Abstract: An improved drive shaft for a positive displacement type water meter includes a flexible spring arm formed on one end of the shaft for engaging the drive spindle of a nutating disk measuring element disposed within a water meter. The other end of the drive shaft is connected to a magnetic drive which, in turn, is magnetically coupled to a conventional mechanical register. Under normal conditions, the nutating disk measuring element and drive spindle oscillate in the water meter at a rate proportional to water meter flow. The drive spindle engages the spring arm of the drive shaft causing the drive shaft and magnet to rotate. The magnet is coupled through the water meter casing to a second magnet in the register. Rotation of the second magnet is used to drive the mechanical register to register water consumption. In the event the first magnet within the meter casing becomes frozen to the casing because of external freezing conditions, the drive spindle will snap past the flexible spring arm.

Abstract: A vortex flowmeter is provided with a vortex-inducing bluff body in the form of a first, upstream, cylinder having a semi-circular or semi-ellipsoidal front surface and a planar rear surface, and a second, downstream, cylinder having a planar front surface and a planar or concave rear surface. The rear surface of the upstream cylinder is parallel to the front surface of the downstream cylinder, and separated from it by a gap whose width is preferably about 25% of the diameter of the upstream cylinder.

Abstract: A Coriolis-type mass flow meter for use in sanitary applications. A pair of sensing tubes have their ends rigidly mounted within bores formed within identical inlet and outlet fixtures. The ends of the tubes fit snugly within the bores and are ends brought out flush with the ends of the bores. The flush ends of the tubes are secured to the bores by means of welding. An annular flange is formed about the flush tube ends of the inlet and outlet fixtures to allow easy assembly and removal of the mass flow meter from its associated fluid flow pipeline or conduit. The inlet and outlet fixtures and tubes preferably are formed from a non-reactive, weldable material such as stainless steel. The mounting arrangement of the tubes within the bores of the inlet and outlet fixtures makes it easy to secure the tube ends to the fixtures by means of welding in a readily accessible location.