Patent ID: 7699066

Claim:
Device for cleaning of underwater surfaces, comprising: a rotary disc member which is constructed and arranged to rotate in a rotational plane and having a rotational axis, the rotary member equipped with a plurality of nozzles for discharging liquid under pressure against the surfaces to be cleaned, said nozzles being arranged along a circular line on a surface of the rotary disc member and being attached to the rotary member obliquely in relation to the rotational axis, such that water jets being discharged from the nozzles will have a velocity component v n that is perpendicular to the rotational plane of the rotary member and a velocity component v p that is parallel to the rotational plane of the rotary member; a hollow spindle concentric with the rotational axis for connection to a source of liquid under pressure to be supplied to said nozzles; and a separate propulsion device for setting the rotary disc member in rotation; wherein arbitrary radial sections of the rotary disc member are substantially equal in shape and size, wherein the velocity component v p that is parallel to the rotational plane is the sum of a velocity component v r that is radial in relation to the rotary disc member and a velocity component v t that is tangential in relation to the circular line along which the nozzles are arranged, and wherein the separate propulsion device causes rotation of the rotary disc member in a direction in relation to the inclination of the nozzles such that the tangential velocity component v t for the liquid being discharged from at least half of the nozzles has a direction which is the same as the direction of rotation of the rotary disc member.