Patent Publication Number: US-9845947-B1

Title: Multi-directional underwater lighting

Description:
The present invention relates generally to underwater lighting and pertains, more specifically, to multi-directional underwater lighting having increased intensity and greater effectiveness over a longer range. 
     Underwater lighting has long been in use, primarily for decorative purposes and for illuminating sites where lighting is employed underwater largely for scientific, commercial, safety or aesthetic purposes such as, for example, in studying and monitoring certain underwater sites, in marking and lighting docking and mooring points, and in illuminating swimming areas and swimming pools. One quite popular use for underwater lighting, both in connection with commercial and sporting operations, is for attracting fish. 
     Conventional underwater lighting has suffered from a lack of range, requiring excessive bulk in order to provide a desired intensity. Moreover, the illumination made available will decrease over time due to natural fouling, requiring frequent periodic cleaning to maintain effective illumination. In addition, increased lighting intensity has required an increase in power made available to each lighting unit, resulting in the requirement for elaborate power distribution networks. 
     The present invention provides unique and highly effective underwater lighting that avoids the above-outlined drawbacks. As such, the present invention attains several objects and advantages, some of which are summarized as follows: Provides multi-directional, high-intensity underwater lighting for increased effectiveness in submerged settings; utilizes cooling available by virtue of immersion to enable increased lighting intensity; allows effective employment of light emitting diodes (LEDs) in underwater venues for increased lighting intensity with reduced power requirements; provides a compact and lightweight lighting source for effective underwater use; resists fouling by marine organisms for effective long-term underwater use with reduced cleaning and maintenance requirements; provides a relatively simple and economical construction for practical widespread use; attains an increased range of effectiveness in multi-directional underwater illumination while reducing bulk and power requirements; provides a rugged construction for reliable operation over an extended service life. 
     The above objects and advantages, as well as further objects and advantages, are attained by the present invention which may be described briefly as underwater lighting apparatus for being immersed in a body of water to be surrounded by the body of water and to illuminate a site juxtaposed with the underwater lighting apparatus during a lighting cycle, the apparatus comprising: a housing constructed of a heat-conductive material; a chamber within the housing; an LED array affixed to the housing, within the chamber so as to conduct heat from the LED array directly to the housing; and a lens member affixed to the housing and sealing the chamber against the body of water, the lens member being in juxtaposition with the LED array for passing light emitted from the LED array to the lens member; whereby heat generated by the LED array during the lighting cycle will be conducted to the housing and dissipated by the housing to the surrounding body of water. 
     In addition, the present invention provides A method for providing underwater lighting to illuminate a site within a body of water during a lighting cycle, the method comprising: immersing within the body of water, a housing constructed of a heat-conductive material; providing a chamber within the housing; affixing an LED array to the housing, within the chamber, so as to conduct heat directly from the LED array to the housing; and affixing a lens member to the housing with the lens member sealing the chamber against the body of water, and juxtaposed with the LED array for passing light emitted from the LED array through the lens member and into the surrounding body of water; whereby heat generated by the LED array during the lighting cycle will be conducted to the housing and dissipated by the housing to the surrounding body of water. 
    
    
     
       The present invention will be understood more fully, while still further objects and advantages will become apparent, in the following detailed description of preferred embodiments of the invention illustrated in the accompanying drawing, in which: 
         FIG. 1  is a partially diagrammatic, pictorial view, partially broken away to show internal details, of an underwater lighting apparatus constructed in accordance with the present invention; 
         FIG. 2  is a partially diagrammatic enlarged cross-sectional view taken along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is an exploded pictorial view of the apparatus; 
         FIG. 4  is a pictorial view, not to scale, showing the apparatus immersed in a body of water during a typical use; and 
         FIG. 5  is a pictorial view similar to  FIG. 4  and showing an alternate arrangement. 
     
    
    
     Referring now to the drawing, and especially to  FIGS. 1 through 3  thereof, an underwater lighting apparatus constructed in accordance with the present invention is shown at  10  and is seen to include a housing  12  having a peripheral rim  14  establishing an inner chamber  16 . A generally centrally located web  18  extends radially across the chamber  16 , spanning the chamber  16  and dividing the chamber  16  into axially opposite compartments  20 , each compartment  20  having an opening  22  such that the openings  22  face in axially opposite directions. A lens member in the form of a transparent lens  24  is affixed to the rim  14  and seals each opening  22 , closing each compartment  20  in a watertight manner. An eye  28  is integral with rim  14  to facilitate suspension and manipulation of lighting apparatus  10  during use. 
     A pair of arrays of light emitting diodes (LED arrays) are shown at  30  and are seen to be placed, one of the two LED arrays  30  in each compartment  20 , with each LED array  30  having a base  32  affixed to web  18  of housing  12  and located in a compact axially back-to-back arrangement, so as to emit light through a corresponding lens  24  such that light is directed in opposite axial directions D. The compact arrangement enables apparatus  10  to have relatively diminutive dimensions, thereby reducing bulk while providing an extensive field of intense light. Exemplary dimensions include a length A and a width B, each of about three inches, and an axial thickness C of about three-quarters of an inch. An electrical power cable  34  having leads  36  is secured to housing  12  by means of a watertight gland  40  threaded into rim  14  of housing  12 . Leads  36  are connected to LED arrays  30  for supplying power to illuminate the LED arrays  30 . 
     Housing  12  is constructed of a heat-conductive material, the preferred material being aluminum, preferably anodized, which is highly heat conductive and which resists corrosion and fouling by marine organisms. Web  18  is integral with rim  14 , the rim  14  and the web  18  preferably being formed in a unitary construction. The base  32  of each LED array  30  is affixed to web  18 , as by bolts  44 , with each base  32  contiguous with and in such intimate contact with web  18  that heat generated by each LED array  30  during an underwater lighting cycle is conducted directly from each LED array  30  to web  18  and through web  18  and rim  14  of housing  12  to be dissipated into the surrounding water. Heat transfer from LED arrays  30  to web  18  may be optimized through the use of thermal grease or thermal pads at the juncture of each base  32  and web  18 . Thus, the housing  12  serves as an effective heat sink that allows efficient operation of the LED arrays  30  for exemplary high-intensity lighting when immersed at a site to be illuminated. A thermal switch  46  is interposed between power cable  34  and the LED arrays  30  and is affixed to web  18  to detect temperature at the web  18  and to interrupt the supply of power to the LED arrays  30  upon detecting excessively high temperature, thereby protecting the LED arrays  30  against failure due to a possible build-up of excessive heat. 
     A typical use of apparatus  10  is illustrated in  FIG. 4  wherein lighting apparatus  10  is seen submerged in a body of water W to attract fish F at a site S by virtue of light emitted in directions D. Here, lighting apparatus  10  is suspended and manipulated by a line  50  coupled to eye  28 . The high-intensity lighting made available by the very compact apparatus  10  provides an unobtrusive source of very bright light throughout an extensive surrounding field, rendering lighting apparatus  10  highly effective in accomplishing the described goal. Further, the high-intensity lighting provided by LED arrays  30  militates against fouling of the submerged lighting apparatus  10  by marine organisms. Alternately, as seen in  FIG. 5 , lighting apparatus  10  may be suspended in water W and manipulated at site S directly by power cable  34 . 
     It will be seen that the present invention attains all of the objects and advantages summarized above, namely: Provides multi-directional, high-intensity underwater lighting for increased effectiveness in submerged settings; utilizes cooling available by virtue of immersion to enable increased lighting intensity; allows effective employment of light emitting diodes (LEDs) in underwater venues for increased lighting intensity with reduced power requirements; provides a compact and lightweight lighting source for effective underwater use; resists fouling by marine organisms for effective long-term underwater use with reduced cleaning and maintenance requirements; provides a relatively simple and economical construction for practical widespread use; attains an increased range of effectiveness in multi-directional underwater illumination while reducing bulk and power requirements; provides a rugged construction for reliable operation over an extended service life. 
     It is to be understood that the above detailed description of preferred embodiments of the invention is provided by way of example only. Various details of design, construction and procedure may be modified without departing from the true spirit and scope of the invention, as set forth in the appended claims.