AU2013101521A4

AU2013101521A4 - Waterproof light housing

Info

Publication number: AU2013101521A4
Application number: AU2013101521A
Authority: AU
Inventors: Pradeep Kumar Tandon
Original assignee: Waterco Ltd
Current assignee: Waterco Ltd
Priority date: 2013-11-21
Filing date: 2013-11-21
Publication date: 2013-12-19
Anticipated expiration: 2021-11-21
Also published as: CN203848189U

Abstract

Water proof Light housing Abstract A waterproof light housing (100) comprising a lens (120) and a backing plate (130) located adjacent to a rear surface of the lens (100), the lens (120) and backing plate (130) together defining a light source chamber (160). A first seal element (140) is located between the lens (120) and backing plate (130). A printed circuit board (150) is located in the light source chamber (160). An aperture (210) is located in the backing plate (130), the aperture (210) permitting a portion of the light source chamber (160) between the backing plate (130) and the printed circuit board (150) to be filled with a waterproof resin. A closing plate (200) is located adjacent to the aperture (210), and is adapted to seal the aperture (210). 130 1381612 209---- --------------- Fig. 1

Description

AUSTRALIA Patents Act 1990 Innovation Patent Specification Title: Waterproof light housing Applicant(s): Waterco Limited Inventor(s): Pradeep Kumar Tandon Agent: OTTERS Patent & Trade Mark Attorneys The following is a full description of the invention which sets forth the best method known to the applicant of performing it.

2 Waterproof light housing Field of the Invention The present invention relates to a waterproof light housing. In particular, the present 5 invention relates to a waterproof light housing for use with swimming pools and spas. However, it will be appreciated that the waterproof light housing may be used in other applications where a light will be fully or partially submerged, or exposed to water or other liquids. Background of the Invention 10 Lights are widely used in swimming pools and spas, and other such applications where they are exposed to moisture. Placing a light in a submerged location under the water surface provides a visually appealing light source, which offers interesting light when seen from above or below the water surface. However, there are inherent difficulties associated with under water lighting. A first problem is that the light housing is known to leak over time. This 15 reduces the life of the light source, such as an LED or halogen globe, which necessitates a costly and often time consuming replacement, generally requiring the services of a qualified electrician. A further problem is that in order to adequately seal the light source against moisture 20 ingression, it is common for heat dissipation problems to arise. This is because the sealed light housing does not provide adequate thermal conductivity to permit the considerable amount of heat generated by the light source to be dissipated. Again, this can result in a reduction of the lifespan of the light source. Furthermore, in the event that the light source overheats, damage may be done to the light fitting or housing, which can be more difficult 25 and costly to repair. Halogen lights sources are commonly used in swimming pool lights. Halogen globes provide a reasonable operating lifespan and are less costly to purchase than LED equivalents. However, halogen globes typically generate a considerable amount of heat during operation. 30 Accordingly, it is common for overheating to occur. Damage by overheating can result in a reduction in the working life of the halogen globe, and may result in damage to the light fitting or even the pool surrounds, which can be significantly more costly to repair for the 3 consumer. LEDs (Light Emitting Diodes) are increasingly popular for use in swimming pool lights. LEDs use significantly less electricity than halogen light sources, and have much longer working 5 lives. However, the replacement cost of a LED globe is significantly more than a comparable halogen globe. For this reason, if the life of the LED is significantly shortened by water ingression, overheating or other damage, the cost to the consumer is significantly more. Object of the Invention It is an object of the present invention to substantially overcome or at least ameliorate one io or more of the above disadvantages, or to provide a useful alternative. Summary of the Invention In a first aspect, the present invention provides a waterproof light housing comprising: a lens; is a backing plate located adjacent to a rear surface of the lens, the lens and backing plate together defining a light source chamber; a first seal element located between the lens and backing plate; a printed circuit board located in the light source chamber; wherein an aperture is located in the backing plate; the aperture permitting a portion 20 of the light source chamber between the backing plate and the printed circuit board to be filled with a waterproof resin; further wherein a closing plate is located adjacent to the aperture, and is adapted to seal the aperture. 25 The waterproof light housing preferably includes a gland assembly having a male threaded portion which engages with a corresponding threaded port formed in the closing plate. The waterproof light housing preferably further comprising a second seal element located between the lens and backing plate. 30 The backing plate preferably includes one or more radially extending cable support plates. The second seal element is preferably seated in a first groove which is located on the lens 4 backing plate, further wherein the lens includes a rearwardly extending annular rib adapted to enter the first groove to compress the second seal element. Brief Description of the Drawings 5 A preferred embodiment of the invention will now be described by way of specific example with reference to the accompanying drawings, in which: Fig. 1 is an exploded perspective view of a waterproof light housing according to a first embodiment; Fig. 2 is an exploded perspective view of a waterproof light housing according to a io second embodiment; Fig. 3 is rear perspective view of a backing plate and a rear cover of the second embodiment; Fig. 4 is a partial side cross-sectional view of the backing plate and a rear cover of the second embodiment; is Fig. 5 is a side partial cross-sectional view of the waterproof light housing of Fig. 1; and Fig. 6 is a partial cross-sectional view of the lens backing plate. Detailed Description of the Preferred Embodiments A first embodiment of a waterproof light housing 100 is depicted in Figs. 1, 5 and 6. The 20 waterproof light housing 100 includes a front lens 120. The lens 120 enables the light to be diffused under the water, and may be provide with a textured, curved or patterned or coloured finish to provide a desired light diffusion and/or colouring effect. The lens 120 is manufactured from a polymeric material, and in the embodiment depicted has a curved front face 121. A plurality of slots or apertures 122 are formed in the curved front face 121, 25 providing an overall dome like appearance. The apertures 122 permit water flow through the lens 120 to assist in cooling the waterproof light housing 100. A lens backing plate 130 is located to the rear of a printed circuit board (PCB) 150. The printed circuit board (PCB) 150 is located between the lens 120 and the lens backing plate 30 130. The lens 120 includes a rearwardly extending annular seat 123, best seen in Fig. 6. The seat 123 is sized to receive and hold the printed circuit board (PCB) 150, and the printed circuit board (PCB) 150 is then held in position using adhesive which may be applied around all or some of the circumference of the printed circuit board (PCB) 150.

5 The lens backing plate 130 includes a plurality of radially extending fins or plates 138. The plates 138 provide a guide to assist in spooling an excess length of low voltage power cable. In the embodiment depicted in the drawings, there are four plates 138, and a space 5 between each adjacent pair of plates 138 may provide a location for a fastener 132 to be inserted to secure the lens 120 and backing plate 130 to a mounting plate 260. The lens backing plate 130 includes four arms 131. The arms 131 each include a hook or projection 133 which can be best seen in the rear view of the lens backing plate 130 which is io shown in Fig. 3. The arms 131 and hooks 133 enable cable to be spooled and supported, and the arms 131 operate with the plates 138 to assist in storing and spooling a length of low voltage power cable within the waterproof light housing 100. During servicing of the waterproof light housing 100, the low voltage cable (not shown) can be unwound from the arms 131, and this additional length of cable permits the waterproof light housing 100 to be 15 moved a short distance from the installation location, away from the water. Referring to Fig. 6, a first seal element 140 in the form of a first rubber O-ring 140 is seated in a first groove 142 which is located on the lens backing plate 130. The first rubber O-ring 140 is located between the backing plate 130 and the rear of the lens 120. In addition, a 20 second seal element 144 in the form of a second rubber O-ring 144 is seated on a second groove or rebate 146 which is also located on the lens backing plate 130. The second rubber O-ring 144 is located between the backing plate 130 and the rear of the lens 120. A rearwardly extending annular rib 125 projects away from the rear of the lens 120. 25 When the screws 132 are fastened, the lens backing plate 130 is pulled toward and secured to the lens 120. As depicted in Fig. 6, as this occurs, the annular rib 125 is forced into the first groove 142, thereby compressing the first rubber O-ring 140. The first and second O-rings 140, 144 prevent the unintentional ingression of water into a 30 light source chamber 160. This also prevents the leakage of resin when injected from the backing plate 130. By fastening each of the screws 132 (which extend through holes formed in the backing plate 130 and corresponding threaded holes formed in the rear of the lens 120), the first and 35 second O-rings 140, 144 are compressed, which creates a watertight seal between the lens 6 body 120 and the backing plate 130, preventing or at least inhibiting the unintentional ingress of water into the light source chamber 160. The light source chamber 160 is formed on the rear side of the lens 120, located between 5 the lens 120 and the lens backing plate 130. The light source chamber 160 houses one or more LED light fittings in electric communication with the printed circuit board PCB 150. A terminal connector 209 is in electric communication on one side with the printed circuit board (PCB) 150 and is in electric communication on an opposing side with a gland assembly 250 which is in communication with a low voltage power supply (not shown). 10 A closing plate 200 is located on the trailing side of the lens backing plate 130. The closing plate is located adjacent to an aperture 210 which is formed in the backing plate 130. An 0 ring or gasket 220 is located between the closing plate 200 and the lens backing plate 130. The O-ring 220 enables sealing of the backing plate 130 relative to the aperture 210. The 15 closing plate 200 is secured to the backing plate 130 with screws 204 which compress the 0 ring 220. Caps 205 are placed over the screws 204. When the backing plate 130 is secured to the lens 120, a thermally conductive resin is injected under pressure through the aperture 210 formed in the closing plate 200. Once the 20 resin has cured fully or to a sufficient degree, the aperture 210 is covered with the closing plate 200, and sealed by the O-ring 220 once the closing plate 200 is fastened in position. The combination of the first rubber O-ring 140 and the second rubber O-ring 144 along with the resin provides good water protection for the printed circuit board (PCB) 150 and LED light. 25 A cable receiving hole 230 is formed in the closing plate 200, adjacent to the aperture 210. The cable receiving hole 230 permits a low voltage power supply cable to be passed from within the watertight sealed light source chamber 160 to the rear of the waterproof light housing 100. 30 The cable receiving hole 230 defines a threaded port for engaging with a corresponding male threaded portion of the waterproof gland assembly 250. The gland assembly 250 provides additional waterproofing.

7 The underwater light assembly 10 includes a mounting plate 260. The mounting plate 260 is secured to the wall of a swimming pool or spa with screws (not shown) which typically engage with plastic masonary screw anchors. The screw anchors are typically inserted in holes formed in the wall of the pool or spa. A plurality of mounting holes 263 are formed in 5 the mounting plate 260. This enables the installer to choose holes which are most convenient, based on where corresponding holes can be most readily formed in the pool or spa. In the embodiments depicted in the drawings, a wall mounting ring 300 is included in the 10 waterproof light housing 100. The wall mounting ring 300 may be secured to the wall of the swimming pool or spa by cementing. In this embodiment, four screws are used to secure the mounting plate 260 to the wall mounting ring 300. Advantageously, a pool builder can choose whether the wall mounting ring 300 is used, or if 15 the mounting plate 260 is secured directly to the pool wall. The mounting plate 260 includes a mounting lug 262. The mounting lug 262 extends away from the body of the mounting plate 260, away from the wall of the pool or spa. As shown in Fig. 1, the mounting lug 262 is generally wedge shaped, having a rectangular upper 20 surface 264. A hole 265 is formed in the rectangular upper surface 264. The mounting plate 260 includes a central aperture 270 for receiving the low voltage power cable. The mounting plate 260 includes an annular skirt or flange 280 having three cut-outs 282 located around the outer circumference, which are equally spaced relative to each other, 25 at approximately 1200. The skirt 280 extends away from the pool, and tapers or curves radially inwardly, to define a shoulder or step. The cut-outs 282 in the skirt 280 are adapted to receive three corresponding tabs (not shown) which are located around the circumference of the lens 120. 30 Accordingly, in order to secure the lens 120 to the mounting plate 260, the tabs are inserted into the cut-outs 282, and the lens 120 is then rotated, such that the tabs slide behind the skirt 280. Because the skirt 280 is stepped or tapered inwardly, this has the effect of securing the lens 130 against the mounting plate 260. 35 A depression 126 is formed on the lens 130. The depression 126 is adapted to line up with 8 the hole formed in the rectangular upper surface 264 of the mounting lug 262. When the lens 130 is located in the assembled position, a screw 128 is inserted through a hole formed in the depression, to secure the lens 130 to the mounting plate 260. 5 In order to change or inspect the LED light fitting, the screw 128 is initially removed. This enables the lens 120 to be pivoted relative to the mounting plate 260, to undo the twist lock between the lens 120 and the mounting plate 260. When the tabs leave the cut-outs 282, the lens 120 is free to be pulled away from the mounting plate 260. The lens body 120 and backing plate 130 can then be removed together. A sufficient length of the low voltage io power cable can be located behind the mounting plate 260. This enables the lens 120 and backing plate 130 to be moved to a remote location, above the pool water level for repair/maintenance/replacement. The lens body 120 and lens backing plate 130 are permanently sealed with the resin, and in 15 the event of a lighting failure, the entire lens body 120 and backing plate 130 are replaced. Advantageously, the presence of the thermally conductive epoxy prevents any water leakage and assists to achieve adequate heat dissipation to reduce the likelihood of the light overheating. 20 A second embodiment of a waterproof light housing 500 is depicted in Figs. 2, 3 and 4. Like reference numerals are used to identify corresponding features which are unchanged between the first and second embodiments. The water proof light housing 500 is similar to the first embodiment, however it does not include the closing plate 200. In contrast the 25 waterproof light housing 500 of the second embodiment includes a rear cover 510. The rear cover 510 has a generally circular body 511, and four screw support arms 513 (although the number of the support arms 513 may vary) which project radially away from the circular body 511. The screw support arms 513 each receive screws 509 which engage 30 with four corresponding mounting bosses 515 which are located on a rear side of the lens backing plate 130. Tightening the screws 509 applies a force to draw the rear cover 510 towards the lens backing plate 130. The seal between the rear cover 510 and the lens backing plate 130 is shown in detail in the partial cross-sectional view of Fig. 4. 35 As shown in Fig. 4, an annular projection or boss 519 extends away from the rear of the lens 9 backing plate 130. An end portion of the boss 519 includes an annular seat. The annular seat is adapted to receive the rubber O-ring 530. In addition, the rear cover 510 includes a complimentary annular projection or boss 517 which is sized to fit within the annular projection or boss 519 of the lens backing plate 130. A step 521 is located on the boss 517, 5 and a further step 523 is located on the boss 519. The two steps 521, 523 together define an annular void, in which the O-ring 520 is seated. The two O-rings 520, 530 provide an increased degree of moisture protection, and tightening the screws 509 to secure the rear cover 510 to the lens backing plate 130 10 compresses the O-rings 520, 530. A central portion of the circular body 511 of the rear cover 510 includes an impression adapted to receive a low voltage junction connector 209. 15 The rear cover 510 includes a radially extending threaded port 512 for engaging with the waterproof gland assembly 250. The waterproof light housing 100 is designed to receive a PCB 150 which is about 145 mm outer diameter. 20 Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

1. A waterproof light housing comprising: a lens; a backing plate located adjacent to a rear surface of the lens, the lens and backing plate together defining a light source chamber; a first seal element located between the lens and backing plate; a printed circuit board located in the light source chamber; wherein an aperture is located in the backing plate; the aperture permitting a portion of the light source chamber between the backing plate and the printed circuit board to be filled with a waterproof resin; further wherein a closing plate is located adjacent to the aperture, and is adapted to seal the aperture.

2. The waterproof light housing of claim 1, including a gland assembly having a male threaded portion which engages with a corresponding threaded port formed in the closing plate.

3. The waterproof light housing of either of the preceding claims, further comprising a second seal element located between the lens and backing plate.

4. The waterproof light housing of anyone of the preceding claims, wherein the backing plate includes one or more radially extending cable support plates.

5. The waterproof light housing of claim 3, wherein the second seal element is seated in a first groove which is located on the lens backing plate, further wherein the lens includes a rearwardly extending annular rib adapted to enter the first groove to compress the second seal element. Waterco Limited By Patent Attorneys for the Applicant W"COTTERS Patent & Trade Mark Attorneys