Linked-spar motion-compensated lifting system
US4280430A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 1979 |
| Grant date | Jul 28, 1981 |
| Priority date | — |
| Expiry date | Jan 26, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB63B2035/442
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A system for operating a lifting cable over the side of a ship at sea in ch a spar buoy having an adjustable lifting capacity is coupled to the ship by a rigid linkage which is free to pivot on an axis attached to the deck. The lifting cable is suspended from a first sheave which is mounted above a central, longitudinal channel in the spar buoy. The linkage is attached to the top of the spar buoy such that the spar buoy may rotate about an axis normal to the deck axis of the linkage and pivot on an axis normal to the longitudinal axis of the spar buoy. A second sheave is mounted on the deck axis so that the distance between the sheaves does not change as the linkage rotates on its axis. The lifting cable is fed from a winch on the ship over the sheaves and falls through the longitudinal channel. The invention operates to decouple the motion of the ship from the lifting cable so that the vertical motion of the cable is controlled by the motion of the spar buoy. A topping lift technique for deck-handling the system and an emergency disconnect feature are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.