Abstract: Apparatus for recovering kinetic energy bound in the movement of water waves. The apparatus comprises a bouyant unit (2) and an energy-absorbing device connected to the bouyant unit. The energy-absorbing device comprises an immersed rigid piston (6) which is slideably arranged in a substantially vertical, elongate accelerating tube (1) which is intended to be immersed in the water and which is open at both ends thereof. The accelerating tube is connected to the buoyant unit (2) so as to accompany movement of the unit imparted thereto by the wave movement of the water. The working stroke (1) of the piston in the accelerating tube is limited by means of movement-limit means (8,9) incorporated in the accelerating tube and arranged to abrogate the force acting on the piston. In accordance with one suitable embodiment, these movement-limiting means comprise openings (9) arranged in the accelerating tube and co-acting with corresponding openings (8) in the piston (6).

Abstract: A plant for utilizing kinetic energy inherent in the wave movement of water or heaving of the sea. The plant comprises a float unit and energy absorption apparatus connected to the unit. The absorption apparatus comprises an immersed piston built into an elongate acceleration pipe, which is open at both ends and substantially vertical, this pipe being connected to the float unit and accompanying it in the wave motion of the water.The piston is connected to a hydraulic motor driving an electric generator.The piston is arranged in a portion with extended cross section upwards in the acceleration pipe.Coupled between the piston and hydraulic motor there is a hydraulic cylinder with a double-sided piston, and a rectifying hydraulic circuit for always supplying hydraulic pressure to the same side of the hydraulic motor.A flywheel can be connected between the hydraulic motor and generator for smoothing out the action of pressure variations on the generator.