Patent ID: 8397587

Claim:
In combination with a pipe through which fluid can flow in a flow direction, a flowmeter comprising: a housing mountable on the pipe; a paddle shaft extending along and pivotal on the pipe about a paddle axis; a paddle carried on the paddle shaft and angularly displaceable in the pipe about the paddle axis between a rest position extending transversely of the direction in the pipe and at least partially blocking flow therethrough, and a deflected position; a spring operatively braced between the paddle and the housing and urging the paddle into the rest position; an indicator shaft extending along and pivotal on the pipe about an indicator axis generally perpendicular to the paddle axis; a scale on the housing; a pointer on the indicator shaft shiftable on rotation of the indicator shaft along the scale; and a respective element fixed on each of the paddle and indicator shafts and each carrying a respective arcuate array of permanent magnets centered on the respective axis, the elements being juxtaposed but not touching so that the indicator shaft is magnetically coupled to the paddle shaft.