The apparatus comprises at least two oscillating rods which are secured spaced from each other to a diaphragm, the edge of which is connected to a screw-in piece. On the side of the diaphragm remote from the oscillating rods a clamping screw is fixedly connected to the diaphragm so that the clamping...http://www.google.de/patents/US5191316?utm_source=gb-gplus-sharePatent US5191316 - Apparatus for determining and/or monitoring a predetermined contents level in a container
