Patent ID: 7798471
Filing Date: 2010-09-21
Classification: B63B,B66C,B66D

Abstract:
1. A device for providing heave compensation for a load suspended from one end of a line into a marine environment, with the other end of the line being handled by a line handling device located at a first location on a vessel, comprising: a sheave support base located at a second location on the vessel displaced from the first location; a sheave for receiving the line from the line handling device and directing the line to the load; a sheave mounting frame with an axle for supporting the sheave for rotation, the sheave mounting frame being mounted on the sheave support base for reciprocating motion along a compensation path; and a compensator control operatively connected to the sheave mounting frame for causing the sheave mounting frame to controllably reciprocate along the compensation path in response to heaving motion of the vessel, the compensation path following a curve profile extending in the general direction of a heaving motion to be compensated, the curve profile being arc-like based on a center point defined by a tangent point of the line with the line handling device, the arc having at least one inflection to reduce line travel from effects of line wrapping at the sheave and line handling device during reciprocating motion.