10/24321 | 2/16/2010 | WO | 00 | 8/16/2011 |
Number | Date | Country | |
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Parent | 61152850 | Feb 2009 | US |
Child | 13201830 | US |