Patent Abstract:
Among other disclosed subject matter, a lighting device cooled by being at least partially submerged is provided. The lighting device includes a housing forming a chamber having at least one transparent portion. The lighting device includes a diode in the chamber emitting light through the transparent portion. The lighting device includes a cooling conduit configured for a liquid to flow along the chamber when the lighting device is at least partially submerged in the liquid, without the liquid contacting the diode. The diode is mounted on a surface that abuts the cooling conduit.

Full Description:
TECHNICAL FIELD 
       [0001]    This document relates to a lighting fixture having a cooling conduit for a liquid. 
       BACKGROUND 
       [0002]    Lighting fixtures are designed for use in one or more environments. For example, some fixtures are limited to indoor use, while others can also be used outdoors or even under water. Generally, a water resistant or water proof fixture will have an enclosed configuration that prevents water or moisture from reaching the light elements or other circuitry. 
         [0003]    One form of light source is a light-emitting diode (LED). LEDs are characterized by ample and reliable light emission from a relatively small physical device. However, LEDs also generate substantial heat when in operation, and unless properly dissipated, this energy can in some situations cause the LED, or materials nearby, to be damaged or destroyed. 
       SUMMARY 
       [0004]    The invention relates to a lighting fixture having a cooling conduit. 
         [0005]    In a first aspect, a lighting device cooled by being at least partially submerged is provided. The lighting device includes a housing forming a chamber having at least one transparent portion. The lighting device includes a diode in the chamber emitting light through the transparent portion. The lighting device includes a cooling conduit configured for a liquid to flow along the chamber when the lighting device is at least partially submerged in the liquid, without the liquid contacting the diode. The diode is mounted on a surface that abuts the cooling conduit. 
         [0006]    Implementations can include any or all of the following features. The cooling conduit can extend at least partially inside the chamber. The housing can have an essentially circular cross section between first and second ends. The chamber can be sealed against the liquid using essentially cylindrical end brackets at the first and second ends. Each of the end brackets can include at least first and second parts clamping a gasket radially outward against an interior surface of the housing around an entire circumference of the end bracket. The first and second parts can form an essentially v-shaped groove facing the interior surface around the entire circumference, wherein the gasket is clamped against the interior surface upon one of the first and second parts being biased toward the other. The gasket can have a cross-section that is essentially v-shaped and fits the v-shaped groove. The cooling conduit can extend inside the chamber between openings in the end brackets. The diode can be mounted on a generally flat surface that forms part of the cooling conduit. The cooling conduit can have a generally semi-circular cross section formed by the flat surface and a curved surface. The conduit can be formed by a conduit housing and the chamber can be formed by attaching the housing and the conduit housing together. At least one row of diodes can be mounted inside the housing along the chamber essentially in a flow direction of the liquid. The cooling conduit can be longitudinally divided by a baffle extending between first and second ends of the cooling conduit, the baffle forming at least a first channel that abuts the chamber and a second channel that does not abut the chamber, the baffle having at least one opening between the first and second ends that connects the first and second channels. 
         [0007]    In a second aspect, a submersible light fixture includes a transparent housing that is generally cylindrical and that forms a waterproof chamber between first and second brackets at respective ends of the transparent housing. The submersible light fixture includes a conduit housing enclosed in the transparent housing and extending between openings in the first and second brackets, the conduit housing forming a cooling conduit through the waterproof chamber for a liquid entering at least one of the openings upon the light fixture being submersed in the liquid. The submersible light fixture includes at least one row of light-emitting diodes mounted inside the waterproof chamber on an outside surface of the conduit housing, wherein the liquid in the cooling conduit cools an opposite side of the outside surface without contacting the light-emitting diodes. 
         [0008]    Implementations can include any or all of the following features. The cooling conduit can have a cross-section with at least one substantially flat surface, and the row of light-emitting diodes can be mounted on the substantially flat surface. The cooling conduit can be longitudinally divided by a baffle extending between the first and second brackets, the baffle forming a first channel that abuts the substantially flat surface and a second channel that does not abut the substantially flat surface, the baffle having at least one opening between the first and second brackets that connects the first and second channels. 
         [0009]    The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  is a diagram of an example lighting fixture. 
           [0011]      FIG. 2  is a partial side section view of an example lighting fixture. 
           [0012]      FIG. 3A  is a side end view of an example lighting fixture. 
           [0013]      FIG. 3B  is a side end view of an example lighting fixture. 
           [0014]      FIG. 3C  is a side end view of another example lighting fixture. 
           [0015]      FIG. 4A  is a diagram of an example lighting fixture mounted on a vertical wall. 
           [0016]      FIG. 4B  is a diagram of an example lighting fixture with a rectangular cross-section. 
           [0017]      FIG. 4C  is a diagram of an example semi-submersed lighting fixture. 
           [0018]      FIG. 4D  is a diagram of an example lighting fixture that can be rotated to align with fluid currents. 
       
    
    
       [0019]    Like reference symbols in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0020]      FIG. 1  is a diagram of an example lighting fixture  100 . The lighting fixture  100 , in this example contains diodes  102 , a cooling conduit  104 , a housing  106 , and end brackets  108 . The example lighting fixture  100  can be used to, for example, illuminate a liquid environment such as a fountain, pool, aquarium, hot tub, or beach. Such illumination can be used for decorative purposes, to illuminate a work area such as for underwater welding, for safety purposes such as to demarcate a shallow end and deep end of a pool, or for other purposes. Particularly, the cooling conduit  104  can provide useful cooling of the lighting fixture by allowing a liquid such as water to contact parts of the fixture that are exposed to significant heat. 
         [0021]    In some embodiments, illumination can be accomplished by diodes such as the light emitting diodes (LEDs)  102 . LEDs  102  can include any or all of a variety of components that emit light when an external voltage is applied to the junction of a P-type and N-type semiconductor. In these embodiments, the LEDs  102  can produce significant heat and may be cooled. 
         [0022]    The LEDs  102  can be mounted on a surface  110  which can be a flat surface. In some examples, the surface  102  is a flat surface of greater length in one dimension than another, which is to say the surface is longer than it is wide. In this example, LEDs  102  can be positioned in one or more rows along the longer dimension. 
         [0023]    In some embodiments, the surface  110  can abut the cooling conduit  104 , which can be a conduit that to be filled with a surrounding liquid. For example, if the lighting fixture  100  is installed in a large fountain, the fountain water can fill and/or flow through the conduit  104  and cool the fixture from heat generated by the LEDs  102 . The cooling conduit  104  can partly be formed by a conduit housing  112  and can be terminated on one or both ends of the lighting fixture  100  by the end bracket  108 . The conduit housing can be made of a rigid or semi-rigid material suitable for a moist or liquid environment, such as extruded plastics or metal. 
         [0024]    The housing  106  can surround the LEDs  102 , the surface  110 , and/or the conduit housing  112 . Some or all of the housing can be transparent or near-transparent, for example, to allow light generated by the LEDs to emerge from the fixture. By affixing the conduit housing  112  and the housing  114  to the end brackets  108 , a chamber  114  can be created. The chamber  114  can contain the LEDs  102  and can be protected from the liquid environment. 
         [0025]    Accordingly, the example lighting fixture  100  can provide a liquid-proof environment for the LEDs  102  while allowing surrounding liquid to absorb heat generated by the LEDs. This facilitates that LEDs can be used that without the liquid-cooling effect would generate too much heat for the installation. As another example, it can allow more LEDs to be used in the fixture than possible without the cooling. 
         [0026]      FIG. 2  is a partial side section view of the example lighting fixture  100 . The lighting fixture  100  can be sealed from surrounding liquid and moisture by an end bracket  202 . The end bracket  202  can be made of any material, such as metal or plastic, which is suitable to extended exposure to wet environments. In some embodiments, the end brackets  202  can be cylindrical in shape. In some embodiments, the end bracket  202  can include of two end bracket sections  202   a  and  202   b  which can be held together by one or more screws  210 . 
         [0027]    In some embodiments, the end bracket  202  can form a groove  204  around its circumference. The groove  204  can be formed between two sections  210   a  and  210   b  of the end bracket  210 . The groove  204  can have any shape, such as a V shape in which the widest section of the groove extends parallel with the outside surface of the end bracket  210 . 
         [0028]    A gasket  208  can be clamped to seal against the interior of the housing  106 . In some implementations, the gasket  208  can be made of any deformable material, such as rubber, silicon or polymer plastic, suitable to extended exposure to wet environments In some implementations, the gasket  208  can be covered with an adhesive or sealing substance, such as silicone or gasket conditioner, to ensure a more efficient seal. The gasket  208  is suitable for being made by production techniques such as injection molding. The gasket  208  can have a V cross-sectional shape and fit in the groove  204 . In some embodiments, one or more screws  210  can be used to pull the end bracket sections  202   a  and  202   b  together, biasing the gasket  204  toward the housing  106 . This bias can radially seal the gasket  204  against the interior of the housing  106 . 
         [0029]      FIG. 3A  is a side end view of an example lighting fixture  100 . In this view, the end bracket  202 , housing  106 , and cooling channel  104  are illustrated. In this example, the housing  106  has a circular cross section that fits around the end bracket  202 . The end bracket  202  includes at least one opening to the cooling channel  104 . The opening(s) allow a liquid to enter and/or flow through the cooling channel  104 . The cooling channel  104  can have a semi-circular cross section with a flat surface and a curved surface. In this example, the curved surface can describe a circular arc with the same center point as the circumference around the end bracket  202 . 
         [0030]    In some embodiments, multiple channels can be formed within the cooling conduit  104 . A baffle  308 , or multiple baffles such as baffles  308  and  310 , can be affixed inside the cooling conduit. In some embodiments, the baffles  308  and  310  can extend for the entire length of the cooling conduit. In some embodiments, the baffles  308  and  310  can create one or more channels that do not abut the surface  110 . One or more passages  312  can be formed in the baffle  308  and/or  310 , for example as openings between the channels that can allow liquid to pass through. In some implementations, this can allow for more efficient liquid flow and/or cooling than in embodiments without the baffles  308  and/or  310 . 
         [0031]      FIG. 3B  is a side end view of another example lighting fixture  350 . The example lighting fixture  350  illustrates an embodiment with another structure and configuration of components. The lighting fixture  350  includes housing  356 , a diode  352  which can emit light, and a cooling conduit housing  354 . The cooling conduit housing  354  can form a cooling conduit  358 , which can allow fluid to pass and can cool the diode  352 . The diode  352  can be mounted on a surface  356 , which can abut the cooling conduit  358 . 
         [0032]    In this example, the housing  356  is shown removed from the cooling conduit housing  354 . If the housing  356  is lowered and affixed to the cooling conduit housing  354 , a chamber can be created inside the housing. In the chamber, the diode  352  can be separated from surrounding liquid if the lighting fixture  350  is partially or wholly submerged in a liquid. 
         [0033]      FIG. 3C  is a side end view of another example lighting fixture  375 . The lighting fixture  375  illustrates an embodiment with an end bracket  377  having three openings  383 ,  385 , and  387  through it. In this example, a housing  379  has a circular cross section that fits around the end bracket  377 . The three openings  383 ,  385 , and  387  can allow surrounding liquid to enter a core cooling conduit. The end bracket  377  can be fitted at one end of the lighting fixture  375  and a corresponding bracket at the other end, allowing liquid to pass through a cooling conduit. Here, the housing  379  is essentially hollow, forming a single cooling conduit that extends between the end brackets. 
         [0034]      FIG. 4A  is a diagram of an example lighting fixture  400  mounted on a vertical wall  402 . The lighting fixture  400  has a cooling channel  404 , LEDs  406 , and a housing  408  that are aligned generally vertically and generally parallel to the vertical wall  402 . The lighting fixture  400  and wall  402  can be in a liquid environment, such as under water in a swimming pool. 
         [0035]    In some embodiments, the lighting fixture  400  can be generally the same lighting fixture as the lighting fixture  100 . In other embodiments, the lighting fixture  400  can differ from the lighting fixture  100 , such as by having more or fewer LEDs  406 , a different shape cooling channel  404 , and/or in other ways. 
         [0036]      FIG. 4B  is a diagram of an example lighting fixture with a rectangular cross-section. The lighting fixture  420  can have a cooling channel  424 , LEDs  426 , and a housing  428 . The lighting fixture  420  can be mounted on a surface  422  and be fully or partially submersed in a liquid environment, such as on any surface of a fountain, or on a boat or other marine vehicle. 
         [0037]      FIG. 4C  is a diagram of an example semi-submersed lighting fixture. The lighting fixture  440  can have a cooling channel  444 , LEDs  446 , and a housing  448 . The lighting fixture  440  can be mounted on a surface  442 . A liquid  450 , such as water, can surround some or all of the lighting fixture  440 . The surface of the liquid  450  can fluctuate, for example because of waves, ripples, or a raising or lowering of the overall surface. In some examples, the some or all of the housing  448  can be partially or wholly transparent. As the surface  440  fluctuates, some or all of the transparent section of  448  can be submerged in the liquid  450 . 
         [0038]    In some embodiments, the lighting fixture  440  can be generally the same lighting fixture as the lighting fixture  100 . In other embodiments, the lighting fixture  440  can differ from the lighting fixture  100 , such as by having more or fewer LEDs  446 , a different shape cooling channel  444 , and/or in other ways. 
         [0039]      FIG. 4D  is a diagram of an example lighting fixture  460  that can be rotated to align with fluid currents. The lighting fixture  460  can have a cooling channel  464 , LEDs  466 , and a housing  464 . The lighting fixture  460  can be mounted on a surface  462  and in a liquid environment, such as on a beach, in a wave pool, or hot tub. Some liquid environments have regular movements, such as waves and/or convection currents. The lighting fixture  460  can be rotated or positioned so that the cooling channel  464  and LEDs  466  align with some or all of the liquid movements. For example, a reflecting pool may have an impeller driven current that circles the pool to prevent growth of bacteria or algae. The lighting fixture  460  can be rotated about it&#39;s base  470  so that the cooling channel  464  and LEDs  466  align with the current. In some examples, the current can increase the movement of liquid through the cooling channel, which can increase the amount of cooling provided to the lighting fixture  460 . 
         [0040]    A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of this disclosure. Accordingly, other implementations are within the scope of the following claims.

Technology Classification (CPC): 5