Device for a buoy-based wave power apparatus

A device for buoy-based water power apparatus where a surface-related buoy coacts with a cylinder/piston arrangement which is connected to the sea bed, where said buoy is connected to the cylinder of said arrangement, and where a piston part of the arrangement is provided with means enabling fluid flow therethrough, said device upon the upward movement of the buoy being arranged to form a pressure chamber in that part of said cylinder which is located on the skirt side of the piston and surrounds a piston rod of said piston, and simultaneously causing suction of fluid into that part of the cylinder which is adjacent the top face of the piston, said fluid being shifted from a suction part of said cylinder to a pressure side of the cylinder during downward movement of the buoy/cylinder, either the piston rod being connected with a bottom base member on the sea bed in an articulated or flexible manner, the piston rod having mounted thereon a submarine buoy having sufficient buoyancy to withstand the pressure and frictional forces acting on the piston and piston rod upon the downward movement of the combination of the surface-related buoy and attached cylinder, or the lower end of the piston rod connecting with a sink weight member located in a bed means, the sink weight member having a heavier weight than the maximum buoyancy of the surface-related buoy, wherein the cylinder has an adjusted weight cast into the lower end, that there is arranged a fluid supplying conduit from the pressure chamber in the cylinder to the buoy, that the conduit has mounted therein a back-pressure valve before the conduit is connected to energy conversion equipment located in or on the buoy, said equipment producing electric current to a signaling device located on the buoy.