Patent Abstract:
A submersible light assembly comprising: 
     (i) at least one light source; 
     (ii) a watertight housing having a base, at least one sidewall and a transparent envelope enclosing a portion of the light source; 
     wherein at least a portion of an outer face of the base of the housing is curved to substantially conform to the profile of the circumference of pilework of the type associated with a jetty.

Full Description:
FIELD OF THE INVENTION  
       [0001]    The present invention relates to underwater lighting technology. It is particularly applicable, but in no way limited, to a submersible lighting device or lamp. 
       BACKGROUND TO THE INVENTION  
       [0002]    Lamps for underwater use are available for various applications. One such application is for illuminating the water around a landing stage or jetty at night. Use of underwater lamps in this application has a number of uses and advantages. They can be a safety feature, by improving visibility in that area. They can be an aesthetic feature, but importantly they can also be used to attract fish. It will be appreciated that this fish-attracting application can be used not only near to or around a landing stage, but anywhere where there is access to a suitable electricity supply. This can include use from a boat or yacht with an electrical generator. This type of use results in a number of inherent problems. Firstly, the lamp must be secured in some way, either on the sea or river bed near the jetty or near a boat, or to supporting pilework associated with the jetty itself. Seabeds or riverbeds close to the shore are generally very soft due to the deposit of sediment or sand. As a consequence, the stable location of a lamp is problematic. This situation is made worse by motorboat traffic passing over the lights, sometimes at speed, creating a considerable wash or wake which can dislodge a light sitting on the bottom. 
         [0003]    An alternative is to affix the lamp to pilework under the jetty, but this may also be problematic since piles can have a number of different profiles. 
         [0004]    In addition, it is necessary to be able to change a blown bulb quickly or easily. Some prior art submersible lamps are “sealed for life” units, where a waterproof seal around the bulb is formed by setting the bulb itself in concrete or a resin. Whilst this may be a cost-effective form of construction initially, the unit must be scrapped if the bulb blows. 
         [0005]    It is an object of the present invention to overcome or at least mitigate some or all of the problems mentioned above. 
       SUMMARY OF THE INVENTION  
       [0006]    According to the present invention there is provided a submersible light assembly comprising: 
         [0007]    (i) at least one light source; 
         [0008]    (ii) a watertight housing having a base, at least one sidewall and a transparent envelope enclosing a portion of the light source; 
         [0009]    wherein at least a portion of an outer face of the base of the housing is profiled to substantially conform to the profile of the surface profile of pilework of the type associated with a jetty. By shaping the base in this way, and as described below, it facilitates securing the light to the underwater structure of a jetty. 
         [0010]    Preferably a portion of the base is curved, preferably in a concave shape. Very often the pilework associated with a jetty is circular in cross-section and a concave, indented shape in the base makes for an easier and more secure fixing. 
         [0011]    Preferably the base incorporates two concave indentations set substantially orthogonal to each other. This arrangement means that the light assembly can be positioned in one of four possible configurations. In this way the power supply cable to the light assembly can be positioned in a convenient orientation. 
         [0012]    Preferably the assembly further comprises a support bracket adapted to be secured to pilework and to partially take the weight of the light assembly. Having a separate bracket means that this can be secured to the pilework during the installation, at the appropriated depth, to take a portion of the weight of the assembly, both during and after installation. 
         [0013]    Preferably the assembly further comprises a cable entry point adapted to form a waterproof seal between an electrical cable or conduit and the assembly. 
         [0014]    In a particularly preferred embodiment the support bracket is so sized and shaped to be adapted to engage with the cable entry point in order to partially support the lamp assembly in use. 
         [0015]    Preferably the assembly housing further comprising eyelets adapted to accommodate one or more straps to strap the light assembly to a pile. Tightly strapping the light assembly to pilework is a preferred method of fixing the assembly under water. 
         [0016]    In a particularly preferred embodiment the assembly further comprises a demountable ground engaging spike, and wherein the demountable ground-engaging spike is secured to the base of the light assembly using spike securing means. This provides an alternative means of securing the light assembly in place, this time on the sea or riverbed. Downward pressure on the light assembly drives the spike into the bed and the spike anchors it there. 
         [0017]    Preferably said housing comprises a base, a body portion and said transparent envelope with sealing gaskets between adjacent components. 
         [0018]    Preferably said base incorporates a weight. Because there must be space between the transparent envelope and the light source, and around the electrical components within the housing, additional weight is needed to reduce the natural buoyancy of the assembly when submerged. 
         [0019]    According to a further embodiment of the present invention there is provided a submersible light assembly comprising at least one light source, a watertight housing having a base, at least one sidewall and a transparent envelope enclosing a portion of the light source; and a demountable ground engaging spike. The feature of a demountable spike, secured to the assembly by securing means, can be employed without the need to incorporate a profiled base. The features described above, and in the description below, in respect of a first embodiment of the invention can be applied equally well to this second embodiment. 
         [0020]    According to a yet further embodiment, there is provided a submersible light assembly comprising at least one light source, a watertight housing having a base, at least one sidewall and a transparent envelope enclosing a portion of the light source, and eyelets adapted to accommodate one or more straps to strap the light and assembly to a pile of the type associated with a jetty. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0021]    The present invention will now be described, by way of example only, with reference to the following drawings wherein: 
           [0022]      FIG. 1  shows a light assembly according to the present invention with the bulb cover removed; 
           [0023]      FIGS. 2 ,  3  and  4  show side, top and bottom elevations of an assembled light assembly of  FIG. 1 ; 
           [0024]      FIG. 5  shows a cross-section through the light assembly of  FIG. 1 ; 
           [0025]      FIGS. 6A  to C show bottom, side and top elevations of an upper part of the housing of a light assembly; 
           [0026]      FIGS. 7A  to C show bottom, side and top elevations of a base portion of a housing of a light assembly; 
           [0027]      FIGS. 8A  and B show a side and bottom elevations of a ground engaging spike; 
           [0028]      FIG. 9  shows a sealing gasket for a bulb cover; 
           [0029]      FIG. 10  shows a sealing gasket for the waterproof joint between the upper part and the base part of a housing; 
           [0030]      FIG. 11  shows detail ‘A’ from  FIG. 10 ; 
           [0031]      FIG. 12  shows a lifting eye; 
           [0032]      FIGS. 13 ,  14  and  15  show various elevations of a support bracket; 
           [0033]      FIG. 16  shows various installation options; 
           [0034]      FIG. 17  shows the ground engaging spike and its connection to the base of the light assembly; 
           [0035]      FIG. 18  shows a support bracket engaged around a cable entry point. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    Preferred embodiments will now be described by way of example only. They are not the only way the invention can be put into practice but they are the best ways currently known to the applicant. 
         [0037]    Referring to  FIGS. 1 to 4 , these show various elevation views of a first embodiment of the submersible lamp assembly. They show a substantially watertight housing assembly consisting of a base portion  19 , an upper portion of the housing  13 , a bulb or lamp  2  and a transparent envelope or lamp cover  1 . A flange ring  33 , held in place by a number of nuts, bolts and washers, acts to compress the lamp cover against a fluid-tight sealing gasket, shown in more detail in  FIG. 9 . 
         [0038]    A similar, but larger fluid-tight gasket, shown in  FIG. 10 , is positioned between the base portion and the upper portion of housing, also held in place by a plurality of nuts, bolts and washers. 
         [0039]    It will be seen from these figures, the base portion is substantially circular cylindrical with a continuous side wall and a closed end wall. Other than the open top end to the cylinder, which is flanged to form a good fluid-tight seal with upper portion, the only other penetration into the base portion is fluid-tight cable gland  16  containing a bush  17 , shown in  FIG. 5 . This allows an electrical supply cable to enter the base in a fluid-tight manner. 
         [0040]    Similarly the upper portion of the housing is substantially circular cylindrical with a flange at its lower end to mate with the base portion and a smaller diameter flange at its upper end to mate with the bulb cover. 
         [0041]    Referring to  FIG. 5 , it will be seen that base portion contains a ballast weight  20 , secured in place by a bolt  22  and spread washer  23 . The weight has a cutout or channel  32  to allow an unrestricted route for the supply cable from the cable gland to the upper part of the housing. This upper part houses the electrical components and circuitry necessary to make the lamp function. These include a ballast  12  and capacitor  11 , a ceramic lamp holder or bulb holder  10  held in place by a bracket  9 . Also attached to the upper portion is an eyelet bolt  29 , shown in more detail in  FIG. 12 . This enables the light assembly to be raised and lowered into position. 
         [0042]    A key feature of the present invention relates to the provisions made to install the light assembly safely and securely. Firstly, a demountable ground-engaging spike  40  is provided, as shown in  FIG. 8 . This consists of a mounting plate  41 A, designed to bolt onto the bottom of the base at a central point. The shaft of the spike  41  is formed from struts  42  to  45  arranged at right angles to each other in a crucifix form, and narrowing towards the tip region  46 . The tip region has a similar form of construction and forms an arrowhead type of arrangement at the ground-engaging end of the spike, with shoulders  47  preventing easy removal of the spike, once it has been sunk into the ground. 
         [0043]    A further view of a ground-engaging spike, and its method of connection to the base of a light assembly, is shown in  FIG. 17 . A corresponding numbering system to that used in  FIGS. 1 to 5  and  8  is used in  FIG. 17 . The base of the spike  41 A is formed in the shape of a substantially flat flange. This flange engages into a correspondingly shaped recess  56  in the base  19 . Apertures  55 ,  57  are provided in the flange  41 A to accommodate bolts  53 ,  54 . These bolts, four in total in this example, act as securing means to secure the spike  41  to the base  19 . Corresponding threaded holes in the base are provided to accommodate these bolts. It follows therefore that the light assemblies of the present invention can be used with, or without, a ground engaging spike depending on the requirements of the installation. 
         [0044]    The spike is demountable in order that the light assembly may also be secured directly to some underwater structure such as a pile or post, such as those used to support a jetty or deck. To facilitate this, the bottom of the base is profiled, in this case the base is concave in shape, as shown at  51  in  FIG. 5 and 51  and  52  in  FIG. 1 . Preferably two concave shaped indentations are formed in the base bottom set at right angles to each other. In this way the light assembly can be placed against a circular pile in any one of 4 configurations. This is shown in  FIG. 1  and ensures that the direction in which the electrical supply cable, which is both heavy and relatively inflexible, can be arranged to suit each particular installation. 
         [0045]    To facilitate installation against a post, a separate bracket  18  is provided as shown in  FIGS. 13 ,  14  and  15 . One face of the bracket  61  has a radius which corresponds to the radius of the base. In this way it fits snugly against the face of the circular cylindrical base body when in use. Extending away from the curved face, substantially at right angles is a face  62  containing two fixing holes  63 , 64 . These holes are used to attach this face of the bracket to the pilework at the appropriate depth below the water. Face  62  is also curved, in this case of a radius to match that in the concave depressions in the bottom of the base portion. This leads to a snug, secure fit against the pilework. 
         [0046]    A further feature of this bracket is a semi-circular cut out  65  in the face  61  which is in contact with the side of the base. This cut out fits around the cable gland  16  and acts to both locate and stabilize the assembly during and after installation. Sides of the bracket  66 ,  67  stretching between the two faces at right angles complete the bracket arrangement and add the necessary strength. 
         [0047]      FIG. 18  shows a perspective view of a bracket  18  in position against the side of the base of a light assembly, nested around a cable gland  16 . This illustrates the neatness of this type of fixing method. 
         [0048]    Two methods of installation are shown in  FIG. 16 . In  FIG. 16A  the light assembly, with spike attached, is lowered from a boat and the spike sinks into or is driven into the sea or riverbed in the desired position. 
         [0049]    In  FIG. 16C  the light assembly is offered up to a pile or post below the water at the appropriate depth. A strap  70  is offered around the post and threaded through two of the eyelets  34 ,  35 ,  36  shown in  FIG. 3 . Pulling strap  70  tight secures the light assembly to the post. Bracket  18  is then offered up to the post and light assembly, slipped around the cable gland and secured in place to the post. This helps to take the weight of the light assembly and complete the installation. 
         [0050]    Whilst a circular cylindrical light assembly has been described in this embodiment it will be appreciated that any substantially cylindrical form will work equally well and also that it is not even necessary for the assembly to be cylindrical in form. 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 KEY TO FIG. 5 
               
             
          
           
               
                 Reference 
                   
                   
                   
               
               
                 Numeral 
                 Designation 
                 Number 
                 Material 
               
               
                   
               
             
          
           
               
                 32 
                   
                   
                   
               
               
                 31 
                 Ground spike 
                 1 
                 ABS 
               
               
                 29 
                 Eyelet bolt M8 
                 1 
                 Stainless Steel 
               
               
                 28 
                 Hex. Nut M4 
                 4 
               
               
                 27 
                 Ballast bracket 
                 1 
                 Iron Plate 
               
               
                 26 
                 Round head bolt M5 × 10 
                 4 
               
               
                 25 
                 Round head bolt M4 × 55 
                 4 
               
               
                 24 
                 Body seal 
                 1 
                 Silicone 
               
               
                 23 
                 Washer 
                 1 
               
               
                 22 
                 Hex. Bolt M10 × 65 
                 1 
               
               
                 21 
                 Gasket 
                 1 
                 Silicone 
               
               
                 20 
                 Loader 
                 1 
               
               
                 19 
                 Bottom lamp body 
                 1 
                 PSU 
               
               
                 18 
                 Support bracket 
                 1 
               
               
                 17 
                 Bush 
                 1 
               
               
                 16 
                 Cable gland 
                 1 
               
               
                 15 
                 Hex. Nut M8 
                 12 
               
               
                 14 
                 Allen screw bolt M8 × 25 
                 12 
               
               
                 13 
                 Top lamp body 
                 1 
               
               
                 12 
                 250 W ballast 
                 1 
               
               
                 11 
                 18UF capacitor 
                 1 
               
               
                 10 
                 Lamp holder bolt 
                 2 
               
               
                 9 
                 Lamp holder bracket 
                 1 
               
               
                 8 
                 Ceramic lamp holder 
                 1 
               
               
                 7 
                 Round head bolt M5 × 10 
                 2 
               
               
                 6 
                 Glass shade seal 
                 1 
                 Silicone 
               
               
                 5 
                 Washer 
                 1 
                 PSU 
               
               
                 4 
                 Butterfly nut M8 × 1.25 
                 6 
                 POM 
               
               
                 3 
                 Bolt 
                 6 
                 Stainless Steel 
               
               
                 2 
                 250 W Hg lamp 
                 1 
               
               
                 1 
                 Glass shade 
                 1 
                 Toughened glass

Technology Classification (CPC): 5