Abstract: A wave energy converter (10) for extracting energy from waves in a body of liquid. The converter (10) comprises an inflatable sleeve (12) having an air inlet (14) at or towards one end and an air outlet (18) at or towards its other end. A flexible diaphragm (22) is located within the sleeve (12) so as to extend lengthwise thereof. The diaphragm (22) is sealingly engaged with the sleeve (12) along opposed, elongate edges (22a,22b) thereof. A flexible spine (24) is retained within the diaphragm (22) so as to extend lengthwise thereof. The spine (24) is fixed with the diaphragm (22), relative to the sleeve (12), at or towards each end of the sleeve (12). The converter (10) also comprises a loading device operable to apply an axial compressive force to the spine (24) relative to the sleeve (12) such that, on operation of the loading device, the spine (24) and the diaphragm (22) are buckled into a waveform (26) constrained within the sleeve (12).

Abstract: A wave energy converter (10) for extracting energy from waves in a body of liquid. The converter (10) comprises an inflatable sleeve (12) having an air inlet (14) at or towards one end and an air outlet (18) at or towards its other end. A flexible diaphragm (22) is located within the sleeve (12) so as to extend lengthwise thereof. The diaphragm (22) is sealingly engaged with the sleeve (12) along opposed, elongate edges (22a,22b) thereof. A flexible spine (24) is retained within the diaphragm (22) so as to extend lengthwise thereof. The spine (24) is fixed with the diaphragm (22), relative to the sleeve (12), at or towards each end of the sleeve (12). The converter (10) also comprises a loading device operable to apply an axial compressive force to the spine (24) relative to the sleeve (12) such that, on operation of the loading device, the spine (24) and the diaphragm (22) are buckled into a waveform (26) constrained within the sleeve (12).

Abstract: A wave energy converter for extracting energy from waves in a body of liquid. The converter comprising an endless spine, the spine including a plurality of spine sections (10). Each of the spine sections (10) houses at least one pneumatic absorber and each pneumatic absorber includes an oscillator that is displaceable cyclically on contact with an incident wave to pump air contained within the pneumatic absorber and thereby extract energy from the wave in the form of pneumatic energy. The spine further includes at least one high pressure duct (31) to direct air pumped from each of the pneumatic absorbers and thereby aggregate and rectify the pneumatic energy extracted via the pneumatic absorbers.

Abstract: The invention provides that a layer of hardened material is created on the surface of an underground passageway, in particular a sewer so as to restore its utility and the method used is to place a first lining tube in the sewer along its length, and then to evert a second tube of smaller diameter, along the sewer into the first tube. The method is to insert into the first tube a fluent mass against which the second tube is everted and the fluent mass comprises a hardenable material, typically a synthetic resin and a solid particulate material, typically even diameter beads, which serves to limit the thickness to which the mass can be compressed between the tubes whereby an even thickness layer of the fluent mass lying circumferentially of the sewer forms between the tubes, and this layer is held and is hardened either by force or naturally.

Abstract: A float operated electrical switch assembly has a housing (10) fitted to an opening in a container wall (14). A float (19) follows the liquid level and is pivoted with a primary magnet (18) about a pivot axis (17). A pivotal secondary magnet (21) acts in repulsion with the primary magnet (18) through a non-magnetic wall (20) of the housing (10). The movement of the secondary magnet (21) causes at least one control rod (48) to reciprocate. A switch contact (32) is normally held under the resilience of its carrier leaf spring (38) in engagement with a fixed switch contact (33). The contacts are opened by movement of the control rod (48) moving the switch contact (32) against the resilience of its carrier.