Abstract: A pressure wave generator (40) for driving one or more cryogenic refrigerator systems. The pressure wave generator (40) comprises a housing with one or more inlet/outlet ports (57,58) through which generated pressure waves of gas may pass through to drive a cryogenic refrigerator system or systems connected to the inlet/outlet ports (57,58). The pressure waves are generated by at least one pair of opposed diaphragms (41,42) located in the housing that are moveable in a reciprocating motion within the housing to create pressure waves in gas spaces (55,56) associated with each diaphragm (41,42). The gas spaces (55,56) each having associated inlet/outlet ports (57,58) through which the pressure waves may pass. An operable drive system is also provided to move the pair of diaphragms (41,42) in a reciprocating motion.

Abstract: A wave energy converter (10) for extracting useful energy from wave motion. The converter (10) comprises an active float (12) that is arranged to float on the water, and being arranged to heave and surge in response to wave motion acting on the active float, and an elongate reactive body (14) that is arranged to be suspended in a substantially submerged state into the water and having sufficient surface area and length such that it pitches in response to wave motion-acting on the reactive body. The active float (12) and reactive body (14) are pivotably coupled for pivotable movement relative to each other about a single pivot axis (16) in response to heaving and surging of the active float and pitching of the reactive body. The converter also comprises a power output system that is driven by the pivotable movement about the pivot axis to capture the useful energy.

Abstract: A pressure wave generator (40) for driving one or more cryogenic refrigerator systems. The pressure wave generator (40) comprises a housing with one or more inlet/outlet ports (57,58) through which generated pressure waves of gas may pass through to drive a cryogenic refrigerator system or systems connected to the inlet/outlet ports (57,58). The pressure waves are generated by at least one pair of opposed diaphragms (41,42) located in the housing that are moveable in a reciprocating motion within the housing to create pressure waves in gas spaces (55,56) associated with each diaphragm (41,42). The gas spaces (55,56) each having associated inlet/outlet ports (57,58) through which the pressure waves may pass. An operable drive system is also provided to move the pair of diaphragms (41,42) in a reciprocating motion.

Abstract: A wave energy converter (10) for extracting useful energy from wave motion. The converter (10) comprises an active float (12) that is arranged to float on the water, and being arranged to heave and surge in response to wave motion acting on the active float, and an elongate reactive body (14) that is arranged to be suspended in a substantially submerged state into the water and having sufficient surface area and length such that it pitches in response to wave motion-acting on the reactive body. The active float (12) and reactive body (14) are pivotably coupled for pivotable movement relative to each other about a single pivot axis (16) in response to heaving and surging of the active float and pitching of the reactive body. The converter also comprises a power output system that is driven by the pivotable movement about the pivot axis to capture the useful energy.