Flow sensing devices
AssigneeHNL Instruments & Controls Limited
InventorTerence J. Hayward
Life of this patent
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Abstract
A flow sensing device comprises a shaft which is axially movable, and extends across a flow passageway, and carries an angled vane in the passageway. At each side of the passageway, the shaft is supported by a diaphragm which also prevents the leakage of fluid from the passageway beside the shaft. The two diaphragms are of equal area, so that any static pressure within the passageway does not result in a net pressure force tending to move the shaft axially. No other support is provided for the shaft.
Claims8
A flow sensing device comprising a conduit for the flow, a shaft extending across said conduit, a flow deflecting member carried by said shaft, said conduit being formed with a hole in each side, said shaft extending through each of said holes, and further comprising respective flexible support and sealing members for supporting said shaft in an axial and a radial direction of said shaft at each side of said conduit;
- said flow deflecting member being so shaped that flow through said conduit will exert on said flow deflecting member a force having at least a component directed axially of said shaft;
- said flexible support and sealing members also serving to seal said holes in said conduit against fluid flow from the interior of said conduit through said holes, while the flexibility of said support and sealing members permits axial movements of said shaft with said flow detecting member;
- and said support and sealing members being so dimensioned that pressure force due to the static pressure within said conduit acting on one of said support and sealing members and tending to move said shaft axially in one direction is balanced by an equal but opposite pressure force due to the static pressure within said conduit acting on the other of said support and sealing members.
Dependencies are inferred from the claim text.