Patent ID: 6500033
Filing Date: 2002-12-31
Classification: B63H

Abstract:
A method for propulsion of water-going vessels, comprising the steps of:arranging a body that is movable forward and backward relative to a hull of the vessel, the body comprising propulsion portion located in water, a rod extending in a longitudinal direction of the vessel and sealingly through a sternpost of the vessel, a rear end portion of the rod being fixedly connected to the propulsion portion and, a flange extending transversely relative to the rod, and fixedly connected to a front end portion of the rod, arranging a drive device so as to move the body in a first direction, the drive device comprising a drive element, arranging a first resiliently elastic device comprising a first spring between the flange and a fixed portion of the hull so as to exert spring forces against and move the body in a second direction opposite the first direction direction, a water resistance of the propulsion portion being greater when the propulsion portion is moved opposite a desired propulsion direction for the vessel than when the propulsion portion is moved in the desired propulsion direction, arranging a second resiliently elastic device comprising a second spring on an opposite side of the flange from the first resiliently elastic device, between the flange and the drive exerting further spring forces on the body in the first direction, and varying an amount of motive power sinusoidally, so as to bring the body into translatory and rectilinear oscillation with a natural frequency (E) in the first and second directions about a neutral position, the neutral position being determined by a static equilibrium between the spring forces influencing the body.