Abstract: Disclosed herein is an electronic float gauge for indicating the level of liquid in a tank. A float follows the liquid level and causes a rotor that has magnets on it to rotate. Surrounding the magnets, in a concentric array, are a series of reed switches. The rotation of the magnets feeds information to the reed switches about the level of fluid in the tank. The reed switches are connected to a fluid level indicator.

Abstract: A cap for a fill pipe of a fluid container, such as a gas tank, is provided. It has a vent hole which is normally held unsealed by the weight of a ball which impinges against and thereby tilts a spring loaded pin carrying an O-ring. When the cap tips away from the vertical by more than a pre-selected angle, the ball rolls away from the pin and the spring urges the pin to an orientation where the O-ring seals the hole. When the container is tipped beyond the pre-selected angle, should the internal tank pressure exceed a pre-determined level, the pressure overcomes the force of the spring allowing relief venting.

Abstract: A gauge for indicating whether the level of a liquid, such as fuel or oil, in a tank has reached one or more preselected levels. A magnet is mounted in a stem attached atop a float which moves up and down with the rising and falling of the liquid level. When the magnet is adjacent an electrical switch housed in a sealed cover, the switch closes and connects an external power supply to a warning light. The float moves within a cylinder which has a small drain hole at the bottom and a vent near the top. Liquid moves into and out of the guide through the drain hole at a relatively slow rate and thereby eliminates intermittent closing and opening of the switch which would otherwise occur due to the sloshing of the liquid when the tank is in motion, such as when mounted in a vehicle.