Abstract: This invention relates to turbines which are arranged to be driven by an oscillating flow of working fluid especially by movement of air above a naturally moving body of water. Conventional turbines require four valves to direct an oscillating flow of fluid to cause continuous unidirectional turning of a single rotor.

Abstract: A turbine or like rotary machine of the kind in which a fluid, either a liquid or gas, is arranged to act on a plurality of generally radially extending rotor blades, has each rotor blade fixed in position relative to the rotor hub and is substantially symmetrical about a plane perpendicular to the rotor axis, the blades having surfaces which are of generally aerofoil shape and being mounted with their leading edges facing in the same circumferential direction. The rotor of such a turbine can be driven by a generally axial flow of fluid, the direction of rotation being unchanged when the direction of flow of the fluid is reversed, so that it can be used to advantage in an oscillating or periodically reversing fluid flow. Such a flow may be provided or produced for example, by naturally occurring movement of air or water.

Abstract: A coupling assembly, suitable for connecting pipes made from brittle materials comprises a tubular locating member and several collets securable to the locating member around a pipe. The aperture of the locating member receives the flanged end section of the pipe, and the collets urge the pipe into the aperture and against a co-operating surface of another pipe, held by a further set of collets. Instead of the further set of collets the locating member may have an integral flange to connect the pipe to a tank or pump.