Abstract: A liquid sensing apparatus includes a liquid sensing chamber 33 having a liquid inlet port that is in communication with an external liquid container in which a liquid is reserved, and a liquid outlet port that is in communication with a liquid consuming apparatus, a movable member 34 movable depending on a liquid level in the liquid sensing chamber 33, a recess portion 33b, 41a for cooperating with a wall surface of the movable member 34 to form a closed space when the movable member 34 is moved to a predetermined position depending the liquid level, and a piezoelectric sensing means 40 for applying a vibration to the recess portion and sensing a state of a free vibration following upon the vibration.

Abstract: A fail-safe fluid transfer control apparatus has full redundancy in the response to various inputs such as overfill probe signals, ground detection signals, and the like. Independent microprocessor controllers independently evaluate the inputs and each output control signals to close a respective relay when the inputs indicate that fluid transfer may commence. The relays are arranged in series such that both must be closed for a fluid transfer to commence. The control signals from each controller include a static signal and an alternating signal, both of which must be properly output to close its respective relay. Each controller monitors the state of each relay, and discontinues its control signals if either relay appears to be malfunctioning. Each controller runs an different, independently written firmware program to process the detected inputs to prevent a common firmware error.

Abstract: A vehicle fuel level sensor comprising a hollow cylindrical body housing a sliding float, the position of which is determined by the fuel level in the fuel tank. The sensor also comprises a filter surrounding as portion of the side wall of the cylindrical body, close to the bottom wall of the same, so as to define, with the side wall, a first chamber; and a plate for supporting the filter and connected to the bottom wall of the hollow cylindrical body so as to define, with the bottom wall, a second chamber communicating directly with the first chamber and, via a through hole in the bottom wall, with the inside of the hollow cylindrical body.

Abstract: A liquid level indicator for a liquid container, such as the crankcase oil reservoir of an internal combustion engine, comprises a source of fluid at a predetermined pressure and a fluid conduit system connected to the fluid source. A gage responsive to fluid pressure and a valve mechanism are coupled to the conduit system downstream of a restriction orifice in the system. The valve mechanism includes an outlet orifice for fluid in the system and a valve body that is movable axially of the orifice so as to vary its cross-sectional flow area. The valve body is coupled to a float that is mounted for limited vertical movement in the container so that when the liquid in the container is at any particular level within a predetermined range, the liquid exerts a buoyancy force on the float which is balanced by opposing forces, including the float weight and a force exerted by the pressurized fluid on the float through the valve body.