Patent Abstract:
An underwater pool light comprises: a housing; a lens sealingly fixed to the housing; a light source located within the housing; and mounting means for mounting the housing to a niche within or on a wall of a pool. The housing includes an integral connector for external connection to an electrical supply cable, and the pool light includes electrical connection means within the housing connecting the light source to the integral connector.

Full Description:
This Application is the U.S. National Phase Application of PCT International Application No PCT/GB2003/005305 filed Dec. 10, 2003. 
   The present invention relates to an underwater pool light. In particular, but not exclusively, the invention relates to disposable underwater pool lights for use in swimming pools and spa baths, hereafter referred to as “pools”. 
   DESCRIPTION OF THE RELATED ART 
   Pools are conventionally built in one of four manners. The first method is to provide two spaced shutters formed from wood or steel, with steel reinforcing bars arranged between the shutters. Apertures are provided at a number of locations in one of the shutters and a niche for the pool light is located in each of the apertures. Typically, the niche is positioned such that a gap exists between the shutter and a flange member provided on the niche. Typically, conventional niches have to be modified so that they are fixed to the shutter by fastening, usually by screwing, a portion of the niche to the shutter. For steel shutters, which are typically hired from a supplier, the cost of repairing or replacing the shutter is incurred. 
   Cement is poured between the shutters and allowed to set and then the shutters are removed. Finishers are then applied to the cement wall, including between the cement wall and flange of the niche. The finishers comprise render, adhesive and tiling, and the thickness of the finishers can range from 5 to 45 millimetres. It is a difficult task, given this variation in thickness, for the pool builder to ensure that the finishers are flush against the flange member of the niche. 
   Another method of building the pool is to provide only one shutter and the reinforcing bars. The niches are suspended in position and concrete is sprayed onto the shutter, and around the niches, to form the concrete wall. The same problem exists for the pool builder when applying the finishers to ensure they are flush with the flange member of each niche. 
   A third method of building the pool is to clamp the lining of a flexible enclosure between two structural layers, typically made of metal, polymer or fibreglass. The two layers also clamp the flange member of each niche and apertures are cut into the material at each niche. A fourth method is to form a fibreglass enclosure in which apertures are cut for receiving each niche which is fastened to the fibreglass wall at the niche flange. 
   Conventional pool lights do not offer a means for adjusting the distance from visible parts of the pool light, such as the flange member, to the wall of the pool to accommodate variation in thickness of the finishers. Furthermore, no pool light presently exists which can be fitted to each of the four types of pools described above without modification by the pool builder. 
   Conventional pool lights use one or more separate replaceable bulbs in a housing. Electrical power is supplied via an insulated cable which enters the housing from the niche via an aperture. The aperture includes a permanent seal in order to prevent water entering the housing. 
   The housing is cooled by the water present in the space between the niche and the housing and also by the water in contact with the lens at the front of the housing. However, there is limited ability for water to flow within the niche. This can cause the accumulation of body fat from swimmers, which can be a health hazard as it encourages the growth of bacteria such as legionella. 
   When it is necessary to replace the bulb, or carry out any other maintenance to the unit, the housing must be removed from the niche and lifted out of the water. Typically the bulb has a life of around 250 to 1,000 hours of use. Removal of the housing typically requires the removal of a number of screws, which is a difficult task to carry out underwater, due to a lack of visibility and mobility. The cable is typically of sufficient length between the niche and the housing to allow the maintenance to be carried out at the side of the pool. 
   An improved type of pool light would comprise a modular unit which includes a bulb in a cavity which is enclosed by a permanently sealed body. When replacement of a bulb for such a unit is necessary the entire unit is replaced. This type of pool light would therefore be disposable. Such a type of pool light would require a wet mateable electrical connection between the pool light and the power cable provided in the niche. Also, fittings would be required to prevent any maintenance or bulb replacement from being attempted. 
   Conventional pool lights do not provide this wet mateable connection or suitable fittings. Such pool lights typically include male connectors which permit electrical arcing if the pool light is connected to the power cable underwater. Also, the male connectors often include a guide pin which is easily damaged. 
   It is desirable that light from the pool light can project from the side wall and across at least half the width of a standard training pool, as well as achieving illumination of the bottom of the pool. In a typical swimming pool, an individual pool light may be required to illuminate an area having a length of 6 metres from the unit, a width of 4 metres (2 metres either side of the unit) and a depth of 2.4 metres from the unit to the base of the pool. It is undesirable and inefficient for the projected light to be projected upwards relative to the base of the pool. 
   Conventional pool lights use a three dimensional parabola shaped reflector to reflect light that is projected from the bulb in a direction towards the rear of the housing. Conventional lens and reflector arrangements are not adapted to direct the radiation of light so that there is a greater proportion of radiation in a downwards direction. Also, the angle of illumination, in the plane of the base of the pool, is limited. Conventional lamps do not significantly hinder the radiation of light in an upwards direction. Dark regions can be present in the pool near to the junction of the base and side walls and at the side walls where the pool lights are situated. 
   BRIEF SUMMARY OF THE INVENTION 
   According to the present invention, there is provided an underwater pool light comprising:
         a housing;   a light source located within the housing:   a lens sealingly connected to the housing by a plurality of fasteners; and   a guard member adapted to prevent unfastening of at least one of the plurality of fasteners such that the light source is enclosed within a permanently sealed body.       

   Preferably the pool light includes mounting means for mounting the housing to a niche within or on a wall of a pool. 
   Preferably the housing includes an integral connector for external connection to an electrical supply cable, and the pool light includes electrical connection means within the housing connecting the light source to the integral connector. 
   Preferably the pool light includes a niche for mounting the housing within or on the wall of a pool. 
   Preferably the connector is wet mateable. 
   Preferably the connector includes a cable receiving recess, and the recess has a keyed portion which is complementary to a keyed portion provided at the cable. Preferably the cable receiving recess is formed by a flange projecting from the housing. 
   Preferably the connector comprises one or more pins projecting externally from the housing and adapted to engage with one or more corresponding sockets on the cable. Preferably the pins project into the recess. Preferably a portion of each pin is encased in the housing. 
   Preferably the connector further comprises one or more sleeves projecting externally from the housing and at least partially surrounding the one or more pins. The sleeves may be formed integrally with the housing. Preferably the or each sleeve is made of plastic or rubber. 
   Preferably the mounting means comprises a component of the housing adapted to slideably engage with a component of the niche, such that the distance between the housing and the niche is selectively adjustable. Preferably the pool light includes clamping means for clamping the component of the housing relative to the component of the niche. 
   Preferably the mounting means is adapted such that the distance between the housing and the niche is infinitely adjustable over the adjustment length. 
   Preferably the component of the housing comprises one or more protrusions provided at the housing and the component of the niche comprises one or more slots provided at the niche. Preferably three protrusions and three slots are provided. Preferably the or each protrusion includes a keyed portion which is complementary in profile to the profile of the slot. 
   Preferably the clamping means comprises at least one screw fastener. 
   Preferably the the component of the housing is provided at lens holding member. 
   Preferably the housing includes a collar projecting from a face of the housing. Preferably the collar has a projecting length of around 50 millimetres. The collar provides an edge up to which a pool builder may apply finishers to the pool wall. The collar may then be trimmed. 
   Preferably the housing includes one or more cam receiving slots, and the lens includes one or more cammed members for pivotally locating the lens relative to the lens holding member. Preferably two cammed members are provided. 
   Preferably the lens includes fastener locating means and a fastener for fastening the lens to the lens holding member. Preferably the fastener locating means comprises a hollow coned protrusion for aligning the lens to a fastener receiving aperture provided at the lens holding member. The cammed members and fastener locating means allow self alignment of the lens to the lens holding member. 
   Preferably the housing includes a lamp enclosure which is sealably connected to the lens by a plurality of fasteners. Preferably the housing includes a trim guard which covers the fasteners to prevent unfastening of the fasteners. Preferably the trim guard includes a plurality of pegs which are received in apertures provided at the lens. The trim guard prevents removal of the lens for replacement of the bulb or other maintenance of the pool light. 
   Preferably the housing includes two or more openings for allowing the flow of water into and out of the niche. Preferably the openings are provided at the perimeter of the lens. Preferably the openings comprise a number of cut-outs or castellations provided at the perimeter of the lens. 
   Preferably the niche includes one or more brackets for receiving one or more fastening rods, such as screwed rod. Preferably the or each bracket is adapted to receive one or more fastening rods of a plurality of sizes. Preferably the or each bracket is adapted to receive fastening rods oriented vertically, horizontally, or obliquely relative to the base of the pool. 
   Preferably the lens has a first portion adapted to direct light substantially normal to the wall of the pool, and a second portion adapted to direct light substantially parallel to the wall of the pool, and wherein the pool light further comprises:
         a reflector located within the housing and having a first portion which is substantially parabolic in vertical cross section and a second portion which is adapted to reflect light substantially towards the second portion of the lens.       

   Preferably the second portion of the lens is provided at the internal surface of the lens. Preferably the second portion of the lens comprises a plurality of Fresnel members adapted to direct light substantially parallel to the wall of the pool. Preferably each Fresnel member includes an edge adapted to bend light so that it is substantially parallel to the wall of the pool. The second portion of the lens may be adapted to cause diffraction of light in a direction substantially parallel to the wall of the pool. The second portion of the lens may include a reflective surface to reflect light in a direction substantially parallel to the wall of the pool. 
   Preferably each Fresnel member is arcuate and substantially concentric about the light source. Preferably the second portion of the lens is adapted to direct light downwards. Preferably the second portion of the lens is further adapted to direct light substantially horizontally in each direction. 
   Preferably the first portion of the reflector is substantially linear in horizontal cross section. 
   Preferably the second portion of the reflector has a planar surface oriented to reflect light substantially towards the second portion of the lens. Preferably the second portion of the reflector is provided at an upper region of the reflector. 
   Preferably the reflector includes a third portion which is adapted to reflect light substantially towards the second portion of the lens. Preferably the third portion of the reflector has a planar surface. Preferably the third portion of the reflector is provided at each side of the reflector. 
   Preferably the pool light further comprises a shading member adapted to inhibit the radiation of light in at least one direction. Preferably the shading member is adapted to inhibit the radiation of light in an upwards direction. 
   Preferably the shading member is positioned at the external surface of the lens. Alternatively the shading member is positioned at the internal surface of the lens. Preferably the shading member is press fit to the lens or housing. 
   Preferably the shading member is positioned at an upper portion of the lens relative to the base of the pool. Preferably the shading member is substantially oval. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
       FIG. 1  is a side view of a pool light; 
       FIG. 2  is a front view of the pool light of  FIG. 1 ; 
       FIG. 3  is a perspective exploded view of the pool light of  FIG. 1 ; 
       FIG. 4  is a perspective front view of a lens of the pool light of  FIG. 1 ; 
       FIG. 5  is a perspective rear view of the lens of  FIG. 4 ; 
       FIG. 6  is diagrammatic side view of the pool light of  FIG. 1 ; 
       FIG. 7  is the diagrammatic view of  FIG. 6  showing the radiation of light; 
       FIG. 8  is a diagrammatic plan view of the pool light of  FIG. 1 ; 
       FIG. 9  is the diagrammatic view of  FIG. 8  showing the radiation of light; 
       FIG. 10  is a perspective view of a reflector of the pool light of  FIG. 1 ; 
       FIG. 11  is a perspective front view of a bezel of the pool light of  FIG. 1 ; 
       FIG. 12  is a perspective rear view of the bezel of  FIG. 11 ; 
       FIG. 13  is perspective front view of a niche of the pool light of  FIG. 1 ; 
       FIG. 14  is a perspective rear view of a housing of the pool light of  FIG. 1 ; 
       FIG. 15  is a perspective front view of a housing of the pool light of  FIG. 1 ; 
       FIG. 16  is a sectional side view of a housing of the pool light of  FIG. 1 ; 
       FIG. 17  is a sectional plan view of a housing of the pool light of  FIG. 1 ; 
       FIG. 18  is a perspective view of a supply cable of the pool light of  FIG. 1 ; 
       FIG. 19  is a sectional side view of the pool light of  FIG. 1 ; and 
       FIG. 20  is a perspective rear view of the niche of  FIG. 13 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1 to 3  there is shown a pool light  10  comprising a housing  20  which has a opening that is covered by a lens  30 . A reflector  40  and a light source in the form of two bulbs  50  are housed within the housing  20 . A trim guard  60  is fitted to the lens  30 . 
   The housing includes a lamp enclosure  70  and lens holding member, or bezel  80 , which is sealably connected to the lamp enclosure  70  using a number of gaskets  90 . 
   A collar (not shown) may be provided as projecting from the inner circumference of the lamp enclosure  70 . This collar, typically of 50 millimetres length, provides an edge up to which a pool builder may apply finishers to the pool wall. Once the finishers had been applied, the collar may then be trimmed so that its projecting edge is flush with the pool wall. 
   The lamp enclosure  70  includes an electrical connector  100  for connection to a power supply cable  110 . Internal wiring (not shown) connects the connector  100  to the two bulbs  50 . 
     FIG. 5  is a rear view of the lens  30 . The lens has a first portion  32  adapted to direct light in a direction substantially normal to the wall in which the pool light  10  is fitted. This direction is shown in  FIG. 1  and is denoted as direction ‘A’. The lens  30  also has a second portion which comprises a number of Fresnel members  34  which are adapted to direct light substantially parallel to the wall of the pool. This direction may be downwards which is shown in  FIGS. 1 and 2  as direction ‘B’. The direction of light from the Fresnel members  34  may also be horizontal which is shown in  FIG. 2  as direction ‘C’. The direction of light may also be at an oblique angle lying anywhere between directions ‘B’ and ‘C’. The Fresnel members  34  are all provided within a lower region of lens  30 , and are arcuate and concentric about the bulbs  50 . Each Fresnel member  34  includes an edge  36  which is adapted to bend light so that it is parallel to the pool wall. 
   Light may reach the lens  30  directly from the bulbs  50  or it may be reflected from the reflector  40 . The reflector  40  is shown in  FIG. 10 , and its sectional profile is shown in  FIGS. 6 to 9 . The reflector  40  has a first portion  42  which is substantially parabolic in vertical cross section and so reflects light in a direction substantially normal to the pool wall. The reflector  40  also has a second portion  44  which has a planer surface and is oriented to reflect light substantially towards the Fresnel members  34 .  FIG. 7  shows that a substantial amount of light is radiated in a direction normal to the pool wall. A significant proportion of light is also radiated downwards. 
   As shown in  FIG. 8 , the first portion of the reflector is linear in horizontal cross section, rather than parabolic. The reflector  40  also includes a third portion  46  which has a planar surface and is oriented to direct light to the Fresnel members  34  so that the light is directed horizontally and parallel to the wall of the pool. The radiation of light can be seen in  FIG. 9 , and it can be seen that a significant proportion of light is radiated in a substantially horizontal direction. 
   It is to be understood that the reflector  40  and Fresnel members  34  co-operate to provide a significant portion of light being directed in a direction parallel to the pool wall and that, if either feature were used individually, the effect would not be significant. 
   The reflector is typically made from aluminium.  FIG. 10  shows that an ‘S’ shape is stamped through the reflector wall at each side at a position near to the bulbs  50 . This allows folding of the material within the ‘S’ shape to produce two legs to hold each bulb  50  while providing an aperture for receiving each bulb  50  and allowing access to electrical wiring. 
   As seen in  FIG. 2 , the trim guard  60  includes a shading member  62  positioned at an upper region of the lens  30 . The shading member  62  is oval and opaque and so inhibits the radiation of light in an upwards direction. 
   Referring to  FIG. 4 , the trim guard  60  is fitted to the lens  30  using alternate holes  38  provided in the lens  30 . The rear of the trim guard  60  includes pegs (not shown) for press fitting into the holes  38 . The remaining holes  39  of the lens  30  are used for connection of the lens  32  to the lamp enclosure  70 . 
   The pool light  10  includes a niche  120  for mounting the pool light  10  within the wall of the pool. Mounting means are provided for mounting the housing  20  to the niche  120 . The mounting means comprises a component of the housing, in the form of three protrusions  82  provided at the rear of the bezel  80 , which are adapted to slidably engage with a component of the niche, in the form of corresponding slots  122  provided at the niche  120 . The bezel  80  and niche  120  are shown in  FIGS. 11 to 13 . The mounting means allows the distance between the housing  20  and niche  120  to be selectively adjusted. Clamping means, in the form of screw fasteners (not shown) are provided for clamping the protrusions  82  at the selected position in the slots  122 . 
   The bezel  80  includes two cam receiving slots  84  (as shown in  FIG. 11 ) for receiving the cammed members  86  provided at the lens  30  (as shown in  FIG. 4 ). The lens  30  may conveniently be fitted to the bezel  80  by locating the cammed members  86  in the cam receiving slots  84  and pivoting the upper region of the lens  30  towards the bezel  80 . The lens  30  includes fastener locating means in the form of a hollow coned protrusion  24  provided at the rear of the lens  30 . The coned profile of the protrusion  24  assists to align the protrusion  24  in a fastener receiving aperture  88 . A fastener such as a screw (not shown) may be inserted through the coned protrusion  24  and screwed within the aperture  88  to hold the lens  30  to the bezel  80 . The cammed members  86 , fastener locating means, and the use of only one fastener allow easier aligning and fastening of the lens  30  to the bezel  80 . 
     FIG. 4  shows that the lens  30  includes a number of openings or castellations  26  provided at the perimeter of the lens  30 . These castellations  26  allow the flow of water into and out of the niche  120 . 
     FIGS. 14 to 17  show the electrical connector  100  of the housing  20  for connection to a power supply cable  110 , a portion of which is shown in  FIG. 18 . The connector is wet mateable in the sense that the pool light  10  may be connected to the power cable  110  under water. 
   The connector  100  includes two terminal pins  106 , each partially enclosed by a sleeve  108  formed from an electrically non-conducting material, such as plastic. The pins  106  and sleeves  108  are permanently fixed within apertures  109  provided in the housing  20 . Any suitable fixing means can be used providing that water is not able to enter the housing  20  via the apertures. In the illustrated embodiment, the pins  106  and sleeves  108  are moulded into the housing. Wiring (not shown) is used to connect the exposed end of each pin  106  to the bulbs  50 . 
   The supply cable  110  includes two sockets  114  which receive the other end of the pins  106  within the sleeves  108  to form an electrical connection when the pins  106  have been fully received. The close fitting of the sleeves  108  to the sockets  114  causes water to be expelled from the sockets  114 . The other end of the cable  110  is permanently fixed to a second connector  130  provided at one of two cable entry ports  132  provided in the niche  120 . A further supply cable (not shown) connects the second connector  130  to the power supply. 
   The connector  100  includes a cable receiving recess  102 . This recess  102  includes a keyed portion  104  which is complementary to a keyed portion  112  of the cable  110 . These keyed portions  104 ,  112  permit insertion of the cable  110  into the recess  102  in one orientation only, thereby ensuring correct insertion of the cable  110 . 
     FIG. 19  shows the pool light  10  within the niche  120 . The pool light  10  can be removed a short distance from the niche  120  and then disconnected from the supply cable  110  while still underwater. Therefore, only a short length of cable  110  need be accommodated between the housing  20  and niche  120 . The L shape of one end of the cable  110  also assists in accommodating the cable  110 . 
     FIG. 20  shows that the niche  120  includes a number of brackets  124  for receiving fastening rods, such as screwed rod  126 . The screwed rod  126  is typically of the standard size such as M6 or M8, and the brackets are adapted to receive more than one size of screwed rod  126 . The brackets  124  are adapted to receive screwed rod  126  which is vertically or horizontally oriented. This allows the vertical position of the pool light  10  to be set during installation. 
   The present invention may be used for any of the four methods of pool building without any further modification. 
   Various modifications and improvements can be made without departing from the scope of the present invention.

Technology Classification (CPC): 5