Pendant luminaire

A luminaire includes an optics module and a heat sink. The optics module includes a body, an LED light source, an electronic driver circuit, and a holder. The LED light source is thermally coupled to the body. The electronic driver circuit is disposed within the body and is electrically connected to the LED light source, the driver circuit having an electrical connector configured to receive electrical power from a power source. The holder is mechanically secured to the body, the LED light source being securely retained between the holder and the body. The heat sink has a plurality of radially projecting fins and is thermally and removably coupled to the body of the optics module.

BACKGROUND OF THE INVENTION

The present invention relates generally to conducting and dissipating heat from a light source, more particularly to effectively dissipating heat from a light source via a heat conducting element and an independent heat dissipating element that allows for economical replacement of an optics module at the end of the lifespan of the light source disposed within the optics module, further particularly to a pendant luminaire, and even more particularly to a pendant luminaire having a light emitting diode (LED) light source and a heat dissipating apparatus.

A variety of different types of light bulbs and other light sources are commercially available. The most common type of light source is the incandescent light bulb, in which electric current is passed through a metal filament disposed in a vacuum, causing the filament to glow and emit light. Another common type of light bulb is the fluorescent light.

A problem with the standard light bulbs having resistive heating elements (e.g. tungsten) is that such a light source expends more energy as heat than as light. Fluorescent lamps run substantially cooler, but have a substantial lag time between when they are initially turned on and when they actually start emitting light, and are often fairly bulky. Halogen lamps are highly efficient, but need to be handled very carefully and generate a considerable amount of heat when manufactured large enough to provide a usable amount of light, even when powered with low voltage (e.g. 12V).

Recent developments in lighting technology involve the expanded use of light emitting diodes (LEDs) that are quite efficient in that they are able to convert virtually all of their supply voltage into light, thereby producing less heat and requiring less overall power consumption. In addition, LEDs may be very small and have an extremely long service life, mainly due to the fact that they operate at cooler temperatures. Compared with a traditional light bulb, an LED lamp may have a lifespan of about 50 to about 100 times that of the traditional light bulb, and the power consumption of such an LED lamp may be about one third to about one fifth that of the traditional light bulb.

General LED light sources are well known in the art. LEDs are light sources based upon a semiconductor structure, specifically a diode structure, which emit incoherent light (which may be in the ultraviolet, visible, or infrared spectrum) when electrical current is passed through the semiconductor junction. One example of such a light source may include phosphors emitting white light. Recent developments in LED technology have increased the output power and efficiency of LED sources so that it is now feasible for them to be utilized in traditional lighting applications previously reserved for incandescent, fluorescent, sodium, and other known lighting technologies.

One current drawback with such LED lamps is that when used to replace a conventional incandescent bulb they must have special driving circuits that convert the incoming alternating-current line voltage to the direct-current low voltage needed by the lamp. Such a circuit is normally a small printed-circuit board that is permanently mounted right in the lamp and to which the LED is normally directly soldered. These circuits typically incorporate a transformer to step down the incoming voltage and a rectifier and similar power-supply elements that produce the necessary steady low voltage. The problem with such a construction is that the driving circuit itself generates heat, particularly when the LED requires some meaningful amperage, albeit at low voltage. Above a temperature of about 25 degrees Celsius, an LED operates less efficiently and produces less light than at lower temperatures. In particular, as the operating temperature progressively increases above 25 degrees Celsius, the light output of the LED progressively decreases. Since the LED itself is typically carried right on the circuit board, when the circuit elements heat up, the LED is heated. Unfortunately the efficiency of an LED falls off rapidly as it gets hot, and thus known LED lamps tend to dim somewhat after they have been in use for a while and their driving circuits have gotten warm.

In order to manage heat, the prior art has attempted to utilize a variety of heat-dissipation techniques, such as an LED attached to a heat sink via heat conductive adhesive, but if the LED stops working, then the entire component must be discarded, making parts replacement costly. Such LEDs are not exchangeable or serviceable and are therefore rendered disposable and very inefficient.

It is desirable that light sources make use of the currently available LED technology due to the significant benefits that such light sources provide including extremely long life, the ability to control output power and spectrum, and a significant reduction in the amount of electrical energy consumed for equivalent light output power. It is also desirable that such light sources be fabricated from materials that are inexpensive and preferably comprise re-usable, recyclable, or replaceable components so as to require a minimum of new raw material and thus preserve limited natural resources. However, utilizing LED light sources in contemporary light sources gives rise to the significant challenge of removing the heat from the LED semiconductor junction and surrounding structures.

While existing LED light sources may be suitable for their intended purpose, there remains, however, a need in the art for an LED light source that provides an improved arrangement for servicing and/or replacement of the illuminating element independent from the heat dissipating element so as to be environmentally friendly and lower overall maintenance and/or replacement costs relative to present illumination apparatus, while at the same time providing for ease of manufacturing.

BRIEF DESCRIPTION OF THE INVENTION

An embodiment of the invention includes a luminaire having an optics module and a heat sink. The optics module includes a body, an LED light source, an electronic driver circuit, and a holder. The LED light source is thermally coupled to the body. The electronic driver circuit is disposed within the body and is electrically connected to the LED light source, the driver circuit having an electrical connector configured to receive electrical power from a power source. The holder is mechanically secured to the body, the LED light source being securely retained between the holder and the body. The heat sink has a plurality of radially projecting fins and is thermally and removably coupled to the body of the optics module.

An embodiment of the invention includes a product having any feature described herein, explicitly or equivalently, either individually or in combination with any other feature, in any configuration.

An embodiment of the invention includes a method of forming the aforementioned product, including any process or sub-process described herein, explicitly or equivalently, or impliedly, in any order, using any modality suitable for the purpose disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the invention, as shown and described by the various figures and accompanying text, provides pendant type luminaire having a light emitting diode (LED) light source module separably connected to a heat sink, which in combination is supportable from a ceiling fixture or track light fixture. While the embodiment described herein depicts a particular geometry for an example luminaire, such as an MR16 lamp for example, it will be appreciated that the disclosed invention is also applicable to other luminaire geometries, such as an MR11 lamp for example.

FIGS. 1 and 2depict a general form of a pendant luminaire100having an optics module105and a heat sink110that is removably coupled to the optics module. An electrical supply wire117provides electrical power to the luminaire100and also has sufficient structural integrity (in a manner known to one skilled in the art) to support the luminaire100when it is installed suspended from a ceiling junction box or from a ceiling track light fixture.

FIGS. 3-8(where reference toFIG. 3andFIG. 5means reference toFIGS. 3A-3DandFIGS. 5A-5D, respectively) depict in more detail the pendant luminaire100(in alternative form to that depicted inFIGS. 1 and 2) having optics module105and removable heat sink110, or portions thereofFIGS. 5-8exclude the heat sink110, but includes a lampshade holder265(depicted inFIGS. 6-8). The following description is made with reference toFIGS. 3-8.

With reference toFIGS. 3 and 4, optics module105includes a body115having a first end120and a second end125, with a first threaded portion130at the first end120, and a second threaded portion135at the second end125. A land surface140is formed in the body115at the first end120, and is configured to receive an LED light source145disposed thereat, the LED light source145being thermally coupled to the body115once the luminaire100is fully assembled. To promote desirable heat transfer from the LED light source145to the body115, a thermally conductive paste150may be disposed therebetween.

Heat sink110includes a first heat sink111and a second heat sink112, with each heat sink111,112having a plurality of radially projecting fins113,114, respectively, configured for both heat dissipation and aesthetic appeal. The first heat sink111is threadably coupled to the first threaded portion130of the body115, and the second heat sink112is threadably coupled to the second threaded portion135of the body115. With appropriately dimensioned internal and external threads, the first and second heat sinks111,112are thermally coupled to the body115while being removable from the body115. In an embodiment, the first and second heat sinks111,112and the body115are each made from aluminum.

Disposed within the body115is an electronic driver circuit155that is electrically connected to the LED light source145via wires160. A grounding wire165is also provided, which will be discussed in more detail below. Connected at an end of the driver circuit155is an electrical connector170that is configured to receive electrical power from a power source via supply wire117. An optic holder175is mechanically secured to the body115via fasteners180. Holder175securely retains the LED light source145with respect to the body115by virtue of the LED light source145being captured between the holder175and the body115. Holder175also securely retains an optic (color mixing and dispersion lens)185that is disposed within the holder175and held in place via snap-fit legs190(three used, two illustrated) on the optic185engaging with snap-fit receptacles195on the holder175.

Referring now toFIGS. 3,7and8in combination, the electrical connector170is a dumbbell shaped connector having a first dumbbell arm200at one end, and a second dumbbell arm205and a post210at a second opposing end. The first dumbbell arm200at the one end mechanically engages with the body115and electrically engages with an edge conductor215of the driver circuit155. The second dumbbell arm205at the second end mechanically engages with the body115, and the post210at the second end extends a defined distance from the body115to engage with an electrical connector220disposed in electrical communication with the supply wires117(seeFIG. 3, Section A-A for example). With such a dumbbell-shaped electrical connector170, good dimensional control for the extension of the post210relative to the body115can be achieved for positive electrical engagement with the electrical connector220of supply wires117, and a good electrical connection can be achieved between the post210and the edge conductor215of the driver circuit155.

Referring toFIG. 8, an embodiment of the invention utilizes a grounding means where the grounding wire165is compressively retained between a surface225of the holder175and a surface230of the body115. Holder175may also be made of an opaque polymer material, thereby acting as a light diffuser. As such, holder175becomes a multi-functional part; a retainer for the LED light source145, a retainer for the optic185, a retainer for the grounding wire165, and a light diffuser.

Still referring toFIG. 8, the outside profile of the circuit board157of the driver circuit155, and the interior profile of the retaining pocket235of the body115that receives the driver circuit155, are so dimensioned and configured as to prevent reverse installation of the driver circuit155into the pocket235, and to provide dimensional control for the degree of insertion of the driver circuit155into the pocket235. For example, the pocket235includes a first step240and a second step245in the interior sidewall that are at different distances from the end250of the body115, and the circuit board157includes mating first and second tabs255,260that engage with the first and second steps240,245, such that if the circuit board157was to be inserted 180-degrees rotated, the second tab260would prematurely mate with the first step240thereby preventing complete insertion.

As seen fromFIGS. 7 and 8, an embodiment includes a circuit board157where all of the electronic components of the driver circuit155are disposed on only one side of the circuit board157.

Referring briefly toFIGS. 6-7, an embodiment includes a lampshade holder265with an opening270that slides over the second end125of the body115, and a flange275that sits on a shoulder280of the body115. When so positioned, slots285and fingers290of the holder265provide a flexible support structure for a lampshade (not shown) to frictionally engage with the holder265to provide for additional lighting effects.

While certain combinations of elements have been described herein, it will be appreciated that these certain combinations are for illustration purposes only and that any combination of any of the elements may be employed when arranged in accordance with an embodiment of the invention. Any and all such combinations are contemplated herein and are considered within the scope of the invention disclosed.