An underwater camera or instrument having a depressible shutter release button or similar actuator is housed within a flexible plastic waterproof housing. A toggle lever is mounted on the camera with one end overlying the button. Surrounding the lever is a frame member that extends upwardly to separate...http://www.google.com.tw/patents/US5339124?utm_source=gb-gplus-share專利 US5339124 - Underwater pressure protection switch
