Abstract: A flow transducer with a variable orifice formed between a conical valve member tapering in the downstream direction and a sliding piston located downstream of the valve member. A throat member is fixed within a housing upstream of the valve member. An annular chamber is formed between the walls of the housing and the throat member. Radial holes open from the annular chamber into the bore of the throat member. The radial holes are equally spaced, all of the same diameter, and at the same axial position. An upstream tapping extends into the annular chamber.

Abstract: A high pressure hydraulic fluid-flow transducer 10 has a frusto-conical throat 13 obturated by a valve member 14 which is fixed to a spindle 16 slidingly carried in a bearing 17 which is fixed to the one-piece housing 11. The bearing 17 engages a substantial length of the spindle, to prevent wobbling, closely adjacent the smaller throat end 15. The housing 11 has internal screw-threads 21, 22 at both ends, for connecting the sensor into an hydraulic system. Because the compression spring 18 is upstream of the valve member 14, and acts upon the upstream end 25 of spindle 16, the valve member 14 and throat 13 are both readily accessible through the downstream end of the housing, both for inspection purposes and for machining of the throat before insertion of the valve member and spindle. Reverse fluid flow is possible by virtue of a second spring 29, acting between valve member 14 and spindle 16.

Abstract: In order to provide a multi-way directional fluid flow control valve arrangement which provides good control while being relatively cheap to manufacture, I use simple main valves all of which have parallel axes and all lie in a common plane, enabling me to form the main valves in a cheap manufacturing operation; the pilot valve however is more complex and has at least four connections, but because the pilot valve is smaller, this extra complexity does not make the whole valve arrangement more expensive.