Abstract: A digital liquid level sensing apparatus for detecting variations in the dielectric of a substance being sensed, to thereby provide a signal indicative of the level of the liquid being sensed in relation to a known full level. The apparatus includes a reservoir having an output plate and an input plate assembly associated therewith. The input plate assembly includes a plurality of independently electrically excitable input plates which transmit a signal through the liquid being sensed to the output plate. The signals from the output plate are processed and a determination is made as to the level of liquid in the reservoir relative to a known full level. If the input plate assembly is located against the exterior surface of one wall of the reservoir, then both of the interior and exterior portions of that particular wall should be devoid of any metallic surface. In an alternative embodiment, a discardable interior reservoir is provided which fits nestably within the reservoir of the sensor.

Abstract: A folding knife includes a lubricated barrel pivot removably mounted in the handle. An oil reservoir within the barrel communicates with the bearing surface by means of an oil wick in a bore. The barrel may be mounted in the handle by engaging male threads at one end of the barrel into female threads in the knife handle in which case an oil conduit is provided within the male threads for filling the oil chamber. Similarly, the barrel may be mounted with a pair of screws engaged with female threads at opposite ends of the barrel in which case an oil conduit is provided within at least one of the female threads for filling the oil chamber. Further, the barrel may be mounted by providing a slotted head at one of the barrel and female threads at the other end. A screw is mounted through the handle to engage the female threads and an oil conduit is provided within the female threads for filling the chamber with oil.