Submersible light fixture with multilayer stack for pressure transfer
An underwater light or submersible luminaire may include a housing and a transparent pressure bearing window positioned at a forward end of the housing. A window supporting structure may be mounted in the housing behind the transparent window. A printed circuit board element having a plurality of LEDs may be positioned within the housing behind the window supporting structure to bear substantially all of the ambient water pressure applied to the transparent window.
1. An underwater light, comprising:
a structural housing for withstanding deep underwater pressures of at least 1500 pounds per square inch (PSI);
a transparent pressure bearing window, having outward and inward facing sides, positioned at a forward end of the housing;
a window retainer assembly;
a multi-layer stack positioned behind the transparent pressure bearing window, the multilayer stack including:
a light engine printed circuit board (PCB) populated with a plurality of light emitting diodes (LEDs); and
an LED spacer including apertures for allowing light emitted from the LEDs to pass through to the transparent pressure bearing window, wherein the LED spacer is positioned between the transparent pressure bearing window and the printed circuit board so as to bear substantially all of the pressure applied to the transparent window by water on an exterior side of the window when the housing and transparent pressure bearing window are subjected to deep underwater pressures;
a light head body subassembly positioned at or near a rearward facing side of the housing; and
a retainer subassembly positioned to clamp the multi-layer stack between the housing and the transparent pressure bearing window;
wherein the transparent pressure bearing window, retainer subassembly, and PCB are positioned so that substantially all of the loading from ambient water applied to the outward facing side of the transparent pressure bearing window at depth is carried through the inward facing side of the transparent pressure bearing window through the multi-layer stack and to the rearward end of the housing.
2. The underwater light of claim 1 , wherein the PCB comprises a metal core printed circuit board (MCPCB).
3. The underwater light of claim 1 , wherein the multi-layer stack further comprises a window support spacer positioned between the LED spacer and the transparent pressure bearing window.
4. The underwater light of claim 1 , wherein the multi-layer stack further comprises a Kapton sheet disposed between the LED spacer and the transparent pressure bearing window.
5. The underwater light of claim 1 , wherein the retainer subassembly comprises a retaining ring, an O-ring retainer, and a window face sealing O-ring.
6. The underwater light of claim 1 , wherein the deep ocean pressures are at least 1500 psi and wherein the housing includes walls having a thickness, based on a selected material comprising the housing, to withstand an external pressure at least 1500 psi before breaking or permanently deforming.
7. The underwater light of claim 1 , wherein the deep ocean pressures are at least 3000 psi and wherein the housing includes walls having a thickness, based on a selected material comprising the housing, to withstand an external pressure at least 3000 psi before breaking or permanently deforming.
8. The underwater light of claim 1 , wherein the housing comprises a housing body having a forward end and a rearward end and a cowl coupled to a forward end of the housing body.
9. The underwater light of claim 8 , further comprising a mounting bracket coupled the housing body.
10. The underwater light of claim 1 , wherein the transparent pressure bearing window comprises sapphire.
11. The underwater light of claim 3 , wherein the window support spacer comprises a high compressive strength material with apertures shaped to fit around the LEDs to allow light from the LEDs to pass therethrough.
12. The underwater light of claim 11 , wherein the LEDs include domes, and wherein the domes are trimmed to a width equal to or less than the width of the window support spacer.
13. The underwater light of claim 1 , further comprising one or more reflectors positioned around one or more of the plurality of LEDs.
14. The underwater light of claim 1 , further comprising one or more lenses positioned around one or more of the plurality of LEDs.
15. The underwater light of claim 1 , further comprising an underwater electrical connector disposed at or near the rearward end of the housing.