Sealing luminaire with dry gas

Abstract

An underwater luminaire and a method for manufacturing the underwater luminaire are provided. The method includes assembling a light fixture into a housing, without a fastener disposed in the light fixture, where an opening of the fastener is in fluid communication with an open volume in the housing. The housing is placed in a vacuum chamber and the vacuum chamber is evacuated to remove air from the open volume of the housing. A dry gas is introduced into the vacuum chamber to fill the open volume in the housing, and a fastener is mounted in the lamp to seal the open volume.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. non-provisional patent application No. 17 / 881,775, filed on August 5, 2022, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a light fixture for an underwater light filled with a dry gas. Background Art

[0004] Condensation of materials such as water or organic materials is a problem in underwater luminaires. The high temperature difference between the lighting element and the surface of the luminaire can cause the material to vaporize and condense on the inside of the surface. In addition, after the luminaire is powered off, cooling can cause the material to condense on the circuitry. This can cause the luminaire to fail prematurely. Summary of the invention

[0005] One embodiment described herein provides a method of manufacturing an underwater light fixture. The method includes assembling the light fixture into a housing without fasteners installed in the light fixture, wherein an opening of the fastener is in fluid communication with an open volume in the housing. The housing is placed in a vacuum chamber, and the vacuum chamber is evacuated to remove air from the open volume of the housing. A dry gas is introduced into the vacuum chamber to fill the open volume in the housing, and fasteners are installed in the light fixture to seal the open volume.

[0006] Another embodiment described herein by way of example provides an underwater light fixture. The underwater light fixture includes a housing including an outer shell and a back plate, wherein the outer shell includes an opening for light to leave the housing, and the back plate includes an opening for a cable. A lighting circuit board mounted in the housing has a visible light lighting element mounted on a front surface facing the opening in the housing. The underwater light fixture includes a lens plate mounted above the lighting element, and a transparent plate mounted above the opening in the housing. The underwater light fixture includes a control circuit board mounted on the back of the lighting circuit board, wherein the back plate is mounted above the control circuit board. The underwater light fixture includes a cable connected to the lighting circuit board, and a dry gas arranged in an open space of the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A is a perspective view of an underwater luminaire designed to be surface mounted.

[0008] Figures 1B to 1D It is various stereoscopic images of underwater lamps.

[0009] Figure 2A This is a front view of a lighting circuit board used in an underwater lamp.

[0010] Figure 2B is a rear view of a lighting circuit board used in an underwater light fixture.

[0011] Figure 3A is a front view of the housing, in which a lighting circuit board is installed.

[0012] Figure 3B is a front view of the housing with a lens plate mounted above the lighting circuit board.

[0013] Figure 4A It is a front view of the housing, in which a decorative plate is installed above the lens plate.

[0014] Figure 4B is a front view of the housing with a transparent panel mounted over the opening in the housing.

[0015] Figure 5A is a rear view of the housing showing the back side of the lighting circuit board.

[0016] Figure 5B is a rear view of the housing showing the control circuit board mounted behind the lighting circuit board.

[0017] Figure 6 is a schematic diagram of the introduction of drying gas into the open volume of the housing.

[0018] Fig. 7A is a rear view of the housing showing the cables soldered to the pins of the control circuit board and the layer of potting compound applied over the control circuit board.

[0019] Figure 7B is a rear view of the housing showing the backplate, cables, and cable nuts.

[0020] Figure 8 is a simplified exploded view showing the components of an underwater light fixture.

[0021] Fig. 9 is a flow chart of a method 900 for manufacturing an underwater light fixture. DETAILED DESCRIPTION

[0022] Underwater luminaires, such as those mounted on boats, docks, levees, etc., are susceptible to condensation formation. Condensation may result in reduced lighting efficiency, shortened life, or both. Assembly techniques for protecting underwater luminaires from condensation and underwater luminaires that are not susceptible to condensation are provided herein.

[0023] During the assembly process of the underwater light fixture, the underwater light fixture is placed in a vacuum chamber to extract humid air from the open space within the housing of the underwater light fixture. A dry gas is introduced into the vacuum chamber to fill the open space in the housing. The dew point of the selected dry gas depends on the temperature at which the underwater light fixture is used. For example, an underwater light fixture used in arctic applications may require a lower dew point than an underwater light fixture used in a warm climate. In some embodiments, the dry gas is nitrogen, which has a dew point between about -70℉ (-57℃) and about -94℉ (-70℃). Other dry gases from compressed cylinders or drying systems may also be used, including dry air, argon, helium, etc. In addition, multiple vacuuming and gas introduction cycles may be performed to lower the dew point of any gas remaining in the open space of the housing.

[0024] Figure 1A is a perspective view of an underwater light fixture 102 designed to be surface mounted. The technology described herein is not limited to this type of underwater light fixture 102, but can also be used to protect a variety of different types of underwater light fixtures from condensation, including surface mounted light fixtures of different shapes, pole mounted light fixtures, portable light fixtures, through-hull light fixtures, etc.

[0025] exist Figure 1A In the embodiment, the housing 104 holds and protects the lighting elements 106 from the environment, for example, by embedding the lighting elements 106 in the housing 104 and mounting a transparent panel over an opening 108 at the front of the housing 104. Each lighting element 106 has a lens covering the lighting element so that light is focused into the environment through the opening 108. A cable 112 provides power to the underwater light fixture 102. In this embodiment, mounting holes 114 are provided in the housing 104 to allow the underwater light fixture 102 to be secured to a surface, such as the hull of a boat, using fasteners (such as marine screws). To simplify the illustration, not every item within a type is labeled. For example, Figures 1A to 1D The underwater light fixture 102 shown in FIG. 1 has 18 lighting elements 106 , arranged as 6 in an inner circle and 12 in an outer circle.

[0026] Any number of configurations of lighting elements 106 and other design features may be used in embodiments. For example, in one embodiment, a rectangular underwater light fixture has 18 lighting elements 106 arranged in 2 rows of 9. Similar variations in mounting may be seen depending on the type of light fixture, for example, a rectangular underwater light fixture has 4 mounting holes, 2 on each side. In some embodiments, the underwater light fixture is mounted on a threaded end of a conduit through which the cable 112 passes.

[0027] Figures 1B to 1D 102 are various stereoscopic views of the underwater lighting fixture 102 . Figure 1B1 is a top view of the underwater light fixture 102. In the top view, the lighting element 106 is visible through the opening 108 at the top of the housing 104. In some embodiments, the underwater light fixture 102 includes an ultraviolet lighting element 116 that emits ultraviolet light (UVC) to inhibit the formation of biofilm on the transparent panel of the opening 108. Other embodiments do not include the ultraviolet lighting element 116. Figure 1C is a side view of the underwater light fixture 102 showing the base plate 118 mounted in the recessed channel of the housing 104 . Figure 1D FIG. 1 is a rear view of the underwater light fixture 102 showing the base plate 118 being secured to the housing 104 using a series of mounting screws disposed in mounting holes 120 in the housing 104. Figure 1A As mentioned above, the technology is not limited to Figures 1A to 1D The underwater light fixture 102 shown in FIG. Any number of different configurations may be used in the embodiments described herein.

[0028] Figure 2A 1 is a front view of a lighting circuit board 202 used in an underwater light fixture 102. In this view, it can be seen that the lighting element 106 may include multiple light emitters, such as light emitting diodes (LEDs) of multiple colors. In some embodiments, the LEDs of each lighting element 106 include blue, red, green, and white LEDs. In some embodiments, the underwater light fixture 102 emits monochromatic light. In these embodiments, all of the LEDs may be blue, white, and green, amber, or red. Figures 1A to 1D To simplify the illustration, not every item is labeled. Figure 2A Six UVC lighting elements 116 are illustrated, although not every instance is labeled.

[0029] Figure 2A A through connector 204 is shown that connects the circuitry on the front of the lighting circuit board 202 (including the lighting element 106) through the lighting circuit board 202 to pins 212, which are connected to the control circuit board. At each longitudinal end of the through connector 204, there is a mounting hole 206 for inserting a screw from a control circuit board as described herein. The mounting holes 206 pass through the lighting circuit board 202 to fluidly connect the back of the lighting circuit board 202 to the open space in the underwater light fixture 102 in front of the lighting circuit board 202. The lighting circuit board 202 also includes six mounting holes 208 for mounting the lighting circuit board 202 to the housing 104 ( Figure 1A ). Four notches 210 in the lighting circuit board 202 allow access to screw holes in the housing 104 for mounting a lens plate over the lighting circuit board 202 as described herein.

[0030] Figure 2B2 is a rear view of a lighting circuit board 202 for use in an underwater light fixture. In some embodiments, for example, a thermal pad 214 is applied to the back of the lighting circuit board 202 to protect the circuitry on the control circuit board from the heat generated by the LEDs of the lighting elements 106 and 114.

[0031] Figure 3A 1 is a front view of the housing 104, wherein the lighting circuit board 202 is mounted in the housing 104. In this embodiment, the lighting circuit board 202 is mounted by screws inserted through the mounting holes 208 around the lighting circuit board 202. Figure 3A As shown, mounting holes 206 at each end of the through connector 204 remain open between the front of the lighting circuit board 202 and the rear of the lighting circuit board 202 .

[0032] Figure 3B 2 is a front view of the housing 104 with a lens plate 302 mounted above the lighting circuit board 202. The lens plate 302 includes a separate lens 110 located above each lighting element 106. In embodiments including UV lighting elements 116, the lens plate 302 does not cover the UV lighting elements 116. In various embodiments, the lens plate 302 is made of a material such as polycarbonate, polyacrylate, quartz, or glass.

[0033] Figure 4A 1 is a front view of the housing 104, wherein a decorative plate 402 is mounted above the lens plate 302. In an embodiment where the decorative plate 402 is used, the decorative plate 402 covers the circuit of the lighting circuit board 202. Figure 4B 1 is a front view of the housing 104, wherein a transparent panel 404 is mounted over the opening 108 in the housing 104. In various embodiments, the transparent panel 404 is made of quartz, glass, microcrystalline spinel structure, sapphire, or the like. In some embodiments, the transparent panel 404 is mounted in the opening 108 by installing an O-ring 406 in a channel around the opening 108 and then mounting the transparent panel 404 over the O-ring, for example, using an adhesive. In some embodiments, the adhesive is a UV-curable liquid adhesive. In other embodiments, the adhesive is a thermoplastic elastomer, a flexible RTV compound, or an elastic epoxy resin, or the like.

[0034] Figure 5A 2 is a rear view of the housing 104, showing the back side of the lighting circuit board 202. In this embodiment, the control circuit board 502 is mounted above the pins 212 that pass through the connector 204. Figure 5B2 is a rear view of the housing showing the control circuit board mounted on the back of the lighting circuit board 202. A mounting screw is installed through one mounting hole 206 at each end of the through connector 204. The remaining mounting holes remain empty and the partially completed lamp 102 is placed in a vacuum furnace, as further described. Figure 6 described.

[0035] Figure 6 Schematic diagram of the introduction of dry gas into the open volume of the housing 104. First, Figure 5B The partially assembled underwater light fixture 102 is placed into a vacuum chamber 602. The vacuum chamber 602 is sealed and a vacuum is drawn 604 by opening a vacuum valve 606 to a vacuum pump (not shown) to evacuate air from the vacuum chamber 602. In some embodiments, a vacuum gauge 608 is used to indicate that the pressure has reached the lowest vacuum that the vacuum pump can draw, such as 0.1 Torr (0.13 mbar), 0.5 Torr (0.67 mbar), 1.0 Torr (1.33 mbar), or 5.0 Torr (6.67 mbar). After the air is evacuated, the vacuum valve 606 is closed and the dry gas valve 610 is opened to introduce dry gas 612 into the vacuum chamber 602. If the pressure level after the vacuum reaches the lowest point is not low enough to achieve the desired dew point, multiple cycles of evacuation and dry gas introduction can be performed. For example, two cycles, three cycles, or more cycles can be performed to achieve a sufficiently low dew point. The rate of evacuation and introduction of drying gas is controlled to avoid stressing components when gases are exchanged in the open space of a partially assembled underwater luminaire.

[0036] After the air in the open space of the housing 104 is replaced with the dry gas, the open space is sealed to prevent further air exchange. Figure 5B This is accomplished by inserting a mounting screw into the remaining mounting hole 206 at the end of the through connector 204. Once this operation is performed, the final assembly of the underwater light fixture can be completed.

[0037] Fig. 7Ais a rear view of the housing showing the cables 112 soldered to the pins 212 of the control circuit board and a layer of potting compound 702 applied over the control circuit board. The potting compound 702 further seals the underwater light fixture 102, protecting the electronic components from water intrusion. In various embodiments, the potting compound 702 is an epoxy compound or an RTV compound, etc. Once the potting compound 702 cures, the back plate 704 is screwed over the cables 112 and sealed to the underwater light fixture 102 by screws inserted through the back plate 704 into the mounting holes 120 in the housing 104. Then, a cable nut 706 can be screwed over the cables 112 and screwed to the accessories attached to the back plate 704. In some embodiments, a separate mounting plate can be attached to the back plate 704 by an adhesive. In these embodiments, the accessories for the cables are part of the separate mounting plate. Figure 7B is a rear view of the housing 104 showing the back plate 704 , the cables 112 , and the cable nut 706 .

[0038] Figure 8 802 is a simplified exploded view showing the components of the underwater light fixture 102. Items with the same number are described with reference to the previous figures. As described herein, in an embodiment, the underwater light fixture 102 includes a transparent panel 404, which is mounted to the opening 108 in the housing using an O-ring 406 between the opening 108 and the housing, and the components are bonded using an adhesive. The lighting circuit board 202 is attached with a thermal pad 214 and is installed in the housing 104. The control circuit board 502 is mounted to the lighting circuit board 202 near the thermal pad 214. In this embodiment, one of two screws (not shown) is installed in the control circuit board 502 to mount it to the lighting circuit board 202. The second screw is not installed to allow gas exchange between the back of the control circuit board 502 and the open space in the housing 104. Then, the assembly 802 is placed in a vacuum chamber, and at least one cycle of vacuum and dry air is performed to exchange the air in the open space in the housing 104 with dry air. After the swap is complete, the second screw is installed into the control circuit board 502 and the assembly of the underwater light fixture 102 as described herein is completed. The use of the partial structure (e.g., the mounting hole that communicates with the open space in the housing 104) is not limited to the structure shown here. In other embodiments, a specific port is built into the underwater light fixture 102 to evacuate the open space. This may be useful when the underwater light fixture 102 is used in an extremely low temperature environment (such as an arctic application).

[0039] Fig. 99 is a flow chart of a method 900 for manufacturing an underwater light fixture. The method 900 begins at block 902, where the light fixture is assembled into a housing. At block 904, no fasteners (such as screws) are installed in the light fixture to provide fluid communication with an open volume in the housing through an opening for the fasteners. At block 906, the housing is placed in a vacuum chamber. At block 908, the vacuum chamber is evacuated to remove air from the open volume of the housing through the opening for the fasteners. At block 912, a dry gas is introduced into the vacuum chamber to fill the open volume in the housing. At block 914, fasteners are installed in the light fixture to seal the open volume.

[0040] Implementation

[0041] Embodiments described herein provide a method for manufacturing an underwater light fixture. The method includes assembling the light fixture in a housing, without fasteners installed in the light fixture, wherein an opening for the fastener is in fluid communication with an open volume in the housing. The housing is placed in a vacuum chamber, and the vacuum chamber is evacuated to remove air from the open volume of the housing. A dry gas is introduced into the vacuum chamber to fill the open volume in the housing, and fasteners are installed in the light fixture to seal the open volume.

[0042] In one aspect, the method includes repeating at least twice the cycle between evacuating the vacuum and introducing the dry gas before installing the fastener.

[0043] In one aspect, the method includes assembling in a clean room.

[0044] In one aspect, the method includes maintaining a temperature between about 22°C and about 28°C during assembly of the lamp.

[0045] In one aspect, the method includes maintaining a relative humidity between about 30% and about 40% during assembly of the luminaire.

[0046] In one aspect, assembling the lamp into the housing includes attaching a thermal pad to a back side of a lighting circuit board, mounting the lighting circuit board in the housing with the lighting elements mounted on the lighting circuit board facing an opening in the housing, sealing a transparent plate to the housing over the lighting circuit board, and mounting a control circuit board to the back side of the lighting circuit board.

[0047] In one aspect, the method includes mounting a lens plate over the lighting circuit board prior to sealing the transparent plate to the housing.

[0048] In one aspect, the method includes heating the lighting circuit board to about 80° C. for about 30 minutes to volatilize the organic compound prior to attaching the thermal pad.

[0049] In one aspect, the method includes soldering the cable to the control circuit board.

[0050] In one aspect, the method includes disposing a layer of potting compound over a control circuit board.

[0051] In one aspect, the method includes mounting a backplate to the housing over a layer of potting compound.

[0052] Another embodiment described herein by way of example provides an underwater light fixture. The underwater light fixture includes a housing including an outer shell and a back plate, wherein the outer shell includes an opening for light to leave the housing, and the back plate includes an opening for a cable. A lighting circuit board mounted in the housing has a visible light lighting element mounted on a front surface facing the opening in the housing. The underwater light fixture includes a lens plate mounted above the lighting element, and a transparent plate mounted above the opening in the housing. The underwater light fixture includes a control circuit board mounted on the back of the lighting circuit board, wherein the back plate is mounted above the control circuit board. The underwater light fixture includes a cable connected to the lighting circuit board, and a dry gas arranged in an open space of the housing.

[0053] In one aspect, an underwater light fixture includes a thermal pad disposed between a lighting circuit board and a control circuit board.

[0054] In one aspect, an underwater light fixture includes a potting compound disposed between a control circuit board and a back plate.

[0055] In one aspect, an underwater light fixture includes a lighting circuit board including ultraviolet lighting elements mounted on a front surface facing toward a transparent plate.

[0056] In one aspect, each lighting element comprises an individual light emitting diode.

[0057] In one aspect, the drying gas comprises nitrogen.

[0058] In one aspect, the drying gas comprises air.

[0059] In one aspect, the drying gas comprises argon.

[0060] Other implementations are within the scope of the following claims.

Claims

1. A method for manufacturing an underwater lamp, comprising: assembling a light fixture into a housing, wherein no fastener is disposed in the light fixture, wherein an opening for the fastener is in fluid communication with an open volume in the housing; placing the housing into a vacuum chamber; evacuating the vacuum chamber to remove air from the open volume of the housing; introducing a dry gas into the vacuum chamber to fill the open volume in the housing; as well as The fastener is installed in the light fixture to seal the open volume.

2. The method of claim 1, comprising repeating the cycle of evacuating and introducing the dry gas at least twice before installing the fastener.

3. The method of claim 1, comprising performing said assembling in a clean room.

4. The method of claim 3, comprising maintaining a temperature between about 22°C and about 28°C during the assembly of the lamp.

5. The method of claim 3, comprising maintaining a relative humidity between about 30% and about 40% during said assembling of said lamp.

6. The method of claim 1 , wherein assembling the light fixture into the housing comprises: Attach the thermal pad to the back of the lighting circuit board; mounting the lighting circuit board in the housing with the lighting elements mounted on the lighting circuit board facing the opening in the housing; sealing a transparent plate to the housing over the lighting circuit board; as well as The control circuit board is mounted on the back side of the lighting circuit board.

7. The method of claim 6, comprising mounting a lens plate over the lighting circuit board before sealing the transparent plate to the housing.

8. The method of claim 6, comprising heating the lighting circuit board to about 80°C for about 30 minutes to volatilize organic compounds before attaching the thermal pad.

9. The method of claim 6, comprising soldering a cable to the control circuit board.

10. The method of claim 6, comprising disposing a layer of potting compound over the control circuit board.

11. The method of claim 10, comprising mounting a back plate to the housing over the layer of potting compound.

12. An underwater lamp, comprising: The housing comprises a shell and a back plate, wherein The housing includes an opening for light to exit the housing; as well as The back panel includes an opening for cables; a lighting circuit board mounted in the housing through the opening and having a visible light lighting element mounted on a front surface facing the opening in the housing; a lens plate mounted above the lighting element; a transparent plate mounted above the opening in the housing; A control circuit board mounted on the back of the lighting circuit board, wherein the back plate is mounted above the control circuit board; a cable connected to the lighting circuit board; as well as A drying gas is disposed in the open space in the housing.

13. The underwater light fixture of claim 12, comprising a thermal pad disposed between the lighting circuit board and the control circuit board.

14. The underwater light fixture of claim 12, comprising a potting compound disposed between the control circuit board and the back plate.

15. The underwater light fixture of claim 12, wherein the lighting circuit board includes an ultraviolet lighting element mounted on a front surface facing the transparent plate.

16. The underwater light fixture of claim 12, wherein each lighting element comprises an individual light emitting diode.

17. The underwater light fixture of claim 12, wherein the dry gas comprises nitrogen.

18. The underwater light fixture of claim 12, wherein the dry gas comprises air.

19. The underwater light fixture of claim 12, wherein the dry gas comprises argon.

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