Vortex-shedding flowmeter with torsional sensor mounted on torque tube

Claim 1

A vortex-shedding flowmeter capable of accurately measuring the flow rate of a fluid even under extreme conditions of temperature, the flowmeter comprising: A. a flow pipe through which the fluid to be metered is conducted along a flow axis; B. a shedder mounted in said pipe to intercept said fluid, vortices being detached from said shedder; C. a sensor torsionally supported in said flow pipe along a pivot axis at right angles to the flow axis whereby said sensor is caused by said vortices to oscillate about said pivot axis at a rate proportional to flow, the support therefor including a torque tube whose base is received within a bore in said flow pipe and is joined thereto and whose tip is joined to one end of said sensor to exclude said fluid from the interior of said tube; D. a transducer external to said pipe to convert the sensor oscillations into corresponding electrical signals; and E. a sensor link assembly coupling said sensor to said transducer and including a main rod extending into the interior of said torque tube and joined at one end to the tip thereof, the other end of said main rod being connected through a diaphragm coupler to an extension rod which is connected to said transducer, whereby the motion of the tube is transmitted via the rod to said transducer, said diaphragm coupler attenuating the transmission of bending forces imposed on said torque tube.